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1/*
2 BlueZ - Bluetooth protocol stack for Linux
3 Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License version 2 as
7 published by the Free Software Foundation;
8
9 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
10 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
11 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
12 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
13 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
14 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17
18 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
19 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
20 SOFTWARE IS DISCLAIMED.
21*/
22
23#include <linux/debugfs.h>
24#include <linux/scatterlist.h>
25#include <crypto/aes.h>
26#include <crypto/hash.h>
27#include <crypto/kpp.h>
28#include <crypto/utils.h>
29
30#include <net/bluetooth/bluetooth.h>
31#include <net/bluetooth/hci_core.h>
32#include <net/bluetooth/l2cap.h>
33#include <net/bluetooth/mgmt.h>
34
35#include "ecdh_helper.h"
36#include "smp.h"
37
38#define SMP_DEV(hdev) \
39 ((struct smp_dev *)((struct l2cap_chan *)((hdev)->smp_data))->data)
40
41/* Low-level debug macros to be used for stuff that we don't want
42 * accidentally in dmesg, i.e. the values of the various crypto keys
43 * and the inputs & outputs of crypto functions.
44 */
45#ifdef DEBUG
46#define SMP_DBG(fmt, ...) printk(KERN_DEBUG "%s: " fmt, __func__, \
47 ##__VA_ARGS__)
48#else
49#define SMP_DBG(fmt, ...) no_printk(KERN_DEBUG "%s: " fmt, __func__, \
50 ##__VA_ARGS__)
51#endif
52
53#define SMP_ALLOW_CMD(smp, code) set_bit(code, &smp->allow_cmd)
54
55/* Keys which are not distributed with Secure Connections */
56#define SMP_SC_NO_DIST (SMP_DIST_ENC_KEY | SMP_DIST_LINK_KEY)
57
58#define SMP_TIMEOUT msecs_to_jiffies(30000)
59
60#define ID_ADDR_TIMEOUT msecs_to_jiffies(200)
61
62#define AUTH_REQ_MASK(dev) (hci_dev_test_flag(dev, HCI_SC_ENABLED) ? \
63 0x3f : 0x07)
64#define KEY_DIST_MASK 0x07
65
66/* Maximum message length that can be passed to aes_cmac */
67#define CMAC_MSG_MAX 80
68
69enum {
70 SMP_FLAG_TK_VALID,
71 SMP_FLAG_CFM_PENDING,
72 SMP_FLAG_MITM_AUTH,
73 SMP_FLAG_COMPLETE,
74 SMP_FLAG_INITIATOR,
75 SMP_FLAG_SC,
76 SMP_FLAG_REMOTE_PK,
77 SMP_FLAG_DEBUG_KEY,
78 SMP_FLAG_WAIT_USER,
79 SMP_FLAG_DHKEY_PENDING,
80 SMP_FLAG_REMOTE_OOB,
81 SMP_FLAG_LOCAL_OOB,
82 SMP_FLAG_CT2,
83};
84
85struct smp_dev {
86 /* Secure Connections OOB data */
87 bool local_oob;
88 u8 local_pk[64];
89 u8 local_rand[16];
90 bool debug_key;
91
92 struct crypto_shash *tfm_cmac;
93 struct crypto_kpp *tfm_ecdh;
94};
95
96struct smp_chan {
97 struct l2cap_conn *conn;
98 struct delayed_work security_timer;
99 unsigned long allow_cmd; /* Bitmask of allowed commands */
100
101 u8 preq[7]; /* SMP Pairing Request */
102 u8 prsp[7]; /* SMP Pairing Response */
103 u8 prnd[16]; /* SMP Pairing Random (local) */
104 u8 rrnd[16]; /* SMP Pairing Random (remote) */
105 u8 pcnf[16]; /* SMP Pairing Confirm */
106 u8 tk[16]; /* SMP Temporary Key */
107 u8 rr[16]; /* Remote OOB ra/rb value */
108 u8 lr[16]; /* Local OOB ra/rb value */
109 u8 enc_key_size;
110 u8 remote_key_dist;
111 bdaddr_t id_addr;
112 u8 id_addr_type;
113 u8 irk[16];
114 struct smp_csrk *csrk;
115 struct smp_csrk *responder_csrk;
116 struct smp_ltk *ltk;
117 struct smp_ltk *responder_ltk;
118 struct smp_irk *remote_irk;
119 u8 *link_key;
120 unsigned long flags;
121 u8 method;
122 u8 passkey_round;
123
124 /* Secure Connections variables */
125 u8 local_pk[64];
126 u8 remote_pk[64];
127 u8 dhkey[32];
128 u8 mackey[16];
129
130 struct crypto_shash *tfm_cmac;
131 struct crypto_kpp *tfm_ecdh;
132};
133
134/* These debug key values are defined in the SMP section of the core
135 * specification. debug_pk is the public debug key and debug_sk the
136 * private debug key.
137 */
138static const u8 debug_pk[64] = {
139 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
140 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
141 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
142 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20,
143
144 0x8b, 0xd2, 0x89, 0x15, 0xd0, 0x8e, 0x1c, 0x74,
145 0x24, 0x30, 0xed, 0x8f, 0xc2, 0x45, 0x63, 0x76,
146 0x5c, 0x15, 0x52, 0x5a, 0xbf, 0x9a, 0x32, 0x63,
147 0x6d, 0xeb, 0x2a, 0x65, 0x49, 0x9c, 0x80, 0xdc,
148};
149
150static const u8 debug_sk[32] = {
151 0xbd, 0x1a, 0x3c, 0xcd, 0xa6, 0xb8, 0x99, 0x58,
152 0x99, 0xb7, 0x40, 0xeb, 0x7b, 0x60, 0xff, 0x4a,
153 0x50, 0x3f, 0x10, 0xd2, 0xe3, 0xb3, 0xc9, 0x74,
154 0x38, 0x5f, 0xc5, 0xa3, 0xd4, 0xf6, 0x49, 0x3f,
155};
156
157static inline void swap_buf(const u8 *src, u8 *dst, size_t len)
158{
159 size_t i;
160
161 for (i = 0; i < len; i++)
162 dst[len - 1 - i] = src[i];
163}
164
165/* The following functions map to the LE SC SMP crypto functions
166 * AES-CMAC, f4, f5, f6, g2 and h6.
167 */
168
169static int aes_cmac(struct crypto_shash *tfm, const u8 k[16], const u8 *m,
170 size_t len, u8 mac[16])
171{
172 uint8_t tmp[16], mac_msb[16], msg_msb[CMAC_MSG_MAX];
173 int err;
174
175 if (len > CMAC_MSG_MAX)
176 return -EFBIG;
177
178 if (!tfm) {
179 BT_ERR("tfm %p", tfm);
180 return -EINVAL;
181 }
182
183 /* Swap key and message from LSB to MSB */
184 swap_buf(k, tmp, 16);
185 swap_buf(m, msg_msb, len);
186
187 SMP_DBG("msg (len %zu) %*phN", len, (int) len, m);
188 SMP_DBG("key %16phN", k);
189
190 err = crypto_shash_setkey(tfm, tmp, 16);
191 if (err) {
192 BT_ERR("cipher setkey failed: %d", err);
193 return err;
194 }
195
196 err = crypto_shash_tfm_digest(tfm, msg_msb, len, mac_msb);
197 if (err) {
198 BT_ERR("Hash computation error %d", err);
199 return err;
200 }
201
202 swap_buf(mac_msb, mac, 16);
203
204 SMP_DBG("mac %16phN", mac);
205
206 return 0;
207}
208
209static int smp_f4(struct crypto_shash *tfm_cmac, const u8 u[32],
210 const u8 v[32], const u8 x[16], u8 z, u8 res[16])
211{
212 u8 m[65];
213 int err;
214
215 SMP_DBG("u %32phN", u);
216 SMP_DBG("v %32phN", v);
217 SMP_DBG("x %16phN z %02x", x, z);
218
219 m[0] = z;
220 memcpy(m + 1, v, 32);
221 memcpy(m + 33, u, 32);
222
223 err = aes_cmac(tfm_cmac, x, m, sizeof(m), res);
224 if (err)
225 return err;
226
227 SMP_DBG("res %16phN", res);
228
229 return err;
230}
231
232static int smp_f5(struct crypto_shash *tfm_cmac, const u8 w[32],
233 const u8 n1[16], const u8 n2[16], const u8 a1[7],
234 const u8 a2[7], u8 mackey[16], u8 ltk[16])
235{
236 /* The btle, salt and length "magic" values are as defined in
237 * the SMP section of the Bluetooth core specification. In ASCII
238 * the btle value ends up being 'btle'. The salt is just a
239 * random number whereas length is the value 256 in little
240 * endian format.
241 */
242 const u8 btle[4] = { 0x65, 0x6c, 0x74, 0x62 };
243 const u8 salt[16] = { 0xbe, 0x83, 0x60, 0x5a, 0xdb, 0x0b, 0x37, 0x60,
244 0x38, 0xa5, 0xf5, 0xaa, 0x91, 0x83, 0x88, 0x6c };
245 const u8 length[2] = { 0x00, 0x01 };
246 u8 m[53], t[16];
247 int err;
248
249 SMP_DBG("w %32phN", w);
250 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
251 SMP_DBG("a1 %7phN a2 %7phN", a1, a2);
252
253 err = aes_cmac(tfm_cmac, salt, w, 32, t);
254 if (err)
255 return err;
256
257 SMP_DBG("t %16phN", t);
258
259 memcpy(m, length, 2);
260 memcpy(m + 2, a2, 7);
261 memcpy(m + 9, a1, 7);
262 memcpy(m + 16, n2, 16);
263 memcpy(m + 32, n1, 16);
264 memcpy(m + 48, btle, 4);
265
266 m[52] = 0; /* Counter */
267
268 err = aes_cmac(tfm_cmac, t, m, sizeof(m), mackey);
269 if (err)
270 return err;
271
272 SMP_DBG("mackey %16phN", mackey);
273
274 m[52] = 1; /* Counter */
275
276 err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk);
277 if (err)
278 return err;
279
280 SMP_DBG("ltk %16phN", ltk);
281
282 return 0;
283}
284
285static int smp_f6(struct crypto_shash *tfm_cmac, const u8 w[16],
286 const u8 n1[16], const u8 n2[16], const u8 r[16],
287 const u8 io_cap[3], const u8 a1[7], const u8 a2[7],
288 u8 res[16])
289{
290 u8 m[65];
291 int err;
292
293 SMP_DBG("w %16phN", w);
294 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
295 SMP_DBG("r %16phN io_cap %3phN a1 %7phN a2 %7phN", r, io_cap, a1, a2);
296
297 memcpy(m, a2, 7);
298 memcpy(m + 7, a1, 7);
299 memcpy(m + 14, io_cap, 3);
300 memcpy(m + 17, r, 16);
301 memcpy(m + 33, n2, 16);
302 memcpy(m + 49, n1, 16);
303
304 err = aes_cmac(tfm_cmac, w, m, sizeof(m), res);
305 if (err)
306 return err;
307
308 SMP_DBG("res %16phN", res);
309
310 return err;
311}
312
313static int smp_g2(struct crypto_shash *tfm_cmac, const u8 u[32], const u8 v[32],
314 const u8 x[16], const u8 y[16], u32 *val)
315{
316 u8 m[80], tmp[16];
317 int err;
318
319 SMP_DBG("u %32phN", u);
320 SMP_DBG("v %32phN", v);
321 SMP_DBG("x %16phN y %16phN", x, y);
322
323 memcpy(m, y, 16);
324 memcpy(m + 16, v, 32);
325 memcpy(m + 48, u, 32);
326
327 err = aes_cmac(tfm_cmac, x, m, sizeof(m), tmp);
328 if (err)
329 return err;
330
331 *val = get_unaligned_le32(tmp);
332 *val %= 1000000;
333
334 SMP_DBG("val %06u", *val);
335
336 return 0;
337}
338
339static int smp_h6(struct crypto_shash *tfm_cmac, const u8 w[16],
340 const u8 key_id[4], u8 res[16])
341{
342 int err;
343
344 SMP_DBG("w %16phN key_id %4phN", w, key_id);
345
346 err = aes_cmac(tfm_cmac, w, key_id, 4, res);
347 if (err)
348 return err;
349
350 SMP_DBG("res %16phN", res);
351
352 return err;
353}
354
355static int smp_h7(struct crypto_shash *tfm_cmac, const u8 w[16],
356 const u8 salt[16], u8 res[16])
357{
358 int err;
359
360 SMP_DBG("w %16phN salt %16phN", w, salt);
361
362 err = aes_cmac(tfm_cmac, salt, w, 16, res);
363 if (err)
364 return err;
365
366 SMP_DBG("res %16phN", res);
367
368 return err;
369}
370
371/* The following functions map to the legacy SMP crypto functions e, c1,
372 * s1 and ah.
373 */
374
375static int smp_e(const u8 *k, u8 *r)
376{
377 struct crypto_aes_ctx ctx;
378 uint8_t tmp[16], data[16];
379 int err;
380
381 SMP_DBG("k %16phN r %16phN", k, r);
382
383 /* The most significant octet of key corresponds to k[0] */
384 swap_buf(k, tmp, 16);
385
386 err = aes_expandkey(&ctx, tmp, 16);
387 if (err) {
388 BT_ERR("cipher setkey failed: %d", err);
389 return err;
390 }
391
392 /* Most significant octet of plaintextData corresponds to data[0] */
393 swap_buf(r, data, 16);
394
395 aes_encrypt(&ctx, data, data);
396
397 /* Most significant octet of encryptedData corresponds to data[0] */
398 swap_buf(data, r, 16);
399
400 SMP_DBG("r %16phN", r);
401
402 memzero_explicit(&ctx, sizeof(ctx));
403 return err;
404}
405
406static int smp_c1(const u8 k[16],
407 const u8 r[16], const u8 preq[7], const u8 pres[7], u8 _iat,
408 const bdaddr_t *ia, u8 _rat, const bdaddr_t *ra, u8 res[16])
409{
410 u8 p1[16], p2[16];
411 int err;
412
413 SMP_DBG("k %16phN r %16phN", k, r);
414 SMP_DBG("iat %u ia %6phN rat %u ra %6phN", _iat, ia, _rat, ra);
415 SMP_DBG("preq %7phN pres %7phN", preq, pres);
416
417 memset(p1, 0, 16);
418
419 /* p1 = pres || preq || _rat || _iat */
420 p1[0] = _iat;
421 p1[1] = _rat;
422 memcpy(p1 + 2, preq, 7);
423 memcpy(p1 + 9, pres, 7);
424
425 SMP_DBG("p1 %16phN", p1);
426
427 /* res = r XOR p1 */
428 crypto_xor_cpy(res, r, p1, sizeof(p1));
429
430 /* res = e(k, res) */
431 err = smp_e(k, res);
432 if (err) {
433 BT_ERR("Encrypt data error");
434 return err;
435 }
436
437 /* p2 = padding || ia || ra */
438 memcpy(p2, ra, 6);
439 memcpy(p2 + 6, ia, 6);
440 memset(p2 + 12, 0, 4);
441
442 SMP_DBG("p2 %16phN", p2);
443
444 /* res = res XOR p2 */
445 crypto_xor(res, p2, sizeof(p2));
446
447 /* res = e(k, res) */
448 err = smp_e(k, res);
449 if (err)
450 BT_ERR("Encrypt data error");
451
452 return err;
453}
454
455static int smp_s1(const u8 k[16],
456 const u8 r1[16], const u8 r2[16], u8 _r[16])
457{
458 int err;
459
460 /* Just least significant octets from r1 and r2 are considered */
461 memcpy(_r, r2, 8);
462 memcpy(_r + 8, r1, 8);
463
464 err = smp_e(k, _r);
465 if (err)
466 BT_ERR("Encrypt data error");
467
468 return err;
469}
470
471static int smp_ah(const u8 irk[16], const u8 r[3], u8 res[3])
472{
473 u8 _res[16];
474 int err;
475
476 /* r' = padding || r */
477 memcpy(_res, r, 3);
478 memset(_res + 3, 0, 13);
479
480 err = smp_e(irk, _res);
481 if (err) {
482 BT_ERR("Encrypt error");
483 return err;
484 }
485
486 /* The output of the random address function ah is:
487 * ah(k, r) = e(k, r') mod 2^24
488 * The output of the security function e is then truncated to 24 bits
489 * by taking the least significant 24 bits of the output of e as the
490 * result of ah.
491 */
492 memcpy(res, _res, 3);
493
494 return 0;
495}
496
497bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16],
498 const bdaddr_t *bdaddr)
499{
500 struct l2cap_chan *chan = hdev->smp_data;
501 u8 hash[3];
502 int err;
503
504 if (!chan || !chan->data)
505 return false;
506
507 bt_dev_dbg(hdev, "RPA %pMR IRK %*phN", bdaddr, 16, irk);
508
509 err = smp_ah(irk, &bdaddr->b[3], hash);
510 if (err)
511 return false;
512
513 return !crypto_memneq(bdaddr->b, hash, 3);
514}
515
516int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa)
517{
518 struct l2cap_chan *chan = hdev->smp_data;
519 int err;
520
521 if (!chan || !chan->data)
522 return -EOPNOTSUPP;
523
524 get_random_bytes(&rpa->b[3], 3);
525
526 rpa->b[5] &= 0x3f; /* Clear two most significant bits */
527 rpa->b[5] |= 0x40; /* Set second most significant bit */
528
529 err = smp_ah(irk, &rpa->b[3], rpa->b);
530 if (err < 0)
531 return err;
532
533 bt_dev_dbg(hdev, "RPA %pMR", rpa);
534
535 return 0;
536}
537
538int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16])
539{
540 struct l2cap_chan *chan = hdev->smp_data;
541 struct smp_dev *smp;
542 int err;
543
544 if (!chan || !chan->data)
545 return -EOPNOTSUPP;
546
547 smp = chan->data;
548
549 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) {
550 bt_dev_dbg(hdev, "Using debug keys");
551 err = set_ecdh_privkey(smp->tfm_ecdh, debug_sk);
552 if (err)
553 return err;
554 memcpy(smp->local_pk, debug_pk, 64);
555 smp->debug_key = true;
556 } else {
557 while (true) {
558 /* Generate key pair for Secure Connections */
559 err = generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk);
560 if (err)
561 return err;
562
563 /* This is unlikely, but we need to check that
564 * we didn't accidentally generate a debug key.
565 */
566 if (crypto_memneq(smp->local_pk, debug_pk, 64))
567 break;
568 }
569 smp->debug_key = false;
570 }
571
572 SMP_DBG("OOB Public Key X: %32phN", smp->local_pk);
573 SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32);
574
575 get_random_bytes(smp->local_rand, 16);
576
577 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->local_pk,
578 smp->local_rand, 0, hash);
579 if (err < 0)
580 return err;
581
582 memcpy(rand, smp->local_rand, 16);
583
584 smp->local_oob = true;
585
586 return 0;
587}
588
589static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
590{
591 struct l2cap_chan *chan = conn->smp;
592 struct smp_chan *smp;
593 struct kvec iv[2];
594 struct msghdr msg;
595
596 if (!chan)
597 return;
598
599 bt_dev_dbg(conn->hcon->hdev, "code 0x%2.2x", code);
600
601 iv[0].iov_base = &code;
602 iv[0].iov_len = 1;
603
604 iv[1].iov_base = data;
605 iv[1].iov_len = len;
606
607 memset(&msg, 0, sizeof(msg));
608
609 iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iv, 2, 1 + len);
610
611 l2cap_chan_send(chan, &msg, 1 + len);
612
613 if (!chan->data)
614 return;
615
616 smp = chan->data;
617
618 cancel_delayed_work_sync(&smp->security_timer);
619 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT);
620}
621
622static u8 authreq_to_seclevel(u8 authreq)
623{
624 if (authreq & SMP_AUTH_MITM) {
625 if (authreq & SMP_AUTH_SC)
626 return BT_SECURITY_FIPS;
627 else
628 return BT_SECURITY_HIGH;
629 } else {
630 return BT_SECURITY_MEDIUM;
631 }
632}
633
634static __u8 seclevel_to_authreq(__u8 sec_level)
635{
636 switch (sec_level) {
637 case BT_SECURITY_FIPS:
638 case BT_SECURITY_HIGH:
639 return SMP_AUTH_MITM | SMP_AUTH_BONDING;
640 case BT_SECURITY_MEDIUM:
641 return SMP_AUTH_BONDING;
642 default:
643 return SMP_AUTH_NONE;
644 }
645}
646
647static void build_pairing_cmd(struct l2cap_conn *conn,
648 struct smp_cmd_pairing *req,
649 struct smp_cmd_pairing *rsp, __u8 authreq)
650{
651 struct l2cap_chan *chan = conn->smp;
652 struct smp_chan *smp = chan->data;
653 struct hci_conn *hcon = conn->hcon;
654 struct hci_dev *hdev = hcon->hdev;
655 u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT;
656
657 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) {
658 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
659 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
660 authreq |= SMP_AUTH_BONDING;
661 } else {
662 authreq &= ~SMP_AUTH_BONDING;
663 }
664
665 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING))
666 remote_dist |= SMP_DIST_ID_KEY;
667
668 if (hci_dev_test_flag(hdev, HCI_PRIVACY))
669 local_dist |= SMP_DIST_ID_KEY;
670
671 if (hci_dev_test_flag(hdev, HCI_SC_ENABLED) &&
672 (authreq & SMP_AUTH_SC)) {
673 struct oob_data *oob_data;
674 u8 bdaddr_type;
675
676 if (hci_dev_test_flag(hdev, HCI_SSP_ENABLED)) {
677 local_dist |= SMP_DIST_LINK_KEY;
678 remote_dist |= SMP_DIST_LINK_KEY;
679 }
680
681 if (hcon->dst_type == ADDR_LE_DEV_PUBLIC)
682 bdaddr_type = BDADDR_LE_PUBLIC;
683 else
684 bdaddr_type = BDADDR_LE_RANDOM;
685
686 oob_data = hci_find_remote_oob_data(hdev, &hcon->dst,
687 bdaddr_type);
688 if (oob_data && oob_data->present) {
689 set_bit(SMP_FLAG_REMOTE_OOB, &smp->flags);
690 oob_flag = SMP_OOB_PRESENT;
691 memcpy(smp->rr, oob_data->rand256, 16);
692 memcpy(smp->pcnf, oob_data->hash256, 16);
693 SMP_DBG("OOB Remote Confirmation: %16phN", smp->pcnf);
694 SMP_DBG("OOB Remote Random: %16phN", smp->rr);
695 }
696
697 } else {
698 authreq &= ~SMP_AUTH_SC;
699 }
700
701 if (rsp == NULL) {
702 req->io_capability = conn->hcon->io_capability;
703 req->oob_flag = oob_flag;
704 req->max_key_size = hdev->le_max_key_size;
705 req->init_key_dist = local_dist;
706 req->resp_key_dist = remote_dist;
707 req->auth_req = (authreq & AUTH_REQ_MASK(hdev));
708
709 smp->remote_key_dist = remote_dist;
710 return;
711 }
712
713 rsp->io_capability = conn->hcon->io_capability;
714 rsp->oob_flag = oob_flag;
715 rsp->max_key_size = hdev->le_max_key_size;
716 rsp->init_key_dist = req->init_key_dist & remote_dist;
717 rsp->resp_key_dist = req->resp_key_dist & local_dist;
718 rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev));
719
720 smp->remote_key_dist = rsp->init_key_dist;
721}
722
723static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)
724{
725 struct l2cap_chan *chan = conn->smp;
726 struct hci_dev *hdev = conn->hcon->hdev;
727 struct smp_chan *smp = chan->data;
728
729 if (conn->hcon->pending_sec_level == BT_SECURITY_FIPS &&
730 max_key_size != SMP_MAX_ENC_KEY_SIZE)
731 return SMP_ENC_KEY_SIZE;
732
733 if (max_key_size > hdev->le_max_key_size ||
734 max_key_size < SMP_MIN_ENC_KEY_SIZE)
735 return SMP_ENC_KEY_SIZE;
736
737 smp->enc_key_size = max_key_size;
738
739 return 0;
740}
741
742static void smp_chan_destroy(struct l2cap_conn *conn)
743{
744 struct l2cap_chan *chan = conn->smp;
745 struct smp_chan *smp = chan->data;
746 struct hci_conn *hcon = conn->hcon;
747 bool complete;
748
749 BUG_ON(!smp);
750
751 cancel_delayed_work_sync(&smp->security_timer);
752
753 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags);
754 mgmt_smp_complete(hcon, complete);
755
756 kfree_sensitive(smp->csrk);
757 kfree_sensitive(smp->responder_csrk);
758 kfree_sensitive(smp->link_key);
759
760 crypto_free_shash(smp->tfm_cmac);
761 crypto_free_kpp(smp->tfm_ecdh);
762
763 /* Ensure that we don't leave any debug key around if debug key
764 * support hasn't been explicitly enabled.
765 */
766 if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG &&
767 !hci_dev_test_flag(hcon->hdev, HCI_KEEP_DEBUG_KEYS)) {
768 list_del_rcu(&smp->ltk->list);
769 kfree_rcu(smp->ltk, rcu);
770 smp->ltk = NULL;
771 }
772
773 /* If pairing failed clean up any keys we might have */
774 if (!complete) {
775 if (smp->ltk) {
776 list_del_rcu(&smp->ltk->list);
777 kfree_rcu(smp->ltk, rcu);
778 }
779
780 if (smp->responder_ltk) {
781 list_del_rcu(&smp->responder_ltk->list);
782 kfree_rcu(smp->responder_ltk, rcu);
783 }
784
785 if (smp->remote_irk) {
786 list_del_rcu(&smp->remote_irk->list);
787 kfree_rcu(smp->remote_irk, rcu);
788 }
789 }
790
791 chan->data = NULL;
792 kfree_sensitive(smp);
793 hci_conn_drop(hcon);
794}
795
796static void smp_failure(struct l2cap_conn *conn, u8 reason)
797{
798 struct hci_conn *hcon = conn->hcon;
799 struct l2cap_chan *chan = conn->smp;
800
801 if (reason)
802 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
803 &reason);
804
805 mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE);
806
807 if (chan->data)
808 smp_chan_destroy(conn);
809}
810
811#define JUST_WORKS 0x00
812#define JUST_CFM 0x01
813#define REQ_PASSKEY 0x02
814#define CFM_PASSKEY 0x03
815#define REQ_OOB 0x04
816#define DSP_PASSKEY 0x05
817#define OVERLAP 0xFF
818
819static const u8 gen_method[5][5] = {
820 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
821 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
822 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
823 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
824 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP },
825};
826
827static const u8 sc_method[5][5] = {
828 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
829 { JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
830 { DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY },
831 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
832 { DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
833};
834
835static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io)
836{
837 /* If either side has unknown io_caps, use JUST_CFM (which gets
838 * converted later to JUST_WORKS if we're initiators.
839 */
840 if (local_io > SMP_IO_KEYBOARD_DISPLAY ||
841 remote_io > SMP_IO_KEYBOARD_DISPLAY)
842 return JUST_CFM;
843
844 if (test_bit(SMP_FLAG_SC, &smp->flags))
845 return sc_method[remote_io][local_io];
846
847 return gen_method[remote_io][local_io];
848}
849
850static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth,
851 u8 local_io, u8 remote_io)
852{
853 struct hci_conn *hcon = conn->hcon;
854 struct l2cap_chan *chan = conn->smp;
855 struct smp_chan *smp = chan->data;
856 u32 passkey = 0;
857 int ret;
858
859 /* Initialize key for JUST WORKS */
860 memset(smp->tk, 0, sizeof(smp->tk));
861 clear_bit(SMP_FLAG_TK_VALID, &smp->flags);
862
863 bt_dev_dbg(hcon->hdev, "auth:%u lcl:%u rem:%u", auth, local_io,
864 remote_io);
865
866 /* If neither side wants MITM, either "just" confirm an incoming
867 * request or use just-works for outgoing ones. The JUST_CFM
868 * will be converted to JUST_WORKS if necessary later in this
869 * function. If either side has MITM look up the method from the
870 * table.
871 */
872 if (!(auth & SMP_AUTH_MITM))
873 smp->method = JUST_CFM;
874 else
875 smp->method = get_auth_method(smp, local_io, remote_io);
876
877 /* Don't confirm locally initiated pairing attempts */
878 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR,
879 &smp->flags))
880 smp->method = JUST_WORKS;
881
882 /* Don't bother user space with no IO capabilities */
883 if (smp->method == JUST_CFM &&
884 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
885 smp->method = JUST_WORKS;
886
887 /* If Just Works, Continue with Zero TK and ask user-space for
888 * confirmation */
889 if (smp->method == JUST_WORKS) {
890 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
891 hcon->type,
892 hcon->dst_type,
893 passkey, 1);
894 if (ret)
895 return ret;
896 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
897 return 0;
898 }
899
900 /* If this function is used for SC -> legacy fallback we
901 * can only recover the just-works case.
902 */
903 if (test_bit(SMP_FLAG_SC, &smp->flags))
904 return -EINVAL;
905
906 /* Not Just Works/Confirm results in MITM Authentication */
907 if (smp->method != JUST_CFM) {
908 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags);
909 if (hcon->pending_sec_level < BT_SECURITY_HIGH)
910 hcon->pending_sec_level = BT_SECURITY_HIGH;
911 }
912
913 /* If both devices have Keyboard-Display I/O, the initiator
914 * Confirms and the responder Enters the passkey.
915 */
916 if (smp->method == OVERLAP) {
917 if (hcon->role == HCI_ROLE_MASTER)
918 smp->method = CFM_PASSKEY;
919 else
920 smp->method = REQ_PASSKEY;
921 }
922
923 /* Generate random passkey. */
924 if (smp->method == CFM_PASSKEY) {
925 memset(smp->tk, 0, sizeof(smp->tk));
926 get_random_bytes(&passkey, sizeof(passkey));
927 passkey %= 1000000;
928 put_unaligned_le32(passkey, smp->tk);
929 bt_dev_dbg(hcon->hdev, "PassKey: %u", passkey);
930 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
931 }
932
933 if (smp->method == REQ_PASSKEY)
934 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst,
935 hcon->type, hcon->dst_type);
936 else if (smp->method == JUST_CFM)
937 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
938 hcon->type, hcon->dst_type,
939 passkey, 1);
940 else
941 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst,
942 hcon->type, hcon->dst_type,
943 passkey, 0);
944
945 return ret;
946}
947
948static u8 smp_confirm(struct smp_chan *smp)
949{
950 struct l2cap_conn *conn = smp->conn;
951 struct smp_cmd_pairing_confirm cp;
952 int ret;
953
954 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn);
955
956 ret = smp_c1(smp->tk, smp->prnd, smp->preq, smp->prsp,
957 conn->hcon->init_addr_type, &conn->hcon->init_addr,
958 conn->hcon->resp_addr_type, &conn->hcon->resp_addr,
959 cp.confirm_val);
960 if (ret)
961 return SMP_UNSPECIFIED;
962
963 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
964
965 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
966
967 if (conn->hcon->out)
968 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
969 else
970 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
971
972 return 0;
973}
974
975static u8 smp_random(struct smp_chan *smp)
976{
977 struct l2cap_conn *conn = smp->conn;
978 struct hci_conn *hcon = conn->hcon;
979 u8 confirm[16];
980 int ret;
981
982 bt_dev_dbg(conn->hcon->hdev, "conn %p %s", conn,
983 conn->hcon->out ? "initiator" : "responder");
984
985 ret = smp_c1(smp->tk, smp->rrnd, smp->preq, smp->prsp,
986 hcon->init_addr_type, &hcon->init_addr,
987 hcon->resp_addr_type, &hcon->resp_addr, confirm);
988 if (ret)
989 return SMP_UNSPECIFIED;
990
991 if (crypto_memneq(smp->pcnf, confirm, sizeof(smp->pcnf))) {
992 bt_dev_err(hcon->hdev, "pairing failed "
993 "(confirmation values mismatch)");
994 return SMP_CONFIRM_FAILED;
995 }
996
997 if (hcon->out) {
998 u8 stk[16];
999 __le64 rand = 0;
1000 __le16 ediv = 0;
1001
1002 smp_s1(smp->tk, smp->rrnd, smp->prnd, stk);
1003
1004 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
1005 return SMP_UNSPECIFIED;
1006
1007 hci_le_start_enc(hcon, ediv, rand, stk, smp->enc_key_size);
1008 hcon->enc_key_size = smp->enc_key_size;
1009 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
1010 } else {
1011 u8 stk[16], auth;
1012 __le64 rand = 0;
1013 __le16 ediv = 0;
1014
1015 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
1016 smp->prnd);
1017
1018 smp_s1(smp->tk, smp->prnd, smp->rrnd, stk);
1019
1020 if (hcon->pending_sec_level == BT_SECURITY_HIGH)
1021 auth = 1;
1022 else
1023 auth = 0;
1024
1025 /* Even though there's no _RESPONDER suffix this is the
1026 * responder STK we're adding for later lookup (the initiator
1027 * STK never needs to be stored).
1028 */
1029 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1030 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand);
1031 }
1032
1033 return 0;
1034}
1035
1036static void smp_notify_keys(struct l2cap_conn *conn)
1037{
1038 struct l2cap_chan *chan = conn->smp;
1039 struct smp_chan *smp = chan->data;
1040 struct hci_conn *hcon = conn->hcon;
1041 struct hci_dev *hdev = hcon->hdev;
1042 struct smp_cmd_pairing *req = (void *) &smp->preq[1];
1043 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1];
1044 bool persistent;
1045
1046 if (hcon->type == ACL_LINK) {
1047 if (hcon->key_type == HCI_LK_DEBUG_COMBINATION)
1048 persistent = false;
1049 else
1050 persistent = !test_bit(HCI_CONN_FLUSH_KEY,
1051 &hcon->flags);
1052 } else {
1053 /* The LTKs, IRKs and CSRKs should be persistent only if
1054 * both sides had the bonding bit set in their
1055 * authentication requests.
1056 */
1057 persistent = !!((req->auth_req & rsp->auth_req) &
1058 SMP_AUTH_BONDING);
1059 }
1060
1061 if (smp->remote_irk) {
1062 smp->remote_irk->link_type = hcon->type;
1063 mgmt_new_irk(hdev, smp->remote_irk, persistent);
1064
1065 /* Now that user space can be considered to know the
1066 * identity address track the connection based on it
1067 * from now on (assuming this is an LE link).
1068 */
1069 if (hcon->type == LE_LINK) {
1070 bacpy(&hcon->dst, &smp->remote_irk->bdaddr);
1071 hcon->dst_type = smp->remote_irk->addr_type;
1072 /* Use a short delay to make sure the new address is
1073 * propagated _before_ the channels.
1074 */
1075 queue_delayed_work(hdev->workqueue,
1076 &conn->id_addr_timer,
1077 ID_ADDR_TIMEOUT);
1078 }
1079 }
1080
1081 if (smp->csrk) {
1082 smp->csrk->link_type = hcon->type;
1083 smp->csrk->bdaddr_type = hcon->dst_type;
1084 bacpy(&smp->csrk->bdaddr, &hcon->dst);
1085 mgmt_new_csrk(hdev, smp->csrk, persistent);
1086 }
1087
1088 if (smp->responder_csrk) {
1089 smp->responder_csrk->link_type = hcon->type;
1090 smp->responder_csrk->bdaddr_type = hcon->dst_type;
1091 bacpy(&smp->responder_csrk->bdaddr, &hcon->dst);
1092 mgmt_new_csrk(hdev, smp->responder_csrk, persistent);
1093 }
1094
1095 if (smp->ltk) {
1096 smp->ltk->link_type = hcon->type;
1097 smp->ltk->bdaddr_type = hcon->dst_type;
1098 bacpy(&smp->ltk->bdaddr, &hcon->dst);
1099 mgmt_new_ltk(hdev, smp->ltk, persistent);
1100 }
1101
1102 if (smp->responder_ltk) {
1103 smp->responder_ltk->link_type = hcon->type;
1104 smp->responder_ltk->bdaddr_type = hcon->dst_type;
1105 bacpy(&smp->responder_ltk->bdaddr, &hcon->dst);
1106 mgmt_new_ltk(hdev, smp->responder_ltk, persistent);
1107 }
1108
1109 if (smp->link_key) {
1110 struct link_key *key;
1111 u8 type;
1112
1113 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1114 type = HCI_LK_DEBUG_COMBINATION;
1115 else if (hcon->sec_level == BT_SECURITY_FIPS)
1116 type = HCI_LK_AUTH_COMBINATION_P256;
1117 else
1118 type = HCI_LK_UNAUTH_COMBINATION_P256;
1119
1120 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst,
1121 smp->link_key, type, 0, &persistent);
1122 if (key) {
1123 key->link_type = hcon->type;
1124 key->bdaddr_type = hcon->dst_type;
1125 mgmt_new_link_key(hdev, key, persistent);
1126
1127 /* Don't keep debug keys around if the relevant
1128 * flag is not set.
1129 */
1130 if (!hci_dev_test_flag(hdev, HCI_KEEP_DEBUG_KEYS) &&
1131 key->type == HCI_LK_DEBUG_COMBINATION) {
1132 list_del_rcu(&key->list);
1133 kfree_rcu(key, rcu);
1134 }
1135 }
1136 }
1137}
1138
1139static void sc_add_ltk(struct smp_chan *smp)
1140{
1141 struct hci_conn *hcon = smp->conn->hcon;
1142 u8 key_type, auth;
1143
1144 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1145 key_type = SMP_LTK_P256_DEBUG;
1146 else
1147 key_type = SMP_LTK_P256;
1148
1149 if (hcon->pending_sec_level == BT_SECURITY_FIPS)
1150 auth = 1;
1151 else
1152 auth = 0;
1153
1154 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1155 key_type, auth, smp->tk, smp->enc_key_size,
1156 0, 0);
1157}
1158
1159static void sc_generate_link_key(struct smp_chan *smp)
1160{
1161 /* From core spec. Spells out in ASCII as 'lebr'. */
1162 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c };
1163
1164 smp->link_key = kzalloc(16, GFP_KERNEL);
1165 if (!smp->link_key)
1166 return;
1167
1168 if (test_bit(SMP_FLAG_CT2, &smp->flags)) {
1169 /* SALT = 0x000000000000000000000000746D7031 */
1170 const u8 salt[16] = { 0x31, 0x70, 0x6d, 0x74 };
1171
1172 if (smp_h7(smp->tfm_cmac, smp->tk, salt, smp->link_key)) {
1173 kfree_sensitive(smp->link_key);
1174 smp->link_key = NULL;
1175 return;
1176 }
1177 } else {
1178 /* From core spec. Spells out in ASCII as 'tmp1'. */
1179 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 };
1180
1181 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) {
1182 kfree_sensitive(smp->link_key);
1183 smp->link_key = NULL;
1184 return;
1185 }
1186 }
1187
1188 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) {
1189 kfree_sensitive(smp->link_key);
1190 smp->link_key = NULL;
1191 return;
1192 }
1193}
1194
1195static void smp_allow_key_dist(struct smp_chan *smp)
1196{
1197 /* Allow the first expected phase 3 PDU. The rest of the PDUs
1198 * will be allowed in each PDU handler to ensure we receive
1199 * them in the correct order.
1200 */
1201 if (smp->remote_key_dist & SMP_DIST_ENC_KEY)
1202 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO);
1203 else if (smp->remote_key_dist & SMP_DIST_ID_KEY)
1204 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
1205 else if (smp->remote_key_dist & SMP_DIST_SIGN)
1206 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
1207}
1208
1209static void sc_generate_ltk(struct smp_chan *smp)
1210{
1211 /* From core spec. Spells out in ASCII as 'brle'. */
1212 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 };
1213 struct hci_conn *hcon = smp->conn->hcon;
1214 struct hci_dev *hdev = hcon->hdev;
1215 struct link_key *key;
1216
1217 key = hci_find_link_key(hdev, &hcon->dst);
1218 if (!key) {
1219 bt_dev_err(hdev, "no Link Key found to generate LTK");
1220 return;
1221 }
1222
1223 if (key->type == HCI_LK_DEBUG_COMBINATION)
1224 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1225
1226 if (test_bit(SMP_FLAG_CT2, &smp->flags)) {
1227 /* SALT = 0x000000000000000000000000746D7032 */
1228 const u8 salt[16] = { 0x32, 0x70, 0x6d, 0x74 };
1229
1230 if (smp_h7(smp->tfm_cmac, key->val, salt, smp->tk))
1231 return;
1232 } else {
1233 /* From core spec. Spells out in ASCII as 'tmp2'. */
1234 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 };
1235
1236 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk))
1237 return;
1238 }
1239
1240 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk))
1241 return;
1242
1243 sc_add_ltk(smp);
1244}
1245
1246static void smp_distribute_keys(struct smp_chan *smp)
1247{
1248 struct smp_cmd_pairing *req, *rsp;
1249 struct l2cap_conn *conn = smp->conn;
1250 struct hci_conn *hcon = conn->hcon;
1251 struct hci_dev *hdev = hcon->hdev;
1252 __u8 *keydist;
1253
1254 bt_dev_dbg(hdev, "conn %p", conn);
1255
1256 rsp = (void *) &smp->prsp[1];
1257
1258 /* The responder sends its keys first */
1259 if (hcon->out && (smp->remote_key_dist & KEY_DIST_MASK)) {
1260 smp_allow_key_dist(smp);
1261 return;
1262 }
1263
1264 req = (void *) &smp->preq[1];
1265
1266 if (hcon->out) {
1267 keydist = &rsp->init_key_dist;
1268 *keydist &= req->init_key_dist;
1269 } else {
1270 keydist = &rsp->resp_key_dist;
1271 *keydist &= req->resp_key_dist;
1272 }
1273
1274 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1275 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY))
1276 sc_generate_link_key(smp);
1277 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY))
1278 sc_generate_ltk(smp);
1279
1280 /* Clear the keys which are generated but not distributed */
1281 *keydist &= ~SMP_SC_NO_DIST;
1282 }
1283
1284 bt_dev_dbg(hdev, "keydist 0x%x", *keydist);
1285
1286 if (*keydist & SMP_DIST_ENC_KEY) {
1287 struct smp_cmd_encrypt_info enc;
1288 struct smp_cmd_initiator_ident ident;
1289 struct smp_ltk *ltk;
1290 u8 authenticated;
1291 __le16 ediv;
1292 __le64 rand;
1293
1294 /* Make sure we generate only the significant amount of
1295 * bytes based on the encryption key size, and set the rest
1296 * of the value to zeroes.
1297 */
1298 get_random_bytes(enc.ltk, smp->enc_key_size);
1299 memset(enc.ltk + smp->enc_key_size, 0,
1300 sizeof(enc.ltk) - smp->enc_key_size);
1301
1302 get_random_bytes(&ediv, sizeof(ediv));
1303 get_random_bytes(&rand, sizeof(rand));
1304
1305 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc);
1306
1307 authenticated = hcon->sec_level == BT_SECURITY_HIGH;
1308 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type,
1309 SMP_LTK_RESPONDER, authenticated, enc.ltk,
1310 smp->enc_key_size, ediv, rand);
1311 smp->responder_ltk = ltk;
1312
1313 ident.ediv = ediv;
1314 ident.rand = rand;
1315
1316 smp_send_cmd(conn, SMP_CMD_INITIATOR_IDENT, sizeof(ident),
1317 &ident);
1318
1319 *keydist &= ~SMP_DIST_ENC_KEY;
1320 }
1321
1322 if (*keydist & SMP_DIST_ID_KEY) {
1323 struct smp_cmd_ident_addr_info addrinfo;
1324 struct smp_cmd_ident_info idinfo;
1325
1326 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk));
1327
1328 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo);
1329
1330 /* The hci_conn contains the local identity address
1331 * after the connection has been established.
1332 *
1333 * This is true even when the connection has been
1334 * established using a resolvable random address.
1335 */
1336 bacpy(&addrinfo.bdaddr, &hcon->src);
1337 addrinfo.addr_type = hcon->src_type;
1338
1339 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo),
1340 &addrinfo);
1341
1342 *keydist &= ~SMP_DIST_ID_KEY;
1343 }
1344
1345 if (*keydist & SMP_DIST_SIGN) {
1346 struct smp_cmd_sign_info sign;
1347 struct smp_csrk *csrk;
1348
1349 /* Generate a new random key */
1350 get_random_bytes(sign.csrk, sizeof(sign.csrk));
1351
1352 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
1353 if (csrk) {
1354 if (hcon->sec_level > BT_SECURITY_MEDIUM)
1355 csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED;
1356 else
1357 csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED;
1358 memcpy(csrk->val, sign.csrk, sizeof(csrk->val));
1359 }
1360 smp->responder_csrk = csrk;
1361
1362 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign);
1363
1364 *keydist &= ~SMP_DIST_SIGN;
1365 }
1366
1367 /* If there are still keys to be received wait for them */
1368 if (smp->remote_key_dist & KEY_DIST_MASK) {
1369 smp_allow_key_dist(smp);
1370 return;
1371 }
1372
1373 set_bit(SMP_FLAG_COMPLETE, &smp->flags);
1374 smp_notify_keys(conn);
1375
1376 smp_chan_destroy(conn);
1377}
1378
1379static void smp_timeout(struct work_struct *work)
1380{
1381 struct smp_chan *smp = container_of(work, struct smp_chan,
1382 security_timer.work);
1383 struct l2cap_conn *conn = smp->conn;
1384
1385 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn);
1386
1387 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM);
1388}
1389
1390static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
1391{
1392 struct hci_conn *hcon = conn->hcon;
1393 struct l2cap_chan *chan = conn->smp;
1394 struct smp_chan *smp;
1395
1396 smp = kzalloc(sizeof(*smp), GFP_ATOMIC);
1397 if (!smp)
1398 return NULL;
1399
1400 smp->tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
1401 if (IS_ERR(smp->tfm_cmac)) {
1402 bt_dev_err(hcon->hdev, "Unable to create CMAC crypto context");
1403 goto zfree_smp;
1404 }
1405
1406 smp->tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0);
1407 if (IS_ERR(smp->tfm_ecdh)) {
1408 bt_dev_err(hcon->hdev, "Unable to create ECDH crypto context");
1409 goto free_shash;
1410 }
1411
1412 smp->conn = conn;
1413 chan->data = smp;
1414
1415 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL);
1416
1417 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout);
1418
1419 hci_conn_hold(hcon);
1420
1421 return smp;
1422
1423free_shash:
1424 crypto_free_shash(smp->tfm_cmac);
1425zfree_smp:
1426 kfree_sensitive(smp);
1427 return NULL;
1428}
1429
1430static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16])
1431{
1432 struct hci_conn *hcon = smp->conn->hcon;
1433 u8 *na, *nb, a[7], b[7];
1434
1435 if (hcon->out) {
1436 na = smp->prnd;
1437 nb = smp->rrnd;
1438 } else {
1439 na = smp->rrnd;
1440 nb = smp->prnd;
1441 }
1442
1443 memcpy(a, &hcon->init_addr, 6);
1444 memcpy(b, &hcon->resp_addr, 6);
1445 a[6] = hcon->init_addr_type;
1446 b[6] = hcon->resp_addr_type;
1447
1448 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk);
1449}
1450
1451static void sc_dhkey_check(struct smp_chan *smp)
1452{
1453 struct hci_conn *hcon = smp->conn->hcon;
1454 struct smp_cmd_dhkey_check check;
1455 u8 a[7], b[7], *local_addr, *remote_addr;
1456 u8 io_cap[3], r[16];
1457
1458 memcpy(a, &hcon->init_addr, 6);
1459 memcpy(b, &hcon->resp_addr, 6);
1460 a[6] = hcon->init_addr_type;
1461 b[6] = hcon->resp_addr_type;
1462
1463 if (hcon->out) {
1464 local_addr = a;
1465 remote_addr = b;
1466 memcpy(io_cap, &smp->preq[1], 3);
1467 } else {
1468 local_addr = b;
1469 remote_addr = a;
1470 memcpy(io_cap, &smp->prsp[1], 3);
1471 }
1472
1473 memset(r, 0, sizeof(r));
1474
1475 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
1476 put_unaligned_le32(hcon->passkey_notify, r);
1477
1478 if (smp->method == REQ_OOB)
1479 memcpy(r, smp->rr, 16);
1480
1481 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap,
1482 local_addr, remote_addr, check.e);
1483
1484 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check);
1485}
1486
1487static u8 sc_passkey_send_confirm(struct smp_chan *smp)
1488{
1489 struct l2cap_conn *conn = smp->conn;
1490 struct hci_conn *hcon = conn->hcon;
1491 struct smp_cmd_pairing_confirm cfm;
1492 u8 r;
1493
1494 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1495 r |= 0x80;
1496
1497 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1498
1499 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r,
1500 cfm.confirm_val))
1501 return SMP_UNSPECIFIED;
1502
1503 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
1504
1505 return 0;
1506}
1507
1508static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op)
1509{
1510 struct l2cap_conn *conn = smp->conn;
1511 struct hci_conn *hcon = conn->hcon;
1512 struct hci_dev *hdev = hcon->hdev;
1513 u8 cfm[16], r;
1514
1515 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */
1516 if (smp->passkey_round >= 20)
1517 return 0;
1518
1519 switch (smp_op) {
1520 case SMP_CMD_PAIRING_RANDOM:
1521 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1522 r |= 0x80;
1523
1524 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
1525 smp->rrnd, r, cfm))
1526 return SMP_UNSPECIFIED;
1527
1528 if (crypto_memneq(smp->pcnf, cfm, 16))
1529 return SMP_CONFIRM_FAILED;
1530
1531 smp->passkey_round++;
1532
1533 if (smp->passkey_round == 20) {
1534 /* Generate MacKey and LTK */
1535 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk))
1536 return SMP_UNSPECIFIED;
1537 }
1538
1539 /* The round is only complete when the initiator
1540 * receives pairing random.
1541 */
1542 if (!hcon->out) {
1543 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1544 sizeof(smp->prnd), smp->prnd);
1545 if (smp->passkey_round == 20)
1546 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1547 else
1548 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1549 return 0;
1550 }
1551
1552 /* Start the next round */
1553 if (smp->passkey_round != 20)
1554 return sc_passkey_round(smp, 0);
1555
1556 /* Passkey rounds are complete - start DHKey Check */
1557 sc_dhkey_check(smp);
1558 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1559
1560 break;
1561
1562 case SMP_CMD_PAIRING_CONFIRM:
1563 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
1564 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
1565 return 0;
1566 }
1567
1568 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
1569
1570 if (hcon->out) {
1571 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1572 sizeof(smp->prnd), smp->prnd);
1573 return 0;
1574 }
1575
1576 return sc_passkey_send_confirm(smp);
1577
1578 case SMP_CMD_PUBLIC_KEY:
1579 default:
1580 /* Initiating device starts the round */
1581 if (!hcon->out)
1582 return 0;
1583
1584 bt_dev_dbg(hdev, "Starting passkey round %u",
1585 smp->passkey_round + 1);
1586
1587 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1588
1589 return sc_passkey_send_confirm(smp);
1590 }
1591
1592 return 0;
1593}
1594
1595static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey)
1596{
1597 struct l2cap_conn *conn = smp->conn;
1598 struct hci_conn *hcon = conn->hcon;
1599 u8 smp_op;
1600
1601 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags);
1602
1603 switch (mgmt_op) {
1604 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1605 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED);
1606 return 0;
1607 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1608 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED);
1609 return 0;
1610 case MGMT_OP_USER_PASSKEY_REPLY:
1611 hcon->passkey_notify = le32_to_cpu(passkey);
1612 smp->passkey_round = 0;
1613
1614 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags))
1615 smp_op = SMP_CMD_PAIRING_CONFIRM;
1616 else
1617 smp_op = 0;
1618
1619 if (sc_passkey_round(smp, smp_op))
1620 return -EIO;
1621
1622 return 0;
1623 }
1624
1625 /* Initiator sends DHKey check first */
1626 if (hcon->out) {
1627 sc_dhkey_check(smp);
1628 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1629 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) {
1630 sc_dhkey_check(smp);
1631 sc_add_ltk(smp);
1632 }
1633
1634 return 0;
1635}
1636
1637int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey)
1638{
1639 struct l2cap_conn *conn = hcon->l2cap_data;
1640 struct l2cap_chan *chan;
1641 struct smp_chan *smp;
1642 u32 value;
1643 int err;
1644
1645 if (!conn)
1646 return -ENOTCONN;
1647
1648 bt_dev_dbg(conn->hcon->hdev, "");
1649
1650 chan = conn->smp;
1651 if (!chan)
1652 return -ENOTCONN;
1653
1654 l2cap_chan_lock(chan);
1655 if (!chan->data) {
1656 err = -ENOTCONN;
1657 goto unlock;
1658 }
1659
1660 smp = chan->data;
1661
1662 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1663 err = sc_user_reply(smp, mgmt_op, passkey);
1664 goto unlock;
1665 }
1666
1667 switch (mgmt_op) {
1668 case MGMT_OP_USER_PASSKEY_REPLY:
1669 value = le32_to_cpu(passkey);
1670 memset(smp->tk, 0, sizeof(smp->tk));
1671 bt_dev_dbg(conn->hcon->hdev, "PassKey: %u", value);
1672 put_unaligned_le32(value, smp->tk);
1673 fallthrough;
1674 case MGMT_OP_USER_CONFIRM_REPLY:
1675 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
1676 break;
1677 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1678 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1679 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1680 err = 0;
1681 goto unlock;
1682 default:
1683 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1684 err = -EOPNOTSUPP;
1685 goto unlock;
1686 }
1687
1688 err = 0;
1689
1690 /* If it is our turn to send Pairing Confirm, do so now */
1691 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) {
1692 u8 rsp = smp_confirm(smp);
1693 if (rsp)
1694 smp_failure(conn, rsp);
1695 }
1696
1697unlock:
1698 l2cap_chan_unlock(chan);
1699 return err;
1700}
1701
1702static void build_bredr_pairing_cmd(struct smp_chan *smp,
1703 struct smp_cmd_pairing *req,
1704 struct smp_cmd_pairing *rsp)
1705{
1706 struct l2cap_conn *conn = smp->conn;
1707 struct hci_dev *hdev = conn->hcon->hdev;
1708 u8 local_dist = 0, remote_dist = 0;
1709
1710 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) {
1711 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1712 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1713 }
1714
1715 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING))
1716 remote_dist |= SMP_DIST_ID_KEY;
1717
1718 if (hci_dev_test_flag(hdev, HCI_PRIVACY))
1719 local_dist |= SMP_DIST_ID_KEY;
1720
1721 if (!rsp) {
1722 memset(req, 0, sizeof(*req));
1723
1724 req->auth_req = SMP_AUTH_CT2;
1725 req->init_key_dist = local_dist;
1726 req->resp_key_dist = remote_dist;
1727 req->max_key_size = conn->hcon->enc_key_size;
1728
1729 smp->remote_key_dist = remote_dist;
1730
1731 return;
1732 }
1733
1734 memset(rsp, 0, sizeof(*rsp));
1735
1736 rsp->auth_req = SMP_AUTH_CT2;
1737 rsp->max_key_size = conn->hcon->enc_key_size;
1738 rsp->init_key_dist = req->init_key_dist & remote_dist;
1739 rsp->resp_key_dist = req->resp_key_dist & local_dist;
1740
1741 smp->remote_key_dist = rsp->init_key_dist;
1742}
1743
1744static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
1745{
1746 struct smp_cmd_pairing rsp, *req = (void *) skb->data;
1747 struct l2cap_chan *chan = conn->smp;
1748 struct hci_dev *hdev = conn->hcon->hdev;
1749 struct smp_chan *smp;
1750 u8 key_size, auth, sec_level;
1751 int ret;
1752
1753 bt_dev_dbg(hdev, "conn %p", conn);
1754
1755 if (skb->len < sizeof(*req))
1756 return SMP_INVALID_PARAMS;
1757
1758 if (conn->hcon->role != HCI_ROLE_SLAVE)
1759 return SMP_CMD_NOTSUPP;
1760
1761 if (!chan->data)
1762 smp = smp_chan_create(conn);
1763 else
1764 smp = chan->data;
1765
1766 if (!smp)
1767 return SMP_UNSPECIFIED;
1768
1769 /* We didn't start the pairing, so match remote */
1770 auth = req->auth_req & AUTH_REQ_MASK(hdev);
1771
1772 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) &&
1773 (auth & SMP_AUTH_BONDING))
1774 return SMP_PAIRING_NOTSUPP;
1775
1776 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
1777 return SMP_AUTH_REQUIREMENTS;
1778
1779 smp->preq[0] = SMP_CMD_PAIRING_REQ;
1780 memcpy(&smp->preq[1], req, sizeof(*req));
1781 skb_pull(skb, sizeof(*req));
1782
1783 /* If the remote side's OOB flag is set it means it has
1784 * successfully received our local OOB data - therefore set the
1785 * flag to indicate that local OOB is in use.
1786 */
1787 if (req->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob)
1788 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);
1789
1790 /* SMP over BR/EDR requires special treatment */
1791 if (conn->hcon->type == ACL_LINK) {
1792 /* We must have a BR/EDR SC link */
1793 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) &&
1794 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
1795 return SMP_CROSS_TRANSP_NOT_ALLOWED;
1796
1797 set_bit(SMP_FLAG_SC, &smp->flags);
1798
1799 build_bredr_pairing_cmd(smp, req, &rsp);
1800
1801 if (req->auth_req & SMP_AUTH_CT2)
1802 set_bit(SMP_FLAG_CT2, &smp->flags);
1803
1804 key_size = min(req->max_key_size, rsp.max_key_size);
1805 if (check_enc_key_size(conn, key_size))
1806 return SMP_ENC_KEY_SIZE;
1807
1808 /* Clear bits which are generated but not distributed */
1809 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1810
1811 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1812 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1813 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1814
1815 smp_distribute_keys(smp);
1816 return 0;
1817 }
1818
1819 build_pairing_cmd(conn, req, &rsp, auth);
1820
1821 if (rsp.auth_req & SMP_AUTH_SC) {
1822 set_bit(SMP_FLAG_SC, &smp->flags);
1823
1824 if (rsp.auth_req & SMP_AUTH_CT2)
1825 set_bit(SMP_FLAG_CT2, &smp->flags);
1826 }
1827
1828 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
1829 sec_level = BT_SECURITY_MEDIUM;
1830 else
1831 sec_level = authreq_to_seclevel(auth);
1832
1833 if (sec_level > conn->hcon->pending_sec_level)
1834 conn->hcon->pending_sec_level = sec_level;
1835
1836 /* If we need MITM check that it can be achieved */
1837 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1838 u8 method;
1839
1840 method = get_auth_method(smp, conn->hcon->io_capability,
1841 req->io_capability);
1842 if (method == JUST_WORKS || method == JUST_CFM)
1843 return SMP_AUTH_REQUIREMENTS;
1844 }
1845
1846 key_size = min(req->max_key_size, rsp.max_key_size);
1847 if (check_enc_key_size(conn, key_size))
1848 return SMP_ENC_KEY_SIZE;
1849
1850 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1851
1852 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1853 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1854
1855 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1856
1857 clear_bit(SMP_FLAG_INITIATOR, &smp->flags);
1858
1859 /* Strictly speaking we shouldn't allow Pairing Confirm for the
1860 * SC case, however some implementations incorrectly copy RFU auth
1861 * req bits from our security request, which may create a false
1862 * positive SC enablement.
1863 */
1864 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1865
1866 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1867 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
1868 /* Clear bits which are generated but not distributed */
1869 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1870 /* Wait for Public Key from Initiating Device */
1871 return 0;
1872 }
1873
1874 /* Request setup of TK */
1875 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability);
1876 if (ret)
1877 return SMP_UNSPECIFIED;
1878
1879 return 0;
1880}
1881
1882static u8 sc_send_public_key(struct smp_chan *smp)
1883{
1884 struct hci_dev *hdev = smp->conn->hcon->hdev;
1885
1886 bt_dev_dbg(hdev, "");
1887
1888 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) {
1889 struct l2cap_chan *chan = hdev->smp_data;
1890 struct smp_dev *smp_dev;
1891
1892 if (!chan || !chan->data)
1893 return SMP_UNSPECIFIED;
1894
1895 smp_dev = chan->data;
1896
1897 memcpy(smp->local_pk, smp_dev->local_pk, 64);
1898 memcpy(smp->lr, smp_dev->local_rand, 16);
1899
1900 if (smp_dev->debug_key)
1901 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1902
1903 goto done;
1904 }
1905
1906 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) {
1907 bt_dev_dbg(hdev, "Using debug keys");
1908 if (set_ecdh_privkey(smp->tfm_ecdh, debug_sk))
1909 return SMP_UNSPECIFIED;
1910 memcpy(smp->local_pk, debug_pk, 64);
1911 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1912 } else {
1913 while (true) {
1914 /* Generate key pair for Secure Connections */
1915 if (generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk))
1916 return SMP_UNSPECIFIED;
1917
1918 /* This is unlikely, but we need to check that
1919 * we didn't accidentally generate a debug key.
1920 */
1921 if (crypto_memneq(smp->local_pk, debug_pk, 64))
1922 break;
1923 }
1924 }
1925
1926done:
1927 SMP_DBG("Local Public Key X: %32phN", smp->local_pk);
1928 SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32);
1929
1930 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk);
1931
1932 return 0;
1933}
1934
1935static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
1936{
1937 struct smp_cmd_pairing *req, *rsp = (void *) skb->data;
1938 struct l2cap_chan *chan = conn->smp;
1939 struct smp_chan *smp = chan->data;
1940 struct hci_dev *hdev = conn->hcon->hdev;
1941 u8 key_size, auth;
1942 int ret;
1943
1944 bt_dev_dbg(hdev, "conn %p", conn);
1945
1946 if (skb->len < sizeof(*rsp))
1947 return SMP_INVALID_PARAMS;
1948
1949 if (conn->hcon->role != HCI_ROLE_MASTER)
1950 return SMP_CMD_NOTSUPP;
1951
1952 skb_pull(skb, sizeof(*rsp));
1953
1954 req = (void *) &smp->preq[1];
1955
1956 key_size = min(req->max_key_size, rsp->max_key_size);
1957 if (check_enc_key_size(conn, key_size))
1958 return SMP_ENC_KEY_SIZE;
1959
1960 auth = rsp->auth_req & AUTH_REQ_MASK(hdev);
1961
1962 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
1963 return SMP_AUTH_REQUIREMENTS;
1964
1965 /* If the remote side's OOB flag is set it means it has
1966 * successfully received our local OOB data - therefore set the
1967 * flag to indicate that local OOB is in use.
1968 */
1969 if (rsp->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob)
1970 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);
1971
1972 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1973 memcpy(&smp->prsp[1], rsp, sizeof(*rsp));
1974
1975 /* Update remote key distribution in case the remote cleared
1976 * some bits that we had enabled in our request.
1977 */
1978 smp->remote_key_dist &= rsp->resp_key_dist;
1979
1980 if ((req->auth_req & SMP_AUTH_CT2) && (auth & SMP_AUTH_CT2))
1981 set_bit(SMP_FLAG_CT2, &smp->flags);
1982
1983 /* For BR/EDR this means we're done and can start phase 3 */
1984 if (conn->hcon->type == ACL_LINK) {
1985 /* Clear bits which are generated but not distributed */
1986 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1987 smp_distribute_keys(smp);
1988 return 0;
1989 }
1990
1991 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC))
1992 set_bit(SMP_FLAG_SC, &smp->flags);
1993 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH)
1994 conn->hcon->pending_sec_level = BT_SECURITY_HIGH;
1995
1996 /* If we need MITM check that it can be achieved */
1997 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1998 u8 method;
1999
2000 method = get_auth_method(smp, req->io_capability,
2001 rsp->io_capability);
2002 if (method == JUST_WORKS || method == JUST_CFM)
2003 return SMP_AUTH_REQUIREMENTS;
2004 }
2005
2006 get_random_bytes(smp->prnd, sizeof(smp->prnd));
2007
2008 /* Update remote key distribution in case the remote cleared
2009 * some bits that we had enabled in our request.
2010 */
2011 smp->remote_key_dist &= rsp->resp_key_dist;
2012
2013 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
2014 /* Clear bits which are generated but not distributed */
2015 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
2016 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
2017 return sc_send_public_key(smp);
2018 }
2019
2020 auth |= req->auth_req;
2021
2022 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability);
2023 if (ret)
2024 return SMP_UNSPECIFIED;
2025
2026 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
2027
2028 /* Can't compose response until we have been confirmed */
2029 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
2030 return smp_confirm(smp);
2031
2032 return 0;
2033}
2034
2035static u8 sc_check_confirm(struct smp_chan *smp)
2036{
2037 struct l2cap_conn *conn = smp->conn;
2038
2039 bt_dev_dbg(conn->hcon->hdev, "");
2040
2041 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2042 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM);
2043
2044 if (conn->hcon->out) {
2045 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2046 smp->prnd);
2047 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2048 }
2049
2050 return 0;
2051}
2052
2053/* Work-around for some implementations that incorrectly copy RFU bits
2054 * from our security request and thereby create the impression that
2055 * we're doing SC when in fact the remote doesn't support it.
2056 */
2057static int fixup_sc_false_positive(struct smp_chan *smp)
2058{
2059 struct l2cap_conn *conn = smp->conn;
2060 struct hci_conn *hcon = conn->hcon;
2061 struct hci_dev *hdev = hcon->hdev;
2062 struct smp_cmd_pairing *req, *rsp;
2063 u8 auth;
2064
2065 /* The issue is only observed when we're in responder role */
2066 if (hcon->out)
2067 return SMP_UNSPECIFIED;
2068
2069 if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) {
2070 bt_dev_err(hdev, "refusing legacy fallback in SC-only mode");
2071 return SMP_UNSPECIFIED;
2072 }
2073
2074 bt_dev_err(hdev, "trying to fall back to legacy SMP");
2075
2076 req = (void *) &smp->preq[1];
2077 rsp = (void *) &smp->prsp[1];
2078
2079 /* Rebuild key dist flags which may have been cleared for SC */
2080 smp->remote_key_dist = (req->init_key_dist & rsp->resp_key_dist);
2081
2082 auth = req->auth_req & AUTH_REQ_MASK(hdev);
2083
2084 if (tk_request(conn, 0, auth, rsp->io_capability, req->io_capability)) {
2085 bt_dev_err(hdev, "failed to fall back to legacy SMP");
2086 return SMP_UNSPECIFIED;
2087 }
2088
2089 clear_bit(SMP_FLAG_SC, &smp->flags);
2090
2091 return 0;
2092}
2093
2094static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
2095{
2096 struct l2cap_chan *chan = conn->smp;
2097 struct smp_chan *smp = chan->data;
2098 struct hci_conn *hcon = conn->hcon;
2099 struct hci_dev *hdev = hcon->hdev;
2100
2101 bt_dev_dbg(hdev, "conn %p %s", conn,
2102 hcon->out ? "initiator" : "responder");
2103
2104 if (skb->len < sizeof(smp->pcnf))
2105 return SMP_INVALID_PARAMS;
2106
2107 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf));
2108 skb_pull(skb, sizeof(smp->pcnf));
2109
2110 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
2111 int ret;
2112
2113 /* Public Key exchange must happen before any other steps */
2114 if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags))
2115 return sc_check_confirm(smp);
2116
2117 bt_dev_err(hdev, "Unexpected SMP Pairing Confirm");
2118
2119 ret = fixup_sc_false_positive(smp);
2120 if (ret)
2121 return ret;
2122 }
2123
2124 if (conn->hcon->out) {
2125 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2126 smp->prnd);
2127 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2128 return 0;
2129 }
2130
2131 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
2132 return smp_confirm(smp);
2133
2134 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
2135
2136 return 0;
2137}
2138
2139static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
2140{
2141 struct l2cap_chan *chan = conn->smp;
2142 struct smp_chan *smp = chan->data;
2143 struct hci_conn *hcon = conn->hcon;
2144 u8 *pkax, *pkbx, *na, *nb, confirm_hint;
2145 u32 passkey;
2146 int err;
2147
2148 bt_dev_dbg(hcon->hdev, "conn %p", conn);
2149
2150 if (skb->len < sizeof(smp->rrnd))
2151 return SMP_INVALID_PARAMS;
2152
2153 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd));
2154 skb_pull(skb, sizeof(smp->rrnd));
2155
2156 if (!test_bit(SMP_FLAG_SC, &smp->flags))
2157 return smp_random(smp);
2158
2159 if (hcon->out) {
2160 pkax = smp->local_pk;
2161 pkbx = smp->remote_pk;
2162 na = smp->prnd;
2163 nb = smp->rrnd;
2164 } else {
2165 pkax = smp->remote_pk;
2166 pkbx = smp->local_pk;
2167 na = smp->rrnd;
2168 nb = smp->prnd;
2169 }
2170
2171 if (smp->method == REQ_OOB) {
2172 if (!hcon->out)
2173 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2174 sizeof(smp->prnd), smp->prnd);
2175 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2176 goto mackey_and_ltk;
2177 }
2178
2179 /* Passkey entry has special treatment */
2180 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2181 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM);
2182
2183 if (hcon->out) {
2184 u8 cfm[16];
2185
2186 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
2187 smp->rrnd, 0, cfm);
2188 if (err)
2189 return SMP_UNSPECIFIED;
2190
2191 if (crypto_memneq(smp->pcnf, cfm, 16))
2192 return SMP_CONFIRM_FAILED;
2193 } else {
2194 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2195 smp->prnd);
2196 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2197
2198 /* Only Just-Works pairing requires extra checks */
2199 if (smp->method != JUST_WORKS)
2200 goto mackey_and_ltk;
2201
2202 /* If there already exists long term key in local host, leave
2203 * the decision to user space since the remote device could
2204 * be legitimate or malicious.
2205 */
2206 if (hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
2207 hcon->role)) {
2208 /* Set passkey to 0. The value can be any number since
2209 * it'll be ignored anyway.
2210 */
2211 passkey = 0;
2212 confirm_hint = 1;
2213 goto confirm;
2214 }
2215 }
2216
2217mackey_and_ltk:
2218 /* Generate MacKey and LTK */
2219 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk);
2220 if (err)
2221 return SMP_UNSPECIFIED;
2222
2223 if (smp->method == REQ_OOB) {
2224 if (hcon->out) {
2225 sc_dhkey_check(smp);
2226 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2227 }
2228 return 0;
2229 }
2230
2231 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
2232 if (err)
2233 return SMP_UNSPECIFIED;
2234
2235 confirm_hint = 0;
2236
2237confirm:
2238 if (smp->method == JUST_WORKS)
2239 confirm_hint = 1;
2240
2241 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type,
2242 hcon->dst_type, passkey, confirm_hint);
2243 if (err)
2244 return SMP_UNSPECIFIED;
2245
2246 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2247
2248 return 0;
2249}
2250
2251static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level)
2252{
2253 struct smp_ltk *key;
2254 struct hci_conn *hcon = conn->hcon;
2255
2256 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role);
2257 if (!key)
2258 return false;
2259
2260 if (smp_ltk_sec_level(key) < sec_level)
2261 return false;
2262
2263 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
2264 return true;
2265
2266 hci_le_start_enc(hcon, key->ediv, key->rand, key->val, key->enc_size);
2267 hcon->enc_key_size = key->enc_size;
2268
2269 /* We never store STKs for initiator role, so clear this flag */
2270 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
2271
2272 return true;
2273}
2274
2275bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level,
2276 enum smp_key_pref key_pref)
2277{
2278 if (sec_level == BT_SECURITY_LOW)
2279 return true;
2280
2281 /* If we're encrypted with an STK but the caller prefers using
2282 * LTK claim insufficient security. This way we allow the
2283 * connection to be re-encrypted with an LTK, even if the LTK
2284 * provides the same level of security. Only exception is if we
2285 * don't have an LTK (e.g. because of key distribution bits).
2286 */
2287 if (key_pref == SMP_USE_LTK &&
2288 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) &&
2289 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role))
2290 return false;
2291
2292 if (hcon->sec_level >= sec_level)
2293 return true;
2294
2295 return false;
2296}
2297
2298static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
2299{
2300 struct smp_cmd_security_req *rp = (void *) skb->data;
2301 struct smp_cmd_pairing cp;
2302 struct hci_conn *hcon = conn->hcon;
2303 struct hci_dev *hdev = hcon->hdev;
2304 struct smp_chan *smp;
2305 u8 sec_level, auth;
2306
2307 bt_dev_dbg(hdev, "conn %p", conn);
2308
2309 if (skb->len < sizeof(*rp))
2310 return SMP_INVALID_PARAMS;
2311
2312 if (hcon->role != HCI_ROLE_MASTER)
2313 return SMP_CMD_NOTSUPP;
2314
2315 auth = rp->auth_req & AUTH_REQ_MASK(hdev);
2316
2317 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
2318 return SMP_AUTH_REQUIREMENTS;
2319
2320 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
2321 sec_level = BT_SECURITY_MEDIUM;
2322 else
2323 sec_level = authreq_to_seclevel(auth);
2324
2325 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) {
2326 /* If link is already encrypted with sufficient security we
2327 * still need refresh encryption as per Core Spec 5.0 Vol 3,
2328 * Part H 2.4.6
2329 */
2330 smp_ltk_encrypt(conn, hcon->sec_level);
2331 return 0;
2332 }
2333
2334 if (sec_level > hcon->pending_sec_level)
2335 hcon->pending_sec_level = sec_level;
2336
2337 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2338 return 0;
2339
2340 smp = smp_chan_create(conn);
2341 if (!smp)
2342 return SMP_UNSPECIFIED;
2343
2344 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) &&
2345 (auth & SMP_AUTH_BONDING))
2346 return SMP_PAIRING_NOTSUPP;
2347
2348 skb_pull(skb, sizeof(*rp));
2349
2350 memset(&cp, 0, sizeof(cp));
2351 build_pairing_cmd(conn, &cp, NULL, auth);
2352
2353 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2354 memcpy(&smp->preq[1], &cp, sizeof(cp));
2355
2356 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
2357 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2358
2359 return 0;
2360}
2361
2362int smp_conn_security(struct hci_conn *hcon, __u8 sec_level)
2363{
2364 struct l2cap_conn *conn = hcon->l2cap_data;
2365 struct l2cap_chan *chan;
2366 struct smp_chan *smp;
2367 __u8 authreq;
2368 int ret;
2369
2370 bt_dev_dbg(hcon->hdev, "conn %p hcon %p level 0x%2.2x", conn, hcon,
2371 sec_level);
2372
2373 /* This may be NULL if there's an unexpected disconnection */
2374 if (!conn)
2375 return 1;
2376
2377 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED))
2378 return 1;
2379
2380 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK))
2381 return 1;
2382
2383 if (sec_level > hcon->pending_sec_level)
2384 hcon->pending_sec_level = sec_level;
2385
2386 if (hcon->role == HCI_ROLE_MASTER)
2387 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2388 return 0;
2389
2390 chan = conn->smp;
2391 if (!chan) {
2392 bt_dev_err(hcon->hdev, "security requested but not available");
2393 return 1;
2394 }
2395
2396 l2cap_chan_lock(chan);
2397
2398 /* If SMP is already in progress ignore this request */
2399 if (chan->data) {
2400 ret = 0;
2401 goto unlock;
2402 }
2403
2404 smp = smp_chan_create(conn);
2405 if (!smp) {
2406 ret = 1;
2407 goto unlock;
2408 }
2409
2410 authreq = seclevel_to_authreq(sec_level);
2411
2412 if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED)) {
2413 authreq |= SMP_AUTH_SC;
2414 if (hci_dev_test_flag(hcon->hdev, HCI_SSP_ENABLED))
2415 authreq |= SMP_AUTH_CT2;
2416 }
2417
2418 /* Don't attempt to set MITM if setting is overridden by debugfs
2419 * Needed to pass certification test SM/MAS/PKE/BV-01-C
2420 */
2421 if (!hci_dev_test_flag(hcon->hdev, HCI_FORCE_NO_MITM)) {
2422 /* Require MITM if IO Capability allows or the security level
2423 * requires it.
2424 */
2425 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT ||
2426 hcon->pending_sec_level > BT_SECURITY_MEDIUM)
2427 authreq |= SMP_AUTH_MITM;
2428 }
2429
2430 if (hcon->role == HCI_ROLE_MASTER) {
2431 struct smp_cmd_pairing cp;
2432
2433 build_pairing_cmd(conn, &cp, NULL, authreq);
2434 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2435 memcpy(&smp->preq[1], &cp, sizeof(cp));
2436
2437 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
2438 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2439 } else {
2440 struct smp_cmd_security_req cp;
2441 cp.auth_req = authreq;
2442 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp);
2443 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ);
2444 }
2445
2446 set_bit(SMP_FLAG_INITIATOR, &smp->flags);
2447 ret = 0;
2448
2449unlock:
2450 l2cap_chan_unlock(chan);
2451 return ret;
2452}
2453
2454int smp_cancel_and_remove_pairing(struct hci_dev *hdev, bdaddr_t *bdaddr,
2455 u8 addr_type)
2456{
2457 struct hci_conn *hcon;
2458 struct l2cap_conn *conn;
2459 struct l2cap_chan *chan;
2460 struct smp_chan *smp;
2461 int err;
2462
2463 err = hci_remove_ltk(hdev, bdaddr, addr_type);
2464 hci_remove_irk(hdev, bdaddr, addr_type);
2465
2466 hcon = hci_conn_hash_lookup_le(hdev, bdaddr, addr_type);
2467 if (!hcon)
2468 goto done;
2469
2470 conn = hcon->l2cap_data;
2471 if (!conn)
2472 goto done;
2473
2474 chan = conn->smp;
2475 if (!chan)
2476 goto done;
2477
2478 l2cap_chan_lock(chan);
2479
2480 smp = chan->data;
2481 if (smp) {
2482 /* Set keys to NULL to make sure smp_failure() does not try to
2483 * remove and free already invalidated rcu list entries. */
2484 smp->ltk = NULL;
2485 smp->responder_ltk = NULL;
2486 smp->remote_irk = NULL;
2487
2488 if (test_bit(SMP_FLAG_COMPLETE, &smp->flags))
2489 smp_failure(conn, 0);
2490 else
2491 smp_failure(conn, SMP_UNSPECIFIED);
2492 err = 0;
2493 }
2494
2495 l2cap_chan_unlock(chan);
2496
2497done:
2498 return err;
2499}
2500
2501static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb)
2502{
2503 struct smp_cmd_encrypt_info *rp = (void *) skb->data;
2504 struct l2cap_chan *chan = conn->smp;
2505 struct smp_chan *smp = chan->data;
2506
2507 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn);
2508
2509 if (skb->len < sizeof(*rp))
2510 return SMP_INVALID_PARAMS;
2511
2512 /* Pairing is aborted if any blocked keys are distributed */
2513 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_LTK,
2514 rp->ltk)) {
2515 bt_dev_warn_ratelimited(conn->hcon->hdev,
2516 "LTK blocked for %pMR",
2517 &conn->hcon->dst);
2518 return SMP_INVALID_PARAMS;
2519 }
2520
2521 SMP_ALLOW_CMD(smp, SMP_CMD_INITIATOR_IDENT);
2522
2523 skb_pull(skb, sizeof(*rp));
2524
2525 memcpy(smp->tk, rp->ltk, sizeof(smp->tk));
2526
2527 return 0;
2528}
2529
2530static int smp_cmd_initiator_ident(struct l2cap_conn *conn, struct sk_buff *skb)
2531{
2532 struct smp_cmd_initiator_ident *rp = (void *)skb->data;
2533 struct l2cap_chan *chan = conn->smp;
2534 struct smp_chan *smp = chan->data;
2535 struct hci_dev *hdev = conn->hcon->hdev;
2536 struct hci_conn *hcon = conn->hcon;
2537 struct smp_ltk *ltk;
2538 u8 authenticated;
2539
2540 bt_dev_dbg(hdev, "conn %p", conn);
2541
2542 if (skb->len < sizeof(*rp))
2543 return SMP_INVALID_PARAMS;
2544
2545 /* Mark the information as received */
2546 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY;
2547
2548 if (smp->remote_key_dist & SMP_DIST_ID_KEY)
2549 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
2550 else if (smp->remote_key_dist & SMP_DIST_SIGN)
2551 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2552
2553 skb_pull(skb, sizeof(*rp));
2554
2555 authenticated = (hcon->sec_level == BT_SECURITY_HIGH);
2556 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK,
2557 authenticated, smp->tk, smp->enc_key_size,
2558 rp->ediv, rp->rand);
2559 smp->ltk = ltk;
2560 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2561 smp_distribute_keys(smp);
2562
2563 return 0;
2564}
2565
2566static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb)
2567{
2568 struct smp_cmd_ident_info *info = (void *) skb->data;
2569 struct l2cap_chan *chan = conn->smp;
2570 struct smp_chan *smp = chan->data;
2571
2572 bt_dev_dbg(conn->hcon->hdev, "");
2573
2574 if (skb->len < sizeof(*info))
2575 return SMP_INVALID_PARAMS;
2576
2577 /* Pairing is aborted if any blocked keys are distributed */
2578 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_IRK,
2579 info->irk)) {
2580 bt_dev_warn_ratelimited(conn->hcon->hdev,
2581 "Identity key blocked for %pMR",
2582 &conn->hcon->dst);
2583 return SMP_INVALID_PARAMS;
2584 }
2585
2586 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO);
2587
2588 skb_pull(skb, sizeof(*info));
2589
2590 memcpy(smp->irk, info->irk, 16);
2591
2592 return 0;
2593}
2594
2595static int smp_cmd_ident_addr_info(struct l2cap_conn *conn,
2596 struct sk_buff *skb)
2597{
2598 struct smp_cmd_ident_addr_info *info = (void *) skb->data;
2599 struct l2cap_chan *chan = conn->smp;
2600 struct smp_chan *smp = chan->data;
2601 struct hci_conn *hcon = conn->hcon;
2602 bdaddr_t rpa;
2603
2604 bt_dev_dbg(hcon->hdev, "");
2605
2606 if (skb->len < sizeof(*info))
2607 return SMP_INVALID_PARAMS;
2608
2609 /* Mark the information as received */
2610 smp->remote_key_dist &= ~SMP_DIST_ID_KEY;
2611
2612 if (smp->remote_key_dist & SMP_DIST_SIGN)
2613 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2614
2615 skb_pull(skb, sizeof(*info));
2616
2617 /* Strictly speaking the Core Specification (4.1) allows sending
2618 * an empty address which would force us to rely on just the IRK
2619 * as "identity information". However, since such
2620 * implementations are not known of and in order to not over
2621 * complicate our implementation, simply pretend that we never
2622 * received an IRK for such a device.
2623 *
2624 * The Identity Address must also be a Static Random or Public
2625 * Address, which hci_is_identity_address() checks for.
2626 */
2627 if (!bacmp(&info->bdaddr, BDADDR_ANY) ||
2628 !hci_is_identity_address(&info->bdaddr, info->addr_type)) {
2629 bt_dev_err(hcon->hdev, "ignoring IRK with no identity address");
2630 goto distribute;
2631 }
2632
2633 /* Drop IRK if peer is using identity address during pairing but is
2634 * providing different address as identity information.
2635 *
2636 * Microsoft Surface Precision Mouse is known to have this bug.
2637 */
2638 if (hci_is_identity_address(&hcon->dst, hcon->dst_type) &&
2639 (bacmp(&info->bdaddr, &hcon->dst) ||
2640 info->addr_type != hcon->dst_type)) {
2641 bt_dev_err(hcon->hdev,
2642 "ignoring IRK with invalid identity address");
2643 goto distribute;
2644 }
2645
2646 bacpy(&smp->id_addr, &info->bdaddr);
2647 smp->id_addr_type = info->addr_type;
2648
2649 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type))
2650 bacpy(&rpa, &hcon->dst);
2651 else
2652 bacpy(&rpa, BDADDR_ANY);
2653
2654 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr,
2655 smp->id_addr_type, smp->irk, &rpa);
2656
2657distribute:
2658 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2659 smp_distribute_keys(smp);
2660
2661 return 0;
2662}
2663
2664static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb)
2665{
2666 struct smp_cmd_sign_info *rp = (void *) skb->data;
2667 struct l2cap_chan *chan = conn->smp;
2668 struct smp_chan *smp = chan->data;
2669 struct smp_csrk *csrk;
2670
2671 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn);
2672
2673 if (skb->len < sizeof(*rp))
2674 return SMP_INVALID_PARAMS;
2675
2676 /* Mark the information as received */
2677 smp->remote_key_dist &= ~SMP_DIST_SIGN;
2678
2679 skb_pull(skb, sizeof(*rp));
2680
2681 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
2682 if (csrk) {
2683 if (conn->hcon->sec_level > BT_SECURITY_MEDIUM)
2684 csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED;
2685 else
2686 csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED;
2687 memcpy(csrk->val, rp->csrk, sizeof(csrk->val));
2688 }
2689 smp->csrk = csrk;
2690 smp_distribute_keys(smp);
2691
2692 return 0;
2693}
2694
2695static u8 sc_select_method(struct smp_chan *smp)
2696{
2697 struct l2cap_conn *conn = smp->conn;
2698 struct hci_conn *hcon = conn->hcon;
2699 struct smp_cmd_pairing *local, *remote;
2700 u8 local_mitm, remote_mitm, local_io, remote_io, method;
2701
2702 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) ||
2703 test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags))
2704 return REQ_OOB;
2705
2706 /* The preq/prsp contain the raw Pairing Request/Response PDUs
2707 * which are needed as inputs to some crypto functions. To get
2708 * the "struct smp_cmd_pairing" from them we need to skip the
2709 * first byte which contains the opcode.
2710 */
2711 if (hcon->out) {
2712 local = (void *) &smp->preq[1];
2713 remote = (void *) &smp->prsp[1];
2714 } else {
2715 local = (void *) &smp->prsp[1];
2716 remote = (void *) &smp->preq[1];
2717 }
2718
2719 local_io = local->io_capability;
2720 remote_io = remote->io_capability;
2721
2722 local_mitm = (local->auth_req & SMP_AUTH_MITM);
2723 remote_mitm = (remote->auth_req & SMP_AUTH_MITM);
2724
2725 /* If either side wants MITM, look up the method from the table,
2726 * otherwise use JUST WORKS.
2727 */
2728 if (local_mitm || remote_mitm)
2729 method = get_auth_method(smp, local_io, remote_io);
2730 else
2731 method = JUST_WORKS;
2732
2733 /* Don't confirm locally initiated pairing attempts */
2734 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2735 method = JUST_WORKS;
2736
2737 return method;
2738}
2739
2740static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb)
2741{
2742 struct smp_cmd_public_key *key = (void *) skb->data;
2743 struct hci_conn *hcon = conn->hcon;
2744 struct l2cap_chan *chan = conn->smp;
2745 struct smp_chan *smp = chan->data;
2746 struct hci_dev *hdev = hcon->hdev;
2747 struct crypto_kpp *tfm_ecdh;
2748 struct smp_cmd_pairing_confirm cfm;
2749 int err;
2750
2751 bt_dev_dbg(hdev, "conn %p", conn);
2752
2753 if (skb->len < sizeof(*key))
2754 return SMP_INVALID_PARAMS;
2755
2756 /* Check if remote and local public keys are the same and debug key is
2757 * not in use.
2758 */
2759 if (!test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags) &&
2760 !crypto_memneq(key, smp->local_pk, 64)) {
2761 bt_dev_err(hdev, "Remote and local public keys are identical");
2762 return SMP_UNSPECIFIED;
2763 }
2764
2765 memcpy(smp->remote_pk, key, 64);
2766
2767 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) {
2768 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk,
2769 smp->rr, 0, cfm.confirm_val);
2770 if (err)
2771 return SMP_UNSPECIFIED;
2772
2773 if (crypto_memneq(cfm.confirm_val, smp->pcnf, 16))
2774 return SMP_CONFIRM_FAILED;
2775 }
2776
2777 /* Non-initiating device sends its public key after receiving
2778 * the key from the initiating device.
2779 */
2780 if (!hcon->out) {
2781 err = sc_send_public_key(smp);
2782 if (err)
2783 return err;
2784 }
2785
2786 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk);
2787 SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32);
2788
2789 /* Compute the shared secret on the same crypto tfm on which the private
2790 * key was set/generated.
2791 */
2792 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) {
2793 struct l2cap_chan *hchan = hdev->smp_data;
2794 struct smp_dev *smp_dev;
2795
2796 if (!hchan || !hchan->data)
2797 return SMP_UNSPECIFIED;
2798
2799 smp_dev = hchan->data;
2800
2801 tfm_ecdh = smp_dev->tfm_ecdh;
2802 } else {
2803 tfm_ecdh = smp->tfm_ecdh;
2804 }
2805
2806 if (compute_ecdh_secret(tfm_ecdh, smp->remote_pk, smp->dhkey))
2807 return SMP_UNSPECIFIED;
2808
2809 SMP_DBG("DHKey %32phN", smp->dhkey);
2810
2811 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags);
2812
2813 smp->method = sc_select_method(smp);
2814
2815 bt_dev_dbg(hdev, "selected method 0x%02x", smp->method);
2816
2817 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */
2818 if (smp->method == JUST_WORKS || smp->method == JUST_CFM)
2819 hcon->pending_sec_level = BT_SECURITY_MEDIUM;
2820 else
2821 hcon->pending_sec_level = BT_SECURITY_FIPS;
2822
2823 if (!crypto_memneq(debug_pk, smp->remote_pk, 64))
2824 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
2825
2826 if (smp->method == DSP_PASSKEY) {
2827 get_random_bytes(&hcon->passkey_notify,
2828 sizeof(hcon->passkey_notify));
2829 hcon->passkey_notify %= 1000000;
2830 hcon->passkey_entered = 0;
2831 smp->passkey_round = 0;
2832 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type,
2833 hcon->dst_type,
2834 hcon->passkey_notify,
2835 hcon->passkey_entered))
2836 return SMP_UNSPECIFIED;
2837 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2838 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY);
2839 }
2840
2841 if (smp->method == REQ_OOB) {
2842 if (hcon->out)
2843 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2844 sizeof(smp->prnd), smp->prnd);
2845
2846 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2847
2848 return 0;
2849 }
2850
2851 if (hcon->out)
2852 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2853
2854 if (smp->method == REQ_PASSKEY) {
2855 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type,
2856 hcon->dst_type))
2857 return SMP_UNSPECIFIED;
2858 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2859 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2860 return 0;
2861 }
2862
2863 /* The Initiating device waits for the non-initiating device to
2864 * send the confirm value.
2865 */
2866 if (conn->hcon->out)
2867 return 0;
2868
2869 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd,
2870 0, cfm.confirm_val);
2871 if (err)
2872 return SMP_UNSPECIFIED;
2873
2874 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
2875 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2876
2877 return 0;
2878}
2879
2880static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb)
2881{
2882 struct smp_cmd_dhkey_check *check = (void *) skb->data;
2883 struct l2cap_chan *chan = conn->smp;
2884 struct hci_conn *hcon = conn->hcon;
2885 struct smp_chan *smp = chan->data;
2886 u8 a[7], b[7], *local_addr, *remote_addr;
2887 u8 io_cap[3], r[16], e[16];
2888 int err;
2889
2890 bt_dev_dbg(hcon->hdev, "conn %p", conn);
2891
2892 if (skb->len < sizeof(*check))
2893 return SMP_INVALID_PARAMS;
2894
2895 memcpy(a, &hcon->init_addr, 6);
2896 memcpy(b, &hcon->resp_addr, 6);
2897 a[6] = hcon->init_addr_type;
2898 b[6] = hcon->resp_addr_type;
2899
2900 if (hcon->out) {
2901 local_addr = a;
2902 remote_addr = b;
2903 memcpy(io_cap, &smp->prsp[1], 3);
2904 } else {
2905 local_addr = b;
2906 remote_addr = a;
2907 memcpy(io_cap, &smp->preq[1], 3);
2908 }
2909
2910 memset(r, 0, sizeof(r));
2911
2912 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2913 put_unaligned_le32(hcon->passkey_notify, r);
2914 else if (smp->method == REQ_OOB)
2915 memcpy(r, smp->lr, 16);
2916
2917 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r,
2918 io_cap, remote_addr, local_addr, e);
2919 if (err)
2920 return SMP_UNSPECIFIED;
2921
2922 if (crypto_memneq(check->e, e, 16))
2923 return SMP_DHKEY_CHECK_FAILED;
2924
2925 if (!hcon->out) {
2926 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
2927 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags);
2928 return 0;
2929 }
2930
2931 /* Responder sends DHKey check as response to initiator */
2932 sc_dhkey_check(smp);
2933 }
2934
2935 sc_add_ltk(smp);
2936
2937 if (hcon->out) {
2938 hci_le_start_enc(hcon, 0, 0, smp->tk, smp->enc_key_size);
2939 hcon->enc_key_size = smp->enc_key_size;
2940 }
2941
2942 return 0;
2943}
2944
2945static int smp_cmd_keypress_notify(struct l2cap_conn *conn,
2946 struct sk_buff *skb)
2947{
2948 struct smp_cmd_keypress_notify *kp = (void *) skb->data;
2949
2950 bt_dev_dbg(conn->hcon->hdev, "value 0x%02x", kp->value);
2951
2952 return 0;
2953}
2954
2955static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb)
2956{
2957 struct l2cap_conn *conn = chan->conn;
2958 struct hci_conn *hcon = conn->hcon;
2959 struct smp_chan *smp;
2960 __u8 code, reason;
2961 int err = 0;
2962
2963 if (skb->len < 1)
2964 return -EILSEQ;
2965
2966 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) {
2967 reason = SMP_PAIRING_NOTSUPP;
2968 goto done;
2969 }
2970
2971 code = skb->data[0];
2972 skb_pull(skb, sizeof(code));
2973
2974 smp = chan->data;
2975
2976 if (code > SMP_CMD_MAX)
2977 goto drop;
2978
2979 if (smp && !test_and_clear_bit(code, &smp->allow_cmd))
2980 goto drop;
2981
2982 /* If we don't have a context the only allowed commands are
2983 * pairing request and security request.
2984 */
2985 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ)
2986 goto drop;
2987
2988 switch (code) {
2989 case SMP_CMD_PAIRING_REQ:
2990 reason = smp_cmd_pairing_req(conn, skb);
2991 break;
2992
2993 case SMP_CMD_PAIRING_FAIL:
2994 smp_failure(conn, 0);
2995 err = -EPERM;
2996 break;
2997
2998 case SMP_CMD_PAIRING_RSP:
2999 reason = smp_cmd_pairing_rsp(conn, skb);
3000 break;
3001
3002 case SMP_CMD_SECURITY_REQ:
3003 reason = smp_cmd_security_req(conn, skb);
3004 break;
3005
3006 case SMP_CMD_PAIRING_CONFIRM:
3007 reason = smp_cmd_pairing_confirm(conn, skb);
3008 break;
3009
3010 case SMP_CMD_PAIRING_RANDOM:
3011 reason = smp_cmd_pairing_random(conn, skb);
3012 break;
3013
3014 case SMP_CMD_ENCRYPT_INFO:
3015 reason = smp_cmd_encrypt_info(conn, skb);
3016 break;
3017
3018 case SMP_CMD_INITIATOR_IDENT:
3019 reason = smp_cmd_initiator_ident(conn, skb);
3020 break;
3021
3022 case SMP_CMD_IDENT_INFO:
3023 reason = smp_cmd_ident_info(conn, skb);
3024 break;
3025
3026 case SMP_CMD_IDENT_ADDR_INFO:
3027 reason = smp_cmd_ident_addr_info(conn, skb);
3028 break;
3029
3030 case SMP_CMD_SIGN_INFO:
3031 reason = smp_cmd_sign_info(conn, skb);
3032 break;
3033
3034 case SMP_CMD_PUBLIC_KEY:
3035 reason = smp_cmd_public_key(conn, skb);
3036 break;
3037
3038 case SMP_CMD_DHKEY_CHECK:
3039 reason = smp_cmd_dhkey_check(conn, skb);
3040 break;
3041
3042 case SMP_CMD_KEYPRESS_NOTIFY:
3043 reason = smp_cmd_keypress_notify(conn, skb);
3044 break;
3045
3046 default:
3047 bt_dev_dbg(hcon->hdev, "Unknown command code 0x%2.2x", code);
3048 reason = SMP_CMD_NOTSUPP;
3049 goto done;
3050 }
3051
3052done:
3053 if (!err) {
3054 if (reason)
3055 smp_failure(conn, reason);
3056 kfree_skb(skb);
3057 }
3058
3059 return err;
3060
3061drop:
3062 bt_dev_err(hcon->hdev, "unexpected SMP command 0x%02x from %pMR",
3063 code, &hcon->dst);
3064 kfree_skb(skb);
3065 return 0;
3066}
3067
3068static void smp_teardown_cb(struct l2cap_chan *chan, int err)
3069{
3070 struct l2cap_conn *conn = chan->conn;
3071
3072 bt_dev_dbg(conn->hcon->hdev, "chan %p", chan);
3073
3074 if (chan->data)
3075 smp_chan_destroy(conn);
3076
3077 conn->smp = NULL;
3078 l2cap_chan_put(chan);
3079}
3080
3081static void bredr_pairing(struct l2cap_chan *chan)
3082{
3083 struct l2cap_conn *conn = chan->conn;
3084 struct hci_conn *hcon = conn->hcon;
3085 struct hci_dev *hdev = hcon->hdev;
3086 struct smp_cmd_pairing req;
3087 struct smp_chan *smp;
3088
3089 bt_dev_dbg(hdev, "chan %p", chan);
3090
3091 /* Only new pairings are interesting */
3092 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags))
3093 return;
3094
3095 /* Don't bother if we're not encrypted */
3096 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3097 return;
3098
3099 /* Only initiator may initiate SMP over BR/EDR */
3100 if (hcon->role != HCI_ROLE_MASTER)
3101 return;
3102
3103 /* Secure Connections support must be enabled */
3104 if (!hci_dev_test_flag(hdev, HCI_SC_ENABLED))
3105 return;
3106
3107 /* BR/EDR must use Secure Connections for SMP */
3108 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) &&
3109 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3110 return;
3111
3112 /* If our LE support is not enabled don't do anything */
3113 if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED))
3114 return;
3115
3116 /* Don't bother if remote LE support is not enabled */
3117 if (!lmp_host_le_capable(hcon))
3118 return;
3119
3120 /* Remote must support SMP fixed chan for BR/EDR */
3121 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR))
3122 return;
3123
3124 /* Don't bother if SMP is already ongoing */
3125 if (chan->data)
3126 return;
3127
3128 smp = smp_chan_create(conn);
3129 if (!smp) {
3130 bt_dev_err(hdev, "unable to create SMP context for BR/EDR");
3131 return;
3132 }
3133
3134 set_bit(SMP_FLAG_SC, &smp->flags);
3135
3136 bt_dev_dbg(hdev, "starting SMP over BR/EDR");
3137
3138 /* Prepare and send the BR/EDR SMP Pairing Request */
3139 build_bredr_pairing_cmd(smp, &req, NULL);
3140
3141 smp->preq[0] = SMP_CMD_PAIRING_REQ;
3142 memcpy(&smp->preq[1], &req, sizeof(req));
3143
3144 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(req), &req);
3145 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
3146}
3147
3148static void smp_resume_cb(struct l2cap_chan *chan)
3149{
3150 struct smp_chan *smp = chan->data;
3151 struct l2cap_conn *conn = chan->conn;
3152 struct hci_conn *hcon = conn->hcon;
3153
3154 bt_dev_dbg(hcon->hdev, "chan %p", chan);
3155
3156 if (hcon->type == ACL_LINK) {
3157 bredr_pairing(chan);
3158 return;
3159 }
3160
3161 if (!smp)
3162 return;
3163
3164 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3165 return;
3166
3167 cancel_delayed_work(&smp->security_timer);
3168
3169 smp_distribute_keys(smp);
3170}
3171
3172static void smp_ready_cb(struct l2cap_chan *chan)
3173{
3174 struct l2cap_conn *conn = chan->conn;
3175 struct hci_conn *hcon = conn->hcon;
3176
3177 bt_dev_dbg(hcon->hdev, "chan %p", chan);
3178
3179 /* No need to call l2cap_chan_hold() here since we already own
3180 * the reference taken in smp_new_conn_cb(). This is just the
3181 * first time that we tie it to a specific pointer. The code in
3182 * l2cap_core.c ensures that there's no risk this function wont
3183 * get called if smp_new_conn_cb was previously called.
3184 */
3185 conn->smp = chan;
3186
3187 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3188 bredr_pairing(chan);
3189}
3190
3191static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
3192{
3193 int err;
3194
3195 bt_dev_dbg(chan->conn->hcon->hdev, "chan %p", chan);
3196
3197 err = smp_sig_channel(chan, skb);
3198 if (err) {
3199 struct smp_chan *smp = chan->data;
3200
3201 if (smp)
3202 cancel_delayed_work_sync(&smp->security_timer);
3203
3204 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE);
3205 }
3206
3207 return err;
3208}
3209
3210static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan,
3211 unsigned long hdr_len,
3212 unsigned long len, int nb)
3213{
3214 struct sk_buff *skb;
3215
3216 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL);
3217 if (!skb)
3218 return ERR_PTR(-ENOMEM);
3219
3220 skb->priority = HCI_PRIO_MAX;
3221 bt_cb(skb)->l2cap.chan = chan;
3222
3223 return skb;
3224}
3225
3226static const struct l2cap_ops smp_chan_ops = {
3227 .name = "Security Manager",
3228 .ready = smp_ready_cb,
3229 .recv = smp_recv_cb,
3230 .alloc_skb = smp_alloc_skb_cb,
3231 .teardown = smp_teardown_cb,
3232 .resume = smp_resume_cb,
3233
3234 .new_connection = l2cap_chan_no_new_connection,
3235 .state_change = l2cap_chan_no_state_change,
3236 .close = l2cap_chan_no_close,
3237 .defer = l2cap_chan_no_defer,
3238 .suspend = l2cap_chan_no_suspend,
3239 .set_shutdown = l2cap_chan_no_set_shutdown,
3240 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
3241};
3242
3243static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan)
3244{
3245 struct l2cap_chan *chan;
3246
3247 BT_DBG("pchan %p", pchan);
3248
3249 chan = l2cap_chan_create();
3250 if (!chan)
3251 return NULL;
3252
3253 chan->chan_type = pchan->chan_type;
3254 chan->ops = &smp_chan_ops;
3255 chan->scid = pchan->scid;
3256 chan->dcid = chan->scid;
3257 chan->imtu = pchan->imtu;
3258 chan->omtu = pchan->omtu;
3259 chan->mode = pchan->mode;
3260
3261 /* Other L2CAP channels may request SMP routines in order to
3262 * change the security level. This means that the SMP channel
3263 * lock must be considered in its own category to avoid lockdep
3264 * warnings.
3265 */
3266 atomic_set(&chan->nesting, L2CAP_NESTING_SMP);
3267
3268 BT_DBG("created chan %p", chan);
3269
3270 return chan;
3271}
3272
3273static const struct l2cap_ops smp_root_chan_ops = {
3274 .name = "Security Manager Root",
3275 .new_connection = smp_new_conn_cb,
3276
3277 /* None of these are implemented for the root channel */
3278 .close = l2cap_chan_no_close,
3279 .alloc_skb = l2cap_chan_no_alloc_skb,
3280 .recv = l2cap_chan_no_recv,
3281 .state_change = l2cap_chan_no_state_change,
3282 .teardown = l2cap_chan_no_teardown,
3283 .ready = l2cap_chan_no_ready,
3284 .defer = l2cap_chan_no_defer,
3285 .suspend = l2cap_chan_no_suspend,
3286 .resume = l2cap_chan_no_resume,
3287 .set_shutdown = l2cap_chan_no_set_shutdown,
3288 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
3289};
3290
3291static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid)
3292{
3293 struct l2cap_chan *chan;
3294 struct smp_dev *smp;
3295 struct crypto_shash *tfm_cmac;
3296 struct crypto_kpp *tfm_ecdh;
3297
3298 if (cid == L2CAP_CID_SMP_BREDR) {
3299 smp = NULL;
3300 goto create_chan;
3301 }
3302
3303 smp = kzalloc(sizeof(*smp), GFP_KERNEL);
3304 if (!smp)
3305 return ERR_PTR(-ENOMEM);
3306
3307 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
3308 if (IS_ERR(tfm_cmac)) {
3309 bt_dev_err(hdev, "Unable to create CMAC crypto context");
3310 kfree_sensitive(smp);
3311 return ERR_CAST(tfm_cmac);
3312 }
3313
3314 tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0);
3315 if (IS_ERR(tfm_ecdh)) {
3316 bt_dev_err(hdev, "Unable to create ECDH crypto context");
3317 crypto_free_shash(tfm_cmac);
3318 kfree_sensitive(smp);
3319 return ERR_CAST(tfm_ecdh);
3320 }
3321
3322 smp->local_oob = false;
3323 smp->tfm_cmac = tfm_cmac;
3324 smp->tfm_ecdh = tfm_ecdh;
3325
3326create_chan:
3327 chan = l2cap_chan_create();
3328 if (!chan) {
3329 if (smp) {
3330 crypto_free_shash(smp->tfm_cmac);
3331 crypto_free_kpp(smp->tfm_ecdh);
3332 kfree_sensitive(smp);
3333 }
3334 return ERR_PTR(-ENOMEM);
3335 }
3336
3337 chan->data = smp;
3338
3339 l2cap_add_scid(chan, cid);
3340
3341 l2cap_chan_set_defaults(chan);
3342
3343 if (cid == L2CAP_CID_SMP) {
3344 u8 bdaddr_type;
3345
3346 hci_copy_identity_address(hdev, &chan->src, &bdaddr_type);
3347
3348 if (bdaddr_type == ADDR_LE_DEV_PUBLIC)
3349 chan->src_type = BDADDR_LE_PUBLIC;
3350 else
3351 chan->src_type = BDADDR_LE_RANDOM;
3352 } else {
3353 bacpy(&chan->src, &hdev->bdaddr);
3354 chan->src_type = BDADDR_BREDR;
3355 }
3356
3357 chan->state = BT_LISTEN;
3358 chan->mode = L2CAP_MODE_BASIC;
3359 chan->imtu = L2CAP_DEFAULT_MTU;
3360 chan->ops = &smp_root_chan_ops;
3361
3362 /* Set correct nesting level for a parent/listening channel */
3363 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
3364
3365 return chan;
3366}
3367
3368static void smp_del_chan(struct l2cap_chan *chan)
3369{
3370 struct smp_dev *smp;
3371
3372 BT_DBG("chan %p", chan);
3373
3374 smp = chan->data;
3375 if (smp) {
3376 chan->data = NULL;
3377 crypto_free_shash(smp->tfm_cmac);
3378 crypto_free_kpp(smp->tfm_ecdh);
3379 kfree_sensitive(smp);
3380 }
3381
3382 l2cap_chan_put(chan);
3383}
3384
3385int smp_force_bredr(struct hci_dev *hdev, bool enable)
3386{
3387 if (enable == hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3388 return -EALREADY;
3389
3390 if (enable) {
3391 struct l2cap_chan *chan;
3392
3393 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
3394 if (IS_ERR(chan))
3395 return PTR_ERR(chan);
3396
3397 hdev->smp_bredr_data = chan;
3398 } else {
3399 struct l2cap_chan *chan;
3400
3401 chan = hdev->smp_bredr_data;
3402 hdev->smp_bredr_data = NULL;
3403 smp_del_chan(chan);
3404 }
3405
3406 hci_dev_change_flag(hdev, HCI_FORCE_BREDR_SMP);
3407
3408 return 0;
3409}
3410
3411int smp_register(struct hci_dev *hdev)
3412{
3413 struct l2cap_chan *chan;
3414
3415 bt_dev_dbg(hdev, "");
3416
3417 /* If the controller does not support Low Energy operation, then
3418 * there is also no need to register any SMP channel.
3419 */
3420 if (!lmp_le_capable(hdev))
3421 return 0;
3422
3423 if (WARN_ON(hdev->smp_data)) {
3424 chan = hdev->smp_data;
3425 hdev->smp_data = NULL;
3426 smp_del_chan(chan);
3427 }
3428
3429 chan = smp_add_cid(hdev, L2CAP_CID_SMP);
3430 if (IS_ERR(chan))
3431 return PTR_ERR(chan);
3432
3433 hdev->smp_data = chan;
3434
3435 if (!lmp_sc_capable(hdev)) {
3436 /* Flag can be already set here (due to power toggle) */
3437 if (!hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3438 return 0;
3439 }
3440
3441 if (WARN_ON(hdev->smp_bredr_data)) {
3442 chan = hdev->smp_bredr_data;
3443 hdev->smp_bredr_data = NULL;
3444 smp_del_chan(chan);
3445 }
3446
3447 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
3448 if (IS_ERR(chan)) {
3449 int err = PTR_ERR(chan);
3450 chan = hdev->smp_data;
3451 hdev->smp_data = NULL;
3452 smp_del_chan(chan);
3453 return err;
3454 }
3455
3456 hdev->smp_bredr_data = chan;
3457
3458 return 0;
3459}
3460
3461void smp_unregister(struct hci_dev *hdev)
3462{
3463 struct l2cap_chan *chan;
3464
3465 if (hdev->smp_bredr_data) {
3466 chan = hdev->smp_bredr_data;
3467 hdev->smp_bredr_data = NULL;
3468 smp_del_chan(chan);
3469 }
3470
3471 if (hdev->smp_data) {
3472 chan = hdev->smp_data;
3473 hdev->smp_data = NULL;
3474 smp_del_chan(chan);
3475 }
3476}
3477
3478#if IS_ENABLED(CONFIG_BT_SELFTEST_SMP)
3479
3480static int __init test_debug_key(struct crypto_kpp *tfm_ecdh)
3481{
3482 u8 pk[64];
3483 int err;
3484
3485 err = set_ecdh_privkey(tfm_ecdh, debug_sk);
3486 if (err)
3487 return err;
3488
3489 err = generate_ecdh_public_key(tfm_ecdh, pk);
3490 if (err)
3491 return err;
3492
3493 if (crypto_memneq(pk, debug_pk, 64))
3494 return -EINVAL;
3495
3496 return 0;
3497}
3498
3499static int __init test_ah(void)
3500{
3501 const u8 irk[16] = {
3502 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3503 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3504 const u8 r[3] = { 0x94, 0x81, 0x70 };
3505 const u8 exp[3] = { 0xaa, 0xfb, 0x0d };
3506 u8 res[3];
3507 int err;
3508
3509 err = smp_ah(irk, r, res);
3510 if (err)
3511 return err;
3512
3513 if (crypto_memneq(res, exp, 3))
3514 return -EINVAL;
3515
3516 return 0;
3517}
3518
3519static int __init test_c1(void)
3520{
3521 const u8 k[16] = {
3522 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
3523 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
3524 const u8 r[16] = {
3525 0xe0, 0x2e, 0x70, 0xc6, 0x4e, 0x27, 0x88, 0x63,
3526 0x0e, 0x6f, 0xad, 0x56, 0x21, 0xd5, 0x83, 0x57 };
3527 const u8 preq[7] = { 0x01, 0x01, 0x00, 0x00, 0x10, 0x07, 0x07 };
3528 const u8 pres[7] = { 0x02, 0x03, 0x00, 0x00, 0x08, 0x00, 0x05 };
3529 const u8 _iat = 0x01;
3530 const u8 _rat = 0x00;
3531 const bdaddr_t ra = { { 0xb6, 0xb5, 0xb4, 0xb3, 0xb2, 0xb1 } };
3532 const bdaddr_t ia = { { 0xa6, 0xa5, 0xa4, 0xa3, 0xa2, 0xa1 } };
3533 const u8 exp[16] = {
3534 0x86, 0x3b, 0xf1, 0xbe, 0xc5, 0x4d, 0xa7, 0xd2,
3535 0xea, 0x88, 0x89, 0x87, 0xef, 0x3f, 0x1e, 0x1e };
3536 u8 res[16];
3537 int err;
3538
3539 err = smp_c1(k, r, preq, pres, _iat, &ia, _rat, &ra, res);
3540 if (err)
3541 return err;
3542
3543 if (crypto_memneq(res, exp, 16))
3544 return -EINVAL;
3545
3546 return 0;
3547}
3548
3549static int __init test_s1(void)
3550{
3551 const u8 k[16] = {
3552 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
3553 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
3554 const u8 r1[16] = {
3555 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 };
3556 const u8 r2[16] = {
3557 0x00, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99 };
3558 const u8 exp[16] = {
3559 0x62, 0xa0, 0x6d, 0x79, 0xae, 0x16, 0x42, 0x5b,
3560 0x9b, 0xf4, 0xb0, 0xe8, 0xf0, 0xe1, 0x1f, 0x9a };
3561 u8 res[16];
3562 int err;
3563
3564 err = smp_s1(k, r1, r2, res);
3565 if (err)
3566 return err;
3567
3568 if (crypto_memneq(res, exp, 16))
3569 return -EINVAL;
3570
3571 return 0;
3572}
3573
3574static int __init test_f4(struct crypto_shash *tfm_cmac)
3575{
3576 const u8 u[32] = {
3577 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
3578 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
3579 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
3580 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 };
3581 const u8 v[32] = {
3582 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b,
3583 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59,
3584 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90,
3585 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 };
3586 const u8 x[16] = {
3587 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3588 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3589 const u8 z = 0x00;
3590 const u8 exp[16] = {
3591 0x2d, 0x87, 0x74, 0xa9, 0xbe, 0xa1, 0xed, 0xf1,
3592 0x1c, 0xbd, 0xa9, 0x07, 0xf1, 0x16, 0xc9, 0xf2 };
3593 u8 res[16];
3594 int err;
3595
3596 err = smp_f4(tfm_cmac, u, v, x, z, res);
3597 if (err)
3598 return err;
3599
3600 if (crypto_memneq(res, exp, 16))
3601 return -EINVAL;
3602
3603 return 0;
3604}
3605
3606static int __init test_f5(struct crypto_shash *tfm_cmac)
3607{
3608 const u8 w[32] = {
3609 0x98, 0xa6, 0xbf, 0x73, 0xf3, 0x34, 0x8d, 0x86,
3610 0xf1, 0x66, 0xf8, 0xb4, 0x13, 0x6b, 0x79, 0x99,
3611 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3612 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3613 const u8 n1[16] = {
3614 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3615 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3616 const u8 n2[16] = {
3617 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3618 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3619 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 };
3620 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 };
3621 const u8 exp_ltk[16] = {
3622 0x38, 0x0a, 0x75, 0x94, 0xb5, 0x22, 0x05, 0x98,
3623 0x23, 0xcd, 0xd7, 0x69, 0x11, 0x79, 0x86, 0x69 };
3624 const u8 exp_mackey[16] = {
3625 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd,
3626 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 };
3627 u8 mackey[16], ltk[16];
3628 int err;
3629
3630 err = smp_f5(tfm_cmac, w, n1, n2, a1, a2, mackey, ltk);
3631 if (err)
3632 return err;
3633
3634 if (crypto_memneq(mackey, exp_mackey, 16))
3635 return -EINVAL;
3636
3637 if (crypto_memneq(ltk, exp_ltk, 16))
3638 return -EINVAL;
3639
3640 return 0;
3641}
3642
3643static int __init test_f6(struct crypto_shash *tfm_cmac)
3644{
3645 const u8 w[16] = {
3646 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd,
3647 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 };
3648 const u8 n1[16] = {
3649 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3650 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3651 const u8 n2[16] = {
3652 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3653 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3654 const u8 r[16] = {
3655 0xc8, 0x0f, 0x2d, 0x0c, 0xd2, 0x42, 0xda, 0x08,
3656 0x54, 0xbb, 0x53, 0xb4, 0x3b, 0x34, 0xa3, 0x12 };
3657 const u8 io_cap[3] = { 0x02, 0x01, 0x01 };
3658 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 };
3659 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 };
3660 const u8 exp[16] = {
3661 0x61, 0x8f, 0x95, 0xda, 0x09, 0x0b, 0x6c, 0xd2,
3662 0xc5, 0xe8, 0xd0, 0x9c, 0x98, 0x73, 0xc4, 0xe3 };
3663 u8 res[16];
3664 int err;
3665
3666 err = smp_f6(tfm_cmac, w, n1, n2, r, io_cap, a1, a2, res);
3667 if (err)
3668 return err;
3669
3670 if (crypto_memneq(res, exp, 16))
3671 return -EINVAL;
3672
3673 return 0;
3674}
3675
3676static int __init test_g2(struct crypto_shash *tfm_cmac)
3677{
3678 const u8 u[32] = {
3679 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
3680 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
3681 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
3682 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 };
3683 const u8 v[32] = {
3684 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b,
3685 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59,
3686 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90,
3687 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 };
3688 const u8 x[16] = {
3689 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3690 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3691 const u8 y[16] = {
3692 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3693 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3694 const u32 exp_val = 0x2f9ed5ba % 1000000;
3695 u32 val;
3696 int err;
3697
3698 err = smp_g2(tfm_cmac, u, v, x, y, &val);
3699 if (err)
3700 return err;
3701
3702 if (val != exp_val)
3703 return -EINVAL;
3704
3705 return 0;
3706}
3707
3708static int __init test_h6(struct crypto_shash *tfm_cmac)
3709{
3710 const u8 w[16] = {
3711 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3712 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3713 const u8 key_id[4] = { 0x72, 0x62, 0x65, 0x6c };
3714 const u8 exp[16] = {
3715 0x99, 0x63, 0xb1, 0x80, 0xe2, 0xa9, 0xd3, 0xe8,
3716 0x1c, 0xc9, 0x6d, 0xe7, 0x02, 0xe1, 0x9a, 0x2d };
3717 u8 res[16];
3718 int err;
3719
3720 err = smp_h6(tfm_cmac, w, key_id, res);
3721 if (err)
3722 return err;
3723
3724 if (crypto_memneq(res, exp, 16))
3725 return -EINVAL;
3726
3727 return 0;
3728}
3729
3730static char test_smp_buffer[32];
3731
3732static ssize_t test_smp_read(struct file *file, char __user *user_buf,
3733 size_t count, loff_t *ppos)
3734{
3735 return simple_read_from_buffer(user_buf, count, ppos, test_smp_buffer,
3736 strlen(test_smp_buffer));
3737}
3738
3739static const struct file_operations test_smp_fops = {
3740 .open = simple_open,
3741 .read = test_smp_read,
3742 .llseek = default_llseek,
3743};
3744
3745static int __init run_selftests(struct crypto_shash *tfm_cmac,
3746 struct crypto_kpp *tfm_ecdh)
3747{
3748 ktime_t calltime, delta, rettime;
3749 unsigned long long duration;
3750 int err;
3751
3752 calltime = ktime_get();
3753
3754 err = test_debug_key(tfm_ecdh);
3755 if (err) {
3756 BT_ERR("debug_key test failed");
3757 goto done;
3758 }
3759
3760 err = test_ah();
3761 if (err) {
3762 BT_ERR("smp_ah test failed");
3763 goto done;
3764 }
3765
3766 err = test_c1();
3767 if (err) {
3768 BT_ERR("smp_c1 test failed");
3769 goto done;
3770 }
3771
3772 err = test_s1();
3773 if (err) {
3774 BT_ERR("smp_s1 test failed");
3775 goto done;
3776 }
3777
3778 err = test_f4(tfm_cmac);
3779 if (err) {
3780 BT_ERR("smp_f4 test failed");
3781 goto done;
3782 }
3783
3784 err = test_f5(tfm_cmac);
3785 if (err) {
3786 BT_ERR("smp_f5 test failed");
3787 goto done;
3788 }
3789
3790 err = test_f6(tfm_cmac);
3791 if (err) {
3792 BT_ERR("smp_f6 test failed");
3793 goto done;
3794 }
3795
3796 err = test_g2(tfm_cmac);
3797 if (err) {
3798 BT_ERR("smp_g2 test failed");
3799 goto done;
3800 }
3801
3802 err = test_h6(tfm_cmac);
3803 if (err) {
3804 BT_ERR("smp_h6 test failed");
3805 goto done;
3806 }
3807
3808 rettime = ktime_get();
3809 delta = ktime_sub(rettime, calltime);
3810 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
3811
3812 BT_INFO("SMP test passed in %llu usecs", duration);
3813
3814done:
3815 if (!err)
3816 snprintf(test_smp_buffer, sizeof(test_smp_buffer),
3817 "PASS (%llu usecs)\n", duration);
3818 else
3819 snprintf(test_smp_buffer, sizeof(test_smp_buffer), "FAIL\n");
3820
3821 debugfs_create_file("selftest_smp", 0444, bt_debugfs, NULL,
3822 &test_smp_fops);
3823
3824 return err;
3825}
3826
3827int __init bt_selftest_smp(void)
3828{
3829 struct crypto_shash *tfm_cmac;
3830 struct crypto_kpp *tfm_ecdh;
3831 int err;
3832
3833 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
3834 if (IS_ERR(tfm_cmac)) {
3835 BT_ERR("Unable to create CMAC crypto context");
3836 return PTR_ERR(tfm_cmac);
3837 }
3838
3839 tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0);
3840 if (IS_ERR(tfm_ecdh)) {
3841 BT_ERR("Unable to create ECDH crypto context");
3842 crypto_free_shash(tfm_cmac);
3843 return PTR_ERR(tfm_ecdh);
3844 }
3845
3846 err = run_selftests(tfm_cmac, tfm_ecdh);
3847
3848 crypto_free_shash(tfm_cmac);
3849 crypto_free_kpp(tfm_ecdh);
3850
3851 return err;
3852}
3853
3854#endif
1/*
2 BlueZ - Bluetooth protocol stack for Linux
3 Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License version 2 as
7 published by the Free Software Foundation;
8
9 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
10 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
11 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
12 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
13 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
14 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17
18 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
19 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
20 SOFTWARE IS DISCLAIMED.
21*/
22
23#include <linux/debugfs.h>
24#include <linux/scatterlist.h>
25#include <linux/crypto.h>
26#include <crypto/algapi.h>
27#include <crypto/b128ops.h>
28#include <crypto/hash.h>
29#include <crypto/kpp.h>
30
31#include <net/bluetooth/bluetooth.h>
32#include <net/bluetooth/hci_core.h>
33#include <net/bluetooth/l2cap.h>
34#include <net/bluetooth/mgmt.h>
35
36#include "ecdh_helper.h"
37#include "smp.h"
38
39#define SMP_DEV(hdev) \
40 ((struct smp_dev *)((struct l2cap_chan *)((hdev)->smp_data))->data)
41
42/* Low-level debug macros to be used for stuff that we don't want
43 * accidentially in dmesg, i.e. the values of the various crypto keys
44 * and the inputs & outputs of crypto functions.
45 */
46#ifdef DEBUG
47#define SMP_DBG(fmt, ...) printk(KERN_DEBUG "%s: " fmt, __func__, \
48 ##__VA_ARGS__)
49#else
50#define SMP_DBG(fmt, ...) no_printk(KERN_DEBUG "%s: " fmt, __func__, \
51 ##__VA_ARGS__)
52#endif
53
54#define SMP_ALLOW_CMD(smp, code) set_bit(code, &smp->allow_cmd)
55
56/* Keys which are not distributed with Secure Connections */
57#define SMP_SC_NO_DIST (SMP_DIST_ENC_KEY | SMP_DIST_LINK_KEY);
58
59#define SMP_TIMEOUT msecs_to_jiffies(30000)
60
61#define AUTH_REQ_MASK(dev) (hci_dev_test_flag(dev, HCI_SC_ENABLED) ? \
62 0x3f : 0x07)
63#define KEY_DIST_MASK 0x07
64
65/* Maximum message length that can be passed to aes_cmac */
66#define CMAC_MSG_MAX 80
67
68enum {
69 SMP_FLAG_TK_VALID,
70 SMP_FLAG_CFM_PENDING,
71 SMP_FLAG_MITM_AUTH,
72 SMP_FLAG_COMPLETE,
73 SMP_FLAG_INITIATOR,
74 SMP_FLAG_SC,
75 SMP_FLAG_REMOTE_PK,
76 SMP_FLAG_DEBUG_KEY,
77 SMP_FLAG_WAIT_USER,
78 SMP_FLAG_DHKEY_PENDING,
79 SMP_FLAG_REMOTE_OOB,
80 SMP_FLAG_LOCAL_OOB,
81 SMP_FLAG_CT2,
82};
83
84struct smp_dev {
85 /* Secure Connections OOB data */
86 u8 local_pk[64];
87 u8 local_rand[16];
88 bool debug_key;
89
90 u8 min_key_size;
91 u8 max_key_size;
92
93 struct crypto_cipher *tfm_aes;
94 struct crypto_shash *tfm_cmac;
95 struct crypto_kpp *tfm_ecdh;
96};
97
98struct smp_chan {
99 struct l2cap_conn *conn;
100 struct delayed_work security_timer;
101 unsigned long allow_cmd; /* Bitmask of allowed commands */
102
103 u8 preq[7]; /* SMP Pairing Request */
104 u8 prsp[7]; /* SMP Pairing Response */
105 u8 prnd[16]; /* SMP Pairing Random (local) */
106 u8 rrnd[16]; /* SMP Pairing Random (remote) */
107 u8 pcnf[16]; /* SMP Pairing Confirm */
108 u8 tk[16]; /* SMP Temporary Key */
109 u8 rr[16]; /* Remote OOB ra/rb value */
110 u8 lr[16]; /* Local OOB ra/rb value */
111 u8 enc_key_size;
112 u8 remote_key_dist;
113 bdaddr_t id_addr;
114 u8 id_addr_type;
115 u8 irk[16];
116 struct smp_csrk *csrk;
117 struct smp_csrk *slave_csrk;
118 struct smp_ltk *ltk;
119 struct smp_ltk *slave_ltk;
120 struct smp_irk *remote_irk;
121 u8 *link_key;
122 unsigned long flags;
123 u8 method;
124 u8 passkey_round;
125
126 /* Secure Connections variables */
127 u8 local_pk[64];
128 u8 remote_pk[64];
129 u8 dhkey[32];
130 u8 mackey[16];
131
132 struct crypto_cipher *tfm_aes;
133 struct crypto_shash *tfm_cmac;
134 struct crypto_kpp *tfm_ecdh;
135};
136
137/* These debug key values are defined in the SMP section of the core
138 * specification. debug_pk is the public debug key and debug_sk the
139 * private debug key.
140 */
141static const u8 debug_pk[64] = {
142 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
143 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
144 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
145 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20,
146
147 0x8b, 0xd2, 0x89, 0x15, 0xd0, 0x8e, 0x1c, 0x74,
148 0x24, 0x30, 0xed, 0x8f, 0xc2, 0x45, 0x63, 0x76,
149 0x5c, 0x15, 0x52, 0x5a, 0xbf, 0x9a, 0x32, 0x63,
150 0x6d, 0xeb, 0x2a, 0x65, 0x49, 0x9c, 0x80, 0xdc,
151};
152
153static const u8 debug_sk[32] = {
154 0xbd, 0x1a, 0x3c, 0xcd, 0xa6, 0xb8, 0x99, 0x58,
155 0x99, 0xb7, 0x40, 0xeb, 0x7b, 0x60, 0xff, 0x4a,
156 0x50, 0x3f, 0x10, 0xd2, 0xe3, 0xb3, 0xc9, 0x74,
157 0x38, 0x5f, 0xc5, 0xa3, 0xd4, 0xf6, 0x49, 0x3f,
158};
159
160static inline void swap_buf(const u8 *src, u8 *dst, size_t len)
161{
162 size_t i;
163
164 for (i = 0; i < len; i++)
165 dst[len - 1 - i] = src[i];
166}
167
168/* The following functions map to the LE SC SMP crypto functions
169 * AES-CMAC, f4, f5, f6, g2 and h6.
170 */
171
172static int aes_cmac(struct crypto_shash *tfm, const u8 k[16], const u8 *m,
173 size_t len, u8 mac[16])
174{
175 uint8_t tmp[16], mac_msb[16], msg_msb[CMAC_MSG_MAX];
176 SHASH_DESC_ON_STACK(desc, tfm);
177 int err;
178
179 if (len > CMAC_MSG_MAX)
180 return -EFBIG;
181
182 if (!tfm) {
183 BT_ERR("tfm %p", tfm);
184 return -EINVAL;
185 }
186
187 desc->tfm = tfm;
188 desc->flags = 0;
189
190 /* Swap key and message from LSB to MSB */
191 swap_buf(k, tmp, 16);
192 swap_buf(m, msg_msb, len);
193
194 SMP_DBG("msg (len %zu) %*phN", len, (int) len, m);
195 SMP_DBG("key %16phN", k);
196
197 err = crypto_shash_setkey(tfm, tmp, 16);
198 if (err) {
199 BT_ERR("cipher setkey failed: %d", err);
200 return err;
201 }
202
203 err = crypto_shash_digest(desc, msg_msb, len, mac_msb);
204 shash_desc_zero(desc);
205 if (err) {
206 BT_ERR("Hash computation error %d", err);
207 return err;
208 }
209
210 swap_buf(mac_msb, mac, 16);
211
212 SMP_DBG("mac %16phN", mac);
213
214 return 0;
215}
216
217static int smp_f4(struct crypto_shash *tfm_cmac, const u8 u[32],
218 const u8 v[32], const u8 x[16], u8 z, u8 res[16])
219{
220 u8 m[65];
221 int err;
222
223 SMP_DBG("u %32phN", u);
224 SMP_DBG("v %32phN", v);
225 SMP_DBG("x %16phN z %02x", x, z);
226
227 m[0] = z;
228 memcpy(m + 1, v, 32);
229 memcpy(m + 33, u, 32);
230
231 err = aes_cmac(tfm_cmac, x, m, sizeof(m), res);
232 if (err)
233 return err;
234
235 SMP_DBG("res %16phN", res);
236
237 return err;
238}
239
240static int smp_f5(struct crypto_shash *tfm_cmac, const u8 w[32],
241 const u8 n1[16], const u8 n2[16], const u8 a1[7],
242 const u8 a2[7], u8 mackey[16], u8 ltk[16])
243{
244 /* The btle, salt and length "magic" values are as defined in
245 * the SMP section of the Bluetooth core specification. In ASCII
246 * the btle value ends up being 'btle'. The salt is just a
247 * random number whereas length is the value 256 in little
248 * endian format.
249 */
250 const u8 btle[4] = { 0x65, 0x6c, 0x74, 0x62 };
251 const u8 salt[16] = { 0xbe, 0x83, 0x60, 0x5a, 0xdb, 0x0b, 0x37, 0x60,
252 0x38, 0xa5, 0xf5, 0xaa, 0x91, 0x83, 0x88, 0x6c };
253 const u8 length[2] = { 0x00, 0x01 };
254 u8 m[53], t[16];
255 int err;
256
257 SMP_DBG("w %32phN", w);
258 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
259 SMP_DBG("a1 %7phN a2 %7phN", a1, a2);
260
261 err = aes_cmac(tfm_cmac, salt, w, 32, t);
262 if (err)
263 return err;
264
265 SMP_DBG("t %16phN", t);
266
267 memcpy(m, length, 2);
268 memcpy(m + 2, a2, 7);
269 memcpy(m + 9, a1, 7);
270 memcpy(m + 16, n2, 16);
271 memcpy(m + 32, n1, 16);
272 memcpy(m + 48, btle, 4);
273
274 m[52] = 0; /* Counter */
275
276 err = aes_cmac(tfm_cmac, t, m, sizeof(m), mackey);
277 if (err)
278 return err;
279
280 SMP_DBG("mackey %16phN", mackey);
281
282 m[52] = 1; /* Counter */
283
284 err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk);
285 if (err)
286 return err;
287
288 SMP_DBG("ltk %16phN", ltk);
289
290 return 0;
291}
292
293static int smp_f6(struct crypto_shash *tfm_cmac, const u8 w[16],
294 const u8 n1[16], const u8 n2[16], const u8 r[16],
295 const u8 io_cap[3], const u8 a1[7], const u8 a2[7],
296 u8 res[16])
297{
298 u8 m[65];
299 int err;
300
301 SMP_DBG("w %16phN", w);
302 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
303 SMP_DBG("r %16phN io_cap %3phN a1 %7phN a2 %7phN", r, io_cap, a1, a2);
304
305 memcpy(m, a2, 7);
306 memcpy(m + 7, a1, 7);
307 memcpy(m + 14, io_cap, 3);
308 memcpy(m + 17, r, 16);
309 memcpy(m + 33, n2, 16);
310 memcpy(m + 49, n1, 16);
311
312 err = aes_cmac(tfm_cmac, w, m, sizeof(m), res);
313 if (err)
314 return err;
315
316 SMP_DBG("res %16phN", res);
317
318 return err;
319}
320
321static int smp_g2(struct crypto_shash *tfm_cmac, const u8 u[32], const u8 v[32],
322 const u8 x[16], const u8 y[16], u32 *val)
323{
324 u8 m[80], tmp[16];
325 int err;
326
327 SMP_DBG("u %32phN", u);
328 SMP_DBG("v %32phN", v);
329 SMP_DBG("x %16phN y %16phN", x, y);
330
331 memcpy(m, y, 16);
332 memcpy(m + 16, v, 32);
333 memcpy(m + 48, u, 32);
334
335 err = aes_cmac(tfm_cmac, x, m, sizeof(m), tmp);
336 if (err)
337 return err;
338
339 *val = get_unaligned_le32(tmp);
340 *val %= 1000000;
341
342 SMP_DBG("val %06u", *val);
343
344 return 0;
345}
346
347static int smp_h6(struct crypto_shash *tfm_cmac, const u8 w[16],
348 const u8 key_id[4], u8 res[16])
349{
350 int err;
351
352 SMP_DBG("w %16phN key_id %4phN", w, key_id);
353
354 err = aes_cmac(tfm_cmac, w, key_id, 4, res);
355 if (err)
356 return err;
357
358 SMP_DBG("res %16phN", res);
359
360 return err;
361}
362
363static int smp_h7(struct crypto_shash *tfm_cmac, const u8 w[16],
364 const u8 salt[16], u8 res[16])
365{
366 int err;
367
368 SMP_DBG("w %16phN salt %16phN", w, salt);
369
370 err = aes_cmac(tfm_cmac, salt, w, 16, res);
371 if (err)
372 return err;
373
374 SMP_DBG("res %16phN", res);
375
376 return err;
377}
378
379/* The following functions map to the legacy SMP crypto functions e, c1,
380 * s1 and ah.
381 */
382
383static int smp_e(struct crypto_cipher *tfm, const u8 *k, u8 *r)
384{
385 uint8_t tmp[16], data[16];
386 int err;
387
388 SMP_DBG("k %16phN r %16phN", k, r);
389
390 if (!tfm) {
391 BT_ERR("tfm %p", tfm);
392 return -EINVAL;
393 }
394
395 /* The most significant octet of key corresponds to k[0] */
396 swap_buf(k, tmp, 16);
397
398 err = crypto_cipher_setkey(tfm, tmp, 16);
399 if (err) {
400 BT_ERR("cipher setkey failed: %d", err);
401 return err;
402 }
403
404 /* Most significant octet of plaintextData corresponds to data[0] */
405 swap_buf(r, data, 16);
406
407 crypto_cipher_encrypt_one(tfm, data, data);
408
409 /* Most significant octet of encryptedData corresponds to data[0] */
410 swap_buf(data, r, 16);
411
412 SMP_DBG("r %16phN", r);
413
414 return err;
415}
416
417static int smp_c1(struct crypto_cipher *tfm_aes, const u8 k[16],
418 const u8 r[16], const u8 preq[7], const u8 pres[7], u8 _iat,
419 const bdaddr_t *ia, u8 _rat, const bdaddr_t *ra, u8 res[16])
420{
421 u8 p1[16], p2[16];
422 int err;
423
424 SMP_DBG("k %16phN r %16phN", k, r);
425 SMP_DBG("iat %u ia %6phN rat %u ra %6phN", _iat, ia, _rat, ra);
426 SMP_DBG("preq %7phN pres %7phN", preq, pres);
427
428 memset(p1, 0, 16);
429
430 /* p1 = pres || preq || _rat || _iat */
431 p1[0] = _iat;
432 p1[1] = _rat;
433 memcpy(p1 + 2, preq, 7);
434 memcpy(p1 + 9, pres, 7);
435
436 SMP_DBG("p1 %16phN", p1);
437
438 /* res = r XOR p1 */
439 u128_xor((u128 *) res, (u128 *) r, (u128 *) p1);
440
441 /* res = e(k, res) */
442 err = smp_e(tfm_aes, k, res);
443 if (err) {
444 BT_ERR("Encrypt data error");
445 return err;
446 }
447
448 /* p2 = padding || ia || ra */
449 memcpy(p2, ra, 6);
450 memcpy(p2 + 6, ia, 6);
451 memset(p2 + 12, 0, 4);
452
453 SMP_DBG("p2 %16phN", p2);
454
455 /* res = res XOR p2 */
456 u128_xor((u128 *) res, (u128 *) res, (u128 *) p2);
457
458 /* res = e(k, res) */
459 err = smp_e(tfm_aes, k, res);
460 if (err)
461 BT_ERR("Encrypt data error");
462
463 return err;
464}
465
466static int smp_s1(struct crypto_cipher *tfm_aes, const u8 k[16],
467 const u8 r1[16], const u8 r2[16], u8 _r[16])
468{
469 int err;
470
471 /* Just least significant octets from r1 and r2 are considered */
472 memcpy(_r, r2, 8);
473 memcpy(_r + 8, r1, 8);
474
475 err = smp_e(tfm_aes, k, _r);
476 if (err)
477 BT_ERR("Encrypt data error");
478
479 return err;
480}
481
482static int smp_ah(struct crypto_cipher *tfm, const u8 irk[16],
483 const u8 r[3], u8 res[3])
484{
485 u8 _res[16];
486 int err;
487
488 /* r' = padding || r */
489 memcpy(_res, r, 3);
490 memset(_res + 3, 0, 13);
491
492 err = smp_e(tfm, irk, _res);
493 if (err) {
494 BT_ERR("Encrypt error");
495 return err;
496 }
497
498 /* The output of the random address function ah is:
499 * ah(k, r) = e(k, r') mod 2^24
500 * The output of the security function e is then truncated to 24 bits
501 * by taking the least significant 24 bits of the output of e as the
502 * result of ah.
503 */
504 memcpy(res, _res, 3);
505
506 return 0;
507}
508
509bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16],
510 const bdaddr_t *bdaddr)
511{
512 struct l2cap_chan *chan = hdev->smp_data;
513 struct smp_dev *smp;
514 u8 hash[3];
515 int err;
516
517 if (!chan || !chan->data)
518 return false;
519
520 smp = chan->data;
521
522 BT_DBG("RPA %pMR IRK %*phN", bdaddr, 16, irk);
523
524 err = smp_ah(smp->tfm_aes, irk, &bdaddr->b[3], hash);
525 if (err)
526 return false;
527
528 return !crypto_memneq(bdaddr->b, hash, 3);
529}
530
531int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa)
532{
533 struct l2cap_chan *chan = hdev->smp_data;
534 struct smp_dev *smp;
535 int err;
536
537 if (!chan || !chan->data)
538 return -EOPNOTSUPP;
539
540 smp = chan->data;
541
542 get_random_bytes(&rpa->b[3], 3);
543
544 rpa->b[5] &= 0x3f; /* Clear two most significant bits */
545 rpa->b[5] |= 0x40; /* Set second most significant bit */
546
547 err = smp_ah(smp->tfm_aes, irk, &rpa->b[3], rpa->b);
548 if (err < 0)
549 return err;
550
551 BT_DBG("RPA %pMR", rpa);
552
553 return 0;
554}
555
556int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16])
557{
558 struct l2cap_chan *chan = hdev->smp_data;
559 struct smp_dev *smp;
560 int err;
561
562 if (!chan || !chan->data)
563 return -EOPNOTSUPP;
564
565 smp = chan->data;
566
567 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) {
568 BT_DBG("Using debug keys");
569 err = set_ecdh_privkey(smp->tfm_ecdh, debug_sk);
570 if (err)
571 return err;
572 memcpy(smp->local_pk, debug_pk, 64);
573 smp->debug_key = true;
574 } else {
575 while (true) {
576 /* Generate key pair for Secure Connections */
577 err = generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk);
578 if (err)
579 return err;
580
581 /* This is unlikely, but we need to check that
582 * we didn't accidentially generate a debug key.
583 */
584 if (crypto_memneq(smp->local_pk, debug_pk, 64))
585 break;
586 }
587 smp->debug_key = false;
588 }
589
590 SMP_DBG("OOB Public Key X: %32phN", smp->local_pk);
591 SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32);
592
593 get_random_bytes(smp->local_rand, 16);
594
595 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->local_pk,
596 smp->local_rand, 0, hash);
597 if (err < 0)
598 return err;
599
600 memcpy(rand, smp->local_rand, 16);
601
602 return 0;
603}
604
605static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
606{
607 struct l2cap_chan *chan = conn->smp;
608 struct smp_chan *smp;
609 struct kvec iv[2];
610 struct msghdr msg;
611
612 if (!chan)
613 return;
614
615 BT_DBG("code 0x%2.2x", code);
616
617 iv[0].iov_base = &code;
618 iv[0].iov_len = 1;
619
620 iv[1].iov_base = data;
621 iv[1].iov_len = len;
622
623 memset(&msg, 0, sizeof(msg));
624
625 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iv, 2, 1 + len);
626
627 l2cap_chan_send(chan, &msg, 1 + len);
628
629 if (!chan->data)
630 return;
631
632 smp = chan->data;
633
634 cancel_delayed_work_sync(&smp->security_timer);
635 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT);
636}
637
638static u8 authreq_to_seclevel(u8 authreq)
639{
640 if (authreq & SMP_AUTH_MITM) {
641 if (authreq & SMP_AUTH_SC)
642 return BT_SECURITY_FIPS;
643 else
644 return BT_SECURITY_HIGH;
645 } else {
646 return BT_SECURITY_MEDIUM;
647 }
648}
649
650static __u8 seclevel_to_authreq(__u8 sec_level)
651{
652 switch (sec_level) {
653 case BT_SECURITY_FIPS:
654 case BT_SECURITY_HIGH:
655 return SMP_AUTH_MITM | SMP_AUTH_BONDING;
656 case BT_SECURITY_MEDIUM:
657 return SMP_AUTH_BONDING;
658 default:
659 return SMP_AUTH_NONE;
660 }
661}
662
663static void build_pairing_cmd(struct l2cap_conn *conn,
664 struct smp_cmd_pairing *req,
665 struct smp_cmd_pairing *rsp, __u8 authreq)
666{
667 struct l2cap_chan *chan = conn->smp;
668 struct smp_chan *smp = chan->data;
669 struct hci_conn *hcon = conn->hcon;
670 struct hci_dev *hdev = hcon->hdev;
671 u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT;
672
673 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) {
674 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
675 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
676 authreq |= SMP_AUTH_BONDING;
677 } else {
678 authreq &= ~SMP_AUTH_BONDING;
679 }
680
681 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING))
682 remote_dist |= SMP_DIST_ID_KEY;
683
684 if (hci_dev_test_flag(hdev, HCI_PRIVACY))
685 local_dist |= SMP_DIST_ID_KEY;
686
687 if (hci_dev_test_flag(hdev, HCI_SC_ENABLED) &&
688 (authreq & SMP_AUTH_SC)) {
689 struct oob_data *oob_data;
690 u8 bdaddr_type;
691
692 if (hci_dev_test_flag(hdev, HCI_SSP_ENABLED)) {
693 local_dist |= SMP_DIST_LINK_KEY;
694 remote_dist |= SMP_DIST_LINK_KEY;
695 }
696
697 if (hcon->dst_type == ADDR_LE_DEV_PUBLIC)
698 bdaddr_type = BDADDR_LE_PUBLIC;
699 else
700 bdaddr_type = BDADDR_LE_RANDOM;
701
702 oob_data = hci_find_remote_oob_data(hdev, &hcon->dst,
703 bdaddr_type);
704 if (oob_data && oob_data->present) {
705 set_bit(SMP_FLAG_REMOTE_OOB, &smp->flags);
706 oob_flag = SMP_OOB_PRESENT;
707 memcpy(smp->rr, oob_data->rand256, 16);
708 memcpy(smp->pcnf, oob_data->hash256, 16);
709 SMP_DBG("OOB Remote Confirmation: %16phN", smp->pcnf);
710 SMP_DBG("OOB Remote Random: %16phN", smp->rr);
711 }
712
713 } else {
714 authreq &= ~SMP_AUTH_SC;
715 }
716
717 if (rsp == NULL) {
718 req->io_capability = conn->hcon->io_capability;
719 req->oob_flag = oob_flag;
720 req->max_key_size = SMP_DEV(hdev)->max_key_size;
721 req->init_key_dist = local_dist;
722 req->resp_key_dist = remote_dist;
723 req->auth_req = (authreq & AUTH_REQ_MASK(hdev));
724
725 smp->remote_key_dist = remote_dist;
726 return;
727 }
728
729 rsp->io_capability = conn->hcon->io_capability;
730 rsp->oob_flag = oob_flag;
731 rsp->max_key_size = SMP_DEV(hdev)->max_key_size;
732 rsp->init_key_dist = req->init_key_dist & remote_dist;
733 rsp->resp_key_dist = req->resp_key_dist & local_dist;
734 rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev));
735
736 smp->remote_key_dist = rsp->init_key_dist;
737}
738
739static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)
740{
741 struct l2cap_chan *chan = conn->smp;
742 struct hci_dev *hdev = conn->hcon->hdev;
743 struct smp_chan *smp = chan->data;
744
745 if (max_key_size > SMP_DEV(hdev)->max_key_size ||
746 max_key_size < SMP_MIN_ENC_KEY_SIZE)
747 return SMP_ENC_KEY_SIZE;
748
749 smp->enc_key_size = max_key_size;
750
751 return 0;
752}
753
754static void smp_chan_destroy(struct l2cap_conn *conn)
755{
756 struct l2cap_chan *chan = conn->smp;
757 struct smp_chan *smp = chan->data;
758 struct hci_conn *hcon = conn->hcon;
759 bool complete;
760
761 BUG_ON(!smp);
762
763 cancel_delayed_work_sync(&smp->security_timer);
764
765 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags);
766 mgmt_smp_complete(hcon, complete);
767
768 kzfree(smp->csrk);
769 kzfree(smp->slave_csrk);
770 kzfree(smp->link_key);
771
772 crypto_free_cipher(smp->tfm_aes);
773 crypto_free_shash(smp->tfm_cmac);
774 crypto_free_kpp(smp->tfm_ecdh);
775
776 /* Ensure that we don't leave any debug key around if debug key
777 * support hasn't been explicitly enabled.
778 */
779 if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG &&
780 !hci_dev_test_flag(hcon->hdev, HCI_KEEP_DEBUG_KEYS)) {
781 list_del_rcu(&smp->ltk->list);
782 kfree_rcu(smp->ltk, rcu);
783 smp->ltk = NULL;
784 }
785
786 /* If pairing failed clean up any keys we might have */
787 if (!complete) {
788 if (smp->ltk) {
789 list_del_rcu(&smp->ltk->list);
790 kfree_rcu(smp->ltk, rcu);
791 }
792
793 if (smp->slave_ltk) {
794 list_del_rcu(&smp->slave_ltk->list);
795 kfree_rcu(smp->slave_ltk, rcu);
796 }
797
798 if (smp->remote_irk) {
799 list_del_rcu(&smp->remote_irk->list);
800 kfree_rcu(smp->remote_irk, rcu);
801 }
802 }
803
804 chan->data = NULL;
805 kzfree(smp);
806 hci_conn_drop(hcon);
807}
808
809static void smp_failure(struct l2cap_conn *conn, u8 reason)
810{
811 struct hci_conn *hcon = conn->hcon;
812 struct l2cap_chan *chan = conn->smp;
813
814 if (reason)
815 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
816 &reason);
817
818 mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE);
819
820 if (chan->data)
821 smp_chan_destroy(conn);
822}
823
824#define JUST_WORKS 0x00
825#define JUST_CFM 0x01
826#define REQ_PASSKEY 0x02
827#define CFM_PASSKEY 0x03
828#define REQ_OOB 0x04
829#define DSP_PASSKEY 0x05
830#define OVERLAP 0xFF
831
832static const u8 gen_method[5][5] = {
833 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
834 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
835 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
836 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
837 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP },
838};
839
840static const u8 sc_method[5][5] = {
841 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
842 { JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
843 { DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY },
844 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
845 { DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
846};
847
848static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io)
849{
850 /* If either side has unknown io_caps, use JUST_CFM (which gets
851 * converted later to JUST_WORKS if we're initiators.
852 */
853 if (local_io > SMP_IO_KEYBOARD_DISPLAY ||
854 remote_io > SMP_IO_KEYBOARD_DISPLAY)
855 return JUST_CFM;
856
857 if (test_bit(SMP_FLAG_SC, &smp->flags))
858 return sc_method[remote_io][local_io];
859
860 return gen_method[remote_io][local_io];
861}
862
863static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth,
864 u8 local_io, u8 remote_io)
865{
866 struct hci_conn *hcon = conn->hcon;
867 struct l2cap_chan *chan = conn->smp;
868 struct smp_chan *smp = chan->data;
869 u32 passkey = 0;
870 int ret = 0;
871
872 /* Initialize key for JUST WORKS */
873 memset(smp->tk, 0, sizeof(smp->tk));
874 clear_bit(SMP_FLAG_TK_VALID, &smp->flags);
875
876 BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io);
877
878 /* If neither side wants MITM, either "just" confirm an incoming
879 * request or use just-works for outgoing ones. The JUST_CFM
880 * will be converted to JUST_WORKS if necessary later in this
881 * function. If either side has MITM look up the method from the
882 * table.
883 */
884 if (!(auth & SMP_AUTH_MITM))
885 smp->method = JUST_CFM;
886 else
887 smp->method = get_auth_method(smp, local_io, remote_io);
888
889 /* Don't confirm locally initiated pairing attempts */
890 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR,
891 &smp->flags))
892 smp->method = JUST_WORKS;
893
894 /* Don't bother user space with no IO capabilities */
895 if (smp->method == JUST_CFM &&
896 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
897 smp->method = JUST_WORKS;
898
899 /* If Just Works, Continue with Zero TK */
900 if (smp->method == JUST_WORKS) {
901 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
902 return 0;
903 }
904
905 /* If this function is used for SC -> legacy fallback we
906 * can only recover the just-works case.
907 */
908 if (test_bit(SMP_FLAG_SC, &smp->flags))
909 return -EINVAL;
910
911 /* Not Just Works/Confirm results in MITM Authentication */
912 if (smp->method != JUST_CFM) {
913 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags);
914 if (hcon->pending_sec_level < BT_SECURITY_HIGH)
915 hcon->pending_sec_level = BT_SECURITY_HIGH;
916 }
917
918 /* If both devices have Keyoard-Display I/O, the master
919 * Confirms and the slave Enters the passkey.
920 */
921 if (smp->method == OVERLAP) {
922 if (hcon->role == HCI_ROLE_MASTER)
923 smp->method = CFM_PASSKEY;
924 else
925 smp->method = REQ_PASSKEY;
926 }
927
928 /* Generate random passkey. */
929 if (smp->method == CFM_PASSKEY) {
930 memset(smp->tk, 0, sizeof(smp->tk));
931 get_random_bytes(&passkey, sizeof(passkey));
932 passkey %= 1000000;
933 put_unaligned_le32(passkey, smp->tk);
934 BT_DBG("PassKey: %d", passkey);
935 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
936 }
937
938 if (smp->method == REQ_PASSKEY)
939 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst,
940 hcon->type, hcon->dst_type);
941 else if (smp->method == JUST_CFM)
942 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
943 hcon->type, hcon->dst_type,
944 passkey, 1);
945 else
946 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst,
947 hcon->type, hcon->dst_type,
948 passkey, 0);
949
950 return ret;
951}
952
953static u8 smp_confirm(struct smp_chan *smp)
954{
955 struct l2cap_conn *conn = smp->conn;
956 struct smp_cmd_pairing_confirm cp;
957 int ret;
958
959 BT_DBG("conn %p", conn);
960
961 ret = smp_c1(smp->tfm_aes, smp->tk, smp->prnd, smp->preq, smp->prsp,
962 conn->hcon->init_addr_type, &conn->hcon->init_addr,
963 conn->hcon->resp_addr_type, &conn->hcon->resp_addr,
964 cp.confirm_val);
965 if (ret)
966 return SMP_UNSPECIFIED;
967
968 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
969
970 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
971
972 if (conn->hcon->out)
973 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
974 else
975 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
976
977 return 0;
978}
979
980static u8 smp_random(struct smp_chan *smp)
981{
982 struct l2cap_conn *conn = smp->conn;
983 struct hci_conn *hcon = conn->hcon;
984 u8 confirm[16];
985 int ret;
986
987 if (IS_ERR_OR_NULL(smp->tfm_aes))
988 return SMP_UNSPECIFIED;
989
990 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
991
992 ret = smp_c1(smp->tfm_aes, smp->tk, smp->rrnd, smp->preq, smp->prsp,
993 hcon->init_addr_type, &hcon->init_addr,
994 hcon->resp_addr_type, &hcon->resp_addr, confirm);
995 if (ret)
996 return SMP_UNSPECIFIED;
997
998 if (crypto_memneq(smp->pcnf, confirm, sizeof(smp->pcnf))) {
999 bt_dev_err(hcon->hdev, "pairing failed "
1000 "(confirmation values mismatch)");
1001 return SMP_CONFIRM_FAILED;
1002 }
1003
1004 if (hcon->out) {
1005 u8 stk[16];
1006 __le64 rand = 0;
1007 __le16 ediv = 0;
1008
1009 smp_s1(smp->tfm_aes, smp->tk, smp->rrnd, smp->prnd, stk);
1010
1011 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
1012 return SMP_UNSPECIFIED;
1013
1014 hci_le_start_enc(hcon, ediv, rand, stk, smp->enc_key_size);
1015 hcon->enc_key_size = smp->enc_key_size;
1016 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
1017 } else {
1018 u8 stk[16], auth;
1019 __le64 rand = 0;
1020 __le16 ediv = 0;
1021
1022 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
1023 smp->prnd);
1024
1025 smp_s1(smp->tfm_aes, smp->tk, smp->prnd, smp->rrnd, stk);
1026
1027 if (hcon->pending_sec_level == BT_SECURITY_HIGH)
1028 auth = 1;
1029 else
1030 auth = 0;
1031
1032 /* Even though there's no _SLAVE suffix this is the
1033 * slave STK we're adding for later lookup (the master
1034 * STK never needs to be stored).
1035 */
1036 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1037 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand);
1038 }
1039
1040 return 0;
1041}
1042
1043static void smp_notify_keys(struct l2cap_conn *conn)
1044{
1045 struct l2cap_chan *chan = conn->smp;
1046 struct smp_chan *smp = chan->data;
1047 struct hci_conn *hcon = conn->hcon;
1048 struct hci_dev *hdev = hcon->hdev;
1049 struct smp_cmd_pairing *req = (void *) &smp->preq[1];
1050 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1];
1051 bool persistent;
1052
1053 if (hcon->type == ACL_LINK) {
1054 if (hcon->key_type == HCI_LK_DEBUG_COMBINATION)
1055 persistent = false;
1056 else
1057 persistent = !test_bit(HCI_CONN_FLUSH_KEY,
1058 &hcon->flags);
1059 } else {
1060 /* The LTKs, IRKs and CSRKs should be persistent only if
1061 * both sides had the bonding bit set in their
1062 * authentication requests.
1063 */
1064 persistent = !!((req->auth_req & rsp->auth_req) &
1065 SMP_AUTH_BONDING);
1066 }
1067
1068 if (smp->remote_irk) {
1069 mgmt_new_irk(hdev, smp->remote_irk, persistent);
1070
1071 /* Now that user space can be considered to know the
1072 * identity address track the connection based on it
1073 * from now on (assuming this is an LE link).
1074 */
1075 if (hcon->type == LE_LINK) {
1076 bacpy(&hcon->dst, &smp->remote_irk->bdaddr);
1077 hcon->dst_type = smp->remote_irk->addr_type;
1078 queue_work(hdev->workqueue, &conn->id_addr_update_work);
1079 }
1080 }
1081
1082 if (smp->csrk) {
1083 smp->csrk->bdaddr_type = hcon->dst_type;
1084 bacpy(&smp->csrk->bdaddr, &hcon->dst);
1085 mgmt_new_csrk(hdev, smp->csrk, persistent);
1086 }
1087
1088 if (smp->slave_csrk) {
1089 smp->slave_csrk->bdaddr_type = hcon->dst_type;
1090 bacpy(&smp->slave_csrk->bdaddr, &hcon->dst);
1091 mgmt_new_csrk(hdev, smp->slave_csrk, persistent);
1092 }
1093
1094 if (smp->ltk) {
1095 smp->ltk->bdaddr_type = hcon->dst_type;
1096 bacpy(&smp->ltk->bdaddr, &hcon->dst);
1097 mgmt_new_ltk(hdev, smp->ltk, persistent);
1098 }
1099
1100 if (smp->slave_ltk) {
1101 smp->slave_ltk->bdaddr_type = hcon->dst_type;
1102 bacpy(&smp->slave_ltk->bdaddr, &hcon->dst);
1103 mgmt_new_ltk(hdev, smp->slave_ltk, persistent);
1104 }
1105
1106 if (smp->link_key) {
1107 struct link_key *key;
1108 u8 type;
1109
1110 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1111 type = HCI_LK_DEBUG_COMBINATION;
1112 else if (hcon->sec_level == BT_SECURITY_FIPS)
1113 type = HCI_LK_AUTH_COMBINATION_P256;
1114 else
1115 type = HCI_LK_UNAUTH_COMBINATION_P256;
1116
1117 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst,
1118 smp->link_key, type, 0, &persistent);
1119 if (key) {
1120 mgmt_new_link_key(hdev, key, persistent);
1121
1122 /* Don't keep debug keys around if the relevant
1123 * flag is not set.
1124 */
1125 if (!hci_dev_test_flag(hdev, HCI_KEEP_DEBUG_KEYS) &&
1126 key->type == HCI_LK_DEBUG_COMBINATION) {
1127 list_del_rcu(&key->list);
1128 kfree_rcu(key, rcu);
1129 }
1130 }
1131 }
1132}
1133
1134static void sc_add_ltk(struct smp_chan *smp)
1135{
1136 struct hci_conn *hcon = smp->conn->hcon;
1137 u8 key_type, auth;
1138
1139 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1140 key_type = SMP_LTK_P256_DEBUG;
1141 else
1142 key_type = SMP_LTK_P256;
1143
1144 if (hcon->pending_sec_level == BT_SECURITY_FIPS)
1145 auth = 1;
1146 else
1147 auth = 0;
1148
1149 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1150 key_type, auth, smp->tk, smp->enc_key_size,
1151 0, 0);
1152}
1153
1154static void sc_generate_link_key(struct smp_chan *smp)
1155{
1156 /* From core spec. Spells out in ASCII as 'lebr'. */
1157 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c };
1158
1159 smp->link_key = kzalloc(16, GFP_KERNEL);
1160 if (!smp->link_key)
1161 return;
1162
1163 if (test_bit(SMP_FLAG_CT2, &smp->flags)) {
1164 /* SALT = 0x00000000000000000000000000000000746D7031 */
1165 const u8 salt[16] = { 0x31, 0x70, 0x6d, 0x74 };
1166
1167 if (smp_h7(smp->tfm_cmac, smp->tk, salt, smp->link_key)) {
1168 kzfree(smp->link_key);
1169 smp->link_key = NULL;
1170 return;
1171 }
1172 } else {
1173 /* From core spec. Spells out in ASCII as 'tmp1'. */
1174 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 };
1175
1176 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) {
1177 kzfree(smp->link_key);
1178 smp->link_key = NULL;
1179 return;
1180 }
1181 }
1182
1183 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) {
1184 kzfree(smp->link_key);
1185 smp->link_key = NULL;
1186 return;
1187 }
1188}
1189
1190static void smp_allow_key_dist(struct smp_chan *smp)
1191{
1192 /* Allow the first expected phase 3 PDU. The rest of the PDUs
1193 * will be allowed in each PDU handler to ensure we receive
1194 * them in the correct order.
1195 */
1196 if (smp->remote_key_dist & SMP_DIST_ENC_KEY)
1197 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO);
1198 else if (smp->remote_key_dist & SMP_DIST_ID_KEY)
1199 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
1200 else if (smp->remote_key_dist & SMP_DIST_SIGN)
1201 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
1202}
1203
1204static void sc_generate_ltk(struct smp_chan *smp)
1205{
1206 /* From core spec. Spells out in ASCII as 'brle'. */
1207 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 };
1208 struct hci_conn *hcon = smp->conn->hcon;
1209 struct hci_dev *hdev = hcon->hdev;
1210 struct link_key *key;
1211
1212 key = hci_find_link_key(hdev, &hcon->dst);
1213 if (!key) {
1214 bt_dev_err(hdev, "no Link Key found to generate LTK");
1215 return;
1216 }
1217
1218 if (key->type == HCI_LK_DEBUG_COMBINATION)
1219 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1220
1221 if (test_bit(SMP_FLAG_CT2, &smp->flags)) {
1222 /* SALT = 0x00000000000000000000000000000000746D7032 */
1223 const u8 salt[16] = { 0x32, 0x70, 0x6d, 0x74 };
1224
1225 if (smp_h7(smp->tfm_cmac, key->val, salt, smp->tk))
1226 return;
1227 } else {
1228 /* From core spec. Spells out in ASCII as 'tmp2'. */
1229 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 };
1230
1231 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk))
1232 return;
1233 }
1234
1235 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk))
1236 return;
1237
1238 sc_add_ltk(smp);
1239}
1240
1241static void smp_distribute_keys(struct smp_chan *smp)
1242{
1243 struct smp_cmd_pairing *req, *rsp;
1244 struct l2cap_conn *conn = smp->conn;
1245 struct hci_conn *hcon = conn->hcon;
1246 struct hci_dev *hdev = hcon->hdev;
1247 __u8 *keydist;
1248
1249 BT_DBG("conn %p", conn);
1250
1251 rsp = (void *) &smp->prsp[1];
1252
1253 /* The responder sends its keys first */
1254 if (hcon->out && (smp->remote_key_dist & KEY_DIST_MASK)) {
1255 smp_allow_key_dist(smp);
1256 return;
1257 }
1258
1259 req = (void *) &smp->preq[1];
1260
1261 if (hcon->out) {
1262 keydist = &rsp->init_key_dist;
1263 *keydist &= req->init_key_dist;
1264 } else {
1265 keydist = &rsp->resp_key_dist;
1266 *keydist &= req->resp_key_dist;
1267 }
1268
1269 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1270 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY))
1271 sc_generate_link_key(smp);
1272 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY))
1273 sc_generate_ltk(smp);
1274
1275 /* Clear the keys which are generated but not distributed */
1276 *keydist &= ~SMP_SC_NO_DIST;
1277 }
1278
1279 BT_DBG("keydist 0x%x", *keydist);
1280
1281 if (*keydist & SMP_DIST_ENC_KEY) {
1282 struct smp_cmd_encrypt_info enc;
1283 struct smp_cmd_master_ident ident;
1284 struct smp_ltk *ltk;
1285 u8 authenticated;
1286 __le16 ediv;
1287 __le64 rand;
1288
1289 /* Make sure we generate only the significant amount of
1290 * bytes based on the encryption key size, and set the rest
1291 * of the value to zeroes.
1292 */
1293 get_random_bytes(enc.ltk, smp->enc_key_size);
1294 memset(enc.ltk + smp->enc_key_size, 0,
1295 sizeof(enc.ltk) - smp->enc_key_size);
1296
1297 get_random_bytes(&ediv, sizeof(ediv));
1298 get_random_bytes(&rand, sizeof(rand));
1299
1300 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc);
1301
1302 authenticated = hcon->sec_level == BT_SECURITY_HIGH;
1303 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type,
1304 SMP_LTK_SLAVE, authenticated, enc.ltk,
1305 smp->enc_key_size, ediv, rand);
1306 smp->slave_ltk = ltk;
1307
1308 ident.ediv = ediv;
1309 ident.rand = rand;
1310
1311 smp_send_cmd(conn, SMP_CMD_MASTER_IDENT, sizeof(ident), &ident);
1312
1313 *keydist &= ~SMP_DIST_ENC_KEY;
1314 }
1315
1316 if (*keydist & SMP_DIST_ID_KEY) {
1317 struct smp_cmd_ident_addr_info addrinfo;
1318 struct smp_cmd_ident_info idinfo;
1319
1320 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk));
1321
1322 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo);
1323
1324 /* The hci_conn contains the local identity address
1325 * after the connection has been established.
1326 *
1327 * This is true even when the connection has been
1328 * established using a resolvable random address.
1329 */
1330 bacpy(&addrinfo.bdaddr, &hcon->src);
1331 addrinfo.addr_type = hcon->src_type;
1332
1333 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo),
1334 &addrinfo);
1335
1336 *keydist &= ~SMP_DIST_ID_KEY;
1337 }
1338
1339 if (*keydist & SMP_DIST_SIGN) {
1340 struct smp_cmd_sign_info sign;
1341 struct smp_csrk *csrk;
1342
1343 /* Generate a new random key */
1344 get_random_bytes(sign.csrk, sizeof(sign.csrk));
1345
1346 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
1347 if (csrk) {
1348 if (hcon->sec_level > BT_SECURITY_MEDIUM)
1349 csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED;
1350 else
1351 csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED;
1352 memcpy(csrk->val, sign.csrk, sizeof(csrk->val));
1353 }
1354 smp->slave_csrk = csrk;
1355
1356 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign);
1357
1358 *keydist &= ~SMP_DIST_SIGN;
1359 }
1360
1361 /* If there are still keys to be received wait for them */
1362 if (smp->remote_key_dist & KEY_DIST_MASK) {
1363 smp_allow_key_dist(smp);
1364 return;
1365 }
1366
1367 set_bit(SMP_FLAG_COMPLETE, &smp->flags);
1368 smp_notify_keys(conn);
1369
1370 smp_chan_destroy(conn);
1371}
1372
1373static void smp_timeout(struct work_struct *work)
1374{
1375 struct smp_chan *smp = container_of(work, struct smp_chan,
1376 security_timer.work);
1377 struct l2cap_conn *conn = smp->conn;
1378
1379 BT_DBG("conn %p", conn);
1380
1381 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM);
1382}
1383
1384static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
1385{
1386 struct l2cap_chan *chan = conn->smp;
1387 struct smp_chan *smp;
1388
1389 smp = kzalloc(sizeof(*smp), GFP_ATOMIC);
1390 if (!smp)
1391 return NULL;
1392
1393 smp->tfm_aes = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
1394 if (IS_ERR(smp->tfm_aes)) {
1395 BT_ERR("Unable to create AES crypto context");
1396 goto zfree_smp;
1397 }
1398
1399 smp->tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
1400 if (IS_ERR(smp->tfm_cmac)) {
1401 BT_ERR("Unable to create CMAC crypto context");
1402 goto free_cipher;
1403 }
1404
1405 smp->tfm_ecdh = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0);
1406 if (IS_ERR(smp->tfm_ecdh)) {
1407 BT_ERR("Unable to create ECDH crypto context");
1408 goto free_shash;
1409 }
1410
1411 smp->conn = conn;
1412 chan->data = smp;
1413
1414 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL);
1415
1416 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout);
1417
1418 hci_conn_hold(conn->hcon);
1419
1420 return smp;
1421
1422free_shash:
1423 crypto_free_shash(smp->tfm_cmac);
1424free_cipher:
1425 crypto_free_cipher(smp->tfm_aes);
1426zfree_smp:
1427 kzfree(smp);
1428 return NULL;
1429}
1430
1431static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16])
1432{
1433 struct hci_conn *hcon = smp->conn->hcon;
1434 u8 *na, *nb, a[7], b[7];
1435
1436 if (hcon->out) {
1437 na = smp->prnd;
1438 nb = smp->rrnd;
1439 } else {
1440 na = smp->rrnd;
1441 nb = smp->prnd;
1442 }
1443
1444 memcpy(a, &hcon->init_addr, 6);
1445 memcpy(b, &hcon->resp_addr, 6);
1446 a[6] = hcon->init_addr_type;
1447 b[6] = hcon->resp_addr_type;
1448
1449 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk);
1450}
1451
1452static void sc_dhkey_check(struct smp_chan *smp)
1453{
1454 struct hci_conn *hcon = smp->conn->hcon;
1455 struct smp_cmd_dhkey_check check;
1456 u8 a[7], b[7], *local_addr, *remote_addr;
1457 u8 io_cap[3], r[16];
1458
1459 memcpy(a, &hcon->init_addr, 6);
1460 memcpy(b, &hcon->resp_addr, 6);
1461 a[6] = hcon->init_addr_type;
1462 b[6] = hcon->resp_addr_type;
1463
1464 if (hcon->out) {
1465 local_addr = a;
1466 remote_addr = b;
1467 memcpy(io_cap, &smp->preq[1], 3);
1468 } else {
1469 local_addr = b;
1470 remote_addr = a;
1471 memcpy(io_cap, &smp->prsp[1], 3);
1472 }
1473
1474 memset(r, 0, sizeof(r));
1475
1476 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
1477 put_unaligned_le32(hcon->passkey_notify, r);
1478
1479 if (smp->method == REQ_OOB)
1480 memcpy(r, smp->rr, 16);
1481
1482 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap,
1483 local_addr, remote_addr, check.e);
1484
1485 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check);
1486}
1487
1488static u8 sc_passkey_send_confirm(struct smp_chan *smp)
1489{
1490 struct l2cap_conn *conn = smp->conn;
1491 struct hci_conn *hcon = conn->hcon;
1492 struct smp_cmd_pairing_confirm cfm;
1493 u8 r;
1494
1495 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1496 r |= 0x80;
1497
1498 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1499
1500 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r,
1501 cfm.confirm_val))
1502 return SMP_UNSPECIFIED;
1503
1504 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
1505
1506 return 0;
1507}
1508
1509static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op)
1510{
1511 struct l2cap_conn *conn = smp->conn;
1512 struct hci_conn *hcon = conn->hcon;
1513 struct hci_dev *hdev = hcon->hdev;
1514 u8 cfm[16], r;
1515
1516 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */
1517 if (smp->passkey_round >= 20)
1518 return 0;
1519
1520 switch (smp_op) {
1521 case SMP_CMD_PAIRING_RANDOM:
1522 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1523 r |= 0x80;
1524
1525 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
1526 smp->rrnd, r, cfm))
1527 return SMP_UNSPECIFIED;
1528
1529 if (crypto_memneq(smp->pcnf, cfm, 16))
1530 return SMP_CONFIRM_FAILED;
1531
1532 smp->passkey_round++;
1533
1534 if (smp->passkey_round == 20) {
1535 /* Generate MacKey and LTK */
1536 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk))
1537 return SMP_UNSPECIFIED;
1538 }
1539
1540 /* The round is only complete when the initiator
1541 * receives pairing random.
1542 */
1543 if (!hcon->out) {
1544 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1545 sizeof(smp->prnd), smp->prnd);
1546 if (smp->passkey_round == 20)
1547 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1548 else
1549 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1550 return 0;
1551 }
1552
1553 /* Start the next round */
1554 if (smp->passkey_round != 20)
1555 return sc_passkey_round(smp, 0);
1556
1557 /* Passkey rounds are complete - start DHKey Check */
1558 sc_dhkey_check(smp);
1559 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1560
1561 break;
1562
1563 case SMP_CMD_PAIRING_CONFIRM:
1564 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
1565 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
1566 return 0;
1567 }
1568
1569 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
1570
1571 if (hcon->out) {
1572 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1573 sizeof(smp->prnd), smp->prnd);
1574 return 0;
1575 }
1576
1577 return sc_passkey_send_confirm(smp);
1578
1579 case SMP_CMD_PUBLIC_KEY:
1580 default:
1581 /* Initiating device starts the round */
1582 if (!hcon->out)
1583 return 0;
1584
1585 BT_DBG("%s Starting passkey round %u", hdev->name,
1586 smp->passkey_round + 1);
1587
1588 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1589
1590 return sc_passkey_send_confirm(smp);
1591 }
1592
1593 return 0;
1594}
1595
1596static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey)
1597{
1598 struct l2cap_conn *conn = smp->conn;
1599 struct hci_conn *hcon = conn->hcon;
1600 u8 smp_op;
1601
1602 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags);
1603
1604 switch (mgmt_op) {
1605 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1606 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED);
1607 return 0;
1608 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1609 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED);
1610 return 0;
1611 case MGMT_OP_USER_PASSKEY_REPLY:
1612 hcon->passkey_notify = le32_to_cpu(passkey);
1613 smp->passkey_round = 0;
1614
1615 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags))
1616 smp_op = SMP_CMD_PAIRING_CONFIRM;
1617 else
1618 smp_op = 0;
1619
1620 if (sc_passkey_round(smp, smp_op))
1621 return -EIO;
1622
1623 return 0;
1624 }
1625
1626 /* Initiator sends DHKey check first */
1627 if (hcon->out) {
1628 sc_dhkey_check(smp);
1629 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1630 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) {
1631 sc_dhkey_check(smp);
1632 sc_add_ltk(smp);
1633 }
1634
1635 return 0;
1636}
1637
1638int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey)
1639{
1640 struct l2cap_conn *conn = hcon->l2cap_data;
1641 struct l2cap_chan *chan;
1642 struct smp_chan *smp;
1643 u32 value;
1644 int err;
1645
1646 BT_DBG("");
1647
1648 if (!conn)
1649 return -ENOTCONN;
1650
1651 chan = conn->smp;
1652 if (!chan)
1653 return -ENOTCONN;
1654
1655 l2cap_chan_lock(chan);
1656 if (!chan->data) {
1657 err = -ENOTCONN;
1658 goto unlock;
1659 }
1660
1661 smp = chan->data;
1662
1663 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1664 err = sc_user_reply(smp, mgmt_op, passkey);
1665 goto unlock;
1666 }
1667
1668 switch (mgmt_op) {
1669 case MGMT_OP_USER_PASSKEY_REPLY:
1670 value = le32_to_cpu(passkey);
1671 memset(smp->tk, 0, sizeof(smp->tk));
1672 BT_DBG("PassKey: %d", value);
1673 put_unaligned_le32(value, smp->tk);
1674 /* Fall Through */
1675 case MGMT_OP_USER_CONFIRM_REPLY:
1676 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
1677 break;
1678 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1679 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1680 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1681 err = 0;
1682 goto unlock;
1683 default:
1684 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1685 err = -EOPNOTSUPP;
1686 goto unlock;
1687 }
1688
1689 err = 0;
1690
1691 /* If it is our turn to send Pairing Confirm, do so now */
1692 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) {
1693 u8 rsp = smp_confirm(smp);
1694 if (rsp)
1695 smp_failure(conn, rsp);
1696 }
1697
1698unlock:
1699 l2cap_chan_unlock(chan);
1700 return err;
1701}
1702
1703static void build_bredr_pairing_cmd(struct smp_chan *smp,
1704 struct smp_cmd_pairing *req,
1705 struct smp_cmd_pairing *rsp)
1706{
1707 struct l2cap_conn *conn = smp->conn;
1708 struct hci_dev *hdev = conn->hcon->hdev;
1709 u8 local_dist = 0, remote_dist = 0;
1710
1711 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) {
1712 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1713 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1714 }
1715
1716 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING))
1717 remote_dist |= SMP_DIST_ID_KEY;
1718
1719 if (hci_dev_test_flag(hdev, HCI_PRIVACY))
1720 local_dist |= SMP_DIST_ID_KEY;
1721
1722 if (!rsp) {
1723 memset(req, 0, sizeof(*req));
1724
1725 req->auth_req = SMP_AUTH_CT2;
1726 req->init_key_dist = local_dist;
1727 req->resp_key_dist = remote_dist;
1728 req->max_key_size = conn->hcon->enc_key_size;
1729
1730 smp->remote_key_dist = remote_dist;
1731
1732 return;
1733 }
1734
1735 memset(rsp, 0, sizeof(*rsp));
1736
1737 rsp->auth_req = SMP_AUTH_CT2;
1738 rsp->max_key_size = conn->hcon->enc_key_size;
1739 rsp->init_key_dist = req->init_key_dist & remote_dist;
1740 rsp->resp_key_dist = req->resp_key_dist & local_dist;
1741
1742 smp->remote_key_dist = rsp->init_key_dist;
1743}
1744
1745static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
1746{
1747 struct smp_cmd_pairing rsp, *req = (void *) skb->data;
1748 struct l2cap_chan *chan = conn->smp;
1749 struct hci_dev *hdev = conn->hcon->hdev;
1750 struct smp_chan *smp;
1751 u8 key_size, auth, sec_level;
1752 int ret;
1753
1754 BT_DBG("conn %p", conn);
1755
1756 if (skb->len < sizeof(*req))
1757 return SMP_INVALID_PARAMS;
1758
1759 if (conn->hcon->role != HCI_ROLE_SLAVE)
1760 return SMP_CMD_NOTSUPP;
1761
1762 if (!chan->data)
1763 smp = smp_chan_create(conn);
1764 else
1765 smp = chan->data;
1766
1767 if (!smp)
1768 return SMP_UNSPECIFIED;
1769
1770 /* We didn't start the pairing, so match remote */
1771 auth = req->auth_req & AUTH_REQ_MASK(hdev);
1772
1773 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) &&
1774 (auth & SMP_AUTH_BONDING))
1775 return SMP_PAIRING_NOTSUPP;
1776
1777 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
1778 return SMP_AUTH_REQUIREMENTS;
1779
1780 smp->preq[0] = SMP_CMD_PAIRING_REQ;
1781 memcpy(&smp->preq[1], req, sizeof(*req));
1782 skb_pull(skb, sizeof(*req));
1783
1784 /* If the remote side's OOB flag is set it means it has
1785 * successfully received our local OOB data - therefore set the
1786 * flag to indicate that local OOB is in use.
1787 */
1788 if (req->oob_flag == SMP_OOB_PRESENT)
1789 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);
1790
1791 /* SMP over BR/EDR requires special treatment */
1792 if (conn->hcon->type == ACL_LINK) {
1793 /* We must have a BR/EDR SC link */
1794 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) &&
1795 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
1796 return SMP_CROSS_TRANSP_NOT_ALLOWED;
1797
1798 set_bit(SMP_FLAG_SC, &smp->flags);
1799
1800 build_bredr_pairing_cmd(smp, req, &rsp);
1801
1802 if (req->auth_req & SMP_AUTH_CT2)
1803 set_bit(SMP_FLAG_CT2, &smp->flags);
1804
1805 key_size = min(req->max_key_size, rsp.max_key_size);
1806 if (check_enc_key_size(conn, key_size))
1807 return SMP_ENC_KEY_SIZE;
1808
1809 /* Clear bits which are generated but not distributed */
1810 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1811
1812 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1813 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1814 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1815
1816 smp_distribute_keys(smp);
1817 return 0;
1818 }
1819
1820 build_pairing_cmd(conn, req, &rsp, auth);
1821
1822 if (rsp.auth_req & SMP_AUTH_SC) {
1823 set_bit(SMP_FLAG_SC, &smp->flags);
1824
1825 if (rsp.auth_req & SMP_AUTH_CT2)
1826 set_bit(SMP_FLAG_CT2, &smp->flags);
1827 }
1828
1829 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
1830 sec_level = BT_SECURITY_MEDIUM;
1831 else
1832 sec_level = authreq_to_seclevel(auth);
1833
1834 if (sec_level > conn->hcon->pending_sec_level)
1835 conn->hcon->pending_sec_level = sec_level;
1836
1837 /* If we need MITM check that it can be achieved */
1838 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1839 u8 method;
1840
1841 method = get_auth_method(smp, conn->hcon->io_capability,
1842 req->io_capability);
1843 if (method == JUST_WORKS || method == JUST_CFM)
1844 return SMP_AUTH_REQUIREMENTS;
1845 }
1846
1847 key_size = min(req->max_key_size, rsp.max_key_size);
1848 if (check_enc_key_size(conn, key_size))
1849 return SMP_ENC_KEY_SIZE;
1850
1851 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1852
1853 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1854 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1855
1856 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1857
1858 clear_bit(SMP_FLAG_INITIATOR, &smp->flags);
1859
1860 /* Strictly speaking we shouldn't allow Pairing Confirm for the
1861 * SC case, however some implementations incorrectly copy RFU auth
1862 * req bits from our security request, which may create a false
1863 * positive SC enablement.
1864 */
1865 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1866
1867 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1868 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
1869 /* Clear bits which are generated but not distributed */
1870 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1871 /* Wait for Public Key from Initiating Device */
1872 return 0;
1873 }
1874
1875 /* Request setup of TK */
1876 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability);
1877 if (ret)
1878 return SMP_UNSPECIFIED;
1879
1880 return 0;
1881}
1882
1883static u8 sc_send_public_key(struct smp_chan *smp)
1884{
1885 struct hci_dev *hdev = smp->conn->hcon->hdev;
1886
1887 BT_DBG("");
1888
1889 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) {
1890 struct l2cap_chan *chan = hdev->smp_data;
1891 struct smp_dev *smp_dev;
1892
1893 if (!chan || !chan->data)
1894 return SMP_UNSPECIFIED;
1895
1896 smp_dev = chan->data;
1897
1898 memcpy(smp->local_pk, smp_dev->local_pk, 64);
1899 memcpy(smp->lr, smp_dev->local_rand, 16);
1900
1901 if (smp_dev->debug_key)
1902 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1903
1904 goto done;
1905 }
1906
1907 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) {
1908 BT_DBG("Using debug keys");
1909 if (set_ecdh_privkey(smp->tfm_ecdh, debug_sk))
1910 return SMP_UNSPECIFIED;
1911 memcpy(smp->local_pk, debug_pk, 64);
1912 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1913 } else {
1914 while (true) {
1915 /* Generate key pair for Secure Connections */
1916 if (generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk))
1917 return SMP_UNSPECIFIED;
1918
1919 /* This is unlikely, but we need to check that
1920 * we didn't accidentially generate a debug key.
1921 */
1922 if (crypto_memneq(smp->local_pk, debug_pk, 64))
1923 break;
1924 }
1925 }
1926
1927done:
1928 SMP_DBG("Local Public Key X: %32phN", smp->local_pk);
1929 SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32);
1930
1931 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk);
1932
1933 return 0;
1934}
1935
1936static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
1937{
1938 struct smp_cmd_pairing *req, *rsp = (void *) skb->data;
1939 struct l2cap_chan *chan = conn->smp;
1940 struct smp_chan *smp = chan->data;
1941 struct hci_dev *hdev = conn->hcon->hdev;
1942 u8 key_size, auth;
1943 int ret;
1944
1945 BT_DBG("conn %p", conn);
1946
1947 if (skb->len < sizeof(*rsp))
1948 return SMP_INVALID_PARAMS;
1949
1950 if (conn->hcon->role != HCI_ROLE_MASTER)
1951 return SMP_CMD_NOTSUPP;
1952
1953 skb_pull(skb, sizeof(*rsp));
1954
1955 req = (void *) &smp->preq[1];
1956
1957 key_size = min(req->max_key_size, rsp->max_key_size);
1958 if (check_enc_key_size(conn, key_size))
1959 return SMP_ENC_KEY_SIZE;
1960
1961 auth = rsp->auth_req & AUTH_REQ_MASK(hdev);
1962
1963 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
1964 return SMP_AUTH_REQUIREMENTS;
1965
1966 /* If the remote side's OOB flag is set it means it has
1967 * successfully received our local OOB data - therefore set the
1968 * flag to indicate that local OOB is in use.
1969 */
1970 if (rsp->oob_flag == SMP_OOB_PRESENT)
1971 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);
1972
1973 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1974 memcpy(&smp->prsp[1], rsp, sizeof(*rsp));
1975
1976 /* Update remote key distribution in case the remote cleared
1977 * some bits that we had enabled in our request.
1978 */
1979 smp->remote_key_dist &= rsp->resp_key_dist;
1980
1981 if ((req->auth_req & SMP_AUTH_CT2) && (auth & SMP_AUTH_CT2))
1982 set_bit(SMP_FLAG_CT2, &smp->flags);
1983
1984 /* For BR/EDR this means we're done and can start phase 3 */
1985 if (conn->hcon->type == ACL_LINK) {
1986 /* Clear bits which are generated but not distributed */
1987 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1988 smp_distribute_keys(smp);
1989 return 0;
1990 }
1991
1992 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC))
1993 set_bit(SMP_FLAG_SC, &smp->flags);
1994 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH)
1995 conn->hcon->pending_sec_level = BT_SECURITY_HIGH;
1996
1997 /* If we need MITM check that it can be achieved */
1998 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1999 u8 method;
2000
2001 method = get_auth_method(smp, req->io_capability,
2002 rsp->io_capability);
2003 if (method == JUST_WORKS || method == JUST_CFM)
2004 return SMP_AUTH_REQUIREMENTS;
2005 }
2006
2007 get_random_bytes(smp->prnd, sizeof(smp->prnd));
2008
2009 /* Update remote key distribution in case the remote cleared
2010 * some bits that we had enabled in our request.
2011 */
2012 smp->remote_key_dist &= rsp->resp_key_dist;
2013
2014 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
2015 /* Clear bits which are generated but not distributed */
2016 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
2017 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
2018 return sc_send_public_key(smp);
2019 }
2020
2021 auth |= req->auth_req;
2022
2023 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability);
2024 if (ret)
2025 return SMP_UNSPECIFIED;
2026
2027 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
2028
2029 /* Can't compose response until we have been confirmed */
2030 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
2031 return smp_confirm(smp);
2032
2033 return 0;
2034}
2035
2036static u8 sc_check_confirm(struct smp_chan *smp)
2037{
2038 struct l2cap_conn *conn = smp->conn;
2039
2040 BT_DBG("");
2041
2042 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2043 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM);
2044
2045 if (conn->hcon->out) {
2046 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2047 smp->prnd);
2048 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2049 }
2050
2051 return 0;
2052}
2053
2054/* Work-around for some implementations that incorrectly copy RFU bits
2055 * from our security request and thereby create the impression that
2056 * we're doing SC when in fact the remote doesn't support it.
2057 */
2058static int fixup_sc_false_positive(struct smp_chan *smp)
2059{
2060 struct l2cap_conn *conn = smp->conn;
2061 struct hci_conn *hcon = conn->hcon;
2062 struct hci_dev *hdev = hcon->hdev;
2063 struct smp_cmd_pairing *req, *rsp;
2064 u8 auth;
2065
2066 /* The issue is only observed when we're in slave role */
2067 if (hcon->out)
2068 return SMP_UNSPECIFIED;
2069
2070 if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) {
2071 bt_dev_err(hdev, "refusing legacy fallback in SC-only mode");
2072 return SMP_UNSPECIFIED;
2073 }
2074
2075 bt_dev_err(hdev, "trying to fall back to legacy SMP");
2076
2077 req = (void *) &smp->preq[1];
2078 rsp = (void *) &smp->prsp[1];
2079
2080 /* Rebuild key dist flags which may have been cleared for SC */
2081 smp->remote_key_dist = (req->init_key_dist & rsp->resp_key_dist);
2082
2083 auth = req->auth_req & AUTH_REQ_MASK(hdev);
2084
2085 if (tk_request(conn, 0, auth, rsp->io_capability, req->io_capability)) {
2086 bt_dev_err(hdev, "failed to fall back to legacy SMP");
2087 return SMP_UNSPECIFIED;
2088 }
2089
2090 clear_bit(SMP_FLAG_SC, &smp->flags);
2091
2092 return 0;
2093}
2094
2095static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
2096{
2097 struct l2cap_chan *chan = conn->smp;
2098 struct smp_chan *smp = chan->data;
2099
2100 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
2101
2102 if (skb->len < sizeof(smp->pcnf))
2103 return SMP_INVALID_PARAMS;
2104
2105 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf));
2106 skb_pull(skb, sizeof(smp->pcnf));
2107
2108 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
2109 int ret;
2110
2111 /* Public Key exchange must happen before any other steps */
2112 if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags))
2113 return sc_check_confirm(smp);
2114
2115 BT_ERR("Unexpected SMP Pairing Confirm");
2116
2117 ret = fixup_sc_false_positive(smp);
2118 if (ret)
2119 return ret;
2120 }
2121
2122 if (conn->hcon->out) {
2123 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2124 smp->prnd);
2125 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2126 return 0;
2127 }
2128
2129 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
2130 return smp_confirm(smp);
2131
2132 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
2133
2134 return 0;
2135}
2136
2137static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
2138{
2139 struct l2cap_chan *chan = conn->smp;
2140 struct smp_chan *smp = chan->data;
2141 struct hci_conn *hcon = conn->hcon;
2142 u8 *pkax, *pkbx, *na, *nb;
2143 u32 passkey;
2144 int err;
2145
2146 BT_DBG("conn %p", conn);
2147
2148 if (skb->len < sizeof(smp->rrnd))
2149 return SMP_INVALID_PARAMS;
2150
2151 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd));
2152 skb_pull(skb, sizeof(smp->rrnd));
2153
2154 if (!test_bit(SMP_FLAG_SC, &smp->flags))
2155 return smp_random(smp);
2156
2157 if (hcon->out) {
2158 pkax = smp->local_pk;
2159 pkbx = smp->remote_pk;
2160 na = smp->prnd;
2161 nb = smp->rrnd;
2162 } else {
2163 pkax = smp->remote_pk;
2164 pkbx = smp->local_pk;
2165 na = smp->rrnd;
2166 nb = smp->prnd;
2167 }
2168
2169 if (smp->method == REQ_OOB) {
2170 if (!hcon->out)
2171 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2172 sizeof(smp->prnd), smp->prnd);
2173 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2174 goto mackey_and_ltk;
2175 }
2176
2177 /* Passkey entry has special treatment */
2178 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2179 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM);
2180
2181 if (hcon->out) {
2182 u8 cfm[16];
2183
2184 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
2185 smp->rrnd, 0, cfm);
2186 if (err)
2187 return SMP_UNSPECIFIED;
2188
2189 if (crypto_memneq(smp->pcnf, cfm, 16))
2190 return SMP_CONFIRM_FAILED;
2191 } else {
2192 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2193 smp->prnd);
2194 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2195 }
2196
2197mackey_and_ltk:
2198 /* Generate MacKey and LTK */
2199 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk);
2200 if (err)
2201 return SMP_UNSPECIFIED;
2202
2203 if (smp->method == JUST_WORKS || smp->method == REQ_OOB) {
2204 if (hcon->out) {
2205 sc_dhkey_check(smp);
2206 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2207 }
2208 return 0;
2209 }
2210
2211 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
2212 if (err)
2213 return SMP_UNSPECIFIED;
2214
2215 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type,
2216 hcon->dst_type, passkey, 0);
2217 if (err)
2218 return SMP_UNSPECIFIED;
2219
2220 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2221
2222 return 0;
2223}
2224
2225static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level)
2226{
2227 struct smp_ltk *key;
2228 struct hci_conn *hcon = conn->hcon;
2229
2230 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role);
2231 if (!key)
2232 return false;
2233
2234 if (smp_ltk_sec_level(key) < sec_level)
2235 return false;
2236
2237 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
2238 return true;
2239
2240 hci_le_start_enc(hcon, key->ediv, key->rand, key->val, key->enc_size);
2241 hcon->enc_key_size = key->enc_size;
2242
2243 /* We never store STKs for master role, so clear this flag */
2244 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
2245
2246 return true;
2247}
2248
2249bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level,
2250 enum smp_key_pref key_pref)
2251{
2252 if (sec_level == BT_SECURITY_LOW)
2253 return true;
2254
2255 /* If we're encrypted with an STK but the caller prefers using
2256 * LTK claim insufficient security. This way we allow the
2257 * connection to be re-encrypted with an LTK, even if the LTK
2258 * provides the same level of security. Only exception is if we
2259 * don't have an LTK (e.g. because of key distribution bits).
2260 */
2261 if (key_pref == SMP_USE_LTK &&
2262 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) &&
2263 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role))
2264 return false;
2265
2266 if (hcon->sec_level >= sec_level)
2267 return true;
2268
2269 return false;
2270}
2271
2272static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
2273{
2274 struct smp_cmd_security_req *rp = (void *) skb->data;
2275 struct smp_cmd_pairing cp;
2276 struct hci_conn *hcon = conn->hcon;
2277 struct hci_dev *hdev = hcon->hdev;
2278 struct smp_chan *smp;
2279 u8 sec_level, auth;
2280
2281 BT_DBG("conn %p", conn);
2282
2283 if (skb->len < sizeof(*rp))
2284 return SMP_INVALID_PARAMS;
2285
2286 if (hcon->role != HCI_ROLE_MASTER)
2287 return SMP_CMD_NOTSUPP;
2288
2289 auth = rp->auth_req & AUTH_REQ_MASK(hdev);
2290
2291 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
2292 return SMP_AUTH_REQUIREMENTS;
2293
2294 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
2295 sec_level = BT_SECURITY_MEDIUM;
2296 else
2297 sec_level = authreq_to_seclevel(auth);
2298
2299 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) {
2300 /* If link is already encrypted with sufficient security we
2301 * still need refresh encryption as per Core Spec 5.0 Vol 3,
2302 * Part H 2.4.6
2303 */
2304 smp_ltk_encrypt(conn, hcon->sec_level);
2305 return 0;
2306 }
2307
2308 if (sec_level > hcon->pending_sec_level)
2309 hcon->pending_sec_level = sec_level;
2310
2311 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2312 return 0;
2313
2314 smp = smp_chan_create(conn);
2315 if (!smp)
2316 return SMP_UNSPECIFIED;
2317
2318 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) &&
2319 (auth & SMP_AUTH_BONDING))
2320 return SMP_PAIRING_NOTSUPP;
2321
2322 skb_pull(skb, sizeof(*rp));
2323
2324 memset(&cp, 0, sizeof(cp));
2325 build_pairing_cmd(conn, &cp, NULL, auth);
2326
2327 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2328 memcpy(&smp->preq[1], &cp, sizeof(cp));
2329
2330 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
2331 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2332
2333 return 0;
2334}
2335
2336int smp_conn_security(struct hci_conn *hcon, __u8 sec_level)
2337{
2338 struct l2cap_conn *conn = hcon->l2cap_data;
2339 struct l2cap_chan *chan;
2340 struct smp_chan *smp;
2341 __u8 authreq;
2342 int ret;
2343
2344 BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level);
2345
2346 /* This may be NULL if there's an unexpected disconnection */
2347 if (!conn)
2348 return 1;
2349
2350 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED))
2351 return 1;
2352
2353 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK))
2354 return 1;
2355
2356 if (sec_level > hcon->pending_sec_level)
2357 hcon->pending_sec_level = sec_level;
2358
2359 if (hcon->role == HCI_ROLE_MASTER)
2360 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2361 return 0;
2362
2363 chan = conn->smp;
2364 if (!chan) {
2365 bt_dev_err(hcon->hdev, "security requested but not available");
2366 return 1;
2367 }
2368
2369 l2cap_chan_lock(chan);
2370
2371 /* If SMP is already in progress ignore this request */
2372 if (chan->data) {
2373 ret = 0;
2374 goto unlock;
2375 }
2376
2377 smp = smp_chan_create(conn);
2378 if (!smp) {
2379 ret = 1;
2380 goto unlock;
2381 }
2382
2383 authreq = seclevel_to_authreq(sec_level);
2384
2385 if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED)) {
2386 authreq |= SMP_AUTH_SC;
2387 if (hci_dev_test_flag(hcon->hdev, HCI_SSP_ENABLED))
2388 authreq |= SMP_AUTH_CT2;
2389 }
2390
2391 /* Require MITM if IO Capability allows or the security level
2392 * requires it.
2393 */
2394 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT ||
2395 hcon->pending_sec_level > BT_SECURITY_MEDIUM)
2396 authreq |= SMP_AUTH_MITM;
2397
2398 if (hcon->role == HCI_ROLE_MASTER) {
2399 struct smp_cmd_pairing cp;
2400
2401 build_pairing_cmd(conn, &cp, NULL, authreq);
2402 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2403 memcpy(&smp->preq[1], &cp, sizeof(cp));
2404
2405 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
2406 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2407 } else {
2408 struct smp_cmd_security_req cp;
2409 cp.auth_req = authreq;
2410 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp);
2411 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ);
2412 }
2413
2414 set_bit(SMP_FLAG_INITIATOR, &smp->flags);
2415 ret = 0;
2416
2417unlock:
2418 l2cap_chan_unlock(chan);
2419 return ret;
2420}
2421
2422void smp_cancel_pairing(struct hci_conn *hcon)
2423{
2424 struct l2cap_conn *conn = hcon->l2cap_data;
2425 struct l2cap_chan *chan;
2426 struct smp_chan *smp;
2427
2428 if (!conn)
2429 return;
2430
2431 chan = conn->smp;
2432 if (!chan)
2433 return;
2434
2435 l2cap_chan_lock(chan);
2436
2437 smp = chan->data;
2438 if (smp) {
2439 if (test_bit(SMP_FLAG_COMPLETE, &smp->flags))
2440 smp_failure(conn, 0);
2441 else
2442 smp_failure(conn, SMP_UNSPECIFIED);
2443 }
2444
2445 l2cap_chan_unlock(chan);
2446}
2447
2448static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb)
2449{
2450 struct smp_cmd_encrypt_info *rp = (void *) skb->data;
2451 struct l2cap_chan *chan = conn->smp;
2452 struct smp_chan *smp = chan->data;
2453
2454 BT_DBG("conn %p", conn);
2455
2456 if (skb->len < sizeof(*rp))
2457 return SMP_INVALID_PARAMS;
2458
2459 SMP_ALLOW_CMD(smp, SMP_CMD_MASTER_IDENT);
2460
2461 skb_pull(skb, sizeof(*rp));
2462
2463 memcpy(smp->tk, rp->ltk, sizeof(smp->tk));
2464
2465 return 0;
2466}
2467
2468static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb)
2469{
2470 struct smp_cmd_master_ident *rp = (void *) skb->data;
2471 struct l2cap_chan *chan = conn->smp;
2472 struct smp_chan *smp = chan->data;
2473 struct hci_dev *hdev = conn->hcon->hdev;
2474 struct hci_conn *hcon = conn->hcon;
2475 struct smp_ltk *ltk;
2476 u8 authenticated;
2477
2478 BT_DBG("conn %p", conn);
2479
2480 if (skb->len < sizeof(*rp))
2481 return SMP_INVALID_PARAMS;
2482
2483 /* Mark the information as received */
2484 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY;
2485
2486 if (smp->remote_key_dist & SMP_DIST_ID_KEY)
2487 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
2488 else if (smp->remote_key_dist & SMP_DIST_SIGN)
2489 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2490
2491 skb_pull(skb, sizeof(*rp));
2492
2493 authenticated = (hcon->sec_level == BT_SECURITY_HIGH);
2494 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK,
2495 authenticated, smp->tk, smp->enc_key_size,
2496 rp->ediv, rp->rand);
2497 smp->ltk = ltk;
2498 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2499 smp_distribute_keys(smp);
2500
2501 return 0;
2502}
2503
2504static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb)
2505{
2506 struct smp_cmd_ident_info *info = (void *) skb->data;
2507 struct l2cap_chan *chan = conn->smp;
2508 struct smp_chan *smp = chan->data;
2509
2510 BT_DBG("");
2511
2512 if (skb->len < sizeof(*info))
2513 return SMP_INVALID_PARAMS;
2514
2515 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO);
2516
2517 skb_pull(skb, sizeof(*info));
2518
2519 memcpy(smp->irk, info->irk, 16);
2520
2521 return 0;
2522}
2523
2524static int smp_cmd_ident_addr_info(struct l2cap_conn *conn,
2525 struct sk_buff *skb)
2526{
2527 struct smp_cmd_ident_addr_info *info = (void *) skb->data;
2528 struct l2cap_chan *chan = conn->smp;
2529 struct smp_chan *smp = chan->data;
2530 struct hci_conn *hcon = conn->hcon;
2531 bdaddr_t rpa;
2532
2533 BT_DBG("");
2534
2535 if (skb->len < sizeof(*info))
2536 return SMP_INVALID_PARAMS;
2537
2538 /* Mark the information as received */
2539 smp->remote_key_dist &= ~SMP_DIST_ID_KEY;
2540
2541 if (smp->remote_key_dist & SMP_DIST_SIGN)
2542 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2543
2544 skb_pull(skb, sizeof(*info));
2545
2546 /* Strictly speaking the Core Specification (4.1) allows sending
2547 * an empty address which would force us to rely on just the IRK
2548 * as "identity information". However, since such
2549 * implementations are not known of and in order to not over
2550 * complicate our implementation, simply pretend that we never
2551 * received an IRK for such a device.
2552 *
2553 * The Identity Address must also be a Static Random or Public
2554 * Address, which hci_is_identity_address() checks for.
2555 */
2556 if (!bacmp(&info->bdaddr, BDADDR_ANY) ||
2557 !hci_is_identity_address(&info->bdaddr, info->addr_type)) {
2558 bt_dev_err(hcon->hdev, "ignoring IRK with no identity address");
2559 goto distribute;
2560 }
2561
2562 bacpy(&smp->id_addr, &info->bdaddr);
2563 smp->id_addr_type = info->addr_type;
2564
2565 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type))
2566 bacpy(&rpa, &hcon->dst);
2567 else
2568 bacpy(&rpa, BDADDR_ANY);
2569
2570 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr,
2571 smp->id_addr_type, smp->irk, &rpa);
2572
2573distribute:
2574 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2575 smp_distribute_keys(smp);
2576
2577 return 0;
2578}
2579
2580static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb)
2581{
2582 struct smp_cmd_sign_info *rp = (void *) skb->data;
2583 struct l2cap_chan *chan = conn->smp;
2584 struct smp_chan *smp = chan->data;
2585 struct smp_csrk *csrk;
2586
2587 BT_DBG("conn %p", conn);
2588
2589 if (skb->len < sizeof(*rp))
2590 return SMP_INVALID_PARAMS;
2591
2592 /* Mark the information as received */
2593 smp->remote_key_dist &= ~SMP_DIST_SIGN;
2594
2595 skb_pull(skb, sizeof(*rp));
2596
2597 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
2598 if (csrk) {
2599 if (conn->hcon->sec_level > BT_SECURITY_MEDIUM)
2600 csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED;
2601 else
2602 csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED;
2603 memcpy(csrk->val, rp->csrk, sizeof(csrk->val));
2604 }
2605 smp->csrk = csrk;
2606 smp_distribute_keys(smp);
2607
2608 return 0;
2609}
2610
2611static u8 sc_select_method(struct smp_chan *smp)
2612{
2613 struct l2cap_conn *conn = smp->conn;
2614 struct hci_conn *hcon = conn->hcon;
2615 struct smp_cmd_pairing *local, *remote;
2616 u8 local_mitm, remote_mitm, local_io, remote_io, method;
2617
2618 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) ||
2619 test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags))
2620 return REQ_OOB;
2621
2622 /* The preq/prsp contain the raw Pairing Request/Response PDUs
2623 * which are needed as inputs to some crypto functions. To get
2624 * the "struct smp_cmd_pairing" from them we need to skip the
2625 * first byte which contains the opcode.
2626 */
2627 if (hcon->out) {
2628 local = (void *) &smp->preq[1];
2629 remote = (void *) &smp->prsp[1];
2630 } else {
2631 local = (void *) &smp->prsp[1];
2632 remote = (void *) &smp->preq[1];
2633 }
2634
2635 local_io = local->io_capability;
2636 remote_io = remote->io_capability;
2637
2638 local_mitm = (local->auth_req & SMP_AUTH_MITM);
2639 remote_mitm = (remote->auth_req & SMP_AUTH_MITM);
2640
2641 /* If either side wants MITM, look up the method from the table,
2642 * otherwise use JUST WORKS.
2643 */
2644 if (local_mitm || remote_mitm)
2645 method = get_auth_method(smp, local_io, remote_io);
2646 else
2647 method = JUST_WORKS;
2648
2649 /* Don't confirm locally initiated pairing attempts */
2650 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2651 method = JUST_WORKS;
2652
2653 return method;
2654}
2655
2656static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb)
2657{
2658 struct smp_cmd_public_key *key = (void *) skb->data;
2659 struct hci_conn *hcon = conn->hcon;
2660 struct l2cap_chan *chan = conn->smp;
2661 struct smp_chan *smp = chan->data;
2662 struct hci_dev *hdev = hcon->hdev;
2663 struct crypto_kpp *tfm_ecdh;
2664 struct smp_cmd_pairing_confirm cfm;
2665 int err;
2666
2667 BT_DBG("conn %p", conn);
2668
2669 if (skb->len < sizeof(*key))
2670 return SMP_INVALID_PARAMS;
2671
2672 memcpy(smp->remote_pk, key, 64);
2673
2674 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) {
2675 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk,
2676 smp->rr, 0, cfm.confirm_val);
2677 if (err)
2678 return SMP_UNSPECIFIED;
2679
2680 if (crypto_memneq(cfm.confirm_val, smp->pcnf, 16))
2681 return SMP_CONFIRM_FAILED;
2682 }
2683
2684 /* Non-initiating device sends its public key after receiving
2685 * the key from the initiating device.
2686 */
2687 if (!hcon->out) {
2688 err = sc_send_public_key(smp);
2689 if (err)
2690 return err;
2691 }
2692
2693 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk);
2694 SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32);
2695
2696 /* Compute the shared secret on the same crypto tfm on which the private
2697 * key was set/generated.
2698 */
2699 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) {
2700 struct smp_dev *smp_dev = chan->data;
2701
2702 tfm_ecdh = smp_dev->tfm_ecdh;
2703 } else {
2704 tfm_ecdh = smp->tfm_ecdh;
2705 }
2706
2707 if (compute_ecdh_secret(tfm_ecdh, smp->remote_pk, smp->dhkey))
2708 return SMP_UNSPECIFIED;
2709
2710 SMP_DBG("DHKey %32phN", smp->dhkey);
2711
2712 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags);
2713
2714 smp->method = sc_select_method(smp);
2715
2716 BT_DBG("%s selected method 0x%02x", hdev->name, smp->method);
2717
2718 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */
2719 if (smp->method == JUST_WORKS || smp->method == JUST_CFM)
2720 hcon->pending_sec_level = BT_SECURITY_MEDIUM;
2721 else
2722 hcon->pending_sec_level = BT_SECURITY_FIPS;
2723
2724 if (!crypto_memneq(debug_pk, smp->remote_pk, 64))
2725 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
2726
2727 if (smp->method == DSP_PASSKEY) {
2728 get_random_bytes(&hcon->passkey_notify,
2729 sizeof(hcon->passkey_notify));
2730 hcon->passkey_notify %= 1000000;
2731 hcon->passkey_entered = 0;
2732 smp->passkey_round = 0;
2733 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type,
2734 hcon->dst_type,
2735 hcon->passkey_notify,
2736 hcon->passkey_entered))
2737 return SMP_UNSPECIFIED;
2738 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2739 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY);
2740 }
2741
2742 if (smp->method == REQ_OOB) {
2743 if (hcon->out)
2744 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2745 sizeof(smp->prnd), smp->prnd);
2746
2747 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2748
2749 return 0;
2750 }
2751
2752 if (hcon->out)
2753 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2754
2755 if (smp->method == REQ_PASSKEY) {
2756 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type,
2757 hcon->dst_type))
2758 return SMP_UNSPECIFIED;
2759 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2760 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2761 return 0;
2762 }
2763
2764 /* The Initiating device waits for the non-initiating device to
2765 * send the confirm value.
2766 */
2767 if (conn->hcon->out)
2768 return 0;
2769
2770 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd,
2771 0, cfm.confirm_val);
2772 if (err)
2773 return SMP_UNSPECIFIED;
2774
2775 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
2776 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2777
2778 return 0;
2779}
2780
2781static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb)
2782{
2783 struct smp_cmd_dhkey_check *check = (void *) skb->data;
2784 struct l2cap_chan *chan = conn->smp;
2785 struct hci_conn *hcon = conn->hcon;
2786 struct smp_chan *smp = chan->data;
2787 u8 a[7], b[7], *local_addr, *remote_addr;
2788 u8 io_cap[3], r[16], e[16];
2789 int err;
2790
2791 BT_DBG("conn %p", conn);
2792
2793 if (skb->len < sizeof(*check))
2794 return SMP_INVALID_PARAMS;
2795
2796 memcpy(a, &hcon->init_addr, 6);
2797 memcpy(b, &hcon->resp_addr, 6);
2798 a[6] = hcon->init_addr_type;
2799 b[6] = hcon->resp_addr_type;
2800
2801 if (hcon->out) {
2802 local_addr = a;
2803 remote_addr = b;
2804 memcpy(io_cap, &smp->prsp[1], 3);
2805 } else {
2806 local_addr = b;
2807 remote_addr = a;
2808 memcpy(io_cap, &smp->preq[1], 3);
2809 }
2810
2811 memset(r, 0, sizeof(r));
2812
2813 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2814 put_unaligned_le32(hcon->passkey_notify, r);
2815 else if (smp->method == REQ_OOB)
2816 memcpy(r, smp->lr, 16);
2817
2818 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r,
2819 io_cap, remote_addr, local_addr, e);
2820 if (err)
2821 return SMP_UNSPECIFIED;
2822
2823 if (crypto_memneq(check->e, e, 16))
2824 return SMP_DHKEY_CHECK_FAILED;
2825
2826 if (!hcon->out) {
2827 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
2828 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags);
2829 return 0;
2830 }
2831
2832 /* Slave sends DHKey check as response to master */
2833 sc_dhkey_check(smp);
2834 }
2835
2836 sc_add_ltk(smp);
2837
2838 if (hcon->out) {
2839 hci_le_start_enc(hcon, 0, 0, smp->tk, smp->enc_key_size);
2840 hcon->enc_key_size = smp->enc_key_size;
2841 }
2842
2843 return 0;
2844}
2845
2846static int smp_cmd_keypress_notify(struct l2cap_conn *conn,
2847 struct sk_buff *skb)
2848{
2849 struct smp_cmd_keypress_notify *kp = (void *) skb->data;
2850
2851 BT_DBG("value 0x%02x", kp->value);
2852
2853 return 0;
2854}
2855
2856static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb)
2857{
2858 struct l2cap_conn *conn = chan->conn;
2859 struct hci_conn *hcon = conn->hcon;
2860 struct smp_chan *smp;
2861 __u8 code, reason;
2862 int err = 0;
2863
2864 if (skb->len < 1)
2865 return -EILSEQ;
2866
2867 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) {
2868 reason = SMP_PAIRING_NOTSUPP;
2869 goto done;
2870 }
2871
2872 code = skb->data[0];
2873 skb_pull(skb, sizeof(code));
2874
2875 smp = chan->data;
2876
2877 if (code > SMP_CMD_MAX)
2878 goto drop;
2879
2880 if (smp && !test_and_clear_bit(code, &smp->allow_cmd))
2881 goto drop;
2882
2883 /* If we don't have a context the only allowed commands are
2884 * pairing request and security request.
2885 */
2886 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ)
2887 goto drop;
2888
2889 switch (code) {
2890 case SMP_CMD_PAIRING_REQ:
2891 reason = smp_cmd_pairing_req(conn, skb);
2892 break;
2893
2894 case SMP_CMD_PAIRING_FAIL:
2895 smp_failure(conn, 0);
2896 err = -EPERM;
2897 break;
2898
2899 case SMP_CMD_PAIRING_RSP:
2900 reason = smp_cmd_pairing_rsp(conn, skb);
2901 break;
2902
2903 case SMP_CMD_SECURITY_REQ:
2904 reason = smp_cmd_security_req(conn, skb);
2905 break;
2906
2907 case SMP_CMD_PAIRING_CONFIRM:
2908 reason = smp_cmd_pairing_confirm(conn, skb);
2909 break;
2910
2911 case SMP_CMD_PAIRING_RANDOM:
2912 reason = smp_cmd_pairing_random(conn, skb);
2913 break;
2914
2915 case SMP_CMD_ENCRYPT_INFO:
2916 reason = smp_cmd_encrypt_info(conn, skb);
2917 break;
2918
2919 case SMP_CMD_MASTER_IDENT:
2920 reason = smp_cmd_master_ident(conn, skb);
2921 break;
2922
2923 case SMP_CMD_IDENT_INFO:
2924 reason = smp_cmd_ident_info(conn, skb);
2925 break;
2926
2927 case SMP_CMD_IDENT_ADDR_INFO:
2928 reason = smp_cmd_ident_addr_info(conn, skb);
2929 break;
2930
2931 case SMP_CMD_SIGN_INFO:
2932 reason = smp_cmd_sign_info(conn, skb);
2933 break;
2934
2935 case SMP_CMD_PUBLIC_KEY:
2936 reason = smp_cmd_public_key(conn, skb);
2937 break;
2938
2939 case SMP_CMD_DHKEY_CHECK:
2940 reason = smp_cmd_dhkey_check(conn, skb);
2941 break;
2942
2943 case SMP_CMD_KEYPRESS_NOTIFY:
2944 reason = smp_cmd_keypress_notify(conn, skb);
2945 break;
2946
2947 default:
2948 BT_DBG("Unknown command code 0x%2.2x", code);
2949 reason = SMP_CMD_NOTSUPP;
2950 goto done;
2951 }
2952
2953done:
2954 if (!err) {
2955 if (reason)
2956 smp_failure(conn, reason);
2957 kfree_skb(skb);
2958 }
2959
2960 return err;
2961
2962drop:
2963 bt_dev_err(hcon->hdev, "unexpected SMP command 0x%02x from %pMR",
2964 code, &hcon->dst);
2965 kfree_skb(skb);
2966 return 0;
2967}
2968
2969static void smp_teardown_cb(struct l2cap_chan *chan, int err)
2970{
2971 struct l2cap_conn *conn = chan->conn;
2972
2973 BT_DBG("chan %p", chan);
2974
2975 if (chan->data)
2976 smp_chan_destroy(conn);
2977
2978 conn->smp = NULL;
2979 l2cap_chan_put(chan);
2980}
2981
2982static void bredr_pairing(struct l2cap_chan *chan)
2983{
2984 struct l2cap_conn *conn = chan->conn;
2985 struct hci_conn *hcon = conn->hcon;
2986 struct hci_dev *hdev = hcon->hdev;
2987 struct smp_cmd_pairing req;
2988 struct smp_chan *smp;
2989
2990 BT_DBG("chan %p", chan);
2991
2992 /* Only new pairings are interesting */
2993 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags))
2994 return;
2995
2996 /* Don't bother if we're not encrypted */
2997 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
2998 return;
2999
3000 /* Only master may initiate SMP over BR/EDR */
3001 if (hcon->role != HCI_ROLE_MASTER)
3002 return;
3003
3004 /* Secure Connections support must be enabled */
3005 if (!hci_dev_test_flag(hdev, HCI_SC_ENABLED))
3006 return;
3007
3008 /* BR/EDR must use Secure Connections for SMP */
3009 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) &&
3010 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3011 return;
3012
3013 /* If our LE support is not enabled don't do anything */
3014 if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED))
3015 return;
3016
3017 /* Don't bother if remote LE support is not enabled */
3018 if (!lmp_host_le_capable(hcon))
3019 return;
3020
3021 /* Remote must support SMP fixed chan for BR/EDR */
3022 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR))
3023 return;
3024
3025 /* Don't bother if SMP is already ongoing */
3026 if (chan->data)
3027 return;
3028
3029 smp = smp_chan_create(conn);
3030 if (!smp) {
3031 bt_dev_err(hdev, "unable to create SMP context for BR/EDR");
3032 return;
3033 }
3034
3035 set_bit(SMP_FLAG_SC, &smp->flags);
3036
3037 BT_DBG("%s starting SMP over BR/EDR", hdev->name);
3038
3039 /* Prepare and send the BR/EDR SMP Pairing Request */
3040 build_bredr_pairing_cmd(smp, &req, NULL);
3041
3042 smp->preq[0] = SMP_CMD_PAIRING_REQ;
3043 memcpy(&smp->preq[1], &req, sizeof(req));
3044
3045 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(req), &req);
3046 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
3047}
3048
3049static void smp_resume_cb(struct l2cap_chan *chan)
3050{
3051 struct smp_chan *smp = chan->data;
3052 struct l2cap_conn *conn = chan->conn;
3053 struct hci_conn *hcon = conn->hcon;
3054
3055 BT_DBG("chan %p", chan);
3056
3057 if (hcon->type == ACL_LINK) {
3058 bredr_pairing(chan);
3059 return;
3060 }
3061
3062 if (!smp)
3063 return;
3064
3065 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3066 return;
3067
3068 cancel_delayed_work(&smp->security_timer);
3069
3070 smp_distribute_keys(smp);
3071}
3072
3073static void smp_ready_cb(struct l2cap_chan *chan)
3074{
3075 struct l2cap_conn *conn = chan->conn;
3076 struct hci_conn *hcon = conn->hcon;
3077
3078 BT_DBG("chan %p", chan);
3079
3080 /* No need to call l2cap_chan_hold() here since we already own
3081 * the reference taken in smp_new_conn_cb(). This is just the
3082 * first time that we tie it to a specific pointer. The code in
3083 * l2cap_core.c ensures that there's no risk this function wont
3084 * get called if smp_new_conn_cb was previously called.
3085 */
3086 conn->smp = chan;
3087
3088 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3089 bredr_pairing(chan);
3090}
3091
3092static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
3093{
3094 int err;
3095
3096 BT_DBG("chan %p", chan);
3097
3098 err = smp_sig_channel(chan, skb);
3099 if (err) {
3100 struct smp_chan *smp = chan->data;
3101
3102 if (smp)
3103 cancel_delayed_work_sync(&smp->security_timer);
3104
3105 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE);
3106 }
3107
3108 return err;
3109}
3110
3111static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan,
3112 unsigned long hdr_len,
3113 unsigned long len, int nb)
3114{
3115 struct sk_buff *skb;
3116
3117 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL);
3118 if (!skb)
3119 return ERR_PTR(-ENOMEM);
3120
3121 skb->priority = HCI_PRIO_MAX;
3122 bt_cb(skb)->l2cap.chan = chan;
3123
3124 return skb;
3125}
3126
3127static const struct l2cap_ops smp_chan_ops = {
3128 .name = "Security Manager",
3129 .ready = smp_ready_cb,
3130 .recv = smp_recv_cb,
3131 .alloc_skb = smp_alloc_skb_cb,
3132 .teardown = smp_teardown_cb,
3133 .resume = smp_resume_cb,
3134
3135 .new_connection = l2cap_chan_no_new_connection,
3136 .state_change = l2cap_chan_no_state_change,
3137 .close = l2cap_chan_no_close,
3138 .defer = l2cap_chan_no_defer,
3139 .suspend = l2cap_chan_no_suspend,
3140 .set_shutdown = l2cap_chan_no_set_shutdown,
3141 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
3142};
3143
3144static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan)
3145{
3146 struct l2cap_chan *chan;
3147
3148 BT_DBG("pchan %p", pchan);
3149
3150 chan = l2cap_chan_create();
3151 if (!chan)
3152 return NULL;
3153
3154 chan->chan_type = pchan->chan_type;
3155 chan->ops = &smp_chan_ops;
3156 chan->scid = pchan->scid;
3157 chan->dcid = chan->scid;
3158 chan->imtu = pchan->imtu;
3159 chan->omtu = pchan->omtu;
3160 chan->mode = pchan->mode;
3161
3162 /* Other L2CAP channels may request SMP routines in order to
3163 * change the security level. This means that the SMP channel
3164 * lock must be considered in its own category to avoid lockdep
3165 * warnings.
3166 */
3167 atomic_set(&chan->nesting, L2CAP_NESTING_SMP);
3168
3169 BT_DBG("created chan %p", chan);
3170
3171 return chan;
3172}
3173
3174static const struct l2cap_ops smp_root_chan_ops = {
3175 .name = "Security Manager Root",
3176 .new_connection = smp_new_conn_cb,
3177
3178 /* None of these are implemented for the root channel */
3179 .close = l2cap_chan_no_close,
3180 .alloc_skb = l2cap_chan_no_alloc_skb,
3181 .recv = l2cap_chan_no_recv,
3182 .state_change = l2cap_chan_no_state_change,
3183 .teardown = l2cap_chan_no_teardown,
3184 .ready = l2cap_chan_no_ready,
3185 .defer = l2cap_chan_no_defer,
3186 .suspend = l2cap_chan_no_suspend,
3187 .resume = l2cap_chan_no_resume,
3188 .set_shutdown = l2cap_chan_no_set_shutdown,
3189 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
3190};
3191
3192static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid)
3193{
3194 struct l2cap_chan *chan;
3195 struct smp_dev *smp;
3196 struct crypto_cipher *tfm_aes;
3197 struct crypto_shash *tfm_cmac;
3198 struct crypto_kpp *tfm_ecdh;
3199
3200 if (cid == L2CAP_CID_SMP_BREDR) {
3201 smp = NULL;
3202 goto create_chan;
3203 }
3204
3205 smp = kzalloc(sizeof(*smp), GFP_KERNEL);
3206 if (!smp)
3207 return ERR_PTR(-ENOMEM);
3208
3209 tfm_aes = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
3210 if (IS_ERR(tfm_aes)) {
3211 BT_ERR("Unable to create AES crypto context");
3212 kzfree(smp);
3213 return ERR_CAST(tfm_aes);
3214 }
3215
3216 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
3217 if (IS_ERR(tfm_cmac)) {
3218 BT_ERR("Unable to create CMAC crypto context");
3219 crypto_free_cipher(tfm_aes);
3220 kzfree(smp);
3221 return ERR_CAST(tfm_cmac);
3222 }
3223
3224 tfm_ecdh = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0);
3225 if (IS_ERR(tfm_ecdh)) {
3226 BT_ERR("Unable to create ECDH crypto context");
3227 crypto_free_shash(tfm_cmac);
3228 crypto_free_cipher(tfm_aes);
3229 kzfree(smp);
3230 return ERR_CAST(tfm_ecdh);
3231 }
3232
3233 smp->tfm_aes = tfm_aes;
3234 smp->tfm_cmac = tfm_cmac;
3235 smp->tfm_ecdh = tfm_ecdh;
3236 smp->min_key_size = SMP_MIN_ENC_KEY_SIZE;
3237 smp->max_key_size = SMP_MAX_ENC_KEY_SIZE;
3238
3239create_chan:
3240 chan = l2cap_chan_create();
3241 if (!chan) {
3242 if (smp) {
3243 crypto_free_cipher(smp->tfm_aes);
3244 crypto_free_shash(smp->tfm_cmac);
3245 crypto_free_kpp(smp->tfm_ecdh);
3246 kzfree(smp);
3247 }
3248 return ERR_PTR(-ENOMEM);
3249 }
3250
3251 chan->data = smp;
3252
3253 l2cap_add_scid(chan, cid);
3254
3255 l2cap_chan_set_defaults(chan);
3256
3257 if (cid == L2CAP_CID_SMP) {
3258 u8 bdaddr_type;
3259
3260 hci_copy_identity_address(hdev, &chan->src, &bdaddr_type);
3261
3262 if (bdaddr_type == ADDR_LE_DEV_PUBLIC)
3263 chan->src_type = BDADDR_LE_PUBLIC;
3264 else
3265 chan->src_type = BDADDR_LE_RANDOM;
3266 } else {
3267 bacpy(&chan->src, &hdev->bdaddr);
3268 chan->src_type = BDADDR_BREDR;
3269 }
3270
3271 chan->state = BT_LISTEN;
3272 chan->mode = L2CAP_MODE_BASIC;
3273 chan->imtu = L2CAP_DEFAULT_MTU;
3274 chan->ops = &smp_root_chan_ops;
3275
3276 /* Set correct nesting level for a parent/listening channel */
3277 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
3278
3279 return chan;
3280}
3281
3282static void smp_del_chan(struct l2cap_chan *chan)
3283{
3284 struct smp_dev *smp;
3285
3286 BT_DBG("chan %p", chan);
3287
3288 smp = chan->data;
3289 if (smp) {
3290 chan->data = NULL;
3291 crypto_free_cipher(smp->tfm_aes);
3292 crypto_free_shash(smp->tfm_cmac);
3293 crypto_free_kpp(smp->tfm_ecdh);
3294 kzfree(smp);
3295 }
3296
3297 l2cap_chan_put(chan);
3298}
3299
3300static ssize_t force_bredr_smp_read(struct file *file,
3301 char __user *user_buf,
3302 size_t count, loff_t *ppos)
3303{
3304 struct hci_dev *hdev = file->private_data;
3305 char buf[3];
3306
3307 buf[0] = hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP) ? 'Y': 'N';
3308 buf[1] = '\n';
3309 buf[2] = '\0';
3310 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
3311}
3312
3313static ssize_t force_bredr_smp_write(struct file *file,
3314 const char __user *user_buf,
3315 size_t count, loff_t *ppos)
3316{
3317 struct hci_dev *hdev = file->private_data;
3318 char buf[32];
3319 size_t buf_size = min(count, (sizeof(buf)-1));
3320 bool enable;
3321
3322 if (copy_from_user(buf, user_buf, buf_size))
3323 return -EFAULT;
3324
3325 buf[buf_size] = '\0';
3326 if (strtobool(buf, &enable))
3327 return -EINVAL;
3328
3329 if (enable == hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3330 return -EALREADY;
3331
3332 if (enable) {
3333 struct l2cap_chan *chan;
3334
3335 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
3336 if (IS_ERR(chan))
3337 return PTR_ERR(chan);
3338
3339 hdev->smp_bredr_data = chan;
3340 } else {
3341 struct l2cap_chan *chan;
3342
3343 chan = hdev->smp_bredr_data;
3344 hdev->smp_bredr_data = NULL;
3345 smp_del_chan(chan);
3346 }
3347
3348 hci_dev_change_flag(hdev, HCI_FORCE_BREDR_SMP);
3349
3350 return count;
3351}
3352
3353static const struct file_operations force_bredr_smp_fops = {
3354 .open = simple_open,
3355 .read = force_bredr_smp_read,
3356 .write = force_bredr_smp_write,
3357 .llseek = default_llseek,
3358};
3359
3360static ssize_t le_min_key_size_read(struct file *file,
3361 char __user *user_buf,
3362 size_t count, loff_t *ppos)
3363{
3364 struct hci_dev *hdev = file->private_data;
3365 char buf[4];
3366
3367 snprintf(buf, sizeof(buf), "%2u\n", SMP_DEV(hdev)->min_key_size);
3368
3369 return simple_read_from_buffer(user_buf, count, ppos, buf, strlen(buf));
3370}
3371
3372static ssize_t le_min_key_size_write(struct file *file,
3373 const char __user *user_buf,
3374 size_t count, loff_t *ppos)
3375{
3376 struct hci_dev *hdev = file->private_data;
3377 char buf[32];
3378 size_t buf_size = min(count, (sizeof(buf) - 1));
3379 u8 key_size;
3380
3381 if (copy_from_user(buf, user_buf, buf_size))
3382 return -EFAULT;
3383
3384 buf[buf_size] = '\0';
3385
3386 sscanf(buf, "%hhu", &key_size);
3387
3388 if (key_size > SMP_DEV(hdev)->max_key_size ||
3389 key_size < SMP_MIN_ENC_KEY_SIZE)
3390 return -EINVAL;
3391
3392 SMP_DEV(hdev)->min_key_size = key_size;
3393
3394 return count;
3395}
3396
3397static const struct file_operations le_min_key_size_fops = {
3398 .open = simple_open,
3399 .read = le_min_key_size_read,
3400 .write = le_min_key_size_write,
3401 .llseek = default_llseek,
3402};
3403
3404static ssize_t le_max_key_size_read(struct file *file,
3405 char __user *user_buf,
3406 size_t count, loff_t *ppos)
3407{
3408 struct hci_dev *hdev = file->private_data;
3409 char buf[4];
3410
3411 snprintf(buf, sizeof(buf), "%2u\n", SMP_DEV(hdev)->max_key_size);
3412
3413 return simple_read_from_buffer(user_buf, count, ppos, buf, strlen(buf));
3414}
3415
3416static ssize_t le_max_key_size_write(struct file *file,
3417 const char __user *user_buf,
3418 size_t count, loff_t *ppos)
3419{
3420 struct hci_dev *hdev = file->private_data;
3421 char buf[32];
3422 size_t buf_size = min(count, (sizeof(buf) - 1));
3423 u8 key_size;
3424
3425 if (copy_from_user(buf, user_buf, buf_size))
3426 return -EFAULT;
3427
3428 buf[buf_size] = '\0';
3429
3430 sscanf(buf, "%hhu", &key_size);
3431
3432 if (key_size > SMP_MAX_ENC_KEY_SIZE ||
3433 key_size < SMP_DEV(hdev)->min_key_size)
3434 return -EINVAL;
3435
3436 SMP_DEV(hdev)->max_key_size = key_size;
3437
3438 return count;
3439}
3440
3441static const struct file_operations le_max_key_size_fops = {
3442 .open = simple_open,
3443 .read = le_max_key_size_read,
3444 .write = le_max_key_size_write,
3445 .llseek = default_llseek,
3446};
3447
3448int smp_register(struct hci_dev *hdev)
3449{
3450 struct l2cap_chan *chan;
3451
3452 BT_DBG("%s", hdev->name);
3453
3454 /* If the controller does not support Low Energy operation, then
3455 * there is also no need to register any SMP channel.
3456 */
3457 if (!lmp_le_capable(hdev))
3458 return 0;
3459
3460 if (WARN_ON(hdev->smp_data)) {
3461 chan = hdev->smp_data;
3462 hdev->smp_data = NULL;
3463 smp_del_chan(chan);
3464 }
3465
3466 chan = smp_add_cid(hdev, L2CAP_CID_SMP);
3467 if (IS_ERR(chan))
3468 return PTR_ERR(chan);
3469
3470 hdev->smp_data = chan;
3471
3472 debugfs_create_file("le_min_key_size", 0644, hdev->debugfs, hdev,
3473 &le_min_key_size_fops);
3474 debugfs_create_file("le_max_key_size", 0644, hdev->debugfs, hdev,
3475 &le_max_key_size_fops);
3476
3477 /* If the controller does not support BR/EDR Secure Connections
3478 * feature, then the BR/EDR SMP channel shall not be present.
3479 *
3480 * To test this with Bluetooth 4.0 controllers, create a debugfs
3481 * switch that allows forcing BR/EDR SMP support and accepting
3482 * cross-transport pairing on non-AES encrypted connections.
3483 */
3484 if (!lmp_sc_capable(hdev)) {
3485 debugfs_create_file("force_bredr_smp", 0644, hdev->debugfs,
3486 hdev, &force_bredr_smp_fops);
3487
3488 /* Flag can be already set here (due to power toggle) */
3489 if (!hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3490 return 0;
3491 }
3492
3493 if (WARN_ON(hdev->smp_bredr_data)) {
3494 chan = hdev->smp_bredr_data;
3495 hdev->smp_bredr_data = NULL;
3496 smp_del_chan(chan);
3497 }
3498
3499 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
3500 if (IS_ERR(chan)) {
3501 int err = PTR_ERR(chan);
3502 chan = hdev->smp_data;
3503 hdev->smp_data = NULL;
3504 smp_del_chan(chan);
3505 return err;
3506 }
3507
3508 hdev->smp_bredr_data = chan;
3509
3510 return 0;
3511}
3512
3513void smp_unregister(struct hci_dev *hdev)
3514{
3515 struct l2cap_chan *chan;
3516
3517 if (hdev->smp_bredr_data) {
3518 chan = hdev->smp_bredr_data;
3519 hdev->smp_bredr_data = NULL;
3520 smp_del_chan(chan);
3521 }
3522
3523 if (hdev->smp_data) {
3524 chan = hdev->smp_data;
3525 hdev->smp_data = NULL;
3526 smp_del_chan(chan);
3527 }
3528}
3529
3530#if IS_ENABLED(CONFIG_BT_SELFTEST_SMP)
3531
3532static int __init test_debug_key(struct crypto_kpp *tfm_ecdh)
3533{
3534 u8 pk[64];
3535 int err;
3536
3537 err = set_ecdh_privkey(tfm_ecdh, debug_sk);
3538 if (err)
3539 return err;
3540
3541 err = generate_ecdh_public_key(tfm_ecdh, pk);
3542 if (err)
3543 return err;
3544
3545 if (crypto_memneq(pk, debug_pk, 64))
3546 return -EINVAL;
3547
3548 return 0;
3549}
3550
3551static int __init test_ah(struct crypto_cipher *tfm_aes)
3552{
3553 const u8 irk[16] = {
3554 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3555 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3556 const u8 r[3] = { 0x94, 0x81, 0x70 };
3557 const u8 exp[3] = { 0xaa, 0xfb, 0x0d };
3558 u8 res[3];
3559 int err;
3560
3561 err = smp_ah(tfm_aes, irk, r, res);
3562 if (err)
3563 return err;
3564
3565 if (crypto_memneq(res, exp, 3))
3566 return -EINVAL;
3567
3568 return 0;
3569}
3570
3571static int __init test_c1(struct crypto_cipher *tfm_aes)
3572{
3573 const u8 k[16] = {
3574 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
3575 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
3576 const u8 r[16] = {
3577 0xe0, 0x2e, 0x70, 0xc6, 0x4e, 0x27, 0x88, 0x63,
3578 0x0e, 0x6f, 0xad, 0x56, 0x21, 0xd5, 0x83, 0x57 };
3579 const u8 preq[7] = { 0x01, 0x01, 0x00, 0x00, 0x10, 0x07, 0x07 };
3580 const u8 pres[7] = { 0x02, 0x03, 0x00, 0x00, 0x08, 0x00, 0x05 };
3581 const u8 _iat = 0x01;
3582 const u8 _rat = 0x00;
3583 const bdaddr_t ra = { { 0xb6, 0xb5, 0xb4, 0xb3, 0xb2, 0xb1 } };
3584 const bdaddr_t ia = { { 0xa6, 0xa5, 0xa4, 0xa3, 0xa2, 0xa1 } };
3585 const u8 exp[16] = {
3586 0x86, 0x3b, 0xf1, 0xbe, 0xc5, 0x4d, 0xa7, 0xd2,
3587 0xea, 0x88, 0x89, 0x87, 0xef, 0x3f, 0x1e, 0x1e };
3588 u8 res[16];
3589 int err;
3590
3591 err = smp_c1(tfm_aes, k, r, preq, pres, _iat, &ia, _rat, &ra, res);
3592 if (err)
3593 return err;
3594
3595 if (crypto_memneq(res, exp, 16))
3596 return -EINVAL;
3597
3598 return 0;
3599}
3600
3601static int __init test_s1(struct crypto_cipher *tfm_aes)
3602{
3603 const u8 k[16] = {
3604 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
3605 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
3606 const u8 r1[16] = {
3607 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 };
3608 const u8 r2[16] = {
3609 0x00, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99 };
3610 const u8 exp[16] = {
3611 0x62, 0xa0, 0x6d, 0x79, 0xae, 0x16, 0x42, 0x5b,
3612 0x9b, 0xf4, 0xb0, 0xe8, 0xf0, 0xe1, 0x1f, 0x9a };
3613 u8 res[16];
3614 int err;
3615
3616 err = smp_s1(tfm_aes, k, r1, r2, res);
3617 if (err)
3618 return err;
3619
3620 if (crypto_memneq(res, exp, 16))
3621 return -EINVAL;
3622
3623 return 0;
3624}
3625
3626static int __init test_f4(struct crypto_shash *tfm_cmac)
3627{
3628 const u8 u[32] = {
3629 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
3630 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
3631 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
3632 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 };
3633 const u8 v[32] = {
3634 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b,
3635 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59,
3636 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90,
3637 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 };
3638 const u8 x[16] = {
3639 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3640 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3641 const u8 z = 0x00;
3642 const u8 exp[16] = {
3643 0x2d, 0x87, 0x74, 0xa9, 0xbe, 0xa1, 0xed, 0xf1,
3644 0x1c, 0xbd, 0xa9, 0x07, 0xf1, 0x16, 0xc9, 0xf2 };
3645 u8 res[16];
3646 int err;
3647
3648 err = smp_f4(tfm_cmac, u, v, x, z, res);
3649 if (err)
3650 return err;
3651
3652 if (crypto_memneq(res, exp, 16))
3653 return -EINVAL;
3654
3655 return 0;
3656}
3657
3658static int __init test_f5(struct crypto_shash *tfm_cmac)
3659{
3660 const u8 w[32] = {
3661 0x98, 0xa6, 0xbf, 0x73, 0xf3, 0x34, 0x8d, 0x86,
3662 0xf1, 0x66, 0xf8, 0xb4, 0x13, 0x6b, 0x79, 0x99,
3663 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3664 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3665 const u8 n1[16] = {
3666 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3667 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3668 const u8 n2[16] = {
3669 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3670 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3671 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 };
3672 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 };
3673 const u8 exp_ltk[16] = {
3674 0x38, 0x0a, 0x75, 0x94, 0xb5, 0x22, 0x05, 0x98,
3675 0x23, 0xcd, 0xd7, 0x69, 0x11, 0x79, 0x86, 0x69 };
3676 const u8 exp_mackey[16] = {
3677 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd,
3678 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 };
3679 u8 mackey[16], ltk[16];
3680 int err;
3681
3682 err = smp_f5(tfm_cmac, w, n1, n2, a1, a2, mackey, ltk);
3683 if (err)
3684 return err;
3685
3686 if (crypto_memneq(mackey, exp_mackey, 16))
3687 return -EINVAL;
3688
3689 if (crypto_memneq(ltk, exp_ltk, 16))
3690 return -EINVAL;
3691
3692 return 0;
3693}
3694
3695static int __init test_f6(struct crypto_shash *tfm_cmac)
3696{
3697 const u8 w[16] = {
3698 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd,
3699 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 };
3700 const u8 n1[16] = {
3701 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3702 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3703 const u8 n2[16] = {
3704 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3705 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3706 const u8 r[16] = {
3707 0xc8, 0x0f, 0x2d, 0x0c, 0xd2, 0x42, 0xda, 0x08,
3708 0x54, 0xbb, 0x53, 0xb4, 0x3b, 0x34, 0xa3, 0x12 };
3709 const u8 io_cap[3] = { 0x02, 0x01, 0x01 };
3710 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 };
3711 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 };
3712 const u8 exp[16] = {
3713 0x61, 0x8f, 0x95, 0xda, 0x09, 0x0b, 0x6c, 0xd2,
3714 0xc5, 0xe8, 0xd0, 0x9c, 0x98, 0x73, 0xc4, 0xe3 };
3715 u8 res[16];
3716 int err;
3717
3718 err = smp_f6(tfm_cmac, w, n1, n2, r, io_cap, a1, a2, res);
3719 if (err)
3720 return err;
3721
3722 if (crypto_memneq(res, exp, 16))
3723 return -EINVAL;
3724
3725 return 0;
3726}
3727
3728static int __init test_g2(struct crypto_shash *tfm_cmac)
3729{
3730 const u8 u[32] = {
3731 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
3732 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
3733 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
3734 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 };
3735 const u8 v[32] = {
3736 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b,
3737 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59,
3738 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90,
3739 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 };
3740 const u8 x[16] = {
3741 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3742 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3743 const u8 y[16] = {
3744 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3745 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3746 const u32 exp_val = 0x2f9ed5ba % 1000000;
3747 u32 val;
3748 int err;
3749
3750 err = smp_g2(tfm_cmac, u, v, x, y, &val);
3751 if (err)
3752 return err;
3753
3754 if (val != exp_val)
3755 return -EINVAL;
3756
3757 return 0;
3758}
3759
3760static int __init test_h6(struct crypto_shash *tfm_cmac)
3761{
3762 const u8 w[16] = {
3763 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3764 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3765 const u8 key_id[4] = { 0x72, 0x62, 0x65, 0x6c };
3766 const u8 exp[16] = {
3767 0x99, 0x63, 0xb1, 0x80, 0xe2, 0xa9, 0xd3, 0xe8,
3768 0x1c, 0xc9, 0x6d, 0xe7, 0x02, 0xe1, 0x9a, 0x2d };
3769 u8 res[16];
3770 int err;
3771
3772 err = smp_h6(tfm_cmac, w, key_id, res);
3773 if (err)
3774 return err;
3775
3776 if (crypto_memneq(res, exp, 16))
3777 return -EINVAL;
3778
3779 return 0;
3780}
3781
3782static char test_smp_buffer[32];
3783
3784static ssize_t test_smp_read(struct file *file, char __user *user_buf,
3785 size_t count, loff_t *ppos)
3786{
3787 return simple_read_from_buffer(user_buf, count, ppos, test_smp_buffer,
3788 strlen(test_smp_buffer));
3789}
3790
3791static const struct file_operations test_smp_fops = {
3792 .open = simple_open,
3793 .read = test_smp_read,
3794 .llseek = default_llseek,
3795};
3796
3797static int __init run_selftests(struct crypto_cipher *tfm_aes,
3798 struct crypto_shash *tfm_cmac,
3799 struct crypto_kpp *tfm_ecdh)
3800{
3801 ktime_t calltime, delta, rettime;
3802 unsigned long long duration;
3803 int err;
3804
3805 calltime = ktime_get();
3806
3807 err = test_debug_key(tfm_ecdh);
3808 if (err) {
3809 BT_ERR("debug_key test failed");
3810 goto done;
3811 }
3812
3813 err = test_ah(tfm_aes);
3814 if (err) {
3815 BT_ERR("smp_ah test failed");
3816 goto done;
3817 }
3818
3819 err = test_c1(tfm_aes);
3820 if (err) {
3821 BT_ERR("smp_c1 test failed");
3822 goto done;
3823 }
3824
3825 err = test_s1(tfm_aes);
3826 if (err) {
3827 BT_ERR("smp_s1 test failed");
3828 goto done;
3829 }
3830
3831 err = test_f4(tfm_cmac);
3832 if (err) {
3833 BT_ERR("smp_f4 test failed");
3834 goto done;
3835 }
3836
3837 err = test_f5(tfm_cmac);
3838 if (err) {
3839 BT_ERR("smp_f5 test failed");
3840 goto done;
3841 }
3842
3843 err = test_f6(tfm_cmac);
3844 if (err) {
3845 BT_ERR("smp_f6 test failed");
3846 goto done;
3847 }
3848
3849 err = test_g2(tfm_cmac);
3850 if (err) {
3851 BT_ERR("smp_g2 test failed");
3852 goto done;
3853 }
3854
3855 err = test_h6(tfm_cmac);
3856 if (err) {
3857 BT_ERR("smp_h6 test failed");
3858 goto done;
3859 }
3860
3861 rettime = ktime_get();
3862 delta = ktime_sub(rettime, calltime);
3863 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
3864
3865 BT_INFO("SMP test passed in %llu usecs", duration);
3866
3867done:
3868 if (!err)
3869 snprintf(test_smp_buffer, sizeof(test_smp_buffer),
3870 "PASS (%llu usecs)\n", duration);
3871 else
3872 snprintf(test_smp_buffer, sizeof(test_smp_buffer), "FAIL\n");
3873
3874 debugfs_create_file("selftest_smp", 0444, bt_debugfs, NULL,
3875 &test_smp_fops);
3876
3877 return err;
3878}
3879
3880int __init bt_selftest_smp(void)
3881{
3882 struct crypto_cipher *tfm_aes;
3883 struct crypto_shash *tfm_cmac;
3884 struct crypto_kpp *tfm_ecdh;
3885 int err;
3886
3887 tfm_aes = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
3888 if (IS_ERR(tfm_aes)) {
3889 BT_ERR("Unable to create AES crypto context");
3890 return PTR_ERR(tfm_aes);
3891 }
3892
3893 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, CRYPTO_ALG_ASYNC);
3894 if (IS_ERR(tfm_cmac)) {
3895 BT_ERR("Unable to create CMAC crypto context");
3896 crypto_free_cipher(tfm_aes);
3897 return PTR_ERR(tfm_cmac);
3898 }
3899
3900 tfm_ecdh = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0);
3901 if (IS_ERR(tfm_ecdh)) {
3902 BT_ERR("Unable to create ECDH crypto context");
3903 crypto_free_shash(tfm_cmac);
3904 crypto_free_cipher(tfm_aes);
3905 return PTR_ERR(tfm_ecdh);
3906 }
3907
3908 err = run_selftests(tfm_aes, tfm_cmac, tfm_ecdh);
3909
3910 crypto_free_shash(tfm_cmac);
3911 crypto_free_cipher(tfm_aes);
3912 crypto_free_kpp(tfm_ecdh);
3913
3914 return err;
3915}
3916
3917#endif