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