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