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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/crypto.h>
24#include <linux/scatterlist.h>
25#include <crypto/b128ops.h>
26
27#include <net/bluetooth/bluetooth.h>
28#include <net/bluetooth/hci_core.h>
29#include <net/bluetooth/l2cap.h>
30#include <net/bluetooth/mgmt.h>
31
32#include "smp.h"
33
34#define SMP_TIMEOUT msecs_to_jiffies(30000)
35
36#define AUTH_REQ_MASK 0x07
37
38static inline void swap128(const u8 src[16], u8 dst[16])
39{
40 int i;
41 for (i = 0; i < 16; i++)
42 dst[15 - i] = src[i];
43}
44
45static inline void swap56(const u8 src[7], u8 dst[7])
46{
47 int i;
48 for (i = 0; i < 7; i++)
49 dst[6 - i] = src[i];
50}
51
52static int smp_e(struct crypto_blkcipher *tfm, const u8 *k, u8 *r)
53{
54 struct blkcipher_desc desc;
55 struct scatterlist sg;
56 uint8_t tmp[16], data[16];
57 int err;
58
59 if (tfm == NULL) {
60 BT_ERR("tfm %p", tfm);
61 return -EINVAL;
62 }
63
64 desc.tfm = tfm;
65 desc.flags = 0;
66
67 /* The most significant octet of key corresponds to k[0] */
68 swap128(k, tmp);
69
70 err = crypto_blkcipher_setkey(tfm, tmp, 16);
71 if (err) {
72 BT_ERR("cipher setkey failed: %d", err);
73 return err;
74 }
75
76 /* Most significant octet of plaintextData corresponds to data[0] */
77 swap128(r, data);
78
79 sg_init_one(&sg, data, 16);
80
81 err = crypto_blkcipher_encrypt(&desc, &sg, &sg, 16);
82 if (err)
83 BT_ERR("Encrypt data error %d", err);
84
85 /* Most significant octet of encryptedData corresponds to data[0] */
86 swap128(data, r);
87
88 return err;
89}
90
91static int smp_ah(struct crypto_blkcipher *tfm, u8 irk[16], u8 r[3], u8 res[3])
92{
93 u8 _res[16];
94 int err;
95
96 /* r' = padding || r */
97 memcpy(_res, r, 3);
98 memset(_res + 3, 0, 13);
99
100 err = smp_e(tfm, irk, _res);
101 if (err) {
102 BT_ERR("Encrypt error");
103 return err;
104 }
105
106 /* The output of the random address function ah is:
107 * ah(h, r) = e(k, r') mod 2^24
108 * The output of the security function e is then truncated to 24 bits
109 * by taking the least significant 24 bits of the output of e as the
110 * result of ah.
111 */
112 memcpy(res, _res, 3);
113
114 return 0;
115}
116
117bool smp_irk_matches(struct crypto_blkcipher *tfm, u8 irk[16],
118 bdaddr_t *bdaddr)
119{
120 u8 hash[3];
121 int err;
122
123 BT_DBG("RPA %pMR IRK %*phN", bdaddr, 16, irk);
124
125 err = smp_ah(tfm, irk, &bdaddr->b[3], hash);
126 if (err)
127 return false;
128
129 return !memcmp(bdaddr->b, hash, 3);
130}
131
132int smp_generate_rpa(struct crypto_blkcipher *tfm, u8 irk[16], bdaddr_t *rpa)
133{
134 int err;
135
136 get_random_bytes(&rpa->b[3], 3);
137
138 rpa->b[5] &= 0x3f; /* Clear two most significant bits */
139 rpa->b[5] |= 0x40; /* Set second most significant bit */
140
141 err = smp_ah(tfm, irk, &rpa->b[3], rpa->b);
142 if (err < 0)
143 return err;
144
145 BT_DBG("RPA %pMR", rpa);
146
147 return 0;
148}
149
150static int smp_c1(struct crypto_blkcipher *tfm, u8 k[16], u8 r[16],
151 u8 preq[7], u8 pres[7], u8 _iat, bdaddr_t *ia,
152 u8 _rat, bdaddr_t *ra, u8 res[16])
153{
154 u8 p1[16], p2[16];
155 int err;
156
157 memset(p1, 0, 16);
158
159 /* p1 = pres || preq || _rat || _iat */
160 p1[0] = _iat;
161 p1[1] = _rat;
162 memcpy(p1 + 2, preq, 7);
163 memcpy(p1 + 9, pres, 7);
164
165 /* p2 = padding || ia || ra */
166 memcpy(p2, ra, 6);
167 memcpy(p2 + 6, ia, 6);
168 memset(p2 + 12, 0, 4);
169
170 /* res = r XOR p1 */
171 u128_xor((u128 *) res, (u128 *) r, (u128 *) p1);
172
173 /* res = e(k, res) */
174 err = smp_e(tfm, k, res);
175 if (err) {
176 BT_ERR("Encrypt data error");
177 return err;
178 }
179
180 /* res = res XOR p2 */
181 u128_xor((u128 *) res, (u128 *) res, (u128 *) p2);
182
183 /* res = e(k, res) */
184 err = smp_e(tfm, k, res);
185 if (err)
186 BT_ERR("Encrypt data error");
187
188 return err;
189}
190
191static int smp_s1(struct crypto_blkcipher *tfm, u8 k[16], u8 r1[16],
192 u8 r2[16], u8 _r[16])
193{
194 int err;
195
196 /* Just least significant octets from r1 and r2 are considered */
197 memcpy(_r, r2, 8);
198 memcpy(_r + 8, r1, 8);
199
200 err = smp_e(tfm, k, _r);
201 if (err)
202 BT_ERR("Encrypt data error");
203
204 return err;
205}
206
207static struct sk_buff *smp_build_cmd(struct l2cap_conn *conn, u8 code,
208 u16 dlen, void *data)
209{
210 struct sk_buff *skb;
211 struct l2cap_hdr *lh;
212 int len;
213
214 len = L2CAP_HDR_SIZE + sizeof(code) + dlen;
215
216 if (len > conn->mtu)
217 return NULL;
218
219 skb = bt_skb_alloc(len, GFP_ATOMIC);
220 if (!skb)
221 return NULL;
222
223 lh = (struct l2cap_hdr *) skb_put(skb, L2CAP_HDR_SIZE);
224 lh->len = cpu_to_le16(sizeof(code) + dlen);
225 lh->cid = cpu_to_le16(L2CAP_CID_SMP);
226
227 memcpy(skb_put(skb, sizeof(code)), &code, sizeof(code));
228
229 memcpy(skb_put(skb, dlen), data, dlen);
230
231 return skb;
232}
233
234static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
235{
236 struct sk_buff *skb = smp_build_cmd(conn, code, len, data);
237
238 BT_DBG("code 0x%2.2x", code);
239
240 if (!skb)
241 return;
242
243 skb->priority = HCI_PRIO_MAX;
244 hci_send_acl(conn->hchan, skb, 0);
245
246 cancel_delayed_work_sync(&conn->security_timer);
247 schedule_delayed_work(&conn->security_timer, SMP_TIMEOUT);
248}
249
250static __u8 authreq_to_seclevel(__u8 authreq)
251{
252 if (authreq & SMP_AUTH_MITM)
253 return BT_SECURITY_HIGH;
254 else
255 return BT_SECURITY_MEDIUM;
256}
257
258static __u8 seclevel_to_authreq(__u8 sec_level)
259{
260 switch (sec_level) {
261 case BT_SECURITY_HIGH:
262 return SMP_AUTH_MITM | SMP_AUTH_BONDING;
263 case BT_SECURITY_MEDIUM:
264 return SMP_AUTH_BONDING;
265 default:
266 return SMP_AUTH_NONE;
267 }
268}
269
270static void build_pairing_cmd(struct l2cap_conn *conn,
271 struct smp_cmd_pairing *req,
272 struct smp_cmd_pairing *rsp, __u8 authreq)
273{
274 struct smp_chan *smp = conn->smp_chan;
275 struct hci_conn *hcon = conn->hcon;
276 struct hci_dev *hdev = hcon->hdev;
277 u8 local_dist = 0, remote_dist = 0;
278
279 if (test_bit(HCI_PAIRABLE, &conn->hcon->hdev->dev_flags)) {
280 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
281 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
282 authreq |= SMP_AUTH_BONDING;
283 } else {
284 authreq &= ~SMP_AUTH_BONDING;
285 }
286
287 if (test_bit(HCI_RPA_RESOLVING, &hdev->dev_flags))
288 remote_dist |= SMP_DIST_ID_KEY;
289
290 if (test_bit(HCI_PRIVACY, &hdev->dev_flags))
291 local_dist |= SMP_DIST_ID_KEY;
292
293 if (rsp == NULL) {
294 req->io_capability = conn->hcon->io_capability;
295 req->oob_flag = SMP_OOB_NOT_PRESENT;
296 req->max_key_size = SMP_MAX_ENC_KEY_SIZE;
297 req->init_key_dist = local_dist;
298 req->resp_key_dist = remote_dist;
299 req->auth_req = (authreq & AUTH_REQ_MASK);
300
301 smp->remote_key_dist = remote_dist;
302 return;
303 }
304
305 rsp->io_capability = conn->hcon->io_capability;
306 rsp->oob_flag = SMP_OOB_NOT_PRESENT;
307 rsp->max_key_size = SMP_MAX_ENC_KEY_SIZE;
308 rsp->init_key_dist = req->init_key_dist & remote_dist;
309 rsp->resp_key_dist = req->resp_key_dist & local_dist;
310 rsp->auth_req = (authreq & AUTH_REQ_MASK);
311
312 smp->remote_key_dist = rsp->init_key_dist;
313}
314
315static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)
316{
317 struct smp_chan *smp = conn->smp_chan;
318
319 if ((max_key_size > SMP_MAX_ENC_KEY_SIZE) ||
320 (max_key_size < SMP_MIN_ENC_KEY_SIZE))
321 return SMP_ENC_KEY_SIZE;
322
323 smp->enc_key_size = max_key_size;
324
325 return 0;
326}
327
328static void smp_failure(struct l2cap_conn *conn, u8 reason)
329{
330 struct hci_conn *hcon = conn->hcon;
331
332 if (reason)
333 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
334 &reason);
335
336 clear_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags);
337 mgmt_auth_failed(hcon->hdev, &hcon->dst, hcon->type, hcon->dst_type,
338 HCI_ERROR_AUTH_FAILURE);
339
340 cancel_delayed_work_sync(&conn->security_timer);
341
342 if (test_and_clear_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags))
343 smp_chan_destroy(conn);
344}
345
346#define JUST_WORKS 0x00
347#define JUST_CFM 0x01
348#define REQ_PASSKEY 0x02
349#define CFM_PASSKEY 0x03
350#define REQ_OOB 0x04
351#define OVERLAP 0xFF
352
353static const u8 gen_method[5][5] = {
354 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
355 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
356 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
357 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
358 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP },
359};
360
361static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth,
362 u8 local_io, u8 remote_io)
363{
364 struct hci_conn *hcon = conn->hcon;
365 struct smp_chan *smp = conn->smp_chan;
366 u8 method;
367 u32 passkey = 0;
368 int ret = 0;
369
370 /* Initialize key for JUST WORKS */
371 memset(smp->tk, 0, sizeof(smp->tk));
372 clear_bit(SMP_FLAG_TK_VALID, &smp->smp_flags);
373
374 BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io);
375
376 /* If neither side wants MITM, use JUST WORKS */
377 /* If either side has unknown io_caps, use JUST WORKS */
378 /* Otherwise, look up method from the table */
379 if (!(auth & SMP_AUTH_MITM) ||
380 local_io > SMP_IO_KEYBOARD_DISPLAY ||
381 remote_io > SMP_IO_KEYBOARD_DISPLAY)
382 method = JUST_WORKS;
383 else
384 method = gen_method[remote_io][local_io];
385
386 /* If not bonding, don't ask user to confirm a Zero TK */
387 if (!(auth & SMP_AUTH_BONDING) && method == JUST_CFM)
388 method = JUST_WORKS;
389
390 /* Don't confirm locally initiated pairing attempts */
391 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR,
392 &smp->smp_flags))
393 method = JUST_WORKS;
394
395 /* If Just Works, Continue with Zero TK */
396 if (method == JUST_WORKS) {
397 set_bit(SMP_FLAG_TK_VALID, &smp->smp_flags);
398 return 0;
399 }
400
401 /* Not Just Works/Confirm results in MITM Authentication */
402 if (method != JUST_CFM)
403 set_bit(SMP_FLAG_MITM_AUTH, &smp->smp_flags);
404
405 /* If both devices have Keyoard-Display I/O, the master
406 * Confirms and the slave Enters the passkey.
407 */
408 if (method == OVERLAP) {
409 if (hcon->link_mode & HCI_LM_MASTER)
410 method = CFM_PASSKEY;
411 else
412 method = REQ_PASSKEY;
413 }
414
415 /* Generate random passkey. */
416 if (method == CFM_PASSKEY) {
417 memset(smp->tk, 0, sizeof(smp->tk));
418 get_random_bytes(&passkey, sizeof(passkey));
419 passkey %= 1000000;
420 put_unaligned_le32(passkey, smp->tk);
421 BT_DBG("PassKey: %d", passkey);
422 set_bit(SMP_FLAG_TK_VALID, &smp->smp_flags);
423 }
424
425 hci_dev_lock(hcon->hdev);
426
427 if (method == REQ_PASSKEY)
428 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst,
429 hcon->type, hcon->dst_type);
430 else if (method == JUST_CFM)
431 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
432 hcon->type, hcon->dst_type,
433 passkey, 1);
434 else
435 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst,
436 hcon->type, hcon->dst_type,
437 passkey, 0);
438
439 hci_dev_unlock(hcon->hdev);
440
441 return ret;
442}
443
444static void confirm_work(struct work_struct *work)
445{
446 struct smp_chan *smp = container_of(work, struct smp_chan, confirm);
447 struct l2cap_conn *conn = smp->conn;
448 struct hci_dev *hdev = conn->hcon->hdev;
449 struct crypto_blkcipher *tfm = hdev->tfm_aes;
450 struct smp_cmd_pairing_confirm cp;
451 int ret;
452 u8 reason;
453
454 BT_DBG("conn %p", conn);
455
456 /* Prevent mutual access to hdev->tfm_aes */
457 hci_dev_lock(hdev);
458
459 ret = smp_c1(tfm, smp->tk, smp->prnd, smp->preq, smp->prsp,
460 conn->hcon->init_addr_type, &conn->hcon->init_addr,
461 conn->hcon->resp_addr_type, &conn->hcon->resp_addr,
462 cp.confirm_val);
463
464 hci_dev_unlock(hdev);
465
466 if (ret) {
467 reason = SMP_UNSPECIFIED;
468 goto error;
469 }
470
471 clear_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags);
472
473 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
474
475 return;
476
477error:
478 smp_failure(conn, reason);
479}
480
481static void random_work(struct work_struct *work)
482{
483 struct smp_chan *smp = container_of(work, struct smp_chan, random);
484 struct l2cap_conn *conn = smp->conn;
485 struct hci_conn *hcon = conn->hcon;
486 struct hci_dev *hdev = hcon->hdev;
487 struct crypto_blkcipher *tfm = hdev->tfm_aes;
488 u8 reason, confirm[16];
489 int ret;
490
491 if (IS_ERR_OR_NULL(tfm)) {
492 reason = SMP_UNSPECIFIED;
493 goto error;
494 }
495
496 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
497
498 /* Prevent mutual access to hdev->tfm_aes */
499 hci_dev_lock(hdev);
500
501 ret = smp_c1(tfm, smp->tk, smp->rrnd, smp->preq, smp->prsp,
502 hcon->init_addr_type, &hcon->init_addr,
503 hcon->resp_addr_type, &hcon->resp_addr, confirm);
504
505 hci_dev_unlock(hdev);
506
507 if (ret) {
508 reason = SMP_UNSPECIFIED;
509 goto error;
510 }
511
512 if (memcmp(smp->pcnf, confirm, sizeof(smp->pcnf)) != 0) {
513 BT_ERR("Pairing failed (confirmation values mismatch)");
514 reason = SMP_CONFIRM_FAILED;
515 goto error;
516 }
517
518 if (hcon->out) {
519 u8 stk[16];
520 __le64 rand = 0;
521 __le16 ediv = 0;
522
523 smp_s1(tfm, smp->tk, smp->rrnd, smp->prnd, stk);
524
525 memset(stk + smp->enc_key_size, 0,
526 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);
527
528 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) {
529 reason = SMP_UNSPECIFIED;
530 goto error;
531 }
532
533 hci_le_start_enc(hcon, ediv, rand, stk);
534 hcon->enc_key_size = smp->enc_key_size;
535 } else {
536 u8 stk[16];
537 __le64 rand = 0;
538 __le16 ediv = 0;
539
540 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
541 smp->prnd);
542
543 smp_s1(tfm, smp->tk, smp->prnd, smp->rrnd, stk);
544
545 memset(stk + smp->enc_key_size, 0,
546 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);
547
548 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
549 HCI_SMP_STK_SLAVE, 0, stk, smp->enc_key_size,
550 ediv, rand);
551 }
552
553 return;
554
555error:
556 smp_failure(conn, reason);
557}
558
559static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
560{
561 struct smp_chan *smp;
562
563 smp = kzalloc(sizeof(*smp), GFP_ATOMIC);
564 if (!smp)
565 return NULL;
566
567 INIT_WORK(&smp->confirm, confirm_work);
568 INIT_WORK(&smp->random, random_work);
569
570 smp->conn = conn;
571 conn->smp_chan = smp;
572 conn->hcon->smp_conn = conn;
573
574 hci_conn_hold(conn->hcon);
575
576 return smp;
577}
578
579void smp_chan_destroy(struct l2cap_conn *conn)
580{
581 struct smp_chan *smp = conn->smp_chan;
582 bool complete;
583
584 BUG_ON(!smp);
585
586 complete = test_bit(SMP_FLAG_COMPLETE, &smp->smp_flags);
587 mgmt_smp_complete(conn->hcon, complete);
588
589 kfree(smp->csrk);
590 kfree(smp->slave_csrk);
591
592 /* If pairing failed clean up any keys we might have */
593 if (!complete) {
594 if (smp->ltk) {
595 list_del(&smp->ltk->list);
596 kfree(smp->ltk);
597 }
598
599 if (smp->slave_ltk) {
600 list_del(&smp->slave_ltk->list);
601 kfree(smp->slave_ltk);
602 }
603
604 if (smp->remote_irk) {
605 list_del(&smp->remote_irk->list);
606 kfree(smp->remote_irk);
607 }
608 }
609
610 kfree(smp);
611 conn->smp_chan = NULL;
612 conn->hcon->smp_conn = NULL;
613 hci_conn_drop(conn->hcon);
614}
615
616int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey)
617{
618 struct l2cap_conn *conn = hcon->smp_conn;
619 struct smp_chan *smp;
620 u32 value;
621
622 BT_DBG("");
623
624 if (!conn)
625 return -ENOTCONN;
626
627 smp = conn->smp_chan;
628
629 switch (mgmt_op) {
630 case MGMT_OP_USER_PASSKEY_REPLY:
631 value = le32_to_cpu(passkey);
632 memset(smp->tk, 0, sizeof(smp->tk));
633 BT_DBG("PassKey: %d", value);
634 put_unaligned_le32(value, smp->tk);
635 /* Fall Through */
636 case MGMT_OP_USER_CONFIRM_REPLY:
637 set_bit(SMP_FLAG_TK_VALID, &smp->smp_flags);
638 break;
639 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
640 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
641 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
642 return 0;
643 default:
644 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
645 return -EOPNOTSUPP;
646 }
647
648 /* If it is our turn to send Pairing Confirm, do so now */
649 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags))
650 queue_work(hcon->hdev->workqueue, &smp->confirm);
651
652 return 0;
653}
654
655static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
656{
657 struct smp_cmd_pairing rsp, *req = (void *) skb->data;
658 struct smp_chan *smp;
659 u8 key_size;
660 u8 auth = SMP_AUTH_NONE;
661 int ret;
662
663 BT_DBG("conn %p", conn);
664
665 if (skb->len < sizeof(*req))
666 return SMP_UNSPECIFIED;
667
668 if (conn->hcon->link_mode & HCI_LM_MASTER)
669 return SMP_CMD_NOTSUPP;
670
671 if (!test_and_set_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->flags))
672 smp = smp_chan_create(conn);
673 else
674 smp = conn->smp_chan;
675
676 if (!smp)
677 return SMP_UNSPECIFIED;
678
679 smp->preq[0] = SMP_CMD_PAIRING_REQ;
680 memcpy(&smp->preq[1], req, sizeof(*req));
681 skb_pull(skb, sizeof(*req));
682
683 /* We didn't start the pairing, so match remote */
684 if (req->auth_req & SMP_AUTH_BONDING)
685 auth = req->auth_req;
686
687 conn->hcon->pending_sec_level = authreq_to_seclevel(auth);
688
689 build_pairing_cmd(conn, req, &rsp, auth);
690
691 key_size = min(req->max_key_size, rsp.max_key_size);
692 if (check_enc_key_size(conn, key_size))
693 return SMP_ENC_KEY_SIZE;
694
695 get_random_bytes(smp->prnd, sizeof(smp->prnd));
696
697 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
698 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
699
700 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
701
702 /* Request setup of TK */
703 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability);
704 if (ret)
705 return SMP_UNSPECIFIED;
706
707 clear_bit(SMP_FLAG_INITIATOR, &smp->smp_flags);
708
709 return 0;
710}
711
712static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
713{
714 struct smp_cmd_pairing *req, *rsp = (void *) skb->data;
715 struct smp_chan *smp = conn->smp_chan;
716 struct hci_dev *hdev = conn->hcon->hdev;
717 u8 key_size, auth = SMP_AUTH_NONE;
718 int ret;
719
720 BT_DBG("conn %p", conn);
721
722 if (skb->len < sizeof(*rsp))
723 return SMP_UNSPECIFIED;
724
725 if (!(conn->hcon->link_mode & HCI_LM_MASTER))
726 return SMP_CMD_NOTSUPP;
727
728 skb_pull(skb, sizeof(*rsp));
729
730 req = (void *) &smp->preq[1];
731
732 key_size = min(req->max_key_size, rsp->max_key_size);
733 if (check_enc_key_size(conn, key_size))
734 return SMP_ENC_KEY_SIZE;
735
736 get_random_bytes(smp->prnd, sizeof(smp->prnd));
737
738 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
739 memcpy(&smp->prsp[1], rsp, sizeof(*rsp));
740
741 /* Update remote key distribution in case the remote cleared
742 * some bits that we had enabled in our request.
743 */
744 smp->remote_key_dist &= rsp->resp_key_dist;
745
746 if ((req->auth_req & SMP_AUTH_BONDING) &&
747 (rsp->auth_req & SMP_AUTH_BONDING))
748 auth = SMP_AUTH_BONDING;
749
750 auth |= (req->auth_req | rsp->auth_req) & SMP_AUTH_MITM;
751
752 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability);
753 if (ret)
754 return SMP_UNSPECIFIED;
755
756 set_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags);
757
758 /* Can't compose response until we have been confirmed */
759 if (test_bit(SMP_FLAG_TK_VALID, &smp->smp_flags))
760 queue_work(hdev->workqueue, &smp->confirm);
761
762 return 0;
763}
764
765static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
766{
767 struct smp_chan *smp = conn->smp_chan;
768 struct hci_dev *hdev = conn->hcon->hdev;
769
770 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
771
772 if (skb->len < sizeof(smp->pcnf))
773 return SMP_UNSPECIFIED;
774
775 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf));
776 skb_pull(skb, sizeof(smp->pcnf));
777
778 if (conn->hcon->out)
779 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
780 smp->prnd);
781 else if (test_bit(SMP_FLAG_TK_VALID, &smp->smp_flags))
782 queue_work(hdev->workqueue, &smp->confirm);
783 else
784 set_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags);
785
786 return 0;
787}
788
789static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
790{
791 struct smp_chan *smp = conn->smp_chan;
792 struct hci_dev *hdev = conn->hcon->hdev;
793
794 BT_DBG("conn %p", conn);
795
796 if (skb->len < sizeof(smp->rrnd))
797 return SMP_UNSPECIFIED;
798
799 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd));
800 skb_pull(skb, sizeof(smp->rrnd));
801
802 queue_work(hdev->workqueue, &smp->random);
803
804 return 0;
805}
806
807static u8 smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level)
808{
809 struct smp_ltk *key;
810 struct hci_conn *hcon = conn->hcon;
811
812 key = hci_find_ltk_by_addr(hcon->hdev, &hcon->dst, hcon->dst_type,
813 hcon->out);
814 if (!key)
815 return 0;
816
817 if (sec_level > BT_SECURITY_MEDIUM && !key->authenticated)
818 return 0;
819
820 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
821 return 1;
822
823 hci_le_start_enc(hcon, key->ediv, key->rand, key->val);
824 hcon->enc_key_size = key->enc_size;
825
826 return 1;
827}
828
829static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
830{
831 struct smp_cmd_security_req *rp = (void *) skb->data;
832 struct smp_cmd_pairing cp;
833 struct hci_conn *hcon = conn->hcon;
834 struct smp_chan *smp;
835
836 BT_DBG("conn %p", conn);
837
838 if (skb->len < sizeof(*rp))
839 return SMP_UNSPECIFIED;
840
841 if (!(conn->hcon->link_mode & HCI_LM_MASTER))
842 return SMP_CMD_NOTSUPP;
843
844 hcon->pending_sec_level = authreq_to_seclevel(rp->auth_req);
845
846 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
847 return 0;
848
849 if (test_and_set_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags))
850 return 0;
851
852 smp = smp_chan_create(conn);
853
854 skb_pull(skb, sizeof(*rp));
855
856 memset(&cp, 0, sizeof(cp));
857 build_pairing_cmd(conn, &cp, NULL, rp->auth_req);
858
859 smp->preq[0] = SMP_CMD_PAIRING_REQ;
860 memcpy(&smp->preq[1], &cp, sizeof(cp));
861
862 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
863
864 clear_bit(SMP_FLAG_INITIATOR, &smp->smp_flags);
865
866 return 0;
867}
868
869bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level)
870{
871 if (sec_level == BT_SECURITY_LOW)
872 return true;
873
874 if (hcon->sec_level >= sec_level)
875 return true;
876
877 return false;
878}
879
880int smp_conn_security(struct hci_conn *hcon, __u8 sec_level)
881{
882 struct l2cap_conn *conn = hcon->l2cap_data;
883 struct smp_chan *smp;
884 __u8 authreq;
885
886 BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level);
887
888 /* This may be NULL if there's an unexpected disconnection */
889 if (!conn)
890 return 1;
891
892 if (!test_bit(HCI_LE_ENABLED, &hcon->hdev->dev_flags))
893 return 1;
894
895 if (smp_sufficient_security(hcon, sec_level))
896 return 1;
897
898 if (hcon->link_mode & HCI_LM_MASTER)
899 if (smp_ltk_encrypt(conn, sec_level))
900 goto done;
901
902 if (test_and_set_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags))
903 return 0;
904
905 smp = smp_chan_create(conn);
906 if (!smp)
907 return 1;
908
909 authreq = seclevel_to_authreq(sec_level);
910
911 /* hcon->auth_type is set by pair_device in mgmt.c. If the MITM
912 * flag is set we should also set it for the SMP request.
913 */
914 if ((hcon->auth_type & 0x01))
915 authreq |= SMP_AUTH_MITM;
916
917 if (hcon->link_mode & HCI_LM_MASTER) {
918 struct smp_cmd_pairing cp;
919
920 build_pairing_cmd(conn, &cp, NULL, authreq);
921 smp->preq[0] = SMP_CMD_PAIRING_REQ;
922 memcpy(&smp->preq[1], &cp, sizeof(cp));
923
924 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
925 } else {
926 struct smp_cmd_security_req cp;
927 cp.auth_req = authreq;
928 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp);
929 }
930
931 set_bit(SMP_FLAG_INITIATOR, &smp->smp_flags);
932
933done:
934 hcon->pending_sec_level = sec_level;
935
936 return 0;
937}
938
939static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb)
940{
941 struct smp_cmd_encrypt_info *rp = (void *) skb->data;
942 struct smp_chan *smp = conn->smp_chan;
943
944 BT_DBG("conn %p", conn);
945
946 if (skb->len < sizeof(*rp))
947 return SMP_UNSPECIFIED;
948
949 /* Ignore this PDU if it wasn't requested */
950 if (!(smp->remote_key_dist & SMP_DIST_ENC_KEY))
951 return 0;
952
953 skb_pull(skb, sizeof(*rp));
954
955 memcpy(smp->tk, rp->ltk, sizeof(smp->tk));
956
957 return 0;
958}
959
960static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb)
961{
962 struct smp_cmd_master_ident *rp = (void *) skb->data;
963 struct smp_chan *smp = conn->smp_chan;
964 struct hci_dev *hdev = conn->hcon->hdev;
965 struct hci_conn *hcon = conn->hcon;
966 struct smp_ltk *ltk;
967 u8 authenticated;
968
969 BT_DBG("conn %p", conn);
970
971 if (skb->len < sizeof(*rp))
972 return SMP_UNSPECIFIED;
973
974 /* Ignore this PDU if it wasn't requested */
975 if (!(smp->remote_key_dist & SMP_DIST_ENC_KEY))
976 return 0;
977
978 /* Mark the information as received */
979 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY;
980
981 skb_pull(skb, sizeof(*rp));
982
983 hci_dev_lock(hdev);
984 authenticated = (hcon->sec_level == BT_SECURITY_HIGH);
985 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, HCI_SMP_LTK,
986 authenticated, smp->tk, smp->enc_key_size,
987 rp->ediv, rp->rand);
988 smp->ltk = ltk;
989 if (!(smp->remote_key_dist & SMP_DIST_ID_KEY))
990 smp_distribute_keys(conn);
991 hci_dev_unlock(hdev);
992
993 return 0;
994}
995
996static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb)
997{
998 struct smp_cmd_ident_info *info = (void *) skb->data;
999 struct smp_chan *smp = conn->smp_chan;
1000
1001 BT_DBG("");
1002
1003 if (skb->len < sizeof(*info))
1004 return SMP_UNSPECIFIED;
1005
1006 /* Ignore this PDU if it wasn't requested */
1007 if (!(smp->remote_key_dist & SMP_DIST_ID_KEY))
1008 return 0;
1009
1010 skb_pull(skb, sizeof(*info));
1011
1012 memcpy(smp->irk, info->irk, 16);
1013
1014 return 0;
1015}
1016
1017static int smp_cmd_ident_addr_info(struct l2cap_conn *conn,
1018 struct sk_buff *skb)
1019{
1020 struct smp_cmd_ident_addr_info *info = (void *) skb->data;
1021 struct smp_chan *smp = conn->smp_chan;
1022 struct hci_conn *hcon = conn->hcon;
1023 bdaddr_t rpa;
1024
1025 BT_DBG("");
1026
1027 if (skb->len < sizeof(*info))
1028 return SMP_UNSPECIFIED;
1029
1030 /* Ignore this PDU if it wasn't requested */
1031 if (!(smp->remote_key_dist & SMP_DIST_ID_KEY))
1032 return 0;
1033
1034 /* Mark the information as received */
1035 smp->remote_key_dist &= ~SMP_DIST_ID_KEY;
1036
1037 skb_pull(skb, sizeof(*info));
1038
1039 /* Strictly speaking the Core Specification (4.1) allows sending
1040 * an empty address which would force us to rely on just the IRK
1041 * as "identity information". However, since such
1042 * implementations are not known of and in order to not over
1043 * complicate our implementation, simply pretend that we never
1044 * received an IRK for such a device.
1045 */
1046 if (!bacmp(&info->bdaddr, BDADDR_ANY)) {
1047 BT_ERR("Ignoring IRK with no identity address");
1048 smp_distribute_keys(conn);
1049 return 0;
1050 }
1051
1052 bacpy(&smp->id_addr, &info->bdaddr);
1053 smp->id_addr_type = info->addr_type;
1054
1055 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type))
1056 bacpy(&rpa, &hcon->dst);
1057 else
1058 bacpy(&rpa, BDADDR_ANY);
1059
1060 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr,
1061 smp->id_addr_type, smp->irk, &rpa);
1062
1063 smp_distribute_keys(conn);
1064
1065 return 0;
1066}
1067
1068static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb)
1069{
1070 struct smp_cmd_sign_info *rp = (void *) skb->data;
1071 struct smp_chan *smp = conn->smp_chan;
1072 struct hci_dev *hdev = conn->hcon->hdev;
1073 struct smp_csrk *csrk;
1074
1075 BT_DBG("conn %p", conn);
1076
1077 if (skb->len < sizeof(*rp))
1078 return SMP_UNSPECIFIED;
1079
1080 /* Ignore this PDU if it wasn't requested */
1081 if (!(smp->remote_key_dist & SMP_DIST_SIGN))
1082 return 0;
1083
1084 /* Mark the information as received */
1085 smp->remote_key_dist &= ~SMP_DIST_SIGN;
1086
1087 skb_pull(skb, sizeof(*rp));
1088
1089 hci_dev_lock(hdev);
1090 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
1091 if (csrk) {
1092 csrk->master = 0x01;
1093 memcpy(csrk->val, rp->csrk, sizeof(csrk->val));
1094 }
1095 smp->csrk = csrk;
1096 if (!(smp->remote_key_dist & SMP_DIST_SIGN))
1097 smp_distribute_keys(conn);
1098 hci_dev_unlock(hdev);
1099
1100 return 0;
1101}
1102
1103int smp_sig_channel(struct l2cap_conn *conn, struct sk_buff *skb)
1104{
1105 struct hci_conn *hcon = conn->hcon;
1106 __u8 code, reason;
1107 int err = 0;
1108
1109 if (hcon->type != LE_LINK) {
1110 kfree_skb(skb);
1111 return 0;
1112 }
1113
1114 if (skb->len < 1) {
1115 kfree_skb(skb);
1116 return -EILSEQ;
1117 }
1118
1119 if (!test_bit(HCI_LE_ENABLED, &hcon->hdev->dev_flags)) {
1120 err = -ENOTSUPP;
1121 reason = SMP_PAIRING_NOTSUPP;
1122 goto done;
1123 }
1124
1125 code = skb->data[0];
1126 skb_pull(skb, sizeof(code));
1127
1128 /*
1129 * The SMP context must be initialized for all other PDUs except
1130 * pairing and security requests. If we get any other PDU when
1131 * not initialized simply disconnect (done if this function
1132 * returns an error).
1133 */
1134 if (code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ &&
1135 !conn->smp_chan) {
1136 BT_ERR("Unexpected SMP command 0x%02x. Disconnecting.", code);
1137 kfree_skb(skb);
1138 return -ENOTSUPP;
1139 }
1140
1141 switch (code) {
1142 case SMP_CMD_PAIRING_REQ:
1143 reason = smp_cmd_pairing_req(conn, skb);
1144 break;
1145
1146 case SMP_CMD_PAIRING_FAIL:
1147 smp_failure(conn, 0);
1148 reason = 0;
1149 err = -EPERM;
1150 break;
1151
1152 case SMP_CMD_PAIRING_RSP:
1153 reason = smp_cmd_pairing_rsp(conn, skb);
1154 break;
1155
1156 case SMP_CMD_SECURITY_REQ:
1157 reason = smp_cmd_security_req(conn, skb);
1158 break;
1159
1160 case SMP_CMD_PAIRING_CONFIRM:
1161 reason = smp_cmd_pairing_confirm(conn, skb);
1162 break;
1163
1164 case SMP_CMD_PAIRING_RANDOM:
1165 reason = smp_cmd_pairing_random(conn, skb);
1166 break;
1167
1168 case SMP_CMD_ENCRYPT_INFO:
1169 reason = smp_cmd_encrypt_info(conn, skb);
1170 break;
1171
1172 case SMP_CMD_MASTER_IDENT:
1173 reason = smp_cmd_master_ident(conn, skb);
1174 break;
1175
1176 case SMP_CMD_IDENT_INFO:
1177 reason = smp_cmd_ident_info(conn, skb);
1178 break;
1179
1180 case SMP_CMD_IDENT_ADDR_INFO:
1181 reason = smp_cmd_ident_addr_info(conn, skb);
1182 break;
1183
1184 case SMP_CMD_SIGN_INFO:
1185 reason = smp_cmd_sign_info(conn, skb);
1186 break;
1187
1188 default:
1189 BT_DBG("Unknown command code 0x%2.2x", code);
1190
1191 reason = SMP_CMD_NOTSUPP;
1192 err = -EOPNOTSUPP;
1193 goto done;
1194 }
1195
1196done:
1197 if (reason)
1198 smp_failure(conn, reason);
1199
1200 kfree_skb(skb);
1201 return err;
1202}
1203
1204static void smp_notify_keys(struct l2cap_conn *conn)
1205{
1206 struct smp_chan *smp = conn->smp_chan;
1207 struct hci_conn *hcon = conn->hcon;
1208 struct hci_dev *hdev = hcon->hdev;
1209 struct smp_cmd_pairing *req = (void *) &smp->preq[1];
1210 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1];
1211 bool persistent;
1212
1213 if (smp->remote_irk) {
1214 mgmt_new_irk(hdev, smp->remote_irk);
1215 /* Now that user space can be considered to know the
1216 * identity address track the connection based on it
1217 * from now on.
1218 */
1219 bacpy(&hcon->dst, &smp->remote_irk->bdaddr);
1220 hcon->dst_type = smp->remote_irk->addr_type;
1221 l2cap_conn_update_id_addr(hcon);
1222 }
1223
1224 /* The LTKs and CSRKs should be persistent only if both sides
1225 * had the bonding bit set in their authentication requests.
1226 */
1227 persistent = !!((req->auth_req & rsp->auth_req) & SMP_AUTH_BONDING);
1228
1229 if (smp->csrk) {
1230 smp->csrk->bdaddr_type = hcon->dst_type;
1231 bacpy(&smp->csrk->bdaddr, &hcon->dst);
1232 mgmt_new_csrk(hdev, smp->csrk, persistent);
1233 }
1234
1235 if (smp->slave_csrk) {
1236 smp->slave_csrk->bdaddr_type = hcon->dst_type;
1237 bacpy(&smp->slave_csrk->bdaddr, &hcon->dst);
1238 mgmt_new_csrk(hdev, smp->slave_csrk, persistent);
1239 }
1240
1241 if (smp->ltk) {
1242 smp->ltk->bdaddr_type = hcon->dst_type;
1243 bacpy(&smp->ltk->bdaddr, &hcon->dst);
1244 mgmt_new_ltk(hdev, smp->ltk, persistent);
1245 }
1246
1247 if (smp->slave_ltk) {
1248 smp->slave_ltk->bdaddr_type = hcon->dst_type;
1249 bacpy(&smp->slave_ltk->bdaddr, &hcon->dst);
1250 mgmt_new_ltk(hdev, smp->slave_ltk, persistent);
1251 }
1252}
1253
1254int smp_distribute_keys(struct l2cap_conn *conn)
1255{
1256 struct smp_cmd_pairing *req, *rsp;
1257 struct smp_chan *smp = conn->smp_chan;
1258 struct hci_conn *hcon = conn->hcon;
1259 struct hci_dev *hdev = hcon->hdev;
1260 __u8 *keydist;
1261
1262 BT_DBG("conn %p", conn);
1263
1264 if (!test_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags))
1265 return 0;
1266
1267 rsp = (void *) &smp->prsp[1];
1268
1269 /* The responder sends its keys first */
1270 if (hcon->out && (smp->remote_key_dist & 0x07))
1271 return 0;
1272
1273 req = (void *) &smp->preq[1];
1274
1275 if (hcon->out) {
1276 keydist = &rsp->init_key_dist;
1277 *keydist &= req->init_key_dist;
1278 } else {
1279 keydist = &rsp->resp_key_dist;
1280 *keydist &= req->resp_key_dist;
1281 }
1282
1283 BT_DBG("keydist 0x%x", *keydist);
1284
1285 if (*keydist & SMP_DIST_ENC_KEY) {
1286 struct smp_cmd_encrypt_info enc;
1287 struct smp_cmd_master_ident ident;
1288 struct smp_ltk *ltk;
1289 u8 authenticated;
1290 __le16 ediv;
1291 __le64 rand;
1292
1293 get_random_bytes(enc.ltk, sizeof(enc.ltk));
1294 get_random_bytes(&ediv, sizeof(ediv));
1295 get_random_bytes(&rand, sizeof(rand));
1296
1297 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc);
1298
1299 authenticated = hcon->sec_level == BT_SECURITY_HIGH;
1300 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type,
1301 HCI_SMP_LTK_SLAVE, authenticated, enc.ltk,
1302 smp->enc_key_size, ediv, rand);
1303 smp->slave_ltk = ltk;
1304
1305 ident.ediv = ediv;
1306 ident.rand = rand;
1307
1308 smp_send_cmd(conn, SMP_CMD_MASTER_IDENT, sizeof(ident), &ident);
1309
1310 *keydist &= ~SMP_DIST_ENC_KEY;
1311 }
1312
1313 if (*keydist & SMP_DIST_ID_KEY) {
1314 struct smp_cmd_ident_addr_info addrinfo;
1315 struct smp_cmd_ident_info idinfo;
1316
1317 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk));
1318
1319 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo);
1320
1321 /* The hci_conn contains the local identity address
1322 * after the connection has been established.
1323 *
1324 * This is true even when the connection has been
1325 * established using a resolvable random address.
1326 */
1327 bacpy(&addrinfo.bdaddr, &hcon->src);
1328 addrinfo.addr_type = hcon->src_type;
1329
1330 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo),
1331 &addrinfo);
1332
1333 *keydist &= ~SMP_DIST_ID_KEY;
1334 }
1335
1336 if (*keydist & SMP_DIST_SIGN) {
1337 struct smp_cmd_sign_info sign;
1338 struct smp_csrk *csrk;
1339
1340 /* Generate a new random key */
1341 get_random_bytes(sign.csrk, sizeof(sign.csrk));
1342
1343 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
1344 if (csrk) {
1345 csrk->master = 0x00;
1346 memcpy(csrk->val, sign.csrk, sizeof(csrk->val));
1347 }
1348 smp->slave_csrk = csrk;
1349
1350 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign);
1351
1352 *keydist &= ~SMP_DIST_SIGN;
1353 }
1354
1355 /* If there are still keys to be received wait for them */
1356 if ((smp->remote_key_dist & 0x07))
1357 return 0;
1358
1359 clear_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags);
1360 cancel_delayed_work_sync(&conn->security_timer);
1361 set_bit(SMP_FLAG_COMPLETE, &smp->smp_flags);
1362 smp_notify_keys(conn);
1363
1364 smp_chan_destroy(conn);
1365
1366 return 0;
1367}