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1/*
2 BlueZ - Bluetooth protocol stack for Linux
3 Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License version 2 as
7 published by the Free Software Foundation;
8
9 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
10 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
11 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
12 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
13 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
14 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17
18 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
19 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
20 SOFTWARE IS DISCLAIMED.
21*/
22
23#include <linux/debugfs.h>
24#include <linux/scatterlist.h>
25#include <crypto/aes.h>
26#include <crypto/hash.h>
27#include <crypto/kpp.h>
28#include <crypto/utils.h>
29
30#include <net/bluetooth/bluetooth.h>
31#include <net/bluetooth/hci_core.h>
32#include <net/bluetooth/l2cap.h>
33#include <net/bluetooth/mgmt.h>
34
35#include "ecdh_helper.h"
36#include "smp.h"
37
38#define SMP_DEV(hdev) \
39 ((struct smp_dev *)((struct l2cap_chan *)((hdev)->smp_data))->data)
40
41/* Low-level debug macros to be used for stuff that we don't want
42 * accidentally in dmesg, i.e. the values of the various crypto keys
43 * and the inputs & outputs of crypto functions.
44 */
45#ifdef DEBUG
46#define SMP_DBG(fmt, ...) printk(KERN_DEBUG "%s: " fmt, __func__, \
47 ##__VA_ARGS__)
48#else
49#define SMP_DBG(fmt, ...) no_printk(KERN_DEBUG "%s: " fmt, __func__, \
50 ##__VA_ARGS__)
51#endif
52
53#define SMP_ALLOW_CMD(smp, code) set_bit(code, &smp->allow_cmd)
54
55/* Keys which are not distributed with Secure Connections */
56#define SMP_SC_NO_DIST (SMP_DIST_ENC_KEY | SMP_DIST_LINK_KEY)
57
58#define SMP_TIMEOUT msecs_to_jiffies(30000)
59
60#define ID_ADDR_TIMEOUT msecs_to_jiffies(200)
61
62#define AUTH_REQ_MASK(dev) (hci_dev_test_flag(dev, HCI_SC_ENABLED) ? \
63 0x3f : 0x07)
64#define KEY_DIST_MASK 0x07
65
66/* Maximum message length that can be passed to aes_cmac */
67#define CMAC_MSG_MAX 80
68
69enum {
70 SMP_FLAG_TK_VALID,
71 SMP_FLAG_CFM_PENDING,
72 SMP_FLAG_MITM_AUTH,
73 SMP_FLAG_COMPLETE,
74 SMP_FLAG_INITIATOR,
75 SMP_FLAG_SC,
76 SMP_FLAG_REMOTE_PK,
77 SMP_FLAG_DEBUG_KEY,
78 SMP_FLAG_WAIT_USER,
79 SMP_FLAG_DHKEY_PENDING,
80 SMP_FLAG_REMOTE_OOB,
81 SMP_FLAG_LOCAL_OOB,
82 SMP_FLAG_CT2,
83};
84
85struct smp_dev {
86 /* Secure Connections OOB data */
87 bool local_oob;
88 u8 local_pk[64];
89 u8 local_rand[16];
90 bool debug_key;
91
92 struct crypto_shash *tfm_cmac;
93 struct crypto_kpp *tfm_ecdh;
94};
95
96struct smp_chan {
97 struct l2cap_conn *conn;
98 struct delayed_work security_timer;
99 unsigned long allow_cmd; /* Bitmask of allowed commands */
100
101 u8 preq[7]; /* SMP Pairing Request */
102 u8 prsp[7]; /* SMP Pairing Response */
103 u8 prnd[16]; /* SMP Pairing Random (local) */
104 u8 rrnd[16]; /* SMP Pairing Random (remote) */
105 u8 pcnf[16]; /* SMP Pairing Confirm */
106 u8 tk[16]; /* SMP Temporary Key */
107 u8 rr[16]; /* Remote OOB ra/rb value */
108 u8 lr[16]; /* Local OOB ra/rb value */
109 u8 enc_key_size;
110 u8 remote_key_dist;
111 bdaddr_t id_addr;
112 u8 id_addr_type;
113 u8 irk[16];
114 struct smp_csrk *csrk;
115 struct smp_csrk *responder_csrk;
116 struct smp_ltk *ltk;
117 struct smp_ltk *responder_ltk;
118 struct smp_irk *remote_irk;
119 u8 *link_key;
120 unsigned long flags;
121 u8 method;
122 u8 passkey_round;
123
124 /* Secure Connections variables */
125 u8 local_pk[64];
126 u8 remote_pk[64];
127 u8 dhkey[32];
128 u8 mackey[16];
129
130 struct crypto_shash *tfm_cmac;
131 struct crypto_kpp *tfm_ecdh;
132};
133
134/* These debug key values are defined in the SMP section of the core
135 * specification. debug_pk is the public debug key and debug_sk the
136 * private debug key.
137 */
138static const u8 debug_pk[64] = {
139 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
140 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
141 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
142 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20,
143
144 0x8b, 0xd2, 0x89, 0x15, 0xd0, 0x8e, 0x1c, 0x74,
145 0x24, 0x30, 0xed, 0x8f, 0xc2, 0x45, 0x63, 0x76,
146 0x5c, 0x15, 0x52, 0x5a, 0xbf, 0x9a, 0x32, 0x63,
147 0x6d, 0xeb, 0x2a, 0x65, 0x49, 0x9c, 0x80, 0xdc,
148};
149
150static const u8 debug_sk[32] = {
151 0xbd, 0x1a, 0x3c, 0xcd, 0xa6, 0xb8, 0x99, 0x58,
152 0x99, 0xb7, 0x40, 0xeb, 0x7b, 0x60, 0xff, 0x4a,
153 0x50, 0x3f, 0x10, 0xd2, 0xe3, 0xb3, 0xc9, 0x74,
154 0x38, 0x5f, 0xc5, 0xa3, 0xd4, 0xf6, 0x49, 0x3f,
155};
156
157static inline void swap_buf(const u8 *src, u8 *dst, size_t len)
158{
159 size_t i;
160
161 for (i = 0; i < len; i++)
162 dst[len - 1 - i] = src[i];
163}
164
165/* The following functions map to the LE SC SMP crypto functions
166 * AES-CMAC, f4, f5, f6, g2 and h6.
167 */
168
169static int aes_cmac(struct crypto_shash *tfm, const u8 k[16], const u8 *m,
170 size_t len, u8 mac[16])
171{
172 uint8_t tmp[16], mac_msb[16], msg_msb[CMAC_MSG_MAX];
173 int err;
174
175 if (len > CMAC_MSG_MAX)
176 return -EFBIG;
177
178 if (!tfm) {
179 BT_ERR("tfm %p", tfm);
180 return -EINVAL;
181 }
182
183 /* Swap key and message from LSB to MSB */
184 swap_buf(k, tmp, 16);
185 swap_buf(m, msg_msb, len);
186
187 SMP_DBG("msg (len %zu) %*phN", len, (int) len, m);
188 SMP_DBG("key %16phN", k);
189
190 err = crypto_shash_setkey(tfm, tmp, 16);
191 if (err) {
192 BT_ERR("cipher setkey failed: %d", err);
193 return err;
194 }
195
196 err = crypto_shash_tfm_digest(tfm, msg_msb, len, mac_msb);
197 if (err) {
198 BT_ERR("Hash computation error %d", err);
199 return err;
200 }
201
202 swap_buf(mac_msb, mac, 16);
203
204 SMP_DBG("mac %16phN", mac);
205
206 return 0;
207}
208
209static int smp_f4(struct crypto_shash *tfm_cmac, const u8 u[32],
210 const u8 v[32], const u8 x[16], u8 z, u8 res[16])
211{
212 u8 m[65];
213 int err;
214
215 SMP_DBG("u %32phN", u);
216 SMP_DBG("v %32phN", v);
217 SMP_DBG("x %16phN z %02x", x, z);
218
219 m[0] = z;
220 memcpy(m + 1, v, 32);
221 memcpy(m + 33, u, 32);
222
223 err = aes_cmac(tfm_cmac, x, m, sizeof(m), res);
224 if (err)
225 return err;
226
227 SMP_DBG("res %16phN", res);
228
229 return err;
230}
231
232static int smp_f5(struct crypto_shash *tfm_cmac, const u8 w[32],
233 const u8 n1[16], const u8 n2[16], const u8 a1[7],
234 const u8 a2[7], u8 mackey[16], u8 ltk[16])
235{
236 /* The btle, salt and length "magic" values are as defined in
237 * the SMP section of the Bluetooth core specification. In ASCII
238 * the btle value ends up being 'btle'. The salt is just a
239 * random number whereas length is the value 256 in little
240 * endian format.
241 */
242 const u8 btle[4] = { 0x65, 0x6c, 0x74, 0x62 };
243 const u8 salt[16] = { 0xbe, 0x83, 0x60, 0x5a, 0xdb, 0x0b, 0x37, 0x60,
244 0x38, 0xa5, 0xf5, 0xaa, 0x91, 0x83, 0x88, 0x6c };
245 const u8 length[2] = { 0x00, 0x01 };
246 u8 m[53], t[16];
247 int err;
248
249 SMP_DBG("w %32phN", w);
250 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
251 SMP_DBG("a1 %7phN a2 %7phN", a1, a2);
252
253 err = aes_cmac(tfm_cmac, salt, w, 32, t);
254 if (err)
255 return err;
256
257 SMP_DBG("t %16phN", t);
258
259 memcpy(m, length, 2);
260 memcpy(m + 2, a2, 7);
261 memcpy(m + 9, a1, 7);
262 memcpy(m + 16, n2, 16);
263 memcpy(m + 32, n1, 16);
264 memcpy(m + 48, btle, 4);
265
266 m[52] = 0; /* Counter */
267
268 err = aes_cmac(tfm_cmac, t, m, sizeof(m), mackey);
269 if (err)
270 return err;
271
272 SMP_DBG("mackey %16phN", mackey);
273
274 m[52] = 1; /* Counter */
275
276 err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk);
277 if (err)
278 return err;
279
280 SMP_DBG("ltk %16phN", ltk);
281
282 return 0;
283}
284
285static int smp_f6(struct crypto_shash *tfm_cmac, const u8 w[16],
286 const u8 n1[16], const u8 n2[16], const u8 r[16],
287 const u8 io_cap[3], const u8 a1[7], const u8 a2[7],
288 u8 res[16])
289{
290 u8 m[65];
291 int err;
292
293 SMP_DBG("w %16phN", w);
294 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
295 SMP_DBG("r %16phN io_cap %3phN a1 %7phN a2 %7phN", r, io_cap, a1, a2);
296
297 memcpy(m, a2, 7);
298 memcpy(m + 7, a1, 7);
299 memcpy(m + 14, io_cap, 3);
300 memcpy(m + 17, r, 16);
301 memcpy(m + 33, n2, 16);
302 memcpy(m + 49, n1, 16);
303
304 err = aes_cmac(tfm_cmac, w, m, sizeof(m), res);
305 if (err)
306 return err;
307
308 SMP_DBG("res %16phN", res);
309
310 return err;
311}
312
313static int smp_g2(struct crypto_shash *tfm_cmac, const u8 u[32], const u8 v[32],
314 const u8 x[16], const u8 y[16], u32 *val)
315{
316 u8 m[80], tmp[16];
317 int err;
318
319 SMP_DBG("u %32phN", u);
320 SMP_DBG("v %32phN", v);
321 SMP_DBG("x %16phN y %16phN", x, y);
322
323 memcpy(m, y, 16);
324 memcpy(m + 16, v, 32);
325 memcpy(m + 48, u, 32);
326
327 err = aes_cmac(tfm_cmac, x, m, sizeof(m), tmp);
328 if (err)
329 return err;
330
331 *val = get_unaligned_le32(tmp);
332 *val %= 1000000;
333
334 SMP_DBG("val %06u", *val);
335
336 return 0;
337}
338
339static int smp_h6(struct crypto_shash *tfm_cmac, const u8 w[16],
340 const u8 key_id[4], u8 res[16])
341{
342 int err;
343
344 SMP_DBG("w %16phN key_id %4phN", w, key_id);
345
346 err = aes_cmac(tfm_cmac, w, key_id, 4, res);
347 if (err)
348 return err;
349
350 SMP_DBG("res %16phN", res);
351
352 return err;
353}
354
355static int smp_h7(struct crypto_shash *tfm_cmac, const u8 w[16],
356 const u8 salt[16], u8 res[16])
357{
358 int err;
359
360 SMP_DBG("w %16phN salt %16phN", w, salt);
361
362 err = aes_cmac(tfm_cmac, salt, w, 16, res);
363 if (err)
364 return err;
365
366 SMP_DBG("res %16phN", res);
367
368 return err;
369}
370
371/* The following functions map to the legacy SMP crypto functions e, c1,
372 * s1 and ah.
373 */
374
375static int smp_e(const u8 *k, u8 *r)
376{
377 struct crypto_aes_ctx ctx;
378 uint8_t tmp[16], data[16];
379 int err;
380
381 SMP_DBG("k %16phN r %16phN", k, r);
382
383 /* The most significant octet of key corresponds to k[0] */
384 swap_buf(k, tmp, 16);
385
386 err = aes_expandkey(&ctx, tmp, 16);
387 if (err) {
388 BT_ERR("cipher setkey failed: %d", err);
389 return err;
390 }
391
392 /* Most significant octet of plaintextData corresponds to data[0] */
393 swap_buf(r, data, 16);
394
395 aes_encrypt(&ctx, data, data);
396
397 /* Most significant octet of encryptedData corresponds to data[0] */
398 swap_buf(data, r, 16);
399
400 SMP_DBG("r %16phN", r);
401
402 memzero_explicit(&ctx, sizeof(ctx));
403 return err;
404}
405
406static int smp_c1(const u8 k[16],
407 const u8 r[16], const u8 preq[7], const u8 pres[7], u8 _iat,
408 const bdaddr_t *ia, u8 _rat, const bdaddr_t *ra, u8 res[16])
409{
410 u8 p1[16], p2[16];
411 int err;
412
413 SMP_DBG("k %16phN r %16phN", k, r);
414 SMP_DBG("iat %u ia %6phN rat %u ra %6phN", _iat, ia, _rat, ra);
415 SMP_DBG("preq %7phN pres %7phN", preq, pres);
416
417 memset(p1, 0, 16);
418
419 /* p1 = pres || preq || _rat || _iat */
420 p1[0] = _iat;
421 p1[1] = _rat;
422 memcpy(p1 + 2, preq, 7);
423 memcpy(p1 + 9, pres, 7);
424
425 SMP_DBG("p1 %16phN", p1);
426
427 /* res = r XOR p1 */
428 crypto_xor_cpy(res, r, p1, sizeof(p1));
429
430 /* res = e(k, res) */
431 err = smp_e(k, res);
432 if (err) {
433 BT_ERR("Encrypt data error");
434 return err;
435 }
436
437 /* p2 = padding || ia || ra */
438 memcpy(p2, ra, 6);
439 memcpy(p2 + 6, ia, 6);
440 memset(p2 + 12, 0, 4);
441
442 SMP_DBG("p2 %16phN", p2);
443
444 /* res = res XOR p2 */
445 crypto_xor(res, p2, sizeof(p2));
446
447 /* res = e(k, res) */
448 err = smp_e(k, res);
449 if (err)
450 BT_ERR("Encrypt data error");
451
452 return err;
453}
454
455static int smp_s1(const u8 k[16],
456 const u8 r1[16], const u8 r2[16], u8 _r[16])
457{
458 int err;
459
460 /* Just least significant octets from r1 and r2 are considered */
461 memcpy(_r, r2, 8);
462 memcpy(_r + 8, r1, 8);
463
464 err = smp_e(k, _r);
465 if (err)
466 BT_ERR("Encrypt data error");
467
468 return err;
469}
470
471static int smp_ah(const u8 irk[16], const u8 r[3], u8 res[3])
472{
473 u8 _res[16];
474 int err;
475
476 /* r' = padding || r */
477 memcpy(_res, r, 3);
478 memset(_res + 3, 0, 13);
479
480 err = smp_e(irk, _res);
481 if (err) {
482 BT_ERR("Encrypt error");
483 return err;
484 }
485
486 /* The output of the random address function ah is:
487 * ah(k, r) = e(k, r') mod 2^24
488 * The output of the security function e is then truncated to 24 bits
489 * by taking the least significant 24 bits of the output of e as the
490 * result of ah.
491 */
492 memcpy(res, _res, 3);
493
494 return 0;
495}
496
497bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16],
498 const bdaddr_t *bdaddr)
499{
500 struct l2cap_chan *chan = hdev->smp_data;
501 u8 hash[3];
502 int err;
503
504 if (!chan || !chan->data)
505 return false;
506
507 bt_dev_dbg(hdev, "RPA %pMR IRK %*phN", bdaddr, 16, irk);
508
509 err = smp_ah(irk, &bdaddr->b[3], hash);
510 if (err)
511 return false;
512
513 return !crypto_memneq(bdaddr->b, hash, 3);
514}
515
516int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa)
517{
518 struct l2cap_chan *chan = hdev->smp_data;
519 int err;
520
521 if (!chan || !chan->data)
522 return -EOPNOTSUPP;
523
524 get_random_bytes(&rpa->b[3], 3);
525
526 rpa->b[5] &= 0x3f; /* Clear two most significant bits */
527 rpa->b[5] |= 0x40; /* Set second most significant bit */
528
529 err = smp_ah(irk, &rpa->b[3], rpa->b);
530 if (err < 0)
531 return err;
532
533 bt_dev_dbg(hdev, "RPA %pMR", rpa);
534
535 return 0;
536}
537
538int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16])
539{
540 struct l2cap_chan *chan = hdev->smp_data;
541 struct smp_dev *smp;
542 int err;
543
544 if (!chan || !chan->data)
545 return -EOPNOTSUPP;
546
547 smp = chan->data;
548
549 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) {
550 bt_dev_dbg(hdev, "Using debug keys");
551 err = set_ecdh_privkey(smp->tfm_ecdh, debug_sk);
552 if (err)
553 return err;
554 memcpy(smp->local_pk, debug_pk, 64);
555 smp->debug_key = true;
556 } else {
557 while (true) {
558 /* Generate key pair for Secure Connections */
559 err = generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk);
560 if (err)
561 return err;
562
563 /* This is unlikely, but we need to check that
564 * we didn't accidentally generate a debug key.
565 */
566 if (crypto_memneq(smp->local_pk, debug_pk, 64))
567 break;
568 }
569 smp->debug_key = false;
570 }
571
572 SMP_DBG("OOB Public Key X: %32phN", smp->local_pk);
573 SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32);
574
575 get_random_bytes(smp->local_rand, 16);
576
577 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->local_pk,
578 smp->local_rand, 0, hash);
579 if (err < 0)
580 return err;
581
582 memcpy(rand, smp->local_rand, 16);
583
584 smp->local_oob = true;
585
586 return 0;
587}
588
589static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
590{
591 struct l2cap_chan *chan = conn->smp;
592 struct smp_chan *smp;
593 struct kvec iv[2];
594 struct msghdr msg;
595
596 if (!chan)
597 return;
598
599 bt_dev_dbg(conn->hcon->hdev, "code 0x%2.2x", code);
600
601 iv[0].iov_base = &code;
602 iv[0].iov_len = 1;
603
604 iv[1].iov_base = data;
605 iv[1].iov_len = len;
606
607 memset(&msg, 0, sizeof(msg));
608
609 iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iv, 2, 1 + len);
610
611 l2cap_chan_send(chan, &msg, 1 + len);
612
613 if (!chan->data)
614 return;
615
616 smp = chan->data;
617
618 cancel_delayed_work_sync(&smp->security_timer);
619 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT);
620}
621
622static u8 authreq_to_seclevel(u8 authreq)
623{
624 if (authreq & SMP_AUTH_MITM) {
625 if (authreq & SMP_AUTH_SC)
626 return BT_SECURITY_FIPS;
627 else
628 return BT_SECURITY_HIGH;
629 } else {
630 return BT_SECURITY_MEDIUM;
631 }
632}
633
634static __u8 seclevel_to_authreq(__u8 sec_level)
635{
636 switch (sec_level) {
637 case BT_SECURITY_FIPS:
638 case BT_SECURITY_HIGH:
639 return SMP_AUTH_MITM | SMP_AUTH_BONDING;
640 case BT_SECURITY_MEDIUM:
641 return SMP_AUTH_BONDING;
642 default:
643 return SMP_AUTH_NONE;
644 }
645}
646
647static void build_pairing_cmd(struct l2cap_conn *conn,
648 struct smp_cmd_pairing *req,
649 struct smp_cmd_pairing *rsp, __u8 authreq)
650{
651 struct l2cap_chan *chan = conn->smp;
652 struct smp_chan *smp = chan->data;
653 struct hci_conn *hcon = conn->hcon;
654 struct hci_dev *hdev = hcon->hdev;
655 u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT;
656
657 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) {
658 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
659 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
660 authreq |= SMP_AUTH_BONDING;
661 } else {
662 authreq &= ~SMP_AUTH_BONDING;
663 }
664
665 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING))
666 remote_dist |= SMP_DIST_ID_KEY;
667
668 if (hci_dev_test_flag(hdev, HCI_PRIVACY))
669 local_dist |= SMP_DIST_ID_KEY;
670
671 if (hci_dev_test_flag(hdev, HCI_SC_ENABLED) &&
672 (authreq & SMP_AUTH_SC)) {
673 struct oob_data *oob_data;
674 u8 bdaddr_type;
675
676 if (hci_dev_test_flag(hdev, HCI_SSP_ENABLED)) {
677 local_dist |= SMP_DIST_LINK_KEY;
678 remote_dist |= SMP_DIST_LINK_KEY;
679 }
680
681 if (hcon->dst_type == ADDR_LE_DEV_PUBLIC)
682 bdaddr_type = BDADDR_LE_PUBLIC;
683 else
684 bdaddr_type = BDADDR_LE_RANDOM;
685
686 oob_data = hci_find_remote_oob_data(hdev, &hcon->dst,
687 bdaddr_type);
688 if (oob_data && oob_data->present) {
689 set_bit(SMP_FLAG_REMOTE_OOB, &smp->flags);
690 oob_flag = SMP_OOB_PRESENT;
691 memcpy(smp->rr, oob_data->rand256, 16);
692 memcpy(smp->pcnf, oob_data->hash256, 16);
693 SMP_DBG("OOB Remote Confirmation: %16phN", smp->pcnf);
694 SMP_DBG("OOB Remote Random: %16phN", smp->rr);
695 }
696
697 } else {
698 authreq &= ~SMP_AUTH_SC;
699 }
700
701 if (rsp == NULL) {
702 req->io_capability = conn->hcon->io_capability;
703 req->oob_flag = oob_flag;
704 req->max_key_size = hdev->le_max_key_size;
705 req->init_key_dist = local_dist;
706 req->resp_key_dist = remote_dist;
707 req->auth_req = (authreq & AUTH_REQ_MASK(hdev));
708
709 smp->remote_key_dist = remote_dist;
710 return;
711 }
712
713 rsp->io_capability = conn->hcon->io_capability;
714 rsp->oob_flag = oob_flag;
715 rsp->max_key_size = hdev->le_max_key_size;
716 rsp->init_key_dist = req->init_key_dist & remote_dist;
717 rsp->resp_key_dist = req->resp_key_dist & local_dist;
718 rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev));
719
720 smp->remote_key_dist = rsp->init_key_dist;
721}
722
723static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)
724{
725 struct l2cap_chan *chan = conn->smp;
726 struct hci_dev *hdev = conn->hcon->hdev;
727 struct smp_chan *smp = chan->data;
728
729 if (conn->hcon->pending_sec_level == BT_SECURITY_FIPS &&
730 max_key_size != SMP_MAX_ENC_KEY_SIZE)
731 return SMP_ENC_KEY_SIZE;
732
733 if (max_key_size > hdev->le_max_key_size ||
734 max_key_size < SMP_MIN_ENC_KEY_SIZE)
735 return SMP_ENC_KEY_SIZE;
736
737 smp->enc_key_size = max_key_size;
738
739 return 0;
740}
741
742static void smp_chan_destroy(struct l2cap_conn *conn)
743{
744 struct l2cap_chan *chan = conn->smp;
745 struct smp_chan *smp = chan->data;
746 struct hci_conn *hcon = conn->hcon;
747 bool complete;
748
749 BUG_ON(!smp);
750
751 cancel_delayed_work_sync(&smp->security_timer);
752
753 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags);
754 mgmt_smp_complete(hcon, complete);
755
756 kfree_sensitive(smp->csrk);
757 kfree_sensitive(smp->responder_csrk);
758 kfree_sensitive(smp->link_key);
759
760 crypto_free_shash(smp->tfm_cmac);
761 crypto_free_kpp(smp->tfm_ecdh);
762
763 /* Ensure that we don't leave any debug key around if debug key
764 * support hasn't been explicitly enabled.
765 */
766 if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG &&
767 !hci_dev_test_flag(hcon->hdev, HCI_KEEP_DEBUG_KEYS)) {
768 list_del_rcu(&smp->ltk->list);
769 kfree_rcu(smp->ltk, rcu);
770 smp->ltk = NULL;
771 }
772
773 /* If pairing failed clean up any keys we might have */
774 if (!complete) {
775 if (smp->ltk) {
776 list_del_rcu(&smp->ltk->list);
777 kfree_rcu(smp->ltk, rcu);
778 }
779
780 if (smp->responder_ltk) {
781 list_del_rcu(&smp->responder_ltk->list);
782 kfree_rcu(smp->responder_ltk, rcu);
783 }
784
785 if (smp->remote_irk) {
786 list_del_rcu(&smp->remote_irk->list);
787 kfree_rcu(smp->remote_irk, rcu);
788 }
789 }
790
791 chan->data = NULL;
792 kfree_sensitive(smp);
793 hci_conn_drop(hcon);
794}
795
796static void smp_failure(struct l2cap_conn *conn, u8 reason)
797{
798 struct hci_conn *hcon = conn->hcon;
799 struct l2cap_chan *chan = conn->smp;
800
801 if (reason)
802 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
803 &reason);
804
805 mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE);
806
807 if (chan->data)
808 smp_chan_destroy(conn);
809}
810
811#define JUST_WORKS 0x00
812#define JUST_CFM 0x01
813#define REQ_PASSKEY 0x02
814#define CFM_PASSKEY 0x03
815#define REQ_OOB 0x04
816#define DSP_PASSKEY 0x05
817#define OVERLAP 0xFF
818
819static const u8 gen_method[5][5] = {
820 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
821 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
822 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
823 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
824 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP },
825};
826
827static const u8 sc_method[5][5] = {
828 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
829 { JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
830 { DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY },
831 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
832 { DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
833};
834
835static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io)
836{
837 /* If either side has unknown io_caps, use JUST_CFM (which gets
838 * converted later to JUST_WORKS if we're initiators.
839 */
840 if (local_io > SMP_IO_KEYBOARD_DISPLAY ||
841 remote_io > SMP_IO_KEYBOARD_DISPLAY)
842 return JUST_CFM;
843
844 if (test_bit(SMP_FLAG_SC, &smp->flags))
845 return sc_method[remote_io][local_io];
846
847 return gen_method[remote_io][local_io];
848}
849
850static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth,
851 u8 local_io, u8 remote_io)
852{
853 struct hci_conn *hcon = conn->hcon;
854 struct l2cap_chan *chan = conn->smp;
855 struct smp_chan *smp = chan->data;
856 u32 passkey = 0;
857 int ret;
858
859 /* Initialize key for JUST WORKS */
860 memset(smp->tk, 0, sizeof(smp->tk));
861 clear_bit(SMP_FLAG_TK_VALID, &smp->flags);
862
863 bt_dev_dbg(hcon->hdev, "auth:%u lcl:%u rem:%u", auth, local_io,
864 remote_io);
865
866 /* If neither side wants MITM, either "just" confirm an incoming
867 * request or use just-works for outgoing ones. The JUST_CFM
868 * will be converted to JUST_WORKS if necessary later in this
869 * function. If either side has MITM look up the method from the
870 * table.
871 */
872 if (!(auth & SMP_AUTH_MITM))
873 smp->method = JUST_CFM;
874 else
875 smp->method = get_auth_method(smp, local_io, remote_io);
876
877 /* Don't confirm locally initiated pairing attempts */
878 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR,
879 &smp->flags))
880 smp->method = JUST_WORKS;
881
882 /* Don't bother user space with no IO capabilities */
883 if (smp->method == JUST_CFM &&
884 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
885 smp->method = JUST_WORKS;
886
887 /* If Just Works, Continue with Zero TK and ask user-space for
888 * confirmation */
889 if (smp->method == JUST_WORKS) {
890 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
891 hcon->type,
892 hcon->dst_type,
893 passkey, 1);
894 if (ret)
895 return ret;
896 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
897 return 0;
898 }
899
900 /* If this function is used for SC -> legacy fallback we
901 * can only recover the just-works case.
902 */
903 if (test_bit(SMP_FLAG_SC, &smp->flags))
904 return -EINVAL;
905
906 /* Not Just Works/Confirm results in MITM Authentication */
907 if (smp->method != JUST_CFM) {
908 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags);
909 if (hcon->pending_sec_level < BT_SECURITY_HIGH)
910 hcon->pending_sec_level = BT_SECURITY_HIGH;
911 }
912
913 /* If both devices have Keyboard-Display I/O, the initiator
914 * Confirms and the responder Enters the passkey.
915 */
916 if (smp->method == OVERLAP) {
917 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags))
918 smp->method = CFM_PASSKEY;
919 else
920 smp->method = REQ_PASSKEY;
921 }
922
923 /* Generate random passkey. */
924 if (smp->method == CFM_PASSKEY) {
925 memset(smp->tk, 0, sizeof(smp->tk));
926 get_random_bytes(&passkey, sizeof(passkey));
927 passkey %= 1000000;
928 put_unaligned_le32(passkey, smp->tk);
929 bt_dev_dbg(hcon->hdev, "PassKey: %u", passkey);
930 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
931 }
932
933 if (smp->method == REQ_PASSKEY)
934 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst,
935 hcon->type, hcon->dst_type);
936 else if (smp->method == JUST_CFM)
937 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
938 hcon->type, hcon->dst_type,
939 passkey, 1);
940 else
941 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst,
942 hcon->type, hcon->dst_type,
943 passkey, 0);
944
945 return ret;
946}
947
948static u8 smp_confirm(struct smp_chan *smp)
949{
950 struct l2cap_conn *conn = smp->conn;
951 struct smp_cmd_pairing_confirm cp;
952 int ret;
953
954 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn);
955
956 ret = smp_c1(smp->tk, smp->prnd, smp->preq, smp->prsp,
957 conn->hcon->init_addr_type, &conn->hcon->init_addr,
958 conn->hcon->resp_addr_type, &conn->hcon->resp_addr,
959 cp.confirm_val);
960 if (ret)
961 return SMP_UNSPECIFIED;
962
963 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
964
965 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
966
967 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags))
968 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
969 else
970 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
971
972 return 0;
973}
974
975static u8 smp_random(struct smp_chan *smp)
976{
977 struct l2cap_conn *conn = smp->conn;
978 struct hci_conn *hcon = conn->hcon;
979 u8 confirm[16];
980 int ret;
981
982 bt_dev_dbg(conn->hcon->hdev, "conn %p %s", conn,
983 test_bit(SMP_FLAG_INITIATOR, &smp->flags) ? "initiator" :
984 "responder");
985
986 ret = smp_c1(smp->tk, smp->rrnd, smp->preq, smp->prsp,
987 hcon->init_addr_type, &hcon->init_addr,
988 hcon->resp_addr_type, &hcon->resp_addr, confirm);
989 if (ret)
990 return SMP_UNSPECIFIED;
991
992 if (crypto_memneq(smp->pcnf, confirm, sizeof(smp->pcnf))) {
993 bt_dev_err(hcon->hdev, "pairing failed "
994 "(confirmation values mismatch)");
995 return SMP_CONFIRM_FAILED;
996 }
997
998 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
999 u8 stk[16];
1000 __le64 rand = 0;
1001 __le16 ediv = 0;
1002
1003 smp_s1(smp->tk, smp->rrnd, smp->prnd, stk);
1004
1005 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
1006 return SMP_UNSPECIFIED;
1007
1008 hci_le_start_enc(hcon, ediv, rand, stk, smp->enc_key_size);
1009 hcon->enc_key_size = smp->enc_key_size;
1010 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
1011 } else {
1012 u8 stk[16], auth;
1013 __le64 rand = 0;
1014 __le16 ediv = 0;
1015
1016 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
1017 smp->prnd);
1018
1019 smp_s1(smp->tk, smp->prnd, smp->rrnd, stk);
1020
1021 if (hcon->pending_sec_level == BT_SECURITY_HIGH)
1022 auth = 1;
1023 else
1024 auth = 0;
1025
1026 /* Even though there's no _RESPONDER suffix this is the
1027 * responder STK we're adding for later lookup (the initiator
1028 * STK never needs to be stored).
1029 */
1030 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1031 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand);
1032 }
1033
1034 return 0;
1035}
1036
1037static void smp_notify_keys(struct l2cap_conn *conn)
1038{
1039 struct l2cap_chan *chan = conn->smp;
1040 struct smp_chan *smp = chan->data;
1041 struct hci_conn *hcon = conn->hcon;
1042 struct hci_dev *hdev = hcon->hdev;
1043 struct smp_cmd_pairing *req = (void *) &smp->preq[1];
1044 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1];
1045 bool persistent;
1046
1047 if (hcon->type == ACL_LINK) {
1048 if (hcon->key_type == HCI_LK_DEBUG_COMBINATION)
1049 persistent = false;
1050 else
1051 persistent = !test_bit(HCI_CONN_FLUSH_KEY,
1052 &hcon->flags);
1053 } else {
1054 /* The LTKs, IRKs and CSRKs should be persistent only if
1055 * both sides had the bonding bit set in their
1056 * authentication requests.
1057 */
1058 persistent = !!((req->auth_req & rsp->auth_req) &
1059 SMP_AUTH_BONDING);
1060 }
1061
1062 if (smp->remote_irk) {
1063 mgmt_new_irk(hdev, smp->remote_irk, persistent);
1064
1065 /* Now that user space can be considered to know the
1066 * identity address track the connection based on it
1067 * from now on (assuming this is an LE link).
1068 */
1069 if (hcon->type == LE_LINK) {
1070 bacpy(&hcon->dst, &smp->remote_irk->bdaddr);
1071 hcon->dst_type = smp->remote_irk->addr_type;
1072 /* Use a short delay to make sure the new address is
1073 * propagated _before_ the channels.
1074 */
1075 queue_delayed_work(hdev->workqueue,
1076 &conn->id_addr_timer,
1077 ID_ADDR_TIMEOUT);
1078 }
1079 }
1080
1081 if (smp->csrk) {
1082 smp->csrk->bdaddr_type = hcon->dst_type;
1083 bacpy(&smp->csrk->bdaddr, &hcon->dst);
1084 mgmt_new_csrk(hdev, smp->csrk, persistent);
1085 }
1086
1087 if (smp->responder_csrk) {
1088 smp->responder_csrk->bdaddr_type = hcon->dst_type;
1089 bacpy(&smp->responder_csrk->bdaddr, &hcon->dst);
1090 mgmt_new_csrk(hdev, smp->responder_csrk, persistent);
1091 }
1092
1093 if (smp->ltk) {
1094 smp->ltk->bdaddr_type = hcon->dst_type;
1095 bacpy(&smp->ltk->bdaddr, &hcon->dst);
1096 mgmt_new_ltk(hdev, smp->ltk, persistent);
1097 }
1098
1099 if (smp->responder_ltk) {
1100 smp->responder_ltk->bdaddr_type = hcon->dst_type;
1101 bacpy(&smp->responder_ltk->bdaddr, &hcon->dst);
1102 mgmt_new_ltk(hdev, smp->responder_ltk, persistent);
1103 }
1104
1105 if (smp->link_key) {
1106 struct link_key *key;
1107 u8 type;
1108
1109 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1110 type = HCI_LK_DEBUG_COMBINATION;
1111 else if (hcon->sec_level == BT_SECURITY_FIPS)
1112 type = HCI_LK_AUTH_COMBINATION_P256;
1113 else
1114 type = HCI_LK_UNAUTH_COMBINATION_P256;
1115
1116 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst,
1117 smp->link_key, type, 0, &persistent);
1118 if (key) {
1119 mgmt_new_link_key(hdev, key, persistent);
1120
1121 /* Don't keep debug keys around if the relevant
1122 * flag is not set.
1123 */
1124 if (!hci_dev_test_flag(hdev, HCI_KEEP_DEBUG_KEYS) &&
1125 key->type == HCI_LK_DEBUG_COMBINATION) {
1126 list_del_rcu(&key->list);
1127 kfree_rcu(key, rcu);
1128 }
1129 }
1130 }
1131}
1132
1133static void sc_add_ltk(struct smp_chan *smp)
1134{
1135 struct hci_conn *hcon = smp->conn->hcon;
1136 u8 key_type, auth;
1137
1138 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1139 key_type = SMP_LTK_P256_DEBUG;
1140 else
1141 key_type = SMP_LTK_P256;
1142
1143 if (hcon->pending_sec_level == BT_SECURITY_FIPS)
1144 auth = 1;
1145 else
1146 auth = 0;
1147
1148 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1149 key_type, auth, smp->tk, smp->enc_key_size,
1150 0, 0);
1151}
1152
1153static void sc_generate_link_key(struct smp_chan *smp)
1154{
1155 /* From core spec. Spells out in ASCII as 'lebr'. */
1156 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c };
1157
1158 smp->link_key = kzalloc(16, GFP_KERNEL);
1159 if (!smp->link_key)
1160 return;
1161
1162 if (test_bit(SMP_FLAG_CT2, &smp->flags)) {
1163 /* SALT = 0x000000000000000000000000746D7031 */
1164 const u8 salt[16] = { 0x31, 0x70, 0x6d, 0x74 };
1165
1166 if (smp_h7(smp->tfm_cmac, smp->tk, salt, smp->link_key)) {
1167 kfree_sensitive(smp->link_key);
1168 smp->link_key = NULL;
1169 return;
1170 }
1171 } else {
1172 /* From core spec. Spells out in ASCII as 'tmp1'. */
1173 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 };
1174
1175 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) {
1176 kfree_sensitive(smp->link_key);
1177 smp->link_key = NULL;
1178 return;
1179 }
1180 }
1181
1182 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) {
1183 kfree_sensitive(smp->link_key);
1184 smp->link_key = NULL;
1185 return;
1186 }
1187}
1188
1189static void smp_allow_key_dist(struct smp_chan *smp)
1190{
1191 /* Allow the first expected phase 3 PDU. The rest of the PDUs
1192 * will be allowed in each PDU handler to ensure we receive
1193 * them in the correct order.
1194 */
1195 if (smp->remote_key_dist & SMP_DIST_ENC_KEY)
1196 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO);
1197 else if (smp->remote_key_dist & SMP_DIST_ID_KEY)
1198 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
1199 else if (smp->remote_key_dist & SMP_DIST_SIGN)
1200 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
1201}
1202
1203static void sc_generate_ltk(struct smp_chan *smp)
1204{
1205 /* From core spec. Spells out in ASCII as 'brle'. */
1206 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 };
1207 struct hci_conn *hcon = smp->conn->hcon;
1208 struct hci_dev *hdev = hcon->hdev;
1209 struct link_key *key;
1210
1211 key = hci_find_link_key(hdev, &hcon->dst);
1212 if (!key) {
1213 bt_dev_err(hdev, "no Link Key found to generate LTK");
1214 return;
1215 }
1216
1217 if (key->type == HCI_LK_DEBUG_COMBINATION)
1218 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1219
1220 if (test_bit(SMP_FLAG_CT2, &smp->flags)) {
1221 /* SALT = 0x000000000000000000000000746D7032 */
1222 const u8 salt[16] = { 0x32, 0x70, 0x6d, 0x74 };
1223
1224 if (smp_h7(smp->tfm_cmac, key->val, salt, smp->tk))
1225 return;
1226 } else {
1227 /* From core spec. Spells out in ASCII as 'tmp2'. */
1228 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 };
1229
1230 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk))
1231 return;
1232 }
1233
1234 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk))
1235 return;
1236
1237 sc_add_ltk(smp);
1238}
1239
1240static void smp_distribute_keys(struct smp_chan *smp)
1241{
1242 struct smp_cmd_pairing *req, *rsp;
1243 struct l2cap_conn *conn = smp->conn;
1244 struct hci_conn *hcon = conn->hcon;
1245 struct hci_dev *hdev = hcon->hdev;
1246 __u8 *keydist;
1247
1248 bt_dev_dbg(hdev, "conn %p", conn);
1249
1250 rsp = (void *) &smp->prsp[1];
1251
1252 /* The responder sends its keys first */
1253 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags) &&
1254 (smp->remote_key_dist & KEY_DIST_MASK)) {
1255 smp_allow_key_dist(smp);
1256 return;
1257 }
1258
1259 req = (void *) &smp->preq[1];
1260
1261 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1262 keydist = &rsp->init_key_dist;
1263 *keydist &= req->init_key_dist;
1264 } else {
1265 keydist = &rsp->resp_key_dist;
1266 *keydist &= req->resp_key_dist;
1267 }
1268
1269 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1270 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY))
1271 sc_generate_link_key(smp);
1272 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY))
1273 sc_generate_ltk(smp);
1274
1275 /* Clear the keys which are generated but not distributed */
1276 *keydist &= ~SMP_SC_NO_DIST;
1277 }
1278
1279 bt_dev_dbg(hdev, "keydist 0x%x", *keydist);
1280
1281 if (*keydist & SMP_DIST_ENC_KEY) {
1282 struct smp_cmd_encrypt_info enc;
1283 struct smp_cmd_initiator_ident ident;
1284 struct smp_ltk *ltk;
1285 u8 authenticated;
1286 __le16 ediv;
1287 __le64 rand;
1288
1289 /* Make sure we generate only the significant amount of
1290 * bytes based on the encryption key size, and set the rest
1291 * of the value to zeroes.
1292 */
1293 get_random_bytes(enc.ltk, smp->enc_key_size);
1294 memset(enc.ltk + smp->enc_key_size, 0,
1295 sizeof(enc.ltk) - smp->enc_key_size);
1296
1297 get_random_bytes(&ediv, sizeof(ediv));
1298 get_random_bytes(&rand, sizeof(rand));
1299
1300 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc);
1301
1302 authenticated = hcon->sec_level == BT_SECURITY_HIGH;
1303 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type,
1304 SMP_LTK_RESPONDER, authenticated, enc.ltk,
1305 smp->enc_key_size, ediv, rand);
1306 smp->responder_ltk = ltk;
1307
1308 ident.ediv = ediv;
1309 ident.rand = rand;
1310
1311 smp_send_cmd(conn, SMP_CMD_INITIATOR_IDENT, sizeof(ident),
1312 &ident);
1313
1314 *keydist &= ~SMP_DIST_ENC_KEY;
1315 }
1316
1317 if (*keydist & SMP_DIST_ID_KEY) {
1318 struct smp_cmd_ident_addr_info addrinfo;
1319 struct smp_cmd_ident_info idinfo;
1320
1321 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk));
1322
1323 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo);
1324
1325 /* The hci_conn contains the local identity address
1326 * after the connection has been established.
1327 *
1328 * This is true even when the connection has been
1329 * established using a resolvable random address.
1330 */
1331 bacpy(&addrinfo.bdaddr, &hcon->src);
1332 addrinfo.addr_type = hcon->src_type;
1333
1334 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo),
1335 &addrinfo);
1336
1337 *keydist &= ~SMP_DIST_ID_KEY;
1338 }
1339
1340 if (*keydist & SMP_DIST_SIGN) {
1341 struct smp_cmd_sign_info sign;
1342 struct smp_csrk *csrk;
1343
1344 /* Generate a new random key */
1345 get_random_bytes(sign.csrk, sizeof(sign.csrk));
1346
1347 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
1348 if (csrk) {
1349 if (hcon->sec_level > BT_SECURITY_MEDIUM)
1350 csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED;
1351 else
1352 csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED;
1353 memcpy(csrk->val, sign.csrk, sizeof(csrk->val));
1354 }
1355 smp->responder_csrk = csrk;
1356
1357 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign);
1358
1359 *keydist &= ~SMP_DIST_SIGN;
1360 }
1361
1362 /* If there are still keys to be received wait for them */
1363 if (smp->remote_key_dist & KEY_DIST_MASK) {
1364 smp_allow_key_dist(smp);
1365 return;
1366 }
1367
1368 set_bit(SMP_FLAG_COMPLETE, &smp->flags);
1369 smp_notify_keys(conn);
1370
1371 smp_chan_destroy(conn);
1372}
1373
1374static void smp_timeout(struct work_struct *work)
1375{
1376 struct smp_chan *smp = container_of(work, struct smp_chan,
1377 security_timer.work);
1378 struct l2cap_conn *conn = smp->conn;
1379
1380 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn);
1381
1382 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM);
1383}
1384
1385static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
1386{
1387 struct hci_conn *hcon = conn->hcon;
1388 struct l2cap_chan *chan = conn->smp;
1389 struct smp_chan *smp;
1390
1391 smp = kzalloc(sizeof(*smp), GFP_ATOMIC);
1392 if (!smp)
1393 return NULL;
1394
1395 smp->tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
1396 if (IS_ERR(smp->tfm_cmac)) {
1397 bt_dev_err(hcon->hdev, "Unable to create CMAC crypto context");
1398 goto zfree_smp;
1399 }
1400
1401 smp->tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0);
1402 if (IS_ERR(smp->tfm_ecdh)) {
1403 bt_dev_err(hcon->hdev, "Unable to create ECDH crypto context");
1404 goto free_shash;
1405 }
1406
1407 smp->conn = conn;
1408 chan->data = smp;
1409
1410 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL);
1411
1412 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout);
1413
1414 hci_conn_hold(hcon);
1415
1416 return smp;
1417
1418free_shash:
1419 crypto_free_shash(smp->tfm_cmac);
1420zfree_smp:
1421 kfree_sensitive(smp);
1422 return NULL;
1423}
1424
1425static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16])
1426{
1427 struct hci_conn *hcon = smp->conn->hcon;
1428 u8 *na, *nb, a[7], b[7];
1429
1430 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1431 na = smp->prnd;
1432 nb = smp->rrnd;
1433 } else {
1434 na = smp->rrnd;
1435 nb = smp->prnd;
1436 }
1437
1438 memcpy(a, &hcon->init_addr, 6);
1439 memcpy(b, &hcon->resp_addr, 6);
1440 a[6] = hcon->init_addr_type;
1441 b[6] = hcon->resp_addr_type;
1442
1443 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk);
1444}
1445
1446static void sc_dhkey_check(struct smp_chan *smp)
1447{
1448 struct hci_conn *hcon = smp->conn->hcon;
1449 struct smp_cmd_dhkey_check check;
1450 u8 a[7], b[7], *local_addr, *remote_addr;
1451 u8 io_cap[3], r[16];
1452
1453 memcpy(a, &hcon->init_addr, 6);
1454 memcpy(b, &hcon->resp_addr, 6);
1455 a[6] = hcon->init_addr_type;
1456 b[6] = hcon->resp_addr_type;
1457
1458 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1459 local_addr = a;
1460 remote_addr = b;
1461 memcpy(io_cap, &smp->preq[1], 3);
1462 } else {
1463 local_addr = b;
1464 remote_addr = a;
1465 memcpy(io_cap, &smp->prsp[1], 3);
1466 }
1467
1468 memset(r, 0, sizeof(r));
1469
1470 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
1471 put_unaligned_le32(hcon->passkey_notify, r);
1472
1473 if (smp->method == REQ_OOB)
1474 memcpy(r, smp->rr, 16);
1475
1476 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap,
1477 local_addr, remote_addr, check.e);
1478
1479 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check);
1480}
1481
1482static u8 sc_passkey_send_confirm(struct smp_chan *smp)
1483{
1484 struct l2cap_conn *conn = smp->conn;
1485 struct hci_conn *hcon = conn->hcon;
1486 struct smp_cmd_pairing_confirm cfm;
1487 u8 r;
1488
1489 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1490 r |= 0x80;
1491
1492 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1493
1494 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r,
1495 cfm.confirm_val))
1496 return SMP_UNSPECIFIED;
1497
1498 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
1499
1500 return 0;
1501}
1502
1503static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op)
1504{
1505 struct l2cap_conn *conn = smp->conn;
1506 struct hci_conn *hcon = conn->hcon;
1507 struct hci_dev *hdev = hcon->hdev;
1508 u8 cfm[16], r;
1509
1510 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */
1511 if (smp->passkey_round >= 20)
1512 return 0;
1513
1514 switch (smp_op) {
1515 case SMP_CMD_PAIRING_RANDOM:
1516 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1517 r |= 0x80;
1518
1519 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
1520 smp->rrnd, r, cfm))
1521 return SMP_UNSPECIFIED;
1522
1523 if (crypto_memneq(smp->pcnf, cfm, 16))
1524 return SMP_CONFIRM_FAILED;
1525
1526 smp->passkey_round++;
1527
1528 if (smp->passkey_round == 20) {
1529 /* Generate MacKey and LTK */
1530 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk))
1531 return SMP_UNSPECIFIED;
1532 }
1533
1534 /* The round is only complete when the initiator
1535 * receives pairing random.
1536 */
1537 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1538 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1539 sizeof(smp->prnd), smp->prnd);
1540 if (smp->passkey_round == 20)
1541 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1542 else
1543 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1544 return 0;
1545 }
1546
1547 /* Start the next round */
1548 if (smp->passkey_round != 20)
1549 return sc_passkey_round(smp, 0);
1550
1551 /* Passkey rounds are complete - start DHKey Check */
1552 sc_dhkey_check(smp);
1553 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1554
1555 break;
1556
1557 case SMP_CMD_PAIRING_CONFIRM:
1558 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
1559 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
1560 return 0;
1561 }
1562
1563 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
1564
1565 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1566 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1567 sizeof(smp->prnd), smp->prnd);
1568 return 0;
1569 }
1570
1571 return sc_passkey_send_confirm(smp);
1572
1573 case SMP_CMD_PUBLIC_KEY:
1574 default:
1575 /* Initiating device starts the round */
1576 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags))
1577 return 0;
1578
1579 bt_dev_dbg(hdev, "Starting passkey round %u",
1580 smp->passkey_round + 1);
1581
1582 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1583
1584 return sc_passkey_send_confirm(smp);
1585 }
1586
1587 return 0;
1588}
1589
1590static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey)
1591{
1592 struct l2cap_conn *conn = smp->conn;
1593 struct hci_conn *hcon = conn->hcon;
1594 u8 smp_op;
1595
1596 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags);
1597
1598 switch (mgmt_op) {
1599 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1600 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED);
1601 return 0;
1602 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1603 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED);
1604 return 0;
1605 case MGMT_OP_USER_PASSKEY_REPLY:
1606 hcon->passkey_notify = le32_to_cpu(passkey);
1607 smp->passkey_round = 0;
1608
1609 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags))
1610 smp_op = SMP_CMD_PAIRING_CONFIRM;
1611 else
1612 smp_op = 0;
1613
1614 if (sc_passkey_round(smp, smp_op))
1615 return -EIO;
1616
1617 return 0;
1618 }
1619
1620 /* Initiator sends DHKey check first */
1621 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1622 sc_dhkey_check(smp);
1623 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1624 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) {
1625 sc_dhkey_check(smp);
1626 sc_add_ltk(smp);
1627 }
1628
1629 return 0;
1630}
1631
1632int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey)
1633{
1634 struct l2cap_conn *conn = hcon->l2cap_data;
1635 struct l2cap_chan *chan;
1636 struct smp_chan *smp;
1637 u32 value;
1638 int err;
1639
1640 if (!conn)
1641 return -ENOTCONN;
1642
1643 bt_dev_dbg(conn->hcon->hdev, "");
1644
1645 chan = conn->smp;
1646 if (!chan)
1647 return -ENOTCONN;
1648
1649 l2cap_chan_lock(chan);
1650 if (!chan->data) {
1651 err = -ENOTCONN;
1652 goto unlock;
1653 }
1654
1655 smp = chan->data;
1656
1657 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1658 err = sc_user_reply(smp, mgmt_op, passkey);
1659 goto unlock;
1660 }
1661
1662 switch (mgmt_op) {
1663 case MGMT_OP_USER_PASSKEY_REPLY:
1664 value = le32_to_cpu(passkey);
1665 memset(smp->tk, 0, sizeof(smp->tk));
1666 bt_dev_dbg(conn->hcon->hdev, "PassKey: %u", value);
1667 put_unaligned_le32(value, smp->tk);
1668 fallthrough;
1669 case MGMT_OP_USER_CONFIRM_REPLY:
1670 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
1671 break;
1672 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1673 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1674 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1675 err = 0;
1676 goto unlock;
1677 default:
1678 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1679 err = -EOPNOTSUPP;
1680 goto unlock;
1681 }
1682
1683 err = 0;
1684
1685 /* If it is our turn to send Pairing Confirm, do so now */
1686 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) {
1687 u8 rsp = smp_confirm(smp);
1688 if (rsp)
1689 smp_failure(conn, rsp);
1690 }
1691
1692unlock:
1693 l2cap_chan_unlock(chan);
1694 return err;
1695}
1696
1697static void build_bredr_pairing_cmd(struct smp_chan *smp,
1698 struct smp_cmd_pairing *req,
1699 struct smp_cmd_pairing *rsp)
1700{
1701 struct l2cap_conn *conn = smp->conn;
1702 struct hci_dev *hdev = conn->hcon->hdev;
1703 u8 local_dist = 0, remote_dist = 0;
1704
1705 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) {
1706 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1707 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1708 }
1709
1710 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING))
1711 remote_dist |= SMP_DIST_ID_KEY;
1712
1713 if (hci_dev_test_flag(hdev, HCI_PRIVACY))
1714 local_dist |= SMP_DIST_ID_KEY;
1715
1716 if (!rsp) {
1717 memset(req, 0, sizeof(*req));
1718
1719 req->auth_req = SMP_AUTH_CT2;
1720 req->init_key_dist = local_dist;
1721 req->resp_key_dist = remote_dist;
1722 req->max_key_size = conn->hcon->enc_key_size;
1723
1724 smp->remote_key_dist = remote_dist;
1725
1726 return;
1727 }
1728
1729 memset(rsp, 0, sizeof(*rsp));
1730
1731 rsp->auth_req = SMP_AUTH_CT2;
1732 rsp->max_key_size = conn->hcon->enc_key_size;
1733 rsp->init_key_dist = req->init_key_dist & remote_dist;
1734 rsp->resp_key_dist = req->resp_key_dist & local_dist;
1735
1736 smp->remote_key_dist = rsp->init_key_dist;
1737}
1738
1739static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
1740{
1741 struct smp_cmd_pairing rsp, *req = (void *) skb->data;
1742 struct l2cap_chan *chan = conn->smp;
1743 struct hci_dev *hdev = conn->hcon->hdev;
1744 struct smp_chan *smp = chan->data;
1745 u8 key_size, auth, sec_level;
1746 int ret;
1747
1748 bt_dev_dbg(hdev, "conn %p", conn);
1749
1750 if (skb->len < sizeof(*req))
1751 return SMP_INVALID_PARAMS;
1752
1753 if (smp && test_bit(SMP_FLAG_INITIATOR, &smp->flags))
1754 return SMP_CMD_NOTSUPP;
1755
1756 if (!smp) {
1757 smp = smp_chan_create(conn);
1758 if (!smp)
1759 return SMP_UNSPECIFIED;
1760 }
1761
1762 /* We didn't start the pairing, so match remote */
1763 auth = req->auth_req & AUTH_REQ_MASK(hdev);
1764
1765 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) &&
1766 (auth & SMP_AUTH_BONDING))
1767 return SMP_PAIRING_NOTSUPP;
1768
1769 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
1770 return SMP_AUTH_REQUIREMENTS;
1771
1772 smp->preq[0] = SMP_CMD_PAIRING_REQ;
1773 memcpy(&smp->preq[1], req, sizeof(*req));
1774 skb_pull(skb, sizeof(*req));
1775
1776 /* If the remote side's OOB flag is set it means it has
1777 * successfully received our local OOB data - therefore set the
1778 * flag to indicate that local OOB is in use.
1779 */
1780 if (req->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob)
1781 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);
1782
1783 /* SMP over BR/EDR requires special treatment */
1784 if (conn->hcon->type == ACL_LINK) {
1785 /* We must have a BR/EDR SC link */
1786 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) &&
1787 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
1788 return SMP_CROSS_TRANSP_NOT_ALLOWED;
1789
1790 set_bit(SMP_FLAG_SC, &smp->flags);
1791
1792 build_bredr_pairing_cmd(smp, req, &rsp);
1793
1794 if (req->auth_req & SMP_AUTH_CT2)
1795 set_bit(SMP_FLAG_CT2, &smp->flags);
1796
1797 key_size = min(req->max_key_size, rsp.max_key_size);
1798 if (check_enc_key_size(conn, key_size))
1799 return SMP_ENC_KEY_SIZE;
1800
1801 /* Clear bits which are generated but not distributed */
1802 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1803
1804 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1805 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1806 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1807
1808 smp_distribute_keys(smp);
1809 return 0;
1810 }
1811
1812 build_pairing_cmd(conn, req, &rsp, auth);
1813
1814 if (rsp.auth_req & SMP_AUTH_SC) {
1815 set_bit(SMP_FLAG_SC, &smp->flags);
1816
1817 if (rsp.auth_req & SMP_AUTH_CT2)
1818 set_bit(SMP_FLAG_CT2, &smp->flags);
1819 }
1820
1821 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
1822 sec_level = BT_SECURITY_MEDIUM;
1823 else
1824 sec_level = authreq_to_seclevel(auth);
1825
1826 if (sec_level > conn->hcon->pending_sec_level)
1827 conn->hcon->pending_sec_level = sec_level;
1828
1829 /* If we need MITM check that it can be achieved */
1830 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1831 u8 method;
1832
1833 method = get_auth_method(smp, conn->hcon->io_capability,
1834 req->io_capability);
1835 if (method == JUST_WORKS || method == JUST_CFM)
1836 return SMP_AUTH_REQUIREMENTS;
1837 }
1838
1839 key_size = min(req->max_key_size, rsp.max_key_size);
1840 if (check_enc_key_size(conn, key_size))
1841 return SMP_ENC_KEY_SIZE;
1842
1843 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1844
1845 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1846 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1847
1848 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1849
1850 clear_bit(SMP_FLAG_INITIATOR, &smp->flags);
1851
1852 /* Strictly speaking we shouldn't allow Pairing Confirm for the
1853 * SC case, however some implementations incorrectly copy RFU auth
1854 * req bits from our security request, which may create a false
1855 * positive SC enablement.
1856 */
1857 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1858
1859 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1860 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
1861 /* Clear bits which are generated but not distributed */
1862 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1863 /* Wait for Public Key from Initiating Device */
1864 return 0;
1865 }
1866
1867 /* Request setup of TK */
1868 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability);
1869 if (ret)
1870 return SMP_UNSPECIFIED;
1871
1872 return 0;
1873}
1874
1875static u8 sc_send_public_key(struct smp_chan *smp)
1876{
1877 struct hci_dev *hdev = smp->conn->hcon->hdev;
1878
1879 bt_dev_dbg(hdev, "");
1880
1881 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) {
1882 struct l2cap_chan *chan = hdev->smp_data;
1883 struct smp_dev *smp_dev;
1884
1885 if (!chan || !chan->data)
1886 return SMP_UNSPECIFIED;
1887
1888 smp_dev = chan->data;
1889
1890 memcpy(smp->local_pk, smp_dev->local_pk, 64);
1891 memcpy(smp->lr, smp_dev->local_rand, 16);
1892
1893 if (smp_dev->debug_key)
1894 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1895
1896 goto done;
1897 }
1898
1899 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) {
1900 bt_dev_dbg(hdev, "Using debug keys");
1901 if (set_ecdh_privkey(smp->tfm_ecdh, debug_sk))
1902 return SMP_UNSPECIFIED;
1903 memcpy(smp->local_pk, debug_pk, 64);
1904 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1905 } else {
1906 while (true) {
1907 /* Generate key pair for Secure Connections */
1908 if (generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk))
1909 return SMP_UNSPECIFIED;
1910
1911 /* This is unlikely, but we need to check that
1912 * we didn't accidentally generate a debug key.
1913 */
1914 if (crypto_memneq(smp->local_pk, debug_pk, 64))
1915 break;
1916 }
1917 }
1918
1919done:
1920 SMP_DBG("Local Public Key X: %32phN", smp->local_pk);
1921 SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32);
1922
1923 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk);
1924
1925 return 0;
1926}
1927
1928static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
1929{
1930 struct smp_cmd_pairing *req, *rsp = (void *) skb->data;
1931 struct l2cap_chan *chan = conn->smp;
1932 struct smp_chan *smp = chan->data;
1933 struct hci_dev *hdev = conn->hcon->hdev;
1934 u8 key_size, auth;
1935 int ret;
1936
1937 bt_dev_dbg(hdev, "conn %p", conn);
1938
1939 if (skb->len < sizeof(*rsp))
1940 return SMP_INVALID_PARAMS;
1941
1942 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags))
1943 return SMP_CMD_NOTSUPP;
1944
1945 skb_pull(skb, sizeof(*rsp));
1946
1947 req = (void *) &smp->preq[1];
1948
1949 key_size = min(req->max_key_size, rsp->max_key_size);
1950 if (check_enc_key_size(conn, key_size))
1951 return SMP_ENC_KEY_SIZE;
1952
1953 auth = rsp->auth_req & AUTH_REQ_MASK(hdev);
1954
1955 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
1956 return SMP_AUTH_REQUIREMENTS;
1957
1958 /* If the remote side's OOB flag is set it means it has
1959 * successfully received our local OOB data - therefore set the
1960 * flag to indicate that local OOB is in use.
1961 */
1962 if (rsp->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob)
1963 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);
1964
1965 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1966 memcpy(&smp->prsp[1], rsp, sizeof(*rsp));
1967
1968 /* Update remote key distribution in case the remote cleared
1969 * some bits that we had enabled in our request.
1970 */
1971 smp->remote_key_dist &= rsp->resp_key_dist;
1972
1973 if ((req->auth_req & SMP_AUTH_CT2) && (auth & SMP_AUTH_CT2))
1974 set_bit(SMP_FLAG_CT2, &smp->flags);
1975
1976 /* For BR/EDR this means we're done and can start phase 3 */
1977 if (conn->hcon->type == ACL_LINK) {
1978 /* Clear bits which are generated but not distributed */
1979 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1980 smp_distribute_keys(smp);
1981 return 0;
1982 }
1983
1984 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC))
1985 set_bit(SMP_FLAG_SC, &smp->flags);
1986 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH)
1987 conn->hcon->pending_sec_level = BT_SECURITY_HIGH;
1988
1989 /* If we need MITM check that it can be achieved */
1990 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1991 u8 method;
1992
1993 method = get_auth_method(smp, req->io_capability,
1994 rsp->io_capability);
1995 if (method == JUST_WORKS || method == JUST_CFM)
1996 return SMP_AUTH_REQUIREMENTS;
1997 }
1998
1999 get_random_bytes(smp->prnd, sizeof(smp->prnd));
2000
2001 /* Update remote key distribution in case the remote cleared
2002 * some bits that we had enabled in our request.
2003 */
2004 smp->remote_key_dist &= rsp->resp_key_dist;
2005
2006 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
2007 /* Clear bits which are generated but not distributed */
2008 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
2009 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
2010 return sc_send_public_key(smp);
2011 }
2012
2013 auth |= req->auth_req;
2014
2015 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability);
2016 if (ret)
2017 return SMP_UNSPECIFIED;
2018
2019 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
2020
2021 /* Can't compose response until we have been confirmed */
2022 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
2023 return smp_confirm(smp);
2024
2025 return 0;
2026}
2027
2028static u8 sc_check_confirm(struct smp_chan *smp)
2029{
2030 struct l2cap_conn *conn = smp->conn;
2031
2032 bt_dev_dbg(conn->hcon->hdev, "");
2033
2034 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2035 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM);
2036
2037 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2038 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2039 smp->prnd);
2040 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2041 }
2042
2043 return 0;
2044}
2045
2046/* Work-around for some implementations that incorrectly copy RFU bits
2047 * from our security request and thereby create the impression that
2048 * we're doing SC when in fact the remote doesn't support it.
2049 */
2050static int fixup_sc_false_positive(struct smp_chan *smp)
2051{
2052 struct l2cap_conn *conn = smp->conn;
2053 struct hci_conn *hcon = conn->hcon;
2054 struct hci_dev *hdev = hcon->hdev;
2055 struct smp_cmd_pairing *req, *rsp;
2056 u8 auth;
2057
2058 /* The issue is only observed when we're in responder role */
2059 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2060 return SMP_UNSPECIFIED;
2061
2062 if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) {
2063 bt_dev_err(hdev, "refusing legacy fallback in SC-only mode");
2064 return SMP_UNSPECIFIED;
2065 }
2066
2067 bt_dev_err(hdev, "trying to fall back to legacy SMP");
2068
2069 req = (void *) &smp->preq[1];
2070 rsp = (void *) &smp->prsp[1];
2071
2072 /* Rebuild key dist flags which may have been cleared for SC */
2073 smp->remote_key_dist = (req->init_key_dist & rsp->resp_key_dist);
2074
2075 auth = req->auth_req & AUTH_REQ_MASK(hdev);
2076
2077 if (tk_request(conn, 0, auth, rsp->io_capability, req->io_capability)) {
2078 bt_dev_err(hdev, "failed to fall back to legacy SMP");
2079 return SMP_UNSPECIFIED;
2080 }
2081
2082 clear_bit(SMP_FLAG_SC, &smp->flags);
2083
2084 return 0;
2085}
2086
2087static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
2088{
2089 struct l2cap_chan *chan = conn->smp;
2090 struct smp_chan *smp = chan->data;
2091 struct hci_conn *hcon = conn->hcon;
2092 struct hci_dev *hdev = hcon->hdev;
2093
2094 bt_dev_dbg(hdev, "conn %p %s", conn,
2095 test_bit(SMP_FLAG_INITIATOR, &smp->flags) ? "initiator" :
2096 "responder");
2097
2098 if (skb->len < sizeof(smp->pcnf))
2099 return SMP_INVALID_PARAMS;
2100
2101 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf));
2102 skb_pull(skb, sizeof(smp->pcnf));
2103
2104 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
2105 int ret;
2106
2107 /* Public Key exchange must happen before any other steps */
2108 if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags))
2109 return sc_check_confirm(smp);
2110
2111 bt_dev_err(hdev, "Unexpected SMP Pairing Confirm");
2112
2113 ret = fixup_sc_false_positive(smp);
2114 if (ret)
2115 return ret;
2116 }
2117
2118 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2119 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2120 smp->prnd);
2121 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2122 return 0;
2123 }
2124
2125 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
2126 return smp_confirm(smp);
2127
2128 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
2129
2130 return 0;
2131}
2132
2133static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
2134{
2135 struct l2cap_chan *chan = conn->smp;
2136 struct smp_chan *smp = chan->data;
2137 struct hci_conn *hcon = conn->hcon;
2138 u8 *pkax, *pkbx, *na, *nb, confirm_hint;
2139 u32 passkey;
2140 int err;
2141
2142 bt_dev_dbg(hcon->hdev, "conn %p", conn);
2143
2144 if (skb->len < sizeof(smp->rrnd))
2145 return SMP_INVALID_PARAMS;
2146
2147 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd));
2148 skb_pull(skb, sizeof(smp->rrnd));
2149
2150 if (!test_bit(SMP_FLAG_SC, &smp->flags))
2151 return smp_random(smp);
2152
2153 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2154 pkax = smp->local_pk;
2155 pkbx = smp->remote_pk;
2156 na = smp->prnd;
2157 nb = smp->rrnd;
2158 } else {
2159 pkax = smp->remote_pk;
2160 pkbx = smp->local_pk;
2161 na = smp->rrnd;
2162 nb = smp->prnd;
2163 }
2164
2165 if (smp->method == REQ_OOB) {
2166 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2167 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2168 sizeof(smp->prnd), smp->prnd);
2169 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2170 goto mackey_and_ltk;
2171 }
2172
2173 /* Passkey entry has special treatment */
2174 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2175 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM);
2176
2177 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2178 u8 cfm[16];
2179
2180 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
2181 smp->rrnd, 0, cfm);
2182 if (err)
2183 return SMP_UNSPECIFIED;
2184
2185 if (crypto_memneq(smp->pcnf, cfm, 16))
2186 return SMP_CONFIRM_FAILED;
2187 } else {
2188 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2189 smp->prnd);
2190 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2191
2192 /* Only Just-Works pairing requires extra checks */
2193 if (smp->method != JUST_WORKS)
2194 goto mackey_and_ltk;
2195
2196 /* If there already exists long term key in local host, leave
2197 * the decision to user space since the remote device could
2198 * be legitimate or malicious.
2199 */
2200 if (hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
2201 hcon->role)) {
2202 /* Set passkey to 0. The value can be any number since
2203 * it'll be ignored anyway.
2204 */
2205 passkey = 0;
2206 confirm_hint = 1;
2207 goto confirm;
2208 }
2209 }
2210
2211mackey_and_ltk:
2212 /* Generate MacKey and LTK */
2213 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk);
2214 if (err)
2215 return SMP_UNSPECIFIED;
2216
2217 if (smp->method == REQ_OOB) {
2218 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2219 sc_dhkey_check(smp);
2220 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2221 }
2222 return 0;
2223 }
2224
2225 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
2226 if (err)
2227 return SMP_UNSPECIFIED;
2228
2229 confirm_hint = 0;
2230
2231confirm:
2232 if (smp->method == JUST_WORKS)
2233 confirm_hint = 1;
2234
2235 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type,
2236 hcon->dst_type, passkey, confirm_hint);
2237 if (err)
2238 return SMP_UNSPECIFIED;
2239
2240 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2241
2242 return 0;
2243}
2244
2245static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level)
2246{
2247 struct smp_ltk *key;
2248 struct hci_conn *hcon = conn->hcon;
2249
2250 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role);
2251 if (!key)
2252 return false;
2253
2254 if (smp_ltk_sec_level(key) < sec_level)
2255 return false;
2256
2257 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
2258 return true;
2259
2260 hci_le_start_enc(hcon, key->ediv, key->rand, key->val, key->enc_size);
2261 hcon->enc_key_size = key->enc_size;
2262
2263 /* We never store STKs for initiator role, so clear this flag */
2264 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
2265
2266 return true;
2267}
2268
2269bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level,
2270 enum smp_key_pref key_pref)
2271{
2272 if (sec_level == BT_SECURITY_LOW)
2273 return true;
2274
2275 /* If we're encrypted with an STK but the caller prefers using
2276 * LTK claim insufficient security. This way we allow the
2277 * connection to be re-encrypted with an LTK, even if the LTK
2278 * provides the same level of security. Only exception is if we
2279 * don't have an LTK (e.g. because of key distribution bits).
2280 */
2281 if (key_pref == SMP_USE_LTK &&
2282 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) &&
2283 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role))
2284 return false;
2285
2286 if (hcon->sec_level >= sec_level)
2287 return true;
2288
2289 return false;
2290}
2291
2292static void smp_send_pairing_req(struct smp_chan *smp, __u8 auth)
2293{
2294 struct smp_cmd_pairing cp;
2295
2296 if (smp->conn->hcon->type == ACL_LINK)
2297 build_bredr_pairing_cmd(smp, &cp, NULL);
2298 else
2299 build_pairing_cmd(smp->conn, &cp, NULL, auth);
2300
2301 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2302 memcpy(&smp->preq[1], &cp, sizeof(cp));
2303
2304 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
2305 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2306
2307 set_bit(SMP_FLAG_INITIATOR, &smp->flags);
2308}
2309
2310static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
2311{
2312 struct smp_cmd_security_req *rp = (void *) skb->data;
2313 struct hci_conn *hcon = conn->hcon;
2314 struct hci_dev *hdev = hcon->hdev;
2315 struct smp_chan *smp;
2316 u8 sec_level, auth;
2317
2318 bt_dev_dbg(hdev, "conn %p", conn);
2319
2320 if (skb->len < sizeof(*rp))
2321 return SMP_INVALID_PARAMS;
2322
2323 if (hcon->role != HCI_ROLE_MASTER)
2324 return SMP_CMD_NOTSUPP;
2325
2326 auth = rp->auth_req & AUTH_REQ_MASK(hdev);
2327
2328 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
2329 return SMP_AUTH_REQUIREMENTS;
2330
2331 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
2332 sec_level = BT_SECURITY_MEDIUM;
2333 else
2334 sec_level = authreq_to_seclevel(auth);
2335
2336 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) {
2337 /* If link is already encrypted with sufficient security we
2338 * still need refresh encryption as per Core Spec 5.0 Vol 3,
2339 * Part H 2.4.6
2340 */
2341 smp_ltk_encrypt(conn, hcon->sec_level);
2342 return 0;
2343 }
2344
2345 if (sec_level > hcon->pending_sec_level)
2346 hcon->pending_sec_level = sec_level;
2347
2348 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2349 return 0;
2350
2351 smp = smp_chan_create(conn);
2352 if (!smp)
2353 return SMP_UNSPECIFIED;
2354
2355 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) &&
2356 (auth & SMP_AUTH_BONDING))
2357 return SMP_PAIRING_NOTSUPP;
2358
2359 skb_pull(skb, sizeof(*rp));
2360
2361 smp_send_pairing_req(smp, auth);
2362
2363 return 0;
2364}
2365
2366static void smp_send_security_req(struct smp_chan *smp, __u8 auth)
2367{
2368 struct smp_cmd_security_req cp;
2369
2370 cp.auth_req = auth;
2371 smp_send_cmd(smp->conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp);
2372 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ);
2373
2374 clear_bit(SMP_FLAG_INITIATOR, &smp->flags);
2375}
2376
2377int smp_conn_security(struct hci_conn *hcon, __u8 sec_level)
2378{
2379 struct l2cap_conn *conn = hcon->l2cap_data;
2380 struct l2cap_chan *chan;
2381 struct smp_chan *smp;
2382 __u8 authreq;
2383 int ret;
2384
2385 bt_dev_dbg(hcon->hdev, "conn %p hcon %p level 0x%2.2x", conn, hcon,
2386 sec_level);
2387
2388 /* This may be NULL if there's an unexpected disconnection */
2389 if (!conn)
2390 return 1;
2391
2392 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED))
2393 return 1;
2394
2395 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK))
2396 return 1;
2397
2398 if (sec_level > hcon->pending_sec_level)
2399 hcon->pending_sec_level = sec_level;
2400
2401 if (hcon->role == HCI_ROLE_MASTER)
2402 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2403 return 0;
2404
2405 chan = conn->smp;
2406 if (!chan) {
2407 bt_dev_err(hcon->hdev, "security requested but not available");
2408 return 1;
2409 }
2410
2411 l2cap_chan_lock(chan);
2412
2413 /* If SMP is already in progress ignore this request */
2414 if (chan->data) {
2415 ret = 0;
2416 goto unlock;
2417 }
2418
2419 smp = smp_chan_create(conn);
2420 if (!smp) {
2421 ret = 1;
2422 goto unlock;
2423 }
2424
2425 authreq = seclevel_to_authreq(sec_level);
2426
2427 if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED)) {
2428 authreq |= SMP_AUTH_SC;
2429 if (hci_dev_test_flag(hcon->hdev, HCI_SSP_ENABLED))
2430 authreq |= SMP_AUTH_CT2;
2431 }
2432
2433 /* Don't attempt to set MITM if setting is overridden by debugfs
2434 * Needed to pass certification test SM/MAS/PKE/BV-01-C
2435 */
2436 if (!hci_dev_test_flag(hcon->hdev, HCI_FORCE_NO_MITM)) {
2437 /* Require MITM if IO Capability allows or the security level
2438 * requires it.
2439 */
2440 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT ||
2441 hcon->pending_sec_level > BT_SECURITY_MEDIUM)
2442 authreq |= SMP_AUTH_MITM;
2443 }
2444
2445 if (hcon->role == HCI_ROLE_MASTER)
2446 smp_send_pairing_req(smp, authreq);
2447 else
2448 smp_send_security_req(smp, authreq);
2449
2450 ret = 0;
2451
2452unlock:
2453 l2cap_chan_unlock(chan);
2454 return ret;
2455}
2456
2457int smp_cancel_and_remove_pairing(struct hci_dev *hdev, bdaddr_t *bdaddr,
2458 u8 addr_type)
2459{
2460 struct hci_conn *hcon;
2461 struct l2cap_conn *conn;
2462 struct l2cap_chan *chan;
2463 struct smp_chan *smp;
2464 int err;
2465
2466 err = hci_remove_ltk(hdev, bdaddr, addr_type);
2467 hci_remove_irk(hdev, bdaddr, addr_type);
2468
2469 hcon = hci_conn_hash_lookup_le(hdev, bdaddr, addr_type);
2470 if (!hcon)
2471 goto done;
2472
2473 conn = hcon->l2cap_data;
2474 if (!conn)
2475 goto done;
2476
2477 chan = conn->smp;
2478 if (!chan)
2479 goto done;
2480
2481 l2cap_chan_lock(chan);
2482
2483 smp = chan->data;
2484 if (smp) {
2485 /* Set keys to NULL to make sure smp_failure() does not try to
2486 * remove and free already invalidated rcu list entries. */
2487 smp->ltk = NULL;
2488 smp->responder_ltk = NULL;
2489 smp->remote_irk = NULL;
2490
2491 if (test_bit(SMP_FLAG_COMPLETE, &smp->flags))
2492 smp_failure(conn, 0);
2493 else
2494 smp_failure(conn, SMP_UNSPECIFIED);
2495 err = 0;
2496 }
2497
2498 l2cap_chan_unlock(chan);
2499
2500done:
2501 return err;
2502}
2503
2504static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb)
2505{
2506 struct smp_cmd_encrypt_info *rp = (void *) skb->data;
2507 struct l2cap_chan *chan = conn->smp;
2508 struct smp_chan *smp = chan->data;
2509
2510 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn);
2511
2512 if (skb->len < sizeof(*rp))
2513 return SMP_INVALID_PARAMS;
2514
2515 /* Pairing is aborted if any blocked keys are distributed */
2516 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_LTK,
2517 rp->ltk)) {
2518 bt_dev_warn_ratelimited(conn->hcon->hdev,
2519 "LTK blocked for %pMR",
2520 &conn->hcon->dst);
2521 return SMP_INVALID_PARAMS;
2522 }
2523
2524 SMP_ALLOW_CMD(smp, SMP_CMD_INITIATOR_IDENT);
2525
2526 skb_pull(skb, sizeof(*rp));
2527
2528 memcpy(smp->tk, rp->ltk, sizeof(smp->tk));
2529
2530 return 0;
2531}
2532
2533static int smp_cmd_initiator_ident(struct l2cap_conn *conn, struct sk_buff *skb)
2534{
2535 struct smp_cmd_initiator_ident *rp = (void *)skb->data;
2536 struct l2cap_chan *chan = conn->smp;
2537 struct smp_chan *smp = chan->data;
2538 struct hci_dev *hdev = conn->hcon->hdev;
2539 struct hci_conn *hcon = conn->hcon;
2540 struct smp_ltk *ltk;
2541 u8 authenticated;
2542
2543 bt_dev_dbg(hdev, "conn %p", conn);
2544
2545 if (skb->len < sizeof(*rp))
2546 return SMP_INVALID_PARAMS;
2547
2548 /* Mark the information as received */
2549 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY;
2550
2551 if (smp->remote_key_dist & SMP_DIST_ID_KEY)
2552 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
2553 else if (smp->remote_key_dist & SMP_DIST_SIGN)
2554 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2555
2556 skb_pull(skb, sizeof(*rp));
2557
2558 authenticated = (hcon->sec_level == BT_SECURITY_HIGH);
2559 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK,
2560 authenticated, smp->tk, smp->enc_key_size,
2561 rp->ediv, rp->rand);
2562 smp->ltk = ltk;
2563 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2564 smp_distribute_keys(smp);
2565
2566 return 0;
2567}
2568
2569static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb)
2570{
2571 struct smp_cmd_ident_info *info = (void *) skb->data;
2572 struct l2cap_chan *chan = conn->smp;
2573 struct smp_chan *smp = chan->data;
2574
2575 bt_dev_dbg(conn->hcon->hdev, "");
2576
2577 if (skb->len < sizeof(*info))
2578 return SMP_INVALID_PARAMS;
2579
2580 /* Pairing is aborted if any blocked keys are distributed */
2581 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_IRK,
2582 info->irk)) {
2583 bt_dev_warn_ratelimited(conn->hcon->hdev,
2584 "Identity key blocked for %pMR",
2585 &conn->hcon->dst);
2586 return SMP_INVALID_PARAMS;
2587 }
2588
2589 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO);
2590
2591 skb_pull(skb, sizeof(*info));
2592
2593 memcpy(smp->irk, info->irk, 16);
2594
2595 return 0;
2596}
2597
2598static int smp_cmd_ident_addr_info(struct l2cap_conn *conn,
2599 struct sk_buff *skb)
2600{
2601 struct smp_cmd_ident_addr_info *info = (void *) skb->data;
2602 struct l2cap_chan *chan = conn->smp;
2603 struct smp_chan *smp = chan->data;
2604 struct hci_conn *hcon = conn->hcon;
2605 bdaddr_t rpa;
2606
2607 bt_dev_dbg(hcon->hdev, "");
2608
2609 if (skb->len < sizeof(*info))
2610 return SMP_INVALID_PARAMS;
2611
2612 /* Mark the information as received */
2613 smp->remote_key_dist &= ~SMP_DIST_ID_KEY;
2614
2615 if (smp->remote_key_dist & SMP_DIST_SIGN)
2616 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2617
2618 skb_pull(skb, sizeof(*info));
2619
2620 /* Strictly speaking the Core Specification (4.1) allows sending
2621 * an empty address which would force us to rely on just the IRK
2622 * as "identity information". However, since such
2623 * implementations are not known of and in order to not over
2624 * complicate our implementation, simply pretend that we never
2625 * received an IRK for such a device.
2626 *
2627 * The Identity Address must also be a Static Random or Public
2628 * Address, which hci_is_identity_address() checks for.
2629 */
2630 if (!bacmp(&info->bdaddr, BDADDR_ANY) ||
2631 !hci_is_identity_address(&info->bdaddr, info->addr_type)) {
2632 bt_dev_err(hcon->hdev, "ignoring IRK with no identity address");
2633 goto distribute;
2634 }
2635
2636 /* Drop IRK if peer is using identity address during pairing but is
2637 * providing different address as identity information.
2638 *
2639 * Microsoft Surface Precision Mouse is known to have this bug.
2640 */
2641 if (hci_is_identity_address(&hcon->dst, hcon->dst_type) &&
2642 (bacmp(&info->bdaddr, &hcon->dst) ||
2643 info->addr_type != hcon->dst_type)) {
2644 bt_dev_err(hcon->hdev,
2645 "ignoring IRK with invalid identity address");
2646 goto distribute;
2647 }
2648
2649 bacpy(&smp->id_addr, &info->bdaddr);
2650 smp->id_addr_type = info->addr_type;
2651
2652 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type))
2653 bacpy(&rpa, &hcon->dst);
2654 else
2655 bacpy(&rpa, BDADDR_ANY);
2656
2657 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr,
2658 smp->id_addr_type, smp->irk, &rpa);
2659
2660distribute:
2661 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2662 smp_distribute_keys(smp);
2663
2664 return 0;
2665}
2666
2667static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb)
2668{
2669 struct smp_cmd_sign_info *rp = (void *) skb->data;
2670 struct l2cap_chan *chan = conn->smp;
2671 struct smp_chan *smp = chan->data;
2672 struct smp_csrk *csrk;
2673
2674 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn);
2675
2676 if (skb->len < sizeof(*rp))
2677 return SMP_INVALID_PARAMS;
2678
2679 /* Mark the information as received */
2680 smp->remote_key_dist &= ~SMP_DIST_SIGN;
2681
2682 skb_pull(skb, sizeof(*rp));
2683
2684 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
2685 if (csrk) {
2686 if (conn->hcon->sec_level > BT_SECURITY_MEDIUM)
2687 csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED;
2688 else
2689 csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED;
2690 memcpy(csrk->val, rp->csrk, sizeof(csrk->val));
2691 }
2692 smp->csrk = csrk;
2693 smp_distribute_keys(smp);
2694
2695 return 0;
2696}
2697
2698static u8 sc_select_method(struct smp_chan *smp)
2699{
2700 struct smp_cmd_pairing *local, *remote;
2701 u8 local_mitm, remote_mitm, local_io, remote_io, method;
2702
2703 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) ||
2704 test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags))
2705 return REQ_OOB;
2706
2707 /* The preq/prsp contain the raw Pairing Request/Response PDUs
2708 * which are needed as inputs to some crypto functions. To get
2709 * the "struct smp_cmd_pairing" from them we need to skip the
2710 * first byte which contains the opcode.
2711 */
2712 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2713 local = (void *) &smp->preq[1];
2714 remote = (void *) &smp->prsp[1];
2715 } else {
2716 local = (void *) &smp->prsp[1];
2717 remote = (void *) &smp->preq[1];
2718 }
2719
2720 local_io = local->io_capability;
2721 remote_io = remote->io_capability;
2722
2723 local_mitm = (local->auth_req & SMP_AUTH_MITM);
2724 remote_mitm = (remote->auth_req & SMP_AUTH_MITM);
2725
2726 /* If either side wants MITM, look up the method from the table,
2727 * otherwise use JUST WORKS.
2728 */
2729 if (local_mitm || remote_mitm)
2730 method = get_auth_method(smp, local_io, remote_io);
2731 else
2732 method = JUST_WORKS;
2733
2734 /* Don't confirm locally initiated pairing attempts */
2735 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2736 method = JUST_WORKS;
2737
2738 return method;
2739}
2740
2741static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb)
2742{
2743 struct smp_cmd_public_key *key = (void *) skb->data;
2744 struct hci_conn *hcon = conn->hcon;
2745 struct l2cap_chan *chan = conn->smp;
2746 struct smp_chan *smp = chan->data;
2747 struct hci_dev *hdev = hcon->hdev;
2748 struct crypto_kpp *tfm_ecdh;
2749 struct smp_cmd_pairing_confirm cfm;
2750 int err;
2751
2752 bt_dev_dbg(hdev, "conn %p", conn);
2753
2754 if (skb->len < sizeof(*key))
2755 return SMP_INVALID_PARAMS;
2756
2757 /* Check if remote and local public keys are the same and debug key is
2758 * not in use.
2759 */
2760 if (!test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags) &&
2761 !crypto_memneq(key, smp->local_pk, 64)) {
2762 bt_dev_err(hdev, "Remote and local public keys are identical");
2763 return SMP_UNSPECIFIED;
2764 }
2765
2766 memcpy(smp->remote_pk, key, 64);
2767
2768 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) {
2769 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk,
2770 smp->rr, 0, cfm.confirm_val);
2771 if (err)
2772 return SMP_UNSPECIFIED;
2773
2774 if (crypto_memneq(cfm.confirm_val, smp->pcnf, 16))
2775 return SMP_CONFIRM_FAILED;
2776 }
2777
2778 /* Non-initiating device sends its public key after receiving
2779 * the key from the initiating device.
2780 */
2781 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2782 err = sc_send_public_key(smp);
2783 if (err)
2784 return err;
2785 }
2786
2787 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk);
2788 SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32);
2789
2790 /* Compute the shared secret on the same crypto tfm on which the private
2791 * key was set/generated.
2792 */
2793 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) {
2794 struct l2cap_chan *hchan = hdev->smp_data;
2795 struct smp_dev *smp_dev;
2796
2797 if (!hchan || !hchan->data)
2798 return SMP_UNSPECIFIED;
2799
2800 smp_dev = hchan->data;
2801
2802 tfm_ecdh = smp_dev->tfm_ecdh;
2803 } else {
2804 tfm_ecdh = smp->tfm_ecdh;
2805 }
2806
2807 if (compute_ecdh_secret(tfm_ecdh, smp->remote_pk, smp->dhkey))
2808 return SMP_UNSPECIFIED;
2809
2810 SMP_DBG("DHKey %32phN", smp->dhkey);
2811
2812 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags);
2813
2814 smp->method = sc_select_method(smp);
2815
2816 bt_dev_dbg(hdev, "selected method 0x%02x", smp->method);
2817
2818 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */
2819 if (smp->method == JUST_WORKS || smp->method == JUST_CFM)
2820 hcon->pending_sec_level = BT_SECURITY_MEDIUM;
2821 else
2822 hcon->pending_sec_level = BT_SECURITY_FIPS;
2823
2824 if (!crypto_memneq(debug_pk, smp->remote_pk, 64))
2825 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
2826
2827 if (smp->method == DSP_PASSKEY) {
2828 get_random_bytes(&hcon->passkey_notify,
2829 sizeof(hcon->passkey_notify));
2830 hcon->passkey_notify %= 1000000;
2831 hcon->passkey_entered = 0;
2832 smp->passkey_round = 0;
2833 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type,
2834 hcon->dst_type,
2835 hcon->passkey_notify,
2836 hcon->passkey_entered))
2837 return SMP_UNSPECIFIED;
2838 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2839 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY);
2840 }
2841
2842 if (smp->method == REQ_OOB) {
2843 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2844 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2845 sizeof(smp->prnd), smp->prnd);
2846
2847 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2848
2849 return 0;
2850 }
2851
2852 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2853 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2854
2855 if (smp->method == REQ_PASSKEY) {
2856 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type,
2857 hcon->dst_type))
2858 return SMP_UNSPECIFIED;
2859 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2860 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2861 return 0;
2862 }
2863
2864 /* The Initiating device waits for the non-initiating device to
2865 * send the confirm value.
2866 */
2867 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2868 return 0;
2869
2870 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd,
2871 0, cfm.confirm_val);
2872 if (err)
2873 return SMP_UNSPECIFIED;
2874
2875 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
2876 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2877
2878 return 0;
2879}
2880
2881static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb)
2882{
2883 struct smp_cmd_dhkey_check *check = (void *) skb->data;
2884 struct l2cap_chan *chan = conn->smp;
2885 struct hci_conn *hcon = conn->hcon;
2886 struct smp_chan *smp = chan->data;
2887 u8 a[7], b[7], *local_addr, *remote_addr;
2888 u8 io_cap[3], r[16], e[16];
2889 int err;
2890
2891 bt_dev_dbg(hcon->hdev, "conn %p", conn);
2892
2893 if (skb->len < sizeof(*check))
2894 return SMP_INVALID_PARAMS;
2895
2896 memcpy(a, &hcon->init_addr, 6);
2897 memcpy(b, &hcon->resp_addr, 6);
2898 a[6] = hcon->init_addr_type;
2899 b[6] = hcon->resp_addr_type;
2900
2901 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2902 local_addr = a;
2903 remote_addr = b;
2904 memcpy(io_cap, &smp->prsp[1], 3);
2905 } else {
2906 local_addr = b;
2907 remote_addr = a;
2908 memcpy(io_cap, &smp->preq[1], 3);
2909 }
2910
2911 memset(r, 0, sizeof(r));
2912
2913 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2914 put_unaligned_le32(hcon->passkey_notify, r);
2915 else if (smp->method == REQ_OOB)
2916 memcpy(r, smp->lr, 16);
2917
2918 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r,
2919 io_cap, remote_addr, local_addr, e);
2920 if (err)
2921 return SMP_UNSPECIFIED;
2922
2923 if (crypto_memneq(check->e, e, 16))
2924 return SMP_DHKEY_CHECK_FAILED;
2925
2926 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2927 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
2928 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags);
2929 return 0;
2930 }
2931
2932 /* Responder sends DHKey check as response to initiator */
2933 sc_dhkey_check(smp);
2934 }
2935
2936 sc_add_ltk(smp);
2937
2938 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2939 hci_le_start_enc(hcon, 0, 0, smp->tk, smp->enc_key_size);
2940 hcon->enc_key_size = smp->enc_key_size;
2941 }
2942
2943 return 0;
2944}
2945
2946static int smp_cmd_keypress_notify(struct l2cap_conn *conn,
2947 struct sk_buff *skb)
2948{
2949 struct smp_cmd_keypress_notify *kp = (void *) skb->data;
2950
2951 bt_dev_dbg(conn->hcon->hdev, "value 0x%02x", kp->value);
2952
2953 return 0;
2954}
2955
2956static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb)
2957{
2958 struct l2cap_conn *conn = chan->conn;
2959 struct hci_conn *hcon = conn->hcon;
2960 struct smp_chan *smp;
2961 __u8 code, reason;
2962 int err = 0;
2963
2964 if (skb->len < 1)
2965 return -EILSEQ;
2966
2967 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) {
2968 reason = SMP_PAIRING_NOTSUPP;
2969 goto done;
2970 }
2971
2972 code = skb->data[0];
2973 skb_pull(skb, sizeof(code));
2974
2975 smp = chan->data;
2976
2977 if (code > SMP_CMD_MAX)
2978 goto drop;
2979
2980 if (smp && !test_and_clear_bit(code, &smp->allow_cmd))
2981 goto drop;
2982
2983 /* If we don't have a context the only allowed commands are
2984 * pairing request and security request.
2985 */
2986 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ)
2987 goto drop;
2988
2989 switch (code) {
2990 case SMP_CMD_PAIRING_REQ:
2991 reason = smp_cmd_pairing_req(conn, skb);
2992 break;
2993
2994 case SMP_CMD_PAIRING_FAIL:
2995 smp_failure(conn, 0);
2996 err = -EPERM;
2997 break;
2998
2999 case SMP_CMD_PAIRING_RSP:
3000 reason = smp_cmd_pairing_rsp(conn, skb);
3001 break;
3002
3003 case SMP_CMD_SECURITY_REQ:
3004 reason = smp_cmd_security_req(conn, skb);
3005 break;
3006
3007 case SMP_CMD_PAIRING_CONFIRM:
3008 reason = smp_cmd_pairing_confirm(conn, skb);
3009 break;
3010
3011 case SMP_CMD_PAIRING_RANDOM:
3012 reason = smp_cmd_pairing_random(conn, skb);
3013 break;
3014
3015 case SMP_CMD_ENCRYPT_INFO:
3016 reason = smp_cmd_encrypt_info(conn, skb);
3017 break;
3018
3019 case SMP_CMD_INITIATOR_IDENT:
3020 reason = smp_cmd_initiator_ident(conn, skb);
3021 break;
3022
3023 case SMP_CMD_IDENT_INFO:
3024 reason = smp_cmd_ident_info(conn, skb);
3025 break;
3026
3027 case SMP_CMD_IDENT_ADDR_INFO:
3028 reason = smp_cmd_ident_addr_info(conn, skb);
3029 break;
3030
3031 case SMP_CMD_SIGN_INFO:
3032 reason = smp_cmd_sign_info(conn, skb);
3033 break;
3034
3035 case SMP_CMD_PUBLIC_KEY:
3036 reason = smp_cmd_public_key(conn, skb);
3037 break;
3038
3039 case SMP_CMD_DHKEY_CHECK:
3040 reason = smp_cmd_dhkey_check(conn, skb);
3041 break;
3042
3043 case SMP_CMD_KEYPRESS_NOTIFY:
3044 reason = smp_cmd_keypress_notify(conn, skb);
3045 break;
3046
3047 default:
3048 bt_dev_dbg(hcon->hdev, "Unknown command code 0x%2.2x", code);
3049 reason = SMP_CMD_NOTSUPP;
3050 goto done;
3051 }
3052
3053done:
3054 if (!err) {
3055 if (reason)
3056 smp_failure(conn, reason);
3057 kfree_skb(skb);
3058 }
3059
3060 return err;
3061
3062drop:
3063 bt_dev_err(hcon->hdev, "unexpected SMP command 0x%02x from %pMR",
3064 code, &hcon->dst);
3065 kfree_skb(skb);
3066 return 0;
3067}
3068
3069static void smp_teardown_cb(struct l2cap_chan *chan, int err)
3070{
3071 struct l2cap_conn *conn = chan->conn;
3072
3073 bt_dev_dbg(conn->hcon->hdev, "chan %p", chan);
3074
3075 if (chan->data)
3076 smp_chan_destroy(conn);
3077
3078 conn->smp = NULL;
3079 l2cap_chan_put(chan);
3080}
3081
3082static void bredr_pairing(struct l2cap_chan *chan)
3083{
3084 struct l2cap_conn *conn = chan->conn;
3085 struct hci_conn *hcon = conn->hcon;
3086 struct hci_dev *hdev = hcon->hdev;
3087 struct smp_chan *smp;
3088
3089 bt_dev_dbg(hdev, "chan %p", chan);
3090
3091 /* Only new pairings are interesting */
3092 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags))
3093 return;
3094
3095 /* Don't bother if we're not encrypted */
3096 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3097 return;
3098
3099 /* Only initiator may initiate SMP over BR/EDR */
3100 if (hcon->role != HCI_ROLE_MASTER)
3101 return;
3102
3103 /* Secure Connections support must be enabled */
3104 if (!hci_dev_test_flag(hdev, HCI_SC_ENABLED))
3105 return;
3106
3107 /* BR/EDR must use Secure Connections for SMP */
3108 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) &&
3109 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3110 return;
3111
3112 /* If our LE support is not enabled don't do anything */
3113 if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED))
3114 return;
3115
3116 /* Don't bother if remote LE support is not enabled */
3117 if (!lmp_host_le_capable(hcon))
3118 return;
3119
3120 /* Remote must support SMP fixed chan for BR/EDR */
3121 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR))
3122 return;
3123
3124 /* Don't bother if SMP is already ongoing */
3125 if (chan->data)
3126 return;
3127
3128 smp = smp_chan_create(conn);
3129 if (!smp) {
3130 bt_dev_err(hdev, "unable to create SMP context for BR/EDR");
3131 return;
3132 }
3133
3134 set_bit(SMP_FLAG_SC, &smp->flags);
3135
3136 bt_dev_dbg(hdev, "starting SMP over BR/EDR");
3137
3138 smp_send_pairing_req(smp, 0x00);
3139}
3140
3141static void smp_resume_cb(struct l2cap_chan *chan)
3142{
3143 struct smp_chan *smp = chan->data;
3144 struct l2cap_conn *conn = chan->conn;
3145 struct hci_conn *hcon = conn->hcon;
3146
3147 bt_dev_dbg(hcon->hdev, "chan %p", chan);
3148
3149 if (hcon->type == ACL_LINK) {
3150 bredr_pairing(chan);
3151 return;
3152 }
3153
3154 if (!smp)
3155 return;
3156
3157 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3158 return;
3159
3160 cancel_delayed_work(&smp->security_timer);
3161
3162 smp_distribute_keys(smp);
3163}
3164
3165static void smp_ready_cb(struct l2cap_chan *chan)
3166{
3167 struct l2cap_conn *conn = chan->conn;
3168 struct hci_conn *hcon = conn->hcon;
3169
3170 bt_dev_dbg(hcon->hdev, "chan %p", chan);
3171
3172 /* No need to call l2cap_chan_hold() here since we already own
3173 * the reference taken in smp_new_conn_cb(). This is just the
3174 * first time that we tie it to a specific pointer. The code in
3175 * l2cap_core.c ensures that there's no risk this function wont
3176 * get called if smp_new_conn_cb was previously called.
3177 */
3178 conn->smp = chan;
3179
3180 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3181 bredr_pairing(chan);
3182}
3183
3184static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
3185{
3186 int err;
3187
3188 bt_dev_dbg(chan->conn->hcon->hdev, "chan %p", chan);
3189
3190 err = smp_sig_channel(chan, skb);
3191 if (err) {
3192 struct smp_chan *smp = chan->data;
3193
3194 if (smp)
3195 cancel_delayed_work_sync(&smp->security_timer);
3196
3197 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE);
3198 }
3199
3200 return err;
3201}
3202
3203static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan,
3204 unsigned long hdr_len,
3205 unsigned long len, int nb)
3206{
3207 struct sk_buff *skb;
3208
3209 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL);
3210 if (!skb)
3211 return ERR_PTR(-ENOMEM);
3212
3213 skb->priority = HCI_PRIO_MAX;
3214 bt_cb(skb)->l2cap.chan = chan;
3215
3216 return skb;
3217}
3218
3219static const struct l2cap_ops smp_chan_ops = {
3220 .name = "Security Manager",
3221 .ready = smp_ready_cb,
3222 .recv = smp_recv_cb,
3223 .alloc_skb = smp_alloc_skb_cb,
3224 .teardown = smp_teardown_cb,
3225 .resume = smp_resume_cb,
3226
3227 .new_connection = l2cap_chan_no_new_connection,
3228 .state_change = l2cap_chan_no_state_change,
3229 .close = l2cap_chan_no_close,
3230 .defer = l2cap_chan_no_defer,
3231 .suspend = l2cap_chan_no_suspend,
3232 .set_shutdown = l2cap_chan_no_set_shutdown,
3233 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
3234};
3235
3236static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan)
3237{
3238 struct l2cap_chan *chan;
3239
3240 BT_DBG("pchan %p", pchan);
3241
3242 chan = l2cap_chan_create();
3243 if (!chan)
3244 return NULL;
3245
3246 chan->chan_type = pchan->chan_type;
3247 chan->ops = &smp_chan_ops;
3248 chan->scid = pchan->scid;
3249 chan->dcid = chan->scid;
3250 chan->imtu = pchan->imtu;
3251 chan->omtu = pchan->omtu;
3252 chan->mode = pchan->mode;
3253
3254 /* Other L2CAP channels may request SMP routines in order to
3255 * change the security level. This means that the SMP channel
3256 * lock must be considered in its own category to avoid lockdep
3257 * warnings.
3258 */
3259 atomic_set(&chan->nesting, L2CAP_NESTING_SMP);
3260
3261 BT_DBG("created chan %p", chan);
3262
3263 return chan;
3264}
3265
3266static const struct l2cap_ops smp_root_chan_ops = {
3267 .name = "Security Manager Root",
3268 .new_connection = smp_new_conn_cb,
3269
3270 /* None of these are implemented for the root channel */
3271 .close = l2cap_chan_no_close,
3272 .alloc_skb = l2cap_chan_no_alloc_skb,
3273 .recv = l2cap_chan_no_recv,
3274 .state_change = l2cap_chan_no_state_change,
3275 .teardown = l2cap_chan_no_teardown,
3276 .ready = l2cap_chan_no_ready,
3277 .defer = l2cap_chan_no_defer,
3278 .suspend = l2cap_chan_no_suspend,
3279 .resume = l2cap_chan_no_resume,
3280 .set_shutdown = l2cap_chan_no_set_shutdown,
3281 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
3282};
3283
3284static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid)
3285{
3286 struct l2cap_chan *chan;
3287 struct smp_dev *smp;
3288 struct crypto_shash *tfm_cmac;
3289 struct crypto_kpp *tfm_ecdh;
3290
3291 if (cid == L2CAP_CID_SMP_BREDR) {
3292 smp = NULL;
3293 goto create_chan;
3294 }
3295
3296 smp = kzalloc(sizeof(*smp), GFP_KERNEL);
3297 if (!smp)
3298 return ERR_PTR(-ENOMEM);
3299
3300 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
3301 if (IS_ERR(tfm_cmac)) {
3302 bt_dev_err(hdev, "Unable to create CMAC crypto context");
3303 kfree_sensitive(smp);
3304 return ERR_CAST(tfm_cmac);
3305 }
3306
3307 tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0);
3308 if (IS_ERR(tfm_ecdh)) {
3309 bt_dev_err(hdev, "Unable to create ECDH crypto context");
3310 crypto_free_shash(tfm_cmac);
3311 kfree_sensitive(smp);
3312 return ERR_CAST(tfm_ecdh);
3313 }
3314
3315 smp->local_oob = false;
3316 smp->tfm_cmac = tfm_cmac;
3317 smp->tfm_ecdh = tfm_ecdh;
3318
3319create_chan:
3320 chan = l2cap_chan_create();
3321 if (!chan) {
3322 if (smp) {
3323 crypto_free_shash(smp->tfm_cmac);
3324 crypto_free_kpp(smp->tfm_ecdh);
3325 kfree_sensitive(smp);
3326 }
3327 return ERR_PTR(-ENOMEM);
3328 }
3329
3330 chan->data = smp;
3331
3332 l2cap_add_scid(chan, cid);
3333
3334 l2cap_chan_set_defaults(chan);
3335
3336 if (cid == L2CAP_CID_SMP) {
3337 u8 bdaddr_type;
3338
3339 hci_copy_identity_address(hdev, &chan->src, &bdaddr_type);
3340
3341 if (bdaddr_type == ADDR_LE_DEV_PUBLIC)
3342 chan->src_type = BDADDR_LE_PUBLIC;
3343 else
3344 chan->src_type = BDADDR_LE_RANDOM;
3345 } else {
3346 bacpy(&chan->src, &hdev->bdaddr);
3347 chan->src_type = BDADDR_BREDR;
3348 }
3349
3350 chan->state = BT_LISTEN;
3351 chan->mode = L2CAP_MODE_BASIC;
3352 chan->imtu = L2CAP_DEFAULT_MTU;
3353 chan->ops = &smp_root_chan_ops;
3354
3355 /* Set correct nesting level for a parent/listening channel */
3356 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
3357
3358 return chan;
3359}
3360
3361static void smp_del_chan(struct l2cap_chan *chan)
3362{
3363 struct smp_dev *smp;
3364
3365 BT_DBG("chan %p", chan);
3366
3367 smp = chan->data;
3368 if (smp) {
3369 chan->data = NULL;
3370 crypto_free_shash(smp->tfm_cmac);
3371 crypto_free_kpp(smp->tfm_ecdh);
3372 kfree_sensitive(smp);
3373 }
3374
3375 l2cap_chan_put(chan);
3376}
3377
3378int smp_force_bredr(struct hci_dev *hdev, bool enable)
3379{
3380 if (enable == hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3381 return -EALREADY;
3382
3383 if (enable) {
3384 struct l2cap_chan *chan;
3385
3386 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
3387 if (IS_ERR(chan))
3388 return PTR_ERR(chan);
3389
3390 hdev->smp_bredr_data = chan;
3391 } else {
3392 struct l2cap_chan *chan;
3393
3394 chan = hdev->smp_bredr_data;
3395 hdev->smp_bredr_data = NULL;
3396 smp_del_chan(chan);
3397 }
3398
3399 hci_dev_change_flag(hdev, HCI_FORCE_BREDR_SMP);
3400
3401 return 0;
3402}
3403
3404int smp_register(struct hci_dev *hdev)
3405{
3406 struct l2cap_chan *chan;
3407
3408 bt_dev_dbg(hdev, "");
3409
3410 /* If the controller does not support Low Energy operation, then
3411 * there is also no need to register any SMP channel.
3412 */
3413 if (!lmp_le_capable(hdev))
3414 return 0;
3415
3416 if (WARN_ON(hdev->smp_data)) {
3417 chan = hdev->smp_data;
3418 hdev->smp_data = NULL;
3419 smp_del_chan(chan);
3420 }
3421
3422 chan = smp_add_cid(hdev, L2CAP_CID_SMP);
3423 if (IS_ERR(chan))
3424 return PTR_ERR(chan);
3425
3426 hdev->smp_data = chan;
3427
3428 if (!lmp_sc_capable(hdev)) {
3429 /* Flag can be already set here (due to power toggle) */
3430 if (!hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3431 return 0;
3432 }
3433
3434 if (WARN_ON(hdev->smp_bredr_data)) {
3435 chan = hdev->smp_bredr_data;
3436 hdev->smp_bredr_data = NULL;
3437 smp_del_chan(chan);
3438 }
3439
3440 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
3441 if (IS_ERR(chan)) {
3442 int err = PTR_ERR(chan);
3443 chan = hdev->smp_data;
3444 hdev->smp_data = NULL;
3445 smp_del_chan(chan);
3446 return err;
3447 }
3448
3449 hdev->smp_bredr_data = chan;
3450
3451 return 0;
3452}
3453
3454void smp_unregister(struct hci_dev *hdev)
3455{
3456 struct l2cap_chan *chan;
3457
3458 if (hdev->smp_bredr_data) {
3459 chan = hdev->smp_bredr_data;
3460 hdev->smp_bredr_data = NULL;
3461 smp_del_chan(chan);
3462 }
3463
3464 if (hdev->smp_data) {
3465 chan = hdev->smp_data;
3466 hdev->smp_data = NULL;
3467 smp_del_chan(chan);
3468 }
3469}
3470
3471#if IS_ENABLED(CONFIG_BT_SELFTEST_SMP)
3472
3473static int __init test_debug_key(struct crypto_kpp *tfm_ecdh)
3474{
3475 u8 pk[64];
3476 int err;
3477
3478 err = set_ecdh_privkey(tfm_ecdh, debug_sk);
3479 if (err)
3480 return err;
3481
3482 err = generate_ecdh_public_key(tfm_ecdh, pk);
3483 if (err)
3484 return err;
3485
3486 if (crypto_memneq(pk, debug_pk, 64))
3487 return -EINVAL;
3488
3489 return 0;
3490}
3491
3492static int __init test_ah(void)
3493{
3494 const u8 irk[16] = {
3495 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3496 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3497 const u8 r[3] = { 0x94, 0x81, 0x70 };
3498 const u8 exp[3] = { 0xaa, 0xfb, 0x0d };
3499 u8 res[3];
3500 int err;
3501
3502 err = smp_ah(irk, r, res);
3503 if (err)
3504 return err;
3505
3506 if (crypto_memneq(res, exp, 3))
3507 return -EINVAL;
3508
3509 return 0;
3510}
3511
3512static int __init test_c1(void)
3513{
3514 const u8 k[16] = {
3515 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
3516 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
3517 const u8 r[16] = {
3518 0xe0, 0x2e, 0x70, 0xc6, 0x4e, 0x27, 0x88, 0x63,
3519 0x0e, 0x6f, 0xad, 0x56, 0x21, 0xd5, 0x83, 0x57 };
3520 const u8 preq[7] = { 0x01, 0x01, 0x00, 0x00, 0x10, 0x07, 0x07 };
3521 const u8 pres[7] = { 0x02, 0x03, 0x00, 0x00, 0x08, 0x00, 0x05 };
3522 const u8 _iat = 0x01;
3523 const u8 _rat = 0x00;
3524 const bdaddr_t ra = { { 0xb6, 0xb5, 0xb4, 0xb3, 0xb2, 0xb1 } };
3525 const bdaddr_t ia = { { 0xa6, 0xa5, 0xa4, 0xa3, 0xa2, 0xa1 } };
3526 const u8 exp[16] = {
3527 0x86, 0x3b, 0xf1, 0xbe, 0xc5, 0x4d, 0xa7, 0xd2,
3528 0xea, 0x88, 0x89, 0x87, 0xef, 0x3f, 0x1e, 0x1e };
3529 u8 res[16];
3530 int err;
3531
3532 err = smp_c1(k, r, preq, pres, _iat, &ia, _rat, &ra, res);
3533 if (err)
3534 return err;
3535
3536 if (crypto_memneq(res, exp, 16))
3537 return -EINVAL;
3538
3539 return 0;
3540}
3541
3542static int __init test_s1(void)
3543{
3544 const u8 k[16] = {
3545 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
3546 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
3547 const u8 r1[16] = {
3548 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 };
3549 const u8 r2[16] = {
3550 0x00, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99 };
3551 const u8 exp[16] = {
3552 0x62, 0xa0, 0x6d, 0x79, 0xae, 0x16, 0x42, 0x5b,
3553 0x9b, 0xf4, 0xb0, 0xe8, 0xf0, 0xe1, 0x1f, 0x9a };
3554 u8 res[16];
3555 int err;
3556
3557 err = smp_s1(k, r1, r2, res);
3558 if (err)
3559 return err;
3560
3561 if (crypto_memneq(res, exp, 16))
3562 return -EINVAL;
3563
3564 return 0;
3565}
3566
3567static int __init test_f4(struct crypto_shash *tfm_cmac)
3568{
3569 const u8 u[32] = {
3570 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
3571 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
3572 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
3573 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 };
3574 const u8 v[32] = {
3575 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b,
3576 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59,
3577 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90,
3578 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 };
3579 const u8 x[16] = {
3580 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3581 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3582 const u8 z = 0x00;
3583 const u8 exp[16] = {
3584 0x2d, 0x87, 0x74, 0xa9, 0xbe, 0xa1, 0xed, 0xf1,
3585 0x1c, 0xbd, 0xa9, 0x07, 0xf1, 0x16, 0xc9, 0xf2 };
3586 u8 res[16];
3587 int err;
3588
3589 err = smp_f4(tfm_cmac, u, v, x, z, res);
3590 if (err)
3591 return err;
3592
3593 if (crypto_memneq(res, exp, 16))
3594 return -EINVAL;
3595
3596 return 0;
3597}
3598
3599static int __init test_f5(struct crypto_shash *tfm_cmac)
3600{
3601 const u8 w[32] = {
3602 0x98, 0xa6, 0xbf, 0x73, 0xf3, 0x34, 0x8d, 0x86,
3603 0xf1, 0x66, 0xf8, 0xb4, 0x13, 0x6b, 0x79, 0x99,
3604 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3605 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3606 const u8 n1[16] = {
3607 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3608 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3609 const u8 n2[16] = {
3610 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3611 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3612 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 };
3613 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 };
3614 const u8 exp_ltk[16] = {
3615 0x38, 0x0a, 0x75, 0x94, 0xb5, 0x22, 0x05, 0x98,
3616 0x23, 0xcd, 0xd7, 0x69, 0x11, 0x79, 0x86, 0x69 };
3617 const u8 exp_mackey[16] = {
3618 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd,
3619 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 };
3620 u8 mackey[16], ltk[16];
3621 int err;
3622
3623 err = smp_f5(tfm_cmac, w, n1, n2, a1, a2, mackey, ltk);
3624 if (err)
3625 return err;
3626
3627 if (crypto_memneq(mackey, exp_mackey, 16))
3628 return -EINVAL;
3629
3630 if (crypto_memneq(ltk, exp_ltk, 16))
3631 return -EINVAL;
3632
3633 return 0;
3634}
3635
3636static int __init test_f6(struct crypto_shash *tfm_cmac)
3637{
3638 const u8 w[16] = {
3639 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd,
3640 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 };
3641 const u8 n1[16] = {
3642 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3643 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3644 const u8 n2[16] = {
3645 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3646 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3647 const u8 r[16] = {
3648 0xc8, 0x0f, 0x2d, 0x0c, 0xd2, 0x42, 0xda, 0x08,
3649 0x54, 0xbb, 0x53, 0xb4, 0x3b, 0x34, 0xa3, 0x12 };
3650 const u8 io_cap[3] = { 0x02, 0x01, 0x01 };
3651 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 };
3652 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 };
3653 const u8 exp[16] = {
3654 0x61, 0x8f, 0x95, 0xda, 0x09, 0x0b, 0x6c, 0xd2,
3655 0xc5, 0xe8, 0xd0, 0x9c, 0x98, 0x73, 0xc4, 0xe3 };
3656 u8 res[16];
3657 int err;
3658
3659 err = smp_f6(tfm_cmac, w, n1, n2, r, io_cap, a1, a2, res);
3660 if (err)
3661 return err;
3662
3663 if (crypto_memneq(res, exp, 16))
3664 return -EINVAL;
3665
3666 return 0;
3667}
3668
3669static int __init test_g2(struct crypto_shash *tfm_cmac)
3670{
3671 const u8 u[32] = {
3672 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
3673 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
3674 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
3675 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 };
3676 const u8 v[32] = {
3677 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b,
3678 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59,
3679 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90,
3680 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 };
3681 const u8 x[16] = {
3682 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3683 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3684 const u8 y[16] = {
3685 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3686 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3687 const u32 exp_val = 0x2f9ed5ba % 1000000;
3688 u32 val;
3689 int err;
3690
3691 err = smp_g2(tfm_cmac, u, v, x, y, &val);
3692 if (err)
3693 return err;
3694
3695 if (val != exp_val)
3696 return -EINVAL;
3697
3698 return 0;
3699}
3700
3701static int __init test_h6(struct crypto_shash *tfm_cmac)
3702{
3703 const u8 w[16] = {
3704 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3705 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3706 const u8 key_id[4] = { 0x72, 0x62, 0x65, 0x6c };
3707 const u8 exp[16] = {
3708 0x99, 0x63, 0xb1, 0x80, 0xe2, 0xa9, 0xd3, 0xe8,
3709 0x1c, 0xc9, 0x6d, 0xe7, 0x02, 0xe1, 0x9a, 0x2d };
3710 u8 res[16];
3711 int err;
3712
3713 err = smp_h6(tfm_cmac, w, key_id, res);
3714 if (err)
3715 return err;
3716
3717 if (crypto_memneq(res, exp, 16))
3718 return -EINVAL;
3719
3720 return 0;
3721}
3722
3723static char test_smp_buffer[32];
3724
3725static ssize_t test_smp_read(struct file *file, char __user *user_buf,
3726 size_t count, loff_t *ppos)
3727{
3728 return simple_read_from_buffer(user_buf, count, ppos, test_smp_buffer,
3729 strlen(test_smp_buffer));
3730}
3731
3732static const struct file_operations test_smp_fops = {
3733 .open = simple_open,
3734 .read = test_smp_read,
3735 .llseek = default_llseek,
3736};
3737
3738static int __init run_selftests(struct crypto_shash *tfm_cmac,
3739 struct crypto_kpp *tfm_ecdh)
3740{
3741 ktime_t calltime, delta, rettime;
3742 unsigned long long duration;
3743 int err;
3744
3745 calltime = ktime_get();
3746
3747 err = test_debug_key(tfm_ecdh);
3748 if (err) {
3749 BT_ERR("debug_key test failed");
3750 goto done;
3751 }
3752
3753 err = test_ah();
3754 if (err) {
3755 BT_ERR("smp_ah test failed");
3756 goto done;
3757 }
3758
3759 err = test_c1();
3760 if (err) {
3761 BT_ERR("smp_c1 test failed");
3762 goto done;
3763 }
3764
3765 err = test_s1();
3766 if (err) {
3767 BT_ERR("smp_s1 test failed");
3768 goto done;
3769 }
3770
3771 err = test_f4(tfm_cmac);
3772 if (err) {
3773 BT_ERR("smp_f4 test failed");
3774 goto done;
3775 }
3776
3777 err = test_f5(tfm_cmac);
3778 if (err) {
3779 BT_ERR("smp_f5 test failed");
3780 goto done;
3781 }
3782
3783 err = test_f6(tfm_cmac);
3784 if (err) {
3785 BT_ERR("smp_f6 test failed");
3786 goto done;
3787 }
3788
3789 err = test_g2(tfm_cmac);
3790 if (err) {
3791 BT_ERR("smp_g2 test failed");
3792 goto done;
3793 }
3794
3795 err = test_h6(tfm_cmac);
3796 if (err) {
3797 BT_ERR("smp_h6 test failed");
3798 goto done;
3799 }
3800
3801 rettime = ktime_get();
3802 delta = ktime_sub(rettime, calltime);
3803 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
3804
3805 BT_INFO("SMP test passed in %llu usecs", duration);
3806
3807done:
3808 if (!err)
3809 snprintf(test_smp_buffer, sizeof(test_smp_buffer),
3810 "PASS (%llu usecs)\n", duration);
3811 else
3812 snprintf(test_smp_buffer, sizeof(test_smp_buffer), "FAIL\n");
3813
3814 debugfs_create_file("selftest_smp", 0444, bt_debugfs, NULL,
3815 &test_smp_fops);
3816
3817 return err;
3818}
3819
3820int __init bt_selftest_smp(void)
3821{
3822 struct crypto_shash *tfm_cmac;
3823 struct crypto_kpp *tfm_ecdh;
3824 int err;
3825
3826 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
3827 if (IS_ERR(tfm_cmac)) {
3828 BT_ERR("Unable to create CMAC crypto context");
3829 return PTR_ERR(tfm_cmac);
3830 }
3831
3832 tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0);
3833 if (IS_ERR(tfm_ecdh)) {
3834 BT_ERR("Unable to create ECDH crypto context");
3835 crypto_free_shash(tfm_cmac);
3836 return PTR_ERR(tfm_ecdh);
3837 }
3838
3839 err = run_selftests(tfm_cmac, tfm_ecdh);
3840
3841 crypto_free_shash(tfm_cmac);
3842 crypto_free_kpp(tfm_ecdh);
3843
3844 return err;
3845}
3846
3847#endif
1/*
2 BlueZ - Bluetooth protocol stack for Linux
3 Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License version 2 as
7 published by the Free Software Foundation;
8
9 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
10 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
11 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
12 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
13 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
14 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17
18 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
19 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
20 SOFTWARE IS DISCLAIMED.
21*/
22
23#include <net/bluetooth/bluetooth.h>
24#include <net/bluetooth/hci_core.h>
25#include <net/bluetooth/l2cap.h>
26#include <net/bluetooth/mgmt.h>
27#include <net/bluetooth/smp.h>
28#include <linux/crypto.h>
29#include <linux/scatterlist.h>
30#include <crypto/b128ops.h>
31
32#define SMP_TIMEOUT msecs_to_jiffies(30000)
33
34static inline void swap128(u8 src[16], u8 dst[16])
35{
36 int i;
37 for (i = 0; i < 16; i++)
38 dst[15 - i] = src[i];
39}
40
41static inline void swap56(u8 src[7], u8 dst[7])
42{
43 int i;
44 for (i = 0; i < 7; i++)
45 dst[6 - i] = src[i];
46}
47
48static int smp_e(struct crypto_blkcipher *tfm, const u8 *k, u8 *r)
49{
50 struct blkcipher_desc desc;
51 struct scatterlist sg;
52 int err, iv_len;
53 unsigned char iv[128];
54
55 if (tfm == NULL) {
56 BT_ERR("tfm %p", tfm);
57 return -EINVAL;
58 }
59
60 desc.tfm = tfm;
61 desc.flags = 0;
62
63 err = crypto_blkcipher_setkey(tfm, k, 16);
64 if (err) {
65 BT_ERR("cipher setkey failed: %d", err);
66 return err;
67 }
68
69 sg_init_one(&sg, r, 16);
70
71 iv_len = crypto_blkcipher_ivsize(tfm);
72 if (iv_len) {
73 memset(&iv, 0xff, iv_len);
74 crypto_blkcipher_set_iv(tfm, iv, iv_len);
75 }
76
77 err = crypto_blkcipher_encrypt(&desc, &sg, &sg, 16);
78 if (err)
79 BT_ERR("Encrypt data error %d", err);
80
81 return err;
82}
83
84static int smp_c1(struct crypto_blkcipher *tfm, u8 k[16], u8 r[16],
85 u8 preq[7], u8 pres[7], u8 _iat, bdaddr_t *ia,
86 u8 _rat, bdaddr_t *ra, u8 res[16])
87{
88 u8 p1[16], p2[16];
89 int err;
90
91 memset(p1, 0, 16);
92
93 /* p1 = pres || preq || _rat || _iat */
94 swap56(pres, p1);
95 swap56(preq, p1 + 7);
96 p1[14] = _rat;
97 p1[15] = _iat;
98
99 memset(p2, 0, 16);
100
101 /* p2 = padding || ia || ra */
102 baswap((bdaddr_t *) (p2 + 4), ia);
103 baswap((bdaddr_t *) (p2 + 10), ra);
104
105 /* res = r XOR p1 */
106 u128_xor((u128 *) res, (u128 *) r, (u128 *) p1);
107
108 /* res = e(k, res) */
109 err = smp_e(tfm, k, res);
110 if (err) {
111 BT_ERR("Encrypt data error");
112 return err;
113 }
114
115 /* res = res XOR p2 */
116 u128_xor((u128 *) res, (u128 *) res, (u128 *) p2);
117
118 /* res = e(k, res) */
119 err = smp_e(tfm, k, res);
120 if (err)
121 BT_ERR("Encrypt data error");
122
123 return err;
124}
125
126static int smp_s1(struct crypto_blkcipher *tfm, u8 k[16],
127 u8 r1[16], u8 r2[16], u8 _r[16])
128{
129 int err;
130
131 /* Just least significant octets from r1 and r2 are considered */
132 memcpy(_r, r1 + 8, 8);
133 memcpy(_r + 8, r2 + 8, 8);
134
135 err = smp_e(tfm, k, _r);
136 if (err)
137 BT_ERR("Encrypt data error");
138
139 return err;
140}
141
142static int smp_rand(u8 *buf)
143{
144 get_random_bytes(buf, 16);
145
146 return 0;
147}
148
149static struct sk_buff *smp_build_cmd(struct l2cap_conn *conn, u8 code,
150 u16 dlen, void *data)
151{
152 struct sk_buff *skb;
153 struct l2cap_hdr *lh;
154 int len;
155
156 len = L2CAP_HDR_SIZE + sizeof(code) + dlen;
157
158 if (len > conn->mtu)
159 return NULL;
160
161 skb = bt_skb_alloc(len, GFP_ATOMIC);
162 if (!skb)
163 return NULL;
164
165 lh = (struct l2cap_hdr *) skb_put(skb, L2CAP_HDR_SIZE);
166 lh->len = cpu_to_le16(sizeof(code) + dlen);
167 lh->cid = cpu_to_le16(L2CAP_CID_SMP);
168
169 memcpy(skb_put(skb, sizeof(code)), &code, sizeof(code));
170
171 memcpy(skb_put(skb, dlen), data, dlen);
172
173 return skb;
174}
175
176static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
177{
178 struct sk_buff *skb = smp_build_cmd(conn, code, len, data);
179
180 BT_DBG("code 0x%2.2x", code);
181
182 if (!skb)
183 return;
184
185 skb->priority = HCI_PRIO_MAX;
186 hci_send_acl(conn->hchan, skb, 0);
187
188 cancel_delayed_work_sync(&conn->security_timer);
189 schedule_delayed_work(&conn->security_timer, SMP_TIMEOUT);
190}
191
192static __u8 authreq_to_seclevel(__u8 authreq)
193{
194 if (authreq & SMP_AUTH_MITM)
195 return BT_SECURITY_HIGH;
196 else
197 return BT_SECURITY_MEDIUM;
198}
199
200static __u8 seclevel_to_authreq(__u8 sec_level)
201{
202 switch (sec_level) {
203 case BT_SECURITY_HIGH:
204 return SMP_AUTH_MITM | SMP_AUTH_BONDING;
205 case BT_SECURITY_MEDIUM:
206 return SMP_AUTH_BONDING;
207 default:
208 return SMP_AUTH_NONE;
209 }
210}
211
212static void build_pairing_cmd(struct l2cap_conn *conn,
213 struct smp_cmd_pairing *req,
214 struct smp_cmd_pairing *rsp,
215 __u8 authreq)
216{
217 u8 dist_keys = 0;
218
219 if (test_bit(HCI_PAIRABLE, &conn->hcon->hdev->dev_flags)) {
220 dist_keys = SMP_DIST_ENC_KEY;
221 authreq |= SMP_AUTH_BONDING;
222 } else {
223 authreq &= ~SMP_AUTH_BONDING;
224 }
225
226 if (rsp == NULL) {
227 req->io_capability = conn->hcon->io_capability;
228 req->oob_flag = SMP_OOB_NOT_PRESENT;
229 req->max_key_size = SMP_MAX_ENC_KEY_SIZE;
230 req->init_key_dist = 0;
231 req->resp_key_dist = dist_keys;
232 req->auth_req = authreq;
233 return;
234 }
235
236 rsp->io_capability = conn->hcon->io_capability;
237 rsp->oob_flag = SMP_OOB_NOT_PRESENT;
238 rsp->max_key_size = SMP_MAX_ENC_KEY_SIZE;
239 rsp->init_key_dist = 0;
240 rsp->resp_key_dist = req->resp_key_dist & dist_keys;
241 rsp->auth_req = authreq;
242}
243
244static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)
245{
246 struct smp_chan *smp = conn->smp_chan;
247
248 if ((max_key_size > SMP_MAX_ENC_KEY_SIZE) ||
249 (max_key_size < SMP_MIN_ENC_KEY_SIZE))
250 return SMP_ENC_KEY_SIZE;
251
252 smp->enc_key_size = max_key_size;
253
254 return 0;
255}
256
257static void smp_failure(struct l2cap_conn *conn, u8 reason, u8 send)
258{
259 struct hci_conn *hcon = conn->hcon;
260
261 if (send)
262 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
263 &reason);
264
265 clear_bit(HCI_CONN_ENCRYPT_PEND, &conn->hcon->flags);
266 mgmt_auth_failed(conn->hcon->hdev, conn->dst, hcon->type,
267 hcon->dst_type, reason);
268
269 cancel_delayed_work_sync(&conn->security_timer);
270
271 if (test_and_clear_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->flags))
272 smp_chan_destroy(conn);
273}
274
275#define JUST_WORKS 0x00
276#define JUST_CFM 0x01
277#define REQ_PASSKEY 0x02
278#define CFM_PASSKEY 0x03
279#define REQ_OOB 0x04
280#define OVERLAP 0xFF
281
282static const u8 gen_method[5][5] = {
283 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
284 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
285 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
286 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
287 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP },
288};
289
290static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth,
291 u8 local_io, u8 remote_io)
292{
293 struct hci_conn *hcon = conn->hcon;
294 struct smp_chan *smp = conn->smp_chan;
295 u8 method;
296 u32 passkey = 0;
297 int ret = 0;
298
299 /* Initialize key for JUST WORKS */
300 memset(smp->tk, 0, sizeof(smp->tk));
301 clear_bit(SMP_FLAG_TK_VALID, &smp->smp_flags);
302
303 BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io);
304
305 /* If neither side wants MITM, use JUST WORKS */
306 /* If either side has unknown io_caps, use JUST WORKS */
307 /* Otherwise, look up method from the table */
308 if (!(auth & SMP_AUTH_MITM) ||
309 local_io > SMP_IO_KEYBOARD_DISPLAY ||
310 remote_io > SMP_IO_KEYBOARD_DISPLAY)
311 method = JUST_WORKS;
312 else
313 method = gen_method[remote_io][local_io];
314
315 /* If not bonding, don't ask user to confirm a Zero TK */
316 if (!(auth & SMP_AUTH_BONDING) && method == JUST_CFM)
317 method = JUST_WORKS;
318
319 /* If Just Works, Continue with Zero TK */
320 if (method == JUST_WORKS) {
321 set_bit(SMP_FLAG_TK_VALID, &smp->smp_flags);
322 return 0;
323 }
324
325 /* Not Just Works/Confirm results in MITM Authentication */
326 if (method != JUST_CFM)
327 set_bit(SMP_FLAG_MITM_AUTH, &smp->smp_flags);
328
329 /* If both devices have Keyoard-Display I/O, the master
330 * Confirms and the slave Enters the passkey.
331 */
332 if (method == OVERLAP) {
333 if (hcon->link_mode & HCI_LM_MASTER)
334 method = CFM_PASSKEY;
335 else
336 method = REQ_PASSKEY;
337 }
338
339 /* Generate random passkey. Not valid until confirmed. */
340 if (method == CFM_PASSKEY) {
341 u8 key[16];
342
343 memset(key, 0, sizeof(key));
344 get_random_bytes(&passkey, sizeof(passkey));
345 passkey %= 1000000;
346 put_unaligned_le32(passkey, key);
347 swap128(key, smp->tk);
348 BT_DBG("PassKey: %d", passkey);
349 }
350
351 hci_dev_lock(hcon->hdev);
352
353 if (method == REQ_PASSKEY)
354 ret = mgmt_user_passkey_request(hcon->hdev, conn->dst,
355 hcon->type, hcon->dst_type);
356 else
357 ret = mgmt_user_confirm_request(hcon->hdev, conn->dst,
358 hcon->type, hcon->dst_type,
359 cpu_to_le32(passkey), 0);
360
361 hci_dev_unlock(hcon->hdev);
362
363 return ret;
364}
365
366static void confirm_work(struct work_struct *work)
367{
368 struct smp_chan *smp = container_of(work, struct smp_chan, confirm);
369 struct l2cap_conn *conn = smp->conn;
370 struct crypto_blkcipher *tfm;
371 struct smp_cmd_pairing_confirm cp;
372 int ret;
373 u8 res[16], reason;
374
375 BT_DBG("conn %p", conn);
376
377 tfm = crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);
378 if (IS_ERR(tfm)) {
379 reason = SMP_UNSPECIFIED;
380 goto error;
381 }
382
383 smp->tfm = tfm;
384
385 if (conn->hcon->out)
386 ret = smp_c1(tfm, smp->tk, smp->prnd, smp->preq, smp->prsp, 0,
387 conn->src, conn->hcon->dst_type, conn->dst, res);
388 else
389 ret = smp_c1(tfm, smp->tk, smp->prnd, smp->preq, smp->prsp,
390 conn->hcon->dst_type, conn->dst, 0, conn->src,
391 res);
392 if (ret) {
393 reason = SMP_UNSPECIFIED;
394 goto error;
395 }
396
397 clear_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags);
398
399 swap128(res, cp.confirm_val);
400 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
401
402 return;
403
404error:
405 smp_failure(conn, reason, 1);
406}
407
408static void random_work(struct work_struct *work)
409{
410 struct smp_chan *smp = container_of(work, struct smp_chan, random);
411 struct l2cap_conn *conn = smp->conn;
412 struct hci_conn *hcon = conn->hcon;
413 struct crypto_blkcipher *tfm = smp->tfm;
414 u8 reason, confirm[16], res[16], key[16];
415 int ret;
416
417 if (IS_ERR_OR_NULL(tfm)) {
418 reason = SMP_UNSPECIFIED;
419 goto error;
420 }
421
422 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
423
424 if (hcon->out)
425 ret = smp_c1(tfm, smp->tk, smp->rrnd, smp->preq, smp->prsp, 0,
426 conn->src, hcon->dst_type, conn->dst, res);
427 else
428 ret = smp_c1(tfm, smp->tk, smp->rrnd, smp->preq, smp->prsp,
429 hcon->dst_type, conn->dst, 0, conn->src, res);
430 if (ret) {
431 reason = SMP_UNSPECIFIED;
432 goto error;
433 }
434
435 swap128(res, confirm);
436
437 if (memcmp(smp->pcnf, confirm, sizeof(smp->pcnf)) != 0) {
438 BT_ERR("Pairing failed (confirmation values mismatch)");
439 reason = SMP_CONFIRM_FAILED;
440 goto error;
441 }
442
443 if (hcon->out) {
444 u8 stk[16], rand[8];
445 __le16 ediv;
446
447 memset(rand, 0, sizeof(rand));
448 ediv = 0;
449
450 smp_s1(tfm, smp->tk, smp->rrnd, smp->prnd, key);
451 swap128(key, stk);
452
453 memset(stk + smp->enc_key_size, 0,
454 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);
455
456 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) {
457 reason = SMP_UNSPECIFIED;
458 goto error;
459 }
460
461 hci_le_start_enc(hcon, ediv, rand, stk);
462 hcon->enc_key_size = smp->enc_key_size;
463 } else {
464 u8 stk[16], r[16], rand[8];
465 __le16 ediv;
466
467 memset(rand, 0, sizeof(rand));
468 ediv = 0;
469
470 swap128(smp->prnd, r);
471 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(r), r);
472
473 smp_s1(tfm, smp->tk, smp->prnd, smp->rrnd, key);
474 swap128(key, stk);
475
476 memset(stk + smp->enc_key_size, 0,
477 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);
478
479 hci_add_ltk(hcon->hdev, conn->dst, hcon->dst_type,
480 HCI_SMP_STK_SLAVE, 0, 0, stk, smp->enc_key_size,
481 ediv, rand);
482 }
483
484 return;
485
486error:
487 smp_failure(conn, reason, 1);
488}
489
490static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
491{
492 struct smp_chan *smp;
493
494 smp = kzalloc(sizeof(struct smp_chan), GFP_ATOMIC);
495 if (!smp)
496 return NULL;
497
498 INIT_WORK(&smp->confirm, confirm_work);
499 INIT_WORK(&smp->random, random_work);
500
501 smp->conn = conn;
502 conn->smp_chan = smp;
503 conn->hcon->smp_conn = conn;
504
505 hci_conn_hold(conn->hcon);
506
507 return smp;
508}
509
510void smp_chan_destroy(struct l2cap_conn *conn)
511{
512 struct smp_chan *smp = conn->smp_chan;
513
514 BUG_ON(!smp);
515
516 if (smp->tfm)
517 crypto_free_blkcipher(smp->tfm);
518
519 kfree(smp);
520 conn->smp_chan = NULL;
521 conn->hcon->smp_conn = NULL;
522 hci_conn_put(conn->hcon);
523}
524
525int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey)
526{
527 struct l2cap_conn *conn = hcon->smp_conn;
528 struct smp_chan *smp;
529 u32 value;
530 u8 key[16];
531
532 BT_DBG("");
533
534 if (!conn)
535 return -ENOTCONN;
536
537 smp = conn->smp_chan;
538
539 switch (mgmt_op) {
540 case MGMT_OP_USER_PASSKEY_REPLY:
541 value = le32_to_cpu(passkey);
542 memset(key, 0, sizeof(key));
543 BT_DBG("PassKey: %d", value);
544 put_unaligned_le32(value, key);
545 swap128(key, smp->tk);
546 /* Fall Through */
547 case MGMT_OP_USER_CONFIRM_REPLY:
548 set_bit(SMP_FLAG_TK_VALID, &smp->smp_flags);
549 break;
550 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
551 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
552 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED, 1);
553 return 0;
554 default:
555 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED, 1);
556 return -EOPNOTSUPP;
557 }
558
559 /* If it is our turn to send Pairing Confirm, do so now */
560 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags))
561 queue_work(hcon->hdev->workqueue, &smp->confirm);
562
563 return 0;
564}
565
566static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
567{
568 struct smp_cmd_pairing rsp, *req = (void *) skb->data;
569 struct smp_chan *smp;
570 u8 key_size;
571 u8 auth = SMP_AUTH_NONE;
572 int ret;
573
574 BT_DBG("conn %p", conn);
575
576 if (conn->hcon->link_mode & HCI_LM_MASTER)
577 return SMP_CMD_NOTSUPP;
578
579 if (!test_and_set_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->flags))
580 smp = smp_chan_create(conn);
581
582 smp = conn->smp_chan;
583
584 smp->preq[0] = SMP_CMD_PAIRING_REQ;
585 memcpy(&smp->preq[1], req, sizeof(*req));
586 skb_pull(skb, sizeof(*req));
587
588 /* We didn't start the pairing, so match remote */
589 if (req->auth_req & SMP_AUTH_BONDING)
590 auth = req->auth_req;
591
592 conn->hcon->pending_sec_level = authreq_to_seclevel(auth);
593
594 build_pairing_cmd(conn, req, &rsp, auth);
595
596 key_size = min(req->max_key_size, rsp.max_key_size);
597 if (check_enc_key_size(conn, key_size))
598 return SMP_ENC_KEY_SIZE;
599
600 ret = smp_rand(smp->prnd);
601 if (ret)
602 return SMP_UNSPECIFIED;
603
604 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
605 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
606
607 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
608
609 /* Request setup of TK */
610 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability);
611 if (ret)
612 return SMP_UNSPECIFIED;
613
614 return 0;
615}
616
617static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
618{
619 struct smp_cmd_pairing *req, *rsp = (void *) skb->data;
620 struct smp_chan *smp = conn->smp_chan;
621 struct hci_dev *hdev = conn->hcon->hdev;
622 u8 key_size, auth = SMP_AUTH_NONE;
623 int ret;
624
625 BT_DBG("conn %p", conn);
626
627 if (!(conn->hcon->link_mode & HCI_LM_MASTER))
628 return SMP_CMD_NOTSUPP;
629
630 skb_pull(skb, sizeof(*rsp));
631
632 req = (void *) &smp->preq[1];
633
634 key_size = min(req->max_key_size, rsp->max_key_size);
635 if (check_enc_key_size(conn, key_size))
636 return SMP_ENC_KEY_SIZE;
637
638 ret = smp_rand(smp->prnd);
639 if (ret)
640 return SMP_UNSPECIFIED;
641
642 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
643 memcpy(&smp->prsp[1], rsp, sizeof(*rsp));
644
645 if ((req->auth_req & SMP_AUTH_BONDING) &&
646 (rsp->auth_req & SMP_AUTH_BONDING))
647 auth = SMP_AUTH_BONDING;
648
649 auth |= (req->auth_req | rsp->auth_req) & SMP_AUTH_MITM;
650
651 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability);
652 if (ret)
653 return SMP_UNSPECIFIED;
654
655 set_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags);
656
657 /* Can't compose response until we have been confirmed */
658 if (!test_bit(SMP_FLAG_TK_VALID, &smp->smp_flags))
659 return 0;
660
661 queue_work(hdev->workqueue, &smp->confirm);
662
663 return 0;
664}
665
666static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
667{
668 struct smp_chan *smp = conn->smp_chan;
669 struct hci_dev *hdev = conn->hcon->hdev;
670
671 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
672
673 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf));
674 skb_pull(skb, sizeof(smp->pcnf));
675
676 if (conn->hcon->out) {
677 u8 random[16];
678
679 swap128(smp->prnd, random);
680 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(random),
681 random);
682 } else if (test_bit(SMP_FLAG_TK_VALID, &smp->smp_flags)) {
683 queue_work(hdev->workqueue, &smp->confirm);
684 } else {
685 set_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags);
686 }
687
688 return 0;
689}
690
691static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
692{
693 struct smp_chan *smp = conn->smp_chan;
694 struct hci_dev *hdev = conn->hcon->hdev;
695
696 BT_DBG("conn %p", conn);
697
698 swap128(skb->data, smp->rrnd);
699 skb_pull(skb, sizeof(smp->rrnd));
700
701 queue_work(hdev->workqueue, &smp->random);
702
703 return 0;
704}
705
706static u8 smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level)
707{
708 struct smp_ltk *key;
709 struct hci_conn *hcon = conn->hcon;
710
711 key = hci_find_ltk_by_addr(hcon->hdev, conn->dst, hcon->dst_type);
712 if (!key)
713 return 0;
714
715 if (sec_level > BT_SECURITY_MEDIUM && !key->authenticated)
716 return 0;
717
718 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
719 return 1;
720
721 hci_le_start_enc(hcon, key->ediv, key->rand, key->val);
722 hcon->enc_key_size = key->enc_size;
723
724 return 1;
725
726}
727static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
728{
729 struct smp_cmd_security_req *rp = (void *) skb->data;
730 struct smp_cmd_pairing cp;
731 struct hci_conn *hcon = conn->hcon;
732 struct smp_chan *smp;
733
734 BT_DBG("conn %p", conn);
735
736 hcon->pending_sec_level = authreq_to_seclevel(rp->auth_req);
737
738 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
739 return 0;
740
741 if (test_and_set_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags))
742 return 0;
743
744 smp = smp_chan_create(conn);
745
746 skb_pull(skb, sizeof(*rp));
747
748 memset(&cp, 0, sizeof(cp));
749 build_pairing_cmd(conn, &cp, NULL, rp->auth_req);
750
751 smp->preq[0] = SMP_CMD_PAIRING_REQ;
752 memcpy(&smp->preq[1], &cp, sizeof(cp));
753
754 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
755
756 return 0;
757}
758
759int smp_conn_security(struct hci_conn *hcon, __u8 sec_level)
760{
761 struct l2cap_conn *conn = hcon->l2cap_data;
762 struct smp_chan *smp = conn->smp_chan;
763 __u8 authreq;
764
765 BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level);
766
767 if (!lmp_host_le_capable(hcon->hdev))
768 return 1;
769
770 if (sec_level == BT_SECURITY_LOW)
771 return 1;
772
773 if (hcon->sec_level >= sec_level)
774 return 1;
775
776 if (hcon->link_mode & HCI_LM_MASTER)
777 if (smp_ltk_encrypt(conn, sec_level))
778 goto done;
779
780 if (test_and_set_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags))
781 return 0;
782
783 smp = smp_chan_create(conn);
784 if (!smp)
785 return 1;
786
787 authreq = seclevel_to_authreq(sec_level);
788
789 if (hcon->link_mode & HCI_LM_MASTER) {
790 struct smp_cmd_pairing cp;
791
792 build_pairing_cmd(conn, &cp, NULL, authreq);
793 smp->preq[0] = SMP_CMD_PAIRING_REQ;
794 memcpy(&smp->preq[1], &cp, sizeof(cp));
795
796 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
797 } else {
798 struct smp_cmd_security_req cp;
799 cp.auth_req = authreq;
800 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp);
801 }
802
803done:
804 hcon->pending_sec_level = sec_level;
805
806 return 0;
807}
808
809static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb)
810{
811 struct smp_cmd_encrypt_info *rp = (void *) skb->data;
812 struct smp_chan *smp = conn->smp_chan;
813
814 skb_pull(skb, sizeof(*rp));
815
816 memcpy(smp->tk, rp->ltk, sizeof(smp->tk));
817
818 return 0;
819}
820
821static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb)
822{
823 struct smp_cmd_master_ident *rp = (void *) skb->data;
824 struct smp_chan *smp = conn->smp_chan;
825 struct hci_dev *hdev = conn->hcon->hdev;
826 struct hci_conn *hcon = conn->hcon;
827 u8 authenticated;
828
829 skb_pull(skb, sizeof(*rp));
830
831 hci_dev_lock(hdev);
832 authenticated = (conn->hcon->sec_level == BT_SECURITY_HIGH);
833 hci_add_ltk(conn->hcon->hdev, conn->dst, hcon->dst_type,
834 HCI_SMP_LTK, 1, authenticated, smp->tk, smp->enc_key_size,
835 rp->ediv, rp->rand);
836 smp_distribute_keys(conn, 1);
837 hci_dev_unlock(hdev);
838
839 return 0;
840}
841
842int smp_sig_channel(struct l2cap_conn *conn, struct sk_buff *skb)
843{
844 __u8 code = skb->data[0];
845 __u8 reason;
846 int err = 0;
847
848 if (!lmp_host_le_capable(conn->hcon->hdev)) {
849 err = -ENOTSUPP;
850 reason = SMP_PAIRING_NOTSUPP;
851 goto done;
852 }
853
854 skb_pull(skb, sizeof(code));
855
856 switch (code) {
857 case SMP_CMD_PAIRING_REQ:
858 reason = smp_cmd_pairing_req(conn, skb);
859 break;
860
861 case SMP_CMD_PAIRING_FAIL:
862 smp_failure(conn, skb->data[0], 0);
863 reason = 0;
864 err = -EPERM;
865 break;
866
867 case SMP_CMD_PAIRING_RSP:
868 reason = smp_cmd_pairing_rsp(conn, skb);
869 break;
870
871 case SMP_CMD_SECURITY_REQ:
872 reason = smp_cmd_security_req(conn, skb);
873 break;
874
875 case SMP_CMD_PAIRING_CONFIRM:
876 reason = smp_cmd_pairing_confirm(conn, skb);
877 break;
878
879 case SMP_CMD_PAIRING_RANDOM:
880 reason = smp_cmd_pairing_random(conn, skb);
881 break;
882
883 case SMP_CMD_ENCRYPT_INFO:
884 reason = smp_cmd_encrypt_info(conn, skb);
885 break;
886
887 case SMP_CMD_MASTER_IDENT:
888 reason = smp_cmd_master_ident(conn, skb);
889 break;
890
891 case SMP_CMD_IDENT_INFO:
892 case SMP_CMD_IDENT_ADDR_INFO:
893 case SMP_CMD_SIGN_INFO:
894 /* Just ignored */
895 reason = 0;
896 break;
897
898 default:
899 BT_DBG("Unknown command code 0x%2.2x", code);
900
901 reason = SMP_CMD_NOTSUPP;
902 err = -EOPNOTSUPP;
903 goto done;
904 }
905
906done:
907 if (reason)
908 smp_failure(conn, reason, 1);
909
910 kfree_skb(skb);
911 return err;
912}
913
914int smp_distribute_keys(struct l2cap_conn *conn, __u8 force)
915{
916 struct smp_cmd_pairing *req, *rsp;
917 struct smp_chan *smp = conn->smp_chan;
918 __u8 *keydist;
919
920 BT_DBG("conn %p force %d", conn, force);
921
922 if (!test_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->flags))
923 return 0;
924
925 rsp = (void *) &smp->prsp[1];
926
927 /* The responder sends its keys first */
928 if (!force && conn->hcon->out && (rsp->resp_key_dist & 0x07))
929 return 0;
930
931 req = (void *) &smp->preq[1];
932
933 if (conn->hcon->out) {
934 keydist = &rsp->init_key_dist;
935 *keydist &= req->init_key_dist;
936 } else {
937 keydist = &rsp->resp_key_dist;
938 *keydist &= req->resp_key_dist;
939 }
940
941
942 BT_DBG("keydist 0x%x", *keydist);
943
944 if (*keydist & SMP_DIST_ENC_KEY) {
945 struct smp_cmd_encrypt_info enc;
946 struct smp_cmd_master_ident ident;
947 struct hci_conn *hcon = conn->hcon;
948 u8 authenticated;
949 __le16 ediv;
950
951 get_random_bytes(enc.ltk, sizeof(enc.ltk));
952 get_random_bytes(&ediv, sizeof(ediv));
953 get_random_bytes(ident.rand, sizeof(ident.rand));
954
955 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc);
956
957 authenticated = hcon->sec_level == BT_SECURITY_HIGH;
958 hci_add_ltk(conn->hcon->hdev, conn->dst, hcon->dst_type,
959 HCI_SMP_LTK_SLAVE, 1, authenticated,
960 enc.ltk, smp->enc_key_size, ediv, ident.rand);
961
962 ident.ediv = ediv;
963
964 smp_send_cmd(conn, SMP_CMD_MASTER_IDENT, sizeof(ident), &ident);
965
966 *keydist &= ~SMP_DIST_ENC_KEY;
967 }
968
969 if (*keydist & SMP_DIST_ID_KEY) {
970 struct smp_cmd_ident_addr_info addrinfo;
971 struct smp_cmd_ident_info idinfo;
972
973 /* Send a dummy key */
974 get_random_bytes(idinfo.irk, sizeof(idinfo.irk));
975
976 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo);
977
978 /* Just public address */
979 memset(&addrinfo, 0, sizeof(addrinfo));
980 bacpy(&addrinfo.bdaddr, conn->src);
981
982 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo),
983 &addrinfo);
984
985 *keydist &= ~SMP_DIST_ID_KEY;
986 }
987
988 if (*keydist & SMP_DIST_SIGN) {
989 struct smp_cmd_sign_info sign;
990
991 /* Send a dummy key */
992 get_random_bytes(sign.csrk, sizeof(sign.csrk));
993
994 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign);
995
996 *keydist &= ~SMP_DIST_SIGN;
997 }
998
999 if (conn->hcon->out || force) {
1000 clear_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->flags);
1001 cancel_delayed_work_sync(&conn->security_timer);
1002 smp_chan_destroy(conn);
1003 }
1004
1005 return 0;
1006}