projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Bluetooth: Add workaround for broken OS X legacy SMP pairing
[deliverable/linux.git] / net / bluetooth / smp.c
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/crypto.h>
25 #include <linux/scatterlist.h>
26 #include <crypto/b128ops.h>
27
28 #include <net/bluetooth/bluetooth.h>
29 #include <net/bluetooth/hci_core.h>
30 #include <net/bluetooth/l2cap.h>
31 #include <net/bluetooth/mgmt.h>
32
33 #include "ecc.h"
34 #include "smp.h"
35
36 /* Low-level debug macros to be used for stuff that we don't want
37 * accidentially in dmesg, i.e. the values of the various crypto keys
38 * and the inputs & outputs of crypto functions.
39 */
40 #ifdef DEBUG
41 #define SMP_DBG(fmt, ...) printk(KERN_DEBUG "%s: " fmt, __func__, \
42 ##__VA_ARGS__)
43 #else
44 #define SMP_DBG(fmt, ...) no_printk(KERN_DEBUG "%s: " fmt, __func__, \
45 ##__VA_ARGS__)
46 #endif
47
48 #define SMP_ALLOW_CMD(smp, code) set_bit(code, &smp->allow_cmd)
49
50 /* Keys which are not distributed with Secure Connections */
51 #define SMP_SC_NO_DIST (SMP_DIST_ENC_KEY | SMP_DIST_LINK_KEY);
52
53 #define SMP_TIMEOUT msecs_to_jiffies(30000)
54
55 #define AUTH_REQ_MASK(dev) (hci_dev_test_flag(dev, HCI_SC_ENABLED) ? \
56 0x1f : 0x07)
57 #define KEY_DIST_MASK 0x07
58
59 /* Maximum message length that can be passed to aes_cmac */
60 #define CMAC_MSG_MAX 80
61
62 enum {
63 SMP_FLAG_TK_VALID,
64 SMP_FLAG_CFM_PENDING,
65 SMP_FLAG_MITM_AUTH,
66 SMP_FLAG_COMPLETE,
67 SMP_FLAG_INITIATOR,
68 SMP_FLAG_SC,
69 SMP_FLAG_REMOTE_PK,
70 SMP_FLAG_DEBUG_KEY,
71 SMP_FLAG_WAIT_USER,
72 SMP_FLAG_DHKEY_PENDING,
73 SMP_FLAG_REMOTE_OOB,
74 SMP_FLAG_LOCAL_OOB,
75 };
76
77 struct smp_dev {
78 /* Secure Connections OOB data */
79 u8 local_pk[64];
80 u8 local_sk[32];
81 u8 local_rand[16];
82 bool debug_key;
83
84 struct crypto_blkcipher *tfm_aes;
85 struct crypto_hash *tfm_cmac;
86 };
87
88 struct smp_chan {
89 struct l2cap_conn *conn;
90 struct delayed_work security_timer;
91 unsigned long allow_cmd; /* Bitmask of allowed commands */
92
93 u8 preq[7]; /* SMP Pairing Request */
94 u8 prsp[7]; /* SMP Pairing Response */
95 u8 prnd[16]; /* SMP Pairing Random (local) */
96 u8 rrnd[16]; /* SMP Pairing Random (remote) */
97 u8 pcnf[16]; /* SMP Pairing Confirm */
98 u8 tk[16]; /* SMP Temporary Key */
99 u8 rr[16]; /* Remote OOB ra/rb value */
100 u8 lr[16]; /* Local OOB ra/rb value */
101 u8 enc_key_size;
102 u8 remote_key_dist;
103 bdaddr_t id_addr;
104 u8 id_addr_type;
105 u8 irk[16];
106 struct smp_csrk *csrk;
107 struct smp_csrk *slave_csrk;
108 struct smp_ltk *ltk;
109 struct smp_ltk *slave_ltk;
110 struct smp_irk *remote_irk;
111 u8 *link_key;
112 unsigned long flags;
113 u8 method;
114 u8 passkey_round;
115
116 /* Secure Connections variables */
117 u8 local_pk[64];
118 u8 local_sk[32];
119 u8 remote_pk[64];
120 u8 dhkey[32];
121 u8 mackey[16];
122
123 struct crypto_blkcipher *tfm_aes;
124 struct crypto_hash *tfm_cmac;
125 };
126
127 /* These debug key values are defined in the SMP section of the core
128 * specification. debug_pk is the public debug key and debug_sk the
129 * private debug key.
130 */
131 static const u8 debug_pk[64] = {
132 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
133 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
134 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
135 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20,
136
137 0x8b, 0xd2, 0x89, 0x15, 0xd0, 0x8e, 0x1c, 0x74,
138 0x24, 0x30, 0xed, 0x8f, 0xc2, 0x45, 0x63, 0x76,
139 0x5c, 0x15, 0x52, 0x5a, 0xbf, 0x9a, 0x32, 0x63,
140 0x6d, 0xeb, 0x2a, 0x65, 0x49, 0x9c, 0x80, 0xdc,
141 };
142
143 static const u8 debug_sk[32] = {
144 0xbd, 0x1a, 0x3c, 0xcd, 0xa6, 0xb8, 0x99, 0x58,
145 0x99, 0xb7, 0x40, 0xeb, 0x7b, 0x60, 0xff, 0x4a,
146 0x50, 0x3f, 0x10, 0xd2, 0xe3, 0xb3, 0xc9, 0x74,
147 0x38, 0x5f, 0xc5, 0xa3, 0xd4, 0xf6, 0x49, 0x3f,
148 };
149
150 static inline void swap_buf(const u8 *src, u8 *dst, size_t len)
151 {
152 size_t i;
153
154 for (i = 0; i < len; i++)
155 dst[len - 1 - i] = src[i];
156 }
157
158 /* The following functions map to the LE SC SMP crypto functions
159 * AES-CMAC, f4, f5, f6, g2 and h6.
160 */
161
162 static int aes_cmac(struct crypto_hash *tfm, const u8 k[16], const u8 *m,
163 size_t len, u8 mac[16])
164 {
165 uint8_t tmp[16], mac_msb[16], msg_msb[CMAC_MSG_MAX];
166 struct hash_desc desc;
167 struct scatterlist sg;
168 int err;
169
170 if (len > CMAC_MSG_MAX)
171 return -EFBIG;
172
173 if (!tfm) {
174 BT_ERR("tfm %p", tfm);
175 return -EINVAL;
176 }
177
178 desc.tfm = tfm;
179 desc.flags = 0;
180
181 crypto_hash_init(&desc);
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_hash_setkey(tfm, tmp, 16);
191 if (err) {
192 BT_ERR("cipher setkey failed: %d", err);
193 return err;
194 }
195
196 sg_init_one(&sg, msg_msb, len);
197
198 err = crypto_hash_update(&desc, &sg, len);
199 if (err) {
200 BT_ERR("Hash update error %d", err);
201 return err;
202 }
203
204 err = crypto_hash_final(&desc, mac_msb);
205 if (err) {
206 BT_ERR("Hash final error %d", err);
207 return err;
208 }
209
210 swap_buf(mac_msb, mac, 16);
211
212 SMP_DBG("mac %16phN", mac);
213
214 return 0;
215 }
216
217 static int smp_f4(struct crypto_hash *tfm_cmac, const u8 u[32], const u8 v[32],
218 const u8 x[16], u8 z, u8 res[16])
219 {
220 u8 m[65];
221 int err;
222
223 SMP_DBG("u %32phN", u);
224 SMP_DBG("v %32phN", v);
225 SMP_DBG("x %16phN z %02x", x, z);
226
227 m[0] = z;
228 memcpy(m + 1, v, 32);
229 memcpy(m + 33, u, 32);
230
231 err = aes_cmac(tfm_cmac, x, m, sizeof(m), res);
232 if (err)
233 return err;
234
235 SMP_DBG("res %16phN", res);
236
237 return err;
238 }
239
240 static int smp_f5(struct crypto_hash *tfm_cmac, const u8 w[32],
241 const u8 n1[16], const u8 n2[16], const u8 a1[7],
242 const u8 a2[7], u8 mackey[16], u8 ltk[16])
243 {
244 /* The btle, salt and length "magic" values are as defined in
245 * the SMP section of the Bluetooth core specification. In ASCII
246 * the btle value ends up being 'btle'. The salt is just a
247 * random number whereas length is the value 256 in little
248 * endian format.
249 */
250 const u8 btle[4] = { 0x65, 0x6c, 0x74, 0x62 };
251 const u8 salt[16] = { 0xbe, 0x83, 0x60, 0x5a, 0xdb, 0x0b, 0x37, 0x60,
252 0x38, 0xa5, 0xf5, 0xaa, 0x91, 0x83, 0x88, 0x6c };
253 const u8 length[2] = { 0x00, 0x01 };
254 u8 m[53], t[16];
255 int err;
256
257 SMP_DBG("w %32phN", w);
258 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
259 SMP_DBG("a1 %7phN a2 %7phN", a1, a2);
260
261 err = aes_cmac(tfm_cmac, salt, w, 32, t);
262 if (err)
263 return err;
264
265 SMP_DBG("t %16phN", t);
266
267 memcpy(m, length, 2);
268 memcpy(m + 2, a2, 7);
269 memcpy(m + 9, a1, 7);
270 memcpy(m + 16, n2, 16);
271 memcpy(m + 32, n1, 16);
272 memcpy(m + 48, btle, 4);
273
274 m[52] = 0; /* Counter */
275
276 err = aes_cmac(tfm_cmac, t, m, sizeof(m), mackey);
277 if (err)
278 return err;
279
280 SMP_DBG("mackey %16phN", mackey);
281
282 m[52] = 1; /* Counter */
283
284 err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk);
285 if (err)
286 return err;
287
288 SMP_DBG("ltk %16phN", ltk);
289
290 return 0;
291 }
292
293 static int smp_f6(struct crypto_hash *tfm_cmac, const u8 w[16],
294 const u8 n1[16], const u8 n2[16], const u8 r[16],
295 const u8 io_cap[3], const u8 a1[7], const u8 a2[7],
296 u8 res[16])
297 {
298 u8 m[65];
299 int err;
300
301 SMP_DBG("w %16phN", w);
302 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
303 SMP_DBG("r %16phN io_cap %3phN a1 %7phN a2 %7phN", r, io_cap, a1, a2);
304
305 memcpy(m, a2, 7);
306 memcpy(m + 7, a1, 7);
307 memcpy(m + 14, io_cap, 3);
308 memcpy(m + 17, r, 16);
309 memcpy(m + 33, n2, 16);
310 memcpy(m + 49, n1, 16);
311
312 err = aes_cmac(tfm_cmac, w, m, sizeof(m), res);
313 if (err)
314 return err;
315
316 SMP_DBG("res %16phN", res);
317
318 return err;
319 }
320
321 static int smp_g2(struct crypto_hash *tfm_cmac, const u8 u[32], const u8 v[32],
322 const u8 x[16], const u8 y[16], u32 *val)
323 {
324 u8 m[80], tmp[16];
325 int err;
326
327 SMP_DBG("u %32phN", u);
328 SMP_DBG("v %32phN", v);
329 SMP_DBG("x %16phN y %16phN", x, y);
330
331 memcpy(m, y, 16);
332 memcpy(m + 16, v, 32);
333 memcpy(m + 48, u, 32);
334
335 err = aes_cmac(tfm_cmac, x, m, sizeof(m), tmp);
336 if (err)
337 return err;
338
339 *val = get_unaligned_le32(tmp);
340 *val %= 1000000;
341
342 SMP_DBG("val %06u", *val);
343
344 return 0;
345 }
346
347 static int smp_h6(struct crypto_hash *tfm_cmac, const u8 w[16],
348 const u8 key_id[4], u8 res[16])
349 {
350 int err;
351
352 SMP_DBG("w %16phN key_id %4phN", w, key_id);
353
354 err = aes_cmac(tfm_cmac, w, key_id, 4, res);
355 if (err)
356 return err;
357
358 SMP_DBG("res %16phN", res);
359
360 return err;
361 }
362
363 /* The following functions map to the legacy SMP crypto functions e, c1,
364 * s1 and ah.
365 */
366
367 static int smp_e(struct crypto_blkcipher *tfm, const u8 *k, u8 *r)
368 {
369 struct blkcipher_desc desc;
370 struct scatterlist sg;
371 uint8_t tmp[16], data[16];
372 int err;
373
374 if (!tfm) {
375 BT_ERR("tfm %p", tfm);
376 return -EINVAL;
377 }
378
379 desc.tfm = tfm;
380 desc.flags = 0;
381
382 /* The most significant octet of key corresponds to k[0] */
383 swap_buf(k, tmp, 16);
384
385 err = crypto_blkcipher_setkey(tfm, tmp, 16);
386 if (err) {
387 BT_ERR("cipher setkey failed: %d", err);
388 return err;
389 }
390
391 /* Most significant octet of plaintextData corresponds to data[0] */
392 swap_buf(r, data, 16);
393
394 sg_init_one(&sg, data, 16);
395
396 err = crypto_blkcipher_encrypt(&desc, &sg, &sg, 16);
397 if (err)
398 BT_ERR("Encrypt data error %d", err);
399
400 /* Most significant octet of encryptedData corresponds to data[0] */
401 swap_buf(data, r, 16);
402
403 return err;
404 }
405
406 static int smp_c1(struct crypto_blkcipher *tfm_aes, 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 memset(p1, 0, 16);
414
415 /* p1 = pres || preq || _rat || _iat */
416 p1[0] = _iat;
417 p1[1] = _rat;
418 memcpy(p1 + 2, preq, 7);
419 memcpy(p1 + 9, pres, 7);
420
421 /* p2 = padding || ia || ra */
422 memcpy(p2, ra, 6);
423 memcpy(p2 + 6, ia, 6);
424 memset(p2 + 12, 0, 4);
425
426 /* res = r XOR p1 */
427 u128_xor((u128 *) res, (u128 *) r, (u128 *) p1);
428
429 /* res = e(k, res) */
430 err = smp_e(tfm_aes, k, res);
431 if (err) {
432 BT_ERR("Encrypt data error");
433 return err;
434 }
435
436 /* res = res XOR p2 */
437 u128_xor((u128 *) res, (u128 *) res, (u128 *) p2);
438
439 /* res = e(k, res) */
440 err = smp_e(tfm_aes, k, res);
441 if (err)
442 BT_ERR("Encrypt data error");
443
444 return err;
445 }
446
447 static int smp_s1(struct crypto_blkcipher *tfm_aes, const u8 k[16],
448 const u8 r1[16], const u8 r2[16], u8 _r[16])
449 {
450 int err;
451
452 /* Just least significant octets from r1 and r2 are considered */
453 memcpy(_r, r2, 8);
454 memcpy(_r + 8, r1, 8);
455
456 err = smp_e(tfm_aes, k, _r);
457 if (err)
458 BT_ERR("Encrypt data error");
459
460 return err;
461 }
462
463 static int smp_ah(struct crypto_blkcipher *tfm, const u8 irk[16],
464 const u8 r[3], u8 res[3])
465 {
466 u8 _res[16];
467 int err;
468
469 /* r' = padding || r */
470 memcpy(_res, r, 3);
471 memset(_res + 3, 0, 13);
472
473 err = smp_e(tfm, irk, _res);
474 if (err) {
475 BT_ERR("Encrypt error");
476 return err;
477 }
478
479 /* The output of the random address function ah is:
480 * ah(h, r) = e(k, r') mod 2^24
481 * The output of the security function e is then truncated to 24 bits
482 * by taking the least significant 24 bits of the output of e as the
483 * result of ah.
484 */
485 memcpy(res, _res, 3);
486
487 return 0;
488 }
489
490 bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16],
491 const bdaddr_t *bdaddr)
492 {
493 struct l2cap_chan *chan = hdev->smp_data;
494 struct smp_dev *smp;
495 u8 hash[3];
496 int err;
497
498 if (!chan || !chan->data)
499 return false;
500
501 smp = chan->data;
502
503 BT_DBG("RPA %pMR IRK %*phN", bdaddr, 16, irk);
504
505 err = smp_ah(smp->tfm_aes, irk, &bdaddr->b[3], hash);
506 if (err)
507 return false;
508
509 return !memcmp(bdaddr->b, hash, 3);
510 }
511
512 int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa)
513 {
514 struct l2cap_chan *chan = hdev->smp_data;
515 struct smp_dev *smp;
516 int err;
517
518 if (!chan || !chan->data)
519 return -EOPNOTSUPP;
520
521 smp = chan->data;
522
523 get_random_bytes(&rpa->b[3], 3);
524
525 rpa->b[5] &= 0x3f; /* Clear two most significant bits */
526 rpa->b[5] |= 0x40; /* Set second most significant bit */
527
528 err = smp_ah(smp->tfm_aes, irk, &rpa->b[3], rpa->b);
529 if (err < 0)
530 return err;
531
532 BT_DBG("RPA %pMR", rpa);
533
534 return 0;
535 }
536
537 int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16])
538 {
539 struct l2cap_chan *chan = hdev->smp_data;
540 struct smp_dev *smp;
541 int err;
542
543 if (!chan || !chan->data)
544 return -EOPNOTSUPP;
545
546 smp = chan->data;
547
548 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) {
549 BT_DBG("Using debug keys");
550 memcpy(smp->local_pk, debug_pk, 64);
551 memcpy(smp->local_sk, debug_sk, 32);
552 smp->debug_key = true;
553 } else {
554 while (true) {
555 /* Generate local key pair for Secure Connections */
556 if (!ecc_make_key(smp->local_pk, smp->local_sk))
557 return -EIO;
558
559 /* This is unlikely, but we need to check that
560 * we didn't accidentially generate a debug key.
561 */
562 if (memcmp(smp->local_sk, debug_sk, 32))
563 break;
564 }
565 smp->debug_key = false;
566 }
567
568 SMP_DBG("OOB Public Key X: %32phN", smp->local_pk);
569 SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32);
570 SMP_DBG("OOB Private Key: %32phN", smp->local_sk);
571
572 get_random_bytes(smp->local_rand, 16);
573
574 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->local_pk,
575 smp->local_rand, 0, hash);
576 if (err < 0)
577 return err;
578
579 memcpy(rand, smp->local_rand, 16);
580
581 return 0;
582 }
583
584 static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
585 {
586 struct l2cap_chan *chan = conn->smp;
587 struct smp_chan *smp;
588 struct kvec iv[2];
589 struct msghdr msg;
590
591 if (!chan)
592 return;
593
594 BT_DBG("code 0x%2.2x", code);
595
596 iv[0].iov_base = &code;
597 iv[0].iov_len = 1;
598
599 iv[1].iov_base = data;
600 iv[1].iov_len = len;
601
602 memset(&msg, 0, sizeof(msg));
603
604 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iv, 2, 1 + len);
605
606 l2cap_chan_send(chan, &msg, 1 + len);
607
608 if (!chan->data)
609 return;
610
611 smp = chan->data;
612
613 cancel_delayed_work_sync(&smp->security_timer);
614 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT);
615 }
616
617 static u8 authreq_to_seclevel(u8 authreq)
618 {
619 if (authreq & SMP_AUTH_MITM) {
620 if (authreq & SMP_AUTH_SC)
621 return BT_SECURITY_FIPS;
622 else
623 return BT_SECURITY_HIGH;
624 } else {
625 return BT_SECURITY_MEDIUM;
626 }
627 }
628
629 static __u8 seclevel_to_authreq(__u8 sec_level)
630 {
631 switch (sec_level) {
632 case BT_SECURITY_FIPS:
633 case BT_SECURITY_HIGH:
634 return SMP_AUTH_MITM | SMP_AUTH_BONDING;
635 case BT_SECURITY_MEDIUM:
636 return SMP_AUTH_BONDING;
637 default:
638 return SMP_AUTH_NONE;
639 }
640 }
641
642 static void build_pairing_cmd(struct l2cap_conn *conn,
643 struct smp_cmd_pairing *req,
644 struct smp_cmd_pairing *rsp, __u8 authreq)
645 {
646 struct l2cap_chan *chan = conn->smp;
647 struct smp_chan *smp = chan->data;
648 struct hci_conn *hcon = conn->hcon;
649 struct hci_dev *hdev = hcon->hdev;
650 u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT;
651
652 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) {
653 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
654 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
655 authreq |= SMP_AUTH_BONDING;
656 } else {
657 authreq &= ~SMP_AUTH_BONDING;
658 }
659
660 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING))
661 remote_dist |= SMP_DIST_ID_KEY;
662
663 if (hci_dev_test_flag(hdev, HCI_PRIVACY))
664 local_dist |= SMP_DIST_ID_KEY;
665
666 if (hci_dev_test_flag(hdev, HCI_SC_ENABLED) &&
667 (authreq & SMP_AUTH_SC)) {
668 struct oob_data *oob_data;
669 u8 bdaddr_type;
670
671 if (hci_dev_test_flag(hdev, HCI_SSP_ENABLED)) {
672 local_dist |= SMP_DIST_LINK_KEY;
673 remote_dist |= SMP_DIST_LINK_KEY;
674 }
675
676 if (hcon->dst_type == ADDR_LE_DEV_PUBLIC)
677 bdaddr_type = BDADDR_LE_PUBLIC;
678 else
679 bdaddr_type = BDADDR_LE_RANDOM;
680
681 oob_data = hci_find_remote_oob_data(hdev, &hcon->dst,
682 bdaddr_type);
683 if (oob_data && oob_data->present) {
684 set_bit(SMP_FLAG_REMOTE_OOB, &smp->flags);
685 oob_flag = SMP_OOB_PRESENT;
686 memcpy(smp->rr, oob_data->rand256, 16);
687 memcpy(smp->pcnf, oob_data->hash256, 16);
688 SMP_DBG("OOB Remote Confirmation: %16phN", smp->pcnf);
689 SMP_DBG("OOB Remote Random: %16phN", smp->rr);
690 }
691
692 } else {
693 authreq &= ~SMP_AUTH_SC;
694 }
695
696 if (rsp == NULL) {
697 req->io_capability = conn->hcon->io_capability;
698 req->oob_flag = oob_flag;
699 req->max_key_size = SMP_MAX_ENC_KEY_SIZE;
700 req->init_key_dist = local_dist;
701 req->resp_key_dist = remote_dist;
702 req->auth_req = (authreq & AUTH_REQ_MASK(hdev));
703
704 smp->remote_key_dist = remote_dist;
705 return;
706 }
707
708 rsp->io_capability = conn->hcon->io_capability;
709 rsp->oob_flag = oob_flag;
710 rsp->max_key_size = SMP_MAX_ENC_KEY_SIZE;
711 rsp->init_key_dist = req->init_key_dist & remote_dist;
712 rsp->resp_key_dist = req->resp_key_dist & local_dist;
713 rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev));
714
715 smp->remote_key_dist = rsp->init_key_dist;
716 }
717
718 static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)
719 {
720 struct l2cap_chan *chan = conn->smp;
721 struct smp_chan *smp = chan->data;
722
723 if ((max_key_size > SMP_MAX_ENC_KEY_SIZE) ||
724 (max_key_size < SMP_MIN_ENC_KEY_SIZE))
725 return SMP_ENC_KEY_SIZE;
726
727 smp->enc_key_size = max_key_size;
728
729 return 0;
730 }
731
732 static void smp_chan_destroy(struct l2cap_conn *conn)
733 {
734 struct l2cap_chan *chan = conn->smp;
735 struct smp_chan *smp = chan->data;
736 struct hci_conn *hcon = conn->hcon;
737 bool complete;
738
739 BUG_ON(!smp);
740
741 cancel_delayed_work_sync(&smp->security_timer);
742
743 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags);
744 mgmt_smp_complete(hcon, complete);
745
746 kzfree(smp->csrk);
747 kzfree(smp->slave_csrk);
748 kzfree(smp->link_key);
749
750 crypto_free_blkcipher(smp->tfm_aes);
751 crypto_free_hash(smp->tfm_cmac);
752
753 /* Ensure that we don't leave any debug key around if debug key
754 * support hasn't been explicitly enabled.
755 */
756 if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG &&
757 !hci_dev_test_flag(hcon->hdev, HCI_KEEP_DEBUG_KEYS)) {
758 list_del_rcu(&smp->ltk->list);
759 kfree_rcu(smp->ltk, rcu);
760 smp->ltk = NULL;
761 }
762
763 /* If pairing failed clean up any keys we might have */
764 if (!complete) {
765 if (smp->ltk) {
766 list_del_rcu(&smp->ltk->list);
767 kfree_rcu(smp->ltk, rcu);
768 }
769
770 if (smp->slave_ltk) {
771 list_del_rcu(&smp->slave_ltk->list);
772 kfree_rcu(smp->slave_ltk, rcu);
773 }
774
775 if (smp->remote_irk) {
776 list_del_rcu(&smp->remote_irk->list);
777 kfree_rcu(smp->remote_irk, rcu);
778 }
779 }
780
781 chan->data = NULL;
782 kzfree(smp);
783 hci_conn_drop(hcon);
784 }
785
786 static void smp_failure(struct l2cap_conn *conn, u8 reason)
787 {
788 struct hci_conn *hcon = conn->hcon;
789 struct l2cap_chan *chan = conn->smp;
790
791 if (reason)
792 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
793 &reason);
794
795 clear_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags);
796 mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE);
797
798 if (chan->data)
799 smp_chan_destroy(conn);
800 }
801
802 #define JUST_WORKS 0x00
803 #define JUST_CFM 0x01
804 #define REQ_PASSKEY 0x02
805 #define CFM_PASSKEY 0x03
806 #define REQ_OOB 0x04
807 #define DSP_PASSKEY 0x05
808 #define OVERLAP 0xFF
809
810 static const u8 gen_method[5][5] = {
811 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
812 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
813 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
814 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
815 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP },
816 };
817
818 static const u8 sc_method[5][5] = {
819 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
820 { JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
821 { DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY },
822 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
823 { DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
824 };
825
826 static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io)
827 {
828 /* If either side has unknown io_caps, use JUST_CFM (which gets
829 * converted later to JUST_WORKS if we're initiators.
830 */
831 if (local_io > SMP_IO_KEYBOARD_DISPLAY ||
832 remote_io > SMP_IO_KEYBOARD_DISPLAY)
833 return JUST_CFM;
834
835 if (test_bit(SMP_FLAG_SC, &smp->flags))
836 return sc_method[remote_io][local_io];
837
838 return gen_method[remote_io][local_io];
839 }
840
841 static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth,
842 u8 local_io, u8 remote_io)
843 {
844 struct hci_conn *hcon = conn->hcon;
845 struct l2cap_chan *chan = conn->smp;
846 struct smp_chan *smp = chan->data;
847 u32 passkey = 0;
848 int ret = 0;
849
850 /* Initialize key for JUST WORKS */
851 memset(smp->tk, 0, sizeof(smp->tk));
852 clear_bit(SMP_FLAG_TK_VALID, &smp->flags);
853
854 BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io);
855
856 /* If neither side wants MITM, either "just" confirm an incoming
857 * request or use just-works for outgoing ones. The JUST_CFM
858 * will be converted to JUST_WORKS if necessary later in this
859 * function. If either side has MITM look up the method from the
860 * table.
861 */
862 if (!(auth & SMP_AUTH_MITM))
863 smp->method = JUST_CFM;
864 else
865 smp->method = get_auth_method(smp, local_io, remote_io);
866
867 /* Don't confirm locally initiated pairing attempts */
868 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR,
869 &smp->flags))
870 smp->method = JUST_WORKS;
871
872 /* Don't bother user space with no IO capabilities */
873 if (smp->method == JUST_CFM &&
874 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
875 smp->method = JUST_WORKS;
876
877 /* If Just Works, Continue with Zero TK */
878 if (smp->method == JUST_WORKS) {
879 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
880 return 0;
881 }
882
883 /* If this function is used for SC -> legacy fallback we
884 * can only recover the just-works case.
885 */
886 if (test_bit(SMP_FLAG_SC, &smp->flags))
887 return -EINVAL;
888
889 /* Not Just Works/Confirm results in MITM Authentication */
890 if (smp->method != JUST_CFM) {
891 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags);
892 if (hcon->pending_sec_level < BT_SECURITY_HIGH)
893 hcon->pending_sec_level = BT_SECURITY_HIGH;
894 }
895
896 /* If both devices have Keyoard-Display I/O, the master
897 * Confirms and the slave Enters the passkey.
898 */
899 if (smp->method == OVERLAP) {
900 if (hcon->role == HCI_ROLE_MASTER)
901 smp->method = CFM_PASSKEY;
902 else
903 smp->method = REQ_PASSKEY;
904 }
905
906 /* Generate random passkey. */
907 if (smp->method == CFM_PASSKEY) {
908 memset(smp->tk, 0, sizeof(smp->tk));
909 get_random_bytes(&passkey, sizeof(passkey));
910 passkey %= 1000000;
911 put_unaligned_le32(passkey, smp->tk);
912 BT_DBG("PassKey: %d", passkey);
913 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
914 }
915
916 if (smp->method == REQ_PASSKEY)
917 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst,
918 hcon->type, hcon->dst_type);
919 else if (smp->method == JUST_CFM)
920 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
921 hcon->type, hcon->dst_type,
922 passkey, 1);
923 else
924 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst,
925 hcon->type, hcon->dst_type,
926 passkey, 0);
927
928 return ret;
929 }
930
931 static u8 smp_confirm(struct smp_chan *smp)
932 {
933 struct l2cap_conn *conn = smp->conn;
934 struct smp_cmd_pairing_confirm cp;
935 int ret;
936
937 BT_DBG("conn %p", conn);
938
939 ret = smp_c1(smp->tfm_aes, smp->tk, smp->prnd, smp->preq, smp->prsp,
940 conn->hcon->init_addr_type, &conn->hcon->init_addr,
941 conn->hcon->resp_addr_type, &conn->hcon->resp_addr,
942 cp.confirm_val);
943 if (ret)
944 return SMP_UNSPECIFIED;
945
946 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
947
948 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
949
950 if (conn->hcon->out)
951 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
952 else
953 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
954
955 return 0;
956 }
957
958 static u8 smp_random(struct smp_chan *smp)
959 {
960 struct l2cap_conn *conn = smp->conn;
961 struct hci_conn *hcon = conn->hcon;
962 u8 confirm[16];
963 int ret;
964
965 if (IS_ERR_OR_NULL(smp->tfm_aes))
966 return SMP_UNSPECIFIED;
967
968 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
969
970 ret = smp_c1(smp->tfm_aes, smp->tk, smp->rrnd, smp->preq, smp->prsp,
971 hcon->init_addr_type, &hcon->init_addr,
972 hcon->resp_addr_type, &hcon->resp_addr, confirm);
973 if (ret)
974 return SMP_UNSPECIFIED;
975
976 if (memcmp(smp->pcnf, confirm, sizeof(smp->pcnf)) != 0) {
977 BT_ERR("Pairing failed (confirmation values mismatch)");
978 return SMP_CONFIRM_FAILED;
979 }
980
981 if (hcon->out) {
982 u8 stk[16];
983 __le64 rand = 0;
984 __le16 ediv = 0;
985
986 smp_s1(smp->tfm_aes, smp->tk, smp->rrnd, smp->prnd, stk);
987
988 memset(stk + smp->enc_key_size, 0,
989 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);
990
991 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
992 return SMP_UNSPECIFIED;
993
994 hci_le_start_enc(hcon, ediv, rand, stk);
995 hcon->enc_key_size = smp->enc_key_size;
996 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
997 } else {
998 u8 stk[16], auth;
999 __le64 rand = 0;
1000 __le16 ediv = 0;
1001
1002 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
1003 smp->prnd);
1004
1005 smp_s1(smp->tfm_aes, smp->tk, smp->prnd, smp->rrnd, stk);
1006
1007 memset(stk + smp->enc_key_size, 0,
1008 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);
1009
1010 if (hcon->pending_sec_level == BT_SECURITY_HIGH)
1011 auth = 1;
1012 else
1013 auth = 0;
1014
1015 /* Even though there's no _SLAVE suffix this is the
1016 * slave STK we're adding for later lookup (the master
1017 * STK never needs to be stored).
1018 */
1019 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1020 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand);
1021 }
1022
1023 return 0;
1024 }
1025
1026 static void smp_notify_keys(struct l2cap_conn *conn)
1027 {
1028 struct l2cap_chan *chan = conn->smp;
1029 struct smp_chan *smp = chan->data;
1030 struct hci_conn *hcon = conn->hcon;
1031 struct hci_dev *hdev = hcon->hdev;
1032 struct smp_cmd_pairing *req = (void *) &smp->preq[1];
1033 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1];
1034 bool persistent;
1035
1036 if (smp->remote_irk) {
1037 mgmt_new_irk(hdev, smp->remote_irk);
1038 /* Now that user space can be considered to know the
1039 * identity address track the connection based on it
1040 * from now on (assuming this is an LE link).
1041 */
1042 if (hcon->type == LE_LINK) {
1043 bacpy(&hcon->dst, &smp->remote_irk->bdaddr);
1044 hcon->dst_type = smp->remote_irk->addr_type;
1045 queue_work(hdev->workqueue, &conn->id_addr_update_work);
1046 }
1047
1048 /* When receiving an indentity resolving key for
1049 * a remote device that does not use a resolvable
1050 * private address, just remove the key so that
1051 * it is possible to use the controller white
1052 * list for scanning.
1053 *
1054 * Userspace will have been told to not store
1055 * this key at this point. So it is safe to
1056 * just remove it.
1057 */
1058 if (!bacmp(&smp->remote_irk->rpa, BDADDR_ANY)) {
1059 list_del_rcu(&smp->remote_irk->list);
1060 kfree_rcu(smp->remote_irk, rcu);
1061 smp->remote_irk = NULL;
1062 }
1063 }
1064
1065 if (hcon->type == ACL_LINK) {
1066 if (hcon->key_type == HCI_LK_DEBUG_COMBINATION)
1067 persistent = false;
1068 else
1069 persistent = !test_bit(HCI_CONN_FLUSH_KEY,
1070 &hcon->flags);
1071 } else {
1072 /* The LTKs and CSRKs should be persistent only if both sides
1073 * had the bonding bit set in their authentication requests.
1074 */
1075 persistent = !!((req->auth_req & rsp->auth_req) &
1076 SMP_AUTH_BONDING);
1077 }
1078
1079
1080 if (smp->csrk) {
1081 smp->csrk->bdaddr_type = hcon->dst_type;
1082 bacpy(&smp->csrk->bdaddr, &hcon->dst);
1083 mgmt_new_csrk(hdev, smp->csrk, persistent);
1084 }
1085
1086 if (smp->slave_csrk) {
1087 smp->slave_csrk->bdaddr_type = hcon->dst_type;
1088 bacpy(&smp->slave_csrk->bdaddr, &hcon->dst);
1089 mgmt_new_csrk(hdev, smp->slave_csrk, persistent);
1090 }
1091
1092 if (smp->ltk) {
1093 smp->ltk->bdaddr_type = hcon->dst_type;
1094 bacpy(&smp->ltk->bdaddr, &hcon->dst);
1095 mgmt_new_ltk(hdev, smp->ltk, persistent);
1096 }
1097
1098 if (smp->slave_ltk) {
1099 smp->slave_ltk->bdaddr_type = hcon->dst_type;
1100 bacpy(&smp->slave_ltk->bdaddr, &hcon->dst);
1101 mgmt_new_ltk(hdev, smp->slave_ltk, persistent);
1102 }
1103
1104 if (smp->link_key) {
1105 struct link_key *key;
1106 u8 type;
1107
1108 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1109 type = HCI_LK_DEBUG_COMBINATION;
1110 else if (hcon->sec_level == BT_SECURITY_FIPS)
1111 type = HCI_LK_AUTH_COMBINATION_P256;
1112 else
1113 type = HCI_LK_UNAUTH_COMBINATION_P256;
1114
1115 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst,
1116 smp->link_key, type, 0, &persistent);
1117 if (key) {
1118 mgmt_new_link_key(hdev, key, persistent);
1119
1120 /* Don't keep debug keys around if the relevant
1121 * flag is not set.
1122 */
1123 if (!hci_dev_test_flag(hdev, HCI_KEEP_DEBUG_KEYS) &&
1124 key->type == HCI_LK_DEBUG_COMBINATION) {
1125 list_del_rcu(&key->list);
1126 kfree_rcu(key, rcu);
1127 }
1128 }
1129 }
1130 }
1131
1132 static void sc_add_ltk(struct smp_chan *smp)
1133 {
1134 struct hci_conn *hcon = smp->conn->hcon;
1135 u8 key_type, auth;
1136
1137 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1138 key_type = SMP_LTK_P256_DEBUG;
1139 else
1140 key_type = SMP_LTK_P256;
1141
1142 if (hcon->pending_sec_level == BT_SECURITY_FIPS)
1143 auth = 1;
1144 else
1145 auth = 0;
1146
1147 memset(smp->tk + smp->enc_key_size, 0,
1148 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);
1149
1150 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1151 key_type, auth, smp->tk, smp->enc_key_size,
1152 0, 0);
1153 }
1154
1155 static void sc_generate_link_key(struct smp_chan *smp)
1156 {
1157 /* These constants are as specified in the core specification.
1158 * In ASCII they spell out to 'tmp1' and 'lebr'.
1159 */
1160 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 };
1161 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c };
1162
1163 smp->link_key = kzalloc(16, GFP_KERNEL);
1164 if (!smp->link_key)
1165 return;
1166
1167 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) {
1168 kzfree(smp->link_key);
1169 smp->link_key = NULL;
1170 return;
1171 }
1172
1173 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) {
1174 kzfree(smp->link_key);
1175 smp->link_key = NULL;
1176 return;
1177 }
1178 }
1179
1180 static void smp_allow_key_dist(struct smp_chan *smp)
1181 {
1182 /* Allow the first expected phase 3 PDU. The rest of the PDUs
1183 * will be allowed in each PDU handler to ensure we receive
1184 * them in the correct order.
1185 */
1186 if (smp->remote_key_dist & SMP_DIST_ENC_KEY)
1187 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO);
1188 else if (smp->remote_key_dist & SMP_DIST_ID_KEY)
1189 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
1190 else if (smp->remote_key_dist & SMP_DIST_SIGN)
1191 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
1192 }
1193
1194 static void sc_generate_ltk(struct smp_chan *smp)
1195 {
1196 /* These constants are as specified in the core specification.
1197 * In ASCII they spell out to 'tmp2' and 'brle'.
1198 */
1199 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 };
1200 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 };
1201 struct hci_conn *hcon = smp->conn->hcon;
1202 struct hci_dev *hdev = hcon->hdev;
1203 struct link_key *key;
1204
1205 key = hci_find_link_key(hdev, &hcon->dst);
1206 if (!key) {
1207 BT_ERR("%s No Link Key found to generate LTK", hdev->name);
1208 return;
1209 }
1210
1211 if (key->type == HCI_LK_DEBUG_COMBINATION)
1212 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1213
1214 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk))
1215 return;
1216
1217 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk))
1218 return;
1219
1220 sc_add_ltk(smp);
1221 }
1222
1223 static void smp_distribute_keys(struct smp_chan *smp)
1224 {
1225 struct smp_cmd_pairing *req, *rsp;
1226 struct l2cap_conn *conn = smp->conn;
1227 struct hci_conn *hcon = conn->hcon;
1228 struct hci_dev *hdev = hcon->hdev;
1229 __u8 *keydist;
1230
1231 BT_DBG("conn %p", conn);
1232
1233 rsp = (void *) &smp->prsp[1];
1234
1235 /* The responder sends its keys first */
1236 if (hcon->out && (smp->remote_key_dist & KEY_DIST_MASK)) {
1237 smp_allow_key_dist(smp);
1238 return;
1239 }
1240
1241 req = (void *) &smp->preq[1];
1242
1243 if (hcon->out) {
1244 keydist = &rsp->init_key_dist;
1245 *keydist &= req->init_key_dist;
1246 } else {
1247 keydist = &rsp->resp_key_dist;
1248 *keydist &= req->resp_key_dist;
1249 }
1250
1251 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1252 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY))
1253 sc_generate_link_key(smp);
1254 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY))
1255 sc_generate_ltk(smp);
1256
1257 /* Clear the keys which are generated but not distributed */
1258 *keydist &= ~SMP_SC_NO_DIST;
1259 }
1260
1261 BT_DBG("keydist 0x%x", *keydist);
1262
1263 if (*keydist & SMP_DIST_ENC_KEY) {
1264 struct smp_cmd_encrypt_info enc;
1265 struct smp_cmd_master_ident ident;
1266 struct smp_ltk *ltk;
1267 u8 authenticated;
1268 __le16 ediv;
1269 __le64 rand;
1270
1271 get_random_bytes(enc.ltk, sizeof(enc.ltk));
1272 get_random_bytes(&ediv, sizeof(ediv));
1273 get_random_bytes(&rand, sizeof(rand));
1274
1275 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc);
1276
1277 authenticated = hcon->sec_level == BT_SECURITY_HIGH;
1278 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type,
1279 SMP_LTK_SLAVE, authenticated, enc.ltk,
1280 smp->enc_key_size, ediv, rand);
1281 smp->slave_ltk = ltk;
1282
1283 ident.ediv = ediv;
1284 ident.rand = rand;
1285
1286 smp_send_cmd(conn, SMP_CMD_MASTER_IDENT, sizeof(ident), &ident);
1287
1288 *keydist &= ~SMP_DIST_ENC_KEY;
1289 }
1290
1291 if (*keydist & SMP_DIST_ID_KEY) {
1292 struct smp_cmd_ident_addr_info addrinfo;
1293 struct smp_cmd_ident_info idinfo;
1294
1295 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk));
1296
1297 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo);
1298
1299 /* The hci_conn contains the local identity address
1300 * after the connection has been established.
1301 *
1302 * This is true even when the connection has been
1303 * established using a resolvable random address.
1304 */
1305 bacpy(&addrinfo.bdaddr, &hcon->src);
1306 addrinfo.addr_type = hcon->src_type;
1307
1308 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo),
1309 &addrinfo);
1310
1311 *keydist &= ~SMP_DIST_ID_KEY;
1312 }
1313
1314 if (*keydist & SMP_DIST_SIGN) {
1315 struct smp_cmd_sign_info sign;
1316 struct smp_csrk *csrk;
1317
1318 /* Generate a new random key */
1319 get_random_bytes(sign.csrk, sizeof(sign.csrk));
1320
1321 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
1322 if (csrk) {
1323 if (hcon->sec_level > BT_SECURITY_MEDIUM)
1324 csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED;
1325 else
1326 csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED;
1327 memcpy(csrk->val, sign.csrk, sizeof(csrk->val));
1328 }
1329 smp->slave_csrk = csrk;
1330
1331 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign);
1332
1333 *keydist &= ~SMP_DIST_SIGN;
1334 }
1335
1336 /* If there are still keys to be received wait for them */
1337 if (smp->remote_key_dist & KEY_DIST_MASK) {
1338 smp_allow_key_dist(smp);
1339 return;
1340 }
1341
1342 set_bit(SMP_FLAG_COMPLETE, &smp->flags);
1343 smp_notify_keys(conn);
1344
1345 smp_chan_destroy(conn);
1346 }
1347
1348 static void smp_timeout(struct work_struct *work)
1349 {
1350 struct smp_chan *smp = container_of(work, struct smp_chan,
1351 security_timer.work);
1352 struct l2cap_conn *conn = smp->conn;
1353
1354 BT_DBG("conn %p", conn);
1355
1356 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM);
1357 }
1358
1359 static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
1360 {
1361 struct l2cap_chan *chan = conn->smp;
1362 struct smp_chan *smp;
1363
1364 smp = kzalloc(sizeof(*smp), GFP_ATOMIC);
1365 if (!smp)
1366 return NULL;
1367
1368 smp->tfm_aes = crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);
1369 if (IS_ERR(smp->tfm_aes)) {
1370 BT_ERR("Unable to create ECB crypto context");
1371 kzfree(smp);
1372 return NULL;
1373 }
1374
1375 smp->tfm_cmac = crypto_alloc_hash("cmac(aes)", 0, CRYPTO_ALG_ASYNC);
1376 if (IS_ERR(smp->tfm_cmac)) {
1377 BT_ERR("Unable to create CMAC crypto context");
1378 crypto_free_blkcipher(smp->tfm_aes);
1379 kzfree(smp);
1380 return NULL;
1381 }
1382
1383 smp->conn = conn;
1384 chan->data = smp;
1385
1386 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL);
1387
1388 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout);
1389
1390 hci_conn_hold(conn->hcon);
1391
1392 return smp;
1393 }
1394
1395 static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16])
1396 {
1397 struct hci_conn *hcon = smp->conn->hcon;
1398 u8 *na, *nb, a[7], b[7];
1399
1400 if (hcon->out) {
1401 na = smp->prnd;
1402 nb = smp->rrnd;
1403 } else {
1404 na = smp->rrnd;
1405 nb = smp->prnd;
1406 }
1407
1408 memcpy(a, &hcon->init_addr, 6);
1409 memcpy(b, &hcon->resp_addr, 6);
1410 a[6] = hcon->init_addr_type;
1411 b[6] = hcon->resp_addr_type;
1412
1413 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk);
1414 }
1415
1416 static void sc_dhkey_check(struct smp_chan *smp)
1417 {
1418 struct hci_conn *hcon = smp->conn->hcon;
1419 struct smp_cmd_dhkey_check check;
1420 u8 a[7], b[7], *local_addr, *remote_addr;
1421 u8 io_cap[3], r[16];
1422
1423 memcpy(a, &hcon->init_addr, 6);
1424 memcpy(b, &hcon->resp_addr, 6);
1425 a[6] = hcon->init_addr_type;
1426 b[6] = hcon->resp_addr_type;
1427
1428 if (hcon->out) {
1429 local_addr = a;
1430 remote_addr = b;
1431 memcpy(io_cap, &smp->preq[1], 3);
1432 } else {
1433 local_addr = b;
1434 remote_addr = a;
1435 memcpy(io_cap, &smp->prsp[1], 3);
1436 }
1437
1438 memset(r, 0, sizeof(r));
1439
1440 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
1441 put_unaligned_le32(hcon->passkey_notify, r);
1442
1443 if (smp->method == REQ_OOB)
1444 memcpy(r, smp->rr, 16);
1445
1446 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap,
1447 local_addr, remote_addr, check.e);
1448
1449 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check);
1450 }
1451
1452 static u8 sc_passkey_send_confirm(struct smp_chan *smp)
1453 {
1454 struct l2cap_conn *conn = smp->conn;
1455 struct hci_conn *hcon = conn->hcon;
1456 struct smp_cmd_pairing_confirm cfm;
1457 u8 r;
1458
1459 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1460 r |= 0x80;
1461
1462 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1463
1464 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r,
1465 cfm.confirm_val))
1466 return SMP_UNSPECIFIED;
1467
1468 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
1469
1470 return 0;
1471 }
1472
1473 static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op)
1474 {
1475 struct l2cap_conn *conn = smp->conn;
1476 struct hci_conn *hcon = conn->hcon;
1477 struct hci_dev *hdev = hcon->hdev;
1478 u8 cfm[16], r;
1479
1480 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */
1481 if (smp->passkey_round >= 20)
1482 return 0;
1483
1484 switch (smp_op) {
1485 case SMP_CMD_PAIRING_RANDOM:
1486 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1487 r |= 0x80;
1488
1489 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
1490 smp->rrnd, r, cfm))
1491 return SMP_UNSPECIFIED;
1492
1493 if (memcmp(smp->pcnf, cfm, 16))
1494 return SMP_CONFIRM_FAILED;
1495
1496 smp->passkey_round++;
1497
1498 if (smp->passkey_round == 20) {
1499 /* Generate MacKey and LTK */
1500 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk))
1501 return SMP_UNSPECIFIED;
1502 }
1503
1504 /* The round is only complete when the initiator
1505 * receives pairing random.
1506 */
1507 if (!hcon->out) {
1508 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1509 sizeof(smp->prnd), smp->prnd);
1510 if (smp->passkey_round == 20)
1511 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1512 else
1513 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1514 return 0;
1515 }
1516
1517 /* Start the next round */
1518 if (smp->passkey_round != 20)
1519 return sc_passkey_round(smp, 0);
1520
1521 /* Passkey rounds are complete - start DHKey Check */
1522 sc_dhkey_check(smp);
1523 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1524
1525 break;
1526
1527 case SMP_CMD_PAIRING_CONFIRM:
1528 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
1529 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
1530 return 0;
1531 }
1532
1533 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
1534
1535 if (hcon->out) {
1536 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1537 sizeof(smp->prnd), smp->prnd);
1538 return 0;
1539 }
1540
1541 return sc_passkey_send_confirm(smp);
1542
1543 case SMP_CMD_PUBLIC_KEY:
1544 default:
1545 /* Initiating device starts the round */
1546 if (!hcon->out)
1547 return 0;
1548
1549 BT_DBG("%s Starting passkey round %u", hdev->name,
1550 smp->passkey_round + 1);
1551
1552 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1553
1554 return sc_passkey_send_confirm(smp);
1555 }
1556
1557 return 0;
1558 }
1559
1560 static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey)
1561 {
1562 struct l2cap_conn *conn = smp->conn;
1563 struct hci_conn *hcon = conn->hcon;
1564 u8 smp_op;
1565
1566 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags);
1567
1568 switch (mgmt_op) {
1569 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1570 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED);
1571 return 0;
1572 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1573 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED);
1574 return 0;
1575 case MGMT_OP_USER_PASSKEY_REPLY:
1576 hcon->passkey_notify = le32_to_cpu(passkey);
1577 smp->passkey_round = 0;
1578
1579 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags))
1580 smp_op = SMP_CMD_PAIRING_CONFIRM;
1581 else
1582 smp_op = 0;
1583
1584 if (sc_passkey_round(smp, smp_op))
1585 return -EIO;
1586
1587 return 0;
1588 }
1589
1590 /* Initiator sends DHKey check first */
1591 if (hcon->out) {
1592 sc_dhkey_check(smp);
1593 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1594 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) {
1595 sc_dhkey_check(smp);
1596 sc_add_ltk(smp);
1597 }
1598
1599 return 0;
1600 }
1601
1602 int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey)
1603 {
1604 struct l2cap_conn *conn = hcon->l2cap_data;
1605 struct l2cap_chan *chan;
1606 struct smp_chan *smp;
1607 u32 value;
1608 int err;
1609
1610 BT_DBG("");
1611
1612 if (!conn)
1613 return -ENOTCONN;
1614
1615 chan = conn->smp;
1616 if (!chan)
1617 return -ENOTCONN;
1618
1619 l2cap_chan_lock(chan);
1620 if (!chan->data) {
1621 err = -ENOTCONN;
1622 goto unlock;
1623 }
1624
1625 smp = chan->data;
1626
1627 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1628 err = sc_user_reply(smp, mgmt_op, passkey);
1629 goto unlock;
1630 }
1631
1632 switch (mgmt_op) {
1633 case MGMT_OP_USER_PASSKEY_REPLY:
1634 value = le32_to_cpu(passkey);
1635 memset(smp->tk, 0, sizeof(smp->tk));
1636 BT_DBG("PassKey: %d", value);
1637 put_unaligned_le32(value, smp->tk);
1638 /* Fall Through */
1639 case MGMT_OP_USER_CONFIRM_REPLY:
1640 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
1641 break;
1642 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1643 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1644 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1645 err = 0;
1646 goto unlock;
1647 default:
1648 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1649 err = -EOPNOTSUPP;
1650 goto unlock;
1651 }
1652
1653 err = 0;
1654
1655 /* If it is our turn to send Pairing Confirm, do so now */
1656 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) {
1657 u8 rsp = smp_confirm(smp);
1658 if (rsp)
1659 smp_failure(conn, rsp);
1660 }
1661
1662 unlock:
1663 l2cap_chan_unlock(chan);
1664 return err;
1665 }
1666
1667 static void build_bredr_pairing_cmd(struct smp_chan *smp,
1668 struct smp_cmd_pairing *req,
1669 struct smp_cmd_pairing *rsp)
1670 {
1671 struct l2cap_conn *conn = smp->conn;
1672 struct hci_dev *hdev = conn->hcon->hdev;
1673 u8 local_dist = 0, remote_dist = 0;
1674
1675 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) {
1676 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1677 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1678 }
1679
1680 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING))
1681 remote_dist |= SMP_DIST_ID_KEY;
1682
1683 if (hci_dev_test_flag(hdev, HCI_PRIVACY))
1684 local_dist |= SMP_DIST_ID_KEY;
1685
1686 if (!rsp) {
1687 memset(req, 0, sizeof(*req));
1688
1689 req->init_key_dist = local_dist;
1690 req->resp_key_dist = remote_dist;
1691 req->max_key_size = SMP_MAX_ENC_KEY_SIZE;
1692
1693 smp->remote_key_dist = remote_dist;
1694
1695 return;
1696 }
1697
1698 memset(rsp, 0, sizeof(*rsp));
1699
1700 rsp->max_key_size = SMP_MAX_ENC_KEY_SIZE;
1701 rsp->init_key_dist = req->init_key_dist & remote_dist;
1702 rsp->resp_key_dist = req->resp_key_dist & local_dist;
1703
1704 smp->remote_key_dist = rsp->init_key_dist;
1705 }
1706
1707 static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
1708 {
1709 struct smp_cmd_pairing rsp, *req = (void *) skb->data;
1710 struct l2cap_chan *chan = conn->smp;
1711 struct hci_dev *hdev = conn->hcon->hdev;
1712 struct smp_chan *smp;
1713 u8 key_size, auth, sec_level;
1714 int ret;
1715
1716 BT_DBG("conn %p", conn);
1717
1718 if (skb->len < sizeof(*req))
1719 return SMP_INVALID_PARAMS;
1720
1721 if (conn->hcon->role != HCI_ROLE_SLAVE)
1722 return SMP_CMD_NOTSUPP;
1723
1724 if (!chan->data)
1725 smp = smp_chan_create(conn);
1726 else
1727 smp = chan->data;
1728
1729 if (!smp)
1730 return SMP_UNSPECIFIED;
1731
1732 /* We didn't start the pairing, so match remote */
1733 auth = req->auth_req & AUTH_REQ_MASK(hdev);
1734
1735 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) &&
1736 (auth & SMP_AUTH_BONDING))
1737 return SMP_PAIRING_NOTSUPP;
1738
1739 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
1740 return SMP_AUTH_REQUIREMENTS;
1741
1742 smp->preq[0] = SMP_CMD_PAIRING_REQ;
1743 memcpy(&smp->preq[1], req, sizeof(*req));
1744 skb_pull(skb, sizeof(*req));
1745
1746 /* If the remote side's OOB flag is set it means it has
1747 * successfully received our local OOB data - therefore set the
1748 * flag to indicate that local OOB is in use.
1749 */
1750 if (req->oob_flag == SMP_OOB_PRESENT)
1751 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);
1752
1753 /* SMP over BR/EDR requires special treatment */
1754 if (conn->hcon->type == ACL_LINK) {
1755 /* We must have a BR/EDR SC link */
1756 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) &&
1757 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
1758 return SMP_CROSS_TRANSP_NOT_ALLOWED;
1759
1760 set_bit(SMP_FLAG_SC, &smp->flags);
1761
1762 build_bredr_pairing_cmd(smp, req, &rsp);
1763
1764 key_size = min(req->max_key_size, rsp.max_key_size);
1765 if (check_enc_key_size(conn, key_size))
1766 return SMP_ENC_KEY_SIZE;
1767
1768 /* Clear bits which are generated but not distributed */
1769 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1770
1771 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1772 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1773 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1774
1775 smp_distribute_keys(smp);
1776 return 0;
1777 }
1778
1779 build_pairing_cmd(conn, req, &rsp, auth);
1780
1781 if (rsp.auth_req & SMP_AUTH_SC)
1782 set_bit(SMP_FLAG_SC, &smp->flags);
1783
1784 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
1785 sec_level = BT_SECURITY_MEDIUM;
1786 else
1787 sec_level = authreq_to_seclevel(auth);
1788
1789 if (sec_level > conn->hcon->pending_sec_level)
1790 conn->hcon->pending_sec_level = sec_level;
1791
1792 /* If we need MITM check that it can be achieved */
1793 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1794 u8 method;
1795
1796 method = get_auth_method(smp, conn->hcon->io_capability,
1797 req->io_capability);
1798 if (method == JUST_WORKS || method == JUST_CFM)
1799 return SMP_AUTH_REQUIREMENTS;
1800 }
1801
1802 key_size = min(req->max_key_size, rsp.max_key_size);
1803 if (check_enc_key_size(conn, key_size))
1804 return SMP_ENC_KEY_SIZE;
1805
1806 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1807
1808 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1809 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1810
1811 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1812
1813 clear_bit(SMP_FLAG_INITIATOR, &smp->flags);
1814
1815 /* Strictly speaking we shouldn't allow Pairing Confirm for the
1816 * SC case, however some implementations incorrectly copy RFU auth
1817 * req bits from our security request, which may create a false
1818 * positive SC enablement.
1819 */
1820 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1821
1822 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1823 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
1824 /* Clear bits which are generated but not distributed */
1825 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1826 /* Wait for Public Key from Initiating Device */
1827 return 0;
1828 }
1829
1830 /* Request setup of TK */
1831 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability);
1832 if (ret)
1833 return SMP_UNSPECIFIED;
1834
1835 return 0;
1836 }
1837
1838 static u8 sc_send_public_key(struct smp_chan *smp)
1839 {
1840 struct hci_dev *hdev = smp->conn->hcon->hdev;
1841
1842 BT_DBG("");
1843
1844 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) {
1845 struct l2cap_chan *chan = hdev->smp_data;
1846 struct smp_dev *smp_dev;
1847
1848 if (!chan || !chan->data)
1849 return SMP_UNSPECIFIED;
1850
1851 smp_dev = chan->data;
1852
1853 memcpy(smp->local_pk, smp_dev->local_pk, 64);
1854 memcpy(smp->local_sk, smp_dev->local_sk, 32);
1855 memcpy(smp->lr, smp_dev->local_rand, 16);
1856
1857 if (smp_dev->debug_key)
1858 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1859
1860 goto done;
1861 }
1862
1863 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) {
1864 BT_DBG("Using debug keys");
1865 memcpy(smp->local_pk, debug_pk, 64);
1866 memcpy(smp->local_sk, debug_sk, 32);
1867 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1868 } else {
1869 while (true) {
1870 /* Generate local key pair for Secure Connections */
1871 if (!ecc_make_key(smp->local_pk, smp->local_sk))
1872 return SMP_UNSPECIFIED;
1873
1874 /* This is unlikely, but we need to check that
1875 * we didn't accidentially generate a debug key.
1876 */
1877 if (memcmp(smp->local_sk, debug_sk, 32))
1878 break;
1879 }
1880 }
1881
1882 done:
1883 SMP_DBG("Local Public Key X: %32phN", smp->local_pk);
1884 SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32);
1885 SMP_DBG("Local Private Key: %32phN", smp->local_sk);
1886
1887 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk);
1888
1889 return 0;
1890 }
1891
1892 static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
1893 {
1894 struct smp_cmd_pairing *req, *rsp = (void *) skb->data;
1895 struct l2cap_chan *chan = conn->smp;
1896 struct smp_chan *smp = chan->data;
1897 struct hci_dev *hdev = conn->hcon->hdev;
1898 u8 key_size, auth;
1899 int ret;
1900
1901 BT_DBG("conn %p", conn);
1902
1903 if (skb->len < sizeof(*rsp))
1904 return SMP_INVALID_PARAMS;
1905
1906 if (conn->hcon->role != HCI_ROLE_MASTER)
1907 return SMP_CMD_NOTSUPP;
1908
1909 skb_pull(skb, sizeof(*rsp));
1910
1911 req = (void *) &smp->preq[1];
1912
1913 key_size = min(req->max_key_size, rsp->max_key_size);
1914 if (check_enc_key_size(conn, key_size))
1915 return SMP_ENC_KEY_SIZE;
1916
1917 auth = rsp->auth_req & AUTH_REQ_MASK(hdev);
1918
1919 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
1920 return SMP_AUTH_REQUIREMENTS;
1921
1922 /* If the remote side's OOB flag is set it means it has
1923 * successfully received our local OOB data - therefore set the
1924 * flag to indicate that local OOB is in use.
1925 */
1926 if (rsp->oob_flag == SMP_OOB_PRESENT)
1927 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);
1928
1929 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1930 memcpy(&smp->prsp[1], rsp, sizeof(*rsp));
1931
1932 /* Update remote key distribution in case the remote cleared
1933 * some bits that we had enabled in our request.
1934 */
1935 smp->remote_key_dist &= rsp->resp_key_dist;
1936
1937 /* For BR/EDR this means we're done and can start phase 3 */
1938 if (conn->hcon->type == ACL_LINK) {
1939 /* Clear bits which are generated but not distributed */
1940 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1941 smp_distribute_keys(smp);
1942 return 0;
1943 }
1944
1945 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC))
1946 set_bit(SMP_FLAG_SC, &smp->flags);
1947 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH)
1948 conn->hcon->pending_sec_level = BT_SECURITY_HIGH;
1949
1950 /* If we need MITM check that it can be achieved */
1951 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1952 u8 method;
1953
1954 method = get_auth_method(smp, req->io_capability,
1955 rsp->io_capability);
1956 if (method == JUST_WORKS || method == JUST_CFM)
1957 return SMP_AUTH_REQUIREMENTS;
1958 }
1959
1960 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1961
1962 /* Update remote key distribution in case the remote cleared
1963 * some bits that we had enabled in our request.
1964 */
1965 smp->remote_key_dist &= rsp->resp_key_dist;
1966
1967 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1968 /* Clear bits which are generated but not distributed */
1969 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1970 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
1971 return sc_send_public_key(smp);
1972 }
1973
1974 auth |= req->auth_req;
1975
1976 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability);
1977 if (ret)
1978 return SMP_UNSPECIFIED;
1979
1980 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
1981
1982 /* Can't compose response until we have been confirmed */
1983 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
1984 return smp_confirm(smp);
1985
1986 return 0;
1987 }
1988
1989 static u8 sc_check_confirm(struct smp_chan *smp)
1990 {
1991 struct l2cap_conn *conn = smp->conn;
1992
1993 BT_DBG("");
1994
1995 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
1996 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM);
1997
1998 if (conn->hcon->out) {
1999 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2000 smp->prnd);
2001 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2002 }
2003
2004 return 0;
2005 }
2006
2007 /* Work-around for some implementations that incorrectly copy RFU bits
2008 * from our security request and thereby create the impression that
2009 * we're doing SC when in fact the remote doesn't support it.
2010 */
2011 static int fixup_sc_false_positive(struct smp_chan *smp)
2012 {
2013 struct l2cap_conn *conn = smp->conn;
2014 struct hci_conn *hcon = conn->hcon;
2015 struct hci_dev *hdev = hcon->hdev;
2016 struct smp_cmd_pairing *req, *rsp;
2017 u8 auth;
2018
2019 /* The issue is only observed when we're in slave role */
2020 if (hcon->out)
2021 return SMP_UNSPECIFIED;
2022
2023 if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) {
2024 BT_ERR("Refusing SMP SC -> legacy fallback in SC-only mode");
2025 return SMP_UNSPECIFIED;
2026 }
2027
2028 BT_ERR("Trying to fall back to legacy SMP");
2029
2030 req = (void *) &smp->preq[1];
2031 rsp = (void *) &smp->prsp[1];
2032
2033 /* Rebuild key dist flags which may have been cleared for SC */
2034 smp->remote_key_dist = (req->init_key_dist & rsp->resp_key_dist);
2035
2036 auth = req->auth_req & AUTH_REQ_MASK(hdev);
2037
2038 if (tk_request(conn, 0, auth, rsp->io_capability, req->io_capability)) {
2039 BT_ERR("Failed to fall back to legacy SMP");
2040 return SMP_UNSPECIFIED;
2041 }
2042
2043 clear_bit(SMP_FLAG_SC, &smp->flags);
2044
2045 return 0;
2046 }
2047
2048 static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
2049 {
2050 struct l2cap_chan *chan = conn->smp;
2051 struct smp_chan *smp = chan->data;
2052
2053 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
2054
2055 if (skb->len < sizeof(smp->pcnf))
2056 return SMP_INVALID_PARAMS;
2057
2058 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf));
2059 skb_pull(skb, sizeof(smp->pcnf));
2060
2061 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
2062 int ret;
2063
2064 /* Public Key exchange must happen before any other steps */
2065 if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags))
2066 return sc_check_confirm(smp);
2067
2068 BT_ERR("Unexpected SMP Pairing Confirm");
2069
2070 ret = fixup_sc_false_positive(smp);
2071 if (ret)
2072 return ret;
2073 }
2074
2075 if (conn->hcon->out) {
2076 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2077 smp->prnd);
2078 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2079 return 0;
2080 }
2081
2082 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
2083 return smp_confirm(smp);
2084
2085 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
2086
2087 return 0;
2088 }
2089
2090 static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
2091 {
2092 struct l2cap_chan *chan = conn->smp;
2093 struct smp_chan *smp = chan->data;
2094 struct hci_conn *hcon = conn->hcon;
2095 u8 *pkax, *pkbx, *na, *nb;
2096 u32 passkey;
2097 int err;
2098
2099 BT_DBG("conn %p", conn);
2100
2101 if (skb->len < sizeof(smp->rrnd))
2102 return SMP_INVALID_PARAMS;
2103
2104 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd));
2105 skb_pull(skb, sizeof(smp->rrnd));
2106
2107 if (!test_bit(SMP_FLAG_SC, &smp->flags))
2108 return smp_random(smp);
2109
2110 if (hcon->out) {
2111 pkax = smp->local_pk;
2112 pkbx = smp->remote_pk;
2113 na = smp->prnd;
2114 nb = smp->rrnd;
2115 } else {
2116 pkax = smp->remote_pk;
2117 pkbx = smp->local_pk;
2118 na = smp->rrnd;
2119 nb = smp->prnd;
2120 }
2121
2122 if (smp->method == REQ_OOB) {
2123 if (!hcon->out)
2124 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2125 sizeof(smp->prnd), smp->prnd);
2126 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2127 goto mackey_and_ltk;
2128 }
2129
2130 /* Passkey entry has special treatment */
2131 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2132 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM);
2133
2134 if (hcon->out) {
2135 u8 cfm[16];
2136
2137 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
2138 smp->rrnd, 0, cfm);
2139 if (err)
2140 return SMP_UNSPECIFIED;
2141
2142 if (memcmp(smp->pcnf, cfm, 16))
2143 return SMP_CONFIRM_FAILED;
2144 } else {
2145 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2146 smp->prnd);
2147 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2148 }
2149
2150 mackey_and_ltk:
2151 /* Generate MacKey and LTK */
2152 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk);
2153 if (err)
2154 return SMP_UNSPECIFIED;
2155
2156 if (smp->method == JUST_WORKS || smp->method == REQ_OOB) {
2157 if (hcon->out) {
2158 sc_dhkey_check(smp);
2159 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2160 }
2161 return 0;
2162 }
2163
2164 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
2165 if (err)
2166 return SMP_UNSPECIFIED;
2167
2168 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type,
2169 hcon->dst_type, passkey, 0);
2170 if (err)
2171 return SMP_UNSPECIFIED;
2172
2173 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2174
2175 return 0;
2176 }
2177
2178 static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level)
2179 {
2180 struct smp_ltk *key;
2181 struct hci_conn *hcon = conn->hcon;
2182
2183 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role);
2184 if (!key)
2185 return false;
2186
2187 if (smp_ltk_sec_level(key) < sec_level)
2188 return false;
2189
2190 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
2191 return true;
2192
2193 hci_le_start_enc(hcon, key->ediv, key->rand, key->val);
2194 hcon->enc_key_size = key->enc_size;
2195
2196 /* We never store STKs for master role, so clear this flag */
2197 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
2198
2199 return true;
2200 }
2201
2202 bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level,
2203 enum smp_key_pref key_pref)
2204 {
2205 if (sec_level == BT_SECURITY_LOW)
2206 return true;
2207
2208 /* If we're encrypted with an STK but the caller prefers using
2209 * LTK claim insufficient security. This way we allow the
2210 * connection to be re-encrypted with an LTK, even if the LTK
2211 * provides the same level of security. Only exception is if we
2212 * don't have an LTK (e.g. because of key distribution bits).
2213 */
2214 if (key_pref == SMP_USE_LTK &&
2215 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) &&
2216 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role))
2217 return false;
2218
2219 if (hcon->sec_level >= sec_level)
2220 return true;
2221
2222 return false;
2223 }
2224
2225 static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
2226 {
2227 struct smp_cmd_security_req *rp = (void *) skb->data;
2228 struct smp_cmd_pairing cp;
2229 struct hci_conn *hcon = conn->hcon;
2230 struct hci_dev *hdev = hcon->hdev;
2231 struct smp_chan *smp;
2232 u8 sec_level, auth;
2233
2234 BT_DBG("conn %p", conn);
2235
2236 if (skb->len < sizeof(*rp))
2237 return SMP_INVALID_PARAMS;
2238
2239 if (hcon->role != HCI_ROLE_MASTER)
2240 return SMP_CMD_NOTSUPP;
2241
2242 auth = rp->auth_req & AUTH_REQ_MASK(hdev);
2243
2244 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
2245 return SMP_AUTH_REQUIREMENTS;
2246
2247 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
2248 sec_level = BT_SECURITY_MEDIUM;
2249 else
2250 sec_level = authreq_to_seclevel(auth);
2251
2252 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK))
2253 return 0;
2254
2255 if (sec_level > hcon->pending_sec_level)
2256 hcon->pending_sec_level = sec_level;
2257
2258 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2259 return 0;
2260
2261 smp = smp_chan_create(conn);
2262 if (!smp)
2263 return SMP_UNSPECIFIED;
2264
2265 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) &&
2266 (auth & SMP_AUTH_BONDING))
2267 return SMP_PAIRING_NOTSUPP;
2268
2269 skb_pull(skb, sizeof(*rp));
2270
2271 memset(&cp, 0, sizeof(cp));
2272 build_pairing_cmd(conn, &cp, NULL, auth);
2273
2274 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2275 memcpy(&smp->preq[1], &cp, sizeof(cp));
2276
2277 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
2278 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2279
2280 return 0;
2281 }
2282
2283 int smp_conn_security(struct hci_conn *hcon, __u8 sec_level)
2284 {
2285 struct l2cap_conn *conn = hcon->l2cap_data;
2286 struct l2cap_chan *chan;
2287 struct smp_chan *smp;
2288 __u8 authreq;
2289 int ret;
2290
2291 BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level);
2292
2293 /* This may be NULL if there's an unexpected disconnection */
2294 if (!conn)
2295 return 1;
2296
2297 chan = conn->smp;
2298
2299 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED))
2300 return 1;
2301
2302 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK))
2303 return 1;
2304
2305 if (sec_level > hcon->pending_sec_level)
2306 hcon->pending_sec_level = sec_level;
2307
2308 if (hcon->role == HCI_ROLE_MASTER)
2309 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2310 return 0;
2311
2312 l2cap_chan_lock(chan);
2313
2314 /* If SMP is already in progress ignore this request */
2315 if (chan->data) {
2316 ret = 0;
2317 goto unlock;
2318 }
2319
2320 smp = smp_chan_create(conn);
2321 if (!smp) {
2322 ret = 1;
2323 goto unlock;
2324 }
2325
2326 authreq = seclevel_to_authreq(sec_level);
2327
2328 if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED))
2329 authreq |= SMP_AUTH_SC;
2330
2331 /* Require MITM if IO Capability allows or the security level
2332 * requires it.
2333 */
2334 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT ||
2335 hcon->pending_sec_level > BT_SECURITY_MEDIUM)
2336 authreq |= SMP_AUTH_MITM;
2337
2338 if (hcon->role == HCI_ROLE_MASTER) {
2339 struct smp_cmd_pairing cp;
2340
2341 build_pairing_cmd(conn, &cp, NULL, authreq);
2342 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2343 memcpy(&smp->preq[1], &cp, sizeof(cp));
2344
2345 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
2346 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2347 } else {
2348 struct smp_cmd_security_req cp;
2349 cp.auth_req = authreq;
2350 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp);
2351 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ);
2352 }
2353
2354 set_bit(SMP_FLAG_INITIATOR, &smp->flags);
2355 ret = 0;
2356
2357 unlock:
2358 l2cap_chan_unlock(chan);
2359 return ret;
2360 }
2361
2362 static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb)
2363 {
2364 struct smp_cmd_encrypt_info *rp = (void *) skb->data;
2365 struct l2cap_chan *chan = conn->smp;
2366 struct smp_chan *smp = chan->data;
2367
2368 BT_DBG("conn %p", conn);
2369
2370 if (skb->len < sizeof(*rp))
2371 return SMP_INVALID_PARAMS;
2372
2373 SMP_ALLOW_CMD(smp, SMP_CMD_MASTER_IDENT);
2374
2375 skb_pull(skb, sizeof(*rp));
2376
2377 memcpy(smp->tk, rp->ltk, sizeof(smp->tk));
2378
2379 return 0;
2380 }
2381
2382 static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb)
2383 {
2384 struct smp_cmd_master_ident *rp = (void *) skb->data;
2385 struct l2cap_chan *chan = conn->smp;
2386 struct smp_chan *smp = chan->data;
2387 struct hci_dev *hdev = conn->hcon->hdev;
2388 struct hci_conn *hcon = conn->hcon;
2389 struct smp_ltk *ltk;
2390 u8 authenticated;
2391
2392 BT_DBG("conn %p", conn);
2393
2394 if (skb->len < sizeof(*rp))
2395 return SMP_INVALID_PARAMS;
2396
2397 /* Mark the information as received */
2398 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY;
2399
2400 if (smp->remote_key_dist & SMP_DIST_ID_KEY)
2401 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
2402 else if (smp->remote_key_dist & SMP_DIST_SIGN)
2403 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2404
2405 skb_pull(skb, sizeof(*rp));
2406
2407 authenticated = (hcon->sec_level == BT_SECURITY_HIGH);
2408 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK,
2409 authenticated, smp->tk, smp->enc_key_size,
2410 rp->ediv, rp->rand);
2411 smp->ltk = ltk;
2412 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2413 smp_distribute_keys(smp);
2414
2415 return 0;
2416 }
2417
2418 static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb)
2419 {
2420 struct smp_cmd_ident_info *info = (void *) skb->data;
2421 struct l2cap_chan *chan = conn->smp;
2422 struct smp_chan *smp = chan->data;
2423
2424 BT_DBG("");
2425
2426 if (skb->len < sizeof(*info))
2427 return SMP_INVALID_PARAMS;
2428
2429 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO);
2430
2431 skb_pull(skb, sizeof(*info));
2432
2433 memcpy(smp->irk, info->irk, 16);
2434
2435 return 0;
2436 }
2437
2438 static int smp_cmd_ident_addr_info(struct l2cap_conn *conn,
2439 struct sk_buff *skb)
2440 {
2441 struct smp_cmd_ident_addr_info *info = (void *) skb->data;
2442 struct l2cap_chan *chan = conn->smp;
2443 struct smp_chan *smp = chan->data;
2444 struct hci_conn *hcon = conn->hcon;
2445 bdaddr_t rpa;
2446
2447 BT_DBG("");
2448
2449 if (skb->len < sizeof(*info))
2450 return SMP_INVALID_PARAMS;
2451
2452 /* Mark the information as received */
2453 smp->remote_key_dist &= ~SMP_DIST_ID_KEY;
2454
2455 if (smp->remote_key_dist & SMP_DIST_SIGN)
2456 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2457
2458 skb_pull(skb, sizeof(*info));
2459
2460 /* Strictly speaking the Core Specification (4.1) allows sending
2461 * an empty address which would force us to rely on just the IRK
2462 * as "identity information". However, since such
2463 * implementations are not known of and in order to not over
2464 * complicate our implementation, simply pretend that we never
2465 * received an IRK for such a device.
2466 *
2467 * The Identity Address must also be a Static Random or Public
2468 * Address, which hci_is_identity_address() checks for.
2469 */
2470 if (!bacmp(&info->bdaddr, BDADDR_ANY) ||
2471 !hci_is_identity_address(&info->bdaddr, info->addr_type)) {
2472 BT_ERR("Ignoring IRK with no identity address");
2473 goto distribute;
2474 }
2475
2476 bacpy(&smp->id_addr, &info->bdaddr);
2477 smp->id_addr_type = info->addr_type;
2478
2479 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type))
2480 bacpy(&rpa, &hcon->dst);
2481 else
2482 bacpy(&rpa, BDADDR_ANY);
2483
2484 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr,
2485 smp->id_addr_type, smp->irk, &rpa);
2486
2487 distribute:
2488 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2489 smp_distribute_keys(smp);
2490
2491 return 0;
2492 }
2493
2494 static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb)
2495 {
2496 struct smp_cmd_sign_info *rp = (void *) skb->data;
2497 struct l2cap_chan *chan = conn->smp;
2498 struct smp_chan *smp = chan->data;
2499 struct smp_csrk *csrk;
2500
2501 BT_DBG("conn %p", conn);
2502
2503 if (skb->len < sizeof(*rp))
2504 return SMP_INVALID_PARAMS;
2505
2506 /* Mark the information as received */
2507 smp->remote_key_dist &= ~SMP_DIST_SIGN;
2508
2509 skb_pull(skb, sizeof(*rp));
2510
2511 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
2512 if (csrk) {
2513 if (conn->hcon->sec_level > BT_SECURITY_MEDIUM)
2514 csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED;
2515 else
2516 csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED;
2517 memcpy(csrk->val, rp->csrk, sizeof(csrk->val));
2518 }
2519 smp->csrk = csrk;
2520 smp_distribute_keys(smp);
2521
2522 return 0;
2523 }
2524
2525 static u8 sc_select_method(struct smp_chan *smp)
2526 {
2527 struct l2cap_conn *conn = smp->conn;
2528 struct hci_conn *hcon = conn->hcon;
2529 struct smp_cmd_pairing *local, *remote;
2530 u8 local_mitm, remote_mitm, local_io, remote_io, method;
2531
2532 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) ||
2533 test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags))
2534 return REQ_OOB;
2535
2536 /* The preq/prsp contain the raw Pairing Request/Response PDUs
2537 * which are needed as inputs to some crypto functions. To get
2538 * the "struct smp_cmd_pairing" from them we need to skip the
2539 * first byte which contains the opcode.
2540 */
2541 if (hcon->out) {
2542 local = (void *) &smp->preq[1];
2543 remote = (void *) &smp->prsp[1];
2544 } else {
2545 local = (void *) &smp->prsp[1];
2546 remote = (void *) &smp->preq[1];
2547 }
2548
2549 local_io = local->io_capability;
2550 remote_io = remote->io_capability;
2551
2552 local_mitm = (local->auth_req & SMP_AUTH_MITM);
2553 remote_mitm = (remote->auth_req & SMP_AUTH_MITM);
2554
2555 /* If either side wants MITM, look up the method from the table,
2556 * otherwise use JUST WORKS.
2557 */
2558 if (local_mitm || remote_mitm)
2559 method = get_auth_method(smp, local_io, remote_io);
2560 else
2561 method = JUST_WORKS;
2562
2563 /* Don't confirm locally initiated pairing attempts */
2564 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2565 method = JUST_WORKS;
2566
2567 return method;
2568 }
2569
2570 static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb)
2571 {
2572 struct smp_cmd_public_key *key = (void *) skb->data;
2573 struct hci_conn *hcon = conn->hcon;
2574 struct l2cap_chan *chan = conn->smp;
2575 struct smp_chan *smp = chan->data;
2576 struct hci_dev *hdev = hcon->hdev;
2577 struct smp_cmd_pairing_confirm cfm;
2578 int err;
2579
2580 BT_DBG("conn %p", conn);
2581
2582 if (skb->len < sizeof(*key))
2583 return SMP_INVALID_PARAMS;
2584
2585 memcpy(smp->remote_pk, key, 64);
2586
2587 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) {
2588 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk,
2589 smp->rr, 0, cfm.confirm_val);
2590 if (err)
2591 return SMP_UNSPECIFIED;
2592
2593 if (memcmp(cfm.confirm_val, smp->pcnf, 16))
2594 return SMP_CONFIRM_FAILED;
2595 }
2596
2597 /* Non-initiating device sends its public key after receiving
2598 * the key from the initiating device.
2599 */
2600 if (!hcon->out) {
2601 err = sc_send_public_key(smp);
2602 if (err)
2603 return err;
2604 }
2605
2606 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk);
2607 SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32);
2608
2609 if (!ecdh_shared_secret(smp->remote_pk, smp->local_sk, smp->dhkey))
2610 return SMP_UNSPECIFIED;
2611
2612 SMP_DBG("DHKey %32phN", smp->dhkey);
2613
2614 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags);
2615
2616 smp->method = sc_select_method(smp);
2617
2618 BT_DBG("%s selected method 0x%02x", hdev->name, smp->method);
2619
2620 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */
2621 if (smp->method == JUST_WORKS || smp->method == JUST_CFM)
2622 hcon->pending_sec_level = BT_SECURITY_MEDIUM;
2623 else
2624 hcon->pending_sec_level = BT_SECURITY_FIPS;
2625
2626 if (!memcmp(debug_pk, smp->remote_pk, 64))
2627 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
2628
2629 if (smp->method == DSP_PASSKEY) {
2630 get_random_bytes(&hcon->passkey_notify,
2631 sizeof(hcon->passkey_notify));
2632 hcon->passkey_notify %= 1000000;
2633 hcon->passkey_entered = 0;
2634 smp->passkey_round = 0;
2635 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type,
2636 hcon->dst_type,
2637 hcon->passkey_notify,
2638 hcon->passkey_entered))
2639 return SMP_UNSPECIFIED;
2640 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2641 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY);
2642 }
2643
2644 if (smp->method == REQ_OOB) {
2645 if (hcon->out)
2646 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2647 sizeof(smp->prnd), smp->prnd);
2648
2649 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2650
2651 return 0;
2652 }
2653
2654 if (hcon->out)
2655 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2656
2657 if (smp->method == REQ_PASSKEY) {
2658 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type,
2659 hcon->dst_type))
2660 return SMP_UNSPECIFIED;
2661 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2662 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2663 return 0;
2664 }
2665
2666 /* The Initiating device waits for the non-initiating device to
2667 * send the confirm value.
2668 */
2669 if (conn->hcon->out)
2670 return 0;
2671
2672 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd,
2673 0, cfm.confirm_val);
2674 if (err)
2675 return SMP_UNSPECIFIED;
2676
2677 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
2678 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2679
2680 return 0;
2681 }
2682
2683 static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb)
2684 {
2685 struct smp_cmd_dhkey_check *check = (void *) skb->data;
2686 struct l2cap_chan *chan = conn->smp;
2687 struct hci_conn *hcon = conn->hcon;
2688 struct smp_chan *smp = chan->data;
2689 u8 a[7], b[7], *local_addr, *remote_addr;
2690 u8 io_cap[3], r[16], e[16];
2691 int err;
2692
2693 BT_DBG("conn %p", conn);
2694
2695 if (skb->len < sizeof(*check))
2696 return SMP_INVALID_PARAMS;
2697
2698 memcpy(a, &hcon->init_addr, 6);
2699 memcpy(b, &hcon->resp_addr, 6);
2700 a[6] = hcon->init_addr_type;
2701 b[6] = hcon->resp_addr_type;
2702
2703 if (hcon->out) {
2704 local_addr = a;
2705 remote_addr = b;
2706 memcpy(io_cap, &smp->prsp[1], 3);
2707 } else {
2708 local_addr = b;
2709 remote_addr = a;
2710 memcpy(io_cap, &smp->preq[1], 3);
2711 }
2712
2713 memset(r, 0, sizeof(r));
2714
2715 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2716 put_unaligned_le32(hcon->passkey_notify, r);
2717 else if (smp->method == REQ_OOB)
2718 memcpy(r, smp->lr, 16);
2719
2720 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r,
2721 io_cap, remote_addr, local_addr, e);
2722 if (err)
2723 return SMP_UNSPECIFIED;
2724
2725 if (memcmp(check->e, e, 16))
2726 return SMP_DHKEY_CHECK_FAILED;
2727
2728 if (!hcon->out) {
2729 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
2730 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags);
2731 return 0;
2732 }
2733
2734 /* Slave sends DHKey check as response to master */
2735 sc_dhkey_check(smp);
2736 }
2737
2738 sc_add_ltk(smp);
2739
2740 if (hcon->out) {
2741 hci_le_start_enc(hcon, 0, 0, smp->tk);
2742 hcon->enc_key_size = smp->enc_key_size;
2743 }
2744
2745 return 0;
2746 }
2747
2748 static int smp_cmd_keypress_notify(struct l2cap_conn *conn,
2749 struct sk_buff *skb)
2750 {
2751 struct smp_cmd_keypress_notify *kp = (void *) skb->data;
2752
2753 BT_DBG("value 0x%02x", kp->value);
2754
2755 return 0;
2756 }
2757
2758 static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb)
2759 {
2760 struct l2cap_conn *conn = chan->conn;
2761 struct hci_conn *hcon = conn->hcon;
2762 struct smp_chan *smp;
2763 __u8 code, reason;
2764 int err = 0;
2765
2766 if (skb->len < 1)
2767 return -EILSEQ;
2768
2769 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) {
2770 reason = SMP_PAIRING_NOTSUPP;
2771 goto done;
2772 }
2773
2774 code = skb->data[0];
2775 skb_pull(skb, sizeof(code));
2776
2777 smp = chan->data;
2778
2779 if (code > SMP_CMD_MAX)
2780 goto drop;
2781
2782 if (smp && !test_and_clear_bit(code, &smp->allow_cmd))
2783 goto drop;
2784
2785 /* If we don't have a context the only allowed commands are
2786 * pairing request and security request.
2787 */
2788 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ)
2789 goto drop;
2790
2791 switch (code) {
2792 case SMP_CMD_PAIRING_REQ:
2793 reason = smp_cmd_pairing_req(conn, skb);
2794 break;
2795
2796 case SMP_CMD_PAIRING_FAIL:
2797 smp_failure(conn, 0);
2798 err = -EPERM;
2799 break;
2800
2801 case SMP_CMD_PAIRING_RSP:
2802 reason = smp_cmd_pairing_rsp(conn, skb);
2803 break;
2804
2805 case SMP_CMD_SECURITY_REQ:
2806 reason = smp_cmd_security_req(conn, skb);
2807 break;
2808
2809 case SMP_CMD_PAIRING_CONFIRM:
2810 reason = smp_cmd_pairing_confirm(conn, skb);
2811 break;
2812
2813 case SMP_CMD_PAIRING_RANDOM:
2814 reason = smp_cmd_pairing_random(conn, skb);
2815 break;
2816
2817 case SMP_CMD_ENCRYPT_INFO:
2818 reason = smp_cmd_encrypt_info(conn, skb);
2819 break;
2820
2821 case SMP_CMD_MASTER_IDENT:
2822 reason = smp_cmd_master_ident(conn, skb);
2823 break;
2824
2825 case SMP_CMD_IDENT_INFO:
2826 reason = smp_cmd_ident_info(conn, skb);
2827 break;
2828
2829 case SMP_CMD_IDENT_ADDR_INFO:
2830 reason = smp_cmd_ident_addr_info(conn, skb);
2831 break;
2832
2833 case SMP_CMD_SIGN_INFO:
2834 reason = smp_cmd_sign_info(conn, skb);
2835 break;
2836
2837 case SMP_CMD_PUBLIC_KEY:
2838 reason = smp_cmd_public_key(conn, skb);
2839 break;
2840
2841 case SMP_CMD_DHKEY_CHECK:
2842 reason = smp_cmd_dhkey_check(conn, skb);
2843 break;
2844
2845 case SMP_CMD_KEYPRESS_NOTIFY:
2846 reason = smp_cmd_keypress_notify(conn, skb);
2847 break;
2848
2849 default:
2850 BT_DBG("Unknown command code 0x%2.2x", code);
2851 reason = SMP_CMD_NOTSUPP;
2852 goto done;
2853 }
2854
2855 done:
2856 if (!err) {
2857 if (reason)
2858 smp_failure(conn, reason);
2859 kfree_skb(skb);
2860 }
2861
2862 return err;
2863
2864 drop:
2865 BT_ERR("%s unexpected SMP command 0x%02x from %pMR", hcon->hdev->name,
2866 code, &hcon->dst);
2867 kfree_skb(skb);
2868 return 0;
2869 }
2870
2871 static void smp_teardown_cb(struct l2cap_chan *chan, int err)
2872 {
2873 struct l2cap_conn *conn = chan->conn;
2874
2875 BT_DBG("chan %p", chan);
2876
2877 if (chan->data)
2878 smp_chan_destroy(conn);
2879
2880 conn->smp = NULL;
2881 l2cap_chan_put(chan);
2882 }
2883
2884 static void bredr_pairing(struct l2cap_chan *chan)
2885 {
2886 struct l2cap_conn *conn = chan->conn;
2887 struct hci_conn *hcon = conn->hcon;
2888 struct hci_dev *hdev = hcon->hdev;
2889 struct smp_cmd_pairing req;
2890 struct smp_chan *smp;
2891
2892 BT_DBG("chan %p", chan);
2893
2894 /* Only new pairings are interesting */
2895 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags))
2896 return;
2897
2898 /* Don't bother if we're not encrypted */
2899 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
2900 return;
2901
2902 /* Only master may initiate SMP over BR/EDR */
2903 if (hcon->role != HCI_ROLE_MASTER)
2904 return;
2905
2906 /* Secure Connections support must be enabled */
2907 if (!hci_dev_test_flag(hdev, HCI_SC_ENABLED))
2908 return;
2909
2910 /* BR/EDR must use Secure Connections for SMP */
2911 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) &&
2912 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
2913 return;
2914
2915 /* If our LE support is not enabled don't do anything */
2916 if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED))
2917 return;
2918
2919 /* Don't bother if remote LE support is not enabled */
2920 if (!lmp_host_le_capable(hcon))
2921 return;
2922
2923 /* Remote must support SMP fixed chan for BR/EDR */
2924 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR))
2925 return;
2926
2927 /* Don't bother if SMP is already ongoing */
2928 if (chan->data)
2929 return;
2930
2931 smp = smp_chan_create(conn);
2932 if (!smp) {
2933 BT_ERR("%s unable to create SMP context for BR/EDR",
2934 hdev->name);
2935 return;
2936 }
2937
2938 set_bit(SMP_FLAG_SC, &smp->flags);
2939
2940 BT_DBG("%s starting SMP over BR/EDR", hdev->name);
2941
2942 /* Prepare and send the BR/EDR SMP Pairing Request */
2943 build_bredr_pairing_cmd(smp, &req, NULL);
2944
2945 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2946 memcpy(&smp->preq[1], &req, sizeof(req));
2947
2948 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(req), &req);
2949 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2950 }
2951
2952 static void smp_resume_cb(struct l2cap_chan *chan)
2953 {
2954 struct smp_chan *smp = chan->data;
2955 struct l2cap_conn *conn = chan->conn;
2956 struct hci_conn *hcon = conn->hcon;
2957
2958 BT_DBG("chan %p", chan);
2959
2960 if (hcon->type == ACL_LINK) {
2961 bredr_pairing(chan);
2962 return;
2963 }
2964
2965 if (!smp)
2966 return;
2967
2968 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
2969 return;
2970
2971 cancel_delayed_work(&smp->security_timer);
2972
2973 smp_distribute_keys(smp);
2974 }
2975
2976 static void smp_ready_cb(struct l2cap_chan *chan)
2977 {
2978 struct l2cap_conn *conn = chan->conn;
2979 struct hci_conn *hcon = conn->hcon;
2980
2981 BT_DBG("chan %p", chan);
2982
2983 conn->smp = chan;
2984 l2cap_chan_hold(chan);
2985
2986 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
2987 bredr_pairing(chan);
2988 }
2989
2990 static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
2991 {
2992 int err;
2993
2994 BT_DBG("chan %p", chan);
2995
2996 err = smp_sig_channel(chan, skb);
2997 if (err) {
2998 struct smp_chan *smp = chan->data;
2999
3000 if (smp)
3001 cancel_delayed_work_sync(&smp->security_timer);
3002
3003 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE);
3004 }
3005
3006 return err;
3007 }
3008
3009 static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan,
3010 unsigned long hdr_len,
3011 unsigned long len, int nb)
3012 {
3013 struct sk_buff *skb;
3014
3015 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL);
3016 if (!skb)
3017 return ERR_PTR(-ENOMEM);
3018
3019 skb->priority = HCI_PRIO_MAX;
3020 bt_cb(skb)->chan = chan;
3021
3022 return skb;
3023 }
3024
3025 static const struct l2cap_ops smp_chan_ops = {
3026 .name = "Security Manager",
3027 .ready = smp_ready_cb,
3028 .recv = smp_recv_cb,
3029 .alloc_skb = smp_alloc_skb_cb,
3030 .teardown = smp_teardown_cb,
3031 .resume = smp_resume_cb,
3032
3033 .new_connection = l2cap_chan_no_new_connection,
3034 .state_change = l2cap_chan_no_state_change,
3035 .close = l2cap_chan_no_close,
3036 .defer = l2cap_chan_no_defer,
3037 .suspend = l2cap_chan_no_suspend,
3038 .set_shutdown = l2cap_chan_no_set_shutdown,
3039 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
3040 };
3041
3042 static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan)
3043 {
3044 struct l2cap_chan *chan;
3045
3046 BT_DBG("pchan %p", pchan);
3047
3048 chan = l2cap_chan_create();
3049 if (!chan)
3050 return NULL;
3051
3052 chan->chan_type = pchan->chan_type;
3053 chan->ops = &smp_chan_ops;
3054 chan->scid = pchan->scid;
3055 chan->dcid = chan->scid;
3056 chan->imtu = pchan->imtu;
3057 chan->omtu = pchan->omtu;
3058 chan->mode = pchan->mode;
3059
3060 /* Other L2CAP channels may request SMP routines in order to
3061 * change the security level. This means that the SMP channel
3062 * lock must be considered in its own category to avoid lockdep
3063 * warnings.
3064 */
3065 atomic_set(&chan->nesting, L2CAP_NESTING_SMP);
3066
3067 BT_DBG("created chan %p", chan);
3068
3069 return chan;
3070 }
3071
3072 static const struct l2cap_ops smp_root_chan_ops = {
3073 .name = "Security Manager Root",
3074 .new_connection = smp_new_conn_cb,
3075
3076 /* None of these are implemented for the root channel */
3077 .close = l2cap_chan_no_close,
3078 .alloc_skb = l2cap_chan_no_alloc_skb,
3079 .recv = l2cap_chan_no_recv,
3080 .state_change = l2cap_chan_no_state_change,
3081 .teardown = l2cap_chan_no_teardown,
3082 .ready = l2cap_chan_no_ready,
3083 .defer = l2cap_chan_no_defer,
3084 .suspend = l2cap_chan_no_suspend,
3085 .resume = l2cap_chan_no_resume,
3086 .set_shutdown = l2cap_chan_no_set_shutdown,
3087 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
3088 };
3089
3090 static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid)
3091 {
3092 struct l2cap_chan *chan;
3093 struct smp_dev *smp;
3094 struct crypto_blkcipher *tfm_aes;
3095 struct crypto_hash *tfm_cmac;
3096
3097 if (cid == L2CAP_CID_SMP_BREDR) {
3098 smp = NULL;
3099 goto create_chan;
3100 }
3101
3102 smp = kzalloc(sizeof(*smp), GFP_KERNEL);
3103 if (!smp)
3104 return ERR_PTR(-ENOMEM);
3105
3106 tfm_aes = crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);
3107 if (IS_ERR(tfm_aes)) {
3108 BT_ERR("Unable to create ECB crypto context");
3109 kzfree(smp);
3110 return ERR_CAST(tfm_aes);
3111 }
3112
3113 tfm_cmac = crypto_alloc_hash("cmac(aes)", 0, CRYPTO_ALG_ASYNC);
3114 if (IS_ERR(tfm_cmac)) {
3115 BT_ERR("Unable to create CMAC crypto context");
3116 crypto_free_blkcipher(tfm_aes);
3117 kzfree(smp);
3118 return ERR_CAST(tfm_cmac);
3119 }
3120
3121 smp->tfm_aes = tfm_aes;
3122 smp->tfm_cmac = tfm_cmac;
3123
3124 create_chan:
3125 chan = l2cap_chan_create();
3126 if (!chan) {
3127 crypto_free_blkcipher(smp->tfm_aes);
3128 crypto_free_hash(smp->tfm_cmac);
3129 kzfree(smp);
3130 return ERR_PTR(-ENOMEM);
3131 }
3132
3133 chan->data = smp;
3134
3135 l2cap_add_scid(chan, cid);
3136
3137 l2cap_chan_set_defaults(chan);
3138
3139 if (cid == L2CAP_CID_SMP) {
3140 u8 bdaddr_type;
3141
3142 hci_copy_identity_address(hdev, &chan->src, &bdaddr_type);
3143
3144 if (bdaddr_type == ADDR_LE_DEV_PUBLIC)
3145 chan->src_type = BDADDR_LE_PUBLIC;
3146 else
3147 chan->src_type = BDADDR_LE_RANDOM;
3148 } else {
3149 bacpy(&chan->src, &hdev->bdaddr);
3150 chan->src_type = BDADDR_BREDR;
3151 }
3152
3153 chan->state = BT_LISTEN;
3154 chan->mode = L2CAP_MODE_BASIC;
3155 chan->imtu = L2CAP_DEFAULT_MTU;
3156 chan->ops = &smp_root_chan_ops;
3157
3158 /* Set correct nesting level for a parent/listening channel */
3159 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
3160
3161 return chan;
3162 }
3163
3164 static void smp_del_chan(struct l2cap_chan *chan)
3165 {
3166 struct smp_dev *smp;
3167
3168 BT_DBG("chan %p", chan);
3169
3170 smp = chan->data;
3171 if (smp) {
3172 chan->data = NULL;
3173 if (smp->tfm_aes)
3174 crypto_free_blkcipher(smp->tfm_aes);
3175 if (smp->tfm_cmac)
3176 crypto_free_hash(smp->tfm_cmac);
3177 kzfree(smp);
3178 }
3179
3180 l2cap_chan_put(chan);
3181 }
3182
3183 static ssize_t force_bredr_smp_read(struct file *file,
3184 char __user *user_buf,
3185 size_t count, loff_t *ppos)
3186 {
3187 struct hci_dev *hdev = file->private_data;
3188 char buf[3];
3189
3190 buf[0] = hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP) ? 'Y': 'N';
3191 buf[1] = '\n';
3192 buf[2] = '\0';
3193 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
3194 }
3195
3196 static ssize_t force_bredr_smp_write(struct file *file,
3197 const char __user *user_buf,
3198 size_t count, loff_t *ppos)
3199 {
3200 struct hci_dev *hdev = file->private_data;
3201 char buf[32];
3202 size_t buf_size = min(count, (sizeof(buf)-1));
3203 bool enable;
3204
3205 if (copy_from_user(buf, user_buf, buf_size))
3206 return -EFAULT;
3207
3208 buf[buf_size] = '\0';
3209 if (strtobool(buf, &enable))
3210 return -EINVAL;
3211
3212 if (enable == hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3213 return -EALREADY;
3214
3215 if (enable) {
3216 struct l2cap_chan *chan;
3217
3218 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
3219 if (IS_ERR(chan))
3220 return PTR_ERR(chan);
3221
3222 hdev->smp_bredr_data = chan;
3223 } else {
3224 struct l2cap_chan *chan;
3225
3226 chan = hdev->smp_bredr_data;
3227 hdev->smp_bredr_data = NULL;
3228 smp_del_chan(chan);
3229 }
3230
3231 hci_dev_change_flag(hdev, HCI_FORCE_BREDR_SMP);
3232
3233 return count;
3234 }
3235
3236 static const struct file_operations force_bredr_smp_fops = {
3237 .open = simple_open,
3238 .read = force_bredr_smp_read,
3239 .write = force_bredr_smp_write,
3240 .llseek = default_llseek,
3241 };
3242
3243 int smp_register(struct hci_dev *hdev)
3244 {
3245 struct l2cap_chan *chan;
3246
3247 BT_DBG("%s", hdev->name);
3248
3249 /* If the controller does not support Low Energy operation, then
3250 * there is also no need to register any SMP channel.
3251 */
3252 if (!lmp_le_capable(hdev))
3253 return 0;
3254
3255 if (WARN_ON(hdev->smp_data)) {
3256 chan = hdev->smp_data;
3257 hdev->smp_data = NULL;
3258 smp_del_chan(chan);
3259 }
3260
3261 chan = smp_add_cid(hdev, L2CAP_CID_SMP);
3262 if (IS_ERR(chan))
3263 return PTR_ERR(chan);
3264
3265 hdev->smp_data = chan;
3266
3267 /* If the controller does not support BR/EDR Secure Connections
3268 * feature, then the BR/EDR SMP channel shall not be present.
3269 *
3270 * To test this with Bluetooth 4.0 controllers, create a debugfs
3271 * switch that allows forcing BR/EDR SMP support and accepting
3272 * cross-transport pairing on non-AES encrypted connections.
3273 */
3274 if (!lmp_sc_capable(hdev)) {
3275 debugfs_create_file("force_bredr_smp", 0644, hdev->debugfs,
3276 hdev, &force_bredr_smp_fops);
3277 return 0;
3278 }
3279
3280 if (WARN_ON(hdev->smp_bredr_data)) {
3281 chan = hdev->smp_bredr_data;
3282 hdev->smp_bredr_data = NULL;
3283 smp_del_chan(chan);
3284 }
3285
3286 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
3287 if (IS_ERR(chan)) {
3288 int err = PTR_ERR(chan);
3289 chan = hdev->smp_data;
3290 hdev->smp_data = NULL;
3291 smp_del_chan(chan);
3292 return err;
3293 }
3294
3295 hdev->smp_bredr_data = chan;
3296
3297 return 0;
3298 }
3299
3300 void smp_unregister(struct hci_dev *hdev)
3301 {
3302 struct l2cap_chan *chan;
3303
3304 if (hdev->smp_bredr_data) {
3305 chan = hdev->smp_bredr_data;
3306 hdev->smp_bredr_data = NULL;
3307 smp_del_chan(chan);
3308 }
3309
3310 if (hdev->smp_data) {
3311 chan = hdev->smp_data;
3312 hdev->smp_data = NULL;
3313 smp_del_chan(chan);
3314 }
3315 }
3316
3317 #if IS_ENABLED(CONFIG_BT_SELFTEST_SMP)
3318
3319 static int __init test_ah(struct crypto_blkcipher *tfm_aes)
3320 {
3321 const u8 irk[16] = {
3322 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3323 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3324 const u8 r[3] = { 0x94, 0x81, 0x70 };
3325 const u8 exp[3] = { 0xaa, 0xfb, 0x0d };
3326 u8 res[3];
3327 int err;
3328
3329 err = smp_ah(tfm_aes, irk, r, res);
3330 if (err)
3331 return err;
3332
3333 if (memcmp(res, exp, 3))
3334 return -EINVAL;
3335
3336 return 0;
3337 }
3338
3339 static int __init test_c1(struct crypto_blkcipher *tfm_aes)
3340 {
3341 const u8 k[16] = {
3342 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
3343 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
3344 const u8 r[16] = {
3345 0xe0, 0x2e, 0x70, 0xc6, 0x4e, 0x27, 0x88, 0x63,
3346 0x0e, 0x6f, 0xad, 0x56, 0x21, 0xd5, 0x83, 0x57 };
3347 const u8 preq[7] = { 0x01, 0x01, 0x00, 0x00, 0x10, 0x07, 0x07 };
3348 const u8 pres[7] = { 0x02, 0x03, 0x00, 0x00, 0x08, 0x00, 0x05 };
3349 const u8 _iat = 0x01;
3350 const u8 _rat = 0x00;
3351 const bdaddr_t ra = { { 0xb6, 0xb5, 0xb4, 0xb3, 0xb2, 0xb1 } };
3352 const bdaddr_t ia = { { 0xa6, 0xa5, 0xa4, 0xa3, 0xa2, 0xa1 } };
3353 const u8 exp[16] = {
3354 0x86, 0x3b, 0xf1, 0xbe, 0xc5, 0x4d, 0xa7, 0xd2,
3355 0xea, 0x88, 0x89, 0x87, 0xef, 0x3f, 0x1e, 0x1e };
3356 u8 res[16];
3357 int err;
3358
3359 err = smp_c1(tfm_aes, k, r, preq, pres, _iat, &ia, _rat, &ra, res);
3360 if (err)
3361 return err;
3362
3363 if (memcmp(res, exp, 16))
3364 return -EINVAL;
3365
3366 return 0;
3367 }
3368
3369 static int __init test_s1(struct crypto_blkcipher *tfm_aes)
3370 {
3371 const u8 k[16] = {
3372 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
3373 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
3374 const u8 r1[16] = {
3375 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 };
3376 const u8 r2[16] = {
3377 0x00, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99 };
3378 const u8 exp[16] = {
3379 0x62, 0xa0, 0x6d, 0x79, 0xae, 0x16, 0x42, 0x5b,
3380 0x9b, 0xf4, 0xb0, 0xe8, 0xf0, 0xe1, 0x1f, 0x9a };
3381 u8 res[16];
3382 int err;
3383
3384 err = smp_s1(tfm_aes, k, r1, r2, res);
3385 if (err)
3386 return err;
3387
3388 if (memcmp(res, exp, 16))
3389 return -EINVAL;
3390
3391 return 0;
3392 }
3393
3394 static int __init test_f4(struct crypto_hash *tfm_cmac)
3395 {
3396 const u8 u[32] = {
3397 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
3398 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
3399 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
3400 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 };
3401 const u8 v[32] = {
3402 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b,
3403 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59,
3404 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90,
3405 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 };
3406 const u8 x[16] = {
3407 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3408 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3409 const u8 z = 0x00;
3410 const u8 exp[16] = {
3411 0x2d, 0x87, 0x74, 0xa9, 0xbe, 0xa1, 0xed, 0xf1,
3412 0x1c, 0xbd, 0xa9, 0x07, 0xf1, 0x16, 0xc9, 0xf2 };
3413 u8 res[16];
3414 int err;
3415
3416 err = smp_f4(tfm_cmac, u, v, x, z, res);
3417 if (err)
3418 return err;
3419
3420 if (memcmp(res, exp, 16))
3421 return -EINVAL;
3422
3423 return 0;
3424 }
3425
3426 static int __init test_f5(struct crypto_hash *tfm_cmac)
3427 {
3428 const u8 w[32] = {
3429 0x98, 0xa6, 0xbf, 0x73, 0xf3, 0x34, 0x8d, 0x86,
3430 0xf1, 0x66, 0xf8, 0xb4, 0x13, 0x6b, 0x79, 0x99,
3431 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3432 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3433 const u8 n1[16] = {
3434 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3435 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3436 const u8 n2[16] = {
3437 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3438 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3439 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 };
3440 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 };
3441 const u8 exp_ltk[16] = {
3442 0x38, 0x0a, 0x75, 0x94, 0xb5, 0x22, 0x05, 0x98,
3443 0x23, 0xcd, 0xd7, 0x69, 0x11, 0x79, 0x86, 0x69 };
3444 const u8 exp_mackey[16] = {
3445 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd,
3446 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 };
3447 u8 mackey[16], ltk[16];
3448 int err;
3449
3450 err = smp_f5(tfm_cmac, w, n1, n2, a1, a2, mackey, ltk);
3451 if (err)
3452 return err;
3453
3454 if (memcmp(mackey, exp_mackey, 16))
3455 return -EINVAL;
3456
3457 if (memcmp(ltk, exp_ltk, 16))
3458 return -EINVAL;
3459
3460 return 0;
3461 }
3462
3463 static int __init test_f6(struct crypto_hash *tfm_cmac)
3464 {
3465 const u8 w[16] = {
3466 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd,
3467 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 };
3468 const u8 n1[16] = {
3469 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3470 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3471 const u8 n2[16] = {
3472 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3473 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3474 const u8 r[16] = {
3475 0xc8, 0x0f, 0x2d, 0x0c, 0xd2, 0x42, 0xda, 0x08,
3476 0x54, 0xbb, 0x53, 0xb4, 0x3b, 0x34, 0xa3, 0x12 };
3477 const u8 io_cap[3] = { 0x02, 0x01, 0x01 };
3478 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 };
3479 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 };
3480 const u8 exp[16] = {
3481 0x61, 0x8f, 0x95, 0xda, 0x09, 0x0b, 0x6c, 0xd2,
3482 0xc5, 0xe8, 0xd0, 0x9c, 0x98, 0x73, 0xc4, 0xe3 };
3483 u8 res[16];
3484 int err;
3485
3486 err = smp_f6(tfm_cmac, w, n1, n2, r, io_cap, a1, a2, res);
3487 if (err)
3488 return err;
3489
3490 if (memcmp(res, exp, 16))
3491 return -EINVAL;
3492
3493 return 0;
3494 }
3495
3496 static int __init test_g2(struct crypto_hash *tfm_cmac)
3497 {
3498 const u8 u[32] = {
3499 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
3500 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
3501 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
3502 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 };
3503 const u8 v[32] = {
3504 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b,
3505 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59,
3506 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90,
3507 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 };
3508 const u8 x[16] = {
3509 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3510 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3511 const u8 y[16] = {
3512 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3513 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3514 const u32 exp_val = 0x2f9ed5ba % 1000000;
3515 u32 val;
3516 int err;
3517
3518 err = smp_g2(tfm_cmac, u, v, x, y, &val);
3519 if (err)
3520 return err;
3521
3522 if (val != exp_val)
3523 return -EINVAL;
3524
3525 return 0;
3526 }
3527
3528 static int __init test_h6(struct crypto_hash *tfm_cmac)
3529 {
3530 const u8 w[16] = {
3531 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3532 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3533 const u8 key_id[4] = { 0x72, 0x62, 0x65, 0x6c };
3534 const u8 exp[16] = {
3535 0x99, 0x63, 0xb1, 0x80, 0xe2, 0xa9, 0xd3, 0xe8,
3536 0x1c, 0xc9, 0x6d, 0xe7, 0x02, 0xe1, 0x9a, 0x2d };
3537 u8 res[16];
3538 int err;
3539
3540 err = smp_h6(tfm_cmac, w, key_id, res);
3541 if (err)
3542 return err;
3543
3544 if (memcmp(res, exp, 16))
3545 return -EINVAL;
3546
3547 return 0;
3548 }
3549
3550 static int __init run_selftests(struct crypto_blkcipher *tfm_aes,
3551 struct crypto_hash *tfm_cmac)
3552 {
3553 ktime_t calltime, delta, rettime;
3554 unsigned long long duration;
3555 int err;
3556
3557 calltime = ktime_get();
3558
3559 err = test_ah(tfm_aes);
3560 if (err) {
3561 BT_ERR("smp_ah test failed");
3562 return err;
3563 }
3564
3565 err = test_c1(tfm_aes);
3566 if (err) {
3567 BT_ERR("smp_c1 test failed");
3568 return err;
3569 }
3570
3571 err = test_s1(tfm_aes);
3572 if (err) {
3573 BT_ERR("smp_s1 test failed");
3574 return err;
3575 }
3576
3577 err = test_f4(tfm_cmac);
3578 if (err) {
3579 BT_ERR("smp_f4 test failed");
3580 return err;
3581 }
3582
3583 err = test_f5(tfm_cmac);
3584 if (err) {
3585 BT_ERR("smp_f5 test failed");
3586 return err;
3587 }
3588
3589 err = test_f6(tfm_cmac);
3590 if (err) {
3591 BT_ERR("smp_f6 test failed");
3592 return err;
3593 }
3594
3595 err = test_g2(tfm_cmac);
3596 if (err) {
3597 BT_ERR("smp_g2 test failed");
3598 return err;
3599 }
3600
3601 err = test_h6(tfm_cmac);
3602 if (err) {
3603 BT_ERR("smp_h6 test failed");
3604 return err;
3605 }
3606
3607 rettime = ktime_get();
3608 delta = ktime_sub(rettime, calltime);
3609 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
3610
3611 BT_INFO("SMP test passed in %llu usecs", duration);
3612
3613 return 0;
3614 }
3615
3616 int __init bt_selftest_smp(void)
3617 {
3618 struct crypto_blkcipher *tfm_aes;
3619 struct crypto_hash *tfm_cmac;
3620 int err;
3621
3622 tfm_aes = crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);
3623 if (IS_ERR(tfm_aes)) {
3624 BT_ERR("Unable to create ECB crypto context");
3625 return PTR_ERR(tfm_aes);
3626 }
3627
3628 tfm_cmac = crypto_alloc_hash("cmac(aes)", 0, CRYPTO_ALG_ASYNC);
3629 if (IS_ERR(tfm_cmac)) {
3630 BT_ERR("Unable to create CMAC crypto context");
3631 crypto_free_blkcipher(tfm_aes);
3632 return PTR_ERR(tfm_cmac);
3633 }
3634
3635 err = run_selftests(tfm_aes, tfm_cmac);
3636
3637 crypto_free_hash(tfm_cmac);
3638 crypto_free_blkcipher(tfm_aes);
3639
3640 return err;
3641 }
3642
3643 #endif
Linux kernel - Deliverables
This page took 0.174696 seconds and 5 git commands to generate.