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1/*
2 BlueZ - Bluetooth protocol stack for Linux
3 Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License version 2 as
7 published by the Free Software Foundation;
8
9 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
10 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
11 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
12 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
13 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
14 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17
18 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
19 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
20 SOFTWARE IS DISCLAIMED.
21*/
22
23#include <linux/debugfs.h>
24#include <linux/scatterlist.h>
25#include <crypto/b128ops.h>
26#include <crypto/hash.h>
27#include <crypto/skcipher.h>
28
29#include <net/bluetooth/bluetooth.h>
30#include <net/bluetooth/hci_core.h>
31#include <net/bluetooth/l2cap.h>
32#include <net/bluetooth/mgmt.h>
33
34#include "ecc.h"
35#include "smp.h"
36
37#define SMP_DEV(hdev) \
38 ((struct smp_dev *)((struct l2cap_chan *)((hdev)->smp_data))->data)
39
40/* Low-level debug macros to be used for stuff that we don't want
41 * accidentially in dmesg, i.e. the values of the various crypto keys
42 * and the inputs & outputs of crypto functions.
43 */
44#ifdef DEBUG
45#define SMP_DBG(fmt, ...) printk(KERN_DEBUG "%s: " fmt, __func__, \
46 ##__VA_ARGS__)
47#else
48#define SMP_DBG(fmt, ...) no_printk(KERN_DEBUG "%s: " fmt, __func__, \
49 ##__VA_ARGS__)
50#endif
51
52#define SMP_ALLOW_CMD(smp, code) set_bit(code, &smp->allow_cmd)
53
54/* Keys which are not distributed with Secure Connections */
55#define SMP_SC_NO_DIST (SMP_DIST_ENC_KEY | SMP_DIST_LINK_KEY);
56
57#define SMP_TIMEOUT msecs_to_jiffies(30000)
58
59#define AUTH_REQ_MASK(dev) (hci_dev_test_flag(dev, HCI_SC_ENABLED) ? \
60 0x1f : 0x07)
61#define KEY_DIST_MASK 0x07
62
63/* Maximum message length that can be passed to aes_cmac */
64#define CMAC_MSG_MAX 80
65
66enum {
67 SMP_FLAG_TK_VALID,
68 SMP_FLAG_CFM_PENDING,
69 SMP_FLAG_MITM_AUTH,
70 SMP_FLAG_COMPLETE,
71 SMP_FLAG_INITIATOR,
72 SMP_FLAG_SC,
73 SMP_FLAG_REMOTE_PK,
74 SMP_FLAG_DEBUG_KEY,
75 SMP_FLAG_WAIT_USER,
76 SMP_FLAG_DHKEY_PENDING,
77 SMP_FLAG_REMOTE_OOB,
78 SMP_FLAG_LOCAL_OOB,
79};
80
81struct smp_dev {
82 /* Secure Connections OOB data */
83 u8 local_pk[64];
84 u8 local_sk[32];
85 u8 local_rand[16];
86 bool debug_key;
87
88 u8 min_key_size;
89 u8 max_key_size;
90
91 struct crypto_skcipher *tfm_aes;
92 struct crypto_shash *tfm_cmac;
93};
94
95struct smp_chan {
96 struct l2cap_conn *conn;
97 struct delayed_work security_timer;
98 unsigned long allow_cmd; /* Bitmask of allowed commands */
99
100 u8 preq[7]; /* SMP Pairing Request */
101 u8 prsp[7]; /* SMP Pairing Response */
102 u8 prnd[16]; /* SMP Pairing Random (local) */
103 u8 rrnd[16]; /* SMP Pairing Random (remote) */
104 u8 pcnf[16]; /* SMP Pairing Confirm */
105 u8 tk[16]; /* SMP Temporary Key */
106 u8 rr[16]; /* Remote OOB ra/rb value */
107 u8 lr[16]; /* Local OOB ra/rb value */
108 u8 enc_key_size;
109 u8 remote_key_dist;
110 bdaddr_t id_addr;
111 u8 id_addr_type;
112 u8 irk[16];
113 struct smp_csrk *csrk;
114 struct smp_csrk *slave_csrk;
115 struct smp_ltk *ltk;
116 struct smp_ltk *slave_ltk;
117 struct smp_irk *remote_irk;
118 u8 *link_key;
119 unsigned long flags;
120 u8 method;
121 u8 passkey_round;
122
123 /* Secure Connections variables */
124 u8 local_pk[64];
125 u8 local_sk[32];
126 u8 remote_pk[64];
127 u8 dhkey[32];
128 u8 mackey[16];
129
130 struct crypto_skcipher *tfm_aes;
131 struct crypto_shash *tfm_cmac;
132};
133
134/* These debug key values are defined in the SMP section of the core
135 * specification. debug_pk is the public debug key and debug_sk the
136 * private debug key.
137 */
138static const u8 debug_pk[64] = {
139 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
140 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
141 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
142 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20,
143
144 0x8b, 0xd2, 0x89, 0x15, 0xd0, 0x8e, 0x1c, 0x74,
145 0x24, 0x30, 0xed, 0x8f, 0xc2, 0x45, 0x63, 0x76,
146 0x5c, 0x15, 0x52, 0x5a, 0xbf, 0x9a, 0x32, 0x63,
147 0x6d, 0xeb, 0x2a, 0x65, 0x49, 0x9c, 0x80, 0xdc,
148};
149
150static const u8 debug_sk[32] = {
151 0xbd, 0x1a, 0x3c, 0xcd, 0xa6, 0xb8, 0x99, 0x58,
152 0x99, 0xb7, 0x40, 0xeb, 0x7b, 0x60, 0xff, 0x4a,
153 0x50, 0x3f, 0x10, 0xd2, 0xe3, 0xb3, 0xc9, 0x74,
154 0x38, 0x5f, 0xc5, 0xa3, 0xd4, 0xf6, 0x49, 0x3f,
155};
156
157static inline void swap_buf(const u8 *src, u8 *dst, size_t len)
158{
159 size_t i;
160
161 for (i = 0; i < len; i++)
162 dst[len - 1 - i] = src[i];
163}
164
165/* The following functions map to the LE SC SMP crypto functions
166 * AES-CMAC, f4, f5, f6, g2 and h6.
167 */
168
169static int aes_cmac(struct crypto_shash *tfm, const u8 k[16], const u8 *m,
170 size_t len, u8 mac[16])
171{
172 uint8_t tmp[16], mac_msb[16], msg_msb[CMAC_MSG_MAX];
173 SHASH_DESC_ON_STACK(desc, tfm);
174 int err;
175
176 if (len > CMAC_MSG_MAX)
177 return -EFBIG;
178
179 if (!tfm) {
180 BT_ERR("tfm %p", tfm);
181 return -EINVAL;
182 }
183
184 desc->tfm = tfm;
185 desc->flags = 0;
186
187 /* Swap key and message from LSB to MSB */
188 swap_buf(k, tmp, 16);
189 swap_buf(m, msg_msb, len);
190
191 SMP_DBG("msg (len %zu) %*phN", len, (int) len, m);
192 SMP_DBG("key %16phN", k);
193
194 err = crypto_shash_setkey(tfm, tmp, 16);
195 if (err) {
196 BT_ERR("cipher setkey failed: %d", err);
197 return err;
198 }
199
200 err = crypto_shash_digest(desc, msg_msb, len, mac_msb);
201 shash_desc_zero(desc);
202 if (err) {
203 BT_ERR("Hash computation error %d", err);
204 return err;
205 }
206
207 swap_buf(mac_msb, mac, 16);
208
209 SMP_DBG("mac %16phN", mac);
210
211 return 0;
212}
213
214static int smp_f4(struct crypto_shash *tfm_cmac, const u8 u[32],
215 const u8 v[32], const u8 x[16], u8 z, u8 res[16])
216{
217 u8 m[65];
218 int err;
219
220 SMP_DBG("u %32phN", u);
221 SMP_DBG("v %32phN", v);
222 SMP_DBG("x %16phN z %02x", x, z);
223
224 m[0] = z;
225 memcpy(m + 1, v, 32);
226 memcpy(m + 33, u, 32);
227
228 err = aes_cmac(tfm_cmac, x, m, sizeof(m), res);
229 if (err)
230 return err;
231
232 SMP_DBG("res %16phN", res);
233
234 return err;
235}
236
237static int smp_f5(struct crypto_shash *tfm_cmac, const u8 w[32],
238 const u8 n1[16], const u8 n2[16], const u8 a1[7],
239 const u8 a2[7], u8 mackey[16], u8 ltk[16])
240{
241 /* The btle, salt and length "magic" values are as defined in
242 * the SMP section of the Bluetooth core specification. In ASCII
243 * the btle value ends up being 'btle'. The salt is just a
244 * random number whereas length is the value 256 in little
245 * endian format.
246 */
247 const u8 btle[4] = { 0x65, 0x6c, 0x74, 0x62 };
248 const u8 salt[16] = { 0xbe, 0x83, 0x60, 0x5a, 0xdb, 0x0b, 0x37, 0x60,
249 0x38, 0xa5, 0xf5, 0xaa, 0x91, 0x83, 0x88, 0x6c };
250 const u8 length[2] = { 0x00, 0x01 };
251 u8 m[53], t[16];
252 int err;
253
254 SMP_DBG("w %32phN", w);
255 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
256 SMP_DBG("a1 %7phN a2 %7phN", a1, a2);
257
258 err = aes_cmac(tfm_cmac, salt, w, 32, t);
259 if (err)
260 return err;
261
262 SMP_DBG("t %16phN", t);
263
264 memcpy(m, length, 2);
265 memcpy(m + 2, a2, 7);
266 memcpy(m + 9, a1, 7);
267 memcpy(m + 16, n2, 16);
268 memcpy(m + 32, n1, 16);
269 memcpy(m + 48, btle, 4);
270
271 m[52] = 0; /* Counter */
272
273 err = aes_cmac(tfm_cmac, t, m, sizeof(m), mackey);
274 if (err)
275 return err;
276
277 SMP_DBG("mackey %16phN", mackey);
278
279 m[52] = 1; /* Counter */
280
281 err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk);
282 if (err)
283 return err;
284
285 SMP_DBG("ltk %16phN", ltk);
286
287 return 0;
288}
289
290static int smp_f6(struct crypto_shash *tfm_cmac, const u8 w[16],
291 const u8 n1[16], const u8 n2[16], const u8 r[16],
292 const u8 io_cap[3], const u8 a1[7], const u8 a2[7],
293 u8 res[16])
294{
295 u8 m[65];
296 int err;
297
298 SMP_DBG("w %16phN", w);
299 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
300 SMP_DBG("r %16phN io_cap %3phN a1 %7phN a2 %7phN", r, io_cap, a1, a2);
301
302 memcpy(m, a2, 7);
303 memcpy(m + 7, a1, 7);
304 memcpy(m + 14, io_cap, 3);
305 memcpy(m + 17, r, 16);
306 memcpy(m + 33, n2, 16);
307 memcpy(m + 49, n1, 16);
308
309 err = aes_cmac(tfm_cmac, w, m, sizeof(m), res);
310 if (err)
311 return err;
312
313 SMP_DBG("res %16phN", res);
314
315 return err;
316}
317
318static int smp_g2(struct crypto_shash *tfm_cmac, const u8 u[32], const u8 v[32],
319 const u8 x[16], const u8 y[16], u32 *val)
320{
321 u8 m[80], tmp[16];
322 int err;
323
324 SMP_DBG("u %32phN", u);
325 SMP_DBG("v %32phN", v);
326 SMP_DBG("x %16phN y %16phN", x, y);
327
328 memcpy(m, y, 16);
329 memcpy(m + 16, v, 32);
330 memcpy(m + 48, u, 32);
331
332 err = aes_cmac(tfm_cmac, x, m, sizeof(m), tmp);
333 if (err)
334 return err;
335
336 *val = get_unaligned_le32(tmp);
337 *val %= 1000000;
338
339 SMP_DBG("val %06u", *val);
340
341 return 0;
342}
343
344static int smp_h6(struct crypto_shash *tfm_cmac, const u8 w[16],
345 const u8 key_id[4], u8 res[16])
346{
347 int err;
348
349 SMP_DBG("w %16phN key_id %4phN", w, key_id);
350
351 err = aes_cmac(tfm_cmac, w, key_id, 4, res);
352 if (err)
353 return err;
354
355 SMP_DBG("res %16phN", res);
356
357 return err;
358}
359
360/* The following functions map to the legacy SMP crypto functions e, c1,
361 * s1 and ah.
362 */
363
364static int smp_e(struct crypto_skcipher *tfm, const u8 *k, u8 *r)
365{
366 SKCIPHER_REQUEST_ON_STACK(req, tfm);
367 struct scatterlist sg;
368 uint8_t tmp[16], data[16];
369 int err;
370
371 SMP_DBG("k %16phN r %16phN", k, r);
372
373 if (!tfm) {
374 BT_ERR("tfm %p", tfm);
375 return -EINVAL;
376 }
377
378 /* The most significant octet of key corresponds to k[0] */
379 swap_buf(k, tmp, 16);
380
381 err = crypto_skcipher_setkey(tfm, tmp, 16);
382 if (err) {
383 BT_ERR("cipher setkey failed: %d", err);
384 return err;
385 }
386
387 /* Most significant octet of plaintextData corresponds to data[0] */
388 swap_buf(r, data, 16);
389
390 sg_init_one(&sg, data, 16);
391
392 skcipher_request_set_tfm(req, tfm);
393 skcipher_request_set_callback(req, 0, NULL, NULL);
394 skcipher_request_set_crypt(req, &sg, &sg, 16, NULL);
395
396 err = crypto_skcipher_encrypt(req);
397 skcipher_request_zero(req);
398 if (err)
399 BT_ERR("Encrypt data error %d", err);
400
401 /* Most significant octet of encryptedData corresponds to data[0] */
402 swap_buf(data, r, 16);
403
404 SMP_DBG("r %16phN", r);
405
406 return err;
407}
408
409static int smp_c1(struct crypto_skcipher *tfm_aes, const u8 k[16],
410 const u8 r[16], const u8 preq[7], const u8 pres[7], u8 _iat,
411 const bdaddr_t *ia, u8 _rat, const bdaddr_t *ra, u8 res[16])
412{
413 u8 p1[16], p2[16];
414 int err;
415
416 SMP_DBG("k %16phN r %16phN", k, r);
417 SMP_DBG("iat %u ia %6phN rat %u ra %6phN", _iat, ia, _rat, ra);
418 SMP_DBG("preq %7phN pres %7phN", preq, pres);
419
420 memset(p1, 0, 16);
421
422 /* p1 = pres || preq || _rat || _iat */
423 p1[0] = _iat;
424 p1[1] = _rat;
425 memcpy(p1 + 2, preq, 7);
426 memcpy(p1 + 9, pres, 7);
427
428 SMP_DBG("p1 %16phN", p1);
429
430 /* res = r XOR p1 */
431 u128_xor((u128 *) res, (u128 *) r, (u128 *) p1);
432
433 /* res = e(k, res) */
434 err = smp_e(tfm_aes, k, res);
435 if (err) {
436 BT_ERR("Encrypt data error");
437 return err;
438 }
439
440 /* p2 = padding || ia || ra */
441 memcpy(p2, ra, 6);
442 memcpy(p2 + 6, ia, 6);
443 memset(p2 + 12, 0, 4);
444
445 SMP_DBG("p2 %16phN", p2);
446
447 /* res = res XOR p2 */
448 u128_xor((u128 *) res, (u128 *) res, (u128 *) p2);
449
450 /* res = e(k, res) */
451 err = smp_e(tfm_aes, k, res);
452 if (err)
453 BT_ERR("Encrypt data error");
454
455 return err;
456}
457
458static int smp_s1(struct crypto_skcipher *tfm_aes, const u8 k[16],
459 const u8 r1[16], const u8 r2[16], u8 _r[16])
460{
461 int err;
462
463 /* Just least significant octets from r1 and r2 are considered */
464 memcpy(_r, r2, 8);
465 memcpy(_r + 8, r1, 8);
466
467 err = smp_e(tfm_aes, k, _r);
468 if (err)
469 BT_ERR("Encrypt data error");
470
471 return err;
472}
473
474static int smp_ah(struct crypto_skcipher *tfm, const u8 irk[16],
475 const u8 r[3], u8 res[3])
476{
477 u8 _res[16];
478 int err;
479
480 /* r' = padding || r */
481 memcpy(_res, r, 3);
482 memset(_res + 3, 0, 13);
483
484 err = smp_e(tfm, irk, _res);
485 if (err) {
486 BT_ERR("Encrypt error");
487 return err;
488 }
489
490 /* The output of the random address function ah is:
491 * ah(k, r) = e(k, r') mod 2^24
492 * The output of the security function e is then truncated to 24 bits
493 * by taking the least significant 24 bits of the output of e as the
494 * result of ah.
495 */
496 memcpy(res, _res, 3);
497
498 return 0;
499}
500
501bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16],
502 const bdaddr_t *bdaddr)
503{
504 struct l2cap_chan *chan = hdev->smp_data;
505 struct smp_dev *smp;
506 u8 hash[3];
507 int err;
508
509 if (!chan || !chan->data)
510 return false;
511
512 smp = chan->data;
513
514 BT_DBG("RPA %pMR IRK %*phN", bdaddr, 16, irk);
515
516 err = smp_ah(smp->tfm_aes, irk, &bdaddr->b[3], hash);
517 if (err)
518 return false;
519
520 return !memcmp(bdaddr->b, hash, 3);
521}
522
523int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa)
524{
525 struct l2cap_chan *chan = hdev->smp_data;
526 struct smp_dev *smp;
527 int err;
528
529 if (!chan || !chan->data)
530 return -EOPNOTSUPP;
531
532 smp = chan->data;
533
534 get_random_bytes(&rpa->b[3], 3);
535
536 rpa->b[5] &= 0x3f; /* Clear two most significant bits */
537 rpa->b[5] |= 0x40; /* Set second most significant bit */
538
539 err = smp_ah(smp->tfm_aes, irk, &rpa->b[3], rpa->b);
540 if (err < 0)
541 return err;
542
543 BT_DBG("RPA %pMR", rpa);
544
545 return 0;
546}
547
548int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16])
549{
550 struct l2cap_chan *chan = hdev->smp_data;
551 struct smp_dev *smp;
552 int err;
553
554 if (!chan || !chan->data)
555 return -EOPNOTSUPP;
556
557 smp = chan->data;
558
559 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) {
560 BT_DBG("Using debug keys");
561 memcpy(smp->local_pk, debug_pk, 64);
562 memcpy(smp->local_sk, debug_sk, 32);
563 smp->debug_key = true;
564 } else {
565 while (true) {
566 /* Generate local key pair for Secure Connections */
567 if (!ecc_make_key(smp->local_pk, smp->local_sk))
568 return -EIO;
569
570 /* This is unlikely, but we need to check that
571 * we didn't accidentially generate a debug key.
572 */
573 if (memcmp(smp->local_sk, debug_sk, 32))
574 break;
575 }
576 smp->debug_key = false;
577 }
578
579 SMP_DBG("OOB Public Key X: %32phN", smp->local_pk);
580 SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32);
581 SMP_DBG("OOB Private Key: %32phN", smp->local_sk);
582
583 get_random_bytes(smp->local_rand, 16);
584
585 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->local_pk,
586 smp->local_rand, 0, hash);
587 if (err < 0)
588 return err;
589
590 memcpy(rand, smp->local_rand, 16);
591
592 return 0;
593}
594
595static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
596{
597 struct l2cap_chan *chan = conn->smp;
598 struct smp_chan *smp;
599 struct kvec iv[2];
600 struct msghdr msg;
601
602 if (!chan)
603 return;
604
605 BT_DBG("code 0x%2.2x", code);
606
607 iv[0].iov_base = &code;
608 iv[0].iov_len = 1;
609
610 iv[1].iov_base = data;
611 iv[1].iov_len = len;
612
613 memset(&msg, 0, sizeof(msg));
614
615 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iv, 2, 1 + len);
616
617 l2cap_chan_send(chan, &msg, 1 + len);
618
619 if (!chan->data)
620 return;
621
622 smp = chan->data;
623
624 cancel_delayed_work_sync(&smp->security_timer);
625 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT);
626}
627
628static u8 authreq_to_seclevel(u8 authreq)
629{
630 if (authreq & SMP_AUTH_MITM) {
631 if (authreq & SMP_AUTH_SC)
632 return BT_SECURITY_FIPS;
633 else
634 return BT_SECURITY_HIGH;
635 } else {
636 return BT_SECURITY_MEDIUM;
637 }
638}
639
640static __u8 seclevel_to_authreq(__u8 sec_level)
641{
642 switch (sec_level) {
643 case BT_SECURITY_FIPS:
644 case BT_SECURITY_HIGH:
645 return SMP_AUTH_MITM | SMP_AUTH_BONDING;
646 case BT_SECURITY_MEDIUM:
647 return SMP_AUTH_BONDING;
648 default:
649 return SMP_AUTH_NONE;
650 }
651}
652
653static void build_pairing_cmd(struct l2cap_conn *conn,
654 struct smp_cmd_pairing *req,
655 struct smp_cmd_pairing *rsp, __u8 authreq)
656{
657 struct l2cap_chan *chan = conn->smp;
658 struct smp_chan *smp = chan->data;
659 struct hci_conn *hcon = conn->hcon;
660 struct hci_dev *hdev = hcon->hdev;
661 u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT;
662
663 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) {
664 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
665 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
666 authreq |= SMP_AUTH_BONDING;
667 } else {
668 authreq &= ~SMP_AUTH_BONDING;
669 }
670
671 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING))
672 remote_dist |= SMP_DIST_ID_KEY;
673
674 if (hci_dev_test_flag(hdev, HCI_PRIVACY))
675 local_dist |= SMP_DIST_ID_KEY;
676
677 if (hci_dev_test_flag(hdev, HCI_SC_ENABLED) &&
678 (authreq & SMP_AUTH_SC)) {
679 struct oob_data *oob_data;
680 u8 bdaddr_type;
681
682 if (hci_dev_test_flag(hdev, HCI_SSP_ENABLED)) {
683 local_dist |= SMP_DIST_LINK_KEY;
684 remote_dist |= SMP_DIST_LINK_KEY;
685 }
686
687 if (hcon->dst_type == ADDR_LE_DEV_PUBLIC)
688 bdaddr_type = BDADDR_LE_PUBLIC;
689 else
690 bdaddr_type = BDADDR_LE_RANDOM;
691
692 oob_data = hci_find_remote_oob_data(hdev, &hcon->dst,
693 bdaddr_type);
694 if (oob_data && oob_data->present) {
695 set_bit(SMP_FLAG_REMOTE_OOB, &smp->flags);
696 oob_flag = SMP_OOB_PRESENT;
697 memcpy(smp->rr, oob_data->rand256, 16);
698 memcpy(smp->pcnf, oob_data->hash256, 16);
699 SMP_DBG("OOB Remote Confirmation: %16phN", smp->pcnf);
700 SMP_DBG("OOB Remote Random: %16phN", smp->rr);
701 }
702
703 } else {
704 authreq &= ~SMP_AUTH_SC;
705 }
706
707 if (rsp == NULL) {
708 req->io_capability = conn->hcon->io_capability;
709 req->oob_flag = oob_flag;
710 req->max_key_size = SMP_DEV(hdev)->max_key_size;
711 req->init_key_dist = local_dist;
712 req->resp_key_dist = remote_dist;
713 req->auth_req = (authreq & AUTH_REQ_MASK(hdev));
714
715 smp->remote_key_dist = remote_dist;
716 return;
717 }
718
719 rsp->io_capability = conn->hcon->io_capability;
720 rsp->oob_flag = oob_flag;
721 rsp->max_key_size = SMP_DEV(hdev)->max_key_size;
722 rsp->init_key_dist = req->init_key_dist & remote_dist;
723 rsp->resp_key_dist = req->resp_key_dist & local_dist;
724 rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev));
725
726 smp->remote_key_dist = rsp->init_key_dist;
727}
728
729static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)
730{
731 struct l2cap_chan *chan = conn->smp;
732 struct hci_dev *hdev = conn->hcon->hdev;
733 struct smp_chan *smp = chan->data;
734
735 if (max_key_size > SMP_DEV(hdev)->max_key_size ||
736 max_key_size < SMP_MIN_ENC_KEY_SIZE)
737 return SMP_ENC_KEY_SIZE;
738
739 smp->enc_key_size = max_key_size;
740
741 return 0;
742}
743
744static void smp_chan_destroy(struct l2cap_conn *conn)
745{
746 struct l2cap_chan *chan = conn->smp;
747 struct smp_chan *smp = chan->data;
748 struct hci_conn *hcon = conn->hcon;
749 bool complete;
750
751 BUG_ON(!smp);
752
753 cancel_delayed_work_sync(&smp->security_timer);
754
755 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags);
756 mgmt_smp_complete(hcon, complete);
757
758 kzfree(smp->csrk);
759 kzfree(smp->slave_csrk);
760 kzfree(smp->link_key);
761
762 crypto_free_skcipher(smp->tfm_aes);
763 crypto_free_shash(smp->tfm_cmac);
764
765 /* Ensure that we don't leave any debug key around if debug key
766 * support hasn't been explicitly enabled.
767 */
768 if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG &&
769 !hci_dev_test_flag(hcon->hdev, HCI_KEEP_DEBUG_KEYS)) {
770 list_del_rcu(&smp->ltk->list);
771 kfree_rcu(smp->ltk, rcu);
772 smp->ltk = NULL;
773 }
774
775 /* If pairing failed clean up any keys we might have */
776 if (!complete) {
777 if (smp->ltk) {
778 list_del_rcu(&smp->ltk->list);
779 kfree_rcu(smp->ltk, rcu);
780 }
781
782 if (smp->slave_ltk) {
783 list_del_rcu(&smp->slave_ltk->list);
784 kfree_rcu(smp->slave_ltk, rcu);
785 }
786
787 if (smp->remote_irk) {
788 list_del_rcu(&smp->remote_irk->list);
789 kfree_rcu(smp->remote_irk, rcu);
790 }
791 }
792
793 chan->data = NULL;
794 kzfree(smp);
795 hci_conn_drop(hcon);
796}
797
798static void smp_failure(struct l2cap_conn *conn, u8 reason)
799{
800 struct hci_conn *hcon = conn->hcon;
801 struct l2cap_chan *chan = conn->smp;
802
803 if (reason)
804 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
805 &reason);
806
807 mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE);
808
809 if (chan->data)
810 smp_chan_destroy(conn);
811}
812
813#define JUST_WORKS 0x00
814#define JUST_CFM 0x01
815#define REQ_PASSKEY 0x02
816#define CFM_PASSKEY 0x03
817#define REQ_OOB 0x04
818#define DSP_PASSKEY 0x05
819#define OVERLAP 0xFF
820
821static const u8 gen_method[5][5] = {
822 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
823 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
824 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
825 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
826 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP },
827};
828
829static const u8 sc_method[5][5] = {
830 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
831 { JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
832 { DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY },
833 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
834 { DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
835};
836
837static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io)
838{
839 /* If either side has unknown io_caps, use JUST_CFM (which gets
840 * converted later to JUST_WORKS if we're initiators.
841 */
842 if (local_io > SMP_IO_KEYBOARD_DISPLAY ||
843 remote_io > SMP_IO_KEYBOARD_DISPLAY)
844 return JUST_CFM;
845
846 if (test_bit(SMP_FLAG_SC, &smp->flags))
847 return sc_method[remote_io][local_io];
848
849 return gen_method[remote_io][local_io];
850}
851
852static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth,
853 u8 local_io, u8 remote_io)
854{
855 struct hci_conn *hcon = conn->hcon;
856 struct l2cap_chan *chan = conn->smp;
857 struct smp_chan *smp = chan->data;
858 u32 passkey = 0;
859 int ret = 0;
860
861 /* Initialize key for JUST WORKS */
862 memset(smp->tk, 0, sizeof(smp->tk));
863 clear_bit(SMP_FLAG_TK_VALID, &smp->flags);
864
865 BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io);
866
867 /* If neither side wants MITM, either "just" confirm an incoming
868 * request or use just-works for outgoing ones. The JUST_CFM
869 * will be converted to JUST_WORKS if necessary later in this
870 * function. If either side has MITM look up the method from the
871 * table.
872 */
873 if (!(auth & SMP_AUTH_MITM))
874 smp->method = JUST_CFM;
875 else
876 smp->method = get_auth_method(smp, local_io, remote_io);
877
878 /* Don't confirm locally initiated pairing attempts */
879 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR,
880 &smp->flags))
881 smp->method = JUST_WORKS;
882
883 /* Don't bother user space with no IO capabilities */
884 if (smp->method == JUST_CFM &&
885 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
886 smp->method = JUST_WORKS;
887
888 /* If Just Works, Continue with Zero TK */
889 if (smp->method == JUST_WORKS) {
890 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
891 return 0;
892 }
893
894 /* If this function is used for SC -> legacy fallback we
895 * can only recover the just-works case.
896 */
897 if (test_bit(SMP_FLAG_SC, &smp->flags))
898 return -EINVAL;
899
900 /* Not Just Works/Confirm results in MITM Authentication */
901 if (smp->method != JUST_CFM) {
902 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags);
903 if (hcon->pending_sec_level < BT_SECURITY_HIGH)
904 hcon->pending_sec_level = BT_SECURITY_HIGH;
905 }
906
907 /* If both devices have Keyoard-Display I/O, the master
908 * Confirms and the slave Enters the passkey.
909 */
910 if (smp->method == OVERLAP) {
911 if (hcon->role == HCI_ROLE_MASTER)
912 smp->method = CFM_PASSKEY;
913 else
914 smp->method = REQ_PASSKEY;
915 }
916
917 /* Generate random passkey. */
918 if (smp->method == CFM_PASSKEY) {
919 memset(smp->tk, 0, sizeof(smp->tk));
920 get_random_bytes(&passkey, sizeof(passkey));
921 passkey %= 1000000;
922 put_unaligned_le32(passkey, smp->tk);
923 BT_DBG("PassKey: %d", passkey);
924 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
925 }
926
927 if (smp->method == REQ_PASSKEY)
928 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst,
929 hcon->type, hcon->dst_type);
930 else if (smp->method == JUST_CFM)
931 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
932 hcon->type, hcon->dst_type,
933 passkey, 1);
934 else
935 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst,
936 hcon->type, hcon->dst_type,
937 passkey, 0);
938
939 return ret;
940}
941
942static u8 smp_confirm(struct smp_chan *smp)
943{
944 struct l2cap_conn *conn = smp->conn;
945 struct smp_cmd_pairing_confirm cp;
946 int ret;
947
948 BT_DBG("conn %p", conn);
949
950 ret = smp_c1(smp->tfm_aes, smp->tk, smp->prnd, smp->preq, smp->prsp,
951 conn->hcon->init_addr_type, &conn->hcon->init_addr,
952 conn->hcon->resp_addr_type, &conn->hcon->resp_addr,
953 cp.confirm_val);
954 if (ret)
955 return SMP_UNSPECIFIED;
956
957 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
958
959 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
960
961 if (conn->hcon->out)
962 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
963 else
964 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
965
966 return 0;
967}
968
969static u8 smp_random(struct smp_chan *smp)
970{
971 struct l2cap_conn *conn = smp->conn;
972 struct hci_conn *hcon = conn->hcon;
973 u8 confirm[16];
974 int ret;
975
976 if (IS_ERR_OR_NULL(smp->tfm_aes))
977 return SMP_UNSPECIFIED;
978
979 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
980
981 ret = smp_c1(smp->tfm_aes, smp->tk, smp->rrnd, smp->preq, smp->prsp,
982 hcon->init_addr_type, &hcon->init_addr,
983 hcon->resp_addr_type, &hcon->resp_addr, confirm);
984 if (ret)
985 return SMP_UNSPECIFIED;
986
987 if (memcmp(smp->pcnf, confirm, sizeof(smp->pcnf)) != 0) {
988 BT_ERR("Pairing failed (confirmation values mismatch)");
989 return SMP_CONFIRM_FAILED;
990 }
991
992 if (hcon->out) {
993 u8 stk[16];
994 __le64 rand = 0;
995 __le16 ediv = 0;
996
997 smp_s1(smp->tfm_aes, smp->tk, smp->rrnd, smp->prnd, stk);
998
999 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
1000 return SMP_UNSPECIFIED;
1001
1002 hci_le_start_enc(hcon, ediv, rand, stk, smp->enc_key_size);
1003 hcon->enc_key_size = smp->enc_key_size;
1004 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
1005 } else {
1006 u8 stk[16], auth;
1007 __le64 rand = 0;
1008 __le16 ediv = 0;
1009
1010 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
1011 smp->prnd);
1012
1013 smp_s1(smp->tfm_aes, smp->tk, smp->prnd, smp->rrnd, stk);
1014
1015 if (hcon->pending_sec_level == BT_SECURITY_HIGH)
1016 auth = 1;
1017 else
1018 auth = 0;
1019
1020 /* Even though there's no _SLAVE suffix this is the
1021 * slave STK we're adding for later lookup (the master
1022 * STK never needs to be stored).
1023 */
1024 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1025 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand);
1026 }
1027
1028 return 0;
1029}
1030
1031static void smp_notify_keys(struct l2cap_conn *conn)
1032{
1033 struct l2cap_chan *chan = conn->smp;
1034 struct smp_chan *smp = chan->data;
1035 struct hci_conn *hcon = conn->hcon;
1036 struct hci_dev *hdev = hcon->hdev;
1037 struct smp_cmd_pairing *req = (void *) &smp->preq[1];
1038 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1];
1039 bool persistent;
1040
1041 if (hcon->type == ACL_LINK) {
1042 if (hcon->key_type == HCI_LK_DEBUG_COMBINATION)
1043 persistent = false;
1044 else
1045 persistent = !test_bit(HCI_CONN_FLUSH_KEY,
1046 &hcon->flags);
1047 } else {
1048 /* The LTKs, IRKs and CSRKs should be persistent only if
1049 * both sides had the bonding bit set in their
1050 * authentication requests.
1051 */
1052 persistent = !!((req->auth_req & rsp->auth_req) &
1053 SMP_AUTH_BONDING);
1054 }
1055
1056 if (smp->remote_irk) {
1057 mgmt_new_irk(hdev, smp->remote_irk, persistent);
1058
1059 /* Now that user space can be considered to know the
1060 * identity address track the connection based on it
1061 * from now on (assuming this is an LE link).
1062 */
1063 if (hcon->type == LE_LINK) {
1064 bacpy(&hcon->dst, &smp->remote_irk->bdaddr);
1065 hcon->dst_type = smp->remote_irk->addr_type;
1066 queue_work(hdev->workqueue, &conn->id_addr_update_work);
1067 }
1068 }
1069
1070 if (smp->csrk) {
1071 smp->csrk->bdaddr_type = hcon->dst_type;
1072 bacpy(&smp->csrk->bdaddr, &hcon->dst);
1073 mgmt_new_csrk(hdev, smp->csrk, persistent);
1074 }
1075
1076 if (smp->slave_csrk) {
1077 smp->slave_csrk->bdaddr_type = hcon->dst_type;
1078 bacpy(&smp->slave_csrk->bdaddr, &hcon->dst);
1079 mgmt_new_csrk(hdev, smp->slave_csrk, persistent);
1080 }
1081
1082 if (smp->ltk) {
1083 smp->ltk->bdaddr_type = hcon->dst_type;
1084 bacpy(&smp->ltk->bdaddr, &hcon->dst);
1085 mgmt_new_ltk(hdev, smp->ltk, persistent);
1086 }
1087
1088 if (smp->slave_ltk) {
1089 smp->slave_ltk->bdaddr_type = hcon->dst_type;
1090 bacpy(&smp->slave_ltk->bdaddr, &hcon->dst);
1091 mgmt_new_ltk(hdev, smp->slave_ltk, persistent);
1092 }
1093
1094 if (smp->link_key) {
1095 struct link_key *key;
1096 u8 type;
1097
1098 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1099 type = HCI_LK_DEBUG_COMBINATION;
1100 else if (hcon->sec_level == BT_SECURITY_FIPS)
1101 type = HCI_LK_AUTH_COMBINATION_P256;
1102 else
1103 type = HCI_LK_UNAUTH_COMBINATION_P256;
1104
1105 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst,
1106 smp->link_key, type, 0, &persistent);
1107 if (key) {
1108 mgmt_new_link_key(hdev, key, persistent);
1109
1110 /* Don't keep debug keys around if the relevant
1111 * flag is not set.
1112 */
1113 if (!hci_dev_test_flag(hdev, HCI_KEEP_DEBUG_KEYS) &&
1114 key->type == HCI_LK_DEBUG_COMBINATION) {
1115 list_del_rcu(&key->list);
1116 kfree_rcu(key, rcu);
1117 }
1118 }
1119 }
1120}
1121
1122static void sc_add_ltk(struct smp_chan *smp)
1123{
1124 struct hci_conn *hcon = smp->conn->hcon;
1125 u8 key_type, auth;
1126
1127 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1128 key_type = SMP_LTK_P256_DEBUG;
1129 else
1130 key_type = SMP_LTK_P256;
1131
1132 if (hcon->pending_sec_level == BT_SECURITY_FIPS)
1133 auth = 1;
1134 else
1135 auth = 0;
1136
1137 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1138 key_type, auth, smp->tk, smp->enc_key_size,
1139 0, 0);
1140}
1141
1142static void sc_generate_link_key(struct smp_chan *smp)
1143{
1144 /* These constants are as specified in the core specification.
1145 * In ASCII they spell out to 'tmp1' and 'lebr'.
1146 */
1147 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 };
1148 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c };
1149
1150 smp->link_key = kzalloc(16, GFP_KERNEL);
1151 if (!smp->link_key)
1152 return;
1153
1154 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) {
1155 kzfree(smp->link_key);
1156 smp->link_key = NULL;
1157 return;
1158 }
1159
1160 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) {
1161 kzfree(smp->link_key);
1162 smp->link_key = NULL;
1163 return;
1164 }
1165}
1166
1167static void smp_allow_key_dist(struct smp_chan *smp)
1168{
1169 /* Allow the first expected phase 3 PDU. The rest of the PDUs
1170 * will be allowed in each PDU handler to ensure we receive
1171 * them in the correct order.
1172 */
1173 if (smp->remote_key_dist & SMP_DIST_ENC_KEY)
1174 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO);
1175 else if (smp->remote_key_dist & SMP_DIST_ID_KEY)
1176 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
1177 else if (smp->remote_key_dist & SMP_DIST_SIGN)
1178 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
1179}
1180
1181static void sc_generate_ltk(struct smp_chan *smp)
1182{
1183 /* These constants are as specified in the core specification.
1184 * In ASCII they spell out to 'tmp2' and 'brle'.
1185 */
1186 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 };
1187 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 };
1188 struct hci_conn *hcon = smp->conn->hcon;
1189 struct hci_dev *hdev = hcon->hdev;
1190 struct link_key *key;
1191
1192 key = hci_find_link_key(hdev, &hcon->dst);
1193 if (!key) {
1194 BT_ERR("%s No Link Key found to generate LTK", hdev->name);
1195 return;
1196 }
1197
1198 if (key->type == HCI_LK_DEBUG_COMBINATION)
1199 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1200
1201 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk))
1202 return;
1203
1204 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk))
1205 return;
1206
1207 sc_add_ltk(smp);
1208}
1209
1210static void smp_distribute_keys(struct smp_chan *smp)
1211{
1212 struct smp_cmd_pairing *req, *rsp;
1213 struct l2cap_conn *conn = smp->conn;
1214 struct hci_conn *hcon = conn->hcon;
1215 struct hci_dev *hdev = hcon->hdev;
1216 __u8 *keydist;
1217
1218 BT_DBG("conn %p", conn);
1219
1220 rsp = (void *) &smp->prsp[1];
1221
1222 /* The responder sends its keys first */
1223 if (hcon->out && (smp->remote_key_dist & KEY_DIST_MASK)) {
1224 smp_allow_key_dist(smp);
1225 return;
1226 }
1227
1228 req = (void *) &smp->preq[1];
1229
1230 if (hcon->out) {
1231 keydist = &rsp->init_key_dist;
1232 *keydist &= req->init_key_dist;
1233 } else {
1234 keydist = &rsp->resp_key_dist;
1235 *keydist &= req->resp_key_dist;
1236 }
1237
1238 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1239 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY))
1240 sc_generate_link_key(smp);
1241 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY))
1242 sc_generate_ltk(smp);
1243
1244 /* Clear the keys which are generated but not distributed */
1245 *keydist &= ~SMP_SC_NO_DIST;
1246 }
1247
1248 BT_DBG("keydist 0x%x", *keydist);
1249
1250 if (*keydist & SMP_DIST_ENC_KEY) {
1251 struct smp_cmd_encrypt_info enc;
1252 struct smp_cmd_master_ident ident;
1253 struct smp_ltk *ltk;
1254 u8 authenticated;
1255 __le16 ediv;
1256 __le64 rand;
1257
1258 /* Make sure we generate only the significant amount of
1259 * bytes based on the encryption key size, and set the rest
1260 * of the value to zeroes.
1261 */
1262 get_random_bytes(enc.ltk, smp->enc_key_size);
1263 memset(enc.ltk + smp->enc_key_size, 0,
1264 sizeof(enc.ltk) - smp->enc_key_size);
1265
1266 get_random_bytes(&ediv, sizeof(ediv));
1267 get_random_bytes(&rand, sizeof(rand));
1268
1269 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc);
1270
1271 authenticated = hcon->sec_level == BT_SECURITY_HIGH;
1272 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type,
1273 SMP_LTK_SLAVE, authenticated, enc.ltk,
1274 smp->enc_key_size, ediv, rand);
1275 smp->slave_ltk = ltk;
1276
1277 ident.ediv = ediv;
1278 ident.rand = rand;
1279
1280 smp_send_cmd(conn, SMP_CMD_MASTER_IDENT, sizeof(ident), &ident);
1281
1282 *keydist &= ~SMP_DIST_ENC_KEY;
1283 }
1284
1285 if (*keydist & SMP_DIST_ID_KEY) {
1286 struct smp_cmd_ident_addr_info addrinfo;
1287 struct smp_cmd_ident_info idinfo;
1288
1289 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk));
1290
1291 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo);
1292
1293 /* The hci_conn contains the local identity address
1294 * after the connection has been established.
1295 *
1296 * This is true even when the connection has been
1297 * established using a resolvable random address.
1298 */
1299 bacpy(&addrinfo.bdaddr, &hcon->src);
1300 addrinfo.addr_type = hcon->src_type;
1301
1302 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo),
1303 &addrinfo);
1304
1305 *keydist &= ~SMP_DIST_ID_KEY;
1306 }
1307
1308 if (*keydist & SMP_DIST_SIGN) {
1309 struct smp_cmd_sign_info sign;
1310 struct smp_csrk *csrk;
1311
1312 /* Generate a new random key */
1313 get_random_bytes(sign.csrk, sizeof(sign.csrk));
1314
1315 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
1316 if (csrk) {
1317 if (hcon->sec_level > BT_SECURITY_MEDIUM)
1318 csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED;
1319 else
1320 csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED;
1321 memcpy(csrk->val, sign.csrk, sizeof(csrk->val));
1322 }
1323 smp->slave_csrk = csrk;
1324
1325 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign);
1326
1327 *keydist &= ~SMP_DIST_SIGN;
1328 }
1329
1330 /* If there are still keys to be received wait for them */
1331 if (smp->remote_key_dist & KEY_DIST_MASK) {
1332 smp_allow_key_dist(smp);
1333 return;
1334 }
1335
1336 set_bit(SMP_FLAG_COMPLETE, &smp->flags);
1337 smp_notify_keys(conn);
1338
1339 smp_chan_destroy(conn);
1340}
1341
1342static void smp_timeout(struct work_struct *work)
1343{
1344 struct smp_chan *smp = container_of(work, struct smp_chan,
1345 security_timer.work);
1346 struct l2cap_conn *conn = smp->conn;
1347
1348 BT_DBG("conn %p", conn);
1349
1350 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM);
1351}
1352
1353static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
1354{
1355 struct l2cap_chan *chan = conn->smp;
1356 struct smp_chan *smp;
1357
1358 smp = kzalloc(sizeof(*smp), GFP_ATOMIC);
1359 if (!smp)
1360 return NULL;
1361
1362 smp->tfm_aes = crypto_alloc_skcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);
1363 if (IS_ERR(smp->tfm_aes)) {
1364 BT_ERR("Unable to create ECB crypto context");
1365 kzfree(smp);
1366 return NULL;
1367 }
1368
1369 smp->tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
1370 if (IS_ERR(smp->tfm_cmac)) {
1371 BT_ERR("Unable to create CMAC crypto context");
1372 crypto_free_skcipher(smp->tfm_aes);
1373 kzfree(smp);
1374 return NULL;
1375 }
1376
1377 smp->conn = conn;
1378 chan->data = smp;
1379
1380 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL);
1381
1382 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout);
1383
1384 hci_conn_hold(conn->hcon);
1385
1386 return smp;
1387}
1388
1389static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16])
1390{
1391 struct hci_conn *hcon = smp->conn->hcon;
1392 u8 *na, *nb, a[7], b[7];
1393
1394 if (hcon->out) {
1395 na = smp->prnd;
1396 nb = smp->rrnd;
1397 } else {
1398 na = smp->rrnd;
1399 nb = smp->prnd;
1400 }
1401
1402 memcpy(a, &hcon->init_addr, 6);
1403 memcpy(b, &hcon->resp_addr, 6);
1404 a[6] = hcon->init_addr_type;
1405 b[6] = hcon->resp_addr_type;
1406
1407 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk);
1408}
1409
1410static void sc_dhkey_check(struct smp_chan *smp)
1411{
1412 struct hci_conn *hcon = smp->conn->hcon;
1413 struct smp_cmd_dhkey_check check;
1414 u8 a[7], b[7], *local_addr, *remote_addr;
1415 u8 io_cap[3], r[16];
1416
1417 memcpy(a, &hcon->init_addr, 6);
1418 memcpy(b, &hcon->resp_addr, 6);
1419 a[6] = hcon->init_addr_type;
1420 b[6] = hcon->resp_addr_type;
1421
1422 if (hcon->out) {
1423 local_addr = a;
1424 remote_addr = b;
1425 memcpy(io_cap, &smp->preq[1], 3);
1426 } else {
1427 local_addr = b;
1428 remote_addr = a;
1429 memcpy(io_cap, &smp->prsp[1], 3);
1430 }
1431
1432 memset(r, 0, sizeof(r));
1433
1434 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
1435 put_unaligned_le32(hcon->passkey_notify, r);
1436
1437 if (smp->method == REQ_OOB)
1438 memcpy(r, smp->rr, 16);
1439
1440 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap,
1441 local_addr, remote_addr, check.e);
1442
1443 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check);
1444}
1445
1446static u8 sc_passkey_send_confirm(struct smp_chan *smp)
1447{
1448 struct l2cap_conn *conn = smp->conn;
1449 struct hci_conn *hcon = conn->hcon;
1450 struct smp_cmd_pairing_confirm cfm;
1451 u8 r;
1452
1453 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1454 r |= 0x80;
1455
1456 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1457
1458 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r,
1459 cfm.confirm_val))
1460 return SMP_UNSPECIFIED;
1461
1462 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
1463
1464 return 0;
1465}
1466
1467static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op)
1468{
1469 struct l2cap_conn *conn = smp->conn;
1470 struct hci_conn *hcon = conn->hcon;
1471 struct hci_dev *hdev = hcon->hdev;
1472 u8 cfm[16], r;
1473
1474 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */
1475 if (smp->passkey_round >= 20)
1476 return 0;
1477
1478 switch (smp_op) {
1479 case SMP_CMD_PAIRING_RANDOM:
1480 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1481 r |= 0x80;
1482
1483 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
1484 smp->rrnd, r, cfm))
1485 return SMP_UNSPECIFIED;
1486
1487 if (memcmp(smp->pcnf, cfm, 16))
1488 return SMP_CONFIRM_FAILED;
1489
1490 smp->passkey_round++;
1491
1492 if (smp->passkey_round == 20) {
1493 /* Generate MacKey and LTK */
1494 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk))
1495 return SMP_UNSPECIFIED;
1496 }
1497
1498 /* The round is only complete when the initiator
1499 * receives pairing random.
1500 */
1501 if (!hcon->out) {
1502 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1503 sizeof(smp->prnd), smp->prnd);
1504 if (smp->passkey_round == 20)
1505 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1506 else
1507 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1508 return 0;
1509 }
1510
1511 /* Start the next round */
1512 if (smp->passkey_round != 20)
1513 return sc_passkey_round(smp, 0);
1514
1515 /* Passkey rounds are complete - start DHKey Check */
1516 sc_dhkey_check(smp);
1517 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1518
1519 break;
1520
1521 case SMP_CMD_PAIRING_CONFIRM:
1522 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
1523 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
1524 return 0;
1525 }
1526
1527 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
1528
1529 if (hcon->out) {
1530 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1531 sizeof(smp->prnd), smp->prnd);
1532 return 0;
1533 }
1534
1535 return sc_passkey_send_confirm(smp);
1536
1537 case SMP_CMD_PUBLIC_KEY:
1538 default:
1539 /* Initiating device starts the round */
1540 if (!hcon->out)
1541 return 0;
1542
1543 BT_DBG("%s Starting passkey round %u", hdev->name,
1544 smp->passkey_round + 1);
1545
1546 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1547
1548 return sc_passkey_send_confirm(smp);
1549 }
1550
1551 return 0;
1552}
1553
1554static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey)
1555{
1556 struct l2cap_conn *conn = smp->conn;
1557 struct hci_conn *hcon = conn->hcon;
1558 u8 smp_op;
1559
1560 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags);
1561
1562 switch (mgmt_op) {
1563 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1564 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED);
1565 return 0;
1566 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1567 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED);
1568 return 0;
1569 case MGMT_OP_USER_PASSKEY_REPLY:
1570 hcon->passkey_notify = le32_to_cpu(passkey);
1571 smp->passkey_round = 0;
1572
1573 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags))
1574 smp_op = SMP_CMD_PAIRING_CONFIRM;
1575 else
1576 smp_op = 0;
1577
1578 if (sc_passkey_round(smp, smp_op))
1579 return -EIO;
1580
1581 return 0;
1582 }
1583
1584 /* Initiator sends DHKey check first */
1585 if (hcon->out) {
1586 sc_dhkey_check(smp);
1587 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1588 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) {
1589 sc_dhkey_check(smp);
1590 sc_add_ltk(smp);
1591 }
1592
1593 return 0;
1594}
1595
1596int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey)
1597{
1598 struct l2cap_conn *conn = hcon->l2cap_data;
1599 struct l2cap_chan *chan;
1600 struct smp_chan *smp;
1601 u32 value;
1602 int err;
1603
1604 BT_DBG("");
1605
1606 if (!conn)
1607 return -ENOTCONN;
1608
1609 chan = conn->smp;
1610 if (!chan)
1611 return -ENOTCONN;
1612
1613 l2cap_chan_lock(chan);
1614 if (!chan->data) {
1615 err = -ENOTCONN;
1616 goto unlock;
1617 }
1618
1619 smp = chan->data;
1620
1621 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1622 err = sc_user_reply(smp, mgmt_op, passkey);
1623 goto unlock;
1624 }
1625
1626 switch (mgmt_op) {
1627 case MGMT_OP_USER_PASSKEY_REPLY:
1628 value = le32_to_cpu(passkey);
1629 memset(smp->tk, 0, sizeof(smp->tk));
1630 BT_DBG("PassKey: %d", value);
1631 put_unaligned_le32(value, smp->tk);
1632 /* Fall Through */
1633 case MGMT_OP_USER_CONFIRM_REPLY:
1634 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
1635 break;
1636 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1637 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1638 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1639 err = 0;
1640 goto unlock;
1641 default:
1642 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1643 err = -EOPNOTSUPP;
1644 goto unlock;
1645 }
1646
1647 err = 0;
1648
1649 /* If it is our turn to send Pairing Confirm, do so now */
1650 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) {
1651 u8 rsp = smp_confirm(smp);
1652 if (rsp)
1653 smp_failure(conn, rsp);
1654 }
1655
1656unlock:
1657 l2cap_chan_unlock(chan);
1658 return err;
1659}
1660
1661static void build_bredr_pairing_cmd(struct smp_chan *smp,
1662 struct smp_cmd_pairing *req,
1663 struct smp_cmd_pairing *rsp)
1664{
1665 struct l2cap_conn *conn = smp->conn;
1666 struct hci_dev *hdev = conn->hcon->hdev;
1667 u8 local_dist = 0, remote_dist = 0;
1668
1669 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) {
1670 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1671 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1672 }
1673
1674 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING))
1675 remote_dist |= SMP_DIST_ID_KEY;
1676
1677 if (hci_dev_test_flag(hdev, HCI_PRIVACY))
1678 local_dist |= SMP_DIST_ID_KEY;
1679
1680 if (!rsp) {
1681 memset(req, 0, sizeof(*req));
1682
1683 req->init_key_dist = local_dist;
1684 req->resp_key_dist = remote_dist;
1685 req->max_key_size = conn->hcon->enc_key_size;
1686
1687 smp->remote_key_dist = remote_dist;
1688
1689 return;
1690 }
1691
1692 memset(rsp, 0, sizeof(*rsp));
1693
1694 rsp->max_key_size = conn->hcon->enc_key_size;
1695 rsp->init_key_dist = req->init_key_dist & remote_dist;
1696 rsp->resp_key_dist = req->resp_key_dist & local_dist;
1697
1698 smp->remote_key_dist = rsp->init_key_dist;
1699}
1700
1701static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
1702{
1703 struct smp_cmd_pairing rsp, *req = (void *) skb->data;
1704 struct l2cap_chan *chan = conn->smp;
1705 struct hci_dev *hdev = conn->hcon->hdev;
1706 struct smp_chan *smp;
1707 u8 key_size, auth, sec_level;
1708 int ret;
1709
1710 BT_DBG("conn %p", conn);
1711
1712 if (skb->len < sizeof(*req))
1713 return SMP_INVALID_PARAMS;
1714
1715 if (conn->hcon->role != HCI_ROLE_SLAVE)
1716 return SMP_CMD_NOTSUPP;
1717
1718 if (!chan->data)
1719 smp = smp_chan_create(conn);
1720 else
1721 smp = chan->data;
1722
1723 if (!smp)
1724 return SMP_UNSPECIFIED;
1725
1726 /* We didn't start the pairing, so match remote */
1727 auth = req->auth_req & AUTH_REQ_MASK(hdev);
1728
1729 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) &&
1730 (auth & SMP_AUTH_BONDING))
1731 return SMP_PAIRING_NOTSUPP;
1732
1733 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
1734 return SMP_AUTH_REQUIREMENTS;
1735
1736 smp->preq[0] = SMP_CMD_PAIRING_REQ;
1737 memcpy(&smp->preq[1], req, sizeof(*req));
1738 skb_pull(skb, sizeof(*req));
1739
1740 /* If the remote side's OOB flag is set it means it has
1741 * successfully received our local OOB data - therefore set the
1742 * flag to indicate that local OOB is in use.
1743 */
1744 if (req->oob_flag == SMP_OOB_PRESENT)
1745 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);
1746
1747 /* SMP over BR/EDR requires special treatment */
1748 if (conn->hcon->type == ACL_LINK) {
1749 /* We must have a BR/EDR SC link */
1750 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) &&
1751 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
1752 return SMP_CROSS_TRANSP_NOT_ALLOWED;
1753
1754 set_bit(SMP_FLAG_SC, &smp->flags);
1755
1756 build_bredr_pairing_cmd(smp, req, &rsp);
1757
1758 key_size = min(req->max_key_size, rsp.max_key_size);
1759 if (check_enc_key_size(conn, key_size))
1760 return SMP_ENC_KEY_SIZE;
1761
1762 /* Clear bits which are generated but not distributed */
1763 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1764
1765 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1766 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1767 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1768
1769 smp_distribute_keys(smp);
1770 return 0;
1771 }
1772
1773 build_pairing_cmd(conn, req, &rsp, auth);
1774
1775 if (rsp.auth_req & SMP_AUTH_SC)
1776 set_bit(SMP_FLAG_SC, &smp->flags);
1777
1778 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
1779 sec_level = BT_SECURITY_MEDIUM;
1780 else
1781 sec_level = authreq_to_seclevel(auth);
1782
1783 if (sec_level > conn->hcon->pending_sec_level)
1784 conn->hcon->pending_sec_level = sec_level;
1785
1786 /* If we need MITM check that it can be achieved */
1787 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1788 u8 method;
1789
1790 method = get_auth_method(smp, conn->hcon->io_capability,
1791 req->io_capability);
1792 if (method == JUST_WORKS || method == JUST_CFM)
1793 return SMP_AUTH_REQUIREMENTS;
1794 }
1795
1796 key_size = min(req->max_key_size, rsp.max_key_size);
1797 if (check_enc_key_size(conn, key_size))
1798 return SMP_ENC_KEY_SIZE;
1799
1800 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1801
1802 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1803 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1804
1805 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1806
1807 clear_bit(SMP_FLAG_INITIATOR, &smp->flags);
1808
1809 /* Strictly speaking we shouldn't allow Pairing Confirm for the
1810 * SC case, however some implementations incorrectly copy RFU auth
1811 * req bits from our security request, which may create a false
1812 * positive SC enablement.
1813 */
1814 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1815
1816 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1817 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
1818 /* Clear bits which are generated but not distributed */
1819 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1820 /* Wait for Public Key from Initiating Device */
1821 return 0;
1822 }
1823
1824 /* Request setup of TK */
1825 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability);
1826 if (ret)
1827 return SMP_UNSPECIFIED;
1828
1829 return 0;
1830}
1831
1832static u8 sc_send_public_key(struct smp_chan *smp)
1833{
1834 struct hci_dev *hdev = smp->conn->hcon->hdev;
1835
1836 BT_DBG("");
1837
1838 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) {
1839 struct l2cap_chan *chan = hdev->smp_data;
1840 struct smp_dev *smp_dev;
1841
1842 if (!chan || !chan->data)
1843 return SMP_UNSPECIFIED;
1844
1845 smp_dev = chan->data;
1846
1847 memcpy(smp->local_pk, smp_dev->local_pk, 64);
1848 memcpy(smp->local_sk, smp_dev->local_sk, 32);
1849 memcpy(smp->lr, smp_dev->local_rand, 16);
1850
1851 if (smp_dev->debug_key)
1852 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1853
1854 goto done;
1855 }
1856
1857 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) {
1858 BT_DBG("Using debug keys");
1859 memcpy(smp->local_pk, debug_pk, 64);
1860 memcpy(smp->local_sk, debug_sk, 32);
1861 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1862 } else {
1863 while (true) {
1864 /* Generate local key pair for Secure Connections */
1865 if (!ecc_make_key(smp->local_pk, smp->local_sk))
1866 return SMP_UNSPECIFIED;
1867
1868 /* This is unlikely, but we need to check that
1869 * we didn't accidentially generate a debug key.
1870 */
1871 if (memcmp(smp->local_sk, debug_sk, 32))
1872 break;
1873 }
1874 }
1875
1876done:
1877 SMP_DBG("Local Public Key X: %32phN", smp->local_pk);
1878 SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32);
1879 SMP_DBG("Local Private Key: %32phN", smp->local_sk);
1880
1881 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk);
1882
1883 return 0;
1884}
1885
1886static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
1887{
1888 struct smp_cmd_pairing *req, *rsp = (void *) skb->data;
1889 struct l2cap_chan *chan = conn->smp;
1890 struct smp_chan *smp = chan->data;
1891 struct hci_dev *hdev = conn->hcon->hdev;
1892 u8 key_size, auth;
1893 int ret;
1894
1895 BT_DBG("conn %p", conn);
1896
1897 if (skb->len < sizeof(*rsp))
1898 return SMP_INVALID_PARAMS;
1899
1900 if (conn->hcon->role != HCI_ROLE_MASTER)
1901 return SMP_CMD_NOTSUPP;
1902
1903 skb_pull(skb, sizeof(*rsp));
1904
1905 req = (void *) &smp->preq[1];
1906
1907 key_size = min(req->max_key_size, rsp->max_key_size);
1908 if (check_enc_key_size(conn, key_size))
1909 return SMP_ENC_KEY_SIZE;
1910
1911 auth = rsp->auth_req & AUTH_REQ_MASK(hdev);
1912
1913 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
1914 return SMP_AUTH_REQUIREMENTS;
1915
1916 /* If the remote side's OOB flag is set it means it has
1917 * successfully received our local OOB data - therefore set the
1918 * flag to indicate that local OOB is in use.
1919 */
1920 if (rsp->oob_flag == SMP_OOB_PRESENT)
1921 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);
1922
1923 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1924 memcpy(&smp->prsp[1], rsp, sizeof(*rsp));
1925
1926 /* Update remote key distribution in case the remote cleared
1927 * some bits that we had enabled in our request.
1928 */
1929 smp->remote_key_dist &= rsp->resp_key_dist;
1930
1931 /* For BR/EDR this means we're done and can start phase 3 */
1932 if (conn->hcon->type == ACL_LINK) {
1933 /* Clear bits which are generated but not distributed */
1934 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1935 smp_distribute_keys(smp);
1936 return 0;
1937 }
1938
1939 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC))
1940 set_bit(SMP_FLAG_SC, &smp->flags);
1941 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH)
1942 conn->hcon->pending_sec_level = BT_SECURITY_HIGH;
1943
1944 /* If we need MITM check that it can be achieved */
1945 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1946 u8 method;
1947
1948 method = get_auth_method(smp, req->io_capability,
1949 rsp->io_capability);
1950 if (method == JUST_WORKS || method == JUST_CFM)
1951 return SMP_AUTH_REQUIREMENTS;
1952 }
1953
1954 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1955
1956 /* Update remote key distribution in case the remote cleared
1957 * some bits that we had enabled in our request.
1958 */
1959 smp->remote_key_dist &= rsp->resp_key_dist;
1960
1961 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1962 /* Clear bits which are generated but not distributed */
1963 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1964 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
1965 return sc_send_public_key(smp);
1966 }
1967
1968 auth |= req->auth_req;
1969
1970 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability);
1971 if (ret)
1972 return SMP_UNSPECIFIED;
1973
1974 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
1975
1976 /* Can't compose response until we have been confirmed */
1977 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
1978 return smp_confirm(smp);
1979
1980 return 0;
1981}
1982
1983static u8 sc_check_confirm(struct smp_chan *smp)
1984{
1985 struct l2cap_conn *conn = smp->conn;
1986
1987 BT_DBG("");
1988
1989 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
1990 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM);
1991
1992 if (conn->hcon->out) {
1993 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
1994 smp->prnd);
1995 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
1996 }
1997
1998 return 0;
1999}
2000
2001/* Work-around for some implementations that incorrectly copy RFU bits
2002 * from our security request and thereby create the impression that
2003 * we're doing SC when in fact the remote doesn't support it.
2004 */
2005static int fixup_sc_false_positive(struct smp_chan *smp)
2006{
2007 struct l2cap_conn *conn = smp->conn;
2008 struct hci_conn *hcon = conn->hcon;
2009 struct hci_dev *hdev = hcon->hdev;
2010 struct smp_cmd_pairing *req, *rsp;
2011 u8 auth;
2012
2013 /* The issue is only observed when we're in slave role */
2014 if (hcon->out)
2015 return SMP_UNSPECIFIED;
2016
2017 if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) {
2018 BT_ERR("Refusing SMP SC -> legacy fallback in SC-only mode");
2019 return SMP_UNSPECIFIED;
2020 }
2021
2022 BT_ERR("Trying to fall back to legacy SMP");
2023
2024 req = (void *) &smp->preq[1];
2025 rsp = (void *) &smp->prsp[1];
2026
2027 /* Rebuild key dist flags which may have been cleared for SC */
2028 smp->remote_key_dist = (req->init_key_dist & rsp->resp_key_dist);
2029
2030 auth = req->auth_req & AUTH_REQ_MASK(hdev);
2031
2032 if (tk_request(conn, 0, auth, rsp->io_capability, req->io_capability)) {
2033 BT_ERR("Failed to fall back to legacy SMP");
2034 return SMP_UNSPECIFIED;
2035 }
2036
2037 clear_bit(SMP_FLAG_SC, &smp->flags);
2038
2039 return 0;
2040}
2041
2042static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
2043{
2044 struct l2cap_chan *chan = conn->smp;
2045 struct smp_chan *smp = chan->data;
2046
2047 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
2048
2049 if (skb->len < sizeof(smp->pcnf))
2050 return SMP_INVALID_PARAMS;
2051
2052 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf));
2053 skb_pull(skb, sizeof(smp->pcnf));
2054
2055 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
2056 int ret;
2057
2058 /* Public Key exchange must happen before any other steps */
2059 if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags))
2060 return sc_check_confirm(smp);
2061
2062 BT_ERR("Unexpected SMP Pairing Confirm");
2063
2064 ret = fixup_sc_false_positive(smp);
2065 if (ret)
2066 return ret;
2067 }
2068
2069 if (conn->hcon->out) {
2070 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2071 smp->prnd);
2072 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2073 return 0;
2074 }
2075
2076 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
2077 return smp_confirm(smp);
2078
2079 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
2080
2081 return 0;
2082}
2083
2084static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
2085{
2086 struct l2cap_chan *chan = conn->smp;
2087 struct smp_chan *smp = chan->data;
2088 struct hci_conn *hcon = conn->hcon;
2089 u8 *pkax, *pkbx, *na, *nb;
2090 u32 passkey;
2091 int err;
2092
2093 BT_DBG("conn %p", conn);
2094
2095 if (skb->len < sizeof(smp->rrnd))
2096 return SMP_INVALID_PARAMS;
2097
2098 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd));
2099 skb_pull(skb, sizeof(smp->rrnd));
2100
2101 if (!test_bit(SMP_FLAG_SC, &smp->flags))
2102 return smp_random(smp);
2103
2104 if (hcon->out) {
2105 pkax = smp->local_pk;
2106 pkbx = smp->remote_pk;
2107 na = smp->prnd;
2108 nb = smp->rrnd;
2109 } else {
2110 pkax = smp->remote_pk;
2111 pkbx = smp->local_pk;
2112 na = smp->rrnd;
2113 nb = smp->prnd;
2114 }
2115
2116 if (smp->method == REQ_OOB) {
2117 if (!hcon->out)
2118 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2119 sizeof(smp->prnd), smp->prnd);
2120 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2121 goto mackey_and_ltk;
2122 }
2123
2124 /* Passkey entry has special treatment */
2125 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2126 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM);
2127
2128 if (hcon->out) {
2129 u8 cfm[16];
2130
2131 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
2132 smp->rrnd, 0, cfm);
2133 if (err)
2134 return SMP_UNSPECIFIED;
2135
2136 if (memcmp(smp->pcnf, cfm, 16))
2137 return SMP_CONFIRM_FAILED;
2138 } else {
2139 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2140 smp->prnd);
2141 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2142 }
2143
2144mackey_and_ltk:
2145 /* Generate MacKey and LTK */
2146 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk);
2147 if (err)
2148 return SMP_UNSPECIFIED;
2149
2150 if (smp->method == JUST_WORKS || smp->method == REQ_OOB) {
2151 if (hcon->out) {
2152 sc_dhkey_check(smp);
2153 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2154 }
2155 return 0;
2156 }
2157
2158 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
2159 if (err)
2160 return SMP_UNSPECIFIED;
2161
2162 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type,
2163 hcon->dst_type, passkey, 0);
2164 if (err)
2165 return SMP_UNSPECIFIED;
2166
2167 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2168
2169 return 0;
2170}
2171
2172static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level)
2173{
2174 struct smp_ltk *key;
2175 struct hci_conn *hcon = conn->hcon;
2176
2177 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role);
2178 if (!key)
2179 return false;
2180
2181 if (smp_ltk_sec_level(key) < sec_level)
2182 return false;
2183
2184 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
2185 return true;
2186
2187 hci_le_start_enc(hcon, key->ediv, key->rand, key->val, key->enc_size);
2188 hcon->enc_key_size = key->enc_size;
2189
2190 /* We never store STKs for master role, so clear this flag */
2191 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
2192
2193 return true;
2194}
2195
2196bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level,
2197 enum smp_key_pref key_pref)
2198{
2199 if (sec_level == BT_SECURITY_LOW)
2200 return true;
2201
2202 /* If we're encrypted with an STK but the caller prefers using
2203 * LTK claim insufficient security. This way we allow the
2204 * connection to be re-encrypted with an LTK, even if the LTK
2205 * provides the same level of security. Only exception is if we
2206 * don't have an LTK (e.g. because of key distribution bits).
2207 */
2208 if (key_pref == SMP_USE_LTK &&
2209 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) &&
2210 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role))
2211 return false;
2212
2213 if (hcon->sec_level >= sec_level)
2214 return true;
2215
2216 return false;
2217}
2218
2219static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
2220{
2221 struct smp_cmd_security_req *rp = (void *) skb->data;
2222 struct smp_cmd_pairing cp;
2223 struct hci_conn *hcon = conn->hcon;
2224 struct hci_dev *hdev = hcon->hdev;
2225 struct smp_chan *smp;
2226 u8 sec_level, auth;
2227
2228 BT_DBG("conn %p", conn);
2229
2230 if (skb->len < sizeof(*rp))
2231 return SMP_INVALID_PARAMS;
2232
2233 if (hcon->role != HCI_ROLE_MASTER)
2234 return SMP_CMD_NOTSUPP;
2235
2236 auth = rp->auth_req & AUTH_REQ_MASK(hdev);
2237
2238 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
2239 return SMP_AUTH_REQUIREMENTS;
2240
2241 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
2242 sec_level = BT_SECURITY_MEDIUM;
2243 else
2244 sec_level = authreq_to_seclevel(auth);
2245
2246 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK))
2247 return 0;
2248
2249 if (sec_level > hcon->pending_sec_level)
2250 hcon->pending_sec_level = sec_level;
2251
2252 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2253 return 0;
2254
2255 smp = smp_chan_create(conn);
2256 if (!smp)
2257 return SMP_UNSPECIFIED;
2258
2259 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) &&
2260 (auth & SMP_AUTH_BONDING))
2261 return SMP_PAIRING_NOTSUPP;
2262
2263 skb_pull(skb, sizeof(*rp));
2264
2265 memset(&cp, 0, sizeof(cp));
2266 build_pairing_cmd(conn, &cp, NULL, auth);
2267
2268 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2269 memcpy(&smp->preq[1], &cp, sizeof(cp));
2270
2271 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
2272 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2273
2274 return 0;
2275}
2276
2277int smp_conn_security(struct hci_conn *hcon, __u8 sec_level)
2278{
2279 struct l2cap_conn *conn = hcon->l2cap_data;
2280 struct l2cap_chan *chan;
2281 struct smp_chan *smp;
2282 __u8 authreq;
2283 int ret;
2284
2285 BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level);
2286
2287 /* This may be NULL if there's an unexpected disconnection */
2288 if (!conn)
2289 return 1;
2290
2291 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED))
2292 return 1;
2293
2294 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK))
2295 return 1;
2296
2297 if (sec_level > hcon->pending_sec_level)
2298 hcon->pending_sec_level = sec_level;
2299
2300 if (hcon->role == HCI_ROLE_MASTER)
2301 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2302 return 0;
2303
2304 chan = conn->smp;
2305 if (!chan) {
2306 BT_ERR("SMP security requested but not available");
2307 return 1;
2308 }
2309
2310 l2cap_chan_lock(chan);
2311
2312 /* If SMP is already in progress ignore this request */
2313 if (chan->data) {
2314 ret = 0;
2315 goto unlock;
2316 }
2317
2318 smp = smp_chan_create(conn);
2319 if (!smp) {
2320 ret = 1;
2321 goto unlock;
2322 }
2323
2324 authreq = seclevel_to_authreq(sec_level);
2325
2326 if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED))
2327 authreq |= SMP_AUTH_SC;
2328
2329 /* Require MITM if IO Capability allows or the security level
2330 * requires it.
2331 */
2332 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT ||
2333 hcon->pending_sec_level > BT_SECURITY_MEDIUM)
2334 authreq |= SMP_AUTH_MITM;
2335
2336 if (hcon->role == HCI_ROLE_MASTER) {
2337 struct smp_cmd_pairing cp;
2338
2339 build_pairing_cmd(conn, &cp, NULL, authreq);
2340 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2341 memcpy(&smp->preq[1], &cp, sizeof(cp));
2342
2343 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
2344 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2345 } else {
2346 struct smp_cmd_security_req cp;
2347 cp.auth_req = authreq;
2348 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp);
2349 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ);
2350 }
2351
2352 set_bit(SMP_FLAG_INITIATOR, &smp->flags);
2353 ret = 0;
2354
2355unlock:
2356 l2cap_chan_unlock(chan);
2357 return ret;
2358}
2359
2360void smp_cancel_pairing(struct hci_conn *hcon)
2361{
2362 struct l2cap_conn *conn = hcon->l2cap_data;
2363 struct l2cap_chan *chan;
2364 struct smp_chan *smp;
2365
2366 if (!conn)
2367 return;
2368
2369 chan = conn->smp;
2370 if (!chan)
2371 return;
2372
2373 l2cap_chan_lock(chan);
2374
2375 smp = chan->data;
2376 if (smp) {
2377 if (test_bit(SMP_FLAG_COMPLETE, &smp->flags))
2378 smp_failure(conn, 0);
2379 else
2380 smp_failure(conn, SMP_UNSPECIFIED);
2381 }
2382
2383 l2cap_chan_unlock(chan);
2384}
2385
2386static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb)
2387{
2388 struct smp_cmd_encrypt_info *rp = (void *) skb->data;
2389 struct l2cap_chan *chan = conn->smp;
2390 struct smp_chan *smp = chan->data;
2391
2392 BT_DBG("conn %p", conn);
2393
2394 if (skb->len < sizeof(*rp))
2395 return SMP_INVALID_PARAMS;
2396
2397 SMP_ALLOW_CMD(smp, SMP_CMD_MASTER_IDENT);
2398
2399 skb_pull(skb, sizeof(*rp));
2400
2401 memcpy(smp->tk, rp->ltk, sizeof(smp->tk));
2402
2403 return 0;
2404}
2405
2406static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb)
2407{
2408 struct smp_cmd_master_ident *rp = (void *) skb->data;
2409 struct l2cap_chan *chan = conn->smp;
2410 struct smp_chan *smp = chan->data;
2411 struct hci_dev *hdev = conn->hcon->hdev;
2412 struct hci_conn *hcon = conn->hcon;
2413 struct smp_ltk *ltk;
2414 u8 authenticated;
2415
2416 BT_DBG("conn %p", conn);
2417
2418 if (skb->len < sizeof(*rp))
2419 return SMP_INVALID_PARAMS;
2420
2421 /* Mark the information as received */
2422 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY;
2423
2424 if (smp->remote_key_dist & SMP_DIST_ID_KEY)
2425 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
2426 else if (smp->remote_key_dist & SMP_DIST_SIGN)
2427 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2428
2429 skb_pull(skb, sizeof(*rp));
2430
2431 authenticated = (hcon->sec_level == BT_SECURITY_HIGH);
2432 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK,
2433 authenticated, smp->tk, smp->enc_key_size,
2434 rp->ediv, rp->rand);
2435 smp->ltk = ltk;
2436 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2437 smp_distribute_keys(smp);
2438
2439 return 0;
2440}
2441
2442static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb)
2443{
2444 struct smp_cmd_ident_info *info = (void *) skb->data;
2445 struct l2cap_chan *chan = conn->smp;
2446 struct smp_chan *smp = chan->data;
2447
2448 BT_DBG("");
2449
2450 if (skb->len < sizeof(*info))
2451 return SMP_INVALID_PARAMS;
2452
2453 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO);
2454
2455 skb_pull(skb, sizeof(*info));
2456
2457 memcpy(smp->irk, info->irk, 16);
2458
2459 return 0;
2460}
2461
2462static int smp_cmd_ident_addr_info(struct l2cap_conn *conn,
2463 struct sk_buff *skb)
2464{
2465 struct smp_cmd_ident_addr_info *info = (void *) skb->data;
2466 struct l2cap_chan *chan = conn->smp;
2467 struct smp_chan *smp = chan->data;
2468 struct hci_conn *hcon = conn->hcon;
2469 bdaddr_t rpa;
2470
2471 BT_DBG("");
2472
2473 if (skb->len < sizeof(*info))
2474 return SMP_INVALID_PARAMS;
2475
2476 /* Mark the information as received */
2477 smp->remote_key_dist &= ~SMP_DIST_ID_KEY;
2478
2479 if (smp->remote_key_dist & SMP_DIST_SIGN)
2480 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2481
2482 skb_pull(skb, sizeof(*info));
2483
2484 /* Strictly speaking the Core Specification (4.1) allows sending
2485 * an empty address which would force us to rely on just the IRK
2486 * as "identity information". However, since such
2487 * implementations are not known of and in order to not over
2488 * complicate our implementation, simply pretend that we never
2489 * received an IRK for such a device.
2490 *
2491 * The Identity Address must also be a Static Random or Public
2492 * Address, which hci_is_identity_address() checks for.
2493 */
2494 if (!bacmp(&info->bdaddr, BDADDR_ANY) ||
2495 !hci_is_identity_address(&info->bdaddr, info->addr_type)) {
2496 BT_ERR("Ignoring IRK with no identity address");
2497 goto distribute;
2498 }
2499
2500 bacpy(&smp->id_addr, &info->bdaddr);
2501 smp->id_addr_type = info->addr_type;
2502
2503 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type))
2504 bacpy(&rpa, &hcon->dst);
2505 else
2506 bacpy(&rpa, BDADDR_ANY);
2507
2508 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr,
2509 smp->id_addr_type, smp->irk, &rpa);
2510
2511distribute:
2512 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2513 smp_distribute_keys(smp);
2514
2515 return 0;
2516}
2517
2518static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb)
2519{
2520 struct smp_cmd_sign_info *rp = (void *) skb->data;
2521 struct l2cap_chan *chan = conn->smp;
2522 struct smp_chan *smp = chan->data;
2523 struct smp_csrk *csrk;
2524
2525 BT_DBG("conn %p", conn);
2526
2527 if (skb->len < sizeof(*rp))
2528 return SMP_INVALID_PARAMS;
2529
2530 /* Mark the information as received */
2531 smp->remote_key_dist &= ~SMP_DIST_SIGN;
2532
2533 skb_pull(skb, sizeof(*rp));
2534
2535 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
2536 if (csrk) {
2537 if (conn->hcon->sec_level > BT_SECURITY_MEDIUM)
2538 csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED;
2539 else
2540 csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED;
2541 memcpy(csrk->val, rp->csrk, sizeof(csrk->val));
2542 }
2543 smp->csrk = csrk;
2544 smp_distribute_keys(smp);
2545
2546 return 0;
2547}
2548
2549static u8 sc_select_method(struct smp_chan *smp)
2550{
2551 struct l2cap_conn *conn = smp->conn;
2552 struct hci_conn *hcon = conn->hcon;
2553 struct smp_cmd_pairing *local, *remote;
2554 u8 local_mitm, remote_mitm, local_io, remote_io, method;
2555
2556 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) ||
2557 test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags))
2558 return REQ_OOB;
2559
2560 /* The preq/prsp contain the raw Pairing Request/Response PDUs
2561 * which are needed as inputs to some crypto functions. To get
2562 * the "struct smp_cmd_pairing" from them we need to skip the
2563 * first byte which contains the opcode.
2564 */
2565 if (hcon->out) {
2566 local = (void *) &smp->preq[1];
2567 remote = (void *) &smp->prsp[1];
2568 } else {
2569 local = (void *) &smp->prsp[1];
2570 remote = (void *) &smp->preq[1];
2571 }
2572
2573 local_io = local->io_capability;
2574 remote_io = remote->io_capability;
2575
2576 local_mitm = (local->auth_req & SMP_AUTH_MITM);
2577 remote_mitm = (remote->auth_req & SMP_AUTH_MITM);
2578
2579 /* If either side wants MITM, look up the method from the table,
2580 * otherwise use JUST WORKS.
2581 */
2582 if (local_mitm || remote_mitm)
2583 method = get_auth_method(smp, local_io, remote_io);
2584 else
2585 method = JUST_WORKS;
2586
2587 /* Don't confirm locally initiated pairing attempts */
2588 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2589 method = JUST_WORKS;
2590
2591 return method;
2592}
2593
2594static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb)
2595{
2596 struct smp_cmd_public_key *key = (void *) skb->data;
2597 struct hci_conn *hcon = conn->hcon;
2598 struct l2cap_chan *chan = conn->smp;
2599 struct smp_chan *smp = chan->data;
2600 struct hci_dev *hdev = hcon->hdev;
2601 struct smp_cmd_pairing_confirm cfm;
2602 int err;
2603
2604 BT_DBG("conn %p", conn);
2605
2606 if (skb->len < sizeof(*key))
2607 return SMP_INVALID_PARAMS;
2608
2609 memcpy(smp->remote_pk, key, 64);
2610
2611 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) {
2612 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk,
2613 smp->rr, 0, cfm.confirm_val);
2614 if (err)
2615 return SMP_UNSPECIFIED;
2616
2617 if (memcmp(cfm.confirm_val, smp->pcnf, 16))
2618 return SMP_CONFIRM_FAILED;
2619 }
2620
2621 /* Non-initiating device sends its public key after receiving
2622 * the key from the initiating device.
2623 */
2624 if (!hcon->out) {
2625 err = sc_send_public_key(smp);
2626 if (err)
2627 return err;
2628 }
2629
2630 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk);
2631 SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32);
2632
2633 if (!ecdh_shared_secret(smp->remote_pk, smp->local_sk, smp->dhkey))
2634 return SMP_UNSPECIFIED;
2635
2636 SMP_DBG("DHKey %32phN", smp->dhkey);
2637
2638 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags);
2639
2640 smp->method = sc_select_method(smp);
2641
2642 BT_DBG("%s selected method 0x%02x", hdev->name, smp->method);
2643
2644 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */
2645 if (smp->method == JUST_WORKS || smp->method == JUST_CFM)
2646 hcon->pending_sec_level = BT_SECURITY_MEDIUM;
2647 else
2648 hcon->pending_sec_level = BT_SECURITY_FIPS;
2649
2650 if (!memcmp(debug_pk, smp->remote_pk, 64))
2651 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
2652
2653 if (smp->method == DSP_PASSKEY) {
2654 get_random_bytes(&hcon->passkey_notify,
2655 sizeof(hcon->passkey_notify));
2656 hcon->passkey_notify %= 1000000;
2657 hcon->passkey_entered = 0;
2658 smp->passkey_round = 0;
2659 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type,
2660 hcon->dst_type,
2661 hcon->passkey_notify,
2662 hcon->passkey_entered))
2663 return SMP_UNSPECIFIED;
2664 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2665 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY);
2666 }
2667
2668 if (smp->method == REQ_OOB) {
2669 if (hcon->out)
2670 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2671 sizeof(smp->prnd), smp->prnd);
2672
2673 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2674
2675 return 0;
2676 }
2677
2678 if (hcon->out)
2679 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2680
2681 if (smp->method == REQ_PASSKEY) {
2682 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type,
2683 hcon->dst_type))
2684 return SMP_UNSPECIFIED;
2685 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2686 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2687 return 0;
2688 }
2689
2690 /* The Initiating device waits for the non-initiating device to
2691 * send the confirm value.
2692 */
2693 if (conn->hcon->out)
2694 return 0;
2695
2696 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd,
2697 0, cfm.confirm_val);
2698 if (err)
2699 return SMP_UNSPECIFIED;
2700
2701 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
2702 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2703
2704 return 0;
2705}
2706
2707static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb)
2708{
2709 struct smp_cmd_dhkey_check *check = (void *) skb->data;
2710 struct l2cap_chan *chan = conn->smp;
2711 struct hci_conn *hcon = conn->hcon;
2712 struct smp_chan *smp = chan->data;
2713 u8 a[7], b[7], *local_addr, *remote_addr;
2714 u8 io_cap[3], r[16], e[16];
2715 int err;
2716
2717 BT_DBG("conn %p", conn);
2718
2719 if (skb->len < sizeof(*check))
2720 return SMP_INVALID_PARAMS;
2721
2722 memcpy(a, &hcon->init_addr, 6);
2723 memcpy(b, &hcon->resp_addr, 6);
2724 a[6] = hcon->init_addr_type;
2725 b[6] = hcon->resp_addr_type;
2726
2727 if (hcon->out) {
2728 local_addr = a;
2729 remote_addr = b;
2730 memcpy(io_cap, &smp->prsp[1], 3);
2731 } else {
2732 local_addr = b;
2733 remote_addr = a;
2734 memcpy(io_cap, &smp->preq[1], 3);
2735 }
2736
2737 memset(r, 0, sizeof(r));
2738
2739 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2740 put_unaligned_le32(hcon->passkey_notify, r);
2741 else if (smp->method == REQ_OOB)
2742 memcpy(r, smp->lr, 16);
2743
2744 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r,
2745 io_cap, remote_addr, local_addr, e);
2746 if (err)
2747 return SMP_UNSPECIFIED;
2748
2749 if (memcmp(check->e, e, 16))
2750 return SMP_DHKEY_CHECK_FAILED;
2751
2752 if (!hcon->out) {
2753 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
2754 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags);
2755 return 0;
2756 }
2757
2758 /* Slave sends DHKey check as response to master */
2759 sc_dhkey_check(smp);
2760 }
2761
2762 sc_add_ltk(smp);
2763
2764 if (hcon->out) {
2765 hci_le_start_enc(hcon, 0, 0, smp->tk, smp->enc_key_size);
2766 hcon->enc_key_size = smp->enc_key_size;
2767 }
2768
2769 return 0;
2770}
2771
2772static int smp_cmd_keypress_notify(struct l2cap_conn *conn,
2773 struct sk_buff *skb)
2774{
2775 struct smp_cmd_keypress_notify *kp = (void *) skb->data;
2776
2777 BT_DBG("value 0x%02x", kp->value);
2778
2779 return 0;
2780}
2781
2782static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb)
2783{
2784 struct l2cap_conn *conn = chan->conn;
2785 struct hci_conn *hcon = conn->hcon;
2786 struct smp_chan *smp;
2787 __u8 code, reason;
2788 int err = 0;
2789
2790 if (skb->len < 1)
2791 return -EILSEQ;
2792
2793 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) {
2794 reason = SMP_PAIRING_NOTSUPP;
2795 goto done;
2796 }
2797
2798 code = skb->data[0];
2799 skb_pull(skb, sizeof(code));
2800
2801 smp = chan->data;
2802
2803 if (code > SMP_CMD_MAX)
2804 goto drop;
2805
2806 if (smp && !test_and_clear_bit(code, &smp->allow_cmd))
2807 goto drop;
2808
2809 /* If we don't have a context the only allowed commands are
2810 * pairing request and security request.
2811 */
2812 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ)
2813 goto drop;
2814
2815 switch (code) {
2816 case SMP_CMD_PAIRING_REQ:
2817 reason = smp_cmd_pairing_req(conn, skb);
2818 break;
2819
2820 case SMP_CMD_PAIRING_FAIL:
2821 smp_failure(conn, 0);
2822 err = -EPERM;
2823 break;
2824
2825 case SMP_CMD_PAIRING_RSP:
2826 reason = smp_cmd_pairing_rsp(conn, skb);
2827 break;
2828
2829 case SMP_CMD_SECURITY_REQ:
2830 reason = smp_cmd_security_req(conn, skb);
2831 break;
2832
2833 case SMP_CMD_PAIRING_CONFIRM:
2834 reason = smp_cmd_pairing_confirm(conn, skb);
2835 break;
2836
2837 case SMP_CMD_PAIRING_RANDOM:
2838 reason = smp_cmd_pairing_random(conn, skb);
2839 break;
2840
2841 case SMP_CMD_ENCRYPT_INFO:
2842 reason = smp_cmd_encrypt_info(conn, skb);
2843 break;
2844
2845 case SMP_CMD_MASTER_IDENT:
2846 reason = smp_cmd_master_ident(conn, skb);
2847 break;
2848
2849 case SMP_CMD_IDENT_INFO:
2850 reason = smp_cmd_ident_info(conn, skb);
2851 break;
2852
2853 case SMP_CMD_IDENT_ADDR_INFO:
2854 reason = smp_cmd_ident_addr_info(conn, skb);
2855 break;
2856
2857 case SMP_CMD_SIGN_INFO:
2858 reason = smp_cmd_sign_info(conn, skb);
2859 break;
2860
2861 case SMP_CMD_PUBLIC_KEY:
2862 reason = smp_cmd_public_key(conn, skb);
2863 break;
2864
2865 case SMP_CMD_DHKEY_CHECK:
2866 reason = smp_cmd_dhkey_check(conn, skb);
2867 break;
2868
2869 case SMP_CMD_KEYPRESS_NOTIFY:
2870 reason = smp_cmd_keypress_notify(conn, skb);
2871 break;
2872
2873 default:
2874 BT_DBG("Unknown command code 0x%2.2x", code);
2875 reason = SMP_CMD_NOTSUPP;
2876 goto done;
2877 }
2878
2879done:
2880 if (!err) {
2881 if (reason)
2882 smp_failure(conn, reason);
2883 kfree_skb(skb);
2884 }
2885
2886 return err;
2887
2888drop:
2889 BT_ERR("%s unexpected SMP command 0x%02x from %pMR", hcon->hdev->name,
2890 code, &hcon->dst);
2891 kfree_skb(skb);
2892 return 0;
2893}
2894
2895static void smp_teardown_cb(struct l2cap_chan *chan, int err)
2896{
2897 struct l2cap_conn *conn = chan->conn;
2898
2899 BT_DBG("chan %p", chan);
2900
2901 if (chan->data)
2902 smp_chan_destroy(conn);
2903
2904 conn->smp = NULL;
2905 l2cap_chan_put(chan);
2906}
2907
2908static void bredr_pairing(struct l2cap_chan *chan)
2909{
2910 struct l2cap_conn *conn = chan->conn;
2911 struct hci_conn *hcon = conn->hcon;
2912 struct hci_dev *hdev = hcon->hdev;
2913 struct smp_cmd_pairing req;
2914 struct smp_chan *smp;
2915
2916 BT_DBG("chan %p", chan);
2917
2918 /* Only new pairings are interesting */
2919 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags))
2920 return;
2921
2922 /* Don't bother if we're not encrypted */
2923 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
2924 return;
2925
2926 /* Only master may initiate SMP over BR/EDR */
2927 if (hcon->role != HCI_ROLE_MASTER)
2928 return;
2929
2930 /* Secure Connections support must be enabled */
2931 if (!hci_dev_test_flag(hdev, HCI_SC_ENABLED))
2932 return;
2933
2934 /* BR/EDR must use Secure Connections for SMP */
2935 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) &&
2936 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
2937 return;
2938
2939 /* If our LE support is not enabled don't do anything */
2940 if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED))
2941 return;
2942
2943 /* Don't bother if remote LE support is not enabled */
2944 if (!lmp_host_le_capable(hcon))
2945 return;
2946
2947 /* Remote must support SMP fixed chan for BR/EDR */
2948 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR))
2949 return;
2950
2951 /* Don't bother if SMP is already ongoing */
2952 if (chan->data)
2953 return;
2954
2955 smp = smp_chan_create(conn);
2956 if (!smp) {
2957 BT_ERR("%s unable to create SMP context for BR/EDR",
2958 hdev->name);
2959 return;
2960 }
2961
2962 set_bit(SMP_FLAG_SC, &smp->flags);
2963
2964 BT_DBG("%s starting SMP over BR/EDR", hdev->name);
2965
2966 /* Prepare and send the BR/EDR SMP Pairing Request */
2967 build_bredr_pairing_cmd(smp, &req, NULL);
2968
2969 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2970 memcpy(&smp->preq[1], &req, sizeof(req));
2971
2972 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(req), &req);
2973 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2974}
2975
2976static void smp_resume_cb(struct l2cap_chan *chan)
2977{
2978 struct smp_chan *smp = chan->data;
2979 struct l2cap_conn *conn = chan->conn;
2980 struct hci_conn *hcon = conn->hcon;
2981
2982 BT_DBG("chan %p", chan);
2983
2984 if (hcon->type == ACL_LINK) {
2985 bredr_pairing(chan);
2986 return;
2987 }
2988
2989 if (!smp)
2990 return;
2991
2992 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
2993 return;
2994
2995 cancel_delayed_work(&smp->security_timer);
2996
2997 smp_distribute_keys(smp);
2998}
2999
3000static void smp_ready_cb(struct l2cap_chan *chan)
3001{
3002 struct l2cap_conn *conn = chan->conn;
3003 struct hci_conn *hcon = conn->hcon;
3004
3005 BT_DBG("chan %p", chan);
3006
3007 /* No need to call l2cap_chan_hold() here since we already own
3008 * the reference taken in smp_new_conn_cb(). This is just the
3009 * first time that we tie it to a specific pointer. The code in
3010 * l2cap_core.c ensures that there's no risk this function wont
3011 * get called if smp_new_conn_cb was previously called.
3012 */
3013 conn->smp = chan;
3014
3015 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3016 bredr_pairing(chan);
3017}
3018
3019static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
3020{
3021 int err;
3022
3023 BT_DBG("chan %p", chan);
3024
3025 err = smp_sig_channel(chan, skb);
3026 if (err) {
3027 struct smp_chan *smp = chan->data;
3028
3029 if (smp)
3030 cancel_delayed_work_sync(&smp->security_timer);
3031
3032 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE);
3033 }
3034
3035 return err;
3036}
3037
3038static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan,
3039 unsigned long hdr_len,
3040 unsigned long len, int nb)
3041{
3042 struct sk_buff *skb;
3043
3044 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL);
3045 if (!skb)
3046 return ERR_PTR(-ENOMEM);
3047
3048 skb->priority = HCI_PRIO_MAX;
3049 bt_cb(skb)->l2cap.chan = chan;
3050
3051 return skb;
3052}
3053
3054static const struct l2cap_ops smp_chan_ops = {
3055 .name = "Security Manager",
3056 .ready = smp_ready_cb,
3057 .recv = smp_recv_cb,
3058 .alloc_skb = smp_alloc_skb_cb,
3059 .teardown = smp_teardown_cb,
3060 .resume = smp_resume_cb,
3061
3062 .new_connection = l2cap_chan_no_new_connection,
3063 .state_change = l2cap_chan_no_state_change,
3064 .close = l2cap_chan_no_close,
3065 .defer = l2cap_chan_no_defer,
3066 .suspend = l2cap_chan_no_suspend,
3067 .set_shutdown = l2cap_chan_no_set_shutdown,
3068 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
3069};
3070
3071static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan)
3072{
3073 struct l2cap_chan *chan;
3074
3075 BT_DBG("pchan %p", pchan);
3076
3077 chan = l2cap_chan_create();
3078 if (!chan)
3079 return NULL;
3080
3081 chan->chan_type = pchan->chan_type;
3082 chan->ops = &smp_chan_ops;
3083 chan->scid = pchan->scid;
3084 chan->dcid = chan->scid;
3085 chan->imtu = pchan->imtu;
3086 chan->omtu = pchan->omtu;
3087 chan->mode = pchan->mode;
3088
3089 /* Other L2CAP channels may request SMP routines in order to
3090 * change the security level. This means that the SMP channel
3091 * lock must be considered in its own category to avoid lockdep
3092 * warnings.
3093 */
3094 atomic_set(&chan->nesting, L2CAP_NESTING_SMP);
3095
3096 BT_DBG("created chan %p", chan);
3097
3098 return chan;
3099}
3100
3101static const struct l2cap_ops smp_root_chan_ops = {
3102 .name = "Security Manager Root",
3103 .new_connection = smp_new_conn_cb,
3104
3105 /* None of these are implemented for the root channel */
3106 .close = l2cap_chan_no_close,
3107 .alloc_skb = l2cap_chan_no_alloc_skb,
3108 .recv = l2cap_chan_no_recv,
3109 .state_change = l2cap_chan_no_state_change,
3110 .teardown = l2cap_chan_no_teardown,
3111 .ready = l2cap_chan_no_ready,
3112 .defer = l2cap_chan_no_defer,
3113 .suspend = l2cap_chan_no_suspend,
3114 .resume = l2cap_chan_no_resume,
3115 .set_shutdown = l2cap_chan_no_set_shutdown,
3116 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
3117};
3118
3119static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid)
3120{
3121 struct l2cap_chan *chan;
3122 struct smp_dev *smp;
3123 struct crypto_skcipher *tfm_aes;
3124 struct crypto_shash *tfm_cmac;
3125
3126 if (cid == L2CAP_CID_SMP_BREDR) {
3127 smp = NULL;
3128 goto create_chan;
3129 }
3130
3131 smp = kzalloc(sizeof(*smp), GFP_KERNEL);
3132 if (!smp)
3133 return ERR_PTR(-ENOMEM);
3134
3135 tfm_aes = crypto_alloc_skcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);
3136 if (IS_ERR(tfm_aes)) {
3137 BT_ERR("Unable to create ECB crypto context");
3138 kzfree(smp);
3139 return ERR_CAST(tfm_aes);
3140 }
3141
3142 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
3143 if (IS_ERR(tfm_cmac)) {
3144 BT_ERR("Unable to create CMAC crypto context");
3145 crypto_free_skcipher(tfm_aes);
3146 kzfree(smp);
3147 return ERR_CAST(tfm_cmac);
3148 }
3149
3150 smp->tfm_aes = tfm_aes;
3151 smp->tfm_cmac = tfm_cmac;
3152 smp->min_key_size = SMP_MIN_ENC_KEY_SIZE;
3153 smp->max_key_size = SMP_MAX_ENC_KEY_SIZE;
3154
3155create_chan:
3156 chan = l2cap_chan_create();
3157 if (!chan) {
3158 if (smp) {
3159 crypto_free_skcipher(smp->tfm_aes);
3160 crypto_free_shash(smp->tfm_cmac);
3161 kzfree(smp);
3162 }
3163 return ERR_PTR(-ENOMEM);
3164 }
3165
3166 chan->data = smp;
3167
3168 l2cap_add_scid(chan, cid);
3169
3170 l2cap_chan_set_defaults(chan);
3171
3172 if (cid == L2CAP_CID_SMP) {
3173 u8 bdaddr_type;
3174
3175 hci_copy_identity_address(hdev, &chan->src, &bdaddr_type);
3176
3177 if (bdaddr_type == ADDR_LE_DEV_PUBLIC)
3178 chan->src_type = BDADDR_LE_PUBLIC;
3179 else
3180 chan->src_type = BDADDR_LE_RANDOM;
3181 } else {
3182 bacpy(&chan->src, &hdev->bdaddr);
3183 chan->src_type = BDADDR_BREDR;
3184 }
3185
3186 chan->state = BT_LISTEN;
3187 chan->mode = L2CAP_MODE_BASIC;
3188 chan->imtu = L2CAP_DEFAULT_MTU;
3189 chan->ops = &smp_root_chan_ops;
3190
3191 /* Set correct nesting level for a parent/listening channel */
3192 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
3193
3194 return chan;
3195}
3196
3197static void smp_del_chan(struct l2cap_chan *chan)
3198{
3199 struct smp_dev *smp;
3200
3201 BT_DBG("chan %p", chan);
3202
3203 smp = chan->data;
3204 if (smp) {
3205 chan->data = NULL;
3206 crypto_free_skcipher(smp->tfm_aes);
3207 crypto_free_shash(smp->tfm_cmac);
3208 kzfree(smp);
3209 }
3210
3211 l2cap_chan_put(chan);
3212}
3213
3214static ssize_t force_bredr_smp_read(struct file *file,
3215 char __user *user_buf,
3216 size_t count, loff_t *ppos)
3217{
3218 struct hci_dev *hdev = file->private_data;
3219 char buf[3];
3220
3221 buf[0] = hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP) ? 'Y': 'N';
3222 buf[1] = '\n';
3223 buf[2] = '\0';
3224 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
3225}
3226
3227static ssize_t force_bredr_smp_write(struct file *file,
3228 const char __user *user_buf,
3229 size_t count, loff_t *ppos)
3230{
3231 struct hci_dev *hdev = file->private_data;
3232 char buf[32];
3233 size_t buf_size = min(count, (sizeof(buf)-1));
3234 bool enable;
3235
3236 if (copy_from_user(buf, user_buf, buf_size))
3237 return -EFAULT;
3238
3239 buf[buf_size] = '\0';
3240 if (strtobool(buf, &enable))
3241 return -EINVAL;
3242
3243 if (enable == hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3244 return -EALREADY;
3245
3246 if (enable) {
3247 struct l2cap_chan *chan;
3248
3249 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
3250 if (IS_ERR(chan))
3251 return PTR_ERR(chan);
3252
3253 hdev->smp_bredr_data = chan;
3254 } else {
3255 struct l2cap_chan *chan;
3256
3257 chan = hdev->smp_bredr_data;
3258 hdev->smp_bredr_data = NULL;
3259 smp_del_chan(chan);
3260 }
3261
3262 hci_dev_change_flag(hdev, HCI_FORCE_BREDR_SMP);
3263
3264 return count;
3265}
3266
3267static const struct file_operations force_bredr_smp_fops = {
3268 .open = simple_open,
3269 .read = force_bredr_smp_read,
3270 .write = force_bredr_smp_write,
3271 .llseek = default_llseek,
3272};
3273
3274static ssize_t le_min_key_size_read(struct file *file,
3275 char __user *user_buf,
3276 size_t count, loff_t *ppos)
3277{
3278 struct hci_dev *hdev = file->private_data;
3279 char buf[4];
3280
3281 snprintf(buf, sizeof(buf), "%2u\n", SMP_DEV(hdev)->min_key_size);
3282
3283 return simple_read_from_buffer(user_buf, count, ppos, buf, strlen(buf));
3284}
3285
3286static ssize_t le_min_key_size_write(struct file *file,
3287 const char __user *user_buf,
3288 size_t count, loff_t *ppos)
3289{
3290 struct hci_dev *hdev = file->private_data;
3291 char buf[32];
3292 size_t buf_size = min(count, (sizeof(buf) - 1));
3293 u8 key_size;
3294
3295 if (copy_from_user(buf, user_buf, buf_size))
3296 return -EFAULT;
3297
3298 buf[buf_size] = '\0';
3299
3300 sscanf(buf, "%hhu", &key_size);
3301
3302 if (key_size > SMP_DEV(hdev)->max_key_size ||
3303 key_size < SMP_MIN_ENC_KEY_SIZE)
3304 return -EINVAL;
3305
3306 SMP_DEV(hdev)->min_key_size = key_size;
3307
3308 return count;
3309}
3310
3311static const struct file_operations le_min_key_size_fops = {
3312 .open = simple_open,
3313 .read = le_min_key_size_read,
3314 .write = le_min_key_size_write,
3315 .llseek = default_llseek,
3316};
3317
3318static ssize_t le_max_key_size_read(struct file *file,
3319 char __user *user_buf,
3320 size_t count, loff_t *ppos)
3321{
3322 struct hci_dev *hdev = file->private_data;
3323 char buf[4];
3324
3325 snprintf(buf, sizeof(buf), "%2u\n", SMP_DEV(hdev)->max_key_size);
3326
3327 return simple_read_from_buffer(user_buf, count, ppos, buf, strlen(buf));
3328}
3329
3330static ssize_t le_max_key_size_write(struct file *file,
3331 const char __user *user_buf,
3332 size_t count, loff_t *ppos)
3333{
3334 struct hci_dev *hdev = file->private_data;
3335 char buf[32];
3336 size_t buf_size = min(count, (sizeof(buf) - 1));
3337 u8 key_size;
3338
3339 if (copy_from_user(buf, user_buf, buf_size))
3340 return -EFAULT;
3341
3342 buf[buf_size] = '\0';
3343
3344 sscanf(buf, "%hhu", &key_size);
3345
3346 if (key_size > SMP_MAX_ENC_KEY_SIZE ||
3347 key_size < SMP_DEV(hdev)->min_key_size)
3348 return -EINVAL;
3349
3350 SMP_DEV(hdev)->max_key_size = key_size;
3351
3352 return count;
3353}
3354
3355static const struct file_operations le_max_key_size_fops = {
3356 .open = simple_open,
3357 .read = le_max_key_size_read,
3358 .write = le_max_key_size_write,
3359 .llseek = default_llseek,
3360};
3361
3362int smp_register(struct hci_dev *hdev)
3363{
3364 struct l2cap_chan *chan;
3365
3366 BT_DBG("%s", hdev->name);
3367
3368 /* If the controller does not support Low Energy operation, then
3369 * there is also no need to register any SMP channel.
3370 */
3371 if (!lmp_le_capable(hdev))
3372 return 0;
3373
3374 if (WARN_ON(hdev->smp_data)) {
3375 chan = hdev->smp_data;
3376 hdev->smp_data = NULL;
3377 smp_del_chan(chan);
3378 }
3379
3380 chan = smp_add_cid(hdev, L2CAP_CID_SMP);
3381 if (IS_ERR(chan))
3382 return PTR_ERR(chan);
3383
3384 hdev->smp_data = chan;
3385
3386 debugfs_create_file("le_min_key_size", 0644, hdev->debugfs, hdev,
3387 &le_min_key_size_fops);
3388 debugfs_create_file("le_max_key_size", 0644, hdev->debugfs, hdev,
3389 &le_max_key_size_fops);
3390
3391 /* If the controller does not support BR/EDR Secure Connections
3392 * feature, then the BR/EDR SMP channel shall not be present.
3393 *
3394 * To test this with Bluetooth 4.0 controllers, create a debugfs
3395 * switch that allows forcing BR/EDR SMP support and accepting
3396 * cross-transport pairing on non-AES encrypted connections.
3397 */
3398 if (!lmp_sc_capable(hdev)) {
3399 debugfs_create_file("force_bredr_smp", 0644, hdev->debugfs,
3400 hdev, &force_bredr_smp_fops);
3401 return 0;
3402 }
3403
3404 if (WARN_ON(hdev->smp_bredr_data)) {
3405 chan = hdev->smp_bredr_data;
3406 hdev->smp_bredr_data = NULL;
3407 smp_del_chan(chan);
3408 }
3409
3410 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
3411 if (IS_ERR(chan)) {
3412 int err = PTR_ERR(chan);
3413 chan = hdev->smp_data;
3414 hdev->smp_data = NULL;
3415 smp_del_chan(chan);
3416 return err;
3417 }
3418
3419 hdev->smp_bredr_data = chan;
3420
3421 return 0;
3422}
3423
3424void smp_unregister(struct hci_dev *hdev)
3425{
3426 struct l2cap_chan *chan;
3427
3428 if (hdev->smp_bredr_data) {
3429 chan = hdev->smp_bredr_data;
3430 hdev->smp_bredr_data = NULL;
3431 smp_del_chan(chan);
3432 }
3433
3434 if (hdev->smp_data) {
3435 chan = hdev->smp_data;
3436 hdev->smp_data = NULL;
3437 smp_del_chan(chan);
3438 }
3439}
3440
3441#if IS_ENABLED(CONFIG_BT_SELFTEST_SMP)
3442
3443static int __init test_ah(struct crypto_skcipher *tfm_aes)
3444{
3445 const u8 irk[16] = {
3446 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3447 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3448 const u8 r[3] = { 0x94, 0x81, 0x70 };
3449 const u8 exp[3] = { 0xaa, 0xfb, 0x0d };
3450 u8 res[3];
3451 int err;
3452
3453 err = smp_ah(tfm_aes, irk, r, res);
3454 if (err)
3455 return err;
3456
3457 if (memcmp(res, exp, 3))
3458 return -EINVAL;
3459
3460 return 0;
3461}
3462
3463static int __init test_c1(struct crypto_skcipher *tfm_aes)
3464{
3465 const u8 k[16] = {
3466 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
3467 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
3468 const u8 r[16] = {
3469 0xe0, 0x2e, 0x70, 0xc6, 0x4e, 0x27, 0x88, 0x63,
3470 0x0e, 0x6f, 0xad, 0x56, 0x21, 0xd5, 0x83, 0x57 };
3471 const u8 preq[7] = { 0x01, 0x01, 0x00, 0x00, 0x10, 0x07, 0x07 };
3472 const u8 pres[7] = { 0x02, 0x03, 0x00, 0x00, 0x08, 0x00, 0x05 };
3473 const u8 _iat = 0x01;
3474 const u8 _rat = 0x00;
3475 const bdaddr_t ra = { { 0xb6, 0xb5, 0xb4, 0xb3, 0xb2, 0xb1 } };
3476 const bdaddr_t ia = { { 0xa6, 0xa5, 0xa4, 0xa3, 0xa2, 0xa1 } };
3477 const u8 exp[16] = {
3478 0x86, 0x3b, 0xf1, 0xbe, 0xc5, 0x4d, 0xa7, 0xd2,
3479 0xea, 0x88, 0x89, 0x87, 0xef, 0x3f, 0x1e, 0x1e };
3480 u8 res[16];
3481 int err;
3482
3483 err = smp_c1(tfm_aes, k, r, preq, pres, _iat, &ia, _rat, &ra, res);
3484 if (err)
3485 return err;
3486
3487 if (memcmp(res, exp, 16))
3488 return -EINVAL;
3489
3490 return 0;
3491}
3492
3493static int __init test_s1(struct crypto_skcipher *tfm_aes)
3494{
3495 const u8 k[16] = {
3496 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
3497 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
3498 const u8 r1[16] = {
3499 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 };
3500 const u8 r2[16] = {
3501 0x00, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99 };
3502 const u8 exp[16] = {
3503 0x62, 0xa0, 0x6d, 0x79, 0xae, 0x16, 0x42, 0x5b,
3504 0x9b, 0xf4, 0xb0, 0xe8, 0xf0, 0xe1, 0x1f, 0x9a };
3505 u8 res[16];
3506 int err;
3507
3508 err = smp_s1(tfm_aes, k, r1, r2, res);
3509 if (err)
3510 return err;
3511
3512 if (memcmp(res, exp, 16))
3513 return -EINVAL;
3514
3515 return 0;
3516}
3517
3518static int __init test_f4(struct crypto_shash *tfm_cmac)
3519{
3520 const u8 u[32] = {
3521 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
3522 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
3523 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
3524 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 };
3525 const u8 v[32] = {
3526 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b,
3527 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59,
3528 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90,
3529 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 };
3530 const u8 x[16] = {
3531 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3532 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3533 const u8 z = 0x00;
3534 const u8 exp[16] = {
3535 0x2d, 0x87, 0x74, 0xa9, 0xbe, 0xa1, 0xed, 0xf1,
3536 0x1c, 0xbd, 0xa9, 0x07, 0xf1, 0x16, 0xc9, 0xf2 };
3537 u8 res[16];
3538 int err;
3539
3540 err = smp_f4(tfm_cmac, u, v, x, z, res);
3541 if (err)
3542 return err;
3543
3544 if (memcmp(res, exp, 16))
3545 return -EINVAL;
3546
3547 return 0;
3548}
3549
3550static int __init test_f5(struct crypto_shash *tfm_cmac)
3551{
3552 const u8 w[32] = {
3553 0x98, 0xa6, 0xbf, 0x73, 0xf3, 0x34, 0x8d, 0x86,
3554 0xf1, 0x66, 0xf8, 0xb4, 0x13, 0x6b, 0x79, 0x99,
3555 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3556 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3557 const u8 n1[16] = {
3558 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3559 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3560 const u8 n2[16] = {
3561 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3562 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3563 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 };
3564 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 };
3565 const u8 exp_ltk[16] = {
3566 0x38, 0x0a, 0x75, 0x94, 0xb5, 0x22, 0x05, 0x98,
3567 0x23, 0xcd, 0xd7, 0x69, 0x11, 0x79, 0x86, 0x69 };
3568 const u8 exp_mackey[16] = {
3569 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd,
3570 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 };
3571 u8 mackey[16], ltk[16];
3572 int err;
3573
3574 err = smp_f5(tfm_cmac, w, n1, n2, a1, a2, mackey, ltk);
3575 if (err)
3576 return err;
3577
3578 if (memcmp(mackey, exp_mackey, 16))
3579 return -EINVAL;
3580
3581 if (memcmp(ltk, exp_ltk, 16))
3582 return -EINVAL;
3583
3584 return 0;
3585}
3586
3587static int __init test_f6(struct crypto_shash *tfm_cmac)
3588{
3589 const u8 w[16] = {
3590 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd,
3591 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 };
3592 const u8 n1[16] = {
3593 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3594 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3595 const u8 n2[16] = {
3596 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3597 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3598 const u8 r[16] = {
3599 0xc8, 0x0f, 0x2d, 0x0c, 0xd2, 0x42, 0xda, 0x08,
3600 0x54, 0xbb, 0x53, 0xb4, 0x3b, 0x34, 0xa3, 0x12 };
3601 const u8 io_cap[3] = { 0x02, 0x01, 0x01 };
3602 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 };
3603 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 };
3604 const u8 exp[16] = {
3605 0x61, 0x8f, 0x95, 0xda, 0x09, 0x0b, 0x6c, 0xd2,
3606 0xc5, 0xe8, 0xd0, 0x9c, 0x98, 0x73, 0xc4, 0xe3 };
3607 u8 res[16];
3608 int err;
3609
3610 err = smp_f6(tfm_cmac, w, n1, n2, r, io_cap, a1, a2, res);
3611 if (err)
3612 return err;
3613
3614 if (memcmp(res, exp, 16))
3615 return -EINVAL;
3616
3617 return 0;
3618}
3619
3620static int __init test_g2(struct crypto_shash *tfm_cmac)
3621{
3622 const u8 u[32] = {
3623 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
3624 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
3625 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
3626 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 };
3627 const u8 v[32] = {
3628 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b,
3629 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59,
3630 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90,
3631 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 };
3632 const u8 x[16] = {
3633 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3634 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3635 const u8 y[16] = {
3636 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3637 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3638 const u32 exp_val = 0x2f9ed5ba % 1000000;
3639 u32 val;
3640 int err;
3641
3642 err = smp_g2(tfm_cmac, u, v, x, y, &val);
3643 if (err)
3644 return err;
3645
3646 if (val != exp_val)
3647 return -EINVAL;
3648
3649 return 0;
3650}
3651
3652static int __init test_h6(struct crypto_shash *tfm_cmac)
3653{
3654 const u8 w[16] = {
3655 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3656 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3657 const u8 key_id[4] = { 0x72, 0x62, 0x65, 0x6c };
3658 const u8 exp[16] = {
3659 0x99, 0x63, 0xb1, 0x80, 0xe2, 0xa9, 0xd3, 0xe8,
3660 0x1c, 0xc9, 0x6d, 0xe7, 0x02, 0xe1, 0x9a, 0x2d };
3661 u8 res[16];
3662 int err;
3663
3664 err = smp_h6(tfm_cmac, w, key_id, res);
3665 if (err)
3666 return err;
3667
3668 if (memcmp(res, exp, 16))
3669 return -EINVAL;
3670
3671 return 0;
3672}
3673
3674static char test_smp_buffer[32];
3675
3676static ssize_t test_smp_read(struct file *file, char __user *user_buf,
3677 size_t count, loff_t *ppos)
3678{
3679 return simple_read_from_buffer(user_buf, count, ppos, test_smp_buffer,
3680 strlen(test_smp_buffer));
3681}
3682
3683static const struct file_operations test_smp_fops = {
3684 .open = simple_open,
3685 .read = test_smp_read,
3686 .llseek = default_llseek,
3687};
3688
3689static int __init run_selftests(struct crypto_skcipher *tfm_aes,
3690 struct crypto_shash *tfm_cmac)
3691{
3692 ktime_t calltime, delta, rettime;
3693 unsigned long long duration;
3694 int err;
3695
3696 calltime = ktime_get();
3697
3698 err = test_ah(tfm_aes);
3699 if (err) {
3700 BT_ERR("smp_ah test failed");
3701 goto done;
3702 }
3703
3704 err = test_c1(tfm_aes);
3705 if (err) {
3706 BT_ERR("smp_c1 test failed");
3707 goto done;
3708 }
3709
3710 err = test_s1(tfm_aes);
3711 if (err) {
3712 BT_ERR("smp_s1 test failed");
3713 goto done;
3714 }
3715
3716 err = test_f4(tfm_cmac);
3717 if (err) {
3718 BT_ERR("smp_f4 test failed");
3719 goto done;
3720 }
3721
3722 err = test_f5(tfm_cmac);
3723 if (err) {
3724 BT_ERR("smp_f5 test failed");
3725 goto done;
3726 }
3727
3728 err = test_f6(tfm_cmac);
3729 if (err) {
3730 BT_ERR("smp_f6 test failed");
3731 goto done;
3732 }
3733
3734 err = test_g2(tfm_cmac);
3735 if (err) {
3736 BT_ERR("smp_g2 test failed");
3737 goto done;
3738 }
3739
3740 err = test_h6(tfm_cmac);
3741 if (err) {
3742 BT_ERR("smp_h6 test failed");
3743 goto done;
3744 }
3745
3746 rettime = ktime_get();
3747 delta = ktime_sub(rettime, calltime);
3748 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
3749
3750 BT_INFO("SMP test passed in %llu usecs", duration);
3751
3752done:
3753 if (!err)
3754 snprintf(test_smp_buffer, sizeof(test_smp_buffer),
3755 "PASS (%llu usecs)\n", duration);
3756 else
3757 snprintf(test_smp_buffer, sizeof(test_smp_buffer), "FAIL\n");
3758
3759 debugfs_create_file("selftest_smp", 0444, bt_debugfs, NULL,
3760 &test_smp_fops);
3761
3762 return err;
3763}
3764
3765int __init bt_selftest_smp(void)
3766{
3767 struct crypto_skcipher *tfm_aes;
3768 struct crypto_shash *tfm_cmac;
3769 int err;
3770
3771 tfm_aes = crypto_alloc_skcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);
3772 if (IS_ERR(tfm_aes)) {
3773 BT_ERR("Unable to create ECB crypto context");
3774 return PTR_ERR(tfm_aes);
3775 }
3776
3777 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, CRYPTO_ALG_ASYNC);
3778 if (IS_ERR(tfm_cmac)) {
3779 BT_ERR("Unable to create CMAC crypto context");
3780 crypto_free_skcipher(tfm_aes);
3781 return PTR_ERR(tfm_cmac);
3782 }
3783
3784 err = run_selftests(tfm_aes, tfm_cmac);
3785
3786 crypto_free_shash(tfm_cmac);
3787 crypto_free_skcipher(tfm_aes);
3788
3789 return err;
3790}
3791
3792#endif
1/*
2 BlueZ - Bluetooth protocol stack for Linux
3 Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License version 2 as
7 published by the Free Software Foundation;
8
9 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
10 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
11 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
12 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
13 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
14 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17
18 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
19 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
20 SOFTWARE IS DISCLAIMED.
21*/
22
23#include <net/bluetooth/bluetooth.h>
24#include <net/bluetooth/hci_core.h>
25#include <net/bluetooth/l2cap.h>
26#include <net/bluetooth/mgmt.h>
27#include <net/bluetooth/smp.h>
28#include <linux/crypto.h>
29#include <linux/scatterlist.h>
30#include <crypto/b128ops.h>
31
32#define SMP_TIMEOUT msecs_to_jiffies(30000)
33
34static inline void swap128(u8 src[16], u8 dst[16])
35{
36 int i;
37 for (i = 0; i < 16; i++)
38 dst[15 - i] = src[i];
39}
40
41static inline void swap56(u8 src[7], u8 dst[7])
42{
43 int i;
44 for (i = 0; i < 7; i++)
45 dst[6 - i] = src[i];
46}
47
48static int smp_e(struct crypto_blkcipher *tfm, const u8 *k, u8 *r)
49{
50 struct blkcipher_desc desc;
51 struct scatterlist sg;
52 int err, iv_len;
53 unsigned char iv[128];
54
55 if (tfm == NULL) {
56 BT_ERR("tfm %p", tfm);
57 return -EINVAL;
58 }
59
60 desc.tfm = tfm;
61 desc.flags = 0;
62
63 err = crypto_blkcipher_setkey(tfm, k, 16);
64 if (err) {
65 BT_ERR("cipher setkey failed: %d", err);
66 return err;
67 }
68
69 sg_init_one(&sg, r, 16);
70
71 iv_len = crypto_blkcipher_ivsize(tfm);
72 if (iv_len) {
73 memset(&iv, 0xff, iv_len);
74 crypto_blkcipher_set_iv(tfm, iv, iv_len);
75 }
76
77 err = crypto_blkcipher_encrypt(&desc, &sg, &sg, 16);
78 if (err)
79 BT_ERR("Encrypt data error %d", err);
80
81 return err;
82}
83
84static int smp_c1(struct crypto_blkcipher *tfm, u8 k[16], u8 r[16],
85 u8 preq[7], u8 pres[7], u8 _iat, bdaddr_t *ia,
86 u8 _rat, bdaddr_t *ra, u8 res[16])
87{
88 u8 p1[16], p2[16];
89 int err;
90
91 memset(p1, 0, 16);
92
93 /* p1 = pres || preq || _rat || _iat */
94 swap56(pres, p1);
95 swap56(preq, p1 + 7);
96 p1[14] = _rat;
97 p1[15] = _iat;
98
99 memset(p2, 0, 16);
100
101 /* p2 = padding || ia || ra */
102 baswap((bdaddr_t *) (p2 + 4), ia);
103 baswap((bdaddr_t *) (p2 + 10), ra);
104
105 /* res = r XOR p1 */
106 u128_xor((u128 *) res, (u128 *) r, (u128 *) p1);
107
108 /* res = e(k, res) */
109 err = smp_e(tfm, k, res);
110 if (err) {
111 BT_ERR("Encrypt data error");
112 return err;
113 }
114
115 /* res = res XOR p2 */
116 u128_xor((u128 *) res, (u128 *) res, (u128 *) p2);
117
118 /* res = e(k, res) */
119 err = smp_e(tfm, k, res);
120 if (err)
121 BT_ERR("Encrypt data error");
122
123 return err;
124}
125
126static int smp_s1(struct crypto_blkcipher *tfm, u8 k[16],
127 u8 r1[16], u8 r2[16], u8 _r[16])
128{
129 int err;
130
131 /* Just least significant octets from r1 and r2 are considered */
132 memcpy(_r, r1 + 8, 8);
133 memcpy(_r + 8, r2 + 8, 8);
134
135 err = smp_e(tfm, k, _r);
136 if (err)
137 BT_ERR("Encrypt data error");
138
139 return err;
140}
141
142static int smp_rand(u8 *buf)
143{
144 get_random_bytes(buf, 16);
145
146 return 0;
147}
148
149static struct sk_buff *smp_build_cmd(struct l2cap_conn *conn, u8 code,
150 u16 dlen, void *data)
151{
152 struct sk_buff *skb;
153 struct l2cap_hdr *lh;
154 int len;
155
156 len = L2CAP_HDR_SIZE + sizeof(code) + dlen;
157
158 if (len > conn->mtu)
159 return NULL;
160
161 skb = bt_skb_alloc(len, GFP_ATOMIC);
162 if (!skb)
163 return NULL;
164
165 lh = (struct l2cap_hdr *) skb_put(skb, L2CAP_HDR_SIZE);
166 lh->len = cpu_to_le16(sizeof(code) + dlen);
167 lh->cid = cpu_to_le16(L2CAP_CID_SMP);
168
169 memcpy(skb_put(skb, sizeof(code)), &code, sizeof(code));
170
171 memcpy(skb_put(skb, dlen), data, dlen);
172
173 return skb;
174}
175
176static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
177{
178 struct sk_buff *skb = smp_build_cmd(conn, code, len, data);
179
180 BT_DBG("code 0x%2.2x", code);
181
182 if (!skb)
183 return;
184
185 skb->priority = HCI_PRIO_MAX;
186 hci_send_acl(conn->hchan, skb, 0);
187
188 cancel_delayed_work_sync(&conn->security_timer);
189 schedule_delayed_work(&conn->security_timer, SMP_TIMEOUT);
190}
191
192static __u8 authreq_to_seclevel(__u8 authreq)
193{
194 if (authreq & SMP_AUTH_MITM)
195 return BT_SECURITY_HIGH;
196 else
197 return BT_SECURITY_MEDIUM;
198}
199
200static __u8 seclevel_to_authreq(__u8 sec_level)
201{
202 switch (sec_level) {
203 case BT_SECURITY_HIGH:
204 return SMP_AUTH_MITM | SMP_AUTH_BONDING;
205 case BT_SECURITY_MEDIUM:
206 return SMP_AUTH_BONDING;
207 default:
208 return SMP_AUTH_NONE;
209 }
210}
211
212static void build_pairing_cmd(struct l2cap_conn *conn,
213 struct smp_cmd_pairing *req,
214 struct smp_cmd_pairing *rsp,
215 __u8 authreq)
216{
217 u8 dist_keys = 0;
218
219 if (test_bit(HCI_PAIRABLE, &conn->hcon->hdev->dev_flags)) {
220 dist_keys = SMP_DIST_ENC_KEY;
221 authreq |= SMP_AUTH_BONDING;
222 } else {
223 authreq &= ~SMP_AUTH_BONDING;
224 }
225
226 if (rsp == NULL) {
227 req->io_capability = conn->hcon->io_capability;
228 req->oob_flag = SMP_OOB_NOT_PRESENT;
229 req->max_key_size = SMP_MAX_ENC_KEY_SIZE;
230 req->init_key_dist = 0;
231 req->resp_key_dist = dist_keys;
232 req->auth_req = authreq;
233 return;
234 }
235
236 rsp->io_capability = conn->hcon->io_capability;
237 rsp->oob_flag = SMP_OOB_NOT_PRESENT;
238 rsp->max_key_size = SMP_MAX_ENC_KEY_SIZE;
239 rsp->init_key_dist = 0;
240 rsp->resp_key_dist = req->resp_key_dist & dist_keys;
241 rsp->auth_req = authreq;
242}
243
244static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)
245{
246 struct smp_chan *smp = conn->smp_chan;
247
248 if ((max_key_size > SMP_MAX_ENC_KEY_SIZE) ||
249 (max_key_size < SMP_MIN_ENC_KEY_SIZE))
250 return SMP_ENC_KEY_SIZE;
251
252 smp->enc_key_size = max_key_size;
253
254 return 0;
255}
256
257static void smp_failure(struct l2cap_conn *conn, u8 reason, u8 send)
258{
259 struct hci_conn *hcon = conn->hcon;
260
261 if (send)
262 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
263 &reason);
264
265 clear_bit(HCI_CONN_ENCRYPT_PEND, &conn->hcon->flags);
266 mgmt_auth_failed(conn->hcon->hdev, conn->dst, hcon->type,
267 hcon->dst_type, reason);
268
269 cancel_delayed_work_sync(&conn->security_timer);
270
271 if (test_and_clear_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->flags))
272 smp_chan_destroy(conn);
273}
274
275#define JUST_WORKS 0x00
276#define JUST_CFM 0x01
277#define REQ_PASSKEY 0x02
278#define CFM_PASSKEY 0x03
279#define REQ_OOB 0x04
280#define OVERLAP 0xFF
281
282static const u8 gen_method[5][5] = {
283 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
284 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
285 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
286 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
287 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP },
288};
289
290static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth,
291 u8 local_io, u8 remote_io)
292{
293 struct hci_conn *hcon = conn->hcon;
294 struct smp_chan *smp = conn->smp_chan;
295 u8 method;
296 u32 passkey = 0;
297 int ret = 0;
298
299 /* Initialize key for JUST WORKS */
300 memset(smp->tk, 0, sizeof(smp->tk));
301 clear_bit(SMP_FLAG_TK_VALID, &smp->smp_flags);
302
303 BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io);
304
305 /* If neither side wants MITM, use JUST WORKS */
306 /* If either side has unknown io_caps, use JUST WORKS */
307 /* Otherwise, look up method from the table */
308 if (!(auth & SMP_AUTH_MITM) ||
309 local_io > SMP_IO_KEYBOARD_DISPLAY ||
310 remote_io > SMP_IO_KEYBOARD_DISPLAY)
311 method = JUST_WORKS;
312 else
313 method = gen_method[remote_io][local_io];
314
315 /* If not bonding, don't ask user to confirm a Zero TK */
316 if (!(auth & SMP_AUTH_BONDING) && method == JUST_CFM)
317 method = JUST_WORKS;
318
319 /* If Just Works, Continue with Zero TK */
320 if (method == JUST_WORKS) {
321 set_bit(SMP_FLAG_TK_VALID, &smp->smp_flags);
322 return 0;
323 }
324
325 /* Not Just Works/Confirm results in MITM Authentication */
326 if (method != JUST_CFM)
327 set_bit(SMP_FLAG_MITM_AUTH, &smp->smp_flags);
328
329 /* If both devices have Keyoard-Display I/O, the master
330 * Confirms and the slave Enters the passkey.
331 */
332 if (method == OVERLAP) {
333 if (hcon->link_mode & HCI_LM_MASTER)
334 method = CFM_PASSKEY;
335 else
336 method = REQ_PASSKEY;
337 }
338
339 /* Generate random passkey. Not valid until confirmed. */
340 if (method == CFM_PASSKEY) {
341 u8 key[16];
342
343 memset(key, 0, sizeof(key));
344 get_random_bytes(&passkey, sizeof(passkey));
345 passkey %= 1000000;
346 put_unaligned_le32(passkey, key);
347 swap128(key, smp->tk);
348 BT_DBG("PassKey: %d", passkey);
349 }
350
351 hci_dev_lock(hcon->hdev);
352
353 if (method == REQ_PASSKEY)
354 ret = mgmt_user_passkey_request(hcon->hdev, conn->dst,
355 hcon->type, hcon->dst_type);
356 else
357 ret = mgmt_user_confirm_request(hcon->hdev, conn->dst,
358 hcon->type, hcon->dst_type,
359 cpu_to_le32(passkey), 0);
360
361 hci_dev_unlock(hcon->hdev);
362
363 return ret;
364}
365
366static void confirm_work(struct work_struct *work)
367{
368 struct smp_chan *smp = container_of(work, struct smp_chan, confirm);
369 struct l2cap_conn *conn = smp->conn;
370 struct crypto_blkcipher *tfm;
371 struct smp_cmd_pairing_confirm cp;
372 int ret;
373 u8 res[16], reason;
374
375 BT_DBG("conn %p", conn);
376
377 tfm = crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);
378 if (IS_ERR(tfm)) {
379 reason = SMP_UNSPECIFIED;
380 goto error;
381 }
382
383 smp->tfm = tfm;
384
385 if (conn->hcon->out)
386 ret = smp_c1(tfm, smp->tk, smp->prnd, smp->preq, smp->prsp, 0,
387 conn->src, conn->hcon->dst_type, conn->dst, res);
388 else
389 ret = smp_c1(tfm, smp->tk, smp->prnd, smp->preq, smp->prsp,
390 conn->hcon->dst_type, conn->dst, 0, conn->src,
391 res);
392 if (ret) {
393 reason = SMP_UNSPECIFIED;
394 goto error;
395 }
396
397 clear_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags);
398
399 swap128(res, cp.confirm_val);
400 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
401
402 return;
403
404error:
405 smp_failure(conn, reason, 1);
406}
407
408static void random_work(struct work_struct *work)
409{
410 struct smp_chan *smp = container_of(work, struct smp_chan, random);
411 struct l2cap_conn *conn = smp->conn;
412 struct hci_conn *hcon = conn->hcon;
413 struct crypto_blkcipher *tfm = smp->tfm;
414 u8 reason, confirm[16], res[16], key[16];
415 int ret;
416
417 if (IS_ERR_OR_NULL(tfm)) {
418 reason = SMP_UNSPECIFIED;
419 goto error;
420 }
421
422 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
423
424 if (hcon->out)
425 ret = smp_c1(tfm, smp->tk, smp->rrnd, smp->preq, smp->prsp, 0,
426 conn->src, hcon->dst_type, conn->dst, res);
427 else
428 ret = smp_c1(tfm, smp->tk, smp->rrnd, smp->preq, smp->prsp,
429 hcon->dst_type, conn->dst, 0, conn->src, res);
430 if (ret) {
431 reason = SMP_UNSPECIFIED;
432 goto error;
433 }
434
435 swap128(res, confirm);
436
437 if (memcmp(smp->pcnf, confirm, sizeof(smp->pcnf)) != 0) {
438 BT_ERR("Pairing failed (confirmation values mismatch)");
439 reason = SMP_CONFIRM_FAILED;
440 goto error;
441 }
442
443 if (hcon->out) {
444 u8 stk[16], rand[8];
445 __le16 ediv;
446
447 memset(rand, 0, sizeof(rand));
448 ediv = 0;
449
450 smp_s1(tfm, smp->tk, smp->rrnd, smp->prnd, key);
451 swap128(key, stk);
452
453 memset(stk + smp->enc_key_size, 0,
454 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);
455
456 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) {
457 reason = SMP_UNSPECIFIED;
458 goto error;
459 }
460
461 hci_le_start_enc(hcon, ediv, rand, stk);
462 hcon->enc_key_size = smp->enc_key_size;
463 } else {
464 u8 stk[16], r[16], rand[8];
465 __le16 ediv;
466
467 memset(rand, 0, sizeof(rand));
468 ediv = 0;
469
470 swap128(smp->prnd, r);
471 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(r), r);
472
473 smp_s1(tfm, smp->tk, smp->prnd, smp->rrnd, key);
474 swap128(key, stk);
475
476 memset(stk + smp->enc_key_size, 0,
477 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);
478
479 hci_add_ltk(hcon->hdev, conn->dst, hcon->dst_type,
480 HCI_SMP_STK_SLAVE, 0, 0, stk, smp->enc_key_size,
481 ediv, rand);
482 }
483
484 return;
485
486error:
487 smp_failure(conn, reason, 1);
488}
489
490static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
491{
492 struct smp_chan *smp;
493
494 smp = kzalloc(sizeof(struct smp_chan), GFP_ATOMIC);
495 if (!smp)
496 return NULL;
497
498 INIT_WORK(&smp->confirm, confirm_work);
499 INIT_WORK(&smp->random, random_work);
500
501 smp->conn = conn;
502 conn->smp_chan = smp;
503 conn->hcon->smp_conn = conn;
504
505 hci_conn_hold(conn->hcon);
506
507 return smp;
508}
509
510void smp_chan_destroy(struct l2cap_conn *conn)
511{
512 struct smp_chan *smp = conn->smp_chan;
513
514 BUG_ON(!smp);
515
516 if (smp->tfm)
517 crypto_free_blkcipher(smp->tfm);
518
519 kfree(smp);
520 conn->smp_chan = NULL;
521 conn->hcon->smp_conn = NULL;
522 hci_conn_put(conn->hcon);
523}
524
525int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey)
526{
527 struct l2cap_conn *conn = hcon->smp_conn;
528 struct smp_chan *smp;
529 u32 value;
530 u8 key[16];
531
532 BT_DBG("");
533
534 if (!conn)
535 return -ENOTCONN;
536
537 smp = conn->smp_chan;
538
539 switch (mgmt_op) {
540 case MGMT_OP_USER_PASSKEY_REPLY:
541 value = le32_to_cpu(passkey);
542 memset(key, 0, sizeof(key));
543 BT_DBG("PassKey: %d", value);
544 put_unaligned_le32(value, key);
545 swap128(key, smp->tk);
546 /* Fall Through */
547 case MGMT_OP_USER_CONFIRM_REPLY:
548 set_bit(SMP_FLAG_TK_VALID, &smp->smp_flags);
549 break;
550 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
551 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
552 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED, 1);
553 return 0;
554 default:
555 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED, 1);
556 return -EOPNOTSUPP;
557 }
558
559 /* If it is our turn to send Pairing Confirm, do so now */
560 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags))
561 queue_work(hcon->hdev->workqueue, &smp->confirm);
562
563 return 0;
564}
565
566static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
567{
568 struct smp_cmd_pairing rsp, *req = (void *) skb->data;
569 struct smp_chan *smp;
570 u8 key_size;
571 u8 auth = SMP_AUTH_NONE;
572 int ret;
573
574 BT_DBG("conn %p", conn);
575
576 if (conn->hcon->link_mode & HCI_LM_MASTER)
577 return SMP_CMD_NOTSUPP;
578
579 if (!test_and_set_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->flags))
580 smp = smp_chan_create(conn);
581
582 smp = conn->smp_chan;
583
584 smp->preq[0] = SMP_CMD_PAIRING_REQ;
585 memcpy(&smp->preq[1], req, sizeof(*req));
586 skb_pull(skb, sizeof(*req));
587
588 /* We didn't start the pairing, so match remote */
589 if (req->auth_req & SMP_AUTH_BONDING)
590 auth = req->auth_req;
591
592 conn->hcon->pending_sec_level = authreq_to_seclevel(auth);
593
594 build_pairing_cmd(conn, req, &rsp, auth);
595
596 key_size = min(req->max_key_size, rsp.max_key_size);
597 if (check_enc_key_size(conn, key_size))
598 return SMP_ENC_KEY_SIZE;
599
600 ret = smp_rand(smp->prnd);
601 if (ret)
602 return SMP_UNSPECIFIED;
603
604 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
605 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
606
607 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
608
609 /* Request setup of TK */
610 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability);
611 if (ret)
612 return SMP_UNSPECIFIED;
613
614 return 0;
615}
616
617static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
618{
619 struct smp_cmd_pairing *req, *rsp = (void *) skb->data;
620 struct smp_chan *smp = conn->smp_chan;
621 struct hci_dev *hdev = conn->hcon->hdev;
622 u8 key_size, auth = SMP_AUTH_NONE;
623 int ret;
624
625 BT_DBG("conn %p", conn);
626
627 if (!(conn->hcon->link_mode & HCI_LM_MASTER))
628 return SMP_CMD_NOTSUPP;
629
630 skb_pull(skb, sizeof(*rsp));
631
632 req = (void *) &smp->preq[1];
633
634 key_size = min(req->max_key_size, rsp->max_key_size);
635 if (check_enc_key_size(conn, key_size))
636 return SMP_ENC_KEY_SIZE;
637
638 ret = smp_rand(smp->prnd);
639 if (ret)
640 return SMP_UNSPECIFIED;
641
642 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
643 memcpy(&smp->prsp[1], rsp, sizeof(*rsp));
644
645 if ((req->auth_req & SMP_AUTH_BONDING) &&
646 (rsp->auth_req & SMP_AUTH_BONDING))
647 auth = SMP_AUTH_BONDING;
648
649 auth |= (req->auth_req | rsp->auth_req) & SMP_AUTH_MITM;
650
651 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability);
652 if (ret)
653 return SMP_UNSPECIFIED;
654
655 set_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags);
656
657 /* Can't compose response until we have been confirmed */
658 if (!test_bit(SMP_FLAG_TK_VALID, &smp->smp_flags))
659 return 0;
660
661 queue_work(hdev->workqueue, &smp->confirm);
662
663 return 0;
664}
665
666static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
667{
668 struct smp_chan *smp = conn->smp_chan;
669 struct hci_dev *hdev = conn->hcon->hdev;
670
671 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
672
673 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf));
674 skb_pull(skb, sizeof(smp->pcnf));
675
676 if (conn->hcon->out) {
677 u8 random[16];
678
679 swap128(smp->prnd, random);
680 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(random),
681 random);
682 } else if (test_bit(SMP_FLAG_TK_VALID, &smp->smp_flags)) {
683 queue_work(hdev->workqueue, &smp->confirm);
684 } else {
685 set_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags);
686 }
687
688 return 0;
689}
690
691static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
692{
693 struct smp_chan *smp = conn->smp_chan;
694 struct hci_dev *hdev = conn->hcon->hdev;
695
696 BT_DBG("conn %p", conn);
697
698 swap128(skb->data, smp->rrnd);
699 skb_pull(skb, sizeof(smp->rrnd));
700
701 queue_work(hdev->workqueue, &smp->random);
702
703 return 0;
704}
705
706static u8 smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level)
707{
708 struct smp_ltk *key;
709 struct hci_conn *hcon = conn->hcon;
710
711 key = hci_find_ltk_by_addr(hcon->hdev, conn->dst, hcon->dst_type);
712 if (!key)
713 return 0;
714
715 if (sec_level > BT_SECURITY_MEDIUM && !key->authenticated)
716 return 0;
717
718 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
719 return 1;
720
721 hci_le_start_enc(hcon, key->ediv, key->rand, key->val);
722 hcon->enc_key_size = key->enc_size;
723
724 return 1;
725
726}
727static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
728{
729 struct smp_cmd_security_req *rp = (void *) skb->data;
730 struct smp_cmd_pairing cp;
731 struct hci_conn *hcon = conn->hcon;
732 struct smp_chan *smp;
733
734 BT_DBG("conn %p", conn);
735
736 hcon->pending_sec_level = authreq_to_seclevel(rp->auth_req);
737
738 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
739 return 0;
740
741 if (test_and_set_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags))
742 return 0;
743
744 smp = smp_chan_create(conn);
745
746 skb_pull(skb, sizeof(*rp));
747
748 memset(&cp, 0, sizeof(cp));
749 build_pairing_cmd(conn, &cp, NULL, rp->auth_req);
750
751 smp->preq[0] = SMP_CMD_PAIRING_REQ;
752 memcpy(&smp->preq[1], &cp, sizeof(cp));
753
754 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
755
756 return 0;
757}
758
759int smp_conn_security(struct hci_conn *hcon, __u8 sec_level)
760{
761 struct l2cap_conn *conn = hcon->l2cap_data;
762 struct smp_chan *smp = conn->smp_chan;
763 __u8 authreq;
764
765 BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level);
766
767 if (!lmp_host_le_capable(hcon->hdev))
768 return 1;
769
770 if (sec_level == BT_SECURITY_LOW)
771 return 1;
772
773 if (hcon->sec_level >= sec_level)
774 return 1;
775
776 if (hcon->link_mode & HCI_LM_MASTER)
777 if (smp_ltk_encrypt(conn, sec_level))
778 goto done;
779
780 if (test_and_set_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags))
781 return 0;
782
783 smp = smp_chan_create(conn);
784 if (!smp)
785 return 1;
786
787 authreq = seclevel_to_authreq(sec_level);
788
789 if (hcon->link_mode & HCI_LM_MASTER) {
790 struct smp_cmd_pairing cp;
791
792 build_pairing_cmd(conn, &cp, NULL, authreq);
793 smp->preq[0] = SMP_CMD_PAIRING_REQ;
794 memcpy(&smp->preq[1], &cp, sizeof(cp));
795
796 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
797 } else {
798 struct smp_cmd_security_req cp;
799 cp.auth_req = authreq;
800 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp);
801 }
802
803done:
804 hcon->pending_sec_level = sec_level;
805
806 return 0;
807}
808
809static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb)
810{
811 struct smp_cmd_encrypt_info *rp = (void *) skb->data;
812 struct smp_chan *smp = conn->smp_chan;
813
814 skb_pull(skb, sizeof(*rp));
815
816 memcpy(smp->tk, rp->ltk, sizeof(smp->tk));
817
818 return 0;
819}
820
821static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb)
822{
823 struct smp_cmd_master_ident *rp = (void *) skb->data;
824 struct smp_chan *smp = conn->smp_chan;
825 struct hci_dev *hdev = conn->hcon->hdev;
826 struct hci_conn *hcon = conn->hcon;
827 u8 authenticated;
828
829 skb_pull(skb, sizeof(*rp));
830
831 hci_dev_lock(hdev);
832 authenticated = (conn->hcon->sec_level == BT_SECURITY_HIGH);
833 hci_add_ltk(conn->hcon->hdev, conn->dst, hcon->dst_type,
834 HCI_SMP_LTK, 1, authenticated, smp->tk, smp->enc_key_size,
835 rp->ediv, rp->rand);
836 smp_distribute_keys(conn, 1);
837 hci_dev_unlock(hdev);
838
839 return 0;
840}
841
842int smp_sig_channel(struct l2cap_conn *conn, struct sk_buff *skb)
843{
844 __u8 code = skb->data[0];
845 __u8 reason;
846 int err = 0;
847
848 if (!lmp_host_le_capable(conn->hcon->hdev)) {
849 err = -ENOTSUPP;
850 reason = SMP_PAIRING_NOTSUPP;
851 goto done;
852 }
853
854 skb_pull(skb, sizeof(code));
855
856 switch (code) {
857 case SMP_CMD_PAIRING_REQ:
858 reason = smp_cmd_pairing_req(conn, skb);
859 break;
860
861 case SMP_CMD_PAIRING_FAIL:
862 smp_failure(conn, skb->data[0], 0);
863 reason = 0;
864 err = -EPERM;
865 break;
866
867 case SMP_CMD_PAIRING_RSP:
868 reason = smp_cmd_pairing_rsp(conn, skb);
869 break;
870
871 case SMP_CMD_SECURITY_REQ:
872 reason = smp_cmd_security_req(conn, skb);
873 break;
874
875 case SMP_CMD_PAIRING_CONFIRM:
876 reason = smp_cmd_pairing_confirm(conn, skb);
877 break;
878
879 case SMP_CMD_PAIRING_RANDOM:
880 reason = smp_cmd_pairing_random(conn, skb);
881 break;
882
883 case SMP_CMD_ENCRYPT_INFO:
884 reason = smp_cmd_encrypt_info(conn, skb);
885 break;
886
887 case SMP_CMD_MASTER_IDENT:
888 reason = smp_cmd_master_ident(conn, skb);
889 break;
890
891 case SMP_CMD_IDENT_INFO:
892 case SMP_CMD_IDENT_ADDR_INFO:
893 case SMP_CMD_SIGN_INFO:
894 /* Just ignored */
895 reason = 0;
896 break;
897
898 default:
899 BT_DBG("Unknown command code 0x%2.2x", code);
900
901 reason = SMP_CMD_NOTSUPP;
902 err = -EOPNOTSUPP;
903 goto done;
904 }
905
906done:
907 if (reason)
908 smp_failure(conn, reason, 1);
909
910 kfree_skb(skb);
911 return err;
912}
913
914int smp_distribute_keys(struct l2cap_conn *conn, __u8 force)
915{
916 struct smp_cmd_pairing *req, *rsp;
917 struct smp_chan *smp = conn->smp_chan;
918 __u8 *keydist;
919
920 BT_DBG("conn %p force %d", conn, force);
921
922 if (!test_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->flags))
923 return 0;
924
925 rsp = (void *) &smp->prsp[1];
926
927 /* The responder sends its keys first */
928 if (!force && conn->hcon->out && (rsp->resp_key_dist & 0x07))
929 return 0;
930
931 req = (void *) &smp->preq[1];
932
933 if (conn->hcon->out) {
934 keydist = &rsp->init_key_dist;
935 *keydist &= req->init_key_dist;
936 } else {
937 keydist = &rsp->resp_key_dist;
938 *keydist &= req->resp_key_dist;
939 }
940
941
942 BT_DBG("keydist 0x%x", *keydist);
943
944 if (*keydist & SMP_DIST_ENC_KEY) {
945 struct smp_cmd_encrypt_info enc;
946 struct smp_cmd_master_ident ident;
947 struct hci_conn *hcon = conn->hcon;
948 u8 authenticated;
949 __le16 ediv;
950
951 get_random_bytes(enc.ltk, sizeof(enc.ltk));
952 get_random_bytes(&ediv, sizeof(ediv));
953 get_random_bytes(ident.rand, sizeof(ident.rand));
954
955 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc);
956
957 authenticated = hcon->sec_level == BT_SECURITY_HIGH;
958 hci_add_ltk(conn->hcon->hdev, conn->dst, hcon->dst_type,
959 HCI_SMP_LTK_SLAVE, 1, authenticated,
960 enc.ltk, smp->enc_key_size, ediv, ident.rand);
961
962 ident.ediv = ediv;
963
964 smp_send_cmd(conn, SMP_CMD_MASTER_IDENT, sizeof(ident), &ident);
965
966 *keydist &= ~SMP_DIST_ENC_KEY;
967 }
968
969 if (*keydist & SMP_DIST_ID_KEY) {
970 struct smp_cmd_ident_addr_info addrinfo;
971 struct smp_cmd_ident_info idinfo;
972
973 /* Send a dummy key */
974 get_random_bytes(idinfo.irk, sizeof(idinfo.irk));
975
976 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo);
977
978 /* Just public address */
979 memset(&addrinfo, 0, sizeof(addrinfo));
980 bacpy(&addrinfo.bdaddr, conn->src);
981
982 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo),
983 &addrinfo);
984
985 *keydist &= ~SMP_DIST_ID_KEY;
986 }
987
988 if (*keydist & SMP_DIST_SIGN) {
989 struct smp_cmd_sign_info sign;
990
991 /* Send a dummy key */
992 get_random_bytes(sign.csrk, sizeof(sign.csrk));
993
994 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign);
995
996 *keydist &= ~SMP_DIST_SIGN;
997 }
998
999 if (conn->hcon->out || force) {
1000 clear_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->flags);
1001 cancel_delayed_work_sync(&conn->security_timer);
1002 smp_chan_destroy(conn);
1003 }
1004
1005 return 0;
1006}