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