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 (test_bit(SMP_FLAG_INITIATOR, &smp->flags))
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 (test_bit(SMP_FLAG_INITIATOR, &smp->flags))
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 test_bit(SMP_FLAG_INITIATOR, &smp->flags) ? "initiator" :
985 "responder");
986
987 ret = smp_c1(smp->tk, smp->rrnd, smp->preq, smp->prsp,
988 hcon->init_addr_type, &hcon->init_addr,
989 hcon->resp_addr_type, &hcon->resp_addr, confirm);
990 if (ret)
991 return SMP_UNSPECIFIED;
992
993 if (crypto_memneq(smp->pcnf, confirm, sizeof(smp->pcnf))) {
994 bt_dev_err(hcon->hdev, "pairing failed "
995 "(confirmation values mismatch)");
996 return SMP_CONFIRM_FAILED;
997 }
998
999 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1000 u8 stk[16];
1001 __le64 rand = 0;
1002 __le16 ediv = 0;
1003
1004 smp_s1(smp->tk, smp->rrnd, smp->prnd, stk);
1005
1006 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
1007 return SMP_UNSPECIFIED;
1008
1009 hci_le_start_enc(hcon, ediv, rand, stk, smp->enc_key_size);
1010 hcon->enc_key_size = smp->enc_key_size;
1011 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
1012 } else {
1013 u8 stk[16], auth;
1014 __le64 rand = 0;
1015 __le16 ediv = 0;
1016
1017 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
1018 smp->prnd);
1019
1020 smp_s1(smp->tk, smp->prnd, smp->rrnd, stk);
1021
1022 if (hcon->pending_sec_level == BT_SECURITY_HIGH)
1023 auth = 1;
1024 else
1025 auth = 0;
1026
1027 /* Even though there's no _RESPONDER suffix this is the
1028 * responder STK we're adding for later lookup (the initiator
1029 * STK never needs to be stored).
1030 */
1031 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1032 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand);
1033 }
1034
1035 return 0;
1036 }
1037
smp_notify_keys(struct l2cap_conn * conn)1038 static void smp_notify_keys(struct l2cap_conn *conn)
1039 {
1040 struct l2cap_chan *chan = conn->smp;
1041 struct smp_chan *smp = chan->data;
1042 struct hci_conn *hcon = conn->hcon;
1043 struct hci_dev *hdev = hcon->hdev;
1044 struct smp_cmd_pairing *req = (void *) &smp->preq[1];
1045 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1];
1046 bool persistent;
1047
1048 if (hcon->type == ACL_LINK) {
1049 if (hcon->key_type == HCI_LK_DEBUG_COMBINATION)
1050 persistent = false;
1051 else
1052 persistent = !test_bit(HCI_CONN_FLUSH_KEY,
1053 &hcon->flags);
1054 } else {
1055 /* The LTKs, IRKs and CSRKs should be persistent only if
1056 * both sides had the bonding bit set in their
1057 * authentication requests.
1058 */
1059 persistent = !!((req->auth_req & rsp->auth_req) &
1060 SMP_AUTH_BONDING);
1061 }
1062
1063 if (smp->remote_irk) {
1064 mgmt_new_irk(hdev, smp->remote_irk, persistent);
1065
1066 /* Now that user space can be considered to know the
1067 * identity address track the connection based on it
1068 * from now on (assuming this is an LE link).
1069 */
1070 if (hcon->type == LE_LINK) {
1071 bacpy(&hcon->dst, &smp->remote_irk->bdaddr);
1072 hcon->dst_type = smp->remote_irk->addr_type;
1073 /* Use a short delay to make sure the new address is
1074 * propagated _before_ the channels.
1075 */
1076 queue_delayed_work(hdev->workqueue,
1077 &conn->id_addr_timer,
1078 ID_ADDR_TIMEOUT);
1079 }
1080 }
1081
1082 if (smp->csrk) {
1083 smp->csrk->bdaddr_type = hcon->dst_type;
1084 bacpy(&smp->csrk->bdaddr, &hcon->dst);
1085 mgmt_new_csrk(hdev, smp->csrk, persistent);
1086 }
1087
1088 if (smp->responder_csrk) {
1089 smp->responder_csrk->bdaddr_type = hcon->dst_type;
1090 bacpy(&smp->responder_csrk->bdaddr, &hcon->dst);
1091 mgmt_new_csrk(hdev, smp->responder_csrk, persistent);
1092 }
1093
1094 if (smp->ltk) {
1095 smp->ltk->bdaddr_type = hcon->dst_type;
1096 bacpy(&smp->ltk->bdaddr, &hcon->dst);
1097 mgmt_new_ltk(hdev, smp->ltk, persistent);
1098 }
1099
1100 if (smp->responder_ltk) {
1101 smp->responder_ltk->bdaddr_type = hcon->dst_type;
1102 bacpy(&smp->responder_ltk->bdaddr, &hcon->dst);
1103 mgmt_new_ltk(hdev, smp->responder_ltk, persistent);
1104 }
1105
1106 if (smp->link_key) {
1107 struct link_key *key;
1108 u8 type;
1109
1110 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1111 type = HCI_LK_DEBUG_COMBINATION;
1112 else if (hcon->sec_level == BT_SECURITY_FIPS)
1113 type = HCI_LK_AUTH_COMBINATION_P256;
1114 else
1115 type = HCI_LK_UNAUTH_COMBINATION_P256;
1116
1117 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst,
1118 smp->link_key, type, 0, &persistent);
1119 if (key) {
1120 mgmt_new_link_key(hdev, key, persistent);
1121
1122 /* Don't keep debug keys around if the relevant
1123 * flag is not set.
1124 */
1125 if (!hci_dev_test_flag(hdev, HCI_KEEP_DEBUG_KEYS) &&
1126 key->type == HCI_LK_DEBUG_COMBINATION) {
1127 list_del_rcu(&key->list);
1128 kfree_rcu(key, rcu);
1129 }
1130 }
1131 }
1132 }
1133
sc_add_ltk(struct smp_chan * smp)1134 static void sc_add_ltk(struct smp_chan *smp)
1135 {
1136 struct hci_conn *hcon = smp->conn->hcon;
1137 u8 key_type, auth;
1138
1139 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1140 key_type = SMP_LTK_P256_DEBUG;
1141 else
1142 key_type = SMP_LTK_P256;
1143
1144 if (hcon->pending_sec_level == BT_SECURITY_FIPS)
1145 auth = 1;
1146 else
1147 auth = 0;
1148
1149 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1150 key_type, auth, smp->tk, smp->enc_key_size,
1151 0, 0);
1152 }
1153
sc_generate_link_key(struct smp_chan * smp)1154 static void sc_generate_link_key(struct smp_chan *smp)
1155 {
1156 /* From core spec. Spells out in ASCII as 'lebr'. */
1157 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c };
1158
1159 smp->link_key = kzalloc(16, GFP_KERNEL);
1160 if (!smp->link_key)
1161 return;
1162
1163 if (test_bit(SMP_FLAG_CT2, &smp->flags)) {
1164 /* SALT = 0x000000000000000000000000746D7031 */
1165 const u8 salt[16] = { 0x31, 0x70, 0x6d, 0x74 };
1166
1167 if (smp_h7(smp->tfm_cmac, smp->tk, salt, smp->link_key)) {
1168 kfree_sensitive(smp->link_key);
1169 smp->link_key = NULL;
1170 return;
1171 }
1172 } else {
1173 /* From core spec. Spells out in ASCII as 'tmp1'. */
1174 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 };
1175
1176 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) {
1177 kfree_sensitive(smp->link_key);
1178 smp->link_key = NULL;
1179 return;
1180 }
1181 }
1182
1183 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) {
1184 kfree_sensitive(smp->link_key);
1185 smp->link_key = NULL;
1186 return;
1187 }
1188 }
1189
smp_allow_key_dist(struct smp_chan * smp)1190 static void smp_allow_key_dist(struct smp_chan *smp)
1191 {
1192 /* Allow the first expected phase 3 PDU. The rest of the PDUs
1193 * will be allowed in each PDU handler to ensure we receive
1194 * them in the correct order.
1195 */
1196 if (smp->remote_key_dist & SMP_DIST_ENC_KEY)
1197 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO);
1198 else if (smp->remote_key_dist & SMP_DIST_ID_KEY)
1199 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
1200 else if (smp->remote_key_dist & SMP_DIST_SIGN)
1201 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
1202 }
1203
sc_generate_ltk(struct smp_chan * smp)1204 static void sc_generate_ltk(struct smp_chan *smp)
1205 {
1206 /* From core spec. Spells out in ASCII as 'brle'. */
1207 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 };
1208 struct hci_conn *hcon = smp->conn->hcon;
1209 struct hci_dev *hdev = hcon->hdev;
1210 struct link_key *key;
1211
1212 key = hci_find_link_key(hdev, &hcon->dst);
1213 if (!key) {
1214 bt_dev_err(hdev, "no Link Key found to generate LTK");
1215 return;
1216 }
1217
1218 if (key->type == HCI_LK_DEBUG_COMBINATION)
1219 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1220
1221 if (test_bit(SMP_FLAG_CT2, &smp->flags)) {
1222 /* SALT = 0x000000000000000000000000746D7032 */
1223 const u8 salt[16] = { 0x32, 0x70, 0x6d, 0x74 };
1224
1225 if (smp_h7(smp->tfm_cmac, key->val, salt, smp->tk))
1226 return;
1227 } else {
1228 /* From core spec. Spells out in ASCII as 'tmp2'. */
1229 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 };
1230
1231 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk))
1232 return;
1233 }
1234
1235 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk))
1236 return;
1237
1238 sc_add_ltk(smp);
1239 }
1240
smp_distribute_keys(struct smp_chan * smp)1241 static void smp_distribute_keys(struct smp_chan *smp)
1242 {
1243 struct smp_cmd_pairing *req, *rsp;
1244 struct l2cap_conn *conn = smp->conn;
1245 struct hci_conn *hcon = conn->hcon;
1246 struct hci_dev *hdev = hcon->hdev;
1247 __u8 *keydist;
1248
1249 bt_dev_dbg(hdev, "conn %p", conn);
1250
1251 rsp = (void *) &smp->prsp[1];
1252
1253 /* The responder sends its keys first */
1254 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags) &&
1255 (smp->remote_key_dist & KEY_DIST_MASK)) {
1256 smp_allow_key_dist(smp);
1257 return;
1258 }
1259
1260 req = (void *) &smp->preq[1];
1261
1262 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1263 keydist = &rsp->init_key_dist;
1264 *keydist &= req->init_key_dist;
1265 } else {
1266 keydist = &rsp->resp_key_dist;
1267 *keydist &= req->resp_key_dist;
1268 }
1269
1270 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1271 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY))
1272 sc_generate_link_key(smp);
1273 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY))
1274 sc_generate_ltk(smp);
1275
1276 /* Clear the keys which are generated but not distributed */
1277 *keydist &= ~SMP_SC_NO_DIST;
1278 }
1279
1280 bt_dev_dbg(hdev, "keydist 0x%x", *keydist);
1281
1282 if (*keydist & SMP_DIST_ENC_KEY) {
1283 struct smp_cmd_encrypt_info enc;
1284 struct smp_cmd_initiator_ident ident;
1285 struct smp_ltk *ltk;
1286 u8 authenticated;
1287 __le16 ediv;
1288 __le64 rand;
1289
1290 /* Make sure we generate only the significant amount of
1291 * bytes based on the encryption key size, and set the rest
1292 * of the value to zeroes.
1293 */
1294 get_random_bytes(enc.ltk, smp->enc_key_size);
1295 memset(enc.ltk + smp->enc_key_size, 0,
1296 sizeof(enc.ltk) - smp->enc_key_size);
1297
1298 get_random_bytes(&ediv, sizeof(ediv));
1299 get_random_bytes(&rand, sizeof(rand));
1300
1301 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc);
1302
1303 authenticated = hcon->sec_level == BT_SECURITY_HIGH;
1304 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type,
1305 SMP_LTK_RESPONDER, authenticated, enc.ltk,
1306 smp->enc_key_size, ediv, rand);
1307 smp->responder_ltk = ltk;
1308
1309 ident.ediv = ediv;
1310 ident.rand = rand;
1311
1312 smp_send_cmd(conn, SMP_CMD_INITIATOR_IDENT, sizeof(ident),
1313 &ident);
1314
1315 *keydist &= ~SMP_DIST_ENC_KEY;
1316 }
1317
1318 if (*keydist & SMP_DIST_ID_KEY) {
1319 struct smp_cmd_ident_addr_info addrinfo;
1320 struct smp_cmd_ident_info idinfo;
1321
1322 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk));
1323
1324 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo);
1325
1326 /* The hci_conn contains the local identity address
1327 * after the connection has been established.
1328 *
1329 * This is true even when the connection has been
1330 * established using a resolvable random address.
1331 */
1332 bacpy(&addrinfo.bdaddr, &hcon->src);
1333 addrinfo.addr_type = hcon->src_type;
1334
1335 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo),
1336 &addrinfo);
1337
1338 *keydist &= ~SMP_DIST_ID_KEY;
1339 }
1340
1341 if (*keydist & SMP_DIST_SIGN) {
1342 struct smp_cmd_sign_info sign;
1343 struct smp_csrk *csrk;
1344
1345 /* Generate a new random key */
1346 get_random_bytes(sign.csrk, sizeof(sign.csrk));
1347
1348 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
1349 if (csrk) {
1350 if (hcon->sec_level > BT_SECURITY_MEDIUM)
1351 csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED;
1352 else
1353 csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED;
1354 memcpy(csrk->val, sign.csrk, sizeof(csrk->val));
1355 }
1356 smp->responder_csrk = csrk;
1357
1358 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign);
1359
1360 *keydist &= ~SMP_DIST_SIGN;
1361 }
1362
1363 /* If there are still keys to be received wait for them */
1364 if (smp->remote_key_dist & KEY_DIST_MASK) {
1365 smp_allow_key_dist(smp);
1366 return;
1367 }
1368
1369 set_bit(SMP_FLAG_COMPLETE, &smp->flags);
1370 smp_notify_keys(conn);
1371
1372 smp_chan_destroy(conn);
1373 }
1374
smp_timeout(struct work_struct * work)1375 static void smp_timeout(struct work_struct *work)
1376 {
1377 struct smp_chan *smp = container_of(work, struct smp_chan,
1378 security_timer.work);
1379 struct l2cap_conn *conn = smp->conn;
1380
1381 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn);
1382
1383 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM);
1384 }
1385
smp_chan_create(struct l2cap_conn * conn)1386 static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
1387 {
1388 struct hci_conn *hcon = conn->hcon;
1389 struct l2cap_chan *chan = conn->smp;
1390 struct smp_chan *smp;
1391
1392 smp = kzalloc(sizeof(*smp), GFP_ATOMIC);
1393 if (!smp)
1394 return NULL;
1395
1396 smp->tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
1397 if (IS_ERR(smp->tfm_cmac)) {
1398 bt_dev_err(hcon->hdev, "Unable to create CMAC crypto context");
1399 goto zfree_smp;
1400 }
1401
1402 smp->tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0);
1403 if (IS_ERR(smp->tfm_ecdh)) {
1404 bt_dev_err(hcon->hdev, "Unable to create ECDH crypto context");
1405 goto free_shash;
1406 }
1407
1408 smp->conn = conn;
1409 chan->data = smp;
1410
1411 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL);
1412
1413 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout);
1414
1415 hci_conn_hold(hcon);
1416
1417 return smp;
1418
1419 free_shash:
1420 crypto_free_shash(smp->tfm_cmac);
1421 zfree_smp:
1422 kfree_sensitive(smp);
1423 return NULL;
1424 }
1425
sc_mackey_and_ltk(struct smp_chan * smp,u8 mackey[16],u8 ltk[16])1426 static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16])
1427 {
1428 struct hci_conn *hcon = smp->conn->hcon;
1429 u8 *na, *nb, a[7], b[7];
1430
1431 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1432 na = smp->prnd;
1433 nb = smp->rrnd;
1434 } else {
1435 na = smp->rrnd;
1436 nb = smp->prnd;
1437 }
1438
1439 memcpy(a, &hcon->init_addr, 6);
1440 memcpy(b, &hcon->resp_addr, 6);
1441 a[6] = hcon->init_addr_type;
1442 b[6] = hcon->resp_addr_type;
1443
1444 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk);
1445 }
1446
sc_dhkey_check(struct smp_chan * smp)1447 static void sc_dhkey_check(struct smp_chan *smp)
1448 {
1449 struct hci_conn *hcon = smp->conn->hcon;
1450 struct smp_cmd_dhkey_check check;
1451 u8 a[7], b[7], *local_addr, *remote_addr;
1452 u8 io_cap[3], r[16];
1453
1454 memcpy(a, &hcon->init_addr, 6);
1455 memcpy(b, &hcon->resp_addr, 6);
1456 a[6] = hcon->init_addr_type;
1457 b[6] = hcon->resp_addr_type;
1458
1459 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1460 local_addr = a;
1461 remote_addr = b;
1462 memcpy(io_cap, &smp->preq[1], 3);
1463 } else {
1464 local_addr = b;
1465 remote_addr = a;
1466 memcpy(io_cap, &smp->prsp[1], 3);
1467 }
1468
1469 memset(r, 0, sizeof(r));
1470
1471 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
1472 put_unaligned_le32(hcon->passkey_notify, r);
1473
1474 if (smp->method == REQ_OOB)
1475 memcpy(r, smp->rr, 16);
1476
1477 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap,
1478 local_addr, remote_addr, check.e);
1479
1480 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check);
1481 }
1482
sc_passkey_send_confirm(struct smp_chan * smp)1483 static u8 sc_passkey_send_confirm(struct smp_chan *smp)
1484 {
1485 struct l2cap_conn *conn = smp->conn;
1486 struct hci_conn *hcon = conn->hcon;
1487 struct smp_cmd_pairing_confirm cfm;
1488 u8 r;
1489
1490 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1491 r |= 0x80;
1492
1493 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1494
1495 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r,
1496 cfm.confirm_val))
1497 return SMP_UNSPECIFIED;
1498
1499 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
1500
1501 return 0;
1502 }
1503
sc_passkey_round(struct smp_chan * smp,u8 smp_op)1504 static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op)
1505 {
1506 struct l2cap_conn *conn = smp->conn;
1507 struct hci_conn *hcon = conn->hcon;
1508 struct hci_dev *hdev = hcon->hdev;
1509 u8 cfm[16], r;
1510
1511 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */
1512 if (smp->passkey_round >= 20)
1513 return 0;
1514
1515 switch (smp_op) {
1516 case SMP_CMD_PAIRING_RANDOM:
1517 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1518 r |= 0x80;
1519
1520 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
1521 smp->rrnd, r, cfm))
1522 return SMP_UNSPECIFIED;
1523
1524 if (crypto_memneq(smp->pcnf, cfm, 16))
1525 return SMP_CONFIRM_FAILED;
1526
1527 smp->passkey_round++;
1528
1529 if (smp->passkey_round == 20) {
1530 /* Generate MacKey and LTK */
1531 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk))
1532 return SMP_UNSPECIFIED;
1533 }
1534
1535 /* The round is only complete when the initiator
1536 * receives pairing random.
1537 */
1538 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1539 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1540 sizeof(smp->prnd), smp->prnd);
1541 if (smp->passkey_round == 20)
1542 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1543 else
1544 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1545 return 0;
1546 }
1547
1548 /* Start the next round */
1549 if (smp->passkey_round != 20)
1550 return sc_passkey_round(smp, 0);
1551
1552 /* Passkey rounds are complete - start DHKey Check */
1553 sc_dhkey_check(smp);
1554 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1555
1556 break;
1557
1558 case SMP_CMD_PAIRING_CONFIRM:
1559 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
1560 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
1561 return 0;
1562 }
1563
1564 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
1565
1566 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1567 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1568 sizeof(smp->prnd), smp->prnd);
1569 return 0;
1570 }
1571
1572 return sc_passkey_send_confirm(smp);
1573
1574 case SMP_CMD_PUBLIC_KEY:
1575 default:
1576 /* Initiating device starts the round */
1577 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags))
1578 return 0;
1579
1580 bt_dev_dbg(hdev, "Starting passkey round %u",
1581 smp->passkey_round + 1);
1582
1583 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1584
1585 return sc_passkey_send_confirm(smp);
1586 }
1587
1588 return 0;
1589 }
1590
sc_user_reply(struct smp_chan * smp,u16 mgmt_op,__le32 passkey)1591 static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey)
1592 {
1593 struct l2cap_conn *conn = smp->conn;
1594 struct hci_conn *hcon = conn->hcon;
1595 u8 smp_op;
1596
1597 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags);
1598
1599 switch (mgmt_op) {
1600 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1601 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED);
1602 return 0;
1603 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1604 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED);
1605 return 0;
1606 case MGMT_OP_USER_PASSKEY_REPLY:
1607 hcon->passkey_notify = le32_to_cpu(passkey);
1608 smp->passkey_round = 0;
1609
1610 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags))
1611 smp_op = SMP_CMD_PAIRING_CONFIRM;
1612 else
1613 smp_op = 0;
1614
1615 if (sc_passkey_round(smp, smp_op))
1616 return -EIO;
1617
1618 return 0;
1619 }
1620
1621 /* Initiator sends DHKey check first */
1622 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1623 sc_dhkey_check(smp);
1624 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1625 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) {
1626 sc_dhkey_check(smp);
1627 sc_add_ltk(smp);
1628 }
1629
1630 return 0;
1631 }
1632
smp_user_confirm_reply(struct hci_conn * hcon,u16 mgmt_op,__le32 passkey)1633 int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey)
1634 {
1635 struct l2cap_conn *conn = hcon->l2cap_data;
1636 struct l2cap_chan *chan;
1637 struct smp_chan *smp;
1638 u32 value;
1639 int err;
1640
1641 if (!conn)
1642 return -ENOTCONN;
1643
1644 bt_dev_dbg(conn->hcon->hdev, "");
1645
1646 chan = conn->smp;
1647 if (!chan)
1648 return -ENOTCONN;
1649
1650 l2cap_chan_lock(chan);
1651 if (!chan->data) {
1652 err = -ENOTCONN;
1653 goto unlock;
1654 }
1655
1656 smp = chan->data;
1657
1658 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1659 err = sc_user_reply(smp, mgmt_op, passkey);
1660 goto unlock;
1661 }
1662
1663 switch (mgmt_op) {
1664 case MGMT_OP_USER_PASSKEY_REPLY:
1665 value = le32_to_cpu(passkey);
1666 memset(smp->tk, 0, sizeof(smp->tk));
1667 bt_dev_dbg(conn->hcon->hdev, "PassKey: %u", value);
1668 put_unaligned_le32(value, smp->tk);
1669 fallthrough;
1670 case MGMT_OP_USER_CONFIRM_REPLY:
1671 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
1672 break;
1673 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1674 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1675 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1676 err = 0;
1677 goto unlock;
1678 default:
1679 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1680 err = -EOPNOTSUPP;
1681 goto unlock;
1682 }
1683
1684 err = 0;
1685
1686 /* If it is our turn to send Pairing Confirm, do so now */
1687 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) {
1688 u8 rsp = smp_confirm(smp);
1689 if (rsp)
1690 smp_failure(conn, rsp);
1691 }
1692
1693 unlock:
1694 l2cap_chan_unlock(chan);
1695 return err;
1696 }
1697
build_bredr_pairing_cmd(struct smp_chan * smp,struct smp_cmd_pairing * req,struct smp_cmd_pairing * rsp)1698 static void build_bredr_pairing_cmd(struct smp_chan *smp,
1699 struct smp_cmd_pairing *req,
1700 struct smp_cmd_pairing *rsp)
1701 {
1702 struct l2cap_conn *conn = smp->conn;
1703 struct hci_dev *hdev = conn->hcon->hdev;
1704 u8 local_dist = 0, remote_dist = 0;
1705
1706 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) {
1707 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1708 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1709 }
1710
1711 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING))
1712 remote_dist |= SMP_DIST_ID_KEY;
1713
1714 if (hci_dev_test_flag(hdev, HCI_PRIVACY))
1715 local_dist |= SMP_DIST_ID_KEY;
1716
1717 if (!rsp) {
1718 memset(req, 0, sizeof(*req));
1719
1720 req->auth_req = SMP_AUTH_CT2;
1721 req->init_key_dist = local_dist;
1722 req->resp_key_dist = remote_dist;
1723 req->max_key_size = conn->hcon->enc_key_size;
1724
1725 smp->remote_key_dist = remote_dist;
1726
1727 return;
1728 }
1729
1730 memset(rsp, 0, sizeof(*rsp));
1731
1732 rsp->auth_req = SMP_AUTH_CT2;
1733 rsp->max_key_size = conn->hcon->enc_key_size;
1734 rsp->init_key_dist = req->init_key_dist & remote_dist;
1735 rsp->resp_key_dist = req->resp_key_dist & local_dist;
1736
1737 smp->remote_key_dist = rsp->init_key_dist;
1738 }
1739
smp_cmd_pairing_req(struct l2cap_conn * conn,struct sk_buff * skb)1740 static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
1741 {
1742 struct smp_cmd_pairing rsp, *req = (void *) skb->data;
1743 struct l2cap_chan *chan = conn->smp;
1744 struct hci_dev *hdev = conn->hcon->hdev;
1745 struct smp_chan *smp = chan->data;
1746 u8 key_size, auth, sec_level;
1747 int ret;
1748
1749 bt_dev_dbg(hdev, "conn %p", conn);
1750
1751 if (skb->len < sizeof(*req))
1752 return SMP_INVALID_PARAMS;
1753
1754 if (smp && test_bit(SMP_FLAG_INITIATOR, &smp->flags))
1755 return SMP_CMD_NOTSUPP;
1756
1757 if (!smp) {
1758 smp = smp_chan_create(conn);
1759 if (!smp)
1760 return SMP_UNSPECIFIED;
1761 }
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 (!test_bit(SMP_FLAG_INITIATOR, &smp->flags))
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 (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
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 (test_bit(SMP_FLAG_INITIATOR, &smp->flags))
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 test_bit(SMP_FLAG_INITIATOR, &smp->flags) ? "initiator" :
2097 "responder");
2098
2099 if (skb->len < sizeof(smp->pcnf))
2100 return SMP_INVALID_PARAMS;
2101
2102 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf));
2103 skb_pull(skb, sizeof(smp->pcnf));
2104
2105 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
2106 int ret;
2107
2108 /* Public Key exchange must happen before any other steps */
2109 if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags))
2110 return sc_check_confirm(smp);
2111
2112 bt_dev_err(hdev, "Unexpected SMP Pairing Confirm");
2113
2114 ret = fixup_sc_false_positive(smp);
2115 if (ret)
2116 return ret;
2117 }
2118
2119 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2120 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2121 smp->prnd);
2122 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2123 return 0;
2124 }
2125
2126 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
2127 return smp_confirm(smp);
2128
2129 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
2130
2131 return 0;
2132 }
2133
smp_cmd_pairing_random(struct l2cap_conn * conn,struct sk_buff * skb)2134 static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
2135 {
2136 struct l2cap_chan *chan = conn->smp;
2137 struct smp_chan *smp = chan->data;
2138 struct hci_conn *hcon = conn->hcon;
2139 u8 *pkax, *pkbx, *na, *nb, confirm_hint;
2140 u32 passkey;
2141 int err;
2142
2143 bt_dev_dbg(hcon->hdev, "conn %p", conn);
2144
2145 if (skb->len < sizeof(smp->rrnd))
2146 return SMP_INVALID_PARAMS;
2147
2148 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd));
2149 skb_pull(skb, sizeof(smp->rrnd));
2150
2151 if (!test_bit(SMP_FLAG_SC, &smp->flags))
2152 return smp_random(smp);
2153
2154 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2155 pkax = smp->local_pk;
2156 pkbx = smp->remote_pk;
2157 na = smp->prnd;
2158 nb = smp->rrnd;
2159 } else {
2160 pkax = smp->remote_pk;
2161 pkbx = smp->local_pk;
2162 na = smp->rrnd;
2163 nb = smp->prnd;
2164 }
2165
2166 if (smp->method == REQ_OOB) {
2167 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2168 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2169 sizeof(smp->prnd), smp->prnd);
2170 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2171 goto mackey_and_ltk;
2172 }
2173
2174 /* Passkey entry has special treatment */
2175 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2176 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM);
2177
2178 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2179 u8 cfm[16];
2180
2181 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
2182 smp->rrnd, 0, cfm);
2183 if (err)
2184 return SMP_UNSPECIFIED;
2185
2186 if (crypto_memneq(smp->pcnf, cfm, 16))
2187 return SMP_CONFIRM_FAILED;
2188 } else {
2189 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2190 smp->prnd);
2191 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2192
2193 /* Only Just-Works pairing requires extra checks */
2194 if (smp->method != JUST_WORKS)
2195 goto mackey_and_ltk;
2196
2197 /* If there already exists long term key in local host, leave
2198 * the decision to user space since the remote device could
2199 * be legitimate or malicious.
2200 */
2201 if (hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
2202 hcon->role)) {
2203 /* Set passkey to 0. The value can be any number since
2204 * it'll be ignored anyway.
2205 */
2206 passkey = 0;
2207 confirm_hint = 1;
2208 goto confirm;
2209 }
2210 }
2211
2212 mackey_and_ltk:
2213 /* Generate MacKey and LTK */
2214 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk);
2215 if (err)
2216 return SMP_UNSPECIFIED;
2217
2218 if (smp->method == REQ_OOB) {
2219 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2220 sc_dhkey_check(smp);
2221 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2222 }
2223 return 0;
2224 }
2225
2226 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
2227 if (err)
2228 return SMP_UNSPECIFIED;
2229
2230 confirm_hint = 0;
2231
2232 confirm:
2233 if (smp->method == JUST_WORKS)
2234 confirm_hint = 1;
2235
2236 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type,
2237 hcon->dst_type, passkey, confirm_hint);
2238 if (err)
2239 return SMP_UNSPECIFIED;
2240
2241 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2242
2243 return 0;
2244 }
2245
smp_ltk_encrypt(struct l2cap_conn * conn,u8 sec_level)2246 static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level)
2247 {
2248 struct smp_ltk *key;
2249 struct hci_conn *hcon = conn->hcon;
2250
2251 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role);
2252 if (!key)
2253 return false;
2254
2255 if (smp_ltk_sec_level(key) < sec_level)
2256 return false;
2257
2258 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
2259 return true;
2260
2261 hci_le_start_enc(hcon, key->ediv, key->rand, key->val, key->enc_size);
2262 hcon->enc_key_size = key->enc_size;
2263
2264 /* We never store STKs for initiator role, so clear this flag */
2265 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
2266
2267 return true;
2268 }
2269
smp_sufficient_security(struct hci_conn * hcon,u8 sec_level,enum smp_key_pref key_pref)2270 bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level,
2271 enum smp_key_pref key_pref)
2272 {
2273 if (sec_level == BT_SECURITY_LOW)
2274 return true;
2275
2276 /* If we're encrypted with an STK but the caller prefers using
2277 * LTK claim insufficient security. This way we allow the
2278 * connection to be re-encrypted with an LTK, even if the LTK
2279 * provides the same level of security. Only exception is if we
2280 * don't have an LTK (e.g. because of key distribution bits).
2281 */
2282 if (key_pref == SMP_USE_LTK &&
2283 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) &&
2284 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role))
2285 return false;
2286
2287 if (hcon->sec_level >= sec_level)
2288 return true;
2289
2290 return false;
2291 }
2292
smp_send_pairing_req(struct smp_chan * smp,__u8 auth)2293 static void smp_send_pairing_req(struct smp_chan *smp, __u8 auth)
2294 {
2295 struct smp_cmd_pairing cp;
2296
2297 if (smp->conn->hcon->type == ACL_LINK)
2298 build_bredr_pairing_cmd(smp, &cp, NULL);
2299 else
2300 build_pairing_cmd(smp->conn, &cp, NULL, auth);
2301
2302 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2303 memcpy(&smp->preq[1], &cp, sizeof(cp));
2304
2305 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
2306 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2307
2308 set_bit(SMP_FLAG_INITIATOR, &smp->flags);
2309 }
2310
smp_cmd_security_req(struct l2cap_conn * conn,struct sk_buff * skb)2311 static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
2312 {
2313 struct smp_cmd_security_req *rp = (void *) skb->data;
2314 struct hci_conn *hcon = conn->hcon;
2315 struct hci_dev *hdev = hcon->hdev;
2316 struct smp_chan *smp;
2317 u8 sec_level, auth;
2318
2319 bt_dev_dbg(hdev, "conn %p", conn);
2320
2321 if (skb->len < sizeof(*rp))
2322 return SMP_INVALID_PARAMS;
2323
2324 if (hcon->role != HCI_ROLE_MASTER)
2325 return SMP_CMD_NOTSUPP;
2326
2327 auth = rp->auth_req & AUTH_REQ_MASK(hdev);
2328
2329 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
2330 return SMP_AUTH_REQUIREMENTS;
2331
2332 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
2333 sec_level = BT_SECURITY_MEDIUM;
2334 else
2335 sec_level = authreq_to_seclevel(auth);
2336
2337 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) {
2338 /* If link is already encrypted with sufficient security we
2339 * still need refresh encryption as per Core Spec 5.0 Vol 3,
2340 * Part H 2.4.6
2341 */
2342 smp_ltk_encrypt(conn, hcon->sec_level);
2343 return 0;
2344 }
2345
2346 if (sec_level > hcon->pending_sec_level)
2347 hcon->pending_sec_level = sec_level;
2348
2349 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2350 return 0;
2351
2352 smp = smp_chan_create(conn);
2353 if (!smp)
2354 return SMP_UNSPECIFIED;
2355
2356 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) &&
2357 (auth & SMP_AUTH_BONDING))
2358 return SMP_PAIRING_NOTSUPP;
2359
2360 skb_pull(skb, sizeof(*rp));
2361
2362 smp_send_pairing_req(smp, auth);
2363
2364 return 0;
2365 }
2366
smp_send_security_req(struct smp_chan * smp,__u8 auth)2367 static void smp_send_security_req(struct smp_chan *smp, __u8 auth)
2368 {
2369 struct smp_cmd_security_req cp;
2370
2371 cp.auth_req = auth;
2372 smp_send_cmd(smp->conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp);
2373 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ);
2374
2375 clear_bit(SMP_FLAG_INITIATOR, &smp->flags);
2376 }
2377
smp_conn_security(struct hci_conn * hcon,__u8 sec_level)2378 int smp_conn_security(struct hci_conn *hcon, __u8 sec_level)
2379 {
2380 struct l2cap_conn *conn = hcon->l2cap_data;
2381 struct l2cap_chan *chan;
2382 struct smp_chan *smp;
2383 __u8 authreq;
2384 int ret;
2385
2386 bt_dev_dbg(hcon->hdev, "conn %p hcon %p level 0x%2.2x", conn, hcon,
2387 sec_level);
2388
2389 /* This may be NULL if there's an unexpected disconnection */
2390 if (!conn)
2391 return 1;
2392
2393 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED))
2394 return 1;
2395
2396 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK))
2397 return 1;
2398
2399 if (sec_level > hcon->pending_sec_level)
2400 hcon->pending_sec_level = sec_level;
2401
2402 if (hcon->role == HCI_ROLE_MASTER)
2403 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2404 return 0;
2405
2406 chan = conn->smp;
2407 if (!chan) {
2408 bt_dev_err(hcon->hdev, "security requested but not available");
2409 return 1;
2410 }
2411
2412 l2cap_chan_lock(chan);
2413
2414 /* If SMP is already in progress ignore this request */
2415 if (chan->data) {
2416 ret = 0;
2417 goto unlock;
2418 }
2419
2420 smp = smp_chan_create(conn);
2421 if (!smp) {
2422 ret = 1;
2423 goto unlock;
2424 }
2425
2426 authreq = seclevel_to_authreq(sec_level);
2427
2428 if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED)) {
2429 authreq |= SMP_AUTH_SC;
2430 if (hci_dev_test_flag(hcon->hdev, HCI_SSP_ENABLED))
2431 authreq |= SMP_AUTH_CT2;
2432 }
2433
2434 /* Don't attempt to set MITM if setting is overridden by debugfs
2435 * Needed to pass certification test SM/MAS/PKE/BV-01-C
2436 */
2437 if (!hci_dev_test_flag(hcon->hdev, HCI_FORCE_NO_MITM)) {
2438 /* Require MITM if IO Capability allows or the security level
2439 * requires it.
2440 */
2441 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT ||
2442 hcon->pending_sec_level > BT_SECURITY_MEDIUM)
2443 authreq |= SMP_AUTH_MITM;
2444 }
2445
2446 if (hcon->role == HCI_ROLE_MASTER)
2447 smp_send_pairing_req(smp, authreq);
2448 else
2449 smp_send_security_req(smp, authreq);
2450
2451 ret = 0;
2452
2453 unlock:
2454 l2cap_chan_unlock(chan);
2455 return ret;
2456 }
2457
smp_cancel_and_remove_pairing(struct hci_dev * hdev,bdaddr_t * bdaddr,u8 addr_type)2458 int smp_cancel_and_remove_pairing(struct hci_dev *hdev, bdaddr_t *bdaddr,
2459 u8 addr_type)
2460 {
2461 struct hci_conn *hcon;
2462 struct l2cap_conn *conn;
2463 struct l2cap_chan *chan;
2464 struct smp_chan *smp;
2465 int err;
2466
2467 err = hci_remove_ltk(hdev, bdaddr, addr_type);
2468 hci_remove_irk(hdev, bdaddr, addr_type);
2469
2470 hcon = hci_conn_hash_lookup_le(hdev, bdaddr, addr_type);
2471 if (!hcon)
2472 goto done;
2473
2474 conn = hcon->l2cap_data;
2475 if (!conn)
2476 goto done;
2477
2478 chan = conn->smp;
2479 if (!chan)
2480 goto done;
2481
2482 l2cap_chan_lock(chan);
2483
2484 smp = chan->data;
2485 if (smp) {
2486 /* Set keys to NULL to make sure smp_failure() does not try to
2487 * remove and free already invalidated rcu list entries. */
2488 smp->ltk = NULL;
2489 smp->responder_ltk = NULL;
2490 smp->remote_irk = NULL;
2491
2492 if (test_bit(SMP_FLAG_COMPLETE, &smp->flags))
2493 smp_failure(conn, 0);
2494 else
2495 smp_failure(conn, SMP_UNSPECIFIED);
2496 err = 0;
2497 }
2498
2499 l2cap_chan_unlock(chan);
2500
2501 done:
2502 return err;
2503 }
2504
smp_cmd_encrypt_info(struct l2cap_conn * conn,struct sk_buff * skb)2505 static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb)
2506 {
2507 struct smp_cmd_encrypt_info *rp = (void *) skb->data;
2508 struct l2cap_chan *chan = conn->smp;
2509 struct smp_chan *smp = chan->data;
2510
2511 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn);
2512
2513 if (skb->len < sizeof(*rp))
2514 return SMP_INVALID_PARAMS;
2515
2516 /* Pairing is aborted if any blocked keys are distributed */
2517 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_LTK,
2518 rp->ltk)) {
2519 bt_dev_warn_ratelimited(conn->hcon->hdev,
2520 "LTK blocked for %pMR",
2521 &conn->hcon->dst);
2522 return SMP_INVALID_PARAMS;
2523 }
2524
2525 SMP_ALLOW_CMD(smp, SMP_CMD_INITIATOR_IDENT);
2526
2527 skb_pull(skb, sizeof(*rp));
2528
2529 memcpy(smp->tk, rp->ltk, sizeof(smp->tk));
2530
2531 return 0;
2532 }
2533
smp_cmd_initiator_ident(struct l2cap_conn * conn,struct sk_buff * skb)2534 static int smp_cmd_initiator_ident(struct l2cap_conn *conn, struct sk_buff *skb)
2535 {
2536 struct smp_cmd_initiator_ident *rp = (void *)skb->data;
2537 struct l2cap_chan *chan = conn->smp;
2538 struct smp_chan *smp = chan->data;
2539 struct hci_dev *hdev = conn->hcon->hdev;
2540 struct hci_conn *hcon = conn->hcon;
2541 struct smp_ltk *ltk;
2542 u8 authenticated;
2543
2544 bt_dev_dbg(hdev, "conn %p", conn);
2545
2546 if (skb->len < sizeof(*rp))
2547 return SMP_INVALID_PARAMS;
2548
2549 /* Mark the information as received */
2550 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY;
2551
2552 if (smp->remote_key_dist & SMP_DIST_ID_KEY)
2553 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
2554 else if (smp->remote_key_dist & SMP_DIST_SIGN)
2555 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2556
2557 skb_pull(skb, sizeof(*rp));
2558
2559 authenticated = (hcon->sec_level == BT_SECURITY_HIGH);
2560 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK,
2561 authenticated, smp->tk, smp->enc_key_size,
2562 rp->ediv, rp->rand);
2563 smp->ltk = ltk;
2564 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2565 smp_distribute_keys(smp);
2566
2567 return 0;
2568 }
2569
smp_cmd_ident_info(struct l2cap_conn * conn,struct sk_buff * skb)2570 static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb)
2571 {
2572 struct smp_cmd_ident_info *info = (void *) skb->data;
2573 struct l2cap_chan *chan = conn->smp;
2574 struct smp_chan *smp = chan->data;
2575
2576 bt_dev_dbg(conn->hcon->hdev, "");
2577
2578 if (skb->len < sizeof(*info))
2579 return SMP_INVALID_PARAMS;
2580
2581 /* Pairing is aborted if any blocked keys are distributed */
2582 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_IRK,
2583 info->irk)) {
2584 bt_dev_warn_ratelimited(conn->hcon->hdev,
2585 "Identity key blocked for %pMR",
2586 &conn->hcon->dst);
2587 return SMP_INVALID_PARAMS;
2588 }
2589
2590 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO);
2591
2592 skb_pull(skb, sizeof(*info));
2593
2594 memcpy(smp->irk, info->irk, 16);
2595
2596 return 0;
2597 }
2598
smp_cmd_ident_addr_info(struct l2cap_conn * conn,struct sk_buff * skb)2599 static int smp_cmd_ident_addr_info(struct l2cap_conn *conn,
2600 struct sk_buff *skb)
2601 {
2602 struct smp_cmd_ident_addr_info *info = (void *) skb->data;
2603 struct l2cap_chan *chan = conn->smp;
2604 struct smp_chan *smp = chan->data;
2605 struct hci_conn *hcon = conn->hcon;
2606 bdaddr_t rpa;
2607
2608 bt_dev_dbg(hcon->hdev, "");
2609
2610 if (skb->len < sizeof(*info))
2611 return SMP_INVALID_PARAMS;
2612
2613 /* Mark the information as received */
2614 smp->remote_key_dist &= ~SMP_DIST_ID_KEY;
2615
2616 if (smp->remote_key_dist & SMP_DIST_SIGN)
2617 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2618
2619 skb_pull(skb, sizeof(*info));
2620
2621 /* Strictly speaking the Core Specification (4.1) allows sending
2622 * an empty address which would force us to rely on just the IRK
2623 * as "identity information". However, since such
2624 * implementations are not known of and in order to not over
2625 * complicate our implementation, simply pretend that we never
2626 * received an IRK for such a device.
2627 *
2628 * The Identity Address must also be a Static Random or Public
2629 * Address, which hci_is_identity_address() checks for.
2630 */
2631 if (!bacmp(&info->bdaddr, BDADDR_ANY) ||
2632 !hci_is_identity_address(&info->bdaddr, info->addr_type)) {
2633 bt_dev_err(hcon->hdev, "ignoring IRK with no identity address");
2634 goto distribute;
2635 }
2636
2637 /* Drop IRK if peer is using identity address during pairing but is
2638 * providing different address as identity information.
2639 *
2640 * Microsoft Surface Precision Mouse is known to have this bug.
2641 */
2642 if (hci_is_identity_address(&hcon->dst, hcon->dst_type) &&
2643 (bacmp(&info->bdaddr, &hcon->dst) ||
2644 info->addr_type != hcon->dst_type)) {
2645 bt_dev_err(hcon->hdev,
2646 "ignoring IRK with invalid identity address");
2647 goto distribute;
2648 }
2649
2650 bacpy(&smp->id_addr, &info->bdaddr);
2651 smp->id_addr_type = info->addr_type;
2652
2653 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type))
2654 bacpy(&rpa, &hcon->dst);
2655 else
2656 bacpy(&rpa, BDADDR_ANY);
2657
2658 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr,
2659 smp->id_addr_type, smp->irk, &rpa);
2660
2661 distribute:
2662 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2663 smp_distribute_keys(smp);
2664
2665 return 0;
2666 }
2667
smp_cmd_sign_info(struct l2cap_conn * conn,struct sk_buff * skb)2668 static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb)
2669 {
2670 struct smp_cmd_sign_info *rp = (void *) skb->data;
2671 struct l2cap_chan *chan = conn->smp;
2672 struct smp_chan *smp = chan->data;
2673 struct smp_csrk *csrk;
2674
2675 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn);
2676
2677 if (skb->len < sizeof(*rp))
2678 return SMP_INVALID_PARAMS;
2679
2680 /* Mark the information as received */
2681 smp->remote_key_dist &= ~SMP_DIST_SIGN;
2682
2683 skb_pull(skb, sizeof(*rp));
2684
2685 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
2686 if (csrk) {
2687 if (conn->hcon->sec_level > BT_SECURITY_MEDIUM)
2688 csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED;
2689 else
2690 csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED;
2691 memcpy(csrk->val, rp->csrk, sizeof(csrk->val));
2692 }
2693 smp->csrk = csrk;
2694 smp_distribute_keys(smp);
2695
2696 return 0;
2697 }
2698
sc_select_method(struct smp_chan * smp)2699 static u8 sc_select_method(struct smp_chan *smp)
2700 {
2701 struct smp_cmd_pairing *local, *remote;
2702 u8 local_mitm, remote_mitm, local_io, remote_io, method;
2703
2704 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) ||
2705 test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags))
2706 return REQ_OOB;
2707
2708 /* The preq/prsp contain the raw Pairing Request/Response PDUs
2709 * which are needed as inputs to some crypto functions. To get
2710 * the "struct smp_cmd_pairing" from them we need to skip the
2711 * first byte which contains the opcode.
2712 */
2713 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2714 local = (void *) &smp->preq[1];
2715 remote = (void *) &smp->prsp[1];
2716 } else {
2717 local = (void *) &smp->prsp[1];
2718 remote = (void *) &smp->preq[1];
2719 }
2720
2721 local_io = local->io_capability;
2722 remote_io = remote->io_capability;
2723
2724 local_mitm = (local->auth_req & SMP_AUTH_MITM);
2725 remote_mitm = (remote->auth_req & SMP_AUTH_MITM);
2726
2727 /* If either side wants MITM, look up the method from the table,
2728 * otherwise use JUST WORKS.
2729 */
2730 if (local_mitm || remote_mitm)
2731 method = get_auth_method(smp, local_io, remote_io);
2732 else
2733 method = JUST_WORKS;
2734
2735 /* Don't confirm locally initiated pairing attempts */
2736 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2737 method = JUST_WORKS;
2738
2739 return method;
2740 }
2741
smp_cmd_public_key(struct l2cap_conn * conn,struct sk_buff * skb)2742 static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb)
2743 {
2744 struct smp_cmd_public_key *key = (void *) skb->data;
2745 struct hci_conn *hcon = conn->hcon;
2746 struct l2cap_chan *chan = conn->smp;
2747 struct smp_chan *smp = chan->data;
2748 struct hci_dev *hdev = hcon->hdev;
2749 struct crypto_kpp *tfm_ecdh;
2750 struct smp_cmd_pairing_confirm cfm;
2751 int err;
2752
2753 bt_dev_dbg(hdev, "conn %p", conn);
2754
2755 if (skb->len < sizeof(*key))
2756 return SMP_INVALID_PARAMS;
2757
2758 /* Check if remote and local public keys are the same and debug key is
2759 * not in use.
2760 */
2761 if (!test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags) &&
2762 !crypto_memneq(key, smp->local_pk, 64)) {
2763 bt_dev_err(hdev, "Remote and local public keys are identical");
2764 return SMP_UNSPECIFIED;
2765 }
2766
2767 memcpy(smp->remote_pk, key, 64);
2768
2769 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) {
2770 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk,
2771 smp->rr, 0, cfm.confirm_val);
2772 if (err)
2773 return SMP_UNSPECIFIED;
2774
2775 if (crypto_memneq(cfm.confirm_val, smp->pcnf, 16))
2776 return SMP_CONFIRM_FAILED;
2777 }
2778
2779 /* Non-initiating device sends its public key after receiving
2780 * the key from the initiating device.
2781 */
2782 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2783 err = sc_send_public_key(smp);
2784 if (err)
2785 return err;
2786 }
2787
2788 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk);
2789 SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32);
2790
2791 /* Compute the shared secret on the same crypto tfm on which the private
2792 * key was set/generated.
2793 */
2794 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) {
2795 struct l2cap_chan *hchan = hdev->smp_data;
2796 struct smp_dev *smp_dev;
2797
2798 if (!hchan || !hchan->data)
2799 return SMP_UNSPECIFIED;
2800
2801 smp_dev = hchan->data;
2802
2803 tfm_ecdh = smp_dev->tfm_ecdh;
2804 } else {
2805 tfm_ecdh = smp->tfm_ecdh;
2806 }
2807
2808 if (compute_ecdh_secret(tfm_ecdh, smp->remote_pk, smp->dhkey))
2809 return SMP_UNSPECIFIED;
2810
2811 SMP_DBG("DHKey %32phN", smp->dhkey);
2812
2813 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags);
2814
2815 smp->method = sc_select_method(smp);
2816
2817 bt_dev_dbg(hdev, "selected method 0x%02x", smp->method);
2818
2819 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */
2820 if (smp->method == JUST_WORKS || smp->method == JUST_CFM)
2821 hcon->pending_sec_level = BT_SECURITY_MEDIUM;
2822 else
2823 hcon->pending_sec_level = BT_SECURITY_FIPS;
2824
2825 if (!crypto_memneq(debug_pk, smp->remote_pk, 64))
2826 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
2827
2828 if (smp->method == DSP_PASSKEY) {
2829 get_random_bytes(&hcon->passkey_notify,
2830 sizeof(hcon->passkey_notify));
2831 hcon->passkey_notify %= 1000000;
2832 hcon->passkey_entered = 0;
2833 smp->passkey_round = 0;
2834 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type,
2835 hcon->dst_type,
2836 hcon->passkey_notify,
2837 hcon->passkey_entered))
2838 return SMP_UNSPECIFIED;
2839 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2840 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY);
2841 }
2842
2843 if (smp->method == REQ_OOB) {
2844 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2845 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2846 sizeof(smp->prnd), smp->prnd);
2847
2848 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2849
2850 return 0;
2851 }
2852
2853 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2854 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2855
2856 if (smp->method == REQ_PASSKEY) {
2857 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type,
2858 hcon->dst_type))
2859 return SMP_UNSPECIFIED;
2860 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2861 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2862 return 0;
2863 }
2864
2865 /* The Initiating device waits for the non-initiating device to
2866 * send the confirm value.
2867 */
2868 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2869 return 0;
2870
2871 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd,
2872 0, cfm.confirm_val);
2873 if (err)
2874 return SMP_UNSPECIFIED;
2875
2876 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
2877 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2878
2879 return 0;
2880 }
2881
smp_cmd_dhkey_check(struct l2cap_conn * conn,struct sk_buff * skb)2882 static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb)
2883 {
2884 struct smp_cmd_dhkey_check *check = (void *) skb->data;
2885 struct l2cap_chan *chan = conn->smp;
2886 struct hci_conn *hcon = conn->hcon;
2887 struct smp_chan *smp = chan->data;
2888 u8 a[7], b[7], *local_addr, *remote_addr;
2889 u8 io_cap[3], r[16], e[16];
2890 int err;
2891
2892 bt_dev_dbg(hcon->hdev, "conn %p", conn);
2893
2894 if (skb->len < sizeof(*check))
2895 return SMP_INVALID_PARAMS;
2896
2897 memcpy(a, &hcon->init_addr, 6);
2898 memcpy(b, &hcon->resp_addr, 6);
2899 a[6] = hcon->init_addr_type;
2900 b[6] = hcon->resp_addr_type;
2901
2902 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2903 local_addr = a;
2904 remote_addr = b;
2905 memcpy(io_cap, &smp->prsp[1], 3);
2906 } else {
2907 local_addr = b;
2908 remote_addr = a;
2909 memcpy(io_cap, &smp->preq[1], 3);
2910 }
2911
2912 memset(r, 0, sizeof(r));
2913
2914 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2915 put_unaligned_le32(hcon->passkey_notify, r);
2916 else if (smp->method == REQ_OOB)
2917 memcpy(r, smp->lr, 16);
2918
2919 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r,
2920 io_cap, remote_addr, local_addr, e);
2921 if (err)
2922 return SMP_UNSPECIFIED;
2923
2924 if (crypto_memneq(check->e, e, 16))
2925 return SMP_DHKEY_CHECK_FAILED;
2926
2927 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2928 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
2929 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags);
2930 return 0;
2931 }
2932
2933 /* Responder sends DHKey check as response to initiator */
2934 sc_dhkey_check(smp);
2935 }
2936
2937 sc_add_ltk(smp);
2938
2939 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2940 hci_le_start_enc(hcon, 0, 0, smp->tk, smp->enc_key_size);
2941 hcon->enc_key_size = smp->enc_key_size;
2942 }
2943
2944 return 0;
2945 }
2946
smp_cmd_keypress_notify(struct l2cap_conn * conn,struct sk_buff * skb)2947 static int smp_cmd_keypress_notify(struct l2cap_conn *conn,
2948 struct sk_buff *skb)
2949 {
2950 struct smp_cmd_keypress_notify *kp = (void *) skb->data;
2951
2952 bt_dev_dbg(conn->hcon->hdev, "value 0x%02x", kp->value);
2953
2954 return 0;
2955 }
2956
smp_sig_channel(struct l2cap_chan * chan,struct sk_buff * skb)2957 static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb)
2958 {
2959 struct l2cap_conn *conn = chan->conn;
2960 struct hci_conn *hcon = conn->hcon;
2961 struct smp_chan *smp;
2962 __u8 code, reason;
2963 int err = 0;
2964
2965 if (skb->len < 1)
2966 return -EILSEQ;
2967
2968 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) {
2969 reason = SMP_PAIRING_NOTSUPP;
2970 goto done;
2971 }
2972
2973 code = skb->data[0];
2974 skb_pull(skb, sizeof(code));
2975
2976 smp = chan->data;
2977
2978 if (code > SMP_CMD_MAX)
2979 goto drop;
2980
2981 if (smp && !test_and_clear_bit(code, &smp->allow_cmd))
2982 goto drop;
2983
2984 /* If we don't have a context the only allowed commands are
2985 * pairing request and security request.
2986 */
2987 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ)
2988 goto drop;
2989
2990 switch (code) {
2991 case SMP_CMD_PAIRING_REQ:
2992 reason = smp_cmd_pairing_req(conn, skb);
2993 break;
2994
2995 case SMP_CMD_PAIRING_FAIL:
2996 smp_failure(conn, 0);
2997 err = -EPERM;
2998 break;
2999
3000 case SMP_CMD_PAIRING_RSP:
3001 reason = smp_cmd_pairing_rsp(conn, skb);
3002 break;
3003
3004 case SMP_CMD_SECURITY_REQ:
3005 reason = smp_cmd_security_req(conn, skb);
3006 break;
3007
3008 case SMP_CMD_PAIRING_CONFIRM:
3009 reason = smp_cmd_pairing_confirm(conn, skb);
3010 break;
3011
3012 case SMP_CMD_PAIRING_RANDOM:
3013 reason = smp_cmd_pairing_random(conn, skb);
3014 break;
3015
3016 case SMP_CMD_ENCRYPT_INFO:
3017 reason = smp_cmd_encrypt_info(conn, skb);
3018 break;
3019
3020 case SMP_CMD_INITIATOR_IDENT:
3021 reason = smp_cmd_initiator_ident(conn, skb);
3022 break;
3023
3024 case SMP_CMD_IDENT_INFO:
3025 reason = smp_cmd_ident_info(conn, skb);
3026 break;
3027
3028 case SMP_CMD_IDENT_ADDR_INFO:
3029 reason = smp_cmd_ident_addr_info(conn, skb);
3030 break;
3031
3032 case SMP_CMD_SIGN_INFO:
3033 reason = smp_cmd_sign_info(conn, skb);
3034 break;
3035
3036 case SMP_CMD_PUBLIC_KEY:
3037 reason = smp_cmd_public_key(conn, skb);
3038 break;
3039
3040 case SMP_CMD_DHKEY_CHECK:
3041 reason = smp_cmd_dhkey_check(conn, skb);
3042 break;
3043
3044 case SMP_CMD_KEYPRESS_NOTIFY:
3045 reason = smp_cmd_keypress_notify(conn, skb);
3046 break;
3047
3048 default:
3049 bt_dev_dbg(hcon->hdev, "Unknown command code 0x%2.2x", code);
3050 reason = SMP_CMD_NOTSUPP;
3051 goto done;
3052 }
3053
3054 done:
3055 if (!err) {
3056 if (reason)
3057 smp_failure(conn, reason);
3058 kfree_skb(skb);
3059 }
3060
3061 return err;
3062
3063 drop:
3064 bt_dev_err(hcon->hdev, "unexpected SMP command 0x%02x from %pMR",
3065 code, &hcon->dst);
3066 kfree_skb(skb);
3067 return 0;
3068 }
3069
smp_teardown_cb(struct l2cap_chan * chan,int err)3070 static void smp_teardown_cb(struct l2cap_chan *chan, int err)
3071 {
3072 struct l2cap_conn *conn = chan->conn;
3073
3074 bt_dev_dbg(conn->hcon->hdev, "chan %p", chan);
3075
3076 if (chan->data)
3077 smp_chan_destroy(conn);
3078
3079 conn->smp = NULL;
3080 l2cap_chan_put(chan);
3081 }
3082
bredr_pairing(struct l2cap_chan * chan)3083 static void bredr_pairing(struct l2cap_chan *chan)
3084 {
3085 struct l2cap_conn *conn = chan->conn;
3086 struct hci_conn *hcon = conn->hcon;
3087 struct hci_dev *hdev = hcon->hdev;
3088 struct smp_chan *smp;
3089
3090 bt_dev_dbg(hdev, "chan %p", chan);
3091
3092 /* Only new pairings are interesting */
3093 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags))
3094 return;
3095
3096 /* Don't bother if we're not encrypted */
3097 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3098 return;
3099
3100 /* Only initiator may initiate SMP over BR/EDR */
3101 if (hcon->role != HCI_ROLE_MASTER)
3102 return;
3103
3104 /* Secure Connections support must be enabled */
3105 if (!hci_dev_test_flag(hdev, HCI_SC_ENABLED))
3106 return;
3107
3108 /* BR/EDR must use Secure Connections for SMP */
3109 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) &&
3110 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3111 return;
3112
3113 /* If our LE support is not enabled don't do anything */
3114 if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED))
3115 return;
3116
3117 /* Don't bother if remote LE support is not enabled */
3118 if (!lmp_host_le_capable(hcon))
3119 return;
3120
3121 /* Remote must support SMP fixed chan for BR/EDR */
3122 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR))
3123 return;
3124
3125 /* Don't bother if SMP is already ongoing */
3126 if (chan->data)
3127 return;
3128
3129 smp = smp_chan_create(conn);
3130 if (!smp) {
3131 bt_dev_err(hdev, "unable to create SMP context for BR/EDR");
3132 return;
3133 }
3134
3135 set_bit(SMP_FLAG_SC, &smp->flags);
3136
3137 bt_dev_dbg(hdev, "starting SMP over BR/EDR");
3138
3139 smp_send_pairing_req(smp, 0x00);
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