1 /*
2 BlueZ - Bluetooth protocol stack for Linux
3 Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License version 2 as
7 published by the Free Software Foundation;
8
9 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
10 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
11 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
12 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
13 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
14 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17
18 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
19 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
20 SOFTWARE IS DISCLAIMED.
21 */
22
23 #include <linux/debugfs.h>
24 #include <linux/scatterlist.h>
25 #include <crypto/aes.h>
26 #include <crypto/hash.h>
27 #include <crypto/kpp.h>
28 #include <crypto/utils.h>
29
30 #include <net/bluetooth/bluetooth.h>
31 #include <net/bluetooth/hci_core.h>
32 #include <net/bluetooth/l2cap.h>
33 #include <net/bluetooth/mgmt.h>
34
35 #include "ecdh_helper.h"
36 #include "smp.h"
37
38 #define SMP_DEV(hdev) \
39 ((struct smp_dev *)((struct l2cap_chan *)((hdev)->smp_data))->data)
40
41 /* Low-level debug macros to be used for stuff that we don't want
42 * accidentally in dmesg, i.e. the values of the various crypto keys
43 * and the inputs & outputs of crypto functions.
44 */
45 #ifdef DEBUG
46 #define SMP_DBG(fmt, ...) printk(KERN_DEBUG "%s: " fmt, __func__, \
47 ##__VA_ARGS__)
48 #else
49 #define SMP_DBG(fmt, ...) no_printk(KERN_DEBUG "%s: " fmt, __func__, \
50 ##__VA_ARGS__)
51 #endif
52
53 #define SMP_ALLOW_CMD(smp, code) set_bit(code, &smp->allow_cmd)
54
55 /* Keys which are not distributed with Secure Connections */
56 #define SMP_SC_NO_DIST (SMP_DIST_ENC_KEY | SMP_DIST_LINK_KEY)
57
58 #define SMP_TIMEOUT secs_to_jiffies(30)
59
60 #define ID_ADDR_TIMEOUT msecs_to_jiffies(200)
61
62 #define AUTH_REQ_MASK(dev) (hci_dev_test_flag(dev, HCI_SC_ENABLED) ? \
63 0x3f : 0x07)
64 #define KEY_DIST_MASK 0x07
65
66 /* Maximum message length that can be passed to aes_cmac */
67 #define CMAC_MSG_MAX 80
68
69 enum {
70 SMP_FLAG_TK_VALID,
71 SMP_FLAG_CFM_PENDING,
72 SMP_FLAG_MITM_AUTH,
73 SMP_FLAG_COMPLETE,
74 SMP_FLAG_INITIATOR,
75 SMP_FLAG_SC,
76 SMP_FLAG_REMOTE_PK,
77 SMP_FLAG_DEBUG_KEY,
78 SMP_FLAG_WAIT_USER,
79 SMP_FLAG_DHKEY_PENDING,
80 SMP_FLAG_REMOTE_OOB,
81 SMP_FLAG_LOCAL_OOB,
82 SMP_FLAG_CT2,
83 };
84
85 struct smp_dev {
86 /* Secure Connections OOB data */
87 bool local_oob;
88 u8 local_pk[64];
89 u8 local_rand[16];
90 bool debug_key;
91
92 struct crypto_shash *tfm_cmac;
93 struct crypto_kpp *tfm_ecdh;
94 };
95
96 struct smp_chan {
97 struct l2cap_conn *conn;
98 struct delayed_work security_timer;
99 unsigned long allow_cmd; /* Bitmask of allowed commands */
100
101 u8 preq[7]; /* SMP Pairing Request */
102 u8 prsp[7]; /* SMP Pairing Response */
103 u8 prnd[16]; /* SMP Pairing Random (local) */
104 u8 rrnd[16]; /* SMP Pairing Random (remote) */
105 u8 pcnf[16]; /* SMP Pairing Confirm */
106 u8 tk[16]; /* SMP Temporary Key */
107 u8 rr[16]; /* Remote OOB ra/rb value */
108 u8 lr[16]; /* Local OOB ra/rb value */
109 u8 enc_key_size;
110 u8 remote_key_dist;
111 bdaddr_t id_addr;
112 u8 id_addr_type;
113 u8 irk[16];
114 struct smp_csrk *csrk;
115 struct smp_csrk *responder_csrk;
116 struct smp_ltk *ltk;
117 struct smp_ltk *responder_ltk;
118 struct smp_irk *remote_irk;
119 u8 *link_key;
120 unsigned long flags;
121 u8 method;
122 u8 passkey_round;
123
124 /* Secure Connections variables */
125 u8 local_pk[64];
126 u8 remote_pk[64];
127 u8 dhkey[32];
128 u8 mackey[16];
129
130 struct crypto_shash *tfm_cmac;
131 struct crypto_kpp *tfm_ecdh;
132 };
133
134 /* These debug key values are defined in the SMP section of the core
135 * specification. debug_pk is the public debug key and debug_sk the
136 * private debug key.
137 */
138 static const u8 debug_pk[64] = {
139 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
140 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
141 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
142 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20,
143
144 0x8b, 0xd2, 0x89, 0x15, 0xd0, 0x8e, 0x1c, 0x74,
145 0x24, 0x30, 0xed, 0x8f, 0xc2, 0x45, 0x63, 0x76,
146 0x5c, 0x15, 0x52, 0x5a, 0xbf, 0x9a, 0x32, 0x63,
147 0x6d, 0xeb, 0x2a, 0x65, 0x49, 0x9c, 0x80, 0xdc,
148 };
149
150 static const u8 debug_sk[32] = {
151 0xbd, 0x1a, 0x3c, 0xcd, 0xa6, 0xb8, 0x99, 0x58,
152 0x99, 0xb7, 0x40, 0xeb, 0x7b, 0x60, 0xff, 0x4a,
153 0x50, 0x3f, 0x10, 0xd2, 0xe3, 0xb3, 0xc9, 0x74,
154 0x38, 0x5f, 0xc5, 0xa3, 0xd4, 0xf6, 0x49, 0x3f,
155 };
156
swap_buf(const u8 * src,u8 * dst,size_t len)157 static inline void swap_buf(const u8 *src, u8 *dst, size_t len)
158 {
159 size_t i;
160
161 for (i = 0; i < len; i++)
162 dst[len - 1 - i] = src[i];
163 }
164
165 /* The following functions map to the LE SC SMP crypto functions
166 * AES-CMAC, f4, f5, f6, g2 and h6.
167 */
168
aes_cmac(struct crypto_shash * tfm,const u8 k[16],const u8 * m,size_t len,u8 mac[16])169 static int aes_cmac(struct crypto_shash *tfm, const u8 k[16], const u8 *m,
170 size_t len, u8 mac[16])
171 {
172 uint8_t tmp[16], mac_msb[16], msg_msb[CMAC_MSG_MAX];
173 int err;
174
175 if (len > CMAC_MSG_MAX)
176 return -EFBIG;
177
178 if (!tfm) {
179 BT_ERR("tfm %p", tfm);
180 return -EINVAL;
181 }
182
183 /* Swap key and message from LSB to MSB */
184 swap_buf(k, tmp, 16);
185 swap_buf(m, msg_msb, len);
186
187 SMP_DBG("msg (len %zu) %*phN", len, (int) len, m);
188 SMP_DBG("key %16phN", k);
189
190 err = crypto_shash_setkey(tfm, tmp, 16);
191 if (err) {
192 BT_ERR("cipher setkey failed: %d", err);
193 return err;
194 }
195
196 err = crypto_shash_tfm_digest(tfm, msg_msb, len, mac_msb);
197 if (err) {
198 BT_ERR("Hash computation error %d", err);
199 return err;
200 }
201
202 swap_buf(mac_msb, mac, 16);
203
204 SMP_DBG("mac %16phN", mac);
205
206 return 0;
207 }
208
smp_f4(struct crypto_shash * tfm_cmac,const u8 u[32],const u8 v[32],const u8 x[16],u8 z,u8 res[16])209 static int smp_f4(struct crypto_shash *tfm_cmac, const u8 u[32],
210 const u8 v[32], const u8 x[16], u8 z, u8 res[16])
211 {
212 u8 m[65];
213 int err;
214
215 SMP_DBG("u %32phN", u);
216 SMP_DBG("v %32phN", v);
217 SMP_DBG("x %16phN z %02x", x, z);
218
219 m[0] = z;
220 memcpy(m + 1, v, 32);
221 memcpy(m + 33, u, 32);
222
223 err = aes_cmac(tfm_cmac, x, m, sizeof(m), res);
224 if (err)
225 return err;
226
227 SMP_DBG("res %16phN", res);
228
229 return err;
230 }
231
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])232 static int smp_f5(struct crypto_shash *tfm_cmac, const u8 w[32],
233 const u8 n1[16], const u8 n2[16], const u8 a1[7],
234 const u8 a2[7], u8 mackey[16], u8 ltk[16])
235 {
236 /* The btle, salt and length "magic" values are as defined in
237 * the SMP section of the Bluetooth core specification. In ASCII
238 * the btle value ends up being 'btle'. The salt is just a
239 * random number whereas length is the value 256 in little
240 * endian format.
241 */
242 const u8 btle[4] = { 0x65, 0x6c, 0x74, 0x62 };
243 const u8 salt[16] = { 0xbe, 0x83, 0x60, 0x5a, 0xdb, 0x0b, 0x37, 0x60,
244 0x38, 0xa5, 0xf5, 0xaa, 0x91, 0x83, 0x88, 0x6c };
245 const u8 length[2] = { 0x00, 0x01 };
246 u8 m[53], t[16];
247 int err;
248
249 SMP_DBG("w %32phN", w);
250 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
251 SMP_DBG("a1 %7phN a2 %7phN", a1, a2);
252
253 err = aes_cmac(tfm_cmac, salt, w, 32, t);
254 if (err)
255 return err;
256
257 SMP_DBG("t %16phN", t);
258
259 memcpy(m, length, 2);
260 memcpy(m + 2, a2, 7);
261 memcpy(m + 9, a1, 7);
262 memcpy(m + 16, n2, 16);
263 memcpy(m + 32, n1, 16);
264 memcpy(m + 48, btle, 4);
265
266 m[52] = 0; /* Counter */
267
268 err = aes_cmac(tfm_cmac, t, m, sizeof(m), mackey);
269 if (err)
270 return err;
271
272 SMP_DBG("mackey %16phN", mackey);
273
274 m[52] = 1; /* Counter */
275
276 err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk);
277 if (err)
278 return err;
279
280 SMP_DBG("ltk %16phN", ltk);
281
282 return 0;
283 }
284
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])285 static int smp_f6(struct crypto_shash *tfm_cmac, const u8 w[16],
286 const u8 n1[16], const u8 n2[16], const u8 r[16],
287 const u8 io_cap[3], const u8 a1[7], const u8 a2[7],
288 u8 res[16])
289 {
290 u8 m[65];
291 int err;
292
293 SMP_DBG("w %16phN", w);
294 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
295 SMP_DBG("r %16phN io_cap %3phN a1 %7phN a2 %7phN", r, io_cap, a1, a2);
296
297 memcpy(m, a2, 7);
298 memcpy(m + 7, a1, 7);
299 memcpy(m + 14, io_cap, 3);
300 memcpy(m + 17, r, 16);
301 memcpy(m + 33, n2, 16);
302 memcpy(m + 49, n1, 16);
303
304 err = aes_cmac(tfm_cmac, w, m, sizeof(m), res);
305 if (err)
306 return err;
307
308 SMP_DBG("res %16phN", res);
309
310 return err;
311 }
312
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)313 static int smp_g2(struct crypto_shash *tfm_cmac, const u8 u[32], const u8 v[32],
314 const u8 x[16], const u8 y[16], u32 *val)
315 {
316 u8 m[80], tmp[16];
317 int err;
318
319 SMP_DBG("u %32phN", u);
320 SMP_DBG("v %32phN", v);
321 SMP_DBG("x %16phN y %16phN", x, y);
322
323 memcpy(m, y, 16);
324 memcpy(m + 16, v, 32);
325 memcpy(m + 48, u, 32);
326
327 err = aes_cmac(tfm_cmac, x, m, sizeof(m), tmp);
328 if (err)
329 return err;
330
331 *val = get_unaligned_le32(tmp);
332 *val %= 1000000;
333
334 SMP_DBG("val %06u", *val);
335
336 return 0;
337 }
338
smp_h6(struct crypto_shash * tfm_cmac,const u8 w[16],const u8 key_id[4],u8 res[16])339 static int smp_h6(struct crypto_shash *tfm_cmac, const u8 w[16],
340 const u8 key_id[4], u8 res[16])
341 {
342 int err;
343
344 SMP_DBG("w %16phN key_id %4phN", w, key_id);
345
346 err = aes_cmac(tfm_cmac, w, key_id, 4, res);
347 if (err)
348 return err;
349
350 SMP_DBG("res %16phN", res);
351
352 return err;
353 }
354
smp_h7(struct crypto_shash * tfm_cmac,const u8 w[16],const u8 salt[16],u8 res[16])355 static int smp_h7(struct crypto_shash *tfm_cmac, const u8 w[16],
356 const u8 salt[16], u8 res[16])
357 {
358 int err;
359
360 SMP_DBG("w %16phN salt %16phN", w, salt);
361
362 err = aes_cmac(tfm_cmac, salt, w, 16, res);
363 if (err)
364 return err;
365
366 SMP_DBG("res %16phN", res);
367
368 return err;
369 }
370
371 /* The following functions map to the legacy SMP crypto functions e, c1,
372 * s1 and ah.
373 */
374
smp_e(const u8 * k,u8 * r)375 static int smp_e(const u8 *k, u8 *r)
376 {
377 struct crypto_aes_ctx ctx;
378 uint8_t tmp[16], data[16];
379 int err;
380
381 SMP_DBG("k %16phN r %16phN", k, r);
382
383 /* The most significant octet of key corresponds to k[0] */
384 swap_buf(k, tmp, 16);
385
386 err = aes_expandkey(&ctx, tmp, 16);
387 if (err) {
388 BT_ERR("cipher setkey failed: %d", err);
389 return err;
390 }
391
392 /* Most significant octet of plaintextData corresponds to data[0] */
393 swap_buf(r, data, 16);
394
395 aes_encrypt(&ctx, data, data);
396
397 /* Most significant octet of encryptedData corresponds to data[0] */
398 swap_buf(data, r, 16);
399
400 SMP_DBG("r %16phN", r);
401
402 memzero_explicit(&ctx, sizeof(ctx));
403 return err;
404 }
405
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])406 static int smp_c1(const u8 k[16],
407 const u8 r[16], const u8 preq[7], const u8 pres[7], u8 _iat,
408 const bdaddr_t *ia, u8 _rat, const bdaddr_t *ra, u8 res[16])
409 {
410 u8 p1[16], p2[16];
411 int err;
412
413 SMP_DBG("k %16phN r %16phN", k, r);
414 SMP_DBG("iat %u ia %6phN rat %u ra %6phN", _iat, ia, _rat, ra);
415 SMP_DBG("preq %7phN pres %7phN", preq, pres);
416
417 memset(p1, 0, 16);
418
419 /* p1 = pres || preq || _rat || _iat */
420 p1[0] = _iat;
421 p1[1] = _rat;
422 memcpy(p1 + 2, preq, 7);
423 memcpy(p1 + 9, pres, 7);
424
425 SMP_DBG("p1 %16phN", p1);
426
427 /* res = r XOR p1 */
428 crypto_xor_cpy(res, r, p1, sizeof(p1));
429
430 /* res = e(k, res) */
431 err = smp_e(k, res);
432 if (err) {
433 BT_ERR("Encrypt data error");
434 return err;
435 }
436
437 /* p2 = padding || ia || ra */
438 memcpy(p2, ra, 6);
439 memcpy(p2 + 6, ia, 6);
440 memset(p2 + 12, 0, 4);
441
442 SMP_DBG("p2 %16phN", p2);
443
444 /* res = res XOR p2 */
445 crypto_xor(res, p2, sizeof(p2));
446
447 /* res = e(k, res) */
448 err = smp_e(k, res);
449 if (err)
450 BT_ERR("Encrypt data error");
451
452 return err;
453 }
454
smp_s1(const u8 k[16],const u8 r1[16],const u8 r2[16],u8 _r[16])455 static int smp_s1(const u8 k[16],
456 const u8 r1[16], const u8 r2[16], u8 _r[16])
457 {
458 int err;
459
460 /* Just least significant octets from r1 and r2 are considered */
461 memcpy(_r, r2, 8);
462 memcpy(_r + 8, r1, 8);
463
464 err = smp_e(k, _r);
465 if (err)
466 BT_ERR("Encrypt data error");
467
468 return err;
469 }
470
smp_ah(const u8 irk[16],const u8 r[3],u8 res[3])471 static int smp_ah(const u8 irk[16], const u8 r[3], u8 res[3])
472 {
473 u8 _res[16];
474 int err;
475
476 /* r' = padding || r */
477 memcpy(_res, r, 3);
478 memset(_res + 3, 0, 13);
479
480 err = smp_e(irk, _res);
481 if (err) {
482 BT_ERR("Encrypt error");
483 return err;
484 }
485
486 /* The output of the random address function ah is:
487 * ah(k, r) = e(k, r') mod 2^24
488 * The output of the security function e is then truncated to 24 bits
489 * by taking the least significant 24 bits of the output of e as the
490 * result of ah.
491 */
492 memcpy(res, _res, 3);
493
494 return 0;
495 }
496
smp_irk_matches(struct hci_dev * hdev,const u8 irk[16],const bdaddr_t * bdaddr)497 bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16],
498 const bdaddr_t *bdaddr)
499 {
500 struct l2cap_chan *chan = hdev->smp_data;
501 u8 hash[3];
502 int err;
503
504 if (!chan || !chan->data)
505 return false;
506
507 bt_dev_dbg(hdev, "RPA %pMR IRK %*phN", bdaddr, 16, irk);
508
509 err = smp_ah(irk, &bdaddr->b[3], hash);
510 if (err)
511 return false;
512
513 return !crypto_memneq(bdaddr->b, hash, 3);
514 }
515
smp_generate_rpa(struct hci_dev * hdev,const u8 irk[16],bdaddr_t * rpa)516 int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa)
517 {
518 struct l2cap_chan *chan = hdev->smp_data;
519 int err;
520
521 if (!chan || !chan->data)
522 return -EOPNOTSUPP;
523
524 get_random_bytes(&rpa->b[3], 3);
525
526 rpa->b[5] &= 0x3f; /* Clear two most significant bits */
527 rpa->b[5] |= 0x40; /* Set second most significant bit */
528
529 err = smp_ah(irk, &rpa->b[3], rpa->b);
530 if (err < 0)
531 return err;
532
533 bt_dev_dbg(hdev, "RPA %pMR", rpa);
534
535 return 0;
536 }
537
smp_generate_oob(struct hci_dev * hdev,u8 hash[16],u8 rand[16])538 int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16])
539 {
540 struct l2cap_chan *chan = hdev->smp_data;
541 struct smp_dev *smp;
542 int err;
543
544 if (!chan || !chan->data)
545 return -EOPNOTSUPP;
546
547 smp = chan->data;
548
549 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) {
550 bt_dev_dbg(hdev, "Using debug keys");
551 err = set_ecdh_privkey(smp->tfm_ecdh, debug_sk);
552 if (err)
553 return err;
554 memcpy(smp->local_pk, debug_pk, 64);
555 smp->debug_key = true;
556 } else {
557 while (true) {
558 /* Generate key pair for Secure Connections */
559 err = generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk);
560 if (err)
561 return err;
562
563 /* This is unlikely, but we need to check that
564 * we didn't accidentally generate a debug key.
565 */
566 if (crypto_memneq(smp->local_pk, debug_pk, 64))
567 break;
568 }
569 smp->debug_key = false;
570 }
571
572 SMP_DBG("OOB Public Key X: %32phN", smp->local_pk);
573 SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32);
574
575 get_random_bytes(smp->local_rand, 16);
576
577 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->local_pk,
578 smp->local_rand, 0, hash);
579 if (err < 0)
580 return err;
581
582 memcpy(rand, smp->local_rand, 16);
583
584 smp->local_oob = true;
585
586 return 0;
587 }
588
smp_send_cmd(struct l2cap_conn * conn,u8 code,u16 len,void * data)589 static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
590 {
591 struct l2cap_chan *chan = conn->smp;
592 struct smp_chan *smp;
593 struct kvec iv[2];
594 struct msghdr msg;
595
596 if (!chan)
597 return;
598
599 bt_dev_dbg(conn->hcon->hdev, "code 0x%2.2x", code);
600
601 iv[0].iov_base = &code;
602 iv[0].iov_len = 1;
603
604 iv[1].iov_base = data;
605 iv[1].iov_len = len;
606
607 memset(&msg, 0, sizeof(msg));
608
609 iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iv, 2, 1 + len);
610
611 l2cap_chan_send(chan, &msg, 1 + len, NULL);
612
613 if (!chan->data)
614 return;
615
616 smp = chan->data;
617
618 cancel_delayed_work_sync(&smp->security_timer);
619 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT);
620 }
621
authreq_to_seclevel(u8 authreq)622 static u8 authreq_to_seclevel(u8 authreq)
623 {
624 if (authreq & SMP_AUTH_MITM) {
625 if (authreq & SMP_AUTH_SC)
626 return BT_SECURITY_FIPS;
627 else
628 return BT_SECURITY_HIGH;
629 } else {
630 return BT_SECURITY_MEDIUM;
631 }
632 }
633
seclevel_to_authreq(__u8 sec_level)634 static __u8 seclevel_to_authreq(__u8 sec_level)
635 {
636 switch (sec_level) {
637 case BT_SECURITY_FIPS:
638 case BT_SECURITY_HIGH:
639 return SMP_AUTH_MITM | SMP_AUTH_BONDING;
640 case BT_SECURITY_MEDIUM:
641 return SMP_AUTH_BONDING;
642 default:
643 return SMP_AUTH_NONE;
644 }
645 }
646
build_pairing_cmd(struct l2cap_conn * conn,struct smp_cmd_pairing * req,struct smp_cmd_pairing * rsp,__u8 authreq)647 static void build_pairing_cmd(struct l2cap_conn *conn,
648 struct smp_cmd_pairing *req,
649 struct smp_cmd_pairing *rsp, __u8 authreq)
650 {
651 struct l2cap_chan *chan = conn->smp;
652 struct smp_chan *smp = chan->data;
653 struct hci_conn *hcon = conn->hcon;
654 struct hci_dev *hdev = hcon->hdev;
655 u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT;
656
657 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) {
658 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
659 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
660 authreq |= SMP_AUTH_BONDING;
661 } else {
662 authreq &= ~SMP_AUTH_BONDING;
663 }
664
665 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING))
666 remote_dist |= SMP_DIST_ID_KEY;
667
668 if (hci_dev_test_flag(hdev, HCI_PRIVACY))
669 local_dist |= SMP_DIST_ID_KEY;
670
671 if (hci_dev_test_flag(hdev, HCI_SC_ENABLED) &&
672 (authreq & SMP_AUTH_SC)) {
673 struct oob_data *oob_data;
674 u8 bdaddr_type;
675
676 if (hci_dev_test_flag(hdev, HCI_SSP_ENABLED)) {
677 local_dist |= SMP_DIST_LINK_KEY;
678 remote_dist |= SMP_DIST_LINK_KEY;
679 }
680
681 if (hcon->dst_type == ADDR_LE_DEV_PUBLIC)
682 bdaddr_type = BDADDR_LE_PUBLIC;
683 else
684 bdaddr_type = BDADDR_LE_RANDOM;
685
686 oob_data = hci_find_remote_oob_data(hdev, &hcon->dst,
687 bdaddr_type);
688 if (oob_data && oob_data->present) {
689 set_bit(SMP_FLAG_REMOTE_OOB, &smp->flags);
690 oob_flag = SMP_OOB_PRESENT;
691 memcpy(smp->rr, oob_data->rand256, 16);
692 memcpy(smp->pcnf, oob_data->hash256, 16);
693 SMP_DBG("OOB Remote Confirmation: %16phN", smp->pcnf);
694 SMP_DBG("OOB Remote Random: %16phN", smp->rr);
695 }
696
697 } else {
698 authreq &= ~SMP_AUTH_SC;
699 }
700
701 if (rsp == NULL) {
702 req->io_capability = conn->hcon->io_capability;
703 req->oob_flag = oob_flag;
704 req->max_key_size = hdev->le_max_key_size;
705 req->init_key_dist = local_dist;
706 req->resp_key_dist = remote_dist;
707 req->auth_req = (authreq & AUTH_REQ_MASK(hdev));
708
709 smp->remote_key_dist = remote_dist;
710 return;
711 }
712
713 rsp->io_capability = conn->hcon->io_capability;
714 rsp->oob_flag = oob_flag;
715 rsp->max_key_size = hdev->le_max_key_size;
716 rsp->init_key_dist = req->init_key_dist & remote_dist;
717 rsp->resp_key_dist = req->resp_key_dist & local_dist;
718 rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev));
719
720 smp->remote_key_dist = rsp->init_key_dist;
721 }
722
check_enc_key_size(struct l2cap_conn * conn,__u8 max_key_size)723 static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)
724 {
725 struct l2cap_chan *chan = conn->smp;
726 struct hci_dev *hdev = conn->hcon->hdev;
727 struct smp_chan *smp = chan->data;
728
729 if (conn->hcon->pending_sec_level == BT_SECURITY_FIPS &&
730 max_key_size != SMP_MAX_ENC_KEY_SIZE)
731 return SMP_ENC_KEY_SIZE;
732
733 if (max_key_size > hdev->le_max_key_size ||
734 max_key_size < SMP_MIN_ENC_KEY_SIZE)
735 return SMP_ENC_KEY_SIZE;
736
737 smp->enc_key_size = max_key_size;
738
739 return 0;
740 }
741
smp_chan_destroy(struct l2cap_conn * conn)742 static void smp_chan_destroy(struct l2cap_conn *conn)
743 {
744 struct l2cap_chan *chan = conn->smp;
745 struct smp_chan *smp = chan->data;
746 struct hci_conn *hcon = conn->hcon;
747 bool complete;
748
749 BUG_ON(!smp);
750
751 cancel_delayed_work_sync(&smp->security_timer);
752
753 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags);
754 mgmt_smp_complete(hcon, complete);
755
756 kfree_sensitive(smp->csrk);
757 kfree_sensitive(smp->responder_csrk);
758 kfree_sensitive(smp->link_key);
759
760 crypto_free_shash(smp->tfm_cmac);
761 crypto_free_kpp(smp->tfm_ecdh);
762
763 /* Ensure that we don't leave any debug key around if debug key
764 * support hasn't been explicitly enabled.
765 */
766 if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG &&
767 !hci_dev_test_flag(hcon->hdev, HCI_KEEP_DEBUG_KEYS)) {
768 list_del_rcu(&smp->ltk->list);
769 kfree_rcu(smp->ltk, rcu);
770 smp->ltk = NULL;
771 }
772
773 /* If pairing failed clean up any keys we might have */
774 if (!complete) {
775 if (smp->ltk) {
776 list_del_rcu(&smp->ltk->list);
777 kfree_rcu(smp->ltk, rcu);
778 }
779
780 if (smp->responder_ltk) {
781 list_del_rcu(&smp->responder_ltk->list);
782 kfree_rcu(smp->responder_ltk, rcu);
783 }
784
785 if (smp->remote_irk) {
786 list_del_rcu(&smp->remote_irk->list);
787 kfree_rcu(smp->remote_irk, rcu);
788 }
789 }
790
791 chan->data = NULL;
792 kfree_sensitive(smp);
793 hci_conn_drop(hcon);
794 }
795
smp_failure(struct l2cap_conn * conn,u8 reason)796 static void smp_failure(struct l2cap_conn *conn, u8 reason)
797 {
798 struct hci_conn *hcon = conn->hcon;
799 struct l2cap_chan *chan = conn->smp;
800
801 if (reason)
802 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
803 &reason);
804
805 mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE);
806
807 if (chan->data)
808 smp_chan_destroy(conn);
809 }
810
811 #define JUST_WORKS 0x00
812 #define JUST_CFM 0x01
813 #define REQ_PASSKEY 0x02
814 #define CFM_PASSKEY 0x03
815 #define REQ_OOB 0x04
816 #define DSP_PASSKEY 0x05
817 #define OVERLAP 0xFF
818
819 static const u8 gen_method[5][5] = {
820 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
821 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
822 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
823 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
824 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP },
825 };
826
827 static const u8 sc_method[5][5] = {
828 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
829 { JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
830 { DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY },
831 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
832 { DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
833 };
834
get_auth_method(struct smp_chan * smp,u8 local_io,u8 remote_io)835 static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io)
836 {
837 /* If either side has unknown io_caps, use JUST_CFM (which gets
838 * converted later to JUST_WORKS if we're initiators.
839 */
840 if (local_io > SMP_IO_KEYBOARD_DISPLAY ||
841 remote_io > SMP_IO_KEYBOARD_DISPLAY)
842 return JUST_CFM;
843
844 if (test_bit(SMP_FLAG_SC, &smp->flags))
845 return sc_method[remote_io][local_io];
846
847 return gen_method[remote_io][local_io];
848 }
849
tk_request(struct l2cap_conn * conn,u8 remote_oob,u8 auth,u8 local_io,u8 remote_io)850 static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth,
851 u8 local_io, u8 remote_io)
852 {
853 struct hci_conn *hcon = conn->hcon;
854 struct l2cap_chan *chan = conn->smp;
855 struct smp_chan *smp = chan->data;
856 u32 passkey = 0;
857 int ret;
858
859 /* Initialize key for JUST WORKS */
860 memset(smp->tk, 0, sizeof(smp->tk));
861 clear_bit(SMP_FLAG_TK_VALID, &smp->flags);
862
863 bt_dev_dbg(hcon->hdev, "auth:%u lcl:%u rem:%u", auth, local_io,
864 remote_io);
865
866 /* If neither side wants MITM, either "just" confirm an incoming
867 * request or use just-works for outgoing ones. The JUST_CFM
868 * will be converted to JUST_WORKS if necessary later in this
869 * function. If either side has MITM look up the method from the
870 * table.
871 */
872 if (!(auth & SMP_AUTH_MITM))
873 smp->method = JUST_CFM;
874 else
875 smp->method = get_auth_method(smp, local_io, remote_io);
876
877 /* Don't confirm locally initiated pairing attempts */
878 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR,
879 &smp->flags))
880 smp->method = JUST_WORKS;
881
882 /* Don't bother user space with no IO capabilities */
883 if (smp->method == JUST_CFM &&
884 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
885 smp->method = JUST_WORKS;
886
887 /* If Just Works, Continue with Zero TK and ask user-space for
888 * confirmation */
889 if (smp->method == JUST_WORKS) {
890 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
891 hcon->type,
892 hcon->dst_type,
893 passkey, 1);
894 if (ret)
895 return ret;
896 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
897 return 0;
898 }
899
900 /* If this function is used for SC -> legacy fallback we
901 * can only recover the just-works case.
902 */
903 if (test_bit(SMP_FLAG_SC, &smp->flags))
904 return -EINVAL;
905
906 /* Not Just Works/Confirm results in MITM Authentication */
907 if (smp->method != JUST_CFM) {
908 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags);
909 if (hcon->pending_sec_level < BT_SECURITY_HIGH)
910 hcon->pending_sec_level = BT_SECURITY_HIGH;
911 }
912
913 /* If both devices have Keyboard-Display I/O, the initiator
914 * Confirms and the responder Enters the passkey.
915 */
916 if (smp->method == OVERLAP) {
917 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags))
918 smp->method = CFM_PASSKEY;
919 else
920 smp->method = REQ_PASSKEY;
921 }
922
923 /* Generate random passkey. */
924 if (smp->method == CFM_PASSKEY) {
925 memset(smp->tk, 0, sizeof(smp->tk));
926 get_random_bytes(&passkey, sizeof(passkey));
927 passkey %= 1000000;
928 put_unaligned_le32(passkey, smp->tk);
929 bt_dev_dbg(hcon->hdev, "PassKey: %u", passkey);
930 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
931 }
932
933 if (smp->method == REQ_PASSKEY)
934 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst,
935 hcon->type, hcon->dst_type);
936 else if (smp->method == JUST_CFM)
937 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
938 hcon->type, hcon->dst_type,
939 passkey, 1);
940 else
941 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst,
942 hcon->type, hcon->dst_type,
943 passkey, 0);
944
945 return ret;
946 }
947
smp_confirm(struct smp_chan * smp)948 static u8 smp_confirm(struct smp_chan *smp)
949 {
950 struct l2cap_conn *conn = smp->conn;
951 struct smp_cmd_pairing_confirm cp;
952 int ret;
953
954 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn);
955
956 ret = smp_c1(smp->tk, smp->prnd, smp->preq, smp->prsp,
957 conn->hcon->init_addr_type, &conn->hcon->init_addr,
958 conn->hcon->resp_addr_type, &conn->hcon->resp_addr,
959 cp.confirm_val);
960 if (ret)
961 return SMP_UNSPECIFIED;
962
963 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
964
965 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
966
967 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags))
968 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
969 else
970 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
971
972 return 0;
973 }
974
smp_random(struct smp_chan * smp)975 static u8 smp_random(struct smp_chan *smp)
976 {
977 struct l2cap_conn *conn = smp->conn;
978 struct hci_conn *hcon = conn->hcon;
979 u8 confirm[16];
980 int ret;
981
982 bt_dev_dbg(conn->hcon->hdev, "conn %p %s", conn,
983 test_bit(SMP_FLAG_INITIATOR, &smp->flags) ? "initiator" :
984 "responder");
985
986 ret = smp_c1(smp->tk, smp->rrnd, smp->preq, smp->prsp,
987 hcon->init_addr_type, &hcon->init_addr,
988 hcon->resp_addr_type, &hcon->resp_addr, confirm);
989 if (ret)
990 return SMP_UNSPECIFIED;
991
992 if (crypto_memneq(smp->pcnf, confirm, sizeof(smp->pcnf))) {
993 bt_dev_err(hcon->hdev, "pairing failed "
994 "(confirmation values mismatch)");
995 return SMP_CONFIRM_FAILED;
996 }
997
998 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
999 u8 stk[16];
1000 __le64 rand = 0;
1001 __le16 ediv = 0;
1002
1003 smp_s1(smp->tk, smp->rrnd, smp->prnd, stk);
1004
1005 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
1006 return SMP_UNSPECIFIED;
1007
1008 hci_le_start_enc(hcon, ediv, rand, stk, smp->enc_key_size);
1009 hcon->enc_key_size = smp->enc_key_size;
1010 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
1011 } else {
1012 u8 stk[16], auth;
1013 __le64 rand = 0;
1014 __le16 ediv = 0;
1015
1016 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
1017 smp->prnd);
1018
1019 smp_s1(smp->tk, smp->prnd, smp->rrnd, stk);
1020
1021 if (hcon->pending_sec_level == BT_SECURITY_HIGH)
1022 auth = 1;
1023 else
1024 auth = 0;
1025
1026 /* Even though there's no _RESPONDER suffix this is the
1027 * responder STK we're adding for later lookup (the initiator
1028 * STK never needs to be stored).
1029 */
1030 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1031 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand);
1032 }
1033
1034 return 0;
1035 }
1036
smp_notify_keys(struct l2cap_conn * conn)1037 static void smp_notify_keys(struct l2cap_conn *conn)
1038 {
1039 struct l2cap_chan *chan = conn->smp;
1040 struct smp_chan *smp = chan->data;
1041 struct hci_conn *hcon = conn->hcon;
1042 struct hci_dev *hdev = hcon->hdev;
1043 struct smp_cmd_pairing *req = (void *) &smp->preq[1];
1044 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1];
1045 bool persistent;
1046
1047 if (hcon->type == ACL_LINK) {
1048 if (hcon->key_type == HCI_LK_DEBUG_COMBINATION)
1049 persistent = false;
1050 else
1051 persistent = !test_bit(HCI_CONN_FLUSH_KEY,
1052 &hcon->flags);
1053 } else {
1054 /* The LTKs, IRKs and CSRKs should be persistent only if
1055 * both sides had the bonding bit set in their
1056 * authentication requests.
1057 */
1058 persistent = !!((req->auth_req & rsp->auth_req) &
1059 SMP_AUTH_BONDING);
1060 }
1061
1062 if (smp->remote_irk) {
1063 mgmt_new_irk(hdev, smp->remote_irk, persistent);
1064
1065 /* Now that user space can be considered to know the
1066 * identity address track the connection based on it
1067 * from now on (assuming this is an LE link).
1068 */
1069 if (hcon->type == LE_LINK) {
1070 bacpy(&hcon->dst, &smp->remote_irk->bdaddr);
1071 hcon->dst_type = smp->remote_irk->addr_type;
1072 /* Use a short delay to make sure the new address is
1073 * propagated _before_ the channels.
1074 */
1075 queue_delayed_work(hdev->workqueue,
1076 &conn->id_addr_timer,
1077 ID_ADDR_TIMEOUT);
1078 }
1079 }
1080
1081 if (smp->csrk) {
1082 smp->csrk->bdaddr_type = hcon->dst_type;
1083 bacpy(&smp->csrk->bdaddr, &hcon->dst);
1084 mgmt_new_csrk(hdev, smp->csrk, persistent);
1085 }
1086
1087 if (smp->responder_csrk) {
1088 smp->responder_csrk->bdaddr_type = hcon->dst_type;
1089 bacpy(&smp->responder_csrk->bdaddr, &hcon->dst);
1090 mgmt_new_csrk(hdev, smp->responder_csrk, persistent);
1091 }
1092
1093 if (smp->ltk) {
1094 smp->ltk->bdaddr_type = hcon->dst_type;
1095 bacpy(&smp->ltk->bdaddr, &hcon->dst);
1096 mgmt_new_ltk(hdev, smp->ltk, persistent);
1097 }
1098
1099 if (smp->responder_ltk) {
1100 smp->responder_ltk->bdaddr_type = hcon->dst_type;
1101 bacpy(&smp->responder_ltk->bdaddr, &hcon->dst);
1102 mgmt_new_ltk(hdev, smp->responder_ltk, persistent);
1103 }
1104
1105 if (smp->link_key) {
1106 struct link_key *key;
1107 u8 type;
1108
1109 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1110 type = HCI_LK_DEBUG_COMBINATION;
1111 else if (hcon->sec_level == BT_SECURITY_FIPS)
1112 type = HCI_LK_AUTH_COMBINATION_P256;
1113 else
1114 type = HCI_LK_UNAUTH_COMBINATION_P256;
1115
1116 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst,
1117 smp->link_key, type, 0, &persistent);
1118 if (key) {
1119 mgmt_new_link_key(hdev, key, persistent);
1120
1121 /* Don't keep debug keys around if the relevant
1122 * flag is not set.
1123 */
1124 if (!hci_dev_test_flag(hdev, HCI_KEEP_DEBUG_KEYS) &&
1125 key->type == HCI_LK_DEBUG_COMBINATION) {
1126 list_del_rcu(&key->list);
1127 kfree_rcu(key, rcu);
1128 }
1129 }
1130 }
1131 }
1132
sc_add_ltk(struct smp_chan * smp)1133 static void sc_add_ltk(struct smp_chan *smp)
1134 {
1135 struct hci_conn *hcon = smp->conn->hcon;
1136 u8 key_type, auth;
1137
1138 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1139 key_type = SMP_LTK_P256_DEBUG;
1140 else
1141 key_type = SMP_LTK_P256;
1142
1143 if (hcon->pending_sec_level == BT_SECURITY_FIPS)
1144 auth = 1;
1145 else
1146 auth = 0;
1147
1148 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1149 key_type, auth, smp->tk, smp->enc_key_size,
1150 0, 0);
1151 }
1152
sc_generate_link_key(struct smp_chan * smp)1153 static void sc_generate_link_key(struct smp_chan *smp)
1154 {
1155 /* From core spec. Spells out in ASCII as 'lebr'. */
1156 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c };
1157
1158 smp->link_key = kzalloc(16, GFP_KERNEL);
1159 if (!smp->link_key)
1160 return;
1161
1162 if (test_bit(SMP_FLAG_CT2, &smp->flags)) {
1163 /* SALT = 0x000000000000000000000000746D7031 */
1164 const u8 salt[16] = { 0x31, 0x70, 0x6d, 0x74 };
1165
1166 if (smp_h7(smp->tfm_cmac, smp->tk, salt, smp->link_key)) {
1167 kfree_sensitive(smp->link_key);
1168 smp->link_key = NULL;
1169 return;
1170 }
1171 } else {
1172 /* From core spec. Spells out in ASCII as 'tmp1'. */
1173 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 };
1174
1175 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) {
1176 kfree_sensitive(smp->link_key);
1177 smp->link_key = NULL;
1178 return;
1179 }
1180 }
1181
1182 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) {
1183 kfree_sensitive(smp->link_key);
1184 smp->link_key = NULL;
1185 return;
1186 }
1187 }
1188
smp_allow_key_dist(struct smp_chan * smp)1189 static void smp_allow_key_dist(struct smp_chan *smp)
1190 {
1191 /* Allow the first expected phase 3 PDU. The rest of the PDUs
1192 * will be allowed in each PDU handler to ensure we receive
1193 * them in the correct order.
1194 */
1195 if (smp->remote_key_dist & SMP_DIST_ENC_KEY)
1196 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO);
1197 else if (smp->remote_key_dist & SMP_DIST_ID_KEY)
1198 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
1199 else if (smp->remote_key_dist & SMP_DIST_SIGN)
1200 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
1201 }
1202
sc_generate_ltk(struct smp_chan * smp)1203 static void sc_generate_ltk(struct smp_chan *smp)
1204 {
1205 /* From core spec. Spells out in ASCII as 'brle'. */
1206 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 };
1207 struct hci_conn *hcon = smp->conn->hcon;
1208 struct hci_dev *hdev = hcon->hdev;
1209 struct link_key *key;
1210
1211 key = hci_find_link_key(hdev, &hcon->dst);
1212 if (!key) {
1213 bt_dev_err(hdev, "no Link Key found to generate LTK");
1214 return;
1215 }
1216
1217 if (key->type == HCI_LK_DEBUG_COMBINATION)
1218 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1219
1220 if (test_bit(SMP_FLAG_CT2, &smp->flags)) {
1221 /* SALT = 0x000000000000000000000000746D7032 */
1222 const u8 salt[16] = { 0x32, 0x70, 0x6d, 0x74 };
1223
1224 if (smp_h7(smp->tfm_cmac, key->val, salt, smp->tk))
1225 return;
1226 } else {
1227 /* From core spec. Spells out in ASCII as 'tmp2'. */
1228 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 };
1229
1230 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk))
1231 return;
1232 }
1233
1234 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk))
1235 return;
1236
1237 sc_add_ltk(smp);
1238 }
1239
smp_distribute_keys(struct smp_chan * smp)1240 static void smp_distribute_keys(struct smp_chan *smp)
1241 {
1242 struct smp_cmd_pairing *req, *rsp;
1243 struct l2cap_conn *conn = smp->conn;
1244 struct hci_conn *hcon = conn->hcon;
1245 struct hci_dev *hdev = hcon->hdev;
1246 __u8 *keydist;
1247
1248 bt_dev_dbg(hdev, "conn %p", conn);
1249
1250 rsp = (void *) &smp->prsp[1];
1251
1252 /* The responder sends its keys first */
1253 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags) &&
1254 (smp->remote_key_dist & KEY_DIST_MASK)) {
1255 smp_allow_key_dist(smp);
1256 return;
1257 }
1258
1259 req = (void *) &smp->preq[1];
1260
1261 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1262 keydist = &rsp->init_key_dist;
1263 *keydist &= req->init_key_dist;
1264 } else {
1265 keydist = &rsp->resp_key_dist;
1266 *keydist &= req->resp_key_dist;
1267 }
1268
1269 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1270 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY))
1271 sc_generate_link_key(smp);
1272 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY))
1273 sc_generate_ltk(smp);
1274
1275 /* Clear the keys which are generated but not distributed */
1276 *keydist &= ~SMP_SC_NO_DIST;
1277 }
1278
1279 bt_dev_dbg(hdev, "keydist 0x%x", *keydist);
1280
1281 if (*keydist & SMP_DIST_ENC_KEY) {
1282 struct smp_cmd_encrypt_info enc;
1283 struct smp_cmd_initiator_ident ident;
1284 struct smp_ltk *ltk;
1285 u8 authenticated;
1286 __le16 ediv;
1287 __le64 rand;
1288
1289 /* Make sure we generate only the significant amount of
1290 * bytes based on the encryption key size, and set the rest
1291 * of the value to zeroes.
1292 */
1293 get_random_bytes(enc.ltk, smp->enc_key_size);
1294 memset(enc.ltk + smp->enc_key_size, 0,
1295 sizeof(enc.ltk) - smp->enc_key_size);
1296
1297 get_random_bytes(&ediv, sizeof(ediv));
1298 get_random_bytes(&rand, sizeof(rand));
1299
1300 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc);
1301
1302 authenticated = hcon->sec_level == BT_SECURITY_HIGH;
1303 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type,
1304 SMP_LTK_RESPONDER, authenticated, enc.ltk,
1305 smp->enc_key_size, ediv, rand);
1306 smp->responder_ltk = ltk;
1307
1308 ident.ediv = ediv;
1309 ident.rand = rand;
1310
1311 smp_send_cmd(conn, SMP_CMD_INITIATOR_IDENT, sizeof(ident),
1312 &ident);
1313
1314 *keydist &= ~SMP_DIST_ENC_KEY;
1315 }
1316
1317 if (*keydist & SMP_DIST_ID_KEY) {
1318 struct smp_cmd_ident_addr_info addrinfo;
1319 struct smp_cmd_ident_info idinfo;
1320
1321 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk));
1322
1323 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo);
1324
1325 /* The hci_conn contains the local identity address
1326 * after the connection has been established.
1327 *
1328 * This is true even when the connection has been
1329 * established using a resolvable random address.
1330 */
1331 bacpy(&addrinfo.bdaddr, &hcon->src);
1332 addrinfo.addr_type = hcon->src_type;
1333
1334 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo),
1335 &addrinfo);
1336
1337 *keydist &= ~SMP_DIST_ID_KEY;
1338 }
1339
1340 if (*keydist & SMP_DIST_SIGN) {
1341 struct smp_cmd_sign_info sign;
1342 struct smp_csrk *csrk;
1343
1344 /* Generate a new random key */
1345 get_random_bytes(sign.csrk, sizeof(sign.csrk));
1346
1347 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
1348 if (csrk) {
1349 if (hcon->sec_level > BT_SECURITY_MEDIUM)
1350 csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED;
1351 else
1352 csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED;
1353 memcpy(csrk->val, sign.csrk, sizeof(csrk->val));
1354 }
1355 smp->responder_csrk = csrk;
1356
1357 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign);
1358
1359 *keydist &= ~SMP_DIST_SIGN;
1360 }
1361
1362 /* If there are still keys to be received wait for them */
1363 if (smp->remote_key_dist & KEY_DIST_MASK) {
1364 smp_allow_key_dist(smp);
1365 return;
1366 }
1367
1368 set_bit(SMP_FLAG_COMPLETE, &smp->flags);
1369 smp_notify_keys(conn);
1370
1371 smp_chan_destroy(conn);
1372 }
1373
smp_timeout(struct work_struct * work)1374 static void smp_timeout(struct work_struct *work)
1375 {
1376 struct smp_chan *smp = container_of(work, struct smp_chan,
1377 security_timer.work);
1378 struct l2cap_conn *conn = smp->conn;
1379
1380 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn);
1381
1382 hci_disconnect(conn->hcon, HCI_ERROR_AUTH_FAILURE);
1383 }
1384
smp_chan_create(struct l2cap_conn * conn)1385 static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
1386 {
1387 struct hci_conn *hcon = conn->hcon;
1388 struct l2cap_chan *chan = conn->smp;
1389 struct smp_chan *smp;
1390
1391 smp = kzalloc(sizeof(*smp), GFP_ATOMIC);
1392 if (!smp)
1393 return NULL;
1394
1395 smp->tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
1396 if (IS_ERR(smp->tfm_cmac)) {
1397 bt_dev_err(hcon->hdev, "Unable to create CMAC crypto context");
1398 goto zfree_smp;
1399 }
1400
1401 smp->tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0);
1402 if (IS_ERR(smp->tfm_ecdh)) {
1403 bt_dev_err(hcon->hdev, "Unable to create ECDH crypto context");
1404 goto free_shash;
1405 }
1406
1407 smp->conn = conn;
1408 chan->data = smp;
1409
1410 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL);
1411
1412 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout);
1413
1414 hci_conn_hold(hcon);
1415
1416 return smp;
1417
1418 free_shash:
1419 crypto_free_shash(smp->tfm_cmac);
1420 zfree_smp:
1421 kfree_sensitive(smp);
1422 return NULL;
1423 }
1424
sc_mackey_and_ltk(struct smp_chan * smp,u8 mackey[16],u8 ltk[16])1425 static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16])
1426 {
1427 struct hci_conn *hcon = smp->conn->hcon;
1428 u8 *na, *nb, a[7], b[7];
1429
1430 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1431 na = smp->prnd;
1432 nb = smp->rrnd;
1433 } else {
1434 na = smp->rrnd;
1435 nb = smp->prnd;
1436 }
1437
1438 memcpy(a, &hcon->init_addr, 6);
1439 memcpy(b, &hcon->resp_addr, 6);
1440 a[6] = hcon->init_addr_type;
1441 b[6] = hcon->resp_addr_type;
1442
1443 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk);
1444 }
1445
sc_dhkey_check(struct smp_chan * smp)1446 static void sc_dhkey_check(struct smp_chan *smp)
1447 {
1448 struct hci_conn *hcon = smp->conn->hcon;
1449 struct smp_cmd_dhkey_check check;
1450 u8 a[7], b[7], *local_addr, *remote_addr;
1451 u8 io_cap[3], r[16];
1452
1453 memcpy(a, &hcon->init_addr, 6);
1454 memcpy(b, &hcon->resp_addr, 6);
1455 a[6] = hcon->init_addr_type;
1456 b[6] = hcon->resp_addr_type;
1457
1458 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1459 local_addr = a;
1460 remote_addr = b;
1461 memcpy(io_cap, &smp->preq[1], 3);
1462 } else {
1463 local_addr = b;
1464 remote_addr = a;
1465 memcpy(io_cap, &smp->prsp[1], 3);
1466 }
1467
1468 memset(r, 0, sizeof(r));
1469
1470 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
1471 put_unaligned_le32(hcon->passkey_notify, r);
1472
1473 if (smp->method == REQ_OOB)
1474 memcpy(r, smp->rr, 16);
1475
1476 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap,
1477 local_addr, remote_addr, check.e);
1478
1479 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check);
1480 }
1481
sc_passkey_send_confirm(struct smp_chan * smp)1482 static u8 sc_passkey_send_confirm(struct smp_chan *smp)
1483 {
1484 struct l2cap_conn *conn = smp->conn;
1485 struct hci_conn *hcon = conn->hcon;
1486 struct smp_cmd_pairing_confirm cfm;
1487 u8 r;
1488
1489 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1490 r |= 0x80;
1491
1492 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1493
1494 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r,
1495 cfm.confirm_val))
1496 return SMP_UNSPECIFIED;
1497
1498 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
1499
1500 return 0;
1501 }
1502
sc_passkey_round(struct smp_chan * smp,u8 smp_op)1503 static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op)
1504 {
1505 struct l2cap_conn *conn = smp->conn;
1506 struct hci_conn *hcon = conn->hcon;
1507 struct hci_dev *hdev = hcon->hdev;
1508 u8 cfm[16], r;
1509
1510 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */
1511 if (smp->passkey_round >= 20)
1512 return 0;
1513
1514 switch (smp_op) {
1515 case SMP_CMD_PAIRING_RANDOM:
1516 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1517 r |= 0x80;
1518
1519 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
1520 smp->rrnd, r, cfm))
1521 return SMP_UNSPECIFIED;
1522
1523 if (crypto_memneq(smp->pcnf, cfm, 16))
1524 return SMP_CONFIRM_FAILED;
1525
1526 smp->passkey_round++;
1527
1528 if (smp->passkey_round == 20) {
1529 /* Generate MacKey and LTK */
1530 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk))
1531 return SMP_UNSPECIFIED;
1532 }
1533
1534 /* The round is only complete when the initiator
1535 * receives pairing random.
1536 */
1537 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1538 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1539 sizeof(smp->prnd), smp->prnd);
1540 if (smp->passkey_round == 20)
1541 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1542 else
1543 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1544 return 0;
1545 }
1546
1547 /* Start the next round */
1548 if (smp->passkey_round != 20)
1549 return sc_passkey_round(smp, 0);
1550
1551 /* Passkey rounds are complete - start DHKey Check */
1552 sc_dhkey_check(smp);
1553 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1554
1555 break;
1556
1557 case SMP_CMD_PAIRING_CONFIRM:
1558 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
1559 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
1560 return 0;
1561 }
1562
1563 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
1564
1565 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1566 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1567 sizeof(smp->prnd), smp->prnd);
1568 return 0;
1569 }
1570
1571 return sc_passkey_send_confirm(smp);
1572
1573 case SMP_CMD_PUBLIC_KEY:
1574 default:
1575 /* Initiating device starts the round */
1576 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags))
1577 return 0;
1578
1579 bt_dev_dbg(hdev, "Starting passkey round %u",
1580 smp->passkey_round + 1);
1581
1582 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1583
1584 return sc_passkey_send_confirm(smp);
1585 }
1586
1587 return 0;
1588 }
1589
sc_user_reply(struct smp_chan * smp,u16 mgmt_op,__le32 passkey)1590 static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey)
1591 {
1592 struct l2cap_conn *conn = smp->conn;
1593 struct hci_conn *hcon = conn->hcon;
1594 u8 smp_op;
1595
1596 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags);
1597
1598 switch (mgmt_op) {
1599 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1600 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED);
1601 return 0;
1602 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1603 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED);
1604 return 0;
1605 case MGMT_OP_USER_PASSKEY_REPLY:
1606 hcon->passkey_notify = le32_to_cpu(passkey);
1607 smp->passkey_round = 0;
1608
1609 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags))
1610 smp_op = SMP_CMD_PAIRING_CONFIRM;
1611 else
1612 smp_op = 0;
1613
1614 if (sc_passkey_round(smp, smp_op))
1615 return -EIO;
1616
1617 return 0;
1618 }
1619
1620 /* Initiator sends DHKey check first */
1621 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
1622 sc_dhkey_check(smp);
1623 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1624 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) {
1625 sc_dhkey_check(smp);
1626 sc_add_ltk(smp);
1627 }
1628
1629 return 0;
1630 }
1631
smp_user_confirm_reply(struct hci_conn * hcon,u16 mgmt_op,__le32 passkey)1632 int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey)
1633 {
1634 struct l2cap_conn *conn = hcon->l2cap_data;
1635 struct l2cap_chan *chan;
1636 struct smp_chan *smp;
1637 u32 value;
1638 int err;
1639
1640 if (!conn)
1641 return -ENOTCONN;
1642
1643 bt_dev_dbg(conn->hcon->hdev, "");
1644
1645 chan = conn->smp;
1646 if (!chan)
1647 return -ENOTCONN;
1648
1649 l2cap_chan_lock(chan);
1650 if (!chan->data) {
1651 err = -ENOTCONN;
1652 goto unlock;
1653 }
1654
1655 smp = chan->data;
1656
1657 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1658 err = sc_user_reply(smp, mgmt_op, passkey);
1659 goto unlock;
1660 }
1661
1662 switch (mgmt_op) {
1663 case MGMT_OP_USER_PASSKEY_REPLY:
1664 value = le32_to_cpu(passkey);
1665 memset(smp->tk, 0, sizeof(smp->tk));
1666 bt_dev_dbg(conn->hcon->hdev, "PassKey: %u", value);
1667 put_unaligned_le32(value, smp->tk);
1668 fallthrough;
1669 case MGMT_OP_USER_CONFIRM_REPLY:
1670 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
1671 break;
1672 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1673 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1674 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1675 err = 0;
1676 goto unlock;
1677 default:
1678 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1679 err = -EOPNOTSUPP;
1680 goto unlock;
1681 }
1682
1683 err = 0;
1684
1685 /* If it is our turn to send Pairing Confirm, do so now */
1686 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) {
1687 u8 rsp = smp_confirm(smp);
1688 if (rsp)
1689 smp_failure(conn, rsp);
1690 }
1691
1692 unlock:
1693 l2cap_chan_unlock(chan);
1694 return err;
1695 }
1696
build_bredr_pairing_cmd(struct smp_chan * smp,struct smp_cmd_pairing * req,struct smp_cmd_pairing * rsp)1697 static void build_bredr_pairing_cmd(struct smp_chan *smp,
1698 struct smp_cmd_pairing *req,
1699 struct smp_cmd_pairing *rsp)
1700 {
1701 struct l2cap_conn *conn = smp->conn;
1702 struct hci_dev *hdev = conn->hcon->hdev;
1703 u8 local_dist = 0, remote_dist = 0;
1704
1705 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) {
1706 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1707 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1708 }
1709
1710 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING))
1711 remote_dist |= SMP_DIST_ID_KEY;
1712
1713 if (hci_dev_test_flag(hdev, HCI_PRIVACY))
1714 local_dist |= SMP_DIST_ID_KEY;
1715
1716 if (!rsp) {
1717 memset(req, 0, sizeof(*req));
1718
1719 req->auth_req = SMP_AUTH_CT2;
1720 req->init_key_dist = local_dist;
1721 req->resp_key_dist = remote_dist;
1722 req->max_key_size = conn->hcon->enc_key_size;
1723
1724 smp->remote_key_dist = remote_dist;
1725
1726 return;
1727 }
1728
1729 memset(rsp, 0, sizeof(*rsp));
1730
1731 rsp->auth_req = SMP_AUTH_CT2;
1732 rsp->max_key_size = conn->hcon->enc_key_size;
1733 rsp->init_key_dist = req->init_key_dist & remote_dist;
1734 rsp->resp_key_dist = req->resp_key_dist & local_dist;
1735
1736 smp->remote_key_dist = rsp->init_key_dist;
1737 }
1738
smp_cmd_pairing_req(struct l2cap_conn * conn,struct sk_buff * skb)1739 static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
1740 {
1741 struct smp_cmd_pairing rsp, *req = (void *) skb->data;
1742 struct l2cap_chan *chan = conn->smp;
1743 struct hci_dev *hdev = conn->hcon->hdev;
1744 struct smp_chan *smp = chan->data;
1745 u8 key_size, auth, sec_level;
1746 int ret;
1747
1748 bt_dev_dbg(hdev, "conn %p", conn);
1749
1750 if (skb->len < sizeof(*req))
1751 return SMP_INVALID_PARAMS;
1752
1753 if (smp && test_bit(SMP_FLAG_INITIATOR, &smp->flags))
1754 return SMP_CMD_NOTSUPP;
1755
1756 if (!smp) {
1757 smp = smp_chan_create(conn);
1758 if (!smp)
1759 return SMP_UNSPECIFIED;
1760 }
1761
1762 /* We didn't start the pairing, so match remote */
1763 auth = req->auth_req & AUTH_REQ_MASK(hdev);
1764
1765 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) &&
1766 (auth & SMP_AUTH_BONDING))
1767 return SMP_PAIRING_NOTSUPP;
1768
1769 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
1770 return SMP_AUTH_REQUIREMENTS;
1771
1772 smp->preq[0] = SMP_CMD_PAIRING_REQ;
1773 memcpy(&smp->preq[1], req, sizeof(*req));
1774 skb_pull(skb, sizeof(*req));
1775
1776 /* If the remote side's OOB flag is set it means it has
1777 * successfully received our local OOB data - therefore set the
1778 * flag to indicate that local OOB is in use.
1779 */
1780 if (req->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob)
1781 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);
1782
1783 /* SMP over BR/EDR requires special treatment */
1784 if (conn->hcon->type == ACL_LINK) {
1785 /* We must have a BR/EDR SC link */
1786 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) &&
1787 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
1788 return SMP_CROSS_TRANSP_NOT_ALLOWED;
1789
1790 set_bit(SMP_FLAG_SC, &smp->flags);
1791
1792 build_bredr_pairing_cmd(smp, req, &rsp);
1793
1794 if (req->auth_req & SMP_AUTH_CT2)
1795 set_bit(SMP_FLAG_CT2, &smp->flags);
1796
1797 key_size = min(req->max_key_size, rsp.max_key_size);
1798 if (check_enc_key_size(conn, key_size))
1799 return SMP_ENC_KEY_SIZE;
1800
1801 /* Clear bits which are generated but not distributed */
1802 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1803
1804 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1805 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1806 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1807
1808 smp_distribute_keys(smp);
1809 return 0;
1810 }
1811
1812 build_pairing_cmd(conn, req, &rsp, auth);
1813
1814 if (rsp.auth_req & SMP_AUTH_SC) {
1815 set_bit(SMP_FLAG_SC, &smp->flags);
1816
1817 if (rsp.auth_req & SMP_AUTH_CT2)
1818 set_bit(SMP_FLAG_CT2, &smp->flags);
1819 }
1820
1821 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
1822 sec_level = BT_SECURITY_MEDIUM;
1823 else
1824 sec_level = authreq_to_seclevel(auth);
1825
1826 if (sec_level > conn->hcon->pending_sec_level)
1827 conn->hcon->pending_sec_level = sec_level;
1828
1829 /* If we need MITM check that it can be achieved */
1830 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1831 u8 method;
1832
1833 method = get_auth_method(smp, conn->hcon->io_capability,
1834 req->io_capability);
1835 if (method == JUST_WORKS || method == JUST_CFM)
1836 return SMP_AUTH_REQUIREMENTS;
1837 }
1838
1839 key_size = min(req->max_key_size, rsp.max_key_size);
1840 if (check_enc_key_size(conn, key_size))
1841 return SMP_ENC_KEY_SIZE;
1842
1843 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1844
1845 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1846 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1847
1848 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1849
1850 clear_bit(SMP_FLAG_INITIATOR, &smp->flags);
1851
1852 /* Strictly speaking we shouldn't allow Pairing Confirm for the
1853 * SC case, however some implementations incorrectly copy RFU auth
1854 * req bits from our security request, which may create a false
1855 * positive SC enablement.
1856 */
1857 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1858
1859 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1860 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
1861 /* Clear bits which are generated but not distributed */
1862 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1863 /* Wait for Public Key from Initiating Device */
1864 return 0;
1865 }
1866
1867 /* Request setup of TK */
1868 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability);
1869 if (ret)
1870 return SMP_UNSPECIFIED;
1871
1872 return 0;
1873 }
1874
sc_send_public_key(struct smp_chan * smp)1875 static u8 sc_send_public_key(struct smp_chan *smp)
1876 {
1877 struct hci_dev *hdev = smp->conn->hcon->hdev;
1878
1879 bt_dev_dbg(hdev, "");
1880
1881 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) {
1882 struct l2cap_chan *chan = hdev->smp_data;
1883 struct smp_dev *smp_dev;
1884
1885 if (!chan || !chan->data)
1886 return SMP_UNSPECIFIED;
1887
1888 smp_dev = chan->data;
1889
1890 memcpy(smp->local_pk, smp_dev->local_pk, 64);
1891 memcpy(smp->lr, smp_dev->local_rand, 16);
1892
1893 if (smp_dev->debug_key)
1894 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1895
1896 goto done;
1897 }
1898
1899 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) {
1900 bt_dev_dbg(hdev, "Using debug keys");
1901 if (set_ecdh_privkey(smp->tfm_ecdh, debug_sk))
1902 return SMP_UNSPECIFIED;
1903 memcpy(smp->local_pk, debug_pk, 64);
1904 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1905 } else {
1906 while (true) {
1907 /* Generate key pair for Secure Connections */
1908 if (generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk))
1909 return SMP_UNSPECIFIED;
1910
1911 /* This is unlikely, but we need to check that
1912 * we didn't accidentally generate a debug key.
1913 */
1914 if (crypto_memneq(smp->local_pk, debug_pk, 64))
1915 break;
1916 }
1917 }
1918
1919 done:
1920 SMP_DBG("Local Public Key X: %32phN", smp->local_pk);
1921 SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32);
1922
1923 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk);
1924
1925 return 0;
1926 }
1927
smp_cmd_pairing_rsp(struct l2cap_conn * conn,struct sk_buff * skb)1928 static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
1929 {
1930 struct smp_cmd_pairing *req, *rsp = (void *) skb->data;
1931 struct l2cap_chan *chan = conn->smp;
1932 struct smp_chan *smp = chan->data;
1933 struct hci_dev *hdev = conn->hcon->hdev;
1934 u8 key_size, auth;
1935 int ret;
1936
1937 bt_dev_dbg(hdev, "conn %p", conn);
1938
1939 if (skb->len < sizeof(*rsp))
1940 return SMP_INVALID_PARAMS;
1941
1942 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags))
1943 return SMP_CMD_NOTSUPP;
1944
1945 skb_pull(skb, sizeof(*rsp));
1946
1947 req = (void *) &smp->preq[1];
1948
1949 key_size = min(req->max_key_size, rsp->max_key_size);
1950 if (check_enc_key_size(conn, key_size))
1951 return SMP_ENC_KEY_SIZE;
1952
1953 auth = rsp->auth_req & AUTH_REQ_MASK(hdev);
1954
1955 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
1956 return SMP_AUTH_REQUIREMENTS;
1957
1958 /* If the remote side's OOB flag is set it means it has
1959 * successfully received our local OOB data - therefore set the
1960 * flag to indicate that local OOB is in use.
1961 */
1962 if (rsp->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob)
1963 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);
1964
1965 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1966 memcpy(&smp->prsp[1], rsp, sizeof(*rsp));
1967
1968 /* Update remote key distribution in case the remote cleared
1969 * some bits that we had enabled in our request.
1970 */
1971 smp->remote_key_dist &= rsp->resp_key_dist;
1972
1973 if ((req->auth_req & SMP_AUTH_CT2) && (auth & SMP_AUTH_CT2))
1974 set_bit(SMP_FLAG_CT2, &smp->flags);
1975
1976 /* For BR/EDR this means we're done and can start phase 3 */
1977 if (conn->hcon->type == ACL_LINK) {
1978 /* Clear bits which are generated but not distributed */
1979 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1980 smp_distribute_keys(smp);
1981 return 0;
1982 }
1983
1984 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC))
1985 set_bit(SMP_FLAG_SC, &smp->flags);
1986 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH)
1987 conn->hcon->pending_sec_level = BT_SECURITY_HIGH;
1988
1989 /* If we need MITM check that it can be achieved */
1990 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1991 u8 method;
1992
1993 method = get_auth_method(smp, req->io_capability,
1994 rsp->io_capability);
1995 if (method == JUST_WORKS || method == JUST_CFM)
1996 return SMP_AUTH_REQUIREMENTS;
1997 }
1998
1999 get_random_bytes(smp->prnd, sizeof(smp->prnd));
2000
2001 /* Update remote key distribution in case the remote cleared
2002 * some bits that we had enabled in our request.
2003 */
2004 smp->remote_key_dist &= rsp->resp_key_dist;
2005
2006 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
2007 /* Clear bits which are generated but not distributed */
2008 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
2009 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
2010 return sc_send_public_key(smp);
2011 }
2012
2013 auth |= req->auth_req;
2014
2015 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability);
2016 if (ret)
2017 return SMP_UNSPECIFIED;
2018
2019 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
2020
2021 /* Can't compose response until we have been confirmed */
2022 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
2023 return smp_confirm(smp);
2024
2025 return 0;
2026 }
2027
sc_check_confirm(struct smp_chan * smp)2028 static u8 sc_check_confirm(struct smp_chan *smp)
2029 {
2030 struct l2cap_conn *conn = smp->conn;
2031
2032 bt_dev_dbg(conn->hcon->hdev, "");
2033
2034 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2035 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM);
2036
2037 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2038 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2039 smp->prnd);
2040 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2041 }
2042
2043 return 0;
2044 }
2045
2046 /* Work-around for some implementations that incorrectly copy RFU bits
2047 * from our security request and thereby create the impression that
2048 * we're doing SC when in fact the remote doesn't support it.
2049 */
fixup_sc_false_positive(struct smp_chan * smp)2050 static int fixup_sc_false_positive(struct smp_chan *smp)
2051 {
2052 struct l2cap_conn *conn = smp->conn;
2053 struct hci_conn *hcon = conn->hcon;
2054 struct hci_dev *hdev = hcon->hdev;
2055 struct smp_cmd_pairing *req, *rsp;
2056 u8 auth;
2057
2058 /* The issue is only observed when we're in responder role */
2059 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2060 return SMP_UNSPECIFIED;
2061
2062 if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) {
2063 bt_dev_err(hdev, "refusing legacy fallback in SC-only mode");
2064 return SMP_UNSPECIFIED;
2065 }
2066
2067 bt_dev_err(hdev, "trying to fall back to legacy SMP");
2068
2069 req = (void *) &smp->preq[1];
2070 rsp = (void *) &smp->prsp[1];
2071
2072 /* Rebuild key dist flags which may have been cleared for SC */
2073 smp->remote_key_dist = (req->init_key_dist & rsp->resp_key_dist);
2074
2075 auth = req->auth_req & AUTH_REQ_MASK(hdev);
2076
2077 if (tk_request(conn, 0, auth, rsp->io_capability, req->io_capability)) {
2078 bt_dev_err(hdev, "failed to fall back to legacy SMP");
2079 return SMP_UNSPECIFIED;
2080 }
2081
2082 clear_bit(SMP_FLAG_SC, &smp->flags);
2083
2084 return 0;
2085 }
2086
smp_cmd_pairing_confirm(struct l2cap_conn * conn,struct sk_buff * skb)2087 static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
2088 {
2089 struct l2cap_chan *chan = conn->smp;
2090 struct smp_chan *smp = chan->data;
2091 struct hci_conn *hcon = conn->hcon;
2092 struct hci_dev *hdev = hcon->hdev;
2093
2094 bt_dev_dbg(hdev, "conn %p %s", conn,
2095 test_bit(SMP_FLAG_INITIATOR, &smp->flags) ? "initiator" :
2096 "responder");
2097
2098 if (skb->len < sizeof(smp->pcnf))
2099 return SMP_INVALID_PARAMS;
2100
2101 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf));
2102 skb_pull(skb, sizeof(smp->pcnf));
2103
2104 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
2105 int ret;
2106
2107 /* Public Key exchange must happen before any other steps */
2108 if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags))
2109 return sc_check_confirm(smp);
2110
2111 bt_dev_err(hdev, "Unexpected SMP Pairing Confirm");
2112
2113 ret = fixup_sc_false_positive(smp);
2114 if (ret)
2115 return ret;
2116 }
2117
2118 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2119 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2120 smp->prnd);
2121 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2122 return 0;
2123 }
2124
2125 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
2126 return smp_confirm(smp);
2127
2128 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
2129
2130 return 0;
2131 }
2132
smp_cmd_pairing_random(struct l2cap_conn * conn,struct sk_buff * skb)2133 static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
2134 {
2135 struct l2cap_chan *chan = conn->smp;
2136 struct smp_chan *smp = chan->data;
2137 struct hci_conn *hcon = conn->hcon;
2138 u8 *pkax, *pkbx, *na, *nb, confirm_hint;
2139 u32 passkey;
2140 int err;
2141
2142 bt_dev_dbg(hcon->hdev, "conn %p", conn);
2143
2144 if (skb->len < sizeof(smp->rrnd))
2145 return SMP_INVALID_PARAMS;
2146
2147 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd));
2148 skb_pull(skb, sizeof(smp->rrnd));
2149
2150 if (!test_bit(SMP_FLAG_SC, &smp->flags))
2151 return smp_random(smp);
2152
2153 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2154 pkax = smp->local_pk;
2155 pkbx = smp->remote_pk;
2156 na = smp->prnd;
2157 nb = smp->rrnd;
2158 } else {
2159 pkax = smp->remote_pk;
2160 pkbx = smp->local_pk;
2161 na = smp->rrnd;
2162 nb = smp->prnd;
2163 }
2164
2165 if (smp->method == REQ_OOB) {
2166 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2167 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2168 sizeof(smp->prnd), smp->prnd);
2169 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2170 goto mackey_and_ltk;
2171 }
2172
2173 /* Passkey entry has special treatment */
2174 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2175 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM);
2176
2177 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2178 u8 cfm[16];
2179
2180 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
2181 smp->rrnd, 0, cfm);
2182 if (err)
2183 return SMP_UNSPECIFIED;
2184
2185 if (crypto_memneq(smp->pcnf, cfm, 16))
2186 return SMP_CONFIRM_FAILED;
2187 } else {
2188 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2189 smp->prnd);
2190 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2191
2192 /* Only Just-Works pairing requires extra checks */
2193 if (smp->method != JUST_WORKS)
2194 goto mackey_and_ltk;
2195
2196 /* If there already exists long term key in local host, leave
2197 * the decision to user space since the remote device could
2198 * be legitimate or malicious.
2199 */
2200 if (hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
2201 hcon->role)) {
2202 /* Set passkey to 0. The value can be any number since
2203 * it'll be ignored anyway.
2204 */
2205 passkey = 0;
2206 confirm_hint = 1;
2207 goto confirm;
2208 }
2209 }
2210
2211 mackey_and_ltk:
2212 /* Generate MacKey and LTK */
2213 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk);
2214 if (err)
2215 return SMP_UNSPECIFIED;
2216
2217 if (smp->method == REQ_OOB) {
2218 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2219 sc_dhkey_check(smp);
2220 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2221 }
2222 return 0;
2223 }
2224
2225 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
2226 if (err)
2227 return SMP_UNSPECIFIED;
2228
2229 confirm_hint = 0;
2230
2231 confirm:
2232 if (smp->method == JUST_WORKS)
2233 confirm_hint = 1;
2234
2235 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type,
2236 hcon->dst_type, passkey, confirm_hint);
2237 if (err)
2238 return SMP_UNSPECIFIED;
2239
2240 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2241
2242 return 0;
2243 }
2244
smp_ltk_encrypt(struct l2cap_conn * conn,u8 sec_level)2245 static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level)
2246 {
2247 struct smp_ltk *key;
2248 struct hci_conn *hcon = conn->hcon;
2249
2250 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role);
2251 if (!key)
2252 return false;
2253
2254 if (smp_ltk_sec_level(key) < sec_level)
2255 return false;
2256
2257 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
2258 return true;
2259
2260 hci_le_start_enc(hcon, key->ediv, key->rand, key->val, key->enc_size);
2261 hcon->enc_key_size = key->enc_size;
2262
2263 /* We never store STKs for initiator role, so clear this flag */
2264 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
2265
2266 return true;
2267 }
2268
smp_sufficient_security(struct hci_conn * hcon,u8 sec_level,enum smp_key_pref key_pref)2269 bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level,
2270 enum smp_key_pref key_pref)
2271 {
2272 if (sec_level == BT_SECURITY_LOW)
2273 return true;
2274
2275 /* If we're encrypted with an STK but the caller prefers using
2276 * LTK claim insufficient security. This way we allow the
2277 * connection to be re-encrypted with an LTK, even if the LTK
2278 * provides the same level of security. Only exception is if we
2279 * don't have an LTK (e.g. because of key distribution bits).
2280 */
2281 if (key_pref == SMP_USE_LTK &&
2282 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) &&
2283 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role))
2284 return false;
2285
2286 if (hcon->sec_level >= sec_level)
2287 return true;
2288
2289 return false;
2290 }
2291
smp_send_pairing_req(struct smp_chan * smp,__u8 auth)2292 static void smp_send_pairing_req(struct smp_chan *smp, __u8 auth)
2293 {
2294 struct smp_cmd_pairing cp;
2295
2296 if (smp->conn->hcon->type == ACL_LINK)
2297 build_bredr_pairing_cmd(smp, &cp, NULL);
2298 else
2299 build_pairing_cmd(smp->conn, &cp, NULL, auth);
2300
2301 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2302 memcpy(&smp->preq[1], &cp, sizeof(cp));
2303
2304 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
2305 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2306
2307 set_bit(SMP_FLAG_INITIATOR, &smp->flags);
2308 }
2309
smp_cmd_security_req(struct l2cap_conn * conn,struct sk_buff * skb)2310 static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
2311 {
2312 struct smp_cmd_security_req *rp = (void *) skb->data;
2313 struct hci_conn *hcon = conn->hcon;
2314 struct hci_dev *hdev = hcon->hdev;
2315 struct smp_chan *smp;
2316 u8 sec_level, auth;
2317
2318 bt_dev_dbg(hdev, "conn %p", conn);
2319
2320 if (skb->len < sizeof(*rp))
2321 return SMP_INVALID_PARAMS;
2322
2323 if (hcon->role != HCI_ROLE_MASTER)
2324 return SMP_CMD_NOTSUPP;
2325
2326 auth = rp->auth_req & AUTH_REQ_MASK(hdev);
2327
2328 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
2329 return SMP_AUTH_REQUIREMENTS;
2330
2331 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
2332 sec_level = BT_SECURITY_MEDIUM;
2333 else
2334 sec_level = authreq_to_seclevel(auth);
2335
2336 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) {
2337 /* If link is already encrypted with sufficient security we
2338 * still need refresh encryption as per Core Spec 5.0 Vol 3,
2339 * Part H 2.4.6
2340 */
2341 smp_ltk_encrypt(conn, hcon->sec_level);
2342 return 0;
2343 }
2344
2345 if (sec_level > hcon->pending_sec_level)
2346 hcon->pending_sec_level = sec_level;
2347
2348 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2349 return 0;
2350
2351 smp = smp_chan_create(conn);
2352 if (!smp)
2353 return SMP_UNSPECIFIED;
2354
2355 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) &&
2356 (auth & SMP_AUTH_BONDING))
2357 return SMP_PAIRING_NOTSUPP;
2358
2359 skb_pull(skb, sizeof(*rp));
2360
2361 smp_send_pairing_req(smp, auth);
2362
2363 return 0;
2364 }
2365
smp_send_security_req(struct smp_chan * smp,__u8 auth)2366 static void smp_send_security_req(struct smp_chan *smp, __u8 auth)
2367 {
2368 struct smp_cmd_security_req cp;
2369
2370 cp.auth_req = auth;
2371 smp_send_cmd(smp->conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp);
2372 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ);
2373
2374 clear_bit(SMP_FLAG_INITIATOR, &smp->flags);
2375 }
2376
smp_conn_security(struct hci_conn * hcon,__u8 sec_level)2377 int smp_conn_security(struct hci_conn *hcon, __u8 sec_level)
2378 {
2379 struct l2cap_conn *conn = hcon->l2cap_data;
2380 struct l2cap_chan *chan;
2381 struct smp_chan *smp;
2382 __u8 authreq;
2383 int ret;
2384
2385 bt_dev_dbg(hcon->hdev, "conn %p hcon %p level 0x%2.2x", conn, hcon,
2386 sec_level);
2387
2388 /* This may be NULL if there's an unexpected disconnection */
2389 if (!conn)
2390 return 1;
2391
2392 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED))
2393 return 1;
2394
2395 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK))
2396 return 1;
2397
2398 if (sec_level > hcon->pending_sec_level)
2399 hcon->pending_sec_level = sec_level;
2400
2401 if (hcon->role == HCI_ROLE_MASTER)
2402 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2403 return 0;
2404
2405 chan = conn->smp;
2406 if (!chan) {
2407 bt_dev_err(hcon->hdev, "security requested but not available");
2408 return 1;
2409 }
2410
2411 l2cap_chan_lock(chan);
2412
2413 /* If SMP is already in progress ignore this request */
2414 if (chan->data) {
2415 ret = 0;
2416 goto unlock;
2417 }
2418
2419 smp = smp_chan_create(conn);
2420 if (!smp) {
2421 ret = 1;
2422 goto unlock;
2423 }
2424
2425 authreq = seclevel_to_authreq(sec_level);
2426
2427 if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED)) {
2428 authreq |= SMP_AUTH_SC;
2429 if (hci_dev_test_flag(hcon->hdev, HCI_SSP_ENABLED))
2430 authreq |= SMP_AUTH_CT2;
2431 }
2432
2433 /* Don't attempt to set MITM if setting is overridden by debugfs
2434 * Needed to pass certification test SM/MAS/PKE/BV-01-C
2435 */
2436 if (!hci_dev_test_flag(hcon->hdev, HCI_FORCE_NO_MITM)) {
2437 /* Require MITM if IO Capability allows or the security level
2438 * requires it.
2439 */
2440 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT ||
2441 hcon->pending_sec_level > BT_SECURITY_MEDIUM)
2442 authreq |= SMP_AUTH_MITM;
2443 }
2444
2445 if (hcon->role == HCI_ROLE_MASTER)
2446 smp_send_pairing_req(smp, authreq);
2447 else
2448 smp_send_security_req(smp, authreq);
2449
2450 ret = 0;
2451
2452 unlock:
2453 l2cap_chan_unlock(chan);
2454 return ret;
2455 }
2456
smp_cancel_and_remove_pairing(struct hci_dev * hdev,bdaddr_t * bdaddr,u8 addr_type)2457 int smp_cancel_and_remove_pairing(struct hci_dev *hdev, bdaddr_t *bdaddr,
2458 u8 addr_type)
2459 {
2460 struct hci_conn *hcon;
2461 struct l2cap_conn *conn;
2462 struct l2cap_chan *chan;
2463 struct smp_chan *smp;
2464 int err;
2465
2466 err = hci_remove_ltk(hdev, bdaddr, addr_type);
2467 hci_remove_irk(hdev, bdaddr, addr_type);
2468
2469 hcon = hci_conn_hash_lookup_le(hdev, bdaddr, addr_type);
2470 if (!hcon)
2471 goto done;
2472
2473 conn = hcon->l2cap_data;
2474 if (!conn)
2475 goto done;
2476
2477 chan = conn->smp;
2478 if (!chan)
2479 goto done;
2480
2481 l2cap_chan_lock(chan);
2482
2483 smp = chan->data;
2484 if (smp) {
2485 /* Set keys to NULL to make sure smp_failure() does not try to
2486 * remove and free already invalidated rcu list entries. */
2487 smp->ltk = NULL;
2488 smp->responder_ltk = NULL;
2489 smp->remote_irk = NULL;
2490
2491 if (test_bit(SMP_FLAG_COMPLETE, &smp->flags))
2492 smp_failure(conn, 0);
2493 else
2494 smp_failure(conn, SMP_UNSPECIFIED);
2495 err = 0;
2496 }
2497
2498 l2cap_chan_unlock(chan);
2499
2500 done:
2501 return err;
2502 }
2503
smp_cmd_encrypt_info(struct l2cap_conn * conn,struct sk_buff * skb)2504 static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb)
2505 {
2506 struct smp_cmd_encrypt_info *rp = (void *) skb->data;
2507 struct l2cap_chan *chan = conn->smp;
2508 struct smp_chan *smp = chan->data;
2509
2510 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn);
2511
2512 if (skb->len < sizeof(*rp))
2513 return SMP_INVALID_PARAMS;
2514
2515 /* Pairing is aborted if any blocked keys are distributed */
2516 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_LTK,
2517 rp->ltk)) {
2518 bt_dev_warn_ratelimited(conn->hcon->hdev,
2519 "LTK blocked for %pMR",
2520 &conn->hcon->dst);
2521 return SMP_INVALID_PARAMS;
2522 }
2523
2524 SMP_ALLOW_CMD(smp, SMP_CMD_INITIATOR_IDENT);
2525
2526 skb_pull(skb, sizeof(*rp));
2527
2528 memcpy(smp->tk, rp->ltk, sizeof(smp->tk));
2529
2530 return 0;
2531 }
2532
smp_cmd_initiator_ident(struct l2cap_conn * conn,struct sk_buff * skb)2533 static int smp_cmd_initiator_ident(struct l2cap_conn *conn, struct sk_buff *skb)
2534 {
2535 struct smp_cmd_initiator_ident *rp = (void *)skb->data;
2536 struct l2cap_chan *chan = conn->smp;
2537 struct smp_chan *smp = chan->data;
2538 struct hci_dev *hdev = conn->hcon->hdev;
2539 struct hci_conn *hcon = conn->hcon;
2540 struct smp_ltk *ltk;
2541 u8 authenticated;
2542
2543 bt_dev_dbg(hdev, "conn %p", conn);
2544
2545 if (skb->len < sizeof(*rp))
2546 return SMP_INVALID_PARAMS;
2547
2548 /* Mark the information as received */
2549 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY;
2550
2551 if (smp->remote_key_dist & SMP_DIST_ID_KEY)
2552 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
2553 else if (smp->remote_key_dist & SMP_DIST_SIGN)
2554 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2555
2556 skb_pull(skb, sizeof(*rp));
2557
2558 authenticated = (hcon->sec_level == BT_SECURITY_HIGH);
2559 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK,
2560 authenticated, smp->tk, smp->enc_key_size,
2561 rp->ediv, rp->rand);
2562 smp->ltk = ltk;
2563 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2564 smp_distribute_keys(smp);
2565
2566 return 0;
2567 }
2568
smp_cmd_ident_info(struct l2cap_conn * conn,struct sk_buff * skb)2569 static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb)
2570 {
2571 struct smp_cmd_ident_info *info = (void *) skb->data;
2572 struct l2cap_chan *chan = conn->smp;
2573 struct smp_chan *smp = chan->data;
2574
2575 bt_dev_dbg(conn->hcon->hdev, "");
2576
2577 if (skb->len < sizeof(*info))
2578 return SMP_INVALID_PARAMS;
2579
2580 /* Pairing is aborted if any blocked keys are distributed */
2581 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_IRK,
2582 info->irk)) {
2583 bt_dev_warn_ratelimited(conn->hcon->hdev,
2584 "Identity key blocked for %pMR",
2585 &conn->hcon->dst);
2586 return SMP_INVALID_PARAMS;
2587 }
2588
2589 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO);
2590
2591 skb_pull(skb, sizeof(*info));
2592
2593 memcpy(smp->irk, info->irk, 16);
2594
2595 return 0;
2596 }
2597
smp_cmd_ident_addr_info(struct l2cap_conn * conn,struct sk_buff * skb)2598 static int smp_cmd_ident_addr_info(struct l2cap_conn *conn,
2599 struct sk_buff *skb)
2600 {
2601 struct smp_cmd_ident_addr_info *info = (void *) skb->data;
2602 struct l2cap_chan *chan = conn->smp;
2603 struct smp_chan *smp = chan->data;
2604 struct hci_conn *hcon = conn->hcon;
2605 bdaddr_t rpa;
2606
2607 bt_dev_dbg(hcon->hdev, "");
2608
2609 if (skb->len < sizeof(*info))
2610 return SMP_INVALID_PARAMS;
2611
2612 /* Mark the information as received */
2613 smp->remote_key_dist &= ~SMP_DIST_ID_KEY;
2614
2615 if (smp->remote_key_dist & SMP_DIST_SIGN)
2616 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2617
2618 skb_pull(skb, sizeof(*info));
2619
2620 /* Strictly speaking the Core Specification (4.1) allows sending
2621 * an empty address which would force us to rely on just the IRK
2622 * as "identity information". However, since such
2623 * implementations are not known of and in order to not over
2624 * complicate our implementation, simply pretend that we never
2625 * received an IRK for such a device.
2626 *
2627 * The Identity Address must also be a Static Random or Public
2628 * Address, which hci_is_identity_address() checks for.
2629 */
2630 if (!bacmp(&info->bdaddr, BDADDR_ANY) ||
2631 !hci_is_identity_address(&info->bdaddr, info->addr_type)) {
2632 bt_dev_err(hcon->hdev, "ignoring IRK with no identity address");
2633 goto distribute;
2634 }
2635
2636 /* Drop IRK if peer is using identity address during pairing but is
2637 * providing different address as identity information.
2638 *
2639 * Microsoft Surface Precision Mouse is known to have this bug.
2640 */
2641 if (hci_is_identity_address(&hcon->dst, hcon->dst_type) &&
2642 (bacmp(&info->bdaddr, &hcon->dst) ||
2643 info->addr_type != hcon->dst_type)) {
2644 bt_dev_err(hcon->hdev,
2645 "ignoring IRK with invalid identity address");
2646 goto distribute;
2647 }
2648
2649 bacpy(&smp->id_addr, &info->bdaddr);
2650 smp->id_addr_type = info->addr_type;
2651
2652 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type))
2653 bacpy(&rpa, &hcon->dst);
2654 else
2655 bacpy(&rpa, BDADDR_ANY);
2656
2657 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr,
2658 smp->id_addr_type, smp->irk, &rpa);
2659
2660 distribute:
2661 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2662 smp_distribute_keys(smp);
2663
2664 return 0;
2665 }
2666
smp_cmd_sign_info(struct l2cap_conn * conn,struct sk_buff * skb)2667 static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb)
2668 {
2669 struct smp_cmd_sign_info *rp = (void *) skb->data;
2670 struct l2cap_chan *chan = conn->smp;
2671 struct smp_chan *smp = chan->data;
2672 struct smp_csrk *csrk;
2673
2674 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn);
2675
2676 if (skb->len < sizeof(*rp))
2677 return SMP_INVALID_PARAMS;
2678
2679 /* Mark the information as received */
2680 smp->remote_key_dist &= ~SMP_DIST_SIGN;
2681
2682 skb_pull(skb, sizeof(*rp));
2683
2684 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
2685 if (csrk) {
2686 if (conn->hcon->sec_level > BT_SECURITY_MEDIUM)
2687 csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED;
2688 else
2689 csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED;
2690 memcpy(csrk->val, rp->csrk, sizeof(csrk->val));
2691 }
2692 smp->csrk = csrk;
2693 smp_distribute_keys(smp);
2694
2695 return 0;
2696 }
2697
sc_select_method(struct smp_chan * smp)2698 static u8 sc_select_method(struct smp_chan *smp)
2699 {
2700 struct smp_cmd_pairing *local, *remote;
2701 u8 local_mitm, remote_mitm, local_io, remote_io, method;
2702
2703 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) ||
2704 test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags))
2705 return REQ_OOB;
2706
2707 /* The preq/prsp contain the raw Pairing Request/Response PDUs
2708 * which are needed as inputs to some crypto functions. To get
2709 * the "struct smp_cmd_pairing" from them we need to skip the
2710 * first byte which contains the opcode.
2711 */
2712 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2713 local = (void *) &smp->preq[1];
2714 remote = (void *) &smp->prsp[1];
2715 } else {
2716 local = (void *) &smp->prsp[1];
2717 remote = (void *) &smp->preq[1];
2718 }
2719
2720 local_io = local->io_capability;
2721 remote_io = remote->io_capability;
2722
2723 local_mitm = (local->auth_req & SMP_AUTH_MITM);
2724 remote_mitm = (remote->auth_req & SMP_AUTH_MITM);
2725
2726 /* If either side wants MITM, look up the method from the table,
2727 * otherwise use JUST WORKS.
2728 */
2729 if (local_mitm || remote_mitm)
2730 method = get_auth_method(smp, local_io, remote_io);
2731 else
2732 method = JUST_WORKS;
2733
2734 /* Don't confirm locally initiated pairing attempts */
2735 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2736 method = JUST_WORKS;
2737
2738 return method;
2739 }
2740
smp_cmd_public_key(struct l2cap_conn * conn,struct sk_buff * skb)2741 static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb)
2742 {
2743 struct smp_cmd_public_key *key = (void *) skb->data;
2744 struct hci_conn *hcon = conn->hcon;
2745 struct l2cap_chan *chan = conn->smp;
2746 struct smp_chan *smp = chan->data;
2747 struct hci_dev *hdev = hcon->hdev;
2748 struct crypto_kpp *tfm_ecdh;
2749 struct smp_cmd_pairing_confirm cfm;
2750 int err;
2751
2752 bt_dev_dbg(hdev, "conn %p", conn);
2753
2754 if (skb->len < sizeof(*key))
2755 return SMP_INVALID_PARAMS;
2756
2757 /* Check if remote and local public keys are the same and debug key is
2758 * not in use.
2759 */
2760 if (!test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags) &&
2761 !crypto_memneq(key, smp->local_pk, 64)) {
2762 bt_dev_err(hdev, "Remote and local public keys are identical");
2763 return SMP_UNSPECIFIED;
2764 }
2765
2766 memcpy(smp->remote_pk, key, 64);
2767
2768 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) {
2769 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk,
2770 smp->rr, 0, cfm.confirm_val);
2771 if (err)
2772 return SMP_UNSPECIFIED;
2773
2774 if (crypto_memneq(cfm.confirm_val, smp->pcnf, 16))
2775 return SMP_CONFIRM_FAILED;
2776 }
2777
2778 /* Non-initiating device sends its public key after receiving
2779 * the key from the initiating device.
2780 */
2781 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2782 err = sc_send_public_key(smp);
2783 if (err)
2784 return err;
2785 }
2786
2787 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk);
2788 SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32);
2789
2790 /* Compute the shared secret on the same crypto tfm on which the private
2791 * key was set/generated.
2792 */
2793 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) {
2794 struct l2cap_chan *hchan = hdev->smp_data;
2795 struct smp_dev *smp_dev;
2796
2797 if (!hchan || !hchan->data)
2798 return SMP_UNSPECIFIED;
2799
2800 smp_dev = hchan->data;
2801
2802 tfm_ecdh = smp_dev->tfm_ecdh;
2803 } else {
2804 tfm_ecdh = smp->tfm_ecdh;
2805 }
2806
2807 if (compute_ecdh_secret(tfm_ecdh, smp->remote_pk, smp->dhkey))
2808 return SMP_UNSPECIFIED;
2809
2810 SMP_DBG("DHKey %32phN", smp->dhkey);
2811
2812 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags);
2813
2814 smp->method = sc_select_method(smp);
2815
2816 bt_dev_dbg(hdev, "selected method 0x%02x", smp->method);
2817
2818 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */
2819 if (smp->method == JUST_WORKS || smp->method == JUST_CFM)
2820 hcon->pending_sec_level = BT_SECURITY_MEDIUM;
2821 else
2822 hcon->pending_sec_level = BT_SECURITY_FIPS;
2823
2824 if (!crypto_memneq(debug_pk, smp->remote_pk, 64))
2825 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
2826
2827 if (smp->method == DSP_PASSKEY) {
2828 get_random_bytes(&hcon->passkey_notify,
2829 sizeof(hcon->passkey_notify));
2830 hcon->passkey_notify %= 1000000;
2831 hcon->passkey_entered = 0;
2832 smp->passkey_round = 0;
2833 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type,
2834 hcon->dst_type,
2835 hcon->passkey_notify,
2836 hcon->passkey_entered))
2837 return SMP_UNSPECIFIED;
2838 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2839 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY);
2840 }
2841
2842 if (smp->method == REQ_OOB) {
2843 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2844 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2845 sizeof(smp->prnd), smp->prnd);
2846
2847 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2848
2849 return 0;
2850 }
2851
2852 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2853 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2854
2855 if (smp->method == REQ_PASSKEY) {
2856 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type,
2857 hcon->dst_type))
2858 return SMP_UNSPECIFIED;
2859 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2860 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2861 return 0;
2862 }
2863
2864 /* The Initiating device waits for the non-initiating device to
2865 * send the confirm value.
2866 */
2867 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2868 return 0;
2869
2870 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd,
2871 0, cfm.confirm_val);
2872 if (err)
2873 return SMP_UNSPECIFIED;
2874
2875 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
2876 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2877
2878 return 0;
2879 }
2880
smp_cmd_dhkey_check(struct l2cap_conn * conn,struct sk_buff * skb)2881 static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb)
2882 {
2883 struct smp_cmd_dhkey_check *check = (void *) skb->data;
2884 struct l2cap_chan *chan = conn->smp;
2885 struct hci_conn *hcon = conn->hcon;
2886 struct smp_chan *smp = chan->data;
2887 u8 a[7], b[7], *local_addr, *remote_addr;
2888 u8 io_cap[3], r[16], e[16];
2889 int err;
2890
2891 bt_dev_dbg(hcon->hdev, "conn %p", conn);
2892
2893 if (skb->len < sizeof(*check))
2894 return SMP_INVALID_PARAMS;
2895
2896 memcpy(a, &hcon->init_addr, 6);
2897 memcpy(b, &hcon->resp_addr, 6);
2898 a[6] = hcon->init_addr_type;
2899 b[6] = hcon->resp_addr_type;
2900
2901 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2902 local_addr = a;
2903 remote_addr = b;
2904 memcpy(io_cap, &smp->prsp[1], 3);
2905 } else {
2906 local_addr = b;
2907 remote_addr = a;
2908 memcpy(io_cap, &smp->preq[1], 3);
2909 }
2910
2911 memset(r, 0, sizeof(r));
2912
2913 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2914 put_unaligned_le32(hcon->passkey_notify, r);
2915 else if (smp->method == REQ_OOB)
2916 memcpy(r, smp->lr, 16);
2917
2918 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r,
2919 io_cap, remote_addr, local_addr, e);
2920 if (err)
2921 return SMP_UNSPECIFIED;
2922
2923 if (crypto_memneq(check->e, e, 16))
2924 return SMP_DHKEY_CHECK_FAILED;
2925
2926 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2927 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
2928 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags);
2929 return 0;
2930 }
2931
2932 /* Responder sends DHKey check as response to initiator */
2933 sc_dhkey_check(smp);
2934 }
2935
2936 sc_add_ltk(smp);
2937
2938 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) {
2939 hci_le_start_enc(hcon, 0, 0, smp->tk, smp->enc_key_size);
2940 hcon->enc_key_size = smp->enc_key_size;
2941 }
2942
2943 return 0;
2944 }
2945
smp_cmd_keypress_notify(struct l2cap_conn * conn,struct sk_buff * skb)2946 static int smp_cmd_keypress_notify(struct l2cap_conn *conn,
2947 struct sk_buff *skb)
2948 {
2949 struct smp_cmd_keypress_notify *kp = (void *) skb->data;
2950
2951 bt_dev_dbg(conn->hcon->hdev, "value 0x%02x", kp->value);
2952
2953 return 0;
2954 }
2955
smp_sig_channel(struct l2cap_chan * chan,struct sk_buff * skb)2956 static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb)
2957 {
2958 struct l2cap_conn *conn = chan->conn;
2959 struct hci_conn *hcon = conn->hcon;
2960 struct smp_chan *smp;
2961 __u8 code, reason;
2962 int err = 0;
2963
2964 if (skb->len < 1)
2965 return -EILSEQ;
2966
2967 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) {
2968 reason = SMP_PAIRING_NOTSUPP;
2969 goto done;
2970 }
2971
2972 code = skb->data[0];
2973 skb_pull(skb, sizeof(code));
2974
2975 smp = chan->data;
2976
2977 if (code > SMP_CMD_MAX)
2978 goto drop;
2979
2980 if (smp && !test_and_clear_bit(code, &smp->allow_cmd)) {
2981 /* If there is a context and the command is not allowed consider
2982 * it a failure so the session is cleanup properly.
2983 */
2984 switch (code) {
2985 case SMP_CMD_IDENT_INFO:
2986 case SMP_CMD_IDENT_ADDR_INFO:
2987 case SMP_CMD_SIGN_INFO:
2988 /* 3.6.1. Key distribution and generation
2989 *
2990 * A device may reject a distributed key by sending the
2991 * Pairing Failed command with the reason set to
2992 * "Key Rejected".
2993 */
2994 smp_failure(conn, SMP_KEY_REJECTED);
2995 break;
2996 }
2997 goto drop;
2998 }
2999
3000 /* If we don't have a context the only allowed commands are
3001 * pairing request and security request.
3002 */
3003 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ)
3004 goto drop;
3005
3006 switch (code) {
3007 case SMP_CMD_PAIRING_REQ:
3008 reason = smp_cmd_pairing_req(conn, skb);
3009 break;
3010
3011 case SMP_CMD_PAIRING_FAIL:
3012 smp_failure(conn, 0);
3013 err = -EPERM;
3014 break;
3015
3016 case SMP_CMD_PAIRING_RSP:
3017 reason = smp_cmd_pairing_rsp(conn, skb);
3018 break;
3019
3020 case SMP_CMD_SECURITY_REQ:
3021 reason = smp_cmd_security_req(conn, skb);
3022 break;
3023
3024 case SMP_CMD_PAIRING_CONFIRM:
3025 reason = smp_cmd_pairing_confirm(conn, skb);
3026 break;
3027
3028 case SMP_CMD_PAIRING_RANDOM:
3029 reason = smp_cmd_pairing_random(conn, skb);
3030 break;
3031
3032 case SMP_CMD_ENCRYPT_INFO:
3033 reason = smp_cmd_encrypt_info(conn, skb);
3034 break;
3035
3036 case SMP_CMD_INITIATOR_IDENT:
3037 reason = smp_cmd_initiator_ident(conn, skb);
3038 break;
3039
3040 case SMP_CMD_IDENT_INFO:
3041 reason = smp_cmd_ident_info(conn, skb);
3042 break;
3043
3044 case SMP_CMD_IDENT_ADDR_INFO:
3045 reason = smp_cmd_ident_addr_info(conn, skb);
3046 break;
3047
3048 case SMP_CMD_SIGN_INFO:
3049 reason = smp_cmd_sign_info(conn, skb);
3050 break;
3051
3052 case SMP_CMD_PUBLIC_KEY:
3053 reason = smp_cmd_public_key(conn, skb);
3054 break;
3055
3056 case SMP_CMD_DHKEY_CHECK:
3057 reason = smp_cmd_dhkey_check(conn, skb);
3058 break;
3059
3060 case SMP_CMD_KEYPRESS_NOTIFY:
3061 reason = smp_cmd_keypress_notify(conn, skb);
3062 break;
3063
3064 default:
3065 bt_dev_dbg(hcon->hdev, "Unknown command code 0x%2.2x", code);
3066 reason = SMP_CMD_NOTSUPP;
3067 goto done;
3068 }
3069
3070 done:
3071 if (!err) {
3072 if (reason)
3073 smp_failure(conn, reason);
3074 kfree_skb(skb);
3075 }
3076
3077 return err;
3078
3079 drop:
3080 bt_dev_err(hcon->hdev, "unexpected SMP command 0x%02x from %pMR",
3081 code, &hcon->dst);
3082 kfree_skb(skb);
3083 return 0;
3084 }
3085
smp_teardown_cb(struct l2cap_chan * chan,int err)3086 static void smp_teardown_cb(struct l2cap_chan *chan, int err)
3087 {
3088 struct l2cap_conn *conn = chan->conn;
3089
3090 bt_dev_dbg(conn->hcon->hdev, "chan %p", chan);
3091
3092 if (chan->data)
3093 smp_chan_destroy(conn);
3094
3095 conn->smp = NULL;
3096 l2cap_chan_put(chan);
3097 }
3098
bredr_pairing(struct l2cap_chan * chan)3099 static void bredr_pairing(struct l2cap_chan *chan)
3100 {
3101 struct l2cap_conn *conn = chan->conn;
3102 struct hci_conn *hcon = conn->hcon;
3103 struct hci_dev *hdev = hcon->hdev;
3104 struct smp_chan *smp;
3105
3106 bt_dev_dbg(hdev, "chan %p", chan);
3107
3108 /* Only new pairings are interesting */
3109 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags))
3110 return;
3111
3112 /* Don't bother if we're not encrypted */
3113 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3114 return;
3115
3116 /* Only initiator may initiate SMP over BR/EDR */
3117 if (hcon->role != HCI_ROLE_MASTER)
3118 return;
3119
3120 /* Secure Connections support must be enabled */
3121 if (!hci_dev_test_flag(hdev, HCI_SC_ENABLED))
3122 return;
3123
3124 /* BR/EDR must use Secure Connections for SMP */
3125 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) &&
3126 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3127 return;
3128
3129 /* If our LE support is not enabled don't do anything */
3130 if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED))
3131 return;
3132
3133 /* Don't bother if remote LE support is not enabled */
3134 if (!lmp_host_le_capable(hcon))
3135 return;
3136
3137 /* Remote must support SMP fixed chan for BR/EDR */
3138 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR))
3139 return;
3140
3141 /* Don't bother if SMP is already ongoing */
3142 if (chan->data)
3143 return;
3144
3145 smp = smp_chan_create(conn);
3146 if (!smp) {
3147 bt_dev_err(hdev, "unable to create SMP context for BR/EDR");
3148 return;
3149 }
3150
3151 set_bit(SMP_FLAG_SC, &smp->flags);
3152
3153 bt_dev_dbg(hdev, "starting SMP over BR/EDR");
3154
3155 smp_send_pairing_req(smp, 0x00);
3156 }
3157
smp_resume_cb(struct l2cap_chan * chan)3158 static void smp_resume_cb(struct l2cap_chan *chan)
3159 {
3160 struct smp_chan *smp = chan->data;
3161 struct l2cap_conn *conn = chan->conn;
3162 struct hci_conn *hcon = conn->hcon;
3163
3164 bt_dev_dbg(hcon->hdev, "chan %p", chan);
3165
3166 if (hcon->type == ACL_LINK) {
3167 bredr_pairing(chan);
3168 return;
3169 }
3170
3171 if (!smp)
3172 return;
3173
3174 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3175 return;
3176
3177 cancel_delayed_work(&smp->security_timer);
3178
3179 smp_distribute_keys(smp);
3180 }
3181
smp_ready_cb(struct l2cap_chan * chan)3182 static void smp_ready_cb(struct l2cap_chan *chan)
3183 {
3184 struct l2cap_conn *conn = chan->conn;
3185 struct hci_conn *hcon = conn->hcon;
3186
3187 bt_dev_dbg(hcon->hdev, "chan %p", chan);
3188
3189 /* No need to call l2cap_chan_hold() here since we already own
3190 * the reference taken in smp_new_conn_cb(). This is just the
3191 * first time that we tie it to a specific pointer. The code in
3192 * l2cap_core.c ensures that there's no risk this function won't
3193 * get called if smp_new_conn_cb was previously called.
3194 */
3195 conn->smp = chan;
3196
3197 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3198 bredr_pairing(chan);
3199 }
3200
smp_recv_cb(struct l2cap_chan * chan,struct sk_buff * skb)3201 static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
3202 {
3203 int err;
3204
3205 bt_dev_dbg(chan->conn->hcon->hdev, "chan %p", chan);
3206
3207 err = smp_sig_channel(chan, skb);
3208 if (err) {
3209 struct smp_chan *smp = chan->data;
3210
3211 if (smp)
3212 cancel_delayed_work_sync(&smp->security_timer);
3213
3214 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE);
3215 }
3216
3217 return err;
3218 }
3219
smp_alloc_skb_cb(struct l2cap_chan * chan,unsigned long hdr_len,unsigned long len,int nb)3220 static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan,
3221 unsigned long hdr_len,
3222 unsigned long len, int nb)
3223 {
3224 struct sk_buff *skb;
3225
3226 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL);
3227 if (!skb)
3228 return ERR_PTR(-ENOMEM);
3229
3230 skb->priority = HCI_PRIO_MAX;
3231 bt_cb(skb)->l2cap.chan = chan;
3232
3233 return skb;
3234 }
3235
3236 static const struct l2cap_ops smp_chan_ops = {
3237 .name = "Security Manager",
3238 .ready = smp_ready_cb,
3239 .recv = smp_recv_cb,
3240 .alloc_skb = smp_alloc_skb_cb,
3241 .teardown = smp_teardown_cb,
3242 .resume = smp_resume_cb,
3243
3244 .new_connection = l2cap_chan_no_new_connection,
3245 .state_change = l2cap_chan_no_state_change,
3246 .close = l2cap_chan_no_close,
3247 .defer = l2cap_chan_no_defer,
3248 .suspend = l2cap_chan_no_suspend,
3249 .set_shutdown = l2cap_chan_no_set_shutdown,
3250 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
3251 };
3252
smp_new_conn_cb(struct l2cap_chan * pchan)3253 static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan)
3254 {
3255 struct l2cap_chan *chan;
3256
3257 BT_DBG("pchan %p", pchan);
3258
3259 chan = l2cap_chan_create();
3260 if (!chan)
3261 return NULL;
3262
3263 chan->chan_type = pchan->chan_type;
3264 chan->ops = &smp_chan_ops;
3265 chan->scid = pchan->scid;
3266 chan->dcid = chan->scid;
3267 chan->imtu = pchan->imtu;
3268 chan->omtu = pchan->omtu;
3269 chan->mode = pchan->mode;
3270
3271 /* Other L2CAP channels may request SMP routines in order to
3272 * change the security level. This means that the SMP channel
3273 * lock must be considered in its own category to avoid lockdep
3274 * warnings.
3275 */
3276 atomic_set(&chan->nesting, L2CAP_NESTING_SMP);
3277
3278 BT_DBG("created chan %p", chan);
3279
3280 return chan;
3281 }
3282
3283 static const struct l2cap_ops smp_root_chan_ops = {
3284 .name = "Security Manager Root",
3285 .new_connection = smp_new_conn_cb,
3286
3287 /* None of these are implemented for the root channel */
3288 .close = l2cap_chan_no_close,
3289 .alloc_skb = l2cap_chan_no_alloc_skb,
3290 .recv = l2cap_chan_no_recv,
3291 .state_change = l2cap_chan_no_state_change,
3292 .teardown = l2cap_chan_no_teardown,
3293 .ready = l2cap_chan_no_ready,
3294 .defer = l2cap_chan_no_defer,
3295 .suspend = l2cap_chan_no_suspend,
3296 .resume = l2cap_chan_no_resume,
3297 .set_shutdown = l2cap_chan_no_set_shutdown,
3298 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
3299 };
3300
smp_add_cid(struct hci_dev * hdev,u16 cid)3301 static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid)
3302 {
3303 struct l2cap_chan *chan;
3304 struct smp_dev *smp;
3305 struct crypto_shash *tfm_cmac;
3306 struct crypto_kpp *tfm_ecdh;
3307
3308 if (cid == L2CAP_CID_SMP_BREDR) {
3309 smp = NULL;
3310 goto create_chan;
3311 }
3312
3313 smp = kzalloc(sizeof(*smp), GFP_KERNEL);
3314 if (!smp)
3315 return ERR_PTR(-ENOMEM);
3316
3317 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
3318 if (IS_ERR(tfm_cmac)) {
3319 bt_dev_err(hdev, "Unable to create CMAC crypto context");
3320 kfree_sensitive(smp);
3321 return ERR_CAST(tfm_cmac);
3322 }
3323
3324 tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0);
3325 if (IS_ERR(tfm_ecdh)) {
3326 bt_dev_err(hdev, "Unable to create ECDH crypto context");
3327 crypto_free_shash(tfm_cmac);
3328 kfree_sensitive(smp);
3329 return ERR_CAST(tfm_ecdh);
3330 }
3331
3332 smp->local_oob = false;
3333 smp->tfm_cmac = tfm_cmac;
3334 smp->tfm_ecdh = tfm_ecdh;
3335
3336 create_chan:
3337 chan = l2cap_chan_create();
3338 if (!chan) {
3339 if (smp) {
3340 crypto_free_shash(smp->tfm_cmac);
3341 crypto_free_kpp(smp->tfm_ecdh);
3342 kfree_sensitive(smp);
3343 }
3344 return ERR_PTR(-ENOMEM);
3345 }
3346
3347 chan->data = smp;
3348
3349 l2cap_add_scid(chan, cid);
3350
3351 l2cap_chan_set_defaults(chan);
3352
3353 if (cid == L2CAP_CID_SMP) {
3354 u8 bdaddr_type;
3355
3356 hci_copy_identity_address(hdev, &chan->src, &bdaddr_type);
3357
3358 if (bdaddr_type == ADDR_LE_DEV_PUBLIC)
3359 chan->src_type = BDADDR_LE_PUBLIC;
3360 else
3361 chan->src_type = BDADDR_LE_RANDOM;
3362 } else {
3363 bacpy(&chan->src, &hdev->bdaddr);
3364 chan->src_type = BDADDR_BREDR;
3365 }
3366
3367 chan->state = BT_LISTEN;
3368 chan->mode = L2CAP_MODE_BASIC;
3369 chan->imtu = L2CAP_DEFAULT_MTU;
3370 chan->ops = &smp_root_chan_ops;
3371
3372 /* Set correct nesting level for a parent/listening channel */
3373 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
3374
3375 return chan;
3376 }
3377
smp_del_chan(struct l2cap_chan * chan)3378 static void smp_del_chan(struct l2cap_chan *chan)
3379 {
3380 struct smp_dev *smp;
3381
3382 BT_DBG("chan %p", chan);
3383
3384 smp = chan->data;
3385 if (smp) {
3386 chan->data = NULL;
3387 crypto_free_shash(smp->tfm_cmac);
3388 crypto_free_kpp(smp->tfm_ecdh);
3389 kfree_sensitive(smp);
3390 }
3391
3392 l2cap_chan_put(chan);
3393 }
3394
smp_force_bredr(struct hci_dev * hdev,bool enable)3395 int smp_force_bredr(struct hci_dev *hdev, bool enable)
3396 {
3397 if (enable == hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3398 return -EALREADY;
3399
3400 if (enable) {
3401 struct l2cap_chan *chan;
3402
3403 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
3404 if (IS_ERR(chan))
3405 return PTR_ERR(chan);
3406
3407 hdev->smp_bredr_data = chan;
3408 } else {
3409 struct l2cap_chan *chan;
3410
3411 chan = hdev->smp_bredr_data;
3412 hdev->smp_bredr_data = NULL;
3413 smp_del_chan(chan);
3414 }
3415
3416 hci_dev_change_flag(hdev, HCI_FORCE_BREDR_SMP);
3417
3418 return 0;
3419 }
3420
smp_register(struct hci_dev * hdev)3421 int smp_register(struct hci_dev *hdev)
3422 {
3423 struct l2cap_chan *chan;
3424
3425 bt_dev_dbg(hdev, "");
3426
3427 /* If the controller does not support Low Energy operation, then
3428 * there is also no need to register any SMP channel.
3429 */
3430 if (!lmp_le_capable(hdev))
3431 return 0;
3432
3433 if (WARN_ON(hdev->smp_data)) {
3434 chan = hdev->smp_data;
3435 hdev->smp_data = NULL;
3436 smp_del_chan(chan);
3437 }
3438
3439 chan = smp_add_cid(hdev, L2CAP_CID_SMP);
3440 if (IS_ERR(chan))
3441 return PTR_ERR(chan);
3442
3443 hdev->smp_data = chan;
3444
3445 if (!lmp_sc_capable(hdev)) {
3446 /* Flag can be already set here (due to power toggle) */
3447 if (!hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3448 return 0;
3449 }
3450
3451 if (WARN_ON(hdev->smp_bredr_data)) {
3452 chan = hdev->smp_bredr_data;
3453 hdev->smp_bredr_data = NULL;
3454 smp_del_chan(chan);
3455 }
3456
3457 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
3458 if (IS_ERR(chan)) {
3459 int err = PTR_ERR(chan);
3460 chan = hdev->smp_data;
3461 hdev->smp_data = NULL;
3462 smp_del_chan(chan);
3463 return err;
3464 }
3465
3466 hdev->smp_bredr_data = chan;
3467
3468 return 0;
3469 }
3470
smp_unregister(struct hci_dev * hdev)3471 void smp_unregister(struct hci_dev *hdev)
3472 {
3473 struct l2cap_chan *chan;
3474
3475 if (hdev->smp_bredr_data) {
3476 chan = hdev->smp_bredr_data;
3477 hdev->smp_bredr_data = NULL;
3478 smp_del_chan(chan);
3479 }
3480
3481 if (hdev->smp_data) {
3482 chan = hdev->smp_data;
3483 hdev->smp_data = NULL;
3484 smp_del_chan(chan);
3485 }
3486 }
3487
3488 #if IS_ENABLED(CONFIG_BT_SELFTEST_SMP)
3489
test_debug_key(struct crypto_kpp * tfm_ecdh)3490 static int __init test_debug_key(struct crypto_kpp *tfm_ecdh)
3491 {
3492 u8 pk[64];
3493 int err;
3494
3495 err = set_ecdh_privkey(tfm_ecdh, debug_sk);
3496 if (err)
3497 return err;
3498
3499 err = generate_ecdh_public_key(tfm_ecdh, pk);
3500 if (err)
3501 return err;
3502
3503 if (crypto_memneq(pk, debug_pk, 64))
3504 return -EINVAL;
3505
3506 return 0;
3507 }
3508
test_ah(void)3509 static int __init test_ah(void)
3510 {
3511 const u8 irk[16] = {
3512 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3513 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3514 const u8 r[3] = { 0x94, 0x81, 0x70 };
3515 const u8 exp[3] = { 0xaa, 0xfb, 0x0d };
3516 u8 res[3];
3517 int err;
3518
3519 err = smp_ah(irk, r, res);
3520 if (err)
3521 return err;
3522
3523 if (crypto_memneq(res, exp, 3))
3524 return -EINVAL;
3525
3526 return 0;
3527 }
3528
test_c1(void)3529 static int __init test_c1(void)
3530 {
3531 const u8 k[16] = {
3532 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
3533 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
3534 const u8 r[16] = {
3535 0xe0, 0x2e, 0x70, 0xc6, 0x4e, 0x27, 0x88, 0x63,
3536 0x0e, 0x6f, 0xad, 0x56, 0x21, 0xd5, 0x83, 0x57 };
3537 const u8 preq[7] = { 0x01, 0x01, 0x00, 0x00, 0x10, 0x07, 0x07 };
3538 const u8 pres[7] = { 0x02, 0x03, 0x00, 0x00, 0x08, 0x00, 0x05 };
3539 const u8 _iat = 0x01;
3540 const u8 _rat = 0x00;
3541 const bdaddr_t ra = { { 0xb6, 0xb5, 0xb4, 0xb3, 0xb2, 0xb1 } };
3542 const bdaddr_t ia = { { 0xa6, 0xa5, 0xa4, 0xa3, 0xa2, 0xa1 } };
3543 const u8 exp[16] = {
3544 0x86, 0x3b, 0xf1, 0xbe, 0xc5, 0x4d, 0xa7, 0xd2,
3545 0xea, 0x88, 0x89, 0x87, 0xef, 0x3f, 0x1e, 0x1e };
3546 u8 res[16];
3547 int err;
3548
3549 err = smp_c1(k, r, preq, pres, _iat, &ia, _rat, &ra, res);
3550 if (err)
3551 return err;
3552
3553 if (crypto_memneq(res, exp, 16))
3554 return -EINVAL;
3555
3556 return 0;
3557 }
3558
test_s1(void)3559 static int __init test_s1(void)
3560 {
3561 const u8 k[16] = {
3562 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
3563 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
3564 const u8 r1[16] = {
3565 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 };
3566 const u8 r2[16] = {
3567 0x00, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99 };
3568 const u8 exp[16] = {
3569 0x62, 0xa0, 0x6d, 0x79, 0xae, 0x16, 0x42, 0x5b,
3570 0x9b, 0xf4, 0xb0, 0xe8, 0xf0, 0xe1, 0x1f, 0x9a };
3571 u8 res[16];
3572 int err;
3573
3574 err = smp_s1(k, r1, r2, res);
3575 if (err)
3576 return err;
3577
3578 if (crypto_memneq(res, exp, 16))
3579 return -EINVAL;
3580
3581 return 0;
3582 }
3583
test_f4(struct crypto_shash * tfm_cmac)3584 static int __init test_f4(struct crypto_shash *tfm_cmac)
3585 {
3586 const u8 u[32] = {
3587 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
3588 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
3589 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
3590 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 };
3591 const u8 v[32] = {
3592 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b,
3593 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59,
3594 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90,
3595 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 };
3596 const u8 x[16] = {
3597 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3598 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3599 const u8 z = 0x00;
3600 const u8 exp[16] = {
3601 0x2d, 0x87, 0x74, 0xa9, 0xbe, 0xa1, 0xed, 0xf1,
3602 0x1c, 0xbd, 0xa9, 0x07, 0xf1, 0x16, 0xc9, 0xf2 };
3603 u8 res[16];
3604 int err;
3605
3606 err = smp_f4(tfm_cmac, u, v, x, z, res);
3607 if (err)
3608 return err;
3609
3610 if (crypto_memneq(res, exp, 16))
3611 return -EINVAL;
3612
3613 return 0;
3614 }
3615
test_f5(struct crypto_shash * tfm_cmac)3616 static int __init test_f5(struct crypto_shash *tfm_cmac)
3617 {
3618 const u8 w[32] = {
3619 0x98, 0xa6, 0xbf, 0x73, 0xf3, 0x34, 0x8d, 0x86,
3620 0xf1, 0x66, 0xf8, 0xb4, 0x13, 0x6b, 0x79, 0x99,
3621 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3622 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3623 const u8 n1[16] = {
3624 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3625 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3626 const u8 n2[16] = {
3627 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3628 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3629 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 };
3630 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 };
3631 const u8 exp_ltk[16] = {
3632 0x38, 0x0a, 0x75, 0x94, 0xb5, 0x22, 0x05, 0x98,
3633 0x23, 0xcd, 0xd7, 0x69, 0x11, 0x79, 0x86, 0x69 };
3634 const u8 exp_mackey[16] = {
3635 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd,
3636 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 };
3637 u8 mackey[16], ltk[16];
3638 int err;
3639
3640 err = smp_f5(tfm_cmac, w, n1, n2, a1, a2, mackey, ltk);
3641 if (err)
3642 return err;
3643
3644 if (crypto_memneq(mackey, exp_mackey, 16))
3645 return -EINVAL;
3646
3647 if (crypto_memneq(ltk, exp_ltk, 16))
3648 return -EINVAL;
3649
3650 return 0;
3651 }
3652
test_f6(struct crypto_shash * tfm_cmac)3653 static int __init test_f6(struct crypto_shash *tfm_cmac)
3654 {
3655 const u8 w[16] = {
3656 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd,
3657 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 };
3658 const u8 n1[16] = {
3659 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3660 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3661 const u8 n2[16] = {
3662 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3663 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3664 const u8 r[16] = {
3665 0xc8, 0x0f, 0x2d, 0x0c, 0xd2, 0x42, 0xda, 0x08,
3666 0x54, 0xbb, 0x53, 0xb4, 0x3b, 0x34, 0xa3, 0x12 };
3667 const u8 io_cap[3] = { 0x02, 0x01, 0x01 };
3668 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 };
3669 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 };
3670 const u8 exp[16] = {
3671 0x61, 0x8f, 0x95, 0xda, 0x09, 0x0b, 0x6c, 0xd2,
3672 0xc5, 0xe8, 0xd0, 0x9c, 0x98, 0x73, 0xc4, 0xe3 };
3673 u8 res[16];
3674 int err;
3675
3676 err = smp_f6(tfm_cmac, w, n1, n2, r, io_cap, a1, a2, res);
3677 if (err)
3678 return err;
3679
3680 if (crypto_memneq(res, exp, 16))
3681 return -EINVAL;
3682
3683 return 0;
3684 }
3685
test_g2(struct crypto_shash * tfm_cmac)3686 static int __init test_g2(struct crypto_shash *tfm_cmac)
3687 {
3688 const u8 u[32] = {
3689 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
3690 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
3691 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
3692 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 };
3693 const u8 v[32] = {
3694 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b,
3695 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59,
3696 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90,
3697 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 };
3698 const u8 x[16] = {
3699 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3700 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3701 const u8 y[16] = {
3702 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3703 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3704 const u32 exp_val = 0x2f9ed5ba % 1000000;
3705 u32 val;
3706 int err;
3707
3708 err = smp_g2(tfm_cmac, u, v, x, y, &val);
3709 if (err)
3710 return err;
3711
3712 if (val != exp_val)
3713 return -EINVAL;
3714
3715 return 0;
3716 }
3717
test_h6(struct crypto_shash * tfm_cmac)3718 static int __init test_h6(struct crypto_shash *tfm_cmac)
3719 {
3720 const u8 w[16] = {
3721 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3722 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3723 const u8 key_id[4] = { 0x72, 0x62, 0x65, 0x6c };
3724 const u8 exp[16] = {
3725 0x99, 0x63, 0xb1, 0x80, 0xe2, 0xa9, 0xd3, 0xe8,
3726 0x1c, 0xc9, 0x6d, 0xe7, 0x02, 0xe1, 0x9a, 0x2d };
3727 u8 res[16];
3728 int err;
3729
3730 err = smp_h6(tfm_cmac, w, key_id, res);
3731 if (err)
3732 return err;
3733
3734 if (crypto_memneq(res, exp, 16))
3735 return -EINVAL;
3736
3737 return 0;
3738 }
3739
3740 static char test_smp_buffer[32];
3741
test_smp_read(struct file * file,char __user * user_buf,size_t count,loff_t * ppos)3742 static ssize_t test_smp_read(struct file *file, char __user *user_buf,
3743 size_t count, loff_t *ppos)
3744 {
3745 return simple_read_from_buffer(user_buf, count, ppos, test_smp_buffer,
3746 strlen(test_smp_buffer));
3747 }
3748
3749 static const struct file_operations test_smp_fops = {
3750 .open = simple_open,
3751 .read = test_smp_read,
3752 .llseek = default_llseek,
3753 };
3754
run_selftests(struct crypto_shash * tfm_cmac,struct crypto_kpp * tfm_ecdh)3755 static int __init run_selftests(struct crypto_shash *tfm_cmac,
3756 struct crypto_kpp *tfm_ecdh)
3757 {
3758 ktime_t calltime, delta, rettime;
3759 unsigned long long duration;
3760 int err;
3761
3762 calltime = ktime_get();
3763
3764 err = test_debug_key(tfm_ecdh);
3765 if (err) {
3766 BT_ERR("debug_key test failed");
3767 goto done;
3768 }
3769
3770 err = test_ah();
3771 if (err) {
3772 BT_ERR("smp_ah test failed");
3773 goto done;
3774 }
3775
3776 err = test_c1();
3777 if (err) {
3778 BT_ERR("smp_c1 test failed");
3779 goto done;
3780 }
3781
3782 err = test_s1();
3783 if (err) {
3784 BT_ERR("smp_s1 test failed");
3785 goto done;
3786 }
3787
3788 err = test_f4(tfm_cmac);
3789 if (err) {
3790 BT_ERR("smp_f4 test failed");
3791 goto done;
3792 }
3793
3794 err = test_f5(tfm_cmac);
3795 if (err) {
3796 BT_ERR("smp_f5 test failed");
3797 goto done;
3798 }
3799
3800 err = test_f6(tfm_cmac);
3801 if (err) {
3802 BT_ERR("smp_f6 test failed");
3803 goto done;
3804 }
3805
3806 err = test_g2(tfm_cmac);
3807 if (err) {
3808 BT_ERR("smp_g2 test failed");
3809 goto done;
3810 }
3811
3812 err = test_h6(tfm_cmac);
3813 if (err) {
3814 BT_ERR("smp_h6 test failed");
3815 goto done;
3816 }
3817
3818 rettime = ktime_get();
3819 delta = ktime_sub(rettime, calltime);
3820 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
3821
3822 BT_INFO("SMP test passed in %llu usecs", duration);
3823
3824 done:
3825 if (!err)
3826 snprintf(test_smp_buffer, sizeof(test_smp_buffer),
3827 "PASS (%llu usecs)\n", duration);
3828 else
3829 snprintf(test_smp_buffer, sizeof(test_smp_buffer), "FAIL\n");
3830
3831 debugfs_create_file("selftest_smp", 0444, bt_debugfs, NULL,
3832 &test_smp_fops);
3833
3834 return err;
3835 }
3836
bt_selftest_smp(void)3837 int __init bt_selftest_smp(void)
3838 {
3839 struct crypto_shash *tfm_cmac;
3840 struct crypto_kpp *tfm_ecdh;
3841 int err;
3842
3843 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
3844 if (IS_ERR(tfm_cmac)) {
3845 BT_ERR("Unable to create CMAC crypto context");
3846 return PTR_ERR(tfm_cmac);
3847 }
3848
3849 tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0);
3850 if (IS_ERR(tfm_ecdh)) {
3851 BT_ERR("Unable to create ECDH crypto context");
3852 crypto_free_shash(tfm_cmac);
3853 return PTR_ERR(tfm_ecdh);
3854 }
3855
3856 err = run_selftests(tfm_cmac, tfm_ecdh);
3857
3858 crypto_free_shash(tfm_cmac);
3859 crypto_free_kpp(tfm_ecdh);
3860
3861 return err;
3862 }
3863
3864 #endif
3865