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Merge tag 'xtensa-next-20141215' of git://github.com/czankel/xtensa-linux
[deliverable/linux.git] / net / bluetooth / smp.c
1 /*
2 BlueZ - Bluetooth protocol stack for Linux
3 Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License version 2 as
7 published by the Free Software Foundation;
8
9 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
10 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
11 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
12 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
13 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
14 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17
18 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
19 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
20 SOFTWARE IS DISCLAIMED.
21 */
22
23 #include <linux/crypto.h>
24 #include <linux/scatterlist.h>
25 #include <crypto/b128ops.h>
26
27 #include <net/bluetooth/bluetooth.h>
28 #include <net/bluetooth/hci_core.h>
29 #include <net/bluetooth/l2cap.h>
30 #include <net/bluetooth/mgmt.h>
31
32 #include "ecc.h"
33 #include "smp.h"
34
35 /* Low-level debug macros to be used for stuff that we don't want
36 * accidentially in dmesg, i.e. the values of the various crypto keys
37 * and the inputs & outputs of crypto functions.
38 */
39 #ifdef DEBUG
40 #define SMP_DBG(fmt, ...) printk(KERN_DEBUG "%s: " fmt, __func__, \
41 ##__VA_ARGS__)
42 #else
43 #define SMP_DBG(fmt, ...) no_printk(KERN_DEBUG "%s: " fmt, __func__, \
44 ##__VA_ARGS__)
45 #endif
46
47 #define SMP_ALLOW_CMD(smp, code) set_bit(code, &smp->allow_cmd)
48
49 /* Keys which are not distributed with Secure Connections */
50 #define SMP_SC_NO_DIST (SMP_DIST_ENC_KEY | SMP_DIST_LINK_KEY);
51
52 #define SMP_TIMEOUT msecs_to_jiffies(30000)
53
54 #define AUTH_REQ_MASK(dev) (test_bit(HCI_SC_ENABLED, &(dev)->dev_flags) ? \
55 0x1f : 0x07)
56 #define KEY_DIST_MASK 0x07
57
58 /* Maximum message length that can be passed to aes_cmac */
59 #define CMAC_MSG_MAX 80
60
61 enum {
62 SMP_FLAG_TK_VALID,
63 SMP_FLAG_CFM_PENDING,
64 SMP_FLAG_MITM_AUTH,
65 SMP_FLAG_COMPLETE,
66 SMP_FLAG_INITIATOR,
67 SMP_FLAG_SC,
68 SMP_FLAG_REMOTE_PK,
69 SMP_FLAG_DEBUG_KEY,
70 SMP_FLAG_WAIT_USER,
71 SMP_FLAG_DHKEY_PENDING,
72 SMP_FLAG_OOB,
73 };
74
75 struct smp_chan {
76 struct l2cap_conn *conn;
77 struct delayed_work security_timer;
78 unsigned long allow_cmd; /* Bitmask of allowed commands */
79
80 u8 preq[7]; /* SMP Pairing Request */
81 u8 prsp[7]; /* SMP Pairing Response */
82 u8 prnd[16]; /* SMP Pairing Random (local) */
83 u8 rrnd[16]; /* SMP Pairing Random (remote) */
84 u8 pcnf[16]; /* SMP Pairing Confirm */
85 u8 tk[16]; /* SMP Temporary Key */
86 u8 rr[16];
87 u8 enc_key_size;
88 u8 remote_key_dist;
89 bdaddr_t id_addr;
90 u8 id_addr_type;
91 u8 irk[16];
92 struct smp_csrk *csrk;
93 struct smp_csrk *slave_csrk;
94 struct smp_ltk *ltk;
95 struct smp_ltk *slave_ltk;
96 struct smp_irk *remote_irk;
97 u8 *link_key;
98 unsigned long flags;
99 u8 method;
100 u8 passkey_round;
101
102 /* Secure Connections variables */
103 u8 local_pk[64];
104 u8 local_sk[32];
105 u8 remote_pk[64];
106 u8 dhkey[32];
107 u8 mackey[16];
108
109 struct crypto_blkcipher *tfm_aes;
110 struct crypto_hash *tfm_cmac;
111 };
112
113 /* These debug key values are defined in the SMP section of the core
114 * specification. debug_pk is the public debug key and debug_sk the
115 * private debug key.
116 */
117 static const u8 debug_pk[64] = {
118 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
119 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
120 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
121 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20,
122
123 0x8b, 0xd2, 0x89, 0x15, 0xd0, 0x8e, 0x1c, 0x74,
124 0x24, 0x30, 0xed, 0x8f, 0xc2, 0x45, 0x63, 0x76,
125 0x5c, 0x15, 0x52, 0x5a, 0xbf, 0x9a, 0x32, 0x63,
126 0x6d, 0xeb, 0x2a, 0x65, 0x49, 0x9c, 0x80, 0xdc,
127 };
128
129 static const u8 debug_sk[32] = {
130 0xbd, 0x1a, 0x3c, 0xcd, 0xa6, 0xb8, 0x99, 0x58,
131 0x99, 0xb7, 0x40, 0xeb, 0x7b, 0x60, 0xff, 0x4a,
132 0x50, 0x3f, 0x10, 0xd2, 0xe3, 0xb3, 0xc9, 0x74,
133 0x38, 0x5f, 0xc5, 0xa3, 0xd4, 0xf6, 0x49, 0x3f,
134 };
135
136 static inline void swap_buf(const u8 *src, u8 *dst, size_t len)
137 {
138 size_t i;
139
140 for (i = 0; i < len; i++)
141 dst[len - 1 - i] = src[i];
142 }
143
144 /* The following functions map to the LE SC SMP crypto functions
145 * AES-CMAC, f4, f5, f6, g2 and h6.
146 */
147
148 static int aes_cmac(struct crypto_hash *tfm, const u8 k[16], const u8 *m,
149 size_t len, u8 mac[16])
150 {
151 uint8_t tmp[16], mac_msb[16], msg_msb[CMAC_MSG_MAX];
152 struct hash_desc desc;
153 struct scatterlist sg;
154 int err;
155
156 if (len > CMAC_MSG_MAX)
157 return -EFBIG;
158
159 if (!tfm) {
160 BT_ERR("tfm %p", tfm);
161 return -EINVAL;
162 }
163
164 desc.tfm = tfm;
165 desc.flags = 0;
166
167 crypto_hash_init(&desc);
168
169 /* Swap key and message from LSB to MSB */
170 swap_buf(k, tmp, 16);
171 swap_buf(m, msg_msb, len);
172
173 SMP_DBG("msg (len %zu) %*phN", len, (int) len, m);
174 SMP_DBG("key %16phN", k);
175
176 err = crypto_hash_setkey(tfm, tmp, 16);
177 if (err) {
178 BT_ERR("cipher setkey failed: %d", err);
179 return err;
180 }
181
182 sg_init_one(&sg, msg_msb, len);
183
184 err = crypto_hash_update(&desc, &sg, len);
185 if (err) {
186 BT_ERR("Hash update error %d", err);
187 return err;
188 }
189
190 err = crypto_hash_final(&desc, mac_msb);
191 if (err) {
192 BT_ERR("Hash final error %d", err);
193 return err;
194 }
195
196 swap_buf(mac_msb, mac, 16);
197
198 SMP_DBG("mac %16phN", mac);
199
200 return 0;
201 }
202
203 static int smp_f4(struct crypto_hash *tfm_cmac, const u8 u[32], const u8 v[32],
204 const u8 x[16], u8 z, u8 res[16])
205 {
206 u8 m[65];
207 int err;
208
209 SMP_DBG("u %32phN", u);
210 SMP_DBG("v %32phN", v);
211 SMP_DBG("x %16phN z %02x", x, z);
212
213 m[0] = z;
214 memcpy(m + 1, v, 32);
215 memcpy(m + 33, u, 32);
216
217 err = aes_cmac(tfm_cmac, x, m, sizeof(m), res);
218 if (err)
219 return err;
220
221 SMP_DBG("res %16phN", res);
222
223 return err;
224 }
225
226 static int smp_f5(struct crypto_hash *tfm_cmac, u8 w[32], u8 n1[16], u8 n2[16],
227 u8 a1[7], u8 a2[7], u8 mackey[16], u8 ltk[16])
228 {
229 /* The btle, salt and length "magic" values are as defined in
230 * the SMP section of the Bluetooth core specification. In ASCII
231 * the btle value ends up being 'btle'. The salt is just a
232 * random number whereas length is the value 256 in little
233 * endian format.
234 */
235 const u8 btle[4] = { 0x65, 0x6c, 0x74, 0x62 };
236 const u8 salt[16] = { 0xbe, 0x83, 0x60, 0x5a, 0xdb, 0x0b, 0x37, 0x60,
237 0x38, 0xa5, 0xf5, 0xaa, 0x91, 0x83, 0x88, 0x6c };
238 const u8 length[2] = { 0x00, 0x01 };
239 u8 m[53], t[16];
240 int err;
241
242 SMP_DBG("w %32phN", w);
243 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
244 SMP_DBG("a1 %7phN a2 %7phN", a1, a2);
245
246 err = aes_cmac(tfm_cmac, salt, w, 32, t);
247 if (err)
248 return err;
249
250 SMP_DBG("t %16phN", t);
251
252 memcpy(m, length, 2);
253 memcpy(m + 2, a2, 7);
254 memcpy(m + 9, a1, 7);
255 memcpy(m + 16, n2, 16);
256 memcpy(m + 32, n1, 16);
257 memcpy(m + 48, btle, 4);
258
259 m[52] = 0; /* Counter */
260
261 err = aes_cmac(tfm_cmac, t, m, sizeof(m), mackey);
262 if (err)
263 return err;
264
265 SMP_DBG("mackey %16phN", mackey);
266
267 m[52] = 1; /* Counter */
268
269 err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk);
270 if (err)
271 return err;
272
273 SMP_DBG("ltk %16phN", ltk);
274
275 return 0;
276 }
277
278 static int smp_f6(struct crypto_hash *tfm_cmac, const u8 w[16],
279 const u8 n1[16], u8 n2[16], const u8 r[16],
280 const u8 io_cap[3], const u8 a1[7], const u8 a2[7],
281 u8 res[16])
282 {
283 u8 m[65];
284 int err;
285
286 SMP_DBG("w %16phN", w);
287 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
288 SMP_DBG("r %16phN io_cap %3phN a1 %7phN a2 %7phN", r, io_cap, a1, a2);
289
290 memcpy(m, a2, 7);
291 memcpy(m + 7, a1, 7);
292 memcpy(m + 14, io_cap, 3);
293 memcpy(m + 17, r, 16);
294 memcpy(m + 33, n2, 16);
295 memcpy(m + 49, n1, 16);
296
297 err = aes_cmac(tfm_cmac, w, m, sizeof(m), res);
298 if (err)
299 return err;
300
301 BT_DBG("res %16phN", res);
302
303 return err;
304 }
305
306 static int smp_g2(struct crypto_hash *tfm_cmac, const u8 u[32], const u8 v[32],
307 const u8 x[16], const u8 y[16], u32 *val)
308 {
309 u8 m[80], tmp[16];
310 int err;
311
312 SMP_DBG("u %32phN", u);
313 SMP_DBG("v %32phN", v);
314 SMP_DBG("x %16phN y %16phN", x, y);
315
316 memcpy(m, y, 16);
317 memcpy(m + 16, v, 32);
318 memcpy(m + 48, u, 32);
319
320 err = aes_cmac(tfm_cmac, x, m, sizeof(m), tmp);
321 if (err)
322 return err;
323
324 *val = get_unaligned_le32(tmp);
325 *val %= 1000000;
326
327 SMP_DBG("val %06u", *val);
328
329 return 0;
330 }
331
332 static int smp_h6(struct crypto_hash *tfm_cmac, const u8 w[16],
333 const u8 key_id[4], u8 res[16])
334 {
335 int err;
336
337 SMP_DBG("w %16phN key_id %4phN", w, key_id);
338
339 err = aes_cmac(tfm_cmac, w, key_id, 4, res);
340 if (err)
341 return err;
342
343 SMP_DBG("res %16phN", res);
344
345 return err;
346 }
347
348 /* The following functions map to the legacy SMP crypto functions e, c1,
349 * s1 and ah.
350 */
351
352 static int smp_e(struct crypto_blkcipher *tfm, const u8 *k, u8 *r)
353 {
354 struct blkcipher_desc desc;
355 struct scatterlist sg;
356 uint8_t tmp[16], data[16];
357 int err;
358
359 if (!tfm) {
360 BT_ERR("tfm %p", tfm);
361 return -EINVAL;
362 }
363
364 desc.tfm = tfm;
365 desc.flags = 0;
366
367 /* The most significant octet of key corresponds to k[0] */
368 swap_buf(k, tmp, 16);
369
370 err = crypto_blkcipher_setkey(tfm, tmp, 16);
371 if (err) {
372 BT_ERR("cipher setkey failed: %d", err);
373 return err;
374 }
375
376 /* Most significant octet of plaintextData corresponds to data[0] */
377 swap_buf(r, data, 16);
378
379 sg_init_one(&sg, data, 16);
380
381 err = crypto_blkcipher_encrypt(&desc, &sg, &sg, 16);
382 if (err)
383 BT_ERR("Encrypt data error %d", err);
384
385 /* Most significant octet of encryptedData corresponds to data[0] */
386 swap_buf(data, r, 16);
387
388 return err;
389 }
390
391 static int smp_c1(struct crypto_blkcipher *tfm_aes, const u8 k[16],
392 const u8 r[16], const u8 preq[7], const u8 pres[7], u8 _iat,
393 const bdaddr_t *ia, u8 _rat, const bdaddr_t *ra, u8 res[16])
394 {
395 u8 p1[16], p2[16];
396 int err;
397
398 memset(p1, 0, 16);
399
400 /* p1 = pres || preq || _rat || _iat */
401 p1[0] = _iat;
402 p1[1] = _rat;
403 memcpy(p1 + 2, preq, 7);
404 memcpy(p1 + 9, pres, 7);
405
406 /* p2 = padding || ia || ra */
407 memcpy(p2, ra, 6);
408 memcpy(p2 + 6, ia, 6);
409 memset(p2 + 12, 0, 4);
410
411 /* res = r XOR p1 */
412 u128_xor((u128 *) res, (u128 *) r, (u128 *) p1);
413
414 /* res = e(k, res) */
415 err = smp_e(tfm_aes, k, res);
416 if (err) {
417 BT_ERR("Encrypt data error");
418 return err;
419 }
420
421 /* res = res XOR p2 */
422 u128_xor((u128 *) res, (u128 *) res, (u128 *) p2);
423
424 /* res = e(k, res) */
425 err = smp_e(tfm_aes, k, res);
426 if (err)
427 BT_ERR("Encrypt data error");
428
429 return err;
430 }
431
432 static int smp_s1(struct crypto_blkcipher *tfm_aes, const u8 k[16],
433 const u8 r1[16], const u8 r2[16], u8 _r[16])
434 {
435 int err;
436
437 /* Just least significant octets from r1 and r2 are considered */
438 memcpy(_r, r2, 8);
439 memcpy(_r + 8, r1, 8);
440
441 err = smp_e(tfm_aes, k, _r);
442 if (err)
443 BT_ERR("Encrypt data error");
444
445 return err;
446 }
447
448 static int smp_ah(struct crypto_blkcipher *tfm, const u8 irk[16],
449 const u8 r[3], u8 res[3])
450 {
451 u8 _res[16];
452 int err;
453
454 /* r' = padding || r */
455 memcpy(_res, r, 3);
456 memset(_res + 3, 0, 13);
457
458 err = smp_e(tfm, irk, _res);
459 if (err) {
460 BT_ERR("Encrypt error");
461 return err;
462 }
463
464 /* The output of the random address function ah is:
465 * ah(h, r) = e(k, r') mod 2^24
466 * The output of the security function e is then truncated to 24 bits
467 * by taking the least significant 24 bits of the output of e as the
468 * result of ah.
469 */
470 memcpy(res, _res, 3);
471
472 return 0;
473 }
474
475 bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16],
476 const bdaddr_t *bdaddr)
477 {
478 struct l2cap_chan *chan = hdev->smp_data;
479 struct crypto_blkcipher *tfm;
480 u8 hash[3];
481 int err;
482
483 if (!chan || !chan->data)
484 return false;
485
486 tfm = chan->data;
487
488 BT_DBG("RPA %pMR IRK %*phN", bdaddr, 16, irk);
489
490 err = smp_ah(tfm, irk, &bdaddr->b[3], hash);
491 if (err)
492 return false;
493
494 return !memcmp(bdaddr->b, hash, 3);
495 }
496
497 int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa)
498 {
499 struct l2cap_chan *chan = hdev->smp_data;
500 struct crypto_blkcipher *tfm;
501 int err;
502
503 if (!chan || !chan->data)
504 return -EOPNOTSUPP;
505
506 tfm = chan->data;
507
508 get_random_bytes(&rpa->b[3], 3);
509
510 rpa->b[5] &= 0x3f; /* Clear two most significant bits */
511 rpa->b[5] |= 0x40; /* Set second most significant bit */
512
513 err = smp_ah(tfm, irk, &rpa->b[3], rpa->b);
514 if (err < 0)
515 return err;
516
517 BT_DBG("RPA %pMR", rpa);
518
519 return 0;
520 }
521
522 static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
523 {
524 struct l2cap_chan *chan = conn->smp;
525 struct smp_chan *smp;
526 struct kvec iv[2];
527 struct msghdr msg;
528
529 if (!chan)
530 return;
531
532 BT_DBG("code 0x%2.2x", code);
533
534 iv[0].iov_base = &code;
535 iv[0].iov_len = 1;
536
537 iv[1].iov_base = data;
538 iv[1].iov_len = len;
539
540 memset(&msg, 0, sizeof(msg));
541
542 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iv, 2, 1 + len);
543
544 l2cap_chan_send(chan, &msg, 1 + len);
545
546 if (!chan->data)
547 return;
548
549 smp = chan->data;
550
551 cancel_delayed_work_sync(&smp->security_timer);
552 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT);
553 }
554
555 static u8 authreq_to_seclevel(u8 authreq)
556 {
557 if (authreq & SMP_AUTH_MITM) {
558 if (authreq & SMP_AUTH_SC)
559 return BT_SECURITY_FIPS;
560 else
561 return BT_SECURITY_HIGH;
562 } else {
563 return BT_SECURITY_MEDIUM;
564 }
565 }
566
567 static __u8 seclevel_to_authreq(__u8 sec_level)
568 {
569 switch (sec_level) {
570 case BT_SECURITY_FIPS:
571 case BT_SECURITY_HIGH:
572 return SMP_AUTH_MITM | SMP_AUTH_BONDING;
573 case BT_SECURITY_MEDIUM:
574 return SMP_AUTH_BONDING;
575 default:
576 return SMP_AUTH_NONE;
577 }
578 }
579
580 static void build_pairing_cmd(struct l2cap_conn *conn,
581 struct smp_cmd_pairing *req,
582 struct smp_cmd_pairing *rsp, __u8 authreq)
583 {
584 struct l2cap_chan *chan = conn->smp;
585 struct smp_chan *smp = chan->data;
586 struct hci_conn *hcon = conn->hcon;
587 struct hci_dev *hdev = hcon->hdev;
588 u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT;
589
590 if (test_bit(HCI_BONDABLE, &conn->hcon->hdev->dev_flags)) {
591 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
592 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
593 authreq |= SMP_AUTH_BONDING;
594 } else {
595 authreq &= ~SMP_AUTH_BONDING;
596 }
597
598 if (test_bit(HCI_RPA_RESOLVING, &hdev->dev_flags))
599 remote_dist |= SMP_DIST_ID_KEY;
600
601 if (test_bit(HCI_PRIVACY, &hdev->dev_flags))
602 local_dist |= SMP_DIST_ID_KEY;
603
604 if (test_bit(HCI_SC_ENABLED, &hdev->dev_flags) &&
605 (authreq & SMP_AUTH_SC)) {
606 struct oob_data *oob_data;
607 u8 bdaddr_type;
608
609 if (test_bit(HCI_SSP_ENABLED, &hdev->dev_flags)) {
610 local_dist |= SMP_DIST_LINK_KEY;
611 remote_dist |= SMP_DIST_LINK_KEY;
612 }
613
614 if (hcon->dst_type == ADDR_LE_DEV_PUBLIC)
615 bdaddr_type = BDADDR_LE_PUBLIC;
616 else
617 bdaddr_type = BDADDR_LE_RANDOM;
618
619 oob_data = hci_find_remote_oob_data(hdev, &hcon->dst,
620 bdaddr_type);
621 if (oob_data) {
622 set_bit(SMP_FLAG_OOB, &smp->flags);
623 oob_flag = SMP_OOB_PRESENT;
624 memcpy(smp->rr, oob_data->rand256, 16);
625 memcpy(smp->pcnf, oob_data->hash256, 16);
626 }
627
628 } else {
629 authreq &= ~SMP_AUTH_SC;
630 }
631
632 if (rsp == NULL) {
633 req->io_capability = conn->hcon->io_capability;
634 req->oob_flag = oob_flag;
635 req->max_key_size = SMP_MAX_ENC_KEY_SIZE;
636 req->init_key_dist = local_dist;
637 req->resp_key_dist = remote_dist;
638 req->auth_req = (authreq & AUTH_REQ_MASK(hdev));
639
640 smp->remote_key_dist = remote_dist;
641 return;
642 }
643
644 rsp->io_capability = conn->hcon->io_capability;
645 rsp->oob_flag = oob_flag;
646 rsp->max_key_size = SMP_MAX_ENC_KEY_SIZE;
647 rsp->init_key_dist = req->init_key_dist & remote_dist;
648 rsp->resp_key_dist = req->resp_key_dist & local_dist;
649 rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev));
650
651 smp->remote_key_dist = rsp->init_key_dist;
652 }
653
654 static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)
655 {
656 struct l2cap_chan *chan = conn->smp;
657 struct smp_chan *smp = chan->data;
658
659 if ((max_key_size > SMP_MAX_ENC_KEY_SIZE) ||
660 (max_key_size < SMP_MIN_ENC_KEY_SIZE))
661 return SMP_ENC_KEY_SIZE;
662
663 smp->enc_key_size = max_key_size;
664
665 return 0;
666 }
667
668 static void smp_chan_destroy(struct l2cap_conn *conn)
669 {
670 struct l2cap_chan *chan = conn->smp;
671 struct smp_chan *smp = chan->data;
672 struct hci_conn *hcon = conn->hcon;
673 bool complete;
674
675 BUG_ON(!smp);
676
677 cancel_delayed_work_sync(&smp->security_timer);
678
679 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags);
680 mgmt_smp_complete(hcon, complete);
681
682 kfree(smp->csrk);
683 kfree(smp->slave_csrk);
684 kfree(smp->link_key);
685
686 crypto_free_blkcipher(smp->tfm_aes);
687 crypto_free_hash(smp->tfm_cmac);
688
689 /* Ensure that we don't leave any debug key around if debug key
690 * support hasn't been explicitly enabled.
691 */
692 if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG &&
693 !test_bit(HCI_KEEP_DEBUG_KEYS, &hcon->hdev->dev_flags)) {
694 list_del_rcu(&smp->ltk->list);
695 kfree_rcu(smp->ltk, rcu);
696 smp->ltk = NULL;
697 }
698
699 /* If pairing failed clean up any keys we might have */
700 if (!complete) {
701 if (smp->ltk) {
702 list_del_rcu(&smp->ltk->list);
703 kfree_rcu(smp->ltk, rcu);
704 }
705
706 if (smp->slave_ltk) {
707 list_del_rcu(&smp->slave_ltk->list);
708 kfree_rcu(smp->slave_ltk, rcu);
709 }
710
711 if (smp->remote_irk) {
712 list_del_rcu(&smp->remote_irk->list);
713 kfree_rcu(smp->remote_irk, rcu);
714 }
715 }
716
717 chan->data = NULL;
718 kfree(smp);
719 hci_conn_drop(hcon);
720 }
721
722 static void smp_failure(struct l2cap_conn *conn, u8 reason)
723 {
724 struct hci_conn *hcon = conn->hcon;
725 struct l2cap_chan *chan = conn->smp;
726
727 if (reason)
728 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
729 &reason);
730
731 clear_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags);
732 mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE);
733
734 if (chan->data)
735 smp_chan_destroy(conn);
736 }
737
738 #define JUST_WORKS 0x00
739 #define JUST_CFM 0x01
740 #define REQ_PASSKEY 0x02
741 #define CFM_PASSKEY 0x03
742 #define REQ_OOB 0x04
743 #define DSP_PASSKEY 0x05
744 #define OVERLAP 0xFF
745
746 static const u8 gen_method[5][5] = {
747 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
748 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
749 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
750 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
751 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP },
752 };
753
754 static const u8 sc_method[5][5] = {
755 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
756 { JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
757 { DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY },
758 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
759 { DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
760 };
761
762 static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io)
763 {
764 /* If either side has unknown io_caps, use JUST_CFM (which gets
765 * converted later to JUST_WORKS if we're initiators.
766 */
767 if (local_io > SMP_IO_KEYBOARD_DISPLAY ||
768 remote_io > SMP_IO_KEYBOARD_DISPLAY)
769 return JUST_CFM;
770
771 if (test_bit(SMP_FLAG_SC, &smp->flags))
772 return sc_method[remote_io][local_io];
773
774 return gen_method[remote_io][local_io];
775 }
776
777 static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth,
778 u8 local_io, u8 remote_io)
779 {
780 struct hci_conn *hcon = conn->hcon;
781 struct l2cap_chan *chan = conn->smp;
782 struct smp_chan *smp = chan->data;
783 u32 passkey = 0;
784 int ret = 0;
785
786 /* Initialize key for JUST WORKS */
787 memset(smp->tk, 0, sizeof(smp->tk));
788 clear_bit(SMP_FLAG_TK_VALID, &smp->flags);
789
790 BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io);
791
792 /* If neither side wants MITM, either "just" confirm an incoming
793 * request or use just-works for outgoing ones. The JUST_CFM
794 * will be converted to JUST_WORKS if necessary later in this
795 * function. If either side has MITM look up the method from the
796 * table.
797 */
798 if (!(auth & SMP_AUTH_MITM))
799 smp->method = JUST_CFM;
800 else
801 smp->method = get_auth_method(smp, local_io, remote_io);
802
803 /* Don't confirm locally initiated pairing attempts */
804 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR,
805 &smp->flags))
806 smp->method = JUST_WORKS;
807
808 /* Don't bother user space with no IO capabilities */
809 if (smp->method == JUST_CFM &&
810 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
811 smp->method = JUST_WORKS;
812
813 /* If Just Works, Continue with Zero TK */
814 if (smp->method == JUST_WORKS) {
815 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
816 return 0;
817 }
818
819 /* Not Just Works/Confirm results in MITM Authentication */
820 if (smp->method != JUST_CFM) {
821 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags);
822 if (hcon->pending_sec_level < BT_SECURITY_HIGH)
823 hcon->pending_sec_level = BT_SECURITY_HIGH;
824 }
825
826 /* If both devices have Keyoard-Display I/O, the master
827 * Confirms and the slave Enters the passkey.
828 */
829 if (smp->method == OVERLAP) {
830 if (hcon->role == HCI_ROLE_MASTER)
831 smp->method = CFM_PASSKEY;
832 else
833 smp->method = REQ_PASSKEY;
834 }
835
836 /* Generate random passkey. */
837 if (smp->method == CFM_PASSKEY) {
838 memset(smp->tk, 0, sizeof(smp->tk));
839 get_random_bytes(&passkey, sizeof(passkey));
840 passkey %= 1000000;
841 put_unaligned_le32(passkey, smp->tk);
842 BT_DBG("PassKey: %d", passkey);
843 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
844 }
845
846 if (smp->method == REQ_PASSKEY)
847 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst,
848 hcon->type, hcon->dst_type);
849 else if (smp->method == JUST_CFM)
850 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
851 hcon->type, hcon->dst_type,
852 passkey, 1);
853 else
854 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst,
855 hcon->type, hcon->dst_type,
856 passkey, 0);
857
858 return ret;
859 }
860
861 static u8 smp_confirm(struct smp_chan *smp)
862 {
863 struct l2cap_conn *conn = smp->conn;
864 struct smp_cmd_pairing_confirm cp;
865 int ret;
866
867 BT_DBG("conn %p", conn);
868
869 ret = smp_c1(smp->tfm_aes, smp->tk, smp->prnd, smp->preq, smp->prsp,
870 conn->hcon->init_addr_type, &conn->hcon->init_addr,
871 conn->hcon->resp_addr_type, &conn->hcon->resp_addr,
872 cp.confirm_val);
873 if (ret)
874 return SMP_UNSPECIFIED;
875
876 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
877
878 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
879
880 if (conn->hcon->out)
881 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
882 else
883 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
884
885 return 0;
886 }
887
888 static u8 smp_random(struct smp_chan *smp)
889 {
890 struct l2cap_conn *conn = smp->conn;
891 struct hci_conn *hcon = conn->hcon;
892 u8 confirm[16];
893 int ret;
894
895 if (IS_ERR_OR_NULL(smp->tfm_aes))
896 return SMP_UNSPECIFIED;
897
898 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
899
900 ret = smp_c1(smp->tfm_aes, smp->tk, smp->rrnd, smp->preq, smp->prsp,
901 hcon->init_addr_type, &hcon->init_addr,
902 hcon->resp_addr_type, &hcon->resp_addr, confirm);
903 if (ret)
904 return SMP_UNSPECIFIED;
905
906 if (memcmp(smp->pcnf, confirm, sizeof(smp->pcnf)) != 0) {
907 BT_ERR("Pairing failed (confirmation values mismatch)");
908 return SMP_CONFIRM_FAILED;
909 }
910
911 if (hcon->out) {
912 u8 stk[16];
913 __le64 rand = 0;
914 __le16 ediv = 0;
915
916 smp_s1(smp->tfm_aes, smp->tk, smp->rrnd, smp->prnd, stk);
917
918 memset(stk + smp->enc_key_size, 0,
919 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);
920
921 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
922 return SMP_UNSPECIFIED;
923
924 hci_le_start_enc(hcon, ediv, rand, stk);
925 hcon->enc_key_size = smp->enc_key_size;
926 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
927 } else {
928 u8 stk[16], auth;
929 __le64 rand = 0;
930 __le16 ediv = 0;
931
932 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
933 smp->prnd);
934
935 smp_s1(smp->tfm_aes, smp->tk, smp->prnd, smp->rrnd, stk);
936
937 memset(stk + smp->enc_key_size, 0,
938 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);
939
940 if (hcon->pending_sec_level == BT_SECURITY_HIGH)
941 auth = 1;
942 else
943 auth = 0;
944
945 /* Even though there's no _SLAVE suffix this is the
946 * slave STK we're adding for later lookup (the master
947 * STK never needs to be stored).
948 */
949 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
950 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand);
951 }
952
953 return 0;
954 }
955
956 static void smp_notify_keys(struct l2cap_conn *conn)
957 {
958 struct l2cap_chan *chan = conn->smp;
959 struct smp_chan *smp = chan->data;
960 struct hci_conn *hcon = conn->hcon;
961 struct hci_dev *hdev = hcon->hdev;
962 struct smp_cmd_pairing *req = (void *) &smp->preq[1];
963 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1];
964 bool persistent;
965
966 if (smp->remote_irk) {
967 mgmt_new_irk(hdev, smp->remote_irk);
968 /* Now that user space can be considered to know the
969 * identity address track the connection based on it
970 * from now on (assuming this is an LE link).
971 */
972 if (hcon->type == LE_LINK) {
973 bacpy(&hcon->dst, &smp->remote_irk->bdaddr);
974 hcon->dst_type = smp->remote_irk->addr_type;
975 queue_work(hdev->workqueue, &conn->id_addr_update_work);
976 }
977
978 /* When receiving an indentity resolving key for
979 * a remote device that does not use a resolvable
980 * private address, just remove the key so that
981 * it is possible to use the controller white
982 * list for scanning.
983 *
984 * Userspace will have been told to not store
985 * this key at this point. So it is safe to
986 * just remove it.
987 */
988 if (!bacmp(&smp->remote_irk->rpa, BDADDR_ANY)) {
989 list_del_rcu(&smp->remote_irk->list);
990 kfree_rcu(smp->remote_irk, rcu);
991 smp->remote_irk = NULL;
992 }
993 }
994
995 if (hcon->type == ACL_LINK) {
996 if (hcon->key_type == HCI_LK_DEBUG_COMBINATION)
997 persistent = false;
998 else
999 persistent = !test_bit(HCI_CONN_FLUSH_KEY,
1000 &hcon->flags);
1001 } else {
1002 /* The LTKs and CSRKs should be persistent only if both sides
1003 * had the bonding bit set in their authentication requests.
1004 */
1005 persistent = !!((req->auth_req & rsp->auth_req) &
1006 SMP_AUTH_BONDING);
1007 }
1008
1009
1010 if (smp->csrk) {
1011 smp->csrk->bdaddr_type = hcon->dst_type;
1012 bacpy(&smp->csrk->bdaddr, &hcon->dst);
1013 mgmt_new_csrk(hdev, smp->csrk, persistent);
1014 }
1015
1016 if (smp->slave_csrk) {
1017 smp->slave_csrk->bdaddr_type = hcon->dst_type;
1018 bacpy(&smp->slave_csrk->bdaddr, &hcon->dst);
1019 mgmt_new_csrk(hdev, smp->slave_csrk, persistent);
1020 }
1021
1022 if (smp->ltk) {
1023 smp->ltk->bdaddr_type = hcon->dst_type;
1024 bacpy(&smp->ltk->bdaddr, &hcon->dst);
1025 mgmt_new_ltk(hdev, smp->ltk, persistent);
1026 }
1027
1028 if (smp->slave_ltk) {
1029 smp->slave_ltk->bdaddr_type = hcon->dst_type;
1030 bacpy(&smp->slave_ltk->bdaddr, &hcon->dst);
1031 mgmt_new_ltk(hdev, smp->slave_ltk, persistent);
1032 }
1033
1034 if (smp->link_key) {
1035 struct link_key *key;
1036 u8 type;
1037
1038 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1039 type = HCI_LK_DEBUG_COMBINATION;
1040 else if (hcon->sec_level == BT_SECURITY_FIPS)
1041 type = HCI_LK_AUTH_COMBINATION_P256;
1042 else
1043 type = HCI_LK_UNAUTH_COMBINATION_P256;
1044
1045 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst,
1046 smp->link_key, type, 0, &persistent);
1047 if (key) {
1048 mgmt_new_link_key(hdev, key, persistent);
1049
1050 /* Don't keep debug keys around if the relevant
1051 * flag is not set.
1052 */
1053 if (!test_bit(HCI_KEEP_DEBUG_KEYS, &hdev->dev_flags) &&
1054 key->type == HCI_LK_DEBUG_COMBINATION) {
1055 list_del_rcu(&key->list);
1056 kfree_rcu(key, rcu);
1057 }
1058 }
1059 }
1060 }
1061
1062 static void sc_add_ltk(struct smp_chan *smp)
1063 {
1064 struct hci_conn *hcon = smp->conn->hcon;
1065 u8 key_type, auth;
1066
1067 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1068 key_type = SMP_LTK_P256_DEBUG;
1069 else
1070 key_type = SMP_LTK_P256;
1071
1072 if (hcon->pending_sec_level == BT_SECURITY_FIPS)
1073 auth = 1;
1074 else
1075 auth = 0;
1076
1077 memset(smp->tk + smp->enc_key_size, 0,
1078 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);
1079
1080 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1081 key_type, auth, smp->tk, smp->enc_key_size,
1082 0, 0);
1083 }
1084
1085 static void sc_generate_link_key(struct smp_chan *smp)
1086 {
1087 /* These constants are as specified in the core specification.
1088 * In ASCII they spell out to 'tmp1' and 'lebr'.
1089 */
1090 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 };
1091 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c };
1092
1093 smp->link_key = kzalloc(16, GFP_KERNEL);
1094 if (!smp->link_key)
1095 return;
1096
1097 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) {
1098 kfree(smp->link_key);
1099 smp->link_key = NULL;
1100 return;
1101 }
1102
1103 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) {
1104 kfree(smp->link_key);
1105 smp->link_key = NULL;
1106 return;
1107 }
1108 }
1109
1110 static void smp_allow_key_dist(struct smp_chan *smp)
1111 {
1112 /* Allow the first expected phase 3 PDU. The rest of the PDUs
1113 * will be allowed in each PDU handler to ensure we receive
1114 * them in the correct order.
1115 */
1116 if (smp->remote_key_dist & SMP_DIST_ENC_KEY)
1117 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO);
1118 else if (smp->remote_key_dist & SMP_DIST_ID_KEY)
1119 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
1120 else if (smp->remote_key_dist & SMP_DIST_SIGN)
1121 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
1122 }
1123
1124 static void sc_generate_ltk(struct smp_chan *smp)
1125 {
1126 /* These constants are as specified in the core specification.
1127 * In ASCII they spell out to 'tmp2' and 'brle'.
1128 */
1129 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 };
1130 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 };
1131 struct hci_conn *hcon = smp->conn->hcon;
1132 struct hci_dev *hdev = hcon->hdev;
1133 struct link_key *key;
1134
1135 key = hci_find_link_key(hdev, &hcon->dst);
1136 if (!key) {
1137 BT_ERR("%s No Link Key found to generate LTK", hdev->name);
1138 return;
1139 }
1140
1141 if (key->type == HCI_LK_DEBUG_COMBINATION)
1142 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1143
1144 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk))
1145 return;
1146
1147 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk))
1148 return;
1149
1150 sc_add_ltk(smp);
1151 }
1152
1153 static void smp_distribute_keys(struct smp_chan *smp)
1154 {
1155 struct smp_cmd_pairing *req, *rsp;
1156 struct l2cap_conn *conn = smp->conn;
1157 struct hci_conn *hcon = conn->hcon;
1158 struct hci_dev *hdev = hcon->hdev;
1159 __u8 *keydist;
1160
1161 BT_DBG("conn %p", conn);
1162
1163 rsp = (void *) &smp->prsp[1];
1164
1165 /* The responder sends its keys first */
1166 if (hcon->out && (smp->remote_key_dist & KEY_DIST_MASK)) {
1167 smp_allow_key_dist(smp);
1168 return;
1169 }
1170
1171 req = (void *) &smp->preq[1];
1172
1173 if (hcon->out) {
1174 keydist = &rsp->init_key_dist;
1175 *keydist &= req->init_key_dist;
1176 } else {
1177 keydist = &rsp->resp_key_dist;
1178 *keydist &= req->resp_key_dist;
1179 }
1180
1181 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1182 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY))
1183 sc_generate_link_key(smp);
1184 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY))
1185 sc_generate_ltk(smp);
1186
1187 /* Clear the keys which are generated but not distributed */
1188 *keydist &= ~SMP_SC_NO_DIST;
1189 }
1190
1191 BT_DBG("keydist 0x%x", *keydist);
1192
1193 if (*keydist & SMP_DIST_ENC_KEY) {
1194 struct smp_cmd_encrypt_info enc;
1195 struct smp_cmd_master_ident ident;
1196 struct smp_ltk *ltk;
1197 u8 authenticated;
1198 __le16 ediv;
1199 __le64 rand;
1200
1201 get_random_bytes(enc.ltk, sizeof(enc.ltk));
1202 get_random_bytes(&ediv, sizeof(ediv));
1203 get_random_bytes(&rand, sizeof(rand));
1204
1205 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc);
1206
1207 authenticated = hcon->sec_level == BT_SECURITY_HIGH;
1208 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type,
1209 SMP_LTK_SLAVE, authenticated, enc.ltk,
1210 smp->enc_key_size, ediv, rand);
1211 smp->slave_ltk = ltk;
1212
1213 ident.ediv = ediv;
1214 ident.rand = rand;
1215
1216 smp_send_cmd(conn, SMP_CMD_MASTER_IDENT, sizeof(ident), &ident);
1217
1218 *keydist &= ~SMP_DIST_ENC_KEY;
1219 }
1220
1221 if (*keydist & SMP_DIST_ID_KEY) {
1222 struct smp_cmd_ident_addr_info addrinfo;
1223 struct smp_cmd_ident_info idinfo;
1224
1225 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk));
1226
1227 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo);
1228
1229 /* The hci_conn contains the local identity address
1230 * after the connection has been established.
1231 *
1232 * This is true even when the connection has been
1233 * established using a resolvable random address.
1234 */
1235 bacpy(&addrinfo.bdaddr, &hcon->src);
1236 addrinfo.addr_type = hcon->src_type;
1237
1238 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo),
1239 &addrinfo);
1240
1241 *keydist &= ~SMP_DIST_ID_KEY;
1242 }
1243
1244 if (*keydist & SMP_DIST_SIGN) {
1245 struct smp_cmd_sign_info sign;
1246 struct smp_csrk *csrk;
1247
1248 /* Generate a new random key */
1249 get_random_bytes(sign.csrk, sizeof(sign.csrk));
1250
1251 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
1252 if (csrk) {
1253 csrk->master = 0x00;
1254 memcpy(csrk->val, sign.csrk, sizeof(csrk->val));
1255 }
1256 smp->slave_csrk = csrk;
1257
1258 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign);
1259
1260 *keydist &= ~SMP_DIST_SIGN;
1261 }
1262
1263 /* If there are still keys to be received wait for them */
1264 if (smp->remote_key_dist & KEY_DIST_MASK) {
1265 smp_allow_key_dist(smp);
1266 return;
1267 }
1268
1269 set_bit(SMP_FLAG_COMPLETE, &smp->flags);
1270 smp_notify_keys(conn);
1271
1272 smp_chan_destroy(conn);
1273 }
1274
1275 static void smp_timeout(struct work_struct *work)
1276 {
1277 struct smp_chan *smp = container_of(work, struct smp_chan,
1278 security_timer.work);
1279 struct l2cap_conn *conn = smp->conn;
1280
1281 BT_DBG("conn %p", conn);
1282
1283 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM);
1284 }
1285
1286 static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
1287 {
1288 struct l2cap_chan *chan = conn->smp;
1289 struct smp_chan *smp;
1290
1291 smp = kzalloc(sizeof(*smp), GFP_ATOMIC);
1292 if (!smp)
1293 return NULL;
1294
1295 smp->tfm_aes = crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);
1296 if (IS_ERR(smp->tfm_aes)) {
1297 BT_ERR("Unable to create ECB crypto context");
1298 kfree(smp);
1299 return NULL;
1300 }
1301
1302 smp->tfm_cmac = crypto_alloc_hash("cmac(aes)", 0, CRYPTO_ALG_ASYNC);
1303 if (IS_ERR(smp->tfm_cmac)) {
1304 BT_ERR("Unable to create CMAC crypto context");
1305 crypto_free_blkcipher(smp->tfm_aes);
1306 kfree(smp);
1307 return NULL;
1308 }
1309
1310 smp->conn = conn;
1311 chan->data = smp;
1312
1313 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL);
1314
1315 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout);
1316
1317 hci_conn_hold(conn->hcon);
1318
1319 return smp;
1320 }
1321
1322 static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16])
1323 {
1324 struct hci_conn *hcon = smp->conn->hcon;
1325 u8 *na, *nb, a[7], b[7];
1326
1327 if (hcon->out) {
1328 na = smp->prnd;
1329 nb = smp->rrnd;
1330 } else {
1331 na = smp->rrnd;
1332 nb = smp->prnd;
1333 }
1334
1335 memcpy(a, &hcon->init_addr, 6);
1336 memcpy(b, &hcon->resp_addr, 6);
1337 a[6] = hcon->init_addr_type;
1338 b[6] = hcon->resp_addr_type;
1339
1340 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk);
1341 }
1342
1343 static void sc_dhkey_check(struct smp_chan *smp)
1344 {
1345 struct hci_conn *hcon = smp->conn->hcon;
1346 struct smp_cmd_dhkey_check check;
1347 u8 a[7], b[7], *local_addr, *remote_addr;
1348 u8 io_cap[3], r[16];
1349
1350 memcpy(a, &hcon->init_addr, 6);
1351 memcpy(b, &hcon->resp_addr, 6);
1352 a[6] = hcon->init_addr_type;
1353 b[6] = hcon->resp_addr_type;
1354
1355 if (hcon->out) {
1356 local_addr = a;
1357 remote_addr = b;
1358 memcpy(io_cap, &smp->preq[1], 3);
1359 } else {
1360 local_addr = b;
1361 remote_addr = a;
1362 memcpy(io_cap, &smp->prsp[1], 3);
1363 }
1364
1365 memset(r, 0, sizeof(r));
1366
1367 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
1368 put_unaligned_le32(hcon->passkey_notify, r);
1369
1370 if (smp->method == REQ_OOB)
1371 memcpy(r, smp->rr, 16);
1372
1373 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap,
1374 local_addr, remote_addr, check.e);
1375
1376 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check);
1377 }
1378
1379 static u8 sc_passkey_send_confirm(struct smp_chan *smp)
1380 {
1381 struct l2cap_conn *conn = smp->conn;
1382 struct hci_conn *hcon = conn->hcon;
1383 struct smp_cmd_pairing_confirm cfm;
1384 u8 r;
1385
1386 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1387 r |= 0x80;
1388
1389 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1390
1391 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r,
1392 cfm.confirm_val))
1393 return SMP_UNSPECIFIED;
1394
1395 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
1396
1397 return 0;
1398 }
1399
1400 static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op)
1401 {
1402 struct l2cap_conn *conn = smp->conn;
1403 struct hci_conn *hcon = conn->hcon;
1404 struct hci_dev *hdev = hcon->hdev;
1405 u8 cfm[16], r;
1406
1407 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */
1408 if (smp->passkey_round >= 20)
1409 return 0;
1410
1411 switch (smp_op) {
1412 case SMP_CMD_PAIRING_RANDOM:
1413 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1414 r |= 0x80;
1415
1416 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
1417 smp->rrnd, r, cfm))
1418 return SMP_UNSPECIFIED;
1419
1420 if (memcmp(smp->pcnf, cfm, 16))
1421 return SMP_CONFIRM_FAILED;
1422
1423 smp->passkey_round++;
1424
1425 if (smp->passkey_round == 20) {
1426 /* Generate MacKey and LTK */
1427 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk))
1428 return SMP_UNSPECIFIED;
1429 }
1430
1431 /* The round is only complete when the initiator
1432 * receives pairing random.
1433 */
1434 if (!hcon->out) {
1435 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1436 sizeof(smp->prnd), smp->prnd);
1437 if (smp->passkey_round == 20)
1438 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1439 else
1440 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1441 return 0;
1442 }
1443
1444 /* Start the next round */
1445 if (smp->passkey_round != 20)
1446 return sc_passkey_round(smp, 0);
1447
1448 /* Passkey rounds are complete - start DHKey Check */
1449 sc_dhkey_check(smp);
1450 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1451
1452 break;
1453
1454 case SMP_CMD_PAIRING_CONFIRM:
1455 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
1456 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
1457 return 0;
1458 }
1459
1460 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
1461
1462 if (hcon->out) {
1463 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1464 sizeof(smp->prnd), smp->prnd);
1465 return 0;
1466 }
1467
1468 return sc_passkey_send_confirm(smp);
1469
1470 case SMP_CMD_PUBLIC_KEY:
1471 default:
1472 /* Initiating device starts the round */
1473 if (!hcon->out)
1474 return 0;
1475
1476 BT_DBG("%s Starting passkey round %u", hdev->name,
1477 smp->passkey_round + 1);
1478
1479 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1480
1481 return sc_passkey_send_confirm(smp);
1482 }
1483
1484 return 0;
1485 }
1486
1487 static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey)
1488 {
1489 struct l2cap_conn *conn = smp->conn;
1490 struct hci_conn *hcon = conn->hcon;
1491 u8 smp_op;
1492
1493 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags);
1494
1495 switch (mgmt_op) {
1496 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1497 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED);
1498 return 0;
1499 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1500 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED);
1501 return 0;
1502 case MGMT_OP_USER_PASSKEY_REPLY:
1503 hcon->passkey_notify = le32_to_cpu(passkey);
1504 smp->passkey_round = 0;
1505
1506 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags))
1507 smp_op = SMP_CMD_PAIRING_CONFIRM;
1508 else
1509 smp_op = 0;
1510
1511 if (sc_passkey_round(smp, smp_op))
1512 return -EIO;
1513
1514 return 0;
1515 }
1516
1517 /* Initiator sends DHKey check first */
1518 if (hcon->out) {
1519 sc_dhkey_check(smp);
1520 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1521 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) {
1522 sc_dhkey_check(smp);
1523 sc_add_ltk(smp);
1524 }
1525
1526 return 0;
1527 }
1528
1529 int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey)
1530 {
1531 struct l2cap_conn *conn = hcon->l2cap_data;
1532 struct l2cap_chan *chan;
1533 struct smp_chan *smp;
1534 u32 value;
1535 int err;
1536
1537 BT_DBG("");
1538
1539 if (!conn)
1540 return -ENOTCONN;
1541
1542 chan = conn->smp;
1543 if (!chan)
1544 return -ENOTCONN;
1545
1546 l2cap_chan_lock(chan);
1547 if (!chan->data) {
1548 err = -ENOTCONN;
1549 goto unlock;
1550 }
1551
1552 smp = chan->data;
1553
1554 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1555 err = sc_user_reply(smp, mgmt_op, passkey);
1556 goto unlock;
1557 }
1558
1559 switch (mgmt_op) {
1560 case MGMT_OP_USER_PASSKEY_REPLY:
1561 value = le32_to_cpu(passkey);
1562 memset(smp->tk, 0, sizeof(smp->tk));
1563 BT_DBG("PassKey: %d", value);
1564 put_unaligned_le32(value, smp->tk);
1565 /* Fall Through */
1566 case MGMT_OP_USER_CONFIRM_REPLY:
1567 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
1568 break;
1569 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1570 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1571 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1572 err = 0;
1573 goto unlock;
1574 default:
1575 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1576 err = -EOPNOTSUPP;
1577 goto unlock;
1578 }
1579
1580 err = 0;
1581
1582 /* If it is our turn to send Pairing Confirm, do so now */
1583 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) {
1584 u8 rsp = smp_confirm(smp);
1585 if (rsp)
1586 smp_failure(conn, rsp);
1587 }
1588
1589 unlock:
1590 l2cap_chan_unlock(chan);
1591 return err;
1592 }
1593
1594 static void build_bredr_pairing_cmd(struct smp_chan *smp,
1595 struct smp_cmd_pairing *req,
1596 struct smp_cmd_pairing *rsp)
1597 {
1598 struct l2cap_conn *conn = smp->conn;
1599 struct hci_dev *hdev = conn->hcon->hdev;
1600 u8 local_dist = 0, remote_dist = 0;
1601
1602 if (test_bit(HCI_BONDABLE, &hdev->dev_flags)) {
1603 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1604 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1605 }
1606
1607 if (test_bit(HCI_RPA_RESOLVING, &hdev->dev_flags))
1608 remote_dist |= SMP_DIST_ID_KEY;
1609
1610 if (test_bit(HCI_PRIVACY, &hdev->dev_flags))
1611 local_dist |= SMP_DIST_ID_KEY;
1612
1613 if (!rsp) {
1614 memset(req, 0, sizeof(*req));
1615
1616 req->init_key_dist = local_dist;
1617 req->resp_key_dist = remote_dist;
1618 req->max_key_size = SMP_MAX_ENC_KEY_SIZE;
1619
1620 smp->remote_key_dist = remote_dist;
1621
1622 return;
1623 }
1624
1625 memset(rsp, 0, sizeof(*rsp));
1626
1627 rsp->max_key_size = SMP_MAX_ENC_KEY_SIZE;
1628 rsp->init_key_dist = req->init_key_dist & remote_dist;
1629 rsp->resp_key_dist = req->resp_key_dist & local_dist;
1630
1631 smp->remote_key_dist = rsp->init_key_dist;
1632 }
1633
1634 static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
1635 {
1636 struct smp_cmd_pairing rsp, *req = (void *) skb->data;
1637 struct l2cap_chan *chan = conn->smp;
1638 struct hci_dev *hdev = conn->hcon->hdev;
1639 struct smp_chan *smp;
1640 u8 key_size, auth, sec_level;
1641 int ret;
1642
1643 BT_DBG("conn %p", conn);
1644
1645 if (skb->len < sizeof(*req))
1646 return SMP_INVALID_PARAMS;
1647
1648 if (conn->hcon->role != HCI_ROLE_SLAVE)
1649 return SMP_CMD_NOTSUPP;
1650
1651 if (!chan->data)
1652 smp = smp_chan_create(conn);
1653 else
1654 smp = chan->data;
1655
1656 if (!smp)
1657 return SMP_UNSPECIFIED;
1658
1659 /* We didn't start the pairing, so match remote */
1660 auth = req->auth_req & AUTH_REQ_MASK(hdev);
1661
1662 if (!test_bit(HCI_BONDABLE, &hdev->dev_flags) &&
1663 (auth & SMP_AUTH_BONDING))
1664 return SMP_PAIRING_NOTSUPP;
1665
1666 if (test_bit(HCI_SC_ONLY, &hdev->dev_flags) && !(auth & SMP_AUTH_SC))
1667 return SMP_AUTH_REQUIREMENTS;
1668
1669 smp->preq[0] = SMP_CMD_PAIRING_REQ;
1670 memcpy(&smp->preq[1], req, sizeof(*req));
1671 skb_pull(skb, sizeof(*req));
1672
1673 /* SMP over BR/EDR requires special treatment */
1674 if (conn->hcon->type == ACL_LINK) {
1675 /* We must have a BR/EDR SC link */
1676 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags))
1677 return SMP_CROSS_TRANSP_NOT_ALLOWED;
1678
1679 set_bit(SMP_FLAG_SC, &smp->flags);
1680
1681 build_bredr_pairing_cmd(smp, req, &rsp);
1682
1683 key_size = min(req->max_key_size, rsp.max_key_size);
1684 if (check_enc_key_size(conn, key_size))
1685 return SMP_ENC_KEY_SIZE;
1686
1687 /* Clear bits which are generated but not distributed */
1688 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1689
1690 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1691 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1692 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1693
1694 smp_distribute_keys(smp);
1695 return 0;
1696 }
1697
1698 build_pairing_cmd(conn, req, &rsp, auth);
1699
1700 if (rsp.auth_req & SMP_AUTH_SC)
1701 set_bit(SMP_FLAG_SC, &smp->flags);
1702
1703 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
1704 sec_level = BT_SECURITY_MEDIUM;
1705 else
1706 sec_level = authreq_to_seclevel(auth);
1707
1708 if (sec_level > conn->hcon->pending_sec_level)
1709 conn->hcon->pending_sec_level = sec_level;
1710
1711 /* If we need MITM check that it can be achieved */
1712 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1713 u8 method;
1714
1715 method = get_auth_method(smp, conn->hcon->io_capability,
1716 req->io_capability);
1717 if (method == JUST_WORKS || method == JUST_CFM)
1718 return SMP_AUTH_REQUIREMENTS;
1719 }
1720
1721 key_size = min(req->max_key_size, rsp.max_key_size);
1722 if (check_enc_key_size(conn, key_size))
1723 return SMP_ENC_KEY_SIZE;
1724
1725 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1726
1727 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1728 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1729
1730 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1731
1732 clear_bit(SMP_FLAG_INITIATOR, &smp->flags);
1733
1734 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1735 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
1736 /* Clear bits which are generated but not distributed */
1737 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1738 /* Wait for Public Key from Initiating Device */
1739 return 0;
1740 } else {
1741 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1742 }
1743
1744 /* Request setup of TK */
1745 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability);
1746 if (ret)
1747 return SMP_UNSPECIFIED;
1748
1749 return 0;
1750 }
1751
1752 static u8 sc_send_public_key(struct smp_chan *smp)
1753 {
1754 struct hci_dev *hdev = smp->conn->hcon->hdev;
1755
1756 BT_DBG("");
1757
1758 if (test_bit(HCI_USE_DEBUG_KEYS, &hdev->dev_flags)) {
1759 BT_DBG("Using debug keys");
1760 memcpy(smp->local_pk, debug_pk, 64);
1761 memcpy(smp->local_sk, debug_sk, 32);
1762 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1763 } else {
1764 while (true) {
1765 /* Generate local key pair for Secure Connections */
1766 if (!ecc_make_key(smp->local_pk, smp->local_sk))
1767 return SMP_UNSPECIFIED;
1768
1769 /* This is unlikely, but we need to check that
1770 * we didn't accidentially generate a debug key.
1771 */
1772 if (memcmp(smp->local_sk, debug_sk, 32))
1773 break;
1774 }
1775 }
1776
1777 SMP_DBG("Local Public Key X: %32phN", smp->local_pk);
1778 SMP_DBG("Local Public Key Y: %32phN", &smp->local_pk[32]);
1779 SMP_DBG("Local Private Key: %32phN", smp->local_sk);
1780
1781 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk);
1782
1783 return 0;
1784 }
1785
1786 static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
1787 {
1788 struct smp_cmd_pairing *req, *rsp = (void *) skb->data;
1789 struct l2cap_chan *chan = conn->smp;
1790 struct smp_chan *smp = chan->data;
1791 struct hci_dev *hdev = conn->hcon->hdev;
1792 u8 key_size, auth;
1793 int ret;
1794
1795 BT_DBG("conn %p", conn);
1796
1797 if (skb->len < sizeof(*rsp))
1798 return SMP_INVALID_PARAMS;
1799
1800 if (conn->hcon->role != HCI_ROLE_MASTER)
1801 return SMP_CMD_NOTSUPP;
1802
1803 skb_pull(skb, sizeof(*rsp));
1804
1805 req = (void *) &smp->preq[1];
1806
1807 key_size = min(req->max_key_size, rsp->max_key_size);
1808 if (check_enc_key_size(conn, key_size))
1809 return SMP_ENC_KEY_SIZE;
1810
1811 auth = rsp->auth_req & AUTH_REQ_MASK(hdev);
1812
1813 if (test_bit(HCI_SC_ONLY, &hdev->dev_flags) && !(auth & SMP_AUTH_SC))
1814 return SMP_AUTH_REQUIREMENTS;
1815
1816 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1817 memcpy(&smp->prsp[1], rsp, sizeof(*rsp));
1818
1819 /* Update remote key distribution in case the remote cleared
1820 * some bits that we had enabled in our request.
1821 */
1822 smp->remote_key_dist &= rsp->resp_key_dist;
1823
1824 /* For BR/EDR this means we're done and can start phase 3 */
1825 if (conn->hcon->type == ACL_LINK) {
1826 /* Clear bits which are generated but not distributed */
1827 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1828 smp_distribute_keys(smp);
1829 return 0;
1830 }
1831
1832 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC))
1833 set_bit(SMP_FLAG_SC, &smp->flags);
1834 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH)
1835 conn->hcon->pending_sec_level = BT_SECURITY_HIGH;
1836
1837 /* If we need MITM check that it can be achieved */
1838 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1839 u8 method;
1840
1841 method = get_auth_method(smp, req->io_capability,
1842 rsp->io_capability);
1843 if (method == JUST_WORKS || method == JUST_CFM)
1844 return SMP_AUTH_REQUIREMENTS;
1845 }
1846
1847 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1848
1849 /* Update remote key distribution in case the remote cleared
1850 * some bits that we had enabled in our request.
1851 */
1852 smp->remote_key_dist &= rsp->resp_key_dist;
1853
1854 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1855 /* Clear bits which are generated but not distributed */
1856 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1857 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
1858 return sc_send_public_key(smp);
1859 }
1860
1861 auth |= req->auth_req;
1862
1863 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability);
1864 if (ret)
1865 return SMP_UNSPECIFIED;
1866
1867 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
1868
1869 /* Can't compose response until we have been confirmed */
1870 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
1871 return smp_confirm(smp);
1872
1873 return 0;
1874 }
1875
1876 static u8 sc_check_confirm(struct smp_chan *smp)
1877 {
1878 struct l2cap_conn *conn = smp->conn;
1879
1880 BT_DBG("");
1881
1882 /* Public Key exchange must happen before any other steps */
1883 if (!test_bit(SMP_FLAG_REMOTE_PK, &smp->flags))
1884 return SMP_UNSPECIFIED;
1885
1886 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
1887 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM);
1888
1889 if (conn->hcon->out) {
1890 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
1891 smp->prnd);
1892 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
1893 }
1894
1895 return 0;
1896 }
1897
1898 static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
1899 {
1900 struct l2cap_chan *chan = conn->smp;
1901 struct smp_chan *smp = chan->data;
1902
1903 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
1904
1905 if (skb->len < sizeof(smp->pcnf))
1906 return SMP_INVALID_PARAMS;
1907
1908 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf));
1909 skb_pull(skb, sizeof(smp->pcnf));
1910
1911 if (test_bit(SMP_FLAG_SC, &smp->flags))
1912 return sc_check_confirm(smp);
1913
1914 if (conn->hcon->out) {
1915 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
1916 smp->prnd);
1917 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
1918 return 0;
1919 }
1920
1921 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
1922 return smp_confirm(smp);
1923 else
1924 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
1925
1926 return 0;
1927 }
1928
1929 static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
1930 {
1931 struct l2cap_chan *chan = conn->smp;
1932 struct smp_chan *smp = chan->data;
1933 struct hci_conn *hcon = conn->hcon;
1934 u8 *pkax, *pkbx, *na, *nb;
1935 u32 passkey;
1936 int err;
1937
1938 BT_DBG("conn %p", conn);
1939
1940 if (skb->len < sizeof(smp->rrnd))
1941 return SMP_INVALID_PARAMS;
1942
1943 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd));
1944 skb_pull(skb, sizeof(smp->rrnd));
1945
1946 if (!test_bit(SMP_FLAG_SC, &smp->flags))
1947 return smp_random(smp);
1948
1949 if (hcon->out) {
1950 pkax = smp->local_pk;
1951 pkbx = smp->remote_pk;
1952 na = smp->prnd;
1953 nb = smp->rrnd;
1954 } else {
1955 pkax = smp->remote_pk;
1956 pkbx = smp->local_pk;
1957 na = smp->rrnd;
1958 nb = smp->prnd;
1959 }
1960
1961 if (smp->method == REQ_OOB) {
1962 if (!hcon->out)
1963 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1964 sizeof(smp->prnd), smp->prnd);
1965 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1966 goto mackey_and_ltk;
1967 }
1968
1969 /* Passkey entry has special treatment */
1970 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
1971 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM);
1972
1973 if (hcon->out) {
1974 u8 cfm[16];
1975
1976 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
1977 smp->rrnd, 0, cfm);
1978 if (err)
1979 return SMP_UNSPECIFIED;
1980
1981 if (memcmp(smp->pcnf, cfm, 16))
1982 return SMP_CONFIRM_FAILED;
1983 } else {
1984 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
1985 smp->prnd);
1986 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1987 }
1988
1989 mackey_and_ltk:
1990 /* Generate MacKey and LTK */
1991 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk);
1992 if (err)
1993 return SMP_UNSPECIFIED;
1994
1995 if (smp->method == JUST_WORKS || smp->method == REQ_OOB) {
1996 if (hcon->out) {
1997 sc_dhkey_check(smp);
1998 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1999 }
2000 return 0;
2001 }
2002
2003 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
2004 if (err)
2005 return SMP_UNSPECIFIED;
2006
2007 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type,
2008 hcon->dst_type, passkey, 0);
2009 if (err)
2010 return SMP_UNSPECIFIED;
2011
2012 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2013
2014 return 0;
2015 }
2016
2017 static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level)
2018 {
2019 struct smp_ltk *key;
2020 struct hci_conn *hcon = conn->hcon;
2021
2022 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role);
2023 if (!key)
2024 return false;
2025
2026 if (smp_ltk_sec_level(key) < sec_level)
2027 return false;
2028
2029 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
2030 return true;
2031
2032 hci_le_start_enc(hcon, key->ediv, key->rand, key->val);
2033 hcon->enc_key_size = key->enc_size;
2034
2035 /* We never store STKs for master role, so clear this flag */
2036 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
2037
2038 return true;
2039 }
2040
2041 bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level,
2042 enum smp_key_pref key_pref)
2043 {
2044 if (sec_level == BT_SECURITY_LOW)
2045 return true;
2046
2047 /* If we're encrypted with an STK but the caller prefers using
2048 * LTK claim insufficient security. This way we allow the
2049 * connection to be re-encrypted with an LTK, even if the LTK
2050 * provides the same level of security. Only exception is if we
2051 * don't have an LTK (e.g. because of key distribution bits).
2052 */
2053 if (key_pref == SMP_USE_LTK &&
2054 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) &&
2055 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role))
2056 return false;
2057
2058 if (hcon->sec_level >= sec_level)
2059 return true;
2060
2061 return false;
2062 }
2063
2064 static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
2065 {
2066 struct smp_cmd_security_req *rp = (void *) skb->data;
2067 struct smp_cmd_pairing cp;
2068 struct hci_conn *hcon = conn->hcon;
2069 struct hci_dev *hdev = hcon->hdev;
2070 struct smp_chan *smp;
2071 u8 sec_level, auth;
2072
2073 BT_DBG("conn %p", conn);
2074
2075 if (skb->len < sizeof(*rp))
2076 return SMP_INVALID_PARAMS;
2077
2078 if (hcon->role != HCI_ROLE_MASTER)
2079 return SMP_CMD_NOTSUPP;
2080
2081 auth = rp->auth_req & AUTH_REQ_MASK(hdev);
2082
2083 if (test_bit(HCI_SC_ONLY, &hdev->dev_flags) && !(auth & SMP_AUTH_SC))
2084 return SMP_AUTH_REQUIREMENTS;
2085
2086 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
2087 sec_level = BT_SECURITY_MEDIUM;
2088 else
2089 sec_level = authreq_to_seclevel(auth);
2090
2091 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK))
2092 return 0;
2093
2094 if (sec_level > hcon->pending_sec_level)
2095 hcon->pending_sec_level = sec_level;
2096
2097 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2098 return 0;
2099
2100 smp = smp_chan_create(conn);
2101 if (!smp)
2102 return SMP_UNSPECIFIED;
2103
2104 if (!test_bit(HCI_BONDABLE, &hcon->hdev->dev_flags) &&
2105 (auth & SMP_AUTH_BONDING))
2106 return SMP_PAIRING_NOTSUPP;
2107
2108 skb_pull(skb, sizeof(*rp));
2109
2110 memset(&cp, 0, sizeof(cp));
2111 build_pairing_cmd(conn, &cp, NULL, auth);
2112
2113 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2114 memcpy(&smp->preq[1], &cp, sizeof(cp));
2115
2116 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
2117 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2118
2119 return 0;
2120 }
2121
2122 int smp_conn_security(struct hci_conn *hcon, __u8 sec_level)
2123 {
2124 struct l2cap_conn *conn = hcon->l2cap_data;
2125 struct l2cap_chan *chan;
2126 struct smp_chan *smp;
2127 __u8 authreq;
2128 int ret;
2129
2130 BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level);
2131
2132 /* This may be NULL if there's an unexpected disconnection */
2133 if (!conn)
2134 return 1;
2135
2136 chan = conn->smp;
2137
2138 if (!test_bit(HCI_LE_ENABLED, &hcon->hdev->dev_flags))
2139 return 1;
2140
2141 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK))
2142 return 1;
2143
2144 if (sec_level > hcon->pending_sec_level)
2145 hcon->pending_sec_level = sec_level;
2146
2147 if (hcon->role == HCI_ROLE_MASTER)
2148 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2149 return 0;
2150
2151 l2cap_chan_lock(chan);
2152
2153 /* If SMP is already in progress ignore this request */
2154 if (chan->data) {
2155 ret = 0;
2156 goto unlock;
2157 }
2158
2159 smp = smp_chan_create(conn);
2160 if (!smp) {
2161 ret = 1;
2162 goto unlock;
2163 }
2164
2165 authreq = seclevel_to_authreq(sec_level);
2166
2167 if (test_bit(HCI_SC_ENABLED, &hcon->hdev->dev_flags))
2168 authreq |= SMP_AUTH_SC;
2169
2170 /* Require MITM if IO Capability allows or the security level
2171 * requires it.
2172 */
2173 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT ||
2174 hcon->pending_sec_level > BT_SECURITY_MEDIUM)
2175 authreq |= SMP_AUTH_MITM;
2176
2177 if (hcon->role == HCI_ROLE_MASTER) {
2178 struct smp_cmd_pairing cp;
2179
2180 build_pairing_cmd(conn, &cp, NULL, authreq);
2181 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2182 memcpy(&smp->preq[1], &cp, sizeof(cp));
2183
2184 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
2185 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2186 } else {
2187 struct smp_cmd_security_req cp;
2188 cp.auth_req = authreq;
2189 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp);
2190 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ);
2191 }
2192
2193 set_bit(SMP_FLAG_INITIATOR, &smp->flags);
2194 ret = 0;
2195
2196 unlock:
2197 l2cap_chan_unlock(chan);
2198 return ret;
2199 }
2200
2201 static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb)
2202 {
2203 struct smp_cmd_encrypt_info *rp = (void *) skb->data;
2204 struct l2cap_chan *chan = conn->smp;
2205 struct smp_chan *smp = chan->data;
2206
2207 BT_DBG("conn %p", conn);
2208
2209 if (skb->len < sizeof(*rp))
2210 return SMP_INVALID_PARAMS;
2211
2212 SMP_ALLOW_CMD(smp, SMP_CMD_MASTER_IDENT);
2213
2214 skb_pull(skb, sizeof(*rp));
2215
2216 memcpy(smp->tk, rp->ltk, sizeof(smp->tk));
2217
2218 return 0;
2219 }
2220
2221 static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb)
2222 {
2223 struct smp_cmd_master_ident *rp = (void *) skb->data;
2224 struct l2cap_chan *chan = conn->smp;
2225 struct smp_chan *smp = chan->data;
2226 struct hci_dev *hdev = conn->hcon->hdev;
2227 struct hci_conn *hcon = conn->hcon;
2228 struct smp_ltk *ltk;
2229 u8 authenticated;
2230
2231 BT_DBG("conn %p", conn);
2232
2233 if (skb->len < sizeof(*rp))
2234 return SMP_INVALID_PARAMS;
2235
2236 /* Mark the information as received */
2237 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY;
2238
2239 if (smp->remote_key_dist & SMP_DIST_ID_KEY)
2240 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
2241 else if (smp->remote_key_dist & SMP_DIST_SIGN)
2242 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2243
2244 skb_pull(skb, sizeof(*rp));
2245
2246 authenticated = (hcon->sec_level == BT_SECURITY_HIGH);
2247 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK,
2248 authenticated, smp->tk, smp->enc_key_size,
2249 rp->ediv, rp->rand);
2250 smp->ltk = ltk;
2251 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2252 smp_distribute_keys(smp);
2253
2254 return 0;
2255 }
2256
2257 static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb)
2258 {
2259 struct smp_cmd_ident_info *info = (void *) skb->data;
2260 struct l2cap_chan *chan = conn->smp;
2261 struct smp_chan *smp = chan->data;
2262
2263 BT_DBG("");
2264
2265 if (skb->len < sizeof(*info))
2266 return SMP_INVALID_PARAMS;
2267
2268 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO);
2269
2270 skb_pull(skb, sizeof(*info));
2271
2272 memcpy(smp->irk, info->irk, 16);
2273
2274 return 0;
2275 }
2276
2277 static int smp_cmd_ident_addr_info(struct l2cap_conn *conn,
2278 struct sk_buff *skb)
2279 {
2280 struct smp_cmd_ident_addr_info *info = (void *) skb->data;
2281 struct l2cap_chan *chan = conn->smp;
2282 struct smp_chan *smp = chan->data;
2283 struct hci_conn *hcon = conn->hcon;
2284 bdaddr_t rpa;
2285
2286 BT_DBG("");
2287
2288 if (skb->len < sizeof(*info))
2289 return SMP_INVALID_PARAMS;
2290
2291 /* Mark the information as received */
2292 smp->remote_key_dist &= ~SMP_DIST_ID_KEY;
2293
2294 if (smp->remote_key_dist & SMP_DIST_SIGN)
2295 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2296
2297 skb_pull(skb, sizeof(*info));
2298
2299 /* Strictly speaking the Core Specification (4.1) allows sending
2300 * an empty address which would force us to rely on just the IRK
2301 * as "identity information". However, since such
2302 * implementations are not known of and in order to not over
2303 * complicate our implementation, simply pretend that we never
2304 * received an IRK for such a device.
2305 */
2306 if (!bacmp(&info->bdaddr, BDADDR_ANY)) {
2307 BT_ERR("Ignoring IRK with no identity address");
2308 goto distribute;
2309 }
2310
2311 bacpy(&smp->id_addr, &info->bdaddr);
2312 smp->id_addr_type = info->addr_type;
2313
2314 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type))
2315 bacpy(&rpa, &hcon->dst);
2316 else
2317 bacpy(&rpa, BDADDR_ANY);
2318
2319 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr,
2320 smp->id_addr_type, smp->irk, &rpa);
2321
2322 distribute:
2323 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2324 smp_distribute_keys(smp);
2325
2326 return 0;
2327 }
2328
2329 static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb)
2330 {
2331 struct smp_cmd_sign_info *rp = (void *) skb->data;
2332 struct l2cap_chan *chan = conn->smp;
2333 struct smp_chan *smp = chan->data;
2334 struct smp_csrk *csrk;
2335
2336 BT_DBG("conn %p", conn);
2337
2338 if (skb->len < sizeof(*rp))
2339 return SMP_INVALID_PARAMS;
2340
2341 /* Mark the information as received */
2342 smp->remote_key_dist &= ~SMP_DIST_SIGN;
2343
2344 skb_pull(skb, sizeof(*rp));
2345
2346 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
2347 if (csrk) {
2348 csrk->master = 0x01;
2349 memcpy(csrk->val, rp->csrk, sizeof(csrk->val));
2350 }
2351 smp->csrk = csrk;
2352 smp_distribute_keys(smp);
2353
2354 return 0;
2355 }
2356
2357 static u8 sc_select_method(struct smp_chan *smp)
2358 {
2359 struct l2cap_conn *conn = smp->conn;
2360 struct hci_conn *hcon = conn->hcon;
2361 struct smp_cmd_pairing *local, *remote;
2362 u8 local_mitm, remote_mitm, local_io, remote_io, method;
2363
2364 if (test_bit(SMP_FLAG_OOB, &smp->flags))
2365 return REQ_OOB;
2366
2367 /* The preq/prsp contain the raw Pairing Request/Response PDUs
2368 * which are needed as inputs to some crypto functions. To get
2369 * the "struct smp_cmd_pairing" from them we need to skip the
2370 * first byte which contains the opcode.
2371 */
2372 if (hcon->out) {
2373 local = (void *) &smp->preq[1];
2374 remote = (void *) &smp->prsp[1];
2375 } else {
2376 local = (void *) &smp->prsp[1];
2377 remote = (void *) &smp->preq[1];
2378 }
2379
2380 local_io = local->io_capability;
2381 remote_io = remote->io_capability;
2382
2383 local_mitm = (local->auth_req & SMP_AUTH_MITM);
2384 remote_mitm = (remote->auth_req & SMP_AUTH_MITM);
2385
2386 /* If either side wants MITM, look up the method from the table,
2387 * otherwise use JUST WORKS.
2388 */
2389 if (local_mitm || remote_mitm)
2390 method = get_auth_method(smp, local_io, remote_io);
2391 else
2392 method = JUST_WORKS;
2393
2394 /* Don't confirm locally initiated pairing attempts */
2395 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2396 method = JUST_WORKS;
2397
2398 return method;
2399 }
2400
2401 static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb)
2402 {
2403 struct smp_cmd_public_key *key = (void *) skb->data;
2404 struct hci_conn *hcon = conn->hcon;
2405 struct l2cap_chan *chan = conn->smp;
2406 struct smp_chan *smp = chan->data;
2407 struct hci_dev *hdev = hcon->hdev;
2408 struct smp_cmd_pairing_confirm cfm;
2409 int err;
2410
2411 BT_DBG("conn %p", conn);
2412
2413 if (skb->len < sizeof(*key))
2414 return SMP_INVALID_PARAMS;
2415
2416 memcpy(smp->remote_pk, key, 64);
2417
2418 /* Non-initiating device sends its public key after receiving
2419 * the key from the initiating device.
2420 */
2421 if (!hcon->out) {
2422 err = sc_send_public_key(smp);
2423 if (err)
2424 return err;
2425 }
2426
2427 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk);
2428 SMP_DBG("Remote Public Key Y: %32phN", &smp->remote_pk[32]);
2429
2430 if (!ecdh_shared_secret(smp->remote_pk, smp->local_sk, smp->dhkey))
2431 return SMP_UNSPECIFIED;
2432
2433 SMP_DBG("DHKey %32phN", smp->dhkey);
2434
2435 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags);
2436
2437 smp->method = sc_select_method(smp);
2438
2439 BT_DBG("%s selected method 0x%02x", hdev->name, smp->method);
2440
2441 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */
2442 if (smp->method == JUST_WORKS || smp->method == JUST_CFM)
2443 hcon->pending_sec_level = BT_SECURITY_MEDIUM;
2444 else
2445 hcon->pending_sec_level = BT_SECURITY_FIPS;
2446
2447 if (!memcmp(debug_pk, smp->remote_pk, 64))
2448 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
2449
2450 if (smp->method == DSP_PASSKEY) {
2451 get_random_bytes(&hcon->passkey_notify,
2452 sizeof(hcon->passkey_notify));
2453 hcon->passkey_notify %= 1000000;
2454 hcon->passkey_entered = 0;
2455 smp->passkey_round = 0;
2456 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type,
2457 hcon->dst_type,
2458 hcon->passkey_notify,
2459 hcon->passkey_entered))
2460 return SMP_UNSPECIFIED;
2461 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2462 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY);
2463 }
2464
2465 if (smp->method == REQ_OOB) {
2466 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk,
2467 smp->rr, 0, cfm.confirm_val);
2468 if (err)
2469 return SMP_UNSPECIFIED;
2470
2471 if (memcmp(cfm.confirm_val, smp->pcnf, 16))
2472 return SMP_CONFIRM_FAILED;
2473
2474 if (hcon->out)
2475 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2476 sizeof(smp->prnd), smp->prnd);
2477
2478 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2479
2480 return 0;
2481 }
2482
2483 if (hcon->out)
2484 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2485
2486 if (smp->method == REQ_PASSKEY) {
2487 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type,
2488 hcon->dst_type))
2489 return SMP_UNSPECIFIED;
2490 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2491 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2492 return 0;
2493 }
2494
2495 /* The Initiating device waits for the non-initiating device to
2496 * send the confirm value.
2497 */
2498 if (conn->hcon->out)
2499 return 0;
2500
2501 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd,
2502 0, cfm.confirm_val);
2503 if (err)
2504 return SMP_UNSPECIFIED;
2505
2506 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
2507 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2508
2509 return 0;
2510 }
2511
2512 static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb)
2513 {
2514 struct smp_cmd_dhkey_check *check = (void *) skb->data;
2515 struct l2cap_chan *chan = conn->smp;
2516 struct hci_conn *hcon = conn->hcon;
2517 struct smp_chan *smp = chan->data;
2518 u8 a[7], b[7], *local_addr, *remote_addr;
2519 u8 io_cap[3], r[16], e[16];
2520 int err;
2521
2522 BT_DBG("conn %p", conn);
2523
2524 if (skb->len < sizeof(*check))
2525 return SMP_INVALID_PARAMS;
2526
2527 memcpy(a, &hcon->init_addr, 6);
2528 memcpy(b, &hcon->resp_addr, 6);
2529 a[6] = hcon->init_addr_type;
2530 b[6] = hcon->resp_addr_type;
2531
2532 if (hcon->out) {
2533 local_addr = a;
2534 remote_addr = b;
2535 memcpy(io_cap, &smp->prsp[1], 3);
2536 } else {
2537 local_addr = b;
2538 remote_addr = a;
2539 memcpy(io_cap, &smp->preq[1], 3);
2540 }
2541
2542 memset(r, 0, sizeof(r));
2543
2544 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2545 put_unaligned_le32(hcon->passkey_notify, r);
2546
2547 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r,
2548 io_cap, remote_addr, local_addr, e);
2549 if (err)
2550 return SMP_UNSPECIFIED;
2551
2552 if (memcmp(check->e, e, 16))
2553 return SMP_DHKEY_CHECK_FAILED;
2554
2555 if (!hcon->out) {
2556 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
2557 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags);
2558 return 0;
2559 }
2560
2561 /* Slave sends DHKey check as response to master */
2562 sc_dhkey_check(smp);
2563 }
2564
2565 sc_add_ltk(smp);
2566
2567 if (hcon->out) {
2568 hci_le_start_enc(hcon, 0, 0, smp->tk);
2569 hcon->enc_key_size = smp->enc_key_size;
2570 }
2571
2572 return 0;
2573 }
2574
2575 static int smp_cmd_keypress_notify(struct l2cap_conn *conn,
2576 struct sk_buff *skb)
2577 {
2578 struct smp_cmd_keypress_notify *kp = (void *) skb->data;
2579
2580 BT_DBG("value 0x%02x", kp->value);
2581
2582 return 0;
2583 }
2584
2585 static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb)
2586 {
2587 struct l2cap_conn *conn = chan->conn;
2588 struct hci_conn *hcon = conn->hcon;
2589 struct smp_chan *smp;
2590 __u8 code, reason;
2591 int err = 0;
2592
2593 if (skb->len < 1)
2594 return -EILSEQ;
2595
2596 if (!test_bit(HCI_LE_ENABLED, &hcon->hdev->dev_flags)) {
2597 reason = SMP_PAIRING_NOTSUPP;
2598 goto done;
2599 }
2600
2601 code = skb->data[0];
2602 skb_pull(skb, sizeof(code));
2603
2604 smp = chan->data;
2605
2606 if (code > SMP_CMD_MAX)
2607 goto drop;
2608
2609 if (smp && !test_and_clear_bit(code, &smp->allow_cmd))
2610 goto drop;
2611
2612 /* If we don't have a context the only allowed commands are
2613 * pairing request and security request.
2614 */
2615 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ)
2616 goto drop;
2617
2618 switch (code) {
2619 case SMP_CMD_PAIRING_REQ:
2620 reason = smp_cmd_pairing_req(conn, skb);
2621 break;
2622
2623 case SMP_CMD_PAIRING_FAIL:
2624 smp_failure(conn, 0);
2625 err = -EPERM;
2626 break;
2627
2628 case SMP_CMD_PAIRING_RSP:
2629 reason = smp_cmd_pairing_rsp(conn, skb);
2630 break;
2631
2632 case SMP_CMD_SECURITY_REQ:
2633 reason = smp_cmd_security_req(conn, skb);
2634 break;
2635
2636 case SMP_CMD_PAIRING_CONFIRM:
2637 reason = smp_cmd_pairing_confirm(conn, skb);
2638 break;
2639
2640 case SMP_CMD_PAIRING_RANDOM:
2641 reason = smp_cmd_pairing_random(conn, skb);
2642 break;
2643
2644 case SMP_CMD_ENCRYPT_INFO:
2645 reason = smp_cmd_encrypt_info(conn, skb);
2646 break;
2647
2648 case SMP_CMD_MASTER_IDENT:
2649 reason = smp_cmd_master_ident(conn, skb);
2650 break;
2651
2652 case SMP_CMD_IDENT_INFO:
2653 reason = smp_cmd_ident_info(conn, skb);
2654 break;
2655
2656 case SMP_CMD_IDENT_ADDR_INFO:
2657 reason = smp_cmd_ident_addr_info(conn, skb);
2658 break;
2659
2660 case SMP_CMD_SIGN_INFO:
2661 reason = smp_cmd_sign_info(conn, skb);
2662 break;
2663
2664 case SMP_CMD_PUBLIC_KEY:
2665 reason = smp_cmd_public_key(conn, skb);
2666 break;
2667
2668 case SMP_CMD_DHKEY_CHECK:
2669 reason = smp_cmd_dhkey_check(conn, skb);
2670 break;
2671
2672 case SMP_CMD_KEYPRESS_NOTIFY:
2673 reason = smp_cmd_keypress_notify(conn, skb);
2674 break;
2675
2676 default:
2677 BT_DBG("Unknown command code 0x%2.2x", code);
2678 reason = SMP_CMD_NOTSUPP;
2679 goto done;
2680 }
2681
2682 done:
2683 if (!err) {
2684 if (reason)
2685 smp_failure(conn, reason);
2686 kfree_skb(skb);
2687 }
2688
2689 return err;
2690
2691 drop:
2692 BT_ERR("%s unexpected SMP command 0x%02x from %pMR", hcon->hdev->name,
2693 code, &hcon->dst);
2694 kfree_skb(skb);
2695 return 0;
2696 }
2697
2698 static void smp_teardown_cb(struct l2cap_chan *chan, int err)
2699 {
2700 struct l2cap_conn *conn = chan->conn;
2701
2702 BT_DBG("chan %p", chan);
2703
2704 if (chan->data)
2705 smp_chan_destroy(conn);
2706
2707 conn->smp = NULL;
2708 l2cap_chan_put(chan);
2709 }
2710
2711 static void bredr_pairing(struct l2cap_chan *chan)
2712 {
2713 struct l2cap_conn *conn = chan->conn;
2714 struct hci_conn *hcon = conn->hcon;
2715 struct hci_dev *hdev = hcon->hdev;
2716 struct smp_cmd_pairing req;
2717 struct smp_chan *smp;
2718
2719 BT_DBG("chan %p", chan);
2720
2721 /* Only new pairings are interesting */
2722 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags))
2723 return;
2724
2725 /* Don't bother if we're not encrypted */
2726 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
2727 return;
2728
2729 /* Only master may initiate SMP over BR/EDR */
2730 if (hcon->role != HCI_ROLE_MASTER)
2731 return;
2732
2733 /* Secure Connections support must be enabled */
2734 if (!test_bit(HCI_SC_ENABLED, &hdev->dev_flags))
2735 return;
2736
2737 /* BR/EDR must use Secure Connections for SMP */
2738 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) &&
2739 !test_bit(HCI_FORCE_LESC, &hdev->dbg_flags))
2740 return;
2741
2742 /* If our LE support is not enabled don't do anything */
2743 if (!test_bit(HCI_LE_ENABLED, &hdev->dev_flags))
2744 return;
2745
2746 /* Don't bother if remote LE support is not enabled */
2747 if (!lmp_host_le_capable(hcon))
2748 return;
2749
2750 /* Remote must support SMP fixed chan for BR/EDR */
2751 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR))
2752 return;
2753
2754 /* Don't bother if SMP is already ongoing */
2755 if (chan->data)
2756 return;
2757
2758 smp = smp_chan_create(conn);
2759 if (!smp) {
2760 BT_ERR("%s unable to create SMP context for BR/EDR",
2761 hdev->name);
2762 return;
2763 }
2764
2765 set_bit(SMP_FLAG_SC, &smp->flags);
2766
2767 BT_DBG("%s starting SMP over BR/EDR", hdev->name);
2768
2769 /* Prepare and send the BR/EDR SMP Pairing Request */
2770 build_bredr_pairing_cmd(smp, &req, NULL);
2771
2772 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2773 memcpy(&smp->preq[1], &req, sizeof(req));
2774
2775 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(req), &req);
2776 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2777 }
2778
2779 static void smp_resume_cb(struct l2cap_chan *chan)
2780 {
2781 struct smp_chan *smp = chan->data;
2782 struct l2cap_conn *conn = chan->conn;
2783 struct hci_conn *hcon = conn->hcon;
2784
2785 BT_DBG("chan %p", chan);
2786
2787 if (hcon->type == ACL_LINK) {
2788 bredr_pairing(chan);
2789 return;
2790 }
2791
2792 if (!smp)
2793 return;
2794
2795 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
2796 return;
2797
2798 cancel_delayed_work(&smp->security_timer);
2799
2800 smp_distribute_keys(smp);
2801 }
2802
2803 static void smp_ready_cb(struct l2cap_chan *chan)
2804 {
2805 struct l2cap_conn *conn = chan->conn;
2806 struct hci_conn *hcon = conn->hcon;
2807
2808 BT_DBG("chan %p", chan);
2809
2810 conn->smp = chan;
2811 l2cap_chan_hold(chan);
2812
2813 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
2814 bredr_pairing(chan);
2815 }
2816
2817 static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
2818 {
2819 int err;
2820
2821 BT_DBG("chan %p", chan);
2822
2823 err = smp_sig_channel(chan, skb);
2824 if (err) {
2825 struct smp_chan *smp = chan->data;
2826
2827 if (smp)
2828 cancel_delayed_work_sync(&smp->security_timer);
2829
2830 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE);
2831 }
2832
2833 return err;
2834 }
2835
2836 static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan,
2837 unsigned long hdr_len,
2838 unsigned long len, int nb)
2839 {
2840 struct sk_buff *skb;
2841
2842 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL);
2843 if (!skb)
2844 return ERR_PTR(-ENOMEM);
2845
2846 skb->priority = HCI_PRIO_MAX;
2847 bt_cb(skb)->chan = chan;
2848
2849 return skb;
2850 }
2851
2852 static const struct l2cap_ops smp_chan_ops = {
2853 .name = "Security Manager",
2854 .ready = smp_ready_cb,
2855 .recv = smp_recv_cb,
2856 .alloc_skb = smp_alloc_skb_cb,
2857 .teardown = smp_teardown_cb,
2858 .resume = smp_resume_cb,
2859
2860 .new_connection = l2cap_chan_no_new_connection,
2861 .state_change = l2cap_chan_no_state_change,
2862 .close = l2cap_chan_no_close,
2863 .defer = l2cap_chan_no_defer,
2864 .suspend = l2cap_chan_no_suspend,
2865 .set_shutdown = l2cap_chan_no_set_shutdown,
2866 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
2867 };
2868
2869 static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan)
2870 {
2871 struct l2cap_chan *chan;
2872
2873 BT_DBG("pchan %p", pchan);
2874
2875 chan = l2cap_chan_create();
2876 if (!chan)
2877 return NULL;
2878
2879 chan->chan_type = pchan->chan_type;
2880 chan->ops = &smp_chan_ops;
2881 chan->scid = pchan->scid;
2882 chan->dcid = chan->scid;
2883 chan->imtu = pchan->imtu;
2884 chan->omtu = pchan->omtu;
2885 chan->mode = pchan->mode;
2886
2887 /* Other L2CAP channels may request SMP routines in order to
2888 * change the security level. This means that the SMP channel
2889 * lock must be considered in its own category to avoid lockdep
2890 * warnings.
2891 */
2892 atomic_set(&chan->nesting, L2CAP_NESTING_SMP);
2893
2894 BT_DBG("created chan %p", chan);
2895
2896 return chan;
2897 }
2898
2899 static const struct l2cap_ops smp_root_chan_ops = {
2900 .name = "Security Manager Root",
2901 .new_connection = smp_new_conn_cb,
2902
2903 /* None of these are implemented for the root channel */
2904 .close = l2cap_chan_no_close,
2905 .alloc_skb = l2cap_chan_no_alloc_skb,
2906 .recv = l2cap_chan_no_recv,
2907 .state_change = l2cap_chan_no_state_change,
2908 .teardown = l2cap_chan_no_teardown,
2909 .ready = l2cap_chan_no_ready,
2910 .defer = l2cap_chan_no_defer,
2911 .suspend = l2cap_chan_no_suspend,
2912 .resume = l2cap_chan_no_resume,
2913 .set_shutdown = l2cap_chan_no_set_shutdown,
2914 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
2915 };
2916
2917 static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid)
2918 {
2919 struct l2cap_chan *chan;
2920 struct crypto_blkcipher *tfm_aes;
2921
2922 if (cid == L2CAP_CID_SMP_BREDR) {
2923 tfm_aes = NULL;
2924 goto create_chan;
2925 }
2926
2927 tfm_aes = crypto_alloc_blkcipher("ecb(aes)", 0, 0);
2928 if (IS_ERR(tfm_aes)) {
2929 BT_ERR("Unable to create crypto context");
2930 return ERR_PTR(PTR_ERR(tfm_aes));
2931 }
2932
2933 create_chan:
2934 chan = l2cap_chan_create();
2935 if (!chan) {
2936 crypto_free_blkcipher(tfm_aes);
2937 return ERR_PTR(-ENOMEM);
2938 }
2939
2940 chan->data = tfm_aes;
2941
2942 l2cap_add_scid(chan, cid);
2943
2944 l2cap_chan_set_defaults(chan);
2945
2946 bacpy(&chan->src, &hdev->bdaddr);
2947 if (cid == L2CAP_CID_SMP)
2948 chan->src_type = BDADDR_LE_PUBLIC;
2949 else
2950 chan->src_type = BDADDR_BREDR;
2951 chan->state = BT_LISTEN;
2952 chan->mode = L2CAP_MODE_BASIC;
2953 chan->imtu = L2CAP_DEFAULT_MTU;
2954 chan->ops = &smp_root_chan_ops;
2955
2956 /* Set correct nesting level for a parent/listening channel */
2957 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
2958
2959 return chan;
2960 }
2961
2962 static void smp_del_chan(struct l2cap_chan *chan)
2963 {
2964 struct crypto_blkcipher *tfm_aes;
2965
2966 BT_DBG("chan %p", chan);
2967
2968 tfm_aes = chan->data;
2969 if (tfm_aes) {
2970 chan->data = NULL;
2971 crypto_free_blkcipher(tfm_aes);
2972 }
2973
2974 l2cap_chan_put(chan);
2975 }
2976
2977 int smp_register(struct hci_dev *hdev)
2978 {
2979 struct l2cap_chan *chan;
2980
2981 BT_DBG("%s", hdev->name);
2982
2983 chan = smp_add_cid(hdev, L2CAP_CID_SMP);
2984 if (IS_ERR(chan))
2985 return PTR_ERR(chan);
2986
2987 hdev->smp_data = chan;
2988
2989 if (!lmp_sc_capable(hdev) &&
2990 !test_bit(HCI_FORCE_LESC, &hdev->dbg_flags))
2991 return 0;
2992
2993 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
2994 if (IS_ERR(chan)) {
2995 int err = PTR_ERR(chan);
2996 chan = hdev->smp_data;
2997 hdev->smp_data = NULL;
2998 smp_del_chan(chan);
2999 return err;
3000 }
3001
3002 hdev->smp_bredr_data = chan;
3003
3004 return 0;
3005 }
3006
3007 void smp_unregister(struct hci_dev *hdev)
3008 {
3009 struct l2cap_chan *chan;
3010
3011 if (hdev->smp_bredr_data) {
3012 chan = hdev->smp_bredr_data;
3013 hdev->smp_bredr_data = NULL;
3014 smp_del_chan(chan);
3015 }
3016
3017 if (hdev->smp_data) {
3018 chan = hdev->smp_data;
3019 hdev->smp_data = NULL;
3020 smp_del_chan(chan);
3021 }
3022 }
Linux kernel - Deliverables
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