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