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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/scatterlist.h>
25#include <linux/crypto.h>
26#include <crypto/aes.h>
27#include <crypto/algapi.h>
28#include <crypto/b128ops.h>
29#include <crypto/hash.h>
30#include <crypto/kpp.h>
31
32#include <net/bluetooth/bluetooth.h>
33#include <net/bluetooth/hci_core.h>
34#include <net/bluetooth/l2cap.h>
35#include <net/bluetooth/mgmt.h>
36
37#include "ecdh_helper.h"
38#include "smp.h"
39
40#define SMP_DEV(hdev) \
41 ((struct smp_dev *)((struct l2cap_chan *)((hdev)->smp_data))->data)
42
43/* Low-level debug macros to be used for stuff that we don't want
44 * accidentially in dmesg, i.e. the values of the various crypto keys
45 * and the inputs & outputs of crypto functions.
46 */
47#ifdef DEBUG
48#define SMP_DBG(fmt, ...) printk(KERN_DEBUG "%s: " fmt, __func__, \
49 ##__VA_ARGS__)
50#else
51#define SMP_DBG(fmt, ...) no_printk(KERN_DEBUG "%s: " fmt, __func__, \
52 ##__VA_ARGS__)
53#endif
54
55#define SMP_ALLOW_CMD(smp, code) set_bit(code, &smp->allow_cmd)
56
57/* Keys which are not distributed with Secure Connections */
58#define SMP_SC_NO_DIST (SMP_DIST_ENC_KEY | SMP_DIST_LINK_KEY);
59
60#define SMP_TIMEOUT msecs_to_jiffies(30000)
61
62#define AUTH_REQ_MASK(dev) (hci_dev_test_flag(dev, HCI_SC_ENABLED) ? \
63 0x3f : 0x07)
64#define KEY_DIST_MASK 0x07
65
66/* Maximum message length that can be passed to aes_cmac */
67#define CMAC_MSG_MAX 80
68
69enum {
70 SMP_FLAG_TK_VALID,
71 SMP_FLAG_CFM_PENDING,
72 SMP_FLAG_MITM_AUTH,
73 SMP_FLAG_COMPLETE,
74 SMP_FLAG_INITIATOR,
75 SMP_FLAG_SC,
76 SMP_FLAG_REMOTE_PK,
77 SMP_FLAG_DEBUG_KEY,
78 SMP_FLAG_WAIT_USER,
79 SMP_FLAG_DHKEY_PENDING,
80 SMP_FLAG_REMOTE_OOB,
81 SMP_FLAG_LOCAL_OOB,
82 SMP_FLAG_CT2,
83};
84
85struct smp_dev {
86 /* Secure Connections OOB data */
87 bool local_oob;
88 u8 local_pk[64];
89 u8 local_rand[16];
90 bool debug_key;
91
92 struct crypto_shash *tfm_cmac;
93 struct crypto_kpp *tfm_ecdh;
94};
95
96struct smp_chan {
97 struct l2cap_conn *conn;
98 struct delayed_work security_timer;
99 unsigned long allow_cmd; /* Bitmask of allowed commands */
100
101 u8 preq[7]; /* SMP Pairing Request */
102 u8 prsp[7]; /* SMP Pairing Response */
103 u8 prnd[16]; /* SMP Pairing Random (local) */
104 u8 rrnd[16]; /* SMP Pairing Random (remote) */
105 u8 pcnf[16]; /* SMP Pairing Confirm */
106 u8 tk[16]; /* SMP Temporary Key */
107 u8 rr[16]; /* Remote OOB ra/rb value */
108 u8 lr[16]; /* Local OOB ra/rb value */
109 u8 enc_key_size;
110 u8 remote_key_dist;
111 bdaddr_t id_addr;
112 u8 id_addr_type;
113 u8 irk[16];
114 struct smp_csrk *csrk;
115 struct smp_csrk *slave_csrk;
116 struct smp_ltk *ltk;
117 struct smp_ltk *slave_ltk;
118 struct smp_irk *remote_irk;
119 u8 *link_key;
120 unsigned long flags;
121 u8 method;
122 u8 passkey_round;
123
124 /* Secure Connections variables */
125 u8 local_pk[64];
126 u8 remote_pk[64];
127 u8 dhkey[32];
128 u8 mackey[16];
129
130 struct crypto_shash *tfm_cmac;
131 struct crypto_kpp *tfm_ecdh;
132};
133
134/* These debug key values are defined in the SMP section of the core
135 * specification. debug_pk is the public debug key and debug_sk the
136 * private debug key.
137 */
138static const u8 debug_pk[64] = {
139 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
140 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
141 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
142 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20,
143
144 0x8b, 0xd2, 0x89, 0x15, 0xd0, 0x8e, 0x1c, 0x74,
145 0x24, 0x30, 0xed, 0x8f, 0xc2, 0x45, 0x63, 0x76,
146 0x5c, 0x15, 0x52, 0x5a, 0xbf, 0x9a, 0x32, 0x63,
147 0x6d, 0xeb, 0x2a, 0x65, 0x49, 0x9c, 0x80, 0xdc,
148};
149
150static const u8 debug_sk[32] = {
151 0xbd, 0x1a, 0x3c, 0xcd, 0xa6, 0xb8, 0x99, 0x58,
152 0x99, 0xb7, 0x40, 0xeb, 0x7b, 0x60, 0xff, 0x4a,
153 0x50, 0x3f, 0x10, 0xd2, 0xe3, 0xb3, 0xc9, 0x74,
154 0x38, 0x5f, 0xc5, 0xa3, 0xd4, 0xf6, 0x49, 0x3f,
155};
156
157static inline void swap_buf(const u8 *src, u8 *dst, size_t len)
158{
159 size_t i;
160
161 for (i = 0; i < len; i++)
162 dst[len - 1 - i] = src[i];
163}
164
165/* The following functions map to the LE SC SMP crypto functions
166 * AES-CMAC, f4, f5, f6, g2 and h6.
167 */
168
169static int aes_cmac(struct crypto_shash *tfm, const u8 k[16], const u8 *m,
170 size_t len, u8 mac[16])
171{
172 uint8_t tmp[16], mac_msb[16], msg_msb[CMAC_MSG_MAX];
173 SHASH_DESC_ON_STACK(desc, tfm);
174 int err;
175
176 if (len > CMAC_MSG_MAX)
177 return -EFBIG;
178
179 if (!tfm) {
180 BT_ERR("tfm %p", tfm);
181 return -EINVAL;
182 }
183
184 desc->tfm = tfm;
185
186 /* Swap key and message from LSB to MSB */
187 swap_buf(k, tmp, 16);
188 swap_buf(m, msg_msb, len);
189
190 SMP_DBG("msg (len %zu) %*phN", len, (int) len, m);
191 SMP_DBG("key %16phN", k);
192
193 err = crypto_shash_setkey(tfm, tmp, 16);
194 if (err) {
195 BT_ERR("cipher setkey failed: %d", err);
196 return err;
197 }
198
199 err = crypto_shash_digest(desc, msg_msb, len, mac_msb);
200 shash_desc_zero(desc);
201 if (err) {
202 BT_ERR("Hash computation error %d", err);
203 return err;
204 }
205
206 swap_buf(mac_msb, mac, 16);
207
208 SMP_DBG("mac %16phN", mac);
209
210 return 0;
211}
212
213static int smp_f4(struct crypto_shash *tfm_cmac, const u8 u[32],
214 const u8 v[32], const u8 x[16], u8 z, u8 res[16])
215{
216 u8 m[65];
217 int err;
218
219 SMP_DBG("u %32phN", u);
220 SMP_DBG("v %32phN", v);
221 SMP_DBG("x %16phN z %02x", x, z);
222
223 m[0] = z;
224 memcpy(m + 1, v, 32);
225 memcpy(m + 33, u, 32);
226
227 err = aes_cmac(tfm_cmac, x, m, sizeof(m), res);
228 if (err)
229 return err;
230
231 SMP_DBG("res %16phN", res);
232
233 return err;
234}
235
236static int smp_f5(struct crypto_shash *tfm_cmac, const u8 w[32],
237 const u8 n1[16], const u8 n2[16], const u8 a1[7],
238 const u8 a2[7], u8 mackey[16], u8 ltk[16])
239{
240 /* The btle, salt and length "magic" values are as defined in
241 * the SMP section of the Bluetooth core specification. In ASCII
242 * the btle value ends up being 'btle'. The salt is just a
243 * random number whereas length is the value 256 in little
244 * endian format.
245 */
246 const u8 btle[4] = { 0x65, 0x6c, 0x74, 0x62 };
247 const u8 salt[16] = { 0xbe, 0x83, 0x60, 0x5a, 0xdb, 0x0b, 0x37, 0x60,
248 0x38, 0xa5, 0xf5, 0xaa, 0x91, 0x83, 0x88, 0x6c };
249 const u8 length[2] = { 0x00, 0x01 };
250 u8 m[53], t[16];
251 int err;
252
253 SMP_DBG("w %32phN", w);
254 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
255 SMP_DBG("a1 %7phN a2 %7phN", a1, a2);
256
257 err = aes_cmac(tfm_cmac, salt, w, 32, t);
258 if (err)
259 return err;
260
261 SMP_DBG("t %16phN", t);
262
263 memcpy(m, length, 2);
264 memcpy(m + 2, a2, 7);
265 memcpy(m + 9, a1, 7);
266 memcpy(m + 16, n2, 16);
267 memcpy(m + 32, n1, 16);
268 memcpy(m + 48, btle, 4);
269
270 m[52] = 0; /* Counter */
271
272 err = aes_cmac(tfm_cmac, t, m, sizeof(m), mackey);
273 if (err)
274 return err;
275
276 SMP_DBG("mackey %16phN", mackey);
277
278 m[52] = 1; /* Counter */
279
280 err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk);
281 if (err)
282 return err;
283
284 SMP_DBG("ltk %16phN", ltk);
285
286 return 0;
287}
288
289static int smp_f6(struct crypto_shash *tfm_cmac, const u8 w[16],
290 const u8 n1[16], const u8 n2[16], const u8 r[16],
291 const u8 io_cap[3], const u8 a1[7], const u8 a2[7],
292 u8 res[16])
293{
294 u8 m[65];
295 int err;
296
297 SMP_DBG("w %16phN", w);
298 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
299 SMP_DBG("r %16phN io_cap %3phN a1 %7phN a2 %7phN", r, io_cap, a1, a2);
300
301 memcpy(m, a2, 7);
302 memcpy(m + 7, a1, 7);
303 memcpy(m + 14, io_cap, 3);
304 memcpy(m + 17, r, 16);
305 memcpy(m + 33, n2, 16);
306 memcpy(m + 49, n1, 16);
307
308 err = aes_cmac(tfm_cmac, w, m, sizeof(m), res);
309 if (err)
310 return err;
311
312 SMP_DBG("res %16phN", res);
313
314 return err;
315}
316
317static int smp_g2(struct crypto_shash *tfm_cmac, const u8 u[32], const u8 v[32],
318 const u8 x[16], const u8 y[16], u32 *val)
319{
320 u8 m[80], tmp[16];
321 int err;
322
323 SMP_DBG("u %32phN", u);
324 SMP_DBG("v %32phN", v);
325 SMP_DBG("x %16phN y %16phN", x, y);
326
327 memcpy(m, y, 16);
328 memcpy(m + 16, v, 32);
329 memcpy(m + 48, u, 32);
330
331 err = aes_cmac(tfm_cmac, x, m, sizeof(m), tmp);
332 if (err)
333 return err;
334
335 *val = get_unaligned_le32(tmp);
336 *val %= 1000000;
337
338 SMP_DBG("val %06u", *val);
339
340 return 0;
341}
342
343static int smp_h6(struct crypto_shash *tfm_cmac, const u8 w[16],
344 const u8 key_id[4], u8 res[16])
345{
346 int err;
347
348 SMP_DBG("w %16phN key_id %4phN", w, key_id);
349
350 err = aes_cmac(tfm_cmac, w, key_id, 4, res);
351 if (err)
352 return err;
353
354 SMP_DBG("res %16phN", res);
355
356 return err;
357}
358
359static int smp_h7(struct crypto_shash *tfm_cmac, const u8 w[16],
360 const u8 salt[16], u8 res[16])
361{
362 int err;
363
364 SMP_DBG("w %16phN salt %16phN", w, salt);
365
366 err = aes_cmac(tfm_cmac, salt, w, 16, res);
367 if (err)
368 return err;
369
370 SMP_DBG("res %16phN", res);
371
372 return err;
373}
374
375/* The following functions map to the legacy SMP crypto functions e, c1,
376 * s1 and ah.
377 */
378
379static int smp_e(const u8 *k, u8 *r)
380{
381 struct crypto_aes_ctx ctx;
382 uint8_t tmp[16], data[16];
383 int err;
384
385 SMP_DBG("k %16phN r %16phN", k, r);
386
387 /* The most significant octet of key corresponds to k[0] */
388 swap_buf(k, tmp, 16);
389
390 err = aes_expandkey(&ctx, tmp, 16);
391 if (err) {
392 BT_ERR("cipher setkey failed: %d", err);
393 return err;
394 }
395
396 /* Most significant octet of plaintextData corresponds to data[0] */
397 swap_buf(r, data, 16);
398
399 aes_encrypt(&ctx, data, data);
400
401 /* Most significant octet of encryptedData corresponds to data[0] */
402 swap_buf(data, r, 16);
403
404 SMP_DBG("r %16phN", r);
405
406 memzero_explicit(&ctx, sizeof (ctx));
407 return err;
408}
409
410static int smp_c1(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(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(k, res);
453 if (err)
454 BT_ERR("Encrypt data error");
455
456 return err;
457}
458
459static int smp_s1(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(k, _r);
469 if (err)
470 BT_ERR("Encrypt data error");
471
472 return err;
473}
474
475static int smp_ah(const u8 irk[16], const u8 r[3], u8 res[3])
476{
477 u8 _res[16];
478 int err;
479
480 /* r' = padding || r */
481 memcpy(_res, r, 3);
482 memset(_res + 3, 0, 13);
483
484 err = smp_e(irk, _res);
485 if (err) {
486 BT_ERR("Encrypt error");
487 return err;
488 }
489
490 /* The output of the random address function ah is:
491 * ah(k, r) = e(k, r') mod 2^24
492 * The output of the security function e is then truncated to 24 bits
493 * by taking the least significant 24 bits of the output of e as the
494 * result of ah.
495 */
496 memcpy(res, _res, 3);
497
498 return 0;
499}
500
501bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16],
502 const bdaddr_t *bdaddr)
503{
504 struct l2cap_chan *chan = hdev->smp_data;
505 struct smp_dev *smp;
506 u8 hash[3];
507 int err;
508
509 if (!chan || !chan->data)
510 return false;
511
512 smp = chan->data;
513
514 BT_DBG("RPA %pMR IRK %*phN", bdaddr, 16, irk);
515
516 err = smp_ah(irk, &bdaddr->b[3], hash);
517 if (err)
518 return false;
519
520 return !crypto_memneq(bdaddr->b, hash, 3);
521}
522
523int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa)
524{
525 struct l2cap_chan *chan = hdev->smp_data;
526 struct smp_dev *smp;
527 int err;
528
529 if (!chan || !chan->data)
530 return -EOPNOTSUPP;
531
532 smp = chan->data;
533
534 get_random_bytes(&rpa->b[3], 3);
535
536 rpa->b[5] &= 0x3f; /* Clear two most significant bits */
537 rpa->b[5] |= 0x40; /* Set second most significant bit */
538
539 err = smp_ah(irk, &rpa->b[3], rpa->b);
540 if (err < 0)
541 return err;
542
543 BT_DBG("RPA %pMR", rpa);
544
545 return 0;
546}
547
548int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16])
549{
550 struct l2cap_chan *chan = hdev->smp_data;
551 struct smp_dev *smp;
552 int err;
553
554 if (!chan || !chan->data)
555 return -EOPNOTSUPP;
556
557 smp = chan->data;
558
559 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) {
560 BT_DBG("Using debug keys");
561 err = set_ecdh_privkey(smp->tfm_ecdh, debug_sk);
562 if (err)
563 return err;
564 memcpy(smp->local_pk, debug_pk, 64);
565 smp->debug_key = true;
566 } else {
567 while (true) {
568 /* Generate key pair for Secure Connections */
569 err = generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk);
570 if (err)
571 return err;
572
573 /* This is unlikely, but we need to check that
574 * we didn't accidentially generate a debug key.
575 */
576 if (crypto_memneq(smp->local_pk, debug_pk, 64))
577 break;
578 }
579 smp->debug_key = false;
580 }
581
582 SMP_DBG("OOB Public Key X: %32phN", smp->local_pk);
583 SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32);
584
585 get_random_bytes(smp->local_rand, 16);
586
587 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->local_pk,
588 smp->local_rand, 0, hash);
589 if (err < 0)
590 return err;
591
592 memcpy(rand, smp->local_rand, 16);
593
594 smp->local_oob = true;
595
596 return 0;
597}
598
599static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
600{
601 struct l2cap_chan *chan = conn->smp;
602 struct smp_chan *smp;
603 struct kvec iv[2];
604 struct msghdr msg;
605
606 if (!chan)
607 return;
608
609 BT_DBG("code 0x%2.2x", code);
610
611 iv[0].iov_base = &code;
612 iv[0].iov_len = 1;
613
614 iv[1].iov_base = data;
615 iv[1].iov_len = len;
616
617 memset(&msg, 0, sizeof(msg));
618
619 iov_iter_kvec(&msg.msg_iter, WRITE, iv, 2, 1 + len);
620
621 l2cap_chan_send(chan, &msg, 1 + len);
622
623 if (!chan->data)
624 return;
625
626 smp = chan->data;
627
628 cancel_delayed_work_sync(&smp->security_timer);
629 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT);
630}
631
632static u8 authreq_to_seclevel(u8 authreq)
633{
634 if (authreq & SMP_AUTH_MITM) {
635 if (authreq & SMP_AUTH_SC)
636 return BT_SECURITY_FIPS;
637 else
638 return BT_SECURITY_HIGH;
639 } else {
640 return BT_SECURITY_MEDIUM;
641 }
642}
643
644static __u8 seclevel_to_authreq(__u8 sec_level)
645{
646 switch (sec_level) {
647 case BT_SECURITY_FIPS:
648 case BT_SECURITY_HIGH:
649 return SMP_AUTH_MITM | SMP_AUTH_BONDING;
650 case BT_SECURITY_MEDIUM:
651 return SMP_AUTH_BONDING;
652 default:
653 return SMP_AUTH_NONE;
654 }
655}
656
657static void build_pairing_cmd(struct l2cap_conn *conn,
658 struct smp_cmd_pairing *req,
659 struct smp_cmd_pairing *rsp, __u8 authreq)
660{
661 struct l2cap_chan *chan = conn->smp;
662 struct smp_chan *smp = chan->data;
663 struct hci_conn *hcon = conn->hcon;
664 struct hci_dev *hdev = hcon->hdev;
665 u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT;
666
667 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) {
668 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
669 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
670 authreq |= SMP_AUTH_BONDING;
671 } else {
672 authreq &= ~SMP_AUTH_BONDING;
673 }
674
675 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING))
676 remote_dist |= SMP_DIST_ID_KEY;
677
678 if (hci_dev_test_flag(hdev, HCI_PRIVACY))
679 local_dist |= SMP_DIST_ID_KEY;
680
681 if (hci_dev_test_flag(hdev, HCI_SC_ENABLED) &&
682 (authreq & SMP_AUTH_SC)) {
683 struct oob_data *oob_data;
684 u8 bdaddr_type;
685
686 if (hci_dev_test_flag(hdev, HCI_SSP_ENABLED)) {
687 local_dist |= SMP_DIST_LINK_KEY;
688 remote_dist |= SMP_DIST_LINK_KEY;
689 }
690
691 if (hcon->dst_type == ADDR_LE_DEV_PUBLIC)
692 bdaddr_type = BDADDR_LE_PUBLIC;
693 else
694 bdaddr_type = BDADDR_LE_RANDOM;
695
696 oob_data = hci_find_remote_oob_data(hdev, &hcon->dst,
697 bdaddr_type);
698 if (oob_data && oob_data->present) {
699 set_bit(SMP_FLAG_REMOTE_OOB, &smp->flags);
700 oob_flag = SMP_OOB_PRESENT;
701 memcpy(smp->rr, oob_data->rand256, 16);
702 memcpy(smp->pcnf, oob_data->hash256, 16);
703 SMP_DBG("OOB Remote Confirmation: %16phN", smp->pcnf);
704 SMP_DBG("OOB Remote Random: %16phN", smp->rr);
705 }
706
707 } else {
708 authreq &= ~SMP_AUTH_SC;
709 }
710
711 if (rsp == NULL) {
712 req->io_capability = conn->hcon->io_capability;
713 req->oob_flag = oob_flag;
714 req->max_key_size = hdev->le_max_key_size;
715 req->init_key_dist = local_dist;
716 req->resp_key_dist = remote_dist;
717 req->auth_req = (authreq & AUTH_REQ_MASK(hdev));
718
719 smp->remote_key_dist = remote_dist;
720 return;
721 }
722
723 rsp->io_capability = conn->hcon->io_capability;
724 rsp->oob_flag = oob_flag;
725 rsp->max_key_size = hdev->le_max_key_size;
726 rsp->init_key_dist = req->init_key_dist & remote_dist;
727 rsp->resp_key_dist = req->resp_key_dist & local_dist;
728 rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev));
729
730 smp->remote_key_dist = rsp->init_key_dist;
731}
732
733static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)
734{
735 struct l2cap_chan *chan = conn->smp;
736 struct hci_dev *hdev = conn->hcon->hdev;
737 struct smp_chan *smp = chan->data;
738
739 if (max_key_size > hdev->le_max_key_size ||
740 max_key_size < SMP_MIN_ENC_KEY_SIZE)
741 return SMP_ENC_KEY_SIZE;
742
743 smp->enc_key_size = max_key_size;
744
745 return 0;
746}
747
748static void smp_chan_destroy(struct l2cap_conn *conn)
749{
750 struct l2cap_chan *chan = conn->smp;
751 struct smp_chan *smp = chan->data;
752 struct hci_conn *hcon = conn->hcon;
753 bool complete;
754
755 BUG_ON(!smp);
756
757 cancel_delayed_work_sync(&smp->security_timer);
758
759 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags);
760 mgmt_smp_complete(hcon, complete);
761
762 kzfree(smp->csrk);
763 kzfree(smp->slave_csrk);
764 kzfree(smp->link_key);
765
766 crypto_free_shash(smp->tfm_cmac);
767 crypto_free_kpp(smp->tfm_ecdh);
768
769 /* Ensure that we don't leave any debug key around if debug key
770 * support hasn't been explicitly enabled.
771 */
772 if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG &&
773 !hci_dev_test_flag(hcon->hdev, HCI_KEEP_DEBUG_KEYS)) {
774 list_del_rcu(&smp->ltk->list);
775 kfree_rcu(smp->ltk, rcu);
776 smp->ltk = NULL;
777 }
778
779 /* If pairing failed clean up any keys we might have */
780 if (!complete) {
781 if (smp->ltk) {
782 list_del_rcu(&smp->ltk->list);
783 kfree_rcu(smp->ltk, rcu);
784 }
785
786 if (smp->slave_ltk) {
787 list_del_rcu(&smp->slave_ltk->list);
788 kfree_rcu(smp->slave_ltk, rcu);
789 }
790
791 if (smp->remote_irk) {
792 list_del_rcu(&smp->remote_irk->list);
793 kfree_rcu(smp->remote_irk, rcu);
794 }
795 }
796
797 chan->data = NULL;
798 kzfree(smp);
799 hci_conn_drop(hcon);
800}
801
802static void smp_failure(struct l2cap_conn *conn, u8 reason)
803{
804 struct hci_conn *hcon = conn->hcon;
805 struct l2cap_chan *chan = conn->smp;
806
807 if (reason)
808 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
809 &reason);
810
811 mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE);
812
813 if (chan->data)
814 smp_chan_destroy(conn);
815}
816
817#define JUST_WORKS 0x00
818#define JUST_CFM 0x01
819#define REQ_PASSKEY 0x02
820#define CFM_PASSKEY 0x03
821#define REQ_OOB 0x04
822#define DSP_PASSKEY 0x05
823#define OVERLAP 0xFF
824
825static const u8 gen_method[5][5] = {
826 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
827 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
828 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
829 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
830 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP },
831};
832
833static const u8 sc_method[5][5] = {
834 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
835 { JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
836 { DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY },
837 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
838 { DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
839};
840
841static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io)
842{
843 /* If either side has unknown io_caps, use JUST_CFM (which gets
844 * converted later to JUST_WORKS if we're initiators.
845 */
846 if (local_io > SMP_IO_KEYBOARD_DISPLAY ||
847 remote_io > SMP_IO_KEYBOARD_DISPLAY)
848 return JUST_CFM;
849
850 if (test_bit(SMP_FLAG_SC, &smp->flags))
851 return sc_method[remote_io][local_io];
852
853 return gen_method[remote_io][local_io];
854}
855
856static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth,
857 u8 local_io, u8 remote_io)
858{
859 struct hci_conn *hcon = conn->hcon;
860 struct l2cap_chan *chan = conn->smp;
861 struct smp_chan *smp = chan->data;
862 u32 passkey = 0;
863 int ret = 0;
864
865 /* Initialize key for JUST WORKS */
866 memset(smp->tk, 0, sizeof(smp->tk));
867 clear_bit(SMP_FLAG_TK_VALID, &smp->flags);
868
869 BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io);
870
871 /* If neither side wants MITM, either "just" confirm an incoming
872 * request or use just-works for outgoing ones. The JUST_CFM
873 * will be converted to JUST_WORKS if necessary later in this
874 * function. If either side has MITM look up the method from the
875 * table.
876 */
877 if (!(auth & SMP_AUTH_MITM))
878 smp->method = JUST_CFM;
879 else
880 smp->method = get_auth_method(smp, local_io, remote_io);
881
882 /* Don't confirm locally initiated pairing attempts */
883 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR,
884 &smp->flags))
885 smp->method = JUST_WORKS;
886
887 /* Don't bother user space with no IO capabilities */
888 if (smp->method == JUST_CFM &&
889 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
890 smp->method = JUST_WORKS;
891
892 /* If Just Works, Continue with Zero TK */
893 if (smp->method == JUST_WORKS) {
894 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
895 return 0;
896 }
897
898 /* If this function is used for SC -> legacy fallback we
899 * can only recover the just-works case.
900 */
901 if (test_bit(SMP_FLAG_SC, &smp->flags))
902 return -EINVAL;
903
904 /* Not Just Works/Confirm results in MITM Authentication */
905 if (smp->method != JUST_CFM) {
906 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags);
907 if (hcon->pending_sec_level < BT_SECURITY_HIGH)
908 hcon->pending_sec_level = BT_SECURITY_HIGH;
909 }
910
911 /* If both devices have Keyoard-Display I/O, the master
912 * Confirms and the slave Enters the passkey.
913 */
914 if (smp->method == OVERLAP) {
915 if (hcon->role == HCI_ROLE_MASTER)
916 smp->method = CFM_PASSKEY;
917 else
918 smp->method = REQ_PASSKEY;
919 }
920
921 /* Generate random passkey. */
922 if (smp->method == CFM_PASSKEY) {
923 memset(smp->tk, 0, sizeof(smp->tk));
924 get_random_bytes(&passkey, sizeof(passkey));
925 passkey %= 1000000;
926 put_unaligned_le32(passkey, smp->tk);
927 BT_DBG("PassKey: %d", passkey);
928 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
929 }
930
931 if (smp->method == REQ_PASSKEY)
932 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst,
933 hcon->type, hcon->dst_type);
934 else if (smp->method == JUST_CFM)
935 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
936 hcon->type, hcon->dst_type,
937 passkey, 1);
938 else
939 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst,
940 hcon->type, hcon->dst_type,
941 passkey, 0);
942
943 return ret;
944}
945
946static u8 smp_confirm(struct smp_chan *smp)
947{
948 struct l2cap_conn *conn = smp->conn;
949 struct smp_cmd_pairing_confirm cp;
950 int ret;
951
952 BT_DBG("conn %p", conn);
953
954 ret = smp_c1(smp->tk, smp->prnd, smp->preq, smp->prsp,
955 conn->hcon->init_addr_type, &conn->hcon->init_addr,
956 conn->hcon->resp_addr_type, &conn->hcon->resp_addr,
957 cp.confirm_val);
958 if (ret)
959 return SMP_UNSPECIFIED;
960
961 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
962
963 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
964
965 if (conn->hcon->out)
966 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
967 else
968 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
969
970 return 0;
971}
972
973static u8 smp_random(struct smp_chan *smp)
974{
975 struct l2cap_conn *conn = smp->conn;
976 struct hci_conn *hcon = conn->hcon;
977 u8 confirm[16];
978 int ret;
979
980 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
981
982 ret = smp_c1(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 (crypto_memneq(smp->pcnf, confirm, sizeof(smp->pcnf))) {
989 bt_dev_err(hcon->hdev, "pairing failed "
990 "(confirmation values mismatch)");
991 return SMP_CONFIRM_FAILED;
992 }
993
994 if (hcon->out) {
995 u8 stk[16];
996 __le64 rand = 0;
997 __le16 ediv = 0;
998
999 smp_s1(smp->tk, smp->rrnd, smp->prnd, stk);
1000
1001 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
1002 return SMP_UNSPECIFIED;
1003
1004 hci_le_start_enc(hcon, ediv, rand, stk, smp->enc_key_size);
1005 hcon->enc_key_size = smp->enc_key_size;
1006 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
1007 } else {
1008 u8 stk[16], auth;
1009 __le64 rand = 0;
1010 __le16 ediv = 0;
1011
1012 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
1013 smp->prnd);
1014
1015 smp_s1(smp->tk, smp->prnd, smp->rrnd, stk);
1016
1017 if (hcon->pending_sec_level == BT_SECURITY_HIGH)
1018 auth = 1;
1019 else
1020 auth = 0;
1021
1022 /* Even though there's no _SLAVE suffix this is the
1023 * slave STK we're adding for later lookup (the master
1024 * STK never needs to be stored).
1025 */
1026 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1027 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand);
1028 }
1029
1030 return 0;
1031}
1032
1033static void smp_notify_keys(struct l2cap_conn *conn)
1034{
1035 struct l2cap_chan *chan = conn->smp;
1036 struct smp_chan *smp = chan->data;
1037 struct hci_conn *hcon = conn->hcon;
1038 struct hci_dev *hdev = hcon->hdev;
1039 struct smp_cmd_pairing *req = (void *) &smp->preq[1];
1040 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1];
1041 bool persistent;
1042
1043 if (hcon->type == ACL_LINK) {
1044 if (hcon->key_type == HCI_LK_DEBUG_COMBINATION)
1045 persistent = false;
1046 else
1047 persistent = !test_bit(HCI_CONN_FLUSH_KEY,
1048 &hcon->flags);
1049 } else {
1050 /* The LTKs, IRKs and CSRKs should be persistent only if
1051 * both sides had the bonding bit set in their
1052 * authentication requests.
1053 */
1054 persistent = !!((req->auth_req & rsp->auth_req) &
1055 SMP_AUTH_BONDING);
1056 }
1057
1058 if (smp->remote_irk) {
1059 mgmt_new_irk(hdev, smp->remote_irk, persistent);
1060
1061 /* Now that user space can be considered to know the
1062 * identity address track the connection based on it
1063 * from now on (assuming this is an LE link).
1064 */
1065 if (hcon->type == LE_LINK) {
1066 bacpy(&hcon->dst, &smp->remote_irk->bdaddr);
1067 hcon->dst_type = smp->remote_irk->addr_type;
1068 queue_work(hdev->workqueue, &conn->id_addr_update_work);
1069 }
1070 }
1071
1072 if (smp->csrk) {
1073 smp->csrk->bdaddr_type = hcon->dst_type;
1074 bacpy(&smp->csrk->bdaddr, &hcon->dst);
1075 mgmt_new_csrk(hdev, smp->csrk, persistent);
1076 }
1077
1078 if (smp->slave_csrk) {
1079 smp->slave_csrk->bdaddr_type = hcon->dst_type;
1080 bacpy(&smp->slave_csrk->bdaddr, &hcon->dst);
1081 mgmt_new_csrk(hdev, smp->slave_csrk, persistent);
1082 }
1083
1084 if (smp->ltk) {
1085 smp->ltk->bdaddr_type = hcon->dst_type;
1086 bacpy(&smp->ltk->bdaddr, &hcon->dst);
1087 mgmt_new_ltk(hdev, smp->ltk, persistent);
1088 }
1089
1090 if (smp->slave_ltk) {
1091 smp->slave_ltk->bdaddr_type = hcon->dst_type;
1092 bacpy(&smp->slave_ltk->bdaddr, &hcon->dst);
1093 mgmt_new_ltk(hdev, smp->slave_ltk, persistent);
1094 }
1095
1096 if (smp->link_key) {
1097 struct link_key *key;
1098 u8 type;
1099
1100 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1101 type = HCI_LK_DEBUG_COMBINATION;
1102 else if (hcon->sec_level == BT_SECURITY_FIPS)
1103 type = HCI_LK_AUTH_COMBINATION_P256;
1104 else
1105 type = HCI_LK_UNAUTH_COMBINATION_P256;
1106
1107 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst,
1108 smp->link_key, type, 0, &persistent);
1109 if (key) {
1110 mgmt_new_link_key(hdev, key, persistent);
1111
1112 /* Don't keep debug keys around if the relevant
1113 * flag is not set.
1114 */
1115 if (!hci_dev_test_flag(hdev, HCI_KEEP_DEBUG_KEYS) &&
1116 key->type == HCI_LK_DEBUG_COMBINATION) {
1117 list_del_rcu(&key->list);
1118 kfree_rcu(key, rcu);
1119 }
1120 }
1121 }
1122}
1123
1124static void sc_add_ltk(struct smp_chan *smp)
1125{
1126 struct hci_conn *hcon = smp->conn->hcon;
1127 u8 key_type, auth;
1128
1129 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1130 key_type = SMP_LTK_P256_DEBUG;
1131 else
1132 key_type = SMP_LTK_P256;
1133
1134 if (hcon->pending_sec_level == BT_SECURITY_FIPS)
1135 auth = 1;
1136 else
1137 auth = 0;
1138
1139 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1140 key_type, auth, smp->tk, smp->enc_key_size,
1141 0, 0);
1142}
1143
1144static void sc_generate_link_key(struct smp_chan *smp)
1145{
1146 /* From core spec. Spells out in ASCII as 'lebr'. */
1147 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c };
1148
1149 smp->link_key = kzalloc(16, GFP_KERNEL);
1150 if (!smp->link_key)
1151 return;
1152
1153 if (test_bit(SMP_FLAG_CT2, &smp->flags)) {
1154 /* SALT = 0x00000000000000000000000000000000746D7031 */
1155 const u8 salt[16] = { 0x31, 0x70, 0x6d, 0x74 };
1156
1157 if (smp_h7(smp->tfm_cmac, smp->tk, salt, smp->link_key)) {
1158 kzfree(smp->link_key);
1159 smp->link_key = NULL;
1160 return;
1161 }
1162 } else {
1163 /* From core spec. Spells out in ASCII as 'tmp1'. */
1164 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 };
1165
1166 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) {
1167 kzfree(smp->link_key);
1168 smp->link_key = NULL;
1169 return;
1170 }
1171 }
1172
1173 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) {
1174 kzfree(smp->link_key);
1175 smp->link_key = NULL;
1176 return;
1177 }
1178}
1179
1180static void smp_allow_key_dist(struct smp_chan *smp)
1181{
1182 /* Allow the first expected phase 3 PDU. The rest of the PDUs
1183 * will be allowed in each PDU handler to ensure we receive
1184 * them in the correct order.
1185 */
1186 if (smp->remote_key_dist & SMP_DIST_ENC_KEY)
1187 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO);
1188 else if (smp->remote_key_dist & SMP_DIST_ID_KEY)
1189 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
1190 else if (smp->remote_key_dist & SMP_DIST_SIGN)
1191 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
1192}
1193
1194static void sc_generate_ltk(struct smp_chan *smp)
1195{
1196 /* From core spec. Spells out in ASCII as 'brle'. */
1197 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 };
1198 struct hci_conn *hcon = smp->conn->hcon;
1199 struct hci_dev *hdev = hcon->hdev;
1200 struct link_key *key;
1201
1202 key = hci_find_link_key(hdev, &hcon->dst);
1203 if (!key) {
1204 bt_dev_err(hdev, "no Link Key found to generate LTK");
1205 return;
1206 }
1207
1208 if (key->type == HCI_LK_DEBUG_COMBINATION)
1209 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1210
1211 if (test_bit(SMP_FLAG_CT2, &smp->flags)) {
1212 /* SALT = 0x00000000000000000000000000000000746D7032 */
1213 const u8 salt[16] = { 0x32, 0x70, 0x6d, 0x74 };
1214
1215 if (smp_h7(smp->tfm_cmac, key->val, salt, smp->tk))
1216 return;
1217 } else {
1218 /* From core spec. Spells out in ASCII as 'tmp2'. */
1219 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 };
1220
1221 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk))
1222 return;
1223 }
1224
1225 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk))
1226 return;
1227
1228 sc_add_ltk(smp);
1229}
1230
1231static void smp_distribute_keys(struct smp_chan *smp)
1232{
1233 struct smp_cmd_pairing *req, *rsp;
1234 struct l2cap_conn *conn = smp->conn;
1235 struct hci_conn *hcon = conn->hcon;
1236 struct hci_dev *hdev = hcon->hdev;
1237 __u8 *keydist;
1238
1239 BT_DBG("conn %p", conn);
1240
1241 rsp = (void *) &smp->prsp[1];
1242
1243 /* The responder sends its keys first */
1244 if (hcon->out && (smp->remote_key_dist & KEY_DIST_MASK)) {
1245 smp_allow_key_dist(smp);
1246 return;
1247 }
1248
1249 req = (void *) &smp->preq[1];
1250
1251 if (hcon->out) {
1252 keydist = &rsp->init_key_dist;
1253 *keydist &= req->init_key_dist;
1254 } else {
1255 keydist = &rsp->resp_key_dist;
1256 *keydist &= req->resp_key_dist;
1257 }
1258
1259 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1260 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY))
1261 sc_generate_link_key(smp);
1262 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY))
1263 sc_generate_ltk(smp);
1264
1265 /* Clear the keys which are generated but not distributed */
1266 *keydist &= ~SMP_SC_NO_DIST;
1267 }
1268
1269 BT_DBG("keydist 0x%x", *keydist);
1270
1271 if (*keydist & SMP_DIST_ENC_KEY) {
1272 struct smp_cmd_encrypt_info enc;
1273 struct smp_cmd_master_ident ident;
1274 struct smp_ltk *ltk;
1275 u8 authenticated;
1276 __le16 ediv;
1277 __le64 rand;
1278
1279 /* Make sure we generate only the significant amount of
1280 * bytes based on the encryption key size, and set the rest
1281 * of the value to zeroes.
1282 */
1283 get_random_bytes(enc.ltk, smp->enc_key_size);
1284 memset(enc.ltk + smp->enc_key_size, 0,
1285 sizeof(enc.ltk) - smp->enc_key_size);
1286
1287 get_random_bytes(&ediv, sizeof(ediv));
1288 get_random_bytes(&rand, sizeof(rand));
1289
1290 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc);
1291
1292 authenticated = hcon->sec_level == BT_SECURITY_HIGH;
1293 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type,
1294 SMP_LTK_SLAVE, authenticated, enc.ltk,
1295 smp->enc_key_size, ediv, rand);
1296 smp->slave_ltk = ltk;
1297
1298 ident.ediv = ediv;
1299 ident.rand = rand;
1300
1301 smp_send_cmd(conn, SMP_CMD_MASTER_IDENT, sizeof(ident), &ident);
1302
1303 *keydist &= ~SMP_DIST_ENC_KEY;
1304 }
1305
1306 if (*keydist & SMP_DIST_ID_KEY) {
1307 struct smp_cmd_ident_addr_info addrinfo;
1308 struct smp_cmd_ident_info idinfo;
1309
1310 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk));
1311
1312 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo);
1313
1314 /* The hci_conn contains the local identity address
1315 * after the connection has been established.
1316 *
1317 * This is true even when the connection has been
1318 * established using a resolvable random address.
1319 */
1320 bacpy(&addrinfo.bdaddr, &hcon->src);
1321 addrinfo.addr_type = hcon->src_type;
1322
1323 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo),
1324 &addrinfo);
1325
1326 *keydist &= ~SMP_DIST_ID_KEY;
1327 }
1328
1329 if (*keydist & SMP_DIST_SIGN) {
1330 struct smp_cmd_sign_info sign;
1331 struct smp_csrk *csrk;
1332
1333 /* Generate a new random key */
1334 get_random_bytes(sign.csrk, sizeof(sign.csrk));
1335
1336 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
1337 if (csrk) {
1338 if (hcon->sec_level > BT_SECURITY_MEDIUM)
1339 csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED;
1340 else
1341 csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED;
1342 memcpy(csrk->val, sign.csrk, sizeof(csrk->val));
1343 }
1344 smp->slave_csrk = csrk;
1345
1346 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign);
1347
1348 *keydist &= ~SMP_DIST_SIGN;
1349 }
1350
1351 /* If there are still keys to be received wait for them */
1352 if (smp->remote_key_dist & KEY_DIST_MASK) {
1353 smp_allow_key_dist(smp);
1354 return;
1355 }
1356
1357 set_bit(SMP_FLAG_COMPLETE, &smp->flags);
1358 smp_notify_keys(conn);
1359
1360 smp_chan_destroy(conn);
1361}
1362
1363static void smp_timeout(struct work_struct *work)
1364{
1365 struct smp_chan *smp = container_of(work, struct smp_chan,
1366 security_timer.work);
1367 struct l2cap_conn *conn = smp->conn;
1368
1369 BT_DBG("conn %p", conn);
1370
1371 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM);
1372}
1373
1374static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
1375{
1376 struct l2cap_chan *chan = conn->smp;
1377 struct smp_chan *smp;
1378
1379 smp = kzalloc(sizeof(*smp), GFP_ATOMIC);
1380 if (!smp)
1381 return NULL;
1382
1383 smp->tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
1384 if (IS_ERR(smp->tfm_cmac)) {
1385 BT_ERR("Unable to create CMAC crypto context");
1386 goto zfree_smp;
1387 }
1388
1389 smp->tfm_ecdh = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0);
1390 if (IS_ERR(smp->tfm_ecdh)) {
1391 BT_ERR("Unable to create ECDH crypto context");
1392 goto free_shash;
1393 }
1394
1395 smp->conn = conn;
1396 chan->data = smp;
1397
1398 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL);
1399
1400 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout);
1401
1402 hci_conn_hold(conn->hcon);
1403
1404 return smp;
1405
1406free_shash:
1407 crypto_free_shash(smp->tfm_cmac);
1408zfree_smp:
1409 kzfree(smp);
1410 return NULL;
1411}
1412
1413static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16])
1414{
1415 struct hci_conn *hcon = smp->conn->hcon;
1416 u8 *na, *nb, a[7], b[7];
1417
1418 if (hcon->out) {
1419 na = smp->prnd;
1420 nb = smp->rrnd;
1421 } else {
1422 na = smp->rrnd;
1423 nb = smp->prnd;
1424 }
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 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk);
1432}
1433
1434static void sc_dhkey_check(struct smp_chan *smp)
1435{
1436 struct hci_conn *hcon = smp->conn->hcon;
1437 struct smp_cmd_dhkey_check check;
1438 u8 a[7], b[7], *local_addr, *remote_addr;
1439 u8 io_cap[3], r[16];
1440
1441 memcpy(a, &hcon->init_addr, 6);
1442 memcpy(b, &hcon->resp_addr, 6);
1443 a[6] = hcon->init_addr_type;
1444 b[6] = hcon->resp_addr_type;
1445
1446 if (hcon->out) {
1447 local_addr = a;
1448 remote_addr = b;
1449 memcpy(io_cap, &smp->preq[1], 3);
1450 } else {
1451 local_addr = b;
1452 remote_addr = a;
1453 memcpy(io_cap, &smp->prsp[1], 3);
1454 }
1455
1456 memset(r, 0, sizeof(r));
1457
1458 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
1459 put_unaligned_le32(hcon->passkey_notify, r);
1460
1461 if (smp->method == REQ_OOB)
1462 memcpy(r, smp->rr, 16);
1463
1464 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap,
1465 local_addr, remote_addr, check.e);
1466
1467 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check);
1468}
1469
1470static u8 sc_passkey_send_confirm(struct smp_chan *smp)
1471{
1472 struct l2cap_conn *conn = smp->conn;
1473 struct hci_conn *hcon = conn->hcon;
1474 struct smp_cmd_pairing_confirm cfm;
1475 u8 r;
1476
1477 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1478 r |= 0x80;
1479
1480 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1481
1482 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r,
1483 cfm.confirm_val))
1484 return SMP_UNSPECIFIED;
1485
1486 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
1487
1488 return 0;
1489}
1490
1491static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op)
1492{
1493 struct l2cap_conn *conn = smp->conn;
1494 struct hci_conn *hcon = conn->hcon;
1495 struct hci_dev *hdev = hcon->hdev;
1496 u8 cfm[16], r;
1497
1498 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */
1499 if (smp->passkey_round >= 20)
1500 return 0;
1501
1502 switch (smp_op) {
1503 case SMP_CMD_PAIRING_RANDOM:
1504 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1505 r |= 0x80;
1506
1507 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
1508 smp->rrnd, r, cfm))
1509 return SMP_UNSPECIFIED;
1510
1511 if (crypto_memneq(smp->pcnf, cfm, 16))
1512 return SMP_CONFIRM_FAILED;
1513
1514 smp->passkey_round++;
1515
1516 if (smp->passkey_round == 20) {
1517 /* Generate MacKey and LTK */
1518 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk))
1519 return SMP_UNSPECIFIED;
1520 }
1521
1522 /* The round is only complete when the initiator
1523 * receives pairing random.
1524 */
1525 if (!hcon->out) {
1526 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1527 sizeof(smp->prnd), smp->prnd);
1528 if (smp->passkey_round == 20)
1529 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1530 else
1531 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1532 return 0;
1533 }
1534
1535 /* Start the next round */
1536 if (smp->passkey_round != 20)
1537 return sc_passkey_round(smp, 0);
1538
1539 /* Passkey rounds are complete - start DHKey Check */
1540 sc_dhkey_check(smp);
1541 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1542
1543 break;
1544
1545 case SMP_CMD_PAIRING_CONFIRM:
1546 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
1547 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
1548 return 0;
1549 }
1550
1551 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
1552
1553 if (hcon->out) {
1554 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1555 sizeof(smp->prnd), smp->prnd);
1556 return 0;
1557 }
1558
1559 return sc_passkey_send_confirm(smp);
1560
1561 case SMP_CMD_PUBLIC_KEY:
1562 default:
1563 /* Initiating device starts the round */
1564 if (!hcon->out)
1565 return 0;
1566
1567 BT_DBG("%s Starting passkey round %u", hdev->name,
1568 smp->passkey_round + 1);
1569
1570 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1571
1572 return sc_passkey_send_confirm(smp);
1573 }
1574
1575 return 0;
1576}
1577
1578static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey)
1579{
1580 struct l2cap_conn *conn = smp->conn;
1581 struct hci_conn *hcon = conn->hcon;
1582 u8 smp_op;
1583
1584 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags);
1585
1586 switch (mgmt_op) {
1587 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1588 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED);
1589 return 0;
1590 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1591 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED);
1592 return 0;
1593 case MGMT_OP_USER_PASSKEY_REPLY:
1594 hcon->passkey_notify = le32_to_cpu(passkey);
1595 smp->passkey_round = 0;
1596
1597 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags))
1598 smp_op = SMP_CMD_PAIRING_CONFIRM;
1599 else
1600 smp_op = 0;
1601
1602 if (sc_passkey_round(smp, smp_op))
1603 return -EIO;
1604
1605 return 0;
1606 }
1607
1608 /* Initiator sends DHKey check first */
1609 if (hcon->out) {
1610 sc_dhkey_check(smp);
1611 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1612 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) {
1613 sc_dhkey_check(smp);
1614 sc_add_ltk(smp);
1615 }
1616
1617 return 0;
1618}
1619
1620int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey)
1621{
1622 struct l2cap_conn *conn = hcon->l2cap_data;
1623 struct l2cap_chan *chan;
1624 struct smp_chan *smp;
1625 u32 value;
1626 int err;
1627
1628 BT_DBG("");
1629
1630 if (!conn)
1631 return -ENOTCONN;
1632
1633 chan = conn->smp;
1634 if (!chan)
1635 return -ENOTCONN;
1636
1637 l2cap_chan_lock(chan);
1638 if (!chan->data) {
1639 err = -ENOTCONN;
1640 goto unlock;
1641 }
1642
1643 smp = chan->data;
1644
1645 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1646 err = sc_user_reply(smp, mgmt_op, passkey);
1647 goto unlock;
1648 }
1649
1650 switch (mgmt_op) {
1651 case MGMT_OP_USER_PASSKEY_REPLY:
1652 value = le32_to_cpu(passkey);
1653 memset(smp->tk, 0, sizeof(smp->tk));
1654 BT_DBG("PassKey: %d", value);
1655 put_unaligned_le32(value, smp->tk);
1656 /* Fall Through */
1657 case MGMT_OP_USER_CONFIRM_REPLY:
1658 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
1659 break;
1660 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1661 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1662 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1663 err = 0;
1664 goto unlock;
1665 default:
1666 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1667 err = -EOPNOTSUPP;
1668 goto unlock;
1669 }
1670
1671 err = 0;
1672
1673 /* If it is our turn to send Pairing Confirm, do so now */
1674 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) {
1675 u8 rsp = smp_confirm(smp);
1676 if (rsp)
1677 smp_failure(conn, rsp);
1678 }
1679
1680unlock:
1681 l2cap_chan_unlock(chan);
1682 return err;
1683}
1684
1685static void build_bredr_pairing_cmd(struct smp_chan *smp,
1686 struct smp_cmd_pairing *req,
1687 struct smp_cmd_pairing *rsp)
1688{
1689 struct l2cap_conn *conn = smp->conn;
1690 struct hci_dev *hdev = conn->hcon->hdev;
1691 u8 local_dist = 0, remote_dist = 0;
1692
1693 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) {
1694 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1695 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1696 }
1697
1698 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING))
1699 remote_dist |= SMP_DIST_ID_KEY;
1700
1701 if (hci_dev_test_flag(hdev, HCI_PRIVACY))
1702 local_dist |= SMP_DIST_ID_KEY;
1703
1704 if (!rsp) {
1705 memset(req, 0, sizeof(*req));
1706
1707 req->auth_req = SMP_AUTH_CT2;
1708 req->init_key_dist = local_dist;
1709 req->resp_key_dist = remote_dist;
1710 req->max_key_size = conn->hcon->enc_key_size;
1711
1712 smp->remote_key_dist = remote_dist;
1713
1714 return;
1715 }
1716
1717 memset(rsp, 0, sizeof(*rsp));
1718
1719 rsp->auth_req = SMP_AUTH_CT2;
1720 rsp->max_key_size = conn->hcon->enc_key_size;
1721 rsp->init_key_dist = req->init_key_dist & remote_dist;
1722 rsp->resp_key_dist = req->resp_key_dist & local_dist;
1723
1724 smp->remote_key_dist = rsp->init_key_dist;
1725}
1726
1727static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
1728{
1729 struct smp_cmd_pairing rsp, *req = (void *) skb->data;
1730 struct l2cap_chan *chan = conn->smp;
1731 struct hci_dev *hdev = conn->hcon->hdev;
1732 struct smp_chan *smp;
1733 u8 key_size, auth, sec_level;
1734 int ret;
1735
1736 BT_DBG("conn %p", conn);
1737
1738 if (skb->len < sizeof(*req))
1739 return SMP_INVALID_PARAMS;
1740
1741 if (conn->hcon->role != HCI_ROLE_SLAVE)
1742 return SMP_CMD_NOTSUPP;
1743
1744 if (!chan->data)
1745 smp = smp_chan_create(conn);
1746 else
1747 smp = chan->data;
1748
1749 if (!smp)
1750 return SMP_UNSPECIFIED;
1751
1752 /* We didn't start the pairing, so match remote */
1753 auth = req->auth_req & AUTH_REQ_MASK(hdev);
1754
1755 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) &&
1756 (auth & SMP_AUTH_BONDING))
1757 return SMP_PAIRING_NOTSUPP;
1758
1759 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
1760 return SMP_AUTH_REQUIREMENTS;
1761
1762 smp->preq[0] = SMP_CMD_PAIRING_REQ;
1763 memcpy(&smp->preq[1], req, sizeof(*req));
1764 skb_pull(skb, sizeof(*req));
1765
1766 /* If the remote side's OOB flag is set it means it has
1767 * successfully received our local OOB data - therefore set the
1768 * flag to indicate that local OOB is in use.
1769 */
1770 if (req->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob)
1771 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);
1772
1773 /* SMP over BR/EDR requires special treatment */
1774 if (conn->hcon->type == ACL_LINK) {
1775 /* We must have a BR/EDR SC link */
1776 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) &&
1777 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
1778 return SMP_CROSS_TRANSP_NOT_ALLOWED;
1779
1780 set_bit(SMP_FLAG_SC, &smp->flags);
1781
1782 build_bredr_pairing_cmd(smp, req, &rsp);
1783
1784 if (req->auth_req & SMP_AUTH_CT2)
1785 set_bit(SMP_FLAG_CT2, &smp->flags);
1786
1787 key_size = min(req->max_key_size, rsp.max_key_size);
1788 if (check_enc_key_size(conn, key_size))
1789 return SMP_ENC_KEY_SIZE;
1790
1791 /* Clear bits which are generated but not distributed */
1792 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1793
1794 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1795 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1796 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1797
1798 smp_distribute_keys(smp);
1799 return 0;
1800 }
1801
1802 build_pairing_cmd(conn, req, &rsp, auth);
1803
1804 if (rsp.auth_req & SMP_AUTH_SC) {
1805 set_bit(SMP_FLAG_SC, &smp->flags);
1806
1807 if (rsp.auth_req & SMP_AUTH_CT2)
1808 set_bit(SMP_FLAG_CT2, &smp->flags);
1809 }
1810
1811 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
1812 sec_level = BT_SECURITY_MEDIUM;
1813 else
1814 sec_level = authreq_to_seclevel(auth);
1815
1816 if (sec_level > conn->hcon->pending_sec_level)
1817 conn->hcon->pending_sec_level = sec_level;
1818
1819 /* If we need MITM check that it can be achieved */
1820 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1821 u8 method;
1822
1823 method = get_auth_method(smp, conn->hcon->io_capability,
1824 req->io_capability);
1825 if (method == JUST_WORKS || method == JUST_CFM)
1826 return SMP_AUTH_REQUIREMENTS;
1827 }
1828
1829 key_size = min(req->max_key_size, rsp.max_key_size);
1830 if (check_enc_key_size(conn, key_size))
1831 return SMP_ENC_KEY_SIZE;
1832
1833 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1834
1835 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1836 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1837
1838 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1839
1840 clear_bit(SMP_FLAG_INITIATOR, &smp->flags);
1841
1842 /* Strictly speaking we shouldn't allow Pairing Confirm for the
1843 * SC case, however some implementations incorrectly copy RFU auth
1844 * req bits from our security request, which may create a false
1845 * positive SC enablement.
1846 */
1847 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1848
1849 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1850 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
1851 /* Clear bits which are generated but not distributed */
1852 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1853 /* Wait for Public Key from Initiating Device */
1854 return 0;
1855 }
1856
1857 /* Request setup of TK */
1858 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability);
1859 if (ret)
1860 return SMP_UNSPECIFIED;
1861
1862 return 0;
1863}
1864
1865static u8 sc_send_public_key(struct smp_chan *smp)
1866{
1867 struct hci_dev *hdev = smp->conn->hcon->hdev;
1868
1869 BT_DBG("");
1870
1871 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) {
1872 struct l2cap_chan *chan = hdev->smp_data;
1873 struct smp_dev *smp_dev;
1874
1875 if (!chan || !chan->data)
1876 return SMP_UNSPECIFIED;
1877
1878 smp_dev = chan->data;
1879
1880 memcpy(smp->local_pk, smp_dev->local_pk, 64);
1881 memcpy(smp->lr, smp_dev->local_rand, 16);
1882
1883 if (smp_dev->debug_key)
1884 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1885
1886 goto done;
1887 }
1888
1889 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) {
1890 BT_DBG("Using debug keys");
1891 if (set_ecdh_privkey(smp->tfm_ecdh, debug_sk))
1892 return SMP_UNSPECIFIED;
1893 memcpy(smp->local_pk, debug_pk, 64);
1894 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1895 } else {
1896 while (true) {
1897 /* Generate key pair for Secure Connections */
1898 if (generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk))
1899 return SMP_UNSPECIFIED;
1900
1901 /* This is unlikely, but we need to check that
1902 * we didn't accidentially generate a debug key.
1903 */
1904 if (crypto_memneq(smp->local_pk, debug_pk, 64))
1905 break;
1906 }
1907 }
1908
1909done:
1910 SMP_DBG("Local Public Key X: %32phN", smp->local_pk);
1911 SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32);
1912
1913 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk);
1914
1915 return 0;
1916}
1917
1918static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
1919{
1920 struct smp_cmd_pairing *req, *rsp = (void *) skb->data;
1921 struct l2cap_chan *chan = conn->smp;
1922 struct smp_chan *smp = chan->data;
1923 struct hci_dev *hdev = conn->hcon->hdev;
1924 u8 key_size, auth;
1925 int ret;
1926
1927 BT_DBG("conn %p", conn);
1928
1929 if (skb->len < sizeof(*rsp))
1930 return SMP_INVALID_PARAMS;
1931
1932 if (conn->hcon->role != HCI_ROLE_MASTER)
1933 return SMP_CMD_NOTSUPP;
1934
1935 skb_pull(skb, sizeof(*rsp));
1936
1937 req = (void *) &smp->preq[1];
1938
1939 key_size = min(req->max_key_size, rsp->max_key_size);
1940 if (check_enc_key_size(conn, key_size))
1941 return SMP_ENC_KEY_SIZE;
1942
1943 auth = rsp->auth_req & AUTH_REQ_MASK(hdev);
1944
1945 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
1946 return SMP_AUTH_REQUIREMENTS;
1947
1948 /* If the remote side's OOB flag is set it means it has
1949 * successfully received our local OOB data - therefore set the
1950 * flag to indicate that local OOB is in use.
1951 */
1952 if (rsp->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob)
1953 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);
1954
1955 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1956 memcpy(&smp->prsp[1], rsp, sizeof(*rsp));
1957
1958 /* Update remote key distribution in case the remote cleared
1959 * some bits that we had enabled in our request.
1960 */
1961 smp->remote_key_dist &= rsp->resp_key_dist;
1962
1963 if ((req->auth_req & SMP_AUTH_CT2) && (auth & SMP_AUTH_CT2))
1964 set_bit(SMP_FLAG_CT2, &smp->flags);
1965
1966 /* For BR/EDR this means we're done and can start phase 3 */
1967 if (conn->hcon->type == ACL_LINK) {
1968 /* Clear bits which are generated but not distributed */
1969 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1970 smp_distribute_keys(smp);
1971 return 0;
1972 }
1973
1974 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC))
1975 set_bit(SMP_FLAG_SC, &smp->flags);
1976 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH)
1977 conn->hcon->pending_sec_level = BT_SECURITY_HIGH;
1978
1979 /* If we need MITM check that it can be achieved */
1980 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1981 u8 method;
1982
1983 method = get_auth_method(smp, req->io_capability,
1984 rsp->io_capability);
1985 if (method == JUST_WORKS || method == JUST_CFM)
1986 return SMP_AUTH_REQUIREMENTS;
1987 }
1988
1989 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1990
1991 /* Update remote key distribution in case the remote cleared
1992 * some bits that we had enabled in our request.
1993 */
1994 smp->remote_key_dist &= rsp->resp_key_dist;
1995
1996 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1997 /* Clear bits which are generated but not distributed */
1998 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1999 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
2000 return sc_send_public_key(smp);
2001 }
2002
2003 auth |= req->auth_req;
2004
2005 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability);
2006 if (ret)
2007 return SMP_UNSPECIFIED;
2008
2009 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
2010
2011 /* Can't compose response until we have been confirmed */
2012 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
2013 return smp_confirm(smp);
2014
2015 return 0;
2016}
2017
2018static u8 sc_check_confirm(struct smp_chan *smp)
2019{
2020 struct l2cap_conn *conn = smp->conn;
2021
2022 BT_DBG("");
2023
2024 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2025 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM);
2026
2027 if (conn->hcon->out) {
2028 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2029 smp->prnd);
2030 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2031 }
2032
2033 return 0;
2034}
2035
2036/* Work-around for some implementations that incorrectly copy RFU bits
2037 * from our security request and thereby create the impression that
2038 * we're doing SC when in fact the remote doesn't support it.
2039 */
2040static int fixup_sc_false_positive(struct smp_chan *smp)
2041{
2042 struct l2cap_conn *conn = smp->conn;
2043 struct hci_conn *hcon = conn->hcon;
2044 struct hci_dev *hdev = hcon->hdev;
2045 struct smp_cmd_pairing *req, *rsp;
2046 u8 auth;
2047
2048 /* The issue is only observed when we're in slave role */
2049 if (hcon->out)
2050 return SMP_UNSPECIFIED;
2051
2052 if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) {
2053 bt_dev_err(hdev, "refusing legacy fallback in SC-only mode");
2054 return SMP_UNSPECIFIED;
2055 }
2056
2057 bt_dev_err(hdev, "trying to fall back to legacy SMP");
2058
2059 req = (void *) &smp->preq[1];
2060 rsp = (void *) &smp->prsp[1];
2061
2062 /* Rebuild key dist flags which may have been cleared for SC */
2063 smp->remote_key_dist = (req->init_key_dist & rsp->resp_key_dist);
2064
2065 auth = req->auth_req & AUTH_REQ_MASK(hdev);
2066
2067 if (tk_request(conn, 0, auth, rsp->io_capability, req->io_capability)) {
2068 bt_dev_err(hdev, "failed to fall back to legacy SMP");
2069 return SMP_UNSPECIFIED;
2070 }
2071
2072 clear_bit(SMP_FLAG_SC, &smp->flags);
2073
2074 return 0;
2075}
2076
2077static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
2078{
2079 struct l2cap_chan *chan = conn->smp;
2080 struct smp_chan *smp = chan->data;
2081
2082 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
2083
2084 if (skb->len < sizeof(smp->pcnf))
2085 return SMP_INVALID_PARAMS;
2086
2087 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf));
2088 skb_pull(skb, sizeof(smp->pcnf));
2089
2090 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
2091 int ret;
2092
2093 /* Public Key exchange must happen before any other steps */
2094 if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags))
2095 return sc_check_confirm(smp);
2096
2097 BT_ERR("Unexpected SMP Pairing Confirm");
2098
2099 ret = fixup_sc_false_positive(smp);
2100 if (ret)
2101 return ret;
2102 }
2103
2104 if (conn->hcon->out) {
2105 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2106 smp->prnd);
2107 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2108 return 0;
2109 }
2110
2111 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
2112 return smp_confirm(smp);
2113
2114 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
2115
2116 return 0;
2117}
2118
2119static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
2120{
2121 struct l2cap_chan *chan = conn->smp;
2122 struct smp_chan *smp = chan->data;
2123 struct hci_conn *hcon = conn->hcon;
2124 u8 *pkax, *pkbx, *na, *nb;
2125 u32 passkey;
2126 int err;
2127
2128 BT_DBG("conn %p", conn);
2129
2130 if (skb->len < sizeof(smp->rrnd))
2131 return SMP_INVALID_PARAMS;
2132
2133 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd));
2134 skb_pull(skb, sizeof(smp->rrnd));
2135
2136 if (!test_bit(SMP_FLAG_SC, &smp->flags))
2137 return smp_random(smp);
2138
2139 if (hcon->out) {
2140 pkax = smp->local_pk;
2141 pkbx = smp->remote_pk;
2142 na = smp->prnd;
2143 nb = smp->rrnd;
2144 } else {
2145 pkax = smp->remote_pk;
2146 pkbx = smp->local_pk;
2147 na = smp->rrnd;
2148 nb = smp->prnd;
2149 }
2150
2151 if (smp->method == REQ_OOB) {
2152 if (!hcon->out)
2153 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2154 sizeof(smp->prnd), smp->prnd);
2155 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2156 goto mackey_and_ltk;
2157 }
2158
2159 /* Passkey entry has special treatment */
2160 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2161 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM);
2162
2163 if (hcon->out) {
2164 u8 cfm[16];
2165
2166 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
2167 smp->rrnd, 0, cfm);
2168 if (err)
2169 return SMP_UNSPECIFIED;
2170
2171 if (crypto_memneq(smp->pcnf, cfm, 16))
2172 return SMP_CONFIRM_FAILED;
2173 } else {
2174 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2175 smp->prnd);
2176 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2177 }
2178
2179mackey_and_ltk:
2180 /* Generate MacKey and LTK */
2181 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk);
2182 if (err)
2183 return SMP_UNSPECIFIED;
2184
2185 if (smp->method == JUST_WORKS || smp->method == REQ_OOB) {
2186 if (hcon->out) {
2187 sc_dhkey_check(smp);
2188 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2189 }
2190 return 0;
2191 }
2192
2193 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
2194 if (err)
2195 return SMP_UNSPECIFIED;
2196
2197 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type,
2198 hcon->dst_type, passkey, 0);
2199 if (err)
2200 return SMP_UNSPECIFIED;
2201
2202 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2203
2204 return 0;
2205}
2206
2207static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level)
2208{
2209 struct smp_ltk *key;
2210 struct hci_conn *hcon = conn->hcon;
2211
2212 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role);
2213 if (!key)
2214 return false;
2215
2216 if (smp_ltk_sec_level(key) < sec_level)
2217 return false;
2218
2219 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
2220 return true;
2221
2222 hci_le_start_enc(hcon, key->ediv, key->rand, key->val, key->enc_size);
2223 hcon->enc_key_size = key->enc_size;
2224
2225 /* We never store STKs for master role, so clear this flag */
2226 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
2227
2228 return true;
2229}
2230
2231bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level,
2232 enum smp_key_pref key_pref)
2233{
2234 if (sec_level == BT_SECURITY_LOW)
2235 return true;
2236
2237 /* If we're encrypted with an STK but the caller prefers using
2238 * LTK claim insufficient security. This way we allow the
2239 * connection to be re-encrypted with an LTK, even if the LTK
2240 * provides the same level of security. Only exception is if we
2241 * don't have an LTK (e.g. because of key distribution bits).
2242 */
2243 if (key_pref == SMP_USE_LTK &&
2244 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) &&
2245 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role))
2246 return false;
2247
2248 if (hcon->sec_level >= sec_level)
2249 return true;
2250
2251 return false;
2252}
2253
2254static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
2255{
2256 struct smp_cmd_security_req *rp = (void *) skb->data;
2257 struct smp_cmd_pairing cp;
2258 struct hci_conn *hcon = conn->hcon;
2259 struct hci_dev *hdev = hcon->hdev;
2260 struct smp_chan *smp;
2261 u8 sec_level, auth;
2262
2263 BT_DBG("conn %p", conn);
2264
2265 if (skb->len < sizeof(*rp))
2266 return SMP_INVALID_PARAMS;
2267
2268 if (hcon->role != HCI_ROLE_MASTER)
2269 return SMP_CMD_NOTSUPP;
2270
2271 auth = rp->auth_req & AUTH_REQ_MASK(hdev);
2272
2273 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
2274 return SMP_AUTH_REQUIREMENTS;
2275
2276 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
2277 sec_level = BT_SECURITY_MEDIUM;
2278 else
2279 sec_level = authreq_to_seclevel(auth);
2280
2281 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) {
2282 /* If link is already encrypted with sufficient security we
2283 * still need refresh encryption as per Core Spec 5.0 Vol 3,
2284 * Part H 2.4.6
2285 */
2286 smp_ltk_encrypt(conn, hcon->sec_level);
2287 return 0;
2288 }
2289
2290 if (sec_level > hcon->pending_sec_level)
2291 hcon->pending_sec_level = sec_level;
2292
2293 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2294 return 0;
2295
2296 smp = smp_chan_create(conn);
2297 if (!smp)
2298 return SMP_UNSPECIFIED;
2299
2300 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) &&
2301 (auth & SMP_AUTH_BONDING))
2302 return SMP_PAIRING_NOTSUPP;
2303
2304 skb_pull(skb, sizeof(*rp));
2305
2306 memset(&cp, 0, sizeof(cp));
2307 build_pairing_cmd(conn, &cp, NULL, auth);
2308
2309 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2310 memcpy(&smp->preq[1], &cp, sizeof(cp));
2311
2312 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
2313 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2314
2315 return 0;
2316}
2317
2318int smp_conn_security(struct hci_conn *hcon, __u8 sec_level)
2319{
2320 struct l2cap_conn *conn = hcon->l2cap_data;
2321 struct l2cap_chan *chan;
2322 struct smp_chan *smp;
2323 __u8 authreq;
2324 int ret;
2325
2326 BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level);
2327
2328 /* This may be NULL if there's an unexpected disconnection */
2329 if (!conn)
2330 return 1;
2331
2332 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED))
2333 return 1;
2334
2335 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK))
2336 return 1;
2337
2338 if (sec_level > hcon->pending_sec_level)
2339 hcon->pending_sec_level = sec_level;
2340
2341 if (hcon->role == HCI_ROLE_MASTER)
2342 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2343 return 0;
2344
2345 chan = conn->smp;
2346 if (!chan) {
2347 bt_dev_err(hcon->hdev, "security requested but not available");
2348 return 1;
2349 }
2350
2351 l2cap_chan_lock(chan);
2352
2353 /* If SMP is already in progress ignore this request */
2354 if (chan->data) {
2355 ret = 0;
2356 goto unlock;
2357 }
2358
2359 smp = smp_chan_create(conn);
2360 if (!smp) {
2361 ret = 1;
2362 goto unlock;
2363 }
2364
2365 authreq = seclevel_to_authreq(sec_level);
2366
2367 if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED)) {
2368 authreq |= SMP_AUTH_SC;
2369 if (hci_dev_test_flag(hcon->hdev, HCI_SSP_ENABLED))
2370 authreq |= SMP_AUTH_CT2;
2371 }
2372
2373 /* Require MITM if IO Capability allows or the security level
2374 * requires it.
2375 */
2376 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT ||
2377 hcon->pending_sec_level > BT_SECURITY_MEDIUM)
2378 authreq |= SMP_AUTH_MITM;
2379
2380 if (hcon->role == HCI_ROLE_MASTER) {
2381 struct smp_cmd_pairing cp;
2382
2383 build_pairing_cmd(conn, &cp, NULL, authreq);
2384 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2385 memcpy(&smp->preq[1], &cp, sizeof(cp));
2386
2387 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
2388 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2389 } else {
2390 struct smp_cmd_security_req cp;
2391 cp.auth_req = authreq;
2392 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp);
2393 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ);
2394 }
2395
2396 set_bit(SMP_FLAG_INITIATOR, &smp->flags);
2397 ret = 0;
2398
2399unlock:
2400 l2cap_chan_unlock(chan);
2401 return ret;
2402}
2403
2404int smp_cancel_and_remove_pairing(struct hci_dev *hdev, bdaddr_t *bdaddr,
2405 u8 addr_type)
2406{
2407 struct hci_conn *hcon;
2408 struct l2cap_conn *conn;
2409 struct l2cap_chan *chan;
2410 struct smp_chan *smp;
2411 int err;
2412
2413 err = hci_remove_ltk(hdev, bdaddr, addr_type);
2414 hci_remove_irk(hdev, bdaddr, addr_type);
2415
2416 hcon = hci_conn_hash_lookup_le(hdev, bdaddr, addr_type);
2417 if (!hcon)
2418 goto done;
2419
2420 conn = hcon->l2cap_data;
2421 if (!conn)
2422 goto done;
2423
2424 chan = conn->smp;
2425 if (!chan)
2426 goto done;
2427
2428 l2cap_chan_lock(chan);
2429
2430 smp = chan->data;
2431 if (smp) {
2432 /* Set keys to NULL to make sure smp_failure() does not try to
2433 * remove and free already invalidated rcu list entries. */
2434 smp->ltk = NULL;
2435 smp->slave_ltk = NULL;
2436 smp->remote_irk = NULL;
2437
2438 if (test_bit(SMP_FLAG_COMPLETE, &smp->flags))
2439 smp_failure(conn, 0);
2440 else
2441 smp_failure(conn, SMP_UNSPECIFIED);
2442 err = 0;
2443 }
2444
2445 l2cap_chan_unlock(chan);
2446
2447done:
2448 return err;
2449}
2450
2451static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb)
2452{
2453 struct smp_cmd_encrypt_info *rp = (void *) skb->data;
2454 struct l2cap_chan *chan = conn->smp;
2455 struct smp_chan *smp = chan->data;
2456
2457 BT_DBG("conn %p", conn);
2458
2459 if (skb->len < sizeof(*rp))
2460 return SMP_INVALID_PARAMS;
2461
2462 SMP_ALLOW_CMD(smp, SMP_CMD_MASTER_IDENT);
2463
2464 skb_pull(skb, sizeof(*rp));
2465
2466 memcpy(smp->tk, rp->ltk, sizeof(smp->tk));
2467
2468 return 0;
2469}
2470
2471static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb)
2472{
2473 struct smp_cmd_master_ident *rp = (void *) skb->data;
2474 struct l2cap_chan *chan = conn->smp;
2475 struct smp_chan *smp = chan->data;
2476 struct hci_dev *hdev = conn->hcon->hdev;
2477 struct hci_conn *hcon = conn->hcon;
2478 struct smp_ltk *ltk;
2479 u8 authenticated;
2480
2481 BT_DBG("conn %p", conn);
2482
2483 if (skb->len < sizeof(*rp))
2484 return SMP_INVALID_PARAMS;
2485
2486 /* Mark the information as received */
2487 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY;
2488
2489 if (smp->remote_key_dist & SMP_DIST_ID_KEY)
2490 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
2491 else if (smp->remote_key_dist & SMP_DIST_SIGN)
2492 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2493
2494 skb_pull(skb, sizeof(*rp));
2495
2496 authenticated = (hcon->sec_level == BT_SECURITY_HIGH);
2497 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK,
2498 authenticated, smp->tk, smp->enc_key_size,
2499 rp->ediv, rp->rand);
2500 smp->ltk = ltk;
2501 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2502 smp_distribute_keys(smp);
2503
2504 return 0;
2505}
2506
2507static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb)
2508{
2509 struct smp_cmd_ident_info *info = (void *) skb->data;
2510 struct l2cap_chan *chan = conn->smp;
2511 struct smp_chan *smp = chan->data;
2512
2513 BT_DBG("");
2514
2515 if (skb->len < sizeof(*info))
2516 return SMP_INVALID_PARAMS;
2517
2518 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO);
2519
2520 skb_pull(skb, sizeof(*info));
2521
2522 memcpy(smp->irk, info->irk, 16);
2523
2524 return 0;
2525}
2526
2527static int smp_cmd_ident_addr_info(struct l2cap_conn *conn,
2528 struct sk_buff *skb)
2529{
2530 struct smp_cmd_ident_addr_info *info = (void *) skb->data;
2531 struct l2cap_chan *chan = conn->smp;
2532 struct smp_chan *smp = chan->data;
2533 struct hci_conn *hcon = conn->hcon;
2534 bdaddr_t rpa;
2535
2536 BT_DBG("");
2537
2538 if (skb->len < sizeof(*info))
2539 return SMP_INVALID_PARAMS;
2540
2541 /* Mark the information as received */
2542 smp->remote_key_dist &= ~SMP_DIST_ID_KEY;
2543
2544 if (smp->remote_key_dist & SMP_DIST_SIGN)
2545 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2546
2547 skb_pull(skb, sizeof(*info));
2548
2549 /* Strictly speaking the Core Specification (4.1) allows sending
2550 * an empty address which would force us to rely on just the IRK
2551 * as "identity information". However, since such
2552 * implementations are not known of and in order to not over
2553 * complicate our implementation, simply pretend that we never
2554 * received an IRK for such a device.
2555 *
2556 * The Identity Address must also be a Static Random or Public
2557 * Address, which hci_is_identity_address() checks for.
2558 */
2559 if (!bacmp(&info->bdaddr, BDADDR_ANY) ||
2560 !hci_is_identity_address(&info->bdaddr, info->addr_type)) {
2561 bt_dev_err(hcon->hdev, "ignoring IRK with no identity address");
2562 goto distribute;
2563 }
2564
2565 /* Drop IRK if peer is using identity address during pairing but is
2566 * providing different address as identity information.
2567 *
2568 * Microsoft Surface Precision Mouse is known to have this bug.
2569 */
2570 if (hci_is_identity_address(&hcon->dst, hcon->dst_type) &&
2571 (bacmp(&info->bdaddr, &hcon->dst) ||
2572 info->addr_type != hcon->dst_type)) {
2573 bt_dev_err(hcon->hdev,
2574 "ignoring IRK with invalid identity address");
2575 goto distribute;
2576 }
2577
2578 bacpy(&smp->id_addr, &info->bdaddr);
2579 smp->id_addr_type = info->addr_type;
2580
2581 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type))
2582 bacpy(&rpa, &hcon->dst);
2583 else
2584 bacpy(&rpa, BDADDR_ANY);
2585
2586 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr,
2587 smp->id_addr_type, smp->irk, &rpa);
2588
2589distribute:
2590 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2591 smp_distribute_keys(smp);
2592
2593 return 0;
2594}
2595
2596static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb)
2597{
2598 struct smp_cmd_sign_info *rp = (void *) skb->data;
2599 struct l2cap_chan *chan = conn->smp;
2600 struct smp_chan *smp = chan->data;
2601 struct smp_csrk *csrk;
2602
2603 BT_DBG("conn %p", conn);
2604
2605 if (skb->len < sizeof(*rp))
2606 return SMP_INVALID_PARAMS;
2607
2608 /* Mark the information as received */
2609 smp->remote_key_dist &= ~SMP_DIST_SIGN;
2610
2611 skb_pull(skb, sizeof(*rp));
2612
2613 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
2614 if (csrk) {
2615 if (conn->hcon->sec_level > BT_SECURITY_MEDIUM)
2616 csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED;
2617 else
2618 csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED;
2619 memcpy(csrk->val, rp->csrk, sizeof(csrk->val));
2620 }
2621 smp->csrk = csrk;
2622 smp_distribute_keys(smp);
2623
2624 return 0;
2625}
2626
2627static u8 sc_select_method(struct smp_chan *smp)
2628{
2629 struct l2cap_conn *conn = smp->conn;
2630 struct hci_conn *hcon = conn->hcon;
2631 struct smp_cmd_pairing *local, *remote;
2632 u8 local_mitm, remote_mitm, local_io, remote_io, method;
2633
2634 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) ||
2635 test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags))
2636 return REQ_OOB;
2637
2638 /* The preq/prsp contain the raw Pairing Request/Response PDUs
2639 * which are needed as inputs to some crypto functions. To get
2640 * the "struct smp_cmd_pairing" from them we need to skip the
2641 * first byte which contains the opcode.
2642 */
2643 if (hcon->out) {
2644 local = (void *) &smp->preq[1];
2645 remote = (void *) &smp->prsp[1];
2646 } else {
2647 local = (void *) &smp->prsp[1];
2648 remote = (void *) &smp->preq[1];
2649 }
2650
2651 local_io = local->io_capability;
2652 remote_io = remote->io_capability;
2653
2654 local_mitm = (local->auth_req & SMP_AUTH_MITM);
2655 remote_mitm = (remote->auth_req & SMP_AUTH_MITM);
2656
2657 /* If either side wants MITM, look up the method from the table,
2658 * otherwise use JUST WORKS.
2659 */
2660 if (local_mitm || remote_mitm)
2661 method = get_auth_method(smp, local_io, remote_io);
2662 else
2663 method = JUST_WORKS;
2664
2665 /* Don't confirm locally initiated pairing attempts */
2666 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2667 method = JUST_WORKS;
2668
2669 return method;
2670}
2671
2672static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb)
2673{
2674 struct smp_cmd_public_key *key = (void *) skb->data;
2675 struct hci_conn *hcon = conn->hcon;
2676 struct l2cap_chan *chan = conn->smp;
2677 struct smp_chan *smp = chan->data;
2678 struct hci_dev *hdev = hcon->hdev;
2679 struct crypto_kpp *tfm_ecdh;
2680 struct smp_cmd_pairing_confirm cfm;
2681 int err;
2682
2683 BT_DBG("conn %p", conn);
2684
2685 if (skb->len < sizeof(*key))
2686 return SMP_INVALID_PARAMS;
2687
2688 memcpy(smp->remote_pk, key, 64);
2689
2690 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) {
2691 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk,
2692 smp->rr, 0, cfm.confirm_val);
2693 if (err)
2694 return SMP_UNSPECIFIED;
2695
2696 if (crypto_memneq(cfm.confirm_val, smp->pcnf, 16))
2697 return SMP_CONFIRM_FAILED;
2698 }
2699
2700 /* Non-initiating device sends its public key after receiving
2701 * the key from the initiating device.
2702 */
2703 if (!hcon->out) {
2704 err = sc_send_public_key(smp);
2705 if (err)
2706 return err;
2707 }
2708
2709 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk);
2710 SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32);
2711
2712 /* Compute the shared secret on the same crypto tfm on which the private
2713 * key was set/generated.
2714 */
2715 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) {
2716 struct l2cap_chan *hchan = hdev->smp_data;
2717 struct smp_dev *smp_dev;
2718
2719 if (!hchan || !hchan->data)
2720 return SMP_UNSPECIFIED;
2721
2722 smp_dev = hchan->data;
2723
2724 tfm_ecdh = smp_dev->tfm_ecdh;
2725 } else {
2726 tfm_ecdh = smp->tfm_ecdh;
2727 }
2728
2729 if (compute_ecdh_secret(tfm_ecdh, smp->remote_pk, smp->dhkey))
2730 return SMP_UNSPECIFIED;
2731
2732 SMP_DBG("DHKey %32phN", smp->dhkey);
2733
2734 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags);
2735
2736 smp->method = sc_select_method(smp);
2737
2738 BT_DBG("%s selected method 0x%02x", hdev->name, smp->method);
2739
2740 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */
2741 if (smp->method == JUST_WORKS || smp->method == JUST_CFM)
2742 hcon->pending_sec_level = BT_SECURITY_MEDIUM;
2743 else
2744 hcon->pending_sec_level = BT_SECURITY_FIPS;
2745
2746 if (!crypto_memneq(debug_pk, smp->remote_pk, 64))
2747 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
2748
2749 if (smp->method == DSP_PASSKEY) {
2750 get_random_bytes(&hcon->passkey_notify,
2751 sizeof(hcon->passkey_notify));
2752 hcon->passkey_notify %= 1000000;
2753 hcon->passkey_entered = 0;
2754 smp->passkey_round = 0;
2755 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type,
2756 hcon->dst_type,
2757 hcon->passkey_notify,
2758 hcon->passkey_entered))
2759 return SMP_UNSPECIFIED;
2760 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2761 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY);
2762 }
2763
2764 if (smp->method == REQ_OOB) {
2765 if (hcon->out)
2766 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2767 sizeof(smp->prnd), smp->prnd);
2768
2769 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2770
2771 return 0;
2772 }
2773
2774 if (hcon->out)
2775 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2776
2777 if (smp->method == REQ_PASSKEY) {
2778 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type,
2779 hcon->dst_type))
2780 return SMP_UNSPECIFIED;
2781 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2782 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2783 return 0;
2784 }
2785
2786 /* The Initiating device waits for the non-initiating device to
2787 * send the confirm value.
2788 */
2789 if (conn->hcon->out)
2790 return 0;
2791
2792 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd,
2793 0, cfm.confirm_val);
2794 if (err)
2795 return SMP_UNSPECIFIED;
2796
2797 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
2798 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2799
2800 return 0;
2801}
2802
2803static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb)
2804{
2805 struct smp_cmd_dhkey_check *check = (void *) skb->data;
2806 struct l2cap_chan *chan = conn->smp;
2807 struct hci_conn *hcon = conn->hcon;
2808 struct smp_chan *smp = chan->data;
2809 u8 a[7], b[7], *local_addr, *remote_addr;
2810 u8 io_cap[3], r[16], e[16];
2811 int err;
2812
2813 BT_DBG("conn %p", conn);
2814
2815 if (skb->len < sizeof(*check))
2816 return SMP_INVALID_PARAMS;
2817
2818 memcpy(a, &hcon->init_addr, 6);
2819 memcpy(b, &hcon->resp_addr, 6);
2820 a[6] = hcon->init_addr_type;
2821 b[6] = hcon->resp_addr_type;
2822
2823 if (hcon->out) {
2824 local_addr = a;
2825 remote_addr = b;
2826 memcpy(io_cap, &smp->prsp[1], 3);
2827 } else {
2828 local_addr = b;
2829 remote_addr = a;
2830 memcpy(io_cap, &smp->preq[1], 3);
2831 }
2832
2833 memset(r, 0, sizeof(r));
2834
2835 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2836 put_unaligned_le32(hcon->passkey_notify, r);
2837 else if (smp->method == REQ_OOB)
2838 memcpy(r, smp->lr, 16);
2839
2840 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r,
2841 io_cap, remote_addr, local_addr, e);
2842 if (err)
2843 return SMP_UNSPECIFIED;
2844
2845 if (crypto_memneq(check->e, e, 16))
2846 return SMP_DHKEY_CHECK_FAILED;
2847
2848 if (!hcon->out) {
2849 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
2850 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags);
2851 return 0;
2852 }
2853
2854 /* Slave sends DHKey check as response to master */
2855 sc_dhkey_check(smp);
2856 }
2857
2858 sc_add_ltk(smp);
2859
2860 if (hcon->out) {
2861 hci_le_start_enc(hcon, 0, 0, smp->tk, smp->enc_key_size);
2862 hcon->enc_key_size = smp->enc_key_size;
2863 }
2864
2865 return 0;
2866}
2867
2868static int smp_cmd_keypress_notify(struct l2cap_conn *conn,
2869 struct sk_buff *skb)
2870{
2871 struct smp_cmd_keypress_notify *kp = (void *) skb->data;
2872
2873 BT_DBG("value 0x%02x", kp->value);
2874
2875 return 0;
2876}
2877
2878static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb)
2879{
2880 struct l2cap_conn *conn = chan->conn;
2881 struct hci_conn *hcon = conn->hcon;
2882 struct smp_chan *smp;
2883 __u8 code, reason;
2884 int err = 0;
2885
2886 if (skb->len < 1)
2887 return -EILSEQ;
2888
2889 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) {
2890 reason = SMP_PAIRING_NOTSUPP;
2891 goto done;
2892 }
2893
2894 code = skb->data[0];
2895 skb_pull(skb, sizeof(code));
2896
2897 smp = chan->data;
2898
2899 if (code > SMP_CMD_MAX)
2900 goto drop;
2901
2902 if (smp && !test_and_clear_bit(code, &smp->allow_cmd))
2903 goto drop;
2904
2905 /* If we don't have a context the only allowed commands are
2906 * pairing request and security request.
2907 */
2908 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ)
2909 goto drop;
2910
2911 switch (code) {
2912 case SMP_CMD_PAIRING_REQ:
2913 reason = smp_cmd_pairing_req(conn, skb);
2914 break;
2915
2916 case SMP_CMD_PAIRING_FAIL:
2917 smp_failure(conn, 0);
2918 err = -EPERM;
2919 break;
2920
2921 case SMP_CMD_PAIRING_RSP:
2922 reason = smp_cmd_pairing_rsp(conn, skb);
2923 break;
2924
2925 case SMP_CMD_SECURITY_REQ:
2926 reason = smp_cmd_security_req(conn, skb);
2927 break;
2928
2929 case SMP_CMD_PAIRING_CONFIRM:
2930 reason = smp_cmd_pairing_confirm(conn, skb);
2931 break;
2932
2933 case SMP_CMD_PAIRING_RANDOM:
2934 reason = smp_cmd_pairing_random(conn, skb);
2935 break;
2936
2937 case SMP_CMD_ENCRYPT_INFO:
2938 reason = smp_cmd_encrypt_info(conn, skb);
2939 break;
2940
2941 case SMP_CMD_MASTER_IDENT:
2942 reason = smp_cmd_master_ident(conn, skb);
2943 break;
2944
2945 case SMP_CMD_IDENT_INFO:
2946 reason = smp_cmd_ident_info(conn, skb);
2947 break;
2948
2949 case SMP_CMD_IDENT_ADDR_INFO:
2950 reason = smp_cmd_ident_addr_info(conn, skb);
2951 break;
2952
2953 case SMP_CMD_SIGN_INFO:
2954 reason = smp_cmd_sign_info(conn, skb);
2955 break;
2956
2957 case SMP_CMD_PUBLIC_KEY:
2958 reason = smp_cmd_public_key(conn, skb);
2959 break;
2960
2961 case SMP_CMD_DHKEY_CHECK:
2962 reason = smp_cmd_dhkey_check(conn, skb);
2963 break;
2964
2965 case SMP_CMD_KEYPRESS_NOTIFY:
2966 reason = smp_cmd_keypress_notify(conn, skb);
2967 break;
2968
2969 default:
2970 BT_DBG("Unknown command code 0x%2.2x", code);
2971 reason = SMP_CMD_NOTSUPP;
2972 goto done;
2973 }
2974
2975done:
2976 if (!err) {
2977 if (reason)
2978 smp_failure(conn, reason);
2979 kfree_skb(skb);
2980 }
2981
2982 return err;
2983
2984drop:
2985 bt_dev_err(hcon->hdev, "unexpected SMP command 0x%02x from %pMR",
2986 code, &hcon->dst);
2987 kfree_skb(skb);
2988 return 0;
2989}
2990
2991static void smp_teardown_cb(struct l2cap_chan *chan, int err)
2992{
2993 struct l2cap_conn *conn = chan->conn;
2994
2995 BT_DBG("chan %p", chan);
2996
2997 if (chan->data)
2998 smp_chan_destroy(conn);
2999
3000 conn->smp = NULL;
3001 l2cap_chan_put(chan);
3002}
3003
3004static void bredr_pairing(struct l2cap_chan *chan)
3005{
3006 struct l2cap_conn *conn = chan->conn;
3007 struct hci_conn *hcon = conn->hcon;
3008 struct hci_dev *hdev = hcon->hdev;
3009 struct smp_cmd_pairing req;
3010 struct smp_chan *smp;
3011
3012 BT_DBG("chan %p", chan);
3013
3014 /* Only new pairings are interesting */
3015 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags))
3016 return;
3017
3018 /* Don't bother if we're not encrypted */
3019 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3020 return;
3021
3022 /* Only master may initiate SMP over BR/EDR */
3023 if (hcon->role != HCI_ROLE_MASTER)
3024 return;
3025
3026 /* Secure Connections support must be enabled */
3027 if (!hci_dev_test_flag(hdev, HCI_SC_ENABLED))
3028 return;
3029
3030 /* BR/EDR must use Secure Connections for SMP */
3031 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) &&
3032 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3033 return;
3034
3035 /* If our LE support is not enabled don't do anything */
3036 if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED))
3037 return;
3038
3039 /* Don't bother if remote LE support is not enabled */
3040 if (!lmp_host_le_capable(hcon))
3041 return;
3042
3043 /* Remote must support SMP fixed chan for BR/EDR */
3044 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR))
3045 return;
3046
3047 /* Don't bother if SMP is already ongoing */
3048 if (chan->data)
3049 return;
3050
3051 smp = smp_chan_create(conn);
3052 if (!smp) {
3053 bt_dev_err(hdev, "unable to create SMP context for BR/EDR");
3054 return;
3055 }
3056
3057 set_bit(SMP_FLAG_SC, &smp->flags);
3058
3059 BT_DBG("%s starting SMP over BR/EDR", hdev->name);
3060
3061 /* Prepare and send the BR/EDR SMP Pairing Request */
3062 build_bredr_pairing_cmd(smp, &req, NULL);
3063
3064 smp->preq[0] = SMP_CMD_PAIRING_REQ;
3065 memcpy(&smp->preq[1], &req, sizeof(req));
3066
3067 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(req), &req);
3068 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
3069}
3070
3071static void smp_resume_cb(struct l2cap_chan *chan)
3072{
3073 struct smp_chan *smp = chan->data;
3074 struct l2cap_conn *conn = chan->conn;
3075 struct hci_conn *hcon = conn->hcon;
3076
3077 BT_DBG("chan %p", chan);
3078
3079 if (hcon->type == ACL_LINK) {
3080 bredr_pairing(chan);
3081 return;
3082 }
3083
3084 if (!smp)
3085 return;
3086
3087 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3088 return;
3089
3090 cancel_delayed_work(&smp->security_timer);
3091
3092 smp_distribute_keys(smp);
3093}
3094
3095static void smp_ready_cb(struct l2cap_chan *chan)
3096{
3097 struct l2cap_conn *conn = chan->conn;
3098 struct hci_conn *hcon = conn->hcon;
3099
3100 BT_DBG("chan %p", chan);
3101
3102 /* No need to call l2cap_chan_hold() here since we already own
3103 * the reference taken in smp_new_conn_cb(). This is just the
3104 * first time that we tie it to a specific pointer. The code in
3105 * l2cap_core.c ensures that there's no risk this function wont
3106 * get called if smp_new_conn_cb was previously called.
3107 */
3108 conn->smp = chan;
3109
3110 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3111 bredr_pairing(chan);
3112}
3113
3114static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
3115{
3116 int err;
3117
3118 BT_DBG("chan %p", chan);
3119
3120 err = smp_sig_channel(chan, skb);
3121 if (err) {
3122 struct smp_chan *smp = chan->data;
3123
3124 if (smp)
3125 cancel_delayed_work_sync(&smp->security_timer);
3126
3127 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE);
3128 }
3129
3130 return err;
3131}
3132
3133static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan,
3134 unsigned long hdr_len,
3135 unsigned long len, int nb)
3136{
3137 struct sk_buff *skb;
3138
3139 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL);
3140 if (!skb)
3141 return ERR_PTR(-ENOMEM);
3142
3143 skb->priority = HCI_PRIO_MAX;
3144 bt_cb(skb)->l2cap.chan = chan;
3145
3146 return skb;
3147}
3148
3149static const struct l2cap_ops smp_chan_ops = {
3150 .name = "Security Manager",
3151 .ready = smp_ready_cb,
3152 .recv = smp_recv_cb,
3153 .alloc_skb = smp_alloc_skb_cb,
3154 .teardown = smp_teardown_cb,
3155 .resume = smp_resume_cb,
3156
3157 .new_connection = l2cap_chan_no_new_connection,
3158 .state_change = l2cap_chan_no_state_change,
3159 .close = l2cap_chan_no_close,
3160 .defer = l2cap_chan_no_defer,
3161 .suspend = l2cap_chan_no_suspend,
3162 .set_shutdown = l2cap_chan_no_set_shutdown,
3163 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
3164};
3165
3166static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan)
3167{
3168 struct l2cap_chan *chan;
3169
3170 BT_DBG("pchan %p", pchan);
3171
3172 chan = l2cap_chan_create();
3173 if (!chan)
3174 return NULL;
3175
3176 chan->chan_type = pchan->chan_type;
3177 chan->ops = &smp_chan_ops;
3178 chan->scid = pchan->scid;
3179 chan->dcid = chan->scid;
3180 chan->imtu = pchan->imtu;
3181 chan->omtu = pchan->omtu;
3182 chan->mode = pchan->mode;
3183
3184 /* Other L2CAP channels may request SMP routines in order to
3185 * change the security level. This means that the SMP channel
3186 * lock must be considered in its own category to avoid lockdep
3187 * warnings.
3188 */
3189 atomic_set(&chan->nesting, L2CAP_NESTING_SMP);
3190
3191 BT_DBG("created chan %p", chan);
3192
3193 return chan;
3194}
3195
3196static const struct l2cap_ops smp_root_chan_ops = {
3197 .name = "Security Manager Root",
3198 .new_connection = smp_new_conn_cb,
3199
3200 /* None of these are implemented for the root channel */
3201 .close = l2cap_chan_no_close,
3202 .alloc_skb = l2cap_chan_no_alloc_skb,
3203 .recv = l2cap_chan_no_recv,
3204 .state_change = l2cap_chan_no_state_change,
3205 .teardown = l2cap_chan_no_teardown,
3206 .ready = l2cap_chan_no_ready,
3207 .defer = l2cap_chan_no_defer,
3208 .suspend = l2cap_chan_no_suspend,
3209 .resume = l2cap_chan_no_resume,
3210 .set_shutdown = l2cap_chan_no_set_shutdown,
3211 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
3212};
3213
3214static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid)
3215{
3216 struct l2cap_chan *chan;
3217 struct smp_dev *smp;
3218 struct crypto_shash *tfm_cmac;
3219 struct crypto_kpp *tfm_ecdh;
3220
3221 if (cid == L2CAP_CID_SMP_BREDR) {
3222 smp = NULL;
3223 goto create_chan;
3224 }
3225
3226 smp = kzalloc(sizeof(*smp), GFP_KERNEL);
3227 if (!smp)
3228 return ERR_PTR(-ENOMEM);
3229
3230 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
3231 if (IS_ERR(tfm_cmac)) {
3232 BT_ERR("Unable to create CMAC crypto context");
3233 kzfree(smp);
3234 return ERR_CAST(tfm_cmac);
3235 }
3236
3237 tfm_ecdh = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0);
3238 if (IS_ERR(tfm_ecdh)) {
3239 BT_ERR("Unable to create ECDH crypto context");
3240 crypto_free_shash(tfm_cmac);
3241 kzfree(smp);
3242 return ERR_CAST(tfm_ecdh);
3243 }
3244
3245 smp->local_oob = false;
3246 smp->tfm_cmac = tfm_cmac;
3247 smp->tfm_ecdh = tfm_ecdh;
3248
3249create_chan:
3250 chan = l2cap_chan_create();
3251 if (!chan) {
3252 if (smp) {
3253 crypto_free_shash(smp->tfm_cmac);
3254 crypto_free_kpp(smp->tfm_ecdh);
3255 kzfree(smp);
3256 }
3257 return ERR_PTR(-ENOMEM);
3258 }
3259
3260 chan->data = smp;
3261
3262 l2cap_add_scid(chan, cid);
3263
3264 l2cap_chan_set_defaults(chan);
3265
3266 if (cid == L2CAP_CID_SMP) {
3267 u8 bdaddr_type;
3268
3269 hci_copy_identity_address(hdev, &chan->src, &bdaddr_type);
3270
3271 if (bdaddr_type == ADDR_LE_DEV_PUBLIC)
3272 chan->src_type = BDADDR_LE_PUBLIC;
3273 else
3274 chan->src_type = BDADDR_LE_RANDOM;
3275 } else {
3276 bacpy(&chan->src, &hdev->bdaddr);
3277 chan->src_type = BDADDR_BREDR;
3278 }
3279
3280 chan->state = BT_LISTEN;
3281 chan->mode = L2CAP_MODE_BASIC;
3282 chan->imtu = L2CAP_DEFAULT_MTU;
3283 chan->ops = &smp_root_chan_ops;
3284
3285 /* Set correct nesting level for a parent/listening channel */
3286 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
3287
3288 return chan;
3289}
3290
3291static void smp_del_chan(struct l2cap_chan *chan)
3292{
3293 struct smp_dev *smp;
3294
3295 BT_DBG("chan %p", chan);
3296
3297 smp = chan->data;
3298 if (smp) {
3299 chan->data = NULL;
3300 crypto_free_shash(smp->tfm_cmac);
3301 crypto_free_kpp(smp->tfm_ecdh);
3302 kzfree(smp);
3303 }
3304
3305 l2cap_chan_put(chan);
3306}
3307
3308static ssize_t force_bredr_smp_read(struct file *file,
3309 char __user *user_buf,
3310 size_t count, loff_t *ppos)
3311{
3312 struct hci_dev *hdev = file->private_data;
3313 char buf[3];
3314
3315 buf[0] = hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP) ? 'Y': 'N';
3316 buf[1] = '\n';
3317 buf[2] = '\0';
3318 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
3319}
3320
3321static ssize_t force_bredr_smp_write(struct file *file,
3322 const char __user *user_buf,
3323 size_t count, loff_t *ppos)
3324{
3325 struct hci_dev *hdev = file->private_data;
3326 bool enable;
3327 int err;
3328
3329 err = kstrtobool_from_user(user_buf, count, &enable);
3330 if (err)
3331 return err;
3332
3333 if (enable == hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3334 return -EALREADY;
3335
3336 if (enable) {
3337 struct l2cap_chan *chan;
3338
3339 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
3340 if (IS_ERR(chan))
3341 return PTR_ERR(chan);
3342
3343 hdev->smp_bredr_data = chan;
3344 } else {
3345 struct l2cap_chan *chan;
3346
3347 chan = hdev->smp_bredr_data;
3348 hdev->smp_bredr_data = NULL;
3349 smp_del_chan(chan);
3350 }
3351
3352 hci_dev_change_flag(hdev, HCI_FORCE_BREDR_SMP);
3353
3354 return count;
3355}
3356
3357static const struct file_operations force_bredr_smp_fops = {
3358 .open = simple_open,
3359 .read = force_bredr_smp_read,
3360 .write = force_bredr_smp_write,
3361 .llseek = default_llseek,
3362};
3363
3364static ssize_t le_min_key_size_read(struct file *file,
3365 char __user *user_buf,
3366 size_t count, loff_t *ppos)
3367{
3368 struct hci_dev *hdev = file->private_data;
3369 char buf[4];
3370
3371 snprintf(buf, sizeof(buf), "%2u\n", hdev->le_min_key_size);
3372
3373 return simple_read_from_buffer(user_buf, count, ppos, buf, strlen(buf));
3374}
3375
3376static ssize_t le_min_key_size_write(struct file *file,
3377 const char __user *user_buf,
3378 size_t count, loff_t *ppos)
3379{
3380 struct hci_dev *hdev = file->private_data;
3381 char buf[32];
3382 size_t buf_size = min(count, (sizeof(buf) - 1));
3383 u8 key_size;
3384
3385 if (copy_from_user(buf, user_buf, buf_size))
3386 return -EFAULT;
3387
3388 buf[buf_size] = '\0';
3389
3390 sscanf(buf, "%hhu", &key_size);
3391
3392 if (key_size > hdev->le_max_key_size ||
3393 key_size < SMP_MIN_ENC_KEY_SIZE)
3394 return -EINVAL;
3395
3396 hdev->le_min_key_size = key_size;
3397
3398 return count;
3399}
3400
3401static const struct file_operations le_min_key_size_fops = {
3402 .open = simple_open,
3403 .read = le_min_key_size_read,
3404 .write = le_min_key_size_write,
3405 .llseek = default_llseek,
3406};
3407
3408static ssize_t le_max_key_size_read(struct file *file,
3409 char __user *user_buf,
3410 size_t count, loff_t *ppos)
3411{
3412 struct hci_dev *hdev = file->private_data;
3413 char buf[4];
3414
3415 snprintf(buf, sizeof(buf), "%2u\n", hdev->le_max_key_size);
3416
3417 return simple_read_from_buffer(user_buf, count, ppos, buf, strlen(buf));
3418}
3419
3420static ssize_t le_max_key_size_write(struct file *file,
3421 const char __user *user_buf,
3422 size_t count, loff_t *ppos)
3423{
3424 struct hci_dev *hdev = file->private_data;
3425 char buf[32];
3426 size_t buf_size = min(count, (sizeof(buf) - 1));
3427 u8 key_size;
3428
3429 if (copy_from_user(buf, user_buf, buf_size))
3430 return -EFAULT;
3431
3432 buf[buf_size] = '\0';
3433
3434 sscanf(buf, "%hhu", &key_size);
3435
3436 if (key_size > SMP_MAX_ENC_KEY_SIZE ||
3437 key_size < hdev->le_min_key_size)
3438 return -EINVAL;
3439
3440 hdev->le_max_key_size = key_size;
3441
3442 return count;
3443}
3444
3445static const struct file_operations le_max_key_size_fops = {
3446 .open = simple_open,
3447 .read = le_max_key_size_read,
3448 .write = le_max_key_size_write,
3449 .llseek = default_llseek,
3450};
3451
3452int smp_register(struct hci_dev *hdev)
3453{
3454 struct l2cap_chan *chan;
3455
3456 BT_DBG("%s", hdev->name);
3457
3458 /* If the controller does not support Low Energy operation, then
3459 * there is also no need to register any SMP channel.
3460 */
3461 if (!lmp_le_capable(hdev))
3462 return 0;
3463
3464 if (WARN_ON(hdev->smp_data)) {
3465 chan = hdev->smp_data;
3466 hdev->smp_data = NULL;
3467 smp_del_chan(chan);
3468 }
3469
3470 chan = smp_add_cid(hdev, L2CAP_CID_SMP);
3471 if (IS_ERR(chan))
3472 return PTR_ERR(chan);
3473
3474 hdev->smp_data = chan;
3475
3476 debugfs_create_file("le_min_key_size", 0644, hdev->debugfs, hdev,
3477 &le_min_key_size_fops);
3478 debugfs_create_file("le_max_key_size", 0644, hdev->debugfs, hdev,
3479 &le_max_key_size_fops);
3480
3481 /* If the controller does not support BR/EDR Secure Connections
3482 * feature, then the BR/EDR SMP channel shall not be present.
3483 *
3484 * To test this with Bluetooth 4.0 controllers, create a debugfs
3485 * switch that allows forcing BR/EDR SMP support and accepting
3486 * cross-transport pairing on non-AES encrypted connections.
3487 */
3488 if (!lmp_sc_capable(hdev)) {
3489 debugfs_create_file("force_bredr_smp", 0644, hdev->debugfs,
3490 hdev, &force_bredr_smp_fops);
3491
3492 /* Flag can be already set here (due to power toggle) */
3493 if (!hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3494 return 0;
3495 }
3496
3497 if (WARN_ON(hdev->smp_bredr_data)) {
3498 chan = hdev->smp_bredr_data;
3499 hdev->smp_bredr_data = NULL;
3500 smp_del_chan(chan);
3501 }
3502
3503 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
3504 if (IS_ERR(chan)) {
3505 int err = PTR_ERR(chan);
3506 chan = hdev->smp_data;
3507 hdev->smp_data = NULL;
3508 smp_del_chan(chan);
3509 return err;
3510 }
3511
3512 hdev->smp_bredr_data = chan;
3513
3514 return 0;
3515}
3516
3517void smp_unregister(struct hci_dev *hdev)
3518{
3519 struct l2cap_chan *chan;
3520
3521 if (hdev->smp_bredr_data) {
3522 chan = hdev->smp_bredr_data;
3523 hdev->smp_bredr_data = NULL;
3524 smp_del_chan(chan);
3525 }
3526
3527 if (hdev->smp_data) {
3528 chan = hdev->smp_data;
3529 hdev->smp_data = NULL;
3530 smp_del_chan(chan);
3531 }
3532}
3533
3534#if IS_ENABLED(CONFIG_BT_SELFTEST_SMP)
3535
3536static int __init test_debug_key(struct crypto_kpp *tfm_ecdh)
3537{
3538 u8 pk[64];
3539 int err;
3540
3541 err = set_ecdh_privkey(tfm_ecdh, debug_sk);
3542 if (err)
3543 return err;
3544
3545 err = generate_ecdh_public_key(tfm_ecdh, pk);
3546 if (err)
3547 return err;
3548
3549 if (crypto_memneq(pk, debug_pk, 64))
3550 return -EINVAL;
3551
3552 return 0;
3553}
3554
3555static int __init test_ah(void)
3556{
3557 const u8 irk[16] = {
3558 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3559 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3560 const u8 r[3] = { 0x94, 0x81, 0x70 };
3561 const u8 exp[3] = { 0xaa, 0xfb, 0x0d };
3562 u8 res[3];
3563 int err;
3564
3565 err = smp_ah(irk, r, res);
3566 if (err)
3567 return err;
3568
3569 if (crypto_memneq(res, exp, 3))
3570 return -EINVAL;
3571
3572 return 0;
3573}
3574
3575static int __init test_c1(void)
3576{
3577 const u8 k[16] = {
3578 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
3579 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
3580 const u8 r[16] = {
3581 0xe0, 0x2e, 0x70, 0xc6, 0x4e, 0x27, 0x88, 0x63,
3582 0x0e, 0x6f, 0xad, 0x56, 0x21, 0xd5, 0x83, 0x57 };
3583 const u8 preq[7] = { 0x01, 0x01, 0x00, 0x00, 0x10, 0x07, 0x07 };
3584 const u8 pres[7] = { 0x02, 0x03, 0x00, 0x00, 0x08, 0x00, 0x05 };
3585 const u8 _iat = 0x01;
3586 const u8 _rat = 0x00;
3587 const bdaddr_t ra = { { 0xb6, 0xb5, 0xb4, 0xb3, 0xb2, 0xb1 } };
3588 const bdaddr_t ia = { { 0xa6, 0xa5, 0xa4, 0xa3, 0xa2, 0xa1 } };
3589 const u8 exp[16] = {
3590 0x86, 0x3b, 0xf1, 0xbe, 0xc5, 0x4d, 0xa7, 0xd2,
3591 0xea, 0x88, 0x89, 0x87, 0xef, 0x3f, 0x1e, 0x1e };
3592 u8 res[16];
3593 int err;
3594
3595 err = smp_c1(k, r, preq, pres, _iat, &ia, _rat, &ra, res);
3596 if (err)
3597 return err;
3598
3599 if (crypto_memneq(res, exp, 16))
3600 return -EINVAL;
3601
3602 return 0;
3603}
3604
3605static int __init test_s1(void)
3606{
3607 const u8 k[16] = {
3608 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
3609 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
3610 const u8 r1[16] = {
3611 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 };
3612 const u8 r2[16] = {
3613 0x00, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99 };
3614 const u8 exp[16] = {
3615 0x62, 0xa0, 0x6d, 0x79, 0xae, 0x16, 0x42, 0x5b,
3616 0x9b, 0xf4, 0xb0, 0xe8, 0xf0, 0xe1, 0x1f, 0x9a };
3617 u8 res[16];
3618 int err;
3619
3620 err = smp_s1(k, r1, r2, res);
3621 if (err)
3622 return err;
3623
3624 if (crypto_memneq(res, exp, 16))
3625 return -EINVAL;
3626
3627 return 0;
3628}
3629
3630static int __init test_f4(struct crypto_shash *tfm_cmac)
3631{
3632 const u8 u[32] = {
3633 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
3634 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
3635 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
3636 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 };
3637 const u8 v[32] = {
3638 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b,
3639 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59,
3640 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90,
3641 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 };
3642 const u8 x[16] = {
3643 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3644 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3645 const u8 z = 0x00;
3646 const u8 exp[16] = {
3647 0x2d, 0x87, 0x74, 0xa9, 0xbe, 0xa1, 0xed, 0xf1,
3648 0x1c, 0xbd, 0xa9, 0x07, 0xf1, 0x16, 0xc9, 0xf2 };
3649 u8 res[16];
3650 int err;
3651
3652 err = smp_f4(tfm_cmac, u, v, x, z, res);
3653 if (err)
3654 return err;
3655
3656 if (crypto_memneq(res, exp, 16))
3657 return -EINVAL;
3658
3659 return 0;
3660}
3661
3662static int __init test_f5(struct crypto_shash *tfm_cmac)
3663{
3664 const u8 w[32] = {
3665 0x98, 0xa6, 0xbf, 0x73, 0xf3, 0x34, 0x8d, 0x86,
3666 0xf1, 0x66, 0xf8, 0xb4, 0x13, 0x6b, 0x79, 0x99,
3667 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3668 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3669 const u8 n1[16] = {
3670 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3671 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3672 const u8 n2[16] = {
3673 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3674 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3675 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 };
3676 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 };
3677 const u8 exp_ltk[16] = {
3678 0x38, 0x0a, 0x75, 0x94, 0xb5, 0x22, 0x05, 0x98,
3679 0x23, 0xcd, 0xd7, 0x69, 0x11, 0x79, 0x86, 0x69 };
3680 const u8 exp_mackey[16] = {
3681 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd,
3682 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 };
3683 u8 mackey[16], ltk[16];
3684 int err;
3685
3686 err = smp_f5(tfm_cmac, w, n1, n2, a1, a2, mackey, ltk);
3687 if (err)
3688 return err;
3689
3690 if (crypto_memneq(mackey, exp_mackey, 16))
3691 return -EINVAL;
3692
3693 if (crypto_memneq(ltk, exp_ltk, 16))
3694 return -EINVAL;
3695
3696 return 0;
3697}
3698
3699static int __init test_f6(struct crypto_shash *tfm_cmac)
3700{
3701 const u8 w[16] = {
3702 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd,
3703 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 };
3704 const u8 n1[16] = {
3705 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3706 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3707 const u8 n2[16] = {
3708 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3709 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3710 const u8 r[16] = {
3711 0xc8, 0x0f, 0x2d, 0x0c, 0xd2, 0x42, 0xda, 0x08,
3712 0x54, 0xbb, 0x53, 0xb4, 0x3b, 0x34, 0xa3, 0x12 };
3713 const u8 io_cap[3] = { 0x02, 0x01, 0x01 };
3714 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 };
3715 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 };
3716 const u8 exp[16] = {
3717 0x61, 0x8f, 0x95, 0xda, 0x09, 0x0b, 0x6c, 0xd2,
3718 0xc5, 0xe8, 0xd0, 0x9c, 0x98, 0x73, 0xc4, 0xe3 };
3719 u8 res[16];
3720 int err;
3721
3722 err = smp_f6(tfm_cmac, w, n1, n2, r, io_cap, a1, a2, res);
3723 if (err)
3724 return err;
3725
3726 if (crypto_memneq(res, exp, 16))
3727 return -EINVAL;
3728
3729 return 0;
3730}
3731
3732static int __init test_g2(struct crypto_shash *tfm_cmac)
3733{
3734 const u8 u[32] = {
3735 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
3736 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
3737 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
3738 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 };
3739 const u8 v[32] = {
3740 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b,
3741 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59,
3742 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90,
3743 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 };
3744 const u8 x[16] = {
3745 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3746 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3747 const u8 y[16] = {
3748 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3749 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3750 const u32 exp_val = 0x2f9ed5ba % 1000000;
3751 u32 val;
3752 int err;
3753
3754 err = smp_g2(tfm_cmac, u, v, x, y, &val);
3755 if (err)
3756 return err;
3757
3758 if (val != exp_val)
3759 return -EINVAL;
3760
3761 return 0;
3762}
3763
3764static int __init test_h6(struct crypto_shash *tfm_cmac)
3765{
3766 const u8 w[16] = {
3767 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3768 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3769 const u8 key_id[4] = { 0x72, 0x62, 0x65, 0x6c };
3770 const u8 exp[16] = {
3771 0x99, 0x63, 0xb1, 0x80, 0xe2, 0xa9, 0xd3, 0xe8,
3772 0x1c, 0xc9, 0x6d, 0xe7, 0x02, 0xe1, 0x9a, 0x2d };
3773 u8 res[16];
3774 int err;
3775
3776 err = smp_h6(tfm_cmac, w, key_id, res);
3777 if (err)
3778 return err;
3779
3780 if (crypto_memneq(res, exp, 16))
3781 return -EINVAL;
3782
3783 return 0;
3784}
3785
3786static char test_smp_buffer[32];
3787
3788static ssize_t test_smp_read(struct file *file, char __user *user_buf,
3789 size_t count, loff_t *ppos)
3790{
3791 return simple_read_from_buffer(user_buf, count, ppos, test_smp_buffer,
3792 strlen(test_smp_buffer));
3793}
3794
3795static const struct file_operations test_smp_fops = {
3796 .open = simple_open,
3797 .read = test_smp_read,
3798 .llseek = default_llseek,
3799};
3800
3801static int __init run_selftests(struct crypto_shash *tfm_cmac,
3802 struct crypto_kpp *tfm_ecdh)
3803{
3804 ktime_t calltime, delta, rettime;
3805 unsigned long long duration;
3806 int err;
3807
3808 calltime = ktime_get();
3809
3810 err = test_debug_key(tfm_ecdh);
3811 if (err) {
3812 BT_ERR("debug_key test failed");
3813 goto done;
3814 }
3815
3816 err = test_ah();
3817 if (err) {
3818 BT_ERR("smp_ah test failed");
3819 goto done;
3820 }
3821
3822 err = test_c1();
3823 if (err) {
3824 BT_ERR("smp_c1 test failed");
3825 goto done;
3826 }
3827
3828 err = test_s1();
3829 if (err) {
3830 BT_ERR("smp_s1 test failed");
3831 goto done;
3832 }
3833
3834 err = test_f4(tfm_cmac);
3835 if (err) {
3836 BT_ERR("smp_f4 test failed");
3837 goto done;
3838 }
3839
3840 err = test_f5(tfm_cmac);
3841 if (err) {
3842 BT_ERR("smp_f5 test failed");
3843 goto done;
3844 }
3845
3846 err = test_f6(tfm_cmac);
3847 if (err) {
3848 BT_ERR("smp_f6 test failed");
3849 goto done;
3850 }
3851
3852 err = test_g2(tfm_cmac);
3853 if (err) {
3854 BT_ERR("smp_g2 test failed");
3855 goto done;
3856 }
3857
3858 err = test_h6(tfm_cmac);
3859 if (err) {
3860 BT_ERR("smp_h6 test failed");
3861 goto done;
3862 }
3863
3864 rettime = ktime_get();
3865 delta = ktime_sub(rettime, calltime);
3866 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
3867
3868 BT_INFO("SMP test passed in %llu usecs", duration);
3869
3870done:
3871 if (!err)
3872 snprintf(test_smp_buffer, sizeof(test_smp_buffer),
3873 "PASS (%llu usecs)\n", duration);
3874 else
3875 snprintf(test_smp_buffer, sizeof(test_smp_buffer), "FAIL\n");
3876
3877 debugfs_create_file("selftest_smp", 0444, bt_debugfs, NULL,
3878 &test_smp_fops);
3879
3880 return err;
3881}
3882
3883int __init bt_selftest_smp(void)
3884{
3885 struct crypto_shash *tfm_cmac;
3886 struct crypto_kpp *tfm_ecdh;
3887 int err;
3888
3889 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
3890 if (IS_ERR(tfm_cmac)) {
3891 BT_ERR("Unable to create CMAC crypto context");
3892 return PTR_ERR(tfm_cmac);
3893 }
3894
3895 tfm_ecdh = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0);
3896 if (IS_ERR(tfm_ecdh)) {
3897 BT_ERR("Unable to create ECDH crypto context");
3898 crypto_free_shash(tfm_cmac);
3899 return PTR_ERR(tfm_ecdh);
3900 }
3901
3902 err = run_selftests(tfm_cmac, tfm_ecdh);
3903
3904 crypto_free_shash(tfm_cmac);
3905 crypto_free_kpp(tfm_ecdh);
3906
3907 return err;
3908}
3909
3910#endif
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 <net/bluetooth/bluetooth.h>
24#include <net/bluetooth/hci_core.h>
25#include <net/bluetooth/l2cap.h>
26#include <net/bluetooth/smp.h>
27#include <linux/crypto.h>
28#include <linux/scatterlist.h>
29#include <crypto/b128ops.h>
30
31#define SMP_TIMEOUT 30000 /* 30 seconds */
32
33static inline void swap128(u8 src[16], u8 dst[16])
34{
35 int i;
36 for (i = 0; i < 16; i++)
37 dst[15 - i] = src[i];
38}
39
40static inline void swap56(u8 src[7], u8 dst[7])
41{
42 int i;
43 for (i = 0; i < 7; i++)
44 dst[6 - i] = src[i];
45}
46
47static int smp_e(struct crypto_blkcipher *tfm, const u8 *k, u8 *r)
48{
49 struct blkcipher_desc desc;
50 struct scatterlist sg;
51 int err, iv_len;
52 unsigned char iv[128];
53
54 if (tfm == NULL) {
55 BT_ERR("tfm %p", tfm);
56 return -EINVAL;
57 }
58
59 desc.tfm = tfm;
60 desc.flags = 0;
61
62 err = crypto_blkcipher_setkey(tfm, k, 16);
63 if (err) {
64 BT_ERR("cipher setkey failed: %d", err);
65 return err;
66 }
67
68 sg_init_one(&sg, r, 16);
69
70 iv_len = crypto_blkcipher_ivsize(tfm);
71 if (iv_len) {
72 memset(&iv, 0xff, iv_len);
73 crypto_blkcipher_set_iv(tfm, iv, iv_len);
74 }
75
76 err = crypto_blkcipher_encrypt(&desc, &sg, &sg, 16);
77 if (err)
78 BT_ERR("Encrypt data error %d", err);
79
80 return err;
81}
82
83static int smp_c1(struct crypto_blkcipher *tfm, u8 k[16], u8 r[16],
84 u8 preq[7], u8 pres[7], u8 _iat, bdaddr_t *ia,
85 u8 _rat, bdaddr_t *ra, u8 res[16])
86{
87 u8 p1[16], p2[16];
88 int err;
89
90 memset(p1, 0, 16);
91
92 /* p1 = pres || preq || _rat || _iat */
93 swap56(pres, p1);
94 swap56(preq, p1 + 7);
95 p1[14] = _rat;
96 p1[15] = _iat;
97
98 memset(p2, 0, 16);
99
100 /* p2 = padding || ia || ra */
101 baswap((bdaddr_t *) (p2 + 4), ia);
102 baswap((bdaddr_t *) (p2 + 10), ra);
103
104 /* res = r XOR p1 */
105 u128_xor((u128 *) res, (u128 *) r, (u128 *) p1);
106
107 /* res = e(k, res) */
108 err = smp_e(tfm, k, res);
109 if (err) {
110 BT_ERR("Encrypt data error");
111 return err;
112 }
113
114 /* res = res XOR p2 */
115 u128_xor((u128 *) res, (u128 *) res, (u128 *) p2);
116
117 /* res = e(k, res) */
118 err = smp_e(tfm, k, res);
119 if (err)
120 BT_ERR("Encrypt data error");
121
122 return err;
123}
124
125static int smp_s1(struct crypto_blkcipher *tfm, u8 k[16],
126 u8 r1[16], u8 r2[16], u8 _r[16])
127{
128 int err;
129
130 /* Just least significant octets from r1 and r2 are considered */
131 memcpy(_r, r1 + 8, 8);
132 memcpy(_r + 8, r2 + 8, 8);
133
134 err = smp_e(tfm, k, _r);
135 if (err)
136 BT_ERR("Encrypt data error");
137
138 return err;
139}
140
141static int smp_rand(u8 *buf)
142{
143 get_random_bytes(buf, 16);
144
145 return 0;
146}
147
148static struct sk_buff *smp_build_cmd(struct l2cap_conn *conn, u8 code,
149 u16 dlen, void *data)
150{
151 struct sk_buff *skb;
152 struct l2cap_hdr *lh;
153 int len;
154
155 len = L2CAP_HDR_SIZE + sizeof(code) + dlen;
156
157 if (len > conn->mtu)
158 return NULL;
159
160 skb = bt_skb_alloc(len, GFP_ATOMIC);
161 if (!skb)
162 return NULL;
163
164 lh = (struct l2cap_hdr *) skb_put(skb, L2CAP_HDR_SIZE);
165 lh->len = cpu_to_le16(sizeof(code) + dlen);
166 lh->cid = cpu_to_le16(L2CAP_CID_SMP);
167
168 memcpy(skb_put(skb, sizeof(code)), &code, sizeof(code));
169
170 memcpy(skb_put(skb, dlen), data, dlen);
171
172 return skb;
173}
174
175static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
176{
177 struct sk_buff *skb = smp_build_cmd(conn, code, len, data);
178
179 BT_DBG("code 0x%2.2x", code);
180
181 if (!skb)
182 return;
183
184 hci_send_acl(conn->hcon, skb, 0);
185}
186
187static __u8 seclevel_to_authreq(__u8 level)
188{
189 switch (level) {
190 case BT_SECURITY_HIGH:
191 /* Right now we don't support bonding */
192 return SMP_AUTH_MITM;
193
194 default:
195 return SMP_AUTH_NONE;
196 }
197}
198
199static void build_pairing_cmd(struct l2cap_conn *conn,
200 struct smp_cmd_pairing *req,
201 struct smp_cmd_pairing *rsp,
202 __u8 authreq)
203{
204 u8 dist_keys;
205
206 dist_keys = 0;
207 if (test_bit(HCI_PAIRABLE, &conn->hcon->hdev->flags)) {
208 dist_keys = SMP_DIST_ENC_KEY | SMP_DIST_ID_KEY | SMP_DIST_SIGN;
209 authreq |= SMP_AUTH_BONDING;
210 }
211
212 if (rsp == NULL) {
213 req->io_capability = conn->hcon->io_capability;
214 req->oob_flag = SMP_OOB_NOT_PRESENT;
215 req->max_key_size = SMP_MAX_ENC_KEY_SIZE;
216 req->init_key_dist = dist_keys;
217 req->resp_key_dist = dist_keys;
218 req->auth_req = authreq;
219 return;
220 }
221
222 rsp->io_capability = conn->hcon->io_capability;
223 rsp->oob_flag = SMP_OOB_NOT_PRESENT;
224 rsp->max_key_size = SMP_MAX_ENC_KEY_SIZE;
225 rsp->init_key_dist = req->init_key_dist & dist_keys;
226 rsp->resp_key_dist = req->resp_key_dist & dist_keys;
227 rsp->auth_req = authreq;
228}
229
230static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)
231{
232 if ((max_key_size > SMP_MAX_ENC_KEY_SIZE) ||
233 (max_key_size < SMP_MIN_ENC_KEY_SIZE))
234 return SMP_ENC_KEY_SIZE;
235
236 conn->smp_key_size = max_key_size;
237
238 return 0;
239}
240
241static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
242{
243 struct smp_cmd_pairing rsp, *req = (void *) skb->data;
244 u8 key_size;
245
246 BT_DBG("conn %p", conn);
247
248 conn->preq[0] = SMP_CMD_PAIRING_REQ;
249 memcpy(&conn->preq[1], req, sizeof(*req));
250 skb_pull(skb, sizeof(*req));
251
252 if (req->oob_flag)
253 return SMP_OOB_NOT_AVAIL;
254
255 /* We didn't start the pairing, so no requirements */
256 build_pairing_cmd(conn, req, &rsp, SMP_AUTH_NONE);
257
258 key_size = min(req->max_key_size, rsp.max_key_size);
259 if (check_enc_key_size(conn, key_size))
260 return SMP_ENC_KEY_SIZE;
261
262 /* Just works */
263 memset(conn->tk, 0, sizeof(conn->tk));
264
265 conn->prsp[0] = SMP_CMD_PAIRING_RSP;
266 memcpy(&conn->prsp[1], &rsp, sizeof(rsp));
267
268 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
269
270 mod_timer(&conn->security_timer, jiffies +
271 msecs_to_jiffies(SMP_TIMEOUT));
272
273 return 0;
274}
275
276static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
277{
278 struct smp_cmd_pairing *req, *rsp = (void *) skb->data;
279 struct smp_cmd_pairing_confirm cp;
280 struct crypto_blkcipher *tfm = conn->hcon->hdev->tfm;
281 int ret;
282 u8 res[16], key_size;
283
284 BT_DBG("conn %p", conn);
285
286 skb_pull(skb, sizeof(*rsp));
287
288 req = (void *) &conn->preq[1];
289
290 key_size = min(req->max_key_size, rsp->max_key_size);
291 if (check_enc_key_size(conn, key_size))
292 return SMP_ENC_KEY_SIZE;
293
294 if (rsp->oob_flag)
295 return SMP_OOB_NOT_AVAIL;
296
297 /* Just works */
298 memset(conn->tk, 0, sizeof(conn->tk));
299
300 conn->prsp[0] = SMP_CMD_PAIRING_RSP;
301 memcpy(&conn->prsp[1], rsp, sizeof(*rsp));
302
303 ret = smp_rand(conn->prnd);
304 if (ret)
305 return SMP_UNSPECIFIED;
306
307 ret = smp_c1(tfm, conn->tk, conn->prnd, conn->preq, conn->prsp, 0,
308 conn->src, conn->hcon->dst_type, conn->dst, res);
309 if (ret)
310 return SMP_UNSPECIFIED;
311
312 swap128(res, cp.confirm_val);
313
314 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
315
316 return 0;
317}
318
319static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
320{
321 struct crypto_blkcipher *tfm = conn->hcon->hdev->tfm;
322
323 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
324
325 memcpy(conn->pcnf, skb->data, sizeof(conn->pcnf));
326 skb_pull(skb, sizeof(conn->pcnf));
327
328 if (conn->hcon->out) {
329 u8 random[16];
330
331 swap128(conn->prnd, random);
332 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(random),
333 random);
334 } else {
335 struct smp_cmd_pairing_confirm cp;
336 int ret;
337 u8 res[16];
338
339 ret = smp_rand(conn->prnd);
340 if (ret)
341 return SMP_UNSPECIFIED;
342
343 ret = smp_c1(tfm, conn->tk, conn->prnd, conn->preq, conn->prsp,
344 conn->hcon->dst_type, conn->dst,
345 0, conn->src, res);
346 if (ret)
347 return SMP_CONFIRM_FAILED;
348
349 swap128(res, cp.confirm_val);
350
351 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
352 }
353
354 mod_timer(&conn->security_timer, jiffies +
355 msecs_to_jiffies(SMP_TIMEOUT));
356
357 return 0;
358}
359
360static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
361{
362 struct hci_conn *hcon = conn->hcon;
363 struct crypto_blkcipher *tfm = hcon->hdev->tfm;
364 int ret;
365 u8 key[16], res[16], random[16], confirm[16];
366
367 swap128(skb->data, random);
368 skb_pull(skb, sizeof(random));
369
370 if (conn->hcon->out)
371 ret = smp_c1(tfm, conn->tk, random, conn->preq, conn->prsp, 0,
372 conn->src, conn->hcon->dst_type, conn->dst,
373 res);
374 else
375 ret = smp_c1(tfm, conn->tk, random, conn->preq, conn->prsp,
376 conn->hcon->dst_type, conn->dst, 0, conn->src,
377 res);
378 if (ret)
379 return SMP_UNSPECIFIED;
380
381 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
382
383 swap128(res, confirm);
384
385 if (memcmp(conn->pcnf, confirm, sizeof(conn->pcnf)) != 0) {
386 BT_ERR("Pairing failed (confirmation values mismatch)");
387 return SMP_CONFIRM_FAILED;
388 }
389
390 if (conn->hcon->out) {
391 u8 stk[16], rand[8];
392 __le16 ediv;
393
394 memset(rand, 0, sizeof(rand));
395 ediv = 0;
396
397 smp_s1(tfm, conn->tk, random, conn->prnd, key);
398 swap128(key, stk);
399
400 memset(stk + conn->smp_key_size, 0,
401 SMP_MAX_ENC_KEY_SIZE - conn->smp_key_size);
402
403 hci_le_start_enc(hcon, ediv, rand, stk);
404 hcon->enc_key_size = conn->smp_key_size;
405 } else {
406 u8 stk[16], r[16], rand[8];
407 __le16 ediv;
408
409 memset(rand, 0, sizeof(rand));
410 ediv = 0;
411
412 swap128(conn->prnd, r);
413 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(r), r);
414
415 smp_s1(tfm, conn->tk, conn->prnd, random, key);
416 swap128(key, stk);
417
418 memset(stk + conn->smp_key_size, 0,
419 SMP_MAX_ENC_KEY_SIZE - conn->smp_key_size);
420
421 hci_add_ltk(conn->hcon->hdev, 0, conn->dst, conn->smp_key_size,
422 ediv, rand, stk);
423 }
424
425 return 0;
426}
427
428static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
429{
430 struct smp_cmd_security_req *rp = (void *) skb->data;
431 struct smp_cmd_pairing cp;
432 struct hci_conn *hcon = conn->hcon;
433
434 BT_DBG("conn %p", conn);
435
436 if (test_bit(HCI_CONN_ENCRYPT_PEND, &hcon->pend))
437 return 0;
438
439 skb_pull(skb, sizeof(*rp));
440
441 memset(&cp, 0, sizeof(cp));
442 build_pairing_cmd(conn, &cp, NULL, rp->auth_req);
443
444 conn->preq[0] = SMP_CMD_PAIRING_REQ;
445 memcpy(&conn->preq[1], &cp, sizeof(cp));
446
447 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
448
449 mod_timer(&conn->security_timer, jiffies +
450 msecs_to_jiffies(SMP_TIMEOUT));
451
452 set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->pend);
453
454 return 0;
455}
456
457int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level)
458{
459 struct hci_conn *hcon = conn->hcon;
460 __u8 authreq;
461
462 BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level);
463
464 if (!lmp_host_le_capable(hcon->hdev))
465 return 1;
466
467 if (IS_ERR(hcon->hdev->tfm))
468 return 1;
469
470 if (test_bit(HCI_CONN_ENCRYPT_PEND, &hcon->pend))
471 return 0;
472
473 if (sec_level == BT_SECURITY_LOW)
474 return 1;
475
476 if (hcon->sec_level >= sec_level)
477 return 1;
478
479 authreq = seclevel_to_authreq(sec_level);
480
481 if (hcon->link_mode & HCI_LM_MASTER) {
482 struct smp_cmd_pairing cp;
483 struct link_key *key;
484
485 key = hci_find_link_key_type(hcon->hdev, conn->dst,
486 HCI_LK_SMP_LTK);
487 if (key) {
488 struct key_master_id *master = (void *) key->data;
489
490 hci_le_start_enc(hcon, master->ediv, master->rand,
491 key->val);
492 hcon->enc_key_size = key->pin_len;
493
494 goto done;
495 }
496
497 build_pairing_cmd(conn, &cp, NULL, authreq);
498 conn->preq[0] = SMP_CMD_PAIRING_REQ;
499 memcpy(&conn->preq[1], &cp, sizeof(cp));
500
501 mod_timer(&conn->security_timer, jiffies +
502 msecs_to_jiffies(SMP_TIMEOUT));
503
504 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
505 } else {
506 struct smp_cmd_security_req cp;
507 cp.auth_req = authreq;
508 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp);
509 }
510
511done:
512 hcon->pending_sec_level = sec_level;
513 set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->pend);
514
515 return 0;
516}
517
518static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb)
519{
520 struct smp_cmd_encrypt_info *rp = (void *) skb->data;
521
522 skb_pull(skb, sizeof(*rp));
523
524 memcpy(conn->tk, rp->ltk, sizeof(conn->tk));
525
526 return 0;
527}
528
529static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb)
530{
531 struct smp_cmd_master_ident *rp = (void *) skb->data;
532
533 skb_pull(skb, sizeof(*rp));
534
535 hci_add_ltk(conn->hcon->hdev, 1, conn->src, conn->smp_key_size,
536 rp->ediv, rp->rand, conn->tk);
537
538 smp_distribute_keys(conn, 1);
539
540 return 0;
541}
542
543int smp_sig_channel(struct l2cap_conn *conn, struct sk_buff *skb)
544{
545 __u8 code = skb->data[0];
546 __u8 reason;
547 int err = 0;
548
549 if (!lmp_host_le_capable(conn->hcon->hdev)) {
550 err = -ENOTSUPP;
551 reason = SMP_PAIRING_NOTSUPP;
552 goto done;
553 }
554
555 if (IS_ERR(conn->hcon->hdev->tfm)) {
556 err = PTR_ERR(conn->hcon->hdev->tfm);
557 reason = SMP_PAIRING_NOTSUPP;
558 goto done;
559 }
560
561 skb_pull(skb, sizeof(code));
562
563 switch (code) {
564 case SMP_CMD_PAIRING_REQ:
565 reason = smp_cmd_pairing_req(conn, skb);
566 break;
567
568 case SMP_CMD_PAIRING_FAIL:
569 reason = 0;
570 err = -EPERM;
571 break;
572
573 case SMP_CMD_PAIRING_RSP:
574 reason = smp_cmd_pairing_rsp(conn, skb);
575 break;
576
577 case SMP_CMD_SECURITY_REQ:
578 reason = smp_cmd_security_req(conn, skb);
579 break;
580
581 case SMP_CMD_PAIRING_CONFIRM:
582 reason = smp_cmd_pairing_confirm(conn, skb);
583 break;
584
585 case SMP_CMD_PAIRING_RANDOM:
586 reason = smp_cmd_pairing_random(conn, skb);
587 break;
588
589 case SMP_CMD_ENCRYPT_INFO:
590 reason = smp_cmd_encrypt_info(conn, skb);
591 break;
592
593 case SMP_CMD_MASTER_IDENT:
594 reason = smp_cmd_master_ident(conn, skb);
595 break;
596
597 case SMP_CMD_IDENT_INFO:
598 case SMP_CMD_IDENT_ADDR_INFO:
599 case SMP_CMD_SIGN_INFO:
600 /* Just ignored */
601 reason = 0;
602 break;
603
604 default:
605 BT_DBG("Unknown command code 0x%2.2x", code);
606
607 reason = SMP_CMD_NOTSUPP;
608 err = -EOPNOTSUPP;
609 goto done;
610 }
611
612done:
613 if (reason)
614 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
615 &reason);
616
617 kfree_skb(skb);
618 return err;
619}
620
621int smp_distribute_keys(struct l2cap_conn *conn, __u8 force)
622{
623 struct smp_cmd_pairing *req, *rsp;
624 __u8 *keydist;
625
626 BT_DBG("conn %p force %d", conn, force);
627
628 if (IS_ERR(conn->hcon->hdev->tfm))
629 return PTR_ERR(conn->hcon->hdev->tfm);
630
631 rsp = (void *) &conn->prsp[1];
632
633 /* The responder sends its keys first */
634 if (!force && conn->hcon->out && (rsp->resp_key_dist & 0x07))
635 return 0;
636
637 req = (void *) &conn->preq[1];
638
639 if (conn->hcon->out) {
640 keydist = &rsp->init_key_dist;
641 *keydist &= req->init_key_dist;
642 } else {
643 keydist = &rsp->resp_key_dist;
644 *keydist &= req->resp_key_dist;
645 }
646
647
648 BT_DBG("keydist 0x%x", *keydist);
649
650 if (*keydist & SMP_DIST_ENC_KEY) {
651 struct smp_cmd_encrypt_info enc;
652 struct smp_cmd_master_ident ident;
653 __le16 ediv;
654
655 get_random_bytes(enc.ltk, sizeof(enc.ltk));
656 get_random_bytes(&ediv, sizeof(ediv));
657 get_random_bytes(ident.rand, sizeof(ident.rand));
658
659 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc);
660
661 hci_add_ltk(conn->hcon->hdev, 1, conn->dst, conn->smp_key_size,
662 ediv, ident.rand, enc.ltk);
663
664 ident.ediv = cpu_to_le16(ediv);
665
666 smp_send_cmd(conn, SMP_CMD_MASTER_IDENT, sizeof(ident), &ident);
667
668 *keydist &= ~SMP_DIST_ENC_KEY;
669 }
670
671 if (*keydist & SMP_DIST_ID_KEY) {
672 struct smp_cmd_ident_addr_info addrinfo;
673 struct smp_cmd_ident_info idinfo;
674
675 /* Send a dummy key */
676 get_random_bytes(idinfo.irk, sizeof(idinfo.irk));
677
678 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo);
679
680 /* Just public address */
681 memset(&addrinfo, 0, sizeof(addrinfo));
682 bacpy(&addrinfo.bdaddr, conn->src);
683
684 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo),
685 &addrinfo);
686
687 *keydist &= ~SMP_DIST_ID_KEY;
688 }
689
690 if (*keydist & SMP_DIST_SIGN) {
691 struct smp_cmd_sign_info sign;
692
693 /* Send a dummy key */
694 get_random_bytes(sign.csrk, sizeof(sign.csrk));
695
696 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign);
697
698 *keydist &= ~SMP_DIST_SIGN;
699 }
700
701 return 0;
702}