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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 <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 int err;
174
175 if (len > CMAC_MSG_MAX)
176 return -EFBIG;
177
178 if (!tfm) {
179 BT_ERR("tfm %p", tfm);
180 return -EINVAL;
181 }
182
183 /* Swap key and message from LSB to MSB */
184 swap_buf(k, tmp, 16);
185 swap_buf(m, msg_msb, len);
186
187 SMP_DBG("msg (len %zu) %*phN", len, (int) len, m);
188 SMP_DBG("key %16phN", k);
189
190 err = crypto_shash_setkey(tfm, tmp, 16);
191 if (err) {
192 BT_ERR("cipher setkey failed: %d", err);
193 return err;
194 }
195
196 err = crypto_shash_tfm_digest(tfm, msg_msb, len, mac_msb);
197 if (err) {
198 BT_ERR("Hash computation error %d", err);
199 return err;
200 }
201
202 swap_buf(mac_msb, mac, 16);
203
204 SMP_DBG("mac %16phN", mac);
205
206 return 0;
207}
208
209static int smp_f4(struct crypto_shash *tfm_cmac, const u8 u[32],
210 const u8 v[32], const u8 x[16], u8 z, u8 res[16])
211{
212 u8 m[65];
213 int err;
214
215 SMP_DBG("u %32phN", u);
216 SMP_DBG("v %32phN", v);
217 SMP_DBG("x %16phN z %02x", x, z);
218
219 m[0] = z;
220 memcpy(m + 1, v, 32);
221 memcpy(m + 33, u, 32);
222
223 err = aes_cmac(tfm_cmac, x, m, sizeof(m), res);
224 if (err)
225 return err;
226
227 SMP_DBG("res %16phN", res);
228
229 return err;
230}
231
232static int smp_f5(struct crypto_shash *tfm_cmac, const u8 w[32],
233 const u8 n1[16], const u8 n2[16], const u8 a1[7],
234 const u8 a2[7], u8 mackey[16], u8 ltk[16])
235{
236 /* The btle, salt and length "magic" values are as defined in
237 * the SMP section of the Bluetooth core specification. In ASCII
238 * the btle value ends up being 'btle'. The salt is just a
239 * random number whereas length is the value 256 in little
240 * endian format.
241 */
242 const u8 btle[4] = { 0x65, 0x6c, 0x74, 0x62 };
243 const u8 salt[16] = { 0xbe, 0x83, 0x60, 0x5a, 0xdb, 0x0b, 0x37, 0x60,
244 0x38, 0xa5, 0xf5, 0xaa, 0x91, 0x83, 0x88, 0x6c };
245 const u8 length[2] = { 0x00, 0x01 };
246 u8 m[53], t[16];
247 int err;
248
249 SMP_DBG("w %32phN", w);
250 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
251 SMP_DBG("a1 %7phN a2 %7phN", a1, a2);
252
253 err = aes_cmac(tfm_cmac, salt, w, 32, t);
254 if (err)
255 return err;
256
257 SMP_DBG("t %16phN", t);
258
259 memcpy(m, length, 2);
260 memcpy(m + 2, a2, 7);
261 memcpy(m + 9, a1, 7);
262 memcpy(m + 16, n2, 16);
263 memcpy(m + 32, n1, 16);
264 memcpy(m + 48, btle, 4);
265
266 m[52] = 0; /* Counter */
267
268 err = aes_cmac(tfm_cmac, t, m, sizeof(m), mackey);
269 if (err)
270 return err;
271
272 SMP_DBG("mackey %16phN", mackey);
273
274 m[52] = 1; /* Counter */
275
276 err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk);
277 if (err)
278 return err;
279
280 SMP_DBG("ltk %16phN", ltk);
281
282 return 0;
283}
284
285static int smp_f6(struct crypto_shash *tfm_cmac, const u8 w[16],
286 const u8 n1[16], const u8 n2[16], const u8 r[16],
287 const u8 io_cap[3], const u8 a1[7], const u8 a2[7],
288 u8 res[16])
289{
290 u8 m[65];
291 int err;
292
293 SMP_DBG("w %16phN", w);
294 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
295 SMP_DBG("r %16phN io_cap %3phN a1 %7phN a2 %7phN", r, io_cap, a1, a2);
296
297 memcpy(m, a2, 7);
298 memcpy(m + 7, a1, 7);
299 memcpy(m + 14, io_cap, 3);
300 memcpy(m + 17, r, 16);
301 memcpy(m + 33, n2, 16);
302 memcpy(m + 49, n1, 16);
303
304 err = aes_cmac(tfm_cmac, w, m, sizeof(m), res);
305 if (err)
306 return err;
307
308 SMP_DBG("res %16phN", res);
309
310 return err;
311}
312
313static int smp_g2(struct crypto_shash *tfm_cmac, const u8 u[32], const u8 v[32],
314 const u8 x[16], const u8 y[16], u32 *val)
315{
316 u8 m[80], tmp[16];
317 int err;
318
319 SMP_DBG("u %32phN", u);
320 SMP_DBG("v %32phN", v);
321 SMP_DBG("x %16phN y %16phN", x, y);
322
323 memcpy(m, y, 16);
324 memcpy(m + 16, v, 32);
325 memcpy(m + 48, u, 32);
326
327 err = aes_cmac(tfm_cmac, x, m, sizeof(m), tmp);
328 if (err)
329 return err;
330
331 *val = get_unaligned_le32(tmp);
332 *val %= 1000000;
333
334 SMP_DBG("val %06u", *val);
335
336 return 0;
337}
338
339static int smp_h6(struct crypto_shash *tfm_cmac, const u8 w[16],
340 const u8 key_id[4], u8 res[16])
341{
342 int err;
343
344 SMP_DBG("w %16phN key_id %4phN", w, key_id);
345
346 err = aes_cmac(tfm_cmac, w, key_id, 4, res);
347 if (err)
348 return err;
349
350 SMP_DBG("res %16phN", res);
351
352 return err;
353}
354
355static int smp_h7(struct crypto_shash *tfm_cmac, const u8 w[16],
356 const u8 salt[16], u8 res[16])
357{
358 int err;
359
360 SMP_DBG("w %16phN salt %16phN", w, salt);
361
362 err = aes_cmac(tfm_cmac, salt, w, 16, res);
363 if (err)
364 return err;
365
366 SMP_DBG("res %16phN", res);
367
368 return err;
369}
370
371/* The following functions map to the legacy SMP crypto functions e, c1,
372 * s1 and ah.
373 */
374
375static int smp_e(const u8 *k, u8 *r)
376{
377 struct crypto_aes_ctx ctx;
378 uint8_t tmp[16], data[16];
379 int err;
380
381 SMP_DBG("k %16phN r %16phN", k, r);
382
383 /* The most significant octet of key corresponds to k[0] */
384 swap_buf(k, tmp, 16);
385
386 err = aes_expandkey(&ctx, tmp, 16);
387 if (err) {
388 BT_ERR("cipher setkey failed: %d", err);
389 return err;
390 }
391
392 /* Most significant octet of plaintextData corresponds to data[0] */
393 swap_buf(r, data, 16);
394
395 aes_encrypt(&ctx, data, data);
396
397 /* Most significant octet of encryptedData corresponds to data[0] */
398 swap_buf(data, r, 16);
399
400 SMP_DBG("r %16phN", r);
401
402 memzero_explicit(&ctx, sizeof (ctx));
403 return err;
404}
405
406static int smp_c1(const u8 k[16],
407 const u8 r[16], const u8 preq[7], const u8 pres[7], u8 _iat,
408 const bdaddr_t *ia, u8 _rat, const bdaddr_t *ra, u8 res[16])
409{
410 u8 p1[16], p2[16];
411 int err;
412
413 SMP_DBG("k %16phN r %16phN", k, r);
414 SMP_DBG("iat %u ia %6phN rat %u ra %6phN", _iat, ia, _rat, ra);
415 SMP_DBG("preq %7phN pres %7phN", preq, pres);
416
417 memset(p1, 0, 16);
418
419 /* p1 = pres || preq || _rat || _iat */
420 p1[0] = _iat;
421 p1[1] = _rat;
422 memcpy(p1 + 2, preq, 7);
423 memcpy(p1 + 9, pres, 7);
424
425 SMP_DBG("p1 %16phN", p1);
426
427 /* res = r XOR p1 */
428 u128_xor((u128 *) res, (u128 *) r, (u128 *) p1);
429
430 /* res = e(k, res) */
431 err = smp_e(k, res);
432 if (err) {
433 BT_ERR("Encrypt data error");
434 return err;
435 }
436
437 /* p2 = padding || ia || ra */
438 memcpy(p2, ra, 6);
439 memcpy(p2 + 6, ia, 6);
440 memset(p2 + 12, 0, 4);
441
442 SMP_DBG("p2 %16phN", p2);
443
444 /* res = res XOR p2 */
445 u128_xor((u128 *) res, (u128 *) res, (u128 *) p2);
446
447 /* res = e(k, res) */
448 err = smp_e(k, res);
449 if (err)
450 BT_ERR("Encrypt data error");
451
452 return err;
453}
454
455static int smp_s1(const u8 k[16],
456 const u8 r1[16], const u8 r2[16], u8 _r[16])
457{
458 int err;
459
460 /* Just least significant octets from r1 and r2 are considered */
461 memcpy(_r, r2, 8);
462 memcpy(_r + 8, r1, 8);
463
464 err = smp_e(k, _r);
465 if (err)
466 BT_ERR("Encrypt data error");
467
468 return err;
469}
470
471static int smp_ah(const u8 irk[16], const u8 r[3], u8 res[3])
472{
473 u8 _res[16];
474 int err;
475
476 /* r' = padding || r */
477 memcpy(_res, r, 3);
478 memset(_res + 3, 0, 13);
479
480 err = smp_e(irk, _res);
481 if (err) {
482 BT_ERR("Encrypt error");
483 return err;
484 }
485
486 /* The output of the random address function ah is:
487 * ah(k, r) = e(k, r') mod 2^24
488 * The output of the security function e is then truncated to 24 bits
489 * by taking the least significant 24 bits of the output of e as the
490 * result of ah.
491 */
492 memcpy(res, _res, 3);
493
494 return 0;
495}
496
497bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16],
498 const bdaddr_t *bdaddr)
499{
500 struct l2cap_chan *chan = hdev->smp_data;
501 u8 hash[3];
502 int err;
503
504 if (!chan || !chan->data)
505 return false;
506
507 bt_dev_dbg(hdev, "RPA %pMR IRK %*phN", bdaddr, 16, irk);
508
509 err = smp_ah(irk, &bdaddr->b[3], hash);
510 if (err)
511 return false;
512
513 return !crypto_memneq(bdaddr->b, hash, 3);
514}
515
516int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa)
517{
518 struct l2cap_chan *chan = hdev->smp_data;
519 int err;
520
521 if (!chan || !chan->data)
522 return -EOPNOTSUPP;
523
524 get_random_bytes(&rpa->b[3], 3);
525
526 rpa->b[5] &= 0x3f; /* Clear two most significant bits */
527 rpa->b[5] |= 0x40; /* Set second most significant bit */
528
529 err = smp_ah(irk, &rpa->b[3], rpa->b);
530 if (err < 0)
531 return err;
532
533 bt_dev_dbg(hdev, "RPA %pMR", rpa);
534
535 return 0;
536}
537
538int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16])
539{
540 struct l2cap_chan *chan = hdev->smp_data;
541 struct smp_dev *smp;
542 int err;
543
544 if (!chan || !chan->data)
545 return -EOPNOTSUPP;
546
547 smp = chan->data;
548
549 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) {
550 bt_dev_dbg(hdev, "Using debug keys");
551 err = set_ecdh_privkey(smp->tfm_ecdh, debug_sk);
552 if (err)
553 return err;
554 memcpy(smp->local_pk, debug_pk, 64);
555 smp->debug_key = true;
556 } else {
557 while (true) {
558 /* Generate key pair for Secure Connections */
559 err = generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk);
560 if (err)
561 return err;
562
563 /* This is unlikely, but we need to check that
564 * we didn't accidentially generate a debug key.
565 */
566 if (crypto_memneq(smp->local_pk, debug_pk, 64))
567 break;
568 }
569 smp->debug_key = false;
570 }
571
572 SMP_DBG("OOB Public Key X: %32phN", smp->local_pk);
573 SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32);
574
575 get_random_bytes(smp->local_rand, 16);
576
577 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->local_pk,
578 smp->local_rand, 0, hash);
579 if (err < 0)
580 return err;
581
582 memcpy(rand, smp->local_rand, 16);
583
584 smp->local_oob = true;
585
586 return 0;
587}
588
589static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
590{
591 struct l2cap_chan *chan = conn->smp;
592 struct smp_chan *smp;
593 struct kvec iv[2];
594 struct msghdr msg;
595
596 if (!chan)
597 return;
598
599 BT_DBG("code 0x%2.2x", code);
600
601 iv[0].iov_base = &code;
602 iv[0].iov_len = 1;
603
604 iv[1].iov_base = data;
605 iv[1].iov_len = len;
606
607 memset(&msg, 0, sizeof(msg));
608
609 iov_iter_kvec(&msg.msg_iter, WRITE, iv, 2, 1 + len);
610
611 l2cap_chan_send(chan, &msg, 1 + len);
612
613 if (!chan->data)
614 return;
615
616 smp = chan->data;
617
618 cancel_delayed_work_sync(&smp->security_timer);
619 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT);
620}
621
622static u8 authreq_to_seclevel(u8 authreq)
623{
624 if (authreq & SMP_AUTH_MITM) {
625 if (authreq & SMP_AUTH_SC)
626 return BT_SECURITY_FIPS;
627 else
628 return BT_SECURITY_HIGH;
629 } else {
630 return BT_SECURITY_MEDIUM;
631 }
632}
633
634static __u8 seclevel_to_authreq(__u8 sec_level)
635{
636 switch (sec_level) {
637 case BT_SECURITY_FIPS:
638 case BT_SECURITY_HIGH:
639 return SMP_AUTH_MITM | SMP_AUTH_BONDING;
640 case BT_SECURITY_MEDIUM:
641 return SMP_AUTH_BONDING;
642 default:
643 return SMP_AUTH_NONE;
644 }
645}
646
647static void build_pairing_cmd(struct l2cap_conn *conn,
648 struct smp_cmd_pairing *req,
649 struct smp_cmd_pairing *rsp, __u8 authreq)
650{
651 struct l2cap_chan *chan = conn->smp;
652 struct smp_chan *smp = chan->data;
653 struct hci_conn *hcon = conn->hcon;
654 struct hci_dev *hdev = hcon->hdev;
655 u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT;
656
657 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) {
658 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
659 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
660 authreq |= SMP_AUTH_BONDING;
661 } else {
662 authreq &= ~SMP_AUTH_BONDING;
663 }
664
665 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING))
666 remote_dist |= SMP_DIST_ID_KEY;
667
668 if (hci_dev_test_flag(hdev, HCI_PRIVACY))
669 local_dist |= SMP_DIST_ID_KEY;
670
671 if (hci_dev_test_flag(hdev, HCI_SC_ENABLED) &&
672 (authreq & SMP_AUTH_SC)) {
673 struct oob_data *oob_data;
674 u8 bdaddr_type;
675
676 if (hci_dev_test_flag(hdev, HCI_SSP_ENABLED)) {
677 local_dist |= SMP_DIST_LINK_KEY;
678 remote_dist |= SMP_DIST_LINK_KEY;
679 }
680
681 if (hcon->dst_type == ADDR_LE_DEV_PUBLIC)
682 bdaddr_type = BDADDR_LE_PUBLIC;
683 else
684 bdaddr_type = BDADDR_LE_RANDOM;
685
686 oob_data = hci_find_remote_oob_data(hdev, &hcon->dst,
687 bdaddr_type);
688 if (oob_data && oob_data->present) {
689 set_bit(SMP_FLAG_REMOTE_OOB, &smp->flags);
690 oob_flag = SMP_OOB_PRESENT;
691 memcpy(smp->rr, oob_data->rand256, 16);
692 memcpy(smp->pcnf, oob_data->hash256, 16);
693 SMP_DBG("OOB Remote Confirmation: %16phN", smp->pcnf);
694 SMP_DBG("OOB Remote Random: %16phN", smp->rr);
695 }
696
697 } else {
698 authreq &= ~SMP_AUTH_SC;
699 }
700
701 if (rsp == NULL) {
702 req->io_capability = conn->hcon->io_capability;
703 req->oob_flag = oob_flag;
704 req->max_key_size = hdev->le_max_key_size;
705 req->init_key_dist = local_dist;
706 req->resp_key_dist = remote_dist;
707 req->auth_req = (authreq & AUTH_REQ_MASK(hdev));
708
709 smp->remote_key_dist = remote_dist;
710 return;
711 }
712
713 rsp->io_capability = conn->hcon->io_capability;
714 rsp->oob_flag = oob_flag;
715 rsp->max_key_size = hdev->le_max_key_size;
716 rsp->init_key_dist = req->init_key_dist & remote_dist;
717 rsp->resp_key_dist = req->resp_key_dist & local_dist;
718 rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev));
719
720 smp->remote_key_dist = rsp->init_key_dist;
721}
722
723static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)
724{
725 struct l2cap_chan *chan = conn->smp;
726 struct hci_dev *hdev = conn->hcon->hdev;
727 struct smp_chan *smp = chan->data;
728
729 if (conn->hcon->pending_sec_level == BT_SECURITY_FIPS &&
730 max_key_size != SMP_MAX_ENC_KEY_SIZE)
731 return SMP_ENC_KEY_SIZE;
732
733 if (max_key_size > hdev->le_max_key_size ||
734 max_key_size < SMP_MIN_ENC_KEY_SIZE)
735 return SMP_ENC_KEY_SIZE;
736
737 smp->enc_key_size = max_key_size;
738
739 return 0;
740}
741
742static void smp_chan_destroy(struct l2cap_conn *conn)
743{
744 struct l2cap_chan *chan = conn->smp;
745 struct smp_chan *smp = chan->data;
746 struct hci_conn *hcon = conn->hcon;
747 bool complete;
748
749 BUG_ON(!smp);
750
751 cancel_delayed_work_sync(&smp->security_timer);
752
753 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags);
754 mgmt_smp_complete(hcon, complete);
755
756 kfree_sensitive(smp->csrk);
757 kfree_sensitive(smp->slave_csrk);
758 kfree_sensitive(smp->link_key);
759
760 crypto_free_shash(smp->tfm_cmac);
761 crypto_free_kpp(smp->tfm_ecdh);
762
763 /* Ensure that we don't leave any debug key around if debug key
764 * support hasn't been explicitly enabled.
765 */
766 if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG &&
767 !hci_dev_test_flag(hcon->hdev, HCI_KEEP_DEBUG_KEYS)) {
768 list_del_rcu(&smp->ltk->list);
769 kfree_rcu(smp->ltk, rcu);
770 smp->ltk = NULL;
771 }
772
773 /* If pairing failed clean up any keys we might have */
774 if (!complete) {
775 if (smp->ltk) {
776 list_del_rcu(&smp->ltk->list);
777 kfree_rcu(smp->ltk, rcu);
778 }
779
780 if (smp->slave_ltk) {
781 list_del_rcu(&smp->slave_ltk->list);
782 kfree_rcu(smp->slave_ltk, rcu);
783 }
784
785 if (smp->remote_irk) {
786 list_del_rcu(&smp->remote_irk->list);
787 kfree_rcu(smp->remote_irk, rcu);
788 }
789 }
790
791 chan->data = NULL;
792 kfree_sensitive(smp);
793 hci_conn_drop(hcon);
794}
795
796static void smp_failure(struct l2cap_conn *conn, u8 reason)
797{
798 struct hci_conn *hcon = conn->hcon;
799 struct l2cap_chan *chan = conn->smp;
800
801 if (reason)
802 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
803 &reason);
804
805 mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE);
806
807 if (chan->data)
808 smp_chan_destroy(conn);
809}
810
811#define JUST_WORKS 0x00
812#define JUST_CFM 0x01
813#define REQ_PASSKEY 0x02
814#define CFM_PASSKEY 0x03
815#define REQ_OOB 0x04
816#define DSP_PASSKEY 0x05
817#define OVERLAP 0xFF
818
819static const u8 gen_method[5][5] = {
820 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
821 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
822 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
823 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
824 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP },
825};
826
827static const u8 sc_method[5][5] = {
828 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
829 { JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
830 { DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY },
831 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
832 { DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
833};
834
835static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io)
836{
837 /* If either side has unknown io_caps, use JUST_CFM (which gets
838 * converted later to JUST_WORKS if we're initiators.
839 */
840 if (local_io > SMP_IO_KEYBOARD_DISPLAY ||
841 remote_io > SMP_IO_KEYBOARD_DISPLAY)
842 return JUST_CFM;
843
844 if (test_bit(SMP_FLAG_SC, &smp->flags))
845 return sc_method[remote_io][local_io];
846
847 return gen_method[remote_io][local_io];
848}
849
850static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth,
851 u8 local_io, u8 remote_io)
852{
853 struct hci_conn *hcon = conn->hcon;
854 struct l2cap_chan *chan = conn->smp;
855 struct smp_chan *smp = chan->data;
856 u32 passkey = 0;
857 int ret;
858
859 /* Initialize key for JUST WORKS */
860 memset(smp->tk, 0, sizeof(smp->tk));
861 clear_bit(SMP_FLAG_TK_VALID, &smp->flags);
862
863 BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io);
864
865 /* If neither side wants MITM, either "just" confirm an incoming
866 * request or use just-works for outgoing ones. The JUST_CFM
867 * will be converted to JUST_WORKS if necessary later in this
868 * function. If either side has MITM look up the method from the
869 * table.
870 */
871 if (!(auth & SMP_AUTH_MITM))
872 smp->method = JUST_CFM;
873 else
874 smp->method = get_auth_method(smp, local_io, remote_io);
875
876 /* Don't confirm locally initiated pairing attempts */
877 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR,
878 &smp->flags))
879 smp->method = JUST_WORKS;
880
881 /* Don't bother user space with no IO capabilities */
882 if (smp->method == JUST_CFM &&
883 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
884 smp->method = JUST_WORKS;
885
886 /* If Just Works, Continue with Zero TK and ask user-space for
887 * confirmation */
888 if (smp->method == JUST_WORKS) {
889 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
890 hcon->type,
891 hcon->dst_type,
892 passkey, 1);
893 if (ret)
894 return ret;
895 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
896 return 0;
897 }
898
899 /* If this function is used for SC -> legacy fallback we
900 * can only recover the just-works case.
901 */
902 if (test_bit(SMP_FLAG_SC, &smp->flags))
903 return -EINVAL;
904
905 /* Not Just Works/Confirm results in MITM Authentication */
906 if (smp->method != JUST_CFM) {
907 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags);
908 if (hcon->pending_sec_level < BT_SECURITY_HIGH)
909 hcon->pending_sec_level = BT_SECURITY_HIGH;
910 }
911
912 /* If both devices have Keyoard-Display I/O, the master
913 * Confirms and the slave Enters the passkey.
914 */
915 if (smp->method == OVERLAP) {
916 if (hcon->role == HCI_ROLE_MASTER)
917 smp->method = CFM_PASSKEY;
918 else
919 smp->method = REQ_PASSKEY;
920 }
921
922 /* Generate random passkey. */
923 if (smp->method == CFM_PASSKEY) {
924 memset(smp->tk, 0, sizeof(smp->tk));
925 get_random_bytes(&passkey, sizeof(passkey));
926 passkey %= 1000000;
927 put_unaligned_le32(passkey, smp->tk);
928 BT_DBG("PassKey: %d", passkey);
929 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
930 }
931
932 if (smp->method == REQ_PASSKEY)
933 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst,
934 hcon->type, hcon->dst_type);
935 else if (smp->method == JUST_CFM)
936 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
937 hcon->type, hcon->dst_type,
938 passkey, 1);
939 else
940 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst,
941 hcon->type, hcon->dst_type,
942 passkey, 0);
943
944 return ret;
945}
946
947static u8 smp_confirm(struct smp_chan *smp)
948{
949 struct l2cap_conn *conn = smp->conn;
950 struct smp_cmd_pairing_confirm cp;
951 int ret;
952
953 BT_DBG("conn %p", conn);
954
955 ret = smp_c1(smp->tk, smp->prnd, smp->preq, smp->prsp,
956 conn->hcon->init_addr_type, &conn->hcon->init_addr,
957 conn->hcon->resp_addr_type, &conn->hcon->resp_addr,
958 cp.confirm_val);
959 if (ret)
960 return SMP_UNSPECIFIED;
961
962 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
963
964 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
965
966 if (conn->hcon->out)
967 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
968 else
969 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
970
971 return 0;
972}
973
974static u8 smp_random(struct smp_chan *smp)
975{
976 struct l2cap_conn *conn = smp->conn;
977 struct hci_conn *hcon = conn->hcon;
978 u8 confirm[16];
979 int ret;
980
981 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
982
983 ret = smp_c1(smp->tk, smp->rrnd, smp->preq, smp->prsp,
984 hcon->init_addr_type, &hcon->init_addr,
985 hcon->resp_addr_type, &hcon->resp_addr, confirm);
986 if (ret)
987 return SMP_UNSPECIFIED;
988
989 if (crypto_memneq(smp->pcnf, confirm, sizeof(smp->pcnf))) {
990 bt_dev_err(hcon->hdev, "pairing failed "
991 "(confirmation values mismatch)");
992 return SMP_CONFIRM_FAILED;
993 }
994
995 if (hcon->out) {
996 u8 stk[16];
997 __le64 rand = 0;
998 __le16 ediv = 0;
999
1000 smp_s1(smp->tk, smp->rrnd, smp->prnd, stk);
1001
1002 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
1003 return SMP_UNSPECIFIED;
1004
1005 hci_le_start_enc(hcon, ediv, rand, stk, smp->enc_key_size);
1006 hcon->enc_key_size = smp->enc_key_size;
1007 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
1008 } else {
1009 u8 stk[16], auth;
1010 __le64 rand = 0;
1011 __le16 ediv = 0;
1012
1013 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
1014 smp->prnd);
1015
1016 smp_s1(smp->tk, smp->prnd, smp->rrnd, stk);
1017
1018 if (hcon->pending_sec_level == BT_SECURITY_HIGH)
1019 auth = 1;
1020 else
1021 auth = 0;
1022
1023 /* Even though there's no _SLAVE suffix this is the
1024 * slave STK we're adding for later lookup (the master
1025 * STK never needs to be stored).
1026 */
1027 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1028 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand);
1029 }
1030
1031 return 0;
1032}
1033
1034static void smp_notify_keys(struct l2cap_conn *conn)
1035{
1036 struct l2cap_chan *chan = conn->smp;
1037 struct smp_chan *smp = chan->data;
1038 struct hci_conn *hcon = conn->hcon;
1039 struct hci_dev *hdev = hcon->hdev;
1040 struct smp_cmd_pairing *req = (void *) &smp->preq[1];
1041 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1];
1042 bool persistent;
1043
1044 if (hcon->type == ACL_LINK) {
1045 if (hcon->key_type == HCI_LK_DEBUG_COMBINATION)
1046 persistent = false;
1047 else
1048 persistent = !test_bit(HCI_CONN_FLUSH_KEY,
1049 &hcon->flags);
1050 } else {
1051 /* The LTKs, IRKs and CSRKs should be persistent only if
1052 * both sides had the bonding bit set in their
1053 * authentication requests.
1054 */
1055 persistent = !!((req->auth_req & rsp->auth_req) &
1056 SMP_AUTH_BONDING);
1057 }
1058
1059 if (smp->remote_irk) {
1060 mgmt_new_irk(hdev, smp->remote_irk, persistent);
1061
1062 /* Now that user space can be considered to know the
1063 * identity address track the connection based on it
1064 * from now on (assuming this is an LE link).
1065 */
1066 if (hcon->type == LE_LINK) {
1067 bacpy(&hcon->dst, &smp->remote_irk->bdaddr);
1068 hcon->dst_type = smp->remote_irk->addr_type;
1069 queue_work(hdev->workqueue, &conn->id_addr_update_work);
1070 }
1071 }
1072
1073 if (smp->csrk) {
1074 smp->csrk->bdaddr_type = hcon->dst_type;
1075 bacpy(&smp->csrk->bdaddr, &hcon->dst);
1076 mgmt_new_csrk(hdev, smp->csrk, persistent);
1077 }
1078
1079 if (smp->slave_csrk) {
1080 smp->slave_csrk->bdaddr_type = hcon->dst_type;
1081 bacpy(&smp->slave_csrk->bdaddr, &hcon->dst);
1082 mgmt_new_csrk(hdev, smp->slave_csrk, persistent);
1083 }
1084
1085 if (smp->ltk) {
1086 smp->ltk->bdaddr_type = hcon->dst_type;
1087 bacpy(&smp->ltk->bdaddr, &hcon->dst);
1088 mgmt_new_ltk(hdev, smp->ltk, persistent);
1089 }
1090
1091 if (smp->slave_ltk) {
1092 smp->slave_ltk->bdaddr_type = hcon->dst_type;
1093 bacpy(&smp->slave_ltk->bdaddr, &hcon->dst);
1094 mgmt_new_ltk(hdev, smp->slave_ltk, persistent);
1095 }
1096
1097 if (smp->link_key) {
1098 struct link_key *key;
1099 u8 type;
1100
1101 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1102 type = HCI_LK_DEBUG_COMBINATION;
1103 else if (hcon->sec_level == BT_SECURITY_FIPS)
1104 type = HCI_LK_AUTH_COMBINATION_P256;
1105 else
1106 type = HCI_LK_UNAUTH_COMBINATION_P256;
1107
1108 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst,
1109 smp->link_key, type, 0, &persistent);
1110 if (key) {
1111 mgmt_new_link_key(hdev, key, persistent);
1112
1113 /* Don't keep debug keys around if the relevant
1114 * flag is not set.
1115 */
1116 if (!hci_dev_test_flag(hdev, HCI_KEEP_DEBUG_KEYS) &&
1117 key->type == HCI_LK_DEBUG_COMBINATION) {
1118 list_del_rcu(&key->list);
1119 kfree_rcu(key, rcu);
1120 }
1121 }
1122 }
1123}
1124
1125static void sc_add_ltk(struct smp_chan *smp)
1126{
1127 struct hci_conn *hcon = smp->conn->hcon;
1128 u8 key_type, auth;
1129
1130 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1131 key_type = SMP_LTK_P256_DEBUG;
1132 else
1133 key_type = SMP_LTK_P256;
1134
1135 if (hcon->pending_sec_level == BT_SECURITY_FIPS)
1136 auth = 1;
1137 else
1138 auth = 0;
1139
1140 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1141 key_type, auth, smp->tk, smp->enc_key_size,
1142 0, 0);
1143}
1144
1145static void sc_generate_link_key(struct smp_chan *smp)
1146{
1147 /* From core spec. Spells out in ASCII as 'lebr'. */
1148 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c };
1149
1150 smp->link_key = kzalloc(16, GFP_KERNEL);
1151 if (!smp->link_key)
1152 return;
1153
1154 if (test_bit(SMP_FLAG_CT2, &smp->flags)) {
1155 /* SALT = 0x000000000000000000000000746D7031 */
1156 const u8 salt[16] = { 0x31, 0x70, 0x6d, 0x74 };
1157
1158 if (smp_h7(smp->tfm_cmac, smp->tk, salt, smp->link_key)) {
1159 kfree_sensitive(smp->link_key);
1160 smp->link_key = NULL;
1161 return;
1162 }
1163 } else {
1164 /* From core spec. Spells out in ASCII as 'tmp1'. */
1165 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 };
1166
1167 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) {
1168 kfree_sensitive(smp->link_key);
1169 smp->link_key = NULL;
1170 return;
1171 }
1172 }
1173
1174 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) {
1175 kfree_sensitive(smp->link_key);
1176 smp->link_key = NULL;
1177 return;
1178 }
1179}
1180
1181static void smp_allow_key_dist(struct smp_chan *smp)
1182{
1183 /* Allow the first expected phase 3 PDU. The rest of the PDUs
1184 * will be allowed in each PDU handler to ensure we receive
1185 * them in the correct order.
1186 */
1187 if (smp->remote_key_dist & SMP_DIST_ENC_KEY)
1188 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO);
1189 else if (smp->remote_key_dist & SMP_DIST_ID_KEY)
1190 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
1191 else if (smp->remote_key_dist & SMP_DIST_SIGN)
1192 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
1193}
1194
1195static void sc_generate_ltk(struct smp_chan *smp)
1196{
1197 /* From core spec. Spells out in ASCII as 'brle'. */
1198 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 };
1199 struct hci_conn *hcon = smp->conn->hcon;
1200 struct hci_dev *hdev = hcon->hdev;
1201 struct link_key *key;
1202
1203 key = hci_find_link_key(hdev, &hcon->dst);
1204 if (!key) {
1205 bt_dev_err(hdev, "no Link Key found to generate LTK");
1206 return;
1207 }
1208
1209 if (key->type == HCI_LK_DEBUG_COMBINATION)
1210 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1211
1212 if (test_bit(SMP_FLAG_CT2, &smp->flags)) {
1213 /* SALT = 0x000000000000000000000000746D7032 */
1214 const u8 salt[16] = { 0x32, 0x70, 0x6d, 0x74 };
1215
1216 if (smp_h7(smp->tfm_cmac, key->val, salt, smp->tk))
1217 return;
1218 } else {
1219 /* From core spec. Spells out in ASCII as 'tmp2'. */
1220 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 };
1221
1222 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk))
1223 return;
1224 }
1225
1226 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk))
1227 return;
1228
1229 sc_add_ltk(smp);
1230}
1231
1232static void smp_distribute_keys(struct smp_chan *smp)
1233{
1234 struct smp_cmd_pairing *req, *rsp;
1235 struct l2cap_conn *conn = smp->conn;
1236 struct hci_conn *hcon = conn->hcon;
1237 struct hci_dev *hdev = hcon->hdev;
1238 __u8 *keydist;
1239
1240 BT_DBG("conn %p", conn);
1241
1242 rsp = (void *) &smp->prsp[1];
1243
1244 /* The responder sends its keys first */
1245 if (hcon->out && (smp->remote_key_dist & KEY_DIST_MASK)) {
1246 smp_allow_key_dist(smp);
1247 return;
1248 }
1249
1250 req = (void *) &smp->preq[1];
1251
1252 if (hcon->out) {
1253 keydist = &rsp->init_key_dist;
1254 *keydist &= req->init_key_dist;
1255 } else {
1256 keydist = &rsp->resp_key_dist;
1257 *keydist &= req->resp_key_dist;
1258 }
1259
1260 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1261 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY))
1262 sc_generate_link_key(smp);
1263 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY))
1264 sc_generate_ltk(smp);
1265
1266 /* Clear the keys which are generated but not distributed */
1267 *keydist &= ~SMP_SC_NO_DIST;
1268 }
1269
1270 BT_DBG("keydist 0x%x", *keydist);
1271
1272 if (*keydist & SMP_DIST_ENC_KEY) {
1273 struct smp_cmd_encrypt_info enc;
1274 struct smp_cmd_master_ident ident;
1275 struct smp_ltk *ltk;
1276 u8 authenticated;
1277 __le16 ediv;
1278 __le64 rand;
1279
1280 /* Make sure we generate only the significant amount of
1281 * bytes based on the encryption key size, and set the rest
1282 * of the value to zeroes.
1283 */
1284 get_random_bytes(enc.ltk, smp->enc_key_size);
1285 memset(enc.ltk + smp->enc_key_size, 0,
1286 sizeof(enc.ltk) - smp->enc_key_size);
1287
1288 get_random_bytes(&ediv, sizeof(ediv));
1289 get_random_bytes(&rand, sizeof(rand));
1290
1291 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc);
1292
1293 authenticated = hcon->sec_level == BT_SECURITY_HIGH;
1294 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type,
1295 SMP_LTK_SLAVE, authenticated, enc.ltk,
1296 smp->enc_key_size, ediv, rand);
1297 smp->slave_ltk = ltk;
1298
1299 ident.ediv = ediv;
1300 ident.rand = rand;
1301
1302 smp_send_cmd(conn, SMP_CMD_MASTER_IDENT, sizeof(ident), &ident);
1303
1304 *keydist &= ~SMP_DIST_ENC_KEY;
1305 }
1306
1307 if (*keydist & SMP_DIST_ID_KEY) {
1308 struct smp_cmd_ident_addr_info addrinfo;
1309 struct smp_cmd_ident_info idinfo;
1310
1311 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk));
1312
1313 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo);
1314
1315 /* The hci_conn contains the local identity address
1316 * after the connection has been established.
1317 *
1318 * This is true even when the connection has been
1319 * established using a resolvable random address.
1320 */
1321 bacpy(&addrinfo.bdaddr, &hcon->src);
1322 addrinfo.addr_type = hcon->src_type;
1323
1324 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo),
1325 &addrinfo);
1326
1327 *keydist &= ~SMP_DIST_ID_KEY;
1328 }
1329
1330 if (*keydist & SMP_DIST_SIGN) {
1331 struct smp_cmd_sign_info sign;
1332 struct smp_csrk *csrk;
1333
1334 /* Generate a new random key */
1335 get_random_bytes(sign.csrk, sizeof(sign.csrk));
1336
1337 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
1338 if (csrk) {
1339 if (hcon->sec_level > BT_SECURITY_MEDIUM)
1340 csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED;
1341 else
1342 csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED;
1343 memcpy(csrk->val, sign.csrk, sizeof(csrk->val));
1344 }
1345 smp->slave_csrk = csrk;
1346
1347 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign);
1348
1349 *keydist &= ~SMP_DIST_SIGN;
1350 }
1351
1352 /* If there are still keys to be received wait for them */
1353 if (smp->remote_key_dist & KEY_DIST_MASK) {
1354 smp_allow_key_dist(smp);
1355 return;
1356 }
1357
1358 set_bit(SMP_FLAG_COMPLETE, &smp->flags);
1359 smp_notify_keys(conn);
1360
1361 smp_chan_destroy(conn);
1362}
1363
1364static void smp_timeout(struct work_struct *work)
1365{
1366 struct smp_chan *smp = container_of(work, struct smp_chan,
1367 security_timer.work);
1368 struct l2cap_conn *conn = smp->conn;
1369
1370 BT_DBG("conn %p", conn);
1371
1372 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM);
1373}
1374
1375static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
1376{
1377 struct l2cap_chan *chan = conn->smp;
1378 struct smp_chan *smp;
1379
1380 smp = kzalloc(sizeof(*smp), GFP_ATOMIC);
1381 if (!smp)
1382 return NULL;
1383
1384 smp->tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
1385 if (IS_ERR(smp->tfm_cmac)) {
1386 BT_ERR("Unable to create CMAC crypto context");
1387 goto zfree_smp;
1388 }
1389
1390 smp->tfm_ecdh = crypto_alloc_kpp("ecdh", 0, 0);
1391 if (IS_ERR(smp->tfm_ecdh)) {
1392 BT_ERR("Unable to create ECDH crypto context");
1393 goto free_shash;
1394 }
1395
1396 smp->conn = conn;
1397 chan->data = smp;
1398
1399 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL);
1400
1401 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout);
1402
1403 hci_conn_hold(conn->hcon);
1404
1405 return smp;
1406
1407free_shash:
1408 crypto_free_shash(smp->tfm_cmac);
1409zfree_smp:
1410 kfree_sensitive(smp);
1411 return NULL;
1412}
1413
1414static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16])
1415{
1416 struct hci_conn *hcon = smp->conn->hcon;
1417 u8 *na, *nb, a[7], b[7];
1418
1419 if (hcon->out) {
1420 na = smp->prnd;
1421 nb = smp->rrnd;
1422 } else {
1423 na = smp->rrnd;
1424 nb = smp->prnd;
1425 }
1426
1427 memcpy(a, &hcon->init_addr, 6);
1428 memcpy(b, &hcon->resp_addr, 6);
1429 a[6] = hcon->init_addr_type;
1430 b[6] = hcon->resp_addr_type;
1431
1432 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk);
1433}
1434
1435static void sc_dhkey_check(struct smp_chan *smp)
1436{
1437 struct hci_conn *hcon = smp->conn->hcon;
1438 struct smp_cmd_dhkey_check check;
1439 u8 a[7], b[7], *local_addr, *remote_addr;
1440 u8 io_cap[3], r[16];
1441
1442 memcpy(a, &hcon->init_addr, 6);
1443 memcpy(b, &hcon->resp_addr, 6);
1444 a[6] = hcon->init_addr_type;
1445 b[6] = hcon->resp_addr_type;
1446
1447 if (hcon->out) {
1448 local_addr = a;
1449 remote_addr = b;
1450 memcpy(io_cap, &smp->preq[1], 3);
1451 } else {
1452 local_addr = b;
1453 remote_addr = a;
1454 memcpy(io_cap, &smp->prsp[1], 3);
1455 }
1456
1457 memset(r, 0, sizeof(r));
1458
1459 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
1460 put_unaligned_le32(hcon->passkey_notify, r);
1461
1462 if (smp->method == REQ_OOB)
1463 memcpy(r, smp->rr, 16);
1464
1465 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap,
1466 local_addr, remote_addr, check.e);
1467
1468 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check);
1469}
1470
1471static u8 sc_passkey_send_confirm(struct smp_chan *smp)
1472{
1473 struct l2cap_conn *conn = smp->conn;
1474 struct hci_conn *hcon = conn->hcon;
1475 struct smp_cmd_pairing_confirm cfm;
1476 u8 r;
1477
1478 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1479 r |= 0x80;
1480
1481 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1482
1483 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r,
1484 cfm.confirm_val))
1485 return SMP_UNSPECIFIED;
1486
1487 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
1488
1489 return 0;
1490}
1491
1492static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op)
1493{
1494 struct l2cap_conn *conn = smp->conn;
1495 struct hci_conn *hcon = conn->hcon;
1496 struct hci_dev *hdev = hcon->hdev;
1497 u8 cfm[16], r;
1498
1499 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */
1500 if (smp->passkey_round >= 20)
1501 return 0;
1502
1503 switch (smp_op) {
1504 case SMP_CMD_PAIRING_RANDOM:
1505 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1506 r |= 0x80;
1507
1508 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
1509 smp->rrnd, r, cfm))
1510 return SMP_UNSPECIFIED;
1511
1512 if (crypto_memneq(smp->pcnf, cfm, 16))
1513 return SMP_CONFIRM_FAILED;
1514
1515 smp->passkey_round++;
1516
1517 if (smp->passkey_round == 20) {
1518 /* Generate MacKey and LTK */
1519 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk))
1520 return SMP_UNSPECIFIED;
1521 }
1522
1523 /* The round is only complete when the initiator
1524 * receives pairing random.
1525 */
1526 if (!hcon->out) {
1527 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1528 sizeof(smp->prnd), smp->prnd);
1529 if (smp->passkey_round == 20)
1530 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1531 else
1532 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1533 return 0;
1534 }
1535
1536 /* Start the next round */
1537 if (smp->passkey_round != 20)
1538 return sc_passkey_round(smp, 0);
1539
1540 /* Passkey rounds are complete - start DHKey Check */
1541 sc_dhkey_check(smp);
1542 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1543
1544 break;
1545
1546 case SMP_CMD_PAIRING_CONFIRM:
1547 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
1548 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
1549 return 0;
1550 }
1551
1552 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
1553
1554 if (hcon->out) {
1555 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1556 sizeof(smp->prnd), smp->prnd);
1557 return 0;
1558 }
1559
1560 return sc_passkey_send_confirm(smp);
1561
1562 case SMP_CMD_PUBLIC_KEY:
1563 default:
1564 /* Initiating device starts the round */
1565 if (!hcon->out)
1566 return 0;
1567
1568 BT_DBG("%s Starting passkey round %u", hdev->name,
1569 smp->passkey_round + 1);
1570
1571 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1572
1573 return sc_passkey_send_confirm(smp);
1574 }
1575
1576 return 0;
1577}
1578
1579static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey)
1580{
1581 struct l2cap_conn *conn = smp->conn;
1582 struct hci_conn *hcon = conn->hcon;
1583 u8 smp_op;
1584
1585 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags);
1586
1587 switch (mgmt_op) {
1588 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1589 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED);
1590 return 0;
1591 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1592 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED);
1593 return 0;
1594 case MGMT_OP_USER_PASSKEY_REPLY:
1595 hcon->passkey_notify = le32_to_cpu(passkey);
1596 smp->passkey_round = 0;
1597
1598 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags))
1599 smp_op = SMP_CMD_PAIRING_CONFIRM;
1600 else
1601 smp_op = 0;
1602
1603 if (sc_passkey_round(smp, smp_op))
1604 return -EIO;
1605
1606 return 0;
1607 }
1608
1609 /* Initiator sends DHKey check first */
1610 if (hcon->out) {
1611 sc_dhkey_check(smp);
1612 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1613 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) {
1614 sc_dhkey_check(smp);
1615 sc_add_ltk(smp);
1616 }
1617
1618 return 0;
1619}
1620
1621int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey)
1622{
1623 struct l2cap_conn *conn = hcon->l2cap_data;
1624 struct l2cap_chan *chan;
1625 struct smp_chan *smp;
1626 u32 value;
1627 int err;
1628
1629 BT_DBG("");
1630
1631 if (!conn)
1632 return -ENOTCONN;
1633
1634 chan = conn->smp;
1635 if (!chan)
1636 return -ENOTCONN;
1637
1638 l2cap_chan_lock(chan);
1639 if (!chan->data) {
1640 err = -ENOTCONN;
1641 goto unlock;
1642 }
1643
1644 smp = chan->data;
1645
1646 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1647 err = sc_user_reply(smp, mgmt_op, passkey);
1648 goto unlock;
1649 }
1650
1651 switch (mgmt_op) {
1652 case MGMT_OP_USER_PASSKEY_REPLY:
1653 value = le32_to_cpu(passkey);
1654 memset(smp->tk, 0, sizeof(smp->tk));
1655 BT_DBG("PassKey: %d", value);
1656 put_unaligned_le32(value, smp->tk);
1657 fallthrough;
1658 case MGMT_OP_USER_CONFIRM_REPLY:
1659 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
1660 break;
1661 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1662 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1663 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1664 err = 0;
1665 goto unlock;
1666 default:
1667 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
1668 err = -EOPNOTSUPP;
1669 goto unlock;
1670 }
1671
1672 err = 0;
1673
1674 /* If it is our turn to send Pairing Confirm, do so now */
1675 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) {
1676 u8 rsp = smp_confirm(smp);
1677 if (rsp)
1678 smp_failure(conn, rsp);
1679 }
1680
1681unlock:
1682 l2cap_chan_unlock(chan);
1683 return err;
1684}
1685
1686static void build_bredr_pairing_cmd(struct smp_chan *smp,
1687 struct smp_cmd_pairing *req,
1688 struct smp_cmd_pairing *rsp)
1689{
1690 struct l2cap_conn *conn = smp->conn;
1691 struct hci_dev *hdev = conn->hcon->hdev;
1692 u8 local_dist = 0, remote_dist = 0;
1693
1694 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) {
1695 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1696 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1697 }
1698
1699 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING))
1700 remote_dist |= SMP_DIST_ID_KEY;
1701
1702 if (hci_dev_test_flag(hdev, HCI_PRIVACY))
1703 local_dist |= SMP_DIST_ID_KEY;
1704
1705 if (!rsp) {
1706 memset(req, 0, sizeof(*req));
1707
1708 req->auth_req = SMP_AUTH_CT2;
1709 req->init_key_dist = local_dist;
1710 req->resp_key_dist = remote_dist;
1711 req->max_key_size = conn->hcon->enc_key_size;
1712
1713 smp->remote_key_dist = remote_dist;
1714
1715 return;
1716 }
1717
1718 memset(rsp, 0, sizeof(*rsp));
1719
1720 rsp->auth_req = SMP_AUTH_CT2;
1721 rsp->max_key_size = conn->hcon->enc_key_size;
1722 rsp->init_key_dist = req->init_key_dist & remote_dist;
1723 rsp->resp_key_dist = req->resp_key_dist & local_dist;
1724
1725 smp->remote_key_dist = rsp->init_key_dist;
1726}
1727
1728static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
1729{
1730 struct smp_cmd_pairing rsp, *req = (void *) skb->data;
1731 struct l2cap_chan *chan = conn->smp;
1732 struct hci_dev *hdev = conn->hcon->hdev;
1733 struct smp_chan *smp;
1734 u8 key_size, auth, sec_level;
1735 int ret;
1736
1737 BT_DBG("conn %p", conn);
1738
1739 if (skb->len < sizeof(*req))
1740 return SMP_INVALID_PARAMS;
1741
1742 if (conn->hcon->role != HCI_ROLE_SLAVE)
1743 return SMP_CMD_NOTSUPP;
1744
1745 if (!chan->data)
1746 smp = smp_chan_create(conn);
1747 else
1748 smp = chan->data;
1749
1750 if (!smp)
1751 return SMP_UNSPECIFIED;
1752
1753 /* We didn't start the pairing, so match remote */
1754 auth = req->auth_req & AUTH_REQ_MASK(hdev);
1755
1756 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) &&
1757 (auth & SMP_AUTH_BONDING))
1758 return SMP_PAIRING_NOTSUPP;
1759
1760 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
1761 return SMP_AUTH_REQUIREMENTS;
1762
1763 smp->preq[0] = SMP_CMD_PAIRING_REQ;
1764 memcpy(&smp->preq[1], req, sizeof(*req));
1765 skb_pull(skb, sizeof(*req));
1766
1767 /* If the remote side's OOB flag is set it means it has
1768 * successfully received our local OOB data - therefore set the
1769 * flag to indicate that local OOB is in use.
1770 */
1771 if (req->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob)
1772 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);
1773
1774 /* SMP over BR/EDR requires special treatment */
1775 if (conn->hcon->type == ACL_LINK) {
1776 /* We must have a BR/EDR SC link */
1777 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) &&
1778 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
1779 return SMP_CROSS_TRANSP_NOT_ALLOWED;
1780
1781 set_bit(SMP_FLAG_SC, &smp->flags);
1782
1783 build_bredr_pairing_cmd(smp, req, &rsp);
1784
1785 if (req->auth_req & SMP_AUTH_CT2)
1786 set_bit(SMP_FLAG_CT2, &smp->flags);
1787
1788 key_size = min(req->max_key_size, rsp.max_key_size);
1789 if (check_enc_key_size(conn, key_size))
1790 return SMP_ENC_KEY_SIZE;
1791
1792 /* Clear bits which are generated but not distributed */
1793 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1794
1795 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1796 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1797 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1798
1799 smp_distribute_keys(smp);
1800 return 0;
1801 }
1802
1803 build_pairing_cmd(conn, req, &rsp, auth);
1804
1805 if (rsp.auth_req & SMP_AUTH_SC) {
1806 set_bit(SMP_FLAG_SC, &smp->flags);
1807
1808 if (rsp.auth_req & SMP_AUTH_CT2)
1809 set_bit(SMP_FLAG_CT2, &smp->flags);
1810 }
1811
1812 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
1813 sec_level = BT_SECURITY_MEDIUM;
1814 else
1815 sec_level = authreq_to_seclevel(auth);
1816
1817 if (sec_level > conn->hcon->pending_sec_level)
1818 conn->hcon->pending_sec_level = sec_level;
1819
1820 /* If we need MITM check that it can be achieved */
1821 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1822 u8 method;
1823
1824 method = get_auth_method(smp, conn->hcon->io_capability,
1825 req->io_capability);
1826 if (method == JUST_WORKS || method == JUST_CFM)
1827 return SMP_AUTH_REQUIREMENTS;
1828 }
1829
1830 key_size = min(req->max_key_size, rsp.max_key_size);
1831 if (check_enc_key_size(conn, key_size))
1832 return SMP_ENC_KEY_SIZE;
1833
1834 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1835
1836 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1837 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1838
1839 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1840
1841 clear_bit(SMP_FLAG_INITIATOR, &smp->flags);
1842
1843 /* Strictly speaking we shouldn't allow Pairing Confirm for the
1844 * SC case, however some implementations incorrectly copy RFU auth
1845 * req bits from our security request, which may create a false
1846 * positive SC enablement.
1847 */
1848 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1849
1850 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1851 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
1852 /* Clear bits which are generated but not distributed */
1853 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1854 /* Wait for Public Key from Initiating Device */
1855 return 0;
1856 }
1857
1858 /* Request setup of TK */
1859 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability);
1860 if (ret)
1861 return SMP_UNSPECIFIED;
1862
1863 return 0;
1864}
1865
1866static u8 sc_send_public_key(struct smp_chan *smp)
1867{
1868 struct hci_dev *hdev = smp->conn->hcon->hdev;
1869
1870 bt_dev_dbg(hdev, "");
1871
1872 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) {
1873 struct l2cap_chan *chan = hdev->smp_data;
1874 struct smp_dev *smp_dev;
1875
1876 if (!chan || !chan->data)
1877 return SMP_UNSPECIFIED;
1878
1879 smp_dev = chan->data;
1880
1881 memcpy(smp->local_pk, smp_dev->local_pk, 64);
1882 memcpy(smp->lr, smp_dev->local_rand, 16);
1883
1884 if (smp_dev->debug_key)
1885 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1886
1887 goto done;
1888 }
1889
1890 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) {
1891 BT_DBG("Using debug keys");
1892 if (set_ecdh_privkey(smp->tfm_ecdh, debug_sk))
1893 return SMP_UNSPECIFIED;
1894 memcpy(smp->local_pk, debug_pk, 64);
1895 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1896 } else {
1897 while (true) {
1898 /* Generate key pair for Secure Connections */
1899 if (generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk))
1900 return SMP_UNSPECIFIED;
1901
1902 /* This is unlikely, but we need to check that
1903 * we didn't accidentially generate a debug key.
1904 */
1905 if (crypto_memneq(smp->local_pk, debug_pk, 64))
1906 break;
1907 }
1908 }
1909
1910done:
1911 SMP_DBG("Local Public Key X: %32phN", smp->local_pk);
1912 SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32);
1913
1914 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk);
1915
1916 return 0;
1917}
1918
1919static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
1920{
1921 struct smp_cmd_pairing *req, *rsp = (void *) skb->data;
1922 struct l2cap_chan *chan = conn->smp;
1923 struct smp_chan *smp = chan->data;
1924 struct hci_dev *hdev = conn->hcon->hdev;
1925 u8 key_size, auth;
1926 int ret;
1927
1928 BT_DBG("conn %p", conn);
1929
1930 if (skb->len < sizeof(*rsp))
1931 return SMP_INVALID_PARAMS;
1932
1933 if (conn->hcon->role != HCI_ROLE_MASTER)
1934 return SMP_CMD_NOTSUPP;
1935
1936 skb_pull(skb, sizeof(*rsp));
1937
1938 req = (void *) &smp->preq[1];
1939
1940 key_size = min(req->max_key_size, rsp->max_key_size);
1941 if (check_enc_key_size(conn, key_size))
1942 return SMP_ENC_KEY_SIZE;
1943
1944 auth = rsp->auth_req & AUTH_REQ_MASK(hdev);
1945
1946 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
1947 return SMP_AUTH_REQUIREMENTS;
1948
1949 /* If the remote side's OOB flag is set it means it has
1950 * successfully received our local OOB data - therefore set the
1951 * flag to indicate that local OOB is in use.
1952 */
1953 if (rsp->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob)
1954 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);
1955
1956 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1957 memcpy(&smp->prsp[1], rsp, sizeof(*rsp));
1958
1959 /* Update remote key distribution in case the remote cleared
1960 * some bits that we had enabled in our request.
1961 */
1962 smp->remote_key_dist &= rsp->resp_key_dist;
1963
1964 if ((req->auth_req & SMP_AUTH_CT2) && (auth & SMP_AUTH_CT2))
1965 set_bit(SMP_FLAG_CT2, &smp->flags);
1966
1967 /* For BR/EDR this means we're done and can start phase 3 */
1968 if (conn->hcon->type == ACL_LINK) {
1969 /* Clear bits which are generated but not distributed */
1970 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1971 smp_distribute_keys(smp);
1972 return 0;
1973 }
1974
1975 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC))
1976 set_bit(SMP_FLAG_SC, &smp->flags);
1977 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH)
1978 conn->hcon->pending_sec_level = BT_SECURITY_HIGH;
1979
1980 /* If we need MITM check that it can be achieved */
1981 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1982 u8 method;
1983
1984 method = get_auth_method(smp, req->io_capability,
1985 rsp->io_capability);
1986 if (method == JUST_WORKS || method == JUST_CFM)
1987 return SMP_AUTH_REQUIREMENTS;
1988 }
1989
1990 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1991
1992 /* Update remote key distribution in case the remote cleared
1993 * some bits that we had enabled in our request.
1994 */
1995 smp->remote_key_dist &= rsp->resp_key_dist;
1996
1997 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1998 /* Clear bits which are generated but not distributed */
1999 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
2000 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
2001 return sc_send_public_key(smp);
2002 }
2003
2004 auth |= req->auth_req;
2005
2006 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability);
2007 if (ret)
2008 return SMP_UNSPECIFIED;
2009
2010 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
2011
2012 /* Can't compose response until we have been confirmed */
2013 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
2014 return smp_confirm(smp);
2015
2016 return 0;
2017}
2018
2019static u8 sc_check_confirm(struct smp_chan *smp)
2020{
2021 struct l2cap_conn *conn = smp->conn;
2022
2023 BT_DBG("");
2024
2025 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2026 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM);
2027
2028 if (conn->hcon->out) {
2029 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2030 smp->prnd);
2031 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2032 }
2033
2034 return 0;
2035}
2036
2037/* Work-around for some implementations that incorrectly copy RFU bits
2038 * from our security request and thereby create the impression that
2039 * we're doing SC when in fact the remote doesn't support it.
2040 */
2041static int fixup_sc_false_positive(struct smp_chan *smp)
2042{
2043 struct l2cap_conn *conn = smp->conn;
2044 struct hci_conn *hcon = conn->hcon;
2045 struct hci_dev *hdev = hcon->hdev;
2046 struct smp_cmd_pairing *req, *rsp;
2047 u8 auth;
2048
2049 /* The issue is only observed when we're in slave role */
2050 if (hcon->out)
2051 return SMP_UNSPECIFIED;
2052
2053 if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) {
2054 bt_dev_err(hdev, "refusing legacy fallback in SC-only mode");
2055 return SMP_UNSPECIFIED;
2056 }
2057
2058 bt_dev_err(hdev, "trying to fall back to legacy SMP");
2059
2060 req = (void *) &smp->preq[1];
2061 rsp = (void *) &smp->prsp[1];
2062
2063 /* Rebuild key dist flags which may have been cleared for SC */
2064 smp->remote_key_dist = (req->init_key_dist & rsp->resp_key_dist);
2065
2066 auth = req->auth_req & AUTH_REQ_MASK(hdev);
2067
2068 if (tk_request(conn, 0, auth, rsp->io_capability, req->io_capability)) {
2069 bt_dev_err(hdev, "failed to fall back to legacy SMP");
2070 return SMP_UNSPECIFIED;
2071 }
2072
2073 clear_bit(SMP_FLAG_SC, &smp->flags);
2074
2075 return 0;
2076}
2077
2078static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
2079{
2080 struct l2cap_chan *chan = conn->smp;
2081 struct smp_chan *smp = chan->data;
2082
2083 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
2084
2085 if (skb->len < sizeof(smp->pcnf))
2086 return SMP_INVALID_PARAMS;
2087
2088 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf));
2089 skb_pull(skb, sizeof(smp->pcnf));
2090
2091 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
2092 int ret;
2093
2094 /* Public Key exchange must happen before any other steps */
2095 if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags))
2096 return sc_check_confirm(smp);
2097
2098 BT_ERR("Unexpected SMP Pairing Confirm");
2099
2100 ret = fixup_sc_false_positive(smp);
2101 if (ret)
2102 return ret;
2103 }
2104
2105 if (conn->hcon->out) {
2106 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2107 smp->prnd);
2108 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2109 return 0;
2110 }
2111
2112 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
2113 return smp_confirm(smp);
2114
2115 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
2116
2117 return 0;
2118}
2119
2120static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
2121{
2122 struct l2cap_chan *chan = conn->smp;
2123 struct smp_chan *smp = chan->data;
2124 struct hci_conn *hcon = conn->hcon;
2125 u8 *pkax, *pkbx, *na, *nb, confirm_hint;
2126 u32 passkey;
2127 int err;
2128
2129 BT_DBG("conn %p", conn);
2130
2131 if (skb->len < sizeof(smp->rrnd))
2132 return SMP_INVALID_PARAMS;
2133
2134 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd));
2135 skb_pull(skb, sizeof(smp->rrnd));
2136
2137 if (!test_bit(SMP_FLAG_SC, &smp->flags))
2138 return smp_random(smp);
2139
2140 if (hcon->out) {
2141 pkax = smp->local_pk;
2142 pkbx = smp->remote_pk;
2143 na = smp->prnd;
2144 nb = smp->rrnd;
2145 } else {
2146 pkax = smp->remote_pk;
2147 pkbx = smp->local_pk;
2148 na = smp->rrnd;
2149 nb = smp->prnd;
2150 }
2151
2152 if (smp->method == REQ_OOB) {
2153 if (!hcon->out)
2154 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2155 sizeof(smp->prnd), smp->prnd);
2156 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2157 goto mackey_and_ltk;
2158 }
2159
2160 /* Passkey entry has special treatment */
2161 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2162 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM);
2163
2164 if (hcon->out) {
2165 u8 cfm[16];
2166
2167 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
2168 smp->rrnd, 0, cfm);
2169 if (err)
2170 return SMP_UNSPECIFIED;
2171
2172 if (crypto_memneq(smp->pcnf, cfm, 16))
2173 return SMP_CONFIRM_FAILED;
2174 } else {
2175 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
2176 smp->prnd);
2177 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2178
2179 /* Only Just-Works pairing requires extra checks */
2180 if (smp->method != JUST_WORKS)
2181 goto mackey_and_ltk;
2182
2183 /* If there already exists long term key in local host, leave
2184 * the decision to user space since the remote device could
2185 * be legitimate or malicious.
2186 */
2187 if (hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
2188 hcon->role)) {
2189 /* Set passkey to 0. The value can be any number since
2190 * it'll be ignored anyway.
2191 */
2192 passkey = 0;
2193 confirm_hint = 1;
2194 goto confirm;
2195 }
2196 }
2197
2198mackey_and_ltk:
2199 /* Generate MacKey and LTK */
2200 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk);
2201 if (err)
2202 return SMP_UNSPECIFIED;
2203
2204 if (smp->method == REQ_OOB) {
2205 if (hcon->out) {
2206 sc_dhkey_check(smp);
2207 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2208 }
2209 return 0;
2210 }
2211
2212 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
2213 if (err)
2214 return SMP_UNSPECIFIED;
2215
2216 confirm_hint = 0;
2217
2218confirm:
2219 if (smp->method == JUST_WORKS)
2220 confirm_hint = 1;
2221
2222 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type,
2223 hcon->dst_type, passkey, confirm_hint);
2224 if (err)
2225 return SMP_UNSPECIFIED;
2226
2227 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2228
2229 return 0;
2230}
2231
2232static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level)
2233{
2234 struct smp_ltk *key;
2235 struct hci_conn *hcon = conn->hcon;
2236
2237 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role);
2238 if (!key)
2239 return false;
2240
2241 if (smp_ltk_sec_level(key) < sec_level)
2242 return false;
2243
2244 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
2245 return true;
2246
2247 hci_le_start_enc(hcon, key->ediv, key->rand, key->val, key->enc_size);
2248 hcon->enc_key_size = key->enc_size;
2249
2250 /* We never store STKs for master role, so clear this flag */
2251 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
2252
2253 return true;
2254}
2255
2256bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level,
2257 enum smp_key_pref key_pref)
2258{
2259 if (sec_level == BT_SECURITY_LOW)
2260 return true;
2261
2262 /* If we're encrypted with an STK but the caller prefers using
2263 * LTK claim insufficient security. This way we allow the
2264 * connection to be re-encrypted with an LTK, even if the LTK
2265 * provides the same level of security. Only exception is if we
2266 * don't have an LTK (e.g. because of key distribution bits).
2267 */
2268 if (key_pref == SMP_USE_LTK &&
2269 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) &&
2270 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role))
2271 return false;
2272
2273 if (hcon->sec_level >= sec_level)
2274 return true;
2275
2276 return false;
2277}
2278
2279static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
2280{
2281 struct smp_cmd_security_req *rp = (void *) skb->data;
2282 struct smp_cmd_pairing cp;
2283 struct hci_conn *hcon = conn->hcon;
2284 struct hci_dev *hdev = hcon->hdev;
2285 struct smp_chan *smp;
2286 u8 sec_level, auth;
2287
2288 BT_DBG("conn %p", conn);
2289
2290 if (skb->len < sizeof(*rp))
2291 return SMP_INVALID_PARAMS;
2292
2293 if (hcon->role != HCI_ROLE_MASTER)
2294 return SMP_CMD_NOTSUPP;
2295
2296 auth = rp->auth_req & AUTH_REQ_MASK(hdev);
2297
2298 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
2299 return SMP_AUTH_REQUIREMENTS;
2300
2301 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
2302 sec_level = BT_SECURITY_MEDIUM;
2303 else
2304 sec_level = authreq_to_seclevel(auth);
2305
2306 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) {
2307 /* If link is already encrypted with sufficient security we
2308 * still need refresh encryption as per Core Spec 5.0 Vol 3,
2309 * Part H 2.4.6
2310 */
2311 smp_ltk_encrypt(conn, hcon->sec_level);
2312 return 0;
2313 }
2314
2315 if (sec_level > hcon->pending_sec_level)
2316 hcon->pending_sec_level = sec_level;
2317
2318 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2319 return 0;
2320
2321 smp = smp_chan_create(conn);
2322 if (!smp)
2323 return SMP_UNSPECIFIED;
2324
2325 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) &&
2326 (auth & SMP_AUTH_BONDING))
2327 return SMP_PAIRING_NOTSUPP;
2328
2329 skb_pull(skb, sizeof(*rp));
2330
2331 memset(&cp, 0, sizeof(cp));
2332 build_pairing_cmd(conn, &cp, NULL, auth);
2333
2334 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2335 memcpy(&smp->preq[1], &cp, sizeof(cp));
2336
2337 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
2338 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2339
2340 return 0;
2341}
2342
2343int smp_conn_security(struct hci_conn *hcon, __u8 sec_level)
2344{
2345 struct l2cap_conn *conn = hcon->l2cap_data;
2346 struct l2cap_chan *chan;
2347 struct smp_chan *smp;
2348 __u8 authreq;
2349 int ret;
2350
2351 BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level);
2352
2353 /* This may be NULL if there's an unexpected disconnection */
2354 if (!conn)
2355 return 1;
2356
2357 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED))
2358 return 1;
2359
2360 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK))
2361 return 1;
2362
2363 if (sec_level > hcon->pending_sec_level)
2364 hcon->pending_sec_level = sec_level;
2365
2366 if (hcon->role == HCI_ROLE_MASTER)
2367 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2368 return 0;
2369
2370 chan = conn->smp;
2371 if (!chan) {
2372 bt_dev_err(hcon->hdev, "security requested but not available");
2373 return 1;
2374 }
2375
2376 l2cap_chan_lock(chan);
2377
2378 /* If SMP is already in progress ignore this request */
2379 if (chan->data) {
2380 ret = 0;
2381 goto unlock;
2382 }
2383
2384 smp = smp_chan_create(conn);
2385 if (!smp) {
2386 ret = 1;
2387 goto unlock;
2388 }
2389
2390 authreq = seclevel_to_authreq(sec_level);
2391
2392 if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED)) {
2393 authreq |= SMP_AUTH_SC;
2394 if (hci_dev_test_flag(hcon->hdev, HCI_SSP_ENABLED))
2395 authreq |= SMP_AUTH_CT2;
2396 }
2397
2398 /* Don't attempt to set MITM if setting is overridden by debugfs
2399 * Needed to pass certification test SM/MAS/PKE/BV-01-C
2400 */
2401 if (!hci_dev_test_flag(hcon->hdev, HCI_FORCE_NO_MITM)) {
2402 /* Require MITM if IO Capability allows or the security level
2403 * requires it.
2404 */
2405 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT ||
2406 hcon->pending_sec_level > BT_SECURITY_MEDIUM)
2407 authreq |= SMP_AUTH_MITM;
2408 }
2409
2410 if (hcon->role == HCI_ROLE_MASTER) {
2411 struct smp_cmd_pairing cp;
2412
2413 build_pairing_cmd(conn, &cp, NULL, authreq);
2414 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2415 memcpy(&smp->preq[1], &cp, sizeof(cp));
2416
2417 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
2418 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2419 } else {
2420 struct smp_cmd_security_req cp;
2421 cp.auth_req = authreq;
2422 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp);
2423 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ);
2424 }
2425
2426 set_bit(SMP_FLAG_INITIATOR, &smp->flags);
2427 ret = 0;
2428
2429unlock:
2430 l2cap_chan_unlock(chan);
2431 return ret;
2432}
2433
2434int smp_cancel_and_remove_pairing(struct hci_dev *hdev, bdaddr_t *bdaddr,
2435 u8 addr_type)
2436{
2437 struct hci_conn *hcon;
2438 struct l2cap_conn *conn;
2439 struct l2cap_chan *chan;
2440 struct smp_chan *smp;
2441 int err;
2442
2443 err = hci_remove_ltk(hdev, bdaddr, addr_type);
2444 hci_remove_irk(hdev, bdaddr, addr_type);
2445
2446 hcon = hci_conn_hash_lookup_le(hdev, bdaddr, addr_type);
2447 if (!hcon)
2448 goto done;
2449
2450 conn = hcon->l2cap_data;
2451 if (!conn)
2452 goto done;
2453
2454 chan = conn->smp;
2455 if (!chan)
2456 goto done;
2457
2458 l2cap_chan_lock(chan);
2459
2460 smp = chan->data;
2461 if (smp) {
2462 /* Set keys to NULL to make sure smp_failure() does not try to
2463 * remove and free already invalidated rcu list entries. */
2464 smp->ltk = NULL;
2465 smp->slave_ltk = NULL;
2466 smp->remote_irk = NULL;
2467
2468 if (test_bit(SMP_FLAG_COMPLETE, &smp->flags))
2469 smp_failure(conn, 0);
2470 else
2471 smp_failure(conn, SMP_UNSPECIFIED);
2472 err = 0;
2473 }
2474
2475 l2cap_chan_unlock(chan);
2476
2477done:
2478 return err;
2479}
2480
2481static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb)
2482{
2483 struct smp_cmd_encrypt_info *rp = (void *) skb->data;
2484 struct l2cap_chan *chan = conn->smp;
2485 struct smp_chan *smp = chan->data;
2486
2487 BT_DBG("conn %p", conn);
2488
2489 if (skb->len < sizeof(*rp))
2490 return SMP_INVALID_PARAMS;
2491
2492 /* Pairing is aborted if any blocked keys are distributed */
2493 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_LTK,
2494 rp->ltk)) {
2495 bt_dev_warn_ratelimited(conn->hcon->hdev,
2496 "LTK blocked for %pMR",
2497 &conn->hcon->dst);
2498 return SMP_INVALID_PARAMS;
2499 }
2500
2501 SMP_ALLOW_CMD(smp, SMP_CMD_MASTER_IDENT);
2502
2503 skb_pull(skb, sizeof(*rp));
2504
2505 memcpy(smp->tk, rp->ltk, sizeof(smp->tk));
2506
2507 return 0;
2508}
2509
2510static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb)
2511{
2512 struct smp_cmd_master_ident *rp = (void *) skb->data;
2513 struct l2cap_chan *chan = conn->smp;
2514 struct smp_chan *smp = chan->data;
2515 struct hci_dev *hdev = conn->hcon->hdev;
2516 struct hci_conn *hcon = conn->hcon;
2517 struct smp_ltk *ltk;
2518 u8 authenticated;
2519
2520 BT_DBG("conn %p", conn);
2521
2522 if (skb->len < sizeof(*rp))
2523 return SMP_INVALID_PARAMS;
2524
2525 /* Mark the information as received */
2526 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY;
2527
2528 if (smp->remote_key_dist & SMP_DIST_ID_KEY)
2529 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
2530 else if (smp->remote_key_dist & SMP_DIST_SIGN)
2531 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2532
2533 skb_pull(skb, sizeof(*rp));
2534
2535 authenticated = (hcon->sec_level == BT_SECURITY_HIGH);
2536 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK,
2537 authenticated, smp->tk, smp->enc_key_size,
2538 rp->ediv, rp->rand);
2539 smp->ltk = ltk;
2540 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2541 smp_distribute_keys(smp);
2542
2543 return 0;
2544}
2545
2546static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb)
2547{
2548 struct smp_cmd_ident_info *info = (void *) skb->data;
2549 struct l2cap_chan *chan = conn->smp;
2550 struct smp_chan *smp = chan->data;
2551
2552 BT_DBG("");
2553
2554 if (skb->len < sizeof(*info))
2555 return SMP_INVALID_PARAMS;
2556
2557 /* Pairing is aborted if any blocked keys are distributed */
2558 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_IRK,
2559 info->irk)) {
2560 bt_dev_warn_ratelimited(conn->hcon->hdev,
2561 "Identity key blocked for %pMR",
2562 &conn->hcon->dst);
2563 return SMP_INVALID_PARAMS;
2564 }
2565
2566 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO);
2567
2568 skb_pull(skb, sizeof(*info));
2569
2570 memcpy(smp->irk, info->irk, 16);
2571
2572 return 0;
2573}
2574
2575static int smp_cmd_ident_addr_info(struct l2cap_conn *conn,
2576 struct sk_buff *skb)
2577{
2578 struct smp_cmd_ident_addr_info *info = (void *) skb->data;
2579 struct l2cap_chan *chan = conn->smp;
2580 struct smp_chan *smp = chan->data;
2581 struct hci_conn *hcon = conn->hcon;
2582 bdaddr_t rpa;
2583
2584 BT_DBG("");
2585
2586 if (skb->len < sizeof(*info))
2587 return SMP_INVALID_PARAMS;
2588
2589 /* Mark the information as received */
2590 smp->remote_key_dist &= ~SMP_DIST_ID_KEY;
2591
2592 if (smp->remote_key_dist & SMP_DIST_SIGN)
2593 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2594
2595 skb_pull(skb, sizeof(*info));
2596
2597 /* Strictly speaking the Core Specification (4.1) allows sending
2598 * an empty address which would force us to rely on just the IRK
2599 * as "identity information". However, since such
2600 * implementations are not known of and in order to not over
2601 * complicate our implementation, simply pretend that we never
2602 * received an IRK for such a device.
2603 *
2604 * The Identity Address must also be a Static Random or Public
2605 * Address, which hci_is_identity_address() checks for.
2606 */
2607 if (!bacmp(&info->bdaddr, BDADDR_ANY) ||
2608 !hci_is_identity_address(&info->bdaddr, info->addr_type)) {
2609 bt_dev_err(hcon->hdev, "ignoring IRK with no identity address");
2610 goto distribute;
2611 }
2612
2613 /* Drop IRK if peer is using identity address during pairing but is
2614 * providing different address as identity information.
2615 *
2616 * Microsoft Surface Precision Mouse is known to have this bug.
2617 */
2618 if (hci_is_identity_address(&hcon->dst, hcon->dst_type) &&
2619 (bacmp(&info->bdaddr, &hcon->dst) ||
2620 info->addr_type != hcon->dst_type)) {
2621 bt_dev_err(hcon->hdev,
2622 "ignoring IRK with invalid identity address");
2623 goto distribute;
2624 }
2625
2626 bacpy(&smp->id_addr, &info->bdaddr);
2627 smp->id_addr_type = info->addr_type;
2628
2629 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type))
2630 bacpy(&rpa, &hcon->dst);
2631 else
2632 bacpy(&rpa, BDADDR_ANY);
2633
2634 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr,
2635 smp->id_addr_type, smp->irk, &rpa);
2636
2637distribute:
2638 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2639 smp_distribute_keys(smp);
2640
2641 return 0;
2642}
2643
2644static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb)
2645{
2646 struct smp_cmd_sign_info *rp = (void *) skb->data;
2647 struct l2cap_chan *chan = conn->smp;
2648 struct smp_chan *smp = chan->data;
2649 struct smp_csrk *csrk;
2650
2651 BT_DBG("conn %p", conn);
2652
2653 if (skb->len < sizeof(*rp))
2654 return SMP_INVALID_PARAMS;
2655
2656 /* Mark the information as received */
2657 smp->remote_key_dist &= ~SMP_DIST_SIGN;
2658
2659 skb_pull(skb, sizeof(*rp));
2660
2661 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
2662 if (csrk) {
2663 if (conn->hcon->sec_level > BT_SECURITY_MEDIUM)
2664 csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED;
2665 else
2666 csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED;
2667 memcpy(csrk->val, rp->csrk, sizeof(csrk->val));
2668 }
2669 smp->csrk = csrk;
2670 smp_distribute_keys(smp);
2671
2672 return 0;
2673}
2674
2675static u8 sc_select_method(struct smp_chan *smp)
2676{
2677 struct l2cap_conn *conn = smp->conn;
2678 struct hci_conn *hcon = conn->hcon;
2679 struct smp_cmd_pairing *local, *remote;
2680 u8 local_mitm, remote_mitm, local_io, remote_io, method;
2681
2682 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) ||
2683 test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags))
2684 return REQ_OOB;
2685
2686 /* The preq/prsp contain the raw Pairing Request/Response PDUs
2687 * which are needed as inputs to some crypto functions. To get
2688 * the "struct smp_cmd_pairing" from them we need to skip the
2689 * first byte which contains the opcode.
2690 */
2691 if (hcon->out) {
2692 local = (void *) &smp->preq[1];
2693 remote = (void *) &smp->prsp[1];
2694 } else {
2695 local = (void *) &smp->prsp[1];
2696 remote = (void *) &smp->preq[1];
2697 }
2698
2699 local_io = local->io_capability;
2700 remote_io = remote->io_capability;
2701
2702 local_mitm = (local->auth_req & SMP_AUTH_MITM);
2703 remote_mitm = (remote->auth_req & SMP_AUTH_MITM);
2704
2705 /* If either side wants MITM, look up the method from the table,
2706 * otherwise use JUST WORKS.
2707 */
2708 if (local_mitm || remote_mitm)
2709 method = get_auth_method(smp, local_io, remote_io);
2710 else
2711 method = JUST_WORKS;
2712
2713 /* Don't confirm locally initiated pairing attempts */
2714 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2715 method = JUST_WORKS;
2716
2717 return method;
2718}
2719
2720static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb)
2721{
2722 struct smp_cmd_public_key *key = (void *) skb->data;
2723 struct hci_conn *hcon = conn->hcon;
2724 struct l2cap_chan *chan = conn->smp;
2725 struct smp_chan *smp = chan->data;
2726 struct hci_dev *hdev = hcon->hdev;
2727 struct crypto_kpp *tfm_ecdh;
2728 struct smp_cmd_pairing_confirm cfm;
2729 int err;
2730
2731 BT_DBG("conn %p", conn);
2732
2733 if (skb->len < sizeof(*key))
2734 return SMP_INVALID_PARAMS;
2735
2736 memcpy(smp->remote_pk, key, 64);
2737
2738 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) {
2739 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk,
2740 smp->rr, 0, cfm.confirm_val);
2741 if (err)
2742 return SMP_UNSPECIFIED;
2743
2744 if (crypto_memneq(cfm.confirm_val, smp->pcnf, 16))
2745 return SMP_CONFIRM_FAILED;
2746 }
2747
2748 /* Non-initiating device sends its public key after receiving
2749 * the key from the initiating device.
2750 */
2751 if (!hcon->out) {
2752 err = sc_send_public_key(smp);
2753 if (err)
2754 return err;
2755 }
2756
2757 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk);
2758 SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32);
2759
2760 /* Compute the shared secret on the same crypto tfm on which the private
2761 * key was set/generated.
2762 */
2763 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) {
2764 struct l2cap_chan *hchan = hdev->smp_data;
2765 struct smp_dev *smp_dev;
2766
2767 if (!hchan || !hchan->data)
2768 return SMP_UNSPECIFIED;
2769
2770 smp_dev = hchan->data;
2771
2772 tfm_ecdh = smp_dev->tfm_ecdh;
2773 } else {
2774 tfm_ecdh = smp->tfm_ecdh;
2775 }
2776
2777 if (compute_ecdh_secret(tfm_ecdh, smp->remote_pk, smp->dhkey))
2778 return SMP_UNSPECIFIED;
2779
2780 SMP_DBG("DHKey %32phN", smp->dhkey);
2781
2782 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags);
2783
2784 smp->method = sc_select_method(smp);
2785
2786 BT_DBG("%s selected method 0x%02x", hdev->name, smp->method);
2787
2788 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */
2789 if (smp->method == JUST_WORKS || smp->method == JUST_CFM)
2790 hcon->pending_sec_level = BT_SECURITY_MEDIUM;
2791 else
2792 hcon->pending_sec_level = BT_SECURITY_FIPS;
2793
2794 if (!crypto_memneq(debug_pk, smp->remote_pk, 64))
2795 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
2796
2797 if (smp->method == DSP_PASSKEY) {
2798 get_random_bytes(&hcon->passkey_notify,
2799 sizeof(hcon->passkey_notify));
2800 hcon->passkey_notify %= 1000000;
2801 hcon->passkey_entered = 0;
2802 smp->passkey_round = 0;
2803 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type,
2804 hcon->dst_type,
2805 hcon->passkey_notify,
2806 hcon->passkey_entered))
2807 return SMP_UNSPECIFIED;
2808 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2809 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY);
2810 }
2811
2812 if (smp->method == REQ_OOB) {
2813 if (hcon->out)
2814 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2815 sizeof(smp->prnd), smp->prnd);
2816
2817 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2818
2819 return 0;
2820 }
2821
2822 if (hcon->out)
2823 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2824
2825 if (smp->method == REQ_PASSKEY) {
2826 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type,
2827 hcon->dst_type))
2828 return SMP_UNSPECIFIED;
2829 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2830 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2831 return 0;
2832 }
2833
2834 /* The Initiating device waits for the non-initiating device to
2835 * send the confirm value.
2836 */
2837 if (conn->hcon->out)
2838 return 0;
2839
2840 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd,
2841 0, cfm.confirm_val);
2842 if (err)
2843 return SMP_UNSPECIFIED;
2844
2845 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
2846 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2847
2848 return 0;
2849}
2850
2851static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb)
2852{
2853 struct smp_cmd_dhkey_check *check = (void *) skb->data;
2854 struct l2cap_chan *chan = conn->smp;
2855 struct hci_conn *hcon = conn->hcon;
2856 struct smp_chan *smp = chan->data;
2857 u8 a[7], b[7], *local_addr, *remote_addr;
2858 u8 io_cap[3], r[16], e[16];
2859 int err;
2860
2861 BT_DBG("conn %p", conn);
2862
2863 if (skb->len < sizeof(*check))
2864 return SMP_INVALID_PARAMS;
2865
2866 memcpy(a, &hcon->init_addr, 6);
2867 memcpy(b, &hcon->resp_addr, 6);
2868 a[6] = hcon->init_addr_type;
2869 b[6] = hcon->resp_addr_type;
2870
2871 if (hcon->out) {
2872 local_addr = a;
2873 remote_addr = b;
2874 memcpy(io_cap, &smp->prsp[1], 3);
2875 } else {
2876 local_addr = b;
2877 remote_addr = a;
2878 memcpy(io_cap, &smp->preq[1], 3);
2879 }
2880
2881 memset(r, 0, sizeof(r));
2882
2883 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2884 put_unaligned_le32(hcon->passkey_notify, r);
2885 else if (smp->method == REQ_OOB)
2886 memcpy(r, smp->lr, 16);
2887
2888 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r,
2889 io_cap, remote_addr, local_addr, e);
2890 if (err)
2891 return SMP_UNSPECIFIED;
2892
2893 if (crypto_memneq(check->e, e, 16))
2894 return SMP_DHKEY_CHECK_FAILED;
2895
2896 if (!hcon->out) {
2897 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
2898 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags);
2899 return 0;
2900 }
2901
2902 /* Slave sends DHKey check as response to master */
2903 sc_dhkey_check(smp);
2904 }
2905
2906 sc_add_ltk(smp);
2907
2908 if (hcon->out) {
2909 hci_le_start_enc(hcon, 0, 0, smp->tk, smp->enc_key_size);
2910 hcon->enc_key_size = smp->enc_key_size;
2911 }
2912
2913 return 0;
2914}
2915
2916static int smp_cmd_keypress_notify(struct l2cap_conn *conn,
2917 struct sk_buff *skb)
2918{
2919 struct smp_cmd_keypress_notify *kp = (void *) skb->data;
2920
2921 BT_DBG("value 0x%02x", kp->value);
2922
2923 return 0;
2924}
2925
2926static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb)
2927{
2928 struct l2cap_conn *conn = chan->conn;
2929 struct hci_conn *hcon = conn->hcon;
2930 struct smp_chan *smp;
2931 __u8 code, reason;
2932 int err = 0;
2933
2934 if (skb->len < 1)
2935 return -EILSEQ;
2936
2937 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) {
2938 reason = SMP_PAIRING_NOTSUPP;
2939 goto done;
2940 }
2941
2942 code = skb->data[0];
2943 skb_pull(skb, sizeof(code));
2944
2945 smp = chan->data;
2946
2947 if (code > SMP_CMD_MAX)
2948 goto drop;
2949
2950 if (smp && !test_and_clear_bit(code, &smp->allow_cmd))
2951 goto drop;
2952
2953 /* If we don't have a context the only allowed commands are
2954 * pairing request and security request.
2955 */
2956 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ)
2957 goto drop;
2958
2959 switch (code) {
2960 case SMP_CMD_PAIRING_REQ:
2961 reason = smp_cmd_pairing_req(conn, skb);
2962 break;
2963
2964 case SMP_CMD_PAIRING_FAIL:
2965 smp_failure(conn, 0);
2966 err = -EPERM;
2967 break;
2968
2969 case SMP_CMD_PAIRING_RSP:
2970 reason = smp_cmd_pairing_rsp(conn, skb);
2971 break;
2972
2973 case SMP_CMD_SECURITY_REQ:
2974 reason = smp_cmd_security_req(conn, skb);
2975 break;
2976
2977 case SMP_CMD_PAIRING_CONFIRM:
2978 reason = smp_cmd_pairing_confirm(conn, skb);
2979 break;
2980
2981 case SMP_CMD_PAIRING_RANDOM:
2982 reason = smp_cmd_pairing_random(conn, skb);
2983 break;
2984
2985 case SMP_CMD_ENCRYPT_INFO:
2986 reason = smp_cmd_encrypt_info(conn, skb);
2987 break;
2988
2989 case SMP_CMD_MASTER_IDENT:
2990 reason = smp_cmd_master_ident(conn, skb);
2991 break;
2992
2993 case SMP_CMD_IDENT_INFO:
2994 reason = smp_cmd_ident_info(conn, skb);
2995 break;
2996
2997 case SMP_CMD_IDENT_ADDR_INFO:
2998 reason = smp_cmd_ident_addr_info(conn, skb);
2999 break;
3000
3001 case SMP_CMD_SIGN_INFO:
3002 reason = smp_cmd_sign_info(conn, skb);
3003 break;
3004
3005 case SMP_CMD_PUBLIC_KEY:
3006 reason = smp_cmd_public_key(conn, skb);
3007 break;
3008
3009 case SMP_CMD_DHKEY_CHECK:
3010 reason = smp_cmd_dhkey_check(conn, skb);
3011 break;
3012
3013 case SMP_CMD_KEYPRESS_NOTIFY:
3014 reason = smp_cmd_keypress_notify(conn, skb);
3015 break;
3016
3017 default:
3018 BT_DBG("Unknown command code 0x%2.2x", code);
3019 reason = SMP_CMD_NOTSUPP;
3020 goto done;
3021 }
3022
3023done:
3024 if (!err) {
3025 if (reason)
3026 smp_failure(conn, reason);
3027 kfree_skb(skb);
3028 }
3029
3030 return err;
3031
3032drop:
3033 bt_dev_err(hcon->hdev, "unexpected SMP command 0x%02x from %pMR",
3034 code, &hcon->dst);
3035 kfree_skb(skb);
3036 return 0;
3037}
3038
3039static void smp_teardown_cb(struct l2cap_chan *chan, int err)
3040{
3041 struct l2cap_conn *conn = chan->conn;
3042
3043 BT_DBG("chan %p", chan);
3044
3045 if (chan->data)
3046 smp_chan_destroy(conn);
3047
3048 conn->smp = NULL;
3049 l2cap_chan_put(chan);
3050}
3051
3052static void bredr_pairing(struct l2cap_chan *chan)
3053{
3054 struct l2cap_conn *conn = chan->conn;
3055 struct hci_conn *hcon = conn->hcon;
3056 struct hci_dev *hdev = hcon->hdev;
3057 struct smp_cmd_pairing req;
3058 struct smp_chan *smp;
3059
3060 BT_DBG("chan %p", chan);
3061
3062 /* Only new pairings are interesting */
3063 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags))
3064 return;
3065
3066 /* Don't bother if we're not encrypted */
3067 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3068 return;
3069
3070 /* Only master may initiate SMP over BR/EDR */
3071 if (hcon->role != HCI_ROLE_MASTER)
3072 return;
3073
3074 /* Secure Connections support must be enabled */
3075 if (!hci_dev_test_flag(hdev, HCI_SC_ENABLED))
3076 return;
3077
3078 /* BR/EDR must use Secure Connections for SMP */
3079 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) &&
3080 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3081 return;
3082
3083 /* If our LE support is not enabled don't do anything */
3084 if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED))
3085 return;
3086
3087 /* Don't bother if remote LE support is not enabled */
3088 if (!lmp_host_le_capable(hcon))
3089 return;
3090
3091 /* Remote must support SMP fixed chan for BR/EDR */
3092 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR))
3093 return;
3094
3095 /* Don't bother if SMP is already ongoing */
3096 if (chan->data)
3097 return;
3098
3099 smp = smp_chan_create(conn);
3100 if (!smp) {
3101 bt_dev_err(hdev, "unable to create SMP context for BR/EDR");
3102 return;
3103 }
3104
3105 set_bit(SMP_FLAG_SC, &smp->flags);
3106
3107 BT_DBG("%s starting SMP over BR/EDR", hdev->name);
3108
3109 /* Prepare and send the BR/EDR SMP Pairing Request */
3110 build_bredr_pairing_cmd(smp, &req, NULL);
3111
3112 smp->preq[0] = SMP_CMD_PAIRING_REQ;
3113 memcpy(&smp->preq[1], &req, sizeof(req));
3114
3115 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(req), &req);
3116 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
3117}
3118
3119static void smp_resume_cb(struct l2cap_chan *chan)
3120{
3121 struct smp_chan *smp = chan->data;
3122 struct l2cap_conn *conn = chan->conn;
3123 struct hci_conn *hcon = conn->hcon;
3124
3125 BT_DBG("chan %p", chan);
3126
3127 if (hcon->type == ACL_LINK) {
3128 bredr_pairing(chan);
3129 return;
3130 }
3131
3132 if (!smp)
3133 return;
3134
3135 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3136 return;
3137
3138 cancel_delayed_work(&smp->security_timer);
3139
3140 smp_distribute_keys(smp);
3141}
3142
3143static void smp_ready_cb(struct l2cap_chan *chan)
3144{
3145 struct l2cap_conn *conn = chan->conn;
3146 struct hci_conn *hcon = conn->hcon;
3147
3148 BT_DBG("chan %p", chan);
3149
3150 /* No need to call l2cap_chan_hold() here since we already own
3151 * the reference taken in smp_new_conn_cb(). This is just the
3152 * first time that we tie it to a specific pointer. The code in
3153 * l2cap_core.c ensures that there's no risk this function wont
3154 * get called if smp_new_conn_cb was previously called.
3155 */
3156 conn->smp = chan;
3157
3158 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
3159 bredr_pairing(chan);
3160}
3161
3162static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
3163{
3164 int err;
3165
3166 BT_DBG("chan %p", chan);
3167
3168 err = smp_sig_channel(chan, skb);
3169 if (err) {
3170 struct smp_chan *smp = chan->data;
3171
3172 if (smp)
3173 cancel_delayed_work_sync(&smp->security_timer);
3174
3175 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE);
3176 }
3177
3178 return err;
3179}
3180
3181static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan,
3182 unsigned long hdr_len,
3183 unsigned long len, int nb)
3184{
3185 struct sk_buff *skb;
3186
3187 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL);
3188 if (!skb)
3189 return ERR_PTR(-ENOMEM);
3190
3191 skb->priority = HCI_PRIO_MAX;
3192 bt_cb(skb)->l2cap.chan = chan;
3193
3194 return skb;
3195}
3196
3197static const struct l2cap_ops smp_chan_ops = {
3198 .name = "Security Manager",
3199 .ready = smp_ready_cb,
3200 .recv = smp_recv_cb,
3201 .alloc_skb = smp_alloc_skb_cb,
3202 .teardown = smp_teardown_cb,
3203 .resume = smp_resume_cb,
3204
3205 .new_connection = l2cap_chan_no_new_connection,
3206 .state_change = l2cap_chan_no_state_change,
3207 .close = l2cap_chan_no_close,
3208 .defer = l2cap_chan_no_defer,
3209 .suspend = l2cap_chan_no_suspend,
3210 .set_shutdown = l2cap_chan_no_set_shutdown,
3211 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
3212};
3213
3214static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan)
3215{
3216 struct l2cap_chan *chan;
3217
3218 BT_DBG("pchan %p", pchan);
3219
3220 chan = l2cap_chan_create();
3221 if (!chan)
3222 return NULL;
3223
3224 chan->chan_type = pchan->chan_type;
3225 chan->ops = &smp_chan_ops;
3226 chan->scid = pchan->scid;
3227 chan->dcid = chan->scid;
3228 chan->imtu = pchan->imtu;
3229 chan->omtu = pchan->omtu;
3230 chan->mode = pchan->mode;
3231
3232 /* Other L2CAP channels may request SMP routines in order to
3233 * change the security level. This means that the SMP channel
3234 * lock must be considered in its own category to avoid lockdep
3235 * warnings.
3236 */
3237 atomic_set(&chan->nesting, L2CAP_NESTING_SMP);
3238
3239 BT_DBG("created chan %p", chan);
3240
3241 return chan;
3242}
3243
3244static const struct l2cap_ops smp_root_chan_ops = {
3245 .name = "Security Manager Root",
3246 .new_connection = smp_new_conn_cb,
3247
3248 /* None of these are implemented for the root channel */
3249 .close = l2cap_chan_no_close,
3250 .alloc_skb = l2cap_chan_no_alloc_skb,
3251 .recv = l2cap_chan_no_recv,
3252 .state_change = l2cap_chan_no_state_change,
3253 .teardown = l2cap_chan_no_teardown,
3254 .ready = l2cap_chan_no_ready,
3255 .defer = l2cap_chan_no_defer,
3256 .suspend = l2cap_chan_no_suspend,
3257 .resume = l2cap_chan_no_resume,
3258 .set_shutdown = l2cap_chan_no_set_shutdown,
3259 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
3260};
3261
3262static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid)
3263{
3264 struct l2cap_chan *chan;
3265 struct smp_dev *smp;
3266 struct crypto_shash *tfm_cmac;
3267 struct crypto_kpp *tfm_ecdh;
3268
3269 if (cid == L2CAP_CID_SMP_BREDR) {
3270 smp = NULL;
3271 goto create_chan;
3272 }
3273
3274 smp = kzalloc(sizeof(*smp), GFP_KERNEL);
3275 if (!smp)
3276 return ERR_PTR(-ENOMEM);
3277
3278 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
3279 if (IS_ERR(tfm_cmac)) {
3280 BT_ERR("Unable to create CMAC crypto context");
3281 kfree_sensitive(smp);
3282 return ERR_CAST(tfm_cmac);
3283 }
3284
3285 tfm_ecdh = crypto_alloc_kpp("ecdh", 0, 0);
3286 if (IS_ERR(tfm_ecdh)) {
3287 BT_ERR("Unable to create ECDH crypto context");
3288 crypto_free_shash(tfm_cmac);
3289 kfree_sensitive(smp);
3290 return ERR_CAST(tfm_ecdh);
3291 }
3292
3293 smp->local_oob = false;
3294 smp->tfm_cmac = tfm_cmac;
3295 smp->tfm_ecdh = tfm_ecdh;
3296
3297create_chan:
3298 chan = l2cap_chan_create();
3299 if (!chan) {
3300 if (smp) {
3301 crypto_free_shash(smp->tfm_cmac);
3302 crypto_free_kpp(smp->tfm_ecdh);
3303 kfree_sensitive(smp);
3304 }
3305 return ERR_PTR(-ENOMEM);
3306 }
3307
3308 chan->data = smp;
3309
3310 l2cap_add_scid(chan, cid);
3311
3312 l2cap_chan_set_defaults(chan);
3313
3314 if (cid == L2CAP_CID_SMP) {
3315 u8 bdaddr_type;
3316
3317 hci_copy_identity_address(hdev, &chan->src, &bdaddr_type);
3318
3319 if (bdaddr_type == ADDR_LE_DEV_PUBLIC)
3320 chan->src_type = BDADDR_LE_PUBLIC;
3321 else
3322 chan->src_type = BDADDR_LE_RANDOM;
3323 } else {
3324 bacpy(&chan->src, &hdev->bdaddr);
3325 chan->src_type = BDADDR_BREDR;
3326 }
3327
3328 chan->state = BT_LISTEN;
3329 chan->mode = L2CAP_MODE_BASIC;
3330 chan->imtu = L2CAP_DEFAULT_MTU;
3331 chan->ops = &smp_root_chan_ops;
3332
3333 /* Set correct nesting level for a parent/listening channel */
3334 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
3335
3336 return chan;
3337}
3338
3339static void smp_del_chan(struct l2cap_chan *chan)
3340{
3341 struct smp_dev *smp;
3342
3343 BT_DBG("chan %p", chan);
3344
3345 smp = chan->data;
3346 if (smp) {
3347 chan->data = NULL;
3348 crypto_free_shash(smp->tfm_cmac);
3349 crypto_free_kpp(smp->tfm_ecdh);
3350 kfree_sensitive(smp);
3351 }
3352
3353 l2cap_chan_put(chan);
3354}
3355
3356static ssize_t force_bredr_smp_read(struct file *file,
3357 char __user *user_buf,
3358 size_t count, loff_t *ppos)
3359{
3360 struct hci_dev *hdev = file->private_data;
3361 char buf[3];
3362
3363 buf[0] = hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP) ? 'Y': 'N';
3364 buf[1] = '\n';
3365 buf[2] = '\0';
3366 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
3367}
3368
3369static ssize_t force_bredr_smp_write(struct file *file,
3370 const char __user *user_buf,
3371 size_t count, loff_t *ppos)
3372{
3373 struct hci_dev *hdev = file->private_data;
3374 bool enable;
3375 int err;
3376
3377 err = kstrtobool_from_user(user_buf, count, &enable);
3378 if (err)
3379 return err;
3380
3381 if (enable == hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3382 return -EALREADY;
3383
3384 if (enable) {
3385 struct l2cap_chan *chan;
3386
3387 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
3388 if (IS_ERR(chan))
3389 return PTR_ERR(chan);
3390
3391 hdev->smp_bredr_data = chan;
3392 } else {
3393 struct l2cap_chan *chan;
3394
3395 chan = hdev->smp_bredr_data;
3396 hdev->smp_bredr_data = NULL;
3397 smp_del_chan(chan);
3398 }
3399
3400 hci_dev_change_flag(hdev, HCI_FORCE_BREDR_SMP);
3401
3402 return count;
3403}
3404
3405static const struct file_operations force_bredr_smp_fops = {
3406 .open = simple_open,
3407 .read = force_bredr_smp_read,
3408 .write = force_bredr_smp_write,
3409 .llseek = default_llseek,
3410};
3411
3412int smp_register(struct hci_dev *hdev)
3413{
3414 struct l2cap_chan *chan;
3415
3416 BT_DBG("%s", hdev->name);
3417
3418 /* If the controller does not support Low Energy operation, then
3419 * there is also no need to register any SMP channel.
3420 */
3421 if (!lmp_le_capable(hdev))
3422 return 0;
3423
3424 if (WARN_ON(hdev->smp_data)) {
3425 chan = hdev->smp_data;
3426 hdev->smp_data = NULL;
3427 smp_del_chan(chan);
3428 }
3429
3430 chan = smp_add_cid(hdev, L2CAP_CID_SMP);
3431 if (IS_ERR(chan))
3432 return PTR_ERR(chan);
3433
3434 hdev->smp_data = chan;
3435
3436 /* If the controller does not support BR/EDR Secure Connections
3437 * feature, then the BR/EDR SMP channel shall not be present.
3438 *
3439 * To test this with Bluetooth 4.0 controllers, create a debugfs
3440 * switch that allows forcing BR/EDR SMP support and accepting
3441 * cross-transport pairing on non-AES encrypted connections.
3442 */
3443 if (!lmp_sc_capable(hdev)) {
3444 debugfs_create_file("force_bredr_smp", 0644, hdev->debugfs,
3445 hdev, &force_bredr_smp_fops);
3446
3447 /* Flag can be already set here (due to power toggle) */
3448 if (!hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
3449 return 0;
3450 }
3451
3452 if (WARN_ON(hdev->smp_bredr_data)) {
3453 chan = hdev->smp_bredr_data;
3454 hdev->smp_bredr_data = NULL;
3455 smp_del_chan(chan);
3456 }
3457
3458 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
3459 if (IS_ERR(chan)) {
3460 int err = PTR_ERR(chan);
3461 chan = hdev->smp_data;
3462 hdev->smp_data = NULL;
3463 smp_del_chan(chan);
3464 return err;
3465 }
3466
3467 hdev->smp_bredr_data = chan;
3468
3469 return 0;
3470}
3471
3472void smp_unregister(struct hci_dev *hdev)
3473{
3474 struct l2cap_chan *chan;
3475
3476 if (hdev->smp_bredr_data) {
3477 chan = hdev->smp_bredr_data;
3478 hdev->smp_bredr_data = NULL;
3479 smp_del_chan(chan);
3480 }
3481
3482 if (hdev->smp_data) {
3483 chan = hdev->smp_data;
3484 hdev->smp_data = NULL;
3485 smp_del_chan(chan);
3486 }
3487}
3488
3489#if IS_ENABLED(CONFIG_BT_SELFTEST_SMP)
3490
3491static int __init test_debug_key(struct crypto_kpp *tfm_ecdh)
3492{
3493 u8 pk[64];
3494 int err;
3495
3496 err = set_ecdh_privkey(tfm_ecdh, debug_sk);
3497 if (err)
3498 return err;
3499
3500 err = generate_ecdh_public_key(tfm_ecdh, pk);
3501 if (err)
3502 return err;
3503
3504 if (crypto_memneq(pk, debug_pk, 64))
3505 return -EINVAL;
3506
3507 return 0;
3508}
3509
3510static int __init test_ah(void)
3511{
3512 const u8 irk[16] = {
3513 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3514 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3515 const u8 r[3] = { 0x94, 0x81, 0x70 };
3516 const u8 exp[3] = { 0xaa, 0xfb, 0x0d };
3517 u8 res[3];
3518 int err;
3519
3520 err = smp_ah(irk, r, res);
3521 if (err)
3522 return err;
3523
3524 if (crypto_memneq(res, exp, 3))
3525 return -EINVAL;
3526
3527 return 0;
3528}
3529
3530static int __init test_c1(void)
3531{
3532 const u8 k[16] = {
3533 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
3534 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
3535 const u8 r[16] = {
3536 0xe0, 0x2e, 0x70, 0xc6, 0x4e, 0x27, 0x88, 0x63,
3537 0x0e, 0x6f, 0xad, 0x56, 0x21, 0xd5, 0x83, 0x57 };
3538 const u8 preq[7] = { 0x01, 0x01, 0x00, 0x00, 0x10, 0x07, 0x07 };
3539 const u8 pres[7] = { 0x02, 0x03, 0x00, 0x00, 0x08, 0x00, 0x05 };
3540 const u8 _iat = 0x01;
3541 const u8 _rat = 0x00;
3542 const bdaddr_t ra = { { 0xb6, 0xb5, 0xb4, 0xb3, 0xb2, 0xb1 } };
3543 const bdaddr_t ia = { { 0xa6, 0xa5, 0xa4, 0xa3, 0xa2, 0xa1 } };
3544 const u8 exp[16] = {
3545 0x86, 0x3b, 0xf1, 0xbe, 0xc5, 0x4d, 0xa7, 0xd2,
3546 0xea, 0x88, 0x89, 0x87, 0xef, 0x3f, 0x1e, 0x1e };
3547 u8 res[16];
3548 int err;
3549
3550 err = smp_c1(k, r, preq, pres, _iat, &ia, _rat, &ra, res);
3551 if (err)
3552 return err;
3553
3554 if (crypto_memneq(res, exp, 16))
3555 return -EINVAL;
3556
3557 return 0;
3558}
3559
3560static int __init test_s1(void)
3561{
3562 const u8 k[16] = {
3563 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
3564 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
3565 const u8 r1[16] = {
3566 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 };
3567 const u8 r2[16] = {
3568 0x00, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99 };
3569 const u8 exp[16] = {
3570 0x62, 0xa0, 0x6d, 0x79, 0xae, 0x16, 0x42, 0x5b,
3571 0x9b, 0xf4, 0xb0, 0xe8, 0xf0, 0xe1, 0x1f, 0x9a };
3572 u8 res[16];
3573 int err;
3574
3575 err = smp_s1(k, r1, r2, res);
3576 if (err)
3577 return err;
3578
3579 if (crypto_memneq(res, exp, 16))
3580 return -EINVAL;
3581
3582 return 0;
3583}
3584
3585static int __init test_f4(struct crypto_shash *tfm_cmac)
3586{
3587 const u8 u[32] = {
3588 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
3589 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
3590 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
3591 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 };
3592 const u8 v[32] = {
3593 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b,
3594 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59,
3595 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90,
3596 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 };
3597 const u8 x[16] = {
3598 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3599 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3600 const u8 z = 0x00;
3601 const u8 exp[16] = {
3602 0x2d, 0x87, 0x74, 0xa9, 0xbe, 0xa1, 0xed, 0xf1,
3603 0x1c, 0xbd, 0xa9, 0x07, 0xf1, 0x16, 0xc9, 0xf2 };
3604 u8 res[16];
3605 int err;
3606
3607 err = smp_f4(tfm_cmac, u, v, x, z, res);
3608 if (err)
3609 return err;
3610
3611 if (crypto_memneq(res, exp, 16))
3612 return -EINVAL;
3613
3614 return 0;
3615}
3616
3617static int __init test_f5(struct crypto_shash *tfm_cmac)
3618{
3619 const u8 w[32] = {
3620 0x98, 0xa6, 0xbf, 0x73, 0xf3, 0x34, 0x8d, 0x86,
3621 0xf1, 0x66, 0xf8, 0xb4, 0x13, 0x6b, 0x79, 0x99,
3622 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3623 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3624 const u8 n1[16] = {
3625 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3626 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3627 const u8 n2[16] = {
3628 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3629 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3630 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 };
3631 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 };
3632 const u8 exp_ltk[16] = {
3633 0x38, 0x0a, 0x75, 0x94, 0xb5, 0x22, 0x05, 0x98,
3634 0x23, 0xcd, 0xd7, 0x69, 0x11, 0x79, 0x86, 0x69 };
3635 const u8 exp_mackey[16] = {
3636 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd,
3637 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 };
3638 u8 mackey[16], ltk[16];
3639 int err;
3640
3641 err = smp_f5(tfm_cmac, w, n1, n2, a1, a2, mackey, ltk);
3642 if (err)
3643 return err;
3644
3645 if (crypto_memneq(mackey, exp_mackey, 16))
3646 return -EINVAL;
3647
3648 if (crypto_memneq(ltk, exp_ltk, 16))
3649 return -EINVAL;
3650
3651 return 0;
3652}
3653
3654static int __init test_f6(struct crypto_shash *tfm_cmac)
3655{
3656 const u8 w[16] = {
3657 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd,
3658 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 };
3659 const u8 n1[16] = {
3660 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3661 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3662 const u8 n2[16] = {
3663 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3664 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3665 const u8 r[16] = {
3666 0xc8, 0x0f, 0x2d, 0x0c, 0xd2, 0x42, 0xda, 0x08,
3667 0x54, 0xbb, 0x53, 0xb4, 0x3b, 0x34, 0xa3, 0x12 };
3668 const u8 io_cap[3] = { 0x02, 0x01, 0x01 };
3669 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 };
3670 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 };
3671 const u8 exp[16] = {
3672 0x61, 0x8f, 0x95, 0xda, 0x09, 0x0b, 0x6c, 0xd2,
3673 0xc5, 0xe8, 0xd0, 0x9c, 0x98, 0x73, 0xc4, 0xe3 };
3674 u8 res[16];
3675 int err;
3676
3677 err = smp_f6(tfm_cmac, w, n1, n2, r, io_cap, a1, a2, res);
3678 if (err)
3679 return err;
3680
3681 if (crypto_memneq(res, exp, 16))
3682 return -EINVAL;
3683
3684 return 0;
3685}
3686
3687static int __init test_g2(struct crypto_shash *tfm_cmac)
3688{
3689 const u8 u[32] = {
3690 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
3691 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
3692 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
3693 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 };
3694 const u8 v[32] = {
3695 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b,
3696 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59,
3697 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90,
3698 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 };
3699 const u8 x[16] = {
3700 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
3701 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
3702 const u8 y[16] = {
3703 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
3704 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
3705 const u32 exp_val = 0x2f9ed5ba % 1000000;
3706 u32 val;
3707 int err;
3708
3709 err = smp_g2(tfm_cmac, u, v, x, y, &val);
3710 if (err)
3711 return err;
3712
3713 if (val != exp_val)
3714 return -EINVAL;
3715
3716 return 0;
3717}
3718
3719static int __init test_h6(struct crypto_shash *tfm_cmac)
3720{
3721 const u8 w[16] = {
3722 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
3723 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
3724 const u8 key_id[4] = { 0x72, 0x62, 0x65, 0x6c };
3725 const u8 exp[16] = {
3726 0x99, 0x63, 0xb1, 0x80, 0xe2, 0xa9, 0xd3, 0xe8,
3727 0x1c, 0xc9, 0x6d, 0xe7, 0x02, 0xe1, 0x9a, 0x2d };
3728 u8 res[16];
3729 int err;
3730
3731 err = smp_h6(tfm_cmac, w, key_id, res);
3732 if (err)
3733 return err;
3734
3735 if (crypto_memneq(res, exp, 16))
3736 return -EINVAL;
3737
3738 return 0;
3739}
3740
3741static char test_smp_buffer[32];
3742
3743static ssize_t test_smp_read(struct file *file, char __user *user_buf,
3744 size_t count, loff_t *ppos)
3745{
3746 return simple_read_from_buffer(user_buf, count, ppos, test_smp_buffer,
3747 strlen(test_smp_buffer));
3748}
3749
3750static const struct file_operations test_smp_fops = {
3751 .open = simple_open,
3752 .read = test_smp_read,
3753 .llseek = default_llseek,
3754};
3755
3756static int __init run_selftests(struct crypto_shash *tfm_cmac,
3757 struct crypto_kpp *tfm_ecdh)
3758{
3759 ktime_t calltime, delta, rettime;
3760 unsigned long long duration;
3761 int err;
3762
3763 calltime = ktime_get();
3764
3765 err = test_debug_key(tfm_ecdh);
3766 if (err) {
3767 BT_ERR("debug_key test failed");
3768 goto done;
3769 }
3770
3771 err = test_ah();
3772 if (err) {
3773 BT_ERR("smp_ah test failed");
3774 goto done;
3775 }
3776
3777 err = test_c1();
3778 if (err) {
3779 BT_ERR("smp_c1 test failed");
3780 goto done;
3781 }
3782
3783 err = test_s1();
3784 if (err) {
3785 BT_ERR("smp_s1 test failed");
3786 goto done;
3787 }
3788
3789 err = test_f4(tfm_cmac);
3790 if (err) {
3791 BT_ERR("smp_f4 test failed");
3792 goto done;
3793 }
3794
3795 err = test_f5(tfm_cmac);
3796 if (err) {
3797 BT_ERR("smp_f5 test failed");
3798 goto done;
3799 }
3800
3801 err = test_f6(tfm_cmac);
3802 if (err) {
3803 BT_ERR("smp_f6 test failed");
3804 goto done;
3805 }
3806
3807 err = test_g2(tfm_cmac);
3808 if (err) {
3809 BT_ERR("smp_g2 test failed");
3810 goto done;
3811 }
3812
3813 err = test_h6(tfm_cmac);
3814 if (err) {
3815 BT_ERR("smp_h6 test failed");
3816 goto done;
3817 }
3818
3819 rettime = ktime_get();
3820 delta = ktime_sub(rettime, calltime);
3821 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
3822
3823 BT_INFO("SMP test passed in %llu usecs", duration);
3824
3825done:
3826 if (!err)
3827 snprintf(test_smp_buffer, sizeof(test_smp_buffer),
3828 "PASS (%llu usecs)\n", duration);
3829 else
3830 snprintf(test_smp_buffer, sizeof(test_smp_buffer), "FAIL\n");
3831
3832 debugfs_create_file("selftest_smp", 0444, bt_debugfs, NULL,
3833 &test_smp_fops);
3834
3835 return err;
3836}
3837
3838int __init bt_selftest_smp(void)
3839{
3840 struct crypto_shash *tfm_cmac;
3841 struct crypto_kpp *tfm_ecdh;
3842 int err;
3843
3844 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
3845 if (IS_ERR(tfm_cmac)) {
3846 BT_ERR("Unable to create CMAC crypto context");
3847 return PTR_ERR(tfm_cmac);
3848 }
3849
3850 tfm_ecdh = crypto_alloc_kpp("ecdh", 0, 0);
3851 if (IS_ERR(tfm_ecdh)) {
3852 BT_ERR("Unable to create ECDH crypto context");
3853 crypto_free_shash(tfm_cmac);
3854 return PTR_ERR(tfm_ecdh);
3855 }
3856
3857 err = run_selftests(tfm_cmac, tfm_ecdh);
3858
3859 crypto_free_shash(tfm_cmac);
3860 crypto_free_kpp(tfm_ecdh);
3861
3862 return err;
3863}
3864
3865#endif