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Bluetooth: Fix false-positive "uninitialized" compiler warning
[deliverable/linux.git] / net / bluetooth / smp.c
CommitLineData
eb492e01
AB		 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
8c520a59
GP		 23#include <linux/crypto.h>
24#include <linux/scatterlist.h>
25#include <crypto/b128ops.h>
26
eb492e01
AB		 27#include <net/bluetooth/bluetooth.h>
28#include <net/bluetooth/hci_core.h>
29#include <net/bluetooth/l2cap.h>
2b64d153 30#include <net/bluetooth/mgmt.h>
ac4b7236 31
3b19146d 32#include "ecc.h"
ac4b7236 33#include "smp.h"
d22ef0bc 34
c7a3d57d
JH		 35/* Low-level debug macros to be used for stuff that we don't want
36 * accidentially in dmesg, i.e. the values of the various crypto keys
37 * and the inputs & outputs of crypto functions.
38 */
39#ifdef DEBUG
40#define SMP_DBG(fmt, ...) printk(KERN_DEBUG "%s: " fmt, __func__, \
41 ##__VA_ARGS__)
42#else
43#define SMP_DBG(fmt, ...) no_printk(KERN_DEBUG "%s: " fmt, __func__, \
44 ##__VA_ARGS__)
45#endif
46
b28b4943 47#define SMP_ALLOW_CMD(smp, code) set_bit(code, &smp->allow_cmd)
b28b4943 48
3b19146d
JH		 49/* Keys which are not distributed with Secure Connections */
50#define SMP_SC_NO_DIST (SMP_DIST_ENC_KEY | SMP_DIST_LINK_KEY);
51
17b02e62 52#define SMP_TIMEOUT msecs_to_jiffies(30000)
5d3de7df 53
0edb14de
JH		 54#define AUTH_REQ_MASK(dev) (test_bit(HCI_SC_ENABLED, &(dev)->dev_flags) ? \
55 0x1f : 0x07)
56#define KEY_DIST_MASK 0x07
065a13e2 57
cbbbe3e2
JH		 58/* Maximum message length that can be passed to aes_cmac */
59#define CMAC_MSG_MAX 80
60
533e35d4
JH		 61enum {
62 SMP_FLAG_TK_VALID,
63 SMP_FLAG_CFM_PENDING,
64 SMP_FLAG_MITM_AUTH,
65 SMP_FLAG_COMPLETE,
66 SMP_FLAG_INITIATOR,
65668776 67 SMP_FLAG_SC,
d8f8edbe 68 SMP_FLAG_REMOTE_PK,
aeb7d461 69 SMP_FLAG_DEBUG_KEY,
38606f14 70 SMP_FLAG_WAIT_USER,
d3e54a87 71 SMP_FLAG_DHKEY_PENDING,
02b05bd8 72 SMP_FLAG_OOB,
533e35d4 73};
4bc58f51
JH		 74
75struct smp_chan {
b68fda68
JH		 76 struct l2cap_conn *conn;
77 struct delayed_work security_timer;
b28b4943 78 unsigned long allow_cmd; /* Bitmask of allowed commands */
b68fda68 79
4bc58f51
JH		 80 u8 preq[7]; /* SMP Pairing Request */
81 u8 prsp[7]; /* SMP Pairing Response */
82 u8 prnd[16]; /* SMP Pairing Random (local) */
83 u8 rrnd[16]; /* SMP Pairing Random (remote) */
84 u8 pcnf[16]; /* SMP Pairing Confirm */
85 u8 tk[16]; /* SMP Temporary Key */
a29b0733 86 u8 rr[16];
4bc58f51
JH		 87 u8 enc_key_size;
88 u8 remote_key_dist;
89 bdaddr_t id_addr;
90 u8 id_addr_type;
91 u8 irk[16];
92 struct smp_csrk *csrk;
93 struct smp_csrk *slave_csrk;
94 struct smp_ltk *ltk;
95 struct smp_ltk *slave_ltk;
96 struct smp_irk *remote_irk;
6a77083a 97 u8 *link_key;
4a74d658 98 unsigned long flags;
783e0574 99 u8 method;
38606f14 100 u8 passkey_round;
6a7bd103 101
3b19146d
JH		 102 /* Secure Connections variables */
103 u8 local_pk[64];
104 u8 local_sk[32];
d8f8edbe
JH		 105 u8 remote_pk[64];
106 u8 dhkey[32];
760b018b 107 u8 mackey[16];
3b19146d 108
6a7bd103 109 struct crypto_blkcipher *tfm_aes;
407cecf6 110 struct crypto_hash *tfm_cmac;
4bc58f51
JH		 111};
112
aeb7d461
JH		 113/* These debug key values are defined in the SMP section of the core
114 * specification. debug_pk is the public debug key and debug_sk the
115 * private debug key.
116 */
117static const u8 debug_pk[64] = {
118 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
119 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
120 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
121 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20,
122
123 0x8b, 0xd2, 0x89, 0x15, 0xd0, 0x8e, 0x1c, 0x74,
124 0x24, 0x30, 0xed, 0x8f, 0xc2, 0x45, 0x63, 0x76,
125 0x5c, 0x15, 0x52, 0x5a, 0xbf, 0x9a, 0x32, 0x63,
126 0x6d, 0xeb, 0x2a, 0x65, 0x49, 0x9c, 0x80, 0xdc,
127};
128
129static const u8 debug_sk[32] = {
130 0xbd, 0x1a, 0x3c, 0xcd, 0xa6, 0xb8, 0x99, 0x58,
131 0x99, 0xb7, 0x40, 0xeb, 0x7b, 0x60, 0xff, 0x4a,
132 0x50, 0x3f, 0x10, 0xd2, 0xe3, 0xb3, 0xc9, 0x74,
133 0x38, 0x5f, 0xc5, 0xa3, 0xd4, 0xf6, 0x49, 0x3f,
134};
135
8a2936f4 136static inline void swap_buf(const u8 *src, u8 *dst, size_t len)
d22ef0bc 137{
8a2936f4 138 size_t i;
d22ef0bc 139
8a2936f4
JH		 140 for (i = 0; i < len; i++)
141 dst[len - 1 - i] = src[i];
d22ef0bc
AB		 142}
143
06edf8de
JH		 144/* The following functions map to the LE SC SMP crypto functions
145 * AES-CMAC, f4, f5, f6, g2 and h6.
146 */
147
cbbbe3e2
JH		 148static int aes_cmac(struct crypto_hash *tfm, const u8 k[16], const u8 *m,
149 size_t len, u8 mac[16])
150{
151 uint8_t tmp[16], mac_msb[16], msg_msb[CMAC_MSG_MAX];
152 struct hash_desc desc;
153 struct scatterlist sg;
154 int err;
155
156 if (len > CMAC_MSG_MAX)
157 return -EFBIG;
158
159 if (!tfm) {
160 BT_ERR("tfm %p", tfm);
161 return -EINVAL;
162 }
163
164 desc.tfm = tfm;
165 desc.flags = 0;
166
167 crypto_hash_init(&desc);
168
169 /* Swap key and message from LSB to MSB */
170 swap_buf(k, tmp, 16);
171 swap_buf(m, msg_msb, len);
172
c7a3d57d
JH		 173 SMP_DBG("msg (len %zu) %*phN", len, (int) len, m);
174 SMP_DBG("key %16phN", k);
cbbbe3e2
JH		 175
176 err = crypto_hash_setkey(tfm, tmp, 16);
177 if (err) {
178 BT_ERR("cipher setkey failed: %d", err);
179 return err;
180 }
181
182 sg_init_one(&sg, msg_msb, len);
183
184 err = crypto_hash_update(&desc, &sg, len);
185 if (err) {
186 BT_ERR("Hash update error %d", err);
187 return err;
188 }
189
190 err = crypto_hash_final(&desc, mac_msb);
191 if (err) {
192 BT_ERR("Hash final error %d", err);
193 return err;
194 }
195
196 swap_buf(mac_msb, mac, 16);
197
c7a3d57d 198 SMP_DBG("mac %16phN", mac);
cbbbe3e2
JH		 199
200 return 0;
201}
202
203static int smp_f4(struct crypto_hash *tfm_cmac, const u8 u[32], const u8 v[32],
204 const u8 x[16], u8 z, u8 res[16])
205{
206 u8 m[65];
207 int err;
208
c7a3d57d
JH		 209 SMP_DBG("u %32phN", u);
210 SMP_DBG("v %32phN", v);
211 SMP_DBG("x %16phN z %02x", x, z);
cbbbe3e2
JH		 212
213 m[0] = z;
214 memcpy(m + 1, v, 32);
215 memcpy(m + 33, u, 32);
216
217 err = aes_cmac(tfm_cmac, x, m, sizeof(m), res);
218 if (err)
219 return err;
220
c7a3d57d 221 SMP_DBG("res %16phN", res);
cbbbe3e2
JH		 222
223 return err;
224}
225
760b018b
JH		 226static int smp_f5(struct crypto_hash *tfm_cmac, u8 w[32], u8 n1[16], u8 n2[16],
227 u8 a1[7], u8 a2[7], u8 mackey[16], u8 ltk[16])
228{
229 /* The btle, salt and length "magic" values are as defined in
230 * the SMP section of the Bluetooth core specification. In ASCII
231 * the btle value ends up being 'btle'. The salt is just a
232 * random number whereas length is the value 256 in little
233 * endian format.
234 */
235 const u8 btle[4] = { 0x65, 0x6c, 0x74, 0x62 };
236 const u8 salt[16] = { 0xbe, 0x83, 0x60, 0x5a, 0xdb, 0x0b, 0x37, 0x60,
237 0x38, 0xa5, 0xf5, 0xaa, 0x91, 0x83, 0x88, 0x6c };
238 const u8 length[2] = { 0x00, 0x01 };
239 u8 m[53], t[16];
240 int err;
241
c7a3d57d
JH		 242 SMP_DBG("w %32phN", w);
243 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
244 SMP_DBG("a1 %7phN a2 %7phN", a1, a2);
760b018b
JH		 245
246 err = aes_cmac(tfm_cmac, salt, w, 32, t);
247 if (err)
248 return err;
249
c7a3d57d 250 SMP_DBG("t %16phN", t);
760b018b
JH		 251
252 memcpy(m, length, 2);
253 memcpy(m + 2, a2, 7);
254 memcpy(m + 9, a1, 7);
255 memcpy(m + 16, n2, 16);
256 memcpy(m + 32, n1, 16);
257 memcpy(m + 48, btle, 4);
258
259 m[52] = 0; /* Counter */
260
261 err = aes_cmac(tfm_cmac, t, m, sizeof(m), mackey);
262 if (err)
263 return err;
264
c7a3d57d 265 SMP_DBG("mackey %16phN", mackey);
760b018b
JH		 266
267 m[52] = 1; /* Counter */
268
269 err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk);
270 if (err)
271 return err;
272
c7a3d57d 273 SMP_DBG("ltk %16phN", ltk);
760b018b
JH		 274
275 return 0;
276}
277
278static int smp_f6(struct crypto_hash *tfm_cmac, const u8 w[16],
279 const u8 n1[16], u8 n2[16], const u8 r[16],
280 const u8 io_cap[3], const u8 a1[7], const u8 a2[7],
281 u8 res[16])
282{
283 u8 m[65];
284 int err;
285
c7a3d57d
JH		 286 SMP_DBG("w %16phN", w);
287 SMP_DBG("n1 %16phN n2 %16phN", n1, n2);
288 SMP_DBG("r %16phN io_cap %3phN a1 %7phN a2 %7phN", r, io_cap, a1, a2);
760b018b
JH		 289
290 memcpy(m, a2, 7);
291 memcpy(m + 7, a1, 7);
292 memcpy(m + 14, io_cap, 3);
293 memcpy(m + 17, r, 16);
294 memcpy(m + 33, n2, 16);
295 memcpy(m + 49, n1, 16);
296
297 err = aes_cmac(tfm_cmac, w, m, sizeof(m), res);
298 if (err)
299 return err;
300
301 BT_DBG("res %16phN", res);
302
303 return err;
304}
305
191dc7fe
JH		 306static int smp_g2(struct crypto_hash *tfm_cmac, const u8 u[32], const u8 v[32],
307 const u8 x[16], const u8 y[16], u32 *val)
308{
309 u8 m[80], tmp[16];
310 int err;
311
c7a3d57d
JH		 312 SMP_DBG("u %32phN", u);
313 SMP_DBG("v %32phN", v);
314 SMP_DBG("x %16phN y %16phN", x, y);
191dc7fe
JH		 315
316 memcpy(m, y, 16);
317 memcpy(m + 16, v, 32);
318 memcpy(m + 48, u, 32);
319
320 err = aes_cmac(tfm_cmac, x, m, sizeof(m), tmp);
321 if (err)
322 return err;
323
324 *val = get_unaligned_le32(tmp);
325 *val %= 1000000;
326
c7a3d57d 327 SMP_DBG("val %06u", *val);
191dc7fe
JH		 328
329 return 0;
330}
331
06edf8de
JH		 332static int smp_h6(struct crypto_hash *tfm_cmac, const u8 w[16],
333 const u8 key_id[4], u8 res[16])
334{
335 int err;
336
337 SMP_DBG("w %16phN key_id %4phN", w, key_id);
338
339 err = aes_cmac(tfm_cmac, w, key_id, 4, res);
340 if (err)
341 return err;
342
343 SMP_DBG("res %16phN", res);
344
345 return err;
346}
347
348/* The following functions map to the legacy SMP crypto functions e, c1,
349 * s1 and ah.
350 */
351
d22ef0bc
AB		 352static int smp_e(struct crypto_blkcipher *tfm, const u8 *k, u8 *r)
353{
354 struct blkcipher_desc desc;
355 struct scatterlist sg;
943a732a 356 uint8_t tmp[16], data[16];
201a5929 357 int err;
d22ef0bc 358
7f376cd6 359 if (!tfm) {
d22ef0bc
AB		 360 BT_ERR("tfm %p", tfm);
361 return -EINVAL;
362 }
363
364 desc.tfm = tfm;
365 desc.flags = 0;
366
943a732a 367 /* The most significant octet of key corresponds to k[0] */
8a2936f4 368 swap_buf(k, tmp, 16);
943a732a
JH		 369
370 err = crypto_blkcipher_setkey(tfm, tmp, 16);
d22ef0bc
AB		 371 if (err) {
372 BT_ERR("cipher setkey failed: %d", err);
373 return err;
374 }
375
943a732a 376 /* Most significant octet of plaintextData corresponds to data[0] */
8a2936f4 377 swap_buf(r, data, 16);
943a732a
JH		 378
379 sg_init_one(&sg, data, 16);
d22ef0bc 380
d22ef0bc
AB		 381 err = crypto_blkcipher_encrypt(&desc, &sg, &sg, 16);
382 if (err)
383 BT_ERR("Encrypt data error %d", err);
384
943a732a 385 /* Most significant octet of encryptedData corresponds to data[0] */
8a2936f4 386 swap_buf(data, r, 16);
943a732a 387
d22ef0bc
AB		 388 return err;
389}
390
06edf8de
JH		 391static int smp_c1(struct crypto_blkcipher *tfm_aes, const u8 k[16],
392 const u8 r[16], const u8 preq[7], const u8 pres[7], u8 _iat,
393 const bdaddr_t *ia, u8 _rat, const bdaddr_t *ra, u8 res[16])
6a77083a 394{
06edf8de 395 u8 p1[16], p2[16];
6a77083a
JH		 396 int err;
397
06edf8de 398 memset(p1, 0, 16);
6a77083a 399
06edf8de
JH		 400 /* p1 = pres || preq || _rat || _iat */
401 p1[0] = _iat;
402 p1[1] = _rat;
403 memcpy(p1 + 2, preq, 7);
404 memcpy(p1 + 9, pres, 7);
405
406 /* p2 = padding || ia || ra */
407 memcpy(p2, ra, 6);
408 memcpy(p2 + 6, ia, 6);
409 memset(p2 + 12, 0, 4);
410
411 /* res = r XOR p1 */
412 u128_xor((u128 *) res, (u128 *) r, (u128 *) p1);
413
414 /* res = e(k, res) */
415 err = smp_e(tfm_aes, k, res);
416 if (err) {
417 BT_ERR("Encrypt data error");
6a77083a 418 return err;
06edf8de 419 }
6a77083a 420
06edf8de
JH		 421 /* res = res XOR p2 */
422 u128_xor((u128 *) res, (u128 *) res, (u128 *) p2);
423
424 /* res = e(k, res) */
425 err = smp_e(tfm_aes, k, res);
426 if (err)
427 BT_ERR("Encrypt data error");
428
429 return err;
430}
431
432static int smp_s1(struct crypto_blkcipher *tfm_aes, const u8 k[16],
433 const u8 r1[16], const u8 r2[16], u8 _r[16])
434{
435 int err;
436
437 /* Just least significant octets from r1 and r2 are considered */
438 memcpy(_r, r2, 8);
439 memcpy(_r + 8, r1, 8);
440
441 err = smp_e(tfm_aes, k, _r);
442 if (err)
443 BT_ERR("Encrypt data error");
6a77083a
JH		 444
445 return err;
446}
447
cd082797
JH		 448static int smp_ah(struct crypto_blkcipher *tfm, const u8 irk[16],
449 const u8 r[3], u8 res[3])
60478054 450{
943a732a 451 u8 _res[16];
60478054
JH		 452 int err;
453
454 /* r' = padding || r */
943a732a
JH		 455 memcpy(_res, r, 3);
456 memset(_res + 3, 0, 13);
60478054 457
943a732a 458 err = smp_e(tfm, irk, _res);
60478054
JH		 459 if (err) {
460 BT_ERR("Encrypt error");
461 return err;
462 }
463
464 /* The output of the random address function ah is:
465 * ah(h, r) = e(k, r') mod 2^24
466 * The output of the security function e is then truncated to 24 bits
467 * by taking the least significant 24 bits of the output of e as the
468 * result of ah.
469 */
943a732a 470 memcpy(res, _res, 3);
60478054
JH		 471
472 return 0;
473}
474
cd082797
JH		 475bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16],
476 const bdaddr_t *bdaddr)
60478054 477{
defce9e8
JH		 478 struct l2cap_chan *chan = hdev->smp_data;
479 struct crypto_blkcipher *tfm;
60478054
JH		 480 u8 hash[3];
481 int err;
482
defce9e8
JH		 483 if (!chan || !chan->data)
484 return false;
485
486 tfm = chan->data;
487
60478054
JH		 488 BT_DBG("RPA %pMR IRK %*phN", bdaddr, 16, irk);
489
490 err = smp_ah(tfm, irk, &bdaddr->b[3], hash);
491 if (err)
492 return false;
493
494 return !memcmp(bdaddr->b, hash, 3);
495}
496
cd082797 497int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa)
b1e2b3ae 498{
defce9e8
JH		 499 struct l2cap_chan *chan = hdev->smp_data;
500 struct crypto_blkcipher *tfm;
b1e2b3ae
JH		 501 int err;
502
defce9e8
JH		 503 if (!chan || !chan->data)
504 return -EOPNOTSUPP;
505
506 tfm = chan->data;
507
b1e2b3ae
JH		 508 get_random_bytes(&rpa->b[3], 3);
509
510 rpa->b[5] &= 0x3f; /* Clear two most significant bits */
511 rpa->b[5] |= 0x40; /* Set second most significant bit */
512
513 err = smp_ah(tfm, irk, &rpa->b[3], rpa->b);
514 if (err < 0)
515 return err;
516
517 BT_DBG("RPA %pMR", rpa);
518
519 return 0;
520}
521
5d88cc73 522static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
eb492e01 523{
5d88cc73 524 struct l2cap_chan *chan = conn->smp;
b68fda68 525 struct smp_chan *smp;
5d88cc73
JH		 526 struct kvec iv[2];
527 struct msghdr msg;
eb492e01 528
5d88cc73
JH		 529 if (!chan)
530 return;
eb492e01 531
5d88cc73 532 BT_DBG("code 0x%2.2x", code);
eb492e01 533
5d88cc73
JH		 534 iv[0].iov_base = &code;
535 iv[0].iov_len = 1;
eb492e01 536
5d88cc73
JH		 537 iv[1].iov_base = data;
538 iv[1].iov_len = len;
eb492e01 539
5d88cc73 540 memset(&msg, 0, sizeof(msg));
eb492e01 541
5d88cc73
JH		 542 msg.msg_iov = (struct iovec *) &iv;
543 msg.msg_iovlen = 2;
eb492e01 544
5d88cc73 545 l2cap_chan_send(chan, &msg, 1 + len);
e2dcd113 546
b68fda68
JH		 547 if (!chan->data)
548 return;
549
550 smp = chan->data;
551
552 cancel_delayed_work_sync(&smp->security_timer);
1b0921d6 553 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT);
eb492e01
AB		 554}
555
d2eb9e10 556static u8 authreq_to_seclevel(u8 authreq)
2b64d153 557{
d2eb9e10
JH		 558 if (authreq & SMP_AUTH_MITM) {
559 if (authreq & SMP_AUTH_SC)
560 return BT_SECURITY_FIPS;
561 else
562 return BT_SECURITY_HIGH;
563 } else {
2b64d153 564 return BT_SECURITY_MEDIUM;
d2eb9e10 565 }
2b64d153
BG		 566}
567
568static __u8 seclevel_to_authreq(__u8 sec_level)
569{
570 switch (sec_level) {
d2eb9e10 571 case BT_SECURITY_FIPS:
2b64d153
BG		 572 case BT_SECURITY_HIGH:
573 return SMP_AUTH_MITM | SMP_AUTH_BONDING;
574 case BT_SECURITY_MEDIUM:
575 return SMP_AUTH_BONDING;
576 default:
577 return SMP_AUTH_NONE;
578 }
579}
580
b8e66eac 581static void build_pairing_cmd(struct l2cap_conn *conn,
f1560463
MH		 582 struct smp_cmd_pairing *req,
583 struct smp_cmd_pairing *rsp, __u8 authreq)
b8e66eac 584{
5d88cc73
JH		 585 struct l2cap_chan *chan = conn->smp;
586 struct smp_chan *smp = chan->data;
fd349c02
JH		 587 struct hci_conn *hcon = conn->hcon;
588 struct hci_dev *hdev = hcon->hdev;
02b05bd8 589 u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT;
54790f73 590
b6ae8457 591 if (test_bit(HCI_BONDABLE, &conn->hcon->hdev->dev_flags)) {
7ee4ea36
MH		 592 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
593 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
54790f73 594 authreq |= SMP_AUTH_BONDING;
2b64d153
BG		 595 } else {
596 authreq &= ~SMP_AUTH_BONDING;
54790f73
VCG		 597 }
598
fd349c02
JH		 599 if (test_bit(HCI_RPA_RESOLVING, &hdev->dev_flags))
600 remote_dist |= SMP_DIST_ID_KEY;
601
863efaf2
JH		 602 if (test_bit(HCI_PRIVACY, &hdev->dev_flags))
603 local_dist |= SMP_DIST_ID_KEY;
604
02b05bd8
JH		 605 if (test_bit(HCI_SC_ENABLED, &hdev->dev_flags) &&
606 (authreq & SMP_AUTH_SC)) {
607 struct oob_data *oob_data;
608 u8 bdaddr_type;
609
610 if (test_bit(HCI_SSP_ENABLED, &hdev->dev_flags)) {
df8e1a4c
JH		 611 local_dist |= SMP_DIST_LINK_KEY;
612 remote_dist |= SMP_DIST_LINK_KEY;
613 }
02b05bd8
JH		 614
615 if (hcon->dst_type == ADDR_LE_DEV_PUBLIC)
616 bdaddr_type = BDADDR_LE_PUBLIC;
617 else
618 bdaddr_type = BDADDR_LE_RANDOM;
619
620 oob_data = hci_find_remote_oob_data(hdev, &hcon->dst,
621 bdaddr_type);
622 if (oob_data) {
623 set_bit(SMP_FLAG_OOB, &smp->flags);
624 oob_flag = SMP_OOB_PRESENT;
a29b0733 625 memcpy(smp->rr, oob_data->rand256, 16);
02b05bd8
JH		 626 memcpy(smp->pcnf, oob_data->hash256, 16);
627 }
628
df8e1a4c
JH		 629 } else {
630 authreq &= ~SMP_AUTH_SC;
631 }
632
54790f73
VCG		 633 if (rsp == NULL) {
634 req->io_capability = conn->hcon->io_capability;
02b05bd8 635 req->oob_flag = oob_flag;
54790f73 636 req->max_key_size = SMP_MAX_ENC_KEY_SIZE;
fd349c02
JH		 637 req->init_key_dist = local_dist;
638 req->resp_key_dist = remote_dist;
0edb14de 639 req->auth_req = (authreq & AUTH_REQ_MASK(hdev));
fd349c02
JH		 640
641 smp->remote_key_dist = remote_dist;
54790f73
VCG		 642 return;
643 }
644
645 rsp->io_capability = conn->hcon->io_capability;
02b05bd8 646 rsp->oob_flag = oob_flag;
54790f73 647 rsp->max_key_size = SMP_MAX_ENC_KEY_SIZE;
fd349c02
JH		 648 rsp->init_key_dist = req->init_key_dist & remote_dist;
649 rsp->resp_key_dist = req->resp_key_dist & local_dist;
0edb14de 650 rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev));
fd349c02
JH		 651
652 smp->remote_key_dist = rsp->init_key_dist;
b8e66eac
VCG		 653}
654
3158c50c
VCG		 655static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)
656{
5d88cc73
JH		 657 struct l2cap_chan *chan = conn->smp;
658 struct smp_chan *smp = chan->data;
1c1def09 659
3158c50c 660 if ((max_key_size > SMP_MAX_ENC_KEY_SIZE) ||
f1560463 661 (max_key_size < SMP_MIN_ENC_KEY_SIZE))
3158c50c
VCG		 662 return SMP_ENC_KEY_SIZE;
663
f7aa611a 664 smp->enc_key_size = max_key_size;
3158c50c
VCG		 665
666 return 0;
667}
668
6f48e260
JH		 669static void smp_chan_destroy(struct l2cap_conn *conn)
670{
671 struct l2cap_chan *chan = conn->smp;
672 struct smp_chan *smp = chan->data;
923e2414 673 struct hci_conn *hcon = conn->hcon;
6f48e260
JH		 674 bool complete;
675
676 BUG_ON(!smp);
677
678 cancel_delayed_work_sync(&smp->security_timer);
6f48e260 679
6f48e260 680 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags);
923e2414 681 mgmt_smp_complete(hcon, complete);
6f48e260
JH		 682
683 kfree(smp->csrk);
684 kfree(smp->slave_csrk);
6a77083a 685 kfree(smp->link_key);
6f48e260
JH		 686
687 crypto_free_blkcipher(smp->tfm_aes);
407cecf6 688 crypto_free_hash(smp->tfm_cmac);
6f48e260 689
923e2414
JH		 690 /* Ensure that we don't leave any debug key around if debug key
691 * support hasn't been explicitly enabled.
692 */
693 if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG &&
694 !test_bit(HCI_KEEP_DEBUG_KEYS, &hcon->hdev->dev_flags)) {
695 list_del_rcu(&smp->ltk->list);
696 kfree_rcu(smp->ltk, rcu);
697 smp->ltk = NULL;
698 }
699
6f48e260
JH		 700 /* If pairing failed clean up any keys we might have */
701 if (!complete) {
702 if (smp->ltk) {
970d0f1b
JH		 703 list_del_rcu(&smp->ltk->list);
704 kfree_rcu(smp->ltk, rcu);
6f48e260
JH		 705 }
706
707 if (smp->slave_ltk) {
970d0f1b
JH		 708 list_del_rcu(&smp->slave_ltk->list);
709 kfree_rcu(smp->slave_ltk, rcu);
6f48e260
JH		 710 }
711
712 if (smp->remote_irk) {
adae20cb
JH		 713 list_del_rcu(&smp->remote_irk->list);
714 kfree_rcu(smp->remote_irk, rcu);
6f48e260
JH		 715 }
716 }
717
718 chan->data = NULL;
719 kfree(smp);
923e2414 720 hci_conn_drop(hcon);
6f48e260
JH		 721}
722
84794e11 723static void smp_failure(struct l2cap_conn *conn, u8 reason)
4f957a76 724{
bab73cb6 725 struct hci_conn *hcon = conn->hcon;
b68fda68 726 struct l2cap_chan *chan = conn->smp;
bab73cb6 727
84794e11 728 if (reason)
4f957a76 729 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
f1560463 730 &reason);
4f957a76 731
ce39fb4e 732 clear_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags);
e1e930f5 733 mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE);
f1c09c07 734
fc75cc86 735 if (chan->data)
f1c09c07 736 smp_chan_destroy(conn);
4f957a76
BG		 737}
738
2b64d153
BG		 739#define JUST_WORKS 0x00
740#define JUST_CFM 0x01
741#define REQ_PASSKEY 0x02
742#define CFM_PASSKEY 0x03
743#define REQ_OOB 0x04
5e3d3d9b 744#define DSP_PASSKEY 0x05
2b64d153
BG		 745#define OVERLAP 0xFF
746
747static const u8 gen_method[5][5] = {
748 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
749 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
750 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
751 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
752 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP },
753};
754
5e3d3d9b
JH		 755static const u8 sc_method[5][5] = {
756 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
757 { JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
758 { DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY },
759 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
760 { DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
761};
762
581370cc
JH		 763static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io)
764{
2bcd4003
JH		 765 /* If either side has unknown io_caps, use JUST_CFM (which gets
766 * converted later to JUST_WORKS if we're initiators.
767 */
581370cc
JH		 768 if (local_io > SMP_IO_KEYBOARD_DISPLAY ||
769 remote_io > SMP_IO_KEYBOARD_DISPLAY)
2bcd4003 770 return JUST_CFM;
581370cc 771
5e3d3d9b
JH		 772 if (test_bit(SMP_FLAG_SC, &smp->flags))
773 return sc_method[remote_io][local_io];
774
581370cc
JH		 775 return gen_method[remote_io][local_io];
776}
777
2b64d153
BG		 778static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth,
779 u8 local_io, u8 remote_io)
780{
781 struct hci_conn *hcon = conn->hcon;
5d88cc73
JH		 782 struct l2cap_chan *chan = conn->smp;
783 struct smp_chan *smp = chan->data;
2b64d153
BG		 784 u32 passkey = 0;
785 int ret = 0;
786
787 /* Initialize key for JUST WORKS */
788 memset(smp->tk, 0, sizeof(smp->tk));
4a74d658 789 clear_bit(SMP_FLAG_TK_VALID, &smp->flags);
2b64d153
BG		 790
791 BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io);
792
2bcd4003
JH		 793 /* If neither side wants MITM, either "just" confirm an incoming
794 * request or use just-works for outgoing ones. The JUST_CFM
795 * will be converted to JUST_WORKS if necessary later in this
796 * function. If either side has MITM look up the method from the
797 * table.
798 */
581370cc 799 if (!(auth & SMP_AUTH_MITM))
783e0574 800 smp->method = JUST_CFM;
2b64d153 801 else
783e0574 802 smp->method = get_auth_method(smp, local_io, remote_io);
2b64d153 803
a82505c7 804 /* Don't confirm locally initiated pairing attempts */
783e0574
JH		 805 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR,
806 &smp->flags))
807 smp->method = JUST_WORKS;
a82505c7 808
02f3e254 809 /* Don't bother user space with no IO capabilities */
783e0574
JH		 810 if (smp->method == JUST_CFM &&
811 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
812 smp->method = JUST_WORKS;
02f3e254 813
2b64d153 814 /* If Just Works, Continue with Zero TK */
783e0574 815 if (smp->method == JUST_WORKS) {
4a74d658 816 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
2b64d153
BG		 817 return 0;
818 }
819
820 /* Not Just Works/Confirm results in MITM Authentication */
783e0574 821 if (smp->method != JUST_CFM) {
4a74d658 822 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags);
5eb596f5
JH		 823 if (hcon->pending_sec_level < BT_SECURITY_HIGH)
824 hcon->pending_sec_level = BT_SECURITY_HIGH;
825 }
2b64d153
BG		 826
827 /* If both devices have Keyoard-Display I/O, the master
828 * Confirms and the slave Enters the passkey.
829 */
783e0574 830 if (smp->method == OVERLAP) {
40bef302 831 if (hcon->role == HCI_ROLE_MASTER)
783e0574 832 smp->method = CFM_PASSKEY;
2b64d153 833 else
783e0574 834 smp->method = REQ_PASSKEY;
2b64d153
BG		 835 }
836
01ad34d2 837 /* Generate random passkey. */
783e0574 838 if (smp->method == CFM_PASSKEY) {
943a732a 839 memset(smp->tk, 0, sizeof(smp->tk));
2b64d153
BG		 840 get_random_bytes(&passkey, sizeof(passkey));
841 passkey %= 1000000;
943a732a 842 put_unaligned_le32(passkey, smp->tk);
2b64d153 843 BT_DBG("PassKey: %d", passkey);
4a74d658 844 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
2b64d153
BG		 845 }
846
783e0574 847 if (smp->method == REQ_PASSKEY)
ce39fb4e 848 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst,
272d90df 849 hcon->type, hcon->dst_type);
783e0574 850 else if (smp->method == JUST_CFM)
4eb65e66
JH		 851 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
852 hcon->type, hcon->dst_type,
853 passkey, 1);
2b64d153 854 else
01ad34d2 855 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst,
272d90df 856 hcon->type, hcon->dst_type,
39adbffe 857 passkey, 0);
2b64d153 858
2b64d153
BG		 859 return ret;
860}
861
1cc61144 862static u8 smp_confirm(struct smp_chan *smp)
8aab4757 863{
8aab4757 864 struct l2cap_conn *conn = smp->conn;
8aab4757
VCG		 865 struct smp_cmd_pairing_confirm cp;
866 int ret;
8aab4757
VCG		 867
868 BT_DBG("conn %p", conn);
869
e491eaf3 870 ret = smp_c1(smp->tfm_aes, smp->tk, smp->prnd, smp->preq, smp->prsp,
b1cd5fd9 871 conn->hcon->init_addr_type, &conn->hcon->init_addr,
943a732a
JH		 872 conn->hcon->resp_addr_type, &conn->hcon->resp_addr,
873 cp.confirm_val);
1cc61144
JH		 874 if (ret)
875 return SMP_UNSPECIFIED;
8aab4757 876
4a74d658 877 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
2b64d153 878
8aab4757
VCG		 879 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
880
b28b4943
JH		 881 if (conn->hcon->out)
882 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
883 else
884 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
885
1cc61144 886 return 0;
8aab4757
VCG		 887}
888
861580a9 889static u8 smp_random(struct smp_chan *smp)
8aab4757 890{
8aab4757
VCG		 891 struct l2cap_conn *conn = smp->conn;
892 struct hci_conn *hcon = conn->hcon;
861580a9 893 u8 confirm[16];
8aab4757
VCG		 894 int ret;
895
ec70f36f 896 if (IS_ERR_OR_NULL(smp->tfm_aes))
861580a9 897 return SMP_UNSPECIFIED;
8aab4757
VCG		 898
899 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
900
e491eaf3 901 ret = smp_c1(smp->tfm_aes, smp->tk, smp->rrnd, smp->preq, smp->prsp,
b1cd5fd9 902 hcon->init_addr_type, &hcon->init_addr,
943a732a 903 hcon->resp_addr_type, &hcon->resp_addr, confirm);
861580a9
JH		 904 if (ret)
905 return SMP_UNSPECIFIED;
8aab4757 906
8aab4757
VCG		 907 if (memcmp(smp->pcnf, confirm, sizeof(smp->pcnf)) != 0) {
908 BT_ERR("Pairing failed (confirmation values mismatch)");
861580a9 909 return SMP_CONFIRM_FAILED;
8aab4757
VCG		 910 }
911
912 if (hcon->out) {
fe39c7b2
MH		 913 u8 stk[16];
914 __le64 rand = 0;
915 __le16 ediv = 0;
8aab4757 916
e491eaf3 917 smp_s1(smp->tfm_aes, smp->tk, smp->rrnd, smp->prnd, stk);
8aab4757 918
f7aa611a 919 memset(stk + smp->enc_key_size, 0,
04124681 920 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);
8aab4757 921
861580a9
JH		 922 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
923 return SMP_UNSPECIFIED;
8aab4757
VCG		 924
925 hci_le_start_enc(hcon, ediv, rand, stk);
f7aa611a 926 hcon->enc_key_size = smp->enc_key_size;
fe59a05f 927 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
8aab4757 928 } else {
fff3490f 929 u8 stk[16], auth;
fe39c7b2
MH		 930 __le64 rand = 0;
931 __le16 ediv = 0;
8aab4757 932
943a732a
JH		 933 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
934 smp->prnd);
8aab4757 935
e491eaf3 936 smp_s1(smp->tfm_aes, smp->tk, smp->prnd, smp->rrnd, stk);
8aab4757 937
f7aa611a 938 memset(stk + smp->enc_key_size, 0,
f1560463 939 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);
8aab4757 940
fff3490f
JH		 941 if (hcon->pending_sec_level == BT_SECURITY_HIGH)
942 auth = 1;
943 else
944 auth = 0;
945
7d5843b7
JH		 946 /* Even though there's no _SLAVE suffix this is the
947 * slave STK we're adding for later lookup (the master
948 * STK never needs to be stored).
949 */
ce39fb4e 950 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
2ceba539 951 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand);
8aab4757
VCG		 952 }
953
861580a9 954 return 0;
8aab4757
VCG		 955}
956
44f1a7ab
JH		 957static void smp_notify_keys(struct l2cap_conn *conn)
958{
959 struct l2cap_chan *chan = conn->smp;
960 struct smp_chan *smp = chan->data;
961 struct hci_conn *hcon = conn->hcon;
962 struct hci_dev *hdev = hcon->hdev;
963 struct smp_cmd_pairing *req = (void *) &smp->preq[1];
964 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1];
965 bool persistent;
966
967 if (smp->remote_irk) {
968 mgmt_new_irk(hdev, smp->remote_irk);
969 /* Now that user space can be considered to know the
970 * identity address track the connection based on it
b5ae344d 971 * from now on (assuming this is an LE link).
44f1a7ab 972 */
b5ae344d
JH		 973 if (hcon->type == LE_LINK) {
974 bacpy(&hcon->dst, &smp->remote_irk->bdaddr);
975 hcon->dst_type = smp->remote_irk->addr_type;
976 queue_work(hdev->workqueue, &conn->id_addr_update_work);
977 }
44f1a7ab
JH		 978
979 /* When receiving an indentity resolving key for
980 * a remote device that does not use a resolvable
981 * private address, just remove the key so that
982 * it is possible to use the controller white
983 * list for scanning.
984 *
985 * Userspace will have been told to not store
986 * this key at this point. So it is safe to
987 * just remove it.
988 */
989 if (!bacmp(&smp->remote_irk->rpa, BDADDR_ANY)) {
adae20cb
JH		 990 list_del_rcu(&smp->remote_irk->list);
991 kfree_rcu(smp->remote_irk, rcu);
44f1a7ab
JH		 992 smp->remote_irk = NULL;
993 }
994 }
995
b5ae344d
JH		 996 if (hcon->type == ACL_LINK) {
997 if (hcon->key_type == HCI_LK_DEBUG_COMBINATION)
998 persistent = false;
999 else
1000 persistent = !test_bit(HCI_CONN_FLUSH_KEY,
1001 &hcon->flags);
1002 } else {
1003 /* The LTKs and CSRKs should be persistent only if both sides
1004 * had the bonding bit set in their authentication requests.
1005 */
1006 persistent = !!((req->auth_req & rsp->auth_req) &
1007 SMP_AUTH_BONDING);
1008 }
1009
44f1a7ab
JH		 1010
1011 if (smp->csrk) {
1012 smp->csrk->bdaddr_type = hcon->dst_type;
1013 bacpy(&smp->csrk->bdaddr, &hcon->dst);
1014 mgmt_new_csrk(hdev, smp->csrk, persistent);
1015 }
1016
1017 if (smp->slave_csrk) {
1018 smp->slave_csrk->bdaddr_type = hcon->dst_type;
1019 bacpy(&smp->slave_csrk->bdaddr, &hcon->dst);
1020 mgmt_new_csrk(hdev, smp->slave_csrk, persistent);
1021 }
1022
1023 if (smp->ltk) {
1024 smp->ltk->bdaddr_type = hcon->dst_type;
1025 bacpy(&smp->ltk->bdaddr, &hcon->dst);
1026 mgmt_new_ltk(hdev, smp->ltk, persistent);
1027 }
1028
1029 if (smp->slave_ltk) {
1030 smp->slave_ltk->bdaddr_type = hcon->dst_type;
1031 bacpy(&smp->slave_ltk->bdaddr, &hcon->dst);
1032 mgmt_new_ltk(hdev, smp->slave_ltk, persistent);
1033 }
6a77083a
JH		 1034
1035 if (smp->link_key) {
e3befab9
JH		 1036 struct link_key *key;
1037 u8 type;
1038
1039 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1040 type = HCI_LK_DEBUG_COMBINATION;
1041 else if (hcon->sec_level == BT_SECURITY_FIPS)
1042 type = HCI_LK_AUTH_COMBINATION_P256;
1043 else
1044 type = HCI_LK_UNAUTH_COMBINATION_P256;
1045
1046 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst,
1047 smp->link_key, type, 0, &persistent);
1048 if (key) {
1049 mgmt_new_link_key(hdev, key, persistent);
1050
1051 /* Don't keep debug keys around if the relevant
1052 * flag is not set.
1053 */
1054 if (!test_bit(HCI_KEEP_DEBUG_KEYS, &hdev->dev_flags) &&
1055 key->type == HCI_LK_DEBUG_COMBINATION) {
1056 list_del_rcu(&key->list);
1057 kfree_rcu(key, rcu);
1058 }
1059 }
6a77083a
JH		 1060 }
1061}
1062
d3e54a87
JH		 1063static void sc_add_ltk(struct smp_chan *smp)
1064{
1065 struct hci_conn *hcon = smp->conn->hcon;
1066 u8 key_type, auth;
1067
1068 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags))
1069 key_type = SMP_LTK_P256_DEBUG;
1070 else
1071 key_type = SMP_LTK_P256;
1072
1073 if (hcon->pending_sec_level == BT_SECURITY_FIPS)
1074 auth = 1;
1075 else
1076 auth = 0;
1077
1078 memset(smp->tk + smp->enc_key_size, 0,
1079 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);
1080
1081 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
1082 key_type, auth, smp->tk, smp->enc_key_size,
1083 0, 0);
1084}
1085
6a77083a
JH		 1086static void sc_generate_link_key(struct smp_chan *smp)
1087{
1088 /* These constants are as specified in the core specification.
1089 * In ASCII they spell out to 'tmp1' and 'lebr'.
1090 */
1091 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 };
1092 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c };
1093
1094 smp->link_key = kzalloc(16, GFP_KERNEL);
1095 if (!smp->link_key)
1096 return;
1097
1098 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) {
1099 kfree(smp->link_key);
1100 smp->link_key = NULL;
1101 return;
1102 }
1103
1104 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) {
1105 kfree(smp->link_key);
1106 smp->link_key = NULL;
1107 return;
1108 }
44f1a7ab
JH		 1109}
1110
b28b4943
JH		 1111static void smp_allow_key_dist(struct smp_chan *smp)
1112{
1113 /* Allow the first expected phase 3 PDU. The rest of the PDUs
1114 * will be allowed in each PDU handler to ensure we receive
1115 * them in the correct order.
1116 */
1117 if (smp->remote_key_dist & SMP_DIST_ENC_KEY)
1118 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO);
1119 else if (smp->remote_key_dist & SMP_DIST_ID_KEY)
1120 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
1121 else if (smp->remote_key_dist & SMP_DIST_SIGN)
1122 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
1123}
1124
b5ae344d
JH		 1125static void sc_generate_ltk(struct smp_chan *smp)
1126{
1127 /* These constants are as specified in the core specification.
1128 * In ASCII they spell out to 'tmp2' and 'brle'.
1129 */
1130 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 };
1131 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 };
1132 struct hci_conn *hcon = smp->conn->hcon;
1133 struct hci_dev *hdev = hcon->hdev;
1134 struct link_key *key;
1135
1136 key = hci_find_link_key(hdev, &hcon->dst);
1137 if (!key) {
1138 BT_ERR("%s No Link Key found to generate LTK", hdev->name);
1139 return;
1140 }
1141
1142 if (key->type == HCI_LK_DEBUG_COMBINATION)
1143 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1144
1145 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk))
1146 return;
1147
1148 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk))
1149 return;
1150
1151 sc_add_ltk(smp);
1152}
1153
d6268e86 1154static void smp_distribute_keys(struct smp_chan *smp)
44f1a7ab
JH		 1155{
1156 struct smp_cmd_pairing *req, *rsp;
86d1407c 1157 struct l2cap_conn *conn = smp->conn;
44f1a7ab
JH		 1158 struct hci_conn *hcon = conn->hcon;
1159 struct hci_dev *hdev = hcon->hdev;
1160 __u8 *keydist;
1161
1162 BT_DBG("conn %p", conn);
1163
44f1a7ab
JH		 1164 rsp = (void *) &smp->prsp[1];
1165
1166 /* The responder sends its keys first */
b28b4943
JH		 1167 if (hcon->out && (smp->remote_key_dist & KEY_DIST_MASK)) {
1168 smp_allow_key_dist(smp);
86d1407c 1169 return;
b28b4943 1170 }
44f1a7ab
JH		 1171
1172 req = (void *) &smp->preq[1];
1173
1174 if (hcon->out) {
1175 keydist = &rsp->init_key_dist;
1176 *keydist &= req->init_key_dist;
1177 } else {
1178 keydist = &rsp->resp_key_dist;
1179 *keydist &= req->resp_key_dist;
1180 }
1181
6a77083a 1182 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
b5ae344d 1183 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY))
6a77083a 1184 sc_generate_link_key(smp);
b5ae344d
JH		 1185 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY))
1186 sc_generate_ltk(smp);
6a77083a
JH		 1187
1188 /* Clear the keys which are generated but not distributed */
1189 *keydist &= ~SMP_SC_NO_DIST;
1190 }
1191
44f1a7ab
JH		 1192 BT_DBG("keydist 0x%x", *keydist);
1193
1194 if (*keydist & SMP_DIST_ENC_KEY) {
1195 struct smp_cmd_encrypt_info enc;
1196 struct smp_cmd_master_ident ident;
1197 struct smp_ltk *ltk;
1198 u8 authenticated;
1199 __le16 ediv;
1200 __le64 rand;
1201
1202 get_random_bytes(enc.ltk, sizeof(enc.ltk));
1203 get_random_bytes(&ediv, sizeof(ediv));
1204 get_random_bytes(&rand, sizeof(rand));
1205
1206 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc);
1207
1208 authenticated = hcon->sec_level == BT_SECURITY_HIGH;
1209 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type,
1210 SMP_LTK_SLAVE, authenticated, enc.ltk,
1211 smp->enc_key_size, ediv, rand);
1212 smp->slave_ltk = ltk;
1213
1214 ident.ediv = ediv;
1215 ident.rand = rand;
1216
1217 smp_send_cmd(conn, SMP_CMD_MASTER_IDENT, sizeof(ident), &ident);
1218
1219 *keydist &= ~SMP_DIST_ENC_KEY;
1220 }
1221
1222 if (*keydist & SMP_DIST_ID_KEY) {
1223 struct smp_cmd_ident_addr_info addrinfo;
1224 struct smp_cmd_ident_info idinfo;
1225
1226 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk));
1227
1228 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo);
1229
1230 /* The hci_conn contains the local identity address
1231 * after the connection has been established.
1232 *
1233 * This is true even when the connection has been
1234 * established using a resolvable random address.
1235 */
1236 bacpy(&addrinfo.bdaddr, &hcon->src);
1237 addrinfo.addr_type = hcon->src_type;
1238
1239 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo),
1240 &addrinfo);
1241
1242 *keydist &= ~SMP_DIST_ID_KEY;
1243 }
1244
1245 if (*keydist & SMP_DIST_SIGN) {
1246 struct smp_cmd_sign_info sign;
1247 struct smp_csrk *csrk;
1248
1249 /* Generate a new random key */
1250 get_random_bytes(sign.csrk, sizeof(sign.csrk));
1251
1252 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
1253 if (csrk) {
1254 csrk->master = 0x00;
1255 memcpy(csrk->val, sign.csrk, sizeof(csrk->val));
1256 }
1257 smp->slave_csrk = csrk;
1258
1259 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign);
1260
1261 *keydist &= ~SMP_DIST_SIGN;
1262 }
1263
1264 /* If there are still keys to be received wait for them */
b28b4943
JH		 1265 if (smp->remote_key_dist & KEY_DIST_MASK) {
1266 smp_allow_key_dist(smp);
86d1407c 1267 return;
b28b4943 1268 }
44f1a7ab 1269
44f1a7ab
JH		 1270 set_bit(SMP_FLAG_COMPLETE, &smp->flags);
1271 smp_notify_keys(conn);
1272
1273 smp_chan_destroy(conn);
44f1a7ab
JH		 1274}
1275
b68fda68
JH		 1276static void smp_timeout(struct work_struct *work)
1277{
1278 struct smp_chan *smp = container_of(work, struct smp_chan,
1279 security_timer.work);
1280 struct l2cap_conn *conn = smp->conn;
1281
1282 BT_DBG("conn %p", conn);
1283
1e91c29e 1284 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM);
b68fda68
JH		 1285}
1286
8aab4757
VCG		 1287static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
1288{
5d88cc73 1289 struct l2cap_chan *chan = conn->smp;
8aab4757
VCG		 1290 struct smp_chan *smp;
1291
f1560463 1292 smp = kzalloc(sizeof(*smp), GFP_ATOMIC);
fc75cc86 1293 if (!smp)
8aab4757
VCG		 1294 return NULL;
1295
6a7bd103
JH		 1296 smp->tfm_aes = crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);
1297 if (IS_ERR(smp->tfm_aes)) {
1298 BT_ERR("Unable to create ECB crypto context");
1299 kfree(smp);
1300 return NULL;
1301 }
1302
407cecf6
JH		 1303 smp->tfm_cmac = crypto_alloc_hash("cmac(aes)", 0, CRYPTO_ALG_ASYNC);
1304 if (IS_ERR(smp->tfm_cmac)) {
1305 BT_ERR("Unable to create CMAC crypto context");
1306 crypto_free_blkcipher(smp->tfm_aes);
1307 kfree(smp);
1308 return NULL;
1309 }
1310
8aab4757 1311 smp->conn = conn;
5d88cc73 1312 chan->data = smp;
8aab4757 1313
b28b4943
JH		 1314 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL);
1315
b68fda68
JH		 1316 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout);
1317
8aab4757
VCG		 1318 hci_conn_hold(conn->hcon);
1319
1320 return smp;
1321}
1322
760b018b
JH		 1323static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16])
1324{
1325 struct hci_conn *hcon = smp->conn->hcon;
1326 u8 *na, *nb, a[7], b[7];
1327
1328 if (hcon->out) {
1329 na = smp->prnd;
1330 nb = smp->rrnd;
1331 } else {
1332 na = smp->rrnd;
1333 nb = smp->prnd;
1334 }
1335
1336 memcpy(a, &hcon->init_addr, 6);
1337 memcpy(b, &hcon->resp_addr, 6);
1338 a[6] = hcon->init_addr_type;
1339 b[6] = hcon->resp_addr_type;
1340
1341 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk);
1342}
1343
38606f14 1344static void sc_dhkey_check(struct smp_chan *smp)
760b018b
JH		 1345{
1346 struct hci_conn *hcon = smp->conn->hcon;
1347 struct smp_cmd_dhkey_check check;
1348 u8 a[7], b[7], *local_addr, *remote_addr;
1349 u8 io_cap[3], r[16];
1350
760b018b
JH		 1351 memcpy(a, &hcon->init_addr, 6);
1352 memcpy(b, &hcon->resp_addr, 6);
1353 a[6] = hcon->init_addr_type;
1354 b[6] = hcon->resp_addr_type;
1355
1356 if (hcon->out) {
1357 local_addr = a;
1358 remote_addr = b;
1359 memcpy(io_cap, &smp->preq[1], 3);
1360 } else {
1361 local_addr = b;
1362 remote_addr = a;
1363 memcpy(io_cap, &smp->prsp[1], 3);
1364 }
1365
dddd3059
JH		 1366 memset(r, 0, sizeof(r));
1367
1368 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
38606f14 1369 put_unaligned_le32(hcon->passkey_notify, r);
760b018b 1370
a29b0733
JH		 1371 if (smp->method == REQ_OOB)
1372 memcpy(r, smp->rr, 16);
1373
760b018b
JH		 1374 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap,
1375 local_addr, remote_addr, check.e);
1376
1377 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check);
dddd3059
JH		 1378}
1379
38606f14
JH		 1380static u8 sc_passkey_send_confirm(struct smp_chan *smp)
1381{
1382 struct l2cap_conn *conn = smp->conn;
1383 struct hci_conn *hcon = conn->hcon;
1384 struct smp_cmd_pairing_confirm cfm;
1385 u8 r;
1386
1387 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1388 r |= 0x80;
1389
1390 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1391
1392 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r,
1393 cfm.confirm_val))
1394 return SMP_UNSPECIFIED;
1395
1396 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
1397
1398 return 0;
1399}
1400
1401static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op)
1402{
1403 struct l2cap_conn *conn = smp->conn;
1404 struct hci_conn *hcon = conn->hcon;
1405 struct hci_dev *hdev = hcon->hdev;
1406 u8 cfm[16], r;
1407
1408 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */
1409 if (smp->passkey_round >= 20)
1410 return 0;
1411
1412 switch (smp_op) {
1413 case SMP_CMD_PAIRING_RANDOM:
1414 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01);
1415 r |= 0x80;
1416
1417 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
1418 smp->rrnd, r, cfm))
1419 return SMP_UNSPECIFIED;
1420
1421 if (memcmp(smp->pcnf, cfm, 16))
1422 return SMP_CONFIRM_FAILED;
1423
1424 smp->passkey_round++;
1425
1426 if (smp->passkey_round == 20) {
1427 /* Generate MacKey and LTK */
1428 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk))
1429 return SMP_UNSPECIFIED;
1430 }
1431
1432 /* The round is only complete when the initiator
1433 * receives pairing random.
1434 */
1435 if (!hcon->out) {
1436 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1437 sizeof(smp->prnd), smp->prnd);
d3e54a87 1438 if (smp->passkey_round == 20)
38606f14 1439 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
d3e54a87 1440 else
38606f14 1441 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
38606f14
JH		 1442 return 0;
1443 }
1444
1445 /* Start the next round */
1446 if (smp->passkey_round != 20)
1447 return sc_passkey_round(smp, 0);
1448
1449 /* Passkey rounds are complete - start DHKey Check */
1450 sc_dhkey_check(smp);
1451 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1452
1453 break;
1454
1455 case SMP_CMD_PAIRING_CONFIRM:
1456 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
1457 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
1458 return 0;
1459 }
1460
1461 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
1462
1463 if (hcon->out) {
1464 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1465 sizeof(smp->prnd), smp->prnd);
1466 return 0;
1467 }
1468
1469 return sc_passkey_send_confirm(smp);
1470
1471 case SMP_CMD_PUBLIC_KEY:
1472 default:
1473 /* Initiating device starts the round */
1474 if (!hcon->out)
1475 return 0;
1476
1477 BT_DBG("%s Starting passkey round %u", hdev->name,
1478 smp->passkey_round + 1);
1479
1480 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1481
1482 return sc_passkey_send_confirm(smp);
1483 }
1484
1485 return 0;
1486}
1487
dddd3059
JH		 1488static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey)
1489{
38606f14
JH		 1490 struct l2cap_conn *conn = smp->conn;
1491 struct hci_conn *hcon = conn->hcon;
1492 u8 smp_op;
1493
1494 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags);
1495
dddd3059
JH		 1496 switch (mgmt_op) {
1497 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1498 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED);
1499 return 0;
1500 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
1501 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED);
1502 return 0;
38606f14
JH		 1503 case MGMT_OP_USER_PASSKEY_REPLY:
1504 hcon->passkey_notify = le32_to_cpu(passkey);
1505 smp->passkey_round = 0;
1506
1507 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags))
1508 smp_op = SMP_CMD_PAIRING_CONFIRM;
1509 else
1510 smp_op = 0;
1511
1512 if (sc_passkey_round(smp, smp_op))
1513 return -EIO;
1514
1515 return 0;
dddd3059
JH		 1516 }
1517
d3e54a87
JH		 1518 /* Initiator sends DHKey check first */
1519 if (hcon->out) {
1520 sc_dhkey_check(smp);
1521 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1522 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) {
1523 sc_dhkey_check(smp);
1524 sc_add_ltk(smp);
1525 }
760b018b
JH		 1526
1527 return 0;
1528}
1529
2b64d153
BG		 1530int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey)
1531{
b10e8017 1532 struct l2cap_conn *conn = hcon->l2cap_data;
5d88cc73 1533 struct l2cap_chan *chan;
2b64d153
BG		 1534 struct smp_chan *smp;
1535 u32 value;
fc75cc86 1536 int err;
2b64d153
BG		 1537
1538 BT_DBG("");
1539
fc75cc86 1540 if (!conn)
2b64d153
BG		 1541 return -ENOTCONN;
1542
5d88cc73
JH		 1543 chan = conn->smp;
1544 if (!chan)
1545 return -ENOTCONN;
1546
fc75cc86
JH		 1547 l2cap_chan_lock(chan);
1548 if (!chan->data) {
1549 err = -ENOTCONN;
1550 goto unlock;
1551 }
1552
5d88cc73 1553 smp = chan->data;
2b64d153 1554
760b018b
JH		 1555 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1556 err = sc_user_reply(smp, mgmt_op, passkey);
1557 goto unlock;
1558 }
1559
2b64d153
BG		 1560 switch (mgmt_op) {
1561 case MGMT_OP_USER_PASSKEY_REPLY:
1562 value = le32_to_cpu(passkey);
943a732a 1563 memset(smp->tk, 0, sizeof(smp->tk));
2b64d153 1564 BT_DBG("PassKey: %d", value);
943a732a 1565 put_unaligned_le32(value, smp->tk);
2b64d153
BG		 1566 /* Fall Through */
1567 case MGMT_OP_USER_CONFIRM_REPLY:
4a74d658 1568 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
2b64d153
BG		 1569 break;
1570 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
1571 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
84794e11 1572 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
fc75cc86
JH		 1573 err = 0;
1574 goto unlock;
2b64d153 1575 default:
84794e11 1576 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
fc75cc86
JH		 1577 err = -EOPNOTSUPP;
1578 goto unlock;
2b64d153
BG		 1579 }
1580
fc75cc86
JH		 1581 err = 0;
1582
2b64d153 1583 /* If it is our turn to send Pairing Confirm, do so now */
1cc61144
JH		 1584 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) {
1585 u8 rsp = smp_confirm(smp);
1586 if (rsp)
1587 smp_failure(conn, rsp);
1588 }
2b64d153 1589
fc75cc86
JH		 1590unlock:
1591 l2cap_chan_unlock(chan);
1592 return err;
2b64d153
BG		 1593}
1594
b5ae344d
JH		 1595static void build_bredr_pairing_cmd(struct smp_chan *smp,
1596 struct smp_cmd_pairing *req,
1597 struct smp_cmd_pairing *rsp)
1598{
1599 struct l2cap_conn *conn = smp->conn;
1600 struct hci_dev *hdev = conn->hcon->hdev;
1601 u8 local_dist = 0, remote_dist = 0;
1602
1603 if (test_bit(HCI_BONDABLE, &hdev->dev_flags)) {
1604 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1605 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
1606 }
1607
1608 if (test_bit(HCI_RPA_RESOLVING, &hdev->dev_flags))
1609 remote_dist |= SMP_DIST_ID_KEY;
1610
1611 if (test_bit(HCI_PRIVACY, &hdev->dev_flags))
1612 local_dist |= SMP_DIST_ID_KEY;
1613
1614 if (!rsp) {
1615 memset(req, 0, sizeof(*req));
1616
1617 req->init_key_dist = local_dist;
1618 req->resp_key_dist = remote_dist;
1619 req->max_key_size = SMP_MAX_ENC_KEY_SIZE;
1620
1621 smp->remote_key_dist = remote_dist;
1622
1623 return;
1624 }
1625
1626 memset(rsp, 0, sizeof(*rsp));
1627
1628 rsp->max_key_size = SMP_MAX_ENC_KEY_SIZE;
1629 rsp->init_key_dist = req->init_key_dist & remote_dist;
1630 rsp->resp_key_dist = req->resp_key_dist & local_dist;
1631
1632 smp->remote_key_dist = rsp->init_key_dist;
1633}
1634
da85e5e5 1635static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
88ba43b6 1636{
3158c50c 1637 struct smp_cmd_pairing rsp, *req = (void *) skb->data;
fc75cc86 1638 struct l2cap_chan *chan = conn->smp;
b3c6410b 1639 struct hci_dev *hdev = conn->hcon->hdev;
8aab4757 1640 struct smp_chan *smp;
c7262e71 1641 u8 key_size, auth, sec_level;
8aab4757 1642 int ret;
88ba43b6
AB		 1643
1644 BT_DBG("conn %p", conn);
1645
c46b98be 1646 if (skb->len < sizeof(*req))
38e4a915 1647 return SMP_INVALID_PARAMS;
c46b98be 1648
40bef302 1649 if (conn->hcon->role != HCI_ROLE_SLAVE)
2b64d153
BG		 1650 return SMP_CMD_NOTSUPP;
1651
fc75cc86 1652 if (!chan->data)
8aab4757 1653 smp = smp_chan_create(conn);
fc75cc86 1654 else
5d88cc73 1655 smp = chan->data;
8aab4757 1656
d08fd0e7
AE		 1657 if (!smp)
1658 return SMP_UNSPECIFIED;
d26a2345 1659
c05b9339 1660 /* We didn't start the pairing, so match remote */
0edb14de 1661 auth = req->auth_req & AUTH_REQ_MASK(hdev);
c05b9339 1662
b6ae8457 1663 if (!test_bit(HCI_BONDABLE, &hdev->dev_flags) &&
c05b9339 1664 (auth & SMP_AUTH_BONDING))
b3c6410b
JH		 1665 return SMP_PAIRING_NOTSUPP;
1666
903b71c7
JH		 1667 if (test_bit(HCI_SC_ONLY, &hdev->dev_flags) && !(auth & SMP_AUTH_SC))
1668 return SMP_AUTH_REQUIREMENTS;
1669
1c1def09
VCG		 1670 smp->preq[0] = SMP_CMD_PAIRING_REQ;
1671 memcpy(&smp->preq[1], req, sizeof(*req));
3158c50c 1672 skb_pull(skb, sizeof(*req));
88ba43b6 1673
b5ae344d
JH		 1674 /* SMP over BR/EDR requires special treatment */
1675 if (conn->hcon->type == ACL_LINK) {
1676 /* We must have a BR/EDR SC link */
1677 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags))
1678 return SMP_CROSS_TRANSP_NOT_ALLOWED;
1679
1680 set_bit(SMP_FLAG_SC, &smp->flags);
1681
1682 build_bredr_pairing_cmd(smp, req, &rsp);
1683
1684 key_size = min(req->max_key_size, rsp.max_key_size);
1685 if (check_enc_key_size(conn, key_size))
1686 return SMP_ENC_KEY_SIZE;
1687
1688 /* Clear bits which are generated but not distributed */
1689 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1690
1691 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1692 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
1693 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
1694
1695 smp_distribute_keys(smp);
1696 return 0;
1697 }
1698
5e3d3d9b
JH		 1699 build_pairing_cmd(conn, req, &rsp, auth);
1700
1701 if (rsp.auth_req & SMP_AUTH_SC)
1702 set_bit(SMP_FLAG_SC, &smp->flags);
1703
5be5e275 1704 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
1afc2a1a
JH		 1705 sec_level = BT_SECURITY_MEDIUM;
1706 else
1707 sec_level = authreq_to_seclevel(auth);
1708
c7262e71
JH		 1709 if (sec_level > conn->hcon->pending_sec_level)
1710 conn->hcon->pending_sec_level = sec_level;
fdde0a26 1711
49c922bb 1712 /* If we need MITM check that it can be achieved */
2ed8f65c
JH		 1713 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1714 u8 method;
1715
1716 method = get_auth_method(smp, conn->hcon->io_capability,
1717 req->io_capability);
1718 if (method == JUST_WORKS || method == JUST_CFM)
1719 return SMP_AUTH_REQUIREMENTS;
1720 }
1721
3158c50c
VCG		 1722 key_size = min(req->max_key_size, rsp.max_key_size);
1723 if (check_enc_key_size(conn, key_size))
1724 return SMP_ENC_KEY_SIZE;
88ba43b6 1725
e84a6b13 1726 get_random_bytes(smp->prnd, sizeof(smp->prnd));
8aab4757 1727
1c1def09
VCG		 1728 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1729 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
f01ead31 1730
3158c50c 1731 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
3b19146d
JH		 1732
1733 clear_bit(SMP_FLAG_INITIATOR, &smp->flags);
1734
1735 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1736 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
1737 /* Clear bits which are generated but not distributed */
1738 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1739 /* Wait for Public Key from Initiating Device */
1740 return 0;
1741 } else {
1742 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
1743 }
da85e5e5 1744
2b64d153
BG		 1745 /* Request setup of TK */
1746 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability);
1747 if (ret)
1748 return SMP_UNSPECIFIED;
1749
da85e5e5 1750 return 0;
88ba43b6
AB		 1751}
1752
3b19146d
JH		 1753static u8 sc_send_public_key(struct smp_chan *smp)
1754{
70157ef5
JH		 1755 struct hci_dev *hdev = smp->conn->hcon->hdev;
1756
3b19146d
JH		 1757 BT_DBG("");
1758
70157ef5
JH		 1759 if (test_bit(HCI_USE_DEBUG_KEYS, &hdev->dev_flags)) {
1760 BT_DBG("Using debug keys");
1761 memcpy(smp->local_pk, debug_pk, 64);
1762 memcpy(smp->local_sk, debug_sk, 32);
1763 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
1764 } else {
1765 while (true) {
1766 /* Generate local key pair for Secure Connections */
1767 if (!ecc_make_key(smp->local_pk, smp->local_sk))
1768 return SMP_UNSPECIFIED;
6c0dcc50 1769
70157ef5
JH		 1770 /* This is unlikely, but we need to check that
1771 * we didn't accidentially generate a debug key.
1772 */
1773 if (memcmp(smp->local_sk, debug_sk, 32))
1774 break;
1775 }
6c0dcc50 1776 }
3b19146d 1777
c7a3d57d
JH		 1778 SMP_DBG("Local Public Key X: %32phN", smp->local_pk);
1779 SMP_DBG("Local Public Key Y: %32phN", &smp->local_pk[32]);
1780 SMP_DBG("Local Private Key: %32phN", smp->local_sk);
3b19146d
JH		 1781
1782 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk);
1783
1784 return 0;
1785}
1786
da85e5e5 1787static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
88ba43b6 1788{
3158c50c 1789 struct smp_cmd_pairing *req, *rsp = (void *) skb->data;
5d88cc73
JH		 1790 struct l2cap_chan *chan = conn->smp;
1791 struct smp_chan *smp = chan->data;
0edb14de 1792 struct hci_dev *hdev = conn->hcon->hdev;
3a7dbfb8 1793 u8 key_size, auth;
7d24ddcc 1794 int ret;
88ba43b6
AB		 1795
1796 BT_DBG("conn %p", conn);
1797
c46b98be 1798 if (skb->len < sizeof(*rsp))
38e4a915 1799 return SMP_INVALID_PARAMS;
c46b98be 1800
40bef302 1801 if (conn->hcon->role != HCI_ROLE_MASTER)
2b64d153
BG		 1802 return SMP_CMD_NOTSUPP;
1803
3158c50c
VCG		 1804 skb_pull(skb, sizeof(*rsp));
1805
1c1def09 1806 req = (void *) &smp->preq[1];
da85e5e5 1807
3158c50c
VCG		 1808 key_size = min(req->max_key_size, rsp->max_key_size);
1809 if (check_enc_key_size(conn, key_size))
1810 return SMP_ENC_KEY_SIZE;
1811
0edb14de 1812 auth = rsp->auth_req & AUTH_REQ_MASK(hdev);
c05b9339 1813
903b71c7
JH		 1814 if (test_bit(HCI_SC_ONLY, &hdev->dev_flags) && !(auth & SMP_AUTH_SC))
1815 return SMP_AUTH_REQUIREMENTS;
1816
b5ae344d
JH		 1817 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1818 memcpy(&smp->prsp[1], rsp, sizeof(*rsp));
1819
1820 /* Update remote key distribution in case the remote cleared
1821 * some bits that we had enabled in our request.
1822 */
1823 smp->remote_key_dist &= rsp->resp_key_dist;
1824
1825 /* For BR/EDR this means we're done and can start phase 3 */
1826 if (conn->hcon->type == ACL_LINK) {
1827 /* Clear bits which are generated but not distributed */
1828 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1829 smp_distribute_keys(smp);
1830 return 0;
1831 }
1832
65668776
JH		 1833 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC))
1834 set_bit(SMP_FLAG_SC, &smp->flags);
d2eb9e10
JH		 1835 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH)
1836 conn->hcon->pending_sec_level = BT_SECURITY_HIGH;
65668776 1837
49c922bb 1838 /* If we need MITM check that it can be achieved */
2ed8f65c
JH		 1839 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1840 u8 method;
1841
1842 method = get_auth_method(smp, req->io_capability,
1843 rsp->io_capability);
1844 if (method == JUST_WORKS || method == JUST_CFM)
1845 return SMP_AUTH_REQUIREMENTS;
1846 }
1847
e84a6b13 1848 get_random_bytes(smp->prnd, sizeof(smp->prnd));
7d24ddcc 1849
fdcc4bec
JH		 1850 /* Update remote key distribution in case the remote cleared
1851 * some bits that we had enabled in our request.
1852 */
1853 smp->remote_key_dist &= rsp->resp_key_dist;
1854
3b19146d
JH		 1855 if (test_bit(SMP_FLAG_SC, &smp->flags)) {
1856 /* Clear bits which are generated but not distributed */
1857 smp->remote_key_dist &= ~SMP_SC_NO_DIST;
1858 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
1859 return sc_send_public_key(smp);
1860 }
1861
c05b9339 1862 auth |= req->auth_req;
2b64d153 1863
476585ec 1864 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability);
2b64d153
BG		 1865 if (ret)
1866 return SMP_UNSPECIFIED;
1867
4a74d658 1868 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
2b64d153
BG		 1869
1870 /* Can't compose response until we have been confirmed */
4a74d658 1871 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
1cc61144 1872 return smp_confirm(smp);
da85e5e5
VCG		 1873
1874 return 0;
88ba43b6
AB		 1875}
1876
dcee2b32
JH		 1877static u8 sc_check_confirm(struct smp_chan *smp)
1878{
1879 struct l2cap_conn *conn = smp->conn;
1880
1881 BT_DBG("");
1882
1883 /* Public Key exchange must happen before any other steps */
1884 if (!test_bit(SMP_FLAG_REMOTE_PK, &smp->flags))
1885 return SMP_UNSPECIFIED;
1886
38606f14
JH		 1887 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
1888 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM);
1889
dcee2b32
JH		 1890 if (conn->hcon->out) {
1891 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
1892 smp->prnd);
1893 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
1894 }
1895
1896 return 0;
1897}
1898
da85e5e5 1899static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
88ba43b6 1900{
5d88cc73
JH		 1901 struct l2cap_chan *chan = conn->smp;
1902 struct smp_chan *smp = chan->data;
7d24ddcc 1903
88ba43b6
AB		 1904 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
1905
c46b98be 1906 if (skb->len < sizeof(smp->pcnf))
38e4a915 1907 return SMP_INVALID_PARAMS;
c46b98be 1908
1c1def09
VCG		 1909 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf));
1910 skb_pull(skb, sizeof(smp->pcnf));
88ba43b6 1911
dcee2b32
JH		 1912 if (test_bit(SMP_FLAG_SC, &smp->flags))
1913 return sc_check_confirm(smp);
1914
b28b4943 1915 if (conn->hcon->out) {
943a732a
JH		 1916 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
1917 smp->prnd);
b28b4943
JH		 1918 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
1919 return 0;
1920 }
1921
1922 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
1cc61144 1923 return smp_confirm(smp);
943a732a 1924 else
4a74d658 1925 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
da85e5e5
VCG		 1926
1927 return 0;
88ba43b6
AB		 1928}
1929
da85e5e5 1930static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
88ba43b6 1931{
5d88cc73
JH		 1932 struct l2cap_chan *chan = conn->smp;
1933 struct smp_chan *smp = chan->data;
191dc7fe
JH		 1934 struct hci_conn *hcon = conn->hcon;
1935 u8 *pkax, *pkbx, *na, *nb;
1936 u32 passkey;
1937 int err;
7d24ddcc 1938
8aab4757 1939 BT_DBG("conn %p", conn);
3158c50c 1940
c46b98be 1941 if (skb->len < sizeof(smp->rrnd))
38e4a915 1942 return SMP_INVALID_PARAMS;
c46b98be 1943
943a732a 1944 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd));
8aab4757 1945 skb_pull(skb, sizeof(smp->rrnd));
e7e62c85 1946
191dc7fe
JH		 1947 if (!test_bit(SMP_FLAG_SC, &smp->flags))
1948 return smp_random(smp);
1949
580039e8
JH		 1950 if (hcon->out) {
1951 pkax = smp->local_pk;
1952 pkbx = smp->remote_pk;
1953 na = smp->prnd;
1954 nb = smp->rrnd;
1955 } else {
1956 pkax = smp->remote_pk;
1957 pkbx = smp->local_pk;
1958 na = smp->rrnd;
1959 nb = smp->prnd;
1960 }
1961
a29b0733
JH		 1962 if (smp->method == REQ_OOB) {
1963 if (!hcon->out)
1964 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
1965 sizeof(smp->prnd), smp->prnd);
1966 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
1967 goto mackey_and_ltk;
1968 }
1969
38606f14
JH		 1970 /* Passkey entry has special treatment */
1971 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
1972 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM);
1973
191dc7fe
JH		 1974 if (hcon->out) {
1975 u8 cfm[16];
1976
1977 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk,
1978 smp->rrnd, 0, cfm);
1979 if (err)
1980 return SMP_UNSPECIFIED;
1981
1982 if (memcmp(smp->pcnf, cfm, 16))
1983 return SMP_CONFIRM_FAILED;
191dc7fe
JH		 1984 } else {
1985 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
1986 smp->prnd);
1987 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
191dc7fe
JH		 1988 }
1989
a29b0733 1990mackey_and_ltk:
760b018b
JH		 1991 /* Generate MacKey and LTK */
1992 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk);
1993 if (err)
1994 return SMP_UNSPECIFIED;
1995
a29b0733 1996 if (smp->method == JUST_WORKS || smp->method == REQ_OOB) {
dddd3059 1997 if (hcon->out) {
38606f14 1998 sc_dhkey_check(smp);
dddd3059
JH		 1999 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
2000 }
2001 return 0;
2002 }
2003
38606f14
JH		 2004 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
2005 if (err)
2006 return SMP_UNSPECIFIED;
2007
2008 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type,
2009 hcon->dst_type, passkey, 0);
191dc7fe
JH		 2010 if (err)
2011 return SMP_UNSPECIFIED;
2012
38606f14
JH		 2013 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2014
191dc7fe 2015 return 0;
88ba43b6
AB		 2016}
2017
f81cd823 2018static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level)
988c5997 2019{
c9839a11 2020 struct smp_ltk *key;
988c5997
VCG		 2021 struct hci_conn *hcon = conn->hcon;
2022
f3a73d97 2023 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role);
988c5997 2024 if (!key)
f81cd823 2025 return false;
988c5997 2026
a6f7833c 2027 if (smp_ltk_sec_level(key) < sec_level)
f81cd823 2028 return false;
4dab7864 2029
51a8efd7 2030 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
f81cd823 2031 return true;
988c5997 2032
c9839a11
VCG		 2033 hci_le_start_enc(hcon, key->ediv, key->rand, key->val);
2034 hcon->enc_key_size = key->enc_size;
988c5997 2035
fe59a05f
JH		 2036 /* We never store STKs for master role, so clear this flag */
2037 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
2038
f81cd823 2039 return true;
988c5997 2040}
f1560463 2041
35dc6f83
JH		 2042bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level,
2043 enum smp_key_pref key_pref)
854f4727
JH		 2044{
2045 if (sec_level == BT_SECURITY_LOW)
2046 return true;
2047
35dc6f83
JH		 2048 /* If we're encrypted with an STK but the caller prefers using
2049 * LTK claim insufficient security. This way we allow the
2050 * connection to be re-encrypted with an LTK, even if the LTK
2051 * provides the same level of security. Only exception is if we
2052 * don't have an LTK (e.g. because of key distribution bits).
9ab65d60 2053 */
35dc6f83
JH		 2054 if (key_pref == SMP_USE_LTK &&
2055 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) &&
f3a73d97 2056 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role))
9ab65d60
JH		 2057 return false;
2058
854f4727
JH		 2059 if (hcon->sec_level >= sec_level)
2060 return true;
2061
2062 return false;
2063}
2064
da85e5e5 2065static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
88ba43b6
AB		 2066{
2067 struct smp_cmd_security_req *rp = (void *) skb->data;
2068 struct smp_cmd_pairing cp;
f1cb9af5 2069 struct hci_conn *hcon = conn->hcon;
0edb14de 2070 struct hci_dev *hdev = hcon->hdev;
8aab4757 2071 struct smp_chan *smp;
c05b9339 2072 u8 sec_level, auth;
88ba43b6
AB		 2073
2074 BT_DBG("conn %p", conn);
2075
c46b98be 2076 if (skb->len < sizeof(*rp))
38e4a915 2077 return SMP_INVALID_PARAMS;
c46b98be 2078
40bef302 2079 if (hcon->role != HCI_ROLE_MASTER)
86ca9eac
JH		 2080 return SMP_CMD_NOTSUPP;
2081
0edb14de 2082 auth = rp->auth_req & AUTH_REQ_MASK(hdev);
c05b9339 2083
903b71c7
JH		 2084 if (test_bit(HCI_SC_ONLY, &hdev->dev_flags) && !(auth & SMP_AUTH_SC))
2085 return SMP_AUTH_REQUIREMENTS;
2086
5be5e275 2087 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
1afc2a1a
JH		 2088 sec_level = BT_SECURITY_MEDIUM;
2089 else
2090 sec_level = authreq_to_seclevel(auth);
2091
35dc6f83 2092 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK))
854f4727
JH		 2093 return 0;
2094
c7262e71
JH		 2095 if (sec_level > hcon->pending_sec_level)
2096 hcon->pending_sec_level = sec_level;
feb45eb5 2097
4dab7864 2098 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
988c5997
VCG		 2099 return 0;
2100
8aab4757 2101 smp = smp_chan_create(conn);
c29d2444
JH		 2102 if (!smp)
2103 return SMP_UNSPECIFIED;
d26a2345 2104
b6ae8457 2105 if (!test_bit(HCI_BONDABLE, &hcon->hdev->dev_flags) &&
c05b9339 2106 (auth & SMP_AUTH_BONDING))
616d55be
JH		 2107 return SMP_PAIRING_NOTSUPP;
2108
88ba43b6 2109 skb_pull(skb, sizeof(*rp));
88ba43b6 2110
da85e5e5 2111 memset(&cp, 0, sizeof(cp));
c05b9339 2112 build_pairing_cmd(conn, &cp, NULL, auth);
88ba43b6 2113
1c1def09
VCG		 2114 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2115 memcpy(&smp->preq[1], &cp, sizeof(cp));
f01ead31 2116
88ba43b6 2117 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
b28b4943 2118 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
f1cb9af5 2119
da85e5e5 2120 return 0;
88ba43b6
AB		 2121}
2122
cc110922 2123int smp_conn_security(struct hci_conn *hcon, __u8 sec_level)
eb492e01 2124{
cc110922 2125 struct l2cap_conn *conn = hcon->l2cap_data;
c68b7f12 2126 struct l2cap_chan *chan;
0a66cf20 2127 struct smp_chan *smp;
2b64d153 2128 __u8 authreq;
fc75cc86 2129 int ret;
eb492e01 2130
3a0259bb
VCG		 2131 BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level);
2132
0a66cf20
JH		 2133 /* This may be NULL if there's an unexpected disconnection */
2134 if (!conn)
2135 return 1;
2136
c68b7f12
JH		 2137 chan = conn->smp;
2138
757aee0f 2139 if (!test_bit(HCI_LE_ENABLED, &hcon->hdev->dev_flags))
2e65c9d2
AG		 2140 return 1;
2141
35dc6f83 2142 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK))
eb492e01 2143 return 1;
f1cb9af5 2144
c7262e71
JH		 2145 if (sec_level > hcon->pending_sec_level)
2146 hcon->pending_sec_level = sec_level;
2147
40bef302 2148 if (hcon->role == HCI_ROLE_MASTER)
c7262e71
JH		 2149 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
2150 return 0;
d26a2345 2151
fc75cc86
JH		 2152 l2cap_chan_lock(chan);
2153
2154 /* If SMP is already in progress ignore this request */
2155 if (chan->data) {
2156 ret = 0;
2157 goto unlock;
2158 }
d26a2345 2159
8aab4757 2160 smp = smp_chan_create(conn);
fc75cc86
JH		 2161 if (!smp) {
2162 ret = 1;
2163 goto unlock;
2164 }
2b64d153
BG		 2165
2166 authreq = seclevel_to_authreq(sec_level);
d26a2345 2167
d2eb9e10
JH		 2168 if (test_bit(HCI_SC_ENABLED, &hcon->hdev->dev_flags))
2169 authreq |= SMP_AUTH_SC;
2170
79897d20
JH		 2171 /* Require MITM if IO Capability allows or the security level
2172 * requires it.
2e233644 2173 */
79897d20 2174 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT ||
c7262e71 2175 hcon->pending_sec_level > BT_SECURITY_MEDIUM)
2e233644
JH		 2176 authreq |= SMP_AUTH_MITM;
2177
40bef302 2178 if (hcon->role == HCI_ROLE_MASTER) {
d26a2345 2179 struct smp_cmd_pairing cp;
f01ead31 2180
2b64d153 2181 build_pairing_cmd(conn, &cp, NULL, authreq);
1c1def09
VCG		 2182 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2183 memcpy(&smp->preq[1], &cp, sizeof(cp));
f01ead31 2184
eb492e01 2185 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
b28b4943 2186 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
eb492e01
AB		 2187 } else {
2188 struct smp_cmd_security_req cp;
2b64d153 2189 cp.auth_req = authreq;
eb492e01 2190 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp);
b28b4943 2191 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ);
eb492e01
AB		 2192 }
2193
4a74d658 2194 set_bit(SMP_FLAG_INITIATOR, &smp->flags);
fc75cc86 2195 ret = 0;
edca792c 2196
fc75cc86
JH		 2197unlock:
2198 l2cap_chan_unlock(chan);
2199 return ret;
eb492e01
AB		 2200}
2201
7034b911
VCG		 2202static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb)
2203{
16b90839 2204 struct smp_cmd_encrypt_info *rp = (void *) skb->data;
5d88cc73
JH		 2205 struct l2cap_chan *chan = conn->smp;
2206 struct smp_chan *smp = chan->data;
16b90839 2207
c46b98be
JH		 2208 BT_DBG("conn %p", conn);
2209
2210 if (skb->len < sizeof(*rp))
38e4a915 2211 return SMP_INVALID_PARAMS;
c46b98be 2212
b28b4943 2213 SMP_ALLOW_CMD(smp, SMP_CMD_MASTER_IDENT);
6131ddc8 2214
16b90839
VCG		 2215 skb_pull(skb, sizeof(*rp));
2216
1c1def09 2217 memcpy(smp->tk, rp->ltk, sizeof(smp->tk));
16b90839 2218
7034b911
VCG		 2219 return 0;
2220}
2221
2222static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb)
2223{
16b90839 2224 struct smp_cmd_master_ident *rp = (void *) skb->data;
5d88cc73
JH		 2225 struct l2cap_chan *chan = conn->smp;
2226 struct smp_chan *smp = chan->data;
c9839a11
VCG		 2227 struct hci_dev *hdev = conn->hcon->hdev;
2228 struct hci_conn *hcon = conn->hcon;
23d0e128 2229 struct smp_ltk *ltk;
c9839a11 2230 u8 authenticated;
16b90839 2231
c46b98be
JH		 2232 BT_DBG("conn %p", conn);
2233
2234 if (skb->len < sizeof(*rp))
38e4a915 2235 return SMP_INVALID_PARAMS;
c46b98be 2236
9747a9f3
JH		 2237 /* Mark the information as received */
2238 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY;
2239
b28b4943
JH		 2240 if (smp->remote_key_dist & SMP_DIST_ID_KEY)
2241 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO);
196332f5
JH		 2242 else if (smp->remote_key_dist & SMP_DIST_SIGN)
2243 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
b28b4943 2244
16b90839 2245 skb_pull(skb, sizeof(*rp));
7034b911 2246
ce39fb4e 2247 authenticated = (hcon->sec_level == BT_SECURITY_HIGH);
2ceba539 2248 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK,
23d0e128
JH		 2249 authenticated, smp->tk, smp->enc_key_size,
2250 rp->ediv, rp->rand);
2251 smp->ltk = ltk;
c6e81e9a 2252 if (!(smp->remote_key_dist & KEY_DIST_MASK))
d6268e86 2253 smp_distribute_keys(smp);
7034b911
VCG		 2254
2255 return 0;
2256}
2257
fd349c02
JH		 2258static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb)
2259{
2260 struct smp_cmd_ident_info *info = (void *) skb->data;
5d88cc73
JH		 2261 struct l2cap_chan *chan = conn->smp;
2262 struct smp_chan *smp = chan->data;
fd349c02
JH		 2263
2264 BT_DBG("");
2265
2266 if (skb->len < sizeof(*info))
38e4a915 2267 return SMP_INVALID_PARAMS;
fd349c02 2268
b28b4943 2269 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO);
6131ddc8 2270
fd349c02
JH		 2271 skb_pull(skb, sizeof(*info));
2272
2273 memcpy(smp->irk, info->irk, 16);
2274
2275 return 0;
2276}
2277
2278static int smp_cmd_ident_addr_info(struct l2cap_conn *conn,
2279 struct sk_buff *skb)
2280{
2281 struct smp_cmd_ident_addr_info *info = (void *) skb->data;
5d88cc73
JH		 2282 struct l2cap_chan *chan = conn->smp;
2283 struct smp_chan *smp = chan->data;
fd349c02
JH		 2284 struct hci_conn *hcon = conn->hcon;
2285 bdaddr_t rpa;
2286
2287 BT_DBG("");
2288
2289 if (skb->len < sizeof(*info))
38e4a915 2290 return SMP_INVALID_PARAMS;
fd349c02 2291
9747a9f3
JH		 2292 /* Mark the information as received */
2293 smp->remote_key_dist &= ~SMP_DIST_ID_KEY;
2294
b28b4943
JH		 2295 if (smp->remote_key_dist & SMP_DIST_SIGN)
2296 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO);
2297
fd349c02
JH		 2298 skb_pull(skb, sizeof(*info));
2299
a9a58f86
JH		 2300 /* Strictly speaking the Core Specification (4.1) allows sending
2301 * an empty address which would force us to rely on just the IRK
2302 * as "identity information". However, since such
2303 * implementations are not known of and in order to not over
2304 * complicate our implementation, simply pretend that we never
2305 * received an IRK for such a device.
2306 */
2307 if (!bacmp(&info->bdaddr, BDADDR_ANY)) {
2308 BT_ERR("Ignoring IRK with no identity address");
31dd624e 2309 goto distribute;
a9a58f86
JH		 2310 }
2311
fd349c02
JH		 2312 bacpy(&smp->id_addr, &info->bdaddr);
2313 smp->id_addr_type = info->addr_type;
2314
2315 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type))
2316 bacpy(&rpa, &hcon->dst);
2317 else
2318 bacpy(&rpa, BDADDR_ANY);
2319
23d0e128
JH		 2320 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr,
2321 smp->id_addr_type, smp->irk, &rpa);
fd349c02 2322
31dd624e 2323distribute:
c6e81e9a
JH		 2324 if (!(smp->remote_key_dist & KEY_DIST_MASK))
2325 smp_distribute_keys(smp);
fd349c02
JH		 2326
2327 return 0;
2328}
2329
7ee4ea36
MH		 2330static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb)
2331{
2332 struct smp_cmd_sign_info *rp = (void *) skb->data;
5d88cc73
JH		 2333 struct l2cap_chan *chan = conn->smp;
2334 struct smp_chan *smp = chan->data;
7ee4ea36
MH		 2335 struct smp_csrk *csrk;
2336
2337 BT_DBG("conn %p", conn);
2338
2339 if (skb->len < sizeof(*rp))
38e4a915 2340 return SMP_INVALID_PARAMS;
7ee4ea36 2341
7ee4ea36
MH		 2342 /* Mark the information as received */
2343 smp->remote_key_dist &= ~SMP_DIST_SIGN;
2344
2345 skb_pull(skb, sizeof(*rp));
2346
7ee4ea36
MH		 2347 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
2348 if (csrk) {
2349 csrk->master = 0x01;
2350 memcpy(csrk->val, rp->csrk, sizeof(csrk->val));
2351 }
2352 smp->csrk = csrk;
d6268e86 2353 smp_distribute_keys(smp);
7ee4ea36
MH		 2354
2355 return 0;
2356}
2357
5e3d3d9b
JH		 2358static u8 sc_select_method(struct smp_chan *smp)
2359{
2360 struct l2cap_conn *conn = smp->conn;
2361 struct hci_conn *hcon = conn->hcon;
2362 struct smp_cmd_pairing *local, *remote;
2363 u8 local_mitm, remote_mitm, local_io, remote_io, method;
2364
a29b0733
JH		 2365 if (test_bit(SMP_FLAG_OOB, &smp->flags))
2366 return REQ_OOB;
2367
5e3d3d9b
JH		 2368 /* The preq/prsp contain the raw Pairing Request/Response PDUs
2369 * which are needed as inputs to some crypto functions. To get
2370 * the "struct smp_cmd_pairing" from them we need to skip the
2371 * first byte which contains the opcode.
2372 */
2373 if (hcon->out) {
2374 local = (void *) &smp->preq[1];
2375 remote = (void *) &smp->prsp[1];
2376 } else {
2377 local = (void *) &smp->prsp[1];
2378 remote = (void *) &smp->preq[1];
2379 }
2380
2381 local_io = local->io_capability;
2382 remote_io = remote->io_capability;
2383
2384 local_mitm = (local->auth_req & SMP_AUTH_MITM);
2385 remote_mitm = (remote->auth_req & SMP_AUTH_MITM);
2386
2387 /* If either side wants MITM, look up the method from the table,
2388 * otherwise use JUST WORKS.
2389 */
2390 if (local_mitm || remote_mitm)
2391 method = get_auth_method(smp, local_io, remote_io);
2392 else
2393 method = JUST_WORKS;
2394
2395 /* Don't confirm locally initiated pairing attempts */
2396 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags))
2397 method = JUST_WORKS;
2398
2399 return method;
2400}
2401
d8f8edbe
JH		 2402static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb)
2403{
2404 struct smp_cmd_public_key *key = (void *) skb->data;
2405 struct hci_conn *hcon = conn->hcon;
2406 struct l2cap_chan *chan = conn->smp;
2407 struct smp_chan *smp = chan->data;
5e3d3d9b 2408 struct hci_dev *hdev = hcon->hdev;
cbbbe3e2 2409 struct smp_cmd_pairing_confirm cfm;
d8f8edbe
JH		 2410 int err;
2411
2412 BT_DBG("conn %p", conn);
2413
2414 if (skb->len < sizeof(*key))
2415 return SMP_INVALID_PARAMS;
2416
2417 memcpy(smp->remote_pk, key, 64);
2418
2419 /* Non-initiating device sends its public key after receiving
2420 * the key from the initiating device.
2421 */
2422 if (!hcon->out) {
2423 err = sc_send_public_key(smp);
2424 if (err)
2425 return err;
2426 }
2427
c7a3d57d
JH		 2428 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk);
2429 SMP_DBG("Remote Public Key Y: %32phN", &smp->remote_pk[32]);
d8f8edbe
JH		 2430
2431 if (!ecdh_shared_secret(smp->remote_pk, smp->local_sk, smp->dhkey))
2432 return SMP_UNSPECIFIED;
2433
c7a3d57d 2434 SMP_DBG("DHKey %32phN", smp->dhkey);
d8f8edbe
JH		 2435
2436 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags);
2437
5e3d3d9b
JH		 2438 smp->method = sc_select_method(smp);
2439
2440 BT_DBG("%s selected method 0x%02x", hdev->name, smp->method);
2441
2442 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */
2443 if (smp->method == JUST_WORKS || smp->method == JUST_CFM)
2444 hcon->pending_sec_level = BT_SECURITY_MEDIUM;
2445 else
2446 hcon->pending_sec_level = BT_SECURITY_FIPS;
2447
aeb7d461
JH		 2448 if (!memcmp(debug_pk, smp->remote_pk, 64))
2449 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
2450
38606f14
JH		 2451 if (smp->method == DSP_PASSKEY) {
2452 get_random_bytes(&hcon->passkey_notify,
2453 sizeof(hcon->passkey_notify));
2454 hcon->passkey_notify %= 1000000;
2455 hcon->passkey_entered = 0;
2456 smp->passkey_round = 0;
2457 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type,
2458 hcon->dst_type,
2459 hcon->passkey_notify,
2460 hcon->passkey_entered))
2461 return SMP_UNSPECIFIED;
2462 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2463 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY);
2464 }
2465
a29b0733
JH		 2466 if (smp->method == REQ_OOB) {
2467 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk,
2468 smp->rr, 0, cfm.confirm_val);
2469 if (err)
2470 return SMP_UNSPECIFIED;
2471
2472 if (memcmp(cfm.confirm_val, smp->pcnf, 16))
2473 return SMP_CONFIRM_FAILED;
2474
2475 if (hcon->out)
2476 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
2477 sizeof(smp->prnd), smp->prnd);
2478
2479 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2480
2481 return 0;
2482 }
2483
38606f14
JH		 2484 if (hcon->out)
2485 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2486
2487 if (smp->method == REQ_PASSKEY) {
2488 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type,
2489 hcon->dst_type))
2490 return SMP_UNSPECIFIED;
2491 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
2492 set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
2493 return 0;
2494 }
2495
cbbbe3e2
JH		 2496 /* The Initiating device waits for the non-initiating device to
2497 * send the confirm value.
2498 */
2499 if (conn->hcon->out)
2500 return 0;
2501
2502 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd,
2503 0, cfm.confirm_val);
2504 if (err)
2505 return SMP_UNSPECIFIED;
2506
2507 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm);
2508 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);
2509
d8f8edbe
JH		 2510 return 0;
2511}
2512
6433a9a2
JH		 2513static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb)
2514{
2515 struct smp_cmd_dhkey_check *check = (void *) skb->data;
2516 struct l2cap_chan *chan = conn->smp;
2517 struct hci_conn *hcon = conn->hcon;
2518 struct smp_chan *smp = chan->data;
2519 u8 a[7], b[7], *local_addr, *remote_addr;
2520 u8 io_cap[3], r[16], e[16];
2521 int err;
2522
2523 BT_DBG("conn %p", conn);
2524
2525 if (skb->len < sizeof(*check))
2526 return SMP_INVALID_PARAMS;
2527
2528 memcpy(a, &hcon->init_addr, 6);
2529 memcpy(b, &hcon->resp_addr, 6);
2530 a[6] = hcon->init_addr_type;
2531 b[6] = hcon->resp_addr_type;
2532
2533 if (hcon->out) {
2534 local_addr = a;
2535 remote_addr = b;
2536 memcpy(io_cap, &smp->prsp[1], 3);
2537 } else {
2538 local_addr = b;
2539 remote_addr = a;
2540 memcpy(io_cap, &smp->preq[1], 3);
2541 }
2542
2543 memset(r, 0, sizeof(r));
2544
38606f14
JH		 2545 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
2546 put_unaligned_le32(hcon->passkey_notify, r);
2547
6433a9a2
JH		 2548 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r,
2549 io_cap, remote_addr, local_addr, e);
2550 if (err)
2551 return SMP_UNSPECIFIED;
2552
2553 if (memcmp(check->e, e, 16))
2554 return SMP_DHKEY_CHECK_FAILED;
2555
d3e54a87
JH		 2556 if (!hcon->out) {
2557 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) {
2558 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags);
2559 return 0;
2560 }
d378a2d7 2561
d3e54a87
JH		 2562 /* Slave sends DHKey check as response to master */
2563 sc_dhkey_check(smp);
2564 }
d378a2d7 2565
d3e54a87 2566 sc_add_ltk(smp);
6433a9a2
JH		 2567
2568 if (hcon->out) {
2569 hci_le_start_enc(hcon, 0, 0, smp->tk);
2570 hcon->enc_key_size = smp->enc_key_size;
2571 }
2572
2573 return 0;
2574}
2575
1408bb6e
JH		 2576static int smp_cmd_keypress_notify(struct l2cap_conn *conn,
2577 struct sk_buff *skb)
2578{
2579 struct smp_cmd_keypress_notify *kp = (void *) skb->data;
2580
2581 BT_DBG("value 0x%02x", kp->value);
2582
2583 return 0;
2584}
2585
4befb867 2586static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb)
eb492e01 2587{
5d88cc73 2588 struct l2cap_conn *conn = chan->conn;
7b9899db 2589 struct hci_conn *hcon = conn->hcon;
b28b4943 2590 struct smp_chan *smp;
92381f5c 2591 __u8 code, reason;
eb492e01
AB		 2592 int err = 0;
2593
8ae9b984 2594 if (skb->len < 1)
92381f5c 2595 return -EILSEQ;
92381f5c 2596
06ae3314 2597 if (!test_bit(HCI_LE_ENABLED, &hcon->hdev->dev_flags)) {
2e65c9d2
AG		 2598 reason = SMP_PAIRING_NOTSUPP;
2599 goto done;
2600 }
2601
92381f5c 2602 code = skb->data[0];
eb492e01
AB		 2603 skb_pull(skb, sizeof(code));
2604
b28b4943
JH		 2605 smp = chan->data;
2606
2607 if (code > SMP_CMD_MAX)
2608 goto drop;
2609
24bd0bd9 2610 if (smp && !test_and_clear_bit(code, &smp->allow_cmd))
b28b4943
JH		 2611 goto drop;
2612
2613 /* If we don't have a context the only allowed commands are
2614 * pairing request and security request.
8cf9fa12 2615 */
b28b4943
JH		 2616 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ)
2617 goto drop;
8cf9fa12 2618
eb492e01
AB		 2619 switch (code) {
2620 case SMP_CMD_PAIRING_REQ:
da85e5e5 2621 reason = smp_cmd_pairing_req(conn, skb);
eb492e01
AB		 2622 break;
2623
2624 case SMP_CMD_PAIRING_FAIL:
84794e11 2625 smp_failure(conn, 0);
da85e5e5 2626 err = -EPERM;
eb492e01
AB		 2627 break;
2628
2629 case SMP_CMD_PAIRING_RSP:
da85e5e5 2630 reason = smp_cmd_pairing_rsp(conn, skb);
88ba43b6
AB		 2631 break;
2632
2633 case SMP_CMD_SECURITY_REQ:
da85e5e5 2634 reason = smp_cmd_security_req(conn, skb);
88ba43b6
AB		 2635 break;
2636
eb492e01 2637 case SMP_CMD_PAIRING_CONFIRM:
da85e5e5 2638 reason = smp_cmd_pairing_confirm(conn, skb);
88ba43b6
AB		 2639 break;
2640
eb492e01 2641 case SMP_CMD_PAIRING_RANDOM:
da85e5e5 2642 reason = smp_cmd_pairing_random(conn, skb);
88ba43b6
AB		 2643 break;
2644
eb492e01 2645 case SMP_CMD_ENCRYPT_INFO:
7034b911
VCG		 2646 reason = smp_cmd_encrypt_info(conn, skb);
2647 break;
2648
eb492e01 2649 case SMP_CMD_MASTER_IDENT:
7034b911
VCG		 2650 reason = smp_cmd_master_ident(conn, skb);
2651 break;
2652
eb492e01 2653 case SMP_CMD_IDENT_INFO:
fd349c02
JH		 2654 reason = smp_cmd_ident_info(conn, skb);
2655 break;
2656
eb492e01 2657 case SMP_CMD_IDENT_ADDR_INFO:
fd349c02
JH		 2658 reason = smp_cmd_ident_addr_info(conn, skb);
2659 break;
2660
eb492e01 2661 case SMP_CMD_SIGN_INFO:
7ee4ea36 2662 reason = smp_cmd_sign_info(conn, skb);
7034b911
VCG		 2663 break;
2664
d8f8edbe
JH		 2665 case SMP_CMD_PUBLIC_KEY:
2666 reason = smp_cmd_public_key(conn, skb);
2667 break;
2668
6433a9a2
JH		 2669 case SMP_CMD_DHKEY_CHECK:
2670 reason = smp_cmd_dhkey_check(conn, skb);
2671 break;
2672
1408bb6e
JH		 2673 case SMP_CMD_KEYPRESS_NOTIFY:
2674 reason = smp_cmd_keypress_notify(conn, skb);
2675 break;
2676
eb492e01
AB		 2677 default:
2678 BT_DBG("Unknown command code 0x%2.2x", code);
eb492e01 2679 reason = SMP_CMD_NOTSUPP;
3a0259bb 2680 goto done;
eb492e01
AB		 2681 }
2682
3a0259bb 2683done:
9b7b18ef
JH		 2684 if (!err) {
2685 if (reason)
2686 smp_failure(conn, reason);
8ae9b984 2687 kfree_skb(skb);
9b7b18ef
JH		 2688 }
2689
eb492e01 2690 return err;
b28b4943
JH		 2691
2692drop:
2693 BT_ERR("%s unexpected SMP command 0x%02x from %pMR", hcon->hdev->name,
2694 code, &hcon->dst);
2695 kfree_skb(skb);
2696 return 0;
eb492e01 2697}
7034b911 2698
70db83c4
JH		 2699static void smp_teardown_cb(struct l2cap_chan *chan, int err)
2700{
2701 struct l2cap_conn *conn = chan->conn;
2702
2703 BT_DBG("chan %p", chan);
2704
fc75cc86 2705 if (chan->data)
5d88cc73 2706 smp_chan_destroy(conn);
5d88cc73 2707
70db83c4
JH		 2708 conn->smp = NULL;
2709 l2cap_chan_put(chan);
2710}
2711
b5ae344d
JH		 2712static void bredr_pairing(struct l2cap_chan *chan)
2713{
2714 struct l2cap_conn *conn = chan->conn;
2715 struct hci_conn *hcon = conn->hcon;
2716 struct hci_dev *hdev = hcon->hdev;
2717 struct smp_cmd_pairing req;
2718 struct smp_chan *smp;
2719
2720 BT_DBG("chan %p", chan);
2721
2722 /* Only new pairings are interesting */
2723 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags))
2724 return;
2725
2726 /* Don't bother if we're not encrypted */
2727 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
2728 return;
2729
2730 /* Only master may initiate SMP over BR/EDR */
2731 if (hcon->role != HCI_ROLE_MASTER)
2732 return;
2733
2734 /* Secure Connections support must be enabled */
2735 if (!test_bit(HCI_SC_ENABLED, &hdev->dev_flags))
2736 return;
2737
2738 /* BR/EDR must use Secure Connections for SMP */
2739 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) &&
2740 !test_bit(HCI_FORCE_LESC, &hdev->dbg_flags))
2741 return;
2742
2743 /* If our LE support is not enabled don't do anything */
2744 if (!test_bit(HCI_LE_ENABLED, &hdev->dev_flags))
2745 return;
2746
2747 /* Don't bother if remote LE support is not enabled */
2748 if (!lmp_host_le_capable(hcon))
2749 return;
2750
2751 /* Remote must support SMP fixed chan for BR/EDR */
2752 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR))
2753 return;
2754
2755 /* Don't bother if SMP is already ongoing */
2756 if (chan->data)
2757 return;
2758
2759 smp = smp_chan_create(conn);
2760 if (!smp) {
2761 BT_ERR("%s unable to create SMP context for BR/EDR",
2762 hdev->name);
2763 return;
2764 }
2765
2766 set_bit(SMP_FLAG_SC, &smp->flags);
2767
2768 BT_DBG("%s starting SMP over BR/EDR", hdev->name);
2769
2770 /* Prepare and send the BR/EDR SMP Pairing Request */
2771 build_bredr_pairing_cmd(smp, &req, NULL);
2772
2773 smp->preq[0] = SMP_CMD_PAIRING_REQ;
2774 memcpy(&smp->preq[1], &req, sizeof(req));
2775
2776 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(req), &req);
2777 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP);
2778}
2779
44f1a7ab
JH		 2780static void smp_resume_cb(struct l2cap_chan *chan)
2781{
b68fda68 2782 struct smp_chan *smp = chan->data;
44f1a7ab
JH		 2783 struct l2cap_conn *conn = chan->conn;
2784 struct hci_conn *hcon = conn->hcon;
2785
2786 BT_DBG("chan %p", chan);
2787
b5ae344d
JH		 2788 if (hcon->type == ACL_LINK) {
2789 bredr_pairing(chan);
ef8efe4b 2790 return;
b5ae344d 2791 }
ef8efe4b 2792
86d1407c
JH		 2793 if (!smp)
2794 return;
b68fda68 2795
84bc0db5
JH		 2796 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
2797 return;
2798
86d1407c
JH		 2799 cancel_delayed_work(&smp->security_timer);
2800
d6268e86 2801 smp_distribute_keys(smp);
44f1a7ab
JH		 2802}
2803
70db83c4
JH		 2804static void smp_ready_cb(struct l2cap_chan *chan)
2805{
2806 struct l2cap_conn *conn = chan->conn;
b5ae344d 2807 struct hci_conn *hcon = conn->hcon;
70db83c4
JH		 2808
2809 BT_DBG("chan %p", chan);
2810
2811 conn->smp = chan;
2812 l2cap_chan_hold(chan);
b5ae344d
JH		 2813
2814 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
2815 bredr_pairing(chan);
70db83c4
JH		 2816}
2817
4befb867
JH		 2818static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
2819{
2820 int err;
2821
2822 BT_DBG("chan %p", chan);
2823
2824 err = smp_sig_channel(chan, skb);
2825 if (err) {
b68fda68 2826 struct smp_chan *smp = chan->data;
4befb867 2827
b68fda68
JH		 2828 if (smp)
2829 cancel_delayed_work_sync(&smp->security_timer);
4befb867 2830
1e91c29e 2831 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE);
4befb867
JH		 2832 }
2833
2834 return err;
2835}
2836
70db83c4
JH		 2837static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan,
2838 unsigned long hdr_len,
2839 unsigned long len, int nb)
2840{
2841 struct sk_buff *skb;
2842
2843 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL);
2844 if (!skb)
2845 return ERR_PTR(-ENOMEM);
2846
2847 skb->priority = HCI_PRIO_MAX;
2848 bt_cb(skb)->chan = chan;
2849
2850 return skb;
2851}
2852
2853static const struct l2cap_ops smp_chan_ops = {
2854 .name = "Security Manager",
2855 .ready = smp_ready_cb,
5d88cc73 2856 .recv = smp_recv_cb,
70db83c4
JH		 2857 .alloc_skb = smp_alloc_skb_cb,
2858 .teardown = smp_teardown_cb,
44f1a7ab 2859 .resume = smp_resume_cb,
70db83c4
JH		 2860
2861 .new_connection = l2cap_chan_no_new_connection,
70db83c4
JH		 2862 .state_change = l2cap_chan_no_state_change,
2863 .close = l2cap_chan_no_close,
2864 .defer = l2cap_chan_no_defer,
2865 .suspend = l2cap_chan_no_suspend,
70db83c4
JH		 2866 .set_shutdown = l2cap_chan_no_set_shutdown,
2867 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
2868 .memcpy_fromiovec = l2cap_chan_no_memcpy_fromiovec,
2869};
2870
2871static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan)
2872{
2873 struct l2cap_chan *chan;
2874
2875 BT_DBG("pchan %p", pchan);
2876
2877 chan = l2cap_chan_create();
2878 if (!chan)
2879 return NULL;
2880
2881 chan->chan_type = pchan->chan_type;
2882 chan->ops = &smp_chan_ops;
2883 chan->scid = pchan->scid;
2884 chan->dcid = chan->scid;
2885 chan->imtu = pchan->imtu;
2886 chan->omtu = pchan->omtu;
2887 chan->mode = pchan->mode;
2888
abe84903
JH		 2889 /* Other L2CAP channels may request SMP routines in order to
2890 * change the security level. This means that the SMP channel
2891 * lock must be considered in its own category to avoid lockdep
2892 * warnings.
2893 */
2894 atomic_set(&chan->nesting, L2CAP_NESTING_SMP);
2895
70db83c4
JH		 2896 BT_DBG("created chan %p", chan);
2897
2898 return chan;
2899}
2900
2901static const struct l2cap_ops smp_root_chan_ops = {
2902 .name = "Security Manager Root",
2903 .new_connection = smp_new_conn_cb,
2904
2905 /* None of these are implemented for the root channel */
2906 .close = l2cap_chan_no_close,
2907 .alloc_skb = l2cap_chan_no_alloc_skb,
2908 .recv = l2cap_chan_no_recv,
2909 .state_change = l2cap_chan_no_state_change,
2910 .teardown = l2cap_chan_no_teardown,
2911 .ready = l2cap_chan_no_ready,
2912 .defer = l2cap_chan_no_defer,
2913 .suspend = l2cap_chan_no_suspend,
2914 .resume = l2cap_chan_no_resume,
2915 .set_shutdown = l2cap_chan_no_set_shutdown,
2916 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
2917 .memcpy_fromiovec = l2cap_chan_no_memcpy_fromiovec,
2918};
2919
ef8efe4b 2920static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid)
711eafe3 2921{
70db83c4 2922 struct l2cap_chan *chan;
defce9e8 2923 struct crypto_blkcipher *tfm_aes;
70db83c4 2924
ef8efe4b
JH		 2925 if (cid == L2CAP_CID_SMP_BREDR) {
2926 tfm_aes = NULL;
2927 goto create_chan;
2928 }
711eafe3 2929
adae20cb 2930 tfm_aes = crypto_alloc_blkcipher("ecb(aes)", 0, 0);
defce9e8 2931 if (IS_ERR(tfm_aes)) {
711eafe3 2932 BT_ERR("Unable to create crypto context");
ef8efe4b 2933 return ERR_PTR(PTR_ERR(tfm_aes));
711eafe3
JH		 2934 }
2935
ef8efe4b 2936create_chan:
70db83c4
JH		 2937 chan = l2cap_chan_create();
2938 if (!chan) {
defce9e8 2939 crypto_free_blkcipher(tfm_aes);
ef8efe4b 2940 return ERR_PTR(-ENOMEM);
70db83c4
JH		 2941 }
2942
defce9e8
JH		 2943 chan->data = tfm_aes;
2944
ef8efe4b 2945 l2cap_add_scid(chan, cid);
70db83c4
JH		 2946
2947 l2cap_chan_set_defaults(chan);
2948
2949 bacpy(&chan->src, &hdev->bdaddr);
ef8efe4b
JH		 2950 if (cid == L2CAP_CID_SMP)
2951 chan->src_type = BDADDR_LE_PUBLIC;
2952 else
2953 chan->src_type = BDADDR_BREDR;
70db83c4
JH		 2954 chan->state = BT_LISTEN;
2955 chan->mode = L2CAP_MODE_BASIC;
2956 chan->imtu = L2CAP_DEFAULT_MTU;
2957 chan->ops = &smp_root_chan_ops;
2958
abe84903
JH		 2959 /* Set correct nesting level for a parent/listening channel */
2960 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
2961
ef8efe4b 2962 return chan;
711eafe3
JH		 2963}
2964
ef8efe4b 2965static void smp_del_chan(struct l2cap_chan *chan)
711eafe3 2966{
ef8efe4b 2967 struct crypto_blkcipher *tfm_aes;
70db83c4 2968
ef8efe4b 2969 BT_DBG("chan %p", chan);
711eafe3 2970
defce9e8
JH		 2971 tfm_aes = chan->data;
2972 if (tfm_aes) {
2973 chan->data = NULL;
2974 crypto_free_blkcipher(tfm_aes);
711eafe3 2975 }
70db83c4 2976
70db83c4 2977 l2cap_chan_put(chan);
711eafe3 2978}
ef8efe4b
JH		 2979
2980int smp_register(struct hci_dev *hdev)
2981{
2982 struct l2cap_chan *chan;
2983
2984 BT_DBG("%s", hdev->name);
2985
2986 chan = smp_add_cid(hdev, L2CAP_CID_SMP);
2987 if (IS_ERR(chan))
2988 return PTR_ERR(chan);
2989
2990 hdev->smp_data = chan;
2991
2992 if (!lmp_sc_capable(hdev) &&
2993 !test_bit(HCI_FORCE_LESC, &hdev->dbg_flags))
2994 return 0;
2995
2996 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
2997 if (IS_ERR(chan)) {
2998 int err = PTR_ERR(chan);
2999 chan = hdev->smp_data;
3000 hdev->smp_data = NULL;
3001 smp_del_chan(chan);
3002 return err;
3003 }
3004
3005 hdev->smp_bredr_data = chan;
3006
3007 return 0;
3008}
3009
3010void smp_unregister(struct hci_dev *hdev)
3011{
3012 struct l2cap_chan *chan;
3013
3014 if (hdev->smp_bredr_data) {
3015 chan = hdev->smp_bredr_data;
3016 hdev->smp_bredr_data = NULL;
3017 smp_del_chan(chan);
3018 }
3019
3020 if (hdev->smp_data) {
3021 chan = hdev->smp_data;
3022 hdev->smp_data = NULL;
3023 smp_del_chan(chan);
3024 }
3025}
Linux kernel - Deliverables
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