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Bluetooth: Always call smp_distribute_keys() from a workqueue
[deliverable/linux.git] / net / bluetooth / smp.c
1 /*
2 BlueZ - Bluetooth protocol stack for Linux
3 Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License version 2 as
7 published by the Free Software Foundation;
8
9 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
10 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
11 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
12 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
13 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
14 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17
18 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
19 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
20 SOFTWARE IS DISCLAIMED.
21 */
22
23 #include <linux/crypto.h>
24 #include <linux/scatterlist.h>
25 #include <crypto/b128ops.h>
26
27 #include <net/bluetooth/bluetooth.h>
28 #include <net/bluetooth/hci_core.h>
29 #include <net/bluetooth/l2cap.h>
30 #include <net/bluetooth/mgmt.h>
31
32 #include "smp.h"
33
34 #define SMP_TIMEOUT msecs_to_jiffies(30000)
35
36 #define AUTH_REQ_MASK 0x07
37
38 enum {
39 SMP_FLAG_TK_VALID,
40 SMP_FLAG_CFM_PENDING,
41 SMP_FLAG_MITM_AUTH,
42 SMP_FLAG_COMPLETE,
43 SMP_FLAG_INITIATOR,
44 };
45
46 struct smp_chan {
47 struct l2cap_conn *conn;
48 struct delayed_work security_timer;
49 struct work_struct distribute_work;
50
51 u8 preq[7]; /* SMP Pairing Request */
52 u8 prsp[7]; /* SMP Pairing Response */
53 u8 prnd[16]; /* SMP Pairing Random (local) */
54 u8 rrnd[16]; /* SMP Pairing Random (remote) */
55 u8 pcnf[16]; /* SMP Pairing Confirm */
56 u8 tk[16]; /* SMP Temporary Key */
57 u8 enc_key_size;
58 u8 remote_key_dist;
59 bdaddr_t id_addr;
60 u8 id_addr_type;
61 u8 irk[16];
62 struct smp_csrk *csrk;
63 struct smp_csrk *slave_csrk;
64 struct smp_ltk *ltk;
65 struct smp_ltk *slave_ltk;
66 struct smp_irk *remote_irk;
67 unsigned long flags;
68
69 struct crypto_blkcipher *tfm_aes;
70 };
71
72 static inline void swap_buf(const u8 *src, u8 *dst, size_t len)
73 {
74 size_t i;
75
76 for (i = 0; i < len; i++)
77 dst[len - 1 - i] = src[i];
78 }
79
80 static int smp_e(struct crypto_blkcipher *tfm, const u8 *k, u8 *r)
81 {
82 struct blkcipher_desc desc;
83 struct scatterlist sg;
84 uint8_t tmp[16], data[16];
85 int err;
86
87 if (tfm == NULL) {
88 BT_ERR("tfm %p", tfm);
89 return -EINVAL;
90 }
91
92 desc.tfm = tfm;
93 desc.flags = 0;
94
95 /* The most significant octet of key corresponds to k[0] */
96 swap_buf(k, tmp, 16);
97
98 err = crypto_blkcipher_setkey(tfm, tmp, 16);
99 if (err) {
100 BT_ERR("cipher setkey failed: %d", err);
101 return err;
102 }
103
104 /* Most significant octet of plaintextData corresponds to data[0] */
105 swap_buf(r, data, 16);
106
107 sg_init_one(&sg, data, 16);
108
109 err = crypto_blkcipher_encrypt(&desc, &sg, &sg, 16);
110 if (err)
111 BT_ERR("Encrypt data error %d", err);
112
113 /* Most significant octet of encryptedData corresponds to data[0] */
114 swap_buf(data, r, 16);
115
116 return err;
117 }
118
119 static int smp_ah(struct crypto_blkcipher *tfm, u8 irk[16], u8 r[3], u8 res[3])
120 {
121 u8 _res[16];
122 int err;
123
124 /* r' = padding || r */
125 memcpy(_res, r, 3);
126 memset(_res + 3, 0, 13);
127
128 err = smp_e(tfm, irk, _res);
129 if (err) {
130 BT_ERR("Encrypt error");
131 return err;
132 }
133
134 /* The output of the random address function ah is:
135 * ah(h, r) = e(k, r') mod 2^24
136 * The output of the security function e is then truncated to 24 bits
137 * by taking the least significant 24 bits of the output of e as the
138 * result of ah.
139 */
140 memcpy(res, _res, 3);
141
142 return 0;
143 }
144
145 bool smp_irk_matches(struct hci_dev *hdev, u8 irk[16], bdaddr_t *bdaddr)
146 {
147 struct l2cap_chan *chan = hdev->smp_data;
148 struct crypto_blkcipher *tfm;
149 u8 hash[3];
150 int err;
151
152 if (!chan || !chan->data)
153 return false;
154
155 tfm = chan->data;
156
157 BT_DBG("RPA %pMR IRK %*phN", bdaddr, 16, irk);
158
159 err = smp_ah(tfm, irk, &bdaddr->b[3], hash);
160 if (err)
161 return false;
162
163 return !memcmp(bdaddr->b, hash, 3);
164 }
165
166 int smp_generate_rpa(struct hci_dev *hdev, u8 irk[16], bdaddr_t *rpa)
167 {
168 struct l2cap_chan *chan = hdev->smp_data;
169 struct crypto_blkcipher *tfm;
170 int err;
171
172 if (!chan || !chan->data)
173 return -EOPNOTSUPP;
174
175 tfm = chan->data;
176
177 get_random_bytes(&rpa->b[3], 3);
178
179 rpa->b[5] &= 0x3f; /* Clear two most significant bits */
180 rpa->b[5] |= 0x40; /* Set second most significant bit */
181
182 err = smp_ah(tfm, irk, &rpa->b[3], rpa->b);
183 if (err < 0)
184 return err;
185
186 BT_DBG("RPA %pMR", rpa);
187
188 return 0;
189 }
190
191 static int smp_c1(struct smp_chan *smp, u8 k[16], u8 r[16], u8 preq[7],
192 u8 pres[7], u8 _iat, bdaddr_t *ia, u8 _rat, bdaddr_t *ra,
193 u8 res[16])
194 {
195 struct hci_dev *hdev = smp->conn->hcon->hdev;
196 u8 p1[16], p2[16];
197 int err;
198
199 BT_DBG("%s", hdev->name);
200
201 memset(p1, 0, 16);
202
203 /* p1 = pres || preq || _rat || _iat */
204 p1[0] = _iat;
205 p1[1] = _rat;
206 memcpy(p1 + 2, preq, 7);
207 memcpy(p1 + 9, pres, 7);
208
209 /* p2 = padding || ia || ra */
210 memcpy(p2, ra, 6);
211 memcpy(p2 + 6, ia, 6);
212 memset(p2 + 12, 0, 4);
213
214 /* res = r XOR p1 */
215 u128_xor((u128 *) res, (u128 *) r, (u128 *) p1);
216
217 /* res = e(k, res) */
218 err = smp_e(smp->tfm_aes, k, res);
219 if (err) {
220 BT_ERR("Encrypt data error");
221 return err;
222 }
223
224 /* res = res XOR p2 */
225 u128_xor((u128 *) res, (u128 *) res, (u128 *) p2);
226
227 /* res = e(k, res) */
228 err = smp_e(smp->tfm_aes, k, res);
229 if (err)
230 BT_ERR("Encrypt data error");
231
232 return err;
233 }
234
235 static int smp_s1(struct smp_chan *smp, u8 k[16], u8 r1[16], u8 r2[16],
236 u8 _r[16])
237 {
238 struct hci_dev *hdev = smp->conn->hcon->hdev;
239 int err;
240
241 BT_DBG("%s", hdev->name);
242
243 /* Just least significant octets from r1 and r2 are considered */
244 memcpy(_r, r2, 8);
245 memcpy(_r + 8, r1, 8);
246
247 err = smp_e(smp->tfm_aes, k, _r);
248 if (err)
249 BT_ERR("Encrypt data error");
250
251 return err;
252 }
253
254 static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
255 {
256 struct l2cap_chan *chan = conn->smp;
257 struct smp_chan *smp;
258 struct kvec iv[2];
259 struct msghdr msg;
260
261 if (!chan)
262 return;
263
264 BT_DBG("code 0x%2.2x", code);
265
266 iv[0].iov_base = &code;
267 iv[0].iov_len = 1;
268
269 iv[1].iov_base = data;
270 iv[1].iov_len = len;
271
272 memset(&msg, 0, sizeof(msg));
273
274 msg.msg_iov = (struct iovec *) &iv;
275 msg.msg_iovlen = 2;
276
277 l2cap_chan_send(chan, &msg, 1 + len);
278
279 if (!chan->data)
280 return;
281
282 smp = chan->data;
283
284 cancel_delayed_work_sync(&smp->security_timer);
285 if (test_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->flags))
286 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT);
287 }
288
289 static __u8 authreq_to_seclevel(__u8 authreq)
290 {
291 if (authreq & SMP_AUTH_MITM)
292 return BT_SECURITY_HIGH;
293 else
294 return BT_SECURITY_MEDIUM;
295 }
296
297 static __u8 seclevel_to_authreq(__u8 sec_level)
298 {
299 switch (sec_level) {
300 case BT_SECURITY_HIGH:
301 return SMP_AUTH_MITM | SMP_AUTH_BONDING;
302 case BT_SECURITY_MEDIUM:
303 return SMP_AUTH_BONDING;
304 default:
305 return SMP_AUTH_NONE;
306 }
307 }
308
309 static void build_pairing_cmd(struct l2cap_conn *conn,
310 struct smp_cmd_pairing *req,
311 struct smp_cmd_pairing *rsp, __u8 authreq)
312 {
313 struct l2cap_chan *chan = conn->smp;
314 struct smp_chan *smp = chan->data;
315 struct hci_conn *hcon = conn->hcon;
316 struct hci_dev *hdev = hcon->hdev;
317 u8 local_dist = 0, remote_dist = 0;
318
319 if (test_bit(HCI_BONDABLE, &conn->hcon->hdev->dev_flags)) {
320 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
321 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN;
322 authreq |= SMP_AUTH_BONDING;
323 } else {
324 authreq &= ~SMP_AUTH_BONDING;
325 }
326
327 if (test_bit(HCI_RPA_RESOLVING, &hdev->dev_flags))
328 remote_dist |= SMP_DIST_ID_KEY;
329
330 if (test_bit(HCI_PRIVACY, &hdev->dev_flags))
331 local_dist |= SMP_DIST_ID_KEY;
332
333 if (rsp == NULL) {
334 req->io_capability = conn->hcon->io_capability;
335 req->oob_flag = SMP_OOB_NOT_PRESENT;
336 req->max_key_size = SMP_MAX_ENC_KEY_SIZE;
337 req->init_key_dist = local_dist;
338 req->resp_key_dist = remote_dist;
339 req->auth_req = (authreq & AUTH_REQ_MASK);
340
341 smp->remote_key_dist = remote_dist;
342 return;
343 }
344
345 rsp->io_capability = conn->hcon->io_capability;
346 rsp->oob_flag = SMP_OOB_NOT_PRESENT;
347 rsp->max_key_size = SMP_MAX_ENC_KEY_SIZE;
348 rsp->init_key_dist = req->init_key_dist & remote_dist;
349 rsp->resp_key_dist = req->resp_key_dist & local_dist;
350 rsp->auth_req = (authreq & AUTH_REQ_MASK);
351
352 smp->remote_key_dist = rsp->init_key_dist;
353 }
354
355 static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)
356 {
357 struct l2cap_chan *chan = conn->smp;
358 struct smp_chan *smp = chan->data;
359
360 if ((max_key_size > SMP_MAX_ENC_KEY_SIZE) ||
361 (max_key_size < SMP_MIN_ENC_KEY_SIZE))
362 return SMP_ENC_KEY_SIZE;
363
364 smp->enc_key_size = max_key_size;
365
366 return 0;
367 }
368
369 static void smp_failure(struct l2cap_conn *conn, u8 reason)
370 {
371 struct hci_conn *hcon = conn->hcon;
372 struct l2cap_chan *chan = conn->smp;
373 struct smp_chan *smp;
374
375 if (reason)
376 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
377 &reason);
378
379 clear_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags);
380 mgmt_auth_failed(hcon->hdev, &hcon->dst, hcon->type, hcon->dst_type,
381 HCI_ERROR_AUTH_FAILURE);
382
383 if (!chan->data)
384 return;
385
386 smp = chan->data;
387
388 if (test_and_clear_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags))
389 smp_chan_destroy(conn);
390 }
391
392 #define JUST_WORKS 0x00
393 #define JUST_CFM 0x01
394 #define REQ_PASSKEY 0x02
395 #define CFM_PASSKEY 0x03
396 #define REQ_OOB 0x04
397 #define OVERLAP 0xFF
398
399 static const u8 gen_method[5][5] = {
400 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
401 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
402 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
403 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
404 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP },
405 };
406
407 static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io)
408 {
409 /* If either side has unknown io_caps, use JUST_CFM (which gets
410 * converted later to JUST_WORKS if we're initiators.
411 */
412 if (local_io > SMP_IO_KEYBOARD_DISPLAY ||
413 remote_io > SMP_IO_KEYBOARD_DISPLAY)
414 return JUST_CFM;
415
416 return gen_method[remote_io][local_io];
417 }
418
419 static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth,
420 u8 local_io, u8 remote_io)
421 {
422 struct hci_conn *hcon = conn->hcon;
423 struct l2cap_chan *chan = conn->smp;
424 struct smp_chan *smp = chan->data;
425 u8 method;
426 u32 passkey = 0;
427 int ret = 0;
428
429 /* Initialize key for JUST WORKS */
430 memset(smp->tk, 0, sizeof(smp->tk));
431 clear_bit(SMP_FLAG_TK_VALID, &smp->flags);
432
433 BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io);
434
435 /* If neither side wants MITM, either "just" confirm an incoming
436 * request or use just-works for outgoing ones. The JUST_CFM
437 * will be converted to JUST_WORKS if necessary later in this
438 * function. If either side has MITM look up the method from the
439 * table.
440 */
441 if (!(auth & SMP_AUTH_MITM))
442 method = JUST_CFM;
443 else
444 method = get_auth_method(smp, local_io, remote_io);
445
446 /* Don't confirm locally initiated pairing attempts */
447 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags))
448 method = JUST_WORKS;
449
450 /* Don't bother user space with no IO capabilities */
451 if (method == JUST_CFM && hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
452 method = JUST_WORKS;
453
454 /* If Just Works, Continue with Zero TK */
455 if (method == JUST_WORKS) {
456 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
457 return 0;
458 }
459
460 /* Not Just Works/Confirm results in MITM Authentication */
461 if (method != JUST_CFM)
462 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags);
463
464 /* If both devices have Keyoard-Display I/O, the master
465 * Confirms and the slave Enters the passkey.
466 */
467 if (method == OVERLAP) {
468 if (hcon->role == HCI_ROLE_MASTER)
469 method = CFM_PASSKEY;
470 else
471 method = REQ_PASSKEY;
472 }
473
474 /* Generate random passkey. */
475 if (method == CFM_PASSKEY) {
476 memset(smp->tk, 0, sizeof(smp->tk));
477 get_random_bytes(&passkey, sizeof(passkey));
478 passkey %= 1000000;
479 put_unaligned_le32(passkey, smp->tk);
480 BT_DBG("PassKey: %d", passkey);
481 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
482 }
483
484 hci_dev_lock(hcon->hdev);
485
486 if (method == REQ_PASSKEY)
487 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst,
488 hcon->type, hcon->dst_type);
489 else if (method == JUST_CFM)
490 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
491 hcon->type, hcon->dst_type,
492 passkey, 1);
493 else
494 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst,
495 hcon->type, hcon->dst_type,
496 passkey, 0);
497
498 hci_dev_unlock(hcon->hdev);
499
500 return ret;
501 }
502
503 static u8 smp_confirm(struct smp_chan *smp)
504 {
505 struct l2cap_conn *conn = smp->conn;
506 struct smp_cmd_pairing_confirm cp;
507 int ret;
508
509 BT_DBG("conn %p", conn);
510
511 ret = smp_c1(smp, smp->tk, smp->prnd, smp->preq, smp->prsp,
512 conn->hcon->init_addr_type, &conn->hcon->init_addr,
513 conn->hcon->resp_addr_type, &conn->hcon->resp_addr,
514 cp.confirm_val);
515 if (ret)
516 return SMP_UNSPECIFIED;
517
518 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
519
520 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
521
522 return 0;
523 }
524
525 static u8 smp_random(struct smp_chan *smp)
526 {
527 struct l2cap_conn *conn = smp->conn;
528 struct hci_conn *hcon = conn->hcon;
529 u8 confirm[16];
530 int ret;
531
532 if (IS_ERR_OR_NULL(smp->tfm_aes))
533 return SMP_UNSPECIFIED;
534
535 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
536
537 ret = smp_c1(smp, smp->tk, smp->rrnd, smp->preq, smp->prsp,
538 hcon->init_addr_type, &hcon->init_addr,
539 hcon->resp_addr_type, &hcon->resp_addr, confirm);
540 if (ret)
541 return SMP_UNSPECIFIED;
542
543 if (memcmp(smp->pcnf, confirm, sizeof(smp->pcnf)) != 0) {
544 BT_ERR("Pairing failed (confirmation values mismatch)");
545 return SMP_CONFIRM_FAILED;
546 }
547
548 if (hcon->out) {
549 u8 stk[16];
550 __le64 rand = 0;
551 __le16 ediv = 0;
552
553 smp_s1(smp, smp->tk, smp->rrnd, smp->prnd, stk);
554
555 memset(stk + smp->enc_key_size, 0,
556 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);
557
558 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
559 return SMP_UNSPECIFIED;
560
561 hci_le_start_enc(hcon, ediv, rand, stk);
562 hcon->enc_key_size = smp->enc_key_size;
563 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
564 } else {
565 u8 stk[16], auth;
566 __le64 rand = 0;
567 __le16 ediv = 0;
568
569 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
570 smp->prnd);
571
572 smp_s1(smp, smp->tk, smp->prnd, smp->rrnd, stk);
573
574 memset(stk + smp->enc_key_size, 0,
575 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);
576
577 if (hcon->pending_sec_level == BT_SECURITY_HIGH)
578 auth = 1;
579 else
580 auth = 0;
581
582 /* Even though there's no _SLAVE suffix this is the
583 * slave STK we're adding for later lookup (the master
584 * STK never needs to be stored).
585 */
586 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
587 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand);
588 }
589
590 return 0;
591 }
592
593 static void smp_notify_keys(struct l2cap_conn *conn)
594 {
595 struct l2cap_chan *chan = conn->smp;
596 struct smp_chan *smp = chan->data;
597 struct hci_conn *hcon = conn->hcon;
598 struct hci_dev *hdev = hcon->hdev;
599 struct smp_cmd_pairing *req = (void *) &smp->preq[1];
600 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1];
601 bool persistent;
602
603 if (smp->remote_irk) {
604 mgmt_new_irk(hdev, smp->remote_irk);
605 /* Now that user space can be considered to know the
606 * identity address track the connection based on it
607 * from now on.
608 */
609 bacpy(&hcon->dst, &smp->remote_irk->bdaddr);
610 hcon->dst_type = smp->remote_irk->addr_type;
611 l2cap_conn_update_id_addr(hcon);
612
613 /* When receiving an indentity resolving key for
614 * a remote device that does not use a resolvable
615 * private address, just remove the key so that
616 * it is possible to use the controller white
617 * list for scanning.
618 *
619 * Userspace will have been told to not store
620 * this key at this point. So it is safe to
621 * just remove it.
622 */
623 if (!bacmp(&smp->remote_irk->rpa, BDADDR_ANY)) {
624 list_del(&smp->remote_irk->list);
625 kfree(smp->remote_irk);
626 smp->remote_irk = NULL;
627 }
628 }
629
630 /* The LTKs and CSRKs should be persistent only if both sides
631 * had the bonding bit set in their authentication requests.
632 */
633 persistent = !!((req->auth_req & rsp->auth_req) & SMP_AUTH_BONDING);
634
635 if (smp->csrk) {
636 smp->csrk->bdaddr_type = hcon->dst_type;
637 bacpy(&smp->csrk->bdaddr, &hcon->dst);
638 mgmt_new_csrk(hdev, smp->csrk, persistent);
639 }
640
641 if (smp->slave_csrk) {
642 smp->slave_csrk->bdaddr_type = hcon->dst_type;
643 bacpy(&smp->slave_csrk->bdaddr, &hcon->dst);
644 mgmt_new_csrk(hdev, smp->slave_csrk, persistent);
645 }
646
647 if (smp->ltk) {
648 smp->ltk->bdaddr_type = hcon->dst_type;
649 bacpy(&smp->ltk->bdaddr, &hcon->dst);
650 mgmt_new_ltk(hdev, smp->ltk, persistent);
651 }
652
653 if (smp->slave_ltk) {
654 smp->slave_ltk->bdaddr_type = hcon->dst_type;
655 bacpy(&smp->slave_ltk->bdaddr, &hcon->dst);
656 mgmt_new_ltk(hdev, smp->slave_ltk, persistent);
657 }
658 }
659
660 static void smp_distribute_keys(struct work_struct *work)
661 {
662 struct smp_chan *smp = container_of(work, struct smp_chan,
663 distribute_work);
664 struct smp_cmd_pairing *req, *rsp;
665 struct l2cap_conn *conn = smp->conn;
666 struct hci_conn *hcon = conn->hcon;
667 struct hci_dev *hdev = hcon->hdev;
668 __u8 *keydist;
669
670 BT_DBG("conn %p", conn);
671
672 if (!test_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags))
673 return;
674
675 rsp = (void *) &smp->prsp[1];
676
677 /* The responder sends its keys first */
678 if (hcon->out && (smp->remote_key_dist & 0x07))
679 return;
680
681 req = (void *) &smp->preq[1];
682
683 if (hcon->out) {
684 keydist = &rsp->init_key_dist;
685 *keydist &= req->init_key_dist;
686 } else {
687 keydist = &rsp->resp_key_dist;
688 *keydist &= req->resp_key_dist;
689 }
690
691 BT_DBG("keydist 0x%x", *keydist);
692
693 if (*keydist & SMP_DIST_ENC_KEY) {
694 struct smp_cmd_encrypt_info enc;
695 struct smp_cmd_master_ident ident;
696 struct smp_ltk *ltk;
697 u8 authenticated;
698 __le16 ediv;
699 __le64 rand;
700
701 get_random_bytes(enc.ltk, sizeof(enc.ltk));
702 get_random_bytes(&ediv, sizeof(ediv));
703 get_random_bytes(&rand, sizeof(rand));
704
705 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc);
706
707 authenticated = hcon->sec_level == BT_SECURITY_HIGH;
708 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type,
709 SMP_LTK_SLAVE, authenticated, enc.ltk,
710 smp->enc_key_size, ediv, rand);
711 smp->slave_ltk = ltk;
712
713 ident.ediv = ediv;
714 ident.rand = rand;
715
716 smp_send_cmd(conn, SMP_CMD_MASTER_IDENT, sizeof(ident), &ident);
717
718 *keydist &= ~SMP_DIST_ENC_KEY;
719 }
720
721 if (*keydist & SMP_DIST_ID_KEY) {
722 struct smp_cmd_ident_addr_info addrinfo;
723 struct smp_cmd_ident_info idinfo;
724
725 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk));
726
727 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo);
728
729 /* The hci_conn contains the local identity address
730 * after the connection has been established.
731 *
732 * This is true even when the connection has been
733 * established using a resolvable random address.
734 */
735 bacpy(&addrinfo.bdaddr, &hcon->src);
736 addrinfo.addr_type = hcon->src_type;
737
738 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo),
739 &addrinfo);
740
741 *keydist &= ~SMP_DIST_ID_KEY;
742 }
743
744 if (*keydist & SMP_DIST_SIGN) {
745 struct smp_cmd_sign_info sign;
746 struct smp_csrk *csrk;
747
748 /* Generate a new random key */
749 get_random_bytes(sign.csrk, sizeof(sign.csrk));
750
751 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
752 if (csrk) {
753 csrk->master = 0x00;
754 memcpy(csrk->val, sign.csrk, sizeof(csrk->val));
755 }
756 smp->slave_csrk = csrk;
757
758 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign);
759
760 *keydist &= ~SMP_DIST_SIGN;
761 }
762
763 /* If there are still keys to be received wait for them */
764 if ((smp->remote_key_dist & 0x07))
765 return;
766
767 clear_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags);
768 set_bit(SMP_FLAG_COMPLETE, &smp->flags);
769 smp_notify_keys(conn);
770
771 smp_chan_destroy(conn);
772 }
773
774 static void smp_timeout(struct work_struct *work)
775 {
776 struct smp_chan *smp = container_of(work, struct smp_chan,
777 security_timer.work);
778 struct l2cap_conn *conn = smp->conn;
779
780 BT_DBG("conn %p", conn);
781
782 l2cap_conn_shutdown(conn, ETIMEDOUT);
783 }
784
785 static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
786 {
787 struct l2cap_chan *chan = conn->smp;
788 struct smp_chan *smp;
789
790 smp = kzalloc(sizeof(*smp), GFP_ATOMIC);
791 if (!smp) {
792 clear_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->flags);
793 return NULL;
794 }
795
796 smp->tfm_aes = crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);
797 if (IS_ERR(smp->tfm_aes)) {
798 BT_ERR("Unable to create ECB crypto context");
799 kfree(smp);
800 clear_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->flags);
801 return NULL;
802 }
803
804 smp->conn = conn;
805 chan->data = smp;
806
807 INIT_WORK(&smp->distribute_work, smp_distribute_keys);
808 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout);
809
810 hci_conn_hold(conn->hcon);
811
812 return smp;
813 }
814
815 void smp_chan_destroy(struct l2cap_conn *conn)
816 {
817 struct l2cap_chan *chan = conn->smp;
818 struct smp_chan *smp = chan->data;
819 bool complete;
820
821 BUG_ON(!smp);
822
823 cancel_delayed_work_sync(&smp->security_timer);
824 /* In case the timeout freed the SMP context */
825 if (!chan->data)
826 return;
827
828 if (work_pending(&smp->distribute_work)) {
829 cancel_work_sync(&smp->distribute_work);
830 if (!chan->data)
831 return;
832 }
833
834 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags);
835 mgmt_smp_complete(conn->hcon, complete);
836
837 kfree(smp->csrk);
838 kfree(smp->slave_csrk);
839
840 crypto_free_blkcipher(smp->tfm_aes);
841
842 /* If pairing failed clean up any keys we might have */
843 if (!complete) {
844 if (smp->ltk) {
845 list_del(&smp->ltk->list);
846 kfree(smp->ltk);
847 }
848
849 if (smp->slave_ltk) {
850 list_del(&smp->slave_ltk->list);
851 kfree(smp->slave_ltk);
852 }
853
854 if (smp->remote_irk) {
855 list_del(&smp->remote_irk->list);
856 kfree(smp->remote_irk);
857 }
858 }
859
860 chan->data = NULL;
861 kfree(smp);
862 hci_conn_drop(conn->hcon);
863 }
864
865 int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey)
866 {
867 struct l2cap_conn *conn = hcon->l2cap_data;
868 struct l2cap_chan *chan;
869 struct smp_chan *smp;
870 u32 value;
871
872 BT_DBG("");
873
874 if (!conn || !test_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags))
875 return -ENOTCONN;
876
877 chan = conn->smp;
878 if (!chan)
879 return -ENOTCONN;
880
881 smp = chan->data;
882
883 switch (mgmt_op) {
884 case MGMT_OP_USER_PASSKEY_REPLY:
885 value = le32_to_cpu(passkey);
886 memset(smp->tk, 0, sizeof(smp->tk));
887 BT_DBG("PassKey: %d", value);
888 put_unaligned_le32(value, smp->tk);
889 /* Fall Through */
890 case MGMT_OP_USER_CONFIRM_REPLY:
891 set_bit(SMP_FLAG_TK_VALID, &smp->flags);
892 break;
893 case MGMT_OP_USER_PASSKEY_NEG_REPLY:
894 case MGMT_OP_USER_CONFIRM_NEG_REPLY:
895 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
896 return 0;
897 default:
898 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED);
899 return -EOPNOTSUPP;
900 }
901
902 /* If it is our turn to send Pairing Confirm, do so now */
903 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) {
904 u8 rsp = smp_confirm(smp);
905 if (rsp)
906 smp_failure(conn, rsp);
907 }
908
909 return 0;
910 }
911
912 static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
913 {
914 struct smp_cmd_pairing rsp, *req = (void *) skb->data;
915 struct hci_dev *hdev = conn->hcon->hdev;
916 struct smp_chan *smp;
917 u8 key_size, auth, sec_level;
918 int ret;
919
920 BT_DBG("conn %p", conn);
921
922 if (skb->len < sizeof(*req))
923 return SMP_INVALID_PARAMS;
924
925 if (conn->hcon->role != HCI_ROLE_SLAVE)
926 return SMP_CMD_NOTSUPP;
927
928 if (!test_and_set_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->flags)) {
929 smp = smp_chan_create(conn);
930 } else {
931 struct l2cap_chan *chan = conn->smp;
932 smp = chan->data;
933 }
934
935 if (!smp)
936 return SMP_UNSPECIFIED;
937
938 if (!test_bit(HCI_BONDABLE, &hdev->dev_flags) &&
939 (req->auth_req & SMP_AUTH_BONDING))
940 return SMP_PAIRING_NOTSUPP;
941
942 smp->preq[0] = SMP_CMD_PAIRING_REQ;
943 memcpy(&smp->preq[1], req, sizeof(*req));
944 skb_pull(skb, sizeof(*req));
945
946 /* We didn't start the pairing, so match remote */
947 auth = req->auth_req;
948
949 sec_level = authreq_to_seclevel(auth);
950 if (sec_level > conn->hcon->pending_sec_level)
951 conn->hcon->pending_sec_level = sec_level;
952
953 /* If we need MITM check that it can be acheived */
954 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
955 u8 method;
956
957 method = get_auth_method(smp, conn->hcon->io_capability,
958 req->io_capability);
959 if (method == JUST_WORKS || method == JUST_CFM)
960 return SMP_AUTH_REQUIREMENTS;
961 }
962
963 build_pairing_cmd(conn, req, &rsp, auth);
964
965 key_size = min(req->max_key_size, rsp.max_key_size);
966 if (check_enc_key_size(conn, key_size))
967 return SMP_ENC_KEY_SIZE;
968
969 get_random_bytes(smp->prnd, sizeof(smp->prnd));
970
971 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
972 memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
973
974 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
975
976 /* Request setup of TK */
977 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability);
978 if (ret)
979 return SMP_UNSPECIFIED;
980
981 return 0;
982 }
983
984 static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
985 {
986 struct smp_cmd_pairing *req, *rsp = (void *) skb->data;
987 struct l2cap_chan *chan = conn->smp;
988 struct smp_chan *smp = chan->data;
989 u8 key_size, auth = SMP_AUTH_NONE;
990 int ret;
991
992 BT_DBG("conn %p", conn);
993
994 if (skb->len < sizeof(*rsp))
995 return SMP_INVALID_PARAMS;
996
997 if (conn->hcon->role != HCI_ROLE_MASTER)
998 return SMP_CMD_NOTSUPP;
999
1000 skb_pull(skb, sizeof(*rsp));
1001
1002 req = (void *) &smp->preq[1];
1003
1004 key_size = min(req->max_key_size, rsp->max_key_size);
1005 if (check_enc_key_size(conn, key_size))
1006 return SMP_ENC_KEY_SIZE;
1007
1008 /* If we need MITM check that it can be acheived */
1009 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
1010 u8 method;
1011
1012 method = get_auth_method(smp, req->io_capability,
1013 rsp->io_capability);
1014 if (method == JUST_WORKS || method == JUST_CFM)
1015 return SMP_AUTH_REQUIREMENTS;
1016 }
1017
1018 get_random_bytes(smp->prnd, sizeof(smp->prnd));
1019
1020 smp->prsp[0] = SMP_CMD_PAIRING_RSP;
1021 memcpy(&smp->prsp[1], rsp, sizeof(*rsp));
1022
1023 /* Update remote key distribution in case the remote cleared
1024 * some bits that we had enabled in our request.
1025 */
1026 smp->remote_key_dist &= rsp->resp_key_dist;
1027
1028 if ((req->auth_req & SMP_AUTH_BONDING) &&
1029 (rsp->auth_req & SMP_AUTH_BONDING))
1030 auth = SMP_AUTH_BONDING;
1031
1032 auth |= (req->auth_req | rsp->auth_req) & SMP_AUTH_MITM;
1033
1034 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability);
1035 if (ret)
1036 return SMP_UNSPECIFIED;
1037
1038 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
1039
1040 /* Can't compose response until we have been confirmed */
1041 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
1042 return smp_confirm(smp);
1043
1044 return 0;
1045 }
1046
1047 static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
1048 {
1049 struct l2cap_chan *chan = conn->smp;
1050 struct smp_chan *smp = chan->data;
1051
1052 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
1053
1054 if (skb->len < sizeof(smp->pcnf))
1055 return SMP_INVALID_PARAMS;
1056
1057 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf));
1058 skb_pull(skb, sizeof(smp->pcnf));
1059
1060 if (conn->hcon->out)
1061 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
1062 smp->prnd);
1063 else if (test_bit(SMP_FLAG_TK_VALID, &smp->flags))
1064 return smp_confirm(smp);
1065 else
1066 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags);
1067
1068 return 0;
1069 }
1070
1071 static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
1072 {
1073 struct l2cap_chan *chan = conn->smp;
1074 struct smp_chan *smp = chan->data;
1075
1076 BT_DBG("conn %p", conn);
1077
1078 if (skb->len < sizeof(smp->rrnd))
1079 return SMP_INVALID_PARAMS;
1080
1081 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd));
1082 skb_pull(skb, sizeof(smp->rrnd));
1083
1084 return smp_random(smp);
1085 }
1086
1087 static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level)
1088 {
1089 struct smp_ltk *key;
1090 struct hci_conn *hcon = conn->hcon;
1091
1092 key = hci_find_ltk_by_addr(hcon->hdev, &hcon->dst, hcon->dst_type,
1093 hcon->role);
1094 if (!key)
1095 return false;
1096
1097 if (sec_level > BT_SECURITY_MEDIUM && !key->authenticated)
1098 return false;
1099
1100 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
1101 return true;
1102
1103 hci_le_start_enc(hcon, key->ediv, key->rand, key->val);
1104 hcon->enc_key_size = key->enc_size;
1105
1106 /* We never store STKs for master role, so clear this flag */
1107 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags);
1108
1109 return true;
1110 }
1111
1112 bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level)
1113 {
1114 if (sec_level == BT_SECURITY_LOW)
1115 return true;
1116
1117 /* If we're encrypted with an STK always claim insufficient
1118 * security. This way we allow the connection to be re-encrypted
1119 * with an LTK, even if the LTK provides the same level of
1120 * security. Only exception is if we don't have an LTK (e.g.
1121 * because of key distribution bits).
1122 */
1123 if (test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) &&
1124 hci_find_ltk_by_addr(hcon->hdev, &hcon->dst, hcon->dst_type,
1125 hcon->role))
1126 return false;
1127
1128 if (hcon->sec_level >= sec_level)
1129 return true;
1130
1131 return false;
1132 }
1133
1134 static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
1135 {
1136 struct smp_cmd_security_req *rp = (void *) skb->data;
1137 struct smp_cmd_pairing cp;
1138 struct hci_conn *hcon = conn->hcon;
1139 struct smp_chan *smp;
1140 u8 sec_level;
1141
1142 BT_DBG("conn %p", conn);
1143
1144 if (skb->len < sizeof(*rp))
1145 return SMP_INVALID_PARAMS;
1146
1147 if (hcon->role != HCI_ROLE_MASTER)
1148 return SMP_CMD_NOTSUPP;
1149
1150 sec_level = authreq_to_seclevel(rp->auth_req);
1151 if (smp_sufficient_security(hcon, sec_level))
1152 return 0;
1153
1154 if (sec_level > hcon->pending_sec_level)
1155 hcon->pending_sec_level = sec_level;
1156
1157 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
1158 return 0;
1159
1160 if (test_and_set_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags))
1161 return 0;
1162
1163 smp = smp_chan_create(conn);
1164 if (!smp)
1165 return SMP_UNSPECIFIED;
1166
1167 if (!test_bit(HCI_BONDABLE, &hcon->hdev->dev_flags) &&
1168 (rp->auth_req & SMP_AUTH_BONDING))
1169 return SMP_PAIRING_NOTSUPP;
1170
1171 skb_pull(skb, sizeof(*rp));
1172
1173 memset(&cp, 0, sizeof(cp));
1174 build_pairing_cmd(conn, &cp, NULL, rp->auth_req);
1175
1176 smp->preq[0] = SMP_CMD_PAIRING_REQ;
1177 memcpy(&smp->preq[1], &cp, sizeof(cp));
1178
1179 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
1180
1181 return 0;
1182 }
1183
1184 int smp_conn_security(struct hci_conn *hcon, __u8 sec_level)
1185 {
1186 struct l2cap_conn *conn = hcon->l2cap_data;
1187 struct smp_chan *smp;
1188 __u8 authreq;
1189
1190 BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level);
1191
1192 /* This may be NULL if there's an unexpected disconnection */
1193 if (!conn)
1194 return 1;
1195
1196 if (!test_bit(HCI_LE_ENABLED, &hcon->hdev->dev_flags))
1197 return 1;
1198
1199 if (smp_sufficient_security(hcon, sec_level))
1200 return 1;
1201
1202 if (sec_level > hcon->pending_sec_level)
1203 hcon->pending_sec_level = sec_level;
1204
1205 if (hcon->role == HCI_ROLE_MASTER)
1206 if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
1207 return 0;
1208
1209 if (test_and_set_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags))
1210 return 0;
1211
1212 smp = smp_chan_create(conn);
1213 if (!smp)
1214 return 1;
1215
1216 authreq = seclevel_to_authreq(sec_level);
1217
1218 /* Require MITM if IO Capability allows or the security level
1219 * requires it.
1220 */
1221 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT ||
1222 hcon->pending_sec_level > BT_SECURITY_MEDIUM)
1223 authreq |= SMP_AUTH_MITM;
1224
1225 if (hcon->role == HCI_ROLE_MASTER) {
1226 struct smp_cmd_pairing cp;
1227
1228 build_pairing_cmd(conn, &cp, NULL, authreq);
1229 smp->preq[0] = SMP_CMD_PAIRING_REQ;
1230 memcpy(&smp->preq[1], &cp, sizeof(cp));
1231
1232 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
1233 } else {
1234 struct smp_cmd_security_req cp;
1235 cp.auth_req = authreq;
1236 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp);
1237 }
1238
1239 set_bit(SMP_FLAG_INITIATOR, &smp->flags);
1240
1241 return 0;
1242 }
1243
1244 static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb)
1245 {
1246 struct smp_cmd_encrypt_info *rp = (void *) skb->data;
1247 struct l2cap_chan *chan = conn->smp;
1248 struct smp_chan *smp = chan->data;
1249
1250 BT_DBG("conn %p", conn);
1251
1252 if (skb->len < sizeof(*rp))
1253 return SMP_INVALID_PARAMS;
1254
1255 /* Ignore this PDU if it wasn't requested */
1256 if (!(smp->remote_key_dist & SMP_DIST_ENC_KEY))
1257 return 0;
1258
1259 skb_pull(skb, sizeof(*rp));
1260
1261 memcpy(smp->tk, rp->ltk, sizeof(smp->tk));
1262
1263 return 0;
1264 }
1265
1266 static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb)
1267 {
1268 struct smp_cmd_master_ident *rp = (void *) skb->data;
1269 struct l2cap_chan *chan = conn->smp;
1270 struct smp_chan *smp = chan->data;
1271 struct hci_dev *hdev = conn->hcon->hdev;
1272 struct hci_conn *hcon = conn->hcon;
1273 struct smp_ltk *ltk;
1274 u8 authenticated;
1275
1276 BT_DBG("conn %p", conn);
1277
1278 if (skb->len < sizeof(*rp))
1279 return SMP_INVALID_PARAMS;
1280
1281 /* Ignore this PDU if it wasn't requested */
1282 if (!(smp->remote_key_dist & SMP_DIST_ENC_KEY))
1283 return 0;
1284
1285 /* Mark the information as received */
1286 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY;
1287
1288 skb_pull(skb, sizeof(*rp));
1289
1290 hci_dev_lock(hdev);
1291 authenticated = (hcon->sec_level == BT_SECURITY_HIGH);
1292 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK,
1293 authenticated, smp->tk, smp->enc_key_size,
1294 rp->ediv, rp->rand);
1295 smp->ltk = ltk;
1296 if (!(smp->remote_key_dist & SMP_DIST_ID_KEY))
1297 queue_work(hdev->workqueue, &smp->distribute_work);
1298 hci_dev_unlock(hdev);
1299
1300 return 0;
1301 }
1302
1303 static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb)
1304 {
1305 struct smp_cmd_ident_info *info = (void *) skb->data;
1306 struct l2cap_chan *chan = conn->smp;
1307 struct smp_chan *smp = chan->data;
1308
1309 BT_DBG("");
1310
1311 if (skb->len < sizeof(*info))
1312 return SMP_INVALID_PARAMS;
1313
1314 /* Ignore this PDU if it wasn't requested */
1315 if (!(smp->remote_key_dist & SMP_DIST_ID_KEY))
1316 return 0;
1317
1318 skb_pull(skb, sizeof(*info));
1319
1320 memcpy(smp->irk, info->irk, 16);
1321
1322 return 0;
1323 }
1324
1325 static int smp_cmd_ident_addr_info(struct l2cap_conn *conn,
1326 struct sk_buff *skb)
1327 {
1328 struct smp_cmd_ident_addr_info *info = (void *) skb->data;
1329 struct l2cap_chan *chan = conn->smp;
1330 struct smp_chan *smp = chan->data;
1331 struct hci_conn *hcon = conn->hcon;
1332 struct hci_dev *hdev = hcon->hdev;
1333 bdaddr_t rpa;
1334
1335 BT_DBG("");
1336
1337 if (skb->len < sizeof(*info))
1338 return SMP_INVALID_PARAMS;
1339
1340 /* Ignore this PDU if it wasn't requested */
1341 if (!(smp->remote_key_dist & SMP_DIST_ID_KEY))
1342 return 0;
1343
1344 /* Mark the information as received */
1345 smp->remote_key_dist &= ~SMP_DIST_ID_KEY;
1346
1347 skb_pull(skb, sizeof(*info));
1348
1349 hci_dev_lock(hcon->hdev);
1350
1351 /* Strictly speaking the Core Specification (4.1) allows sending
1352 * an empty address which would force us to rely on just the IRK
1353 * as "identity information". However, since such
1354 * implementations are not known of and in order to not over
1355 * complicate our implementation, simply pretend that we never
1356 * received an IRK for such a device.
1357 */
1358 if (!bacmp(&info->bdaddr, BDADDR_ANY)) {
1359 BT_ERR("Ignoring IRK with no identity address");
1360 goto distribute;
1361 }
1362
1363 bacpy(&smp->id_addr, &info->bdaddr);
1364 smp->id_addr_type = info->addr_type;
1365
1366 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type))
1367 bacpy(&rpa, &hcon->dst);
1368 else
1369 bacpy(&rpa, BDADDR_ANY);
1370
1371 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr,
1372 smp->id_addr_type, smp->irk, &rpa);
1373
1374 distribute:
1375 queue_work(hdev->workqueue, &smp->distribute_work);
1376
1377 hci_dev_unlock(hcon->hdev);
1378
1379 return 0;
1380 }
1381
1382 static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb)
1383 {
1384 struct smp_cmd_sign_info *rp = (void *) skb->data;
1385 struct l2cap_chan *chan = conn->smp;
1386 struct smp_chan *smp = chan->data;
1387 struct hci_dev *hdev = conn->hcon->hdev;
1388 struct smp_csrk *csrk;
1389
1390 BT_DBG("conn %p", conn);
1391
1392 if (skb->len < sizeof(*rp))
1393 return SMP_INVALID_PARAMS;
1394
1395 /* Ignore this PDU if it wasn't requested */
1396 if (!(smp->remote_key_dist & SMP_DIST_SIGN))
1397 return 0;
1398
1399 /* Mark the information as received */
1400 smp->remote_key_dist &= ~SMP_DIST_SIGN;
1401
1402 skb_pull(skb, sizeof(*rp));
1403
1404 hci_dev_lock(hdev);
1405 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL);
1406 if (csrk) {
1407 csrk->master = 0x01;
1408 memcpy(csrk->val, rp->csrk, sizeof(csrk->val));
1409 }
1410 smp->csrk = csrk;
1411 queue_work(hdev->workqueue, &smp->distribute_work);
1412 hci_dev_unlock(hdev);
1413
1414 return 0;
1415 }
1416
1417 static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb)
1418 {
1419 struct l2cap_conn *conn = chan->conn;
1420 struct hci_conn *hcon = conn->hcon;
1421 __u8 code, reason;
1422 int err = 0;
1423
1424 if (hcon->type != LE_LINK) {
1425 kfree_skb(skb);
1426 return 0;
1427 }
1428
1429 if (skb->len < 1)
1430 return -EILSEQ;
1431
1432 if (!test_bit(HCI_LE_ENABLED, &hcon->hdev->dev_flags)) {
1433 err = -EOPNOTSUPP;
1434 reason = SMP_PAIRING_NOTSUPP;
1435 goto done;
1436 }
1437
1438 code = skb->data[0];
1439 skb_pull(skb, sizeof(code));
1440
1441 /*
1442 * The SMP context must be initialized for all other PDUs except
1443 * pairing and security requests. If we get any other PDU when
1444 * not initialized simply disconnect (done if this function
1445 * returns an error).
1446 */
1447 if (code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ &&
1448 !test_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags)) {
1449 BT_ERR("Unexpected SMP command 0x%02x. Disconnecting.", code);
1450 reason = SMP_CMD_NOTSUPP;
1451 err = -EOPNOTSUPP;
1452 goto done;
1453 }
1454
1455 switch (code) {
1456 case SMP_CMD_PAIRING_REQ:
1457 reason = smp_cmd_pairing_req(conn, skb);
1458 break;
1459
1460 case SMP_CMD_PAIRING_FAIL:
1461 smp_failure(conn, 0);
1462 reason = 0;
1463 err = -EPERM;
1464 break;
1465
1466 case SMP_CMD_PAIRING_RSP:
1467 reason = smp_cmd_pairing_rsp(conn, skb);
1468 break;
1469
1470 case SMP_CMD_SECURITY_REQ:
1471 reason = smp_cmd_security_req(conn, skb);
1472 break;
1473
1474 case SMP_CMD_PAIRING_CONFIRM:
1475 reason = smp_cmd_pairing_confirm(conn, skb);
1476 break;
1477
1478 case SMP_CMD_PAIRING_RANDOM:
1479 reason = smp_cmd_pairing_random(conn, skb);
1480 break;
1481
1482 case SMP_CMD_ENCRYPT_INFO:
1483 reason = smp_cmd_encrypt_info(conn, skb);
1484 break;
1485
1486 case SMP_CMD_MASTER_IDENT:
1487 reason = smp_cmd_master_ident(conn, skb);
1488 break;
1489
1490 case SMP_CMD_IDENT_INFO:
1491 reason = smp_cmd_ident_info(conn, skb);
1492 break;
1493
1494 case SMP_CMD_IDENT_ADDR_INFO:
1495 reason = smp_cmd_ident_addr_info(conn, skb);
1496 break;
1497
1498 case SMP_CMD_SIGN_INFO:
1499 reason = smp_cmd_sign_info(conn, skb);
1500 break;
1501
1502 default:
1503 BT_DBG("Unknown command code 0x%2.2x", code);
1504
1505 reason = SMP_CMD_NOTSUPP;
1506 err = -EOPNOTSUPP;
1507 goto done;
1508 }
1509
1510 done:
1511 if (reason)
1512 smp_failure(conn, reason);
1513 if (!err)
1514 kfree_skb(skb);
1515 return err;
1516 }
1517
1518 static void smp_teardown_cb(struct l2cap_chan *chan, int err)
1519 {
1520 struct l2cap_conn *conn = chan->conn;
1521
1522 BT_DBG("chan %p", chan);
1523
1524 if (test_and_clear_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->flags))
1525 smp_chan_destroy(conn);
1526
1527 conn->smp = NULL;
1528 l2cap_chan_put(chan);
1529 }
1530
1531 static void smp_resume_cb(struct l2cap_chan *chan)
1532 {
1533 struct smp_chan *smp = chan->data;
1534 struct l2cap_conn *conn = chan->conn;
1535 struct hci_conn *hcon = conn->hcon;
1536 struct hci_dev *hdev = hcon->hdev;
1537
1538 BT_DBG("chan %p", chan);
1539
1540 if (!smp)
1541 return;
1542
1543 cancel_delayed_work(&smp->security_timer);
1544
1545 if (test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
1546 queue_work(hdev->workqueue, &smp->distribute_work);
1547 }
1548
1549 static void smp_ready_cb(struct l2cap_chan *chan)
1550 {
1551 struct l2cap_conn *conn = chan->conn;
1552
1553 BT_DBG("chan %p", chan);
1554
1555 conn->smp = chan;
1556 l2cap_chan_hold(chan);
1557 }
1558
1559 static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
1560 {
1561 int err;
1562
1563 BT_DBG("chan %p", chan);
1564
1565 err = smp_sig_channel(chan, skb);
1566 if (err) {
1567 struct smp_chan *smp = chan->data;
1568
1569 if (smp)
1570 cancel_delayed_work_sync(&smp->security_timer);
1571
1572 l2cap_conn_shutdown(chan->conn, -err);
1573 }
1574
1575 return err;
1576 }
1577
1578 static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan,
1579 unsigned long hdr_len,
1580 unsigned long len, int nb)
1581 {
1582 struct sk_buff *skb;
1583
1584 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL);
1585 if (!skb)
1586 return ERR_PTR(-ENOMEM);
1587
1588 skb->priority = HCI_PRIO_MAX;
1589 bt_cb(skb)->chan = chan;
1590
1591 return skb;
1592 }
1593
1594 static const struct l2cap_ops smp_chan_ops = {
1595 .name = "Security Manager",
1596 .ready = smp_ready_cb,
1597 .recv = smp_recv_cb,
1598 .alloc_skb = smp_alloc_skb_cb,
1599 .teardown = smp_teardown_cb,
1600 .resume = smp_resume_cb,
1601
1602 .new_connection = l2cap_chan_no_new_connection,
1603 .state_change = l2cap_chan_no_state_change,
1604 .close = l2cap_chan_no_close,
1605 .defer = l2cap_chan_no_defer,
1606 .suspend = l2cap_chan_no_suspend,
1607 .set_shutdown = l2cap_chan_no_set_shutdown,
1608 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
1609 .memcpy_fromiovec = l2cap_chan_no_memcpy_fromiovec,
1610 };
1611
1612 static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan)
1613 {
1614 struct l2cap_chan *chan;
1615
1616 BT_DBG("pchan %p", pchan);
1617
1618 chan = l2cap_chan_create();
1619 if (!chan)
1620 return NULL;
1621
1622 chan->chan_type = pchan->chan_type;
1623 chan->ops = &smp_chan_ops;
1624 chan->scid = pchan->scid;
1625 chan->dcid = chan->scid;
1626 chan->imtu = pchan->imtu;
1627 chan->omtu = pchan->omtu;
1628 chan->mode = pchan->mode;
1629
1630 BT_DBG("created chan %p", chan);
1631
1632 return chan;
1633 }
1634
1635 static const struct l2cap_ops smp_root_chan_ops = {
1636 .name = "Security Manager Root",
1637 .new_connection = smp_new_conn_cb,
1638
1639 /* None of these are implemented for the root channel */
1640 .close = l2cap_chan_no_close,
1641 .alloc_skb = l2cap_chan_no_alloc_skb,
1642 .recv = l2cap_chan_no_recv,
1643 .state_change = l2cap_chan_no_state_change,
1644 .teardown = l2cap_chan_no_teardown,
1645 .ready = l2cap_chan_no_ready,
1646 .defer = l2cap_chan_no_defer,
1647 .suspend = l2cap_chan_no_suspend,
1648 .resume = l2cap_chan_no_resume,
1649 .set_shutdown = l2cap_chan_no_set_shutdown,
1650 .get_sndtimeo = l2cap_chan_no_get_sndtimeo,
1651 .memcpy_fromiovec = l2cap_chan_no_memcpy_fromiovec,
1652 };
1653
1654 int smp_register(struct hci_dev *hdev)
1655 {
1656 struct l2cap_chan *chan;
1657 struct crypto_blkcipher *tfm_aes;
1658
1659 BT_DBG("%s", hdev->name);
1660
1661 tfm_aes = crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);
1662 if (IS_ERR(tfm_aes)) {
1663 int err = PTR_ERR(tfm_aes);
1664 BT_ERR("Unable to create crypto context");
1665 return err;
1666 }
1667
1668 chan = l2cap_chan_create();
1669 if (!chan) {
1670 crypto_free_blkcipher(tfm_aes);
1671 return -ENOMEM;
1672 }
1673
1674 chan->data = tfm_aes;
1675
1676 l2cap_add_scid(chan, L2CAP_CID_SMP);
1677
1678 l2cap_chan_set_defaults(chan);
1679
1680 bacpy(&chan->src, &hdev->bdaddr);
1681 chan->src_type = BDADDR_LE_PUBLIC;
1682 chan->state = BT_LISTEN;
1683 chan->mode = L2CAP_MODE_BASIC;
1684 chan->imtu = L2CAP_DEFAULT_MTU;
1685 chan->ops = &smp_root_chan_ops;
1686
1687 hdev->smp_data = chan;
1688
1689 return 0;
1690 }
1691
1692 void smp_unregister(struct hci_dev *hdev)
1693 {
1694 struct l2cap_chan *chan = hdev->smp_data;
1695 struct crypto_blkcipher *tfm_aes;
1696
1697 if (!chan)
1698 return;
1699
1700 BT_DBG("%s chan %p", hdev->name, chan);
1701
1702 tfm_aes = chan->data;
1703 if (tfm_aes) {
1704 chan->data = NULL;
1705 crypto_free_blkcipher(tfm_aes);
1706 }
1707
1708 hdev->smp_data = NULL;
1709 l2cap_chan_put(chan);
1710 }
Linux kernel - Deliverables
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