1 /* 2 BlueZ - Bluetooth protocol stack for Linux 3 Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). 4 5 This program is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License version 2 as 7 published by the Free Software Foundation; 8 9 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 10 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 11 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. 12 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY 13 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES 14 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 18 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS, 19 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS 20 SOFTWARE IS DISCLAIMED. 21 */ 22 23 #include <linux/debugfs.h> 24 #include <linux/crypto.h> 25 #include <linux/scatterlist.h> 26 #include <crypto/b128ops.h> 27 28 #include <net/bluetooth/bluetooth.h> 29 #include <net/bluetooth/hci_core.h> 30 #include <net/bluetooth/l2cap.h> 31 #include <net/bluetooth/mgmt.h> 32 33 #include "ecc.h" 34 #include "smp.h" 35 36 /* Low-level debug macros to be used for stuff that we don't want 37 * accidentially in dmesg, i.e. the values of the various crypto keys 38 * and the inputs & outputs of crypto functions. 39 */ 40 #ifdef DEBUG 41 #define SMP_DBG(fmt, ...) printk(KERN_DEBUG "%s: " fmt, __func__, \ 42 ##__VA_ARGS__) 43 #else 44 #define SMP_DBG(fmt, ...) no_printk(KERN_DEBUG "%s: " fmt, __func__, \ 45 ##__VA_ARGS__) 46 #endif 47 48 #define SMP_ALLOW_CMD(smp, code) set_bit(code, &smp->allow_cmd) 49 50 /* Keys which are not distributed with Secure Connections */ 51 #define SMP_SC_NO_DIST (SMP_DIST_ENC_KEY | SMP_DIST_LINK_KEY); 52 53 #define SMP_TIMEOUT msecs_to_jiffies(30000) 54 55 #define AUTH_REQ_MASK(dev) (hci_dev_test_flag(dev, HCI_SC_ENABLED) ? \ 56 0x1f : 0x07) 57 #define KEY_DIST_MASK 0x07 58 59 /* Maximum message length that can be passed to aes_cmac */ 60 #define CMAC_MSG_MAX 80 61 62 enum { 63 SMP_FLAG_TK_VALID, 64 SMP_FLAG_CFM_PENDING, 65 SMP_FLAG_MITM_AUTH, 66 SMP_FLAG_COMPLETE, 67 SMP_FLAG_INITIATOR, 68 SMP_FLAG_SC, 69 SMP_FLAG_REMOTE_PK, 70 SMP_FLAG_DEBUG_KEY, 71 SMP_FLAG_WAIT_USER, 72 SMP_FLAG_DHKEY_PENDING, 73 SMP_FLAG_REMOTE_OOB, 74 SMP_FLAG_LOCAL_OOB, 75 }; 76 77 struct smp_dev { 78 /* Secure Connections OOB data */ 79 u8 local_pk[64]; 80 u8 local_sk[32]; 81 u8 local_rand[16]; 82 bool debug_key; 83 84 struct crypto_blkcipher *tfm_aes; 85 struct crypto_hash *tfm_cmac; 86 }; 87 88 struct smp_chan { 89 struct l2cap_conn *conn; 90 struct delayed_work security_timer; 91 unsigned long allow_cmd; /* Bitmask of allowed commands */ 92 93 u8 preq[7]; /* SMP Pairing Request */ 94 u8 prsp[7]; /* SMP Pairing Response */ 95 u8 prnd[16]; /* SMP Pairing Random (local) */ 96 u8 rrnd[16]; /* SMP Pairing Random (remote) */ 97 u8 pcnf[16]; /* SMP Pairing Confirm */ 98 u8 tk[16]; /* SMP Temporary Key */ 99 u8 rr[16]; /* Remote OOB ra/rb value */ 100 u8 lr[16]; /* Local OOB ra/rb value */ 101 u8 enc_key_size; 102 u8 remote_key_dist; 103 bdaddr_t id_addr; 104 u8 id_addr_type; 105 u8 irk[16]; 106 struct smp_csrk *csrk; 107 struct smp_csrk *slave_csrk; 108 struct smp_ltk *ltk; 109 struct smp_ltk *slave_ltk; 110 struct smp_irk *remote_irk; 111 u8 *link_key; 112 unsigned long flags; 113 u8 method; 114 u8 passkey_round; 115 116 /* Secure Connections variables */ 117 u8 local_pk[64]; 118 u8 local_sk[32]; 119 u8 remote_pk[64]; 120 u8 dhkey[32]; 121 u8 mackey[16]; 122 123 struct crypto_blkcipher *tfm_aes; 124 struct crypto_hash *tfm_cmac; 125 }; 126 127 /* These debug key values are defined in the SMP section of the core 128 * specification. debug_pk is the public debug key and debug_sk the 129 * private debug key. 130 */ 131 static const u8 debug_pk[64] = { 132 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 133 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 134 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 135 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20, 136 137 0x8b, 0xd2, 0x89, 0x15, 0xd0, 0x8e, 0x1c, 0x74, 138 0x24, 0x30, 0xed, 0x8f, 0xc2, 0x45, 0x63, 0x76, 139 0x5c, 0x15, 0x52, 0x5a, 0xbf, 0x9a, 0x32, 0x63, 140 0x6d, 0xeb, 0x2a, 0x65, 0x49, 0x9c, 0x80, 0xdc, 141 }; 142 143 static const u8 debug_sk[32] = { 144 0xbd, 0x1a, 0x3c, 0xcd, 0xa6, 0xb8, 0x99, 0x58, 145 0x99, 0xb7, 0x40, 0xeb, 0x7b, 0x60, 0xff, 0x4a, 146 0x50, 0x3f, 0x10, 0xd2, 0xe3, 0xb3, 0xc9, 0x74, 147 0x38, 0x5f, 0xc5, 0xa3, 0xd4, 0xf6, 0x49, 0x3f, 148 }; 149 150 static inline void swap_buf(const u8 *src, u8 *dst, size_t len) 151 { 152 size_t i; 153 154 for (i = 0; i < len; i++) 155 dst[len - 1 - i] = src[i]; 156 } 157 158 /* The following functions map to the LE SC SMP crypto functions 159 * AES-CMAC, f4, f5, f6, g2 and h6. 160 */ 161 162 static int aes_cmac(struct crypto_hash *tfm, const u8 k[16], const u8 *m, 163 size_t len, u8 mac[16]) 164 { 165 uint8_t tmp[16], mac_msb[16], msg_msb[CMAC_MSG_MAX]; 166 struct hash_desc desc; 167 struct scatterlist sg; 168 int err; 169 170 if (len > CMAC_MSG_MAX) 171 return -EFBIG; 172 173 if (!tfm) { 174 BT_ERR("tfm %p", tfm); 175 return -EINVAL; 176 } 177 178 desc.tfm = tfm; 179 desc.flags = 0; 180 181 crypto_hash_init(&desc); 182 183 /* Swap key and message from LSB to MSB */ 184 swap_buf(k, tmp, 16); 185 swap_buf(m, msg_msb, len); 186 187 SMP_DBG("msg (len %zu) %*phN", len, (int) len, m); 188 SMP_DBG("key %16phN", k); 189 190 err = crypto_hash_setkey(tfm, tmp, 16); 191 if (err) { 192 BT_ERR("cipher setkey failed: %d", err); 193 return err; 194 } 195 196 sg_init_one(&sg, msg_msb, len); 197 198 err = crypto_hash_update(&desc, &sg, len); 199 if (err) { 200 BT_ERR("Hash update error %d", err); 201 return err; 202 } 203 204 err = crypto_hash_final(&desc, mac_msb); 205 if (err) { 206 BT_ERR("Hash final error %d", err); 207 return err; 208 } 209 210 swap_buf(mac_msb, mac, 16); 211 212 SMP_DBG("mac %16phN", mac); 213 214 return 0; 215 } 216 217 static int smp_f4(struct crypto_hash *tfm_cmac, const u8 u[32], const u8 v[32], 218 const u8 x[16], u8 z, u8 res[16]) 219 { 220 u8 m[65]; 221 int err; 222 223 SMP_DBG("u %32phN", u); 224 SMP_DBG("v %32phN", v); 225 SMP_DBG("x %16phN z %02x", x, z); 226 227 m[0] = z; 228 memcpy(m + 1, v, 32); 229 memcpy(m + 33, u, 32); 230 231 err = aes_cmac(tfm_cmac, x, m, sizeof(m), res); 232 if (err) 233 return err; 234 235 SMP_DBG("res %16phN", res); 236 237 return err; 238 } 239 240 static int smp_f5(struct crypto_hash *tfm_cmac, const u8 w[32], 241 const u8 n1[16], const u8 n2[16], const u8 a1[7], 242 const u8 a2[7], u8 mackey[16], u8 ltk[16]) 243 { 244 /* The btle, salt and length "magic" values are as defined in 245 * the SMP section of the Bluetooth core specification. In ASCII 246 * the btle value ends up being 'btle'. The salt is just a 247 * random number whereas length is the value 256 in little 248 * endian format. 249 */ 250 const u8 btle[4] = { 0x65, 0x6c, 0x74, 0x62 }; 251 const u8 salt[16] = { 0xbe, 0x83, 0x60, 0x5a, 0xdb, 0x0b, 0x37, 0x60, 252 0x38, 0xa5, 0xf5, 0xaa, 0x91, 0x83, 0x88, 0x6c }; 253 const u8 length[2] = { 0x00, 0x01 }; 254 u8 m[53], t[16]; 255 int err; 256 257 SMP_DBG("w %32phN", w); 258 SMP_DBG("n1 %16phN n2 %16phN", n1, n2); 259 SMP_DBG("a1 %7phN a2 %7phN", a1, a2); 260 261 err = aes_cmac(tfm_cmac, salt, w, 32, t); 262 if (err) 263 return err; 264 265 SMP_DBG("t %16phN", t); 266 267 memcpy(m, length, 2); 268 memcpy(m + 2, a2, 7); 269 memcpy(m + 9, a1, 7); 270 memcpy(m + 16, n2, 16); 271 memcpy(m + 32, n1, 16); 272 memcpy(m + 48, btle, 4); 273 274 m[52] = 0; /* Counter */ 275 276 err = aes_cmac(tfm_cmac, t, m, sizeof(m), mackey); 277 if (err) 278 return err; 279 280 SMP_DBG("mackey %16phN", mackey); 281 282 m[52] = 1; /* Counter */ 283 284 err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk); 285 if (err) 286 return err; 287 288 SMP_DBG("ltk %16phN", ltk); 289 290 return 0; 291 } 292 293 static int smp_f6(struct crypto_hash *tfm_cmac, const u8 w[16], 294 const u8 n1[16], const u8 n2[16], const u8 r[16], 295 const u8 io_cap[3], const u8 a1[7], const u8 a2[7], 296 u8 res[16]) 297 { 298 u8 m[65]; 299 int err; 300 301 SMP_DBG("w %16phN", w); 302 SMP_DBG("n1 %16phN n2 %16phN", n1, n2); 303 SMP_DBG("r %16phN io_cap %3phN a1 %7phN a2 %7phN", r, io_cap, a1, a2); 304 305 memcpy(m, a2, 7); 306 memcpy(m + 7, a1, 7); 307 memcpy(m + 14, io_cap, 3); 308 memcpy(m + 17, r, 16); 309 memcpy(m + 33, n2, 16); 310 memcpy(m + 49, n1, 16); 311 312 err = aes_cmac(tfm_cmac, w, m, sizeof(m), res); 313 if (err) 314 return err; 315 316 SMP_DBG("res %16phN", res); 317 318 return err; 319 } 320 321 static int smp_g2(struct crypto_hash *tfm_cmac, const u8 u[32], const u8 v[32], 322 const u8 x[16], const u8 y[16], u32 *val) 323 { 324 u8 m[80], tmp[16]; 325 int err; 326 327 SMP_DBG("u %32phN", u); 328 SMP_DBG("v %32phN", v); 329 SMP_DBG("x %16phN y %16phN", x, y); 330 331 memcpy(m, y, 16); 332 memcpy(m + 16, v, 32); 333 memcpy(m + 48, u, 32); 334 335 err = aes_cmac(tfm_cmac, x, m, sizeof(m), tmp); 336 if (err) 337 return err; 338 339 *val = get_unaligned_le32(tmp); 340 *val %= 1000000; 341 342 SMP_DBG("val %06u", *val); 343 344 return 0; 345 } 346 347 static int smp_h6(struct crypto_hash *tfm_cmac, const u8 w[16], 348 const u8 key_id[4], u8 res[16]) 349 { 350 int err; 351 352 SMP_DBG("w %16phN key_id %4phN", w, key_id); 353 354 err = aes_cmac(tfm_cmac, w, key_id, 4, res); 355 if (err) 356 return err; 357 358 SMP_DBG("res %16phN", res); 359 360 return err; 361 } 362 363 /* The following functions map to the legacy SMP crypto functions e, c1, 364 * s1 and ah. 365 */ 366 367 static int smp_e(struct crypto_blkcipher *tfm, const u8 *k, u8 *r) 368 { 369 struct blkcipher_desc desc; 370 struct scatterlist sg; 371 uint8_t tmp[16], data[16]; 372 int err; 373 374 if (!tfm) { 375 BT_ERR("tfm %p", tfm); 376 return -EINVAL; 377 } 378 379 desc.tfm = tfm; 380 desc.flags = 0; 381 382 /* The most significant octet of key corresponds to k[0] */ 383 swap_buf(k, tmp, 16); 384 385 err = crypto_blkcipher_setkey(tfm, tmp, 16); 386 if (err) { 387 BT_ERR("cipher setkey failed: %d", err); 388 return err; 389 } 390 391 /* Most significant octet of plaintextData corresponds to data[0] */ 392 swap_buf(r, data, 16); 393 394 sg_init_one(&sg, data, 16); 395 396 err = crypto_blkcipher_encrypt(&desc, &sg, &sg, 16); 397 if (err) 398 BT_ERR("Encrypt data error %d", err); 399 400 /* Most significant octet of encryptedData corresponds to data[0] */ 401 swap_buf(data, r, 16); 402 403 return err; 404 } 405 406 static int smp_c1(struct crypto_blkcipher *tfm_aes, const u8 k[16], 407 const u8 r[16], const u8 preq[7], const u8 pres[7], u8 _iat, 408 const bdaddr_t *ia, u8 _rat, const bdaddr_t *ra, u8 res[16]) 409 { 410 u8 p1[16], p2[16]; 411 int err; 412 413 memset(p1, 0, 16); 414 415 /* p1 = pres || preq || _rat || _iat */ 416 p1[0] = _iat; 417 p1[1] = _rat; 418 memcpy(p1 + 2, preq, 7); 419 memcpy(p1 + 9, pres, 7); 420 421 /* p2 = padding || ia || ra */ 422 memcpy(p2, ra, 6); 423 memcpy(p2 + 6, ia, 6); 424 memset(p2 + 12, 0, 4); 425 426 /* res = r XOR p1 */ 427 u128_xor((u128 *) res, (u128 *) r, (u128 *) p1); 428 429 /* res = e(k, res) */ 430 err = smp_e(tfm_aes, k, res); 431 if (err) { 432 BT_ERR("Encrypt data error"); 433 return err; 434 } 435 436 /* res = res XOR p2 */ 437 u128_xor((u128 *) res, (u128 *) res, (u128 *) p2); 438 439 /* res = e(k, res) */ 440 err = smp_e(tfm_aes, k, res); 441 if (err) 442 BT_ERR("Encrypt data error"); 443 444 return err; 445 } 446 447 static int smp_s1(struct crypto_blkcipher *tfm_aes, const u8 k[16], 448 const u8 r1[16], const u8 r2[16], u8 _r[16]) 449 { 450 int err; 451 452 /* Just least significant octets from r1 and r2 are considered */ 453 memcpy(_r, r2, 8); 454 memcpy(_r + 8, r1, 8); 455 456 err = smp_e(tfm_aes, k, _r); 457 if (err) 458 BT_ERR("Encrypt data error"); 459 460 return err; 461 } 462 463 static int smp_ah(struct crypto_blkcipher *tfm, const u8 irk[16], 464 const u8 r[3], u8 res[3]) 465 { 466 u8 _res[16]; 467 int err; 468 469 /* r' = padding || r */ 470 memcpy(_res, r, 3); 471 memset(_res + 3, 0, 13); 472 473 err = smp_e(tfm, irk, _res); 474 if (err) { 475 BT_ERR("Encrypt error"); 476 return err; 477 } 478 479 /* The output of the random address function ah is: 480 * ah(h, r) = e(k, r') mod 2^24 481 * The output of the security function e is then truncated to 24 bits 482 * by taking the least significant 24 bits of the output of e as the 483 * result of ah. 484 */ 485 memcpy(res, _res, 3); 486 487 return 0; 488 } 489 490 bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16], 491 const bdaddr_t *bdaddr) 492 { 493 struct l2cap_chan *chan = hdev->smp_data; 494 struct smp_dev *smp; 495 u8 hash[3]; 496 int err; 497 498 if (!chan || !chan->data) 499 return false; 500 501 smp = chan->data; 502 503 BT_DBG("RPA %pMR IRK %*phN", bdaddr, 16, irk); 504 505 err = smp_ah(smp->tfm_aes, irk, &bdaddr->b[3], hash); 506 if (err) 507 return false; 508 509 return !memcmp(bdaddr->b, hash, 3); 510 } 511 512 int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa) 513 { 514 struct l2cap_chan *chan = hdev->smp_data; 515 struct smp_dev *smp; 516 int err; 517 518 if (!chan || !chan->data) 519 return -EOPNOTSUPP; 520 521 smp = chan->data; 522 523 get_random_bytes(&rpa->b[3], 3); 524 525 rpa->b[5] &= 0x3f; /* Clear two most significant bits */ 526 rpa->b[5] |= 0x40; /* Set second most significant bit */ 527 528 err = smp_ah(smp->tfm_aes, irk, &rpa->b[3], rpa->b); 529 if (err < 0) 530 return err; 531 532 BT_DBG("RPA %pMR", rpa); 533 534 return 0; 535 } 536 537 int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16]) 538 { 539 struct l2cap_chan *chan = hdev->smp_data; 540 struct smp_dev *smp; 541 int err; 542 543 if (!chan || !chan->data) 544 return -EOPNOTSUPP; 545 546 smp = chan->data; 547 548 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { 549 BT_DBG("Using debug keys"); 550 memcpy(smp->local_pk, debug_pk, 64); 551 memcpy(smp->local_sk, debug_sk, 32); 552 smp->debug_key = true; 553 } else { 554 while (true) { 555 /* Generate local key pair for Secure Connections */ 556 if (!ecc_make_key(smp->local_pk, smp->local_sk)) 557 return -EIO; 558 559 /* This is unlikely, but we need to check that 560 * we didn't accidentially generate a debug key. 561 */ 562 if (memcmp(smp->local_sk, debug_sk, 32)) 563 break; 564 } 565 smp->debug_key = false; 566 } 567 568 SMP_DBG("OOB Public Key X: %32phN", smp->local_pk); 569 SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32); 570 SMP_DBG("OOB Private Key: %32phN", smp->local_sk); 571 572 get_random_bytes(smp->local_rand, 16); 573 574 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->local_pk, 575 smp->local_rand, 0, hash); 576 if (err < 0) 577 return err; 578 579 memcpy(rand, smp->local_rand, 16); 580 581 return 0; 582 } 583 584 static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data) 585 { 586 struct l2cap_chan *chan = conn->smp; 587 struct smp_chan *smp; 588 struct kvec iv[2]; 589 struct msghdr msg; 590 591 if (!chan) 592 return; 593 594 BT_DBG("code 0x%2.2x", code); 595 596 iv[0].iov_base = &code; 597 iv[0].iov_len = 1; 598 599 iv[1].iov_base = data; 600 iv[1].iov_len = len; 601 602 memset(&msg, 0, sizeof(msg)); 603 604 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iv, 2, 1 + len); 605 606 l2cap_chan_send(chan, &msg, 1 + len); 607 608 if (!chan->data) 609 return; 610 611 smp = chan->data; 612 613 cancel_delayed_work_sync(&smp->security_timer); 614 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT); 615 } 616 617 static u8 authreq_to_seclevel(u8 authreq) 618 { 619 if (authreq & SMP_AUTH_MITM) { 620 if (authreq & SMP_AUTH_SC) 621 return BT_SECURITY_FIPS; 622 else 623 return BT_SECURITY_HIGH; 624 } else { 625 return BT_SECURITY_MEDIUM; 626 } 627 } 628 629 static __u8 seclevel_to_authreq(__u8 sec_level) 630 { 631 switch (sec_level) { 632 case BT_SECURITY_FIPS: 633 case BT_SECURITY_HIGH: 634 return SMP_AUTH_MITM | SMP_AUTH_BONDING; 635 case BT_SECURITY_MEDIUM: 636 return SMP_AUTH_BONDING; 637 default: 638 return SMP_AUTH_NONE; 639 } 640 } 641 642 static void build_pairing_cmd(struct l2cap_conn *conn, 643 struct smp_cmd_pairing *req, 644 struct smp_cmd_pairing *rsp, __u8 authreq) 645 { 646 struct l2cap_chan *chan = conn->smp; 647 struct smp_chan *smp = chan->data; 648 struct hci_conn *hcon = conn->hcon; 649 struct hci_dev *hdev = hcon->hdev; 650 u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT; 651 652 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { 653 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 654 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 655 authreq |= SMP_AUTH_BONDING; 656 } else { 657 authreq &= ~SMP_AUTH_BONDING; 658 } 659 660 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) 661 remote_dist |= SMP_DIST_ID_KEY; 662 663 if (hci_dev_test_flag(hdev, HCI_PRIVACY)) 664 local_dist |= SMP_DIST_ID_KEY; 665 666 if (hci_dev_test_flag(hdev, HCI_SC_ENABLED) && 667 (authreq & SMP_AUTH_SC)) { 668 struct oob_data *oob_data; 669 u8 bdaddr_type; 670 671 if (hci_dev_test_flag(hdev, HCI_SSP_ENABLED)) { 672 local_dist |= SMP_DIST_LINK_KEY; 673 remote_dist |= SMP_DIST_LINK_KEY; 674 } 675 676 if (hcon->dst_type == ADDR_LE_DEV_PUBLIC) 677 bdaddr_type = BDADDR_LE_PUBLIC; 678 else 679 bdaddr_type = BDADDR_LE_RANDOM; 680 681 oob_data = hci_find_remote_oob_data(hdev, &hcon->dst, 682 bdaddr_type); 683 if (oob_data && oob_data->present) { 684 set_bit(SMP_FLAG_REMOTE_OOB, &smp->flags); 685 oob_flag = SMP_OOB_PRESENT; 686 memcpy(smp->rr, oob_data->rand256, 16); 687 memcpy(smp->pcnf, oob_data->hash256, 16); 688 SMP_DBG("OOB Remote Confirmation: %16phN", smp->pcnf); 689 SMP_DBG("OOB Remote Random: %16phN", smp->rr); 690 } 691 692 } else { 693 authreq &= ~SMP_AUTH_SC; 694 } 695 696 if (rsp == NULL) { 697 req->io_capability = conn->hcon->io_capability; 698 req->oob_flag = oob_flag; 699 req->max_key_size = SMP_MAX_ENC_KEY_SIZE; 700 req->init_key_dist = local_dist; 701 req->resp_key_dist = remote_dist; 702 req->auth_req = (authreq & AUTH_REQ_MASK(hdev)); 703 704 smp->remote_key_dist = remote_dist; 705 return; 706 } 707 708 rsp->io_capability = conn->hcon->io_capability; 709 rsp->oob_flag = oob_flag; 710 rsp->max_key_size = SMP_MAX_ENC_KEY_SIZE; 711 rsp->init_key_dist = req->init_key_dist & remote_dist; 712 rsp->resp_key_dist = req->resp_key_dist & local_dist; 713 rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev)); 714 715 smp->remote_key_dist = rsp->init_key_dist; 716 } 717 718 static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size) 719 { 720 struct l2cap_chan *chan = conn->smp; 721 struct smp_chan *smp = chan->data; 722 723 if ((max_key_size > SMP_MAX_ENC_KEY_SIZE) || 724 (max_key_size < SMP_MIN_ENC_KEY_SIZE)) 725 return SMP_ENC_KEY_SIZE; 726 727 smp->enc_key_size = max_key_size; 728 729 return 0; 730 } 731 732 static void smp_chan_destroy(struct l2cap_conn *conn) 733 { 734 struct l2cap_chan *chan = conn->smp; 735 struct smp_chan *smp = chan->data; 736 struct hci_conn *hcon = conn->hcon; 737 bool complete; 738 739 BUG_ON(!smp); 740 741 cancel_delayed_work_sync(&smp->security_timer); 742 743 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags); 744 mgmt_smp_complete(hcon, complete); 745 746 kzfree(smp->csrk); 747 kzfree(smp->slave_csrk); 748 kzfree(smp->link_key); 749 750 crypto_free_blkcipher(smp->tfm_aes); 751 crypto_free_hash(smp->tfm_cmac); 752 753 /* Ensure that we don't leave any debug key around if debug key 754 * support hasn't been explicitly enabled. 755 */ 756 if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG && 757 !hci_dev_test_flag(hcon->hdev, HCI_KEEP_DEBUG_KEYS)) { 758 list_del_rcu(&smp->ltk->list); 759 kfree_rcu(smp->ltk, rcu); 760 smp->ltk = NULL; 761 } 762 763 /* If pairing failed clean up any keys we might have */ 764 if (!complete) { 765 if (smp->ltk) { 766 list_del_rcu(&smp->ltk->list); 767 kfree_rcu(smp->ltk, rcu); 768 } 769 770 if (smp->slave_ltk) { 771 list_del_rcu(&smp->slave_ltk->list); 772 kfree_rcu(smp->slave_ltk, rcu); 773 } 774 775 if (smp->remote_irk) { 776 list_del_rcu(&smp->remote_irk->list); 777 kfree_rcu(smp->remote_irk, rcu); 778 } 779 } 780 781 chan->data = NULL; 782 kzfree(smp); 783 hci_conn_drop(hcon); 784 } 785 786 static void smp_failure(struct l2cap_conn *conn, u8 reason) 787 { 788 struct hci_conn *hcon = conn->hcon; 789 struct l2cap_chan *chan = conn->smp; 790 791 if (reason) 792 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason), 793 &reason); 794 795 clear_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags); 796 mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE); 797 798 if (chan->data) 799 smp_chan_destroy(conn); 800 } 801 802 #define JUST_WORKS 0x00 803 #define JUST_CFM 0x01 804 #define REQ_PASSKEY 0x02 805 #define CFM_PASSKEY 0x03 806 #define REQ_OOB 0x04 807 #define DSP_PASSKEY 0x05 808 #define OVERLAP 0xFF 809 810 static const u8 gen_method[5][5] = { 811 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 812 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 813 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 814 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM }, 815 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP }, 816 }; 817 818 static const u8 sc_method[5][5] = { 819 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 820 { JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 821 { DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY }, 822 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM }, 823 { DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 824 }; 825 826 static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io) 827 { 828 /* If either side has unknown io_caps, use JUST_CFM (which gets 829 * converted later to JUST_WORKS if we're initiators. 830 */ 831 if (local_io > SMP_IO_KEYBOARD_DISPLAY || 832 remote_io > SMP_IO_KEYBOARD_DISPLAY) 833 return JUST_CFM; 834 835 if (test_bit(SMP_FLAG_SC, &smp->flags)) 836 return sc_method[remote_io][local_io]; 837 838 return gen_method[remote_io][local_io]; 839 } 840 841 static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth, 842 u8 local_io, u8 remote_io) 843 { 844 struct hci_conn *hcon = conn->hcon; 845 struct l2cap_chan *chan = conn->smp; 846 struct smp_chan *smp = chan->data; 847 u32 passkey = 0; 848 int ret = 0; 849 850 /* Initialize key for JUST WORKS */ 851 memset(smp->tk, 0, sizeof(smp->tk)); 852 clear_bit(SMP_FLAG_TK_VALID, &smp->flags); 853 854 BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io); 855 856 /* If neither side wants MITM, either "just" confirm an incoming 857 * request or use just-works for outgoing ones. The JUST_CFM 858 * will be converted to JUST_WORKS if necessary later in this 859 * function. If either side has MITM look up the method from the 860 * table. 861 */ 862 if (!(auth & SMP_AUTH_MITM)) 863 smp->method = JUST_CFM; 864 else 865 smp->method = get_auth_method(smp, local_io, remote_io); 866 867 /* Don't confirm locally initiated pairing attempts */ 868 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, 869 &smp->flags)) 870 smp->method = JUST_WORKS; 871 872 /* Don't bother user space with no IO capabilities */ 873 if (smp->method == JUST_CFM && 874 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 875 smp->method = JUST_WORKS; 876 877 /* If Just Works, Continue with Zero TK */ 878 if (smp->method == JUST_WORKS) { 879 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 880 return 0; 881 } 882 883 /* If this function is used for SC -> legacy fallback we 884 * can only recover the just-works case. 885 */ 886 if (test_bit(SMP_FLAG_SC, &smp->flags)) 887 return -EINVAL; 888 889 /* Not Just Works/Confirm results in MITM Authentication */ 890 if (smp->method != JUST_CFM) { 891 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags); 892 if (hcon->pending_sec_level < BT_SECURITY_HIGH) 893 hcon->pending_sec_level = BT_SECURITY_HIGH; 894 } 895 896 /* If both devices have Keyoard-Display I/O, the master 897 * Confirms and the slave Enters the passkey. 898 */ 899 if (smp->method == OVERLAP) { 900 if (hcon->role == HCI_ROLE_MASTER) 901 smp->method = CFM_PASSKEY; 902 else 903 smp->method = REQ_PASSKEY; 904 } 905 906 /* Generate random passkey. */ 907 if (smp->method == CFM_PASSKEY) { 908 memset(smp->tk, 0, sizeof(smp->tk)); 909 get_random_bytes(&passkey, sizeof(passkey)); 910 passkey %= 1000000; 911 put_unaligned_le32(passkey, smp->tk); 912 BT_DBG("PassKey: %d", passkey); 913 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 914 } 915 916 if (smp->method == REQ_PASSKEY) 917 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst, 918 hcon->type, hcon->dst_type); 919 else if (smp->method == JUST_CFM) 920 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, 921 hcon->type, hcon->dst_type, 922 passkey, 1); 923 else 924 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst, 925 hcon->type, hcon->dst_type, 926 passkey, 0); 927 928 return ret; 929 } 930 931 static u8 smp_confirm(struct smp_chan *smp) 932 { 933 struct l2cap_conn *conn = smp->conn; 934 struct smp_cmd_pairing_confirm cp; 935 int ret; 936 937 BT_DBG("conn %p", conn); 938 939 ret = smp_c1(smp->tfm_aes, smp->tk, smp->prnd, smp->preq, smp->prsp, 940 conn->hcon->init_addr_type, &conn->hcon->init_addr, 941 conn->hcon->resp_addr_type, &conn->hcon->resp_addr, 942 cp.confirm_val); 943 if (ret) 944 return SMP_UNSPECIFIED; 945 946 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 947 948 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp); 949 950 if (conn->hcon->out) 951 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 952 else 953 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 954 955 return 0; 956 } 957 958 static u8 smp_random(struct smp_chan *smp) 959 { 960 struct l2cap_conn *conn = smp->conn; 961 struct hci_conn *hcon = conn->hcon; 962 u8 confirm[16]; 963 int ret; 964 965 if (IS_ERR_OR_NULL(smp->tfm_aes)) 966 return SMP_UNSPECIFIED; 967 968 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave"); 969 970 ret = smp_c1(smp->tfm_aes, smp->tk, smp->rrnd, smp->preq, smp->prsp, 971 hcon->init_addr_type, &hcon->init_addr, 972 hcon->resp_addr_type, &hcon->resp_addr, confirm); 973 if (ret) 974 return SMP_UNSPECIFIED; 975 976 if (memcmp(smp->pcnf, confirm, sizeof(smp->pcnf)) != 0) { 977 BT_ERR("Pairing failed (confirmation values mismatch)"); 978 return SMP_CONFIRM_FAILED; 979 } 980 981 if (hcon->out) { 982 u8 stk[16]; 983 __le64 rand = 0; 984 __le16 ediv = 0; 985 986 smp_s1(smp->tfm_aes, smp->tk, smp->rrnd, smp->prnd, stk); 987 988 memset(stk + smp->enc_key_size, 0, 989 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size); 990 991 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) 992 return SMP_UNSPECIFIED; 993 994 hci_le_start_enc(hcon, ediv, rand, stk); 995 hcon->enc_key_size = smp->enc_key_size; 996 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); 997 } else { 998 u8 stk[16], auth; 999 __le64 rand = 0; 1000 __le16 ediv = 0; 1001 1002 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 1003 smp->prnd); 1004 1005 smp_s1(smp->tfm_aes, smp->tk, smp->prnd, smp->rrnd, stk); 1006 1007 memset(stk + smp->enc_key_size, 0, 1008 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size); 1009 1010 if (hcon->pending_sec_level == BT_SECURITY_HIGH) 1011 auth = 1; 1012 else 1013 auth = 0; 1014 1015 /* Even though there's no _SLAVE suffix this is the 1016 * slave STK we're adding for later lookup (the master 1017 * STK never needs to be stored). 1018 */ 1019 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 1020 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand); 1021 } 1022 1023 return 0; 1024 } 1025 1026 static void smp_notify_keys(struct l2cap_conn *conn) 1027 { 1028 struct l2cap_chan *chan = conn->smp; 1029 struct smp_chan *smp = chan->data; 1030 struct hci_conn *hcon = conn->hcon; 1031 struct hci_dev *hdev = hcon->hdev; 1032 struct smp_cmd_pairing *req = (void *) &smp->preq[1]; 1033 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1]; 1034 bool persistent; 1035 1036 if (smp->remote_irk) { 1037 mgmt_new_irk(hdev, smp->remote_irk); 1038 /* Now that user space can be considered to know the 1039 * identity address track the connection based on it 1040 * from now on (assuming this is an LE link). 1041 */ 1042 if (hcon->type == LE_LINK) { 1043 bacpy(&hcon->dst, &smp->remote_irk->bdaddr); 1044 hcon->dst_type = smp->remote_irk->addr_type; 1045 queue_work(hdev->workqueue, &conn->id_addr_update_work); 1046 } 1047 1048 /* When receiving an indentity resolving key for 1049 * a remote device that does not use a resolvable 1050 * private address, just remove the key so that 1051 * it is possible to use the controller white 1052 * list for scanning. 1053 * 1054 * Userspace will have been told to not store 1055 * this key at this point. So it is safe to 1056 * just remove it. 1057 */ 1058 if (!bacmp(&smp->remote_irk->rpa, BDADDR_ANY)) { 1059 list_del_rcu(&smp->remote_irk->list); 1060 kfree_rcu(smp->remote_irk, rcu); 1061 smp->remote_irk = NULL; 1062 } 1063 } 1064 1065 if (hcon->type == ACL_LINK) { 1066 if (hcon->key_type == HCI_LK_DEBUG_COMBINATION) 1067 persistent = false; 1068 else 1069 persistent = !test_bit(HCI_CONN_FLUSH_KEY, 1070 &hcon->flags); 1071 } else { 1072 /* The LTKs and CSRKs should be persistent only if both sides 1073 * had the bonding bit set in their authentication requests. 1074 */ 1075 persistent = !!((req->auth_req & rsp->auth_req) & 1076 SMP_AUTH_BONDING); 1077 } 1078 1079 1080 if (smp->csrk) { 1081 smp->csrk->bdaddr_type = hcon->dst_type; 1082 bacpy(&smp->csrk->bdaddr, &hcon->dst); 1083 mgmt_new_csrk(hdev, smp->csrk, persistent); 1084 } 1085 1086 if (smp->slave_csrk) { 1087 smp->slave_csrk->bdaddr_type = hcon->dst_type; 1088 bacpy(&smp->slave_csrk->bdaddr, &hcon->dst); 1089 mgmt_new_csrk(hdev, smp->slave_csrk, persistent); 1090 } 1091 1092 if (smp->ltk) { 1093 smp->ltk->bdaddr_type = hcon->dst_type; 1094 bacpy(&smp->ltk->bdaddr, &hcon->dst); 1095 mgmt_new_ltk(hdev, smp->ltk, persistent); 1096 } 1097 1098 if (smp->slave_ltk) { 1099 smp->slave_ltk->bdaddr_type = hcon->dst_type; 1100 bacpy(&smp->slave_ltk->bdaddr, &hcon->dst); 1101 mgmt_new_ltk(hdev, smp->slave_ltk, persistent); 1102 } 1103 1104 if (smp->link_key) { 1105 struct link_key *key; 1106 u8 type; 1107 1108 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags)) 1109 type = HCI_LK_DEBUG_COMBINATION; 1110 else if (hcon->sec_level == BT_SECURITY_FIPS) 1111 type = HCI_LK_AUTH_COMBINATION_P256; 1112 else 1113 type = HCI_LK_UNAUTH_COMBINATION_P256; 1114 1115 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst, 1116 smp->link_key, type, 0, &persistent); 1117 if (key) { 1118 mgmt_new_link_key(hdev, key, persistent); 1119 1120 /* Don't keep debug keys around if the relevant 1121 * flag is not set. 1122 */ 1123 if (!hci_dev_test_flag(hdev, HCI_KEEP_DEBUG_KEYS) && 1124 key->type == HCI_LK_DEBUG_COMBINATION) { 1125 list_del_rcu(&key->list); 1126 kfree_rcu(key, rcu); 1127 } 1128 } 1129 } 1130 } 1131 1132 static void sc_add_ltk(struct smp_chan *smp) 1133 { 1134 struct hci_conn *hcon = smp->conn->hcon; 1135 u8 key_type, auth; 1136 1137 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags)) 1138 key_type = SMP_LTK_P256_DEBUG; 1139 else 1140 key_type = SMP_LTK_P256; 1141 1142 if (hcon->pending_sec_level == BT_SECURITY_FIPS) 1143 auth = 1; 1144 else 1145 auth = 0; 1146 1147 memset(smp->tk + smp->enc_key_size, 0, 1148 SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size); 1149 1150 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 1151 key_type, auth, smp->tk, smp->enc_key_size, 1152 0, 0); 1153 } 1154 1155 static void sc_generate_link_key(struct smp_chan *smp) 1156 { 1157 /* These constants are as specified in the core specification. 1158 * In ASCII they spell out to 'tmp1' and 'lebr'. 1159 */ 1160 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 }; 1161 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c }; 1162 1163 smp->link_key = kzalloc(16, GFP_KERNEL); 1164 if (!smp->link_key) 1165 return; 1166 1167 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) { 1168 kzfree(smp->link_key); 1169 smp->link_key = NULL; 1170 return; 1171 } 1172 1173 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) { 1174 kzfree(smp->link_key); 1175 smp->link_key = NULL; 1176 return; 1177 } 1178 } 1179 1180 static void smp_allow_key_dist(struct smp_chan *smp) 1181 { 1182 /* Allow the first expected phase 3 PDU. The rest of the PDUs 1183 * will be allowed in each PDU handler to ensure we receive 1184 * them in the correct order. 1185 */ 1186 if (smp->remote_key_dist & SMP_DIST_ENC_KEY) 1187 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO); 1188 else if (smp->remote_key_dist & SMP_DIST_ID_KEY) 1189 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); 1190 else if (smp->remote_key_dist & SMP_DIST_SIGN) 1191 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 1192 } 1193 1194 static void sc_generate_ltk(struct smp_chan *smp) 1195 { 1196 /* These constants are as specified in the core specification. 1197 * In ASCII they spell out to 'tmp2' and 'brle'. 1198 */ 1199 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 }; 1200 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 }; 1201 struct hci_conn *hcon = smp->conn->hcon; 1202 struct hci_dev *hdev = hcon->hdev; 1203 struct link_key *key; 1204 1205 key = hci_find_link_key(hdev, &hcon->dst); 1206 if (!key) { 1207 BT_ERR("%s No Link Key found to generate LTK", hdev->name); 1208 return; 1209 } 1210 1211 if (key->type == HCI_LK_DEBUG_COMBINATION) 1212 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1213 1214 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk)) 1215 return; 1216 1217 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk)) 1218 return; 1219 1220 sc_add_ltk(smp); 1221 } 1222 1223 static void smp_distribute_keys(struct smp_chan *smp) 1224 { 1225 struct smp_cmd_pairing *req, *rsp; 1226 struct l2cap_conn *conn = smp->conn; 1227 struct hci_conn *hcon = conn->hcon; 1228 struct hci_dev *hdev = hcon->hdev; 1229 __u8 *keydist; 1230 1231 BT_DBG("conn %p", conn); 1232 1233 rsp = (void *) &smp->prsp[1]; 1234 1235 /* The responder sends its keys first */ 1236 if (hcon->out && (smp->remote_key_dist & KEY_DIST_MASK)) { 1237 smp_allow_key_dist(smp); 1238 return; 1239 } 1240 1241 req = (void *) &smp->preq[1]; 1242 1243 if (hcon->out) { 1244 keydist = &rsp->init_key_dist; 1245 *keydist &= req->init_key_dist; 1246 } else { 1247 keydist = &rsp->resp_key_dist; 1248 *keydist &= req->resp_key_dist; 1249 } 1250 1251 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1252 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY)) 1253 sc_generate_link_key(smp); 1254 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY)) 1255 sc_generate_ltk(smp); 1256 1257 /* Clear the keys which are generated but not distributed */ 1258 *keydist &= ~SMP_SC_NO_DIST; 1259 } 1260 1261 BT_DBG("keydist 0x%x", *keydist); 1262 1263 if (*keydist & SMP_DIST_ENC_KEY) { 1264 struct smp_cmd_encrypt_info enc; 1265 struct smp_cmd_master_ident ident; 1266 struct smp_ltk *ltk; 1267 u8 authenticated; 1268 __le16 ediv; 1269 __le64 rand; 1270 1271 get_random_bytes(enc.ltk, sizeof(enc.ltk)); 1272 get_random_bytes(&ediv, sizeof(ediv)); 1273 get_random_bytes(&rand, sizeof(rand)); 1274 1275 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc); 1276 1277 authenticated = hcon->sec_level == BT_SECURITY_HIGH; 1278 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, 1279 SMP_LTK_SLAVE, authenticated, enc.ltk, 1280 smp->enc_key_size, ediv, rand); 1281 smp->slave_ltk = ltk; 1282 1283 ident.ediv = ediv; 1284 ident.rand = rand; 1285 1286 smp_send_cmd(conn, SMP_CMD_MASTER_IDENT, sizeof(ident), &ident); 1287 1288 *keydist &= ~SMP_DIST_ENC_KEY; 1289 } 1290 1291 if (*keydist & SMP_DIST_ID_KEY) { 1292 struct smp_cmd_ident_addr_info addrinfo; 1293 struct smp_cmd_ident_info idinfo; 1294 1295 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk)); 1296 1297 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo); 1298 1299 /* The hci_conn contains the local identity address 1300 * after the connection has been established. 1301 * 1302 * This is true even when the connection has been 1303 * established using a resolvable random address. 1304 */ 1305 bacpy(&addrinfo.bdaddr, &hcon->src); 1306 addrinfo.addr_type = hcon->src_type; 1307 1308 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo), 1309 &addrinfo); 1310 1311 *keydist &= ~SMP_DIST_ID_KEY; 1312 } 1313 1314 if (*keydist & SMP_DIST_SIGN) { 1315 struct smp_cmd_sign_info sign; 1316 struct smp_csrk *csrk; 1317 1318 /* Generate a new random key */ 1319 get_random_bytes(sign.csrk, sizeof(sign.csrk)); 1320 1321 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); 1322 if (csrk) { 1323 if (hcon->sec_level > BT_SECURITY_MEDIUM) 1324 csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED; 1325 else 1326 csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED; 1327 memcpy(csrk->val, sign.csrk, sizeof(csrk->val)); 1328 } 1329 smp->slave_csrk = csrk; 1330 1331 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign); 1332 1333 *keydist &= ~SMP_DIST_SIGN; 1334 } 1335 1336 /* If there are still keys to be received wait for them */ 1337 if (smp->remote_key_dist & KEY_DIST_MASK) { 1338 smp_allow_key_dist(smp); 1339 return; 1340 } 1341 1342 set_bit(SMP_FLAG_COMPLETE, &smp->flags); 1343 smp_notify_keys(conn); 1344 1345 smp_chan_destroy(conn); 1346 } 1347 1348 static void smp_timeout(struct work_struct *work) 1349 { 1350 struct smp_chan *smp = container_of(work, struct smp_chan, 1351 security_timer.work); 1352 struct l2cap_conn *conn = smp->conn; 1353 1354 BT_DBG("conn %p", conn); 1355 1356 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM); 1357 } 1358 1359 static struct smp_chan *smp_chan_create(struct l2cap_conn *conn) 1360 { 1361 struct l2cap_chan *chan = conn->smp; 1362 struct smp_chan *smp; 1363 1364 smp = kzalloc(sizeof(*smp), GFP_ATOMIC); 1365 if (!smp) 1366 return NULL; 1367 1368 smp->tfm_aes = crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC); 1369 if (IS_ERR(smp->tfm_aes)) { 1370 BT_ERR("Unable to create ECB crypto context"); 1371 kzfree(smp); 1372 return NULL; 1373 } 1374 1375 smp->tfm_cmac = crypto_alloc_hash("cmac(aes)", 0, CRYPTO_ALG_ASYNC); 1376 if (IS_ERR(smp->tfm_cmac)) { 1377 BT_ERR("Unable to create CMAC crypto context"); 1378 crypto_free_blkcipher(smp->tfm_aes); 1379 kzfree(smp); 1380 return NULL; 1381 } 1382 1383 smp->conn = conn; 1384 chan->data = smp; 1385 1386 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL); 1387 1388 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout); 1389 1390 hci_conn_hold(conn->hcon); 1391 1392 return smp; 1393 } 1394 1395 static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16]) 1396 { 1397 struct hci_conn *hcon = smp->conn->hcon; 1398 u8 *na, *nb, a[7], b[7]; 1399 1400 if (hcon->out) { 1401 na = smp->prnd; 1402 nb = smp->rrnd; 1403 } else { 1404 na = smp->rrnd; 1405 nb = smp->prnd; 1406 } 1407 1408 memcpy(a, &hcon->init_addr, 6); 1409 memcpy(b, &hcon->resp_addr, 6); 1410 a[6] = hcon->init_addr_type; 1411 b[6] = hcon->resp_addr_type; 1412 1413 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk); 1414 } 1415 1416 static void sc_dhkey_check(struct smp_chan *smp) 1417 { 1418 struct hci_conn *hcon = smp->conn->hcon; 1419 struct smp_cmd_dhkey_check check; 1420 u8 a[7], b[7], *local_addr, *remote_addr; 1421 u8 io_cap[3], r[16]; 1422 1423 memcpy(a, &hcon->init_addr, 6); 1424 memcpy(b, &hcon->resp_addr, 6); 1425 a[6] = hcon->init_addr_type; 1426 b[6] = hcon->resp_addr_type; 1427 1428 if (hcon->out) { 1429 local_addr = a; 1430 remote_addr = b; 1431 memcpy(io_cap, &smp->preq[1], 3); 1432 } else { 1433 local_addr = b; 1434 remote_addr = a; 1435 memcpy(io_cap, &smp->prsp[1], 3); 1436 } 1437 1438 memset(r, 0, sizeof(r)); 1439 1440 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 1441 put_unaligned_le32(hcon->passkey_notify, r); 1442 1443 if (smp->method == REQ_OOB) 1444 memcpy(r, smp->rr, 16); 1445 1446 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap, 1447 local_addr, remote_addr, check.e); 1448 1449 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check); 1450 } 1451 1452 static u8 sc_passkey_send_confirm(struct smp_chan *smp) 1453 { 1454 struct l2cap_conn *conn = smp->conn; 1455 struct hci_conn *hcon = conn->hcon; 1456 struct smp_cmd_pairing_confirm cfm; 1457 u8 r; 1458 1459 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); 1460 r |= 0x80; 1461 1462 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1463 1464 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r, 1465 cfm.confirm_val)) 1466 return SMP_UNSPECIFIED; 1467 1468 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); 1469 1470 return 0; 1471 } 1472 1473 static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op) 1474 { 1475 struct l2cap_conn *conn = smp->conn; 1476 struct hci_conn *hcon = conn->hcon; 1477 struct hci_dev *hdev = hcon->hdev; 1478 u8 cfm[16], r; 1479 1480 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */ 1481 if (smp->passkey_round >= 20) 1482 return 0; 1483 1484 switch (smp_op) { 1485 case SMP_CMD_PAIRING_RANDOM: 1486 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); 1487 r |= 0x80; 1488 1489 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, 1490 smp->rrnd, r, cfm)) 1491 return SMP_UNSPECIFIED; 1492 1493 if (memcmp(smp->pcnf, cfm, 16)) 1494 return SMP_CONFIRM_FAILED; 1495 1496 smp->passkey_round++; 1497 1498 if (smp->passkey_round == 20) { 1499 /* Generate MacKey and LTK */ 1500 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk)) 1501 return SMP_UNSPECIFIED; 1502 } 1503 1504 /* The round is only complete when the initiator 1505 * receives pairing random. 1506 */ 1507 if (!hcon->out) { 1508 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 1509 sizeof(smp->prnd), smp->prnd); 1510 if (smp->passkey_round == 20) 1511 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1512 else 1513 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1514 return 0; 1515 } 1516 1517 /* Start the next round */ 1518 if (smp->passkey_round != 20) 1519 return sc_passkey_round(smp, 0); 1520 1521 /* Passkey rounds are complete - start DHKey Check */ 1522 sc_dhkey_check(smp); 1523 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1524 1525 break; 1526 1527 case SMP_CMD_PAIRING_CONFIRM: 1528 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { 1529 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 1530 return 0; 1531 } 1532 1533 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 1534 1535 if (hcon->out) { 1536 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 1537 sizeof(smp->prnd), smp->prnd); 1538 return 0; 1539 } 1540 1541 return sc_passkey_send_confirm(smp); 1542 1543 case SMP_CMD_PUBLIC_KEY: 1544 default: 1545 /* Initiating device starts the round */ 1546 if (!hcon->out) 1547 return 0; 1548 1549 BT_DBG("%s Starting passkey round %u", hdev->name, 1550 smp->passkey_round + 1); 1551 1552 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1553 1554 return sc_passkey_send_confirm(smp); 1555 } 1556 1557 return 0; 1558 } 1559 1560 static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey) 1561 { 1562 struct l2cap_conn *conn = smp->conn; 1563 struct hci_conn *hcon = conn->hcon; 1564 u8 smp_op; 1565 1566 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags); 1567 1568 switch (mgmt_op) { 1569 case MGMT_OP_USER_PASSKEY_NEG_REPLY: 1570 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED); 1571 return 0; 1572 case MGMT_OP_USER_CONFIRM_NEG_REPLY: 1573 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED); 1574 return 0; 1575 case MGMT_OP_USER_PASSKEY_REPLY: 1576 hcon->passkey_notify = le32_to_cpu(passkey); 1577 smp->passkey_round = 0; 1578 1579 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) 1580 smp_op = SMP_CMD_PAIRING_CONFIRM; 1581 else 1582 smp_op = 0; 1583 1584 if (sc_passkey_round(smp, smp_op)) 1585 return -EIO; 1586 1587 return 0; 1588 } 1589 1590 /* Initiator sends DHKey check first */ 1591 if (hcon->out) { 1592 sc_dhkey_check(smp); 1593 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1594 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) { 1595 sc_dhkey_check(smp); 1596 sc_add_ltk(smp); 1597 } 1598 1599 return 0; 1600 } 1601 1602 int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey) 1603 { 1604 struct l2cap_conn *conn = hcon->l2cap_data; 1605 struct l2cap_chan *chan; 1606 struct smp_chan *smp; 1607 u32 value; 1608 int err; 1609 1610 BT_DBG(""); 1611 1612 if (!conn) 1613 return -ENOTCONN; 1614 1615 chan = conn->smp; 1616 if (!chan) 1617 return -ENOTCONN; 1618 1619 l2cap_chan_lock(chan); 1620 if (!chan->data) { 1621 err = -ENOTCONN; 1622 goto unlock; 1623 } 1624 1625 smp = chan->data; 1626 1627 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1628 err = sc_user_reply(smp, mgmt_op, passkey); 1629 goto unlock; 1630 } 1631 1632 switch (mgmt_op) { 1633 case MGMT_OP_USER_PASSKEY_REPLY: 1634 value = le32_to_cpu(passkey); 1635 memset(smp->tk, 0, sizeof(smp->tk)); 1636 BT_DBG("PassKey: %d", value); 1637 put_unaligned_le32(value, smp->tk); 1638 /* Fall Through */ 1639 case MGMT_OP_USER_CONFIRM_REPLY: 1640 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 1641 break; 1642 case MGMT_OP_USER_PASSKEY_NEG_REPLY: 1643 case MGMT_OP_USER_CONFIRM_NEG_REPLY: 1644 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); 1645 err = 0; 1646 goto unlock; 1647 default: 1648 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); 1649 err = -EOPNOTSUPP; 1650 goto unlock; 1651 } 1652 1653 err = 0; 1654 1655 /* If it is our turn to send Pairing Confirm, do so now */ 1656 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) { 1657 u8 rsp = smp_confirm(smp); 1658 if (rsp) 1659 smp_failure(conn, rsp); 1660 } 1661 1662 unlock: 1663 l2cap_chan_unlock(chan); 1664 return err; 1665 } 1666 1667 static void build_bredr_pairing_cmd(struct smp_chan *smp, 1668 struct smp_cmd_pairing *req, 1669 struct smp_cmd_pairing *rsp) 1670 { 1671 struct l2cap_conn *conn = smp->conn; 1672 struct hci_dev *hdev = conn->hcon->hdev; 1673 u8 local_dist = 0, remote_dist = 0; 1674 1675 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { 1676 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 1677 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 1678 } 1679 1680 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) 1681 remote_dist |= SMP_DIST_ID_KEY; 1682 1683 if (hci_dev_test_flag(hdev, HCI_PRIVACY)) 1684 local_dist |= SMP_DIST_ID_KEY; 1685 1686 if (!rsp) { 1687 memset(req, 0, sizeof(*req)); 1688 1689 req->init_key_dist = local_dist; 1690 req->resp_key_dist = remote_dist; 1691 req->max_key_size = SMP_MAX_ENC_KEY_SIZE; 1692 1693 smp->remote_key_dist = remote_dist; 1694 1695 return; 1696 } 1697 1698 memset(rsp, 0, sizeof(*rsp)); 1699 1700 rsp->max_key_size = SMP_MAX_ENC_KEY_SIZE; 1701 rsp->init_key_dist = req->init_key_dist & remote_dist; 1702 rsp->resp_key_dist = req->resp_key_dist & local_dist; 1703 1704 smp->remote_key_dist = rsp->init_key_dist; 1705 } 1706 1707 static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) 1708 { 1709 struct smp_cmd_pairing rsp, *req = (void *) skb->data; 1710 struct l2cap_chan *chan = conn->smp; 1711 struct hci_dev *hdev = conn->hcon->hdev; 1712 struct smp_chan *smp; 1713 u8 key_size, auth, sec_level; 1714 int ret; 1715 1716 BT_DBG("conn %p", conn); 1717 1718 if (skb->len < sizeof(*req)) 1719 return SMP_INVALID_PARAMS; 1720 1721 if (conn->hcon->role != HCI_ROLE_SLAVE) 1722 return SMP_CMD_NOTSUPP; 1723 1724 if (!chan->data) 1725 smp = smp_chan_create(conn); 1726 else 1727 smp = chan->data; 1728 1729 if (!smp) 1730 return SMP_UNSPECIFIED; 1731 1732 /* We didn't start the pairing, so match remote */ 1733 auth = req->auth_req & AUTH_REQ_MASK(hdev); 1734 1735 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && 1736 (auth & SMP_AUTH_BONDING)) 1737 return SMP_PAIRING_NOTSUPP; 1738 1739 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 1740 return SMP_AUTH_REQUIREMENTS; 1741 1742 smp->preq[0] = SMP_CMD_PAIRING_REQ; 1743 memcpy(&smp->preq[1], req, sizeof(*req)); 1744 skb_pull(skb, sizeof(*req)); 1745 1746 /* If the remote side's OOB flag is set it means it has 1747 * successfully received our local OOB data - therefore set the 1748 * flag to indicate that local OOB is in use. 1749 */ 1750 if (req->oob_flag == SMP_OOB_PRESENT) 1751 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); 1752 1753 /* SMP over BR/EDR requires special treatment */ 1754 if (conn->hcon->type == ACL_LINK) { 1755 /* We must have a BR/EDR SC link */ 1756 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) && 1757 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 1758 return SMP_CROSS_TRANSP_NOT_ALLOWED; 1759 1760 set_bit(SMP_FLAG_SC, &smp->flags); 1761 1762 build_bredr_pairing_cmd(smp, req, &rsp); 1763 1764 key_size = min(req->max_key_size, rsp.max_key_size); 1765 if (check_enc_key_size(conn, key_size)) 1766 return SMP_ENC_KEY_SIZE; 1767 1768 /* Clear bits which are generated but not distributed */ 1769 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1770 1771 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1772 memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); 1773 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); 1774 1775 smp_distribute_keys(smp); 1776 return 0; 1777 } 1778 1779 build_pairing_cmd(conn, req, &rsp, auth); 1780 1781 if (rsp.auth_req & SMP_AUTH_SC) 1782 set_bit(SMP_FLAG_SC, &smp->flags); 1783 1784 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 1785 sec_level = BT_SECURITY_MEDIUM; 1786 else 1787 sec_level = authreq_to_seclevel(auth); 1788 1789 if (sec_level > conn->hcon->pending_sec_level) 1790 conn->hcon->pending_sec_level = sec_level; 1791 1792 /* If we need MITM check that it can be achieved */ 1793 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { 1794 u8 method; 1795 1796 method = get_auth_method(smp, conn->hcon->io_capability, 1797 req->io_capability); 1798 if (method == JUST_WORKS || method == JUST_CFM) 1799 return SMP_AUTH_REQUIREMENTS; 1800 } 1801 1802 key_size = min(req->max_key_size, rsp.max_key_size); 1803 if (check_enc_key_size(conn, key_size)) 1804 return SMP_ENC_KEY_SIZE; 1805 1806 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1807 1808 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1809 memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); 1810 1811 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); 1812 1813 clear_bit(SMP_FLAG_INITIATOR, &smp->flags); 1814 1815 /* Strictly speaking we shouldn't allow Pairing Confirm for the 1816 * SC case, however some implementations incorrectly copy RFU auth 1817 * req bits from our security request, which may create a false 1818 * positive SC enablement. 1819 */ 1820 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1821 1822 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1823 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); 1824 /* Clear bits which are generated but not distributed */ 1825 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1826 /* Wait for Public Key from Initiating Device */ 1827 return 0; 1828 } 1829 1830 /* Request setup of TK */ 1831 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability); 1832 if (ret) 1833 return SMP_UNSPECIFIED; 1834 1835 return 0; 1836 } 1837 1838 static u8 sc_send_public_key(struct smp_chan *smp) 1839 { 1840 struct hci_dev *hdev = smp->conn->hcon->hdev; 1841 1842 BT_DBG(""); 1843 1844 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { 1845 struct l2cap_chan *chan = hdev->smp_data; 1846 struct smp_dev *smp_dev; 1847 1848 if (!chan || !chan->data) 1849 return SMP_UNSPECIFIED; 1850 1851 smp_dev = chan->data; 1852 1853 memcpy(smp->local_pk, smp_dev->local_pk, 64); 1854 memcpy(smp->local_sk, smp_dev->local_sk, 32); 1855 memcpy(smp->lr, smp_dev->local_rand, 16); 1856 1857 if (smp_dev->debug_key) 1858 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1859 1860 goto done; 1861 } 1862 1863 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { 1864 BT_DBG("Using debug keys"); 1865 memcpy(smp->local_pk, debug_pk, 64); 1866 memcpy(smp->local_sk, debug_sk, 32); 1867 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1868 } else { 1869 while (true) { 1870 /* Generate local key pair for Secure Connections */ 1871 if (!ecc_make_key(smp->local_pk, smp->local_sk)) 1872 return SMP_UNSPECIFIED; 1873 1874 /* This is unlikely, but we need to check that 1875 * we didn't accidentially generate a debug key. 1876 */ 1877 if (memcmp(smp->local_sk, debug_sk, 32)) 1878 break; 1879 } 1880 } 1881 1882 done: 1883 SMP_DBG("Local Public Key X: %32phN", smp->local_pk); 1884 SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32); 1885 SMP_DBG("Local Private Key: %32phN", smp->local_sk); 1886 1887 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk); 1888 1889 return 0; 1890 } 1891 1892 static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) 1893 { 1894 struct smp_cmd_pairing *req, *rsp = (void *) skb->data; 1895 struct l2cap_chan *chan = conn->smp; 1896 struct smp_chan *smp = chan->data; 1897 struct hci_dev *hdev = conn->hcon->hdev; 1898 u8 key_size, auth; 1899 int ret; 1900 1901 BT_DBG("conn %p", conn); 1902 1903 if (skb->len < sizeof(*rsp)) 1904 return SMP_INVALID_PARAMS; 1905 1906 if (conn->hcon->role != HCI_ROLE_MASTER) 1907 return SMP_CMD_NOTSUPP; 1908 1909 skb_pull(skb, sizeof(*rsp)); 1910 1911 req = (void *) &smp->preq[1]; 1912 1913 key_size = min(req->max_key_size, rsp->max_key_size); 1914 if (check_enc_key_size(conn, key_size)) 1915 return SMP_ENC_KEY_SIZE; 1916 1917 auth = rsp->auth_req & AUTH_REQ_MASK(hdev); 1918 1919 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 1920 return SMP_AUTH_REQUIREMENTS; 1921 1922 /* If the remote side's OOB flag is set it means it has 1923 * successfully received our local OOB data - therefore set the 1924 * flag to indicate that local OOB is in use. 1925 */ 1926 if (rsp->oob_flag == SMP_OOB_PRESENT) 1927 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); 1928 1929 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1930 memcpy(&smp->prsp[1], rsp, sizeof(*rsp)); 1931 1932 /* Update remote key distribution in case the remote cleared 1933 * some bits that we had enabled in our request. 1934 */ 1935 smp->remote_key_dist &= rsp->resp_key_dist; 1936 1937 /* For BR/EDR this means we're done and can start phase 3 */ 1938 if (conn->hcon->type == ACL_LINK) { 1939 /* Clear bits which are generated but not distributed */ 1940 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1941 smp_distribute_keys(smp); 1942 return 0; 1943 } 1944 1945 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC)) 1946 set_bit(SMP_FLAG_SC, &smp->flags); 1947 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH) 1948 conn->hcon->pending_sec_level = BT_SECURITY_HIGH; 1949 1950 /* If we need MITM check that it can be achieved */ 1951 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { 1952 u8 method; 1953 1954 method = get_auth_method(smp, req->io_capability, 1955 rsp->io_capability); 1956 if (method == JUST_WORKS || method == JUST_CFM) 1957 return SMP_AUTH_REQUIREMENTS; 1958 } 1959 1960 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1961 1962 /* Update remote key distribution in case the remote cleared 1963 * some bits that we had enabled in our request. 1964 */ 1965 smp->remote_key_dist &= rsp->resp_key_dist; 1966 1967 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1968 /* Clear bits which are generated but not distributed */ 1969 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1970 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); 1971 return sc_send_public_key(smp); 1972 } 1973 1974 auth |= req->auth_req; 1975 1976 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability); 1977 if (ret) 1978 return SMP_UNSPECIFIED; 1979 1980 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 1981 1982 /* Can't compose response until we have been confirmed */ 1983 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) 1984 return smp_confirm(smp); 1985 1986 return 0; 1987 } 1988 1989 static u8 sc_check_confirm(struct smp_chan *smp) 1990 { 1991 struct l2cap_conn *conn = smp->conn; 1992 1993 BT_DBG(""); 1994 1995 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 1996 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM); 1997 1998 if (conn->hcon->out) { 1999 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2000 smp->prnd); 2001 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2002 } 2003 2004 return 0; 2005 } 2006 2007 /* Work-around for some implementations that incorrectly copy RFU bits 2008 * from our security request and thereby create the impression that 2009 * we're doing SC when in fact the remote doesn't support it. 2010 */ 2011 static int fixup_sc_false_positive(struct smp_chan *smp) 2012 { 2013 struct l2cap_conn *conn = smp->conn; 2014 struct hci_conn *hcon = conn->hcon; 2015 struct hci_dev *hdev = hcon->hdev; 2016 struct smp_cmd_pairing *req, *rsp; 2017 u8 auth; 2018 2019 /* The issue is only observed when we're in slave role */ 2020 if (hcon->out) 2021 return SMP_UNSPECIFIED; 2022 2023 if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) { 2024 BT_ERR("Refusing SMP SC -> legacy fallback in SC-only mode"); 2025 return SMP_UNSPECIFIED; 2026 } 2027 2028 BT_ERR("Trying to fall back to legacy SMP"); 2029 2030 req = (void *) &smp->preq[1]; 2031 rsp = (void *) &smp->prsp[1]; 2032 2033 /* Rebuild key dist flags which may have been cleared for SC */ 2034 smp->remote_key_dist = (req->init_key_dist & rsp->resp_key_dist); 2035 2036 auth = req->auth_req & AUTH_REQ_MASK(hdev); 2037 2038 if (tk_request(conn, 0, auth, rsp->io_capability, req->io_capability)) { 2039 BT_ERR("Failed to fall back to legacy SMP"); 2040 return SMP_UNSPECIFIED; 2041 } 2042 2043 clear_bit(SMP_FLAG_SC, &smp->flags); 2044 2045 return 0; 2046 } 2047 2048 static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb) 2049 { 2050 struct l2cap_chan *chan = conn->smp; 2051 struct smp_chan *smp = chan->data; 2052 2053 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave"); 2054 2055 if (skb->len < sizeof(smp->pcnf)) 2056 return SMP_INVALID_PARAMS; 2057 2058 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf)); 2059 skb_pull(skb, sizeof(smp->pcnf)); 2060 2061 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 2062 int ret; 2063 2064 /* Public Key exchange must happen before any other steps */ 2065 if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags)) 2066 return sc_check_confirm(smp); 2067 2068 BT_ERR("Unexpected SMP Pairing Confirm"); 2069 2070 ret = fixup_sc_false_positive(smp); 2071 if (ret) 2072 return ret; 2073 } 2074 2075 if (conn->hcon->out) { 2076 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2077 smp->prnd); 2078 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2079 return 0; 2080 } 2081 2082 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) 2083 return smp_confirm(smp); 2084 2085 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 2086 2087 return 0; 2088 } 2089 2090 static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb) 2091 { 2092 struct l2cap_chan *chan = conn->smp; 2093 struct smp_chan *smp = chan->data; 2094 struct hci_conn *hcon = conn->hcon; 2095 u8 *pkax, *pkbx, *na, *nb; 2096 u32 passkey; 2097 int err; 2098 2099 BT_DBG("conn %p", conn); 2100 2101 if (skb->len < sizeof(smp->rrnd)) 2102 return SMP_INVALID_PARAMS; 2103 2104 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd)); 2105 skb_pull(skb, sizeof(smp->rrnd)); 2106 2107 if (!test_bit(SMP_FLAG_SC, &smp->flags)) 2108 return smp_random(smp); 2109 2110 if (hcon->out) { 2111 pkax = smp->local_pk; 2112 pkbx = smp->remote_pk; 2113 na = smp->prnd; 2114 nb = smp->rrnd; 2115 } else { 2116 pkax = smp->remote_pk; 2117 pkbx = smp->local_pk; 2118 na = smp->rrnd; 2119 nb = smp->prnd; 2120 } 2121 2122 if (smp->method == REQ_OOB) { 2123 if (!hcon->out) 2124 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 2125 sizeof(smp->prnd), smp->prnd); 2126 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2127 goto mackey_and_ltk; 2128 } 2129 2130 /* Passkey entry has special treatment */ 2131 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2132 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM); 2133 2134 if (hcon->out) { 2135 u8 cfm[16]; 2136 2137 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, 2138 smp->rrnd, 0, cfm); 2139 if (err) 2140 return SMP_UNSPECIFIED; 2141 2142 if (memcmp(smp->pcnf, cfm, 16)) 2143 return SMP_CONFIRM_FAILED; 2144 } else { 2145 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2146 smp->prnd); 2147 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2148 } 2149 2150 mackey_and_ltk: 2151 /* Generate MacKey and LTK */ 2152 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk); 2153 if (err) 2154 return SMP_UNSPECIFIED; 2155 2156 if (smp->method == JUST_WORKS || smp->method == REQ_OOB) { 2157 if (hcon->out) { 2158 sc_dhkey_check(smp); 2159 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2160 } 2161 return 0; 2162 } 2163 2164 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey); 2165 if (err) 2166 return SMP_UNSPECIFIED; 2167 2168 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type, 2169 hcon->dst_type, passkey, 0); 2170 if (err) 2171 return SMP_UNSPECIFIED; 2172 2173 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 2174 2175 return 0; 2176 } 2177 2178 static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level) 2179 { 2180 struct smp_ltk *key; 2181 struct hci_conn *hcon = conn->hcon; 2182 2183 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role); 2184 if (!key) 2185 return false; 2186 2187 if (smp_ltk_sec_level(key) < sec_level) 2188 return false; 2189 2190 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) 2191 return true; 2192 2193 hci_le_start_enc(hcon, key->ediv, key->rand, key->val); 2194 hcon->enc_key_size = key->enc_size; 2195 2196 /* We never store STKs for master role, so clear this flag */ 2197 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); 2198 2199 return true; 2200 } 2201 2202 bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level, 2203 enum smp_key_pref key_pref) 2204 { 2205 if (sec_level == BT_SECURITY_LOW) 2206 return true; 2207 2208 /* If we're encrypted with an STK but the caller prefers using 2209 * LTK claim insufficient security. This way we allow the 2210 * connection to be re-encrypted with an LTK, even if the LTK 2211 * provides the same level of security. Only exception is if we 2212 * don't have an LTK (e.g. because of key distribution bits). 2213 */ 2214 if (key_pref == SMP_USE_LTK && 2215 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) && 2216 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role)) 2217 return false; 2218 2219 if (hcon->sec_level >= sec_level) 2220 return true; 2221 2222 return false; 2223 } 2224 2225 static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb) 2226 { 2227 struct smp_cmd_security_req *rp = (void *) skb->data; 2228 struct smp_cmd_pairing cp; 2229 struct hci_conn *hcon = conn->hcon; 2230 struct hci_dev *hdev = hcon->hdev; 2231 struct smp_chan *smp; 2232 u8 sec_level, auth; 2233 2234 BT_DBG("conn %p", conn); 2235 2236 if (skb->len < sizeof(*rp)) 2237 return SMP_INVALID_PARAMS; 2238 2239 if (hcon->role != HCI_ROLE_MASTER) 2240 return SMP_CMD_NOTSUPP; 2241 2242 auth = rp->auth_req & AUTH_REQ_MASK(hdev); 2243 2244 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 2245 return SMP_AUTH_REQUIREMENTS; 2246 2247 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 2248 sec_level = BT_SECURITY_MEDIUM; 2249 else 2250 sec_level = authreq_to_seclevel(auth); 2251 2252 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) 2253 return 0; 2254 2255 if (sec_level > hcon->pending_sec_level) 2256 hcon->pending_sec_level = sec_level; 2257 2258 if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) 2259 return 0; 2260 2261 smp = smp_chan_create(conn); 2262 if (!smp) 2263 return SMP_UNSPECIFIED; 2264 2265 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && 2266 (auth & SMP_AUTH_BONDING)) 2267 return SMP_PAIRING_NOTSUPP; 2268 2269 skb_pull(skb, sizeof(*rp)); 2270 2271 memset(&cp, 0, sizeof(cp)); 2272 build_pairing_cmd(conn, &cp, NULL, auth); 2273 2274 smp->preq[0] = SMP_CMD_PAIRING_REQ; 2275 memcpy(&smp->preq[1], &cp, sizeof(cp)); 2276 2277 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); 2278 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 2279 2280 return 0; 2281 } 2282 2283 int smp_conn_security(struct hci_conn *hcon, __u8 sec_level) 2284 { 2285 struct l2cap_conn *conn = hcon->l2cap_data; 2286 struct l2cap_chan *chan; 2287 struct smp_chan *smp; 2288 __u8 authreq; 2289 int ret; 2290 2291 BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level); 2292 2293 /* This may be NULL if there's an unexpected disconnection */ 2294 if (!conn) 2295 return 1; 2296 2297 chan = conn->smp; 2298 2299 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) 2300 return 1; 2301 2302 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) 2303 return 1; 2304 2305 if (sec_level > hcon->pending_sec_level) 2306 hcon->pending_sec_level = sec_level; 2307 2308 if (hcon->role == HCI_ROLE_MASTER) 2309 if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) 2310 return 0; 2311 2312 l2cap_chan_lock(chan); 2313 2314 /* If SMP is already in progress ignore this request */ 2315 if (chan->data) { 2316 ret = 0; 2317 goto unlock; 2318 } 2319 2320 smp = smp_chan_create(conn); 2321 if (!smp) { 2322 ret = 1; 2323 goto unlock; 2324 } 2325 2326 authreq = seclevel_to_authreq(sec_level); 2327 2328 if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED)) 2329 authreq |= SMP_AUTH_SC; 2330 2331 /* Require MITM if IO Capability allows or the security level 2332 * requires it. 2333 */ 2334 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT || 2335 hcon->pending_sec_level > BT_SECURITY_MEDIUM) 2336 authreq |= SMP_AUTH_MITM; 2337 2338 if (hcon->role == HCI_ROLE_MASTER) { 2339 struct smp_cmd_pairing cp; 2340 2341 build_pairing_cmd(conn, &cp, NULL, authreq); 2342 smp->preq[0] = SMP_CMD_PAIRING_REQ; 2343 memcpy(&smp->preq[1], &cp, sizeof(cp)); 2344 2345 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); 2346 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 2347 } else { 2348 struct smp_cmd_security_req cp; 2349 cp.auth_req = authreq; 2350 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp); 2351 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ); 2352 } 2353 2354 set_bit(SMP_FLAG_INITIATOR, &smp->flags); 2355 ret = 0; 2356 2357 unlock: 2358 l2cap_chan_unlock(chan); 2359 return ret; 2360 } 2361 2362 static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb) 2363 { 2364 struct smp_cmd_encrypt_info *rp = (void *) skb->data; 2365 struct l2cap_chan *chan = conn->smp; 2366 struct smp_chan *smp = chan->data; 2367 2368 BT_DBG("conn %p", conn); 2369 2370 if (skb->len < sizeof(*rp)) 2371 return SMP_INVALID_PARAMS; 2372 2373 SMP_ALLOW_CMD(smp, SMP_CMD_MASTER_IDENT); 2374 2375 skb_pull(skb, sizeof(*rp)); 2376 2377 memcpy(smp->tk, rp->ltk, sizeof(smp->tk)); 2378 2379 return 0; 2380 } 2381 2382 static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb) 2383 { 2384 struct smp_cmd_master_ident *rp = (void *) skb->data; 2385 struct l2cap_chan *chan = conn->smp; 2386 struct smp_chan *smp = chan->data; 2387 struct hci_dev *hdev = conn->hcon->hdev; 2388 struct hci_conn *hcon = conn->hcon; 2389 struct smp_ltk *ltk; 2390 u8 authenticated; 2391 2392 BT_DBG("conn %p", conn); 2393 2394 if (skb->len < sizeof(*rp)) 2395 return SMP_INVALID_PARAMS; 2396 2397 /* Mark the information as received */ 2398 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY; 2399 2400 if (smp->remote_key_dist & SMP_DIST_ID_KEY) 2401 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); 2402 else if (smp->remote_key_dist & SMP_DIST_SIGN) 2403 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 2404 2405 skb_pull(skb, sizeof(*rp)); 2406 2407 authenticated = (hcon->sec_level == BT_SECURITY_HIGH); 2408 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK, 2409 authenticated, smp->tk, smp->enc_key_size, 2410 rp->ediv, rp->rand); 2411 smp->ltk = ltk; 2412 if (!(smp->remote_key_dist & KEY_DIST_MASK)) 2413 smp_distribute_keys(smp); 2414 2415 return 0; 2416 } 2417 2418 static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb) 2419 { 2420 struct smp_cmd_ident_info *info = (void *) skb->data; 2421 struct l2cap_chan *chan = conn->smp; 2422 struct smp_chan *smp = chan->data; 2423 2424 BT_DBG(""); 2425 2426 if (skb->len < sizeof(*info)) 2427 return SMP_INVALID_PARAMS; 2428 2429 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO); 2430 2431 skb_pull(skb, sizeof(*info)); 2432 2433 memcpy(smp->irk, info->irk, 16); 2434 2435 return 0; 2436 } 2437 2438 static int smp_cmd_ident_addr_info(struct l2cap_conn *conn, 2439 struct sk_buff *skb) 2440 { 2441 struct smp_cmd_ident_addr_info *info = (void *) skb->data; 2442 struct l2cap_chan *chan = conn->smp; 2443 struct smp_chan *smp = chan->data; 2444 struct hci_conn *hcon = conn->hcon; 2445 bdaddr_t rpa; 2446 2447 BT_DBG(""); 2448 2449 if (skb->len < sizeof(*info)) 2450 return SMP_INVALID_PARAMS; 2451 2452 /* Mark the information as received */ 2453 smp->remote_key_dist &= ~SMP_DIST_ID_KEY; 2454 2455 if (smp->remote_key_dist & SMP_DIST_SIGN) 2456 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 2457 2458 skb_pull(skb, sizeof(*info)); 2459 2460 /* Strictly speaking the Core Specification (4.1) allows sending 2461 * an empty address which would force us to rely on just the IRK 2462 * as "identity information". However, since such 2463 * implementations are not known of and in order to not over 2464 * complicate our implementation, simply pretend that we never 2465 * received an IRK for such a device. 2466 * 2467 * The Identity Address must also be a Static Random or Public 2468 * Address, which hci_is_identity_address() checks for. 2469 */ 2470 if (!bacmp(&info->bdaddr, BDADDR_ANY) || 2471 !hci_is_identity_address(&info->bdaddr, info->addr_type)) { 2472 BT_ERR("Ignoring IRK with no identity address"); 2473 goto distribute; 2474 } 2475 2476 bacpy(&smp->id_addr, &info->bdaddr); 2477 smp->id_addr_type = info->addr_type; 2478 2479 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type)) 2480 bacpy(&rpa, &hcon->dst); 2481 else 2482 bacpy(&rpa, BDADDR_ANY); 2483 2484 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr, 2485 smp->id_addr_type, smp->irk, &rpa); 2486 2487 distribute: 2488 if (!(smp->remote_key_dist & KEY_DIST_MASK)) 2489 smp_distribute_keys(smp); 2490 2491 return 0; 2492 } 2493 2494 static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb) 2495 { 2496 struct smp_cmd_sign_info *rp = (void *) skb->data; 2497 struct l2cap_chan *chan = conn->smp; 2498 struct smp_chan *smp = chan->data; 2499 struct smp_csrk *csrk; 2500 2501 BT_DBG("conn %p", conn); 2502 2503 if (skb->len < sizeof(*rp)) 2504 return SMP_INVALID_PARAMS; 2505 2506 /* Mark the information as received */ 2507 smp->remote_key_dist &= ~SMP_DIST_SIGN; 2508 2509 skb_pull(skb, sizeof(*rp)); 2510 2511 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); 2512 if (csrk) { 2513 if (conn->hcon->sec_level > BT_SECURITY_MEDIUM) 2514 csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED; 2515 else 2516 csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED; 2517 memcpy(csrk->val, rp->csrk, sizeof(csrk->val)); 2518 } 2519 smp->csrk = csrk; 2520 smp_distribute_keys(smp); 2521 2522 return 0; 2523 } 2524 2525 static u8 sc_select_method(struct smp_chan *smp) 2526 { 2527 struct l2cap_conn *conn = smp->conn; 2528 struct hci_conn *hcon = conn->hcon; 2529 struct smp_cmd_pairing *local, *remote; 2530 u8 local_mitm, remote_mitm, local_io, remote_io, method; 2531 2532 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) || 2533 test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) 2534 return REQ_OOB; 2535 2536 /* The preq/prsp contain the raw Pairing Request/Response PDUs 2537 * which are needed as inputs to some crypto functions. To get 2538 * the "struct smp_cmd_pairing" from them we need to skip the 2539 * first byte which contains the opcode. 2540 */ 2541 if (hcon->out) { 2542 local = (void *) &smp->preq[1]; 2543 remote = (void *) &smp->prsp[1]; 2544 } else { 2545 local = (void *) &smp->prsp[1]; 2546 remote = (void *) &smp->preq[1]; 2547 } 2548 2549 local_io = local->io_capability; 2550 remote_io = remote->io_capability; 2551 2552 local_mitm = (local->auth_req & SMP_AUTH_MITM); 2553 remote_mitm = (remote->auth_req & SMP_AUTH_MITM); 2554 2555 /* If either side wants MITM, look up the method from the table, 2556 * otherwise use JUST WORKS. 2557 */ 2558 if (local_mitm || remote_mitm) 2559 method = get_auth_method(smp, local_io, remote_io); 2560 else 2561 method = JUST_WORKS; 2562 2563 /* Don't confirm locally initiated pairing attempts */ 2564 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2565 method = JUST_WORKS; 2566 2567 return method; 2568 } 2569 2570 static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb) 2571 { 2572 struct smp_cmd_public_key *key = (void *) skb->data; 2573 struct hci_conn *hcon = conn->hcon; 2574 struct l2cap_chan *chan = conn->smp; 2575 struct smp_chan *smp = chan->data; 2576 struct hci_dev *hdev = hcon->hdev; 2577 struct smp_cmd_pairing_confirm cfm; 2578 int err; 2579 2580 BT_DBG("conn %p", conn); 2581 2582 if (skb->len < sizeof(*key)) 2583 return SMP_INVALID_PARAMS; 2584 2585 memcpy(smp->remote_pk, key, 64); 2586 2587 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) { 2588 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk, 2589 smp->rr, 0, cfm.confirm_val); 2590 if (err) 2591 return SMP_UNSPECIFIED; 2592 2593 if (memcmp(cfm.confirm_val, smp->pcnf, 16)) 2594 return SMP_CONFIRM_FAILED; 2595 } 2596 2597 /* Non-initiating device sends its public key after receiving 2598 * the key from the initiating device. 2599 */ 2600 if (!hcon->out) { 2601 err = sc_send_public_key(smp); 2602 if (err) 2603 return err; 2604 } 2605 2606 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk); 2607 SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32); 2608 2609 if (!ecdh_shared_secret(smp->remote_pk, smp->local_sk, smp->dhkey)) 2610 return SMP_UNSPECIFIED; 2611 2612 SMP_DBG("DHKey %32phN", smp->dhkey); 2613 2614 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags); 2615 2616 smp->method = sc_select_method(smp); 2617 2618 BT_DBG("%s selected method 0x%02x", hdev->name, smp->method); 2619 2620 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */ 2621 if (smp->method == JUST_WORKS || smp->method == JUST_CFM) 2622 hcon->pending_sec_level = BT_SECURITY_MEDIUM; 2623 else 2624 hcon->pending_sec_level = BT_SECURITY_FIPS; 2625 2626 if (!memcmp(debug_pk, smp->remote_pk, 64)) 2627 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 2628 2629 if (smp->method == DSP_PASSKEY) { 2630 get_random_bytes(&hcon->passkey_notify, 2631 sizeof(hcon->passkey_notify)); 2632 hcon->passkey_notify %= 1000000; 2633 hcon->passkey_entered = 0; 2634 smp->passkey_round = 0; 2635 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type, 2636 hcon->dst_type, 2637 hcon->passkey_notify, 2638 hcon->passkey_entered)) 2639 return SMP_UNSPECIFIED; 2640 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2641 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY); 2642 } 2643 2644 if (smp->method == REQ_OOB) { 2645 if (hcon->out) 2646 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 2647 sizeof(smp->prnd), smp->prnd); 2648 2649 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2650 2651 return 0; 2652 } 2653 2654 if (hcon->out) 2655 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2656 2657 if (smp->method == REQ_PASSKEY) { 2658 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type, 2659 hcon->dst_type)) 2660 return SMP_UNSPECIFIED; 2661 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2662 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 2663 return 0; 2664 } 2665 2666 /* The Initiating device waits for the non-initiating device to 2667 * send the confirm value. 2668 */ 2669 if (conn->hcon->out) 2670 return 0; 2671 2672 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, 2673 0, cfm.confirm_val); 2674 if (err) 2675 return SMP_UNSPECIFIED; 2676 2677 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); 2678 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2679 2680 return 0; 2681 } 2682 2683 static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb) 2684 { 2685 struct smp_cmd_dhkey_check *check = (void *) skb->data; 2686 struct l2cap_chan *chan = conn->smp; 2687 struct hci_conn *hcon = conn->hcon; 2688 struct smp_chan *smp = chan->data; 2689 u8 a[7], b[7], *local_addr, *remote_addr; 2690 u8 io_cap[3], r[16], e[16]; 2691 int err; 2692 2693 BT_DBG("conn %p", conn); 2694 2695 if (skb->len < sizeof(*check)) 2696 return SMP_INVALID_PARAMS; 2697 2698 memcpy(a, &hcon->init_addr, 6); 2699 memcpy(b, &hcon->resp_addr, 6); 2700 a[6] = hcon->init_addr_type; 2701 b[6] = hcon->resp_addr_type; 2702 2703 if (hcon->out) { 2704 local_addr = a; 2705 remote_addr = b; 2706 memcpy(io_cap, &smp->prsp[1], 3); 2707 } else { 2708 local_addr = b; 2709 remote_addr = a; 2710 memcpy(io_cap, &smp->preq[1], 3); 2711 } 2712 2713 memset(r, 0, sizeof(r)); 2714 2715 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2716 put_unaligned_le32(hcon->passkey_notify, r); 2717 else if (smp->method == REQ_OOB) 2718 memcpy(r, smp->lr, 16); 2719 2720 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r, 2721 io_cap, remote_addr, local_addr, e); 2722 if (err) 2723 return SMP_UNSPECIFIED; 2724 2725 if (memcmp(check->e, e, 16)) 2726 return SMP_DHKEY_CHECK_FAILED; 2727 2728 if (!hcon->out) { 2729 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { 2730 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags); 2731 return 0; 2732 } 2733 2734 /* Slave sends DHKey check as response to master */ 2735 sc_dhkey_check(smp); 2736 } 2737 2738 sc_add_ltk(smp); 2739 2740 if (hcon->out) { 2741 hci_le_start_enc(hcon, 0, 0, smp->tk); 2742 hcon->enc_key_size = smp->enc_key_size; 2743 } 2744 2745 return 0; 2746 } 2747 2748 static int smp_cmd_keypress_notify(struct l2cap_conn *conn, 2749 struct sk_buff *skb) 2750 { 2751 struct smp_cmd_keypress_notify *kp = (void *) skb->data; 2752 2753 BT_DBG("value 0x%02x", kp->value); 2754 2755 return 0; 2756 } 2757 2758 static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb) 2759 { 2760 struct l2cap_conn *conn = chan->conn; 2761 struct hci_conn *hcon = conn->hcon; 2762 struct smp_chan *smp; 2763 __u8 code, reason; 2764 int err = 0; 2765 2766 if (skb->len < 1) 2767 return -EILSEQ; 2768 2769 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) { 2770 reason = SMP_PAIRING_NOTSUPP; 2771 goto done; 2772 } 2773 2774 code = skb->data[0]; 2775 skb_pull(skb, sizeof(code)); 2776 2777 smp = chan->data; 2778 2779 if (code > SMP_CMD_MAX) 2780 goto drop; 2781 2782 if (smp && !test_and_clear_bit(code, &smp->allow_cmd)) 2783 goto drop; 2784 2785 /* If we don't have a context the only allowed commands are 2786 * pairing request and security request. 2787 */ 2788 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ) 2789 goto drop; 2790 2791 switch (code) { 2792 case SMP_CMD_PAIRING_REQ: 2793 reason = smp_cmd_pairing_req(conn, skb); 2794 break; 2795 2796 case SMP_CMD_PAIRING_FAIL: 2797 smp_failure(conn, 0); 2798 err = -EPERM; 2799 break; 2800 2801 case SMP_CMD_PAIRING_RSP: 2802 reason = smp_cmd_pairing_rsp(conn, skb); 2803 break; 2804 2805 case SMP_CMD_SECURITY_REQ: 2806 reason = smp_cmd_security_req(conn, skb); 2807 break; 2808 2809 case SMP_CMD_PAIRING_CONFIRM: 2810 reason = smp_cmd_pairing_confirm(conn, skb); 2811 break; 2812 2813 case SMP_CMD_PAIRING_RANDOM: 2814 reason = smp_cmd_pairing_random(conn, skb); 2815 break; 2816 2817 case SMP_CMD_ENCRYPT_INFO: 2818 reason = smp_cmd_encrypt_info(conn, skb); 2819 break; 2820 2821 case SMP_CMD_MASTER_IDENT: 2822 reason = smp_cmd_master_ident(conn, skb); 2823 break; 2824 2825 case SMP_CMD_IDENT_INFO: 2826 reason = smp_cmd_ident_info(conn, skb); 2827 break; 2828 2829 case SMP_CMD_IDENT_ADDR_INFO: 2830 reason = smp_cmd_ident_addr_info(conn, skb); 2831 break; 2832 2833 case SMP_CMD_SIGN_INFO: 2834 reason = smp_cmd_sign_info(conn, skb); 2835 break; 2836 2837 case SMP_CMD_PUBLIC_KEY: 2838 reason = smp_cmd_public_key(conn, skb); 2839 break; 2840 2841 case SMP_CMD_DHKEY_CHECK: 2842 reason = smp_cmd_dhkey_check(conn, skb); 2843 break; 2844 2845 case SMP_CMD_KEYPRESS_NOTIFY: 2846 reason = smp_cmd_keypress_notify(conn, skb); 2847 break; 2848 2849 default: 2850 BT_DBG("Unknown command code 0x%2.2x", code); 2851 reason = SMP_CMD_NOTSUPP; 2852 goto done; 2853 } 2854 2855 done: 2856 if (!err) { 2857 if (reason) 2858 smp_failure(conn, reason); 2859 kfree_skb(skb); 2860 } 2861 2862 return err; 2863 2864 drop: 2865 BT_ERR("%s unexpected SMP command 0x%02x from %pMR", hcon->hdev->name, 2866 code, &hcon->dst); 2867 kfree_skb(skb); 2868 return 0; 2869 } 2870 2871 static void smp_teardown_cb(struct l2cap_chan *chan, int err) 2872 { 2873 struct l2cap_conn *conn = chan->conn; 2874 2875 BT_DBG("chan %p", chan); 2876 2877 if (chan->data) 2878 smp_chan_destroy(conn); 2879 2880 conn->smp = NULL; 2881 l2cap_chan_put(chan); 2882 } 2883 2884 static void bredr_pairing(struct l2cap_chan *chan) 2885 { 2886 struct l2cap_conn *conn = chan->conn; 2887 struct hci_conn *hcon = conn->hcon; 2888 struct hci_dev *hdev = hcon->hdev; 2889 struct smp_cmd_pairing req; 2890 struct smp_chan *smp; 2891 2892 BT_DBG("chan %p", chan); 2893 2894 /* Only new pairings are interesting */ 2895 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags)) 2896 return; 2897 2898 /* Don't bother if we're not encrypted */ 2899 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 2900 return; 2901 2902 /* Only master may initiate SMP over BR/EDR */ 2903 if (hcon->role != HCI_ROLE_MASTER) 2904 return; 2905 2906 /* Secure Connections support must be enabled */ 2907 if (!hci_dev_test_flag(hdev, HCI_SC_ENABLED)) 2908 return; 2909 2910 /* BR/EDR must use Secure Connections for SMP */ 2911 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) && 2912 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 2913 return; 2914 2915 /* If our LE support is not enabled don't do anything */ 2916 if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) 2917 return; 2918 2919 /* Don't bother if remote LE support is not enabled */ 2920 if (!lmp_host_le_capable(hcon)) 2921 return; 2922 2923 /* Remote must support SMP fixed chan for BR/EDR */ 2924 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR)) 2925 return; 2926 2927 /* Don't bother if SMP is already ongoing */ 2928 if (chan->data) 2929 return; 2930 2931 smp = smp_chan_create(conn); 2932 if (!smp) { 2933 BT_ERR("%s unable to create SMP context for BR/EDR", 2934 hdev->name); 2935 return; 2936 } 2937 2938 set_bit(SMP_FLAG_SC, &smp->flags); 2939 2940 BT_DBG("%s starting SMP over BR/EDR", hdev->name); 2941 2942 /* Prepare and send the BR/EDR SMP Pairing Request */ 2943 build_bredr_pairing_cmd(smp, &req, NULL); 2944 2945 smp->preq[0] = SMP_CMD_PAIRING_REQ; 2946 memcpy(&smp->preq[1], &req, sizeof(req)); 2947 2948 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(req), &req); 2949 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 2950 } 2951 2952 static void smp_resume_cb(struct l2cap_chan *chan) 2953 { 2954 struct smp_chan *smp = chan->data; 2955 struct l2cap_conn *conn = chan->conn; 2956 struct hci_conn *hcon = conn->hcon; 2957 2958 BT_DBG("chan %p", chan); 2959 2960 if (hcon->type == ACL_LINK) { 2961 bredr_pairing(chan); 2962 return; 2963 } 2964 2965 if (!smp) 2966 return; 2967 2968 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 2969 return; 2970 2971 cancel_delayed_work(&smp->security_timer); 2972 2973 smp_distribute_keys(smp); 2974 } 2975 2976 static void smp_ready_cb(struct l2cap_chan *chan) 2977 { 2978 struct l2cap_conn *conn = chan->conn; 2979 struct hci_conn *hcon = conn->hcon; 2980 2981 BT_DBG("chan %p", chan); 2982 2983 conn->smp = chan; 2984 l2cap_chan_hold(chan); 2985 2986 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 2987 bredr_pairing(chan); 2988 } 2989 2990 static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 2991 { 2992 int err; 2993 2994 BT_DBG("chan %p", chan); 2995 2996 err = smp_sig_channel(chan, skb); 2997 if (err) { 2998 struct smp_chan *smp = chan->data; 2999 3000 if (smp) 3001 cancel_delayed_work_sync(&smp->security_timer); 3002 3003 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE); 3004 } 3005 3006 return err; 3007 } 3008 3009 static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan, 3010 unsigned long hdr_len, 3011 unsigned long len, int nb) 3012 { 3013 struct sk_buff *skb; 3014 3015 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL); 3016 if (!skb) 3017 return ERR_PTR(-ENOMEM); 3018 3019 skb->priority = HCI_PRIO_MAX; 3020 bt_cb(skb)->l2cap.chan = chan; 3021 3022 return skb; 3023 } 3024 3025 static const struct l2cap_ops smp_chan_ops = { 3026 .name = "Security Manager", 3027 .ready = smp_ready_cb, 3028 .recv = smp_recv_cb, 3029 .alloc_skb = smp_alloc_skb_cb, 3030 .teardown = smp_teardown_cb, 3031 .resume = smp_resume_cb, 3032 3033 .new_connection = l2cap_chan_no_new_connection, 3034 .state_change = l2cap_chan_no_state_change, 3035 .close = l2cap_chan_no_close, 3036 .defer = l2cap_chan_no_defer, 3037 .suspend = l2cap_chan_no_suspend, 3038 .set_shutdown = l2cap_chan_no_set_shutdown, 3039 .get_sndtimeo = l2cap_chan_no_get_sndtimeo, 3040 }; 3041 3042 static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan) 3043 { 3044 struct l2cap_chan *chan; 3045 3046 BT_DBG("pchan %p", pchan); 3047 3048 chan = l2cap_chan_create(); 3049 if (!chan) 3050 return NULL; 3051 3052 chan->chan_type = pchan->chan_type; 3053 chan->ops = &smp_chan_ops; 3054 chan->scid = pchan->scid; 3055 chan->dcid = chan->scid; 3056 chan->imtu = pchan->imtu; 3057 chan->omtu = pchan->omtu; 3058 chan->mode = pchan->mode; 3059 3060 /* Other L2CAP channels may request SMP routines in order to 3061 * change the security level. This means that the SMP channel 3062 * lock must be considered in its own category to avoid lockdep 3063 * warnings. 3064 */ 3065 atomic_set(&chan->nesting, L2CAP_NESTING_SMP); 3066 3067 BT_DBG("created chan %p", chan); 3068 3069 return chan; 3070 } 3071 3072 static const struct l2cap_ops smp_root_chan_ops = { 3073 .name = "Security Manager Root", 3074 .new_connection = smp_new_conn_cb, 3075 3076 /* None of these are implemented for the root channel */ 3077 .close = l2cap_chan_no_close, 3078 .alloc_skb = l2cap_chan_no_alloc_skb, 3079 .recv = l2cap_chan_no_recv, 3080 .state_change = l2cap_chan_no_state_change, 3081 .teardown = l2cap_chan_no_teardown, 3082 .ready = l2cap_chan_no_ready, 3083 .defer = l2cap_chan_no_defer, 3084 .suspend = l2cap_chan_no_suspend, 3085 .resume = l2cap_chan_no_resume, 3086 .set_shutdown = l2cap_chan_no_set_shutdown, 3087 .get_sndtimeo = l2cap_chan_no_get_sndtimeo, 3088 }; 3089 3090 static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid) 3091 { 3092 struct l2cap_chan *chan; 3093 struct smp_dev *smp; 3094 struct crypto_blkcipher *tfm_aes; 3095 struct crypto_hash *tfm_cmac; 3096 3097 if (cid == L2CAP_CID_SMP_BREDR) { 3098 smp = NULL; 3099 goto create_chan; 3100 } 3101 3102 smp = kzalloc(sizeof(*smp), GFP_KERNEL); 3103 if (!smp) 3104 return ERR_PTR(-ENOMEM); 3105 3106 tfm_aes = crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC); 3107 if (IS_ERR(tfm_aes)) { 3108 BT_ERR("Unable to create ECB crypto context"); 3109 kzfree(smp); 3110 return ERR_CAST(tfm_aes); 3111 } 3112 3113 tfm_cmac = crypto_alloc_hash("cmac(aes)", 0, CRYPTO_ALG_ASYNC); 3114 if (IS_ERR(tfm_cmac)) { 3115 BT_ERR("Unable to create CMAC crypto context"); 3116 crypto_free_blkcipher(tfm_aes); 3117 kzfree(smp); 3118 return ERR_CAST(tfm_cmac); 3119 } 3120 3121 smp->tfm_aes = tfm_aes; 3122 smp->tfm_cmac = tfm_cmac; 3123 3124 create_chan: 3125 chan = l2cap_chan_create(); 3126 if (!chan) { 3127 if (smp) { 3128 crypto_free_blkcipher(smp->tfm_aes); 3129 crypto_free_hash(smp->tfm_cmac); 3130 kzfree(smp); 3131 } 3132 return ERR_PTR(-ENOMEM); 3133 } 3134 3135 chan->data = smp; 3136 3137 l2cap_add_scid(chan, cid); 3138 3139 l2cap_chan_set_defaults(chan); 3140 3141 if (cid == L2CAP_CID_SMP) { 3142 u8 bdaddr_type; 3143 3144 hci_copy_identity_address(hdev, &chan->src, &bdaddr_type); 3145 3146 if (bdaddr_type == ADDR_LE_DEV_PUBLIC) 3147 chan->src_type = BDADDR_LE_PUBLIC; 3148 else 3149 chan->src_type = BDADDR_LE_RANDOM; 3150 } else { 3151 bacpy(&chan->src, &hdev->bdaddr); 3152 chan->src_type = BDADDR_BREDR; 3153 } 3154 3155 chan->state = BT_LISTEN; 3156 chan->mode = L2CAP_MODE_BASIC; 3157 chan->imtu = L2CAP_DEFAULT_MTU; 3158 chan->ops = &smp_root_chan_ops; 3159 3160 /* Set correct nesting level for a parent/listening channel */ 3161 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 3162 3163 return chan; 3164 } 3165 3166 static void smp_del_chan(struct l2cap_chan *chan) 3167 { 3168 struct smp_dev *smp; 3169 3170 BT_DBG("chan %p", chan); 3171 3172 smp = chan->data; 3173 if (smp) { 3174 chan->data = NULL; 3175 if (smp->tfm_aes) 3176 crypto_free_blkcipher(smp->tfm_aes); 3177 if (smp->tfm_cmac) 3178 crypto_free_hash(smp->tfm_cmac); 3179 kzfree(smp); 3180 } 3181 3182 l2cap_chan_put(chan); 3183 } 3184 3185 static ssize_t force_bredr_smp_read(struct file *file, 3186 char __user *user_buf, 3187 size_t count, loff_t *ppos) 3188 { 3189 struct hci_dev *hdev = file->private_data; 3190 char buf[3]; 3191 3192 buf[0] = hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP) ? 'Y': 'N'; 3193 buf[1] = '\n'; 3194 buf[2] = '\0'; 3195 return simple_read_from_buffer(user_buf, count, ppos, buf, 2); 3196 } 3197 3198 static ssize_t force_bredr_smp_write(struct file *file, 3199 const char __user *user_buf, 3200 size_t count, loff_t *ppos) 3201 { 3202 struct hci_dev *hdev = file->private_data; 3203 char buf[32]; 3204 size_t buf_size = min(count, (sizeof(buf)-1)); 3205 bool enable; 3206 3207 if (copy_from_user(buf, user_buf, buf_size)) 3208 return -EFAULT; 3209 3210 buf[buf_size] = '\0'; 3211 if (strtobool(buf, &enable)) 3212 return -EINVAL; 3213 3214 if (enable == hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3215 return -EALREADY; 3216 3217 if (enable) { 3218 struct l2cap_chan *chan; 3219 3220 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); 3221 if (IS_ERR(chan)) 3222 return PTR_ERR(chan); 3223 3224 hdev->smp_bredr_data = chan; 3225 } else { 3226 struct l2cap_chan *chan; 3227 3228 chan = hdev->smp_bredr_data; 3229 hdev->smp_bredr_data = NULL; 3230 smp_del_chan(chan); 3231 } 3232 3233 hci_dev_change_flag(hdev, HCI_FORCE_BREDR_SMP); 3234 3235 return count; 3236 } 3237 3238 static const struct file_operations force_bredr_smp_fops = { 3239 .open = simple_open, 3240 .read = force_bredr_smp_read, 3241 .write = force_bredr_smp_write, 3242 .llseek = default_llseek, 3243 }; 3244 3245 int smp_register(struct hci_dev *hdev) 3246 { 3247 struct l2cap_chan *chan; 3248 3249 BT_DBG("%s", hdev->name); 3250 3251 /* If the controller does not support Low Energy operation, then 3252 * there is also no need to register any SMP channel. 3253 */ 3254 if (!lmp_le_capable(hdev)) 3255 return 0; 3256 3257 if (WARN_ON(hdev->smp_data)) { 3258 chan = hdev->smp_data; 3259 hdev->smp_data = NULL; 3260 smp_del_chan(chan); 3261 } 3262 3263 chan = smp_add_cid(hdev, L2CAP_CID_SMP); 3264 if (IS_ERR(chan)) 3265 return PTR_ERR(chan); 3266 3267 hdev->smp_data = chan; 3268 3269 /* If the controller does not support BR/EDR Secure Connections 3270 * feature, then the BR/EDR SMP channel shall not be present. 3271 * 3272 * To test this with Bluetooth 4.0 controllers, create a debugfs 3273 * switch that allows forcing BR/EDR SMP support and accepting 3274 * cross-transport pairing on non-AES encrypted connections. 3275 */ 3276 if (!lmp_sc_capable(hdev)) { 3277 debugfs_create_file("force_bredr_smp", 0644, hdev->debugfs, 3278 hdev, &force_bredr_smp_fops); 3279 return 0; 3280 } 3281 3282 if (WARN_ON(hdev->smp_bredr_data)) { 3283 chan = hdev->smp_bredr_data; 3284 hdev->smp_bredr_data = NULL; 3285 smp_del_chan(chan); 3286 } 3287 3288 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); 3289 if (IS_ERR(chan)) { 3290 int err = PTR_ERR(chan); 3291 chan = hdev->smp_data; 3292 hdev->smp_data = NULL; 3293 smp_del_chan(chan); 3294 return err; 3295 } 3296 3297 hdev->smp_bredr_data = chan; 3298 3299 return 0; 3300 } 3301 3302 void smp_unregister(struct hci_dev *hdev) 3303 { 3304 struct l2cap_chan *chan; 3305 3306 if (hdev->smp_bredr_data) { 3307 chan = hdev->smp_bredr_data; 3308 hdev->smp_bredr_data = NULL; 3309 smp_del_chan(chan); 3310 } 3311 3312 if (hdev->smp_data) { 3313 chan = hdev->smp_data; 3314 hdev->smp_data = NULL; 3315 smp_del_chan(chan); 3316 } 3317 } 3318 3319 #if IS_ENABLED(CONFIG_BT_SELFTEST_SMP) 3320 3321 static int __init test_ah(struct crypto_blkcipher *tfm_aes) 3322 { 3323 const u8 irk[16] = { 3324 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3325 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3326 const u8 r[3] = { 0x94, 0x81, 0x70 }; 3327 const u8 exp[3] = { 0xaa, 0xfb, 0x0d }; 3328 u8 res[3]; 3329 int err; 3330 3331 err = smp_ah(tfm_aes, irk, r, res); 3332 if (err) 3333 return err; 3334 3335 if (memcmp(res, exp, 3)) 3336 return -EINVAL; 3337 3338 return 0; 3339 } 3340 3341 static int __init test_c1(struct crypto_blkcipher *tfm_aes) 3342 { 3343 const u8 k[16] = { 3344 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 3345 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; 3346 const u8 r[16] = { 3347 0xe0, 0x2e, 0x70, 0xc6, 0x4e, 0x27, 0x88, 0x63, 3348 0x0e, 0x6f, 0xad, 0x56, 0x21, 0xd5, 0x83, 0x57 }; 3349 const u8 preq[7] = { 0x01, 0x01, 0x00, 0x00, 0x10, 0x07, 0x07 }; 3350 const u8 pres[7] = { 0x02, 0x03, 0x00, 0x00, 0x08, 0x00, 0x05 }; 3351 const u8 _iat = 0x01; 3352 const u8 _rat = 0x00; 3353 const bdaddr_t ra = { { 0xb6, 0xb5, 0xb4, 0xb3, 0xb2, 0xb1 } }; 3354 const bdaddr_t ia = { { 0xa6, 0xa5, 0xa4, 0xa3, 0xa2, 0xa1 } }; 3355 const u8 exp[16] = { 3356 0x86, 0x3b, 0xf1, 0xbe, 0xc5, 0x4d, 0xa7, 0xd2, 3357 0xea, 0x88, 0x89, 0x87, 0xef, 0x3f, 0x1e, 0x1e }; 3358 u8 res[16]; 3359 int err; 3360 3361 err = smp_c1(tfm_aes, k, r, preq, pres, _iat, &ia, _rat, &ra, res); 3362 if (err) 3363 return err; 3364 3365 if (memcmp(res, exp, 16)) 3366 return -EINVAL; 3367 3368 return 0; 3369 } 3370 3371 static int __init test_s1(struct crypto_blkcipher *tfm_aes) 3372 { 3373 const u8 k[16] = { 3374 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 3375 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; 3376 const u8 r1[16] = { 3377 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 }; 3378 const u8 r2[16] = { 3379 0x00, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99 }; 3380 const u8 exp[16] = { 3381 0x62, 0xa0, 0x6d, 0x79, 0xae, 0x16, 0x42, 0x5b, 3382 0x9b, 0xf4, 0xb0, 0xe8, 0xf0, 0xe1, 0x1f, 0x9a }; 3383 u8 res[16]; 3384 int err; 3385 3386 err = smp_s1(tfm_aes, k, r1, r2, res); 3387 if (err) 3388 return err; 3389 3390 if (memcmp(res, exp, 16)) 3391 return -EINVAL; 3392 3393 return 0; 3394 } 3395 3396 static int __init test_f4(struct crypto_hash *tfm_cmac) 3397 { 3398 const u8 u[32] = { 3399 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 3400 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 3401 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 3402 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 }; 3403 const u8 v[32] = { 3404 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b, 3405 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59, 3406 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90, 3407 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 }; 3408 const u8 x[16] = { 3409 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3410 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3411 const u8 z = 0x00; 3412 const u8 exp[16] = { 3413 0x2d, 0x87, 0x74, 0xa9, 0xbe, 0xa1, 0xed, 0xf1, 3414 0x1c, 0xbd, 0xa9, 0x07, 0xf1, 0x16, 0xc9, 0xf2 }; 3415 u8 res[16]; 3416 int err; 3417 3418 err = smp_f4(tfm_cmac, u, v, x, z, res); 3419 if (err) 3420 return err; 3421 3422 if (memcmp(res, exp, 16)) 3423 return -EINVAL; 3424 3425 return 0; 3426 } 3427 3428 static int __init test_f5(struct crypto_hash *tfm_cmac) 3429 { 3430 const u8 w[32] = { 3431 0x98, 0xa6, 0xbf, 0x73, 0xf3, 0x34, 0x8d, 0x86, 3432 0xf1, 0x66, 0xf8, 0xb4, 0x13, 0x6b, 0x79, 0x99, 3433 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3434 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3435 const u8 n1[16] = { 3436 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3437 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3438 const u8 n2[16] = { 3439 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3440 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3441 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 }; 3442 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 }; 3443 const u8 exp_ltk[16] = { 3444 0x38, 0x0a, 0x75, 0x94, 0xb5, 0x22, 0x05, 0x98, 3445 0x23, 0xcd, 0xd7, 0x69, 0x11, 0x79, 0x86, 0x69 }; 3446 const u8 exp_mackey[16] = { 3447 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd, 3448 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 }; 3449 u8 mackey[16], ltk[16]; 3450 int err; 3451 3452 err = smp_f5(tfm_cmac, w, n1, n2, a1, a2, mackey, ltk); 3453 if (err) 3454 return err; 3455 3456 if (memcmp(mackey, exp_mackey, 16)) 3457 return -EINVAL; 3458 3459 if (memcmp(ltk, exp_ltk, 16)) 3460 return -EINVAL; 3461 3462 return 0; 3463 } 3464 3465 static int __init test_f6(struct crypto_hash *tfm_cmac) 3466 { 3467 const u8 w[16] = { 3468 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd, 3469 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 }; 3470 const u8 n1[16] = { 3471 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3472 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3473 const u8 n2[16] = { 3474 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3475 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3476 const u8 r[16] = { 3477 0xc8, 0x0f, 0x2d, 0x0c, 0xd2, 0x42, 0xda, 0x08, 3478 0x54, 0xbb, 0x53, 0xb4, 0x3b, 0x34, 0xa3, 0x12 }; 3479 const u8 io_cap[3] = { 0x02, 0x01, 0x01 }; 3480 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 }; 3481 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 }; 3482 const u8 exp[16] = { 3483 0x61, 0x8f, 0x95, 0xda, 0x09, 0x0b, 0x6c, 0xd2, 3484 0xc5, 0xe8, 0xd0, 0x9c, 0x98, 0x73, 0xc4, 0xe3 }; 3485 u8 res[16]; 3486 int err; 3487 3488 err = smp_f6(tfm_cmac, w, n1, n2, r, io_cap, a1, a2, res); 3489 if (err) 3490 return err; 3491 3492 if (memcmp(res, exp, 16)) 3493 return -EINVAL; 3494 3495 return 0; 3496 } 3497 3498 static int __init test_g2(struct crypto_hash *tfm_cmac) 3499 { 3500 const u8 u[32] = { 3501 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 3502 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 3503 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 3504 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 }; 3505 const u8 v[32] = { 3506 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b, 3507 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59, 3508 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90, 3509 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 }; 3510 const u8 x[16] = { 3511 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3512 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3513 const u8 y[16] = { 3514 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3515 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3516 const u32 exp_val = 0x2f9ed5ba % 1000000; 3517 u32 val; 3518 int err; 3519 3520 err = smp_g2(tfm_cmac, u, v, x, y, &val); 3521 if (err) 3522 return err; 3523 3524 if (val != exp_val) 3525 return -EINVAL; 3526 3527 return 0; 3528 } 3529 3530 static int __init test_h6(struct crypto_hash *tfm_cmac) 3531 { 3532 const u8 w[16] = { 3533 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3534 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3535 const u8 key_id[4] = { 0x72, 0x62, 0x65, 0x6c }; 3536 const u8 exp[16] = { 3537 0x99, 0x63, 0xb1, 0x80, 0xe2, 0xa9, 0xd3, 0xe8, 3538 0x1c, 0xc9, 0x6d, 0xe7, 0x02, 0xe1, 0x9a, 0x2d }; 3539 u8 res[16]; 3540 int err; 3541 3542 err = smp_h6(tfm_cmac, w, key_id, res); 3543 if (err) 3544 return err; 3545 3546 if (memcmp(res, exp, 16)) 3547 return -EINVAL; 3548 3549 return 0; 3550 } 3551 3552 static char test_smp_buffer[32]; 3553 3554 static ssize_t test_smp_read(struct file *file, char __user *user_buf, 3555 size_t count, loff_t *ppos) 3556 { 3557 return simple_read_from_buffer(user_buf, count, ppos, test_smp_buffer, 3558 strlen(test_smp_buffer)); 3559 } 3560 3561 static const struct file_operations test_smp_fops = { 3562 .open = simple_open, 3563 .read = test_smp_read, 3564 .llseek = default_llseek, 3565 }; 3566 3567 static int __init run_selftests(struct crypto_blkcipher *tfm_aes, 3568 struct crypto_hash *tfm_cmac) 3569 { 3570 ktime_t calltime, delta, rettime; 3571 unsigned long long duration; 3572 int err; 3573 3574 calltime = ktime_get(); 3575 3576 err = test_ah(tfm_aes); 3577 if (err) { 3578 BT_ERR("smp_ah test failed"); 3579 goto done; 3580 } 3581 3582 err = test_c1(tfm_aes); 3583 if (err) { 3584 BT_ERR("smp_c1 test failed"); 3585 goto done; 3586 } 3587 3588 err = test_s1(tfm_aes); 3589 if (err) { 3590 BT_ERR("smp_s1 test failed"); 3591 goto done; 3592 } 3593 3594 err = test_f4(tfm_cmac); 3595 if (err) { 3596 BT_ERR("smp_f4 test failed"); 3597 goto done; 3598 } 3599 3600 err = test_f5(tfm_cmac); 3601 if (err) { 3602 BT_ERR("smp_f5 test failed"); 3603 goto done; 3604 } 3605 3606 err = test_f6(tfm_cmac); 3607 if (err) { 3608 BT_ERR("smp_f6 test failed"); 3609 goto done; 3610 } 3611 3612 err = test_g2(tfm_cmac); 3613 if (err) { 3614 BT_ERR("smp_g2 test failed"); 3615 goto done; 3616 } 3617 3618 err = test_h6(tfm_cmac); 3619 if (err) { 3620 BT_ERR("smp_h6 test failed"); 3621 goto done; 3622 } 3623 3624 rettime = ktime_get(); 3625 delta = ktime_sub(rettime, calltime); 3626 duration = (unsigned long long) ktime_to_ns(delta) >> 10; 3627 3628 BT_INFO("SMP test passed in %llu usecs", duration); 3629 3630 done: 3631 if (!err) 3632 snprintf(test_smp_buffer, sizeof(test_smp_buffer), 3633 "PASS (%llu usecs)\n", duration); 3634 else 3635 snprintf(test_smp_buffer, sizeof(test_smp_buffer), "FAIL\n"); 3636 3637 debugfs_create_file("selftest_smp", 0444, bt_debugfs, NULL, 3638 &test_smp_fops); 3639 3640 return err; 3641 } 3642 3643 int __init bt_selftest_smp(void) 3644 { 3645 struct crypto_blkcipher *tfm_aes; 3646 struct crypto_hash *tfm_cmac; 3647 int err; 3648 3649 tfm_aes = crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC); 3650 if (IS_ERR(tfm_aes)) { 3651 BT_ERR("Unable to create ECB crypto context"); 3652 return PTR_ERR(tfm_aes); 3653 } 3654 3655 tfm_cmac = crypto_alloc_hash("cmac(aes)", 0, CRYPTO_ALG_ASYNC); 3656 if (IS_ERR(tfm_cmac)) { 3657 BT_ERR("Unable to create CMAC crypto context"); 3658 crypto_free_blkcipher(tfm_aes); 3659 return PTR_ERR(tfm_cmac); 3660 } 3661 3662 err = run_selftests(tfm_aes, tfm_cmac); 3663 3664 crypto_free_hash(tfm_cmac); 3665 crypto_free_blkcipher(tfm_aes); 3666 3667 return err; 3668 } 3669 3670 #endif 3671