1 /* 2 BlueZ - Bluetooth protocol stack for Linux 3 Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). 4 5 This program is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License version 2 as 7 published by the Free Software Foundation; 8 9 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 10 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 11 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. 12 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY 13 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES 14 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 18 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS, 19 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS 20 SOFTWARE IS DISCLAIMED. 21 */ 22 23 #include <linux/debugfs.h> 24 #include <linux/scatterlist.h> 25 #include <linux/crypto.h> 26 #include <crypto/algapi.h> 27 #include <crypto/b128ops.h> 28 #include <crypto/hash.h> 29 #include <crypto/kpp.h> 30 31 #include <net/bluetooth/bluetooth.h> 32 #include <net/bluetooth/hci_core.h> 33 #include <net/bluetooth/l2cap.h> 34 #include <net/bluetooth/mgmt.h> 35 36 #include "ecdh_helper.h" 37 #include "smp.h" 38 39 #define SMP_DEV(hdev) \ 40 ((struct smp_dev *)((struct l2cap_chan *)((hdev)->smp_data))->data) 41 42 /* Low-level debug macros to be used for stuff that we don't want 43 * accidentially in dmesg, i.e. the values of the various crypto keys 44 * and the inputs & outputs of crypto functions. 45 */ 46 #ifdef DEBUG 47 #define SMP_DBG(fmt, ...) printk(KERN_DEBUG "%s: " fmt, __func__, \ 48 ##__VA_ARGS__) 49 #else 50 #define SMP_DBG(fmt, ...) no_printk(KERN_DEBUG "%s: " fmt, __func__, \ 51 ##__VA_ARGS__) 52 #endif 53 54 #define SMP_ALLOW_CMD(smp, code) set_bit(code, &smp->allow_cmd) 55 56 /* Keys which are not distributed with Secure Connections */ 57 #define SMP_SC_NO_DIST (SMP_DIST_ENC_KEY | SMP_DIST_LINK_KEY); 58 59 #define SMP_TIMEOUT msecs_to_jiffies(30000) 60 61 #define AUTH_REQ_MASK(dev) (hci_dev_test_flag(dev, HCI_SC_ENABLED) ? \ 62 0x3f : 0x07) 63 #define KEY_DIST_MASK 0x07 64 65 /* Maximum message length that can be passed to aes_cmac */ 66 #define CMAC_MSG_MAX 80 67 68 enum { 69 SMP_FLAG_TK_VALID, 70 SMP_FLAG_CFM_PENDING, 71 SMP_FLAG_MITM_AUTH, 72 SMP_FLAG_COMPLETE, 73 SMP_FLAG_INITIATOR, 74 SMP_FLAG_SC, 75 SMP_FLAG_REMOTE_PK, 76 SMP_FLAG_DEBUG_KEY, 77 SMP_FLAG_WAIT_USER, 78 SMP_FLAG_DHKEY_PENDING, 79 SMP_FLAG_REMOTE_OOB, 80 SMP_FLAG_LOCAL_OOB, 81 SMP_FLAG_CT2, 82 }; 83 84 struct smp_dev { 85 /* Secure Connections OOB data */ 86 bool local_oob; 87 u8 local_pk[64]; 88 u8 local_rand[16]; 89 bool debug_key; 90 91 u8 min_key_size; 92 u8 max_key_size; 93 94 struct crypto_cipher *tfm_aes; 95 struct crypto_shash *tfm_cmac; 96 struct crypto_kpp *tfm_ecdh; 97 }; 98 99 struct smp_chan { 100 struct l2cap_conn *conn; 101 struct delayed_work security_timer; 102 unsigned long allow_cmd; /* Bitmask of allowed commands */ 103 104 u8 preq[7]; /* SMP Pairing Request */ 105 u8 prsp[7]; /* SMP Pairing Response */ 106 u8 prnd[16]; /* SMP Pairing Random (local) */ 107 u8 rrnd[16]; /* SMP Pairing Random (remote) */ 108 u8 pcnf[16]; /* SMP Pairing Confirm */ 109 u8 tk[16]; /* SMP Temporary Key */ 110 u8 rr[16]; /* Remote OOB ra/rb value */ 111 u8 lr[16]; /* Local OOB ra/rb value */ 112 u8 enc_key_size; 113 u8 remote_key_dist; 114 bdaddr_t id_addr; 115 u8 id_addr_type; 116 u8 irk[16]; 117 struct smp_csrk *csrk; 118 struct smp_csrk *slave_csrk; 119 struct smp_ltk *ltk; 120 struct smp_ltk *slave_ltk; 121 struct smp_irk *remote_irk; 122 u8 *link_key; 123 unsigned long flags; 124 u8 method; 125 u8 passkey_round; 126 127 /* Secure Connections variables */ 128 u8 local_pk[64]; 129 u8 remote_pk[64]; 130 u8 dhkey[32]; 131 u8 mackey[16]; 132 133 struct crypto_cipher *tfm_aes; 134 struct crypto_shash *tfm_cmac; 135 struct crypto_kpp *tfm_ecdh; 136 }; 137 138 /* These debug key values are defined in the SMP section of the core 139 * specification. debug_pk is the public debug key and debug_sk the 140 * private debug key. 141 */ 142 static const u8 debug_pk[64] = { 143 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 144 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 145 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 146 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20, 147 148 0x8b, 0xd2, 0x89, 0x15, 0xd0, 0x8e, 0x1c, 0x74, 149 0x24, 0x30, 0xed, 0x8f, 0xc2, 0x45, 0x63, 0x76, 150 0x5c, 0x15, 0x52, 0x5a, 0xbf, 0x9a, 0x32, 0x63, 151 0x6d, 0xeb, 0x2a, 0x65, 0x49, 0x9c, 0x80, 0xdc, 152 }; 153 154 static const u8 debug_sk[32] = { 155 0xbd, 0x1a, 0x3c, 0xcd, 0xa6, 0xb8, 0x99, 0x58, 156 0x99, 0xb7, 0x40, 0xeb, 0x7b, 0x60, 0xff, 0x4a, 157 0x50, 0x3f, 0x10, 0xd2, 0xe3, 0xb3, 0xc9, 0x74, 158 0x38, 0x5f, 0xc5, 0xa3, 0xd4, 0xf6, 0x49, 0x3f, 159 }; 160 161 static inline void swap_buf(const u8 *src, u8 *dst, size_t len) 162 { 163 size_t i; 164 165 for (i = 0; i < len; i++) 166 dst[len - 1 - i] = src[i]; 167 } 168 169 /* The following functions map to the LE SC SMP crypto functions 170 * AES-CMAC, f4, f5, f6, g2 and h6. 171 */ 172 173 static int aes_cmac(struct crypto_shash *tfm, const u8 k[16], const u8 *m, 174 size_t len, u8 mac[16]) 175 { 176 uint8_t tmp[16], mac_msb[16], msg_msb[CMAC_MSG_MAX]; 177 SHASH_DESC_ON_STACK(desc, tfm); 178 int err; 179 180 if (len > CMAC_MSG_MAX) 181 return -EFBIG; 182 183 if (!tfm) { 184 BT_ERR("tfm %p", tfm); 185 return -EINVAL; 186 } 187 188 desc->tfm = tfm; 189 desc->flags = 0; 190 191 /* Swap key and message from LSB to MSB */ 192 swap_buf(k, tmp, 16); 193 swap_buf(m, msg_msb, len); 194 195 SMP_DBG("msg (len %zu) %*phN", len, (int) len, m); 196 SMP_DBG("key %16phN", k); 197 198 err = crypto_shash_setkey(tfm, tmp, 16); 199 if (err) { 200 BT_ERR("cipher setkey failed: %d", err); 201 return err; 202 } 203 204 err = crypto_shash_digest(desc, msg_msb, len, mac_msb); 205 shash_desc_zero(desc); 206 if (err) { 207 BT_ERR("Hash computation error %d", err); 208 return err; 209 } 210 211 swap_buf(mac_msb, mac, 16); 212 213 SMP_DBG("mac %16phN", mac); 214 215 return 0; 216 } 217 218 static int smp_f4(struct crypto_shash *tfm_cmac, const u8 u[32], 219 const u8 v[32], const u8 x[16], u8 z, u8 res[16]) 220 { 221 u8 m[65]; 222 int err; 223 224 SMP_DBG("u %32phN", u); 225 SMP_DBG("v %32phN", v); 226 SMP_DBG("x %16phN z %02x", x, z); 227 228 m[0] = z; 229 memcpy(m + 1, v, 32); 230 memcpy(m + 33, u, 32); 231 232 err = aes_cmac(tfm_cmac, x, m, sizeof(m), res); 233 if (err) 234 return err; 235 236 SMP_DBG("res %16phN", res); 237 238 return err; 239 } 240 241 static int smp_f5(struct crypto_shash *tfm_cmac, const u8 w[32], 242 const u8 n1[16], const u8 n2[16], const u8 a1[7], 243 const u8 a2[7], u8 mackey[16], u8 ltk[16]) 244 { 245 /* The btle, salt and length "magic" values are as defined in 246 * the SMP section of the Bluetooth core specification. In ASCII 247 * the btle value ends up being 'btle'. The salt is just a 248 * random number whereas length is the value 256 in little 249 * endian format. 250 */ 251 const u8 btle[4] = { 0x65, 0x6c, 0x74, 0x62 }; 252 const u8 salt[16] = { 0xbe, 0x83, 0x60, 0x5a, 0xdb, 0x0b, 0x37, 0x60, 253 0x38, 0xa5, 0xf5, 0xaa, 0x91, 0x83, 0x88, 0x6c }; 254 const u8 length[2] = { 0x00, 0x01 }; 255 u8 m[53], t[16]; 256 int err; 257 258 SMP_DBG("w %32phN", w); 259 SMP_DBG("n1 %16phN n2 %16phN", n1, n2); 260 SMP_DBG("a1 %7phN a2 %7phN", a1, a2); 261 262 err = aes_cmac(tfm_cmac, salt, w, 32, t); 263 if (err) 264 return err; 265 266 SMP_DBG("t %16phN", t); 267 268 memcpy(m, length, 2); 269 memcpy(m + 2, a2, 7); 270 memcpy(m + 9, a1, 7); 271 memcpy(m + 16, n2, 16); 272 memcpy(m + 32, n1, 16); 273 memcpy(m + 48, btle, 4); 274 275 m[52] = 0; /* Counter */ 276 277 err = aes_cmac(tfm_cmac, t, m, sizeof(m), mackey); 278 if (err) 279 return err; 280 281 SMP_DBG("mackey %16phN", mackey); 282 283 m[52] = 1; /* Counter */ 284 285 err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk); 286 if (err) 287 return err; 288 289 SMP_DBG("ltk %16phN", ltk); 290 291 return 0; 292 } 293 294 static int smp_f6(struct crypto_shash *tfm_cmac, const u8 w[16], 295 const u8 n1[16], const u8 n2[16], const u8 r[16], 296 const u8 io_cap[3], const u8 a1[7], const u8 a2[7], 297 u8 res[16]) 298 { 299 u8 m[65]; 300 int err; 301 302 SMP_DBG("w %16phN", w); 303 SMP_DBG("n1 %16phN n2 %16phN", n1, n2); 304 SMP_DBG("r %16phN io_cap %3phN a1 %7phN a2 %7phN", r, io_cap, a1, a2); 305 306 memcpy(m, a2, 7); 307 memcpy(m + 7, a1, 7); 308 memcpy(m + 14, io_cap, 3); 309 memcpy(m + 17, r, 16); 310 memcpy(m + 33, n2, 16); 311 memcpy(m + 49, n1, 16); 312 313 err = aes_cmac(tfm_cmac, w, m, sizeof(m), res); 314 if (err) 315 return err; 316 317 SMP_DBG("res %16phN", res); 318 319 return err; 320 } 321 322 static int smp_g2(struct crypto_shash *tfm_cmac, const u8 u[32], const u8 v[32], 323 const u8 x[16], const u8 y[16], u32 *val) 324 { 325 u8 m[80], tmp[16]; 326 int err; 327 328 SMP_DBG("u %32phN", u); 329 SMP_DBG("v %32phN", v); 330 SMP_DBG("x %16phN y %16phN", x, y); 331 332 memcpy(m, y, 16); 333 memcpy(m + 16, v, 32); 334 memcpy(m + 48, u, 32); 335 336 err = aes_cmac(tfm_cmac, x, m, sizeof(m), tmp); 337 if (err) 338 return err; 339 340 *val = get_unaligned_le32(tmp); 341 *val %= 1000000; 342 343 SMP_DBG("val %06u", *val); 344 345 return 0; 346 } 347 348 static int smp_h6(struct crypto_shash *tfm_cmac, const u8 w[16], 349 const u8 key_id[4], u8 res[16]) 350 { 351 int err; 352 353 SMP_DBG("w %16phN key_id %4phN", w, key_id); 354 355 err = aes_cmac(tfm_cmac, w, key_id, 4, res); 356 if (err) 357 return err; 358 359 SMP_DBG("res %16phN", res); 360 361 return err; 362 } 363 364 static int smp_h7(struct crypto_shash *tfm_cmac, const u8 w[16], 365 const u8 salt[16], u8 res[16]) 366 { 367 int err; 368 369 SMP_DBG("w %16phN salt %16phN", w, salt); 370 371 err = aes_cmac(tfm_cmac, salt, w, 16, res); 372 if (err) 373 return err; 374 375 SMP_DBG("res %16phN", res); 376 377 return err; 378 } 379 380 /* The following functions map to the legacy SMP crypto functions e, c1, 381 * s1 and ah. 382 */ 383 384 static int smp_e(struct crypto_cipher *tfm, const u8 *k, u8 *r) 385 { 386 uint8_t tmp[16], data[16]; 387 int err; 388 389 SMP_DBG("k %16phN r %16phN", k, r); 390 391 if (!tfm) { 392 BT_ERR("tfm %p", tfm); 393 return -EINVAL; 394 } 395 396 /* The most significant octet of key corresponds to k[0] */ 397 swap_buf(k, tmp, 16); 398 399 err = crypto_cipher_setkey(tfm, tmp, 16); 400 if (err) { 401 BT_ERR("cipher setkey failed: %d", err); 402 return err; 403 } 404 405 /* Most significant octet of plaintextData corresponds to data[0] */ 406 swap_buf(r, data, 16); 407 408 crypto_cipher_encrypt_one(tfm, data, data); 409 410 /* Most significant octet of encryptedData corresponds to data[0] */ 411 swap_buf(data, r, 16); 412 413 SMP_DBG("r %16phN", r); 414 415 return err; 416 } 417 418 static int smp_c1(struct crypto_cipher *tfm_aes, const u8 k[16], 419 const u8 r[16], const u8 preq[7], const u8 pres[7], u8 _iat, 420 const bdaddr_t *ia, u8 _rat, const bdaddr_t *ra, u8 res[16]) 421 { 422 u8 p1[16], p2[16]; 423 int err; 424 425 SMP_DBG("k %16phN r %16phN", k, r); 426 SMP_DBG("iat %u ia %6phN rat %u ra %6phN", _iat, ia, _rat, ra); 427 SMP_DBG("preq %7phN pres %7phN", preq, pres); 428 429 memset(p1, 0, 16); 430 431 /* p1 = pres || preq || _rat || _iat */ 432 p1[0] = _iat; 433 p1[1] = _rat; 434 memcpy(p1 + 2, preq, 7); 435 memcpy(p1 + 9, pres, 7); 436 437 SMP_DBG("p1 %16phN", p1); 438 439 /* res = r XOR p1 */ 440 u128_xor((u128 *) res, (u128 *) r, (u128 *) p1); 441 442 /* res = e(k, res) */ 443 err = smp_e(tfm_aes, k, res); 444 if (err) { 445 BT_ERR("Encrypt data error"); 446 return err; 447 } 448 449 /* p2 = padding || ia || ra */ 450 memcpy(p2, ra, 6); 451 memcpy(p2 + 6, ia, 6); 452 memset(p2 + 12, 0, 4); 453 454 SMP_DBG("p2 %16phN", p2); 455 456 /* res = res XOR p2 */ 457 u128_xor((u128 *) res, (u128 *) res, (u128 *) p2); 458 459 /* res = e(k, res) */ 460 err = smp_e(tfm_aes, k, res); 461 if (err) 462 BT_ERR("Encrypt data error"); 463 464 return err; 465 } 466 467 static int smp_s1(struct crypto_cipher *tfm_aes, const u8 k[16], 468 const u8 r1[16], const u8 r2[16], u8 _r[16]) 469 { 470 int err; 471 472 /* Just least significant octets from r1 and r2 are considered */ 473 memcpy(_r, r2, 8); 474 memcpy(_r + 8, r1, 8); 475 476 err = smp_e(tfm_aes, k, _r); 477 if (err) 478 BT_ERR("Encrypt data error"); 479 480 return err; 481 } 482 483 static int smp_ah(struct crypto_cipher *tfm, const u8 irk[16], 484 const u8 r[3], u8 res[3]) 485 { 486 u8 _res[16]; 487 int err; 488 489 /* r' = padding || r */ 490 memcpy(_res, r, 3); 491 memset(_res + 3, 0, 13); 492 493 err = smp_e(tfm, irk, _res); 494 if (err) { 495 BT_ERR("Encrypt error"); 496 return err; 497 } 498 499 /* The output of the random address function ah is: 500 * ah(k, r) = e(k, r') mod 2^24 501 * The output of the security function e is then truncated to 24 bits 502 * by taking the least significant 24 bits of the output of e as the 503 * result of ah. 504 */ 505 memcpy(res, _res, 3); 506 507 return 0; 508 } 509 510 bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16], 511 const bdaddr_t *bdaddr) 512 { 513 struct l2cap_chan *chan = hdev->smp_data; 514 struct smp_dev *smp; 515 u8 hash[3]; 516 int err; 517 518 if (!chan || !chan->data) 519 return false; 520 521 smp = chan->data; 522 523 BT_DBG("RPA %pMR IRK %*phN", bdaddr, 16, irk); 524 525 err = smp_ah(smp->tfm_aes, irk, &bdaddr->b[3], hash); 526 if (err) 527 return false; 528 529 return !crypto_memneq(bdaddr->b, hash, 3); 530 } 531 532 int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa) 533 { 534 struct l2cap_chan *chan = hdev->smp_data; 535 struct smp_dev *smp; 536 int err; 537 538 if (!chan || !chan->data) 539 return -EOPNOTSUPP; 540 541 smp = chan->data; 542 543 get_random_bytes(&rpa->b[3], 3); 544 545 rpa->b[5] &= 0x3f; /* Clear two most significant bits */ 546 rpa->b[5] |= 0x40; /* Set second most significant bit */ 547 548 err = smp_ah(smp->tfm_aes, irk, &rpa->b[3], rpa->b); 549 if (err < 0) 550 return err; 551 552 BT_DBG("RPA %pMR", rpa); 553 554 return 0; 555 } 556 557 int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16]) 558 { 559 struct l2cap_chan *chan = hdev->smp_data; 560 struct smp_dev *smp; 561 int err; 562 563 if (!chan || !chan->data) 564 return -EOPNOTSUPP; 565 566 smp = chan->data; 567 568 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { 569 BT_DBG("Using debug keys"); 570 err = set_ecdh_privkey(smp->tfm_ecdh, debug_sk); 571 if (err) 572 return err; 573 memcpy(smp->local_pk, debug_pk, 64); 574 smp->debug_key = true; 575 } else { 576 while (true) { 577 /* Generate key pair for Secure Connections */ 578 err = generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk); 579 if (err) 580 return err; 581 582 /* This is unlikely, but we need to check that 583 * we didn't accidentially generate a debug key. 584 */ 585 if (crypto_memneq(smp->local_pk, debug_pk, 64)) 586 break; 587 } 588 smp->debug_key = false; 589 } 590 591 SMP_DBG("OOB Public Key X: %32phN", smp->local_pk); 592 SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32); 593 594 get_random_bytes(smp->local_rand, 16); 595 596 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->local_pk, 597 smp->local_rand, 0, hash); 598 if (err < 0) 599 return err; 600 601 memcpy(rand, smp->local_rand, 16); 602 603 smp->local_oob = true; 604 605 return 0; 606 } 607 608 static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data) 609 { 610 struct l2cap_chan *chan = conn->smp; 611 struct smp_chan *smp; 612 struct kvec iv[2]; 613 struct msghdr msg; 614 615 if (!chan) 616 return; 617 618 BT_DBG("code 0x%2.2x", code); 619 620 iv[0].iov_base = &code; 621 iv[0].iov_len = 1; 622 623 iv[1].iov_base = data; 624 iv[1].iov_len = len; 625 626 memset(&msg, 0, sizeof(msg)); 627 628 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iv, 2, 1 + len); 629 630 l2cap_chan_send(chan, &msg, 1 + len); 631 632 if (!chan->data) 633 return; 634 635 smp = chan->data; 636 637 cancel_delayed_work_sync(&smp->security_timer); 638 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT); 639 } 640 641 static u8 authreq_to_seclevel(u8 authreq) 642 { 643 if (authreq & SMP_AUTH_MITM) { 644 if (authreq & SMP_AUTH_SC) 645 return BT_SECURITY_FIPS; 646 else 647 return BT_SECURITY_HIGH; 648 } else { 649 return BT_SECURITY_MEDIUM; 650 } 651 } 652 653 static __u8 seclevel_to_authreq(__u8 sec_level) 654 { 655 switch (sec_level) { 656 case BT_SECURITY_FIPS: 657 case BT_SECURITY_HIGH: 658 return SMP_AUTH_MITM | SMP_AUTH_BONDING; 659 case BT_SECURITY_MEDIUM: 660 return SMP_AUTH_BONDING; 661 default: 662 return SMP_AUTH_NONE; 663 } 664 } 665 666 static void build_pairing_cmd(struct l2cap_conn *conn, 667 struct smp_cmd_pairing *req, 668 struct smp_cmd_pairing *rsp, __u8 authreq) 669 { 670 struct l2cap_chan *chan = conn->smp; 671 struct smp_chan *smp = chan->data; 672 struct hci_conn *hcon = conn->hcon; 673 struct hci_dev *hdev = hcon->hdev; 674 u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT; 675 676 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { 677 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 678 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 679 authreq |= SMP_AUTH_BONDING; 680 } else { 681 authreq &= ~SMP_AUTH_BONDING; 682 } 683 684 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) 685 remote_dist |= SMP_DIST_ID_KEY; 686 687 if (hci_dev_test_flag(hdev, HCI_PRIVACY)) 688 local_dist |= SMP_DIST_ID_KEY; 689 690 if (hci_dev_test_flag(hdev, HCI_SC_ENABLED) && 691 (authreq & SMP_AUTH_SC)) { 692 struct oob_data *oob_data; 693 u8 bdaddr_type; 694 695 if (hci_dev_test_flag(hdev, HCI_SSP_ENABLED)) { 696 local_dist |= SMP_DIST_LINK_KEY; 697 remote_dist |= SMP_DIST_LINK_KEY; 698 } 699 700 if (hcon->dst_type == ADDR_LE_DEV_PUBLIC) 701 bdaddr_type = BDADDR_LE_PUBLIC; 702 else 703 bdaddr_type = BDADDR_LE_RANDOM; 704 705 oob_data = hci_find_remote_oob_data(hdev, &hcon->dst, 706 bdaddr_type); 707 if (oob_data && oob_data->present) { 708 set_bit(SMP_FLAG_REMOTE_OOB, &smp->flags); 709 oob_flag = SMP_OOB_PRESENT; 710 memcpy(smp->rr, oob_data->rand256, 16); 711 memcpy(smp->pcnf, oob_data->hash256, 16); 712 SMP_DBG("OOB Remote Confirmation: %16phN", smp->pcnf); 713 SMP_DBG("OOB Remote Random: %16phN", smp->rr); 714 } 715 716 } else { 717 authreq &= ~SMP_AUTH_SC; 718 } 719 720 if (rsp == NULL) { 721 req->io_capability = conn->hcon->io_capability; 722 req->oob_flag = oob_flag; 723 req->max_key_size = SMP_DEV(hdev)->max_key_size; 724 req->init_key_dist = local_dist; 725 req->resp_key_dist = remote_dist; 726 req->auth_req = (authreq & AUTH_REQ_MASK(hdev)); 727 728 smp->remote_key_dist = remote_dist; 729 return; 730 } 731 732 rsp->io_capability = conn->hcon->io_capability; 733 rsp->oob_flag = oob_flag; 734 rsp->max_key_size = SMP_DEV(hdev)->max_key_size; 735 rsp->init_key_dist = req->init_key_dist & remote_dist; 736 rsp->resp_key_dist = req->resp_key_dist & local_dist; 737 rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev)); 738 739 smp->remote_key_dist = rsp->init_key_dist; 740 } 741 742 static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size) 743 { 744 struct l2cap_chan *chan = conn->smp; 745 struct hci_dev *hdev = conn->hcon->hdev; 746 struct smp_chan *smp = chan->data; 747 748 if (max_key_size > SMP_DEV(hdev)->max_key_size || 749 max_key_size < SMP_MIN_ENC_KEY_SIZE) 750 return SMP_ENC_KEY_SIZE; 751 752 smp->enc_key_size = max_key_size; 753 754 return 0; 755 } 756 757 static void smp_chan_destroy(struct l2cap_conn *conn) 758 { 759 struct l2cap_chan *chan = conn->smp; 760 struct smp_chan *smp = chan->data; 761 struct hci_conn *hcon = conn->hcon; 762 bool complete; 763 764 BUG_ON(!smp); 765 766 cancel_delayed_work_sync(&smp->security_timer); 767 768 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags); 769 mgmt_smp_complete(hcon, complete); 770 771 kzfree(smp->csrk); 772 kzfree(smp->slave_csrk); 773 kzfree(smp->link_key); 774 775 crypto_free_cipher(smp->tfm_aes); 776 crypto_free_shash(smp->tfm_cmac); 777 crypto_free_kpp(smp->tfm_ecdh); 778 779 /* Ensure that we don't leave any debug key around if debug key 780 * support hasn't been explicitly enabled. 781 */ 782 if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG && 783 !hci_dev_test_flag(hcon->hdev, HCI_KEEP_DEBUG_KEYS)) { 784 list_del_rcu(&smp->ltk->list); 785 kfree_rcu(smp->ltk, rcu); 786 smp->ltk = NULL; 787 } 788 789 /* If pairing failed clean up any keys we might have */ 790 if (!complete) { 791 if (smp->ltk) { 792 list_del_rcu(&smp->ltk->list); 793 kfree_rcu(smp->ltk, rcu); 794 } 795 796 if (smp->slave_ltk) { 797 list_del_rcu(&smp->slave_ltk->list); 798 kfree_rcu(smp->slave_ltk, rcu); 799 } 800 801 if (smp->remote_irk) { 802 list_del_rcu(&smp->remote_irk->list); 803 kfree_rcu(smp->remote_irk, rcu); 804 } 805 } 806 807 chan->data = NULL; 808 kzfree(smp); 809 hci_conn_drop(hcon); 810 } 811 812 static void smp_failure(struct l2cap_conn *conn, u8 reason) 813 { 814 struct hci_conn *hcon = conn->hcon; 815 struct l2cap_chan *chan = conn->smp; 816 817 if (reason) 818 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason), 819 &reason); 820 821 mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE); 822 823 if (chan->data) 824 smp_chan_destroy(conn); 825 } 826 827 #define JUST_WORKS 0x00 828 #define JUST_CFM 0x01 829 #define REQ_PASSKEY 0x02 830 #define CFM_PASSKEY 0x03 831 #define REQ_OOB 0x04 832 #define DSP_PASSKEY 0x05 833 #define OVERLAP 0xFF 834 835 static const u8 gen_method[5][5] = { 836 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 837 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 838 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 839 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM }, 840 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP }, 841 }; 842 843 static const u8 sc_method[5][5] = { 844 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 845 { JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 846 { DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY }, 847 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM }, 848 { DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 849 }; 850 851 static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io) 852 { 853 /* If either side has unknown io_caps, use JUST_CFM (which gets 854 * converted later to JUST_WORKS if we're initiators. 855 */ 856 if (local_io > SMP_IO_KEYBOARD_DISPLAY || 857 remote_io > SMP_IO_KEYBOARD_DISPLAY) 858 return JUST_CFM; 859 860 if (test_bit(SMP_FLAG_SC, &smp->flags)) 861 return sc_method[remote_io][local_io]; 862 863 return gen_method[remote_io][local_io]; 864 } 865 866 static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth, 867 u8 local_io, u8 remote_io) 868 { 869 struct hci_conn *hcon = conn->hcon; 870 struct l2cap_chan *chan = conn->smp; 871 struct smp_chan *smp = chan->data; 872 u32 passkey = 0; 873 int ret = 0; 874 875 /* Initialize key for JUST WORKS */ 876 memset(smp->tk, 0, sizeof(smp->tk)); 877 clear_bit(SMP_FLAG_TK_VALID, &smp->flags); 878 879 BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io); 880 881 /* If neither side wants MITM, either "just" confirm an incoming 882 * request or use just-works for outgoing ones. The JUST_CFM 883 * will be converted to JUST_WORKS if necessary later in this 884 * function. If either side has MITM look up the method from the 885 * table. 886 */ 887 if (!(auth & SMP_AUTH_MITM)) 888 smp->method = JUST_CFM; 889 else 890 smp->method = get_auth_method(smp, local_io, remote_io); 891 892 /* Don't confirm locally initiated pairing attempts */ 893 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, 894 &smp->flags)) 895 smp->method = JUST_WORKS; 896 897 /* Don't bother user space with no IO capabilities */ 898 if (smp->method == JUST_CFM && 899 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 900 smp->method = JUST_WORKS; 901 902 /* If Just Works, Continue with Zero TK */ 903 if (smp->method == JUST_WORKS) { 904 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 905 return 0; 906 } 907 908 /* If this function is used for SC -> legacy fallback we 909 * can only recover the just-works case. 910 */ 911 if (test_bit(SMP_FLAG_SC, &smp->flags)) 912 return -EINVAL; 913 914 /* Not Just Works/Confirm results in MITM Authentication */ 915 if (smp->method != JUST_CFM) { 916 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags); 917 if (hcon->pending_sec_level < BT_SECURITY_HIGH) 918 hcon->pending_sec_level = BT_SECURITY_HIGH; 919 } 920 921 /* If both devices have Keyoard-Display I/O, the master 922 * Confirms and the slave Enters the passkey. 923 */ 924 if (smp->method == OVERLAP) { 925 if (hcon->role == HCI_ROLE_MASTER) 926 smp->method = CFM_PASSKEY; 927 else 928 smp->method = REQ_PASSKEY; 929 } 930 931 /* Generate random passkey. */ 932 if (smp->method == CFM_PASSKEY) { 933 memset(smp->tk, 0, sizeof(smp->tk)); 934 get_random_bytes(&passkey, sizeof(passkey)); 935 passkey %= 1000000; 936 put_unaligned_le32(passkey, smp->tk); 937 BT_DBG("PassKey: %d", passkey); 938 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 939 } 940 941 if (smp->method == REQ_PASSKEY) 942 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst, 943 hcon->type, hcon->dst_type); 944 else if (smp->method == JUST_CFM) 945 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, 946 hcon->type, hcon->dst_type, 947 passkey, 1); 948 else 949 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst, 950 hcon->type, hcon->dst_type, 951 passkey, 0); 952 953 return ret; 954 } 955 956 static u8 smp_confirm(struct smp_chan *smp) 957 { 958 struct l2cap_conn *conn = smp->conn; 959 struct smp_cmd_pairing_confirm cp; 960 int ret; 961 962 BT_DBG("conn %p", conn); 963 964 ret = smp_c1(smp->tfm_aes, smp->tk, smp->prnd, smp->preq, smp->prsp, 965 conn->hcon->init_addr_type, &conn->hcon->init_addr, 966 conn->hcon->resp_addr_type, &conn->hcon->resp_addr, 967 cp.confirm_val); 968 if (ret) 969 return SMP_UNSPECIFIED; 970 971 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 972 973 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp); 974 975 if (conn->hcon->out) 976 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 977 else 978 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 979 980 return 0; 981 } 982 983 static u8 smp_random(struct smp_chan *smp) 984 { 985 struct l2cap_conn *conn = smp->conn; 986 struct hci_conn *hcon = conn->hcon; 987 u8 confirm[16]; 988 int ret; 989 990 if (IS_ERR_OR_NULL(smp->tfm_aes)) 991 return SMP_UNSPECIFIED; 992 993 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave"); 994 995 ret = smp_c1(smp->tfm_aes, smp->tk, smp->rrnd, smp->preq, smp->prsp, 996 hcon->init_addr_type, &hcon->init_addr, 997 hcon->resp_addr_type, &hcon->resp_addr, confirm); 998 if (ret) 999 return SMP_UNSPECIFIED; 1000 1001 if (crypto_memneq(smp->pcnf, confirm, sizeof(smp->pcnf))) { 1002 bt_dev_err(hcon->hdev, "pairing failed " 1003 "(confirmation values mismatch)"); 1004 return SMP_CONFIRM_FAILED; 1005 } 1006 1007 if (hcon->out) { 1008 u8 stk[16]; 1009 __le64 rand = 0; 1010 __le16 ediv = 0; 1011 1012 smp_s1(smp->tfm_aes, smp->tk, smp->rrnd, smp->prnd, stk); 1013 1014 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) 1015 return SMP_UNSPECIFIED; 1016 1017 hci_le_start_enc(hcon, ediv, rand, stk, smp->enc_key_size); 1018 hcon->enc_key_size = smp->enc_key_size; 1019 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); 1020 } else { 1021 u8 stk[16], auth; 1022 __le64 rand = 0; 1023 __le16 ediv = 0; 1024 1025 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 1026 smp->prnd); 1027 1028 smp_s1(smp->tfm_aes, smp->tk, smp->prnd, smp->rrnd, stk); 1029 1030 if (hcon->pending_sec_level == BT_SECURITY_HIGH) 1031 auth = 1; 1032 else 1033 auth = 0; 1034 1035 /* Even though there's no _SLAVE suffix this is the 1036 * slave STK we're adding for later lookup (the master 1037 * STK never needs to be stored). 1038 */ 1039 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 1040 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand); 1041 } 1042 1043 return 0; 1044 } 1045 1046 static void smp_notify_keys(struct l2cap_conn *conn) 1047 { 1048 struct l2cap_chan *chan = conn->smp; 1049 struct smp_chan *smp = chan->data; 1050 struct hci_conn *hcon = conn->hcon; 1051 struct hci_dev *hdev = hcon->hdev; 1052 struct smp_cmd_pairing *req = (void *) &smp->preq[1]; 1053 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1]; 1054 bool persistent; 1055 1056 if (hcon->type == ACL_LINK) { 1057 if (hcon->key_type == HCI_LK_DEBUG_COMBINATION) 1058 persistent = false; 1059 else 1060 persistent = !test_bit(HCI_CONN_FLUSH_KEY, 1061 &hcon->flags); 1062 } else { 1063 /* The LTKs, IRKs and CSRKs should be persistent only if 1064 * both sides had the bonding bit set in their 1065 * authentication requests. 1066 */ 1067 persistent = !!((req->auth_req & rsp->auth_req) & 1068 SMP_AUTH_BONDING); 1069 } 1070 1071 if (smp->remote_irk) { 1072 mgmt_new_irk(hdev, smp->remote_irk, persistent); 1073 1074 /* Now that user space can be considered to know the 1075 * identity address track the connection based on it 1076 * from now on (assuming this is an LE link). 1077 */ 1078 if (hcon->type == LE_LINK) { 1079 bacpy(&hcon->dst, &smp->remote_irk->bdaddr); 1080 hcon->dst_type = smp->remote_irk->addr_type; 1081 queue_work(hdev->workqueue, &conn->id_addr_update_work); 1082 } 1083 } 1084 1085 if (smp->csrk) { 1086 smp->csrk->bdaddr_type = hcon->dst_type; 1087 bacpy(&smp->csrk->bdaddr, &hcon->dst); 1088 mgmt_new_csrk(hdev, smp->csrk, persistent); 1089 } 1090 1091 if (smp->slave_csrk) { 1092 smp->slave_csrk->bdaddr_type = hcon->dst_type; 1093 bacpy(&smp->slave_csrk->bdaddr, &hcon->dst); 1094 mgmt_new_csrk(hdev, smp->slave_csrk, persistent); 1095 } 1096 1097 if (smp->ltk) { 1098 smp->ltk->bdaddr_type = hcon->dst_type; 1099 bacpy(&smp->ltk->bdaddr, &hcon->dst); 1100 mgmt_new_ltk(hdev, smp->ltk, persistent); 1101 } 1102 1103 if (smp->slave_ltk) { 1104 smp->slave_ltk->bdaddr_type = hcon->dst_type; 1105 bacpy(&smp->slave_ltk->bdaddr, &hcon->dst); 1106 mgmt_new_ltk(hdev, smp->slave_ltk, persistent); 1107 } 1108 1109 if (smp->link_key) { 1110 struct link_key *key; 1111 u8 type; 1112 1113 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags)) 1114 type = HCI_LK_DEBUG_COMBINATION; 1115 else if (hcon->sec_level == BT_SECURITY_FIPS) 1116 type = HCI_LK_AUTH_COMBINATION_P256; 1117 else 1118 type = HCI_LK_UNAUTH_COMBINATION_P256; 1119 1120 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst, 1121 smp->link_key, type, 0, &persistent); 1122 if (key) { 1123 mgmt_new_link_key(hdev, key, persistent); 1124 1125 /* Don't keep debug keys around if the relevant 1126 * flag is not set. 1127 */ 1128 if (!hci_dev_test_flag(hdev, HCI_KEEP_DEBUG_KEYS) && 1129 key->type == HCI_LK_DEBUG_COMBINATION) { 1130 list_del_rcu(&key->list); 1131 kfree_rcu(key, rcu); 1132 } 1133 } 1134 } 1135 } 1136 1137 static void sc_add_ltk(struct smp_chan *smp) 1138 { 1139 struct hci_conn *hcon = smp->conn->hcon; 1140 u8 key_type, auth; 1141 1142 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags)) 1143 key_type = SMP_LTK_P256_DEBUG; 1144 else 1145 key_type = SMP_LTK_P256; 1146 1147 if (hcon->pending_sec_level == BT_SECURITY_FIPS) 1148 auth = 1; 1149 else 1150 auth = 0; 1151 1152 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 1153 key_type, auth, smp->tk, smp->enc_key_size, 1154 0, 0); 1155 } 1156 1157 static void sc_generate_link_key(struct smp_chan *smp) 1158 { 1159 /* From core spec. Spells out in ASCII as 'lebr'. */ 1160 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c }; 1161 1162 smp->link_key = kzalloc(16, GFP_KERNEL); 1163 if (!smp->link_key) 1164 return; 1165 1166 if (test_bit(SMP_FLAG_CT2, &smp->flags)) { 1167 /* SALT = 0x00000000000000000000000000000000746D7031 */ 1168 const u8 salt[16] = { 0x31, 0x70, 0x6d, 0x74 }; 1169 1170 if (smp_h7(smp->tfm_cmac, smp->tk, salt, smp->link_key)) { 1171 kzfree(smp->link_key); 1172 smp->link_key = NULL; 1173 return; 1174 } 1175 } else { 1176 /* From core spec. Spells out in ASCII as 'tmp1'. */ 1177 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 }; 1178 1179 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) { 1180 kzfree(smp->link_key); 1181 smp->link_key = NULL; 1182 return; 1183 } 1184 } 1185 1186 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) { 1187 kzfree(smp->link_key); 1188 smp->link_key = NULL; 1189 return; 1190 } 1191 } 1192 1193 static void smp_allow_key_dist(struct smp_chan *smp) 1194 { 1195 /* Allow the first expected phase 3 PDU. The rest of the PDUs 1196 * will be allowed in each PDU handler to ensure we receive 1197 * them in the correct order. 1198 */ 1199 if (smp->remote_key_dist & SMP_DIST_ENC_KEY) 1200 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO); 1201 else if (smp->remote_key_dist & SMP_DIST_ID_KEY) 1202 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); 1203 else if (smp->remote_key_dist & SMP_DIST_SIGN) 1204 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 1205 } 1206 1207 static void sc_generate_ltk(struct smp_chan *smp) 1208 { 1209 /* From core spec. Spells out in ASCII as 'brle'. */ 1210 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 }; 1211 struct hci_conn *hcon = smp->conn->hcon; 1212 struct hci_dev *hdev = hcon->hdev; 1213 struct link_key *key; 1214 1215 key = hci_find_link_key(hdev, &hcon->dst); 1216 if (!key) { 1217 bt_dev_err(hdev, "no Link Key found to generate LTK"); 1218 return; 1219 } 1220 1221 if (key->type == HCI_LK_DEBUG_COMBINATION) 1222 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1223 1224 if (test_bit(SMP_FLAG_CT2, &smp->flags)) { 1225 /* SALT = 0x00000000000000000000000000000000746D7032 */ 1226 const u8 salt[16] = { 0x32, 0x70, 0x6d, 0x74 }; 1227 1228 if (smp_h7(smp->tfm_cmac, key->val, salt, smp->tk)) 1229 return; 1230 } else { 1231 /* From core spec. Spells out in ASCII as 'tmp2'. */ 1232 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 }; 1233 1234 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk)) 1235 return; 1236 } 1237 1238 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk)) 1239 return; 1240 1241 sc_add_ltk(smp); 1242 } 1243 1244 static void smp_distribute_keys(struct smp_chan *smp) 1245 { 1246 struct smp_cmd_pairing *req, *rsp; 1247 struct l2cap_conn *conn = smp->conn; 1248 struct hci_conn *hcon = conn->hcon; 1249 struct hci_dev *hdev = hcon->hdev; 1250 __u8 *keydist; 1251 1252 BT_DBG("conn %p", conn); 1253 1254 rsp = (void *) &smp->prsp[1]; 1255 1256 /* The responder sends its keys first */ 1257 if (hcon->out && (smp->remote_key_dist & KEY_DIST_MASK)) { 1258 smp_allow_key_dist(smp); 1259 return; 1260 } 1261 1262 req = (void *) &smp->preq[1]; 1263 1264 if (hcon->out) { 1265 keydist = &rsp->init_key_dist; 1266 *keydist &= req->init_key_dist; 1267 } else { 1268 keydist = &rsp->resp_key_dist; 1269 *keydist &= req->resp_key_dist; 1270 } 1271 1272 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1273 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY)) 1274 sc_generate_link_key(smp); 1275 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY)) 1276 sc_generate_ltk(smp); 1277 1278 /* Clear the keys which are generated but not distributed */ 1279 *keydist &= ~SMP_SC_NO_DIST; 1280 } 1281 1282 BT_DBG("keydist 0x%x", *keydist); 1283 1284 if (*keydist & SMP_DIST_ENC_KEY) { 1285 struct smp_cmd_encrypt_info enc; 1286 struct smp_cmd_master_ident ident; 1287 struct smp_ltk *ltk; 1288 u8 authenticated; 1289 __le16 ediv; 1290 __le64 rand; 1291 1292 /* Make sure we generate only the significant amount of 1293 * bytes based on the encryption key size, and set the rest 1294 * of the value to zeroes. 1295 */ 1296 get_random_bytes(enc.ltk, smp->enc_key_size); 1297 memset(enc.ltk + smp->enc_key_size, 0, 1298 sizeof(enc.ltk) - smp->enc_key_size); 1299 1300 get_random_bytes(&ediv, sizeof(ediv)); 1301 get_random_bytes(&rand, sizeof(rand)); 1302 1303 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc); 1304 1305 authenticated = hcon->sec_level == BT_SECURITY_HIGH; 1306 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, 1307 SMP_LTK_SLAVE, authenticated, enc.ltk, 1308 smp->enc_key_size, ediv, rand); 1309 smp->slave_ltk = ltk; 1310 1311 ident.ediv = ediv; 1312 ident.rand = rand; 1313 1314 smp_send_cmd(conn, SMP_CMD_MASTER_IDENT, sizeof(ident), &ident); 1315 1316 *keydist &= ~SMP_DIST_ENC_KEY; 1317 } 1318 1319 if (*keydist & SMP_DIST_ID_KEY) { 1320 struct smp_cmd_ident_addr_info addrinfo; 1321 struct smp_cmd_ident_info idinfo; 1322 1323 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk)); 1324 1325 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo); 1326 1327 /* The hci_conn contains the local identity address 1328 * after the connection has been established. 1329 * 1330 * This is true even when the connection has been 1331 * established using a resolvable random address. 1332 */ 1333 bacpy(&addrinfo.bdaddr, &hcon->src); 1334 addrinfo.addr_type = hcon->src_type; 1335 1336 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo), 1337 &addrinfo); 1338 1339 *keydist &= ~SMP_DIST_ID_KEY; 1340 } 1341 1342 if (*keydist & SMP_DIST_SIGN) { 1343 struct smp_cmd_sign_info sign; 1344 struct smp_csrk *csrk; 1345 1346 /* Generate a new random key */ 1347 get_random_bytes(sign.csrk, sizeof(sign.csrk)); 1348 1349 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); 1350 if (csrk) { 1351 if (hcon->sec_level > BT_SECURITY_MEDIUM) 1352 csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED; 1353 else 1354 csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED; 1355 memcpy(csrk->val, sign.csrk, sizeof(csrk->val)); 1356 } 1357 smp->slave_csrk = csrk; 1358 1359 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign); 1360 1361 *keydist &= ~SMP_DIST_SIGN; 1362 } 1363 1364 /* If there are still keys to be received wait for them */ 1365 if (smp->remote_key_dist & KEY_DIST_MASK) { 1366 smp_allow_key_dist(smp); 1367 return; 1368 } 1369 1370 set_bit(SMP_FLAG_COMPLETE, &smp->flags); 1371 smp_notify_keys(conn); 1372 1373 smp_chan_destroy(conn); 1374 } 1375 1376 static void smp_timeout(struct work_struct *work) 1377 { 1378 struct smp_chan *smp = container_of(work, struct smp_chan, 1379 security_timer.work); 1380 struct l2cap_conn *conn = smp->conn; 1381 1382 BT_DBG("conn %p", conn); 1383 1384 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM); 1385 } 1386 1387 static struct smp_chan *smp_chan_create(struct l2cap_conn *conn) 1388 { 1389 struct l2cap_chan *chan = conn->smp; 1390 struct smp_chan *smp; 1391 1392 smp = kzalloc(sizeof(*smp), GFP_ATOMIC); 1393 if (!smp) 1394 return NULL; 1395 1396 smp->tfm_aes = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC); 1397 if (IS_ERR(smp->tfm_aes)) { 1398 BT_ERR("Unable to create AES crypto context"); 1399 goto zfree_smp; 1400 } 1401 1402 smp->tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 1403 if (IS_ERR(smp->tfm_cmac)) { 1404 BT_ERR("Unable to create CMAC crypto context"); 1405 goto free_cipher; 1406 } 1407 1408 smp->tfm_ecdh = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0); 1409 if (IS_ERR(smp->tfm_ecdh)) { 1410 BT_ERR("Unable to create ECDH crypto context"); 1411 goto free_shash; 1412 } 1413 1414 smp->conn = conn; 1415 chan->data = smp; 1416 1417 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL); 1418 1419 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout); 1420 1421 hci_conn_hold(conn->hcon); 1422 1423 return smp; 1424 1425 free_shash: 1426 crypto_free_shash(smp->tfm_cmac); 1427 free_cipher: 1428 crypto_free_cipher(smp->tfm_aes); 1429 zfree_smp: 1430 kzfree(smp); 1431 return NULL; 1432 } 1433 1434 static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16]) 1435 { 1436 struct hci_conn *hcon = smp->conn->hcon; 1437 u8 *na, *nb, a[7], b[7]; 1438 1439 if (hcon->out) { 1440 na = smp->prnd; 1441 nb = smp->rrnd; 1442 } else { 1443 na = smp->rrnd; 1444 nb = smp->prnd; 1445 } 1446 1447 memcpy(a, &hcon->init_addr, 6); 1448 memcpy(b, &hcon->resp_addr, 6); 1449 a[6] = hcon->init_addr_type; 1450 b[6] = hcon->resp_addr_type; 1451 1452 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk); 1453 } 1454 1455 static void sc_dhkey_check(struct smp_chan *smp) 1456 { 1457 struct hci_conn *hcon = smp->conn->hcon; 1458 struct smp_cmd_dhkey_check check; 1459 u8 a[7], b[7], *local_addr, *remote_addr; 1460 u8 io_cap[3], r[16]; 1461 1462 memcpy(a, &hcon->init_addr, 6); 1463 memcpy(b, &hcon->resp_addr, 6); 1464 a[6] = hcon->init_addr_type; 1465 b[6] = hcon->resp_addr_type; 1466 1467 if (hcon->out) { 1468 local_addr = a; 1469 remote_addr = b; 1470 memcpy(io_cap, &smp->preq[1], 3); 1471 } else { 1472 local_addr = b; 1473 remote_addr = a; 1474 memcpy(io_cap, &smp->prsp[1], 3); 1475 } 1476 1477 memset(r, 0, sizeof(r)); 1478 1479 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 1480 put_unaligned_le32(hcon->passkey_notify, r); 1481 1482 if (smp->method == REQ_OOB) 1483 memcpy(r, smp->rr, 16); 1484 1485 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap, 1486 local_addr, remote_addr, check.e); 1487 1488 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check); 1489 } 1490 1491 static u8 sc_passkey_send_confirm(struct smp_chan *smp) 1492 { 1493 struct l2cap_conn *conn = smp->conn; 1494 struct hci_conn *hcon = conn->hcon; 1495 struct smp_cmd_pairing_confirm cfm; 1496 u8 r; 1497 1498 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); 1499 r |= 0x80; 1500 1501 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1502 1503 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r, 1504 cfm.confirm_val)) 1505 return SMP_UNSPECIFIED; 1506 1507 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); 1508 1509 return 0; 1510 } 1511 1512 static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op) 1513 { 1514 struct l2cap_conn *conn = smp->conn; 1515 struct hci_conn *hcon = conn->hcon; 1516 struct hci_dev *hdev = hcon->hdev; 1517 u8 cfm[16], r; 1518 1519 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */ 1520 if (smp->passkey_round >= 20) 1521 return 0; 1522 1523 switch (smp_op) { 1524 case SMP_CMD_PAIRING_RANDOM: 1525 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); 1526 r |= 0x80; 1527 1528 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, 1529 smp->rrnd, r, cfm)) 1530 return SMP_UNSPECIFIED; 1531 1532 if (crypto_memneq(smp->pcnf, cfm, 16)) 1533 return SMP_CONFIRM_FAILED; 1534 1535 smp->passkey_round++; 1536 1537 if (smp->passkey_round == 20) { 1538 /* Generate MacKey and LTK */ 1539 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk)) 1540 return SMP_UNSPECIFIED; 1541 } 1542 1543 /* The round is only complete when the initiator 1544 * receives pairing random. 1545 */ 1546 if (!hcon->out) { 1547 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 1548 sizeof(smp->prnd), smp->prnd); 1549 if (smp->passkey_round == 20) 1550 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1551 else 1552 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1553 return 0; 1554 } 1555 1556 /* Start the next round */ 1557 if (smp->passkey_round != 20) 1558 return sc_passkey_round(smp, 0); 1559 1560 /* Passkey rounds are complete - start DHKey Check */ 1561 sc_dhkey_check(smp); 1562 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1563 1564 break; 1565 1566 case SMP_CMD_PAIRING_CONFIRM: 1567 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { 1568 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 1569 return 0; 1570 } 1571 1572 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 1573 1574 if (hcon->out) { 1575 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 1576 sizeof(smp->prnd), smp->prnd); 1577 return 0; 1578 } 1579 1580 return sc_passkey_send_confirm(smp); 1581 1582 case SMP_CMD_PUBLIC_KEY: 1583 default: 1584 /* Initiating device starts the round */ 1585 if (!hcon->out) 1586 return 0; 1587 1588 BT_DBG("%s Starting passkey round %u", hdev->name, 1589 smp->passkey_round + 1); 1590 1591 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1592 1593 return sc_passkey_send_confirm(smp); 1594 } 1595 1596 return 0; 1597 } 1598 1599 static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey) 1600 { 1601 struct l2cap_conn *conn = smp->conn; 1602 struct hci_conn *hcon = conn->hcon; 1603 u8 smp_op; 1604 1605 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags); 1606 1607 switch (mgmt_op) { 1608 case MGMT_OP_USER_PASSKEY_NEG_REPLY: 1609 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED); 1610 return 0; 1611 case MGMT_OP_USER_CONFIRM_NEG_REPLY: 1612 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED); 1613 return 0; 1614 case MGMT_OP_USER_PASSKEY_REPLY: 1615 hcon->passkey_notify = le32_to_cpu(passkey); 1616 smp->passkey_round = 0; 1617 1618 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) 1619 smp_op = SMP_CMD_PAIRING_CONFIRM; 1620 else 1621 smp_op = 0; 1622 1623 if (sc_passkey_round(smp, smp_op)) 1624 return -EIO; 1625 1626 return 0; 1627 } 1628 1629 /* Initiator sends DHKey check first */ 1630 if (hcon->out) { 1631 sc_dhkey_check(smp); 1632 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1633 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) { 1634 sc_dhkey_check(smp); 1635 sc_add_ltk(smp); 1636 } 1637 1638 return 0; 1639 } 1640 1641 int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey) 1642 { 1643 struct l2cap_conn *conn = hcon->l2cap_data; 1644 struct l2cap_chan *chan; 1645 struct smp_chan *smp; 1646 u32 value; 1647 int err; 1648 1649 BT_DBG(""); 1650 1651 if (!conn) 1652 return -ENOTCONN; 1653 1654 chan = conn->smp; 1655 if (!chan) 1656 return -ENOTCONN; 1657 1658 l2cap_chan_lock(chan); 1659 if (!chan->data) { 1660 err = -ENOTCONN; 1661 goto unlock; 1662 } 1663 1664 smp = chan->data; 1665 1666 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1667 err = sc_user_reply(smp, mgmt_op, passkey); 1668 goto unlock; 1669 } 1670 1671 switch (mgmt_op) { 1672 case MGMT_OP_USER_PASSKEY_REPLY: 1673 value = le32_to_cpu(passkey); 1674 memset(smp->tk, 0, sizeof(smp->tk)); 1675 BT_DBG("PassKey: %d", value); 1676 put_unaligned_le32(value, smp->tk); 1677 /* Fall Through */ 1678 case MGMT_OP_USER_CONFIRM_REPLY: 1679 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 1680 break; 1681 case MGMT_OP_USER_PASSKEY_NEG_REPLY: 1682 case MGMT_OP_USER_CONFIRM_NEG_REPLY: 1683 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); 1684 err = 0; 1685 goto unlock; 1686 default: 1687 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); 1688 err = -EOPNOTSUPP; 1689 goto unlock; 1690 } 1691 1692 err = 0; 1693 1694 /* If it is our turn to send Pairing Confirm, do so now */ 1695 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) { 1696 u8 rsp = smp_confirm(smp); 1697 if (rsp) 1698 smp_failure(conn, rsp); 1699 } 1700 1701 unlock: 1702 l2cap_chan_unlock(chan); 1703 return err; 1704 } 1705 1706 static void build_bredr_pairing_cmd(struct smp_chan *smp, 1707 struct smp_cmd_pairing *req, 1708 struct smp_cmd_pairing *rsp) 1709 { 1710 struct l2cap_conn *conn = smp->conn; 1711 struct hci_dev *hdev = conn->hcon->hdev; 1712 u8 local_dist = 0, remote_dist = 0; 1713 1714 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { 1715 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 1716 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 1717 } 1718 1719 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) 1720 remote_dist |= SMP_DIST_ID_KEY; 1721 1722 if (hci_dev_test_flag(hdev, HCI_PRIVACY)) 1723 local_dist |= SMP_DIST_ID_KEY; 1724 1725 if (!rsp) { 1726 memset(req, 0, sizeof(*req)); 1727 1728 req->auth_req = SMP_AUTH_CT2; 1729 req->init_key_dist = local_dist; 1730 req->resp_key_dist = remote_dist; 1731 req->max_key_size = conn->hcon->enc_key_size; 1732 1733 smp->remote_key_dist = remote_dist; 1734 1735 return; 1736 } 1737 1738 memset(rsp, 0, sizeof(*rsp)); 1739 1740 rsp->auth_req = SMP_AUTH_CT2; 1741 rsp->max_key_size = conn->hcon->enc_key_size; 1742 rsp->init_key_dist = req->init_key_dist & remote_dist; 1743 rsp->resp_key_dist = req->resp_key_dist & local_dist; 1744 1745 smp->remote_key_dist = rsp->init_key_dist; 1746 } 1747 1748 static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) 1749 { 1750 struct smp_cmd_pairing rsp, *req = (void *) skb->data; 1751 struct l2cap_chan *chan = conn->smp; 1752 struct hci_dev *hdev = conn->hcon->hdev; 1753 struct smp_chan *smp; 1754 u8 key_size, auth, sec_level; 1755 int ret; 1756 1757 BT_DBG("conn %p", conn); 1758 1759 if (skb->len < sizeof(*req)) 1760 return SMP_INVALID_PARAMS; 1761 1762 if (conn->hcon->role != HCI_ROLE_SLAVE) 1763 return SMP_CMD_NOTSUPP; 1764 1765 if (!chan->data) 1766 smp = smp_chan_create(conn); 1767 else 1768 smp = chan->data; 1769 1770 if (!smp) 1771 return SMP_UNSPECIFIED; 1772 1773 /* We didn't start the pairing, so match remote */ 1774 auth = req->auth_req & AUTH_REQ_MASK(hdev); 1775 1776 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && 1777 (auth & SMP_AUTH_BONDING)) 1778 return SMP_PAIRING_NOTSUPP; 1779 1780 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 1781 return SMP_AUTH_REQUIREMENTS; 1782 1783 smp->preq[0] = SMP_CMD_PAIRING_REQ; 1784 memcpy(&smp->preq[1], req, sizeof(*req)); 1785 skb_pull(skb, sizeof(*req)); 1786 1787 /* If the remote side's OOB flag is set it means it has 1788 * successfully received our local OOB data - therefore set the 1789 * flag to indicate that local OOB is in use. 1790 */ 1791 if (req->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob) 1792 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); 1793 1794 /* SMP over BR/EDR requires special treatment */ 1795 if (conn->hcon->type == ACL_LINK) { 1796 /* We must have a BR/EDR SC link */ 1797 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) && 1798 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 1799 return SMP_CROSS_TRANSP_NOT_ALLOWED; 1800 1801 set_bit(SMP_FLAG_SC, &smp->flags); 1802 1803 build_bredr_pairing_cmd(smp, req, &rsp); 1804 1805 if (req->auth_req & SMP_AUTH_CT2) 1806 set_bit(SMP_FLAG_CT2, &smp->flags); 1807 1808 key_size = min(req->max_key_size, rsp.max_key_size); 1809 if (check_enc_key_size(conn, key_size)) 1810 return SMP_ENC_KEY_SIZE; 1811 1812 /* Clear bits which are generated but not distributed */ 1813 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1814 1815 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1816 memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); 1817 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); 1818 1819 smp_distribute_keys(smp); 1820 return 0; 1821 } 1822 1823 build_pairing_cmd(conn, req, &rsp, auth); 1824 1825 if (rsp.auth_req & SMP_AUTH_SC) { 1826 set_bit(SMP_FLAG_SC, &smp->flags); 1827 1828 if (rsp.auth_req & SMP_AUTH_CT2) 1829 set_bit(SMP_FLAG_CT2, &smp->flags); 1830 } 1831 1832 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 1833 sec_level = BT_SECURITY_MEDIUM; 1834 else 1835 sec_level = authreq_to_seclevel(auth); 1836 1837 if (sec_level > conn->hcon->pending_sec_level) 1838 conn->hcon->pending_sec_level = sec_level; 1839 1840 /* If we need MITM check that it can be achieved */ 1841 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { 1842 u8 method; 1843 1844 method = get_auth_method(smp, conn->hcon->io_capability, 1845 req->io_capability); 1846 if (method == JUST_WORKS || method == JUST_CFM) 1847 return SMP_AUTH_REQUIREMENTS; 1848 } 1849 1850 key_size = min(req->max_key_size, rsp.max_key_size); 1851 if (check_enc_key_size(conn, key_size)) 1852 return SMP_ENC_KEY_SIZE; 1853 1854 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1855 1856 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1857 memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); 1858 1859 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); 1860 1861 clear_bit(SMP_FLAG_INITIATOR, &smp->flags); 1862 1863 /* Strictly speaking we shouldn't allow Pairing Confirm for the 1864 * SC case, however some implementations incorrectly copy RFU auth 1865 * req bits from our security request, which may create a false 1866 * positive SC enablement. 1867 */ 1868 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1869 1870 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1871 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); 1872 /* Clear bits which are generated but not distributed */ 1873 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1874 /* Wait for Public Key from Initiating Device */ 1875 return 0; 1876 } 1877 1878 /* Request setup of TK */ 1879 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability); 1880 if (ret) 1881 return SMP_UNSPECIFIED; 1882 1883 return 0; 1884 } 1885 1886 static u8 sc_send_public_key(struct smp_chan *smp) 1887 { 1888 struct hci_dev *hdev = smp->conn->hcon->hdev; 1889 1890 BT_DBG(""); 1891 1892 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { 1893 struct l2cap_chan *chan = hdev->smp_data; 1894 struct smp_dev *smp_dev; 1895 1896 if (!chan || !chan->data) 1897 return SMP_UNSPECIFIED; 1898 1899 smp_dev = chan->data; 1900 1901 memcpy(smp->local_pk, smp_dev->local_pk, 64); 1902 memcpy(smp->lr, smp_dev->local_rand, 16); 1903 1904 if (smp_dev->debug_key) 1905 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1906 1907 goto done; 1908 } 1909 1910 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { 1911 BT_DBG("Using debug keys"); 1912 if (set_ecdh_privkey(smp->tfm_ecdh, debug_sk)) 1913 return SMP_UNSPECIFIED; 1914 memcpy(smp->local_pk, debug_pk, 64); 1915 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1916 } else { 1917 while (true) { 1918 /* Generate key pair for Secure Connections */ 1919 if (generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk)) 1920 return SMP_UNSPECIFIED; 1921 1922 /* This is unlikely, but we need to check that 1923 * we didn't accidentially generate a debug key. 1924 */ 1925 if (crypto_memneq(smp->local_pk, debug_pk, 64)) 1926 break; 1927 } 1928 } 1929 1930 done: 1931 SMP_DBG("Local Public Key X: %32phN", smp->local_pk); 1932 SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32); 1933 1934 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk); 1935 1936 return 0; 1937 } 1938 1939 static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) 1940 { 1941 struct smp_cmd_pairing *req, *rsp = (void *) skb->data; 1942 struct l2cap_chan *chan = conn->smp; 1943 struct smp_chan *smp = chan->data; 1944 struct hci_dev *hdev = conn->hcon->hdev; 1945 u8 key_size, auth; 1946 int ret; 1947 1948 BT_DBG("conn %p", conn); 1949 1950 if (skb->len < sizeof(*rsp)) 1951 return SMP_INVALID_PARAMS; 1952 1953 if (conn->hcon->role != HCI_ROLE_MASTER) 1954 return SMP_CMD_NOTSUPP; 1955 1956 skb_pull(skb, sizeof(*rsp)); 1957 1958 req = (void *) &smp->preq[1]; 1959 1960 key_size = min(req->max_key_size, rsp->max_key_size); 1961 if (check_enc_key_size(conn, key_size)) 1962 return SMP_ENC_KEY_SIZE; 1963 1964 auth = rsp->auth_req & AUTH_REQ_MASK(hdev); 1965 1966 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 1967 return SMP_AUTH_REQUIREMENTS; 1968 1969 /* If the remote side's OOB flag is set it means it has 1970 * successfully received our local OOB data - therefore set the 1971 * flag to indicate that local OOB is in use. 1972 */ 1973 if (rsp->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob) 1974 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); 1975 1976 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1977 memcpy(&smp->prsp[1], rsp, sizeof(*rsp)); 1978 1979 /* Update remote key distribution in case the remote cleared 1980 * some bits that we had enabled in our request. 1981 */ 1982 smp->remote_key_dist &= rsp->resp_key_dist; 1983 1984 if ((req->auth_req & SMP_AUTH_CT2) && (auth & SMP_AUTH_CT2)) 1985 set_bit(SMP_FLAG_CT2, &smp->flags); 1986 1987 /* For BR/EDR this means we're done and can start phase 3 */ 1988 if (conn->hcon->type == ACL_LINK) { 1989 /* Clear bits which are generated but not distributed */ 1990 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1991 smp_distribute_keys(smp); 1992 return 0; 1993 } 1994 1995 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC)) 1996 set_bit(SMP_FLAG_SC, &smp->flags); 1997 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH) 1998 conn->hcon->pending_sec_level = BT_SECURITY_HIGH; 1999 2000 /* If we need MITM check that it can be achieved */ 2001 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { 2002 u8 method; 2003 2004 method = get_auth_method(smp, req->io_capability, 2005 rsp->io_capability); 2006 if (method == JUST_WORKS || method == JUST_CFM) 2007 return SMP_AUTH_REQUIREMENTS; 2008 } 2009 2010 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 2011 2012 /* Update remote key distribution in case the remote cleared 2013 * some bits that we had enabled in our request. 2014 */ 2015 smp->remote_key_dist &= rsp->resp_key_dist; 2016 2017 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 2018 /* Clear bits which are generated but not distributed */ 2019 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 2020 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); 2021 return sc_send_public_key(smp); 2022 } 2023 2024 auth |= req->auth_req; 2025 2026 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability); 2027 if (ret) 2028 return SMP_UNSPECIFIED; 2029 2030 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 2031 2032 /* Can't compose response until we have been confirmed */ 2033 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) 2034 return smp_confirm(smp); 2035 2036 return 0; 2037 } 2038 2039 static u8 sc_check_confirm(struct smp_chan *smp) 2040 { 2041 struct l2cap_conn *conn = smp->conn; 2042 2043 BT_DBG(""); 2044 2045 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2046 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM); 2047 2048 if (conn->hcon->out) { 2049 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2050 smp->prnd); 2051 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2052 } 2053 2054 return 0; 2055 } 2056 2057 /* Work-around for some implementations that incorrectly copy RFU bits 2058 * from our security request and thereby create the impression that 2059 * we're doing SC when in fact the remote doesn't support it. 2060 */ 2061 static int fixup_sc_false_positive(struct smp_chan *smp) 2062 { 2063 struct l2cap_conn *conn = smp->conn; 2064 struct hci_conn *hcon = conn->hcon; 2065 struct hci_dev *hdev = hcon->hdev; 2066 struct smp_cmd_pairing *req, *rsp; 2067 u8 auth; 2068 2069 /* The issue is only observed when we're in slave role */ 2070 if (hcon->out) 2071 return SMP_UNSPECIFIED; 2072 2073 if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) { 2074 bt_dev_err(hdev, "refusing legacy fallback in SC-only mode"); 2075 return SMP_UNSPECIFIED; 2076 } 2077 2078 bt_dev_err(hdev, "trying to fall back to legacy SMP"); 2079 2080 req = (void *) &smp->preq[1]; 2081 rsp = (void *) &smp->prsp[1]; 2082 2083 /* Rebuild key dist flags which may have been cleared for SC */ 2084 smp->remote_key_dist = (req->init_key_dist & rsp->resp_key_dist); 2085 2086 auth = req->auth_req & AUTH_REQ_MASK(hdev); 2087 2088 if (tk_request(conn, 0, auth, rsp->io_capability, req->io_capability)) { 2089 bt_dev_err(hdev, "failed to fall back to legacy SMP"); 2090 return SMP_UNSPECIFIED; 2091 } 2092 2093 clear_bit(SMP_FLAG_SC, &smp->flags); 2094 2095 return 0; 2096 } 2097 2098 static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb) 2099 { 2100 struct l2cap_chan *chan = conn->smp; 2101 struct smp_chan *smp = chan->data; 2102 2103 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave"); 2104 2105 if (skb->len < sizeof(smp->pcnf)) 2106 return SMP_INVALID_PARAMS; 2107 2108 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf)); 2109 skb_pull(skb, sizeof(smp->pcnf)); 2110 2111 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 2112 int ret; 2113 2114 /* Public Key exchange must happen before any other steps */ 2115 if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags)) 2116 return sc_check_confirm(smp); 2117 2118 BT_ERR("Unexpected SMP Pairing Confirm"); 2119 2120 ret = fixup_sc_false_positive(smp); 2121 if (ret) 2122 return ret; 2123 } 2124 2125 if (conn->hcon->out) { 2126 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2127 smp->prnd); 2128 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2129 return 0; 2130 } 2131 2132 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) 2133 return smp_confirm(smp); 2134 2135 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 2136 2137 return 0; 2138 } 2139 2140 static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb) 2141 { 2142 struct l2cap_chan *chan = conn->smp; 2143 struct smp_chan *smp = chan->data; 2144 struct hci_conn *hcon = conn->hcon; 2145 u8 *pkax, *pkbx, *na, *nb; 2146 u32 passkey; 2147 int err; 2148 2149 BT_DBG("conn %p", conn); 2150 2151 if (skb->len < sizeof(smp->rrnd)) 2152 return SMP_INVALID_PARAMS; 2153 2154 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd)); 2155 skb_pull(skb, sizeof(smp->rrnd)); 2156 2157 if (!test_bit(SMP_FLAG_SC, &smp->flags)) 2158 return smp_random(smp); 2159 2160 if (hcon->out) { 2161 pkax = smp->local_pk; 2162 pkbx = smp->remote_pk; 2163 na = smp->prnd; 2164 nb = smp->rrnd; 2165 } else { 2166 pkax = smp->remote_pk; 2167 pkbx = smp->local_pk; 2168 na = smp->rrnd; 2169 nb = smp->prnd; 2170 } 2171 2172 if (smp->method == REQ_OOB) { 2173 if (!hcon->out) 2174 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 2175 sizeof(smp->prnd), smp->prnd); 2176 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2177 goto mackey_and_ltk; 2178 } 2179 2180 /* Passkey entry has special treatment */ 2181 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2182 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM); 2183 2184 if (hcon->out) { 2185 u8 cfm[16]; 2186 2187 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, 2188 smp->rrnd, 0, cfm); 2189 if (err) 2190 return SMP_UNSPECIFIED; 2191 2192 if (crypto_memneq(smp->pcnf, cfm, 16)) 2193 return SMP_CONFIRM_FAILED; 2194 } else { 2195 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2196 smp->prnd); 2197 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2198 } 2199 2200 mackey_and_ltk: 2201 /* Generate MacKey and LTK */ 2202 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk); 2203 if (err) 2204 return SMP_UNSPECIFIED; 2205 2206 if (smp->method == JUST_WORKS || smp->method == REQ_OOB) { 2207 if (hcon->out) { 2208 sc_dhkey_check(smp); 2209 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2210 } 2211 return 0; 2212 } 2213 2214 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey); 2215 if (err) 2216 return SMP_UNSPECIFIED; 2217 2218 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type, 2219 hcon->dst_type, passkey, 0); 2220 if (err) 2221 return SMP_UNSPECIFIED; 2222 2223 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 2224 2225 return 0; 2226 } 2227 2228 static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level) 2229 { 2230 struct smp_ltk *key; 2231 struct hci_conn *hcon = conn->hcon; 2232 2233 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role); 2234 if (!key) 2235 return false; 2236 2237 if (smp_ltk_sec_level(key) < sec_level) 2238 return false; 2239 2240 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) 2241 return true; 2242 2243 hci_le_start_enc(hcon, key->ediv, key->rand, key->val, key->enc_size); 2244 hcon->enc_key_size = key->enc_size; 2245 2246 /* We never store STKs for master role, so clear this flag */ 2247 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); 2248 2249 return true; 2250 } 2251 2252 bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level, 2253 enum smp_key_pref key_pref) 2254 { 2255 if (sec_level == BT_SECURITY_LOW) 2256 return true; 2257 2258 /* If we're encrypted with an STK but the caller prefers using 2259 * LTK claim insufficient security. This way we allow the 2260 * connection to be re-encrypted with an LTK, even if the LTK 2261 * provides the same level of security. Only exception is if we 2262 * don't have an LTK (e.g. because of key distribution bits). 2263 */ 2264 if (key_pref == SMP_USE_LTK && 2265 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) && 2266 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role)) 2267 return false; 2268 2269 if (hcon->sec_level >= sec_level) 2270 return true; 2271 2272 return false; 2273 } 2274 2275 static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb) 2276 { 2277 struct smp_cmd_security_req *rp = (void *) skb->data; 2278 struct smp_cmd_pairing cp; 2279 struct hci_conn *hcon = conn->hcon; 2280 struct hci_dev *hdev = hcon->hdev; 2281 struct smp_chan *smp; 2282 u8 sec_level, auth; 2283 2284 BT_DBG("conn %p", conn); 2285 2286 if (skb->len < sizeof(*rp)) 2287 return SMP_INVALID_PARAMS; 2288 2289 if (hcon->role != HCI_ROLE_MASTER) 2290 return SMP_CMD_NOTSUPP; 2291 2292 auth = rp->auth_req & AUTH_REQ_MASK(hdev); 2293 2294 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 2295 return SMP_AUTH_REQUIREMENTS; 2296 2297 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 2298 sec_level = BT_SECURITY_MEDIUM; 2299 else 2300 sec_level = authreq_to_seclevel(auth); 2301 2302 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) { 2303 /* If link is already encrypted with sufficient security we 2304 * still need refresh encryption as per Core Spec 5.0 Vol 3, 2305 * Part H 2.4.6 2306 */ 2307 smp_ltk_encrypt(conn, hcon->sec_level); 2308 return 0; 2309 } 2310 2311 if (sec_level > hcon->pending_sec_level) 2312 hcon->pending_sec_level = sec_level; 2313 2314 if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) 2315 return 0; 2316 2317 smp = smp_chan_create(conn); 2318 if (!smp) 2319 return SMP_UNSPECIFIED; 2320 2321 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && 2322 (auth & SMP_AUTH_BONDING)) 2323 return SMP_PAIRING_NOTSUPP; 2324 2325 skb_pull(skb, sizeof(*rp)); 2326 2327 memset(&cp, 0, sizeof(cp)); 2328 build_pairing_cmd(conn, &cp, NULL, auth); 2329 2330 smp->preq[0] = SMP_CMD_PAIRING_REQ; 2331 memcpy(&smp->preq[1], &cp, sizeof(cp)); 2332 2333 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); 2334 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 2335 2336 return 0; 2337 } 2338 2339 int smp_conn_security(struct hci_conn *hcon, __u8 sec_level) 2340 { 2341 struct l2cap_conn *conn = hcon->l2cap_data; 2342 struct l2cap_chan *chan; 2343 struct smp_chan *smp; 2344 __u8 authreq; 2345 int ret; 2346 2347 BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level); 2348 2349 /* This may be NULL if there's an unexpected disconnection */ 2350 if (!conn) 2351 return 1; 2352 2353 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) 2354 return 1; 2355 2356 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) 2357 return 1; 2358 2359 if (sec_level > hcon->pending_sec_level) 2360 hcon->pending_sec_level = sec_level; 2361 2362 if (hcon->role == HCI_ROLE_MASTER) 2363 if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) 2364 return 0; 2365 2366 chan = conn->smp; 2367 if (!chan) { 2368 bt_dev_err(hcon->hdev, "security requested but not available"); 2369 return 1; 2370 } 2371 2372 l2cap_chan_lock(chan); 2373 2374 /* If SMP is already in progress ignore this request */ 2375 if (chan->data) { 2376 ret = 0; 2377 goto unlock; 2378 } 2379 2380 smp = smp_chan_create(conn); 2381 if (!smp) { 2382 ret = 1; 2383 goto unlock; 2384 } 2385 2386 authreq = seclevel_to_authreq(sec_level); 2387 2388 if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED)) { 2389 authreq |= SMP_AUTH_SC; 2390 if (hci_dev_test_flag(hcon->hdev, HCI_SSP_ENABLED)) 2391 authreq |= SMP_AUTH_CT2; 2392 } 2393 2394 /* Require MITM if IO Capability allows or the security level 2395 * requires it. 2396 */ 2397 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT || 2398 hcon->pending_sec_level > BT_SECURITY_MEDIUM) 2399 authreq |= SMP_AUTH_MITM; 2400 2401 if (hcon->role == HCI_ROLE_MASTER) { 2402 struct smp_cmd_pairing cp; 2403 2404 build_pairing_cmd(conn, &cp, NULL, authreq); 2405 smp->preq[0] = SMP_CMD_PAIRING_REQ; 2406 memcpy(&smp->preq[1], &cp, sizeof(cp)); 2407 2408 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); 2409 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 2410 } else { 2411 struct smp_cmd_security_req cp; 2412 cp.auth_req = authreq; 2413 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp); 2414 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ); 2415 } 2416 2417 set_bit(SMP_FLAG_INITIATOR, &smp->flags); 2418 ret = 0; 2419 2420 unlock: 2421 l2cap_chan_unlock(chan); 2422 return ret; 2423 } 2424 2425 int smp_cancel_and_remove_pairing(struct hci_dev *hdev, bdaddr_t *bdaddr, 2426 u8 addr_type) 2427 { 2428 struct hci_conn *hcon; 2429 struct l2cap_conn *conn; 2430 struct l2cap_chan *chan; 2431 struct smp_chan *smp; 2432 int err; 2433 2434 err = hci_remove_ltk(hdev, bdaddr, addr_type); 2435 hci_remove_irk(hdev, bdaddr, addr_type); 2436 2437 hcon = hci_conn_hash_lookup_le(hdev, bdaddr, addr_type); 2438 if (!hcon) 2439 goto done; 2440 2441 conn = hcon->l2cap_data; 2442 if (!conn) 2443 goto done; 2444 2445 chan = conn->smp; 2446 if (!chan) 2447 goto done; 2448 2449 l2cap_chan_lock(chan); 2450 2451 smp = chan->data; 2452 if (smp) { 2453 /* Set keys to NULL to make sure smp_failure() does not try to 2454 * remove and free already invalidated rcu list entries. */ 2455 smp->ltk = NULL; 2456 smp->slave_ltk = NULL; 2457 smp->remote_irk = NULL; 2458 2459 if (test_bit(SMP_FLAG_COMPLETE, &smp->flags)) 2460 smp_failure(conn, 0); 2461 else 2462 smp_failure(conn, SMP_UNSPECIFIED); 2463 err = 0; 2464 } 2465 2466 l2cap_chan_unlock(chan); 2467 2468 done: 2469 return err; 2470 } 2471 2472 static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb) 2473 { 2474 struct smp_cmd_encrypt_info *rp = (void *) skb->data; 2475 struct l2cap_chan *chan = conn->smp; 2476 struct smp_chan *smp = chan->data; 2477 2478 BT_DBG("conn %p", conn); 2479 2480 if (skb->len < sizeof(*rp)) 2481 return SMP_INVALID_PARAMS; 2482 2483 SMP_ALLOW_CMD(smp, SMP_CMD_MASTER_IDENT); 2484 2485 skb_pull(skb, sizeof(*rp)); 2486 2487 memcpy(smp->tk, rp->ltk, sizeof(smp->tk)); 2488 2489 return 0; 2490 } 2491 2492 static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb) 2493 { 2494 struct smp_cmd_master_ident *rp = (void *) skb->data; 2495 struct l2cap_chan *chan = conn->smp; 2496 struct smp_chan *smp = chan->data; 2497 struct hci_dev *hdev = conn->hcon->hdev; 2498 struct hci_conn *hcon = conn->hcon; 2499 struct smp_ltk *ltk; 2500 u8 authenticated; 2501 2502 BT_DBG("conn %p", conn); 2503 2504 if (skb->len < sizeof(*rp)) 2505 return SMP_INVALID_PARAMS; 2506 2507 /* Mark the information as received */ 2508 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY; 2509 2510 if (smp->remote_key_dist & SMP_DIST_ID_KEY) 2511 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); 2512 else if (smp->remote_key_dist & SMP_DIST_SIGN) 2513 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 2514 2515 skb_pull(skb, sizeof(*rp)); 2516 2517 authenticated = (hcon->sec_level == BT_SECURITY_HIGH); 2518 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK, 2519 authenticated, smp->tk, smp->enc_key_size, 2520 rp->ediv, rp->rand); 2521 smp->ltk = ltk; 2522 if (!(smp->remote_key_dist & KEY_DIST_MASK)) 2523 smp_distribute_keys(smp); 2524 2525 return 0; 2526 } 2527 2528 static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb) 2529 { 2530 struct smp_cmd_ident_info *info = (void *) skb->data; 2531 struct l2cap_chan *chan = conn->smp; 2532 struct smp_chan *smp = chan->data; 2533 2534 BT_DBG(""); 2535 2536 if (skb->len < sizeof(*info)) 2537 return SMP_INVALID_PARAMS; 2538 2539 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO); 2540 2541 skb_pull(skb, sizeof(*info)); 2542 2543 memcpy(smp->irk, info->irk, 16); 2544 2545 return 0; 2546 } 2547 2548 static int smp_cmd_ident_addr_info(struct l2cap_conn *conn, 2549 struct sk_buff *skb) 2550 { 2551 struct smp_cmd_ident_addr_info *info = (void *) skb->data; 2552 struct l2cap_chan *chan = conn->smp; 2553 struct smp_chan *smp = chan->data; 2554 struct hci_conn *hcon = conn->hcon; 2555 bdaddr_t rpa; 2556 2557 BT_DBG(""); 2558 2559 if (skb->len < sizeof(*info)) 2560 return SMP_INVALID_PARAMS; 2561 2562 /* Mark the information as received */ 2563 smp->remote_key_dist &= ~SMP_DIST_ID_KEY; 2564 2565 if (smp->remote_key_dist & SMP_DIST_SIGN) 2566 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 2567 2568 skb_pull(skb, sizeof(*info)); 2569 2570 /* Strictly speaking the Core Specification (4.1) allows sending 2571 * an empty address which would force us to rely on just the IRK 2572 * as "identity information". However, since such 2573 * implementations are not known of and in order to not over 2574 * complicate our implementation, simply pretend that we never 2575 * received an IRK for such a device. 2576 * 2577 * The Identity Address must also be a Static Random or Public 2578 * Address, which hci_is_identity_address() checks for. 2579 */ 2580 if (!bacmp(&info->bdaddr, BDADDR_ANY) || 2581 !hci_is_identity_address(&info->bdaddr, info->addr_type)) { 2582 bt_dev_err(hcon->hdev, "ignoring IRK with no identity address"); 2583 goto distribute; 2584 } 2585 2586 bacpy(&smp->id_addr, &info->bdaddr); 2587 smp->id_addr_type = info->addr_type; 2588 2589 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type)) 2590 bacpy(&rpa, &hcon->dst); 2591 else 2592 bacpy(&rpa, BDADDR_ANY); 2593 2594 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr, 2595 smp->id_addr_type, smp->irk, &rpa); 2596 2597 distribute: 2598 if (!(smp->remote_key_dist & KEY_DIST_MASK)) 2599 smp_distribute_keys(smp); 2600 2601 return 0; 2602 } 2603 2604 static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb) 2605 { 2606 struct smp_cmd_sign_info *rp = (void *) skb->data; 2607 struct l2cap_chan *chan = conn->smp; 2608 struct smp_chan *smp = chan->data; 2609 struct smp_csrk *csrk; 2610 2611 BT_DBG("conn %p", conn); 2612 2613 if (skb->len < sizeof(*rp)) 2614 return SMP_INVALID_PARAMS; 2615 2616 /* Mark the information as received */ 2617 smp->remote_key_dist &= ~SMP_DIST_SIGN; 2618 2619 skb_pull(skb, sizeof(*rp)); 2620 2621 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); 2622 if (csrk) { 2623 if (conn->hcon->sec_level > BT_SECURITY_MEDIUM) 2624 csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED; 2625 else 2626 csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED; 2627 memcpy(csrk->val, rp->csrk, sizeof(csrk->val)); 2628 } 2629 smp->csrk = csrk; 2630 smp_distribute_keys(smp); 2631 2632 return 0; 2633 } 2634 2635 static u8 sc_select_method(struct smp_chan *smp) 2636 { 2637 struct l2cap_conn *conn = smp->conn; 2638 struct hci_conn *hcon = conn->hcon; 2639 struct smp_cmd_pairing *local, *remote; 2640 u8 local_mitm, remote_mitm, local_io, remote_io, method; 2641 2642 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) || 2643 test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) 2644 return REQ_OOB; 2645 2646 /* The preq/prsp contain the raw Pairing Request/Response PDUs 2647 * which are needed as inputs to some crypto functions. To get 2648 * the "struct smp_cmd_pairing" from them we need to skip the 2649 * first byte which contains the opcode. 2650 */ 2651 if (hcon->out) { 2652 local = (void *) &smp->preq[1]; 2653 remote = (void *) &smp->prsp[1]; 2654 } else { 2655 local = (void *) &smp->prsp[1]; 2656 remote = (void *) &smp->preq[1]; 2657 } 2658 2659 local_io = local->io_capability; 2660 remote_io = remote->io_capability; 2661 2662 local_mitm = (local->auth_req & SMP_AUTH_MITM); 2663 remote_mitm = (remote->auth_req & SMP_AUTH_MITM); 2664 2665 /* If either side wants MITM, look up the method from the table, 2666 * otherwise use JUST WORKS. 2667 */ 2668 if (local_mitm || remote_mitm) 2669 method = get_auth_method(smp, local_io, remote_io); 2670 else 2671 method = JUST_WORKS; 2672 2673 /* Don't confirm locally initiated pairing attempts */ 2674 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2675 method = JUST_WORKS; 2676 2677 return method; 2678 } 2679 2680 static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb) 2681 { 2682 struct smp_cmd_public_key *key = (void *) skb->data; 2683 struct hci_conn *hcon = conn->hcon; 2684 struct l2cap_chan *chan = conn->smp; 2685 struct smp_chan *smp = chan->data; 2686 struct hci_dev *hdev = hcon->hdev; 2687 struct crypto_kpp *tfm_ecdh; 2688 struct smp_cmd_pairing_confirm cfm; 2689 int err; 2690 2691 BT_DBG("conn %p", conn); 2692 2693 if (skb->len < sizeof(*key)) 2694 return SMP_INVALID_PARAMS; 2695 2696 memcpy(smp->remote_pk, key, 64); 2697 2698 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) { 2699 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk, 2700 smp->rr, 0, cfm.confirm_val); 2701 if (err) 2702 return SMP_UNSPECIFIED; 2703 2704 if (crypto_memneq(cfm.confirm_val, smp->pcnf, 16)) 2705 return SMP_CONFIRM_FAILED; 2706 } 2707 2708 /* Non-initiating device sends its public key after receiving 2709 * the key from the initiating device. 2710 */ 2711 if (!hcon->out) { 2712 err = sc_send_public_key(smp); 2713 if (err) 2714 return err; 2715 } 2716 2717 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk); 2718 SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32); 2719 2720 /* Compute the shared secret on the same crypto tfm on which the private 2721 * key was set/generated. 2722 */ 2723 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { 2724 struct l2cap_chan *hchan = hdev->smp_data; 2725 struct smp_dev *smp_dev; 2726 2727 if (!hchan || !hchan->data) 2728 return SMP_UNSPECIFIED; 2729 2730 smp_dev = hchan->data; 2731 2732 tfm_ecdh = smp_dev->tfm_ecdh; 2733 } else { 2734 tfm_ecdh = smp->tfm_ecdh; 2735 } 2736 2737 if (compute_ecdh_secret(tfm_ecdh, smp->remote_pk, smp->dhkey)) 2738 return SMP_UNSPECIFIED; 2739 2740 SMP_DBG("DHKey %32phN", smp->dhkey); 2741 2742 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags); 2743 2744 smp->method = sc_select_method(smp); 2745 2746 BT_DBG("%s selected method 0x%02x", hdev->name, smp->method); 2747 2748 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */ 2749 if (smp->method == JUST_WORKS || smp->method == JUST_CFM) 2750 hcon->pending_sec_level = BT_SECURITY_MEDIUM; 2751 else 2752 hcon->pending_sec_level = BT_SECURITY_FIPS; 2753 2754 if (!crypto_memneq(debug_pk, smp->remote_pk, 64)) 2755 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 2756 2757 if (smp->method == DSP_PASSKEY) { 2758 get_random_bytes(&hcon->passkey_notify, 2759 sizeof(hcon->passkey_notify)); 2760 hcon->passkey_notify %= 1000000; 2761 hcon->passkey_entered = 0; 2762 smp->passkey_round = 0; 2763 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type, 2764 hcon->dst_type, 2765 hcon->passkey_notify, 2766 hcon->passkey_entered)) 2767 return SMP_UNSPECIFIED; 2768 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2769 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY); 2770 } 2771 2772 if (smp->method == REQ_OOB) { 2773 if (hcon->out) 2774 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 2775 sizeof(smp->prnd), smp->prnd); 2776 2777 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2778 2779 return 0; 2780 } 2781 2782 if (hcon->out) 2783 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2784 2785 if (smp->method == REQ_PASSKEY) { 2786 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type, 2787 hcon->dst_type)) 2788 return SMP_UNSPECIFIED; 2789 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2790 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 2791 return 0; 2792 } 2793 2794 /* The Initiating device waits for the non-initiating device to 2795 * send the confirm value. 2796 */ 2797 if (conn->hcon->out) 2798 return 0; 2799 2800 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, 2801 0, cfm.confirm_val); 2802 if (err) 2803 return SMP_UNSPECIFIED; 2804 2805 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); 2806 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2807 2808 return 0; 2809 } 2810 2811 static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb) 2812 { 2813 struct smp_cmd_dhkey_check *check = (void *) skb->data; 2814 struct l2cap_chan *chan = conn->smp; 2815 struct hci_conn *hcon = conn->hcon; 2816 struct smp_chan *smp = chan->data; 2817 u8 a[7], b[7], *local_addr, *remote_addr; 2818 u8 io_cap[3], r[16], e[16]; 2819 int err; 2820 2821 BT_DBG("conn %p", conn); 2822 2823 if (skb->len < sizeof(*check)) 2824 return SMP_INVALID_PARAMS; 2825 2826 memcpy(a, &hcon->init_addr, 6); 2827 memcpy(b, &hcon->resp_addr, 6); 2828 a[6] = hcon->init_addr_type; 2829 b[6] = hcon->resp_addr_type; 2830 2831 if (hcon->out) { 2832 local_addr = a; 2833 remote_addr = b; 2834 memcpy(io_cap, &smp->prsp[1], 3); 2835 } else { 2836 local_addr = b; 2837 remote_addr = a; 2838 memcpy(io_cap, &smp->preq[1], 3); 2839 } 2840 2841 memset(r, 0, sizeof(r)); 2842 2843 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2844 put_unaligned_le32(hcon->passkey_notify, r); 2845 else if (smp->method == REQ_OOB) 2846 memcpy(r, smp->lr, 16); 2847 2848 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r, 2849 io_cap, remote_addr, local_addr, e); 2850 if (err) 2851 return SMP_UNSPECIFIED; 2852 2853 if (crypto_memneq(check->e, e, 16)) 2854 return SMP_DHKEY_CHECK_FAILED; 2855 2856 if (!hcon->out) { 2857 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { 2858 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags); 2859 return 0; 2860 } 2861 2862 /* Slave sends DHKey check as response to master */ 2863 sc_dhkey_check(smp); 2864 } 2865 2866 sc_add_ltk(smp); 2867 2868 if (hcon->out) { 2869 hci_le_start_enc(hcon, 0, 0, smp->tk, smp->enc_key_size); 2870 hcon->enc_key_size = smp->enc_key_size; 2871 } 2872 2873 return 0; 2874 } 2875 2876 static int smp_cmd_keypress_notify(struct l2cap_conn *conn, 2877 struct sk_buff *skb) 2878 { 2879 struct smp_cmd_keypress_notify *kp = (void *) skb->data; 2880 2881 BT_DBG("value 0x%02x", kp->value); 2882 2883 return 0; 2884 } 2885 2886 static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb) 2887 { 2888 struct l2cap_conn *conn = chan->conn; 2889 struct hci_conn *hcon = conn->hcon; 2890 struct smp_chan *smp; 2891 __u8 code, reason; 2892 int err = 0; 2893 2894 if (skb->len < 1) 2895 return -EILSEQ; 2896 2897 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) { 2898 reason = SMP_PAIRING_NOTSUPP; 2899 goto done; 2900 } 2901 2902 code = skb->data[0]; 2903 skb_pull(skb, sizeof(code)); 2904 2905 smp = chan->data; 2906 2907 if (code > SMP_CMD_MAX) 2908 goto drop; 2909 2910 if (smp && !test_and_clear_bit(code, &smp->allow_cmd)) 2911 goto drop; 2912 2913 /* If we don't have a context the only allowed commands are 2914 * pairing request and security request. 2915 */ 2916 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ) 2917 goto drop; 2918 2919 switch (code) { 2920 case SMP_CMD_PAIRING_REQ: 2921 reason = smp_cmd_pairing_req(conn, skb); 2922 break; 2923 2924 case SMP_CMD_PAIRING_FAIL: 2925 smp_failure(conn, 0); 2926 err = -EPERM; 2927 break; 2928 2929 case SMP_CMD_PAIRING_RSP: 2930 reason = smp_cmd_pairing_rsp(conn, skb); 2931 break; 2932 2933 case SMP_CMD_SECURITY_REQ: 2934 reason = smp_cmd_security_req(conn, skb); 2935 break; 2936 2937 case SMP_CMD_PAIRING_CONFIRM: 2938 reason = smp_cmd_pairing_confirm(conn, skb); 2939 break; 2940 2941 case SMP_CMD_PAIRING_RANDOM: 2942 reason = smp_cmd_pairing_random(conn, skb); 2943 break; 2944 2945 case SMP_CMD_ENCRYPT_INFO: 2946 reason = smp_cmd_encrypt_info(conn, skb); 2947 break; 2948 2949 case SMP_CMD_MASTER_IDENT: 2950 reason = smp_cmd_master_ident(conn, skb); 2951 break; 2952 2953 case SMP_CMD_IDENT_INFO: 2954 reason = smp_cmd_ident_info(conn, skb); 2955 break; 2956 2957 case SMP_CMD_IDENT_ADDR_INFO: 2958 reason = smp_cmd_ident_addr_info(conn, skb); 2959 break; 2960 2961 case SMP_CMD_SIGN_INFO: 2962 reason = smp_cmd_sign_info(conn, skb); 2963 break; 2964 2965 case SMP_CMD_PUBLIC_KEY: 2966 reason = smp_cmd_public_key(conn, skb); 2967 break; 2968 2969 case SMP_CMD_DHKEY_CHECK: 2970 reason = smp_cmd_dhkey_check(conn, skb); 2971 break; 2972 2973 case SMP_CMD_KEYPRESS_NOTIFY: 2974 reason = smp_cmd_keypress_notify(conn, skb); 2975 break; 2976 2977 default: 2978 BT_DBG("Unknown command code 0x%2.2x", code); 2979 reason = SMP_CMD_NOTSUPP; 2980 goto done; 2981 } 2982 2983 done: 2984 if (!err) { 2985 if (reason) 2986 smp_failure(conn, reason); 2987 kfree_skb(skb); 2988 } 2989 2990 return err; 2991 2992 drop: 2993 bt_dev_err(hcon->hdev, "unexpected SMP command 0x%02x from %pMR", 2994 code, &hcon->dst); 2995 kfree_skb(skb); 2996 return 0; 2997 } 2998 2999 static void smp_teardown_cb(struct l2cap_chan *chan, int err) 3000 { 3001 struct l2cap_conn *conn = chan->conn; 3002 3003 BT_DBG("chan %p", chan); 3004 3005 if (chan->data) 3006 smp_chan_destroy(conn); 3007 3008 conn->smp = NULL; 3009 l2cap_chan_put(chan); 3010 } 3011 3012 static void bredr_pairing(struct l2cap_chan *chan) 3013 { 3014 struct l2cap_conn *conn = chan->conn; 3015 struct hci_conn *hcon = conn->hcon; 3016 struct hci_dev *hdev = hcon->hdev; 3017 struct smp_cmd_pairing req; 3018 struct smp_chan *smp; 3019 3020 BT_DBG("chan %p", chan); 3021 3022 /* Only new pairings are interesting */ 3023 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags)) 3024 return; 3025 3026 /* Don't bother if we're not encrypted */ 3027 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3028 return; 3029 3030 /* Only master may initiate SMP over BR/EDR */ 3031 if (hcon->role != HCI_ROLE_MASTER) 3032 return; 3033 3034 /* Secure Connections support must be enabled */ 3035 if (!hci_dev_test_flag(hdev, HCI_SC_ENABLED)) 3036 return; 3037 3038 /* BR/EDR must use Secure Connections for SMP */ 3039 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) && 3040 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3041 return; 3042 3043 /* If our LE support is not enabled don't do anything */ 3044 if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) 3045 return; 3046 3047 /* Don't bother if remote LE support is not enabled */ 3048 if (!lmp_host_le_capable(hcon)) 3049 return; 3050 3051 /* Remote must support SMP fixed chan for BR/EDR */ 3052 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR)) 3053 return; 3054 3055 /* Don't bother if SMP is already ongoing */ 3056 if (chan->data) 3057 return; 3058 3059 smp = smp_chan_create(conn); 3060 if (!smp) { 3061 bt_dev_err(hdev, "unable to create SMP context for BR/EDR"); 3062 return; 3063 } 3064 3065 set_bit(SMP_FLAG_SC, &smp->flags); 3066 3067 BT_DBG("%s starting SMP over BR/EDR", hdev->name); 3068 3069 /* Prepare and send the BR/EDR SMP Pairing Request */ 3070 build_bredr_pairing_cmd(smp, &req, NULL); 3071 3072 smp->preq[0] = SMP_CMD_PAIRING_REQ; 3073 memcpy(&smp->preq[1], &req, sizeof(req)); 3074 3075 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(req), &req); 3076 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 3077 } 3078 3079 static void smp_resume_cb(struct l2cap_chan *chan) 3080 { 3081 struct smp_chan *smp = chan->data; 3082 struct l2cap_conn *conn = chan->conn; 3083 struct hci_conn *hcon = conn->hcon; 3084 3085 BT_DBG("chan %p", chan); 3086 3087 if (hcon->type == ACL_LINK) { 3088 bredr_pairing(chan); 3089 return; 3090 } 3091 3092 if (!smp) 3093 return; 3094 3095 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3096 return; 3097 3098 cancel_delayed_work(&smp->security_timer); 3099 3100 smp_distribute_keys(smp); 3101 } 3102 3103 static void smp_ready_cb(struct l2cap_chan *chan) 3104 { 3105 struct l2cap_conn *conn = chan->conn; 3106 struct hci_conn *hcon = conn->hcon; 3107 3108 BT_DBG("chan %p", chan); 3109 3110 /* No need to call l2cap_chan_hold() here since we already own 3111 * the reference taken in smp_new_conn_cb(). This is just the 3112 * first time that we tie it to a specific pointer. The code in 3113 * l2cap_core.c ensures that there's no risk this function wont 3114 * get called if smp_new_conn_cb was previously called. 3115 */ 3116 conn->smp = chan; 3117 3118 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3119 bredr_pairing(chan); 3120 } 3121 3122 static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 3123 { 3124 int err; 3125 3126 BT_DBG("chan %p", chan); 3127 3128 err = smp_sig_channel(chan, skb); 3129 if (err) { 3130 struct smp_chan *smp = chan->data; 3131 3132 if (smp) 3133 cancel_delayed_work_sync(&smp->security_timer); 3134 3135 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE); 3136 } 3137 3138 return err; 3139 } 3140 3141 static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan, 3142 unsigned long hdr_len, 3143 unsigned long len, int nb) 3144 { 3145 struct sk_buff *skb; 3146 3147 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL); 3148 if (!skb) 3149 return ERR_PTR(-ENOMEM); 3150 3151 skb->priority = HCI_PRIO_MAX; 3152 bt_cb(skb)->l2cap.chan = chan; 3153 3154 return skb; 3155 } 3156 3157 static const struct l2cap_ops smp_chan_ops = { 3158 .name = "Security Manager", 3159 .ready = smp_ready_cb, 3160 .recv = smp_recv_cb, 3161 .alloc_skb = smp_alloc_skb_cb, 3162 .teardown = smp_teardown_cb, 3163 .resume = smp_resume_cb, 3164 3165 .new_connection = l2cap_chan_no_new_connection, 3166 .state_change = l2cap_chan_no_state_change, 3167 .close = l2cap_chan_no_close, 3168 .defer = l2cap_chan_no_defer, 3169 .suspend = l2cap_chan_no_suspend, 3170 .set_shutdown = l2cap_chan_no_set_shutdown, 3171 .get_sndtimeo = l2cap_chan_no_get_sndtimeo, 3172 }; 3173 3174 static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan) 3175 { 3176 struct l2cap_chan *chan; 3177 3178 BT_DBG("pchan %p", pchan); 3179 3180 chan = l2cap_chan_create(); 3181 if (!chan) 3182 return NULL; 3183 3184 chan->chan_type = pchan->chan_type; 3185 chan->ops = &smp_chan_ops; 3186 chan->scid = pchan->scid; 3187 chan->dcid = chan->scid; 3188 chan->imtu = pchan->imtu; 3189 chan->omtu = pchan->omtu; 3190 chan->mode = pchan->mode; 3191 3192 /* Other L2CAP channels may request SMP routines in order to 3193 * change the security level. This means that the SMP channel 3194 * lock must be considered in its own category to avoid lockdep 3195 * warnings. 3196 */ 3197 atomic_set(&chan->nesting, L2CAP_NESTING_SMP); 3198 3199 BT_DBG("created chan %p", chan); 3200 3201 return chan; 3202 } 3203 3204 static const struct l2cap_ops smp_root_chan_ops = { 3205 .name = "Security Manager Root", 3206 .new_connection = smp_new_conn_cb, 3207 3208 /* None of these are implemented for the root channel */ 3209 .close = l2cap_chan_no_close, 3210 .alloc_skb = l2cap_chan_no_alloc_skb, 3211 .recv = l2cap_chan_no_recv, 3212 .state_change = l2cap_chan_no_state_change, 3213 .teardown = l2cap_chan_no_teardown, 3214 .ready = l2cap_chan_no_ready, 3215 .defer = l2cap_chan_no_defer, 3216 .suspend = l2cap_chan_no_suspend, 3217 .resume = l2cap_chan_no_resume, 3218 .set_shutdown = l2cap_chan_no_set_shutdown, 3219 .get_sndtimeo = l2cap_chan_no_get_sndtimeo, 3220 }; 3221 3222 static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid) 3223 { 3224 struct l2cap_chan *chan; 3225 struct smp_dev *smp; 3226 struct crypto_cipher *tfm_aes; 3227 struct crypto_shash *tfm_cmac; 3228 struct crypto_kpp *tfm_ecdh; 3229 3230 if (cid == L2CAP_CID_SMP_BREDR) { 3231 smp = NULL; 3232 goto create_chan; 3233 } 3234 3235 smp = kzalloc(sizeof(*smp), GFP_KERNEL); 3236 if (!smp) 3237 return ERR_PTR(-ENOMEM); 3238 3239 tfm_aes = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC); 3240 if (IS_ERR(tfm_aes)) { 3241 BT_ERR("Unable to create AES crypto context"); 3242 kzfree(smp); 3243 return ERR_CAST(tfm_aes); 3244 } 3245 3246 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 3247 if (IS_ERR(tfm_cmac)) { 3248 BT_ERR("Unable to create CMAC crypto context"); 3249 crypto_free_cipher(tfm_aes); 3250 kzfree(smp); 3251 return ERR_CAST(tfm_cmac); 3252 } 3253 3254 tfm_ecdh = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0); 3255 if (IS_ERR(tfm_ecdh)) { 3256 BT_ERR("Unable to create ECDH crypto context"); 3257 crypto_free_shash(tfm_cmac); 3258 crypto_free_cipher(tfm_aes); 3259 kzfree(smp); 3260 return ERR_CAST(tfm_ecdh); 3261 } 3262 3263 smp->local_oob = false; 3264 smp->tfm_aes = tfm_aes; 3265 smp->tfm_cmac = tfm_cmac; 3266 smp->tfm_ecdh = tfm_ecdh; 3267 smp->min_key_size = SMP_MIN_ENC_KEY_SIZE; 3268 smp->max_key_size = SMP_MAX_ENC_KEY_SIZE; 3269 3270 create_chan: 3271 chan = l2cap_chan_create(); 3272 if (!chan) { 3273 if (smp) { 3274 crypto_free_cipher(smp->tfm_aes); 3275 crypto_free_shash(smp->tfm_cmac); 3276 crypto_free_kpp(smp->tfm_ecdh); 3277 kzfree(smp); 3278 } 3279 return ERR_PTR(-ENOMEM); 3280 } 3281 3282 chan->data = smp; 3283 3284 l2cap_add_scid(chan, cid); 3285 3286 l2cap_chan_set_defaults(chan); 3287 3288 if (cid == L2CAP_CID_SMP) { 3289 u8 bdaddr_type; 3290 3291 hci_copy_identity_address(hdev, &chan->src, &bdaddr_type); 3292 3293 if (bdaddr_type == ADDR_LE_DEV_PUBLIC) 3294 chan->src_type = BDADDR_LE_PUBLIC; 3295 else 3296 chan->src_type = BDADDR_LE_RANDOM; 3297 } else { 3298 bacpy(&chan->src, &hdev->bdaddr); 3299 chan->src_type = BDADDR_BREDR; 3300 } 3301 3302 chan->state = BT_LISTEN; 3303 chan->mode = L2CAP_MODE_BASIC; 3304 chan->imtu = L2CAP_DEFAULT_MTU; 3305 chan->ops = &smp_root_chan_ops; 3306 3307 /* Set correct nesting level for a parent/listening channel */ 3308 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 3309 3310 return chan; 3311 } 3312 3313 static void smp_del_chan(struct l2cap_chan *chan) 3314 { 3315 struct smp_dev *smp; 3316 3317 BT_DBG("chan %p", chan); 3318 3319 smp = chan->data; 3320 if (smp) { 3321 chan->data = NULL; 3322 crypto_free_cipher(smp->tfm_aes); 3323 crypto_free_shash(smp->tfm_cmac); 3324 crypto_free_kpp(smp->tfm_ecdh); 3325 kzfree(smp); 3326 } 3327 3328 l2cap_chan_put(chan); 3329 } 3330 3331 static ssize_t force_bredr_smp_read(struct file *file, 3332 char __user *user_buf, 3333 size_t count, loff_t *ppos) 3334 { 3335 struct hci_dev *hdev = file->private_data; 3336 char buf[3]; 3337 3338 buf[0] = hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP) ? 'Y': 'N'; 3339 buf[1] = '\n'; 3340 buf[2] = '\0'; 3341 return simple_read_from_buffer(user_buf, count, ppos, buf, 2); 3342 } 3343 3344 static ssize_t force_bredr_smp_write(struct file *file, 3345 const char __user *user_buf, 3346 size_t count, loff_t *ppos) 3347 { 3348 struct hci_dev *hdev = file->private_data; 3349 bool enable; 3350 int err; 3351 3352 err = kstrtobool_from_user(user_buf, count, &enable); 3353 if (err) 3354 return err; 3355 3356 if (enable == hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3357 return -EALREADY; 3358 3359 if (enable) { 3360 struct l2cap_chan *chan; 3361 3362 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); 3363 if (IS_ERR(chan)) 3364 return PTR_ERR(chan); 3365 3366 hdev->smp_bredr_data = chan; 3367 } else { 3368 struct l2cap_chan *chan; 3369 3370 chan = hdev->smp_bredr_data; 3371 hdev->smp_bredr_data = NULL; 3372 smp_del_chan(chan); 3373 } 3374 3375 hci_dev_change_flag(hdev, HCI_FORCE_BREDR_SMP); 3376 3377 return count; 3378 } 3379 3380 static const struct file_operations force_bredr_smp_fops = { 3381 .open = simple_open, 3382 .read = force_bredr_smp_read, 3383 .write = force_bredr_smp_write, 3384 .llseek = default_llseek, 3385 }; 3386 3387 static ssize_t le_min_key_size_read(struct file *file, 3388 char __user *user_buf, 3389 size_t count, loff_t *ppos) 3390 { 3391 struct hci_dev *hdev = file->private_data; 3392 char buf[4]; 3393 3394 snprintf(buf, sizeof(buf), "%2u\n", SMP_DEV(hdev)->min_key_size); 3395 3396 return simple_read_from_buffer(user_buf, count, ppos, buf, strlen(buf)); 3397 } 3398 3399 static ssize_t le_min_key_size_write(struct file *file, 3400 const char __user *user_buf, 3401 size_t count, loff_t *ppos) 3402 { 3403 struct hci_dev *hdev = file->private_data; 3404 char buf[32]; 3405 size_t buf_size = min(count, (sizeof(buf) - 1)); 3406 u8 key_size; 3407 3408 if (copy_from_user(buf, user_buf, buf_size)) 3409 return -EFAULT; 3410 3411 buf[buf_size] = '\0'; 3412 3413 sscanf(buf, "%hhu", &key_size); 3414 3415 if (key_size > SMP_DEV(hdev)->max_key_size || 3416 key_size < SMP_MIN_ENC_KEY_SIZE) 3417 return -EINVAL; 3418 3419 SMP_DEV(hdev)->min_key_size = key_size; 3420 3421 return count; 3422 } 3423 3424 static const struct file_operations le_min_key_size_fops = { 3425 .open = simple_open, 3426 .read = le_min_key_size_read, 3427 .write = le_min_key_size_write, 3428 .llseek = default_llseek, 3429 }; 3430 3431 static ssize_t le_max_key_size_read(struct file *file, 3432 char __user *user_buf, 3433 size_t count, loff_t *ppos) 3434 { 3435 struct hci_dev *hdev = file->private_data; 3436 char buf[4]; 3437 3438 snprintf(buf, sizeof(buf), "%2u\n", SMP_DEV(hdev)->max_key_size); 3439 3440 return simple_read_from_buffer(user_buf, count, ppos, buf, strlen(buf)); 3441 } 3442 3443 static ssize_t le_max_key_size_write(struct file *file, 3444 const char __user *user_buf, 3445 size_t count, loff_t *ppos) 3446 { 3447 struct hci_dev *hdev = file->private_data; 3448 char buf[32]; 3449 size_t buf_size = min(count, (sizeof(buf) - 1)); 3450 u8 key_size; 3451 3452 if (copy_from_user(buf, user_buf, buf_size)) 3453 return -EFAULT; 3454 3455 buf[buf_size] = '\0'; 3456 3457 sscanf(buf, "%hhu", &key_size); 3458 3459 if (key_size > SMP_MAX_ENC_KEY_SIZE || 3460 key_size < SMP_DEV(hdev)->min_key_size) 3461 return -EINVAL; 3462 3463 SMP_DEV(hdev)->max_key_size = key_size; 3464 3465 return count; 3466 } 3467 3468 static const struct file_operations le_max_key_size_fops = { 3469 .open = simple_open, 3470 .read = le_max_key_size_read, 3471 .write = le_max_key_size_write, 3472 .llseek = default_llseek, 3473 }; 3474 3475 int smp_register(struct hci_dev *hdev) 3476 { 3477 struct l2cap_chan *chan; 3478 3479 BT_DBG("%s", hdev->name); 3480 3481 /* If the controller does not support Low Energy operation, then 3482 * there is also no need to register any SMP channel. 3483 */ 3484 if (!lmp_le_capable(hdev)) 3485 return 0; 3486 3487 if (WARN_ON(hdev->smp_data)) { 3488 chan = hdev->smp_data; 3489 hdev->smp_data = NULL; 3490 smp_del_chan(chan); 3491 } 3492 3493 chan = smp_add_cid(hdev, L2CAP_CID_SMP); 3494 if (IS_ERR(chan)) 3495 return PTR_ERR(chan); 3496 3497 hdev->smp_data = chan; 3498 3499 debugfs_create_file("le_min_key_size", 0644, hdev->debugfs, hdev, 3500 &le_min_key_size_fops); 3501 debugfs_create_file("le_max_key_size", 0644, hdev->debugfs, hdev, 3502 &le_max_key_size_fops); 3503 3504 /* If the controller does not support BR/EDR Secure Connections 3505 * feature, then the BR/EDR SMP channel shall not be present. 3506 * 3507 * To test this with Bluetooth 4.0 controllers, create a debugfs 3508 * switch that allows forcing BR/EDR SMP support and accepting 3509 * cross-transport pairing on non-AES encrypted connections. 3510 */ 3511 if (!lmp_sc_capable(hdev)) { 3512 debugfs_create_file("force_bredr_smp", 0644, hdev->debugfs, 3513 hdev, &force_bredr_smp_fops); 3514 3515 /* Flag can be already set here (due to power toggle) */ 3516 if (!hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3517 return 0; 3518 } 3519 3520 if (WARN_ON(hdev->smp_bredr_data)) { 3521 chan = hdev->smp_bredr_data; 3522 hdev->smp_bredr_data = NULL; 3523 smp_del_chan(chan); 3524 } 3525 3526 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); 3527 if (IS_ERR(chan)) { 3528 int err = PTR_ERR(chan); 3529 chan = hdev->smp_data; 3530 hdev->smp_data = NULL; 3531 smp_del_chan(chan); 3532 return err; 3533 } 3534 3535 hdev->smp_bredr_data = chan; 3536 3537 return 0; 3538 } 3539 3540 void smp_unregister(struct hci_dev *hdev) 3541 { 3542 struct l2cap_chan *chan; 3543 3544 if (hdev->smp_bredr_data) { 3545 chan = hdev->smp_bredr_data; 3546 hdev->smp_bredr_data = NULL; 3547 smp_del_chan(chan); 3548 } 3549 3550 if (hdev->smp_data) { 3551 chan = hdev->smp_data; 3552 hdev->smp_data = NULL; 3553 smp_del_chan(chan); 3554 } 3555 } 3556 3557 #if IS_ENABLED(CONFIG_BT_SELFTEST_SMP) 3558 3559 static int __init test_debug_key(struct crypto_kpp *tfm_ecdh) 3560 { 3561 u8 pk[64]; 3562 int err; 3563 3564 err = set_ecdh_privkey(tfm_ecdh, debug_sk); 3565 if (err) 3566 return err; 3567 3568 err = generate_ecdh_public_key(tfm_ecdh, pk); 3569 if (err) 3570 return err; 3571 3572 if (crypto_memneq(pk, debug_pk, 64)) 3573 return -EINVAL; 3574 3575 return 0; 3576 } 3577 3578 static int __init test_ah(struct crypto_cipher *tfm_aes) 3579 { 3580 const u8 irk[16] = { 3581 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3582 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3583 const u8 r[3] = { 0x94, 0x81, 0x70 }; 3584 const u8 exp[3] = { 0xaa, 0xfb, 0x0d }; 3585 u8 res[3]; 3586 int err; 3587 3588 err = smp_ah(tfm_aes, irk, r, res); 3589 if (err) 3590 return err; 3591 3592 if (crypto_memneq(res, exp, 3)) 3593 return -EINVAL; 3594 3595 return 0; 3596 } 3597 3598 static int __init test_c1(struct crypto_cipher *tfm_aes) 3599 { 3600 const u8 k[16] = { 3601 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 3602 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; 3603 const u8 r[16] = { 3604 0xe0, 0x2e, 0x70, 0xc6, 0x4e, 0x27, 0x88, 0x63, 3605 0x0e, 0x6f, 0xad, 0x56, 0x21, 0xd5, 0x83, 0x57 }; 3606 const u8 preq[7] = { 0x01, 0x01, 0x00, 0x00, 0x10, 0x07, 0x07 }; 3607 const u8 pres[7] = { 0x02, 0x03, 0x00, 0x00, 0x08, 0x00, 0x05 }; 3608 const u8 _iat = 0x01; 3609 const u8 _rat = 0x00; 3610 const bdaddr_t ra = { { 0xb6, 0xb5, 0xb4, 0xb3, 0xb2, 0xb1 } }; 3611 const bdaddr_t ia = { { 0xa6, 0xa5, 0xa4, 0xa3, 0xa2, 0xa1 } }; 3612 const u8 exp[16] = { 3613 0x86, 0x3b, 0xf1, 0xbe, 0xc5, 0x4d, 0xa7, 0xd2, 3614 0xea, 0x88, 0x89, 0x87, 0xef, 0x3f, 0x1e, 0x1e }; 3615 u8 res[16]; 3616 int err; 3617 3618 err = smp_c1(tfm_aes, k, r, preq, pres, _iat, &ia, _rat, &ra, res); 3619 if (err) 3620 return err; 3621 3622 if (crypto_memneq(res, exp, 16)) 3623 return -EINVAL; 3624 3625 return 0; 3626 } 3627 3628 static int __init test_s1(struct crypto_cipher *tfm_aes) 3629 { 3630 const u8 k[16] = { 3631 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 3632 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; 3633 const u8 r1[16] = { 3634 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 }; 3635 const u8 r2[16] = { 3636 0x00, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99 }; 3637 const u8 exp[16] = { 3638 0x62, 0xa0, 0x6d, 0x79, 0xae, 0x16, 0x42, 0x5b, 3639 0x9b, 0xf4, 0xb0, 0xe8, 0xf0, 0xe1, 0x1f, 0x9a }; 3640 u8 res[16]; 3641 int err; 3642 3643 err = smp_s1(tfm_aes, k, r1, r2, res); 3644 if (err) 3645 return err; 3646 3647 if (crypto_memneq(res, exp, 16)) 3648 return -EINVAL; 3649 3650 return 0; 3651 } 3652 3653 static int __init test_f4(struct crypto_shash *tfm_cmac) 3654 { 3655 const u8 u[32] = { 3656 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 3657 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 3658 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 3659 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 }; 3660 const u8 v[32] = { 3661 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b, 3662 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59, 3663 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90, 3664 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 }; 3665 const u8 x[16] = { 3666 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3667 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3668 const u8 z = 0x00; 3669 const u8 exp[16] = { 3670 0x2d, 0x87, 0x74, 0xa9, 0xbe, 0xa1, 0xed, 0xf1, 3671 0x1c, 0xbd, 0xa9, 0x07, 0xf1, 0x16, 0xc9, 0xf2 }; 3672 u8 res[16]; 3673 int err; 3674 3675 err = smp_f4(tfm_cmac, u, v, x, z, res); 3676 if (err) 3677 return err; 3678 3679 if (crypto_memneq(res, exp, 16)) 3680 return -EINVAL; 3681 3682 return 0; 3683 } 3684 3685 static int __init test_f5(struct crypto_shash *tfm_cmac) 3686 { 3687 const u8 w[32] = { 3688 0x98, 0xa6, 0xbf, 0x73, 0xf3, 0x34, 0x8d, 0x86, 3689 0xf1, 0x66, 0xf8, 0xb4, 0x13, 0x6b, 0x79, 0x99, 3690 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3691 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3692 const u8 n1[16] = { 3693 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3694 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3695 const u8 n2[16] = { 3696 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3697 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3698 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 }; 3699 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 }; 3700 const u8 exp_ltk[16] = { 3701 0x38, 0x0a, 0x75, 0x94, 0xb5, 0x22, 0x05, 0x98, 3702 0x23, 0xcd, 0xd7, 0x69, 0x11, 0x79, 0x86, 0x69 }; 3703 const u8 exp_mackey[16] = { 3704 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd, 3705 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 }; 3706 u8 mackey[16], ltk[16]; 3707 int err; 3708 3709 err = smp_f5(tfm_cmac, w, n1, n2, a1, a2, mackey, ltk); 3710 if (err) 3711 return err; 3712 3713 if (crypto_memneq(mackey, exp_mackey, 16)) 3714 return -EINVAL; 3715 3716 if (crypto_memneq(ltk, exp_ltk, 16)) 3717 return -EINVAL; 3718 3719 return 0; 3720 } 3721 3722 static int __init test_f6(struct crypto_shash *tfm_cmac) 3723 { 3724 const u8 w[16] = { 3725 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd, 3726 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 }; 3727 const u8 n1[16] = { 3728 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3729 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3730 const u8 n2[16] = { 3731 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3732 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3733 const u8 r[16] = { 3734 0xc8, 0x0f, 0x2d, 0x0c, 0xd2, 0x42, 0xda, 0x08, 3735 0x54, 0xbb, 0x53, 0xb4, 0x3b, 0x34, 0xa3, 0x12 }; 3736 const u8 io_cap[3] = { 0x02, 0x01, 0x01 }; 3737 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 }; 3738 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 }; 3739 const u8 exp[16] = { 3740 0x61, 0x8f, 0x95, 0xda, 0x09, 0x0b, 0x6c, 0xd2, 3741 0xc5, 0xe8, 0xd0, 0x9c, 0x98, 0x73, 0xc4, 0xe3 }; 3742 u8 res[16]; 3743 int err; 3744 3745 err = smp_f6(tfm_cmac, w, n1, n2, r, io_cap, a1, a2, res); 3746 if (err) 3747 return err; 3748 3749 if (crypto_memneq(res, exp, 16)) 3750 return -EINVAL; 3751 3752 return 0; 3753 } 3754 3755 static int __init test_g2(struct crypto_shash *tfm_cmac) 3756 { 3757 const u8 u[32] = { 3758 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 3759 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 3760 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 3761 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 }; 3762 const u8 v[32] = { 3763 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b, 3764 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59, 3765 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90, 3766 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 }; 3767 const u8 x[16] = { 3768 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3769 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3770 const u8 y[16] = { 3771 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3772 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3773 const u32 exp_val = 0x2f9ed5ba % 1000000; 3774 u32 val; 3775 int err; 3776 3777 err = smp_g2(tfm_cmac, u, v, x, y, &val); 3778 if (err) 3779 return err; 3780 3781 if (val != exp_val) 3782 return -EINVAL; 3783 3784 return 0; 3785 } 3786 3787 static int __init test_h6(struct crypto_shash *tfm_cmac) 3788 { 3789 const u8 w[16] = { 3790 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3791 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3792 const u8 key_id[4] = { 0x72, 0x62, 0x65, 0x6c }; 3793 const u8 exp[16] = { 3794 0x99, 0x63, 0xb1, 0x80, 0xe2, 0xa9, 0xd3, 0xe8, 3795 0x1c, 0xc9, 0x6d, 0xe7, 0x02, 0xe1, 0x9a, 0x2d }; 3796 u8 res[16]; 3797 int err; 3798 3799 err = smp_h6(tfm_cmac, w, key_id, res); 3800 if (err) 3801 return err; 3802 3803 if (crypto_memneq(res, exp, 16)) 3804 return -EINVAL; 3805 3806 return 0; 3807 } 3808 3809 static char test_smp_buffer[32]; 3810 3811 static ssize_t test_smp_read(struct file *file, char __user *user_buf, 3812 size_t count, loff_t *ppos) 3813 { 3814 return simple_read_from_buffer(user_buf, count, ppos, test_smp_buffer, 3815 strlen(test_smp_buffer)); 3816 } 3817 3818 static const struct file_operations test_smp_fops = { 3819 .open = simple_open, 3820 .read = test_smp_read, 3821 .llseek = default_llseek, 3822 }; 3823 3824 static int __init run_selftests(struct crypto_cipher *tfm_aes, 3825 struct crypto_shash *tfm_cmac, 3826 struct crypto_kpp *tfm_ecdh) 3827 { 3828 ktime_t calltime, delta, rettime; 3829 unsigned long long duration; 3830 int err; 3831 3832 calltime = ktime_get(); 3833 3834 err = test_debug_key(tfm_ecdh); 3835 if (err) { 3836 BT_ERR("debug_key test failed"); 3837 goto done; 3838 } 3839 3840 err = test_ah(tfm_aes); 3841 if (err) { 3842 BT_ERR("smp_ah test failed"); 3843 goto done; 3844 } 3845 3846 err = test_c1(tfm_aes); 3847 if (err) { 3848 BT_ERR("smp_c1 test failed"); 3849 goto done; 3850 } 3851 3852 err = test_s1(tfm_aes); 3853 if (err) { 3854 BT_ERR("smp_s1 test failed"); 3855 goto done; 3856 } 3857 3858 err = test_f4(tfm_cmac); 3859 if (err) { 3860 BT_ERR("smp_f4 test failed"); 3861 goto done; 3862 } 3863 3864 err = test_f5(tfm_cmac); 3865 if (err) { 3866 BT_ERR("smp_f5 test failed"); 3867 goto done; 3868 } 3869 3870 err = test_f6(tfm_cmac); 3871 if (err) { 3872 BT_ERR("smp_f6 test failed"); 3873 goto done; 3874 } 3875 3876 err = test_g2(tfm_cmac); 3877 if (err) { 3878 BT_ERR("smp_g2 test failed"); 3879 goto done; 3880 } 3881 3882 err = test_h6(tfm_cmac); 3883 if (err) { 3884 BT_ERR("smp_h6 test failed"); 3885 goto done; 3886 } 3887 3888 rettime = ktime_get(); 3889 delta = ktime_sub(rettime, calltime); 3890 duration = (unsigned long long) ktime_to_ns(delta) >> 10; 3891 3892 BT_INFO("SMP test passed in %llu usecs", duration); 3893 3894 done: 3895 if (!err) 3896 snprintf(test_smp_buffer, sizeof(test_smp_buffer), 3897 "PASS (%llu usecs)\n", duration); 3898 else 3899 snprintf(test_smp_buffer, sizeof(test_smp_buffer), "FAIL\n"); 3900 3901 debugfs_create_file("selftest_smp", 0444, bt_debugfs, NULL, 3902 &test_smp_fops); 3903 3904 return err; 3905 } 3906 3907 int __init bt_selftest_smp(void) 3908 { 3909 struct crypto_cipher *tfm_aes; 3910 struct crypto_shash *tfm_cmac; 3911 struct crypto_kpp *tfm_ecdh; 3912 int err; 3913 3914 tfm_aes = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC); 3915 if (IS_ERR(tfm_aes)) { 3916 BT_ERR("Unable to create AES crypto context"); 3917 return PTR_ERR(tfm_aes); 3918 } 3919 3920 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, CRYPTO_ALG_ASYNC); 3921 if (IS_ERR(tfm_cmac)) { 3922 BT_ERR("Unable to create CMAC crypto context"); 3923 crypto_free_cipher(tfm_aes); 3924 return PTR_ERR(tfm_cmac); 3925 } 3926 3927 tfm_ecdh = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0); 3928 if (IS_ERR(tfm_ecdh)) { 3929 BT_ERR("Unable to create ECDH crypto context"); 3930 crypto_free_shash(tfm_cmac); 3931 crypto_free_cipher(tfm_aes); 3932 return PTR_ERR(tfm_ecdh); 3933 } 3934 3935 err = run_selftests(tfm_aes, tfm_cmac, tfm_ecdh); 3936 3937 crypto_free_shash(tfm_cmac); 3938 crypto_free_cipher(tfm_aes); 3939 crypto_free_kpp(tfm_ecdh); 3940 3941 return err; 3942 } 3943 3944 #endif 3945