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