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/aes.h> 27 #include <crypto/algapi.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 * accidentally 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_shash *tfm_cmac; 92 struct crypto_kpp *tfm_ecdh; 93 }; 94 95 struct smp_chan { 96 struct l2cap_conn *conn; 97 struct delayed_work security_timer; 98 unsigned long allow_cmd; /* Bitmask of allowed commands */ 99 100 u8 preq[7]; /* SMP Pairing Request */ 101 u8 prsp[7]; /* SMP Pairing Response */ 102 u8 prnd[16]; /* SMP Pairing Random (local) */ 103 u8 rrnd[16]; /* SMP Pairing Random (remote) */ 104 u8 pcnf[16]; /* SMP Pairing Confirm */ 105 u8 tk[16]; /* SMP Temporary Key */ 106 u8 rr[16]; /* Remote OOB ra/rb value */ 107 u8 lr[16]; /* Local OOB ra/rb value */ 108 u8 enc_key_size; 109 u8 remote_key_dist; 110 bdaddr_t id_addr; 111 u8 id_addr_type; 112 u8 irk[16]; 113 struct smp_csrk *csrk; 114 struct smp_csrk *responder_csrk; 115 struct smp_ltk *ltk; 116 struct smp_ltk *responder_ltk; 117 struct smp_irk *remote_irk; 118 u8 *link_key; 119 unsigned long flags; 120 u8 method; 121 u8 passkey_round; 122 123 /* Secure Connections variables */ 124 u8 local_pk[64]; 125 u8 remote_pk[64]; 126 u8 dhkey[32]; 127 u8 mackey[16]; 128 129 struct crypto_shash *tfm_cmac; 130 struct crypto_kpp *tfm_ecdh; 131 }; 132 133 /* These debug key values are defined in the SMP section of the core 134 * specification. debug_pk is the public debug key and debug_sk the 135 * private debug key. 136 */ 137 static const u8 debug_pk[64] = { 138 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 139 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 140 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 141 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20, 142 143 0x8b, 0xd2, 0x89, 0x15, 0xd0, 0x8e, 0x1c, 0x74, 144 0x24, 0x30, 0xed, 0x8f, 0xc2, 0x45, 0x63, 0x76, 145 0x5c, 0x15, 0x52, 0x5a, 0xbf, 0x9a, 0x32, 0x63, 146 0x6d, 0xeb, 0x2a, 0x65, 0x49, 0x9c, 0x80, 0xdc, 147 }; 148 149 static const u8 debug_sk[32] = { 150 0xbd, 0x1a, 0x3c, 0xcd, 0xa6, 0xb8, 0x99, 0x58, 151 0x99, 0xb7, 0x40, 0xeb, 0x7b, 0x60, 0xff, 0x4a, 152 0x50, 0x3f, 0x10, 0xd2, 0xe3, 0xb3, 0xc9, 0x74, 153 0x38, 0x5f, 0xc5, 0xa3, 0xd4, 0xf6, 0x49, 0x3f, 154 }; 155 156 static inline void swap_buf(const u8 *src, u8 *dst, size_t len) 157 { 158 size_t i; 159 160 for (i = 0; i < len; i++) 161 dst[len - 1 - i] = src[i]; 162 } 163 164 /* The following functions map to the LE SC SMP crypto functions 165 * AES-CMAC, f4, f5, f6, g2 and h6. 166 */ 167 168 static int aes_cmac(struct crypto_shash *tfm, const u8 k[16], const u8 *m, 169 size_t len, u8 mac[16]) 170 { 171 uint8_t tmp[16], mac_msb[16], msg_msb[CMAC_MSG_MAX]; 172 int err; 173 174 if (len > CMAC_MSG_MAX) 175 return -EFBIG; 176 177 if (!tfm) { 178 BT_ERR("tfm %p", tfm); 179 return -EINVAL; 180 } 181 182 /* Swap key and message from LSB to MSB */ 183 swap_buf(k, tmp, 16); 184 swap_buf(m, msg_msb, len); 185 186 SMP_DBG("msg (len %zu) %*phN", len, (int) len, m); 187 SMP_DBG("key %16phN", k); 188 189 err = crypto_shash_setkey(tfm, tmp, 16); 190 if (err) { 191 BT_ERR("cipher setkey failed: %d", err); 192 return err; 193 } 194 195 err = crypto_shash_tfm_digest(tfm, msg_msb, len, mac_msb); 196 if (err) { 197 BT_ERR("Hash computation error %d", err); 198 return err; 199 } 200 201 swap_buf(mac_msb, mac, 16); 202 203 SMP_DBG("mac %16phN", mac); 204 205 return 0; 206 } 207 208 static int smp_f4(struct crypto_shash *tfm_cmac, const u8 u[32], 209 const u8 v[32], const u8 x[16], u8 z, u8 res[16]) 210 { 211 u8 m[65]; 212 int err; 213 214 SMP_DBG("u %32phN", u); 215 SMP_DBG("v %32phN", v); 216 SMP_DBG("x %16phN z %02x", x, z); 217 218 m[0] = z; 219 memcpy(m + 1, v, 32); 220 memcpy(m + 33, u, 32); 221 222 err = aes_cmac(tfm_cmac, x, m, sizeof(m), res); 223 if (err) 224 return err; 225 226 SMP_DBG("res %16phN", res); 227 228 return err; 229 } 230 231 static int smp_f5(struct crypto_shash *tfm_cmac, const u8 w[32], 232 const u8 n1[16], const u8 n2[16], const u8 a1[7], 233 const u8 a2[7], u8 mackey[16], u8 ltk[16]) 234 { 235 /* The btle, salt and length "magic" values are as defined in 236 * the SMP section of the Bluetooth core specification. In ASCII 237 * the btle value ends up being 'btle'. The salt is just a 238 * random number whereas length is the value 256 in little 239 * endian format. 240 */ 241 const u8 btle[4] = { 0x65, 0x6c, 0x74, 0x62 }; 242 const u8 salt[16] = { 0xbe, 0x83, 0x60, 0x5a, 0xdb, 0x0b, 0x37, 0x60, 243 0x38, 0xa5, 0xf5, 0xaa, 0x91, 0x83, 0x88, 0x6c }; 244 const u8 length[2] = { 0x00, 0x01 }; 245 u8 m[53], t[16]; 246 int err; 247 248 SMP_DBG("w %32phN", w); 249 SMP_DBG("n1 %16phN n2 %16phN", n1, n2); 250 SMP_DBG("a1 %7phN a2 %7phN", a1, a2); 251 252 err = aes_cmac(tfm_cmac, salt, w, 32, t); 253 if (err) 254 return err; 255 256 SMP_DBG("t %16phN", t); 257 258 memcpy(m, length, 2); 259 memcpy(m + 2, a2, 7); 260 memcpy(m + 9, a1, 7); 261 memcpy(m + 16, n2, 16); 262 memcpy(m + 32, n1, 16); 263 memcpy(m + 48, btle, 4); 264 265 m[52] = 0; /* Counter */ 266 267 err = aes_cmac(tfm_cmac, t, m, sizeof(m), mackey); 268 if (err) 269 return err; 270 271 SMP_DBG("mackey %16phN", mackey); 272 273 m[52] = 1; /* Counter */ 274 275 err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk); 276 if (err) 277 return err; 278 279 SMP_DBG("ltk %16phN", ltk); 280 281 return 0; 282 } 283 284 static int smp_f6(struct crypto_shash *tfm_cmac, const u8 w[16], 285 const u8 n1[16], const u8 n2[16], const u8 r[16], 286 const u8 io_cap[3], const u8 a1[7], const u8 a2[7], 287 u8 res[16]) 288 { 289 u8 m[65]; 290 int err; 291 292 SMP_DBG("w %16phN", w); 293 SMP_DBG("n1 %16phN n2 %16phN", n1, n2); 294 SMP_DBG("r %16phN io_cap %3phN a1 %7phN a2 %7phN", r, io_cap, a1, a2); 295 296 memcpy(m, a2, 7); 297 memcpy(m + 7, a1, 7); 298 memcpy(m + 14, io_cap, 3); 299 memcpy(m + 17, r, 16); 300 memcpy(m + 33, n2, 16); 301 memcpy(m + 49, n1, 16); 302 303 err = aes_cmac(tfm_cmac, w, m, sizeof(m), res); 304 if (err) 305 return err; 306 307 SMP_DBG("res %16phN", res); 308 309 return err; 310 } 311 312 static int smp_g2(struct crypto_shash *tfm_cmac, const u8 u[32], const u8 v[32], 313 const u8 x[16], const u8 y[16], u32 *val) 314 { 315 u8 m[80], tmp[16]; 316 int err; 317 318 SMP_DBG("u %32phN", u); 319 SMP_DBG("v %32phN", v); 320 SMP_DBG("x %16phN y %16phN", x, y); 321 322 memcpy(m, y, 16); 323 memcpy(m + 16, v, 32); 324 memcpy(m + 48, u, 32); 325 326 err = aes_cmac(tfm_cmac, x, m, sizeof(m), tmp); 327 if (err) 328 return err; 329 330 *val = get_unaligned_le32(tmp); 331 *val %= 1000000; 332 333 SMP_DBG("val %06u", *val); 334 335 return 0; 336 } 337 338 static int smp_h6(struct crypto_shash *tfm_cmac, const u8 w[16], 339 const u8 key_id[4], u8 res[16]) 340 { 341 int err; 342 343 SMP_DBG("w %16phN key_id %4phN", w, key_id); 344 345 err = aes_cmac(tfm_cmac, w, key_id, 4, res); 346 if (err) 347 return err; 348 349 SMP_DBG("res %16phN", res); 350 351 return err; 352 } 353 354 static int smp_h7(struct crypto_shash *tfm_cmac, const u8 w[16], 355 const u8 salt[16], u8 res[16]) 356 { 357 int err; 358 359 SMP_DBG("w %16phN salt %16phN", w, salt); 360 361 err = aes_cmac(tfm_cmac, salt, w, 16, res); 362 if (err) 363 return err; 364 365 SMP_DBG("res %16phN", res); 366 367 return err; 368 } 369 370 /* The following functions map to the legacy SMP crypto functions e, c1, 371 * s1 and ah. 372 */ 373 374 static int smp_e(const u8 *k, u8 *r) 375 { 376 struct crypto_aes_ctx ctx; 377 uint8_t tmp[16], data[16]; 378 int err; 379 380 SMP_DBG("k %16phN r %16phN", k, r); 381 382 /* The most significant octet of key corresponds to k[0] */ 383 swap_buf(k, tmp, 16); 384 385 err = aes_expandkey(&ctx, tmp, 16); 386 if (err) { 387 BT_ERR("cipher setkey failed: %d", err); 388 return err; 389 } 390 391 /* Most significant octet of plaintextData corresponds to data[0] */ 392 swap_buf(r, data, 16); 393 394 aes_encrypt(&ctx, data, data); 395 396 /* Most significant octet of encryptedData corresponds to data[0] */ 397 swap_buf(data, r, 16); 398 399 SMP_DBG("r %16phN", r); 400 401 memzero_explicit(&ctx, sizeof(ctx)); 402 return err; 403 } 404 405 static int smp_c1(const u8 k[16], 406 const u8 r[16], const u8 preq[7], const u8 pres[7], u8 _iat, 407 const bdaddr_t *ia, u8 _rat, const bdaddr_t *ra, u8 res[16]) 408 { 409 u8 p1[16], p2[16]; 410 int err; 411 412 SMP_DBG("k %16phN r %16phN", k, r); 413 SMP_DBG("iat %u ia %6phN rat %u ra %6phN", _iat, ia, _rat, ra); 414 SMP_DBG("preq %7phN pres %7phN", preq, pres); 415 416 memset(p1, 0, 16); 417 418 /* p1 = pres || preq || _rat || _iat */ 419 p1[0] = _iat; 420 p1[1] = _rat; 421 memcpy(p1 + 2, preq, 7); 422 memcpy(p1 + 9, pres, 7); 423 424 SMP_DBG("p1 %16phN", p1); 425 426 /* res = r XOR p1 */ 427 crypto_xor_cpy(res, r, p1, sizeof(p1)); 428 429 /* res = e(k, res) */ 430 err = smp_e(k, res); 431 if (err) { 432 BT_ERR("Encrypt data error"); 433 return err; 434 } 435 436 /* p2 = padding || ia || ra */ 437 memcpy(p2, ra, 6); 438 memcpy(p2 + 6, ia, 6); 439 memset(p2 + 12, 0, 4); 440 441 SMP_DBG("p2 %16phN", p2); 442 443 /* res = res XOR p2 */ 444 crypto_xor(res, p2, sizeof(p2)); 445 446 /* res = e(k, res) */ 447 err = smp_e(k, res); 448 if (err) 449 BT_ERR("Encrypt data error"); 450 451 return err; 452 } 453 454 static int smp_s1(const u8 k[16], 455 const u8 r1[16], const u8 r2[16], u8 _r[16]) 456 { 457 int err; 458 459 /* Just least significant octets from r1 and r2 are considered */ 460 memcpy(_r, r2, 8); 461 memcpy(_r + 8, r1, 8); 462 463 err = smp_e(k, _r); 464 if (err) 465 BT_ERR("Encrypt data error"); 466 467 return err; 468 } 469 470 static int smp_ah(const u8 irk[16], const u8 r[3], u8 res[3]) 471 { 472 u8 _res[16]; 473 int err; 474 475 /* r' = padding || r */ 476 memcpy(_res, r, 3); 477 memset(_res + 3, 0, 13); 478 479 err = smp_e(irk, _res); 480 if (err) { 481 BT_ERR("Encrypt error"); 482 return err; 483 } 484 485 /* The output of the random address function ah is: 486 * ah(k, r) = e(k, r') mod 2^24 487 * The output of the security function e is then truncated to 24 bits 488 * by taking the least significant 24 bits of the output of e as the 489 * result of ah. 490 */ 491 memcpy(res, _res, 3); 492 493 return 0; 494 } 495 496 bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16], 497 const bdaddr_t *bdaddr) 498 { 499 struct l2cap_chan *chan = hdev->smp_data; 500 u8 hash[3]; 501 int err; 502 503 if (!chan || !chan->data) 504 return false; 505 506 bt_dev_dbg(hdev, "RPA %pMR IRK %*phN", bdaddr, 16, irk); 507 508 err = smp_ah(irk, &bdaddr->b[3], hash); 509 if (err) 510 return false; 511 512 return !crypto_memneq(bdaddr->b, hash, 3); 513 } 514 515 int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa) 516 { 517 struct l2cap_chan *chan = hdev->smp_data; 518 int err; 519 520 if (!chan || !chan->data) 521 return -EOPNOTSUPP; 522 523 get_random_bytes(&rpa->b[3], 3); 524 525 rpa->b[5] &= 0x3f; /* Clear two most significant bits */ 526 rpa->b[5] |= 0x40; /* Set second most significant bit */ 527 528 err = smp_ah(irk, &rpa->b[3], rpa->b); 529 if (err < 0) 530 return err; 531 532 bt_dev_dbg(hdev, "RPA %pMR", rpa); 533 534 return 0; 535 } 536 537 int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16]) 538 { 539 struct l2cap_chan *chan = hdev->smp_data; 540 struct smp_dev *smp; 541 int err; 542 543 if (!chan || !chan->data) 544 return -EOPNOTSUPP; 545 546 smp = chan->data; 547 548 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { 549 bt_dev_dbg(hdev, "Using debug keys"); 550 err = set_ecdh_privkey(smp->tfm_ecdh, debug_sk); 551 if (err) 552 return err; 553 memcpy(smp->local_pk, debug_pk, 64); 554 smp->debug_key = true; 555 } else { 556 while (true) { 557 /* Generate key pair for Secure Connections */ 558 err = generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk); 559 if (err) 560 return err; 561 562 /* This is unlikely, but we need to check that 563 * we didn't accidentally generate a debug key. 564 */ 565 if (crypto_memneq(smp->local_pk, debug_pk, 64)) 566 break; 567 } 568 smp->debug_key = false; 569 } 570 571 SMP_DBG("OOB Public Key X: %32phN", smp->local_pk); 572 SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32); 573 574 get_random_bytes(smp->local_rand, 16); 575 576 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->local_pk, 577 smp->local_rand, 0, hash); 578 if (err < 0) 579 return err; 580 581 memcpy(rand, smp->local_rand, 16); 582 583 smp->local_oob = true; 584 585 return 0; 586 } 587 588 static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data) 589 { 590 struct l2cap_chan *chan = conn->smp; 591 struct smp_chan *smp; 592 struct kvec iv[2]; 593 struct msghdr msg; 594 595 if (!chan) 596 return; 597 598 bt_dev_dbg(conn->hcon->hdev, "code 0x%2.2x", code); 599 600 iv[0].iov_base = &code; 601 iv[0].iov_len = 1; 602 603 iv[1].iov_base = data; 604 iv[1].iov_len = len; 605 606 memset(&msg, 0, sizeof(msg)); 607 608 iov_iter_kvec(&msg.msg_iter, WRITE, iv, 2, 1 + len); 609 610 l2cap_chan_send(chan, &msg, 1 + len); 611 612 if (!chan->data) 613 return; 614 615 smp = chan->data; 616 617 cancel_delayed_work_sync(&smp->security_timer); 618 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT); 619 } 620 621 static u8 authreq_to_seclevel(u8 authreq) 622 { 623 if (authreq & SMP_AUTH_MITM) { 624 if (authreq & SMP_AUTH_SC) 625 return BT_SECURITY_FIPS; 626 else 627 return BT_SECURITY_HIGH; 628 } else { 629 return BT_SECURITY_MEDIUM; 630 } 631 } 632 633 static __u8 seclevel_to_authreq(__u8 sec_level) 634 { 635 switch (sec_level) { 636 case BT_SECURITY_FIPS: 637 case BT_SECURITY_HIGH: 638 return SMP_AUTH_MITM | SMP_AUTH_BONDING; 639 case BT_SECURITY_MEDIUM: 640 return SMP_AUTH_BONDING; 641 default: 642 return SMP_AUTH_NONE; 643 } 644 } 645 646 static void build_pairing_cmd(struct l2cap_conn *conn, 647 struct smp_cmd_pairing *req, 648 struct smp_cmd_pairing *rsp, __u8 authreq) 649 { 650 struct l2cap_chan *chan = conn->smp; 651 struct smp_chan *smp = chan->data; 652 struct hci_conn *hcon = conn->hcon; 653 struct hci_dev *hdev = hcon->hdev; 654 u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT; 655 656 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { 657 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 658 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 659 authreq |= SMP_AUTH_BONDING; 660 } else { 661 authreq &= ~SMP_AUTH_BONDING; 662 } 663 664 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) 665 remote_dist |= SMP_DIST_ID_KEY; 666 667 if (hci_dev_test_flag(hdev, HCI_PRIVACY)) 668 local_dist |= SMP_DIST_ID_KEY; 669 670 if (hci_dev_test_flag(hdev, HCI_SC_ENABLED) && 671 (authreq & SMP_AUTH_SC)) { 672 struct oob_data *oob_data; 673 u8 bdaddr_type; 674 675 if (hci_dev_test_flag(hdev, HCI_SSP_ENABLED)) { 676 local_dist |= SMP_DIST_LINK_KEY; 677 remote_dist |= SMP_DIST_LINK_KEY; 678 } 679 680 if (hcon->dst_type == ADDR_LE_DEV_PUBLIC) 681 bdaddr_type = BDADDR_LE_PUBLIC; 682 else 683 bdaddr_type = BDADDR_LE_RANDOM; 684 685 oob_data = hci_find_remote_oob_data(hdev, &hcon->dst, 686 bdaddr_type); 687 if (oob_data && oob_data->present) { 688 set_bit(SMP_FLAG_REMOTE_OOB, &smp->flags); 689 oob_flag = SMP_OOB_PRESENT; 690 memcpy(smp->rr, oob_data->rand256, 16); 691 memcpy(smp->pcnf, oob_data->hash256, 16); 692 SMP_DBG("OOB Remote Confirmation: %16phN", smp->pcnf); 693 SMP_DBG("OOB Remote Random: %16phN", smp->rr); 694 } 695 696 } else { 697 authreq &= ~SMP_AUTH_SC; 698 } 699 700 if (rsp == NULL) { 701 req->io_capability = conn->hcon->io_capability; 702 req->oob_flag = oob_flag; 703 req->max_key_size = hdev->le_max_key_size; 704 req->init_key_dist = local_dist; 705 req->resp_key_dist = remote_dist; 706 req->auth_req = (authreq & AUTH_REQ_MASK(hdev)); 707 708 smp->remote_key_dist = remote_dist; 709 return; 710 } 711 712 rsp->io_capability = conn->hcon->io_capability; 713 rsp->oob_flag = oob_flag; 714 rsp->max_key_size = hdev->le_max_key_size; 715 rsp->init_key_dist = req->init_key_dist & remote_dist; 716 rsp->resp_key_dist = req->resp_key_dist & local_dist; 717 rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev)); 718 719 smp->remote_key_dist = rsp->init_key_dist; 720 } 721 722 static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size) 723 { 724 struct l2cap_chan *chan = conn->smp; 725 struct hci_dev *hdev = conn->hcon->hdev; 726 struct smp_chan *smp = chan->data; 727 728 if (conn->hcon->pending_sec_level == BT_SECURITY_FIPS && 729 max_key_size != SMP_MAX_ENC_KEY_SIZE) 730 return SMP_ENC_KEY_SIZE; 731 732 if (max_key_size > hdev->le_max_key_size || 733 max_key_size < SMP_MIN_ENC_KEY_SIZE) 734 return SMP_ENC_KEY_SIZE; 735 736 smp->enc_key_size = max_key_size; 737 738 return 0; 739 } 740 741 static void smp_chan_destroy(struct l2cap_conn *conn) 742 { 743 struct l2cap_chan *chan = conn->smp; 744 struct smp_chan *smp = chan->data; 745 struct hci_conn *hcon = conn->hcon; 746 bool complete; 747 748 BUG_ON(!smp); 749 750 cancel_delayed_work_sync(&smp->security_timer); 751 752 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags); 753 mgmt_smp_complete(hcon, complete); 754 755 kfree_sensitive(smp->csrk); 756 kfree_sensitive(smp->responder_csrk); 757 kfree_sensitive(smp->link_key); 758 759 crypto_free_shash(smp->tfm_cmac); 760 crypto_free_kpp(smp->tfm_ecdh); 761 762 /* Ensure that we don't leave any debug key around if debug key 763 * support hasn't been explicitly enabled. 764 */ 765 if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG && 766 !hci_dev_test_flag(hcon->hdev, HCI_KEEP_DEBUG_KEYS)) { 767 list_del_rcu(&smp->ltk->list); 768 kfree_rcu(smp->ltk, rcu); 769 smp->ltk = NULL; 770 } 771 772 /* If pairing failed clean up any keys we might have */ 773 if (!complete) { 774 if (smp->ltk) { 775 list_del_rcu(&smp->ltk->list); 776 kfree_rcu(smp->ltk, rcu); 777 } 778 779 if (smp->responder_ltk) { 780 list_del_rcu(&smp->responder_ltk->list); 781 kfree_rcu(smp->responder_ltk, rcu); 782 } 783 784 if (smp->remote_irk) { 785 list_del_rcu(&smp->remote_irk->list); 786 kfree_rcu(smp->remote_irk, rcu); 787 } 788 } 789 790 chan->data = NULL; 791 kfree_sensitive(smp); 792 hci_conn_drop(hcon); 793 } 794 795 static void smp_failure(struct l2cap_conn *conn, u8 reason) 796 { 797 struct hci_conn *hcon = conn->hcon; 798 struct l2cap_chan *chan = conn->smp; 799 800 if (reason) 801 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason), 802 &reason); 803 804 mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE); 805 806 if (chan->data) 807 smp_chan_destroy(conn); 808 } 809 810 #define JUST_WORKS 0x00 811 #define JUST_CFM 0x01 812 #define REQ_PASSKEY 0x02 813 #define CFM_PASSKEY 0x03 814 #define REQ_OOB 0x04 815 #define DSP_PASSKEY 0x05 816 #define OVERLAP 0xFF 817 818 static const u8 gen_method[5][5] = { 819 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 820 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 821 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 822 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM }, 823 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP }, 824 }; 825 826 static const u8 sc_method[5][5] = { 827 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 828 { JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 829 { DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY }, 830 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM }, 831 { DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 832 }; 833 834 static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io) 835 { 836 /* If either side has unknown io_caps, use JUST_CFM (which gets 837 * converted later to JUST_WORKS if we're initiators. 838 */ 839 if (local_io > SMP_IO_KEYBOARD_DISPLAY || 840 remote_io > SMP_IO_KEYBOARD_DISPLAY) 841 return JUST_CFM; 842 843 if (test_bit(SMP_FLAG_SC, &smp->flags)) 844 return sc_method[remote_io][local_io]; 845 846 return gen_method[remote_io][local_io]; 847 } 848 849 static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth, 850 u8 local_io, u8 remote_io) 851 { 852 struct hci_conn *hcon = conn->hcon; 853 struct l2cap_chan *chan = conn->smp; 854 struct smp_chan *smp = chan->data; 855 u32 passkey = 0; 856 int ret; 857 858 /* Initialize key for JUST WORKS */ 859 memset(smp->tk, 0, sizeof(smp->tk)); 860 clear_bit(SMP_FLAG_TK_VALID, &smp->flags); 861 862 bt_dev_dbg(hcon->hdev, "auth:%u lcl:%u rem:%u", auth, local_io, 863 remote_io); 864 865 /* If neither side wants MITM, either "just" confirm an incoming 866 * request or use just-works for outgoing ones. The JUST_CFM 867 * will be converted to JUST_WORKS if necessary later in this 868 * function. If either side has MITM look up the method from the 869 * table. 870 */ 871 if (!(auth & SMP_AUTH_MITM)) 872 smp->method = JUST_CFM; 873 else 874 smp->method = get_auth_method(smp, local_io, remote_io); 875 876 /* Don't confirm locally initiated pairing attempts */ 877 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, 878 &smp->flags)) 879 smp->method = JUST_WORKS; 880 881 /* Don't bother user space with no IO capabilities */ 882 if (smp->method == JUST_CFM && 883 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 884 smp->method = JUST_WORKS; 885 886 /* If Just Works, Continue with Zero TK and ask user-space for 887 * confirmation */ 888 if (smp->method == JUST_WORKS) { 889 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, 890 hcon->type, 891 hcon->dst_type, 892 passkey, 1); 893 if (ret) 894 return ret; 895 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 896 return 0; 897 } 898 899 /* If this function is used for SC -> legacy fallback we 900 * can only recover the just-works case. 901 */ 902 if (test_bit(SMP_FLAG_SC, &smp->flags)) 903 return -EINVAL; 904 905 /* Not Just Works/Confirm results in MITM Authentication */ 906 if (smp->method != JUST_CFM) { 907 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags); 908 if (hcon->pending_sec_level < BT_SECURITY_HIGH) 909 hcon->pending_sec_level = BT_SECURITY_HIGH; 910 } 911 912 /* If both devices have Keyboard-Display I/O, the initiator 913 * Confirms and the responder Enters the passkey. 914 */ 915 if (smp->method == OVERLAP) { 916 if (hcon->role == HCI_ROLE_MASTER) 917 smp->method = CFM_PASSKEY; 918 else 919 smp->method = REQ_PASSKEY; 920 } 921 922 /* Generate random passkey. */ 923 if (smp->method == CFM_PASSKEY) { 924 memset(smp->tk, 0, sizeof(smp->tk)); 925 get_random_bytes(&passkey, sizeof(passkey)); 926 passkey %= 1000000; 927 put_unaligned_le32(passkey, smp->tk); 928 bt_dev_dbg(hcon->hdev, "PassKey: %u", passkey); 929 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 930 } 931 932 if (smp->method == REQ_PASSKEY) 933 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst, 934 hcon->type, hcon->dst_type); 935 else if (smp->method == JUST_CFM) 936 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, 937 hcon->type, hcon->dst_type, 938 passkey, 1); 939 else 940 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst, 941 hcon->type, hcon->dst_type, 942 passkey, 0); 943 944 return ret; 945 } 946 947 static u8 smp_confirm(struct smp_chan *smp) 948 { 949 struct l2cap_conn *conn = smp->conn; 950 struct smp_cmd_pairing_confirm cp; 951 int ret; 952 953 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 954 955 ret = smp_c1(smp->tk, smp->prnd, smp->preq, smp->prsp, 956 conn->hcon->init_addr_type, &conn->hcon->init_addr, 957 conn->hcon->resp_addr_type, &conn->hcon->resp_addr, 958 cp.confirm_val); 959 if (ret) 960 return SMP_UNSPECIFIED; 961 962 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 963 964 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp); 965 966 if (conn->hcon->out) 967 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 968 else 969 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 970 971 return 0; 972 } 973 974 static u8 smp_random(struct smp_chan *smp) 975 { 976 struct l2cap_conn *conn = smp->conn; 977 struct hci_conn *hcon = conn->hcon; 978 u8 confirm[16]; 979 int ret; 980 981 bt_dev_dbg(conn->hcon->hdev, "conn %p %s", conn, 982 conn->hcon->out ? "initiator" : "responder"); 983 984 ret = smp_c1(smp->tk, smp->rrnd, smp->preq, smp->prsp, 985 hcon->init_addr_type, &hcon->init_addr, 986 hcon->resp_addr_type, &hcon->resp_addr, confirm); 987 if (ret) 988 return SMP_UNSPECIFIED; 989 990 if (crypto_memneq(smp->pcnf, confirm, sizeof(smp->pcnf))) { 991 bt_dev_err(hcon->hdev, "pairing failed " 992 "(confirmation values mismatch)"); 993 return SMP_CONFIRM_FAILED; 994 } 995 996 if (hcon->out) { 997 u8 stk[16]; 998 __le64 rand = 0; 999 __le16 ediv = 0; 1000 1001 smp_s1(smp->tk, smp->rrnd, smp->prnd, stk); 1002 1003 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) 1004 return SMP_UNSPECIFIED; 1005 1006 hci_le_start_enc(hcon, ediv, rand, stk, smp->enc_key_size); 1007 hcon->enc_key_size = smp->enc_key_size; 1008 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); 1009 } else { 1010 u8 stk[16], auth; 1011 __le64 rand = 0; 1012 __le16 ediv = 0; 1013 1014 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 1015 smp->prnd); 1016 1017 smp_s1(smp->tk, smp->prnd, smp->rrnd, stk); 1018 1019 if (hcon->pending_sec_level == BT_SECURITY_HIGH) 1020 auth = 1; 1021 else 1022 auth = 0; 1023 1024 /* Even though there's no _RESPONDER suffix this is the 1025 * responder STK we're adding for later lookup (the initiator 1026 * STK never needs to be stored). 1027 */ 1028 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 1029 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand); 1030 } 1031 1032 return 0; 1033 } 1034 1035 static void smp_notify_keys(struct l2cap_conn *conn) 1036 { 1037 struct l2cap_chan *chan = conn->smp; 1038 struct smp_chan *smp = chan->data; 1039 struct hci_conn *hcon = conn->hcon; 1040 struct hci_dev *hdev = hcon->hdev; 1041 struct smp_cmd_pairing *req = (void *) &smp->preq[1]; 1042 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1]; 1043 bool persistent; 1044 1045 if (hcon->type == ACL_LINK) { 1046 if (hcon->key_type == HCI_LK_DEBUG_COMBINATION) 1047 persistent = false; 1048 else 1049 persistent = !test_bit(HCI_CONN_FLUSH_KEY, 1050 &hcon->flags); 1051 } else { 1052 /* The LTKs, IRKs and CSRKs should be persistent only if 1053 * both sides had the bonding bit set in their 1054 * authentication requests. 1055 */ 1056 persistent = !!((req->auth_req & rsp->auth_req) & 1057 SMP_AUTH_BONDING); 1058 } 1059 1060 if (smp->remote_irk) { 1061 mgmt_new_irk(hdev, smp->remote_irk, persistent); 1062 1063 /* Now that user space can be considered to know the 1064 * identity address track the connection based on it 1065 * from now on (assuming this is an LE link). 1066 */ 1067 if (hcon->type == LE_LINK) { 1068 bacpy(&hcon->dst, &smp->remote_irk->bdaddr); 1069 hcon->dst_type = smp->remote_irk->addr_type; 1070 queue_work(hdev->workqueue, &conn->id_addr_update_work); 1071 } 1072 } 1073 1074 if (smp->csrk) { 1075 smp->csrk->bdaddr_type = hcon->dst_type; 1076 bacpy(&smp->csrk->bdaddr, &hcon->dst); 1077 mgmt_new_csrk(hdev, smp->csrk, persistent); 1078 } 1079 1080 if (smp->responder_csrk) { 1081 smp->responder_csrk->bdaddr_type = hcon->dst_type; 1082 bacpy(&smp->responder_csrk->bdaddr, &hcon->dst); 1083 mgmt_new_csrk(hdev, smp->responder_csrk, persistent); 1084 } 1085 1086 if (smp->ltk) { 1087 smp->ltk->bdaddr_type = hcon->dst_type; 1088 bacpy(&smp->ltk->bdaddr, &hcon->dst); 1089 mgmt_new_ltk(hdev, smp->ltk, persistent); 1090 } 1091 1092 if (smp->responder_ltk) { 1093 smp->responder_ltk->bdaddr_type = hcon->dst_type; 1094 bacpy(&smp->responder_ltk->bdaddr, &hcon->dst); 1095 mgmt_new_ltk(hdev, smp->responder_ltk, persistent); 1096 } 1097 1098 if (smp->link_key) { 1099 struct link_key *key; 1100 u8 type; 1101 1102 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags)) 1103 type = HCI_LK_DEBUG_COMBINATION; 1104 else if (hcon->sec_level == BT_SECURITY_FIPS) 1105 type = HCI_LK_AUTH_COMBINATION_P256; 1106 else 1107 type = HCI_LK_UNAUTH_COMBINATION_P256; 1108 1109 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst, 1110 smp->link_key, type, 0, &persistent); 1111 if (key) { 1112 mgmt_new_link_key(hdev, key, persistent); 1113 1114 /* Don't keep debug keys around if the relevant 1115 * flag is not set. 1116 */ 1117 if (!hci_dev_test_flag(hdev, HCI_KEEP_DEBUG_KEYS) && 1118 key->type == HCI_LK_DEBUG_COMBINATION) { 1119 list_del_rcu(&key->list); 1120 kfree_rcu(key, rcu); 1121 } 1122 } 1123 } 1124 } 1125 1126 static void sc_add_ltk(struct smp_chan *smp) 1127 { 1128 struct hci_conn *hcon = smp->conn->hcon; 1129 u8 key_type, auth; 1130 1131 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags)) 1132 key_type = SMP_LTK_P256_DEBUG; 1133 else 1134 key_type = SMP_LTK_P256; 1135 1136 if (hcon->pending_sec_level == BT_SECURITY_FIPS) 1137 auth = 1; 1138 else 1139 auth = 0; 1140 1141 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 1142 key_type, auth, smp->tk, smp->enc_key_size, 1143 0, 0); 1144 } 1145 1146 static void sc_generate_link_key(struct smp_chan *smp) 1147 { 1148 /* From core spec. Spells out in ASCII as 'lebr'. */ 1149 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c }; 1150 1151 smp->link_key = kzalloc(16, GFP_KERNEL); 1152 if (!smp->link_key) 1153 return; 1154 1155 if (test_bit(SMP_FLAG_CT2, &smp->flags)) { 1156 /* SALT = 0x000000000000000000000000746D7031 */ 1157 const u8 salt[16] = { 0x31, 0x70, 0x6d, 0x74 }; 1158 1159 if (smp_h7(smp->tfm_cmac, smp->tk, salt, smp->link_key)) { 1160 kfree_sensitive(smp->link_key); 1161 smp->link_key = NULL; 1162 return; 1163 } 1164 } else { 1165 /* From core spec. Spells out in ASCII as 'tmp1'. */ 1166 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 }; 1167 1168 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) { 1169 kfree_sensitive(smp->link_key); 1170 smp->link_key = NULL; 1171 return; 1172 } 1173 } 1174 1175 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) { 1176 kfree_sensitive(smp->link_key); 1177 smp->link_key = NULL; 1178 return; 1179 } 1180 } 1181 1182 static void smp_allow_key_dist(struct smp_chan *smp) 1183 { 1184 /* Allow the first expected phase 3 PDU. The rest of the PDUs 1185 * will be allowed in each PDU handler to ensure we receive 1186 * them in the correct order. 1187 */ 1188 if (smp->remote_key_dist & SMP_DIST_ENC_KEY) 1189 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO); 1190 else if (smp->remote_key_dist & SMP_DIST_ID_KEY) 1191 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); 1192 else if (smp->remote_key_dist & SMP_DIST_SIGN) 1193 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 1194 } 1195 1196 static void sc_generate_ltk(struct smp_chan *smp) 1197 { 1198 /* From core spec. Spells out in ASCII as 'brle'. */ 1199 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 }; 1200 struct hci_conn *hcon = smp->conn->hcon; 1201 struct hci_dev *hdev = hcon->hdev; 1202 struct link_key *key; 1203 1204 key = hci_find_link_key(hdev, &hcon->dst); 1205 if (!key) { 1206 bt_dev_err(hdev, "no Link Key found to generate LTK"); 1207 return; 1208 } 1209 1210 if (key->type == HCI_LK_DEBUG_COMBINATION) 1211 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1212 1213 if (test_bit(SMP_FLAG_CT2, &smp->flags)) { 1214 /* SALT = 0x000000000000000000000000746D7032 */ 1215 const u8 salt[16] = { 0x32, 0x70, 0x6d, 0x74 }; 1216 1217 if (smp_h7(smp->tfm_cmac, key->val, salt, smp->tk)) 1218 return; 1219 } else { 1220 /* From core spec. Spells out in ASCII as 'tmp2'. */ 1221 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 }; 1222 1223 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk)) 1224 return; 1225 } 1226 1227 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk)) 1228 return; 1229 1230 sc_add_ltk(smp); 1231 } 1232 1233 static void smp_distribute_keys(struct smp_chan *smp) 1234 { 1235 struct smp_cmd_pairing *req, *rsp; 1236 struct l2cap_conn *conn = smp->conn; 1237 struct hci_conn *hcon = conn->hcon; 1238 struct hci_dev *hdev = hcon->hdev; 1239 __u8 *keydist; 1240 1241 bt_dev_dbg(hdev, "conn %p", conn); 1242 1243 rsp = (void *) &smp->prsp[1]; 1244 1245 /* The responder sends its keys first */ 1246 if (hcon->out && (smp->remote_key_dist & KEY_DIST_MASK)) { 1247 smp_allow_key_dist(smp); 1248 return; 1249 } 1250 1251 req = (void *) &smp->preq[1]; 1252 1253 if (hcon->out) { 1254 keydist = &rsp->init_key_dist; 1255 *keydist &= req->init_key_dist; 1256 } else { 1257 keydist = &rsp->resp_key_dist; 1258 *keydist &= req->resp_key_dist; 1259 } 1260 1261 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1262 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY)) 1263 sc_generate_link_key(smp); 1264 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY)) 1265 sc_generate_ltk(smp); 1266 1267 /* Clear the keys which are generated but not distributed */ 1268 *keydist &= ~SMP_SC_NO_DIST; 1269 } 1270 1271 bt_dev_dbg(hdev, "keydist 0x%x", *keydist); 1272 1273 if (*keydist & SMP_DIST_ENC_KEY) { 1274 struct smp_cmd_encrypt_info enc; 1275 struct smp_cmd_initiator_ident ident; 1276 struct smp_ltk *ltk; 1277 u8 authenticated; 1278 __le16 ediv; 1279 __le64 rand; 1280 1281 /* Make sure we generate only the significant amount of 1282 * bytes based on the encryption key size, and set the rest 1283 * of the value to zeroes. 1284 */ 1285 get_random_bytes(enc.ltk, smp->enc_key_size); 1286 memset(enc.ltk + smp->enc_key_size, 0, 1287 sizeof(enc.ltk) - smp->enc_key_size); 1288 1289 get_random_bytes(&ediv, sizeof(ediv)); 1290 get_random_bytes(&rand, sizeof(rand)); 1291 1292 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc); 1293 1294 authenticated = hcon->sec_level == BT_SECURITY_HIGH; 1295 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, 1296 SMP_LTK_RESPONDER, authenticated, enc.ltk, 1297 smp->enc_key_size, ediv, rand); 1298 smp->responder_ltk = ltk; 1299 1300 ident.ediv = ediv; 1301 ident.rand = rand; 1302 1303 smp_send_cmd(conn, SMP_CMD_INITIATOR_IDENT, sizeof(ident), 1304 &ident); 1305 1306 *keydist &= ~SMP_DIST_ENC_KEY; 1307 } 1308 1309 if (*keydist & SMP_DIST_ID_KEY) { 1310 struct smp_cmd_ident_addr_info addrinfo; 1311 struct smp_cmd_ident_info idinfo; 1312 1313 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk)); 1314 1315 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo); 1316 1317 /* The hci_conn contains the local identity address 1318 * after the connection has been established. 1319 * 1320 * This is true even when the connection has been 1321 * established using a resolvable random address. 1322 */ 1323 bacpy(&addrinfo.bdaddr, &hcon->src); 1324 addrinfo.addr_type = hcon->src_type; 1325 1326 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo), 1327 &addrinfo); 1328 1329 *keydist &= ~SMP_DIST_ID_KEY; 1330 } 1331 1332 if (*keydist & SMP_DIST_SIGN) { 1333 struct smp_cmd_sign_info sign; 1334 struct smp_csrk *csrk; 1335 1336 /* Generate a new random key */ 1337 get_random_bytes(sign.csrk, sizeof(sign.csrk)); 1338 1339 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); 1340 if (csrk) { 1341 if (hcon->sec_level > BT_SECURITY_MEDIUM) 1342 csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED; 1343 else 1344 csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED; 1345 memcpy(csrk->val, sign.csrk, sizeof(csrk->val)); 1346 } 1347 smp->responder_csrk = csrk; 1348 1349 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign); 1350 1351 *keydist &= ~SMP_DIST_SIGN; 1352 } 1353 1354 /* If there are still keys to be received wait for them */ 1355 if (smp->remote_key_dist & KEY_DIST_MASK) { 1356 smp_allow_key_dist(smp); 1357 return; 1358 } 1359 1360 set_bit(SMP_FLAG_COMPLETE, &smp->flags); 1361 smp_notify_keys(conn); 1362 1363 smp_chan_destroy(conn); 1364 } 1365 1366 static void smp_timeout(struct work_struct *work) 1367 { 1368 struct smp_chan *smp = container_of(work, struct smp_chan, 1369 security_timer.work); 1370 struct l2cap_conn *conn = smp->conn; 1371 1372 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 1373 1374 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM); 1375 } 1376 1377 static struct smp_chan *smp_chan_create(struct l2cap_conn *conn) 1378 { 1379 struct hci_conn *hcon = conn->hcon; 1380 struct l2cap_chan *chan = conn->smp; 1381 struct smp_chan *smp; 1382 1383 smp = kzalloc(sizeof(*smp), GFP_ATOMIC); 1384 if (!smp) 1385 return NULL; 1386 1387 smp->tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 1388 if (IS_ERR(smp->tfm_cmac)) { 1389 bt_dev_err(hcon->hdev, "Unable to create CMAC crypto context"); 1390 goto zfree_smp; 1391 } 1392 1393 smp->tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0); 1394 if (IS_ERR(smp->tfm_ecdh)) { 1395 bt_dev_err(hcon->hdev, "Unable to create ECDH crypto context"); 1396 goto free_shash; 1397 } 1398 1399 smp->conn = conn; 1400 chan->data = smp; 1401 1402 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL); 1403 1404 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout); 1405 1406 hci_conn_hold(hcon); 1407 1408 return smp; 1409 1410 free_shash: 1411 crypto_free_shash(smp->tfm_cmac); 1412 zfree_smp: 1413 kfree_sensitive(smp); 1414 return NULL; 1415 } 1416 1417 static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16]) 1418 { 1419 struct hci_conn *hcon = smp->conn->hcon; 1420 u8 *na, *nb, a[7], b[7]; 1421 1422 if (hcon->out) { 1423 na = smp->prnd; 1424 nb = smp->rrnd; 1425 } else { 1426 na = smp->rrnd; 1427 nb = smp->prnd; 1428 } 1429 1430 memcpy(a, &hcon->init_addr, 6); 1431 memcpy(b, &hcon->resp_addr, 6); 1432 a[6] = hcon->init_addr_type; 1433 b[6] = hcon->resp_addr_type; 1434 1435 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk); 1436 } 1437 1438 static void sc_dhkey_check(struct smp_chan *smp) 1439 { 1440 struct hci_conn *hcon = smp->conn->hcon; 1441 struct smp_cmd_dhkey_check check; 1442 u8 a[7], b[7], *local_addr, *remote_addr; 1443 u8 io_cap[3], r[16]; 1444 1445 memcpy(a, &hcon->init_addr, 6); 1446 memcpy(b, &hcon->resp_addr, 6); 1447 a[6] = hcon->init_addr_type; 1448 b[6] = hcon->resp_addr_type; 1449 1450 if (hcon->out) { 1451 local_addr = a; 1452 remote_addr = b; 1453 memcpy(io_cap, &smp->preq[1], 3); 1454 } else { 1455 local_addr = b; 1456 remote_addr = a; 1457 memcpy(io_cap, &smp->prsp[1], 3); 1458 } 1459 1460 memset(r, 0, sizeof(r)); 1461 1462 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 1463 put_unaligned_le32(hcon->passkey_notify, r); 1464 1465 if (smp->method == REQ_OOB) 1466 memcpy(r, smp->rr, 16); 1467 1468 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap, 1469 local_addr, remote_addr, check.e); 1470 1471 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check); 1472 } 1473 1474 static u8 sc_passkey_send_confirm(struct smp_chan *smp) 1475 { 1476 struct l2cap_conn *conn = smp->conn; 1477 struct hci_conn *hcon = conn->hcon; 1478 struct smp_cmd_pairing_confirm cfm; 1479 u8 r; 1480 1481 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); 1482 r |= 0x80; 1483 1484 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1485 1486 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r, 1487 cfm.confirm_val)) 1488 return SMP_UNSPECIFIED; 1489 1490 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); 1491 1492 return 0; 1493 } 1494 1495 static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op) 1496 { 1497 struct l2cap_conn *conn = smp->conn; 1498 struct hci_conn *hcon = conn->hcon; 1499 struct hci_dev *hdev = hcon->hdev; 1500 u8 cfm[16], r; 1501 1502 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */ 1503 if (smp->passkey_round >= 20) 1504 return 0; 1505 1506 switch (smp_op) { 1507 case SMP_CMD_PAIRING_RANDOM: 1508 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); 1509 r |= 0x80; 1510 1511 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, 1512 smp->rrnd, r, cfm)) 1513 return SMP_UNSPECIFIED; 1514 1515 if (crypto_memneq(smp->pcnf, cfm, 16)) 1516 return SMP_CONFIRM_FAILED; 1517 1518 smp->passkey_round++; 1519 1520 if (smp->passkey_round == 20) { 1521 /* Generate MacKey and LTK */ 1522 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk)) 1523 return SMP_UNSPECIFIED; 1524 } 1525 1526 /* The round is only complete when the initiator 1527 * receives pairing random. 1528 */ 1529 if (!hcon->out) { 1530 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 1531 sizeof(smp->prnd), smp->prnd); 1532 if (smp->passkey_round == 20) 1533 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1534 else 1535 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1536 return 0; 1537 } 1538 1539 /* Start the next round */ 1540 if (smp->passkey_round != 20) 1541 return sc_passkey_round(smp, 0); 1542 1543 /* Passkey rounds are complete - start DHKey Check */ 1544 sc_dhkey_check(smp); 1545 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1546 1547 break; 1548 1549 case SMP_CMD_PAIRING_CONFIRM: 1550 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { 1551 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 1552 return 0; 1553 } 1554 1555 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 1556 1557 if (hcon->out) { 1558 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 1559 sizeof(smp->prnd), smp->prnd); 1560 return 0; 1561 } 1562 1563 return sc_passkey_send_confirm(smp); 1564 1565 case SMP_CMD_PUBLIC_KEY: 1566 default: 1567 /* Initiating device starts the round */ 1568 if (!hcon->out) 1569 return 0; 1570 1571 bt_dev_dbg(hdev, "Starting passkey round %u", 1572 smp->passkey_round + 1); 1573 1574 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1575 1576 return sc_passkey_send_confirm(smp); 1577 } 1578 1579 return 0; 1580 } 1581 1582 static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey) 1583 { 1584 struct l2cap_conn *conn = smp->conn; 1585 struct hci_conn *hcon = conn->hcon; 1586 u8 smp_op; 1587 1588 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags); 1589 1590 switch (mgmt_op) { 1591 case MGMT_OP_USER_PASSKEY_NEG_REPLY: 1592 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED); 1593 return 0; 1594 case MGMT_OP_USER_CONFIRM_NEG_REPLY: 1595 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED); 1596 return 0; 1597 case MGMT_OP_USER_PASSKEY_REPLY: 1598 hcon->passkey_notify = le32_to_cpu(passkey); 1599 smp->passkey_round = 0; 1600 1601 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) 1602 smp_op = SMP_CMD_PAIRING_CONFIRM; 1603 else 1604 smp_op = 0; 1605 1606 if (sc_passkey_round(smp, smp_op)) 1607 return -EIO; 1608 1609 return 0; 1610 } 1611 1612 /* Initiator sends DHKey check first */ 1613 if (hcon->out) { 1614 sc_dhkey_check(smp); 1615 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1616 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) { 1617 sc_dhkey_check(smp); 1618 sc_add_ltk(smp); 1619 } 1620 1621 return 0; 1622 } 1623 1624 int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey) 1625 { 1626 struct l2cap_conn *conn = hcon->l2cap_data; 1627 struct l2cap_chan *chan; 1628 struct smp_chan *smp; 1629 u32 value; 1630 int err; 1631 1632 if (!conn) 1633 return -ENOTCONN; 1634 1635 bt_dev_dbg(conn->hcon->hdev, ""); 1636 1637 chan = conn->smp; 1638 if (!chan) 1639 return -ENOTCONN; 1640 1641 l2cap_chan_lock(chan); 1642 if (!chan->data) { 1643 err = -ENOTCONN; 1644 goto unlock; 1645 } 1646 1647 smp = chan->data; 1648 1649 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1650 err = sc_user_reply(smp, mgmt_op, passkey); 1651 goto unlock; 1652 } 1653 1654 switch (mgmt_op) { 1655 case MGMT_OP_USER_PASSKEY_REPLY: 1656 value = le32_to_cpu(passkey); 1657 memset(smp->tk, 0, sizeof(smp->tk)); 1658 bt_dev_dbg(conn->hcon->hdev, "PassKey: %u", value); 1659 put_unaligned_le32(value, smp->tk); 1660 fallthrough; 1661 case MGMT_OP_USER_CONFIRM_REPLY: 1662 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 1663 break; 1664 case MGMT_OP_USER_PASSKEY_NEG_REPLY: 1665 case MGMT_OP_USER_CONFIRM_NEG_REPLY: 1666 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); 1667 err = 0; 1668 goto unlock; 1669 default: 1670 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); 1671 err = -EOPNOTSUPP; 1672 goto unlock; 1673 } 1674 1675 err = 0; 1676 1677 /* If it is our turn to send Pairing Confirm, do so now */ 1678 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) { 1679 u8 rsp = smp_confirm(smp); 1680 if (rsp) 1681 smp_failure(conn, rsp); 1682 } 1683 1684 unlock: 1685 l2cap_chan_unlock(chan); 1686 return err; 1687 } 1688 1689 static void build_bredr_pairing_cmd(struct smp_chan *smp, 1690 struct smp_cmd_pairing *req, 1691 struct smp_cmd_pairing *rsp) 1692 { 1693 struct l2cap_conn *conn = smp->conn; 1694 struct hci_dev *hdev = conn->hcon->hdev; 1695 u8 local_dist = 0, remote_dist = 0; 1696 1697 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { 1698 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 1699 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 1700 } 1701 1702 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) 1703 remote_dist |= SMP_DIST_ID_KEY; 1704 1705 if (hci_dev_test_flag(hdev, HCI_PRIVACY)) 1706 local_dist |= SMP_DIST_ID_KEY; 1707 1708 if (!rsp) { 1709 memset(req, 0, sizeof(*req)); 1710 1711 req->auth_req = SMP_AUTH_CT2; 1712 req->init_key_dist = local_dist; 1713 req->resp_key_dist = remote_dist; 1714 req->max_key_size = conn->hcon->enc_key_size; 1715 1716 smp->remote_key_dist = remote_dist; 1717 1718 return; 1719 } 1720 1721 memset(rsp, 0, sizeof(*rsp)); 1722 1723 rsp->auth_req = SMP_AUTH_CT2; 1724 rsp->max_key_size = conn->hcon->enc_key_size; 1725 rsp->init_key_dist = req->init_key_dist & remote_dist; 1726 rsp->resp_key_dist = req->resp_key_dist & local_dist; 1727 1728 smp->remote_key_dist = rsp->init_key_dist; 1729 } 1730 1731 static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) 1732 { 1733 struct smp_cmd_pairing rsp, *req = (void *) skb->data; 1734 struct l2cap_chan *chan = conn->smp; 1735 struct hci_dev *hdev = conn->hcon->hdev; 1736 struct smp_chan *smp; 1737 u8 key_size, auth, sec_level; 1738 int ret; 1739 1740 bt_dev_dbg(hdev, "conn %p", conn); 1741 1742 if (skb->len < sizeof(*req)) 1743 return SMP_INVALID_PARAMS; 1744 1745 if (conn->hcon->role != HCI_ROLE_SLAVE) 1746 return SMP_CMD_NOTSUPP; 1747 1748 if (!chan->data) 1749 smp = smp_chan_create(conn); 1750 else 1751 smp = chan->data; 1752 1753 if (!smp) 1754 return SMP_UNSPECIFIED; 1755 1756 /* We didn't start the pairing, so match remote */ 1757 auth = req->auth_req & AUTH_REQ_MASK(hdev); 1758 1759 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && 1760 (auth & SMP_AUTH_BONDING)) 1761 return SMP_PAIRING_NOTSUPP; 1762 1763 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 1764 return SMP_AUTH_REQUIREMENTS; 1765 1766 smp->preq[0] = SMP_CMD_PAIRING_REQ; 1767 memcpy(&smp->preq[1], req, sizeof(*req)); 1768 skb_pull(skb, sizeof(*req)); 1769 1770 /* If the remote side's OOB flag is set it means it has 1771 * successfully received our local OOB data - therefore set the 1772 * flag to indicate that local OOB is in use. 1773 */ 1774 if (req->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob) 1775 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); 1776 1777 /* SMP over BR/EDR requires special treatment */ 1778 if (conn->hcon->type == ACL_LINK) { 1779 /* We must have a BR/EDR SC link */ 1780 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) && 1781 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 1782 return SMP_CROSS_TRANSP_NOT_ALLOWED; 1783 1784 set_bit(SMP_FLAG_SC, &smp->flags); 1785 1786 build_bredr_pairing_cmd(smp, req, &rsp); 1787 1788 if (req->auth_req & SMP_AUTH_CT2) 1789 set_bit(SMP_FLAG_CT2, &smp->flags); 1790 1791 key_size = min(req->max_key_size, rsp.max_key_size); 1792 if (check_enc_key_size(conn, key_size)) 1793 return SMP_ENC_KEY_SIZE; 1794 1795 /* Clear bits which are generated but not distributed */ 1796 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1797 1798 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1799 memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); 1800 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); 1801 1802 smp_distribute_keys(smp); 1803 return 0; 1804 } 1805 1806 build_pairing_cmd(conn, req, &rsp, auth); 1807 1808 if (rsp.auth_req & SMP_AUTH_SC) { 1809 set_bit(SMP_FLAG_SC, &smp->flags); 1810 1811 if (rsp.auth_req & SMP_AUTH_CT2) 1812 set_bit(SMP_FLAG_CT2, &smp->flags); 1813 } 1814 1815 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 1816 sec_level = BT_SECURITY_MEDIUM; 1817 else 1818 sec_level = authreq_to_seclevel(auth); 1819 1820 if (sec_level > conn->hcon->pending_sec_level) 1821 conn->hcon->pending_sec_level = sec_level; 1822 1823 /* If we need MITM check that it can be achieved */ 1824 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { 1825 u8 method; 1826 1827 method = get_auth_method(smp, conn->hcon->io_capability, 1828 req->io_capability); 1829 if (method == JUST_WORKS || method == JUST_CFM) 1830 return SMP_AUTH_REQUIREMENTS; 1831 } 1832 1833 key_size = min(req->max_key_size, rsp.max_key_size); 1834 if (check_enc_key_size(conn, key_size)) 1835 return SMP_ENC_KEY_SIZE; 1836 1837 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1838 1839 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1840 memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); 1841 1842 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); 1843 1844 clear_bit(SMP_FLAG_INITIATOR, &smp->flags); 1845 1846 /* Strictly speaking we shouldn't allow Pairing Confirm for the 1847 * SC case, however some implementations incorrectly copy RFU auth 1848 * req bits from our security request, which may create a false 1849 * positive SC enablement. 1850 */ 1851 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1852 1853 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1854 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); 1855 /* Clear bits which are generated but not distributed */ 1856 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1857 /* Wait for Public Key from Initiating Device */ 1858 return 0; 1859 } 1860 1861 /* Request setup of TK */ 1862 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability); 1863 if (ret) 1864 return SMP_UNSPECIFIED; 1865 1866 return 0; 1867 } 1868 1869 static u8 sc_send_public_key(struct smp_chan *smp) 1870 { 1871 struct hci_dev *hdev = smp->conn->hcon->hdev; 1872 1873 bt_dev_dbg(hdev, ""); 1874 1875 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { 1876 struct l2cap_chan *chan = hdev->smp_data; 1877 struct smp_dev *smp_dev; 1878 1879 if (!chan || !chan->data) 1880 return SMP_UNSPECIFIED; 1881 1882 smp_dev = chan->data; 1883 1884 memcpy(smp->local_pk, smp_dev->local_pk, 64); 1885 memcpy(smp->lr, smp_dev->local_rand, 16); 1886 1887 if (smp_dev->debug_key) 1888 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1889 1890 goto done; 1891 } 1892 1893 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { 1894 bt_dev_dbg(hdev, "Using debug keys"); 1895 if (set_ecdh_privkey(smp->tfm_ecdh, debug_sk)) 1896 return SMP_UNSPECIFIED; 1897 memcpy(smp->local_pk, debug_pk, 64); 1898 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1899 } else { 1900 while (true) { 1901 /* Generate key pair for Secure Connections */ 1902 if (generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk)) 1903 return SMP_UNSPECIFIED; 1904 1905 /* This is unlikely, but we need to check that 1906 * we didn't accidentally generate a debug key. 1907 */ 1908 if (crypto_memneq(smp->local_pk, debug_pk, 64)) 1909 break; 1910 } 1911 } 1912 1913 done: 1914 SMP_DBG("Local Public Key X: %32phN", smp->local_pk); 1915 SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32); 1916 1917 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk); 1918 1919 return 0; 1920 } 1921 1922 static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) 1923 { 1924 struct smp_cmd_pairing *req, *rsp = (void *) skb->data; 1925 struct l2cap_chan *chan = conn->smp; 1926 struct smp_chan *smp = chan->data; 1927 struct hci_dev *hdev = conn->hcon->hdev; 1928 u8 key_size, auth; 1929 int ret; 1930 1931 bt_dev_dbg(hdev, "conn %p", conn); 1932 1933 if (skb->len < sizeof(*rsp)) 1934 return SMP_INVALID_PARAMS; 1935 1936 if (conn->hcon->role != HCI_ROLE_MASTER) 1937 return SMP_CMD_NOTSUPP; 1938 1939 skb_pull(skb, sizeof(*rsp)); 1940 1941 req = (void *) &smp->preq[1]; 1942 1943 key_size = min(req->max_key_size, rsp->max_key_size); 1944 if (check_enc_key_size(conn, key_size)) 1945 return SMP_ENC_KEY_SIZE; 1946 1947 auth = rsp->auth_req & AUTH_REQ_MASK(hdev); 1948 1949 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 1950 return SMP_AUTH_REQUIREMENTS; 1951 1952 /* If the remote side's OOB flag is set it means it has 1953 * successfully received our local OOB data - therefore set the 1954 * flag to indicate that local OOB is in use. 1955 */ 1956 if (rsp->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob) 1957 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); 1958 1959 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1960 memcpy(&smp->prsp[1], rsp, sizeof(*rsp)); 1961 1962 /* Update remote key distribution in case the remote cleared 1963 * some bits that we had enabled in our request. 1964 */ 1965 smp->remote_key_dist &= rsp->resp_key_dist; 1966 1967 if ((req->auth_req & SMP_AUTH_CT2) && (auth & SMP_AUTH_CT2)) 1968 set_bit(SMP_FLAG_CT2, &smp->flags); 1969 1970 /* For BR/EDR this means we're done and can start phase 3 */ 1971 if (conn->hcon->type == ACL_LINK) { 1972 /* Clear bits which are generated but not distributed */ 1973 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1974 smp_distribute_keys(smp); 1975 return 0; 1976 } 1977 1978 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC)) 1979 set_bit(SMP_FLAG_SC, &smp->flags); 1980 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH) 1981 conn->hcon->pending_sec_level = BT_SECURITY_HIGH; 1982 1983 /* If we need MITM check that it can be achieved */ 1984 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { 1985 u8 method; 1986 1987 method = get_auth_method(smp, req->io_capability, 1988 rsp->io_capability); 1989 if (method == JUST_WORKS || method == JUST_CFM) 1990 return SMP_AUTH_REQUIREMENTS; 1991 } 1992 1993 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1994 1995 /* Update remote key distribution in case the remote cleared 1996 * some bits that we had enabled in our request. 1997 */ 1998 smp->remote_key_dist &= rsp->resp_key_dist; 1999 2000 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 2001 /* Clear bits which are generated but not distributed */ 2002 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 2003 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); 2004 return sc_send_public_key(smp); 2005 } 2006 2007 auth |= req->auth_req; 2008 2009 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability); 2010 if (ret) 2011 return SMP_UNSPECIFIED; 2012 2013 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 2014 2015 /* Can't compose response until we have been confirmed */ 2016 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) 2017 return smp_confirm(smp); 2018 2019 return 0; 2020 } 2021 2022 static u8 sc_check_confirm(struct smp_chan *smp) 2023 { 2024 struct l2cap_conn *conn = smp->conn; 2025 2026 bt_dev_dbg(conn->hcon->hdev, ""); 2027 2028 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2029 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM); 2030 2031 if (conn->hcon->out) { 2032 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2033 smp->prnd); 2034 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2035 } 2036 2037 return 0; 2038 } 2039 2040 /* Work-around for some implementations that incorrectly copy RFU bits 2041 * from our security request and thereby create the impression that 2042 * we're doing SC when in fact the remote doesn't support it. 2043 */ 2044 static int fixup_sc_false_positive(struct smp_chan *smp) 2045 { 2046 struct l2cap_conn *conn = smp->conn; 2047 struct hci_conn *hcon = conn->hcon; 2048 struct hci_dev *hdev = hcon->hdev; 2049 struct smp_cmd_pairing *req, *rsp; 2050 u8 auth; 2051 2052 /* The issue is only observed when we're in responder role */ 2053 if (hcon->out) 2054 return SMP_UNSPECIFIED; 2055 2056 if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) { 2057 bt_dev_err(hdev, "refusing legacy fallback in SC-only mode"); 2058 return SMP_UNSPECIFIED; 2059 } 2060 2061 bt_dev_err(hdev, "trying to fall back to legacy SMP"); 2062 2063 req = (void *) &smp->preq[1]; 2064 rsp = (void *) &smp->prsp[1]; 2065 2066 /* Rebuild key dist flags which may have been cleared for SC */ 2067 smp->remote_key_dist = (req->init_key_dist & rsp->resp_key_dist); 2068 2069 auth = req->auth_req & AUTH_REQ_MASK(hdev); 2070 2071 if (tk_request(conn, 0, auth, rsp->io_capability, req->io_capability)) { 2072 bt_dev_err(hdev, "failed to fall back to legacy SMP"); 2073 return SMP_UNSPECIFIED; 2074 } 2075 2076 clear_bit(SMP_FLAG_SC, &smp->flags); 2077 2078 return 0; 2079 } 2080 2081 static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb) 2082 { 2083 struct l2cap_chan *chan = conn->smp; 2084 struct smp_chan *smp = chan->data; 2085 struct hci_conn *hcon = conn->hcon; 2086 struct hci_dev *hdev = hcon->hdev; 2087 2088 bt_dev_dbg(hdev, "conn %p %s", conn, 2089 hcon->out ? "initiator" : "responder"); 2090 2091 if (skb->len < sizeof(smp->pcnf)) 2092 return SMP_INVALID_PARAMS; 2093 2094 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf)); 2095 skb_pull(skb, sizeof(smp->pcnf)); 2096 2097 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 2098 int ret; 2099 2100 /* Public Key exchange must happen before any other steps */ 2101 if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags)) 2102 return sc_check_confirm(smp); 2103 2104 bt_dev_err(hdev, "Unexpected SMP Pairing Confirm"); 2105 2106 ret = fixup_sc_false_positive(smp); 2107 if (ret) 2108 return ret; 2109 } 2110 2111 if (conn->hcon->out) { 2112 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2113 smp->prnd); 2114 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2115 return 0; 2116 } 2117 2118 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) 2119 return smp_confirm(smp); 2120 2121 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 2122 2123 return 0; 2124 } 2125 2126 static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb) 2127 { 2128 struct l2cap_chan *chan = conn->smp; 2129 struct smp_chan *smp = chan->data; 2130 struct hci_conn *hcon = conn->hcon; 2131 u8 *pkax, *pkbx, *na, *nb, confirm_hint; 2132 u32 passkey; 2133 int err; 2134 2135 bt_dev_dbg(hcon->hdev, "conn %p", conn); 2136 2137 if (skb->len < sizeof(smp->rrnd)) 2138 return SMP_INVALID_PARAMS; 2139 2140 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd)); 2141 skb_pull(skb, sizeof(smp->rrnd)); 2142 2143 if (!test_bit(SMP_FLAG_SC, &smp->flags)) 2144 return smp_random(smp); 2145 2146 if (hcon->out) { 2147 pkax = smp->local_pk; 2148 pkbx = smp->remote_pk; 2149 na = smp->prnd; 2150 nb = smp->rrnd; 2151 } else { 2152 pkax = smp->remote_pk; 2153 pkbx = smp->local_pk; 2154 na = smp->rrnd; 2155 nb = smp->prnd; 2156 } 2157 2158 if (smp->method == REQ_OOB) { 2159 if (!hcon->out) 2160 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 2161 sizeof(smp->prnd), smp->prnd); 2162 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2163 goto mackey_and_ltk; 2164 } 2165 2166 /* Passkey entry has special treatment */ 2167 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2168 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM); 2169 2170 if (hcon->out) { 2171 u8 cfm[16]; 2172 2173 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, 2174 smp->rrnd, 0, cfm); 2175 if (err) 2176 return SMP_UNSPECIFIED; 2177 2178 if (crypto_memneq(smp->pcnf, cfm, 16)) 2179 return SMP_CONFIRM_FAILED; 2180 } else { 2181 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2182 smp->prnd); 2183 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2184 2185 /* Only Just-Works pairing requires extra checks */ 2186 if (smp->method != JUST_WORKS) 2187 goto mackey_and_ltk; 2188 2189 /* If there already exists long term key in local host, leave 2190 * the decision to user space since the remote device could 2191 * be legitimate or malicious. 2192 */ 2193 if (hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 2194 hcon->role)) { 2195 /* Set passkey to 0. The value can be any number since 2196 * it'll be ignored anyway. 2197 */ 2198 passkey = 0; 2199 confirm_hint = 1; 2200 goto confirm; 2201 } 2202 } 2203 2204 mackey_and_ltk: 2205 /* Generate MacKey and LTK */ 2206 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk); 2207 if (err) 2208 return SMP_UNSPECIFIED; 2209 2210 if (smp->method == REQ_OOB) { 2211 if (hcon->out) { 2212 sc_dhkey_check(smp); 2213 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2214 } 2215 return 0; 2216 } 2217 2218 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey); 2219 if (err) 2220 return SMP_UNSPECIFIED; 2221 2222 confirm_hint = 0; 2223 2224 confirm: 2225 if (smp->method == JUST_WORKS) 2226 confirm_hint = 1; 2227 2228 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type, 2229 hcon->dst_type, passkey, confirm_hint); 2230 if (err) 2231 return SMP_UNSPECIFIED; 2232 2233 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 2234 2235 return 0; 2236 } 2237 2238 static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level) 2239 { 2240 struct smp_ltk *key; 2241 struct hci_conn *hcon = conn->hcon; 2242 2243 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role); 2244 if (!key) 2245 return false; 2246 2247 if (smp_ltk_sec_level(key) < sec_level) 2248 return false; 2249 2250 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) 2251 return true; 2252 2253 hci_le_start_enc(hcon, key->ediv, key->rand, key->val, key->enc_size); 2254 hcon->enc_key_size = key->enc_size; 2255 2256 /* We never store STKs for initiator role, so clear this flag */ 2257 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); 2258 2259 return true; 2260 } 2261 2262 bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level, 2263 enum smp_key_pref key_pref) 2264 { 2265 if (sec_level == BT_SECURITY_LOW) 2266 return true; 2267 2268 /* If we're encrypted with an STK but the caller prefers using 2269 * LTK claim insufficient security. This way we allow the 2270 * connection to be re-encrypted with an LTK, even if the LTK 2271 * provides the same level of security. Only exception is if we 2272 * don't have an LTK (e.g. because of key distribution bits). 2273 */ 2274 if (key_pref == SMP_USE_LTK && 2275 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) && 2276 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role)) 2277 return false; 2278 2279 if (hcon->sec_level >= sec_level) 2280 return true; 2281 2282 return false; 2283 } 2284 2285 static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb) 2286 { 2287 struct smp_cmd_security_req *rp = (void *) skb->data; 2288 struct smp_cmd_pairing cp; 2289 struct hci_conn *hcon = conn->hcon; 2290 struct hci_dev *hdev = hcon->hdev; 2291 struct smp_chan *smp; 2292 u8 sec_level, auth; 2293 2294 bt_dev_dbg(hdev, "conn %p", conn); 2295 2296 if (skb->len < sizeof(*rp)) 2297 return SMP_INVALID_PARAMS; 2298 2299 if (hcon->role != HCI_ROLE_MASTER) 2300 return SMP_CMD_NOTSUPP; 2301 2302 auth = rp->auth_req & AUTH_REQ_MASK(hdev); 2303 2304 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 2305 return SMP_AUTH_REQUIREMENTS; 2306 2307 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 2308 sec_level = BT_SECURITY_MEDIUM; 2309 else 2310 sec_level = authreq_to_seclevel(auth); 2311 2312 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) { 2313 /* If link is already encrypted with sufficient security we 2314 * still need refresh encryption as per Core Spec 5.0 Vol 3, 2315 * Part H 2.4.6 2316 */ 2317 smp_ltk_encrypt(conn, hcon->sec_level); 2318 return 0; 2319 } 2320 2321 if (sec_level > hcon->pending_sec_level) 2322 hcon->pending_sec_level = sec_level; 2323 2324 if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) 2325 return 0; 2326 2327 smp = smp_chan_create(conn); 2328 if (!smp) 2329 return SMP_UNSPECIFIED; 2330 2331 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && 2332 (auth & SMP_AUTH_BONDING)) 2333 return SMP_PAIRING_NOTSUPP; 2334 2335 skb_pull(skb, sizeof(*rp)); 2336 2337 memset(&cp, 0, sizeof(cp)); 2338 build_pairing_cmd(conn, &cp, NULL, auth); 2339 2340 smp->preq[0] = SMP_CMD_PAIRING_REQ; 2341 memcpy(&smp->preq[1], &cp, sizeof(cp)); 2342 2343 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); 2344 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 2345 2346 return 0; 2347 } 2348 2349 int smp_conn_security(struct hci_conn *hcon, __u8 sec_level) 2350 { 2351 struct l2cap_conn *conn = hcon->l2cap_data; 2352 struct l2cap_chan *chan; 2353 struct smp_chan *smp; 2354 __u8 authreq; 2355 int ret; 2356 2357 bt_dev_dbg(hcon->hdev, "conn %p hcon %p level 0x%2.2x", conn, hcon, 2358 sec_level); 2359 2360 /* This may be NULL if there's an unexpected disconnection */ 2361 if (!conn) 2362 return 1; 2363 2364 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) 2365 return 1; 2366 2367 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) 2368 return 1; 2369 2370 if (sec_level > hcon->pending_sec_level) 2371 hcon->pending_sec_level = sec_level; 2372 2373 if (hcon->role == HCI_ROLE_MASTER) 2374 if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) 2375 return 0; 2376 2377 chan = conn->smp; 2378 if (!chan) { 2379 bt_dev_err(hcon->hdev, "security requested but not available"); 2380 return 1; 2381 } 2382 2383 l2cap_chan_lock(chan); 2384 2385 /* If SMP is already in progress ignore this request */ 2386 if (chan->data) { 2387 ret = 0; 2388 goto unlock; 2389 } 2390 2391 smp = smp_chan_create(conn); 2392 if (!smp) { 2393 ret = 1; 2394 goto unlock; 2395 } 2396 2397 authreq = seclevel_to_authreq(sec_level); 2398 2399 if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED)) { 2400 authreq |= SMP_AUTH_SC; 2401 if (hci_dev_test_flag(hcon->hdev, HCI_SSP_ENABLED)) 2402 authreq |= SMP_AUTH_CT2; 2403 } 2404 2405 /* Don't attempt to set MITM if setting is overridden by debugfs 2406 * Needed to pass certification test SM/MAS/PKE/BV-01-C 2407 */ 2408 if (!hci_dev_test_flag(hcon->hdev, HCI_FORCE_NO_MITM)) { 2409 /* Require MITM if IO Capability allows or the security level 2410 * requires it. 2411 */ 2412 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT || 2413 hcon->pending_sec_level > BT_SECURITY_MEDIUM) 2414 authreq |= SMP_AUTH_MITM; 2415 } 2416 2417 if (hcon->role == HCI_ROLE_MASTER) { 2418 struct smp_cmd_pairing cp; 2419 2420 build_pairing_cmd(conn, &cp, NULL, authreq); 2421 smp->preq[0] = SMP_CMD_PAIRING_REQ; 2422 memcpy(&smp->preq[1], &cp, sizeof(cp)); 2423 2424 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); 2425 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 2426 } else { 2427 struct smp_cmd_security_req cp; 2428 cp.auth_req = authreq; 2429 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp); 2430 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ); 2431 } 2432 2433 set_bit(SMP_FLAG_INITIATOR, &smp->flags); 2434 ret = 0; 2435 2436 unlock: 2437 l2cap_chan_unlock(chan); 2438 return ret; 2439 } 2440 2441 int smp_cancel_and_remove_pairing(struct hci_dev *hdev, bdaddr_t *bdaddr, 2442 u8 addr_type) 2443 { 2444 struct hci_conn *hcon; 2445 struct l2cap_conn *conn; 2446 struct l2cap_chan *chan; 2447 struct smp_chan *smp; 2448 int err; 2449 2450 err = hci_remove_ltk(hdev, bdaddr, addr_type); 2451 hci_remove_irk(hdev, bdaddr, addr_type); 2452 2453 hcon = hci_conn_hash_lookup_le(hdev, bdaddr, addr_type); 2454 if (!hcon) 2455 goto done; 2456 2457 conn = hcon->l2cap_data; 2458 if (!conn) 2459 goto done; 2460 2461 chan = conn->smp; 2462 if (!chan) 2463 goto done; 2464 2465 l2cap_chan_lock(chan); 2466 2467 smp = chan->data; 2468 if (smp) { 2469 /* Set keys to NULL to make sure smp_failure() does not try to 2470 * remove and free already invalidated rcu list entries. */ 2471 smp->ltk = NULL; 2472 smp->responder_ltk = NULL; 2473 smp->remote_irk = NULL; 2474 2475 if (test_bit(SMP_FLAG_COMPLETE, &smp->flags)) 2476 smp_failure(conn, 0); 2477 else 2478 smp_failure(conn, SMP_UNSPECIFIED); 2479 err = 0; 2480 } 2481 2482 l2cap_chan_unlock(chan); 2483 2484 done: 2485 return err; 2486 } 2487 2488 static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb) 2489 { 2490 struct smp_cmd_encrypt_info *rp = (void *) skb->data; 2491 struct l2cap_chan *chan = conn->smp; 2492 struct smp_chan *smp = chan->data; 2493 2494 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 2495 2496 if (skb->len < sizeof(*rp)) 2497 return SMP_INVALID_PARAMS; 2498 2499 /* Pairing is aborted if any blocked keys are distributed */ 2500 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_LTK, 2501 rp->ltk)) { 2502 bt_dev_warn_ratelimited(conn->hcon->hdev, 2503 "LTK blocked for %pMR", 2504 &conn->hcon->dst); 2505 return SMP_INVALID_PARAMS; 2506 } 2507 2508 SMP_ALLOW_CMD(smp, SMP_CMD_INITIATOR_IDENT); 2509 2510 skb_pull(skb, sizeof(*rp)); 2511 2512 memcpy(smp->tk, rp->ltk, sizeof(smp->tk)); 2513 2514 return 0; 2515 } 2516 2517 static int smp_cmd_initiator_ident(struct l2cap_conn *conn, struct sk_buff *skb) 2518 { 2519 struct smp_cmd_initiator_ident *rp = (void *)skb->data; 2520 struct l2cap_chan *chan = conn->smp; 2521 struct smp_chan *smp = chan->data; 2522 struct hci_dev *hdev = conn->hcon->hdev; 2523 struct hci_conn *hcon = conn->hcon; 2524 struct smp_ltk *ltk; 2525 u8 authenticated; 2526 2527 bt_dev_dbg(hdev, "conn %p", conn); 2528 2529 if (skb->len < sizeof(*rp)) 2530 return SMP_INVALID_PARAMS; 2531 2532 /* Mark the information as received */ 2533 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY; 2534 2535 if (smp->remote_key_dist & SMP_DIST_ID_KEY) 2536 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); 2537 else if (smp->remote_key_dist & SMP_DIST_SIGN) 2538 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 2539 2540 skb_pull(skb, sizeof(*rp)); 2541 2542 authenticated = (hcon->sec_level == BT_SECURITY_HIGH); 2543 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK, 2544 authenticated, smp->tk, smp->enc_key_size, 2545 rp->ediv, rp->rand); 2546 smp->ltk = ltk; 2547 if (!(smp->remote_key_dist & KEY_DIST_MASK)) 2548 smp_distribute_keys(smp); 2549 2550 return 0; 2551 } 2552 2553 static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb) 2554 { 2555 struct smp_cmd_ident_info *info = (void *) skb->data; 2556 struct l2cap_chan *chan = conn->smp; 2557 struct smp_chan *smp = chan->data; 2558 2559 bt_dev_dbg(conn->hcon->hdev, ""); 2560 2561 if (skb->len < sizeof(*info)) 2562 return SMP_INVALID_PARAMS; 2563 2564 /* Pairing is aborted if any blocked keys are distributed */ 2565 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_IRK, 2566 info->irk)) { 2567 bt_dev_warn_ratelimited(conn->hcon->hdev, 2568 "Identity key blocked for %pMR", 2569 &conn->hcon->dst); 2570 return SMP_INVALID_PARAMS; 2571 } 2572 2573 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO); 2574 2575 skb_pull(skb, sizeof(*info)); 2576 2577 memcpy(smp->irk, info->irk, 16); 2578 2579 return 0; 2580 } 2581 2582 static int smp_cmd_ident_addr_info(struct l2cap_conn *conn, 2583 struct sk_buff *skb) 2584 { 2585 struct smp_cmd_ident_addr_info *info = (void *) skb->data; 2586 struct l2cap_chan *chan = conn->smp; 2587 struct smp_chan *smp = chan->data; 2588 struct hci_conn *hcon = conn->hcon; 2589 bdaddr_t rpa; 2590 2591 bt_dev_dbg(hcon->hdev, ""); 2592 2593 if (skb->len < sizeof(*info)) 2594 return SMP_INVALID_PARAMS; 2595 2596 /* Mark the information as received */ 2597 smp->remote_key_dist &= ~SMP_DIST_ID_KEY; 2598 2599 if (smp->remote_key_dist & SMP_DIST_SIGN) 2600 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 2601 2602 skb_pull(skb, sizeof(*info)); 2603 2604 /* Strictly speaking the Core Specification (4.1) allows sending 2605 * an empty address which would force us to rely on just the IRK 2606 * as "identity information". However, since such 2607 * implementations are not known of and in order to not over 2608 * complicate our implementation, simply pretend that we never 2609 * received an IRK for such a device. 2610 * 2611 * The Identity Address must also be a Static Random or Public 2612 * Address, which hci_is_identity_address() checks for. 2613 */ 2614 if (!bacmp(&info->bdaddr, BDADDR_ANY) || 2615 !hci_is_identity_address(&info->bdaddr, info->addr_type)) { 2616 bt_dev_err(hcon->hdev, "ignoring IRK with no identity address"); 2617 goto distribute; 2618 } 2619 2620 /* Drop IRK if peer is using identity address during pairing but is 2621 * providing different address as identity information. 2622 * 2623 * Microsoft Surface Precision Mouse is known to have this bug. 2624 */ 2625 if (hci_is_identity_address(&hcon->dst, hcon->dst_type) && 2626 (bacmp(&info->bdaddr, &hcon->dst) || 2627 info->addr_type != hcon->dst_type)) { 2628 bt_dev_err(hcon->hdev, 2629 "ignoring IRK with invalid identity address"); 2630 goto distribute; 2631 } 2632 2633 bacpy(&smp->id_addr, &info->bdaddr); 2634 smp->id_addr_type = info->addr_type; 2635 2636 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type)) 2637 bacpy(&rpa, &hcon->dst); 2638 else 2639 bacpy(&rpa, BDADDR_ANY); 2640 2641 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr, 2642 smp->id_addr_type, smp->irk, &rpa); 2643 2644 distribute: 2645 if (!(smp->remote_key_dist & KEY_DIST_MASK)) 2646 smp_distribute_keys(smp); 2647 2648 return 0; 2649 } 2650 2651 static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb) 2652 { 2653 struct smp_cmd_sign_info *rp = (void *) skb->data; 2654 struct l2cap_chan *chan = conn->smp; 2655 struct smp_chan *smp = chan->data; 2656 struct smp_csrk *csrk; 2657 2658 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 2659 2660 if (skb->len < sizeof(*rp)) 2661 return SMP_INVALID_PARAMS; 2662 2663 /* Mark the information as received */ 2664 smp->remote_key_dist &= ~SMP_DIST_SIGN; 2665 2666 skb_pull(skb, sizeof(*rp)); 2667 2668 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); 2669 if (csrk) { 2670 if (conn->hcon->sec_level > BT_SECURITY_MEDIUM) 2671 csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED; 2672 else 2673 csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED; 2674 memcpy(csrk->val, rp->csrk, sizeof(csrk->val)); 2675 } 2676 smp->csrk = csrk; 2677 smp_distribute_keys(smp); 2678 2679 return 0; 2680 } 2681 2682 static u8 sc_select_method(struct smp_chan *smp) 2683 { 2684 struct l2cap_conn *conn = smp->conn; 2685 struct hci_conn *hcon = conn->hcon; 2686 struct smp_cmd_pairing *local, *remote; 2687 u8 local_mitm, remote_mitm, local_io, remote_io, method; 2688 2689 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) || 2690 test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) 2691 return REQ_OOB; 2692 2693 /* The preq/prsp contain the raw Pairing Request/Response PDUs 2694 * which are needed as inputs to some crypto functions. To get 2695 * the "struct smp_cmd_pairing" from them we need to skip the 2696 * first byte which contains the opcode. 2697 */ 2698 if (hcon->out) { 2699 local = (void *) &smp->preq[1]; 2700 remote = (void *) &smp->prsp[1]; 2701 } else { 2702 local = (void *) &smp->prsp[1]; 2703 remote = (void *) &smp->preq[1]; 2704 } 2705 2706 local_io = local->io_capability; 2707 remote_io = remote->io_capability; 2708 2709 local_mitm = (local->auth_req & SMP_AUTH_MITM); 2710 remote_mitm = (remote->auth_req & SMP_AUTH_MITM); 2711 2712 /* If either side wants MITM, look up the method from the table, 2713 * otherwise use JUST WORKS. 2714 */ 2715 if (local_mitm || remote_mitm) 2716 method = get_auth_method(smp, local_io, remote_io); 2717 else 2718 method = JUST_WORKS; 2719 2720 /* Don't confirm locally initiated pairing attempts */ 2721 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2722 method = JUST_WORKS; 2723 2724 return method; 2725 } 2726 2727 static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb) 2728 { 2729 struct smp_cmd_public_key *key = (void *) skb->data; 2730 struct hci_conn *hcon = conn->hcon; 2731 struct l2cap_chan *chan = conn->smp; 2732 struct smp_chan *smp = chan->data; 2733 struct hci_dev *hdev = hcon->hdev; 2734 struct crypto_kpp *tfm_ecdh; 2735 struct smp_cmd_pairing_confirm cfm; 2736 int err; 2737 2738 bt_dev_dbg(hdev, "conn %p", conn); 2739 2740 if (skb->len < sizeof(*key)) 2741 return SMP_INVALID_PARAMS; 2742 2743 /* Check if remote and local public keys are the same and debug key is 2744 * not in use. 2745 */ 2746 if (!test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags) && 2747 !crypto_memneq(key, smp->local_pk, 64)) { 2748 bt_dev_err(hdev, "Remote and local public keys are identical"); 2749 return SMP_UNSPECIFIED; 2750 } 2751 2752 memcpy(smp->remote_pk, key, 64); 2753 2754 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) { 2755 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk, 2756 smp->rr, 0, cfm.confirm_val); 2757 if (err) 2758 return SMP_UNSPECIFIED; 2759 2760 if (crypto_memneq(cfm.confirm_val, smp->pcnf, 16)) 2761 return SMP_CONFIRM_FAILED; 2762 } 2763 2764 /* Non-initiating device sends its public key after receiving 2765 * the key from the initiating device. 2766 */ 2767 if (!hcon->out) { 2768 err = sc_send_public_key(smp); 2769 if (err) 2770 return err; 2771 } 2772 2773 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk); 2774 SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32); 2775 2776 /* Compute the shared secret on the same crypto tfm on which the private 2777 * key was set/generated. 2778 */ 2779 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { 2780 struct l2cap_chan *hchan = hdev->smp_data; 2781 struct smp_dev *smp_dev; 2782 2783 if (!hchan || !hchan->data) 2784 return SMP_UNSPECIFIED; 2785 2786 smp_dev = hchan->data; 2787 2788 tfm_ecdh = smp_dev->tfm_ecdh; 2789 } else { 2790 tfm_ecdh = smp->tfm_ecdh; 2791 } 2792 2793 if (compute_ecdh_secret(tfm_ecdh, smp->remote_pk, smp->dhkey)) 2794 return SMP_UNSPECIFIED; 2795 2796 SMP_DBG("DHKey %32phN", smp->dhkey); 2797 2798 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags); 2799 2800 smp->method = sc_select_method(smp); 2801 2802 bt_dev_dbg(hdev, "selected method 0x%02x", smp->method); 2803 2804 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */ 2805 if (smp->method == JUST_WORKS || smp->method == JUST_CFM) 2806 hcon->pending_sec_level = BT_SECURITY_MEDIUM; 2807 else 2808 hcon->pending_sec_level = BT_SECURITY_FIPS; 2809 2810 if (!crypto_memneq(debug_pk, smp->remote_pk, 64)) 2811 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 2812 2813 if (smp->method == DSP_PASSKEY) { 2814 get_random_bytes(&hcon->passkey_notify, 2815 sizeof(hcon->passkey_notify)); 2816 hcon->passkey_notify %= 1000000; 2817 hcon->passkey_entered = 0; 2818 smp->passkey_round = 0; 2819 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type, 2820 hcon->dst_type, 2821 hcon->passkey_notify, 2822 hcon->passkey_entered)) 2823 return SMP_UNSPECIFIED; 2824 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2825 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY); 2826 } 2827 2828 if (smp->method == REQ_OOB) { 2829 if (hcon->out) 2830 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 2831 sizeof(smp->prnd), smp->prnd); 2832 2833 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2834 2835 return 0; 2836 } 2837 2838 if (hcon->out) 2839 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2840 2841 if (smp->method == REQ_PASSKEY) { 2842 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type, 2843 hcon->dst_type)) 2844 return SMP_UNSPECIFIED; 2845 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2846 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 2847 return 0; 2848 } 2849 2850 /* The Initiating device waits for the non-initiating device to 2851 * send the confirm value. 2852 */ 2853 if (conn->hcon->out) 2854 return 0; 2855 2856 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, 2857 0, cfm.confirm_val); 2858 if (err) 2859 return SMP_UNSPECIFIED; 2860 2861 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); 2862 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2863 2864 return 0; 2865 } 2866 2867 static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb) 2868 { 2869 struct smp_cmd_dhkey_check *check = (void *) skb->data; 2870 struct l2cap_chan *chan = conn->smp; 2871 struct hci_conn *hcon = conn->hcon; 2872 struct smp_chan *smp = chan->data; 2873 u8 a[7], b[7], *local_addr, *remote_addr; 2874 u8 io_cap[3], r[16], e[16]; 2875 int err; 2876 2877 bt_dev_dbg(hcon->hdev, "conn %p", conn); 2878 2879 if (skb->len < sizeof(*check)) 2880 return SMP_INVALID_PARAMS; 2881 2882 memcpy(a, &hcon->init_addr, 6); 2883 memcpy(b, &hcon->resp_addr, 6); 2884 a[6] = hcon->init_addr_type; 2885 b[6] = hcon->resp_addr_type; 2886 2887 if (hcon->out) { 2888 local_addr = a; 2889 remote_addr = b; 2890 memcpy(io_cap, &smp->prsp[1], 3); 2891 } else { 2892 local_addr = b; 2893 remote_addr = a; 2894 memcpy(io_cap, &smp->preq[1], 3); 2895 } 2896 2897 memset(r, 0, sizeof(r)); 2898 2899 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2900 put_unaligned_le32(hcon->passkey_notify, r); 2901 else if (smp->method == REQ_OOB) 2902 memcpy(r, smp->lr, 16); 2903 2904 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r, 2905 io_cap, remote_addr, local_addr, e); 2906 if (err) 2907 return SMP_UNSPECIFIED; 2908 2909 if (crypto_memneq(check->e, e, 16)) 2910 return SMP_DHKEY_CHECK_FAILED; 2911 2912 if (!hcon->out) { 2913 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { 2914 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags); 2915 return 0; 2916 } 2917 2918 /* Responder sends DHKey check as response to initiator */ 2919 sc_dhkey_check(smp); 2920 } 2921 2922 sc_add_ltk(smp); 2923 2924 if (hcon->out) { 2925 hci_le_start_enc(hcon, 0, 0, smp->tk, smp->enc_key_size); 2926 hcon->enc_key_size = smp->enc_key_size; 2927 } 2928 2929 return 0; 2930 } 2931 2932 static int smp_cmd_keypress_notify(struct l2cap_conn *conn, 2933 struct sk_buff *skb) 2934 { 2935 struct smp_cmd_keypress_notify *kp = (void *) skb->data; 2936 2937 bt_dev_dbg(conn->hcon->hdev, "value 0x%02x", kp->value); 2938 2939 return 0; 2940 } 2941 2942 static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb) 2943 { 2944 struct l2cap_conn *conn = chan->conn; 2945 struct hci_conn *hcon = conn->hcon; 2946 struct smp_chan *smp; 2947 __u8 code, reason; 2948 int err = 0; 2949 2950 if (skb->len < 1) 2951 return -EILSEQ; 2952 2953 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) { 2954 reason = SMP_PAIRING_NOTSUPP; 2955 goto done; 2956 } 2957 2958 code = skb->data[0]; 2959 skb_pull(skb, sizeof(code)); 2960 2961 smp = chan->data; 2962 2963 if (code > SMP_CMD_MAX) 2964 goto drop; 2965 2966 if (smp && !test_and_clear_bit(code, &smp->allow_cmd)) 2967 goto drop; 2968 2969 /* If we don't have a context the only allowed commands are 2970 * pairing request and security request. 2971 */ 2972 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ) 2973 goto drop; 2974 2975 switch (code) { 2976 case SMP_CMD_PAIRING_REQ: 2977 reason = smp_cmd_pairing_req(conn, skb); 2978 break; 2979 2980 case SMP_CMD_PAIRING_FAIL: 2981 smp_failure(conn, 0); 2982 err = -EPERM; 2983 break; 2984 2985 case SMP_CMD_PAIRING_RSP: 2986 reason = smp_cmd_pairing_rsp(conn, skb); 2987 break; 2988 2989 case SMP_CMD_SECURITY_REQ: 2990 reason = smp_cmd_security_req(conn, skb); 2991 break; 2992 2993 case SMP_CMD_PAIRING_CONFIRM: 2994 reason = smp_cmd_pairing_confirm(conn, skb); 2995 break; 2996 2997 case SMP_CMD_PAIRING_RANDOM: 2998 reason = smp_cmd_pairing_random(conn, skb); 2999 break; 3000 3001 case SMP_CMD_ENCRYPT_INFO: 3002 reason = smp_cmd_encrypt_info(conn, skb); 3003 break; 3004 3005 case SMP_CMD_INITIATOR_IDENT: 3006 reason = smp_cmd_initiator_ident(conn, skb); 3007 break; 3008 3009 case SMP_CMD_IDENT_INFO: 3010 reason = smp_cmd_ident_info(conn, skb); 3011 break; 3012 3013 case SMP_CMD_IDENT_ADDR_INFO: 3014 reason = smp_cmd_ident_addr_info(conn, skb); 3015 break; 3016 3017 case SMP_CMD_SIGN_INFO: 3018 reason = smp_cmd_sign_info(conn, skb); 3019 break; 3020 3021 case SMP_CMD_PUBLIC_KEY: 3022 reason = smp_cmd_public_key(conn, skb); 3023 break; 3024 3025 case SMP_CMD_DHKEY_CHECK: 3026 reason = smp_cmd_dhkey_check(conn, skb); 3027 break; 3028 3029 case SMP_CMD_KEYPRESS_NOTIFY: 3030 reason = smp_cmd_keypress_notify(conn, skb); 3031 break; 3032 3033 default: 3034 bt_dev_dbg(hcon->hdev, "Unknown command code 0x%2.2x", code); 3035 reason = SMP_CMD_NOTSUPP; 3036 goto done; 3037 } 3038 3039 done: 3040 if (!err) { 3041 if (reason) 3042 smp_failure(conn, reason); 3043 kfree_skb(skb); 3044 } 3045 3046 return err; 3047 3048 drop: 3049 bt_dev_err(hcon->hdev, "unexpected SMP command 0x%02x from %pMR", 3050 code, &hcon->dst); 3051 kfree_skb(skb); 3052 return 0; 3053 } 3054 3055 static void smp_teardown_cb(struct l2cap_chan *chan, int err) 3056 { 3057 struct l2cap_conn *conn = chan->conn; 3058 3059 bt_dev_dbg(conn->hcon->hdev, "chan %p", chan); 3060 3061 if (chan->data) 3062 smp_chan_destroy(conn); 3063 3064 conn->smp = NULL; 3065 l2cap_chan_put(chan); 3066 } 3067 3068 static void bredr_pairing(struct l2cap_chan *chan) 3069 { 3070 struct l2cap_conn *conn = chan->conn; 3071 struct hci_conn *hcon = conn->hcon; 3072 struct hci_dev *hdev = hcon->hdev; 3073 struct smp_cmd_pairing req; 3074 struct smp_chan *smp; 3075 3076 bt_dev_dbg(hdev, "chan %p", chan); 3077 3078 /* Only new pairings are interesting */ 3079 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags)) 3080 return; 3081 3082 /* Don't bother if we're not encrypted */ 3083 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3084 return; 3085 3086 /* Only initiator may initiate SMP over BR/EDR */ 3087 if (hcon->role != HCI_ROLE_MASTER) 3088 return; 3089 3090 /* Secure Connections support must be enabled */ 3091 if (!hci_dev_test_flag(hdev, HCI_SC_ENABLED)) 3092 return; 3093 3094 /* BR/EDR must use Secure Connections for SMP */ 3095 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) && 3096 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3097 return; 3098 3099 /* If our LE support is not enabled don't do anything */ 3100 if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) 3101 return; 3102 3103 /* Don't bother if remote LE support is not enabled */ 3104 if (!lmp_host_le_capable(hcon)) 3105 return; 3106 3107 /* Remote must support SMP fixed chan for BR/EDR */ 3108 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR)) 3109 return; 3110 3111 /* Don't bother if SMP is already ongoing */ 3112 if (chan->data) 3113 return; 3114 3115 smp = smp_chan_create(conn); 3116 if (!smp) { 3117 bt_dev_err(hdev, "unable to create SMP context for BR/EDR"); 3118 return; 3119 } 3120 3121 set_bit(SMP_FLAG_SC, &smp->flags); 3122 3123 bt_dev_dbg(hdev, "starting SMP over BR/EDR"); 3124 3125 /* Prepare and send the BR/EDR SMP Pairing Request */ 3126 build_bredr_pairing_cmd(smp, &req, NULL); 3127 3128 smp->preq[0] = SMP_CMD_PAIRING_REQ; 3129 memcpy(&smp->preq[1], &req, sizeof(req)); 3130 3131 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(req), &req); 3132 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 3133 } 3134 3135 static void smp_resume_cb(struct l2cap_chan *chan) 3136 { 3137 struct smp_chan *smp = chan->data; 3138 struct l2cap_conn *conn = chan->conn; 3139 struct hci_conn *hcon = conn->hcon; 3140 3141 bt_dev_dbg(hcon->hdev, "chan %p", chan); 3142 3143 if (hcon->type == ACL_LINK) { 3144 bredr_pairing(chan); 3145 return; 3146 } 3147 3148 if (!smp) 3149 return; 3150 3151 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3152 return; 3153 3154 cancel_delayed_work(&smp->security_timer); 3155 3156 smp_distribute_keys(smp); 3157 } 3158 3159 static void smp_ready_cb(struct l2cap_chan *chan) 3160 { 3161 struct l2cap_conn *conn = chan->conn; 3162 struct hci_conn *hcon = conn->hcon; 3163 3164 bt_dev_dbg(hcon->hdev, "chan %p", chan); 3165 3166 /* No need to call l2cap_chan_hold() here since we already own 3167 * the reference taken in smp_new_conn_cb(). This is just the 3168 * first time that we tie it to a specific pointer. The code in 3169 * l2cap_core.c ensures that there's no risk this function wont 3170 * get called if smp_new_conn_cb was previously called. 3171 */ 3172 conn->smp = chan; 3173 3174 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3175 bredr_pairing(chan); 3176 } 3177 3178 static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 3179 { 3180 int err; 3181 3182 bt_dev_dbg(chan->conn->hcon->hdev, "chan %p", chan); 3183 3184 err = smp_sig_channel(chan, skb); 3185 if (err) { 3186 struct smp_chan *smp = chan->data; 3187 3188 if (smp) 3189 cancel_delayed_work_sync(&smp->security_timer); 3190 3191 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE); 3192 } 3193 3194 return err; 3195 } 3196 3197 static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan, 3198 unsigned long hdr_len, 3199 unsigned long len, int nb) 3200 { 3201 struct sk_buff *skb; 3202 3203 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL); 3204 if (!skb) 3205 return ERR_PTR(-ENOMEM); 3206 3207 skb->priority = HCI_PRIO_MAX; 3208 bt_cb(skb)->l2cap.chan = chan; 3209 3210 return skb; 3211 } 3212 3213 static const struct l2cap_ops smp_chan_ops = { 3214 .name = "Security Manager", 3215 .ready = smp_ready_cb, 3216 .recv = smp_recv_cb, 3217 .alloc_skb = smp_alloc_skb_cb, 3218 .teardown = smp_teardown_cb, 3219 .resume = smp_resume_cb, 3220 3221 .new_connection = l2cap_chan_no_new_connection, 3222 .state_change = l2cap_chan_no_state_change, 3223 .close = l2cap_chan_no_close, 3224 .defer = l2cap_chan_no_defer, 3225 .suspend = l2cap_chan_no_suspend, 3226 .set_shutdown = l2cap_chan_no_set_shutdown, 3227 .get_sndtimeo = l2cap_chan_no_get_sndtimeo, 3228 }; 3229 3230 static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan) 3231 { 3232 struct l2cap_chan *chan; 3233 3234 BT_DBG("pchan %p", pchan); 3235 3236 chan = l2cap_chan_create(); 3237 if (!chan) 3238 return NULL; 3239 3240 chan->chan_type = pchan->chan_type; 3241 chan->ops = &smp_chan_ops; 3242 chan->scid = pchan->scid; 3243 chan->dcid = chan->scid; 3244 chan->imtu = pchan->imtu; 3245 chan->omtu = pchan->omtu; 3246 chan->mode = pchan->mode; 3247 3248 /* Other L2CAP channels may request SMP routines in order to 3249 * change the security level. This means that the SMP channel 3250 * lock must be considered in its own category to avoid lockdep 3251 * warnings. 3252 */ 3253 atomic_set(&chan->nesting, L2CAP_NESTING_SMP); 3254 3255 BT_DBG("created chan %p", chan); 3256 3257 return chan; 3258 } 3259 3260 static const struct l2cap_ops smp_root_chan_ops = { 3261 .name = "Security Manager Root", 3262 .new_connection = smp_new_conn_cb, 3263 3264 /* None of these are implemented for the root channel */ 3265 .close = l2cap_chan_no_close, 3266 .alloc_skb = l2cap_chan_no_alloc_skb, 3267 .recv = l2cap_chan_no_recv, 3268 .state_change = l2cap_chan_no_state_change, 3269 .teardown = l2cap_chan_no_teardown, 3270 .ready = l2cap_chan_no_ready, 3271 .defer = l2cap_chan_no_defer, 3272 .suspend = l2cap_chan_no_suspend, 3273 .resume = l2cap_chan_no_resume, 3274 .set_shutdown = l2cap_chan_no_set_shutdown, 3275 .get_sndtimeo = l2cap_chan_no_get_sndtimeo, 3276 }; 3277 3278 static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid) 3279 { 3280 struct l2cap_chan *chan; 3281 struct smp_dev *smp; 3282 struct crypto_shash *tfm_cmac; 3283 struct crypto_kpp *tfm_ecdh; 3284 3285 if (cid == L2CAP_CID_SMP_BREDR) { 3286 smp = NULL; 3287 goto create_chan; 3288 } 3289 3290 smp = kzalloc(sizeof(*smp), GFP_KERNEL); 3291 if (!smp) 3292 return ERR_PTR(-ENOMEM); 3293 3294 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 3295 if (IS_ERR(tfm_cmac)) { 3296 bt_dev_err(hdev, "Unable to create CMAC crypto context"); 3297 kfree_sensitive(smp); 3298 return ERR_CAST(tfm_cmac); 3299 } 3300 3301 tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0); 3302 if (IS_ERR(tfm_ecdh)) { 3303 bt_dev_err(hdev, "Unable to create ECDH crypto context"); 3304 crypto_free_shash(tfm_cmac); 3305 kfree_sensitive(smp); 3306 return ERR_CAST(tfm_ecdh); 3307 } 3308 3309 smp->local_oob = false; 3310 smp->tfm_cmac = tfm_cmac; 3311 smp->tfm_ecdh = tfm_ecdh; 3312 3313 create_chan: 3314 chan = l2cap_chan_create(); 3315 if (!chan) { 3316 if (smp) { 3317 crypto_free_shash(smp->tfm_cmac); 3318 crypto_free_kpp(smp->tfm_ecdh); 3319 kfree_sensitive(smp); 3320 } 3321 return ERR_PTR(-ENOMEM); 3322 } 3323 3324 chan->data = smp; 3325 3326 l2cap_add_scid(chan, cid); 3327 3328 l2cap_chan_set_defaults(chan); 3329 3330 if (cid == L2CAP_CID_SMP) { 3331 u8 bdaddr_type; 3332 3333 hci_copy_identity_address(hdev, &chan->src, &bdaddr_type); 3334 3335 if (bdaddr_type == ADDR_LE_DEV_PUBLIC) 3336 chan->src_type = BDADDR_LE_PUBLIC; 3337 else 3338 chan->src_type = BDADDR_LE_RANDOM; 3339 } else { 3340 bacpy(&chan->src, &hdev->bdaddr); 3341 chan->src_type = BDADDR_BREDR; 3342 } 3343 3344 chan->state = BT_LISTEN; 3345 chan->mode = L2CAP_MODE_BASIC; 3346 chan->imtu = L2CAP_DEFAULT_MTU; 3347 chan->ops = &smp_root_chan_ops; 3348 3349 /* Set correct nesting level for a parent/listening channel */ 3350 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 3351 3352 return chan; 3353 } 3354 3355 static void smp_del_chan(struct l2cap_chan *chan) 3356 { 3357 struct smp_dev *smp; 3358 3359 BT_DBG("chan %p", chan); 3360 3361 smp = chan->data; 3362 if (smp) { 3363 chan->data = NULL; 3364 crypto_free_shash(smp->tfm_cmac); 3365 crypto_free_kpp(smp->tfm_ecdh); 3366 kfree_sensitive(smp); 3367 } 3368 3369 l2cap_chan_put(chan); 3370 } 3371 3372 int smp_force_bredr(struct hci_dev *hdev, bool enable) 3373 { 3374 if (enable == hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3375 return -EALREADY; 3376 3377 if (enable) { 3378 struct l2cap_chan *chan; 3379 3380 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); 3381 if (IS_ERR(chan)) 3382 return PTR_ERR(chan); 3383 3384 hdev->smp_bredr_data = chan; 3385 } else { 3386 struct l2cap_chan *chan; 3387 3388 chan = hdev->smp_bredr_data; 3389 hdev->smp_bredr_data = NULL; 3390 smp_del_chan(chan); 3391 } 3392 3393 hci_dev_change_flag(hdev, HCI_FORCE_BREDR_SMP); 3394 3395 return 0; 3396 } 3397 3398 int smp_register(struct hci_dev *hdev) 3399 { 3400 struct l2cap_chan *chan; 3401 3402 bt_dev_dbg(hdev, ""); 3403 3404 /* If the controller does not support Low Energy operation, then 3405 * there is also no need to register any SMP channel. 3406 */ 3407 if (!lmp_le_capable(hdev)) 3408 return 0; 3409 3410 if (WARN_ON(hdev->smp_data)) { 3411 chan = hdev->smp_data; 3412 hdev->smp_data = NULL; 3413 smp_del_chan(chan); 3414 } 3415 3416 chan = smp_add_cid(hdev, L2CAP_CID_SMP); 3417 if (IS_ERR(chan)) 3418 return PTR_ERR(chan); 3419 3420 hdev->smp_data = chan; 3421 3422 if (!lmp_sc_capable(hdev)) { 3423 /* Flag can be already set here (due to power toggle) */ 3424 if (!hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3425 return 0; 3426 } 3427 3428 if (WARN_ON(hdev->smp_bredr_data)) { 3429 chan = hdev->smp_bredr_data; 3430 hdev->smp_bredr_data = NULL; 3431 smp_del_chan(chan); 3432 } 3433 3434 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); 3435 if (IS_ERR(chan)) { 3436 int err = PTR_ERR(chan); 3437 chan = hdev->smp_data; 3438 hdev->smp_data = NULL; 3439 smp_del_chan(chan); 3440 return err; 3441 } 3442 3443 hdev->smp_bredr_data = chan; 3444 3445 return 0; 3446 } 3447 3448 void smp_unregister(struct hci_dev *hdev) 3449 { 3450 struct l2cap_chan *chan; 3451 3452 if (hdev->smp_bredr_data) { 3453 chan = hdev->smp_bredr_data; 3454 hdev->smp_bredr_data = NULL; 3455 smp_del_chan(chan); 3456 } 3457 3458 if (hdev->smp_data) { 3459 chan = hdev->smp_data; 3460 hdev->smp_data = NULL; 3461 smp_del_chan(chan); 3462 } 3463 } 3464 3465 #if IS_ENABLED(CONFIG_BT_SELFTEST_SMP) 3466 3467 static int __init test_debug_key(struct crypto_kpp *tfm_ecdh) 3468 { 3469 u8 pk[64]; 3470 int err; 3471 3472 err = set_ecdh_privkey(tfm_ecdh, debug_sk); 3473 if (err) 3474 return err; 3475 3476 err = generate_ecdh_public_key(tfm_ecdh, pk); 3477 if (err) 3478 return err; 3479 3480 if (crypto_memneq(pk, debug_pk, 64)) 3481 return -EINVAL; 3482 3483 return 0; 3484 } 3485 3486 static int __init test_ah(void) 3487 { 3488 const u8 irk[16] = { 3489 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3490 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3491 const u8 r[3] = { 0x94, 0x81, 0x70 }; 3492 const u8 exp[3] = { 0xaa, 0xfb, 0x0d }; 3493 u8 res[3]; 3494 int err; 3495 3496 err = smp_ah(irk, r, res); 3497 if (err) 3498 return err; 3499 3500 if (crypto_memneq(res, exp, 3)) 3501 return -EINVAL; 3502 3503 return 0; 3504 } 3505 3506 static int __init test_c1(void) 3507 { 3508 const u8 k[16] = { 3509 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 3510 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; 3511 const u8 r[16] = { 3512 0xe0, 0x2e, 0x70, 0xc6, 0x4e, 0x27, 0x88, 0x63, 3513 0x0e, 0x6f, 0xad, 0x56, 0x21, 0xd5, 0x83, 0x57 }; 3514 const u8 preq[7] = { 0x01, 0x01, 0x00, 0x00, 0x10, 0x07, 0x07 }; 3515 const u8 pres[7] = { 0x02, 0x03, 0x00, 0x00, 0x08, 0x00, 0x05 }; 3516 const u8 _iat = 0x01; 3517 const u8 _rat = 0x00; 3518 const bdaddr_t ra = { { 0xb6, 0xb5, 0xb4, 0xb3, 0xb2, 0xb1 } }; 3519 const bdaddr_t ia = { { 0xa6, 0xa5, 0xa4, 0xa3, 0xa2, 0xa1 } }; 3520 const u8 exp[16] = { 3521 0x86, 0x3b, 0xf1, 0xbe, 0xc5, 0x4d, 0xa7, 0xd2, 3522 0xea, 0x88, 0x89, 0x87, 0xef, 0x3f, 0x1e, 0x1e }; 3523 u8 res[16]; 3524 int err; 3525 3526 err = smp_c1(k, r, preq, pres, _iat, &ia, _rat, &ra, res); 3527 if (err) 3528 return err; 3529 3530 if (crypto_memneq(res, exp, 16)) 3531 return -EINVAL; 3532 3533 return 0; 3534 } 3535 3536 static int __init test_s1(void) 3537 { 3538 const u8 k[16] = { 3539 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 3540 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; 3541 const u8 r1[16] = { 3542 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 }; 3543 const u8 r2[16] = { 3544 0x00, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99 }; 3545 const u8 exp[16] = { 3546 0x62, 0xa0, 0x6d, 0x79, 0xae, 0x16, 0x42, 0x5b, 3547 0x9b, 0xf4, 0xb0, 0xe8, 0xf0, 0xe1, 0x1f, 0x9a }; 3548 u8 res[16]; 3549 int err; 3550 3551 err = smp_s1(k, r1, r2, res); 3552 if (err) 3553 return err; 3554 3555 if (crypto_memneq(res, exp, 16)) 3556 return -EINVAL; 3557 3558 return 0; 3559 } 3560 3561 static int __init test_f4(struct crypto_shash *tfm_cmac) 3562 { 3563 const u8 u[32] = { 3564 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 3565 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 3566 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 3567 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 }; 3568 const u8 v[32] = { 3569 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b, 3570 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59, 3571 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90, 3572 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 }; 3573 const u8 x[16] = { 3574 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3575 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3576 const u8 z = 0x00; 3577 const u8 exp[16] = { 3578 0x2d, 0x87, 0x74, 0xa9, 0xbe, 0xa1, 0xed, 0xf1, 3579 0x1c, 0xbd, 0xa9, 0x07, 0xf1, 0x16, 0xc9, 0xf2 }; 3580 u8 res[16]; 3581 int err; 3582 3583 err = smp_f4(tfm_cmac, u, v, x, z, res); 3584 if (err) 3585 return err; 3586 3587 if (crypto_memneq(res, exp, 16)) 3588 return -EINVAL; 3589 3590 return 0; 3591 } 3592 3593 static int __init test_f5(struct crypto_shash *tfm_cmac) 3594 { 3595 const u8 w[32] = { 3596 0x98, 0xa6, 0xbf, 0x73, 0xf3, 0x34, 0x8d, 0x86, 3597 0xf1, 0x66, 0xf8, 0xb4, 0x13, 0x6b, 0x79, 0x99, 3598 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3599 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3600 const u8 n1[16] = { 3601 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3602 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3603 const u8 n2[16] = { 3604 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3605 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3606 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 }; 3607 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 }; 3608 const u8 exp_ltk[16] = { 3609 0x38, 0x0a, 0x75, 0x94, 0xb5, 0x22, 0x05, 0x98, 3610 0x23, 0xcd, 0xd7, 0x69, 0x11, 0x79, 0x86, 0x69 }; 3611 const u8 exp_mackey[16] = { 3612 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd, 3613 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 }; 3614 u8 mackey[16], ltk[16]; 3615 int err; 3616 3617 err = smp_f5(tfm_cmac, w, n1, n2, a1, a2, mackey, ltk); 3618 if (err) 3619 return err; 3620 3621 if (crypto_memneq(mackey, exp_mackey, 16)) 3622 return -EINVAL; 3623 3624 if (crypto_memneq(ltk, exp_ltk, 16)) 3625 return -EINVAL; 3626 3627 return 0; 3628 } 3629 3630 static int __init test_f6(struct crypto_shash *tfm_cmac) 3631 { 3632 const u8 w[16] = { 3633 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd, 3634 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 }; 3635 const u8 n1[16] = { 3636 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3637 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3638 const u8 n2[16] = { 3639 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3640 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3641 const u8 r[16] = { 3642 0xc8, 0x0f, 0x2d, 0x0c, 0xd2, 0x42, 0xda, 0x08, 3643 0x54, 0xbb, 0x53, 0xb4, 0x3b, 0x34, 0xa3, 0x12 }; 3644 const u8 io_cap[3] = { 0x02, 0x01, 0x01 }; 3645 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 }; 3646 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 }; 3647 const u8 exp[16] = { 3648 0x61, 0x8f, 0x95, 0xda, 0x09, 0x0b, 0x6c, 0xd2, 3649 0xc5, 0xe8, 0xd0, 0x9c, 0x98, 0x73, 0xc4, 0xe3 }; 3650 u8 res[16]; 3651 int err; 3652 3653 err = smp_f6(tfm_cmac, w, n1, n2, r, io_cap, a1, a2, res); 3654 if (err) 3655 return err; 3656 3657 if (crypto_memneq(res, exp, 16)) 3658 return -EINVAL; 3659 3660 return 0; 3661 } 3662 3663 static int __init test_g2(struct crypto_shash *tfm_cmac) 3664 { 3665 const u8 u[32] = { 3666 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 3667 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 3668 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 3669 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 }; 3670 const u8 v[32] = { 3671 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b, 3672 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59, 3673 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90, 3674 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 }; 3675 const u8 x[16] = { 3676 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3677 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3678 const u8 y[16] = { 3679 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3680 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3681 const u32 exp_val = 0x2f9ed5ba % 1000000; 3682 u32 val; 3683 int err; 3684 3685 err = smp_g2(tfm_cmac, u, v, x, y, &val); 3686 if (err) 3687 return err; 3688 3689 if (val != exp_val) 3690 return -EINVAL; 3691 3692 return 0; 3693 } 3694 3695 static int __init test_h6(struct crypto_shash *tfm_cmac) 3696 { 3697 const u8 w[16] = { 3698 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3699 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3700 const u8 key_id[4] = { 0x72, 0x62, 0x65, 0x6c }; 3701 const u8 exp[16] = { 3702 0x99, 0x63, 0xb1, 0x80, 0xe2, 0xa9, 0xd3, 0xe8, 3703 0x1c, 0xc9, 0x6d, 0xe7, 0x02, 0xe1, 0x9a, 0x2d }; 3704 u8 res[16]; 3705 int err; 3706 3707 err = smp_h6(tfm_cmac, w, key_id, res); 3708 if (err) 3709 return err; 3710 3711 if (crypto_memneq(res, exp, 16)) 3712 return -EINVAL; 3713 3714 return 0; 3715 } 3716 3717 static char test_smp_buffer[32]; 3718 3719 static ssize_t test_smp_read(struct file *file, char __user *user_buf, 3720 size_t count, loff_t *ppos) 3721 { 3722 return simple_read_from_buffer(user_buf, count, ppos, test_smp_buffer, 3723 strlen(test_smp_buffer)); 3724 } 3725 3726 static const struct file_operations test_smp_fops = { 3727 .open = simple_open, 3728 .read = test_smp_read, 3729 .llseek = default_llseek, 3730 }; 3731 3732 static int __init run_selftests(struct crypto_shash *tfm_cmac, 3733 struct crypto_kpp *tfm_ecdh) 3734 { 3735 ktime_t calltime, delta, rettime; 3736 unsigned long long duration; 3737 int err; 3738 3739 calltime = ktime_get(); 3740 3741 err = test_debug_key(tfm_ecdh); 3742 if (err) { 3743 BT_ERR("debug_key test failed"); 3744 goto done; 3745 } 3746 3747 err = test_ah(); 3748 if (err) { 3749 BT_ERR("smp_ah test failed"); 3750 goto done; 3751 } 3752 3753 err = test_c1(); 3754 if (err) { 3755 BT_ERR("smp_c1 test failed"); 3756 goto done; 3757 } 3758 3759 err = test_s1(); 3760 if (err) { 3761 BT_ERR("smp_s1 test failed"); 3762 goto done; 3763 } 3764 3765 err = test_f4(tfm_cmac); 3766 if (err) { 3767 BT_ERR("smp_f4 test failed"); 3768 goto done; 3769 } 3770 3771 err = test_f5(tfm_cmac); 3772 if (err) { 3773 BT_ERR("smp_f5 test failed"); 3774 goto done; 3775 } 3776 3777 err = test_f6(tfm_cmac); 3778 if (err) { 3779 BT_ERR("smp_f6 test failed"); 3780 goto done; 3781 } 3782 3783 err = test_g2(tfm_cmac); 3784 if (err) { 3785 BT_ERR("smp_g2 test failed"); 3786 goto done; 3787 } 3788 3789 err = test_h6(tfm_cmac); 3790 if (err) { 3791 BT_ERR("smp_h6 test failed"); 3792 goto done; 3793 } 3794 3795 rettime = ktime_get(); 3796 delta = ktime_sub(rettime, calltime); 3797 duration = (unsigned long long) ktime_to_ns(delta) >> 10; 3798 3799 BT_INFO("SMP test passed in %llu usecs", duration); 3800 3801 done: 3802 if (!err) 3803 snprintf(test_smp_buffer, sizeof(test_smp_buffer), 3804 "PASS (%llu usecs)\n", duration); 3805 else 3806 snprintf(test_smp_buffer, sizeof(test_smp_buffer), "FAIL\n"); 3807 3808 debugfs_create_file("selftest_smp", 0444, bt_debugfs, NULL, 3809 &test_smp_fops); 3810 3811 return err; 3812 } 3813 3814 int __init bt_selftest_smp(void) 3815 { 3816 struct crypto_shash *tfm_cmac; 3817 struct crypto_kpp *tfm_ecdh; 3818 int err; 3819 3820 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 3821 if (IS_ERR(tfm_cmac)) { 3822 BT_ERR("Unable to create CMAC crypto context"); 3823 return PTR_ERR(tfm_cmac); 3824 } 3825 3826 tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0); 3827 if (IS_ERR(tfm_ecdh)) { 3828 BT_ERR("Unable to create ECDH crypto context"); 3829 crypto_free_shash(tfm_cmac); 3830 return PTR_ERR(tfm_ecdh); 3831 } 3832 3833 err = run_selftests(tfm_cmac, tfm_ecdh); 3834 3835 crypto_free_shash(tfm_cmac); 3836 crypto_free_kpp(tfm_ecdh); 3837 3838 return err; 3839 } 3840 3841 #endif 3842