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 * accidentially in dmesg, i.e. the values of the various crypto keys 44 * and the inputs & outputs of crypto functions. 45 */ 46 #ifdef DEBUG 47 #define SMP_DBG(fmt, ...) printk(KERN_DEBUG "%s: " fmt, __func__, \ 48 ##__VA_ARGS__) 49 #else 50 #define SMP_DBG(fmt, ...) no_printk(KERN_DEBUG "%s: " fmt, __func__, \ 51 ##__VA_ARGS__) 52 #endif 53 54 #define SMP_ALLOW_CMD(smp, code) set_bit(code, &smp->allow_cmd) 55 56 /* Keys which are not distributed with Secure Connections */ 57 #define SMP_SC_NO_DIST (SMP_DIST_ENC_KEY | SMP_DIST_LINK_KEY) 58 59 #define SMP_TIMEOUT msecs_to_jiffies(30000) 60 61 #define AUTH_REQ_MASK(dev) (hci_dev_test_flag(dev, HCI_SC_ENABLED) ? \ 62 0x3f : 0x07) 63 #define KEY_DIST_MASK 0x07 64 65 /* Maximum message length that can be passed to aes_cmac */ 66 #define CMAC_MSG_MAX 80 67 68 enum { 69 SMP_FLAG_TK_VALID, 70 SMP_FLAG_CFM_PENDING, 71 SMP_FLAG_MITM_AUTH, 72 SMP_FLAG_COMPLETE, 73 SMP_FLAG_INITIATOR, 74 SMP_FLAG_SC, 75 SMP_FLAG_REMOTE_PK, 76 SMP_FLAG_DEBUG_KEY, 77 SMP_FLAG_WAIT_USER, 78 SMP_FLAG_DHKEY_PENDING, 79 SMP_FLAG_REMOTE_OOB, 80 SMP_FLAG_LOCAL_OOB, 81 SMP_FLAG_CT2, 82 }; 83 84 struct smp_dev { 85 /* Secure Connections OOB data */ 86 bool local_oob; 87 u8 local_pk[64]; 88 u8 local_rand[16]; 89 bool debug_key; 90 91 struct crypto_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 *slave_csrk; 115 struct smp_ltk *ltk; 116 struct smp_ltk *slave_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 accidentially 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->slave_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->slave_ltk) { 780 list_del_rcu(&smp->slave_ltk->list); 781 kfree_rcu(smp->slave_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:%d lcl:%d rem:%d", 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 Keyoard-Display I/O, the master 913 * Confirms and the slave 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: %d", 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 ? "master" : "slave"); 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 _SLAVE suffix this is the 1025 * slave STK we're adding for later lookup (the master 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->slave_csrk) { 1081 smp->slave_csrk->bdaddr_type = hcon->dst_type; 1082 bacpy(&smp->slave_csrk->bdaddr, &hcon->dst); 1083 mgmt_new_csrk(hdev, smp->slave_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->slave_ltk) { 1093 smp->slave_ltk->bdaddr_type = hcon->dst_type; 1094 bacpy(&smp->slave_ltk->bdaddr, &hcon->dst); 1095 mgmt_new_ltk(hdev, smp->slave_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_master_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_SLAVE, authenticated, enc.ltk, 1297 smp->enc_key_size, ediv, rand); 1298 smp->slave_ltk = ltk; 1299 1300 ident.ediv = ediv; 1301 ident.rand = rand; 1302 1303 smp_send_cmd(conn, SMP_CMD_MASTER_IDENT, sizeof(ident), &ident); 1304 1305 *keydist &= ~SMP_DIST_ENC_KEY; 1306 } 1307 1308 if (*keydist & SMP_DIST_ID_KEY) { 1309 struct smp_cmd_ident_addr_info addrinfo; 1310 struct smp_cmd_ident_info idinfo; 1311 1312 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk)); 1313 1314 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo); 1315 1316 /* The hci_conn contains the local identity address 1317 * after the connection has been established. 1318 * 1319 * This is true even when the connection has been 1320 * established using a resolvable random address. 1321 */ 1322 bacpy(&addrinfo.bdaddr, &hcon->src); 1323 addrinfo.addr_type = hcon->src_type; 1324 1325 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo), 1326 &addrinfo); 1327 1328 *keydist &= ~SMP_DIST_ID_KEY; 1329 } 1330 1331 if (*keydist & SMP_DIST_SIGN) { 1332 struct smp_cmd_sign_info sign; 1333 struct smp_csrk *csrk; 1334 1335 /* Generate a new random key */ 1336 get_random_bytes(sign.csrk, sizeof(sign.csrk)); 1337 1338 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); 1339 if (csrk) { 1340 if (hcon->sec_level > BT_SECURITY_MEDIUM) 1341 csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED; 1342 else 1343 csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED; 1344 memcpy(csrk->val, sign.csrk, sizeof(csrk->val)); 1345 } 1346 smp->slave_csrk = csrk; 1347 1348 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign); 1349 1350 *keydist &= ~SMP_DIST_SIGN; 1351 } 1352 1353 /* If there are still keys to be received wait for them */ 1354 if (smp->remote_key_dist & KEY_DIST_MASK) { 1355 smp_allow_key_dist(smp); 1356 return; 1357 } 1358 1359 set_bit(SMP_FLAG_COMPLETE, &smp->flags); 1360 smp_notify_keys(conn); 1361 1362 smp_chan_destroy(conn); 1363 } 1364 1365 static void smp_timeout(struct work_struct *work) 1366 { 1367 struct smp_chan *smp = container_of(work, struct smp_chan, 1368 security_timer.work); 1369 struct l2cap_conn *conn = smp->conn; 1370 1371 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 1372 1373 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM); 1374 } 1375 1376 static struct smp_chan *smp_chan_create(struct l2cap_conn *conn) 1377 { 1378 struct hci_conn *hcon = conn->hcon; 1379 struct l2cap_chan *chan = conn->smp; 1380 struct smp_chan *smp; 1381 1382 smp = kzalloc(sizeof(*smp), GFP_ATOMIC); 1383 if (!smp) 1384 return NULL; 1385 1386 smp->tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 1387 if (IS_ERR(smp->tfm_cmac)) { 1388 bt_dev_err(hcon->hdev, "Unable to create CMAC crypto context"); 1389 goto zfree_smp; 1390 } 1391 1392 smp->tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0); 1393 if (IS_ERR(smp->tfm_ecdh)) { 1394 bt_dev_err(hcon->hdev, "Unable to create ECDH crypto context"); 1395 goto free_shash; 1396 } 1397 1398 smp->conn = conn; 1399 chan->data = smp; 1400 1401 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL); 1402 1403 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout); 1404 1405 hci_conn_hold(hcon); 1406 1407 return smp; 1408 1409 free_shash: 1410 crypto_free_shash(smp->tfm_cmac); 1411 zfree_smp: 1412 kfree_sensitive(smp); 1413 return NULL; 1414 } 1415 1416 static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16]) 1417 { 1418 struct hci_conn *hcon = smp->conn->hcon; 1419 u8 *na, *nb, a[7], b[7]; 1420 1421 if (hcon->out) { 1422 na = smp->prnd; 1423 nb = smp->rrnd; 1424 } else { 1425 na = smp->rrnd; 1426 nb = smp->prnd; 1427 } 1428 1429 memcpy(a, &hcon->init_addr, 6); 1430 memcpy(b, &hcon->resp_addr, 6); 1431 a[6] = hcon->init_addr_type; 1432 b[6] = hcon->resp_addr_type; 1433 1434 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk); 1435 } 1436 1437 static void sc_dhkey_check(struct smp_chan *smp) 1438 { 1439 struct hci_conn *hcon = smp->conn->hcon; 1440 struct smp_cmd_dhkey_check check; 1441 u8 a[7], b[7], *local_addr, *remote_addr; 1442 u8 io_cap[3], r[16]; 1443 1444 memcpy(a, &hcon->init_addr, 6); 1445 memcpy(b, &hcon->resp_addr, 6); 1446 a[6] = hcon->init_addr_type; 1447 b[6] = hcon->resp_addr_type; 1448 1449 if (hcon->out) { 1450 local_addr = a; 1451 remote_addr = b; 1452 memcpy(io_cap, &smp->preq[1], 3); 1453 } else { 1454 local_addr = b; 1455 remote_addr = a; 1456 memcpy(io_cap, &smp->prsp[1], 3); 1457 } 1458 1459 memset(r, 0, sizeof(r)); 1460 1461 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 1462 put_unaligned_le32(hcon->passkey_notify, r); 1463 1464 if (smp->method == REQ_OOB) 1465 memcpy(r, smp->rr, 16); 1466 1467 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap, 1468 local_addr, remote_addr, check.e); 1469 1470 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check); 1471 } 1472 1473 static u8 sc_passkey_send_confirm(struct smp_chan *smp) 1474 { 1475 struct l2cap_conn *conn = smp->conn; 1476 struct hci_conn *hcon = conn->hcon; 1477 struct smp_cmd_pairing_confirm cfm; 1478 u8 r; 1479 1480 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); 1481 r |= 0x80; 1482 1483 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1484 1485 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r, 1486 cfm.confirm_val)) 1487 return SMP_UNSPECIFIED; 1488 1489 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); 1490 1491 return 0; 1492 } 1493 1494 static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op) 1495 { 1496 struct l2cap_conn *conn = smp->conn; 1497 struct hci_conn *hcon = conn->hcon; 1498 struct hci_dev *hdev = hcon->hdev; 1499 u8 cfm[16], r; 1500 1501 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */ 1502 if (smp->passkey_round >= 20) 1503 return 0; 1504 1505 switch (smp_op) { 1506 case SMP_CMD_PAIRING_RANDOM: 1507 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); 1508 r |= 0x80; 1509 1510 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, 1511 smp->rrnd, r, cfm)) 1512 return SMP_UNSPECIFIED; 1513 1514 if (crypto_memneq(smp->pcnf, cfm, 16)) 1515 return SMP_CONFIRM_FAILED; 1516 1517 smp->passkey_round++; 1518 1519 if (smp->passkey_round == 20) { 1520 /* Generate MacKey and LTK */ 1521 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk)) 1522 return SMP_UNSPECIFIED; 1523 } 1524 1525 /* The round is only complete when the initiator 1526 * receives pairing random. 1527 */ 1528 if (!hcon->out) { 1529 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 1530 sizeof(smp->prnd), smp->prnd); 1531 if (smp->passkey_round == 20) 1532 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1533 else 1534 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1535 return 0; 1536 } 1537 1538 /* Start the next round */ 1539 if (smp->passkey_round != 20) 1540 return sc_passkey_round(smp, 0); 1541 1542 /* Passkey rounds are complete - start DHKey Check */ 1543 sc_dhkey_check(smp); 1544 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1545 1546 break; 1547 1548 case SMP_CMD_PAIRING_CONFIRM: 1549 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { 1550 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 1551 return 0; 1552 } 1553 1554 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 1555 1556 if (hcon->out) { 1557 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 1558 sizeof(smp->prnd), smp->prnd); 1559 return 0; 1560 } 1561 1562 return sc_passkey_send_confirm(smp); 1563 1564 case SMP_CMD_PUBLIC_KEY: 1565 default: 1566 /* Initiating device starts the round */ 1567 if (!hcon->out) 1568 return 0; 1569 1570 bt_dev_dbg(hdev, "Starting passkey round %u", 1571 smp->passkey_round + 1); 1572 1573 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1574 1575 return sc_passkey_send_confirm(smp); 1576 } 1577 1578 return 0; 1579 } 1580 1581 static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey) 1582 { 1583 struct l2cap_conn *conn = smp->conn; 1584 struct hci_conn *hcon = conn->hcon; 1585 u8 smp_op; 1586 1587 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags); 1588 1589 switch (mgmt_op) { 1590 case MGMT_OP_USER_PASSKEY_NEG_REPLY: 1591 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED); 1592 return 0; 1593 case MGMT_OP_USER_CONFIRM_NEG_REPLY: 1594 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED); 1595 return 0; 1596 case MGMT_OP_USER_PASSKEY_REPLY: 1597 hcon->passkey_notify = le32_to_cpu(passkey); 1598 smp->passkey_round = 0; 1599 1600 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) 1601 smp_op = SMP_CMD_PAIRING_CONFIRM; 1602 else 1603 smp_op = 0; 1604 1605 if (sc_passkey_round(smp, smp_op)) 1606 return -EIO; 1607 1608 return 0; 1609 } 1610 1611 /* Initiator sends DHKey check first */ 1612 if (hcon->out) { 1613 sc_dhkey_check(smp); 1614 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1615 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) { 1616 sc_dhkey_check(smp); 1617 sc_add_ltk(smp); 1618 } 1619 1620 return 0; 1621 } 1622 1623 int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey) 1624 { 1625 struct l2cap_conn *conn = hcon->l2cap_data; 1626 struct l2cap_chan *chan; 1627 struct smp_chan *smp; 1628 u32 value; 1629 int err; 1630 1631 if (!conn) 1632 return -ENOTCONN; 1633 1634 bt_dev_dbg(conn->hcon->hdev, ""); 1635 1636 chan = conn->smp; 1637 if (!chan) 1638 return -ENOTCONN; 1639 1640 l2cap_chan_lock(chan); 1641 if (!chan->data) { 1642 err = -ENOTCONN; 1643 goto unlock; 1644 } 1645 1646 smp = chan->data; 1647 1648 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1649 err = sc_user_reply(smp, mgmt_op, passkey); 1650 goto unlock; 1651 } 1652 1653 switch (mgmt_op) { 1654 case MGMT_OP_USER_PASSKEY_REPLY: 1655 value = le32_to_cpu(passkey); 1656 memset(smp->tk, 0, sizeof(smp->tk)); 1657 bt_dev_dbg(conn->hcon->hdev, "PassKey: %d", value); 1658 put_unaligned_le32(value, smp->tk); 1659 fallthrough; 1660 case MGMT_OP_USER_CONFIRM_REPLY: 1661 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 1662 break; 1663 case MGMT_OP_USER_PASSKEY_NEG_REPLY: 1664 case MGMT_OP_USER_CONFIRM_NEG_REPLY: 1665 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); 1666 err = 0; 1667 goto unlock; 1668 default: 1669 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); 1670 err = -EOPNOTSUPP; 1671 goto unlock; 1672 } 1673 1674 err = 0; 1675 1676 /* If it is our turn to send Pairing Confirm, do so now */ 1677 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) { 1678 u8 rsp = smp_confirm(smp); 1679 if (rsp) 1680 smp_failure(conn, rsp); 1681 } 1682 1683 unlock: 1684 l2cap_chan_unlock(chan); 1685 return err; 1686 } 1687 1688 static void build_bredr_pairing_cmd(struct smp_chan *smp, 1689 struct smp_cmd_pairing *req, 1690 struct smp_cmd_pairing *rsp) 1691 { 1692 struct l2cap_conn *conn = smp->conn; 1693 struct hci_dev *hdev = conn->hcon->hdev; 1694 u8 local_dist = 0, remote_dist = 0; 1695 1696 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { 1697 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 1698 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 1699 } 1700 1701 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) 1702 remote_dist |= SMP_DIST_ID_KEY; 1703 1704 if (hci_dev_test_flag(hdev, HCI_PRIVACY)) 1705 local_dist |= SMP_DIST_ID_KEY; 1706 1707 if (!rsp) { 1708 memset(req, 0, sizeof(*req)); 1709 1710 req->auth_req = SMP_AUTH_CT2; 1711 req->init_key_dist = local_dist; 1712 req->resp_key_dist = remote_dist; 1713 req->max_key_size = conn->hcon->enc_key_size; 1714 1715 smp->remote_key_dist = remote_dist; 1716 1717 return; 1718 } 1719 1720 memset(rsp, 0, sizeof(*rsp)); 1721 1722 rsp->auth_req = SMP_AUTH_CT2; 1723 rsp->max_key_size = conn->hcon->enc_key_size; 1724 rsp->init_key_dist = req->init_key_dist & remote_dist; 1725 rsp->resp_key_dist = req->resp_key_dist & local_dist; 1726 1727 smp->remote_key_dist = rsp->init_key_dist; 1728 } 1729 1730 static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) 1731 { 1732 struct smp_cmd_pairing rsp, *req = (void *) skb->data; 1733 struct l2cap_chan *chan = conn->smp; 1734 struct hci_dev *hdev = conn->hcon->hdev; 1735 struct smp_chan *smp; 1736 u8 key_size, auth, sec_level; 1737 int ret; 1738 1739 bt_dev_dbg(hdev, "conn %p", conn); 1740 1741 if (skb->len < sizeof(*req)) 1742 return SMP_INVALID_PARAMS; 1743 1744 if (conn->hcon->role != HCI_ROLE_SLAVE) 1745 return SMP_CMD_NOTSUPP; 1746 1747 if (!chan->data) 1748 smp = smp_chan_create(conn); 1749 else 1750 smp = chan->data; 1751 1752 if (!smp) 1753 return SMP_UNSPECIFIED; 1754 1755 /* We didn't start the pairing, so match remote */ 1756 auth = req->auth_req & AUTH_REQ_MASK(hdev); 1757 1758 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && 1759 (auth & SMP_AUTH_BONDING)) 1760 return SMP_PAIRING_NOTSUPP; 1761 1762 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 1763 return SMP_AUTH_REQUIREMENTS; 1764 1765 smp->preq[0] = SMP_CMD_PAIRING_REQ; 1766 memcpy(&smp->preq[1], req, sizeof(*req)); 1767 skb_pull(skb, sizeof(*req)); 1768 1769 /* If the remote side's OOB flag is set it means it has 1770 * successfully received our local OOB data - therefore set the 1771 * flag to indicate that local OOB is in use. 1772 */ 1773 if (req->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob) 1774 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); 1775 1776 /* SMP over BR/EDR requires special treatment */ 1777 if (conn->hcon->type == ACL_LINK) { 1778 /* We must have a BR/EDR SC link */ 1779 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) && 1780 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 1781 return SMP_CROSS_TRANSP_NOT_ALLOWED; 1782 1783 set_bit(SMP_FLAG_SC, &smp->flags); 1784 1785 build_bredr_pairing_cmd(smp, req, &rsp); 1786 1787 if (req->auth_req & SMP_AUTH_CT2) 1788 set_bit(SMP_FLAG_CT2, &smp->flags); 1789 1790 key_size = min(req->max_key_size, rsp.max_key_size); 1791 if (check_enc_key_size(conn, key_size)) 1792 return SMP_ENC_KEY_SIZE; 1793 1794 /* Clear bits which are generated but not distributed */ 1795 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1796 1797 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1798 memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); 1799 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); 1800 1801 smp_distribute_keys(smp); 1802 return 0; 1803 } 1804 1805 build_pairing_cmd(conn, req, &rsp, auth); 1806 1807 if (rsp.auth_req & SMP_AUTH_SC) { 1808 set_bit(SMP_FLAG_SC, &smp->flags); 1809 1810 if (rsp.auth_req & SMP_AUTH_CT2) 1811 set_bit(SMP_FLAG_CT2, &smp->flags); 1812 } 1813 1814 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 1815 sec_level = BT_SECURITY_MEDIUM; 1816 else 1817 sec_level = authreq_to_seclevel(auth); 1818 1819 if (sec_level > conn->hcon->pending_sec_level) 1820 conn->hcon->pending_sec_level = sec_level; 1821 1822 /* If we need MITM check that it can be achieved */ 1823 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { 1824 u8 method; 1825 1826 method = get_auth_method(smp, conn->hcon->io_capability, 1827 req->io_capability); 1828 if (method == JUST_WORKS || method == JUST_CFM) 1829 return SMP_AUTH_REQUIREMENTS; 1830 } 1831 1832 key_size = min(req->max_key_size, rsp.max_key_size); 1833 if (check_enc_key_size(conn, key_size)) 1834 return SMP_ENC_KEY_SIZE; 1835 1836 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1837 1838 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1839 memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); 1840 1841 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); 1842 1843 clear_bit(SMP_FLAG_INITIATOR, &smp->flags); 1844 1845 /* Strictly speaking we shouldn't allow Pairing Confirm for the 1846 * SC case, however some implementations incorrectly copy RFU auth 1847 * req bits from our security request, which may create a false 1848 * positive SC enablement. 1849 */ 1850 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1851 1852 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1853 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); 1854 /* Clear bits which are generated but not distributed */ 1855 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1856 /* Wait for Public Key from Initiating Device */ 1857 return 0; 1858 } 1859 1860 /* Request setup of TK */ 1861 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability); 1862 if (ret) 1863 return SMP_UNSPECIFIED; 1864 1865 return 0; 1866 } 1867 1868 static u8 sc_send_public_key(struct smp_chan *smp) 1869 { 1870 struct hci_dev *hdev = smp->conn->hcon->hdev; 1871 1872 bt_dev_dbg(hdev, ""); 1873 1874 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { 1875 struct l2cap_chan *chan = hdev->smp_data; 1876 struct smp_dev *smp_dev; 1877 1878 if (!chan || !chan->data) 1879 return SMP_UNSPECIFIED; 1880 1881 smp_dev = chan->data; 1882 1883 memcpy(smp->local_pk, smp_dev->local_pk, 64); 1884 memcpy(smp->lr, smp_dev->local_rand, 16); 1885 1886 if (smp_dev->debug_key) 1887 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1888 1889 goto done; 1890 } 1891 1892 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { 1893 bt_dev_dbg(hdev, "Using debug keys"); 1894 if (set_ecdh_privkey(smp->tfm_ecdh, debug_sk)) 1895 return SMP_UNSPECIFIED; 1896 memcpy(smp->local_pk, debug_pk, 64); 1897 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1898 } else { 1899 while (true) { 1900 /* Generate key pair for Secure Connections */ 1901 if (generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk)) 1902 return SMP_UNSPECIFIED; 1903 1904 /* This is unlikely, but we need to check that 1905 * we didn't accidentially generate a debug key. 1906 */ 1907 if (crypto_memneq(smp->local_pk, debug_pk, 64)) 1908 break; 1909 } 1910 } 1911 1912 done: 1913 SMP_DBG("Local Public Key X: %32phN", smp->local_pk); 1914 SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32); 1915 1916 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk); 1917 1918 return 0; 1919 } 1920 1921 static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) 1922 { 1923 struct smp_cmd_pairing *req, *rsp = (void *) skb->data; 1924 struct l2cap_chan *chan = conn->smp; 1925 struct smp_chan *smp = chan->data; 1926 struct hci_dev *hdev = conn->hcon->hdev; 1927 u8 key_size, auth; 1928 int ret; 1929 1930 bt_dev_dbg(hdev, "conn %p", conn); 1931 1932 if (skb->len < sizeof(*rsp)) 1933 return SMP_INVALID_PARAMS; 1934 1935 if (conn->hcon->role != HCI_ROLE_MASTER) 1936 return SMP_CMD_NOTSUPP; 1937 1938 skb_pull(skb, sizeof(*rsp)); 1939 1940 req = (void *) &smp->preq[1]; 1941 1942 key_size = min(req->max_key_size, rsp->max_key_size); 1943 if (check_enc_key_size(conn, key_size)) 1944 return SMP_ENC_KEY_SIZE; 1945 1946 auth = rsp->auth_req & AUTH_REQ_MASK(hdev); 1947 1948 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 1949 return SMP_AUTH_REQUIREMENTS; 1950 1951 /* If the remote side's OOB flag is set it means it has 1952 * successfully received our local OOB data - therefore set the 1953 * flag to indicate that local OOB is in use. 1954 */ 1955 if (rsp->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob) 1956 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); 1957 1958 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1959 memcpy(&smp->prsp[1], rsp, sizeof(*rsp)); 1960 1961 /* Update remote key distribution in case the remote cleared 1962 * some bits that we had enabled in our request. 1963 */ 1964 smp->remote_key_dist &= rsp->resp_key_dist; 1965 1966 if ((req->auth_req & SMP_AUTH_CT2) && (auth & SMP_AUTH_CT2)) 1967 set_bit(SMP_FLAG_CT2, &smp->flags); 1968 1969 /* For BR/EDR this means we're done and can start phase 3 */ 1970 if (conn->hcon->type == ACL_LINK) { 1971 /* Clear bits which are generated but not distributed */ 1972 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1973 smp_distribute_keys(smp); 1974 return 0; 1975 } 1976 1977 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC)) 1978 set_bit(SMP_FLAG_SC, &smp->flags); 1979 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH) 1980 conn->hcon->pending_sec_level = BT_SECURITY_HIGH; 1981 1982 /* If we need MITM check that it can be achieved */ 1983 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { 1984 u8 method; 1985 1986 method = get_auth_method(smp, req->io_capability, 1987 rsp->io_capability); 1988 if (method == JUST_WORKS || method == JUST_CFM) 1989 return SMP_AUTH_REQUIREMENTS; 1990 } 1991 1992 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1993 1994 /* Update remote key distribution in case the remote cleared 1995 * some bits that we had enabled in our request. 1996 */ 1997 smp->remote_key_dist &= rsp->resp_key_dist; 1998 1999 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 2000 /* Clear bits which are generated but not distributed */ 2001 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 2002 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); 2003 return sc_send_public_key(smp); 2004 } 2005 2006 auth |= req->auth_req; 2007 2008 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability); 2009 if (ret) 2010 return SMP_UNSPECIFIED; 2011 2012 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 2013 2014 /* Can't compose response until we have been confirmed */ 2015 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) 2016 return smp_confirm(smp); 2017 2018 return 0; 2019 } 2020 2021 static u8 sc_check_confirm(struct smp_chan *smp) 2022 { 2023 struct l2cap_conn *conn = smp->conn; 2024 2025 bt_dev_dbg(conn->hcon->hdev, ""); 2026 2027 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2028 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM); 2029 2030 if (conn->hcon->out) { 2031 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2032 smp->prnd); 2033 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2034 } 2035 2036 return 0; 2037 } 2038 2039 /* Work-around for some implementations that incorrectly copy RFU bits 2040 * from our security request and thereby create the impression that 2041 * we're doing SC when in fact the remote doesn't support it. 2042 */ 2043 static int fixup_sc_false_positive(struct smp_chan *smp) 2044 { 2045 struct l2cap_conn *conn = smp->conn; 2046 struct hci_conn *hcon = conn->hcon; 2047 struct hci_dev *hdev = hcon->hdev; 2048 struct smp_cmd_pairing *req, *rsp; 2049 u8 auth; 2050 2051 /* The issue is only observed when we're in slave role */ 2052 if (hcon->out) 2053 return SMP_UNSPECIFIED; 2054 2055 if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) { 2056 bt_dev_err(hdev, "refusing legacy fallback in SC-only mode"); 2057 return SMP_UNSPECIFIED; 2058 } 2059 2060 bt_dev_err(hdev, "trying to fall back to legacy SMP"); 2061 2062 req = (void *) &smp->preq[1]; 2063 rsp = (void *) &smp->prsp[1]; 2064 2065 /* Rebuild key dist flags which may have been cleared for SC */ 2066 smp->remote_key_dist = (req->init_key_dist & rsp->resp_key_dist); 2067 2068 auth = req->auth_req & AUTH_REQ_MASK(hdev); 2069 2070 if (tk_request(conn, 0, auth, rsp->io_capability, req->io_capability)) { 2071 bt_dev_err(hdev, "failed to fall back to legacy SMP"); 2072 return SMP_UNSPECIFIED; 2073 } 2074 2075 clear_bit(SMP_FLAG_SC, &smp->flags); 2076 2077 return 0; 2078 } 2079 2080 static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb) 2081 { 2082 struct l2cap_chan *chan = conn->smp; 2083 struct smp_chan *smp = chan->data; 2084 struct hci_conn *hcon = conn->hcon; 2085 struct hci_dev *hdev = hcon->hdev; 2086 2087 bt_dev_dbg(hdev, "conn %p %s", conn, hcon->out ? "master" : "slave"); 2088 2089 if (skb->len < sizeof(smp->pcnf)) 2090 return SMP_INVALID_PARAMS; 2091 2092 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf)); 2093 skb_pull(skb, sizeof(smp->pcnf)); 2094 2095 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 2096 int ret; 2097 2098 /* Public Key exchange must happen before any other steps */ 2099 if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags)) 2100 return sc_check_confirm(smp); 2101 2102 bt_dev_err(hdev, "Unexpected SMP Pairing Confirm"); 2103 2104 ret = fixup_sc_false_positive(smp); 2105 if (ret) 2106 return ret; 2107 } 2108 2109 if (conn->hcon->out) { 2110 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2111 smp->prnd); 2112 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2113 return 0; 2114 } 2115 2116 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) 2117 return smp_confirm(smp); 2118 2119 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 2120 2121 return 0; 2122 } 2123 2124 static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb) 2125 { 2126 struct l2cap_chan *chan = conn->smp; 2127 struct smp_chan *smp = chan->data; 2128 struct hci_conn *hcon = conn->hcon; 2129 u8 *pkax, *pkbx, *na, *nb, confirm_hint; 2130 u32 passkey; 2131 int err; 2132 2133 bt_dev_dbg(hcon->hdev, "conn %p", conn); 2134 2135 if (skb->len < sizeof(smp->rrnd)) 2136 return SMP_INVALID_PARAMS; 2137 2138 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd)); 2139 skb_pull(skb, sizeof(smp->rrnd)); 2140 2141 if (!test_bit(SMP_FLAG_SC, &smp->flags)) 2142 return smp_random(smp); 2143 2144 if (hcon->out) { 2145 pkax = smp->local_pk; 2146 pkbx = smp->remote_pk; 2147 na = smp->prnd; 2148 nb = smp->rrnd; 2149 } else { 2150 pkax = smp->remote_pk; 2151 pkbx = smp->local_pk; 2152 na = smp->rrnd; 2153 nb = smp->prnd; 2154 } 2155 2156 if (smp->method == REQ_OOB) { 2157 if (!hcon->out) 2158 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 2159 sizeof(smp->prnd), smp->prnd); 2160 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2161 goto mackey_and_ltk; 2162 } 2163 2164 /* Passkey entry has special treatment */ 2165 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2166 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM); 2167 2168 if (hcon->out) { 2169 u8 cfm[16]; 2170 2171 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, 2172 smp->rrnd, 0, cfm); 2173 if (err) 2174 return SMP_UNSPECIFIED; 2175 2176 if (crypto_memneq(smp->pcnf, cfm, 16)) 2177 return SMP_CONFIRM_FAILED; 2178 } else { 2179 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2180 smp->prnd); 2181 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2182 2183 /* Only Just-Works pairing requires extra checks */ 2184 if (smp->method != JUST_WORKS) 2185 goto mackey_and_ltk; 2186 2187 /* If there already exists long term key in local host, leave 2188 * the decision to user space since the remote device could 2189 * be legitimate or malicious. 2190 */ 2191 if (hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 2192 hcon->role)) { 2193 /* Set passkey to 0. The value can be any number since 2194 * it'll be ignored anyway. 2195 */ 2196 passkey = 0; 2197 confirm_hint = 1; 2198 goto confirm; 2199 } 2200 } 2201 2202 mackey_and_ltk: 2203 /* Generate MacKey and LTK */ 2204 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk); 2205 if (err) 2206 return SMP_UNSPECIFIED; 2207 2208 if (smp->method == REQ_OOB) { 2209 if (hcon->out) { 2210 sc_dhkey_check(smp); 2211 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2212 } 2213 return 0; 2214 } 2215 2216 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey); 2217 if (err) 2218 return SMP_UNSPECIFIED; 2219 2220 confirm_hint = 0; 2221 2222 confirm: 2223 if (smp->method == JUST_WORKS) 2224 confirm_hint = 1; 2225 2226 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type, 2227 hcon->dst_type, passkey, confirm_hint); 2228 if (err) 2229 return SMP_UNSPECIFIED; 2230 2231 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 2232 2233 return 0; 2234 } 2235 2236 static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level) 2237 { 2238 struct smp_ltk *key; 2239 struct hci_conn *hcon = conn->hcon; 2240 2241 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role); 2242 if (!key) 2243 return false; 2244 2245 if (smp_ltk_sec_level(key) < sec_level) 2246 return false; 2247 2248 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) 2249 return true; 2250 2251 hci_le_start_enc(hcon, key->ediv, key->rand, key->val, key->enc_size); 2252 hcon->enc_key_size = key->enc_size; 2253 2254 /* We never store STKs for master role, so clear this flag */ 2255 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); 2256 2257 return true; 2258 } 2259 2260 bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level, 2261 enum smp_key_pref key_pref) 2262 { 2263 if (sec_level == BT_SECURITY_LOW) 2264 return true; 2265 2266 /* If we're encrypted with an STK but the caller prefers using 2267 * LTK claim insufficient security. This way we allow the 2268 * connection to be re-encrypted with an LTK, even if the LTK 2269 * provides the same level of security. Only exception is if we 2270 * don't have an LTK (e.g. because of key distribution bits). 2271 */ 2272 if (key_pref == SMP_USE_LTK && 2273 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) && 2274 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role)) 2275 return false; 2276 2277 if (hcon->sec_level >= sec_level) 2278 return true; 2279 2280 return false; 2281 } 2282 2283 static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb) 2284 { 2285 struct smp_cmd_security_req *rp = (void *) skb->data; 2286 struct smp_cmd_pairing cp; 2287 struct hci_conn *hcon = conn->hcon; 2288 struct hci_dev *hdev = hcon->hdev; 2289 struct smp_chan *smp; 2290 u8 sec_level, auth; 2291 2292 bt_dev_dbg(hdev, "conn %p", conn); 2293 2294 if (skb->len < sizeof(*rp)) 2295 return SMP_INVALID_PARAMS; 2296 2297 if (hcon->role != HCI_ROLE_MASTER) 2298 return SMP_CMD_NOTSUPP; 2299 2300 auth = rp->auth_req & AUTH_REQ_MASK(hdev); 2301 2302 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 2303 return SMP_AUTH_REQUIREMENTS; 2304 2305 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 2306 sec_level = BT_SECURITY_MEDIUM; 2307 else 2308 sec_level = authreq_to_seclevel(auth); 2309 2310 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) { 2311 /* If link is already encrypted with sufficient security we 2312 * still need refresh encryption as per Core Spec 5.0 Vol 3, 2313 * Part H 2.4.6 2314 */ 2315 smp_ltk_encrypt(conn, hcon->sec_level); 2316 return 0; 2317 } 2318 2319 if (sec_level > hcon->pending_sec_level) 2320 hcon->pending_sec_level = sec_level; 2321 2322 if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) 2323 return 0; 2324 2325 smp = smp_chan_create(conn); 2326 if (!smp) 2327 return SMP_UNSPECIFIED; 2328 2329 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && 2330 (auth & SMP_AUTH_BONDING)) 2331 return SMP_PAIRING_NOTSUPP; 2332 2333 skb_pull(skb, sizeof(*rp)); 2334 2335 memset(&cp, 0, sizeof(cp)); 2336 build_pairing_cmd(conn, &cp, NULL, auth); 2337 2338 smp->preq[0] = SMP_CMD_PAIRING_REQ; 2339 memcpy(&smp->preq[1], &cp, sizeof(cp)); 2340 2341 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); 2342 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 2343 2344 return 0; 2345 } 2346 2347 int smp_conn_security(struct hci_conn *hcon, __u8 sec_level) 2348 { 2349 struct l2cap_conn *conn = hcon->l2cap_data; 2350 struct l2cap_chan *chan; 2351 struct smp_chan *smp; 2352 __u8 authreq; 2353 int ret; 2354 2355 bt_dev_dbg(hcon->hdev, "conn %p hcon %p level 0x%2.2x", conn, hcon, 2356 sec_level); 2357 2358 /* This may be NULL if there's an unexpected disconnection */ 2359 if (!conn) 2360 return 1; 2361 2362 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) 2363 return 1; 2364 2365 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) 2366 return 1; 2367 2368 if (sec_level > hcon->pending_sec_level) 2369 hcon->pending_sec_level = sec_level; 2370 2371 if (hcon->role == HCI_ROLE_MASTER) 2372 if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) 2373 return 0; 2374 2375 chan = conn->smp; 2376 if (!chan) { 2377 bt_dev_err(hcon->hdev, "security requested but not available"); 2378 return 1; 2379 } 2380 2381 l2cap_chan_lock(chan); 2382 2383 /* If SMP is already in progress ignore this request */ 2384 if (chan->data) { 2385 ret = 0; 2386 goto unlock; 2387 } 2388 2389 smp = smp_chan_create(conn); 2390 if (!smp) { 2391 ret = 1; 2392 goto unlock; 2393 } 2394 2395 authreq = seclevel_to_authreq(sec_level); 2396 2397 if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED)) { 2398 authreq |= SMP_AUTH_SC; 2399 if (hci_dev_test_flag(hcon->hdev, HCI_SSP_ENABLED)) 2400 authreq |= SMP_AUTH_CT2; 2401 } 2402 2403 /* Don't attempt to set MITM if setting is overridden by debugfs 2404 * Needed to pass certification test SM/MAS/PKE/BV-01-C 2405 */ 2406 if (!hci_dev_test_flag(hcon->hdev, HCI_FORCE_NO_MITM)) { 2407 /* Require MITM if IO Capability allows or the security level 2408 * requires it. 2409 */ 2410 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT || 2411 hcon->pending_sec_level > BT_SECURITY_MEDIUM) 2412 authreq |= SMP_AUTH_MITM; 2413 } 2414 2415 if (hcon->role == HCI_ROLE_MASTER) { 2416 struct smp_cmd_pairing cp; 2417 2418 build_pairing_cmd(conn, &cp, NULL, authreq); 2419 smp->preq[0] = SMP_CMD_PAIRING_REQ; 2420 memcpy(&smp->preq[1], &cp, sizeof(cp)); 2421 2422 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); 2423 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 2424 } else { 2425 struct smp_cmd_security_req cp; 2426 cp.auth_req = authreq; 2427 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp); 2428 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ); 2429 } 2430 2431 set_bit(SMP_FLAG_INITIATOR, &smp->flags); 2432 ret = 0; 2433 2434 unlock: 2435 l2cap_chan_unlock(chan); 2436 return ret; 2437 } 2438 2439 int smp_cancel_and_remove_pairing(struct hci_dev *hdev, bdaddr_t *bdaddr, 2440 u8 addr_type) 2441 { 2442 struct hci_conn *hcon; 2443 struct l2cap_conn *conn; 2444 struct l2cap_chan *chan; 2445 struct smp_chan *smp; 2446 int err; 2447 2448 err = hci_remove_ltk(hdev, bdaddr, addr_type); 2449 hci_remove_irk(hdev, bdaddr, addr_type); 2450 2451 hcon = hci_conn_hash_lookup_le(hdev, bdaddr, addr_type); 2452 if (!hcon) 2453 goto done; 2454 2455 conn = hcon->l2cap_data; 2456 if (!conn) 2457 goto done; 2458 2459 chan = conn->smp; 2460 if (!chan) 2461 goto done; 2462 2463 l2cap_chan_lock(chan); 2464 2465 smp = chan->data; 2466 if (smp) { 2467 /* Set keys to NULL to make sure smp_failure() does not try to 2468 * remove and free already invalidated rcu list entries. */ 2469 smp->ltk = NULL; 2470 smp->slave_ltk = NULL; 2471 smp->remote_irk = NULL; 2472 2473 if (test_bit(SMP_FLAG_COMPLETE, &smp->flags)) 2474 smp_failure(conn, 0); 2475 else 2476 smp_failure(conn, SMP_UNSPECIFIED); 2477 err = 0; 2478 } 2479 2480 l2cap_chan_unlock(chan); 2481 2482 done: 2483 return err; 2484 } 2485 2486 static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb) 2487 { 2488 struct smp_cmd_encrypt_info *rp = (void *) skb->data; 2489 struct l2cap_chan *chan = conn->smp; 2490 struct smp_chan *smp = chan->data; 2491 2492 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 2493 2494 if (skb->len < sizeof(*rp)) 2495 return SMP_INVALID_PARAMS; 2496 2497 /* Pairing is aborted if any blocked keys are distributed */ 2498 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_LTK, 2499 rp->ltk)) { 2500 bt_dev_warn_ratelimited(conn->hcon->hdev, 2501 "LTK blocked for %pMR", 2502 &conn->hcon->dst); 2503 return SMP_INVALID_PARAMS; 2504 } 2505 2506 SMP_ALLOW_CMD(smp, SMP_CMD_MASTER_IDENT); 2507 2508 skb_pull(skb, sizeof(*rp)); 2509 2510 memcpy(smp->tk, rp->ltk, sizeof(smp->tk)); 2511 2512 return 0; 2513 } 2514 2515 static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb) 2516 { 2517 struct smp_cmd_master_ident *rp = (void *) skb->data; 2518 struct l2cap_chan *chan = conn->smp; 2519 struct smp_chan *smp = chan->data; 2520 struct hci_dev *hdev = conn->hcon->hdev; 2521 struct hci_conn *hcon = conn->hcon; 2522 struct smp_ltk *ltk; 2523 u8 authenticated; 2524 2525 bt_dev_dbg(hdev, "conn %p", conn); 2526 2527 if (skb->len < sizeof(*rp)) 2528 return SMP_INVALID_PARAMS; 2529 2530 /* Mark the information as received */ 2531 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY; 2532 2533 if (smp->remote_key_dist & SMP_DIST_ID_KEY) 2534 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); 2535 else if (smp->remote_key_dist & SMP_DIST_SIGN) 2536 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 2537 2538 skb_pull(skb, sizeof(*rp)); 2539 2540 authenticated = (hcon->sec_level == BT_SECURITY_HIGH); 2541 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK, 2542 authenticated, smp->tk, smp->enc_key_size, 2543 rp->ediv, rp->rand); 2544 smp->ltk = ltk; 2545 if (!(smp->remote_key_dist & KEY_DIST_MASK)) 2546 smp_distribute_keys(smp); 2547 2548 return 0; 2549 } 2550 2551 static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb) 2552 { 2553 struct smp_cmd_ident_info *info = (void *) skb->data; 2554 struct l2cap_chan *chan = conn->smp; 2555 struct smp_chan *smp = chan->data; 2556 2557 bt_dev_dbg(conn->hcon->hdev, ""); 2558 2559 if (skb->len < sizeof(*info)) 2560 return SMP_INVALID_PARAMS; 2561 2562 /* Pairing is aborted if any blocked keys are distributed */ 2563 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_IRK, 2564 info->irk)) { 2565 bt_dev_warn_ratelimited(conn->hcon->hdev, 2566 "Identity key blocked for %pMR", 2567 &conn->hcon->dst); 2568 return SMP_INVALID_PARAMS; 2569 } 2570 2571 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO); 2572 2573 skb_pull(skb, sizeof(*info)); 2574 2575 memcpy(smp->irk, info->irk, 16); 2576 2577 return 0; 2578 } 2579 2580 static int smp_cmd_ident_addr_info(struct l2cap_conn *conn, 2581 struct sk_buff *skb) 2582 { 2583 struct smp_cmd_ident_addr_info *info = (void *) skb->data; 2584 struct l2cap_chan *chan = conn->smp; 2585 struct smp_chan *smp = chan->data; 2586 struct hci_conn *hcon = conn->hcon; 2587 bdaddr_t rpa; 2588 2589 bt_dev_dbg(hcon->hdev, ""); 2590 2591 if (skb->len < sizeof(*info)) 2592 return SMP_INVALID_PARAMS; 2593 2594 /* Mark the information as received */ 2595 smp->remote_key_dist &= ~SMP_DIST_ID_KEY; 2596 2597 if (smp->remote_key_dist & SMP_DIST_SIGN) 2598 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 2599 2600 skb_pull(skb, sizeof(*info)); 2601 2602 /* Strictly speaking the Core Specification (4.1) allows sending 2603 * an empty address which would force us to rely on just the IRK 2604 * as "identity information". However, since such 2605 * implementations are not known of and in order to not over 2606 * complicate our implementation, simply pretend that we never 2607 * received an IRK for such a device. 2608 * 2609 * The Identity Address must also be a Static Random or Public 2610 * Address, which hci_is_identity_address() checks for. 2611 */ 2612 if (!bacmp(&info->bdaddr, BDADDR_ANY) || 2613 !hci_is_identity_address(&info->bdaddr, info->addr_type)) { 2614 bt_dev_err(hcon->hdev, "ignoring IRK with no identity address"); 2615 goto distribute; 2616 } 2617 2618 /* Drop IRK if peer is using identity address during pairing but is 2619 * providing different address as identity information. 2620 * 2621 * Microsoft Surface Precision Mouse is known to have this bug. 2622 */ 2623 if (hci_is_identity_address(&hcon->dst, hcon->dst_type) && 2624 (bacmp(&info->bdaddr, &hcon->dst) || 2625 info->addr_type != hcon->dst_type)) { 2626 bt_dev_err(hcon->hdev, 2627 "ignoring IRK with invalid identity address"); 2628 goto distribute; 2629 } 2630 2631 bacpy(&smp->id_addr, &info->bdaddr); 2632 smp->id_addr_type = info->addr_type; 2633 2634 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type)) 2635 bacpy(&rpa, &hcon->dst); 2636 else 2637 bacpy(&rpa, BDADDR_ANY); 2638 2639 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr, 2640 smp->id_addr_type, smp->irk, &rpa); 2641 2642 distribute: 2643 if (!(smp->remote_key_dist & KEY_DIST_MASK)) 2644 smp_distribute_keys(smp); 2645 2646 return 0; 2647 } 2648 2649 static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb) 2650 { 2651 struct smp_cmd_sign_info *rp = (void *) skb->data; 2652 struct l2cap_chan *chan = conn->smp; 2653 struct smp_chan *smp = chan->data; 2654 struct smp_csrk *csrk; 2655 2656 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 2657 2658 if (skb->len < sizeof(*rp)) 2659 return SMP_INVALID_PARAMS; 2660 2661 /* Mark the information as received */ 2662 smp->remote_key_dist &= ~SMP_DIST_SIGN; 2663 2664 skb_pull(skb, sizeof(*rp)); 2665 2666 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); 2667 if (csrk) { 2668 if (conn->hcon->sec_level > BT_SECURITY_MEDIUM) 2669 csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED; 2670 else 2671 csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED; 2672 memcpy(csrk->val, rp->csrk, sizeof(csrk->val)); 2673 } 2674 smp->csrk = csrk; 2675 smp_distribute_keys(smp); 2676 2677 return 0; 2678 } 2679 2680 static u8 sc_select_method(struct smp_chan *smp) 2681 { 2682 struct l2cap_conn *conn = smp->conn; 2683 struct hci_conn *hcon = conn->hcon; 2684 struct smp_cmd_pairing *local, *remote; 2685 u8 local_mitm, remote_mitm, local_io, remote_io, method; 2686 2687 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) || 2688 test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) 2689 return REQ_OOB; 2690 2691 /* The preq/prsp contain the raw Pairing Request/Response PDUs 2692 * which are needed as inputs to some crypto functions. To get 2693 * the "struct smp_cmd_pairing" from them we need to skip the 2694 * first byte which contains the opcode. 2695 */ 2696 if (hcon->out) { 2697 local = (void *) &smp->preq[1]; 2698 remote = (void *) &smp->prsp[1]; 2699 } else { 2700 local = (void *) &smp->prsp[1]; 2701 remote = (void *) &smp->preq[1]; 2702 } 2703 2704 local_io = local->io_capability; 2705 remote_io = remote->io_capability; 2706 2707 local_mitm = (local->auth_req & SMP_AUTH_MITM); 2708 remote_mitm = (remote->auth_req & SMP_AUTH_MITM); 2709 2710 /* If either side wants MITM, look up the method from the table, 2711 * otherwise use JUST WORKS. 2712 */ 2713 if (local_mitm || remote_mitm) 2714 method = get_auth_method(smp, local_io, remote_io); 2715 else 2716 method = JUST_WORKS; 2717 2718 /* Don't confirm locally initiated pairing attempts */ 2719 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2720 method = JUST_WORKS; 2721 2722 return method; 2723 } 2724 2725 static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb) 2726 { 2727 struct smp_cmd_public_key *key = (void *) skb->data; 2728 struct hci_conn *hcon = conn->hcon; 2729 struct l2cap_chan *chan = conn->smp; 2730 struct smp_chan *smp = chan->data; 2731 struct hci_dev *hdev = hcon->hdev; 2732 struct crypto_kpp *tfm_ecdh; 2733 struct smp_cmd_pairing_confirm cfm; 2734 int err; 2735 2736 bt_dev_dbg(hdev, "conn %p", conn); 2737 2738 if (skb->len < sizeof(*key)) 2739 return SMP_INVALID_PARAMS; 2740 2741 /* Check if remote and local public keys are the same and debug key is 2742 * not in use. 2743 */ 2744 if (!test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags) && 2745 !crypto_memneq(key, smp->local_pk, 64)) { 2746 bt_dev_err(hdev, "Remote and local public keys are identical"); 2747 return SMP_UNSPECIFIED; 2748 } 2749 2750 memcpy(smp->remote_pk, key, 64); 2751 2752 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) { 2753 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk, 2754 smp->rr, 0, cfm.confirm_val); 2755 if (err) 2756 return SMP_UNSPECIFIED; 2757 2758 if (crypto_memneq(cfm.confirm_val, smp->pcnf, 16)) 2759 return SMP_CONFIRM_FAILED; 2760 } 2761 2762 /* Non-initiating device sends its public key after receiving 2763 * the key from the initiating device. 2764 */ 2765 if (!hcon->out) { 2766 err = sc_send_public_key(smp); 2767 if (err) 2768 return err; 2769 } 2770 2771 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk); 2772 SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32); 2773 2774 /* Compute the shared secret on the same crypto tfm on which the private 2775 * key was set/generated. 2776 */ 2777 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { 2778 struct l2cap_chan *hchan = hdev->smp_data; 2779 struct smp_dev *smp_dev; 2780 2781 if (!hchan || !hchan->data) 2782 return SMP_UNSPECIFIED; 2783 2784 smp_dev = hchan->data; 2785 2786 tfm_ecdh = smp_dev->tfm_ecdh; 2787 } else { 2788 tfm_ecdh = smp->tfm_ecdh; 2789 } 2790 2791 if (compute_ecdh_secret(tfm_ecdh, smp->remote_pk, smp->dhkey)) 2792 return SMP_UNSPECIFIED; 2793 2794 SMP_DBG("DHKey %32phN", smp->dhkey); 2795 2796 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags); 2797 2798 smp->method = sc_select_method(smp); 2799 2800 bt_dev_dbg(hdev, "selected method 0x%02x", smp->method); 2801 2802 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */ 2803 if (smp->method == JUST_WORKS || smp->method == JUST_CFM) 2804 hcon->pending_sec_level = BT_SECURITY_MEDIUM; 2805 else 2806 hcon->pending_sec_level = BT_SECURITY_FIPS; 2807 2808 if (!crypto_memneq(debug_pk, smp->remote_pk, 64)) 2809 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 2810 2811 if (smp->method == DSP_PASSKEY) { 2812 get_random_bytes(&hcon->passkey_notify, 2813 sizeof(hcon->passkey_notify)); 2814 hcon->passkey_notify %= 1000000; 2815 hcon->passkey_entered = 0; 2816 smp->passkey_round = 0; 2817 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type, 2818 hcon->dst_type, 2819 hcon->passkey_notify, 2820 hcon->passkey_entered)) 2821 return SMP_UNSPECIFIED; 2822 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2823 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY); 2824 } 2825 2826 if (smp->method == REQ_OOB) { 2827 if (hcon->out) 2828 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 2829 sizeof(smp->prnd), smp->prnd); 2830 2831 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2832 2833 return 0; 2834 } 2835 2836 if (hcon->out) 2837 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2838 2839 if (smp->method == REQ_PASSKEY) { 2840 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type, 2841 hcon->dst_type)) 2842 return SMP_UNSPECIFIED; 2843 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2844 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 2845 return 0; 2846 } 2847 2848 /* The Initiating device waits for the non-initiating device to 2849 * send the confirm value. 2850 */ 2851 if (conn->hcon->out) 2852 return 0; 2853 2854 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, 2855 0, cfm.confirm_val); 2856 if (err) 2857 return SMP_UNSPECIFIED; 2858 2859 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); 2860 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2861 2862 return 0; 2863 } 2864 2865 static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb) 2866 { 2867 struct smp_cmd_dhkey_check *check = (void *) skb->data; 2868 struct l2cap_chan *chan = conn->smp; 2869 struct hci_conn *hcon = conn->hcon; 2870 struct smp_chan *smp = chan->data; 2871 u8 a[7], b[7], *local_addr, *remote_addr; 2872 u8 io_cap[3], r[16], e[16]; 2873 int err; 2874 2875 bt_dev_dbg(hcon->hdev, "conn %p", conn); 2876 2877 if (skb->len < sizeof(*check)) 2878 return SMP_INVALID_PARAMS; 2879 2880 memcpy(a, &hcon->init_addr, 6); 2881 memcpy(b, &hcon->resp_addr, 6); 2882 a[6] = hcon->init_addr_type; 2883 b[6] = hcon->resp_addr_type; 2884 2885 if (hcon->out) { 2886 local_addr = a; 2887 remote_addr = b; 2888 memcpy(io_cap, &smp->prsp[1], 3); 2889 } else { 2890 local_addr = b; 2891 remote_addr = a; 2892 memcpy(io_cap, &smp->preq[1], 3); 2893 } 2894 2895 memset(r, 0, sizeof(r)); 2896 2897 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2898 put_unaligned_le32(hcon->passkey_notify, r); 2899 else if (smp->method == REQ_OOB) 2900 memcpy(r, smp->lr, 16); 2901 2902 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r, 2903 io_cap, remote_addr, local_addr, e); 2904 if (err) 2905 return SMP_UNSPECIFIED; 2906 2907 if (crypto_memneq(check->e, e, 16)) 2908 return SMP_DHKEY_CHECK_FAILED; 2909 2910 if (!hcon->out) { 2911 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { 2912 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags); 2913 return 0; 2914 } 2915 2916 /* Slave sends DHKey check as response to master */ 2917 sc_dhkey_check(smp); 2918 } 2919 2920 sc_add_ltk(smp); 2921 2922 if (hcon->out) { 2923 hci_le_start_enc(hcon, 0, 0, smp->tk, smp->enc_key_size); 2924 hcon->enc_key_size = smp->enc_key_size; 2925 } 2926 2927 return 0; 2928 } 2929 2930 static int smp_cmd_keypress_notify(struct l2cap_conn *conn, 2931 struct sk_buff *skb) 2932 { 2933 struct smp_cmd_keypress_notify *kp = (void *) skb->data; 2934 2935 bt_dev_dbg(conn->hcon->hdev, "value 0x%02x", kp->value); 2936 2937 return 0; 2938 } 2939 2940 static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb) 2941 { 2942 struct l2cap_conn *conn = chan->conn; 2943 struct hci_conn *hcon = conn->hcon; 2944 struct smp_chan *smp; 2945 __u8 code, reason; 2946 int err = 0; 2947 2948 if (skb->len < 1) 2949 return -EILSEQ; 2950 2951 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) { 2952 reason = SMP_PAIRING_NOTSUPP; 2953 goto done; 2954 } 2955 2956 code = skb->data[0]; 2957 skb_pull(skb, sizeof(code)); 2958 2959 smp = chan->data; 2960 2961 if (code > SMP_CMD_MAX) 2962 goto drop; 2963 2964 if (smp && !test_and_clear_bit(code, &smp->allow_cmd)) 2965 goto drop; 2966 2967 /* If we don't have a context the only allowed commands are 2968 * pairing request and security request. 2969 */ 2970 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ) 2971 goto drop; 2972 2973 switch (code) { 2974 case SMP_CMD_PAIRING_REQ: 2975 reason = smp_cmd_pairing_req(conn, skb); 2976 break; 2977 2978 case SMP_CMD_PAIRING_FAIL: 2979 smp_failure(conn, 0); 2980 err = -EPERM; 2981 break; 2982 2983 case SMP_CMD_PAIRING_RSP: 2984 reason = smp_cmd_pairing_rsp(conn, skb); 2985 break; 2986 2987 case SMP_CMD_SECURITY_REQ: 2988 reason = smp_cmd_security_req(conn, skb); 2989 break; 2990 2991 case SMP_CMD_PAIRING_CONFIRM: 2992 reason = smp_cmd_pairing_confirm(conn, skb); 2993 break; 2994 2995 case SMP_CMD_PAIRING_RANDOM: 2996 reason = smp_cmd_pairing_random(conn, skb); 2997 break; 2998 2999 case SMP_CMD_ENCRYPT_INFO: 3000 reason = smp_cmd_encrypt_info(conn, skb); 3001 break; 3002 3003 case SMP_CMD_MASTER_IDENT: 3004 reason = smp_cmd_master_ident(conn, skb); 3005 break; 3006 3007 case SMP_CMD_IDENT_INFO: 3008 reason = smp_cmd_ident_info(conn, skb); 3009 break; 3010 3011 case SMP_CMD_IDENT_ADDR_INFO: 3012 reason = smp_cmd_ident_addr_info(conn, skb); 3013 break; 3014 3015 case SMP_CMD_SIGN_INFO: 3016 reason = smp_cmd_sign_info(conn, skb); 3017 break; 3018 3019 case SMP_CMD_PUBLIC_KEY: 3020 reason = smp_cmd_public_key(conn, skb); 3021 break; 3022 3023 case SMP_CMD_DHKEY_CHECK: 3024 reason = smp_cmd_dhkey_check(conn, skb); 3025 break; 3026 3027 case SMP_CMD_KEYPRESS_NOTIFY: 3028 reason = smp_cmd_keypress_notify(conn, skb); 3029 break; 3030 3031 default: 3032 bt_dev_dbg(hcon->hdev, "Unknown command code 0x%2.2x", code); 3033 reason = SMP_CMD_NOTSUPP; 3034 goto done; 3035 } 3036 3037 done: 3038 if (!err) { 3039 if (reason) 3040 smp_failure(conn, reason); 3041 kfree_skb(skb); 3042 } 3043 3044 return err; 3045 3046 drop: 3047 bt_dev_err(hcon->hdev, "unexpected SMP command 0x%02x from %pMR", 3048 code, &hcon->dst); 3049 kfree_skb(skb); 3050 return 0; 3051 } 3052 3053 static void smp_teardown_cb(struct l2cap_chan *chan, int err) 3054 { 3055 struct l2cap_conn *conn = chan->conn; 3056 3057 bt_dev_dbg(conn->hcon->hdev, "chan %p", chan); 3058 3059 if (chan->data) 3060 smp_chan_destroy(conn); 3061 3062 conn->smp = NULL; 3063 l2cap_chan_put(chan); 3064 } 3065 3066 static void bredr_pairing(struct l2cap_chan *chan) 3067 { 3068 struct l2cap_conn *conn = chan->conn; 3069 struct hci_conn *hcon = conn->hcon; 3070 struct hci_dev *hdev = hcon->hdev; 3071 struct smp_cmd_pairing req; 3072 struct smp_chan *smp; 3073 3074 bt_dev_dbg(hdev, "chan %p", chan); 3075 3076 /* Only new pairings are interesting */ 3077 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags)) 3078 return; 3079 3080 /* Don't bother if we're not encrypted */ 3081 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3082 return; 3083 3084 /* Only master may initiate SMP over BR/EDR */ 3085 if (hcon->role != HCI_ROLE_MASTER) 3086 return; 3087 3088 /* Secure Connections support must be enabled */ 3089 if (!hci_dev_test_flag(hdev, HCI_SC_ENABLED)) 3090 return; 3091 3092 /* BR/EDR must use Secure Connections for SMP */ 3093 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) && 3094 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3095 return; 3096 3097 /* If our LE support is not enabled don't do anything */ 3098 if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) 3099 return; 3100 3101 /* Don't bother if remote LE support is not enabled */ 3102 if (!lmp_host_le_capable(hcon)) 3103 return; 3104 3105 /* Remote must support SMP fixed chan for BR/EDR */ 3106 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR)) 3107 return; 3108 3109 /* Don't bother if SMP is already ongoing */ 3110 if (chan->data) 3111 return; 3112 3113 smp = smp_chan_create(conn); 3114 if (!smp) { 3115 bt_dev_err(hdev, "unable to create SMP context for BR/EDR"); 3116 return; 3117 } 3118 3119 set_bit(SMP_FLAG_SC, &smp->flags); 3120 3121 bt_dev_dbg(hdev, "starting SMP over BR/EDR"); 3122 3123 /* Prepare and send the BR/EDR SMP Pairing Request */ 3124 build_bredr_pairing_cmd(smp, &req, NULL); 3125 3126 smp->preq[0] = SMP_CMD_PAIRING_REQ; 3127 memcpy(&smp->preq[1], &req, sizeof(req)); 3128 3129 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(req), &req); 3130 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 3131 } 3132 3133 static void smp_resume_cb(struct l2cap_chan *chan) 3134 { 3135 struct smp_chan *smp = chan->data; 3136 struct l2cap_conn *conn = chan->conn; 3137 struct hci_conn *hcon = conn->hcon; 3138 3139 bt_dev_dbg(hcon->hdev, "chan %p", chan); 3140 3141 if (hcon->type == ACL_LINK) { 3142 bredr_pairing(chan); 3143 return; 3144 } 3145 3146 if (!smp) 3147 return; 3148 3149 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3150 return; 3151 3152 cancel_delayed_work(&smp->security_timer); 3153 3154 smp_distribute_keys(smp); 3155 } 3156 3157 static void smp_ready_cb(struct l2cap_chan *chan) 3158 { 3159 struct l2cap_conn *conn = chan->conn; 3160 struct hci_conn *hcon = conn->hcon; 3161 3162 bt_dev_dbg(hcon->hdev, "chan %p", chan); 3163 3164 /* No need to call l2cap_chan_hold() here since we already own 3165 * the reference taken in smp_new_conn_cb(). This is just the 3166 * first time that we tie it to a specific pointer. The code in 3167 * l2cap_core.c ensures that there's no risk this function wont 3168 * get called if smp_new_conn_cb was previously called. 3169 */ 3170 conn->smp = chan; 3171 3172 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3173 bredr_pairing(chan); 3174 } 3175 3176 static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 3177 { 3178 int err; 3179 3180 bt_dev_dbg(chan->conn->hcon->hdev, "chan %p", chan); 3181 3182 err = smp_sig_channel(chan, skb); 3183 if (err) { 3184 struct smp_chan *smp = chan->data; 3185 3186 if (smp) 3187 cancel_delayed_work_sync(&smp->security_timer); 3188 3189 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE); 3190 } 3191 3192 return err; 3193 } 3194 3195 static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan, 3196 unsigned long hdr_len, 3197 unsigned long len, int nb) 3198 { 3199 struct sk_buff *skb; 3200 3201 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL); 3202 if (!skb) 3203 return ERR_PTR(-ENOMEM); 3204 3205 skb->priority = HCI_PRIO_MAX; 3206 bt_cb(skb)->l2cap.chan = chan; 3207 3208 return skb; 3209 } 3210 3211 static const struct l2cap_ops smp_chan_ops = { 3212 .name = "Security Manager", 3213 .ready = smp_ready_cb, 3214 .recv = smp_recv_cb, 3215 .alloc_skb = smp_alloc_skb_cb, 3216 .teardown = smp_teardown_cb, 3217 .resume = smp_resume_cb, 3218 3219 .new_connection = l2cap_chan_no_new_connection, 3220 .state_change = l2cap_chan_no_state_change, 3221 .close = l2cap_chan_no_close, 3222 .defer = l2cap_chan_no_defer, 3223 .suspend = l2cap_chan_no_suspend, 3224 .set_shutdown = l2cap_chan_no_set_shutdown, 3225 .get_sndtimeo = l2cap_chan_no_get_sndtimeo, 3226 }; 3227 3228 static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan) 3229 { 3230 struct l2cap_chan *chan; 3231 3232 BT_DBG("pchan %p", pchan); 3233 3234 chan = l2cap_chan_create(); 3235 if (!chan) 3236 return NULL; 3237 3238 chan->chan_type = pchan->chan_type; 3239 chan->ops = &smp_chan_ops; 3240 chan->scid = pchan->scid; 3241 chan->dcid = chan->scid; 3242 chan->imtu = pchan->imtu; 3243 chan->omtu = pchan->omtu; 3244 chan->mode = pchan->mode; 3245 3246 /* Other L2CAP channels may request SMP routines in order to 3247 * change the security level. This means that the SMP channel 3248 * lock must be considered in its own category to avoid lockdep 3249 * warnings. 3250 */ 3251 atomic_set(&chan->nesting, L2CAP_NESTING_SMP); 3252 3253 BT_DBG("created chan %p", chan); 3254 3255 return chan; 3256 } 3257 3258 static const struct l2cap_ops smp_root_chan_ops = { 3259 .name = "Security Manager Root", 3260 .new_connection = smp_new_conn_cb, 3261 3262 /* None of these are implemented for the root channel */ 3263 .close = l2cap_chan_no_close, 3264 .alloc_skb = l2cap_chan_no_alloc_skb, 3265 .recv = l2cap_chan_no_recv, 3266 .state_change = l2cap_chan_no_state_change, 3267 .teardown = l2cap_chan_no_teardown, 3268 .ready = l2cap_chan_no_ready, 3269 .defer = l2cap_chan_no_defer, 3270 .suspend = l2cap_chan_no_suspend, 3271 .resume = l2cap_chan_no_resume, 3272 .set_shutdown = l2cap_chan_no_set_shutdown, 3273 .get_sndtimeo = l2cap_chan_no_get_sndtimeo, 3274 }; 3275 3276 static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid) 3277 { 3278 struct l2cap_chan *chan; 3279 struct smp_dev *smp; 3280 struct crypto_shash *tfm_cmac; 3281 struct crypto_kpp *tfm_ecdh; 3282 3283 if (cid == L2CAP_CID_SMP_BREDR) { 3284 smp = NULL; 3285 goto create_chan; 3286 } 3287 3288 smp = kzalloc(sizeof(*smp), GFP_KERNEL); 3289 if (!smp) 3290 return ERR_PTR(-ENOMEM); 3291 3292 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 3293 if (IS_ERR(tfm_cmac)) { 3294 bt_dev_err(hdev, "Unable to create CMAC crypto context"); 3295 kfree_sensitive(smp); 3296 return ERR_CAST(tfm_cmac); 3297 } 3298 3299 tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0); 3300 if (IS_ERR(tfm_ecdh)) { 3301 bt_dev_err(hdev, "Unable to create ECDH crypto context"); 3302 crypto_free_shash(tfm_cmac); 3303 kfree_sensitive(smp); 3304 return ERR_CAST(tfm_ecdh); 3305 } 3306 3307 smp->local_oob = false; 3308 smp->tfm_cmac = tfm_cmac; 3309 smp->tfm_ecdh = tfm_ecdh; 3310 3311 create_chan: 3312 chan = l2cap_chan_create(); 3313 if (!chan) { 3314 if (smp) { 3315 crypto_free_shash(smp->tfm_cmac); 3316 crypto_free_kpp(smp->tfm_ecdh); 3317 kfree_sensitive(smp); 3318 } 3319 return ERR_PTR(-ENOMEM); 3320 } 3321 3322 chan->data = smp; 3323 3324 l2cap_add_scid(chan, cid); 3325 3326 l2cap_chan_set_defaults(chan); 3327 3328 if (cid == L2CAP_CID_SMP) { 3329 u8 bdaddr_type; 3330 3331 hci_copy_identity_address(hdev, &chan->src, &bdaddr_type); 3332 3333 if (bdaddr_type == ADDR_LE_DEV_PUBLIC) 3334 chan->src_type = BDADDR_LE_PUBLIC; 3335 else 3336 chan->src_type = BDADDR_LE_RANDOM; 3337 } else { 3338 bacpy(&chan->src, &hdev->bdaddr); 3339 chan->src_type = BDADDR_BREDR; 3340 } 3341 3342 chan->state = BT_LISTEN; 3343 chan->mode = L2CAP_MODE_BASIC; 3344 chan->imtu = L2CAP_DEFAULT_MTU; 3345 chan->ops = &smp_root_chan_ops; 3346 3347 /* Set correct nesting level for a parent/listening channel */ 3348 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 3349 3350 return chan; 3351 } 3352 3353 static void smp_del_chan(struct l2cap_chan *chan) 3354 { 3355 struct smp_dev *smp; 3356 3357 BT_DBG("chan %p", chan); 3358 3359 smp = chan->data; 3360 if (smp) { 3361 chan->data = NULL; 3362 crypto_free_shash(smp->tfm_cmac); 3363 crypto_free_kpp(smp->tfm_ecdh); 3364 kfree_sensitive(smp); 3365 } 3366 3367 l2cap_chan_put(chan); 3368 } 3369 3370 int smp_force_bredr(struct hci_dev *hdev, bool enable) 3371 { 3372 if (enable == hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3373 return -EALREADY; 3374 3375 if (enable) { 3376 struct l2cap_chan *chan; 3377 3378 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); 3379 if (IS_ERR(chan)) 3380 return PTR_ERR(chan); 3381 3382 hdev->smp_bredr_data = chan; 3383 } else { 3384 struct l2cap_chan *chan; 3385 3386 chan = hdev->smp_bredr_data; 3387 hdev->smp_bredr_data = NULL; 3388 smp_del_chan(chan); 3389 } 3390 3391 hci_dev_change_flag(hdev, HCI_FORCE_BREDR_SMP); 3392 3393 return 0; 3394 } 3395 3396 int smp_register(struct hci_dev *hdev) 3397 { 3398 struct l2cap_chan *chan; 3399 3400 bt_dev_dbg(hdev, ""); 3401 3402 /* If the controller does not support Low Energy operation, then 3403 * there is also no need to register any SMP channel. 3404 */ 3405 if (!lmp_le_capable(hdev)) 3406 return 0; 3407 3408 if (WARN_ON(hdev->smp_data)) { 3409 chan = hdev->smp_data; 3410 hdev->smp_data = NULL; 3411 smp_del_chan(chan); 3412 } 3413 3414 chan = smp_add_cid(hdev, L2CAP_CID_SMP); 3415 if (IS_ERR(chan)) 3416 return PTR_ERR(chan); 3417 3418 hdev->smp_data = chan; 3419 3420 if (!lmp_sc_capable(hdev)) { 3421 /* Flag can be already set here (due to power toggle) */ 3422 if (!hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3423 return 0; 3424 } 3425 3426 if (WARN_ON(hdev->smp_bredr_data)) { 3427 chan = hdev->smp_bredr_data; 3428 hdev->smp_bredr_data = NULL; 3429 smp_del_chan(chan); 3430 } 3431 3432 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); 3433 if (IS_ERR(chan)) { 3434 int err = PTR_ERR(chan); 3435 chan = hdev->smp_data; 3436 hdev->smp_data = NULL; 3437 smp_del_chan(chan); 3438 return err; 3439 } 3440 3441 hdev->smp_bredr_data = chan; 3442 3443 return 0; 3444 } 3445 3446 void smp_unregister(struct hci_dev *hdev) 3447 { 3448 struct l2cap_chan *chan; 3449 3450 if (hdev->smp_bredr_data) { 3451 chan = hdev->smp_bredr_data; 3452 hdev->smp_bredr_data = NULL; 3453 smp_del_chan(chan); 3454 } 3455 3456 if (hdev->smp_data) { 3457 chan = hdev->smp_data; 3458 hdev->smp_data = NULL; 3459 smp_del_chan(chan); 3460 } 3461 } 3462 3463 #if IS_ENABLED(CONFIG_BT_SELFTEST_SMP) 3464 3465 static int __init test_debug_key(struct crypto_kpp *tfm_ecdh) 3466 { 3467 u8 pk[64]; 3468 int err; 3469 3470 err = set_ecdh_privkey(tfm_ecdh, debug_sk); 3471 if (err) 3472 return err; 3473 3474 err = generate_ecdh_public_key(tfm_ecdh, pk); 3475 if (err) 3476 return err; 3477 3478 if (crypto_memneq(pk, debug_pk, 64)) 3479 return -EINVAL; 3480 3481 return 0; 3482 } 3483 3484 static int __init test_ah(void) 3485 { 3486 const u8 irk[16] = { 3487 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3488 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3489 const u8 r[3] = { 0x94, 0x81, 0x70 }; 3490 const u8 exp[3] = { 0xaa, 0xfb, 0x0d }; 3491 u8 res[3]; 3492 int err; 3493 3494 err = smp_ah(irk, r, res); 3495 if (err) 3496 return err; 3497 3498 if (crypto_memneq(res, exp, 3)) 3499 return -EINVAL; 3500 3501 return 0; 3502 } 3503 3504 static int __init test_c1(void) 3505 { 3506 const u8 k[16] = { 3507 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 3508 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; 3509 const u8 r[16] = { 3510 0xe0, 0x2e, 0x70, 0xc6, 0x4e, 0x27, 0x88, 0x63, 3511 0x0e, 0x6f, 0xad, 0x56, 0x21, 0xd5, 0x83, 0x57 }; 3512 const u8 preq[7] = { 0x01, 0x01, 0x00, 0x00, 0x10, 0x07, 0x07 }; 3513 const u8 pres[7] = { 0x02, 0x03, 0x00, 0x00, 0x08, 0x00, 0x05 }; 3514 const u8 _iat = 0x01; 3515 const u8 _rat = 0x00; 3516 const bdaddr_t ra = { { 0xb6, 0xb5, 0xb4, 0xb3, 0xb2, 0xb1 } }; 3517 const bdaddr_t ia = { { 0xa6, 0xa5, 0xa4, 0xa3, 0xa2, 0xa1 } }; 3518 const u8 exp[16] = { 3519 0x86, 0x3b, 0xf1, 0xbe, 0xc5, 0x4d, 0xa7, 0xd2, 3520 0xea, 0x88, 0x89, 0x87, 0xef, 0x3f, 0x1e, 0x1e }; 3521 u8 res[16]; 3522 int err; 3523 3524 err = smp_c1(k, r, preq, pres, _iat, &ia, _rat, &ra, res); 3525 if (err) 3526 return err; 3527 3528 if (crypto_memneq(res, exp, 16)) 3529 return -EINVAL; 3530 3531 return 0; 3532 } 3533 3534 static int __init test_s1(void) 3535 { 3536 const u8 k[16] = { 3537 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 3538 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; 3539 const u8 r1[16] = { 3540 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 }; 3541 const u8 r2[16] = { 3542 0x00, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99 }; 3543 const u8 exp[16] = { 3544 0x62, 0xa0, 0x6d, 0x79, 0xae, 0x16, 0x42, 0x5b, 3545 0x9b, 0xf4, 0xb0, 0xe8, 0xf0, 0xe1, 0x1f, 0x9a }; 3546 u8 res[16]; 3547 int err; 3548 3549 err = smp_s1(k, r1, r2, res); 3550 if (err) 3551 return err; 3552 3553 if (crypto_memneq(res, exp, 16)) 3554 return -EINVAL; 3555 3556 return 0; 3557 } 3558 3559 static int __init test_f4(struct crypto_shash *tfm_cmac) 3560 { 3561 const u8 u[32] = { 3562 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 3563 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 3564 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 3565 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 }; 3566 const u8 v[32] = { 3567 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b, 3568 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59, 3569 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90, 3570 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 }; 3571 const u8 x[16] = { 3572 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3573 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3574 const u8 z = 0x00; 3575 const u8 exp[16] = { 3576 0x2d, 0x87, 0x74, 0xa9, 0xbe, 0xa1, 0xed, 0xf1, 3577 0x1c, 0xbd, 0xa9, 0x07, 0xf1, 0x16, 0xc9, 0xf2 }; 3578 u8 res[16]; 3579 int err; 3580 3581 err = smp_f4(tfm_cmac, u, v, x, z, res); 3582 if (err) 3583 return err; 3584 3585 if (crypto_memneq(res, exp, 16)) 3586 return -EINVAL; 3587 3588 return 0; 3589 } 3590 3591 static int __init test_f5(struct crypto_shash *tfm_cmac) 3592 { 3593 const u8 w[32] = { 3594 0x98, 0xa6, 0xbf, 0x73, 0xf3, 0x34, 0x8d, 0x86, 3595 0xf1, 0x66, 0xf8, 0xb4, 0x13, 0x6b, 0x79, 0x99, 3596 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3597 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3598 const u8 n1[16] = { 3599 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3600 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3601 const u8 n2[16] = { 3602 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3603 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3604 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 }; 3605 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 }; 3606 const u8 exp_ltk[16] = { 3607 0x38, 0x0a, 0x75, 0x94, 0xb5, 0x22, 0x05, 0x98, 3608 0x23, 0xcd, 0xd7, 0x69, 0x11, 0x79, 0x86, 0x69 }; 3609 const u8 exp_mackey[16] = { 3610 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd, 3611 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 }; 3612 u8 mackey[16], ltk[16]; 3613 int err; 3614 3615 err = smp_f5(tfm_cmac, w, n1, n2, a1, a2, mackey, ltk); 3616 if (err) 3617 return err; 3618 3619 if (crypto_memneq(mackey, exp_mackey, 16)) 3620 return -EINVAL; 3621 3622 if (crypto_memneq(ltk, exp_ltk, 16)) 3623 return -EINVAL; 3624 3625 return 0; 3626 } 3627 3628 static int __init test_f6(struct crypto_shash *tfm_cmac) 3629 { 3630 const u8 w[16] = { 3631 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd, 3632 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 }; 3633 const u8 n1[16] = { 3634 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3635 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3636 const u8 n2[16] = { 3637 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3638 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3639 const u8 r[16] = { 3640 0xc8, 0x0f, 0x2d, 0x0c, 0xd2, 0x42, 0xda, 0x08, 3641 0x54, 0xbb, 0x53, 0xb4, 0x3b, 0x34, 0xa3, 0x12 }; 3642 const u8 io_cap[3] = { 0x02, 0x01, 0x01 }; 3643 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 }; 3644 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 }; 3645 const u8 exp[16] = { 3646 0x61, 0x8f, 0x95, 0xda, 0x09, 0x0b, 0x6c, 0xd2, 3647 0xc5, 0xe8, 0xd0, 0x9c, 0x98, 0x73, 0xc4, 0xe3 }; 3648 u8 res[16]; 3649 int err; 3650 3651 err = smp_f6(tfm_cmac, w, n1, n2, r, io_cap, a1, a2, res); 3652 if (err) 3653 return err; 3654 3655 if (crypto_memneq(res, exp, 16)) 3656 return -EINVAL; 3657 3658 return 0; 3659 } 3660 3661 static int __init test_g2(struct crypto_shash *tfm_cmac) 3662 { 3663 const u8 u[32] = { 3664 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 3665 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 3666 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 3667 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 }; 3668 const u8 v[32] = { 3669 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b, 3670 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59, 3671 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90, 3672 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 }; 3673 const u8 x[16] = { 3674 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3675 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3676 const u8 y[16] = { 3677 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3678 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3679 const u32 exp_val = 0x2f9ed5ba % 1000000; 3680 u32 val; 3681 int err; 3682 3683 err = smp_g2(tfm_cmac, u, v, x, y, &val); 3684 if (err) 3685 return err; 3686 3687 if (val != exp_val) 3688 return -EINVAL; 3689 3690 return 0; 3691 } 3692 3693 static int __init test_h6(struct crypto_shash *tfm_cmac) 3694 { 3695 const u8 w[16] = { 3696 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3697 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3698 const u8 key_id[4] = { 0x72, 0x62, 0x65, 0x6c }; 3699 const u8 exp[16] = { 3700 0x99, 0x63, 0xb1, 0x80, 0xe2, 0xa9, 0xd3, 0xe8, 3701 0x1c, 0xc9, 0x6d, 0xe7, 0x02, 0xe1, 0x9a, 0x2d }; 3702 u8 res[16]; 3703 int err; 3704 3705 err = smp_h6(tfm_cmac, w, key_id, res); 3706 if (err) 3707 return err; 3708 3709 if (crypto_memneq(res, exp, 16)) 3710 return -EINVAL; 3711 3712 return 0; 3713 } 3714 3715 static char test_smp_buffer[32]; 3716 3717 static ssize_t test_smp_read(struct file *file, char __user *user_buf, 3718 size_t count, loff_t *ppos) 3719 { 3720 return simple_read_from_buffer(user_buf, count, ppos, test_smp_buffer, 3721 strlen(test_smp_buffer)); 3722 } 3723 3724 static const struct file_operations test_smp_fops = { 3725 .open = simple_open, 3726 .read = test_smp_read, 3727 .llseek = default_llseek, 3728 }; 3729 3730 static int __init run_selftests(struct crypto_shash *tfm_cmac, 3731 struct crypto_kpp *tfm_ecdh) 3732 { 3733 ktime_t calltime, delta, rettime; 3734 unsigned long long duration; 3735 int err; 3736 3737 calltime = ktime_get(); 3738 3739 err = test_debug_key(tfm_ecdh); 3740 if (err) { 3741 BT_ERR("debug_key test failed"); 3742 goto done; 3743 } 3744 3745 err = test_ah(); 3746 if (err) { 3747 BT_ERR("smp_ah test failed"); 3748 goto done; 3749 } 3750 3751 err = test_c1(); 3752 if (err) { 3753 BT_ERR("smp_c1 test failed"); 3754 goto done; 3755 } 3756 3757 err = test_s1(); 3758 if (err) { 3759 BT_ERR("smp_s1 test failed"); 3760 goto done; 3761 } 3762 3763 err = test_f4(tfm_cmac); 3764 if (err) { 3765 BT_ERR("smp_f4 test failed"); 3766 goto done; 3767 } 3768 3769 err = test_f5(tfm_cmac); 3770 if (err) { 3771 BT_ERR("smp_f5 test failed"); 3772 goto done; 3773 } 3774 3775 err = test_f6(tfm_cmac); 3776 if (err) { 3777 BT_ERR("smp_f6 test failed"); 3778 goto done; 3779 } 3780 3781 err = test_g2(tfm_cmac); 3782 if (err) { 3783 BT_ERR("smp_g2 test failed"); 3784 goto done; 3785 } 3786 3787 err = test_h6(tfm_cmac); 3788 if (err) { 3789 BT_ERR("smp_h6 test failed"); 3790 goto done; 3791 } 3792 3793 rettime = ktime_get(); 3794 delta = ktime_sub(rettime, calltime); 3795 duration = (unsigned long long) ktime_to_ns(delta) >> 10; 3796 3797 BT_INFO("SMP test passed in %llu usecs", duration); 3798 3799 done: 3800 if (!err) 3801 snprintf(test_smp_buffer, sizeof(test_smp_buffer), 3802 "PASS (%llu usecs)\n", duration); 3803 else 3804 snprintf(test_smp_buffer, sizeof(test_smp_buffer), "FAIL\n"); 3805 3806 debugfs_create_file("selftest_smp", 0444, bt_debugfs, NULL, 3807 &test_smp_fops); 3808 3809 return err; 3810 } 3811 3812 int __init bt_selftest_smp(void) 3813 { 3814 struct crypto_shash *tfm_cmac; 3815 struct crypto_kpp *tfm_ecdh; 3816 int err; 3817 3818 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 3819 if (IS_ERR(tfm_cmac)) { 3820 BT_ERR("Unable to create CMAC crypto context"); 3821 return PTR_ERR(tfm_cmac); 3822 } 3823 3824 tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0); 3825 if (IS_ERR(tfm_ecdh)) { 3826 BT_ERR("Unable to create ECDH crypto context"); 3827 crypto_free_shash(tfm_cmac); 3828 return PTR_ERR(tfm_ecdh); 3829 } 3830 3831 err = run_selftests(tfm_cmac, tfm_ecdh); 3832 3833 crypto_free_shash(tfm_cmac); 3834 crypto_free_kpp(tfm_ecdh); 3835 3836 return err; 3837 } 3838 3839 #endif 3840