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 <crypto/aes.h> 26 #include <crypto/hash.h> 27 #include <crypto/kpp.h> 28 #include <crypto/utils.h> 29 30 #include <net/bluetooth/bluetooth.h> 31 #include <net/bluetooth/hci_core.h> 32 #include <net/bluetooth/l2cap.h> 33 #include <net/bluetooth/mgmt.h> 34 35 #include "ecdh_helper.h" 36 #include "smp.h" 37 38 #define SMP_DEV(hdev) \ 39 ((struct smp_dev *)((struct l2cap_chan *)((hdev)->smp_data))->data) 40 41 /* Low-level debug macros to be used for stuff that we don't want 42 * accidentally in dmesg, i.e. the values of the various crypto keys 43 * and the inputs & outputs of crypto functions. 44 */ 45 #ifdef DEBUG 46 #define SMP_DBG(fmt, ...) printk(KERN_DEBUG "%s: " fmt, __func__, \ 47 ##__VA_ARGS__) 48 #else 49 #define SMP_DBG(fmt, ...) no_printk(KERN_DEBUG "%s: " fmt, __func__, \ 50 ##__VA_ARGS__) 51 #endif 52 53 #define SMP_ALLOW_CMD(smp, code) set_bit(code, &smp->allow_cmd) 54 55 /* Keys which are not distributed with Secure Connections */ 56 #define SMP_SC_NO_DIST (SMP_DIST_ENC_KEY | SMP_DIST_LINK_KEY) 57 58 #define SMP_TIMEOUT msecs_to_jiffies(30000) 59 60 #define ID_ADDR_TIMEOUT msecs_to_jiffies(200) 61 62 #define AUTH_REQ_MASK(dev) (hci_dev_test_flag(dev, HCI_SC_ENABLED) ? \ 63 0x3f : 0x07) 64 #define KEY_DIST_MASK 0x07 65 66 /* Maximum message length that can be passed to aes_cmac */ 67 #define CMAC_MSG_MAX 80 68 69 enum { 70 SMP_FLAG_TK_VALID, 71 SMP_FLAG_CFM_PENDING, 72 SMP_FLAG_MITM_AUTH, 73 SMP_FLAG_COMPLETE, 74 SMP_FLAG_INITIATOR, 75 SMP_FLAG_SC, 76 SMP_FLAG_REMOTE_PK, 77 SMP_FLAG_DEBUG_KEY, 78 SMP_FLAG_WAIT_USER, 79 SMP_FLAG_DHKEY_PENDING, 80 SMP_FLAG_REMOTE_OOB, 81 SMP_FLAG_LOCAL_OOB, 82 SMP_FLAG_CT2, 83 }; 84 85 struct smp_dev { 86 /* Secure Connections OOB data */ 87 bool local_oob; 88 u8 local_pk[64]; 89 u8 local_rand[16]; 90 bool debug_key; 91 92 struct crypto_shash *tfm_cmac; 93 struct crypto_kpp *tfm_ecdh; 94 }; 95 96 struct smp_chan { 97 struct l2cap_conn *conn; 98 struct delayed_work security_timer; 99 unsigned long allow_cmd; /* Bitmask of allowed commands */ 100 101 u8 preq[7]; /* SMP Pairing Request */ 102 u8 prsp[7]; /* SMP Pairing Response */ 103 u8 prnd[16]; /* SMP Pairing Random (local) */ 104 u8 rrnd[16]; /* SMP Pairing Random (remote) */ 105 u8 pcnf[16]; /* SMP Pairing Confirm */ 106 u8 tk[16]; /* SMP Temporary Key */ 107 u8 rr[16]; /* Remote OOB ra/rb value */ 108 u8 lr[16]; /* Local OOB ra/rb value */ 109 u8 enc_key_size; 110 u8 remote_key_dist; 111 bdaddr_t id_addr; 112 u8 id_addr_type; 113 u8 irk[16]; 114 struct smp_csrk *csrk; 115 struct smp_csrk *responder_csrk; 116 struct smp_ltk *ltk; 117 struct smp_ltk *responder_ltk; 118 struct smp_irk *remote_irk; 119 u8 *link_key; 120 unsigned long flags; 121 u8 method; 122 u8 passkey_round; 123 124 /* Secure Connections variables */ 125 u8 local_pk[64]; 126 u8 remote_pk[64]; 127 u8 dhkey[32]; 128 u8 mackey[16]; 129 130 struct crypto_shash *tfm_cmac; 131 struct crypto_kpp *tfm_ecdh; 132 }; 133 134 /* These debug key values are defined in the SMP section of the core 135 * specification. debug_pk is the public debug key and debug_sk the 136 * private debug key. 137 */ 138 static const u8 debug_pk[64] = { 139 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 140 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 141 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 142 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20, 143 144 0x8b, 0xd2, 0x89, 0x15, 0xd0, 0x8e, 0x1c, 0x74, 145 0x24, 0x30, 0xed, 0x8f, 0xc2, 0x45, 0x63, 0x76, 146 0x5c, 0x15, 0x52, 0x5a, 0xbf, 0x9a, 0x32, 0x63, 147 0x6d, 0xeb, 0x2a, 0x65, 0x49, 0x9c, 0x80, 0xdc, 148 }; 149 150 static const u8 debug_sk[32] = { 151 0xbd, 0x1a, 0x3c, 0xcd, 0xa6, 0xb8, 0x99, 0x58, 152 0x99, 0xb7, 0x40, 0xeb, 0x7b, 0x60, 0xff, 0x4a, 153 0x50, 0x3f, 0x10, 0xd2, 0xe3, 0xb3, 0xc9, 0x74, 154 0x38, 0x5f, 0xc5, 0xa3, 0xd4, 0xf6, 0x49, 0x3f, 155 }; 156 157 static inline void swap_buf(const u8 *src, u8 *dst, size_t len) 158 { 159 size_t i; 160 161 for (i = 0; i < len; i++) 162 dst[len - 1 - i] = src[i]; 163 } 164 165 /* The following functions map to the LE SC SMP crypto functions 166 * AES-CMAC, f4, f5, f6, g2 and h6. 167 */ 168 169 static int aes_cmac(struct crypto_shash *tfm, const u8 k[16], const u8 *m, 170 size_t len, u8 mac[16]) 171 { 172 uint8_t tmp[16], mac_msb[16], msg_msb[CMAC_MSG_MAX]; 173 int err; 174 175 if (len > CMAC_MSG_MAX) 176 return -EFBIG; 177 178 if (!tfm) { 179 BT_ERR("tfm %p", tfm); 180 return -EINVAL; 181 } 182 183 /* Swap key and message from LSB to MSB */ 184 swap_buf(k, tmp, 16); 185 swap_buf(m, msg_msb, len); 186 187 SMP_DBG("msg (len %zu) %*phN", len, (int) len, m); 188 SMP_DBG("key %16phN", k); 189 190 err = crypto_shash_setkey(tfm, tmp, 16); 191 if (err) { 192 BT_ERR("cipher setkey failed: %d", err); 193 return err; 194 } 195 196 err = crypto_shash_tfm_digest(tfm, msg_msb, len, mac_msb); 197 if (err) { 198 BT_ERR("Hash computation error %d", err); 199 return err; 200 } 201 202 swap_buf(mac_msb, mac, 16); 203 204 SMP_DBG("mac %16phN", mac); 205 206 return 0; 207 } 208 209 static int smp_f4(struct crypto_shash *tfm_cmac, const u8 u[32], 210 const u8 v[32], const u8 x[16], u8 z, u8 res[16]) 211 { 212 u8 m[65]; 213 int err; 214 215 SMP_DBG("u %32phN", u); 216 SMP_DBG("v %32phN", v); 217 SMP_DBG("x %16phN z %02x", x, z); 218 219 m[0] = z; 220 memcpy(m + 1, v, 32); 221 memcpy(m + 33, u, 32); 222 223 err = aes_cmac(tfm_cmac, x, m, sizeof(m), res); 224 if (err) 225 return err; 226 227 SMP_DBG("res %16phN", res); 228 229 return err; 230 } 231 232 static int smp_f5(struct crypto_shash *tfm_cmac, const u8 w[32], 233 const u8 n1[16], const u8 n2[16], const u8 a1[7], 234 const u8 a2[7], u8 mackey[16], u8 ltk[16]) 235 { 236 /* The btle, salt and length "magic" values are as defined in 237 * the SMP section of the Bluetooth core specification. In ASCII 238 * the btle value ends up being 'btle'. The salt is just a 239 * random number whereas length is the value 256 in little 240 * endian format. 241 */ 242 const u8 btle[4] = { 0x65, 0x6c, 0x74, 0x62 }; 243 const u8 salt[16] = { 0xbe, 0x83, 0x60, 0x5a, 0xdb, 0x0b, 0x37, 0x60, 244 0x38, 0xa5, 0xf5, 0xaa, 0x91, 0x83, 0x88, 0x6c }; 245 const u8 length[2] = { 0x00, 0x01 }; 246 u8 m[53], t[16]; 247 int err; 248 249 SMP_DBG("w %32phN", w); 250 SMP_DBG("n1 %16phN n2 %16phN", n1, n2); 251 SMP_DBG("a1 %7phN a2 %7phN", a1, a2); 252 253 err = aes_cmac(tfm_cmac, salt, w, 32, t); 254 if (err) 255 return err; 256 257 SMP_DBG("t %16phN", t); 258 259 memcpy(m, length, 2); 260 memcpy(m + 2, a2, 7); 261 memcpy(m + 9, a1, 7); 262 memcpy(m + 16, n2, 16); 263 memcpy(m + 32, n1, 16); 264 memcpy(m + 48, btle, 4); 265 266 m[52] = 0; /* Counter */ 267 268 err = aes_cmac(tfm_cmac, t, m, sizeof(m), mackey); 269 if (err) 270 return err; 271 272 SMP_DBG("mackey %16phN", mackey); 273 274 m[52] = 1; /* Counter */ 275 276 err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk); 277 if (err) 278 return err; 279 280 SMP_DBG("ltk %16phN", ltk); 281 282 return 0; 283 } 284 285 static int smp_f6(struct crypto_shash *tfm_cmac, const u8 w[16], 286 const u8 n1[16], const u8 n2[16], const u8 r[16], 287 const u8 io_cap[3], const u8 a1[7], const u8 a2[7], 288 u8 res[16]) 289 { 290 u8 m[65]; 291 int err; 292 293 SMP_DBG("w %16phN", w); 294 SMP_DBG("n1 %16phN n2 %16phN", n1, n2); 295 SMP_DBG("r %16phN io_cap %3phN a1 %7phN a2 %7phN", r, io_cap, a1, a2); 296 297 memcpy(m, a2, 7); 298 memcpy(m + 7, a1, 7); 299 memcpy(m + 14, io_cap, 3); 300 memcpy(m + 17, r, 16); 301 memcpy(m + 33, n2, 16); 302 memcpy(m + 49, n1, 16); 303 304 err = aes_cmac(tfm_cmac, w, m, sizeof(m), res); 305 if (err) 306 return err; 307 308 SMP_DBG("res %16phN", res); 309 310 return err; 311 } 312 313 static int smp_g2(struct crypto_shash *tfm_cmac, const u8 u[32], const u8 v[32], 314 const u8 x[16], const u8 y[16], u32 *val) 315 { 316 u8 m[80], tmp[16]; 317 int err; 318 319 SMP_DBG("u %32phN", u); 320 SMP_DBG("v %32phN", v); 321 SMP_DBG("x %16phN y %16phN", x, y); 322 323 memcpy(m, y, 16); 324 memcpy(m + 16, v, 32); 325 memcpy(m + 48, u, 32); 326 327 err = aes_cmac(tfm_cmac, x, m, sizeof(m), tmp); 328 if (err) 329 return err; 330 331 *val = get_unaligned_le32(tmp); 332 *val %= 1000000; 333 334 SMP_DBG("val %06u", *val); 335 336 return 0; 337 } 338 339 static int smp_h6(struct crypto_shash *tfm_cmac, const u8 w[16], 340 const u8 key_id[4], u8 res[16]) 341 { 342 int err; 343 344 SMP_DBG("w %16phN key_id %4phN", w, key_id); 345 346 err = aes_cmac(tfm_cmac, w, key_id, 4, res); 347 if (err) 348 return err; 349 350 SMP_DBG("res %16phN", res); 351 352 return err; 353 } 354 355 static int smp_h7(struct crypto_shash *tfm_cmac, const u8 w[16], 356 const u8 salt[16], u8 res[16]) 357 { 358 int err; 359 360 SMP_DBG("w %16phN salt %16phN", w, salt); 361 362 err = aes_cmac(tfm_cmac, salt, w, 16, res); 363 if (err) 364 return err; 365 366 SMP_DBG("res %16phN", res); 367 368 return err; 369 } 370 371 /* The following functions map to the legacy SMP crypto functions e, c1, 372 * s1 and ah. 373 */ 374 375 static int smp_e(const u8 *k, u8 *r) 376 { 377 struct crypto_aes_ctx ctx; 378 uint8_t tmp[16], data[16]; 379 int err; 380 381 SMP_DBG("k %16phN r %16phN", k, r); 382 383 /* The most significant octet of key corresponds to k[0] */ 384 swap_buf(k, tmp, 16); 385 386 err = aes_expandkey(&ctx, tmp, 16); 387 if (err) { 388 BT_ERR("cipher setkey failed: %d", err); 389 return err; 390 } 391 392 /* Most significant octet of plaintextData corresponds to data[0] */ 393 swap_buf(r, data, 16); 394 395 aes_encrypt(&ctx, data, data); 396 397 /* Most significant octet of encryptedData corresponds to data[0] */ 398 swap_buf(data, r, 16); 399 400 SMP_DBG("r %16phN", r); 401 402 memzero_explicit(&ctx, sizeof(ctx)); 403 return err; 404 } 405 406 static int smp_c1(const u8 k[16], 407 const u8 r[16], const u8 preq[7], const u8 pres[7], u8 _iat, 408 const bdaddr_t *ia, u8 _rat, const bdaddr_t *ra, u8 res[16]) 409 { 410 u8 p1[16], p2[16]; 411 int err; 412 413 SMP_DBG("k %16phN r %16phN", k, r); 414 SMP_DBG("iat %u ia %6phN rat %u ra %6phN", _iat, ia, _rat, ra); 415 SMP_DBG("preq %7phN pres %7phN", preq, pres); 416 417 memset(p1, 0, 16); 418 419 /* p1 = pres || preq || _rat || _iat */ 420 p1[0] = _iat; 421 p1[1] = _rat; 422 memcpy(p1 + 2, preq, 7); 423 memcpy(p1 + 9, pres, 7); 424 425 SMP_DBG("p1 %16phN", p1); 426 427 /* res = r XOR p1 */ 428 crypto_xor_cpy(res, r, p1, sizeof(p1)); 429 430 /* res = e(k, res) */ 431 err = smp_e(k, res); 432 if (err) { 433 BT_ERR("Encrypt data error"); 434 return err; 435 } 436 437 /* p2 = padding || ia || ra */ 438 memcpy(p2, ra, 6); 439 memcpy(p2 + 6, ia, 6); 440 memset(p2 + 12, 0, 4); 441 442 SMP_DBG("p2 %16phN", p2); 443 444 /* res = res XOR p2 */ 445 crypto_xor(res, p2, sizeof(p2)); 446 447 /* res = e(k, res) */ 448 err = smp_e(k, res); 449 if (err) 450 BT_ERR("Encrypt data error"); 451 452 return err; 453 } 454 455 static int smp_s1(const u8 k[16], 456 const u8 r1[16], const u8 r2[16], u8 _r[16]) 457 { 458 int err; 459 460 /* Just least significant octets from r1 and r2 are considered */ 461 memcpy(_r, r2, 8); 462 memcpy(_r + 8, r1, 8); 463 464 err = smp_e(k, _r); 465 if (err) 466 BT_ERR("Encrypt data error"); 467 468 return err; 469 } 470 471 static int smp_ah(const u8 irk[16], const u8 r[3], u8 res[3]) 472 { 473 u8 _res[16]; 474 int err; 475 476 /* r' = padding || r */ 477 memcpy(_res, r, 3); 478 memset(_res + 3, 0, 13); 479 480 err = smp_e(irk, _res); 481 if (err) { 482 BT_ERR("Encrypt error"); 483 return err; 484 } 485 486 /* The output of the random address function ah is: 487 * ah(k, r) = e(k, r') mod 2^24 488 * The output of the security function e is then truncated to 24 bits 489 * by taking the least significant 24 bits of the output of e as the 490 * result of ah. 491 */ 492 memcpy(res, _res, 3); 493 494 return 0; 495 } 496 497 bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16], 498 const bdaddr_t *bdaddr) 499 { 500 struct l2cap_chan *chan = hdev->smp_data; 501 u8 hash[3]; 502 int err; 503 504 if (!chan || !chan->data) 505 return false; 506 507 bt_dev_dbg(hdev, "RPA %pMR IRK %*phN", bdaddr, 16, irk); 508 509 err = smp_ah(irk, &bdaddr->b[3], hash); 510 if (err) 511 return false; 512 513 return !crypto_memneq(bdaddr->b, hash, 3); 514 } 515 516 int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa) 517 { 518 struct l2cap_chan *chan = hdev->smp_data; 519 int err; 520 521 if (!chan || !chan->data) 522 return -EOPNOTSUPP; 523 524 get_random_bytes(&rpa->b[3], 3); 525 526 rpa->b[5] &= 0x3f; /* Clear two most significant bits */ 527 rpa->b[5] |= 0x40; /* Set second most significant bit */ 528 529 err = smp_ah(irk, &rpa->b[3], rpa->b); 530 if (err < 0) 531 return err; 532 533 bt_dev_dbg(hdev, "RPA %pMR", rpa); 534 535 return 0; 536 } 537 538 int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16]) 539 { 540 struct l2cap_chan *chan = hdev->smp_data; 541 struct smp_dev *smp; 542 int err; 543 544 if (!chan || !chan->data) 545 return -EOPNOTSUPP; 546 547 smp = chan->data; 548 549 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { 550 bt_dev_dbg(hdev, "Using debug keys"); 551 err = set_ecdh_privkey(smp->tfm_ecdh, debug_sk); 552 if (err) 553 return err; 554 memcpy(smp->local_pk, debug_pk, 64); 555 smp->debug_key = true; 556 } else { 557 while (true) { 558 /* Generate key pair for Secure Connections */ 559 err = generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk); 560 if (err) 561 return err; 562 563 /* This is unlikely, but we need to check that 564 * we didn't accidentally generate a debug key. 565 */ 566 if (crypto_memneq(smp->local_pk, debug_pk, 64)) 567 break; 568 } 569 smp->debug_key = false; 570 } 571 572 SMP_DBG("OOB Public Key X: %32phN", smp->local_pk); 573 SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32); 574 575 get_random_bytes(smp->local_rand, 16); 576 577 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->local_pk, 578 smp->local_rand, 0, hash); 579 if (err < 0) 580 return err; 581 582 memcpy(rand, smp->local_rand, 16); 583 584 smp->local_oob = true; 585 586 return 0; 587 } 588 589 static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data) 590 { 591 struct l2cap_chan *chan = conn->smp; 592 struct smp_chan *smp; 593 struct kvec iv[2]; 594 struct msghdr msg; 595 596 if (!chan) 597 return; 598 599 bt_dev_dbg(conn->hcon->hdev, "code 0x%2.2x", code); 600 601 iv[0].iov_base = &code; 602 iv[0].iov_len = 1; 603 604 iv[1].iov_base = data; 605 iv[1].iov_len = len; 606 607 memset(&msg, 0, sizeof(msg)); 608 609 iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iv, 2, 1 + len); 610 611 l2cap_chan_send(chan, &msg, 1 + len); 612 613 if (!chan->data) 614 return; 615 616 smp = chan->data; 617 618 cancel_delayed_work_sync(&smp->security_timer); 619 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT); 620 } 621 622 static u8 authreq_to_seclevel(u8 authreq) 623 { 624 if (authreq & SMP_AUTH_MITM) { 625 if (authreq & SMP_AUTH_SC) 626 return BT_SECURITY_FIPS; 627 else 628 return BT_SECURITY_HIGH; 629 } else { 630 return BT_SECURITY_MEDIUM; 631 } 632 } 633 634 static __u8 seclevel_to_authreq(__u8 sec_level) 635 { 636 switch (sec_level) { 637 case BT_SECURITY_FIPS: 638 case BT_SECURITY_HIGH: 639 return SMP_AUTH_MITM | SMP_AUTH_BONDING; 640 case BT_SECURITY_MEDIUM: 641 return SMP_AUTH_BONDING; 642 default: 643 return SMP_AUTH_NONE; 644 } 645 } 646 647 static void build_pairing_cmd(struct l2cap_conn *conn, 648 struct smp_cmd_pairing *req, 649 struct smp_cmd_pairing *rsp, __u8 authreq) 650 { 651 struct l2cap_chan *chan = conn->smp; 652 struct smp_chan *smp = chan->data; 653 struct hci_conn *hcon = conn->hcon; 654 struct hci_dev *hdev = hcon->hdev; 655 u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT; 656 657 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { 658 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 659 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 660 authreq |= SMP_AUTH_BONDING; 661 } else { 662 authreq &= ~SMP_AUTH_BONDING; 663 } 664 665 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) 666 remote_dist |= SMP_DIST_ID_KEY; 667 668 if (hci_dev_test_flag(hdev, HCI_PRIVACY)) 669 local_dist |= SMP_DIST_ID_KEY; 670 671 if (hci_dev_test_flag(hdev, HCI_SC_ENABLED) && 672 (authreq & SMP_AUTH_SC)) { 673 struct oob_data *oob_data; 674 u8 bdaddr_type; 675 676 if (hci_dev_test_flag(hdev, HCI_SSP_ENABLED)) { 677 local_dist |= SMP_DIST_LINK_KEY; 678 remote_dist |= SMP_DIST_LINK_KEY; 679 } 680 681 if (hcon->dst_type == ADDR_LE_DEV_PUBLIC) 682 bdaddr_type = BDADDR_LE_PUBLIC; 683 else 684 bdaddr_type = BDADDR_LE_RANDOM; 685 686 oob_data = hci_find_remote_oob_data(hdev, &hcon->dst, 687 bdaddr_type); 688 if (oob_data && oob_data->present) { 689 set_bit(SMP_FLAG_REMOTE_OOB, &smp->flags); 690 oob_flag = SMP_OOB_PRESENT; 691 memcpy(smp->rr, oob_data->rand256, 16); 692 memcpy(smp->pcnf, oob_data->hash256, 16); 693 SMP_DBG("OOB Remote Confirmation: %16phN", smp->pcnf); 694 SMP_DBG("OOB Remote Random: %16phN", smp->rr); 695 } 696 697 } else { 698 authreq &= ~SMP_AUTH_SC; 699 } 700 701 if (rsp == NULL) { 702 req->io_capability = conn->hcon->io_capability; 703 req->oob_flag = oob_flag; 704 req->max_key_size = hdev->le_max_key_size; 705 req->init_key_dist = local_dist; 706 req->resp_key_dist = remote_dist; 707 req->auth_req = (authreq & AUTH_REQ_MASK(hdev)); 708 709 smp->remote_key_dist = remote_dist; 710 return; 711 } 712 713 rsp->io_capability = conn->hcon->io_capability; 714 rsp->oob_flag = oob_flag; 715 rsp->max_key_size = hdev->le_max_key_size; 716 rsp->init_key_dist = req->init_key_dist & remote_dist; 717 rsp->resp_key_dist = req->resp_key_dist & local_dist; 718 rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev)); 719 720 smp->remote_key_dist = rsp->init_key_dist; 721 } 722 723 static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size) 724 { 725 struct l2cap_chan *chan = conn->smp; 726 struct hci_dev *hdev = conn->hcon->hdev; 727 struct smp_chan *smp = chan->data; 728 729 if (conn->hcon->pending_sec_level == BT_SECURITY_FIPS && 730 max_key_size != SMP_MAX_ENC_KEY_SIZE) 731 return SMP_ENC_KEY_SIZE; 732 733 if (max_key_size > hdev->le_max_key_size || 734 max_key_size < SMP_MIN_ENC_KEY_SIZE) 735 return SMP_ENC_KEY_SIZE; 736 737 smp->enc_key_size = max_key_size; 738 739 return 0; 740 } 741 742 static void smp_chan_destroy(struct l2cap_conn *conn) 743 { 744 struct l2cap_chan *chan = conn->smp; 745 struct smp_chan *smp = chan->data; 746 struct hci_conn *hcon = conn->hcon; 747 bool complete; 748 749 BUG_ON(!smp); 750 751 cancel_delayed_work_sync(&smp->security_timer); 752 753 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags); 754 mgmt_smp_complete(hcon, complete); 755 756 kfree_sensitive(smp->csrk); 757 kfree_sensitive(smp->responder_csrk); 758 kfree_sensitive(smp->link_key); 759 760 crypto_free_shash(smp->tfm_cmac); 761 crypto_free_kpp(smp->tfm_ecdh); 762 763 /* Ensure that we don't leave any debug key around if debug key 764 * support hasn't been explicitly enabled. 765 */ 766 if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG && 767 !hci_dev_test_flag(hcon->hdev, HCI_KEEP_DEBUG_KEYS)) { 768 list_del_rcu(&smp->ltk->list); 769 kfree_rcu(smp->ltk, rcu); 770 smp->ltk = NULL; 771 } 772 773 /* If pairing failed clean up any keys we might have */ 774 if (!complete) { 775 if (smp->ltk) { 776 list_del_rcu(&smp->ltk->list); 777 kfree_rcu(smp->ltk, rcu); 778 } 779 780 if (smp->responder_ltk) { 781 list_del_rcu(&smp->responder_ltk->list); 782 kfree_rcu(smp->responder_ltk, rcu); 783 } 784 785 if (smp->remote_irk) { 786 list_del_rcu(&smp->remote_irk->list); 787 kfree_rcu(smp->remote_irk, rcu); 788 } 789 } 790 791 chan->data = NULL; 792 kfree_sensitive(smp); 793 hci_conn_drop(hcon); 794 } 795 796 static void smp_failure(struct l2cap_conn *conn, u8 reason) 797 { 798 struct hci_conn *hcon = conn->hcon; 799 struct l2cap_chan *chan = conn->smp; 800 801 if (reason) 802 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason), 803 &reason); 804 805 mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE); 806 807 if (chan->data) 808 smp_chan_destroy(conn); 809 } 810 811 #define JUST_WORKS 0x00 812 #define JUST_CFM 0x01 813 #define REQ_PASSKEY 0x02 814 #define CFM_PASSKEY 0x03 815 #define REQ_OOB 0x04 816 #define DSP_PASSKEY 0x05 817 #define OVERLAP 0xFF 818 819 static const u8 gen_method[5][5] = { 820 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 821 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 822 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 823 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM }, 824 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP }, 825 }; 826 827 static const u8 sc_method[5][5] = { 828 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 829 { JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 830 { DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY }, 831 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM }, 832 { DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 833 }; 834 835 static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io) 836 { 837 /* If either side has unknown io_caps, use JUST_CFM (which gets 838 * converted later to JUST_WORKS if we're initiators. 839 */ 840 if (local_io > SMP_IO_KEYBOARD_DISPLAY || 841 remote_io > SMP_IO_KEYBOARD_DISPLAY) 842 return JUST_CFM; 843 844 if (test_bit(SMP_FLAG_SC, &smp->flags)) 845 return sc_method[remote_io][local_io]; 846 847 return gen_method[remote_io][local_io]; 848 } 849 850 static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth, 851 u8 local_io, u8 remote_io) 852 { 853 struct hci_conn *hcon = conn->hcon; 854 struct l2cap_chan *chan = conn->smp; 855 struct smp_chan *smp = chan->data; 856 u32 passkey = 0; 857 int ret; 858 859 /* Initialize key for JUST WORKS */ 860 memset(smp->tk, 0, sizeof(smp->tk)); 861 clear_bit(SMP_FLAG_TK_VALID, &smp->flags); 862 863 bt_dev_dbg(hcon->hdev, "auth:%u lcl:%u rem:%u", auth, local_io, 864 remote_io); 865 866 /* If neither side wants MITM, either "just" confirm an incoming 867 * request or use just-works for outgoing ones. The JUST_CFM 868 * will be converted to JUST_WORKS if necessary later in this 869 * function. If either side has MITM look up the method from the 870 * table. 871 */ 872 if (!(auth & SMP_AUTH_MITM)) 873 smp->method = JUST_CFM; 874 else 875 smp->method = get_auth_method(smp, local_io, remote_io); 876 877 /* Don't confirm locally initiated pairing attempts */ 878 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, 879 &smp->flags)) 880 smp->method = JUST_WORKS; 881 882 /* Don't bother user space with no IO capabilities */ 883 if (smp->method == JUST_CFM && 884 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 885 smp->method = JUST_WORKS; 886 887 /* If Just Works, Continue with Zero TK and ask user-space for 888 * confirmation */ 889 if (smp->method == JUST_WORKS) { 890 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, 891 hcon->type, 892 hcon->dst_type, 893 passkey, 1); 894 if (ret) 895 return ret; 896 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 897 return 0; 898 } 899 900 /* If this function is used for SC -> legacy fallback we 901 * can only recover the just-works case. 902 */ 903 if (test_bit(SMP_FLAG_SC, &smp->flags)) 904 return -EINVAL; 905 906 /* Not Just Works/Confirm results in MITM Authentication */ 907 if (smp->method != JUST_CFM) { 908 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags); 909 if (hcon->pending_sec_level < BT_SECURITY_HIGH) 910 hcon->pending_sec_level = BT_SECURITY_HIGH; 911 } 912 913 /* If both devices have Keyboard-Display I/O, the initiator 914 * Confirms and the responder Enters the passkey. 915 */ 916 if (smp->method == OVERLAP) { 917 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 918 smp->method = CFM_PASSKEY; 919 else 920 smp->method = REQ_PASSKEY; 921 } 922 923 /* Generate random passkey. */ 924 if (smp->method == CFM_PASSKEY) { 925 memset(smp->tk, 0, sizeof(smp->tk)); 926 get_random_bytes(&passkey, sizeof(passkey)); 927 passkey %= 1000000; 928 put_unaligned_le32(passkey, smp->tk); 929 bt_dev_dbg(hcon->hdev, "PassKey: %u", passkey); 930 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 931 } 932 933 if (smp->method == REQ_PASSKEY) 934 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst, 935 hcon->type, hcon->dst_type); 936 else if (smp->method == JUST_CFM) 937 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, 938 hcon->type, hcon->dst_type, 939 passkey, 1); 940 else 941 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst, 942 hcon->type, hcon->dst_type, 943 passkey, 0); 944 945 return ret; 946 } 947 948 static u8 smp_confirm(struct smp_chan *smp) 949 { 950 struct l2cap_conn *conn = smp->conn; 951 struct smp_cmd_pairing_confirm cp; 952 int ret; 953 954 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 955 956 ret = smp_c1(smp->tk, smp->prnd, smp->preq, smp->prsp, 957 conn->hcon->init_addr_type, &conn->hcon->init_addr, 958 conn->hcon->resp_addr_type, &conn->hcon->resp_addr, 959 cp.confirm_val); 960 if (ret) 961 return SMP_UNSPECIFIED; 962 963 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 964 965 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp); 966 967 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 968 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 969 else 970 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 971 972 return 0; 973 } 974 975 static u8 smp_random(struct smp_chan *smp) 976 { 977 struct l2cap_conn *conn = smp->conn; 978 struct hci_conn *hcon = conn->hcon; 979 u8 confirm[16]; 980 int ret; 981 982 bt_dev_dbg(conn->hcon->hdev, "conn %p %s", conn, 983 test_bit(SMP_FLAG_INITIATOR, &smp->flags) ? "initiator" : 984 "responder"); 985 986 ret = smp_c1(smp->tk, smp->rrnd, smp->preq, smp->prsp, 987 hcon->init_addr_type, &hcon->init_addr, 988 hcon->resp_addr_type, &hcon->resp_addr, confirm); 989 if (ret) 990 return SMP_UNSPECIFIED; 991 992 if (crypto_memneq(smp->pcnf, confirm, sizeof(smp->pcnf))) { 993 bt_dev_err(hcon->hdev, "pairing failed " 994 "(confirmation values mismatch)"); 995 return SMP_CONFIRM_FAILED; 996 } 997 998 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 999 u8 stk[16]; 1000 __le64 rand = 0; 1001 __le16 ediv = 0; 1002 1003 smp_s1(smp->tk, smp->rrnd, smp->prnd, stk); 1004 1005 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) 1006 return SMP_UNSPECIFIED; 1007 1008 hci_le_start_enc(hcon, ediv, rand, stk, smp->enc_key_size); 1009 hcon->enc_key_size = smp->enc_key_size; 1010 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); 1011 } else { 1012 u8 stk[16], auth; 1013 __le64 rand = 0; 1014 __le16 ediv = 0; 1015 1016 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 1017 smp->prnd); 1018 1019 smp_s1(smp->tk, smp->prnd, smp->rrnd, stk); 1020 1021 if (hcon->pending_sec_level == BT_SECURITY_HIGH) 1022 auth = 1; 1023 else 1024 auth = 0; 1025 1026 /* Even though there's no _RESPONDER suffix this is the 1027 * responder STK we're adding for later lookup (the initiator 1028 * STK never needs to be stored). 1029 */ 1030 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 1031 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand); 1032 } 1033 1034 return 0; 1035 } 1036 1037 static void smp_notify_keys(struct l2cap_conn *conn) 1038 { 1039 struct l2cap_chan *chan = conn->smp; 1040 struct smp_chan *smp = chan->data; 1041 struct hci_conn *hcon = conn->hcon; 1042 struct hci_dev *hdev = hcon->hdev; 1043 struct smp_cmd_pairing *req = (void *) &smp->preq[1]; 1044 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1]; 1045 bool persistent; 1046 1047 if (hcon->type == ACL_LINK) { 1048 if (hcon->key_type == HCI_LK_DEBUG_COMBINATION) 1049 persistent = false; 1050 else 1051 persistent = !test_bit(HCI_CONN_FLUSH_KEY, 1052 &hcon->flags); 1053 } else { 1054 /* The LTKs, IRKs and CSRKs should be persistent only if 1055 * both sides had the bonding bit set in their 1056 * authentication requests. 1057 */ 1058 persistent = !!((req->auth_req & rsp->auth_req) & 1059 SMP_AUTH_BONDING); 1060 } 1061 1062 if (smp->remote_irk) { 1063 smp->remote_irk->link_type = hcon->type; 1064 mgmt_new_irk(hdev, smp->remote_irk, persistent); 1065 1066 /* Now that user space can be considered to know the 1067 * identity address track the connection based on it 1068 * from now on (assuming this is an LE link). 1069 */ 1070 if (hcon->type == LE_LINK) { 1071 bacpy(&hcon->dst, &smp->remote_irk->bdaddr); 1072 hcon->dst_type = smp->remote_irk->addr_type; 1073 /* Use a short delay to make sure the new address is 1074 * propagated _before_ the channels. 1075 */ 1076 queue_delayed_work(hdev->workqueue, 1077 &conn->id_addr_timer, 1078 ID_ADDR_TIMEOUT); 1079 } 1080 } 1081 1082 if (smp->csrk) { 1083 smp->csrk->link_type = hcon->type; 1084 smp->csrk->bdaddr_type = hcon->dst_type; 1085 bacpy(&smp->csrk->bdaddr, &hcon->dst); 1086 mgmt_new_csrk(hdev, smp->csrk, persistent); 1087 } 1088 1089 if (smp->responder_csrk) { 1090 smp->responder_csrk->link_type = hcon->type; 1091 smp->responder_csrk->bdaddr_type = hcon->dst_type; 1092 bacpy(&smp->responder_csrk->bdaddr, &hcon->dst); 1093 mgmt_new_csrk(hdev, smp->responder_csrk, persistent); 1094 } 1095 1096 if (smp->ltk) { 1097 smp->ltk->link_type = hcon->type; 1098 smp->ltk->bdaddr_type = hcon->dst_type; 1099 bacpy(&smp->ltk->bdaddr, &hcon->dst); 1100 mgmt_new_ltk(hdev, smp->ltk, persistent); 1101 } 1102 1103 if (smp->responder_ltk) { 1104 smp->responder_ltk->link_type = hcon->type; 1105 smp->responder_ltk->bdaddr_type = hcon->dst_type; 1106 bacpy(&smp->responder_ltk->bdaddr, &hcon->dst); 1107 mgmt_new_ltk(hdev, smp->responder_ltk, persistent); 1108 } 1109 1110 if (smp->link_key) { 1111 struct link_key *key; 1112 u8 type; 1113 1114 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags)) 1115 type = HCI_LK_DEBUG_COMBINATION; 1116 else if (hcon->sec_level == BT_SECURITY_FIPS) 1117 type = HCI_LK_AUTH_COMBINATION_P256; 1118 else 1119 type = HCI_LK_UNAUTH_COMBINATION_P256; 1120 1121 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst, 1122 smp->link_key, type, 0, &persistent); 1123 if (key) { 1124 key->link_type = hcon->type; 1125 key->bdaddr_type = hcon->dst_type; 1126 mgmt_new_link_key(hdev, key, persistent); 1127 1128 /* Don't keep debug keys around if the relevant 1129 * flag is not set. 1130 */ 1131 if (!hci_dev_test_flag(hdev, HCI_KEEP_DEBUG_KEYS) && 1132 key->type == HCI_LK_DEBUG_COMBINATION) { 1133 list_del_rcu(&key->list); 1134 kfree_rcu(key, rcu); 1135 } 1136 } 1137 } 1138 } 1139 1140 static void sc_add_ltk(struct smp_chan *smp) 1141 { 1142 struct hci_conn *hcon = smp->conn->hcon; 1143 u8 key_type, auth; 1144 1145 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags)) 1146 key_type = SMP_LTK_P256_DEBUG; 1147 else 1148 key_type = SMP_LTK_P256; 1149 1150 if (hcon->pending_sec_level == BT_SECURITY_FIPS) 1151 auth = 1; 1152 else 1153 auth = 0; 1154 1155 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 1156 key_type, auth, smp->tk, smp->enc_key_size, 1157 0, 0); 1158 } 1159 1160 static void sc_generate_link_key(struct smp_chan *smp) 1161 { 1162 /* From core spec. Spells out in ASCII as 'lebr'. */ 1163 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c }; 1164 1165 smp->link_key = kzalloc(16, GFP_KERNEL); 1166 if (!smp->link_key) 1167 return; 1168 1169 if (test_bit(SMP_FLAG_CT2, &smp->flags)) { 1170 /* SALT = 0x000000000000000000000000746D7031 */ 1171 const u8 salt[16] = { 0x31, 0x70, 0x6d, 0x74 }; 1172 1173 if (smp_h7(smp->tfm_cmac, smp->tk, salt, smp->link_key)) { 1174 kfree_sensitive(smp->link_key); 1175 smp->link_key = NULL; 1176 return; 1177 } 1178 } else { 1179 /* From core spec. Spells out in ASCII as 'tmp1'. */ 1180 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 }; 1181 1182 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) { 1183 kfree_sensitive(smp->link_key); 1184 smp->link_key = NULL; 1185 return; 1186 } 1187 } 1188 1189 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) { 1190 kfree_sensitive(smp->link_key); 1191 smp->link_key = NULL; 1192 return; 1193 } 1194 } 1195 1196 static void smp_allow_key_dist(struct smp_chan *smp) 1197 { 1198 /* Allow the first expected phase 3 PDU. The rest of the PDUs 1199 * will be allowed in each PDU handler to ensure we receive 1200 * them in the correct order. 1201 */ 1202 if (smp->remote_key_dist & SMP_DIST_ENC_KEY) 1203 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO); 1204 else if (smp->remote_key_dist & SMP_DIST_ID_KEY) 1205 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); 1206 else if (smp->remote_key_dist & SMP_DIST_SIGN) 1207 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 1208 } 1209 1210 static void sc_generate_ltk(struct smp_chan *smp) 1211 { 1212 /* From core spec. Spells out in ASCII as 'brle'. */ 1213 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 }; 1214 struct hci_conn *hcon = smp->conn->hcon; 1215 struct hci_dev *hdev = hcon->hdev; 1216 struct link_key *key; 1217 1218 key = hci_find_link_key(hdev, &hcon->dst); 1219 if (!key) { 1220 bt_dev_err(hdev, "no Link Key found to generate LTK"); 1221 return; 1222 } 1223 1224 if (key->type == HCI_LK_DEBUG_COMBINATION) 1225 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1226 1227 if (test_bit(SMP_FLAG_CT2, &smp->flags)) { 1228 /* SALT = 0x000000000000000000000000746D7032 */ 1229 const u8 salt[16] = { 0x32, 0x70, 0x6d, 0x74 }; 1230 1231 if (smp_h7(smp->tfm_cmac, key->val, salt, smp->tk)) 1232 return; 1233 } else { 1234 /* From core spec. Spells out in ASCII as 'tmp2'. */ 1235 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 }; 1236 1237 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk)) 1238 return; 1239 } 1240 1241 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk)) 1242 return; 1243 1244 sc_add_ltk(smp); 1245 } 1246 1247 static void smp_distribute_keys(struct smp_chan *smp) 1248 { 1249 struct smp_cmd_pairing *req, *rsp; 1250 struct l2cap_conn *conn = smp->conn; 1251 struct hci_conn *hcon = conn->hcon; 1252 struct hci_dev *hdev = hcon->hdev; 1253 __u8 *keydist; 1254 1255 bt_dev_dbg(hdev, "conn %p", conn); 1256 1257 rsp = (void *) &smp->prsp[1]; 1258 1259 /* The responder sends its keys first */ 1260 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags) && 1261 (smp->remote_key_dist & KEY_DIST_MASK)) { 1262 smp_allow_key_dist(smp); 1263 return; 1264 } 1265 1266 req = (void *) &smp->preq[1]; 1267 1268 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 1269 keydist = &rsp->init_key_dist; 1270 *keydist &= req->init_key_dist; 1271 } else { 1272 keydist = &rsp->resp_key_dist; 1273 *keydist &= req->resp_key_dist; 1274 } 1275 1276 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1277 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY)) 1278 sc_generate_link_key(smp); 1279 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY)) 1280 sc_generate_ltk(smp); 1281 1282 /* Clear the keys which are generated but not distributed */ 1283 *keydist &= ~SMP_SC_NO_DIST; 1284 } 1285 1286 bt_dev_dbg(hdev, "keydist 0x%x", *keydist); 1287 1288 if (*keydist & SMP_DIST_ENC_KEY) { 1289 struct smp_cmd_encrypt_info enc; 1290 struct smp_cmd_initiator_ident ident; 1291 struct smp_ltk *ltk; 1292 u8 authenticated; 1293 __le16 ediv; 1294 __le64 rand; 1295 1296 /* Make sure we generate only the significant amount of 1297 * bytes based on the encryption key size, and set the rest 1298 * of the value to zeroes. 1299 */ 1300 get_random_bytes(enc.ltk, smp->enc_key_size); 1301 memset(enc.ltk + smp->enc_key_size, 0, 1302 sizeof(enc.ltk) - smp->enc_key_size); 1303 1304 get_random_bytes(&ediv, sizeof(ediv)); 1305 get_random_bytes(&rand, sizeof(rand)); 1306 1307 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc); 1308 1309 authenticated = hcon->sec_level == BT_SECURITY_HIGH; 1310 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, 1311 SMP_LTK_RESPONDER, authenticated, enc.ltk, 1312 smp->enc_key_size, ediv, rand); 1313 smp->responder_ltk = ltk; 1314 1315 ident.ediv = ediv; 1316 ident.rand = rand; 1317 1318 smp_send_cmd(conn, SMP_CMD_INITIATOR_IDENT, sizeof(ident), 1319 &ident); 1320 1321 *keydist &= ~SMP_DIST_ENC_KEY; 1322 } 1323 1324 if (*keydist & SMP_DIST_ID_KEY) { 1325 struct smp_cmd_ident_addr_info addrinfo; 1326 struct smp_cmd_ident_info idinfo; 1327 1328 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk)); 1329 1330 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo); 1331 1332 /* The hci_conn contains the local identity address 1333 * after the connection has been established. 1334 * 1335 * This is true even when the connection has been 1336 * established using a resolvable random address. 1337 */ 1338 bacpy(&addrinfo.bdaddr, &hcon->src); 1339 addrinfo.addr_type = hcon->src_type; 1340 1341 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo), 1342 &addrinfo); 1343 1344 *keydist &= ~SMP_DIST_ID_KEY; 1345 } 1346 1347 if (*keydist & SMP_DIST_SIGN) { 1348 struct smp_cmd_sign_info sign; 1349 struct smp_csrk *csrk; 1350 1351 /* Generate a new random key */ 1352 get_random_bytes(sign.csrk, sizeof(sign.csrk)); 1353 1354 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); 1355 if (csrk) { 1356 if (hcon->sec_level > BT_SECURITY_MEDIUM) 1357 csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED; 1358 else 1359 csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED; 1360 memcpy(csrk->val, sign.csrk, sizeof(csrk->val)); 1361 } 1362 smp->responder_csrk = csrk; 1363 1364 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign); 1365 1366 *keydist &= ~SMP_DIST_SIGN; 1367 } 1368 1369 /* If there are still keys to be received wait for them */ 1370 if (smp->remote_key_dist & KEY_DIST_MASK) { 1371 smp_allow_key_dist(smp); 1372 return; 1373 } 1374 1375 set_bit(SMP_FLAG_COMPLETE, &smp->flags); 1376 smp_notify_keys(conn); 1377 1378 smp_chan_destroy(conn); 1379 } 1380 1381 static void smp_timeout(struct work_struct *work) 1382 { 1383 struct smp_chan *smp = container_of(work, struct smp_chan, 1384 security_timer.work); 1385 struct l2cap_conn *conn = smp->conn; 1386 1387 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 1388 1389 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM); 1390 } 1391 1392 static struct smp_chan *smp_chan_create(struct l2cap_conn *conn) 1393 { 1394 struct hci_conn *hcon = conn->hcon; 1395 struct l2cap_chan *chan = conn->smp; 1396 struct smp_chan *smp; 1397 1398 smp = kzalloc(sizeof(*smp), GFP_ATOMIC); 1399 if (!smp) 1400 return NULL; 1401 1402 smp->tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 1403 if (IS_ERR(smp->tfm_cmac)) { 1404 bt_dev_err(hcon->hdev, "Unable to create CMAC crypto context"); 1405 goto zfree_smp; 1406 } 1407 1408 smp->tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0); 1409 if (IS_ERR(smp->tfm_ecdh)) { 1410 bt_dev_err(hcon->hdev, "Unable to create ECDH crypto context"); 1411 goto free_shash; 1412 } 1413 1414 smp->conn = conn; 1415 chan->data = smp; 1416 1417 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL); 1418 1419 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout); 1420 1421 hci_conn_hold(hcon); 1422 1423 return smp; 1424 1425 free_shash: 1426 crypto_free_shash(smp->tfm_cmac); 1427 zfree_smp: 1428 kfree_sensitive(smp); 1429 return NULL; 1430 } 1431 1432 static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16]) 1433 { 1434 struct hci_conn *hcon = smp->conn->hcon; 1435 u8 *na, *nb, a[7], b[7]; 1436 1437 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 1438 na = smp->prnd; 1439 nb = smp->rrnd; 1440 } else { 1441 na = smp->rrnd; 1442 nb = smp->prnd; 1443 } 1444 1445 memcpy(a, &hcon->init_addr, 6); 1446 memcpy(b, &hcon->resp_addr, 6); 1447 a[6] = hcon->init_addr_type; 1448 b[6] = hcon->resp_addr_type; 1449 1450 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk); 1451 } 1452 1453 static void sc_dhkey_check(struct smp_chan *smp) 1454 { 1455 struct hci_conn *hcon = smp->conn->hcon; 1456 struct smp_cmd_dhkey_check check; 1457 u8 a[7], b[7], *local_addr, *remote_addr; 1458 u8 io_cap[3], r[16]; 1459 1460 memcpy(a, &hcon->init_addr, 6); 1461 memcpy(b, &hcon->resp_addr, 6); 1462 a[6] = hcon->init_addr_type; 1463 b[6] = hcon->resp_addr_type; 1464 1465 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 1466 local_addr = a; 1467 remote_addr = b; 1468 memcpy(io_cap, &smp->preq[1], 3); 1469 } else { 1470 local_addr = b; 1471 remote_addr = a; 1472 memcpy(io_cap, &smp->prsp[1], 3); 1473 } 1474 1475 memset(r, 0, sizeof(r)); 1476 1477 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 1478 put_unaligned_le32(hcon->passkey_notify, r); 1479 1480 if (smp->method == REQ_OOB) 1481 memcpy(r, smp->rr, 16); 1482 1483 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap, 1484 local_addr, remote_addr, check.e); 1485 1486 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check); 1487 } 1488 1489 static u8 sc_passkey_send_confirm(struct smp_chan *smp) 1490 { 1491 struct l2cap_conn *conn = smp->conn; 1492 struct hci_conn *hcon = conn->hcon; 1493 struct smp_cmd_pairing_confirm cfm; 1494 u8 r; 1495 1496 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); 1497 r |= 0x80; 1498 1499 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1500 1501 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r, 1502 cfm.confirm_val)) 1503 return SMP_UNSPECIFIED; 1504 1505 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); 1506 1507 return 0; 1508 } 1509 1510 static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op) 1511 { 1512 struct l2cap_conn *conn = smp->conn; 1513 struct hci_conn *hcon = conn->hcon; 1514 struct hci_dev *hdev = hcon->hdev; 1515 u8 cfm[16], r; 1516 1517 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */ 1518 if (smp->passkey_round >= 20) 1519 return 0; 1520 1521 switch (smp_op) { 1522 case SMP_CMD_PAIRING_RANDOM: 1523 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); 1524 r |= 0x80; 1525 1526 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, 1527 smp->rrnd, r, cfm)) 1528 return SMP_UNSPECIFIED; 1529 1530 if (crypto_memneq(smp->pcnf, cfm, 16)) 1531 return SMP_CONFIRM_FAILED; 1532 1533 smp->passkey_round++; 1534 1535 if (smp->passkey_round == 20) { 1536 /* Generate MacKey and LTK */ 1537 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk)) 1538 return SMP_UNSPECIFIED; 1539 } 1540 1541 /* The round is only complete when the initiator 1542 * receives pairing random. 1543 */ 1544 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 1545 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 1546 sizeof(smp->prnd), smp->prnd); 1547 if (smp->passkey_round == 20) 1548 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1549 else 1550 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1551 return 0; 1552 } 1553 1554 /* Start the next round */ 1555 if (smp->passkey_round != 20) 1556 return sc_passkey_round(smp, 0); 1557 1558 /* Passkey rounds are complete - start DHKey Check */ 1559 sc_dhkey_check(smp); 1560 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1561 1562 break; 1563 1564 case SMP_CMD_PAIRING_CONFIRM: 1565 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { 1566 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 1567 return 0; 1568 } 1569 1570 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 1571 1572 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 1573 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 1574 sizeof(smp->prnd), smp->prnd); 1575 return 0; 1576 } 1577 1578 return sc_passkey_send_confirm(smp); 1579 1580 case SMP_CMD_PUBLIC_KEY: 1581 default: 1582 /* Initiating device starts the round */ 1583 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 1584 return 0; 1585 1586 bt_dev_dbg(hdev, "Starting passkey round %u", 1587 smp->passkey_round + 1); 1588 1589 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1590 1591 return sc_passkey_send_confirm(smp); 1592 } 1593 1594 return 0; 1595 } 1596 1597 static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey) 1598 { 1599 struct l2cap_conn *conn = smp->conn; 1600 struct hci_conn *hcon = conn->hcon; 1601 u8 smp_op; 1602 1603 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags); 1604 1605 switch (mgmt_op) { 1606 case MGMT_OP_USER_PASSKEY_NEG_REPLY: 1607 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED); 1608 return 0; 1609 case MGMT_OP_USER_CONFIRM_NEG_REPLY: 1610 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED); 1611 return 0; 1612 case MGMT_OP_USER_PASSKEY_REPLY: 1613 hcon->passkey_notify = le32_to_cpu(passkey); 1614 smp->passkey_round = 0; 1615 1616 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) 1617 smp_op = SMP_CMD_PAIRING_CONFIRM; 1618 else 1619 smp_op = 0; 1620 1621 if (sc_passkey_round(smp, smp_op)) 1622 return -EIO; 1623 1624 return 0; 1625 } 1626 1627 /* Initiator sends DHKey check first */ 1628 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 1629 sc_dhkey_check(smp); 1630 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1631 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) { 1632 sc_dhkey_check(smp); 1633 sc_add_ltk(smp); 1634 } 1635 1636 return 0; 1637 } 1638 1639 int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey) 1640 { 1641 struct l2cap_conn *conn = hcon->l2cap_data; 1642 struct l2cap_chan *chan; 1643 struct smp_chan *smp; 1644 u32 value; 1645 int err; 1646 1647 if (!conn) 1648 return -ENOTCONN; 1649 1650 bt_dev_dbg(conn->hcon->hdev, ""); 1651 1652 chan = conn->smp; 1653 if (!chan) 1654 return -ENOTCONN; 1655 1656 l2cap_chan_lock(chan); 1657 if (!chan->data) { 1658 err = -ENOTCONN; 1659 goto unlock; 1660 } 1661 1662 smp = chan->data; 1663 1664 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1665 err = sc_user_reply(smp, mgmt_op, passkey); 1666 goto unlock; 1667 } 1668 1669 switch (mgmt_op) { 1670 case MGMT_OP_USER_PASSKEY_REPLY: 1671 value = le32_to_cpu(passkey); 1672 memset(smp->tk, 0, sizeof(smp->tk)); 1673 bt_dev_dbg(conn->hcon->hdev, "PassKey: %u", value); 1674 put_unaligned_le32(value, smp->tk); 1675 fallthrough; 1676 case MGMT_OP_USER_CONFIRM_REPLY: 1677 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 1678 break; 1679 case MGMT_OP_USER_PASSKEY_NEG_REPLY: 1680 case MGMT_OP_USER_CONFIRM_NEG_REPLY: 1681 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); 1682 err = 0; 1683 goto unlock; 1684 default: 1685 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); 1686 err = -EOPNOTSUPP; 1687 goto unlock; 1688 } 1689 1690 err = 0; 1691 1692 /* If it is our turn to send Pairing Confirm, do so now */ 1693 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) { 1694 u8 rsp = smp_confirm(smp); 1695 if (rsp) 1696 smp_failure(conn, rsp); 1697 } 1698 1699 unlock: 1700 l2cap_chan_unlock(chan); 1701 return err; 1702 } 1703 1704 static void build_bredr_pairing_cmd(struct smp_chan *smp, 1705 struct smp_cmd_pairing *req, 1706 struct smp_cmd_pairing *rsp) 1707 { 1708 struct l2cap_conn *conn = smp->conn; 1709 struct hci_dev *hdev = conn->hcon->hdev; 1710 u8 local_dist = 0, remote_dist = 0; 1711 1712 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { 1713 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 1714 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 1715 } 1716 1717 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) 1718 remote_dist |= SMP_DIST_ID_KEY; 1719 1720 if (hci_dev_test_flag(hdev, HCI_PRIVACY)) 1721 local_dist |= SMP_DIST_ID_KEY; 1722 1723 if (!rsp) { 1724 memset(req, 0, sizeof(*req)); 1725 1726 req->auth_req = SMP_AUTH_CT2; 1727 req->init_key_dist = local_dist; 1728 req->resp_key_dist = remote_dist; 1729 req->max_key_size = conn->hcon->enc_key_size; 1730 1731 smp->remote_key_dist = remote_dist; 1732 1733 return; 1734 } 1735 1736 memset(rsp, 0, sizeof(*rsp)); 1737 1738 rsp->auth_req = SMP_AUTH_CT2; 1739 rsp->max_key_size = conn->hcon->enc_key_size; 1740 rsp->init_key_dist = req->init_key_dist & remote_dist; 1741 rsp->resp_key_dist = req->resp_key_dist & local_dist; 1742 1743 smp->remote_key_dist = rsp->init_key_dist; 1744 } 1745 1746 static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) 1747 { 1748 struct smp_cmd_pairing rsp, *req = (void *) skb->data; 1749 struct l2cap_chan *chan = conn->smp; 1750 struct hci_dev *hdev = conn->hcon->hdev; 1751 struct smp_chan *smp = chan->data; 1752 u8 key_size, auth, sec_level; 1753 int ret; 1754 1755 bt_dev_dbg(hdev, "conn %p", conn); 1756 1757 if (skb->len < sizeof(*req)) 1758 return SMP_INVALID_PARAMS; 1759 1760 if (smp && test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 1761 return SMP_CMD_NOTSUPP; 1762 1763 if (!smp) { 1764 smp = smp_chan_create(conn); 1765 if (!smp) 1766 return SMP_UNSPECIFIED; 1767 } 1768 1769 /* We didn't start the pairing, so match remote */ 1770 auth = req->auth_req & AUTH_REQ_MASK(hdev); 1771 1772 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && 1773 (auth & SMP_AUTH_BONDING)) 1774 return SMP_PAIRING_NOTSUPP; 1775 1776 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 1777 return SMP_AUTH_REQUIREMENTS; 1778 1779 smp->preq[0] = SMP_CMD_PAIRING_REQ; 1780 memcpy(&smp->preq[1], req, sizeof(*req)); 1781 skb_pull(skb, sizeof(*req)); 1782 1783 /* If the remote side's OOB flag is set it means it has 1784 * successfully received our local OOB data - therefore set the 1785 * flag to indicate that local OOB is in use. 1786 */ 1787 if (req->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob) 1788 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); 1789 1790 /* SMP over BR/EDR requires special treatment */ 1791 if (conn->hcon->type == ACL_LINK) { 1792 /* We must have a BR/EDR SC link */ 1793 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) && 1794 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 1795 return SMP_CROSS_TRANSP_NOT_ALLOWED; 1796 1797 set_bit(SMP_FLAG_SC, &smp->flags); 1798 1799 build_bredr_pairing_cmd(smp, req, &rsp); 1800 1801 if (req->auth_req & SMP_AUTH_CT2) 1802 set_bit(SMP_FLAG_CT2, &smp->flags); 1803 1804 key_size = min(req->max_key_size, rsp.max_key_size); 1805 if (check_enc_key_size(conn, key_size)) 1806 return SMP_ENC_KEY_SIZE; 1807 1808 /* Clear bits which are generated but not distributed */ 1809 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1810 1811 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1812 memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); 1813 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); 1814 1815 smp_distribute_keys(smp); 1816 return 0; 1817 } 1818 1819 build_pairing_cmd(conn, req, &rsp, auth); 1820 1821 if (rsp.auth_req & SMP_AUTH_SC) { 1822 set_bit(SMP_FLAG_SC, &smp->flags); 1823 1824 if (rsp.auth_req & SMP_AUTH_CT2) 1825 set_bit(SMP_FLAG_CT2, &smp->flags); 1826 } 1827 1828 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 1829 sec_level = BT_SECURITY_MEDIUM; 1830 else 1831 sec_level = authreq_to_seclevel(auth); 1832 1833 if (sec_level > conn->hcon->pending_sec_level) 1834 conn->hcon->pending_sec_level = sec_level; 1835 1836 /* If we need MITM check that it can be achieved */ 1837 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { 1838 u8 method; 1839 1840 method = get_auth_method(smp, conn->hcon->io_capability, 1841 req->io_capability); 1842 if (method == JUST_WORKS || method == JUST_CFM) 1843 return SMP_AUTH_REQUIREMENTS; 1844 } 1845 1846 key_size = min(req->max_key_size, rsp.max_key_size); 1847 if (check_enc_key_size(conn, key_size)) 1848 return SMP_ENC_KEY_SIZE; 1849 1850 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1851 1852 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1853 memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); 1854 1855 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); 1856 1857 clear_bit(SMP_FLAG_INITIATOR, &smp->flags); 1858 1859 /* Strictly speaking we shouldn't allow Pairing Confirm for the 1860 * SC case, however some implementations incorrectly copy RFU auth 1861 * req bits from our security request, which may create a false 1862 * positive SC enablement. 1863 */ 1864 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1865 1866 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1867 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); 1868 /* Clear bits which are generated but not distributed */ 1869 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1870 /* Wait for Public Key from Initiating Device */ 1871 return 0; 1872 } 1873 1874 /* Request setup of TK */ 1875 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability); 1876 if (ret) 1877 return SMP_UNSPECIFIED; 1878 1879 return 0; 1880 } 1881 1882 static u8 sc_send_public_key(struct smp_chan *smp) 1883 { 1884 struct hci_dev *hdev = smp->conn->hcon->hdev; 1885 1886 bt_dev_dbg(hdev, ""); 1887 1888 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { 1889 struct l2cap_chan *chan = hdev->smp_data; 1890 struct smp_dev *smp_dev; 1891 1892 if (!chan || !chan->data) 1893 return SMP_UNSPECIFIED; 1894 1895 smp_dev = chan->data; 1896 1897 memcpy(smp->local_pk, smp_dev->local_pk, 64); 1898 memcpy(smp->lr, smp_dev->local_rand, 16); 1899 1900 if (smp_dev->debug_key) 1901 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1902 1903 goto done; 1904 } 1905 1906 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { 1907 bt_dev_dbg(hdev, "Using debug keys"); 1908 if (set_ecdh_privkey(smp->tfm_ecdh, debug_sk)) 1909 return SMP_UNSPECIFIED; 1910 memcpy(smp->local_pk, debug_pk, 64); 1911 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1912 } else { 1913 while (true) { 1914 /* Generate key pair for Secure Connections */ 1915 if (generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk)) 1916 return SMP_UNSPECIFIED; 1917 1918 /* This is unlikely, but we need to check that 1919 * we didn't accidentally generate a debug key. 1920 */ 1921 if (crypto_memneq(smp->local_pk, debug_pk, 64)) 1922 break; 1923 } 1924 } 1925 1926 done: 1927 SMP_DBG("Local Public Key X: %32phN", smp->local_pk); 1928 SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32); 1929 1930 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk); 1931 1932 return 0; 1933 } 1934 1935 static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) 1936 { 1937 struct smp_cmd_pairing *req, *rsp = (void *) skb->data; 1938 struct l2cap_chan *chan = conn->smp; 1939 struct smp_chan *smp = chan->data; 1940 struct hci_dev *hdev = conn->hcon->hdev; 1941 u8 key_size, auth; 1942 int ret; 1943 1944 bt_dev_dbg(hdev, "conn %p", conn); 1945 1946 if (skb->len < sizeof(*rsp)) 1947 return SMP_INVALID_PARAMS; 1948 1949 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 1950 return SMP_CMD_NOTSUPP; 1951 1952 skb_pull(skb, sizeof(*rsp)); 1953 1954 req = (void *) &smp->preq[1]; 1955 1956 key_size = min(req->max_key_size, rsp->max_key_size); 1957 if (check_enc_key_size(conn, key_size)) 1958 return SMP_ENC_KEY_SIZE; 1959 1960 auth = rsp->auth_req & AUTH_REQ_MASK(hdev); 1961 1962 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 1963 return SMP_AUTH_REQUIREMENTS; 1964 1965 /* If the remote side's OOB flag is set it means it has 1966 * successfully received our local OOB data - therefore set the 1967 * flag to indicate that local OOB is in use. 1968 */ 1969 if (rsp->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob) 1970 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); 1971 1972 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1973 memcpy(&smp->prsp[1], rsp, sizeof(*rsp)); 1974 1975 /* Update remote key distribution in case the remote cleared 1976 * some bits that we had enabled in our request. 1977 */ 1978 smp->remote_key_dist &= rsp->resp_key_dist; 1979 1980 if ((req->auth_req & SMP_AUTH_CT2) && (auth & SMP_AUTH_CT2)) 1981 set_bit(SMP_FLAG_CT2, &smp->flags); 1982 1983 /* For BR/EDR this means we're done and can start phase 3 */ 1984 if (conn->hcon->type == ACL_LINK) { 1985 /* Clear bits which are generated but not distributed */ 1986 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1987 smp_distribute_keys(smp); 1988 return 0; 1989 } 1990 1991 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC)) 1992 set_bit(SMP_FLAG_SC, &smp->flags); 1993 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH) 1994 conn->hcon->pending_sec_level = BT_SECURITY_HIGH; 1995 1996 /* If we need MITM check that it can be achieved */ 1997 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { 1998 u8 method; 1999 2000 method = get_auth_method(smp, req->io_capability, 2001 rsp->io_capability); 2002 if (method == JUST_WORKS || method == JUST_CFM) 2003 return SMP_AUTH_REQUIREMENTS; 2004 } 2005 2006 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 2007 2008 /* Update remote key distribution in case the remote cleared 2009 * some bits that we had enabled in our request. 2010 */ 2011 smp->remote_key_dist &= rsp->resp_key_dist; 2012 2013 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 2014 /* Clear bits which are generated but not distributed */ 2015 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 2016 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); 2017 return sc_send_public_key(smp); 2018 } 2019 2020 auth |= req->auth_req; 2021 2022 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability); 2023 if (ret) 2024 return SMP_UNSPECIFIED; 2025 2026 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 2027 2028 /* Can't compose response until we have been confirmed */ 2029 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) 2030 return smp_confirm(smp); 2031 2032 return 0; 2033 } 2034 2035 static u8 sc_check_confirm(struct smp_chan *smp) 2036 { 2037 struct l2cap_conn *conn = smp->conn; 2038 2039 bt_dev_dbg(conn->hcon->hdev, ""); 2040 2041 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2042 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM); 2043 2044 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2045 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2046 smp->prnd); 2047 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2048 } 2049 2050 return 0; 2051 } 2052 2053 /* Work-around for some implementations that incorrectly copy RFU bits 2054 * from our security request and thereby create the impression that 2055 * we're doing SC when in fact the remote doesn't support it. 2056 */ 2057 static int fixup_sc_false_positive(struct smp_chan *smp) 2058 { 2059 struct l2cap_conn *conn = smp->conn; 2060 struct hci_conn *hcon = conn->hcon; 2061 struct hci_dev *hdev = hcon->hdev; 2062 struct smp_cmd_pairing *req, *rsp; 2063 u8 auth; 2064 2065 /* The issue is only observed when we're in responder role */ 2066 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2067 return SMP_UNSPECIFIED; 2068 2069 if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) { 2070 bt_dev_err(hdev, "refusing legacy fallback in SC-only mode"); 2071 return SMP_UNSPECIFIED; 2072 } 2073 2074 bt_dev_err(hdev, "trying to fall back to legacy SMP"); 2075 2076 req = (void *) &smp->preq[1]; 2077 rsp = (void *) &smp->prsp[1]; 2078 2079 /* Rebuild key dist flags which may have been cleared for SC */ 2080 smp->remote_key_dist = (req->init_key_dist & rsp->resp_key_dist); 2081 2082 auth = req->auth_req & AUTH_REQ_MASK(hdev); 2083 2084 if (tk_request(conn, 0, auth, rsp->io_capability, req->io_capability)) { 2085 bt_dev_err(hdev, "failed to fall back to legacy SMP"); 2086 return SMP_UNSPECIFIED; 2087 } 2088 2089 clear_bit(SMP_FLAG_SC, &smp->flags); 2090 2091 return 0; 2092 } 2093 2094 static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb) 2095 { 2096 struct l2cap_chan *chan = conn->smp; 2097 struct smp_chan *smp = chan->data; 2098 struct hci_conn *hcon = conn->hcon; 2099 struct hci_dev *hdev = hcon->hdev; 2100 2101 bt_dev_dbg(hdev, "conn %p %s", conn, 2102 test_bit(SMP_FLAG_INITIATOR, &smp->flags) ? "initiator" : 2103 "responder"); 2104 2105 if (skb->len < sizeof(smp->pcnf)) 2106 return SMP_INVALID_PARAMS; 2107 2108 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf)); 2109 skb_pull(skb, sizeof(smp->pcnf)); 2110 2111 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 2112 int ret; 2113 2114 /* Public Key exchange must happen before any other steps */ 2115 if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags)) 2116 return sc_check_confirm(smp); 2117 2118 bt_dev_err(hdev, "Unexpected SMP Pairing Confirm"); 2119 2120 ret = fixup_sc_false_positive(smp); 2121 if (ret) 2122 return ret; 2123 } 2124 2125 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2126 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2127 smp->prnd); 2128 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2129 return 0; 2130 } 2131 2132 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) 2133 return smp_confirm(smp); 2134 2135 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 2136 2137 return 0; 2138 } 2139 2140 static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb) 2141 { 2142 struct l2cap_chan *chan = conn->smp; 2143 struct smp_chan *smp = chan->data; 2144 struct hci_conn *hcon = conn->hcon; 2145 u8 *pkax, *pkbx, *na, *nb, confirm_hint; 2146 u32 passkey; 2147 int err; 2148 2149 bt_dev_dbg(hcon->hdev, "conn %p", conn); 2150 2151 if (skb->len < sizeof(smp->rrnd)) 2152 return SMP_INVALID_PARAMS; 2153 2154 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd)); 2155 skb_pull(skb, sizeof(smp->rrnd)); 2156 2157 if (!test_bit(SMP_FLAG_SC, &smp->flags)) 2158 return smp_random(smp); 2159 2160 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2161 pkax = smp->local_pk; 2162 pkbx = smp->remote_pk; 2163 na = smp->prnd; 2164 nb = smp->rrnd; 2165 } else { 2166 pkax = smp->remote_pk; 2167 pkbx = smp->local_pk; 2168 na = smp->rrnd; 2169 nb = smp->prnd; 2170 } 2171 2172 if (smp->method == REQ_OOB) { 2173 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2174 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 2175 sizeof(smp->prnd), smp->prnd); 2176 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2177 goto mackey_and_ltk; 2178 } 2179 2180 /* Passkey entry has special treatment */ 2181 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2182 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM); 2183 2184 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2185 u8 cfm[16]; 2186 2187 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, 2188 smp->rrnd, 0, cfm); 2189 if (err) 2190 return SMP_UNSPECIFIED; 2191 2192 if (crypto_memneq(smp->pcnf, cfm, 16)) 2193 return SMP_CONFIRM_FAILED; 2194 } else { 2195 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2196 smp->prnd); 2197 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2198 2199 /* Only Just-Works pairing requires extra checks */ 2200 if (smp->method != JUST_WORKS) 2201 goto mackey_and_ltk; 2202 2203 /* If there already exists long term key in local host, leave 2204 * the decision to user space since the remote device could 2205 * be legitimate or malicious. 2206 */ 2207 if (hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 2208 hcon->role)) { 2209 /* Set passkey to 0. The value can be any number since 2210 * it'll be ignored anyway. 2211 */ 2212 passkey = 0; 2213 confirm_hint = 1; 2214 goto confirm; 2215 } 2216 } 2217 2218 mackey_and_ltk: 2219 /* Generate MacKey and LTK */ 2220 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk); 2221 if (err) 2222 return SMP_UNSPECIFIED; 2223 2224 if (smp->method == REQ_OOB) { 2225 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2226 sc_dhkey_check(smp); 2227 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2228 } 2229 return 0; 2230 } 2231 2232 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey); 2233 if (err) 2234 return SMP_UNSPECIFIED; 2235 2236 confirm_hint = 0; 2237 2238 confirm: 2239 if (smp->method == JUST_WORKS) 2240 confirm_hint = 1; 2241 2242 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type, 2243 hcon->dst_type, passkey, confirm_hint); 2244 if (err) 2245 return SMP_UNSPECIFIED; 2246 2247 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 2248 2249 return 0; 2250 } 2251 2252 static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level) 2253 { 2254 struct smp_ltk *key; 2255 struct hci_conn *hcon = conn->hcon; 2256 2257 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role); 2258 if (!key) 2259 return false; 2260 2261 if (smp_ltk_sec_level(key) < sec_level) 2262 return false; 2263 2264 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) 2265 return true; 2266 2267 hci_le_start_enc(hcon, key->ediv, key->rand, key->val, key->enc_size); 2268 hcon->enc_key_size = key->enc_size; 2269 2270 /* We never store STKs for initiator role, so clear this flag */ 2271 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); 2272 2273 return true; 2274 } 2275 2276 bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level, 2277 enum smp_key_pref key_pref) 2278 { 2279 if (sec_level == BT_SECURITY_LOW) 2280 return true; 2281 2282 /* If we're encrypted with an STK but the caller prefers using 2283 * LTK claim insufficient security. This way we allow the 2284 * connection to be re-encrypted with an LTK, even if the LTK 2285 * provides the same level of security. Only exception is if we 2286 * don't have an LTK (e.g. because of key distribution bits). 2287 */ 2288 if (key_pref == SMP_USE_LTK && 2289 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) && 2290 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role)) 2291 return false; 2292 2293 if (hcon->sec_level >= sec_level) 2294 return true; 2295 2296 return false; 2297 } 2298 2299 static void smp_send_pairing_req(struct smp_chan *smp, __u8 auth) 2300 { 2301 struct smp_cmd_pairing cp; 2302 2303 if (smp->conn->hcon->type == ACL_LINK) 2304 build_bredr_pairing_cmd(smp, &cp, NULL); 2305 else 2306 build_pairing_cmd(smp->conn, &cp, NULL, auth); 2307 2308 smp->preq[0] = SMP_CMD_PAIRING_REQ; 2309 memcpy(&smp->preq[1], &cp, sizeof(cp)); 2310 2311 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); 2312 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 2313 2314 set_bit(SMP_FLAG_INITIATOR, &smp->flags); 2315 } 2316 2317 static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb) 2318 { 2319 struct smp_cmd_security_req *rp = (void *) skb->data; 2320 struct hci_conn *hcon = conn->hcon; 2321 struct hci_dev *hdev = hcon->hdev; 2322 struct smp_chan *smp; 2323 u8 sec_level, auth; 2324 2325 bt_dev_dbg(hdev, "conn %p", conn); 2326 2327 if (skb->len < sizeof(*rp)) 2328 return SMP_INVALID_PARAMS; 2329 2330 if (hcon->role != HCI_ROLE_MASTER) 2331 return SMP_CMD_NOTSUPP; 2332 2333 auth = rp->auth_req & AUTH_REQ_MASK(hdev); 2334 2335 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 2336 return SMP_AUTH_REQUIREMENTS; 2337 2338 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 2339 sec_level = BT_SECURITY_MEDIUM; 2340 else 2341 sec_level = authreq_to_seclevel(auth); 2342 2343 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) { 2344 /* If link is already encrypted with sufficient security we 2345 * still need refresh encryption as per Core Spec 5.0 Vol 3, 2346 * Part H 2.4.6 2347 */ 2348 smp_ltk_encrypt(conn, hcon->sec_level); 2349 return 0; 2350 } 2351 2352 if (sec_level > hcon->pending_sec_level) 2353 hcon->pending_sec_level = sec_level; 2354 2355 if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) 2356 return 0; 2357 2358 smp = smp_chan_create(conn); 2359 if (!smp) 2360 return SMP_UNSPECIFIED; 2361 2362 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && 2363 (auth & SMP_AUTH_BONDING)) 2364 return SMP_PAIRING_NOTSUPP; 2365 2366 skb_pull(skb, sizeof(*rp)); 2367 2368 smp_send_pairing_req(smp, auth); 2369 2370 return 0; 2371 } 2372 2373 static void smp_send_security_req(struct smp_chan *smp, __u8 auth) 2374 { 2375 struct smp_cmd_security_req cp; 2376 2377 cp.auth_req = auth; 2378 smp_send_cmd(smp->conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp); 2379 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ); 2380 2381 clear_bit(SMP_FLAG_INITIATOR, &smp->flags); 2382 } 2383 2384 int smp_conn_security(struct hci_conn *hcon, __u8 sec_level) 2385 { 2386 struct l2cap_conn *conn = hcon->l2cap_data; 2387 struct l2cap_chan *chan; 2388 struct smp_chan *smp; 2389 __u8 authreq; 2390 int ret; 2391 2392 bt_dev_dbg(hcon->hdev, "conn %p hcon %p level 0x%2.2x", conn, hcon, 2393 sec_level); 2394 2395 /* This may be NULL if there's an unexpected disconnection */ 2396 if (!conn) 2397 return 1; 2398 2399 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) 2400 return 1; 2401 2402 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) 2403 return 1; 2404 2405 if (sec_level > hcon->pending_sec_level) 2406 hcon->pending_sec_level = sec_level; 2407 2408 if (hcon->role == HCI_ROLE_MASTER) 2409 if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) 2410 return 0; 2411 2412 chan = conn->smp; 2413 if (!chan) { 2414 bt_dev_err(hcon->hdev, "security requested but not available"); 2415 return 1; 2416 } 2417 2418 l2cap_chan_lock(chan); 2419 2420 /* If SMP is already in progress ignore this request */ 2421 if (chan->data) { 2422 ret = 0; 2423 goto unlock; 2424 } 2425 2426 smp = smp_chan_create(conn); 2427 if (!smp) { 2428 ret = 1; 2429 goto unlock; 2430 } 2431 2432 authreq = seclevel_to_authreq(sec_level); 2433 2434 if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED)) { 2435 authreq |= SMP_AUTH_SC; 2436 if (hci_dev_test_flag(hcon->hdev, HCI_SSP_ENABLED)) 2437 authreq |= SMP_AUTH_CT2; 2438 } 2439 2440 /* Don't attempt to set MITM if setting is overridden by debugfs 2441 * Needed to pass certification test SM/MAS/PKE/BV-01-C 2442 */ 2443 if (!hci_dev_test_flag(hcon->hdev, HCI_FORCE_NO_MITM)) { 2444 /* Require MITM if IO Capability allows or the security level 2445 * requires it. 2446 */ 2447 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT || 2448 hcon->pending_sec_level > BT_SECURITY_MEDIUM) 2449 authreq |= SMP_AUTH_MITM; 2450 } 2451 2452 if (hcon->role == HCI_ROLE_MASTER) 2453 smp_send_pairing_req(smp, authreq); 2454 else 2455 smp_send_security_req(smp, authreq); 2456 2457 ret = 0; 2458 2459 unlock: 2460 l2cap_chan_unlock(chan); 2461 return ret; 2462 } 2463 2464 int smp_cancel_and_remove_pairing(struct hci_dev *hdev, bdaddr_t *bdaddr, 2465 u8 addr_type) 2466 { 2467 struct hci_conn *hcon; 2468 struct l2cap_conn *conn; 2469 struct l2cap_chan *chan; 2470 struct smp_chan *smp; 2471 int err; 2472 2473 err = hci_remove_ltk(hdev, bdaddr, addr_type); 2474 hci_remove_irk(hdev, bdaddr, addr_type); 2475 2476 hcon = hci_conn_hash_lookup_le(hdev, bdaddr, addr_type); 2477 if (!hcon) 2478 goto done; 2479 2480 conn = hcon->l2cap_data; 2481 if (!conn) 2482 goto done; 2483 2484 chan = conn->smp; 2485 if (!chan) 2486 goto done; 2487 2488 l2cap_chan_lock(chan); 2489 2490 smp = chan->data; 2491 if (smp) { 2492 /* Set keys to NULL to make sure smp_failure() does not try to 2493 * remove and free already invalidated rcu list entries. */ 2494 smp->ltk = NULL; 2495 smp->responder_ltk = NULL; 2496 smp->remote_irk = NULL; 2497 2498 if (test_bit(SMP_FLAG_COMPLETE, &smp->flags)) 2499 smp_failure(conn, 0); 2500 else 2501 smp_failure(conn, SMP_UNSPECIFIED); 2502 err = 0; 2503 } 2504 2505 l2cap_chan_unlock(chan); 2506 2507 done: 2508 return err; 2509 } 2510 2511 static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb) 2512 { 2513 struct smp_cmd_encrypt_info *rp = (void *) skb->data; 2514 struct l2cap_chan *chan = conn->smp; 2515 struct smp_chan *smp = chan->data; 2516 2517 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 2518 2519 if (skb->len < sizeof(*rp)) 2520 return SMP_INVALID_PARAMS; 2521 2522 /* Pairing is aborted if any blocked keys are distributed */ 2523 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_LTK, 2524 rp->ltk)) { 2525 bt_dev_warn_ratelimited(conn->hcon->hdev, 2526 "LTK blocked for %pMR", 2527 &conn->hcon->dst); 2528 return SMP_INVALID_PARAMS; 2529 } 2530 2531 SMP_ALLOW_CMD(smp, SMP_CMD_INITIATOR_IDENT); 2532 2533 skb_pull(skb, sizeof(*rp)); 2534 2535 memcpy(smp->tk, rp->ltk, sizeof(smp->tk)); 2536 2537 return 0; 2538 } 2539 2540 static int smp_cmd_initiator_ident(struct l2cap_conn *conn, struct sk_buff *skb) 2541 { 2542 struct smp_cmd_initiator_ident *rp = (void *)skb->data; 2543 struct l2cap_chan *chan = conn->smp; 2544 struct smp_chan *smp = chan->data; 2545 struct hci_dev *hdev = conn->hcon->hdev; 2546 struct hci_conn *hcon = conn->hcon; 2547 struct smp_ltk *ltk; 2548 u8 authenticated; 2549 2550 bt_dev_dbg(hdev, "conn %p", conn); 2551 2552 if (skb->len < sizeof(*rp)) 2553 return SMP_INVALID_PARAMS; 2554 2555 /* Mark the information as received */ 2556 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY; 2557 2558 if (smp->remote_key_dist & SMP_DIST_ID_KEY) 2559 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); 2560 else if (smp->remote_key_dist & SMP_DIST_SIGN) 2561 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 2562 2563 skb_pull(skb, sizeof(*rp)); 2564 2565 authenticated = (hcon->sec_level == BT_SECURITY_HIGH); 2566 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK, 2567 authenticated, smp->tk, smp->enc_key_size, 2568 rp->ediv, rp->rand); 2569 smp->ltk = ltk; 2570 if (!(smp->remote_key_dist & KEY_DIST_MASK)) 2571 smp_distribute_keys(smp); 2572 2573 return 0; 2574 } 2575 2576 static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb) 2577 { 2578 struct smp_cmd_ident_info *info = (void *) skb->data; 2579 struct l2cap_chan *chan = conn->smp; 2580 struct smp_chan *smp = chan->data; 2581 2582 bt_dev_dbg(conn->hcon->hdev, ""); 2583 2584 if (skb->len < sizeof(*info)) 2585 return SMP_INVALID_PARAMS; 2586 2587 /* Pairing is aborted if any blocked keys are distributed */ 2588 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_IRK, 2589 info->irk)) { 2590 bt_dev_warn_ratelimited(conn->hcon->hdev, 2591 "Identity key blocked for %pMR", 2592 &conn->hcon->dst); 2593 return SMP_INVALID_PARAMS; 2594 } 2595 2596 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO); 2597 2598 skb_pull(skb, sizeof(*info)); 2599 2600 memcpy(smp->irk, info->irk, 16); 2601 2602 return 0; 2603 } 2604 2605 static int smp_cmd_ident_addr_info(struct l2cap_conn *conn, 2606 struct sk_buff *skb) 2607 { 2608 struct smp_cmd_ident_addr_info *info = (void *) skb->data; 2609 struct l2cap_chan *chan = conn->smp; 2610 struct smp_chan *smp = chan->data; 2611 struct hci_conn *hcon = conn->hcon; 2612 bdaddr_t rpa; 2613 2614 bt_dev_dbg(hcon->hdev, ""); 2615 2616 if (skb->len < sizeof(*info)) 2617 return SMP_INVALID_PARAMS; 2618 2619 /* Mark the information as received */ 2620 smp->remote_key_dist &= ~SMP_DIST_ID_KEY; 2621 2622 if (smp->remote_key_dist & SMP_DIST_SIGN) 2623 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 2624 2625 skb_pull(skb, sizeof(*info)); 2626 2627 /* Strictly speaking the Core Specification (4.1) allows sending 2628 * an empty address which would force us to rely on just the IRK 2629 * as "identity information". However, since such 2630 * implementations are not known of and in order to not over 2631 * complicate our implementation, simply pretend that we never 2632 * received an IRK for such a device. 2633 * 2634 * The Identity Address must also be a Static Random or Public 2635 * Address, which hci_is_identity_address() checks for. 2636 */ 2637 if (!bacmp(&info->bdaddr, BDADDR_ANY) || 2638 !hci_is_identity_address(&info->bdaddr, info->addr_type)) { 2639 bt_dev_err(hcon->hdev, "ignoring IRK with no identity address"); 2640 goto distribute; 2641 } 2642 2643 /* Drop IRK if peer is using identity address during pairing but is 2644 * providing different address as identity information. 2645 * 2646 * Microsoft Surface Precision Mouse is known to have this bug. 2647 */ 2648 if (hci_is_identity_address(&hcon->dst, hcon->dst_type) && 2649 (bacmp(&info->bdaddr, &hcon->dst) || 2650 info->addr_type != hcon->dst_type)) { 2651 bt_dev_err(hcon->hdev, 2652 "ignoring IRK with invalid identity address"); 2653 goto distribute; 2654 } 2655 2656 bacpy(&smp->id_addr, &info->bdaddr); 2657 smp->id_addr_type = info->addr_type; 2658 2659 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type)) 2660 bacpy(&rpa, &hcon->dst); 2661 else 2662 bacpy(&rpa, BDADDR_ANY); 2663 2664 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr, 2665 smp->id_addr_type, smp->irk, &rpa); 2666 2667 distribute: 2668 if (!(smp->remote_key_dist & KEY_DIST_MASK)) 2669 smp_distribute_keys(smp); 2670 2671 return 0; 2672 } 2673 2674 static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb) 2675 { 2676 struct smp_cmd_sign_info *rp = (void *) skb->data; 2677 struct l2cap_chan *chan = conn->smp; 2678 struct smp_chan *smp = chan->data; 2679 struct smp_csrk *csrk; 2680 2681 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 2682 2683 if (skb->len < sizeof(*rp)) 2684 return SMP_INVALID_PARAMS; 2685 2686 /* Mark the information as received */ 2687 smp->remote_key_dist &= ~SMP_DIST_SIGN; 2688 2689 skb_pull(skb, sizeof(*rp)); 2690 2691 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); 2692 if (csrk) { 2693 if (conn->hcon->sec_level > BT_SECURITY_MEDIUM) 2694 csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED; 2695 else 2696 csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED; 2697 memcpy(csrk->val, rp->csrk, sizeof(csrk->val)); 2698 } 2699 smp->csrk = csrk; 2700 smp_distribute_keys(smp); 2701 2702 return 0; 2703 } 2704 2705 static u8 sc_select_method(struct smp_chan *smp) 2706 { 2707 struct smp_cmd_pairing *local, *remote; 2708 u8 local_mitm, remote_mitm, local_io, remote_io, method; 2709 2710 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) || 2711 test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) 2712 return REQ_OOB; 2713 2714 /* The preq/prsp contain the raw Pairing Request/Response PDUs 2715 * which are needed as inputs to some crypto functions. To get 2716 * the "struct smp_cmd_pairing" from them we need to skip the 2717 * first byte which contains the opcode. 2718 */ 2719 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2720 local = (void *) &smp->preq[1]; 2721 remote = (void *) &smp->prsp[1]; 2722 } else { 2723 local = (void *) &smp->prsp[1]; 2724 remote = (void *) &smp->preq[1]; 2725 } 2726 2727 local_io = local->io_capability; 2728 remote_io = remote->io_capability; 2729 2730 local_mitm = (local->auth_req & SMP_AUTH_MITM); 2731 remote_mitm = (remote->auth_req & SMP_AUTH_MITM); 2732 2733 /* If either side wants MITM, look up the method from the table, 2734 * otherwise use JUST WORKS. 2735 */ 2736 if (local_mitm || remote_mitm) 2737 method = get_auth_method(smp, local_io, remote_io); 2738 else 2739 method = JUST_WORKS; 2740 2741 /* Don't confirm locally initiated pairing attempts */ 2742 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2743 method = JUST_WORKS; 2744 2745 return method; 2746 } 2747 2748 static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb) 2749 { 2750 struct smp_cmd_public_key *key = (void *) skb->data; 2751 struct hci_conn *hcon = conn->hcon; 2752 struct l2cap_chan *chan = conn->smp; 2753 struct smp_chan *smp = chan->data; 2754 struct hci_dev *hdev = hcon->hdev; 2755 struct crypto_kpp *tfm_ecdh; 2756 struct smp_cmd_pairing_confirm cfm; 2757 int err; 2758 2759 bt_dev_dbg(hdev, "conn %p", conn); 2760 2761 if (skb->len < sizeof(*key)) 2762 return SMP_INVALID_PARAMS; 2763 2764 /* Check if remote and local public keys are the same and debug key is 2765 * not in use. 2766 */ 2767 if (!test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags) && 2768 !crypto_memneq(key, smp->local_pk, 64)) { 2769 bt_dev_err(hdev, "Remote and local public keys are identical"); 2770 return SMP_UNSPECIFIED; 2771 } 2772 2773 memcpy(smp->remote_pk, key, 64); 2774 2775 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) { 2776 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk, 2777 smp->rr, 0, cfm.confirm_val); 2778 if (err) 2779 return SMP_UNSPECIFIED; 2780 2781 if (crypto_memneq(cfm.confirm_val, smp->pcnf, 16)) 2782 return SMP_CONFIRM_FAILED; 2783 } 2784 2785 /* Non-initiating device sends its public key after receiving 2786 * the key from the initiating device. 2787 */ 2788 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2789 err = sc_send_public_key(smp); 2790 if (err) 2791 return err; 2792 } 2793 2794 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk); 2795 SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32); 2796 2797 /* Compute the shared secret on the same crypto tfm on which the private 2798 * key was set/generated. 2799 */ 2800 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { 2801 struct l2cap_chan *hchan = hdev->smp_data; 2802 struct smp_dev *smp_dev; 2803 2804 if (!hchan || !hchan->data) 2805 return SMP_UNSPECIFIED; 2806 2807 smp_dev = hchan->data; 2808 2809 tfm_ecdh = smp_dev->tfm_ecdh; 2810 } else { 2811 tfm_ecdh = smp->tfm_ecdh; 2812 } 2813 2814 if (compute_ecdh_secret(tfm_ecdh, smp->remote_pk, smp->dhkey)) 2815 return SMP_UNSPECIFIED; 2816 2817 SMP_DBG("DHKey %32phN", smp->dhkey); 2818 2819 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags); 2820 2821 smp->method = sc_select_method(smp); 2822 2823 bt_dev_dbg(hdev, "selected method 0x%02x", smp->method); 2824 2825 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */ 2826 if (smp->method == JUST_WORKS || smp->method == JUST_CFM) 2827 hcon->pending_sec_level = BT_SECURITY_MEDIUM; 2828 else 2829 hcon->pending_sec_level = BT_SECURITY_FIPS; 2830 2831 if (!crypto_memneq(debug_pk, smp->remote_pk, 64)) 2832 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 2833 2834 if (smp->method == DSP_PASSKEY) { 2835 get_random_bytes(&hcon->passkey_notify, 2836 sizeof(hcon->passkey_notify)); 2837 hcon->passkey_notify %= 1000000; 2838 hcon->passkey_entered = 0; 2839 smp->passkey_round = 0; 2840 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type, 2841 hcon->dst_type, 2842 hcon->passkey_notify, 2843 hcon->passkey_entered)) 2844 return SMP_UNSPECIFIED; 2845 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2846 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY); 2847 } 2848 2849 if (smp->method == REQ_OOB) { 2850 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2851 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 2852 sizeof(smp->prnd), smp->prnd); 2853 2854 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2855 2856 return 0; 2857 } 2858 2859 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2860 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2861 2862 if (smp->method == REQ_PASSKEY) { 2863 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type, 2864 hcon->dst_type)) 2865 return SMP_UNSPECIFIED; 2866 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2867 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 2868 return 0; 2869 } 2870 2871 /* The Initiating device waits for the non-initiating device to 2872 * send the confirm value. 2873 */ 2874 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2875 return 0; 2876 2877 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, 2878 0, cfm.confirm_val); 2879 if (err) 2880 return SMP_UNSPECIFIED; 2881 2882 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); 2883 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2884 2885 return 0; 2886 } 2887 2888 static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb) 2889 { 2890 struct smp_cmd_dhkey_check *check = (void *) skb->data; 2891 struct l2cap_chan *chan = conn->smp; 2892 struct hci_conn *hcon = conn->hcon; 2893 struct smp_chan *smp = chan->data; 2894 u8 a[7], b[7], *local_addr, *remote_addr; 2895 u8 io_cap[3], r[16], e[16]; 2896 int err; 2897 2898 bt_dev_dbg(hcon->hdev, "conn %p", conn); 2899 2900 if (skb->len < sizeof(*check)) 2901 return SMP_INVALID_PARAMS; 2902 2903 memcpy(a, &hcon->init_addr, 6); 2904 memcpy(b, &hcon->resp_addr, 6); 2905 a[6] = hcon->init_addr_type; 2906 b[6] = hcon->resp_addr_type; 2907 2908 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2909 local_addr = a; 2910 remote_addr = b; 2911 memcpy(io_cap, &smp->prsp[1], 3); 2912 } else { 2913 local_addr = b; 2914 remote_addr = a; 2915 memcpy(io_cap, &smp->preq[1], 3); 2916 } 2917 2918 memset(r, 0, sizeof(r)); 2919 2920 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2921 put_unaligned_le32(hcon->passkey_notify, r); 2922 else if (smp->method == REQ_OOB) 2923 memcpy(r, smp->lr, 16); 2924 2925 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r, 2926 io_cap, remote_addr, local_addr, e); 2927 if (err) 2928 return SMP_UNSPECIFIED; 2929 2930 if (crypto_memneq(check->e, e, 16)) 2931 return SMP_DHKEY_CHECK_FAILED; 2932 2933 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2934 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { 2935 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags); 2936 return 0; 2937 } 2938 2939 /* Responder sends DHKey check as response to initiator */ 2940 sc_dhkey_check(smp); 2941 } 2942 2943 sc_add_ltk(smp); 2944 2945 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2946 hci_le_start_enc(hcon, 0, 0, smp->tk, smp->enc_key_size); 2947 hcon->enc_key_size = smp->enc_key_size; 2948 } 2949 2950 return 0; 2951 } 2952 2953 static int smp_cmd_keypress_notify(struct l2cap_conn *conn, 2954 struct sk_buff *skb) 2955 { 2956 struct smp_cmd_keypress_notify *kp = (void *) skb->data; 2957 2958 bt_dev_dbg(conn->hcon->hdev, "value 0x%02x", kp->value); 2959 2960 return 0; 2961 } 2962 2963 static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb) 2964 { 2965 struct l2cap_conn *conn = chan->conn; 2966 struct hci_conn *hcon = conn->hcon; 2967 struct smp_chan *smp; 2968 __u8 code, reason; 2969 int err = 0; 2970 2971 if (skb->len < 1) 2972 return -EILSEQ; 2973 2974 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) { 2975 reason = SMP_PAIRING_NOTSUPP; 2976 goto done; 2977 } 2978 2979 code = skb->data[0]; 2980 skb_pull(skb, sizeof(code)); 2981 2982 smp = chan->data; 2983 2984 if (code > SMP_CMD_MAX) 2985 goto drop; 2986 2987 if (smp && !test_and_clear_bit(code, &smp->allow_cmd)) 2988 goto drop; 2989 2990 /* If we don't have a context the only allowed commands are 2991 * pairing request and security request. 2992 */ 2993 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ) 2994 goto drop; 2995 2996 switch (code) { 2997 case SMP_CMD_PAIRING_REQ: 2998 reason = smp_cmd_pairing_req(conn, skb); 2999 break; 3000 3001 case SMP_CMD_PAIRING_FAIL: 3002 smp_failure(conn, 0); 3003 err = -EPERM; 3004 break; 3005 3006 case SMP_CMD_PAIRING_RSP: 3007 reason = smp_cmd_pairing_rsp(conn, skb); 3008 break; 3009 3010 case SMP_CMD_SECURITY_REQ: 3011 reason = smp_cmd_security_req(conn, skb); 3012 break; 3013 3014 case SMP_CMD_PAIRING_CONFIRM: 3015 reason = smp_cmd_pairing_confirm(conn, skb); 3016 break; 3017 3018 case SMP_CMD_PAIRING_RANDOM: 3019 reason = smp_cmd_pairing_random(conn, skb); 3020 break; 3021 3022 case SMP_CMD_ENCRYPT_INFO: 3023 reason = smp_cmd_encrypt_info(conn, skb); 3024 break; 3025 3026 case SMP_CMD_INITIATOR_IDENT: 3027 reason = smp_cmd_initiator_ident(conn, skb); 3028 break; 3029 3030 case SMP_CMD_IDENT_INFO: 3031 reason = smp_cmd_ident_info(conn, skb); 3032 break; 3033 3034 case SMP_CMD_IDENT_ADDR_INFO: 3035 reason = smp_cmd_ident_addr_info(conn, skb); 3036 break; 3037 3038 case SMP_CMD_SIGN_INFO: 3039 reason = smp_cmd_sign_info(conn, skb); 3040 break; 3041 3042 case SMP_CMD_PUBLIC_KEY: 3043 reason = smp_cmd_public_key(conn, skb); 3044 break; 3045 3046 case SMP_CMD_DHKEY_CHECK: 3047 reason = smp_cmd_dhkey_check(conn, skb); 3048 break; 3049 3050 case SMP_CMD_KEYPRESS_NOTIFY: 3051 reason = smp_cmd_keypress_notify(conn, skb); 3052 break; 3053 3054 default: 3055 bt_dev_dbg(hcon->hdev, "Unknown command code 0x%2.2x", code); 3056 reason = SMP_CMD_NOTSUPP; 3057 goto done; 3058 } 3059 3060 done: 3061 if (!err) { 3062 if (reason) 3063 smp_failure(conn, reason); 3064 kfree_skb(skb); 3065 } 3066 3067 return err; 3068 3069 drop: 3070 bt_dev_err(hcon->hdev, "unexpected SMP command 0x%02x from %pMR", 3071 code, &hcon->dst); 3072 kfree_skb(skb); 3073 return 0; 3074 } 3075 3076 static void smp_teardown_cb(struct l2cap_chan *chan, int err) 3077 { 3078 struct l2cap_conn *conn = chan->conn; 3079 3080 bt_dev_dbg(conn->hcon->hdev, "chan %p", chan); 3081 3082 if (chan->data) 3083 smp_chan_destroy(conn); 3084 3085 conn->smp = NULL; 3086 l2cap_chan_put(chan); 3087 } 3088 3089 static void bredr_pairing(struct l2cap_chan *chan) 3090 { 3091 struct l2cap_conn *conn = chan->conn; 3092 struct hci_conn *hcon = conn->hcon; 3093 struct hci_dev *hdev = hcon->hdev; 3094 struct smp_chan *smp; 3095 3096 bt_dev_dbg(hdev, "chan %p", chan); 3097 3098 /* Only new pairings are interesting */ 3099 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags)) 3100 return; 3101 3102 /* Don't bother if we're not encrypted */ 3103 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3104 return; 3105 3106 /* Only initiator may initiate SMP over BR/EDR */ 3107 if (hcon->role != HCI_ROLE_MASTER) 3108 return; 3109 3110 /* Secure Connections support must be enabled */ 3111 if (!hci_dev_test_flag(hdev, HCI_SC_ENABLED)) 3112 return; 3113 3114 /* BR/EDR must use Secure Connections for SMP */ 3115 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) && 3116 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3117 return; 3118 3119 /* If our LE support is not enabled don't do anything */ 3120 if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) 3121 return; 3122 3123 /* Don't bother if remote LE support is not enabled */ 3124 if (!lmp_host_le_capable(hcon)) 3125 return; 3126 3127 /* Remote must support SMP fixed chan for BR/EDR */ 3128 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR)) 3129 return; 3130 3131 /* Don't bother if SMP is already ongoing */ 3132 if (chan->data) 3133 return; 3134 3135 smp = smp_chan_create(conn); 3136 if (!smp) { 3137 bt_dev_err(hdev, "unable to create SMP context for BR/EDR"); 3138 return; 3139 } 3140 3141 set_bit(SMP_FLAG_SC, &smp->flags); 3142 3143 bt_dev_dbg(hdev, "starting SMP over BR/EDR"); 3144 3145 smp_send_pairing_req(smp, 0x00); 3146 } 3147 3148 static void smp_resume_cb(struct l2cap_chan *chan) 3149 { 3150 struct smp_chan *smp = chan->data; 3151 struct l2cap_conn *conn = chan->conn; 3152 struct hci_conn *hcon = conn->hcon; 3153 3154 bt_dev_dbg(hcon->hdev, "chan %p", chan); 3155 3156 if (hcon->type == ACL_LINK) { 3157 bredr_pairing(chan); 3158 return; 3159 } 3160 3161 if (!smp) 3162 return; 3163 3164 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3165 return; 3166 3167 cancel_delayed_work(&smp->security_timer); 3168 3169 smp_distribute_keys(smp); 3170 } 3171 3172 static void smp_ready_cb(struct l2cap_chan *chan) 3173 { 3174 struct l2cap_conn *conn = chan->conn; 3175 struct hci_conn *hcon = conn->hcon; 3176 3177 bt_dev_dbg(hcon->hdev, "chan %p", chan); 3178 3179 /* No need to call l2cap_chan_hold() here since we already own 3180 * the reference taken in smp_new_conn_cb(). This is just the 3181 * first time that we tie it to a specific pointer. The code in 3182 * l2cap_core.c ensures that there's no risk this function wont 3183 * get called if smp_new_conn_cb was previously called. 3184 */ 3185 conn->smp = chan; 3186 3187 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3188 bredr_pairing(chan); 3189 } 3190 3191 static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 3192 { 3193 int err; 3194 3195 bt_dev_dbg(chan->conn->hcon->hdev, "chan %p", chan); 3196 3197 err = smp_sig_channel(chan, skb); 3198 if (err) { 3199 struct smp_chan *smp = chan->data; 3200 3201 if (smp) 3202 cancel_delayed_work_sync(&smp->security_timer); 3203 3204 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE); 3205 } 3206 3207 return err; 3208 } 3209 3210 static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan, 3211 unsigned long hdr_len, 3212 unsigned long len, int nb) 3213 { 3214 struct sk_buff *skb; 3215 3216 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL); 3217 if (!skb) 3218 return ERR_PTR(-ENOMEM); 3219 3220 skb->priority = HCI_PRIO_MAX; 3221 bt_cb(skb)->l2cap.chan = chan; 3222 3223 return skb; 3224 } 3225 3226 static const struct l2cap_ops smp_chan_ops = { 3227 .name = "Security Manager", 3228 .ready = smp_ready_cb, 3229 .recv = smp_recv_cb, 3230 .alloc_skb = smp_alloc_skb_cb, 3231 .teardown = smp_teardown_cb, 3232 .resume = smp_resume_cb, 3233 3234 .new_connection = l2cap_chan_no_new_connection, 3235 .state_change = l2cap_chan_no_state_change, 3236 .close = l2cap_chan_no_close, 3237 .defer = l2cap_chan_no_defer, 3238 .suspend = l2cap_chan_no_suspend, 3239 .set_shutdown = l2cap_chan_no_set_shutdown, 3240 .get_sndtimeo = l2cap_chan_no_get_sndtimeo, 3241 }; 3242 3243 static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan) 3244 { 3245 struct l2cap_chan *chan; 3246 3247 BT_DBG("pchan %p", pchan); 3248 3249 chan = l2cap_chan_create(); 3250 if (!chan) 3251 return NULL; 3252 3253 chan->chan_type = pchan->chan_type; 3254 chan->ops = &smp_chan_ops; 3255 chan->scid = pchan->scid; 3256 chan->dcid = chan->scid; 3257 chan->imtu = pchan->imtu; 3258 chan->omtu = pchan->omtu; 3259 chan->mode = pchan->mode; 3260 3261 /* Other L2CAP channels may request SMP routines in order to 3262 * change the security level. This means that the SMP channel 3263 * lock must be considered in its own category to avoid lockdep 3264 * warnings. 3265 */ 3266 atomic_set(&chan->nesting, L2CAP_NESTING_SMP); 3267 3268 BT_DBG("created chan %p", chan); 3269 3270 return chan; 3271 } 3272 3273 static const struct l2cap_ops smp_root_chan_ops = { 3274 .name = "Security Manager Root", 3275 .new_connection = smp_new_conn_cb, 3276 3277 /* None of these are implemented for the root channel */ 3278 .close = l2cap_chan_no_close, 3279 .alloc_skb = l2cap_chan_no_alloc_skb, 3280 .recv = l2cap_chan_no_recv, 3281 .state_change = l2cap_chan_no_state_change, 3282 .teardown = l2cap_chan_no_teardown, 3283 .ready = l2cap_chan_no_ready, 3284 .defer = l2cap_chan_no_defer, 3285 .suspend = l2cap_chan_no_suspend, 3286 .resume = l2cap_chan_no_resume, 3287 .set_shutdown = l2cap_chan_no_set_shutdown, 3288 .get_sndtimeo = l2cap_chan_no_get_sndtimeo, 3289 }; 3290 3291 static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid) 3292 { 3293 struct l2cap_chan *chan; 3294 struct smp_dev *smp; 3295 struct crypto_shash *tfm_cmac; 3296 struct crypto_kpp *tfm_ecdh; 3297 3298 if (cid == L2CAP_CID_SMP_BREDR) { 3299 smp = NULL; 3300 goto create_chan; 3301 } 3302 3303 smp = kzalloc(sizeof(*smp), GFP_KERNEL); 3304 if (!smp) 3305 return ERR_PTR(-ENOMEM); 3306 3307 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 3308 if (IS_ERR(tfm_cmac)) { 3309 bt_dev_err(hdev, "Unable to create CMAC crypto context"); 3310 kfree_sensitive(smp); 3311 return ERR_CAST(tfm_cmac); 3312 } 3313 3314 tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0); 3315 if (IS_ERR(tfm_ecdh)) { 3316 bt_dev_err(hdev, "Unable to create ECDH crypto context"); 3317 crypto_free_shash(tfm_cmac); 3318 kfree_sensitive(smp); 3319 return ERR_CAST(tfm_ecdh); 3320 } 3321 3322 smp->local_oob = false; 3323 smp->tfm_cmac = tfm_cmac; 3324 smp->tfm_ecdh = tfm_ecdh; 3325 3326 create_chan: 3327 chan = l2cap_chan_create(); 3328 if (!chan) { 3329 if (smp) { 3330 crypto_free_shash(smp->tfm_cmac); 3331 crypto_free_kpp(smp->tfm_ecdh); 3332 kfree_sensitive(smp); 3333 } 3334 return ERR_PTR(-ENOMEM); 3335 } 3336 3337 chan->data = smp; 3338 3339 l2cap_add_scid(chan, cid); 3340 3341 l2cap_chan_set_defaults(chan); 3342 3343 if (cid == L2CAP_CID_SMP) { 3344 u8 bdaddr_type; 3345 3346 hci_copy_identity_address(hdev, &chan->src, &bdaddr_type); 3347 3348 if (bdaddr_type == ADDR_LE_DEV_PUBLIC) 3349 chan->src_type = BDADDR_LE_PUBLIC; 3350 else 3351 chan->src_type = BDADDR_LE_RANDOM; 3352 } else { 3353 bacpy(&chan->src, &hdev->bdaddr); 3354 chan->src_type = BDADDR_BREDR; 3355 } 3356 3357 chan->state = BT_LISTEN; 3358 chan->mode = L2CAP_MODE_BASIC; 3359 chan->imtu = L2CAP_DEFAULT_MTU; 3360 chan->ops = &smp_root_chan_ops; 3361 3362 /* Set correct nesting level for a parent/listening channel */ 3363 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 3364 3365 return chan; 3366 } 3367 3368 static void smp_del_chan(struct l2cap_chan *chan) 3369 { 3370 struct smp_dev *smp; 3371 3372 BT_DBG("chan %p", chan); 3373 3374 smp = chan->data; 3375 if (smp) { 3376 chan->data = NULL; 3377 crypto_free_shash(smp->tfm_cmac); 3378 crypto_free_kpp(smp->tfm_ecdh); 3379 kfree_sensitive(smp); 3380 } 3381 3382 l2cap_chan_put(chan); 3383 } 3384 3385 int smp_force_bredr(struct hci_dev *hdev, bool enable) 3386 { 3387 if (enable == hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3388 return -EALREADY; 3389 3390 if (enable) { 3391 struct l2cap_chan *chan; 3392 3393 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); 3394 if (IS_ERR(chan)) 3395 return PTR_ERR(chan); 3396 3397 hdev->smp_bredr_data = chan; 3398 } else { 3399 struct l2cap_chan *chan; 3400 3401 chan = hdev->smp_bredr_data; 3402 hdev->smp_bredr_data = NULL; 3403 smp_del_chan(chan); 3404 } 3405 3406 hci_dev_change_flag(hdev, HCI_FORCE_BREDR_SMP); 3407 3408 return 0; 3409 } 3410 3411 int smp_register(struct hci_dev *hdev) 3412 { 3413 struct l2cap_chan *chan; 3414 3415 bt_dev_dbg(hdev, ""); 3416 3417 /* If the controller does not support Low Energy operation, then 3418 * there is also no need to register any SMP channel. 3419 */ 3420 if (!lmp_le_capable(hdev)) 3421 return 0; 3422 3423 if (WARN_ON(hdev->smp_data)) { 3424 chan = hdev->smp_data; 3425 hdev->smp_data = NULL; 3426 smp_del_chan(chan); 3427 } 3428 3429 chan = smp_add_cid(hdev, L2CAP_CID_SMP); 3430 if (IS_ERR(chan)) 3431 return PTR_ERR(chan); 3432 3433 hdev->smp_data = chan; 3434 3435 if (!lmp_sc_capable(hdev)) { 3436 /* Flag can be already set here (due to power toggle) */ 3437 if (!hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3438 return 0; 3439 } 3440 3441 if (WARN_ON(hdev->smp_bredr_data)) { 3442 chan = hdev->smp_bredr_data; 3443 hdev->smp_bredr_data = NULL; 3444 smp_del_chan(chan); 3445 } 3446 3447 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); 3448 if (IS_ERR(chan)) { 3449 int err = PTR_ERR(chan); 3450 chan = hdev->smp_data; 3451 hdev->smp_data = NULL; 3452 smp_del_chan(chan); 3453 return err; 3454 } 3455 3456 hdev->smp_bredr_data = chan; 3457 3458 return 0; 3459 } 3460 3461 void smp_unregister(struct hci_dev *hdev) 3462 { 3463 struct l2cap_chan *chan; 3464 3465 if (hdev->smp_bredr_data) { 3466 chan = hdev->smp_bredr_data; 3467 hdev->smp_bredr_data = NULL; 3468 smp_del_chan(chan); 3469 } 3470 3471 if (hdev->smp_data) { 3472 chan = hdev->smp_data; 3473 hdev->smp_data = NULL; 3474 smp_del_chan(chan); 3475 } 3476 } 3477 3478 #if IS_ENABLED(CONFIG_BT_SELFTEST_SMP) 3479 3480 static int __init test_debug_key(struct crypto_kpp *tfm_ecdh) 3481 { 3482 u8 pk[64]; 3483 int err; 3484 3485 err = set_ecdh_privkey(tfm_ecdh, debug_sk); 3486 if (err) 3487 return err; 3488 3489 err = generate_ecdh_public_key(tfm_ecdh, pk); 3490 if (err) 3491 return err; 3492 3493 if (crypto_memneq(pk, debug_pk, 64)) 3494 return -EINVAL; 3495 3496 return 0; 3497 } 3498 3499 static int __init test_ah(void) 3500 { 3501 const u8 irk[16] = { 3502 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3503 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3504 const u8 r[3] = { 0x94, 0x81, 0x70 }; 3505 const u8 exp[3] = { 0xaa, 0xfb, 0x0d }; 3506 u8 res[3]; 3507 int err; 3508 3509 err = smp_ah(irk, r, res); 3510 if (err) 3511 return err; 3512 3513 if (crypto_memneq(res, exp, 3)) 3514 return -EINVAL; 3515 3516 return 0; 3517 } 3518 3519 static int __init test_c1(void) 3520 { 3521 const u8 k[16] = { 3522 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 3523 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; 3524 const u8 r[16] = { 3525 0xe0, 0x2e, 0x70, 0xc6, 0x4e, 0x27, 0x88, 0x63, 3526 0x0e, 0x6f, 0xad, 0x56, 0x21, 0xd5, 0x83, 0x57 }; 3527 const u8 preq[7] = { 0x01, 0x01, 0x00, 0x00, 0x10, 0x07, 0x07 }; 3528 const u8 pres[7] = { 0x02, 0x03, 0x00, 0x00, 0x08, 0x00, 0x05 }; 3529 const u8 _iat = 0x01; 3530 const u8 _rat = 0x00; 3531 const bdaddr_t ra = { { 0xb6, 0xb5, 0xb4, 0xb3, 0xb2, 0xb1 } }; 3532 const bdaddr_t ia = { { 0xa6, 0xa5, 0xa4, 0xa3, 0xa2, 0xa1 } }; 3533 const u8 exp[16] = { 3534 0x86, 0x3b, 0xf1, 0xbe, 0xc5, 0x4d, 0xa7, 0xd2, 3535 0xea, 0x88, 0x89, 0x87, 0xef, 0x3f, 0x1e, 0x1e }; 3536 u8 res[16]; 3537 int err; 3538 3539 err = smp_c1(k, r, preq, pres, _iat, &ia, _rat, &ra, res); 3540 if (err) 3541 return err; 3542 3543 if (crypto_memneq(res, exp, 16)) 3544 return -EINVAL; 3545 3546 return 0; 3547 } 3548 3549 static int __init test_s1(void) 3550 { 3551 const u8 k[16] = { 3552 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 3553 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; 3554 const u8 r1[16] = { 3555 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 }; 3556 const u8 r2[16] = { 3557 0x00, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99 }; 3558 const u8 exp[16] = { 3559 0x62, 0xa0, 0x6d, 0x79, 0xae, 0x16, 0x42, 0x5b, 3560 0x9b, 0xf4, 0xb0, 0xe8, 0xf0, 0xe1, 0x1f, 0x9a }; 3561 u8 res[16]; 3562 int err; 3563 3564 err = smp_s1(k, r1, r2, res); 3565 if (err) 3566 return err; 3567 3568 if (crypto_memneq(res, exp, 16)) 3569 return -EINVAL; 3570 3571 return 0; 3572 } 3573 3574 static int __init test_f4(struct crypto_shash *tfm_cmac) 3575 { 3576 const u8 u[32] = { 3577 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 3578 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 3579 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 3580 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 }; 3581 const u8 v[32] = { 3582 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b, 3583 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59, 3584 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90, 3585 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 }; 3586 const u8 x[16] = { 3587 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3588 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3589 const u8 z = 0x00; 3590 const u8 exp[16] = { 3591 0x2d, 0x87, 0x74, 0xa9, 0xbe, 0xa1, 0xed, 0xf1, 3592 0x1c, 0xbd, 0xa9, 0x07, 0xf1, 0x16, 0xc9, 0xf2 }; 3593 u8 res[16]; 3594 int err; 3595 3596 err = smp_f4(tfm_cmac, u, v, x, z, res); 3597 if (err) 3598 return err; 3599 3600 if (crypto_memneq(res, exp, 16)) 3601 return -EINVAL; 3602 3603 return 0; 3604 } 3605 3606 static int __init test_f5(struct crypto_shash *tfm_cmac) 3607 { 3608 const u8 w[32] = { 3609 0x98, 0xa6, 0xbf, 0x73, 0xf3, 0x34, 0x8d, 0x86, 3610 0xf1, 0x66, 0xf8, 0xb4, 0x13, 0x6b, 0x79, 0x99, 3611 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3612 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3613 const u8 n1[16] = { 3614 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3615 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3616 const u8 n2[16] = { 3617 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3618 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3619 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 }; 3620 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 }; 3621 const u8 exp_ltk[16] = { 3622 0x38, 0x0a, 0x75, 0x94, 0xb5, 0x22, 0x05, 0x98, 3623 0x23, 0xcd, 0xd7, 0x69, 0x11, 0x79, 0x86, 0x69 }; 3624 const u8 exp_mackey[16] = { 3625 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd, 3626 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 }; 3627 u8 mackey[16], ltk[16]; 3628 int err; 3629 3630 err = smp_f5(tfm_cmac, w, n1, n2, a1, a2, mackey, ltk); 3631 if (err) 3632 return err; 3633 3634 if (crypto_memneq(mackey, exp_mackey, 16)) 3635 return -EINVAL; 3636 3637 if (crypto_memneq(ltk, exp_ltk, 16)) 3638 return -EINVAL; 3639 3640 return 0; 3641 } 3642 3643 static int __init test_f6(struct crypto_shash *tfm_cmac) 3644 { 3645 const u8 w[16] = { 3646 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd, 3647 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 }; 3648 const u8 n1[16] = { 3649 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3650 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3651 const u8 n2[16] = { 3652 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3653 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3654 const u8 r[16] = { 3655 0xc8, 0x0f, 0x2d, 0x0c, 0xd2, 0x42, 0xda, 0x08, 3656 0x54, 0xbb, 0x53, 0xb4, 0x3b, 0x34, 0xa3, 0x12 }; 3657 const u8 io_cap[3] = { 0x02, 0x01, 0x01 }; 3658 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 }; 3659 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 }; 3660 const u8 exp[16] = { 3661 0x61, 0x8f, 0x95, 0xda, 0x09, 0x0b, 0x6c, 0xd2, 3662 0xc5, 0xe8, 0xd0, 0x9c, 0x98, 0x73, 0xc4, 0xe3 }; 3663 u8 res[16]; 3664 int err; 3665 3666 err = smp_f6(tfm_cmac, w, n1, n2, r, io_cap, a1, a2, res); 3667 if (err) 3668 return err; 3669 3670 if (crypto_memneq(res, exp, 16)) 3671 return -EINVAL; 3672 3673 return 0; 3674 } 3675 3676 static int __init test_g2(struct crypto_shash *tfm_cmac) 3677 { 3678 const u8 u[32] = { 3679 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 3680 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 3681 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 3682 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 }; 3683 const u8 v[32] = { 3684 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b, 3685 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59, 3686 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90, 3687 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 }; 3688 const u8 x[16] = { 3689 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3690 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3691 const u8 y[16] = { 3692 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3693 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3694 const u32 exp_val = 0x2f9ed5ba % 1000000; 3695 u32 val; 3696 int err; 3697 3698 err = smp_g2(tfm_cmac, u, v, x, y, &val); 3699 if (err) 3700 return err; 3701 3702 if (val != exp_val) 3703 return -EINVAL; 3704 3705 return 0; 3706 } 3707 3708 static int __init test_h6(struct crypto_shash *tfm_cmac) 3709 { 3710 const u8 w[16] = { 3711 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3712 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3713 const u8 key_id[4] = { 0x72, 0x62, 0x65, 0x6c }; 3714 const u8 exp[16] = { 3715 0x99, 0x63, 0xb1, 0x80, 0xe2, 0xa9, 0xd3, 0xe8, 3716 0x1c, 0xc9, 0x6d, 0xe7, 0x02, 0xe1, 0x9a, 0x2d }; 3717 u8 res[16]; 3718 int err; 3719 3720 err = smp_h6(tfm_cmac, w, key_id, res); 3721 if (err) 3722 return err; 3723 3724 if (crypto_memneq(res, exp, 16)) 3725 return -EINVAL; 3726 3727 return 0; 3728 } 3729 3730 static char test_smp_buffer[32]; 3731 3732 static ssize_t test_smp_read(struct file *file, char __user *user_buf, 3733 size_t count, loff_t *ppos) 3734 { 3735 return simple_read_from_buffer(user_buf, count, ppos, test_smp_buffer, 3736 strlen(test_smp_buffer)); 3737 } 3738 3739 static const struct file_operations test_smp_fops = { 3740 .open = simple_open, 3741 .read = test_smp_read, 3742 .llseek = default_llseek, 3743 }; 3744 3745 static int __init run_selftests(struct crypto_shash *tfm_cmac, 3746 struct crypto_kpp *tfm_ecdh) 3747 { 3748 ktime_t calltime, delta, rettime; 3749 unsigned long long duration; 3750 int err; 3751 3752 calltime = ktime_get(); 3753 3754 err = test_debug_key(tfm_ecdh); 3755 if (err) { 3756 BT_ERR("debug_key test failed"); 3757 goto done; 3758 } 3759 3760 err = test_ah(); 3761 if (err) { 3762 BT_ERR("smp_ah test failed"); 3763 goto done; 3764 } 3765 3766 err = test_c1(); 3767 if (err) { 3768 BT_ERR("smp_c1 test failed"); 3769 goto done; 3770 } 3771 3772 err = test_s1(); 3773 if (err) { 3774 BT_ERR("smp_s1 test failed"); 3775 goto done; 3776 } 3777 3778 err = test_f4(tfm_cmac); 3779 if (err) { 3780 BT_ERR("smp_f4 test failed"); 3781 goto done; 3782 } 3783 3784 err = test_f5(tfm_cmac); 3785 if (err) { 3786 BT_ERR("smp_f5 test failed"); 3787 goto done; 3788 } 3789 3790 err = test_f6(tfm_cmac); 3791 if (err) { 3792 BT_ERR("smp_f6 test failed"); 3793 goto done; 3794 } 3795 3796 err = test_g2(tfm_cmac); 3797 if (err) { 3798 BT_ERR("smp_g2 test failed"); 3799 goto done; 3800 } 3801 3802 err = test_h6(tfm_cmac); 3803 if (err) { 3804 BT_ERR("smp_h6 test failed"); 3805 goto done; 3806 } 3807 3808 rettime = ktime_get(); 3809 delta = ktime_sub(rettime, calltime); 3810 duration = (unsigned long long) ktime_to_ns(delta) >> 10; 3811 3812 BT_INFO("SMP test passed in %llu usecs", duration); 3813 3814 done: 3815 if (!err) 3816 snprintf(test_smp_buffer, sizeof(test_smp_buffer), 3817 "PASS (%llu usecs)\n", duration); 3818 else 3819 snprintf(test_smp_buffer, sizeof(test_smp_buffer), "FAIL\n"); 3820 3821 debugfs_create_file("selftest_smp", 0444, bt_debugfs, NULL, 3822 &test_smp_fops); 3823 3824 return err; 3825 } 3826 3827 int __init bt_selftest_smp(void) 3828 { 3829 struct crypto_shash *tfm_cmac; 3830 struct crypto_kpp *tfm_ecdh; 3831 int err; 3832 3833 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 3834 if (IS_ERR(tfm_cmac)) { 3835 BT_ERR("Unable to create CMAC crypto context"); 3836 return PTR_ERR(tfm_cmac); 3837 } 3838 3839 tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0); 3840 if (IS_ERR(tfm_ecdh)) { 3841 BT_ERR("Unable to create ECDH crypto context"); 3842 crypto_free_shash(tfm_cmac); 3843 return PTR_ERR(tfm_ecdh); 3844 } 3845 3846 err = run_selftests(tfm_cmac, tfm_ecdh); 3847 3848 crypto_free_shash(tfm_cmac); 3849 crypto_free_kpp(tfm_ecdh); 3850 3851 return err; 3852 } 3853 3854 #endif 3855