1 /* 2 BlueZ - Bluetooth protocol stack for Linux 3 Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). 4 5 This program is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License version 2 as 7 published by the Free Software Foundation; 8 9 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 10 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 11 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. 12 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY 13 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES 14 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 18 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS, 19 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS 20 SOFTWARE IS DISCLAIMED. 21 */ 22 23 #include <linux/debugfs.h> 24 #include <linux/scatterlist.h> 25 #include <linux/crypto.h> 26 #include <crypto/aes.h> 27 #include <crypto/algapi.h> 28 #include <crypto/hash.h> 29 #include <crypto/kpp.h> 30 31 #include <net/bluetooth/bluetooth.h> 32 #include <net/bluetooth/hci_core.h> 33 #include <net/bluetooth/l2cap.h> 34 #include <net/bluetooth/mgmt.h> 35 36 #include "ecdh_helper.h" 37 #include "smp.h" 38 39 #define SMP_DEV(hdev) \ 40 ((struct smp_dev *)((struct l2cap_chan *)((hdev)->smp_data))->data) 41 42 /* Low-level debug macros to be used for stuff that we don't want 43 * accidentally in dmesg, i.e. the values of the various crypto keys 44 * and the inputs & outputs of crypto functions. 45 */ 46 #ifdef DEBUG 47 #define SMP_DBG(fmt, ...) printk(KERN_DEBUG "%s: " fmt, __func__, \ 48 ##__VA_ARGS__) 49 #else 50 #define SMP_DBG(fmt, ...) no_printk(KERN_DEBUG "%s: " fmt, __func__, \ 51 ##__VA_ARGS__) 52 #endif 53 54 #define SMP_ALLOW_CMD(smp, code) set_bit(code, &smp->allow_cmd) 55 56 /* Keys which are not distributed with Secure Connections */ 57 #define SMP_SC_NO_DIST (SMP_DIST_ENC_KEY | SMP_DIST_LINK_KEY) 58 59 #define SMP_TIMEOUT msecs_to_jiffies(30000) 60 61 #define ID_ADDR_TIMEOUT msecs_to_jiffies(200) 62 63 #define AUTH_REQ_MASK(dev) (hci_dev_test_flag(dev, HCI_SC_ENABLED) ? \ 64 0x3f : 0x07) 65 #define KEY_DIST_MASK 0x07 66 67 /* Maximum message length that can be passed to aes_cmac */ 68 #define CMAC_MSG_MAX 80 69 70 enum { 71 SMP_FLAG_TK_VALID, 72 SMP_FLAG_CFM_PENDING, 73 SMP_FLAG_MITM_AUTH, 74 SMP_FLAG_COMPLETE, 75 SMP_FLAG_INITIATOR, 76 SMP_FLAG_SC, 77 SMP_FLAG_REMOTE_PK, 78 SMP_FLAG_DEBUG_KEY, 79 SMP_FLAG_WAIT_USER, 80 SMP_FLAG_DHKEY_PENDING, 81 SMP_FLAG_REMOTE_OOB, 82 SMP_FLAG_LOCAL_OOB, 83 SMP_FLAG_CT2, 84 }; 85 86 struct smp_dev { 87 /* Secure Connections OOB data */ 88 bool local_oob; 89 u8 local_pk[64]; 90 u8 local_rand[16]; 91 bool debug_key; 92 93 struct crypto_shash *tfm_cmac; 94 struct crypto_kpp *tfm_ecdh; 95 }; 96 97 struct smp_chan { 98 struct l2cap_conn *conn; 99 struct delayed_work security_timer; 100 unsigned long allow_cmd; /* Bitmask of allowed commands */ 101 102 u8 preq[7]; /* SMP Pairing Request */ 103 u8 prsp[7]; /* SMP Pairing Response */ 104 u8 prnd[16]; /* SMP Pairing Random (local) */ 105 u8 rrnd[16]; /* SMP Pairing Random (remote) */ 106 u8 pcnf[16]; /* SMP Pairing Confirm */ 107 u8 tk[16]; /* SMP Temporary Key */ 108 u8 rr[16]; /* Remote OOB ra/rb value */ 109 u8 lr[16]; /* Local OOB ra/rb value */ 110 u8 enc_key_size; 111 u8 remote_key_dist; 112 bdaddr_t id_addr; 113 u8 id_addr_type; 114 u8 irk[16]; 115 struct smp_csrk *csrk; 116 struct smp_csrk *responder_csrk; 117 struct smp_ltk *ltk; 118 struct smp_ltk *responder_ltk; 119 struct smp_irk *remote_irk; 120 u8 *link_key; 121 unsigned long flags; 122 u8 method; 123 u8 passkey_round; 124 125 /* Secure Connections variables */ 126 u8 local_pk[64]; 127 u8 remote_pk[64]; 128 u8 dhkey[32]; 129 u8 mackey[16]; 130 131 struct crypto_shash *tfm_cmac; 132 struct crypto_kpp *tfm_ecdh; 133 }; 134 135 /* These debug key values are defined in the SMP section of the core 136 * specification. debug_pk is the public debug key and debug_sk the 137 * private debug key. 138 */ 139 static const u8 debug_pk[64] = { 140 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 141 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 142 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 143 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20, 144 145 0x8b, 0xd2, 0x89, 0x15, 0xd0, 0x8e, 0x1c, 0x74, 146 0x24, 0x30, 0xed, 0x8f, 0xc2, 0x45, 0x63, 0x76, 147 0x5c, 0x15, 0x52, 0x5a, 0xbf, 0x9a, 0x32, 0x63, 148 0x6d, 0xeb, 0x2a, 0x65, 0x49, 0x9c, 0x80, 0xdc, 149 }; 150 151 static const u8 debug_sk[32] = { 152 0xbd, 0x1a, 0x3c, 0xcd, 0xa6, 0xb8, 0x99, 0x58, 153 0x99, 0xb7, 0x40, 0xeb, 0x7b, 0x60, 0xff, 0x4a, 154 0x50, 0x3f, 0x10, 0xd2, 0xe3, 0xb3, 0xc9, 0x74, 155 0x38, 0x5f, 0xc5, 0xa3, 0xd4, 0xf6, 0x49, 0x3f, 156 }; 157 158 static inline void swap_buf(const u8 *src, u8 *dst, size_t len) 159 { 160 size_t i; 161 162 for (i = 0; i < len; i++) 163 dst[len - 1 - i] = src[i]; 164 } 165 166 /* The following functions map to the LE SC SMP crypto functions 167 * AES-CMAC, f4, f5, f6, g2 and h6. 168 */ 169 170 static int aes_cmac(struct crypto_shash *tfm, const u8 k[16], const u8 *m, 171 size_t len, u8 mac[16]) 172 { 173 uint8_t tmp[16], mac_msb[16], msg_msb[CMAC_MSG_MAX]; 174 int err; 175 176 if (len > CMAC_MSG_MAX) 177 return -EFBIG; 178 179 if (!tfm) { 180 BT_ERR("tfm %p", tfm); 181 return -EINVAL; 182 } 183 184 /* Swap key and message from LSB to MSB */ 185 swap_buf(k, tmp, 16); 186 swap_buf(m, msg_msb, len); 187 188 SMP_DBG("msg (len %zu) %*phN", len, (int) len, m); 189 SMP_DBG("key %16phN", k); 190 191 err = crypto_shash_setkey(tfm, tmp, 16); 192 if (err) { 193 BT_ERR("cipher setkey failed: %d", err); 194 return err; 195 } 196 197 err = crypto_shash_tfm_digest(tfm, msg_msb, len, mac_msb); 198 if (err) { 199 BT_ERR("Hash computation error %d", err); 200 return err; 201 } 202 203 swap_buf(mac_msb, mac, 16); 204 205 SMP_DBG("mac %16phN", mac); 206 207 return 0; 208 } 209 210 static int smp_f4(struct crypto_shash *tfm_cmac, const u8 u[32], 211 const u8 v[32], const u8 x[16], u8 z, u8 res[16]) 212 { 213 u8 m[65]; 214 int err; 215 216 SMP_DBG("u %32phN", u); 217 SMP_DBG("v %32phN", v); 218 SMP_DBG("x %16phN z %02x", x, z); 219 220 m[0] = z; 221 memcpy(m + 1, v, 32); 222 memcpy(m + 33, u, 32); 223 224 err = aes_cmac(tfm_cmac, x, m, sizeof(m), res); 225 if (err) 226 return err; 227 228 SMP_DBG("res %16phN", res); 229 230 return err; 231 } 232 233 static int smp_f5(struct crypto_shash *tfm_cmac, const u8 w[32], 234 const u8 n1[16], const u8 n2[16], const u8 a1[7], 235 const u8 a2[7], u8 mackey[16], u8 ltk[16]) 236 { 237 /* The btle, salt and length "magic" values are as defined in 238 * the SMP section of the Bluetooth core specification. In ASCII 239 * the btle value ends up being 'btle'. The salt is just a 240 * random number whereas length is the value 256 in little 241 * endian format. 242 */ 243 const u8 btle[4] = { 0x65, 0x6c, 0x74, 0x62 }; 244 const u8 salt[16] = { 0xbe, 0x83, 0x60, 0x5a, 0xdb, 0x0b, 0x37, 0x60, 245 0x38, 0xa5, 0xf5, 0xaa, 0x91, 0x83, 0x88, 0x6c }; 246 const u8 length[2] = { 0x00, 0x01 }; 247 u8 m[53], t[16]; 248 int err; 249 250 SMP_DBG("w %32phN", w); 251 SMP_DBG("n1 %16phN n2 %16phN", n1, n2); 252 SMP_DBG("a1 %7phN a2 %7phN", a1, a2); 253 254 err = aes_cmac(tfm_cmac, salt, w, 32, t); 255 if (err) 256 return err; 257 258 SMP_DBG("t %16phN", t); 259 260 memcpy(m, length, 2); 261 memcpy(m + 2, a2, 7); 262 memcpy(m + 9, a1, 7); 263 memcpy(m + 16, n2, 16); 264 memcpy(m + 32, n1, 16); 265 memcpy(m + 48, btle, 4); 266 267 m[52] = 0; /* Counter */ 268 269 err = aes_cmac(tfm_cmac, t, m, sizeof(m), mackey); 270 if (err) 271 return err; 272 273 SMP_DBG("mackey %16phN", mackey); 274 275 m[52] = 1; /* Counter */ 276 277 err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk); 278 if (err) 279 return err; 280 281 SMP_DBG("ltk %16phN", ltk); 282 283 return 0; 284 } 285 286 static int smp_f6(struct crypto_shash *tfm_cmac, const u8 w[16], 287 const u8 n1[16], const u8 n2[16], const u8 r[16], 288 const u8 io_cap[3], const u8 a1[7], const u8 a2[7], 289 u8 res[16]) 290 { 291 u8 m[65]; 292 int err; 293 294 SMP_DBG("w %16phN", w); 295 SMP_DBG("n1 %16phN n2 %16phN", n1, n2); 296 SMP_DBG("r %16phN io_cap %3phN a1 %7phN a2 %7phN", r, io_cap, a1, a2); 297 298 memcpy(m, a2, 7); 299 memcpy(m + 7, a1, 7); 300 memcpy(m + 14, io_cap, 3); 301 memcpy(m + 17, r, 16); 302 memcpy(m + 33, n2, 16); 303 memcpy(m + 49, n1, 16); 304 305 err = aes_cmac(tfm_cmac, w, m, sizeof(m), res); 306 if (err) 307 return err; 308 309 SMP_DBG("res %16phN", res); 310 311 return err; 312 } 313 314 static int smp_g2(struct crypto_shash *tfm_cmac, const u8 u[32], const u8 v[32], 315 const u8 x[16], const u8 y[16], u32 *val) 316 { 317 u8 m[80], tmp[16]; 318 int err; 319 320 SMP_DBG("u %32phN", u); 321 SMP_DBG("v %32phN", v); 322 SMP_DBG("x %16phN y %16phN", x, y); 323 324 memcpy(m, y, 16); 325 memcpy(m + 16, v, 32); 326 memcpy(m + 48, u, 32); 327 328 err = aes_cmac(tfm_cmac, x, m, sizeof(m), tmp); 329 if (err) 330 return err; 331 332 *val = get_unaligned_le32(tmp); 333 *val %= 1000000; 334 335 SMP_DBG("val %06u", *val); 336 337 return 0; 338 } 339 340 static int smp_h6(struct crypto_shash *tfm_cmac, const u8 w[16], 341 const u8 key_id[4], u8 res[16]) 342 { 343 int err; 344 345 SMP_DBG("w %16phN key_id %4phN", w, key_id); 346 347 err = aes_cmac(tfm_cmac, w, key_id, 4, res); 348 if (err) 349 return err; 350 351 SMP_DBG("res %16phN", res); 352 353 return err; 354 } 355 356 static int smp_h7(struct crypto_shash *tfm_cmac, const u8 w[16], 357 const u8 salt[16], u8 res[16]) 358 { 359 int err; 360 361 SMP_DBG("w %16phN salt %16phN", w, salt); 362 363 err = aes_cmac(tfm_cmac, salt, w, 16, res); 364 if (err) 365 return err; 366 367 SMP_DBG("res %16phN", res); 368 369 return err; 370 } 371 372 /* The following functions map to the legacy SMP crypto functions e, c1, 373 * s1 and ah. 374 */ 375 376 static int smp_e(const u8 *k, u8 *r) 377 { 378 struct crypto_aes_ctx ctx; 379 uint8_t tmp[16], data[16]; 380 int err; 381 382 SMP_DBG("k %16phN r %16phN", k, r); 383 384 /* The most significant octet of key corresponds to k[0] */ 385 swap_buf(k, tmp, 16); 386 387 err = aes_expandkey(&ctx, tmp, 16); 388 if (err) { 389 BT_ERR("cipher setkey failed: %d", err); 390 return err; 391 } 392 393 /* Most significant octet of plaintextData corresponds to data[0] */ 394 swap_buf(r, data, 16); 395 396 aes_encrypt(&ctx, data, data); 397 398 /* Most significant octet of encryptedData corresponds to data[0] */ 399 swap_buf(data, r, 16); 400 401 SMP_DBG("r %16phN", r); 402 403 memzero_explicit(&ctx, sizeof(ctx)); 404 return err; 405 } 406 407 static int smp_c1(const u8 k[16], 408 const u8 r[16], const u8 preq[7], const u8 pres[7], u8 _iat, 409 const bdaddr_t *ia, u8 _rat, const bdaddr_t *ra, u8 res[16]) 410 { 411 u8 p1[16], p2[16]; 412 int err; 413 414 SMP_DBG("k %16phN r %16phN", k, r); 415 SMP_DBG("iat %u ia %6phN rat %u ra %6phN", _iat, ia, _rat, ra); 416 SMP_DBG("preq %7phN pres %7phN", preq, pres); 417 418 memset(p1, 0, 16); 419 420 /* p1 = pres || preq || _rat || _iat */ 421 p1[0] = _iat; 422 p1[1] = _rat; 423 memcpy(p1 + 2, preq, 7); 424 memcpy(p1 + 9, pres, 7); 425 426 SMP_DBG("p1 %16phN", p1); 427 428 /* res = r XOR p1 */ 429 crypto_xor_cpy(res, r, p1, sizeof(p1)); 430 431 /* res = e(k, res) */ 432 err = smp_e(k, res); 433 if (err) { 434 BT_ERR("Encrypt data error"); 435 return err; 436 } 437 438 /* p2 = padding || ia || ra */ 439 memcpy(p2, ra, 6); 440 memcpy(p2 + 6, ia, 6); 441 memset(p2 + 12, 0, 4); 442 443 SMP_DBG("p2 %16phN", p2); 444 445 /* res = res XOR p2 */ 446 crypto_xor(res, p2, sizeof(p2)); 447 448 /* res = e(k, res) */ 449 err = smp_e(k, res); 450 if (err) 451 BT_ERR("Encrypt data error"); 452 453 return err; 454 } 455 456 static int smp_s1(const u8 k[16], 457 const u8 r1[16], const u8 r2[16], u8 _r[16]) 458 { 459 int err; 460 461 /* Just least significant octets from r1 and r2 are considered */ 462 memcpy(_r, r2, 8); 463 memcpy(_r + 8, r1, 8); 464 465 err = smp_e(k, _r); 466 if (err) 467 BT_ERR("Encrypt data error"); 468 469 return err; 470 } 471 472 static int smp_ah(const u8 irk[16], const u8 r[3], u8 res[3]) 473 { 474 u8 _res[16]; 475 int err; 476 477 /* r' = padding || r */ 478 memcpy(_res, r, 3); 479 memset(_res + 3, 0, 13); 480 481 err = smp_e(irk, _res); 482 if (err) { 483 BT_ERR("Encrypt error"); 484 return err; 485 } 486 487 /* The output of the random address function ah is: 488 * ah(k, r) = e(k, r') mod 2^24 489 * The output of the security function e is then truncated to 24 bits 490 * by taking the least significant 24 bits of the output of e as the 491 * result of ah. 492 */ 493 memcpy(res, _res, 3); 494 495 return 0; 496 } 497 498 bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16], 499 const bdaddr_t *bdaddr) 500 { 501 struct l2cap_chan *chan = hdev->smp_data; 502 u8 hash[3]; 503 int err; 504 505 if (!chan || !chan->data) 506 return false; 507 508 bt_dev_dbg(hdev, "RPA %pMR IRK %*phN", bdaddr, 16, irk); 509 510 err = smp_ah(irk, &bdaddr->b[3], hash); 511 if (err) 512 return false; 513 514 return !crypto_memneq(bdaddr->b, hash, 3); 515 } 516 517 int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa) 518 { 519 struct l2cap_chan *chan = hdev->smp_data; 520 int err; 521 522 if (!chan || !chan->data) 523 return -EOPNOTSUPP; 524 525 get_random_bytes(&rpa->b[3], 3); 526 527 rpa->b[5] &= 0x3f; /* Clear two most significant bits */ 528 rpa->b[5] |= 0x40; /* Set second most significant bit */ 529 530 err = smp_ah(irk, &rpa->b[3], rpa->b); 531 if (err < 0) 532 return err; 533 534 bt_dev_dbg(hdev, "RPA %pMR", rpa); 535 536 return 0; 537 } 538 539 int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16]) 540 { 541 struct l2cap_chan *chan = hdev->smp_data; 542 struct smp_dev *smp; 543 int err; 544 545 if (!chan || !chan->data) 546 return -EOPNOTSUPP; 547 548 smp = chan->data; 549 550 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { 551 bt_dev_dbg(hdev, "Using debug keys"); 552 err = set_ecdh_privkey(smp->tfm_ecdh, debug_sk); 553 if (err) 554 return err; 555 memcpy(smp->local_pk, debug_pk, 64); 556 smp->debug_key = true; 557 } else { 558 while (true) { 559 /* Generate key pair for Secure Connections */ 560 err = generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk); 561 if (err) 562 return err; 563 564 /* This is unlikely, but we need to check that 565 * we didn't accidentally generate a debug key. 566 */ 567 if (crypto_memneq(smp->local_pk, debug_pk, 64)) 568 break; 569 } 570 smp->debug_key = false; 571 } 572 573 SMP_DBG("OOB Public Key X: %32phN", smp->local_pk); 574 SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32); 575 576 get_random_bytes(smp->local_rand, 16); 577 578 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->local_pk, 579 smp->local_rand, 0, hash); 580 if (err < 0) 581 return err; 582 583 memcpy(rand, smp->local_rand, 16); 584 585 smp->local_oob = true; 586 587 return 0; 588 } 589 590 static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data) 591 { 592 struct l2cap_chan *chan = conn->smp; 593 struct smp_chan *smp; 594 struct kvec iv[2]; 595 struct msghdr msg; 596 597 if (!chan) 598 return; 599 600 bt_dev_dbg(conn->hcon->hdev, "code 0x%2.2x", code); 601 602 iv[0].iov_base = &code; 603 iv[0].iov_len = 1; 604 605 iv[1].iov_base = data; 606 iv[1].iov_len = len; 607 608 memset(&msg, 0, sizeof(msg)); 609 610 iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iv, 2, 1 + len); 611 612 l2cap_chan_send(chan, &msg, 1 + len); 613 614 if (!chan->data) 615 return; 616 617 smp = chan->data; 618 619 cancel_delayed_work_sync(&smp->security_timer); 620 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT); 621 } 622 623 static u8 authreq_to_seclevel(u8 authreq) 624 { 625 if (authreq & SMP_AUTH_MITM) { 626 if (authreq & SMP_AUTH_SC) 627 return BT_SECURITY_FIPS; 628 else 629 return BT_SECURITY_HIGH; 630 } else { 631 return BT_SECURITY_MEDIUM; 632 } 633 } 634 635 static __u8 seclevel_to_authreq(__u8 sec_level) 636 { 637 switch (sec_level) { 638 case BT_SECURITY_FIPS: 639 case BT_SECURITY_HIGH: 640 return SMP_AUTH_MITM | SMP_AUTH_BONDING; 641 case BT_SECURITY_MEDIUM: 642 return SMP_AUTH_BONDING; 643 default: 644 return SMP_AUTH_NONE; 645 } 646 } 647 648 static void build_pairing_cmd(struct l2cap_conn *conn, 649 struct smp_cmd_pairing *req, 650 struct smp_cmd_pairing *rsp, __u8 authreq) 651 { 652 struct l2cap_chan *chan = conn->smp; 653 struct smp_chan *smp = chan->data; 654 struct hci_conn *hcon = conn->hcon; 655 struct hci_dev *hdev = hcon->hdev; 656 u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT; 657 658 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { 659 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 660 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 661 authreq |= SMP_AUTH_BONDING; 662 } else { 663 authreq &= ~SMP_AUTH_BONDING; 664 } 665 666 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) 667 remote_dist |= SMP_DIST_ID_KEY; 668 669 if (hci_dev_test_flag(hdev, HCI_PRIVACY)) 670 local_dist |= SMP_DIST_ID_KEY; 671 672 if (hci_dev_test_flag(hdev, HCI_SC_ENABLED) && 673 (authreq & SMP_AUTH_SC)) { 674 struct oob_data *oob_data; 675 u8 bdaddr_type; 676 677 if (hci_dev_test_flag(hdev, HCI_SSP_ENABLED)) { 678 local_dist |= SMP_DIST_LINK_KEY; 679 remote_dist |= SMP_DIST_LINK_KEY; 680 } 681 682 if (hcon->dst_type == ADDR_LE_DEV_PUBLIC) 683 bdaddr_type = BDADDR_LE_PUBLIC; 684 else 685 bdaddr_type = BDADDR_LE_RANDOM; 686 687 oob_data = hci_find_remote_oob_data(hdev, &hcon->dst, 688 bdaddr_type); 689 if (oob_data && oob_data->present) { 690 set_bit(SMP_FLAG_REMOTE_OOB, &smp->flags); 691 oob_flag = SMP_OOB_PRESENT; 692 memcpy(smp->rr, oob_data->rand256, 16); 693 memcpy(smp->pcnf, oob_data->hash256, 16); 694 SMP_DBG("OOB Remote Confirmation: %16phN", smp->pcnf); 695 SMP_DBG("OOB Remote Random: %16phN", smp->rr); 696 } 697 698 } else { 699 authreq &= ~SMP_AUTH_SC; 700 } 701 702 if (rsp == NULL) { 703 req->io_capability = conn->hcon->io_capability; 704 req->oob_flag = oob_flag; 705 req->max_key_size = hdev->le_max_key_size; 706 req->init_key_dist = local_dist; 707 req->resp_key_dist = remote_dist; 708 req->auth_req = (authreq & AUTH_REQ_MASK(hdev)); 709 710 smp->remote_key_dist = remote_dist; 711 return; 712 } 713 714 rsp->io_capability = conn->hcon->io_capability; 715 rsp->oob_flag = oob_flag; 716 rsp->max_key_size = hdev->le_max_key_size; 717 rsp->init_key_dist = req->init_key_dist & remote_dist; 718 rsp->resp_key_dist = req->resp_key_dist & local_dist; 719 rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev)); 720 721 smp->remote_key_dist = rsp->init_key_dist; 722 } 723 724 static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size) 725 { 726 struct l2cap_chan *chan = conn->smp; 727 struct hci_dev *hdev = conn->hcon->hdev; 728 struct smp_chan *smp = chan->data; 729 730 if (conn->hcon->pending_sec_level == BT_SECURITY_FIPS && 731 max_key_size != SMP_MAX_ENC_KEY_SIZE) 732 return SMP_ENC_KEY_SIZE; 733 734 if (max_key_size > hdev->le_max_key_size || 735 max_key_size < SMP_MIN_ENC_KEY_SIZE) 736 return SMP_ENC_KEY_SIZE; 737 738 smp->enc_key_size = max_key_size; 739 740 return 0; 741 } 742 743 static void smp_chan_destroy(struct l2cap_conn *conn) 744 { 745 struct l2cap_chan *chan = conn->smp; 746 struct smp_chan *smp = chan->data; 747 struct hci_conn *hcon = conn->hcon; 748 bool complete; 749 750 BUG_ON(!smp); 751 752 cancel_delayed_work_sync(&smp->security_timer); 753 754 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags); 755 mgmt_smp_complete(hcon, complete); 756 757 kfree_sensitive(smp->csrk); 758 kfree_sensitive(smp->responder_csrk); 759 kfree_sensitive(smp->link_key); 760 761 crypto_free_shash(smp->tfm_cmac); 762 crypto_free_kpp(smp->tfm_ecdh); 763 764 /* Ensure that we don't leave any debug key around if debug key 765 * support hasn't been explicitly enabled. 766 */ 767 if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG && 768 !hci_dev_test_flag(hcon->hdev, HCI_KEEP_DEBUG_KEYS)) { 769 list_del_rcu(&smp->ltk->list); 770 kfree_rcu(smp->ltk, rcu); 771 smp->ltk = NULL; 772 } 773 774 /* If pairing failed clean up any keys we might have */ 775 if (!complete) { 776 if (smp->ltk) { 777 list_del_rcu(&smp->ltk->list); 778 kfree_rcu(smp->ltk, rcu); 779 } 780 781 if (smp->responder_ltk) { 782 list_del_rcu(&smp->responder_ltk->list); 783 kfree_rcu(smp->responder_ltk, rcu); 784 } 785 786 if (smp->remote_irk) { 787 list_del_rcu(&smp->remote_irk->list); 788 kfree_rcu(smp->remote_irk, rcu); 789 } 790 } 791 792 chan->data = NULL; 793 kfree_sensitive(smp); 794 hci_conn_drop(hcon); 795 } 796 797 static void smp_failure(struct l2cap_conn *conn, u8 reason) 798 { 799 struct hci_conn *hcon = conn->hcon; 800 struct l2cap_chan *chan = conn->smp; 801 802 if (reason) 803 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason), 804 &reason); 805 806 mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE); 807 808 if (chan->data) 809 smp_chan_destroy(conn); 810 } 811 812 #define JUST_WORKS 0x00 813 #define JUST_CFM 0x01 814 #define REQ_PASSKEY 0x02 815 #define CFM_PASSKEY 0x03 816 #define REQ_OOB 0x04 817 #define DSP_PASSKEY 0x05 818 #define OVERLAP 0xFF 819 820 static const u8 gen_method[5][5] = { 821 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 822 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 823 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 824 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM }, 825 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP }, 826 }; 827 828 static const u8 sc_method[5][5] = { 829 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 830 { JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 831 { DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY }, 832 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM }, 833 { DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 834 }; 835 836 static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io) 837 { 838 /* If either side has unknown io_caps, use JUST_CFM (which gets 839 * converted later to JUST_WORKS if we're initiators. 840 */ 841 if (local_io > SMP_IO_KEYBOARD_DISPLAY || 842 remote_io > SMP_IO_KEYBOARD_DISPLAY) 843 return JUST_CFM; 844 845 if (test_bit(SMP_FLAG_SC, &smp->flags)) 846 return sc_method[remote_io][local_io]; 847 848 return gen_method[remote_io][local_io]; 849 } 850 851 static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth, 852 u8 local_io, u8 remote_io) 853 { 854 struct hci_conn *hcon = conn->hcon; 855 struct l2cap_chan *chan = conn->smp; 856 struct smp_chan *smp = chan->data; 857 u32 passkey = 0; 858 int ret; 859 860 /* Initialize key for JUST WORKS */ 861 memset(smp->tk, 0, sizeof(smp->tk)); 862 clear_bit(SMP_FLAG_TK_VALID, &smp->flags); 863 864 bt_dev_dbg(hcon->hdev, "auth:%u lcl:%u rem:%u", auth, local_io, 865 remote_io); 866 867 /* If neither side wants MITM, either "just" confirm an incoming 868 * request or use just-works for outgoing ones. The JUST_CFM 869 * will be converted to JUST_WORKS if necessary later in this 870 * function. If either side has MITM look up the method from the 871 * table. 872 */ 873 if (!(auth & SMP_AUTH_MITM)) 874 smp->method = JUST_CFM; 875 else 876 smp->method = get_auth_method(smp, local_io, remote_io); 877 878 /* Don't confirm locally initiated pairing attempts */ 879 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, 880 &smp->flags)) 881 smp->method = JUST_WORKS; 882 883 /* Don't bother user space with no IO capabilities */ 884 if (smp->method == JUST_CFM && 885 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 886 smp->method = JUST_WORKS; 887 888 /* If Just Works, Continue with Zero TK and ask user-space for 889 * confirmation */ 890 if (smp->method == JUST_WORKS) { 891 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, 892 hcon->type, 893 hcon->dst_type, 894 passkey, 1); 895 if (ret) 896 return ret; 897 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 898 return 0; 899 } 900 901 /* If this function is used for SC -> legacy fallback we 902 * can only recover the just-works case. 903 */ 904 if (test_bit(SMP_FLAG_SC, &smp->flags)) 905 return -EINVAL; 906 907 /* Not Just Works/Confirm results in MITM Authentication */ 908 if (smp->method != JUST_CFM) { 909 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags); 910 if (hcon->pending_sec_level < BT_SECURITY_HIGH) 911 hcon->pending_sec_level = BT_SECURITY_HIGH; 912 } 913 914 /* If both devices have Keyboard-Display I/O, the initiator 915 * Confirms and the responder Enters the passkey. 916 */ 917 if (smp->method == OVERLAP) { 918 if (hcon->role == HCI_ROLE_MASTER) 919 smp->method = CFM_PASSKEY; 920 else 921 smp->method = REQ_PASSKEY; 922 } 923 924 /* Generate random passkey. */ 925 if (smp->method == CFM_PASSKEY) { 926 memset(smp->tk, 0, sizeof(smp->tk)); 927 get_random_bytes(&passkey, sizeof(passkey)); 928 passkey %= 1000000; 929 put_unaligned_le32(passkey, smp->tk); 930 bt_dev_dbg(hcon->hdev, "PassKey: %u", passkey); 931 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 932 } 933 934 if (smp->method == REQ_PASSKEY) 935 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst, 936 hcon->type, hcon->dst_type); 937 else if (smp->method == JUST_CFM) 938 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, 939 hcon->type, hcon->dst_type, 940 passkey, 1); 941 else 942 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst, 943 hcon->type, hcon->dst_type, 944 passkey, 0); 945 946 return ret; 947 } 948 949 static u8 smp_confirm(struct smp_chan *smp) 950 { 951 struct l2cap_conn *conn = smp->conn; 952 struct smp_cmd_pairing_confirm cp; 953 int ret; 954 955 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 956 957 ret = smp_c1(smp->tk, smp->prnd, smp->preq, smp->prsp, 958 conn->hcon->init_addr_type, &conn->hcon->init_addr, 959 conn->hcon->resp_addr_type, &conn->hcon->resp_addr, 960 cp.confirm_val); 961 if (ret) 962 return SMP_UNSPECIFIED; 963 964 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 965 966 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp); 967 968 if (conn->hcon->out) 969 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 970 else 971 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 972 973 return 0; 974 } 975 976 static u8 smp_random(struct smp_chan *smp) 977 { 978 struct l2cap_conn *conn = smp->conn; 979 struct hci_conn *hcon = conn->hcon; 980 u8 confirm[16]; 981 int ret; 982 983 bt_dev_dbg(conn->hcon->hdev, "conn %p %s", conn, 984 conn->hcon->out ? "initiator" : "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 (hcon->out) { 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 mgmt_new_irk(hdev, smp->remote_irk, persistent); 1064 1065 /* Now that user space can be considered to know the 1066 * identity address track the connection based on it 1067 * from now on (assuming this is an LE link). 1068 */ 1069 if (hcon->type == LE_LINK) { 1070 bacpy(&hcon->dst, &smp->remote_irk->bdaddr); 1071 hcon->dst_type = smp->remote_irk->addr_type; 1072 /* Use a short delay to make sure the new address is 1073 * propagated _before_ the channels. 1074 */ 1075 queue_delayed_work(hdev->workqueue, 1076 &conn->id_addr_timer, 1077 ID_ADDR_TIMEOUT); 1078 } 1079 } 1080 1081 if (smp->csrk) { 1082 smp->csrk->bdaddr_type = hcon->dst_type; 1083 bacpy(&smp->csrk->bdaddr, &hcon->dst); 1084 mgmt_new_csrk(hdev, smp->csrk, persistent); 1085 } 1086 1087 if (smp->responder_csrk) { 1088 smp->responder_csrk->bdaddr_type = hcon->dst_type; 1089 bacpy(&smp->responder_csrk->bdaddr, &hcon->dst); 1090 mgmt_new_csrk(hdev, smp->responder_csrk, persistent); 1091 } 1092 1093 if (smp->ltk) { 1094 smp->ltk->bdaddr_type = hcon->dst_type; 1095 bacpy(&smp->ltk->bdaddr, &hcon->dst); 1096 mgmt_new_ltk(hdev, smp->ltk, persistent); 1097 } 1098 1099 if (smp->responder_ltk) { 1100 smp->responder_ltk->bdaddr_type = hcon->dst_type; 1101 bacpy(&smp->responder_ltk->bdaddr, &hcon->dst); 1102 mgmt_new_ltk(hdev, smp->responder_ltk, persistent); 1103 } 1104 1105 if (smp->link_key) { 1106 struct link_key *key; 1107 u8 type; 1108 1109 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags)) 1110 type = HCI_LK_DEBUG_COMBINATION; 1111 else if (hcon->sec_level == BT_SECURITY_FIPS) 1112 type = HCI_LK_AUTH_COMBINATION_P256; 1113 else 1114 type = HCI_LK_UNAUTH_COMBINATION_P256; 1115 1116 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst, 1117 smp->link_key, type, 0, &persistent); 1118 if (key) { 1119 mgmt_new_link_key(hdev, key, persistent); 1120 1121 /* Don't keep debug keys around if the relevant 1122 * flag is not set. 1123 */ 1124 if (!hci_dev_test_flag(hdev, HCI_KEEP_DEBUG_KEYS) && 1125 key->type == HCI_LK_DEBUG_COMBINATION) { 1126 list_del_rcu(&key->list); 1127 kfree_rcu(key, rcu); 1128 } 1129 } 1130 } 1131 } 1132 1133 static void sc_add_ltk(struct smp_chan *smp) 1134 { 1135 struct hci_conn *hcon = smp->conn->hcon; 1136 u8 key_type, auth; 1137 1138 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags)) 1139 key_type = SMP_LTK_P256_DEBUG; 1140 else 1141 key_type = SMP_LTK_P256; 1142 1143 if (hcon->pending_sec_level == BT_SECURITY_FIPS) 1144 auth = 1; 1145 else 1146 auth = 0; 1147 1148 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 1149 key_type, auth, smp->tk, smp->enc_key_size, 1150 0, 0); 1151 } 1152 1153 static void sc_generate_link_key(struct smp_chan *smp) 1154 { 1155 /* From core spec. Spells out in ASCII as 'lebr'. */ 1156 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c }; 1157 1158 smp->link_key = kzalloc(16, GFP_KERNEL); 1159 if (!smp->link_key) 1160 return; 1161 1162 if (test_bit(SMP_FLAG_CT2, &smp->flags)) { 1163 /* SALT = 0x000000000000000000000000746D7031 */ 1164 const u8 salt[16] = { 0x31, 0x70, 0x6d, 0x74 }; 1165 1166 if (smp_h7(smp->tfm_cmac, smp->tk, salt, smp->link_key)) { 1167 kfree_sensitive(smp->link_key); 1168 smp->link_key = NULL; 1169 return; 1170 } 1171 } else { 1172 /* From core spec. Spells out in ASCII as 'tmp1'. */ 1173 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 }; 1174 1175 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) { 1176 kfree_sensitive(smp->link_key); 1177 smp->link_key = NULL; 1178 return; 1179 } 1180 } 1181 1182 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) { 1183 kfree_sensitive(smp->link_key); 1184 smp->link_key = NULL; 1185 return; 1186 } 1187 } 1188 1189 static void smp_allow_key_dist(struct smp_chan *smp) 1190 { 1191 /* Allow the first expected phase 3 PDU. The rest of the PDUs 1192 * will be allowed in each PDU handler to ensure we receive 1193 * them in the correct order. 1194 */ 1195 if (smp->remote_key_dist & SMP_DIST_ENC_KEY) 1196 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO); 1197 else if (smp->remote_key_dist & SMP_DIST_ID_KEY) 1198 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); 1199 else if (smp->remote_key_dist & SMP_DIST_SIGN) 1200 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 1201 } 1202 1203 static void sc_generate_ltk(struct smp_chan *smp) 1204 { 1205 /* From core spec. Spells out in ASCII as 'brle'. */ 1206 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 }; 1207 struct hci_conn *hcon = smp->conn->hcon; 1208 struct hci_dev *hdev = hcon->hdev; 1209 struct link_key *key; 1210 1211 key = hci_find_link_key(hdev, &hcon->dst); 1212 if (!key) { 1213 bt_dev_err(hdev, "no Link Key found to generate LTK"); 1214 return; 1215 } 1216 1217 if (key->type == HCI_LK_DEBUG_COMBINATION) 1218 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1219 1220 if (test_bit(SMP_FLAG_CT2, &smp->flags)) { 1221 /* SALT = 0x000000000000000000000000746D7032 */ 1222 const u8 salt[16] = { 0x32, 0x70, 0x6d, 0x74 }; 1223 1224 if (smp_h7(smp->tfm_cmac, key->val, salt, smp->tk)) 1225 return; 1226 } else { 1227 /* From core spec. Spells out in ASCII as 'tmp2'. */ 1228 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 }; 1229 1230 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk)) 1231 return; 1232 } 1233 1234 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk)) 1235 return; 1236 1237 sc_add_ltk(smp); 1238 } 1239 1240 static void smp_distribute_keys(struct smp_chan *smp) 1241 { 1242 struct smp_cmd_pairing *req, *rsp; 1243 struct l2cap_conn *conn = smp->conn; 1244 struct hci_conn *hcon = conn->hcon; 1245 struct hci_dev *hdev = hcon->hdev; 1246 __u8 *keydist; 1247 1248 bt_dev_dbg(hdev, "conn %p", conn); 1249 1250 rsp = (void *) &smp->prsp[1]; 1251 1252 /* The responder sends its keys first */ 1253 if (hcon->out && (smp->remote_key_dist & KEY_DIST_MASK)) { 1254 smp_allow_key_dist(smp); 1255 return; 1256 } 1257 1258 req = (void *) &smp->preq[1]; 1259 1260 if (hcon->out) { 1261 keydist = &rsp->init_key_dist; 1262 *keydist &= req->init_key_dist; 1263 } else { 1264 keydist = &rsp->resp_key_dist; 1265 *keydist &= req->resp_key_dist; 1266 } 1267 1268 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1269 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY)) 1270 sc_generate_link_key(smp); 1271 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY)) 1272 sc_generate_ltk(smp); 1273 1274 /* Clear the keys which are generated but not distributed */ 1275 *keydist &= ~SMP_SC_NO_DIST; 1276 } 1277 1278 bt_dev_dbg(hdev, "keydist 0x%x", *keydist); 1279 1280 if (*keydist & SMP_DIST_ENC_KEY) { 1281 struct smp_cmd_encrypt_info enc; 1282 struct smp_cmd_initiator_ident ident; 1283 struct smp_ltk *ltk; 1284 u8 authenticated; 1285 __le16 ediv; 1286 __le64 rand; 1287 1288 /* Make sure we generate only the significant amount of 1289 * bytes based on the encryption key size, and set the rest 1290 * of the value to zeroes. 1291 */ 1292 get_random_bytes(enc.ltk, smp->enc_key_size); 1293 memset(enc.ltk + smp->enc_key_size, 0, 1294 sizeof(enc.ltk) - smp->enc_key_size); 1295 1296 get_random_bytes(&ediv, sizeof(ediv)); 1297 get_random_bytes(&rand, sizeof(rand)); 1298 1299 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc); 1300 1301 authenticated = hcon->sec_level == BT_SECURITY_HIGH; 1302 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, 1303 SMP_LTK_RESPONDER, authenticated, enc.ltk, 1304 smp->enc_key_size, ediv, rand); 1305 smp->responder_ltk = ltk; 1306 1307 ident.ediv = ediv; 1308 ident.rand = rand; 1309 1310 smp_send_cmd(conn, SMP_CMD_INITIATOR_IDENT, sizeof(ident), 1311 &ident); 1312 1313 *keydist &= ~SMP_DIST_ENC_KEY; 1314 } 1315 1316 if (*keydist & SMP_DIST_ID_KEY) { 1317 struct smp_cmd_ident_addr_info addrinfo; 1318 struct smp_cmd_ident_info idinfo; 1319 1320 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk)); 1321 1322 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo); 1323 1324 /* The hci_conn contains the local identity address 1325 * after the connection has been established. 1326 * 1327 * This is true even when the connection has been 1328 * established using a resolvable random address. 1329 */ 1330 bacpy(&addrinfo.bdaddr, &hcon->src); 1331 addrinfo.addr_type = hcon->src_type; 1332 1333 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo), 1334 &addrinfo); 1335 1336 *keydist &= ~SMP_DIST_ID_KEY; 1337 } 1338 1339 if (*keydist & SMP_DIST_SIGN) { 1340 struct smp_cmd_sign_info sign; 1341 struct smp_csrk *csrk; 1342 1343 /* Generate a new random key */ 1344 get_random_bytes(sign.csrk, sizeof(sign.csrk)); 1345 1346 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); 1347 if (csrk) { 1348 if (hcon->sec_level > BT_SECURITY_MEDIUM) 1349 csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED; 1350 else 1351 csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED; 1352 memcpy(csrk->val, sign.csrk, sizeof(csrk->val)); 1353 } 1354 smp->responder_csrk = csrk; 1355 1356 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign); 1357 1358 *keydist &= ~SMP_DIST_SIGN; 1359 } 1360 1361 /* If there are still keys to be received wait for them */ 1362 if (smp->remote_key_dist & KEY_DIST_MASK) { 1363 smp_allow_key_dist(smp); 1364 return; 1365 } 1366 1367 set_bit(SMP_FLAG_COMPLETE, &smp->flags); 1368 smp_notify_keys(conn); 1369 1370 smp_chan_destroy(conn); 1371 } 1372 1373 static void smp_timeout(struct work_struct *work) 1374 { 1375 struct smp_chan *smp = container_of(work, struct smp_chan, 1376 security_timer.work); 1377 struct l2cap_conn *conn = smp->conn; 1378 1379 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 1380 1381 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM); 1382 } 1383 1384 static struct smp_chan *smp_chan_create(struct l2cap_conn *conn) 1385 { 1386 struct hci_conn *hcon = conn->hcon; 1387 struct l2cap_chan *chan = conn->smp; 1388 struct smp_chan *smp; 1389 1390 smp = kzalloc(sizeof(*smp), GFP_ATOMIC); 1391 if (!smp) 1392 return NULL; 1393 1394 smp->tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 1395 if (IS_ERR(smp->tfm_cmac)) { 1396 bt_dev_err(hcon->hdev, "Unable to create CMAC crypto context"); 1397 goto zfree_smp; 1398 } 1399 1400 smp->tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0); 1401 if (IS_ERR(smp->tfm_ecdh)) { 1402 bt_dev_err(hcon->hdev, "Unable to create ECDH crypto context"); 1403 goto free_shash; 1404 } 1405 1406 smp->conn = conn; 1407 chan->data = smp; 1408 1409 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL); 1410 1411 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout); 1412 1413 hci_conn_hold(hcon); 1414 1415 return smp; 1416 1417 free_shash: 1418 crypto_free_shash(smp->tfm_cmac); 1419 zfree_smp: 1420 kfree_sensitive(smp); 1421 return NULL; 1422 } 1423 1424 static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16]) 1425 { 1426 struct hci_conn *hcon = smp->conn->hcon; 1427 u8 *na, *nb, a[7], b[7]; 1428 1429 if (hcon->out) { 1430 na = smp->prnd; 1431 nb = smp->rrnd; 1432 } else { 1433 na = smp->rrnd; 1434 nb = smp->prnd; 1435 } 1436 1437 memcpy(a, &hcon->init_addr, 6); 1438 memcpy(b, &hcon->resp_addr, 6); 1439 a[6] = hcon->init_addr_type; 1440 b[6] = hcon->resp_addr_type; 1441 1442 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk); 1443 } 1444 1445 static void sc_dhkey_check(struct smp_chan *smp) 1446 { 1447 struct hci_conn *hcon = smp->conn->hcon; 1448 struct smp_cmd_dhkey_check check; 1449 u8 a[7], b[7], *local_addr, *remote_addr; 1450 u8 io_cap[3], r[16]; 1451 1452 memcpy(a, &hcon->init_addr, 6); 1453 memcpy(b, &hcon->resp_addr, 6); 1454 a[6] = hcon->init_addr_type; 1455 b[6] = hcon->resp_addr_type; 1456 1457 if (hcon->out) { 1458 local_addr = a; 1459 remote_addr = b; 1460 memcpy(io_cap, &smp->preq[1], 3); 1461 } else { 1462 local_addr = b; 1463 remote_addr = a; 1464 memcpy(io_cap, &smp->prsp[1], 3); 1465 } 1466 1467 memset(r, 0, sizeof(r)); 1468 1469 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 1470 put_unaligned_le32(hcon->passkey_notify, r); 1471 1472 if (smp->method == REQ_OOB) 1473 memcpy(r, smp->rr, 16); 1474 1475 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap, 1476 local_addr, remote_addr, check.e); 1477 1478 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check); 1479 } 1480 1481 static u8 sc_passkey_send_confirm(struct smp_chan *smp) 1482 { 1483 struct l2cap_conn *conn = smp->conn; 1484 struct hci_conn *hcon = conn->hcon; 1485 struct smp_cmd_pairing_confirm cfm; 1486 u8 r; 1487 1488 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); 1489 r |= 0x80; 1490 1491 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1492 1493 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r, 1494 cfm.confirm_val)) 1495 return SMP_UNSPECIFIED; 1496 1497 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); 1498 1499 return 0; 1500 } 1501 1502 static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op) 1503 { 1504 struct l2cap_conn *conn = smp->conn; 1505 struct hci_conn *hcon = conn->hcon; 1506 struct hci_dev *hdev = hcon->hdev; 1507 u8 cfm[16], r; 1508 1509 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */ 1510 if (smp->passkey_round >= 20) 1511 return 0; 1512 1513 switch (smp_op) { 1514 case SMP_CMD_PAIRING_RANDOM: 1515 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); 1516 r |= 0x80; 1517 1518 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, 1519 smp->rrnd, r, cfm)) 1520 return SMP_UNSPECIFIED; 1521 1522 if (crypto_memneq(smp->pcnf, cfm, 16)) 1523 return SMP_CONFIRM_FAILED; 1524 1525 smp->passkey_round++; 1526 1527 if (smp->passkey_round == 20) { 1528 /* Generate MacKey and LTK */ 1529 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk)) 1530 return SMP_UNSPECIFIED; 1531 } 1532 1533 /* The round is only complete when the initiator 1534 * receives pairing random. 1535 */ 1536 if (!hcon->out) { 1537 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 1538 sizeof(smp->prnd), smp->prnd); 1539 if (smp->passkey_round == 20) 1540 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1541 else 1542 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1543 return 0; 1544 } 1545 1546 /* Start the next round */ 1547 if (smp->passkey_round != 20) 1548 return sc_passkey_round(smp, 0); 1549 1550 /* Passkey rounds are complete - start DHKey Check */ 1551 sc_dhkey_check(smp); 1552 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1553 1554 break; 1555 1556 case SMP_CMD_PAIRING_CONFIRM: 1557 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { 1558 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 1559 return 0; 1560 } 1561 1562 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 1563 1564 if (hcon->out) { 1565 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 1566 sizeof(smp->prnd), smp->prnd); 1567 return 0; 1568 } 1569 1570 return sc_passkey_send_confirm(smp); 1571 1572 case SMP_CMD_PUBLIC_KEY: 1573 default: 1574 /* Initiating device starts the round */ 1575 if (!hcon->out) 1576 return 0; 1577 1578 bt_dev_dbg(hdev, "Starting passkey round %u", 1579 smp->passkey_round + 1); 1580 1581 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1582 1583 return sc_passkey_send_confirm(smp); 1584 } 1585 1586 return 0; 1587 } 1588 1589 static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey) 1590 { 1591 struct l2cap_conn *conn = smp->conn; 1592 struct hci_conn *hcon = conn->hcon; 1593 u8 smp_op; 1594 1595 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags); 1596 1597 switch (mgmt_op) { 1598 case MGMT_OP_USER_PASSKEY_NEG_REPLY: 1599 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED); 1600 return 0; 1601 case MGMT_OP_USER_CONFIRM_NEG_REPLY: 1602 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED); 1603 return 0; 1604 case MGMT_OP_USER_PASSKEY_REPLY: 1605 hcon->passkey_notify = le32_to_cpu(passkey); 1606 smp->passkey_round = 0; 1607 1608 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) 1609 smp_op = SMP_CMD_PAIRING_CONFIRM; 1610 else 1611 smp_op = 0; 1612 1613 if (sc_passkey_round(smp, smp_op)) 1614 return -EIO; 1615 1616 return 0; 1617 } 1618 1619 /* Initiator sends DHKey check first */ 1620 if (hcon->out) { 1621 sc_dhkey_check(smp); 1622 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1623 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) { 1624 sc_dhkey_check(smp); 1625 sc_add_ltk(smp); 1626 } 1627 1628 return 0; 1629 } 1630 1631 int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey) 1632 { 1633 struct l2cap_conn *conn = hcon->l2cap_data; 1634 struct l2cap_chan *chan; 1635 struct smp_chan *smp; 1636 u32 value; 1637 int err; 1638 1639 if (!conn) 1640 return -ENOTCONN; 1641 1642 bt_dev_dbg(conn->hcon->hdev, ""); 1643 1644 chan = conn->smp; 1645 if (!chan) 1646 return -ENOTCONN; 1647 1648 l2cap_chan_lock(chan); 1649 if (!chan->data) { 1650 err = -ENOTCONN; 1651 goto unlock; 1652 } 1653 1654 smp = chan->data; 1655 1656 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1657 err = sc_user_reply(smp, mgmt_op, passkey); 1658 goto unlock; 1659 } 1660 1661 switch (mgmt_op) { 1662 case MGMT_OP_USER_PASSKEY_REPLY: 1663 value = le32_to_cpu(passkey); 1664 memset(smp->tk, 0, sizeof(smp->tk)); 1665 bt_dev_dbg(conn->hcon->hdev, "PassKey: %u", value); 1666 put_unaligned_le32(value, smp->tk); 1667 fallthrough; 1668 case MGMT_OP_USER_CONFIRM_REPLY: 1669 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 1670 break; 1671 case MGMT_OP_USER_PASSKEY_NEG_REPLY: 1672 case MGMT_OP_USER_CONFIRM_NEG_REPLY: 1673 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); 1674 err = 0; 1675 goto unlock; 1676 default: 1677 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); 1678 err = -EOPNOTSUPP; 1679 goto unlock; 1680 } 1681 1682 err = 0; 1683 1684 /* If it is our turn to send Pairing Confirm, do so now */ 1685 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) { 1686 u8 rsp = smp_confirm(smp); 1687 if (rsp) 1688 smp_failure(conn, rsp); 1689 } 1690 1691 unlock: 1692 l2cap_chan_unlock(chan); 1693 return err; 1694 } 1695 1696 static void build_bredr_pairing_cmd(struct smp_chan *smp, 1697 struct smp_cmd_pairing *req, 1698 struct smp_cmd_pairing *rsp) 1699 { 1700 struct l2cap_conn *conn = smp->conn; 1701 struct hci_dev *hdev = conn->hcon->hdev; 1702 u8 local_dist = 0, remote_dist = 0; 1703 1704 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { 1705 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 1706 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 1707 } 1708 1709 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) 1710 remote_dist |= SMP_DIST_ID_KEY; 1711 1712 if (hci_dev_test_flag(hdev, HCI_PRIVACY)) 1713 local_dist |= SMP_DIST_ID_KEY; 1714 1715 if (!rsp) { 1716 memset(req, 0, sizeof(*req)); 1717 1718 req->auth_req = SMP_AUTH_CT2; 1719 req->init_key_dist = local_dist; 1720 req->resp_key_dist = remote_dist; 1721 req->max_key_size = conn->hcon->enc_key_size; 1722 1723 smp->remote_key_dist = remote_dist; 1724 1725 return; 1726 } 1727 1728 memset(rsp, 0, sizeof(*rsp)); 1729 1730 rsp->auth_req = SMP_AUTH_CT2; 1731 rsp->max_key_size = conn->hcon->enc_key_size; 1732 rsp->init_key_dist = req->init_key_dist & remote_dist; 1733 rsp->resp_key_dist = req->resp_key_dist & local_dist; 1734 1735 smp->remote_key_dist = rsp->init_key_dist; 1736 } 1737 1738 static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) 1739 { 1740 struct smp_cmd_pairing rsp, *req = (void *) skb->data; 1741 struct l2cap_chan *chan = conn->smp; 1742 struct hci_dev *hdev = conn->hcon->hdev; 1743 struct smp_chan *smp; 1744 u8 key_size, auth, sec_level; 1745 int ret; 1746 1747 bt_dev_dbg(hdev, "conn %p", conn); 1748 1749 if (skb->len < sizeof(*req)) 1750 return SMP_INVALID_PARAMS; 1751 1752 if (conn->hcon->role != HCI_ROLE_SLAVE) 1753 return SMP_CMD_NOTSUPP; 1754 1755 if (!chan->data) 1756 smp = smp_chan_create(conn); 1757 else 1758 smp = chan->data; 1759 1760 if (!smp) 1761 return SMP_UNSPECIFIED; 1762 1763 /* We didn't start the pairing, so match remote */ 1764 auth = req->auth_req & AUTH_REQ_MASK(hdev); 1765 1766 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && 1767 (auth & SMP_AUTH_BONDING)) 1768 return SMP_PAIRING_NOTSUPP; 1769 1770 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 1771 return SMP_AUTH_REQUIREMENTS; 1772 1773 smp->preq[0] = SMP_CMD_PAIRING_REQ; 1774 memcpy(&smp->preq[1], req, sizeof(*req)); 1775 skb_pull(skb, sizeof(*req)); 1776 1777 /* If the remote side's OOB flag is set it means it has 1778 * successfully received our local OOB data - therefore set the 1779 * flag to indicate that local OOB is in use. 1780 */ 1781 if (req->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob) 1782 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); 1783 1784 /* SMP over BR/EDR requires special treatment */ 1785 if (conn->hcon->type == ACL_LINK) { 1786 /* We must have a BR/EDR SC link */ 1787 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) && 1788 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 1789 return SMP_CROSS_TRANSP_NOT_ALLOWED; 1790 1791 set_bit(SMP_FLAG_SC, &smp->flags); 1792 1793 build_bredr_pairing_cmd(smp, req, &rsp); 1794 1795 if (req->auth_req & SMP_AUTH_CT2) 1796 set_bit(SMP_FLAG_CT2, &smp->flags); 1797 1798 key_size = min(req->max_key_size, rsp.max_key_size); 1799 if (check_enc_key_size(conn, key_size)) 1800 return SMP_ENC_KEY_SIZE; 1801 1802 /* Clear bits which are generated but not distributed */ 1803 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1804 1805 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1806 memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); 1807 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); 1808 1809 smp_distribute_keys(smp); 1810 return 0; 1811 } 1812 1813 build_pairing_cmd(conn, req, &rsp, auth); 1814 1815 if (rsp.auth_req & SMP_AUTH_SC) { 1816 set_bit(SMP_FLAG_SC, &smp->flags); 1817 1818 if (rsp.auth_req & SMP_AUTH_CT2) 1819 set_bit(SMP_FLAG_CT2, &smp->flags); 1820 } 1821 1822 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 1823 sec_level = BT_SECURITY_MEDIUM; 1824 else 1825 sec_level = authreq_to_seclevel(auth); 1826 1827 if (sec_level > conn->hcon->pending_sec_level) 1828 conn->hcon->pending_sec_level = sec_level; 1829 1830 /* If we need MITM check that it can be achieved */ 1831 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { 1832 u8 method; 1833 1834 method = get_auth_method(smp, conn->hcon->io_capability, 1835 req->io_capability); 1836 if (method == JUST_WORKS || method == JUST_CFM) 1837 return SMP_AUTH_REQUIREMENTS; 1838 } 1839 1840 key_size = min(req->max_key_size, rsp.max_key_size); 1841 if (check_enc_key_size(conn, key_size)) 1842 return SMP_ENC_KEY_SIZE; 1843 1844 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1845 1846 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1847 memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); 1848 1849 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); 1850 1851 clear_bit(SMP_FLAG_INITIATOR, &smp->flags); 1852 1853 /* Strictly speaking we shouldn't allow Pairing Confirm for the 1854 * SC case, however some implementations incorrectly copy RFU auth 1855 * req bits from our security request, which may create a false 1856 * positive SC enablement. 1857 */ 1858 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1859 1860 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1861 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); 1862 /* Clear bits which are generated but not distributed */ 1863 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1864 /* Wait for Public Key from Initiating Device */ 1865 return 0; 1866 } 1867 1868 /* Request setup of TK */ 1869 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability); 1870 if (ret) 1871 return SMP_UNSPECIFIED; 1872 1873 return 0; 1874 } 1875 1876 static u8 sc_send_public_key(struct smp_chan *smp) 1877 { 1878 struct hci_dev *hdev = smp->conn->hcon->hdev; 1879 1880 bt_dev_dbg(hdev, ""); 1881 1882 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { 1883 struct l2cap_chan *chan = hdev->smp_data; 1884 struct smp_dev *smp_dev; 1885 1886 if (!chan || !chan->data) 1887 return SMP_UNSPECIFIED; 1888 1889 smp_dev = chan->data; 1890 1891 memcpy(smp->local_pk, smp_dev->local_pk, 64); 1892 memcpy(smp->lr, smp_dev->local_rand, 16); 1893 1894 if (smp_dev->debug_key) 1895 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1896 1897 goto done; 1898 } 1899 1900 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { 1901 bt_dev_dbg(hdev, "Using debug keys"); 1902 if (set_ecdh_privkey(smp->tfm_ecdh, debug_sk)) 1903 return SMP_UNSPECIFIED; 1904 memcpy(smp->local_pk, debug_pk, 64); 1905 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1906 } else { 1907 while (true) { 1908 /* Generate key pair for Secure Connections */ 1909 if (generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk)) 1910 return SMP_UNSPECIFIED; 1911 1912 /* This is unlikely, but we need to check that 1913 * we didn't accidentally generate a debug key. 1914 */ 1915 if (crypto_memneq(smp->local_pk, debug_pk, 64)) 1916 break; 1917 } 1918 } 1919 1920 done: 1921 SMP_DBG("Local Public Key X: %32phN", smp->local_pk); 1922 SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32); 1923 1924 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk); 1925 1926 return 0; 1927 } 1928 1929 static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) 1930 { 1931 struct smp_cmd_pairing *req, *rsp = (void *) skb->data; 1932 struct l2cap_chan *chan = conn->smp; 1933 struct smp_chan *smp = chan->data; 1934 struct hci_dev *hdev = conn->hcon->hdev; 1935 u8 key_size, auth; 1936 int ret; 1937 1938 bt_dev_dbg(hdev, "conn %p", conn); 1939 1940 if (skb->len < sizeof(*rsp)) 1941 return SMP_INVALID_PARAMS; 1942 1943 if (conn->hcon->role != HCI_ROLE_MASTER) 1944 return SMP_CMD_NOTSUPP; 1945 1946 skb_pull(skb, sizeof(*rsp)); 1947 1948 req = (void *) &smp->preq[1]; 1949 1950 key_size = min(req->max_key_size, rsp->max_key_size); 1951 if (check_enc_key_size(conn, key_size)) 1952 return SMP_ENC_KEY_SIZE; 1953 1954 auth = rsp->auth_req & AUTH_REQ_MASK(hdev); 1955 1956 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 1957 return SMP_AUTH_REQUIREMENTS; 1958 1959 /* If the remote side's OOB flag is set it means it has 1960 * successfully received our local OOB data - therefore set the 1961 * flag to indicate that local OOB is in use. 1962 */ 1963 if (rsp->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob) 1964 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); 1965 1966 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1967 memcpy(&smp->prsp[1], rsp, sizeof(*rsp)); 1968 1969 /* Update remote key distribution in case the remote cleared 1970 * some bits that we had enabled in our request. 1971 */ 1972 smp->remote_key_dist &= rsp->resp_key_dist; 1973 1974 if ((req->auth_req & SMP_AUTH_CT2) && (auth & SMP_AUTH_CT2)) 1975 set_bit(SMP_FLAG_CT2, &smp->flags); 1976 1977 /* For BR/EDR this means we're done and can start phase 3 */ 1978 if (conn->hcon->type == ACL_LINK) { 1979 /* Clear bits which are generated but not distributed */ 1980 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1981 smp_distribute_keys(smp); 1982 return 0; 1983 } 1984 1985 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC)) 1986 set_bit(SMP_FLAG_SC, &smp->flags); 1987 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH) 1988 conn->hcon->pending_sec_level = BT_SECURITY_HIGH; 1989 1990 /* If we need MITM check that it can be achieved */ 1991 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { 1992 u8 method; 1993 1994 method = get_auth_method(smp, req->io_capability, 1995 rsp->io_capability); 1996 if (method == JUST_WORKS || method == JUST_CFM) 1997 return SMP_AUTH_REQUIREMENTS; 1998 } 1999 2000 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 2001 2002 /* Update remote key distribution in case the remote cleared 2003 * some bits that we had enabled in our request. 2004 */ 2005 smp->remote_key_dist &= rsp->resp_key_dist; 2006 2007 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 2008 /* Clear bits which are generated but not distributed */ 2009 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 2010 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); 2011 return sc_send_public_key(smp); 2012 } 2013 2014 auth |= req->auth_req; 2015 2016 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability); 2017 if (ret) 2018 return SMP_UNSPECIFIED; 2019 2020 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 2021 2022 /* Can't compose response until we have been confirmed */ 2023 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) 2024 return smp_confirm(smp); 2025 2026 return 0; 2027 } 2028 2029 static u8 sc_check_confirm(struct smp_chan *smp) 2030 { 2031 struct l2cap_conn *conn = smp->conn; 2032 2033 bt_dev_dbg(conn->hcon->hdev, ""); 2034 2035 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2036 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM); 2037 2038 if (conn->hcon->out) { 2039 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2040 smp->prnd); 2041 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2042 } 2043 2044 return 0; 2045 } 2046 2047 /* Work-around for some implementations that incorrectly copy RFU bits 2048 * from our security request and thereby create the impression that 2049 * we're doing SC when in fact the remote doesn't support it. 2050 */ 2051 static int fixup_sc_false_positive(struct smp_chan *smp) 2052 { 2053 struct l2cap_conn *conn = smp->conn; 2054 struct hci_conn *hcon = conn->hcon; 2055 struct hci_dev *hdev = hcon->hdev; 2056 struct smp_cmd_pairing *req, *rsp; 2057 u8 auth; 2058 2059 /* The issue is only observed when we're in responder role */ 2060 if (hcon->out) 2061 return SMP_UNSPECIFIED; 2062 2063 if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) { 2064 bt_dev_err(hdev, "refusing legacy fallback in SC-only mode"); 2065 return SMP_UNSPECIFIED; 2066 } 2067 2068 bt_dev_err(hdev, "trying to fall back to legacy SMP"); 2069 2070 req = (void *) &smp->preq[1]; 2071 rsp = (void *) &smp->prsp[1]; 2072 2073 /* Rebuild key dist flags which may have been cleared for SC */ 2074 smp->remote_key_dist = (req->init_key_dist & rsp->resp_key_dist); 2075 2076 auth = req->auth_req & AUTH_REQ_MASK(hdev); 2077 2078 if (tk_request(conn, 0, auth, rsp->io_capability, req->io_capability)) { 2079 bt_dev_err(hdev, "failed to fall back to legacy SMP"); 2080 return SMP_UNSPECIFIED; 2081 } 2082 2083 clear_bit(SMP_FLAG_SC, &smp->flags); 2084 2085 return 0; 2086 } 2087 2088 static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb) 2089 { 2090 struct l2cap_chan *chan = conn->smp; 2091 struct smp_chan *smp = chan->data; 2092 struct hci_conn *hcon = conn->hcon; 2093 struct hci_dev *hdev = hcon->hdev; 2094 2095 bt_dev_dbg(hdev, "conn %p %s", conn, 2096 hcon->out ? "initiator" : "responder"); 2097 2098 if (skb->len < sizeof(smp->pcnf)) 2099 return SMP_INVALID_PARAMS; 2100 2101 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf)); 2102 skb_pull(skb, sizeof(smp->pcnf)); 2103 2104 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 2105 int ret; 2106 2107 /* Public Key exchange must happen before any other steps */ 2108 if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags)) 2109 return sc_check_confirm(smp); 2110 2111 bt_dev_err(hdev, "Unexpected SMP Pairing Confirm"); 2112 2113 ret = fixup_sc_false_positive(smp); 2114 if (ret) 2115 return ret; 2116 } 2117 2118 if (conn->hcon->out) { 2119 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2120 smp->prnd); 2121 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2122 return 0; 2123 } 2124 2125 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) 2126 return smp_confirm(smp); 2127 2128 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 2129 2130 return 0; 2131 } 2132 2133 static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb) 2134 { 2135 struct l2cap_chan *chan = conn->smp; 2136 struct smp_chan *smp = chan->data; 2137 struct hci_conn *hcon = conn->hcon; 2138 u8 *pkax, *pkbx, *na, *nb, confirm_hint; 2139 u32 passkey; 2140 int err; 2141 2142 bt_dev_dbg(hcon->hdev, "conn %p", conn); 2143 2144 if (skb->len < sizeof(smp->rrnd)) 2145 return SMP_INVALID_PARAMS; 2146 2147 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd)); 2148 skb_pull(skb, sizeof(smp->rrnd)); 2149 2150 if (!test_bit(SMP_FLAG_SC, &smp->flags)) 2151 return smp_random(smp); 2152 2153 if (hcon->out) { 2154 pkax = smp->local_pk; 2155 pkbx = smp->remote_pk; 2156 na = smp->prnd; 2157 nb = smp->rrnd; 2158 } else { 2159 pkax = smp->remote_pk; 2160 pkbx = smp->local_pk; 2161 na = smp->rrnd; 2162 nb = smp->prnd; 2163 } 2164 2165 if (smp->method == REQ_OOB) { 2166 if (!hcon->out) 2167 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 2168 sizeof(smp->prnd), smp->prnd); 2169 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2170 goto mackey_and_ltk; 2171 } 2172 2173 /* Passkey entry has special treatment */ 2174 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2175 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM); 2176 2177 if (hcon->out) { 2178 u8 cfm[16]; 2179 2180 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, 2181 smp->rrnd, 0, cfm); 2182 if (err) 2183 return SMP_UNSPECIFIED; 2184 2185 if (crypto_memneq(smp->pcnf, cfm, 16)) 2186 return SMP_CONFIRM_FAILED; 2187 } else { 2188 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2189 smp->prnd); 2190 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2191 2192 /* Only Just-Works pairing requires extra checks */ 2193 if (smp->method != JUST_WORKS) 2194 goto mackey_and_ltk; 2195 2196 /* If there already exists long term key in local host, leave 2197 * the decision to user space since the remote device could 2198 * be legitimate or malicious. 2199 */ 2200 if (hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 2201 hcon->role)) { 2202 /* Set passkey to 0. The value can be any number since 2203 * it'll be ignored anyway. 2204 */ 2205 passkey = 0; 2206 confirm_hint = 1; 2207 goto confirm; 2208 } 2209 } 2210 2211 mackey_and_ltk: 2212 /* Generate MacKey and LTK */ 2213 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk); 2214 if (err) 2215 return SMP_UNSPECIFIED; 2216 2217 if (smp->method == REQ_OOB) { 2218 if (hcon->out) { 2219 sc_dhkey_check(smp); 2220 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2221 } 2222 return 0; 2223 } 2224 2225 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey); 2226 if (err) 2227 return SMP_UNSPECIFIED; 2228 2229 confirm_hint = 0; 2230 2231 confirm: 2232 if (smp->method == JUST_WORKS) 2233 confirm_hint = 1; 2234 2235 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type, 2236 hcon->dst_type, passkey, confirm_hint); 2237 if (err) 2238 return SMP_UNSPECIFIED; 2239 2240 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 2241 2242 return 0; 2243 } 2244 2245 static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level) 2246 { 2247 struct smp_ltk *key; 2248 struct hci_conn *hcon = conn->hcon; 2249 2250 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role); 2251 if (!key) 2252 return false; 2253 2254 if (smp_ltk_sec_level(key) < sec_level) 2255 return false; 2256 2257 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) 2258 return true; 2259 2260 hci_le_start_enc(hcon, key->ediv, key->rand, key->val, key->enc_size); 2261 hcon->enc_key_size = key->enc_size; 2262 2263 /* We never store STKs for initiator role, so clear this flag */ 2264 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); 2265 2266 return true; 2267 } 2268 2269 bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level, 2270 enum smp_key_pref key_pref) 2271 { 2272 if (sec_level == BT_SECURITY_LOW) 2273 return true; 2274 2275 /* If we're encrypted with an STK but the caller prefers using 2276 * LTK claim insufficient security. This way we allow the 2277 * connection to be re-encrypted with an LTK, even if the LTK 2278 * provides the same level of security. Only exception is if we 2279 * don't have an LTK (e.g. because of key distribution bits). 2280 */ 2281 if (key_pref == SMP_USE_LTK && 2282 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) && 2283 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role)) 2284 return false; 2285 2286 if (hcon->sec_level >= sec_level) 2287 return true; 2288 2289 return false; 2290 } 2291 2292 static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb) 2293 { 2294 struct smp_cmd_security_req *rp = (void *) skb->data; 2295 struct smp_cmd_pairing cp; 2296 struct hci_conn *hcon = conn->hcon; 2297 struct hci_dev *hdev = hcon->hdev; 2298 struct smp_chan *smp; 2299 u8 sec_level, auth; 2300 2301 bt_dev_dbg(hdev, "conn %p", conn); 2302 2303 if (skb->len < sizeof(*rp)) 2304 return SMP_INVALID_PARAMS; 2305 2306 if (hcon->role != HCI_ROLE_MASTER) 2307 return SMP_CMD_NOTSUPP; 2308 2309 auth = rp->auth_req & AUTH_REQ_MASK(hdev); 2310 2311 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 2312 return SMP_AUTH_REQUIREMENTS; 2313 2314 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 2315 sec_level = BT_SECURITY_MEDIUM; 2316 else 2317 sec_level = authreq_to_seclevel(auth); 2318 2319 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) { 2320 /* If link is already encrypted with sufficient security we 2321 * still need refresh encryption as per Core Spec 5.0 Vol 3, 2322 * Part H 2.4.6 2323 */ 2324 smp_ltk_encrypt(conn, hcon->sec_level); 2325 return 0; 2326 } 2327 2328 if (sec_level > hcon->pending_sec_level) 2329 hcon->pending_sec_level = sec_level; 2330 2331 if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) 2332 return 0; 2333 2334 smp = smp_chan_create(conn); 2335 if (!smp) 2336 return SMP_UNSPECIFIED; 2337 2338 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && 2339 (auth & SMP_AUTH_BONDING)) 2340 return SMP_PAIRING_NOTSUPP; 2341 2342 skb_pull(skb, sizeof(*rp)); 2343 2344 memset(&cp, 0, sizeof(cp)); 2345 build_pairing_cmd(conn, &cp, NULL, auth); 2346 2347 smp->preq[0] = SMP_CMD_PAIRING_REQ; 2348 memcpy(&smp->preq[1], &cp, sizeof(cp)); 2349 2350 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); 2351 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 2352 2353 return 0; 2354 } 2355 2356 int smp_conn_security(struct hci_conn *hcon, __u8 sec_level) 2357 { 2358 struct l2cap_conn *conn = hcon->l2cap_data; 2359 struct l2cap_chan *chan; 2360 struct smp_chan *smp; 2361 __u8 authreq; 2362 int ret; 2363 2364 bt_dev_dbg(hcon->hdev, "conn %p hcon %p level 0x%2.2x", conn, hcon, 2365 sec_level); 2366 2367 /* This may be NULL if there's an unexpected disconnection */ 2368 if (!conn) 2369 return 1; 2370 2371 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) 2372 return 1; 2373 2374 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) 2375 return 1; 2376 2377 if (sec_level > hcon->pending_sec_level) 2378 hcon->pending_sec_level = sec_level; 2379 2380 if (hcon->role == HCI_ROLE_MASTER) 2381 if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) 2382 return 0; 2383 2384 chan = conn->smp; 2385 if (!chan) { 2386 bt_dev_err(hcon->hdev, "security requested but not available"); 2387 return 1; 2388 } 2389 2390 l2cap_chan_lock(chan); 2391 2392 /* If SMP is already in progress ignore this request */ 2393 if (chan->data) { 2394 ret = 0; 2395 goto unlock; 2396 } 2397 2398 smp = smp_chan_create(conn); 2399 if (!smp) { 2400 ret = 1; 2401 goto unlock; 2402 } 2403 2404 authreq = seclevel_to_authreq(sec_level); 2405 2406 if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED)) { 2407 authreq |= SMP_AUTH_SC; 2408 if (hci_dev_test_flag(hcon->hdev, HCI_SSP_ENABLED)) 2409 authreq |= SMP_AUTH_CT2; 2410 } 2411 2412 /* Don't attempt to set MITM if setting is overridden by debugfs 2413 * Needed to pass certification test SM/MAS/PKE/BV-01-C 2414 */ 2415 if (!hci_dev_test_flag(hcon->hdev, HCI_FORCE_NO_MITM)) { 2416 /* Require MITM if IO Capability allows or the security level 2417 * requires it. 2418 */ 2419 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT || 2420 hcon->pending_sec_level > BT_SECURITY_MEDIUM) 2421 authreq |= SMP_AUTH_MITM; 2422 } 2423 2424 if (hcon->role == HCI_ROLE_MASTER) { 2425 struct smp_cmd_pairing cp; 2426 2427 build_pairing_cmd(conn, &cp, NULL, authreq); 2428 smp->preq[0] = SMP_CMD_PAIRING_REQ; 2429 memcpy(&smp->preq[1], &cp, sizeof(cp)); 2430 2431 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); 2432 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 2433 } else { 2434 struct smp_cmd_security_req cp; 2435 cp.auth_req = authreq; 2436 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp); 2437 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ); 2438 } 2439 2440 set_bit(SMP_FLAG_INITIATOR, &smp->flags); 2441 ret = 0; 2442 2443 unlock: 2444 l2cap_chan_unlock(chan); 2445 return ret; 2446 } 2447 2448 int smp_cancel_and_remove_pairing(struct hci_dev *hdev, bdaddr_t *bdaddr, 2449 u8 addr_type) 2450 { 2451 struct hci_conn *hcon; 2452 struct l2cap_conn *conn; 2453 struct l2cap_chan *chan; 2454 struct smp_chan *smp; 2455 int err; 2456 2457 err = hci_remove_ltk(hdev, bdaddr, addr_type); 2458 hci_remove_irk(hdev, bdaddr, addr_type); 2459 2460 hcon = hci_conn_hash_lookup_le(hdev, bdaddr, addr_type); 2461 if (!hcon) 2462 goto done; 2463 2464 conn = hcon->l2cap_data; 2465 if (!conn) 2466 goto done; 2467 2468 chan = conn->smp; 2469 if (!chan) 2470 goto done; 2471 2472 l2cap_chan_lock(chan); 2473 2474 smp = chan->data; 2475 if (smp) { 2476 /* Set keys to NULL to make sure smp_failure() does not try to 2477 * remove and free already invalidated rcu list entries. */ 2478 smp->ltk = NULL; 2479 smp->responder_ltk = NULL; 2480 smp->remote_irk = NULL; 2481 2482 if (test_bit(SMP_FLAG_COMPLETE, &smp->flags)) 2483 smp_failure(conn, 0); 2484 else 2485 smp_failure(conn, SMP_UNSPECIFIED); 2486 err = 0; 2487 } 2488 2489 l2cap_chan_unlock(chan); 2490 2491 done: 2492 return err; 2493 } 2494 2495 static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb) 2496 { 2497 struct smp_cmd_encrypt_info *rp = (void *) skb->data; 2498 struct l2cap_chan *chan = conn->smp; 2499 struct smp_chan *smp = chan->data; 2500 2501 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 2502 2503 if (skb->len < sizeof(*rp)) 2504 return SMP_INVALID_PARAMS; 2505 2506 /* Pairing is aborted if any blocked keys are distributed */ 2507 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_LTK, 2508 rp->ltk)) { 2509 bt_dev_warn_ratelimited(conn->hcon->hdev, 2510 "LTK blocked for %pMR", 2511 &conn->hcon->dst); 2512 return SMP_INVALID_PARAMS; 2513 } 2514 2515 SMP_ALLOW_CMD(smp, SMP_CMD_INITIATOR_IDENT); 2516 2517 skb_pull(skb, sizeof(*rp)); 2518 2519 memcpy(smp->tk, rp->ltk, sizeof(smp->tk)); 2520 2521 return 0; 2522 } 2523 2524 static int smp_cmd_initiator_ident(struct l2cap_conn *conn, struct sk_buff *skb) 2525 { 2526 struct smp_cmd_initiator_ident *rp = (void *)skb->data; 2527 struct l2cap_chan *chan = conn->smp; 2528 struct smp_chan *smp = chan->data; 2529 struct hci_dev *hdev = conn->hcon->hdev; 2530 struct hci_conn *hcon = conn->hcon; 2531 struct smp_ltk *ltk; 2532 u8 authenticated; 2533 2534 bt_dev_dbg(hdev, "conn %p", conn); 2535 2536 if (skb->len < sizeof(*rp)) 2537 return SMP_INVALID_PARAMS; 2538 2539 /* Mark the information as received */ 2540 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY; 2541 2542 if (smp->remote_key_dist & SMP_DIST_ID_KEY) 2543 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); 2544 else if (smp->remote_key_dist & SMP_DIST_SIGN) 2545 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 2546 2547 skb_pull(skb, sizeof(*rp)); 2548 2549 authenticated = (hcon->sec_level == BT_SECURITY_HIGH); 2550 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK, 2551 authenticated, smp->tk, smp->enc_key_size, 2552 rp->ediv, rp->rand); 2553 smp->ltk = ltk; 2554 if (!(smp->remote_key_dist & KEY_DIST_MASK)) 2555 smp_distribute_keys(smp); 2556 2557 return 0; 2558 } 2559 2560 static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb) 2561 { 2562 struct smp_cmd_ident_info *info = (void *) skb->data; 2563 struct l2cap_chan *chan = conn->smp; 2564 struct smp_chan *smp = chan->data; 2565 2566 bt_dev_dbg(conn->hcon->hdev, ""); 2567 2568 if (skb->len < sizeof(*info)) 2569 return SMP_INVALID_PARAMS; 2570 2571 /* Pairing is aborted if any blocked keys are distributed */ 2572 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_IRK, 2573 info->irk)) { 2574 bt_dev_warn_ratelimited(conn->hcon->hdev, 2575 "Identity key blocked for %pMR", 2576 &conn->hcon->dst); 2577 return SMP_INVALID_PARAMS; 2578 } 2579 2580 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO); 2581 2582 skb_pull(skb, sizeof(*info)); 2583 2584 memcpy(smp->irk, info->irk, 16); 2585 2586 return 0; 2587 } 2588 2589 static int smp_cmd_ident_addr_info(struct l2cap_conn *conn, 2590 struct sk_buff *skb) 2591 { 2592 struct smp_cmd_ident_addr_info *info = (void *) skb->data; 2593 struct l2cap_chan *chan = conn->smp; 2594 struct smp_chan *smp = chan->data; 2595 struct hci_conn *hcon = conn->hcon; 2596 bdaddr_t rpa; 2597 2598 bt_dev_dbg(hcon->hdev, ""); 2599 2600 if (skb->len < sizeof(*info)) 2601 return SMP_INVALID_PARAMS; 2602 2603 /* Mark the information as received */ 2604 smp->remote_key_dist &= ~SMP_DIST_ID_KEY; 2605 2606 if (smp->remote_key_dist & SMP_DIST_SIGN) 2607 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 2608 2609 skb_pull(skb, sizeof(*info)); 2610 2611 /* Strictly speaking the Core Specification (4.1) allows sending 2612 * an empty address which would force us to rely on just the IRK 2613 * as "identity information". However, since such 2614 * implementations are not known of and in order to not over 2615 * complicate our implementation, simply pretend that we never 2616 * received an IRK for such a device. 2617 * 2618 * The Identity Address must also be a Static Random or Public 2619 * Address, which hci_is_identity_address() checks for. 2620 */ 2621 if (!bacmp(&info->bdaddr, BDADDR_ANY) || 2622 !hci_is_identity_address(&info->bdaddr, info->addr_type)) { 2623 bt_dev_err(hcon->hdev, "ignoring IRK with no identity address"); 2624 goto distribute; 2625 } 2626 2627 /* Drop IRK if peer is using identity address during pairing but is 2628 * providing different address as identity information. 2629 * 2630 * Microsoft Surface Precision Mouse is known to have this bug. 2631 */ 2632 if (hci_is_identity_address(&hcon->dst, hcon->dst_type) && 2633 (bacmp(&info->bdaddr, &hcon->dst) || 2634 info->addr_type != hcon->dst_type)) { 2635 bt_dev_err(hcon->hdev, 2636 "ignoring IRK with invalid identity address"); 2637 goto distribute; 2638 } 2639 2640 bacpy(&smp->id_addr, &info->bdaddr); 2641 smp->id_addr_type = info->addr_type; 2642 2643 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type)) 2644 bacpy(&rpa, &hcon->dst); 2645 else 2646 bacpy(&rpa, BDADDR_ANY); 2647 2648 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr, 2649 smp->id_addr_type, smp->irk, &rpa); 2650 2651 distribute: 2652 if (!(smp->remote_key_dist & KEY_DIST_MASK)) 2653 smp_distribute_keys(smp); 2654 2655 return 0; 2656 } 2657 2658 static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb) 2659 { 2660 struct smp_cmd_sign_info *rp = (void *) skb->data; 2661 struct l2cap_chan *chan = conn->smp; 2662 struct smp_chan *smp = chan->data; 2663 struct smp_csrk *csrk; 2664 2665 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 2666 2667 if (skb->len < sizeof(*rp)) 2668 return SMP_INVALID_PARAMS; 2669 2670 /* Mark the information as received */ 2671 smp->remote_key_dist &= ~SMP_DIST_SIGN; 2672 2673 skb_pull(skb, sizeof(*rp)); 2674 2675 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); 2676 if (csrk) { 2677 if (conn->hcon->sec_level > BT_SECURITY_MEDIUM) 2678 csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED; 2679 else 2680 csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED; 2681 memcpy(csrk->val, rp->csrk, sizeof(csrk->val)); 2682 } 2683 smp->csrk = csrk; 2684 smp_distribute_keys(smp); 2685 2686 return 0; 2687 } 2688 2689 static u8 sc_select_method(struct smp_chan *smp) 2690 { 2691 struct l2cap_conn *conn = smp->conn; 2692 struct hci_conn *hcon = conn->hcon; 2693 struct smp_cmd_pairing *local, *remote; 2694 u8 local_mitm, remote_mitm, local_io, remote_io, method; 2695 2696 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) || 2697 test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) 2698 return REQ_OOB; 2699 2700 /* The preq/prsp contain the raw Pairing Request/Response PDUs 2701 * which are needed as inputs to some crypto functions. To get 2702 * the "struct smp_cmd_pairing" from them we need to skip the 2703 * first byte which contains the opcode. 2704 */ 2705 if (hcon->out) { 2706 local = (void *) &smp->preq[1]; 2707 remote = (void *) &smp->prsp[1]; 2708 } else { 2709 local = (void *) &smp->prsp[1]; 2710 remote = (void *) &smp->preq[1]; 2711 } 2712 2713 local_io = local->io_capability; 2714 remote_io = remote->io_capability; 2715 2716 local_mitm = (local->auth_req & SMP_AUTH_MITM); 2717 remote_mitm = (remote->auth_req & SMP_AUTH_MITM); 2718 2719 /* If either side wants MITM, look up the method from the table, 2720 * otherwise use JUST WORKS. 2721 */ 2722 if (local_mitm || remote_mitm) 2723 method = get_auth_method(smp, local_io, remote_io); 2724 else 2725 method = JUST_WORKS; 2726 2727 /* Don't confirm locally initiated pairing attempts */ 2728 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2729 method = JUST_WORKS; 2730 2731 return method; 2732 } 2733 2734 static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb) 2735 { 2736 struct smp_cmd_public_key *key = (void *) skb->data; 2737 struct hci_conn *hcon = conn->hcon; 2738 struct l2cap_chan *chan = conn->smp; 2739 struct smp_chan *smp = chan->data; 2740 struct hci_dev *hdev = hcon->hdev; 2741 struct crypto_kpp *tfm_ecdh; 2742 struct smp_cmd_pairing_confirm cfm; 2743 int err; 2744 2745 bt_dev_dbg(hdev, "conn %p", conn); 2746 2747 if (skb->len < sizeof(*key)) 2748 return SMP_INVALID_PARAMS; 2749 2750 /* Check if remote and local public keys are the same and debug key is 2751 * not in use. 2752 */ 2753 if (!test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags) && 2754 !crypto_memneq(key, smp->local_pk, 64)) { 2755 bt_dev_err(hdev, "Remote and local public keys are identical"); 2756 return SMP_UNSPECIFIED; 2757 } 2758 2759 memcpy(smp->remote_pk, key, 64); 2760 2761 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) { 2762 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk, 2763 smp->rr, 0, cfm.confirm_val); 2764 if (err) 2765 return SMP_UNSPECIFIED; 2766 2767 if (crypto_memneq(cfm.confirm_val, smp->pcnf, 16)) 2768 return SMP_CONFIRM_FAILED; 2769 } 2770 2771 /* Non-initiating device sends its public key after receiving 2772 * the key from the initiating device. 2773 */ 2774 if (!hcon->out) { 2775 err = sc_send_public_key(smp); 2776 if (err) 2777 return err; 2778 } 2779 2780 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk); 2781 SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32); 2782 2783 /* Compute the shared secret on the same crypto tfm on which the private 2784 * key was set/generated. 2785 */ 2786 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { 2787 struct l2cap_chan *hchan = hdev->smp_data; 2788 struct smp_dev *smp_dev; 2789 2790 if (!hchan || !hchan->data) 2791 return SMP_UNSPECIFIED; 2792 2793 smp_dev = hchan->data; 2794 2795 tfm_ecdh = smp_dev->tfm_ecdh; 2796 } else { 2797 tfm_ecdh = smp->tfm_ecdh; 2798 } 2799 2800 if (compute_ecdh_secret(tfm_ecdh, smp->remote_pk, smp->dhkey)) 2801 return SMP_UNSPECIFIED; 2802 2803 SMP_DBG("DHKey %32phN", smp->dhkey); 2804 2805 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags); 2806 2807 smp->method = sc_select_method(smp); 2808 2809 bt_dev_dbg(hdev, "selected method 0x%02x", smp->method); 2810 2811 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */ 2812 if (smp->method == JUST_WORKS || smp->method == JUST_CFM) 2813 hcon->pending_sec_level = BT_SECURITY_MEDIUM; 2814 else 2815 hcon->pending_sec_level = BT_SECURITY_FIPS; 2816 2817 if (!crypto_memneq(debug_pk, smp->remote_pk, 64)) 2818 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 2819 2820 if (smp->method == DSP_PASSKEY) { 2821 get_random_bytes(&hcon->passkey_notify, 2822 sizeof(hcon->passkey_notify)); 2823 hcon->passkey_notify %= 1000000; 2824 hcon->passkey_entered = 0; 2825 smp->passkey_round = 0; 2826 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type, 2827 hcon->dst_type, 2828 hcon->passkey_notify, 2829 hcon->passkey_entered)) 2830 return SMP_UNSPECIFIED; 2831 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2832 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY); 2833 } 2834 2835 if (smp->method == REQ_OOB) { 2836 if (hcon->out) 2837 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 2838 sizeof(smp->prnd), smp->prnd); 2839 2840 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2841 2842 return 0; 2843 } 2844 2845 if (hcon->out) 2846 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2847 2848 if (smp->method == REQ_PASSKEY) { 2849 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type, 2850 hcon->dst_type)) 2851 return SMP_UNSPECIFIED; 2852 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2853 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 2854 return 0; 2855 } 2856 2857 /* The Initiating device waits for the non-initiating device to 2858 * send the confirm value. 2859 */ 2860 if (conn->hcon->out) 2861 return 0; 2862 2863 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, 2864 0, cfm.confirm_val); 2865 if (err) 2866 return SMP_UNSPECIFIED; 2867 2868 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); 2869 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2870 2871 return 0; 2872 } 2873 2874 static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb) 2875 { 2876 struct smp_cmd_dhkey_check *check = (void *) skb->data; 2877 struct l2cap_chan *chan = conn->smp; 2878 struct hci_conn *hcon = conn->hcon; 2879 struct smp_chan *smp = chan->data; 2880 u8 a[7], b[7], *local_addr, *remote_addr; 2881 u8 io_cap[3], r[16], e[16]; 2882 int err; 2883 2884 bt_dev_dbg(hcon->hdev, "conn %p", conn); 2885 2886 if (skb->len < sizeof(*check)) 2887 return SMP_INVALID_PARAMS; 2888 2889 memcpy(a, &hcon->init_addr, 6); 2890 memcpy(b, &hcon->resp_addr, 6); 2891 a[6] = hcon->init_addr_type; 2892 b[6] = hcon->resp_addr_type; 2893 2894 if (hcon->out) { 2895 local_addr = a; 2896 remote_addr = b; 2897 memcpy(io_cap, &smp->prsp[1], 3); 2898 } else { 2899 local_addr = b; 2900 remote_addr = a; 2901 memcpy(io_cap, &smp->preq[1], 3); 2902 } 2903 2904 memset(r, 0, sizeof(r)); 2905 2906 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2907 put_unaligned_le32(hcon->passkey_notify, r); 2908 else if (smp->method == REQ_OOB) 2909 memcpy(r, smp->lr, 16); 2910 2911 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r, 2912 io_cap, remote_addr, local_addr, e); 2913 if (err) 2914 return SMP_UNSPECIFIED; 2915 2916 if (crypto_memneq(check->e, e, 16)) 2917 return SMP_DHKEY_CHECK_FAILED; 2918 2919 if (!hcon->out) { 2920 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { 2921 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags); 2922 return 0; 2923 } 2924 2925 /* Responder sends DHKey check as response to initiator */ 2926 sc_dhkey_check(smp); 2927 } 2928 2929 sc_add_ltk(smp); 2930 2931 if (hcon->out) { 2932 hci_le_start_enc(hcon, 0, 0, smp->tk, smp->enc_key_size); 2933 hcon->enc_key_size = smp->enc_key_size; 2934 } 2935 2936 return 0; 2937 } 2938 2939 static int smp_cmd_keypress_notify(struct l2cap_conn *conn, 2940 struct sk_buff *skb) 2941 { 2942 struct smp_cmd_keypress_notify *kp = (void *) skb->data; 2943 2944 bt_dev_dbg(conn->hcon->hdev, "value 0x%02x", kp->value); 2945 2946 return 0; 2947 } 2948 2949 static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb) 2950 { 2951 struct l2cap_conn *conn = chan->conn; 2952 struct hci_conn *hcon = conn->hcon; 2953 struct smp_chan *smp; 2954 __u8 code, reason; 2955 int err = 0; 2956 2957 if (skb->len < 1) 2958 return -EILSEQ; 2959 2960 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) { 2961 reason = SMP_PAIRING_NOTSUPP; 2962 goto done; 2963 } 2964 2965 code = skb->data[0]; 2966 skb_pull(skb, sizeof(code)); 2967 2968 smp = chan->data; 2969 2970 if (code > SMP_CMD_MAX) 2971 goto drop; 2972 2973 if (smp && !test_and_clear_bit(code, &smp->allow_cmd)) 2974 goto drop; 2975 2976 /* If we don't have a context the only allowed commands are 2977 * pairing request and security request. 2978 */ 2979 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ) 2980 goto drop; 2981 2982 switch (code) { 2983 case SMP_CMD_PAIRING_REQ: 2984 reason = smp_cmd_pairing_req(conn, skb); 2985 break; 2986 2987 case SMP_CMD_PAIRING_FAIL: 2988 smp_failure(conn, 0); 2989 err = -EPERM; 2990 break; 2991 2992 case SMP_CMD_PAIRING_RSP: 2993 reason = smp_cmd_pairing_rsp(conn, skb); 2994 break; 2995 2996 case SMP_CMD_SECURITY_REQ: 2997 reason = smp_cmd_security_req(conn, skb); 2998 break; 2999 3000 case SMP_CMD_PAIRING_CONFIRM: 3001 reason = smp_cmd_pairing_confirm(conn, skb); 3002 break; 3003 3004 case SMP_CMD_PAIRING_RANDOM: 3005 reason = smp_cmd_pairing_random(conn, skb); 3006 break; 3007 3008 case SMP_CMD_ENCRYPT_INFO: 3009 reason = smp_cmd_encrypt_info(conn, skb); 3010 break; 3011 3012 case SMP_CMD_INITIATOR_IDENT: 3013 reason = smp_cmd_initiator_ident(conn, skb); 3014 break; 3015 3016 case SMP_CMD_IDENT_INFO: 3017 reason = smp_cmd_ident_info(conn, skb); 3018 break; 3019 3020 case SMP_CMD_IDENT_ADDR_INFO: 3021 reason = smp_cmd_ident_addr_info(conn, skb); 3022 break; 3023 3024 case SMP_CMD_SIGN_INFO: 3025 reason = smp_cmd_sign_info(conn, skb); 3026 break; 3027 3028 case SMP_CMD_PUBLIC_KEY: 3029 reason = smp_cmd_public_key(conn, skb); 3030 break; 3031 3032 case SMP_CMD_DHKEY_CHECK: 3033 reason = smp_cmd_dhkey_check(conn, skb); 3034 break; 3035 3036 case SMP_CMD_KEYPRESS_NOTIFY: 3037 reason = smp_cmd_keypress_notify(conn, skb); 3038 break; 3039 3040 default: 3041 bt_dev_dbg(hcon->hdev, "Unknown command code 0x%2.2x", code); 3042 reason = SMP_CMD_NOTSUPP; 3043 goto done; 3044 } 3045 3046 done: 3047 if (!err) { 3048 if (reason) 3049 smp_failure(conn, reason); 3050 kfree_skb(skb); 3051 } 3052 3053 return err; 3054 3055 drop: 3056 bt_dev_err(hcon->hdev, "unexpected SMP command 0x%02x from %pMR", 3057 code, &hcon->dst); 3058 kfree_skb(skb); 3059 return 0; 3060 } 3061 3062 static void smp_teardown_cb(struct l2cap_chan *chan, int err) 3063 { 3064 struct l2cap_conn *conn = chan->conn; 3065 3066 bt_dev_dbg(conn->hcon->hdev, "chan %p", chan); 3067 3068 if (chan->data) 3069 smp_chan_destroy(conn); 3070 3071 conn->smp = NULL; 3072 l2cap_chan_put(chan); 3073 } 3074 3075 static void bredr_pairing(struct l2cap_chan *chan) 3076 { 3077 struct l2cap_conn *conn = chan->conn; 3078 struct hci_conn *hcon = conn->hcon; 3079 struct hci_dev *hdev = hcon->hdev; 3080 struct smp_cmd_pairing req; 3081 struct smp_chan *smp; 3082 3083 bt_dev_dbg(hdev, "chan %p", chan); 3084 3085 /* Only new pairings are interesting */ 3086 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags)) 3087 return; 3088 3089 /* Don't bother if we're not encrypted */ 3090 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3091 return; 3092 3093 /* Only initiator may initiate SMP over BR/EDR */ 3094 if (hcon->role != HCI_ROLE_MASTER) 3095 return; 3096 3097 /* Secure Connections support must be enabled */ 3098 if (!hci_dev_test_flag(hdev, HCI_SC_ENABLED)) 3099 return; 3100 3101 /* BR/EDR must use Secure Connections for SMP */ 3102 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) && 3103 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3104 return; 3105 3106 /* If our LE support is not enabled don't do anything */ 3107 if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) 3108 return; 3109 3110 /* Don't bother if remote LE support is not enabled */ 3111 if (!lmp_host_le_capable(hcon)) 3112 return; 3113 3114 /* Remote must support SMP fixed chan for BR/EDR */ 3115 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR)) 3116 return; 3117 3118 /* Don't bother if SMP is already ongoing */ 3119 if (chan->data) 3120 return; 3121 3122 smp = smp_chan_create(conn); 3123 if (!smp) { 3124 bt_dev_err(hdev, "unable to create SMP context for BR/EDR"); 3125 return; 3126 } 3127 3128 set_bit(SMP_FLAG_SC, &smp->flags); 3129 3130 bt_dev_dbg(hdev, "starting SMP over BR/EDR"); 3131 3132 /* Prepare and send the BR/EDR SMP Pairing Request */ 3133 build_bredr_pairing_cmd(smp, &req, NULL); 3134 3135 smp->preq[0] = SMP_CMD_PAIRING_REQ; 3136 memcpy(&smp->preq[1], &req, sizeof(req)); 3137 3138 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(req), &req); 3139 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 3140 } 3141 3142 static void smp_resume_cb(struct l2cap_chan *chan) 3143 { 3144 struct smp_chan *smp = chan->data; 3145 struct l2cap_conn *conn = chan->conn; 3146 struct hci_conn *hcon = conn->hcon; 3147 3148 bt_dev_dbg(hcon->hdev, "chan %p", chan); 3149 3150 if (hcon->type == ACL_LINK) { 3151 bredr_pairing(chan); 3152 return; 3153 } 3154 3155 if (!smp) 3156 return; 3157 3158 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3159 return; 3160 3161 cancel_delayed_work(&smp->security_timer); 3162 3163 smp_distribute_keys(smp); 3164 } 3165 3166 static void smp_ready_cb(struct l2cap_chan *chan) 3167 { 3168 struct l2cap_conn *conn = chan->conn; 3169 struct hci_conn *hcon = conn->hcon; 3170 3171 bt_dev_dbg(hcon->hdev, "chan %p", chan); 3172 3173 /* No need to call l2cap_chan_hold() here since we already own 3174 * the reference taken in smp_new_conn_cb(). This is just the 3175 * first time that we tie it to a specific pointer. The code in 3176 * l2cap_core.c ensures that there's no risk this function wont 3177 * get called if smp_new_conn_cb was previously called. 3178 */ 3179 conn->smp = chan; 3180 3181 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3182 bredr_pairing(chan); 3183 } 3184 3185 static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 3186 { 3187 int err; 3188 3189 bt_dev_dbg(chan->conn->hcon->hdev, "chan %p", chan); 3190 3191 err = smp_sig_channel(chan, skb); 3192 if (err) { 3193 struct smp_chan *smp = chan->data; 3194 3195 if (smp) 3196 cancel_delayed_work_sync(&smp->security_timer); 3197 3198 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE); 3199 } 3200 3201 return err; 3202 } 3203 3204 static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan, 3205 unsigned long hdr_len, 3206 unsigned long len, int nb) 3207 { 3208 struct sk_buff *skb; 3209 3210 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL); 3211 if (!skb) 3212 return ERR_PTR(-ENOMEM); 3213 3214 skb->priority = HCI_PRIO_MAX; 3215 bt_cb(skb)->l2cap.chan = chan; 3216 3217 return skb; 3218 } 3219 3220 static const struct l2cap_ops smp_chan_ops = { 3221 .name = "Security Manager", 3222 .ready = smp_ready_cb, 3223 .recv = smp_recv_cb, 3224 .alloc_skb = smp_alloc_skb_cb, 3225 .teardown = smp_teardown_cb, 3226 .resume = smp_resume_cb, 3227 3228 .new_connection = l2cap_chan_no_new_connection, 3229 .state_change = l2cap_chan_no_state_change, 3230 .close = l2cap_chan_no_close, 3231 .defer = l2cap_chan_no_defer, 3232 .suspend = l2cap_chan_no_suspend, 3233 .set_shutdown = l2cap_chan_no_set_shutdown, 3234 .get_sndtimeo = l2cap_chan_no_get_sndtimeo, 3235 }; 3236 3237 static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan) 3238 { 3239 struct l2cap_chan *chan; 3240 3241 BT_DBG("pchan %p", pchan); 3242 3243 chan = l2cap_chan_create(); 3244 if (!chan) 3245 return NULL; 3246 3247 chan->chan_type = pchan->chan_type; 3248 chan->ops = &smp_chan_ops; 3249 chan->scid = pchan->scid; 3250 chan->dcid = chan->scid; 3251 chan->imtu = pchan->imtu; 3252 chan->omtu = pchan->omtu; 3253 chan->mode = pchan->mode; 3254 3255 /* Other L2CAP channels may request SMP routines in order to 3256 * change the security level. This means that the SMP channel 3257 * lock must be considered in its own category to avoid lockdep 3258 * warnings. 3259 */ 3260 atomic_set(&chan->nesting, L2CAP_NESTING_SMP); 3261 3262 BT_DBG("created chan %p", chan); 3263 3264 return chan; 3265 } 3266 3267 static const struct l2cap_ops smp_root_chan_ops = { 3268 .name = "Security Manager Root", 3269 .new_connection = smp_new_conn_cb, 3270 3271 /* None of these are implemented for the root channel */ 3272 .close = l2cap_chan_no_close, 3273 .alloc_skb = l2cap_chan_no_alloc_skb, 3274 .recv = l2cap_chan_no_recv, 3275 .state_change = l2cap_chan_no_state_change, 3276 .teardown = l2cap_chan_no_teardown, 3277 .ready = l2cap_chan_no_ready, 3278 .defer = l2cap_chan_no_defer, 3279 .suspend = l2cap_chan_no_suspend, 3280 .resume = l2cap_chan_no_resume, 3281 .set_shutdown = l2cap_chan_no_set_shutdown, 3282 .get_sndtimeo = l2cap_chan_no_get_sndtimeo, 3283 }; 3284 3285 static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid) 3286 { 3287 struct l2cap_chan *chan; 3288 struct smp_dev *smp; 3289 struct crypto_shash *tfm_cmac; 3290 struct crypto_kpp *tfm_ecdh; 3291 3292 if (cid == L2CAP_CID_SMP_BREDR) { 3293 smp = NULL; 3294 goto create_chan; 3295 } 3296 3297 smp = kzalloc(sizeof(*smp), GFP_KERNEL); 3298 if (!smp) 3299 return ERR_PTR(-ENOMEM); 3300 3301 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 3302 if (IS_ERR(tfm_cmac)) { 3303 bt_dev_err(hdev, "Unable to create CMAC crypto context"); 3304 kfree_sensitive(smp); 3305 return ERR_CAST(tfm_cmac); 3306 } 3307 3308 tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0); 3309 if (IS_ERR(tfm_ecdh)) { 3310 bt_dev_err(hdev, "Unable to create ECDH crypto context"); 3311 crypto_free_shash(tfm_cmac); 3312 kfree_sensitive(smp); 3313 return ERR_CAST(tfm_ecdh); 3314 } 3315 3316 smp->local_oob = false; 3317 smp->tfm_cmac = tfm_cmac; 3318 smp->tfm_ecdh = tfm_ecdh; 3319 3320 create_chan: 3321 chan = l2cap_chan_create(); 3322 if (!chan) { 3323 if (smp) { 3324 crypto_free_shash(smp->tfm_cmac); 3325 crypto_free_kpp(smp->tfm_ecdh); 3326 kfree_sensitive(smp); 3327 } 3328 return ERR_PTR(-ENOMEM); 3329 } 3330 3331 chan->data = smp; 3332 3333 l2cap_add_scid(chan, cid); 3334 3335 l2cap_chan_set_defaults(chan); 3336 3337 if (cid == L2CAP_CID_SMP) { 3338 u8 bdaddr_type; 3339 3340 hci_copy_identity_address(hdev, &chan->src, &bdaddr_type); 3341 3342 if (bdaddr_type == ADDR_LE_DEV_PUBLIC) 3343 chan->src_type = BDADDR_LE_PUBLIC; 3344 else 3345 chan->src_type = BDADDR_LE_RANDOM; 3346 } else { 3347 bacpy(&chan->src, &hdev->bdaddr); 3348 chan->src_type = BDADDR_BREDR; 3349 } 3350 3351 chan->state = BT_LISTEN; 3352 chan->mode = L2CAP_MODE_BASIC; 3353 chan->imtu = L2CAP_DEFAULT_MTU; 3354 chan->ops = &smp_root_chan_ops; 3355 3356 /* Set correct nesting level for a parent/listening channel */ 3357 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 3358 3359 return chan; 3360 } 3361 3362 static void smp_del_chan(struct l2cap_chan *chan) 3363 { 3364 struct smp_dev *smp; 3365 3366 BT_DBG("chan %p", chan); 3367 3368 smp = chan->data; 3369 if (smp) { 3370 chan->data = NULL; 3371 crypto_free_shash(smp->tfm_cmac); 3372 crypto_free_kpp(smp->tfm_ecdh); 3373 kfree_sensitive(smp); 3374 } 3375 3376 l2cap_chan_put(chan); 3377 } 3378 3379 int smp_force_bredr(struct hci_dev *hdev, bool enable) 3380 { 3381 if (enable == hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3382 return -EALREADY; 3383 3384 if (enable) { 3385 struct l2cap_chan *chan; 3386 3387 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); 3388 if (IS_ERR(chan)) 3389 return PTR_ERR(chan); 3390 3391 hdev->smp_bredr_data = chan; 3392 } else { 3393 struct l2cap_chan *chan; 3394 3395 chan = hdev->smp_bredr_data; 3396 hdev->smp_bredr_data = NULL; 3397 smp_del_chan(chan); 3398 } 3399 3400 hci_dev_change_flag(hdev, HCI_FORCE_BREDR_SMP); 3401 3402 return 0; 3403 } 3404 3405 int smp_register(struct hci_dev *hdev) 3406 { 3407 struct l2cap_chan *chan; 3408 3409 bt_dev_dbg(hdev, ""); 3410 3411 /* If the controller does not support Low Energy operation, then 3412 * there is also no need to register any SMP channel. 3413 */ 3414 if (!lmp_le_capable(hdev)) 3415 return 0; 3416 3417 if (WARN_ON(hdev->smp_data)) { 3418 chan = hdev->smp_data; 3419 hdev->smp_data = NULL; 3420 smp_del_chan(chan); 3421 } 3422 3423 chan = smp_add_cid(hdev, L2CAP_CID_SMP); 3424 if (IS_ERR(chan)) 3425 return PTR_ERR(chan); 3426 3427 hdev->smp_data = chan; 3428 3429 if (!lmp_sc_capable(hdev)) { 3430 /* Flag can be already set here (due to power toggle) */ 3431 if (!hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3432 return 0; 3433 } 3434 3435 if (WARN_ON(hdev->smp_bredr_data)) { 3436 chan = hdev->smp_bredr_data; 3437 hdev->smp_bredr_data = NULL; 3438 smp_del_chan(chan); 3439 } 3440 3441 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); 3442 if (IS_ERR(chan)) { 3443 int err = PTR_ERR(chan); 3444 chan = hdev->smp_data; 3445 hdev->smp_data = NULL; 3446 smp_del_chan(chan); 3447 return err; 3448 } 3449 3450 hdev->smp_bredr_data = chan; 3451 3452 return 0; 3453 } 3454 3455 void smp_unregister(struct hci_dev *hdev) 3456 { 3457 struct l2cap_chan *chan; 3458 3459 if (hdev->smp_bredr_data) { 3460 chan = hdev->smp_bredr_data; 3461 hdev->smp_bredr_data = NULL; 3462 smp_del_chan(chan); 3463 } 3464 3465 if (hdev->smp_data) { 3466 chan = hdev->smp_data; 3467 hdev->smp_data = NULL; 3468 smp_del_chan(chan); 3469 } 3470 } 3471 3472 #if IS_ENABLED(CONFIG_BT_SELFTEST_SMP) 3473 3474 static int __init test_debug_key(struct crypto_kpp *tfm_ecdh) 3475 { 3476 u8 pk[64]; 3477 int err; 3478 3479 err = set_ecdh_privkey(tfm_ecdh, debug_sk); 3480 if (err) 3481 return err; 3482 3483 err = generate_ecdh_public_key(tfm_ecdh, pk); 3484 if (err) 3485 return err; 3486 3487 if (crypto_memneq(pk, debug_pk, 64)) 3488 return -EINVAL; 3489 3490 return 0; 3491 } 3492 3493 static int __init test_ah(void) 3494 { 3495 const u8 irk[16] = { 3496 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3497 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3498 const u8 r[3] = { 0x94, 0x81, 0x70 }; 3499 const u8 exp[3] = { 0xaa, 0xfb, 0x0d }; 3500 u8 res[3]; 3501 int err; 3502 3503 err = smp_ah(irk, r, res); 3504 if (err) 3505 return err; 3506 3507 if (crypto_memneq(res, exp, 3)) 3508 return -EINVAL; 3509 3510 return 0; 3511 } 3512 3513 static int __init test_c1(void) 3514 { 3515 const u8 k[16] = { 3516 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 3517 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; 3518 const u8 r[16] = { 3519 0xe0, 0x2e, 0x70, 0xc6, 0x4e, 0x27, 0x88, 0x63, 3520 0x0e, 0x6f, 0xad, 0x56, 0x21, 0xd5, 0x83, 0x57 }; 3521 const u8 preq[7] = { 0x01, 0x01, 0x00, 0x00, 0x10, 0x07, 0x07 }; 3522 const u8 pres[7] = { 0x02, 0x03, 0x00, 0x00, 0x08, 0x00, 0x05 }; 3523 const u8 _iat = 0x01; 3524 const u8 _rat = 0x00; 3525 const bdaddr_t ra = { { 0xb6, 0xb5, 0xb4, 0xb3, 0xb2, 0xb1 } }; 3526 const bdaddr_t ia = { { 0xa6, 0xa5, 0xa4, 0xa3, 0xa2, 0xa1 } }; 3527 const u8 exp[16] = { 3528 0x86, 0x3b, 0xf1, 0xbe, 0xc5, 0x4d, 0xa7, 0xd2, 3529 0xea, 0x88, 0x89, 0x87, 0xef, 0x3f, 0x1e, 0x1e }; 3530 u8 res[16]; 3531 int err; 3532 3533 err = smp_c1(k, r, preq, pres, _iat, &ia, _rat, &ra, res); 3534 if (err) 3535 return err; 3536 3537 if (crypto_memneq(res, exp, 16)) 3538 return -EINVAL; 3539 3540 return 0; 3541 } 3542 3543 static int __init test_s1(void) 3544 { 3545 const u8 k[16] = { 3546 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 3547 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; 3548 const u8 r1[16] = { 3549 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 }; 3550 const u8 r2[16] = { 3551 0x00, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99 }; 3552 const u8 exp[16] = { 3553 0x62, 0xa0, 0x6d, 0x79, 0xae, 0x16, 0x42, 0x5b, 3554 0x9b, 0xf4, 0xb0, 0xe8, 0xf0, 0xe1, 0x1f, 0x9a }; 3555 u8 res[16]; 3556 int err; 3557 3558 err = smp_s1(k, r1, r2, res); 3559 if (err) 3560 return err; 3561 3562 if (crypto_memneq(res, exp, 16)) 3563 return -EINVAL; 3564 3565 return 0; 3566 } 3567 3568 static int __init test_f4(struct crypto_shash *tfm_cmac) 3569 { 3570 const u8 u[32] = { 3571 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 3572 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 3573 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 3574 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 }; 3575 const u8 v[32] = { 3576 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b, 3577 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59, 3578 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90, 3579 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 }; 3580 const u8 x[16] = { 3581 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3582 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3583 const u8 z = 0x00; 3584 const u8 exp[16] = { 3585 0x2d, 0x87, 0x74, 0xa9, 0xbe, 0xa1, 0xed, 0xf1, 3586 0x1c, 0xbd, 0xa9, 0x07, 0xf1, 0x16, 0xc9, 0xf2 }; 3587 u8 res[16]; 3588 int err; 3589 3590 err = smp_f4(tfm_cmac, u, v, x, z, res); 3591 if (err) 3592 return err; 3593 3594 if (crypto_memneq(res, exp, 16)) 3595 return -EINVAL; 3596 3597 return 0; 3598 } 3599 3600 static int __init test_f5(struct crypto_shash *tfm_cmac) 3601 { 3602 const u8 w[32] = { 3603 0x98, 0xa6, 0xbf, 0x73, 0xf3, 0x34, 0x8d, 0x86, 3604 0xf1, 0x66, 0xf8, 0xb4, 0x13, 0x6b, 0x79, 0x99, 3605 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3606 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3607 const u8 n1[16] = { 3608 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3609 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3610 const u8 n2[16] = { 3611 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3612 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3613 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 }; 3614 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 }; 3615 const u8 exp_ltk[16] = { 3616 0x38, 0x0a, 0x75, 0x94, 0xb5, 0x22, 0x05, 0x98, 3617 0x23, 0xcd, 0xd7, 0x69, 0x11, 0x79, 0x86, 0x69 }; 3618 const u8 exp_mackey[16] = { 3619 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd, 3620 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 }; 3621 u8 mackey[16], ltk[16]; 3622 int err; 3623 3624 err = smp_f5(tfm_cmac, w, n1, n2, a1, a2, mackey, ltk); 3625 if (err) 3626 return err; 3627 3628 if (crypto_memneq(mackey, exp_mackey, 16)) 3629 return -EINVAL; 3630 3631 if (crypto_memneq(ltk, exp_ltk, 16)) 3632 return -EINVAL; 3633 3634 return 0; 3635 } 3636 3637 static int __init test_f6(struct crypto_shash *tfm_cmac) 3638 { 3639 const u8 w[16] = { 3640 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd, 3641 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 }; 3642 const u8 n1[16] = { 3643 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3644 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3645 const u8 n2[16] = { 3646 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3647 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3648 const u8 r[16] = { 3649 0xc8, 0x0f, 0x2d, 0x0c, 0xd2, 0x42, 0xda, 0x08, 3650 0x54, 0xbb, 0x53, 0xb4, 0x3b, 0x34, 0xa3, 0x12 }; 3651 const u8 io_cap[3] = { 0x02, 0x01, 0x01 }; 3652 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 }; 3653 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 }; 3654 const u8 exp[16] = { 3655 0x61, 0x8f, 0x95, 0xda, 0x09, 0x0b, 0x6c, 0xd2, 3656 0xc5, 0xe8, 0xd0, 0x9c, 0x98, 0x73, 0xc4, 0xe3 }; 3657 u8 res[16]; 3658 int err; 3659 3660 err = smp_f6(tfm_cmac, w, n1, n2, r, io_cap, a1, a2, res); 3661 if (err) 3662 return err; 3663 3664 if (crypto_memneq(res, exp, 16)) 3665 return -EINVAL; 3666 3667 return 0; 3668 } 3669 3670 static int __init test_g2(struct crypto_shash *tfm_cmac) 3671 { 3672 const u8 u[32] = { 3673 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 3674 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 3675 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 3676 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 }; 3677 const u8 v[32] = { 3678 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b, 3679 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59, 3680 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90, 3681 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 }; 3682 const u8 x[16] = { 3683 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3684 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3685 const u8 y[16] = { 3686 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3687 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3688 const u32 exp_val = 0x2f9ed5ba % 1000000; 3689 u32 val; 3690 int err; 3691 3692 err = smp_g2(tfm_cmac, u, v, x, y, &val); 3693 if (err) 3694 return err; 3695 3696 if (val != exp_val) 3697 return -EINVAL; 3698 3699 return 0; 3700 } 3701 3702 static int __init test_h6(struct crypto_shash *tfm_cmac) 3703 { 3704 const u8 w[16] = { 3705 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3706 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3707 const u8 key_id[4] = { 0x72, 0x62, 0x65, 0x6c }; 3708 const u8 exp[16] = { 3709 0x99, 0x63, 0xb1, 0x80, 0xe2, 0xa9, 0xd3, 0xe8, 3710 0x1c, 0xc9, 0x6d, 0xe7, 0x02, 0xe1, 0x9a, 0x2d }; 3711 u8 res[16]; 3712 int err; 3713 3714 err = smp_h6(tfm_cmac, w, key_id, res); 3715 if (err) 3716 return err; 3717 3718 if (crypto_memneq(res, exp, 16)) 3719 return -EINVAL; 3720 3721 return 0; 3722 } 3723 3724 static char test_smp_buffer[32]; 3725 3726 static ssize_t test_smp_read(struct file *file, char __user *user_buf, 3727 size_t count, loff_t *ppos) 3728 { 3729 return simple_read_from_buffer(user_buf, count, ppos, test_smp_buffer, 3730 strlen(test_smp_buffer)); 3731 } 3732 3733 static const struct file_operations test_smp_fops = { 3734 .open = simple_open, 3735 .read = test_smp_read, 3736 .llseek = default_llseek, 3737 }; 3738 3739 static int __init run_selftests(struct crypto_shash *tfm_cmac, 3740 struct crypto_kpp *tfm_ecdh) 3741 { 3742 ktime_t calltime, delta, rettime; 3743 unsigned long long duration; 3744 int err; 3745 3746 calltime = ktime_get(); 3747 3748 err = test_debug_key(tfm_ecdh); 3749 if (err) { 3750 BT_ERR("debug_key test failed"); 3751 goto done; 3752 } 3753 3754 err = test_ah(); 3755 if (err) { 3756 BT_ERR("smp_ah test failed"); 3757 goto done; 3758 } 3759 3760 err = test_c1(); 3761 if (err) { 3762 BT_ERR("smp_c1 test failed"); 3763 goto done; 3764 } 3765 3766 err = test_s1(); 3767 if (err) { 3768 BT_ERR("smp_s1 test failed"); 3769 goto done; 3770 } 3771 3772 err = test_f4(tfm_cmac); 3773 if (err) { 3774 BT_ERR("smp_f4 test failed"); 3775 goto done; 3776 } 3777 3778 err = test_f5(tfm_cmac); 3779 if (err) { 3780 BT_ERR("smp_f5 test failed"); 3781 goto done; 3782 } 3783 3784 err = test_f6(tfm_cmac); 3785 if (err) { 3786 BT_ERR("smp_f6 test failed"); 3787 goto done; 3788 } 3789 3790 err = test_g2(tfm_cmac); 3791 if (err) { 3792 BT_ERR("smp_g2 test failed"); 3793 goto done; 3794 } 3795 3796 err = test_h6(tfm_cmac); 3797 if (err) { 3798 BT_ERR("smp_h6 test failed"); 3799 goto done; 3800 } 3801 3802 rettime = ktime_get(); 3803 delta = ktime_sub(rettime, calltime); 3804 duration = (unsigned long long) ktime_to_ns(delta) >> 10; 3805 3806 BT_INFO("SMP test passed in %llu usecs", duration); 3807 3808 done: 3809 if (!err) 3810 snprintf(test_smp_buffer, sizeof(test_smp_buffer), 3811 "PASS (%llu usecs)\n", duration); 3812 else 3813 snprintf(test_smp_buffer, sizeof(test_smp_buffer), "FAIL\n"); 3814 3815 debugfs_create_file("selftest_smp", 0444, bt_debugfs, NULL, 3816 &test_smp_fops); 3817 3818 return err; 3819 } 3820 3821 int __init bt_selftest_smp(void) 3822 { 3823 struct crypto_shash *tfm_cmac; 3824 struct crypto_kpp *tfm_ecdh; 3825 int err; 3826 3827 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 3828 if (IS_ERR(tfm_cmac)) { 3829 BT_ERR("Unable to create CMAC crypto context"); 3830 return PTR_ERR(tfm_cmac); 3831 } 3832 3833 tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0); 3834 if (IS_ERR(tfm_ecdh)) { 3835 BT_ERR("Unable to create ECDH crypto context"); 3836 crypto_free_shash(tfm_cmac); 3837 return PTR_ERR(tfm_ecdh); 3838 } 3839 3840 err = run_selftests(tfm_cmac, tfm_ecdh); 3841 3842 crypto_free_shash(tfm_cmac); 3843 crypto_free_kpp(tfm_ecdh); 3844 3845 return err; 3846 } 3847 3848 #endif 3849