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/b128ops.h> 29 #include <crypto/hash.h> 30 #include <crypto/kpp.h> 31 32 #include <net/bluetooth/bluetooth.h> 33 #include <net/bluetooth/hci_core.h> 34 #include <net/bluetooth/l2cap.h> 35 #include <net/bluetooth/mgmt.h> 36 37 #include "ecdh_helper.h" 38 #include "smp.h" 39 40 #define SMP_DEV(hdev) \ 41 ((struct smp_dev *)((struct l2cap_chan *)((hdev)->smp_data))->data) 42 43 /* Low-level debug macros to be used for stuff that we don't want 44 * accidentially in dmesg, i.e. the values of the various crypto keys 45 * and the inputs & outputs of crypto functions. 46 */ 47 #ifdef DEBUG 48 #define SMP_DBG(fmt, ...) printk(KERN_DEBUG "%s: " fmt, __func__, \ 49 ##__VA_ARGS__) 50 #else 51 #define SMP_DBG(fmt, ...) no_printk(KERN_DEBUG "%s: " fmt, __func__, \ 52 ##__VA_ARGS__) 53 #endif 54 55 #define SMP_ALLOW_CMD(smp, code) set_bit(code, &smp->allow_cmd) 56 57 /* Keys which are not distributed with Secure Connections */ 58 #define SMP_SC_NO_DIST (SMP_DIST_ENC_KEY | SMP_DIST_LINK_KEY); 59 60 #define SMP_TIMEOUT msecs_to_jiffies(30000) 61 62 #define AUTH_REQ_MASK(dev) (hci_dev_test_flag(dev, HCI_SC_ENABLED) ? \ 63 0x3f : 0x07) 64 #define KEY_DIST_MASK 0x07 65 66 /* Maximum message length that can be passed to aes_cmac */ 67 #define CMAC_MSG_MAX 80 68 69 enum { 70 SMP_FLAG_TK_VALID, 71 SMP_FLAG_CFM_PENDING, 72 SMP_FLAG_MITM_AUTH, 73 SMP_FLAG_COMPLETE, 74 SMP_FLAG_INITIATOR, 75 SMP_FLAG_SC, 76 SMP_FLAG_REMOTE_PK, 77 SMP_FLAG_DEBUG_KEY, 78 SMP_FLAG_WAIT_USER, 79 SMP_FLAG_DHKEY_PENDING, 80 SMP_FLAG_REMOTE_OOB, 81 SMP_FLAG_LOCAL_OOB, 82 SMP_FLAG_CT2, 83 }; 84 85 struct smp_dev { 86 /* Secure Connections OOB data */ 87 bool local_oob; 88 u8 local_pk[64]; 89 u8 local_rand[16]; 90 bool debug_key; 91 92 struct crypto_shash *tfm_cmac; 93 struct crypto_kpp *tfm_ecdh; 94 }; 95 96 struct smp_chan { 97 struct l2cap_conn *conn; 98 struct delayed_work security_timer; 99 unsigned long allow_cmd; /* Bitmask of allowed commands */ 100 101 u8 preq[7]; /* SMP Pairing Request */ 102 u8 prsp[7]; /* SMP Pairing Response */ 103 u8 prnd[16]; /* SMP Pairing Random (local) */ 104 u8 rrnd[16]; /* SMP Pairing Random (remote) */ 105 u8 pcnf[16]; /* SMP Pairing Confirm */ 106 u8 tk[16]; /* SMP Temporary Key */ 107 u8 rr[16]; /* Remote OOB ra/rb value */ 108 u8 lr[16]; /* Local OOB ra/rb value */ 109 u8 enc_key_size; 110 u8 remote_key_dist; 111 bdaddr_t id_addr; 112 u8 id_addr_type; 113 u8 irk[16]; 114 struct smp_csrk *csrk; 115 struct smp_csrk *slave_csrk; 116 struct smp_ltk *ltk; 117 struct smp_ltk *slave_ltk; 118 struct smp_irk *remote_irk; 119 u8 *link_key; 120 unsigned long flags; 121 u8 method; 122 u8 passkey_round; 123 124 /* Secure Connections variables */ 125 u8 local_pk[64]; 126 u8 remote_pk[64]; 127 u8 dhkey[32]; 128 u8 mackey[16]; 129 130 struct crypto_shash *tfm_cmac; 131 struct crypto_kpp *tfm_ecdh; 132 }; 133 134 /* These debug key values are defined in the SMP section of the core 135 * specification. debug_pk is the public debug key and debug_sk the 136 * private debug key. 137 */ 138 static const u8 debug_pk[64] = { 139 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 140 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 141 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 142 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20, 143 144 0x8b, 0xd2, 0x89, 0x15, 0xd0, 0x8e, 0x1c, 0x74, 145 0x24, 0x30, 0xed, 0x8f, 0xc2, 0x45, 0x63, 0x76, 146 0x5c, 0x15, 0x52, 0x5a, 0xbf, 0x9a, 0x32, 0x63, 147 0x6d, 0xeb, 0x2a, 0x65, 0x49, 0x9c, 0x80, 0xdc, 148 }; 149 150 static const u8 debug_sk[32] = { 151 0xbd, 0x1a, 0x3c, 0xcd, 0xa6, 0xb8, 0x99, 0x58, 152 0x99, 0xb7, 0x40, 0xeb, 0x7b, 0x60, 0xff, 0x4a, 153 0x50, 0x3f, 0x10, 0xd2, 0xe3, 0xb3, 0xc9, 0x74, 154 0x38, 0x5f, 0xc5, 0xa3, 0xd4, 0xf6, 0x49, 0x3f, 155 }; 156 157 static inline void swap_buf(const u8 *src, u8 *dst, size_t len) 158 { 159 size_t i; 160 161 for (i = 0; i < len; i++) 162 dst[len - 1 - i] = src[i]; 163 } 164 165 /* The following functions map to the LE SC SMP crypto functions 166 * AES-CMAC, f4, f5, f6, g2 and h6. 167 */ 168 169 static int aes_cmac(struct crypto_shash *tfm, const u8 k[16], const u8 *m, 170 size_t len, u8 mac[16]) 171 { 172 uint8_t tmp[16], mac_msb[16], msg_msb[CMAC_MSG_MAX]; 173 SHASH_DESC_ON_STACK(desc, tfm); 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 desc->tfm = tfm; 185 186 /* Swap key and message from LSB to MSB */ 187 swap_buf(k, tmp, 16); 188 swap_buf(m, msg_msb, len); 189 190 SMP_DBG("msg (len %zu) %*phN", len, (int) len, m); 191 SMP_DBG("key %16phN", k); 192 193 err = crypto_shash_setkey(tfm, tmp, 16); 194 if (err) { 195 BT_ERR("cipher setkey failed: %d", err); 196 return err; 197 } 198 199 err = crypto_shash_digest(desc, msg_msb, len, mac_msb); 200 shash_desc_zero(desc); 201 if (err) { 202 BT_ERR("Hash computation error %d", err); 203 return err; 204 } 205 206 swap_buf(mac_msb, mac, 16); 207 208 SMP_DBG("mac %16phN", mac); 209 210 return 0; 211 } 212 213 static int smp_f4(struct crypto_shash *tfm_cmac, const u8 u[32], 214 const u8 v[32], const u8 x[16], u8 z, u8 res[16]) 215 { 216 u8 m[65]; 217 int err; 218 219 SMP_DBG("u %32phN", u); 220 SMP_DBG("v %32phN", v); 221 SMP_DBG("x %16phN z %02x", x, z); 222 223 m[0] = z; 224 memcpy(m + 1, v, 32); 225 memcpy(m + 33, u, 32); 226 227 err = aes_cmac(tfm_cmac, x, m, sizeof(m), res); 228 if (err) 229 return err; 230 231 SMP_DBG("res %16phN", res); 232 233 return err; 234 } 235 236 static int smp_f5(struct crypto_shash *tfm_cmac, const u8 w[32], 237 const u8 n1[16], const u8 n2[16], const u8 a1[7], 238 const u8 a2[7], u8 mackey[16], u8 ltk[16]) 239 { 240 /* The btle, salt and length "magic" values are as defined in 241 * the SMP section of the Bluetooth core specification. In ASCII 242 * the btle value ends up being 'btle'. The salt is just a 243 * random number whereas length is the value 256 in little 244 * endian format. 245 */ 246 const u8 btle[4] = { 0x65, 0x6c, 0x74, 0x62 }; 247 const u8 salt[16] = { 0xbe, 0x83, 0x60, 0x5a, 0xdb, 0x0b, 0x37, 0x60, 248 0x38, 0xa5, 0xf5, 0xaa, 0x91, 0x83, 0x88, 0x6c }; 249 const u8 length[2] = { 0x00, 0x01 }; 250 u8 m[53], t[16]; 251 int err; 252 253 SMP_DBG("w %32phN", w); 254 SMP_DBG("n1 %16phN n2 %16phN", n1, n2); 255 SMP_DBG("a1 %7phN a2 %7phN", a1, a2); 256 257 err = aes_cmac(tfm_cmac, salt, w, 32, t); 258 if (err) 259 return err; 260 261 SMP_DBG("t %16phN", t); 262 263 memcpy(m, length, 2); 264 memcpy(m + 2, a2, 7); 265 memcpy(m + 9, a1, 7); 266 memcpy(m + 16, n2, 16); 267 memcpy(m + 32, n1, 16); 268 memcpy(m + 48, btle, 4); 269 270 m[52] = 0; /* Counter */ 271 272 err = aes_cmac(tfm_cmac, t, m, sizeof(m), mackey); 273 if (err) 274 return err; 275 276 SMP_DBG("mackey %16phN", mackey); 277 278 m[52] = 1; /* Counter */ 279 280 err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk); 281 if (err) 282 return err; 283 284 SMP_DBG("ltk %16phN", ltk); 285 286 return 0; 287 } 288 289 static int smp_f6(struct crypto_shash *tfm_cmac, const u8 w[16], 290 const u8 n1[16], const u8 n2[16], const u8 r[16], 291 const u8 io_cap[3], const u8 a1[7], const u8 a2[7], 292 u8 res[16]) 293 { 294 u8 m[65]; 295 int err; 296 297 SMP_DBG("w %16phN", w); 298 SMP_DBG("n1 %16phN n2 %16phN", n1, n2); 299 SMP_DBG("r %16phN io_cap %3phN a1 %7phN a2 %7phN", r, io_cap, a1, a2); 300 301 memcpy(m, a2, 7); 302 memcpy(m + 7, a1, 7); 303 memcpy(m + 14, io_cap, 3); 304 memcpy(m + 17, r, 16); 305 memcpy(m + 33, n2, 16); 306 memcpy(m + 49, n1, 16); 307 308 err = aes_cmac(tfm_cmac, w, m, sizeof(m), res); 309 if (err) 310 return err; 311 312 SMP_DBG("res %16phN", res); 313 314 return err; 315 } 316 317 static int smp_g2(struct crypto_shash *tfm_cmac, const u8 u[32], const u8 v[32], 318 const u8 x[16], const u8 y[16], u32 *val) 319 { 320 u8 m[80], tmp[16]; 321 int err; 322 323 SMP_DBG("u %32phN", u); 324 SMP_DBG("v %32phN", v); 325 SMP_DBG("x %16phN y %16phN", x, y); 326 327 memcpy(m, y, 16); 328 memcpy(m + 16, v, 32); 329 memcpy(m + 48, u, 32); 330 331 err = aes_cmac(tfm_cmac, x, m, sizeof(m), tmp); 332 if (err) 333 return err; 334 335 *val = get_unaligned_le32(tmp); 336 *val %= 1000000; 337 338 SMP_DBG("val %06u", *val); 339 340 return 0; 341 } 342 343 static int smp_h6(struct crypto_shash *tfm_cmac, const u8 w[16], 344 const u8 key_id[4], u8 res[16]) 345 { 346 int err; 347 348 SMP_DBG("w %16phN key_id %4phN", w, key_id); 349 350 err = aes_cmac(tfm_cmac, w, key_id, 4, res); 351 if (err) 352 return err; 353 354 SMP_DBG("res %16phN", res); 355 356 return err; 357 } 358 359 static int smp_h7(struct crypto_shash *tfm_cmac, const u8 w[16], 360 const u8 salt[16], u8 res[16]) 361 { 362 int err; 363 364 SMP_DBG("w %16phN salt %16phN", w, salt); 365 366 err = aes_cmac(tfm_cmac, salt, w, 16, res); 367 if (err) 368 return err; 369 370 SMP_DBG("res %16phN", res); 371 372 return err; 373 } 374 375 /* The following functions map to the legacy SMP crypto functions e, c1, 376 * s1 and ah. 377 */ 378 379 static int smp_e(const u8 *k, u8 *r) 380 { 381 struct crypto_aes_ctx ctx; 382 uint8_t tmp[16], data[16]; 383 int err; 384 385 SMP_DBG("k %16phN r %16phN", k, r); 386 387 /* The most significant octet of key corresponds to k[0] */ 388 swap_buf(k, tmp, 16); 389 390 err = aes_expandkey(&ctx, tmp, 16); 391 if (err) { 392 BT_ERR("cipher setkey failed: %d", err); 393 return err; 394 } 395 396 /* Most significant octet of plaintextData corresponds to data[0] */ 397 swap_buf(r, data, 16); 398 399 aes_encrypt(&ctx, data, data); 400 401 /* Most significant octet of encryptedData corresponds to data[0] */ 402 swap_buf(data, r, 16); 403 404 SMP_DBG("r %16phN", r); 405 406 memzero_explicit(&ctx, sizeof (ctx)); 407 return err; 408 } 409 410 static int smp_c1(const u8 k[16], 411 const u8 r[16], const u8 preq[7], const u8 pres[7], u8 _iat, 412 const bdaddr_t *ia, u8 _rat, const bdaddr_t *ra, u8 res[16]) 413 { 414 u8 p1[16], p2[16]; 415 int err; 416 417 SMP_DBG("k %16phN r %16phN", k, r); 418 SMP_DBG("iat %u ia %6phN rat %u ra %6phN", _iat, ia, _rat, ra); 419 SMP_DBG("preq %7phN pres %7phN", preq, pres); 420 421 memset(p1, 0, 16); 422 423 /* p1 = pres || preq || _rat || _iat */ 424 p1[0] = _iat; 425 p1[1] = _rat; 426 memcpy(p1 + 2, preq, 7); 427 memcpy(p1 + 9, pres, 7); 428 429 SMP_DBG("p1 %16phN", p1); 430 431 /* res = r XOR p1 */ 432 u128_xor((u128 *) res, (u128 *) r, (u128 *) p1); 433 434 /* res = e(k, res) */ 435 err = smp_e(k, res); 436 if (err) { 437 BT_ERR("Encrypt data error"); 438 return err; 439 } 440 441 /* p2 = padding || ia || ra */ 442 memcpy(p2, ra, 6); 443 memcpy(p2 + 6, ia, 6); 444 memset(p2 + 12, 0, 4); 445 446 SMP_DBG("p2 %16phN", p2); 447 448 /* res = res XOR p2 */ 449 u128_xor((u128 *) res, (u128 *) res, (u128 *) p2); 450 451 /* res = e(k, res) */ 452 err = smp_e(k, res); 453 if (err) 454 BT_ERR("Encrypt data error"); 455 456 return err; 457 } 458 459 static int smp_s1(const u8 k[16], 460 const u8 r1[16], const u8 r2[16], u8 _r[16]) 461 { 462 int err; 463 464 /* Just least significant octets from r1 and r2 are considered */ 465 memcpy(_r, r2, 8); 466 memcpy(_r + 8, r1, 8); 467 468 err = smp_e(k, _r); 469 if (err) 470 BT_ERR("Encrypt data error"); 471 472 return err; 473 } 474 475 static int smp_ah(const u8 irk[16], const u8 r[3], u8 res[3]) 476 { 477 u8 _res[16]; 478 int err; 479 480 /* r' = padding || r */ 481 memcpy(_res, r, 3); 482 memset(_res + 3, 0, 13); 483 484 err = smp_e(irk, _res); 485 if (err) { 486 BT_ERR("Encrypt error"); 487 return err; 488 } 489 490 /* The output of the random address function ah is: 491 * ah(k, r) = e(k, r') mod 2^24 492 * The output of the security function e is then truncated to 24 bits 493 * by taking the least significant 24 bits of the output of e as the 494 * result of ah. 495 */ 496 memcpy(res, _res, 3); 497 498 return 0; 499 } 500 501 bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16], 502 const bdaddr_t *bdaddr) 503 { 504 struct l2cap_chan *chan = hdev->smp_data; 505 struct smp_dev *smp; 506 u8 hash[3]; 507 int err; 508 509 if (!chan || !chan->data) 510 return false; 511 512 smp = chan->data; 513 514 BT_DBG("RPA %pMR IRK %*phN", bdaddr, 16, irk); 515 516 err = smp_ah(irk, &bdaddr->b[3], hash); 517 if (err) 518 return false; 519 520 return !crypto_memneq(bdaddr->b, hash, 3); 521 } 522 523 int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa) 524 { 525 struct l2cap_chan *chan = hdev->smp_data; 526 struct smp_dev *smp; 527 int err; 528 529 if (!chan || !chan->data) 530 return -EOPNOTSUPP; 531 532 smp = chan->data; 533 534 get_random_bytes(&rpa->b[3], 3); 535 536 rpa->b[5] &= 0x3f; /* Clear two most significant bits */ 537 rpa->b[5] |= 0x40; /* Set second most significant bit */ 538 539 err = smp_ah(irk, &rpa->b[3], rpa->b); 540 if (err < 0) 541 return err; 542 543 BT_DBG("RPA %pMR", rpa); 544 545 return 0; 546 } 547 548 int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16]) 549 { 550 struct l2cap_chan *chan = hdev->smp_data; 551 struct smp_dev *smp; 552 int err; 553 554 if (!chan || !chan->data) 555 return -EOPNOTSUPP; 556 557 smp = chan->data; 558 559 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { 560 BT_DBG("Using debug keys"); 561 err = set_ecdh_privkey(smp->tfm_ecdh, debug_sk); 562 if (err) 563 return err; 564 memcpy(smp->local_pk, debug_pk, 64); 565 smp->debug_key = true; 566 } else { 567 while (true) { 568 /* Generate key pair for Secure Connections */ 569 err = generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk); 570 if (err) 571 return err; 572 573 /* This is unlikely, but we need to check that 574 * we didn't accidentially generate a debug key. 575 */ 576 if (crypto_memneq(smp->local_pk, debug_pk, 64)) 577 break; 578 } 579 smp->debug_key = false; 580 } 581 582 SMP_DBG("OOB Public Key X: %32phN", smp->local_pk); 583 SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32); 584 585 get_random_bytes(smp->local_rand, 16); 586 587 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->local_pk, 588 smp->local_rand, 0, hash); 589 if (err < 0) 590 return err; 591 592 memcpy(rand, smp->local_rand, 16); 593 594 smp->local_oob = true; 595 596 return 0; 597 } 598 599 static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data) 600 { 601 struct l2cap_chan *chan = conn->smp; 602 struct smp_chan *smp; 603 struct kvec iv[2]; 604 struct msghdr msg; 605 606 if (!chan) 607 return; 608 609 BT_DBG("code 0x%2.2x", code); 610 611 iv[0].iov_base = &code; 612 iv[0].iov_len = 1; 613 614 iv[1].iov_base = data; 615 iv[1].iov_len = len; 616 617 memset(&msg, 0, sizeof(msg)); 618 619 iov_iter_kvec(&msg.msg_iter, WRITE, iv, 2, 1 + len); 620 621 l2cap_chan_send(chan, &msg, 1 + len); 622 623 if (!chan->data) 624 return; 625 626 smp = chan->data; 627 628 cancel_delayed_work_sync(&smp->security_timer); 629 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT); 630 } 631 632 static u8 authreq_to_seclevel(u8 authreq) 633 { 634 if (authreq & SMP_AUTH_MITM) { 635 if (authreq & SMP_AUTH_SC) 636 return BT_SECURITY_FIPS; 637 else 638 return BT_SECURITY_HIGH; 639 } else { 640 return BT_SECURITY_MEDIUM; 641 } 642 } 643 644 static __u8 seclevel_to_authreq(__u8 sec_level) 645 { 646 switch (sec_level) { 647 case BT_SECURITY_FIPS: 648 case BT_SECURITY_HIGH: 649 return SMP_AUTH_MITM | SMP_AUTH_BONDING; 650 case BT_SECURITY_MEDIUM: 651 return SMP_AUTH_BONDING; 652 default: 653 return SMP_AUTH_NONE; 654 } 655 } 656 657 static void build_pairing_cmd(struct l2cap_conn *conn, 658 struct smp_cmd_pairing *req, 659 struct smp_cmd_pairing *rsp, __u8 authreq) 660 { 661 struct l2cap_chan *chan = conn->smp; 662 struct smp_chan *smp = chan->data; 663 struct hci_conn *hcon = conn->hcon; 664 struct hci_dev *hdev = hcon->hdev; 665 u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT; 666 667 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { 668 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 669 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 670 authreq |= SMP_AUTH_BONDING; 671 } else { 672 authreq &= ~SMP_AUTH_BONDING; 673 } 674 675 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) 676 remote_dist |= SMP_DIST_ID_KEY; 677 678 if (hci_dev_test_flag(hdev, HCI_PRIVACY)) 679 local_dist |= SMP_DIST_ID_KEY; 680 681 if (hci_dev_test_flag(hdev, HCI_SC_ENABLED) && 682 (authreq & SMP_AUTH_SC)) { 683 struct oob_data *oob_data; 684 u8 bdaddr_type; 685 686 if (hci_dev_test_flag(hdev, HCI_SSP_ENABLED)) { 687 local_dist |= SMP_DIST_LINK_KEY; 688 remote_dist |= SMP_DIST_LINK_KEY; 689 } 690 691 if (hcon->dst_type == ADDR_LE_DEV_PUBLIC) 692 bdaddr_type = BDADDR_LE_PUBLIC; 693 else 694 bdaddr_type = BDADDR_LE_RANDOM; 695 696 oob_data = hci_find_remote_oob_data(hdev, &hcon->dst, 697 bdaddr_type); 698 if (oob_data && oob_data->present) { 699 set_bit(SMP_FLAG_REMOTE_OOB, &smp->flags); 700 oob_flag = SMP_OOB_PRESENT; 701 memcpy(smp->rr, oob_data->rand256, 16); 702 memcpy(smp->pcnf, oob_data->hash256, 16); 703 SMP_DBG("OOB Remote Confirmation: %16phN", smp->pcnf); 704 SMP_DBG("OOB Remote Random: %16phN", smp->rr); 705 } 706 707 } else { 708 authreq &= ~SMP_AUTH_SC; 709 } 710 711 if (rsp == NULL) { 712 req->io_capability = conn->hcon->io_capability; 713 req->oob_flag = oob_flag; 714 req->max_key_size = hdev->le_max_key_size; 715 req->init_key_dist = local_dist; 716 req->resp_key_dist = remote_dist; 717 req->auth_req = (authreq & AUTH_REQ_MASK(hdev)); 718 719 smp->remote_key_dist = remote_dist; 720 return; 721 } 722 723 rsp->io_capability = conn->hcon->io_capability; 724 rsp->oob_flag = oob_flag; 725 rsp->max_key_size = hdev->le_max_key_size; 726 rsp->init_key_dist = req->init_key_dist & remote_dist; 727 rsp->resp_key_dist = req->resp_key_dist & local_dist; 728 rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev)); 729 730 smp->remote_key_dist = rsp->init_key_dist; 731 } 732 733 static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size) 734 { 735 struct l2cap_chan *chan = conn->smp; 736 struct hci_dev *hdev = conn->hcon->hdev; 737 struct smp_chan *smp = chan->data; 738 739 if (max_key_size > hdev->le_max_key_size || 740 max_key_size < SMP_MIN_ENC_KEY_SIZE) 741 return SMP_ENC_KEY_SIZE; 742 743 smp->enc_key_size = max_key_size; 744 745 return 0; 746 } 747 748 static void smp_chan_destroy(struct l2cap_conn *conn) 749 { 750 struct l2cap_chan *chan = conn->smp; 751 struct smp_chan *smp = chan->data; 752 struct hci_conn *hcon = conn->hcon; 753 bool complete; 754 755 BUG_ON(!smp); 756 757 cancel_delayed_work_sync(&smp->security_timer); 758 759 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags); 760 mgmt_smp_complete(hcon, complete); 761 762 kzfree(smp->csrk); 763 kzfree(smp->slave_csrk); 764 kzfree(smp->link_key); 765 766 crypto_free_shash(smp->tfm_cmac); 767 crypto_free_kpp(smp->tfm_ecdh); 768 769 /* Ensure that we don't leave any debug key around if debug key 770 * support hasn't been explicitly enabled. 771 */ 772 if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG && 773 !hci_dev_test_flag(hcon->hdev, HCI_KEEP_DEBUG_KEYS)) { 774 list_del_rcu(&smp->ltk->list); 775 kfree_rcu(smp->ltk, rcu); 776 smp->ltk = NULL; 777 } 778 779 /* If pairing failed clean up any keys we might have */ 780 if (!complete) { 781 if (smp->ltk) { 782 list_del_rcu(&smp->ltk->list); 783 kfree_rcu(smp->ltk, rcu); 784 } 785 786 if (smp->slave_ltk) { 787 list_del_rcu(&smp->slave_ltk->list); 788 kfree_rcu(smp->slave_ltk, rcu); 789 } 790 791 if (smp->remote_irk) { 792 list_del_rcu(&smp->remote_irk->list); 793 kfree_rcu(smp->remote_irk, rcu); 794 } 795 } 796 797 chan->data = NULL; 798 kzfree(smp); 799 hci_conn_drop(hcon); 800 } 801 802 static void smp_failure(struct l2cap_conn *conn, u8 reason) 803 { 804 struct hci_conn *hcon = conn->hcon; 805 struct l2cap_chan *chan = conn->smp; 806 807 if (reason) 808 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason), 809 &reason); 810 811 mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE); 812 813 if (chan->data) 814 smp_chan_destroy(conn); 815 } 816 817 #define JUST_WORKS 0x00 818 #define JUST_CFM 0x01 819 #define REQ_PASSKEY 0x02 820 #define CFM_PASSKEY 0x03 821 #define REQ_OOB 0x04 822 #define DSP_PASSKEY 0x05 823 #define OVERLAP 0xFF 824 825 static const u8 gen_method[5][5] = { 826 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 827 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 828 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 829 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM }, 830 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP }, 831 }; 832 833 static const u8 sc_method[5][5] = { 834 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 835 { JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 836 { DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY }, 837 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM }, 838 { DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 839 }; 840 841 static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io) 842 { 843 /* If either side has unknown io_caps, use JUST_CFM (which gets 844 * converted later to JUST_WORKS if we're initiators. 845 */ 846 if (local_io > SMP_IO_KEYBOARD_DISPLAY || 847 remote_io > SMP_IO_KEYBOARD_DISPLAY) 848 return JUST_CFM; 849 850 if (test_bit(SMP_FLAG_SC, &smp->flags)) 851 return sc_method[remote_io][local_io]; 852 853 return gen_method[remote_io][local_io]; 854 } 855 856 static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth, 857 u8 local_io, u8 remote_io) 858 { 859 struct hci_conn *hcon = conn->hcon; 860 struct l2cap_chan *chan = conn->smp; 861 struct smp_chan *smp = chan->data; 862 u32 passkey = 0; 863 int ret = 0; 864 865 /* Initialize key for JUST WORKS */ 866 memset(smp->tk, 0, sizeof(smp->tk)); 867 clear_bit(SMP_FLAG_TK_VALID, &smp->flags); 868 869 BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io); 870 871 /* If neither side wants MITM, either "just" confirm an incoming 872 * request or use just-works for outgoing ones. The JUST_CFM 873 * will be converted to JUST_WORKS if necessary later in this 874 * function. If either side has MITM look up the method from the 875 * table. 876 */ 877 if (!(auth & SMP_AUTH_MITM)) 878 smp->method = JUST_CFM; 879 else 880 smp->method = get_auth_method(smp, local_io, remote_io); 881 882 /* Don't confirm locally initiated pairing attempts */ 883 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, 884 &smp->flags)) 885 smp->method = JUST_WORKS; 886 887 /* Don't bother user space with no IO capabilities */ 888 if (smp->method == JUST_CFM && 889 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 890 smp->method = JUST_WORKS; 891 892 /* If Just Works, Continue with Zero TK */ 893 if (smp->method == JUST_WORKS) { 894 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 895 return 0; 896 } 897 898 /* If this function is used for SC -> legacy fallback we 899 * can only recover the just-works case. 900 */ 901 if (test_bit(SMP_FLAG_SC, &smp->flags)) 902 return -EINVAL; 903 904 /* Not Just Works/Confirm results in MITM Authentication */ 905 if (smp->method != JUST_CFM) { 906 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags); 907 if (hcon->pending_sec_level < BT_SECURITY_HIGH) 908 hcon->pending_sec_level = BT_SECURITY_HIGH; 909 } 910 911 /* If both devices have Keyoard-Display I/O, the master 912 * Confirms and the slave Enters the passkey. 913 */ 914 if (smp->method == OVERLAP) { 915 if (hcon->role == HCI_ROLE_MASTER) 916 smp->method = CFM_PASSKEY; 917 else 918 smp->method = REQ_PASSKEY; 919 } 920 921 /* Generate random passkey. */ 922 if (smp->method == CFM_PASSKEY) { 923 memset(smp->tk, 0, sizeof(smp->tk)); 924 get_random_bytes(&passkey, sizeof(passkey)); 925 passkey %= 1000000; 926 put_unaligned_le32(passkey, smp->tk); 927 BT_DBG("PassKey: %d", passkey); 928 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 929 } 930 931 if (smp->method == REQ_PASSKEY) 932 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst, 933 hcon->type, hcon->dst_type); 934 else if (smp->method == JUST_CFM) 935 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, 936 hcon->type, hcon->dst_type, 937 passkey, 1); 938 else 939 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst, 940 hcon->type, hcon->dst_type, 941 passkey, 0); 942 943 return ret; 944 } 945 946 static u8 smp_confirm(struct smp_chan *smp) 947 { 948 struct l2cap_conn *conn = smp->conn; 949 struct smp_cmd_pairing_confirm cp; 950 int ret; 951 952 BT_DBG("conn %p", conn); 953 954 ret = smp_c1(smp->tk, smp->prnd, smp->preq, smp->prsp, 955 conn->hcon->init_addr_type, &conn->hcon->init_addr, 956 conn->hcon->resp_addr_type, &conn->hcon->resp_addr, 957 cp.confirm_val); 958 if (ret) 959 return SMP_UNSPECIFIED; 960 961 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 962 963 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp); 964 965 if (conn->hcon->out) 966 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 967 else 968 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 969 970 return 0; 971 } 972 973 static u8 smp_random(struct smp_chan *smp) 974 { 975 struct l2cap_conn *conn = smp->conn; 976 struct hci_conn *hcon = conn->hcon; 977 u8 confirm[16]; 978 int ret; 979 980 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave"); 981 982 ret = smp_c1(smp->tk, smp->rrnd, smp->preq, smp->prsp, 983 hcon->init_addr_type, &hcon->init_addr, 984 hcon->resp_addr_type, &hcon->resp_addr, confirm); 985 if (ret) 986 return SMP_UNSPECIFIED; 987 988 if (crypto_memneq(smp->pcnf, confirm, sizeof(smp->pcnf))) { 989 bt_dev_err(hcon->hdev, "pairing failed " 990 "(confirmation values mismatch)"); 991 return SMP_CONFIRM_FAILED; 992 } 993 994 if (hcon->out) { 995 u8 stk[16]; 996 __le64 rand = 0; 997 __le16 ediv = 0; 998 999 smp_s1(smp->tk, smp->rrnd, smp->prnd, stk); 1000 1001 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) 1002 return SMP_UNSPECIFIED; 1003 1004 hci_le_start_enc(hcon, ediv, rand, stk, smp->enc_key_size); 1005 hcon->enc_key_size = smp->enc_key_size; 1006 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); 1007 } else { 1008 u8 stk[16], auth; 1009 __le64 rand = 0; 1010 __le16 ediv = 0; 1011 1012 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 1013 smp->prnd); 1014 1015 smp_s1(smp->tk, smp->prnd, smp->rrnd, stk); 1016 1017 if (hcon->pending_sec_level == BT_SECURITY_HIGH) 1018 auth = 1; 1019 else 1020 auth = 0; 1021 1022 /* Even though there's no _SLAVE suffix this is the 1023 * slave STK we're adding for later lookup (the master 1024 * STK never needs to be stored). 1025 */ 1026 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 1027 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand); 1028 } 1029 1030 return 0; 1031 } 1032 1033 static void smp_notify_keys(struct l2cap_conn *conn) 1034 { 1035 struct l2cap_chan *chan = conn->smp; 1036 struct smp_chan *smp = chan->data; 1037 struct hci_conn *hcon = conn->hcon; 1038 struct hci_dev *hdev = hcon->hdev; 1039 struct smp_cmd_pairing *req = (void *) &smp->preq[1]; 1040 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1]; 1041 bool persistent; 1042 1043 if (hcon->type == ACL_LINK) { 1044 if (hcon->key_type == HCI_LK_DEBUG_COMBINATION) 1045 persistent = false; 1046 else 1047 persistent = !test_bit(HCI_CONN_FLUSH_KEY, 1048 &hcon->flags); 1049 } else { 1050 /* The LTKs, IRKs and CSRKs should be persistent only if 1051 * both sides had the bonding bit set in their 1052 * authentication requests. 1053 */ 1054 persistent = !!((req->auth_req & rsp->auth_req) & 1055 SMP_AUTH_BONDING); 1056 } 1057 1058 if (smp->remote_irk) { 1059 mgmt_new_irk(hdev, smp->remote_irk, persistent); 1060 1061 /* Now that user space can be considered to know the 1062 * identity address track the connection based on it 1063 * from now on (assuming this is an LE link). 1064 */ 1065 if (hcon->type == LE_LINK) { 1066 bacpy(&hcon->dst, &smp->remote_irk->bdaddr); 1067 hcon->dst_type = smp->remote_irk->addr_type; 1068 queue_work(hdev->workqueue, &conn->id_addr_update_work); 1069 } 1070 } 1071 1072 if (smp->csrk) { 1073 smp->csrk->bdaddr_type = hcon->dst_type; 1074 bacpy(&smp->csrk->bdaddr, &hcon->dst); 1075 mgmt_new_csrk(hdev, smp->csrk, persistent); 1076 } 1077 1078 if (smp->slave_csrk) { 1079 smp->slave_csrk->bdaddr_type = hcon->dst_type; 1080 bacpy(&smp->slave_csrk->bdaddr, &hcon->dst); 1081 mgmt_new_csrk(hdev, smp->slave_csrk, persistent); 1082 } 1083 1084 if (smp->ltk) { 1085 smp->ltk->bdaddr_type = hcon->dst_type; 1086 bacpy(&smp->ltk->bdaddr, &hcon->dst); 1087 mgmt_new_ltk(hdev, smp->ltk, persistent); 1088 } 1089 1090 if (smp->slave_ltk) { 1091 smp->slave_ltk->bdaddr_type = hcon->dst_type; 1092 bacpy(&smp->slave_ltk->bdaddr, &hcon->dst); 1093 mgmt_new_ltk(hdev, smp->slave_ltk, persistent); 1094 } 1095 1096 if (smp->link_key) { 1097 struct link_key *key; 1098 u8 type; 1099 1100 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags)) 1101 type = HCI_LK_DEBUG_COMBINATION; 1102 else if (hcon->sec_level == BT_SECURITY_FIPS) 1103 type = HCI_LK_AUTH_COMBINATION_P256; 1104 else 1105 type = HCI_LK_UNAUTH_COMBINATION_P256; 1106 1107 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst, 1108 smp->link_key, type, 0, &persistent); 1109 if (key) { 1110 mgmt_new_link_key(hdev, key, persistent); 1111 1112 /* Don't keep debug keys around if the relevant 1113 * flag is not set. 1114 */ 1115 if (!hci_dev_test_flag(hdev, HCI_KEEP_DEBUG_KEYS) && 1116 key->type == HCI_LK_DEBUG_COMBINATION) { 1117 list_del_rcu(&key->list); 1118 kfree_rcu(key, rcu); 1119 } 1120 } 1121 } 1122 } 1123 1124 static void sc_add_ltk(struct smp_chan *smp) 1125 { 1126 struct hci_conn *hcon = smp->conn->hcon; 1127 u8 key_type, auth; 1128 1129 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags)) 1130 key_type = SMP_LTK_P256_DEBUG; 1131 else 1132 key_type = SMP_LTK_P256; 1133 1134 if (hcon->pending_sec_level == BT_SECURITY_FIPS) 1135 auth = 1; 1136 else 1137 auth = 0; 1138 1139 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 1140 key_type, auth, smp->tk, smp->enc_key_size, 1141 0, 0); 1142 } 1143 1144 static void sc_generate_link_key(struct smp_chan *smp) 1145 { 1146 /* From core spec. Spells out in ASCII as 'lebr'. */ 1147 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c }; 1148 1149 smp->link_key = kzalloc(16, GFP_KERNEL); 1150 if (!smp->link_key) 1151 return; 1152 1153 if (test_bit(SMP_FLAG_CT2, &smp->flags)) { 1154 /* SALT = 0x00000000000000000000000000000000746D7031 */ 1155 const u8 salt[16] = { 0x31, 0x70, 0x6d, 0x74 }; 1156 1157 if (smp_h7(smp->tfm_cmac, smp->tk, salt, smp->link_key)) { 1158 kzfree(smp->link_key); 1159 smp->link_key = NULL; 1160 return; 1161 } 1162 } else { 1163 /* From core spec. Spells out in ASCII as 'tmp1'. */ 1164 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 }; 1165 1166 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) { 1167 kzfree(smp->link_key); 1168 smp->link_key = NULL; 1169 return; 1170 } 1171 } 1172 1173 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) { 1174 kzfree(smp->link_key); 1175 smp->link_key = NULL; 1176 return; 1177 } 1178 } 1179 1180 static void smp_allow_key_dist(struct smp_chan *smp) 1181 { 1182 /* Allow the first expected phase 3 PDU. The rest of the PDUs 1183 * will be allowed in each PDU handler to ensure we receive 1184 * them in the correct order. 1185 */ 1186 if (smp->remote_key_dist & SMP_DIST_ENC_KEY) 1187 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO); 1188 else if (smp->remote_key_dist & SMP_DIST_ID_KEY) 1189 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); 1190 else if (smp->remote_key_dist & SMP_DIST_SIGN) 1191 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 1192 } 1193 1194 static void sc_generate_ltk(struct smp_chan *smp) 1195 { 1196 /* From core spec. Spells out in ASCII as 'brle'. */ 1197 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 }; 1198 struct hci_conn *hcon = smp->conn->hcon; 1199 struct hci_dev *hdev = hcon->hdev; 1200 struct link_key *key; 1201 1202 key = hci_find_link_key(hdev, &hcon->dst); 1203 if (!key) { 1204 bt_dev_err(hdev, "no Link Key found to generate LTK"); 1205 return; 1206 } 1207 1208 if (key->type == HCI_LK_DEBUG_COMBINATION) 1209 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1210 1211 if (test_bit(SMP_FLAG_CT2, &smp->flags)) { 1212 /* SALT = 0x00000000000000000000000000000000746D7032 */ 1213 const u8 salt[16] = { 0x32, 0x70, 0x6d, 0x74 }; 1214 1215 if (smp_h7(smp->tfm_cmac, key->val, salt, smp->tk)) 1216 return; 1217 } else { 1218 /* From core spec. Spells out in ASCII as 'tmp2'. */ 1219 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 }; 1220 1221 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk)) 1222 return; 1223 } 1224 1225 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk)) 1226 return; 1227 1228 sc_add_ltk(smp); 1229 } 1230 1231 static void smp_distribute_keys(struct smp_chan *smp) 1232 { 1233 struct smp_cmd_pairing *req, *rsp; 1234 struct l2cap_conn *conn = smp->conn; 1235 struct hci_conn *hcon = conn->hcon; 1236 struct hci_dev *hdev = hcon->hdev; 1237 __u8 *keydist; 1238 1239 BT_DBG("conn %p", conn); 1240 1241 rsp = (void *) &smp->prsp[1]; 1242 1243 /* The responder sends its keys first */ 1244 if (hcon->out && (smp->remote_key_dist & KEY_DIST_MASK)) { 1245 smp_allow_key_dist(smp); 1246 return; 1247 } 1248 1249 req = (void *) &smp->preq[1]; 1250 1251 if (hcon->out) { 1252 keydist = &rsp->init_key_dist; 1253 *keydist &= req->init_key_dist; 1254 } else { 1255 keydist = &rsp->resp_key_dist; 1256 *keydist &= req->resp_key_dist; 1257 } 1258 1259 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1260 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY)) 1261 sc_generate_link_key(smp); 1262 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY)) 1263 sc_generate_ltk(smp); 1264 1265 /* Clear the keys which are generated but not distributed */ 1266 *keydist &= ~SMP_SC_NO_DIST; 1267 } 1268 1269 BT_DBG("keydist 0x%x", *keydist); 1270 1271 if (*keydist & SMP_DIST_ENC_KEY) { 1272 struct smp_cmd_encrypt_info enc; 1273 struct smp_cmd_master_ident ident; 1274 struct smp_ltk *ltk; 1275 u8 authenticated; 1276 __le16 ediv; 1277 __le64 rand; 1278 1279 /* Make sure we generate only the significant amount of 1280 * bytes based on the encryption key size, and set the rest 1281 * of the value to zeroes. 1282 */ 1283 get_random_bytes(enc.ltk, smp->enc_key_size); 1284 memset(enc.ltk + smp->enc_key_size, 0, 1285 sizeof(enc.ltk) - smp->enc_key_size); 1286 1287 get_random_bytes(&ediv, sizeof(ediv)); 1288 get_random_bytes(&rand, sizeof(rand)); 1289 1290 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc); 1291 1292 authenticated = hcon->sec_level == BT_SECURITY_HIGH; 1293 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, 1294 SMP_LTK_SLAVE, authenticated, enc.ltk, 1295 smp->enc_key_size, ediv, rand); 1296 smp->slave_ltk = ltk; 1297 1298 ident.ediv = ediv; 1299 ident.rand = rand; 1300 1301 smp_send_cmd(conn, SMP_CMD_MASTER_IDENT, sizeof(ident), &ident); 1302 1303 *keydist &= ~SMP_DIST_ENC_KEY; 1304 } 1305 1306 if (*keydist & SMP_DIST_ID_KEY) { 1307 struct smp_cmd_ident_addr_info addrinfo; 1308 struct smp_cmd_ident_info idinfo; 1309 1310 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk)); 1311 1312 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo); 1313 1314 /* The hci_conn contains the local identity address 1315 * after the connection has been established. 1316 * 1317 * This is true even when the connection has been 1318 * established using a resolvable random address. 1319 */ 1320 bacpy(&addrinfo.bdaddr, &hcon->src); 1321 addrinfo.addr_type = hcon->src_type; 1322 1323 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo), 1324 &addrinfo); 1325 1326 *keydist &= ~SMP_DIST_ID_KEY; 1327 } 1328 1329 if (*keydist & SMP_DIST_SIGN) { 1330 struct smp_cmd_sign_info sign; 1331 struct smp_csrk *csrk; 1332 1333 /* Generate a new random key */ 1334 get_random_bytes(sign.csrk, sizeof(sign.csrk)); 1335 1336 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); 1337 if (csrk) { 1338 if (hcon->sec_level > BT_SECURITY_MEDIUM) 1339 csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED; 1340 else 1341 csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED; 1342 memcpy(csrk->val, sign.csrk, sizeof(csrk->val)); 1343 } 1344 smp->slave_csrk = csrk; 1345 1346 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign); 1347 1348 *keydist &= ~SMP_DIST_SIGN; 1349 } 1350 1351 /* If there are still keys to be received wait for them */ 1352 if (smp->remote_key_dist & KEY_DIST_MASK) { 1353 smp_allow_key_dist(smp); 1354 return; 1355 } 1356 1357 set_bit(SMP_FLAG_COMPLETE, &smp->flags); 1358 smp_notify_keys(conn); 1359 1360 smp_chan_destroy(conn); 1361 } 1362 1363 static void smp_timeout(struct work_struct *work) 1364 { 1365 struct smp_chan *smp = container_of(work, struct smp_chan, 1366 security_timer.work); 1367 struct l2cap_conn *conn = smp->conn; 1368 1369 BT_DBG("conn %p", conn); 1370 1371 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM); 1372 } 1373 1374 static struct smp_chan *smp_chan_create(struct l2cap_conn *conn) 1375 { 1376 struct l2cap_chan *chan = conn->smp; 1377 struct smp_chan *smp; 1378 1379 smp = kzalloc(sizeof(*smp), GFP_ATOMIC); 1380 if (!smp) 1381 return NULL; 1382 1383 smp->tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 1384 if (IS_ERR(smp->tfm_cmac)) { 1385 BT_ERR("Unable to create CMAC crypto context"); 1386 goto zfree_smp; 1387 } 1388 1389 smp->tfm_ecdh = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0); 1390 if (IS_ERR(smp->tfm_ecdh)) { 1391 BT_ERR("Unable to create ECDH crypto context"); 1392 goto free_shash; 1393 } 1394 1395 smp->conn = conn; 1396 chan->data = smp; 1397 1398 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL); 1399 1400 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout); 1401 1402 hci_conn_hold(conn->hcon); 1403 1404 return smp; 1405 1406 free_shash: 1407 crypto_free_shash(smp->tfm_cmac); 1408 zfree_smp: 1409 kzfree(smp); 1410 return NULL; 1411 } 1412 1413 static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16]) 1414 { 1415 struct hci_conn *hcon = smp->conn->hcon; 1416 u8 *na, *nb, a[7], b[7]; 1417 1418 if (hcon->out) { 1419 na = smp->prnd; 1420 nb = smp->rrnd; 1421 } else { 1422 na = smp->rrnd; 1423 nb = smp->prnd; 1424 } 1425 1426 memcpy(a, &hcon->init_addr, 6); 1427 memcpy(b, &hcon->resp_addr, 6); 1428 a[6] = hcon->init_addr_type; 1429 b[6] = hcon->resp_addr_type; 1430 1431 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk); 1432 } 1433 1434 static void sc_dhkey_check(struct smp_chan *smp) 1435 { 1436 struct hci_conn *hcon = smp->conn->hcon; 1437 struct smp_cmd_dhkey_check check; 1438 u8 a[7], b[7], *local_addr, *remote_addr; 1439 u8 io_cap[3], r[16]; 1440 1441 memcpy(a, &hcon->init_addr, 6); 1442 memcpy(b, &hcon->resp_addr, 6); 1443 a[6] = hcon->init_addr_type; 1444 b[6] = hcon->resp_addr_type; 1445 1446 if (hcon->out) { 1447 local_addr = a; 1448 remote_addr = b; 1449 memcpy(io_cap, &smp->preq[1], 3); 1450 } else { 1451 local_addr = b; 1452 remote_addr = a; 1453 memcpy(io_cap, &smp->prsp[1], 3); 1454 } 1455 1456 memset(r, 0, sizeof(r)); 1457 1458 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 1459 put_unaligned_le32(hcon->passkey_notify, r); 1460 1461 if (smp->method == REQ_OOB) 1462 memcpy(r, smp->rr, 16); 1463 1464 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap, 1465 local_addr, remote_addr, check.e); 1466 1467 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check); 1468 } 1469 1470 static u8 sc_passkey_send_confirm(struct smp_chan *smp) 1471 { 1472 struct l2cap_conn *conn = smp->conn; 1473 struct hci_conn *hcon = conn->hcon; 1474 struct smp_cmd_pairing_confirm cfm; 1475 u8 r; 1476 1477 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); 1478 r |= 0x80; 1479 1480 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1481 1482 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r, 1483 cfm.confirm_val)) 1484 return SMP_UNSPECIFIED; 1485 1486 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); 1487 1488 return 0; 1489 } 1490 1491 static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op) 1492 { 1493 struct l2cap_conn *conn = smp->conn; 1494 struct hci_conn *hcon = conn->hcon; 1495 struct hci_dev *hdev = hcon->hdev; 1496 u8 cfm[16], r; 1497 1498 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */ 1499 if (smp->passkey_round >= 20) 1500 return 0; 1501 1502 switch (smp_op) { 1503 case SMP_CMD_PAIRING_RANDOM: 1504 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); 1505 r |= 0x80; 1506 1507 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, 1508 smp->rrnd, r, cfm)) 1509 return SMP_UNSPECIFIED; 1510 1511 if (crypto_memneq(smp->pcnf, cfm, 16)) 1512 return SMP_CONFIRM_FAILED; 1513 1514 smp->passkey_round++; 1515 1516 if (smp->passkey_round == 20) { 1517 /* Generate MacKey and LTK */ 1518 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk)) 1519 return SMP_UNSPECIFIED; 1520 } 1521 1522 /* The round is only complete when the initiator 1523 * receives pairing random. 1524 */ 1525 if (!hcon->out) { 1526 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 1527 sizeof(smp->prnd), smp->prnd); 1528 if (smp->passkey_round == 20) 1529 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1530 else 1531 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1532 return 0; 1533 } 1534 1535 /* Start the next round */ 1536 if (smp->passkey_round != 20) 1537 return sc_passkey_round(smp, 0); 1538 1539 /* Passkey rounds are complete - start DHKey Check */ 1540 sc_dhkey_check(smp); 1541 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1542 1543 break; 1544 1545 case SMP_CMD_PAIRING_CONFIRM: 1546 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { 1547 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 1548 return 0; 1549 } 1550 1551 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 1552 1553 if (hcon->out) { 1554 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 1555 sizeof(smp->prnd), smp->prnd); 1556 return 0; 1557 } 1558 1559 return sc_passkey_send_confirm(smp); 1560 1561 case SMP_CMD_PUBLIC_KEY: 1562 default: 1563 /* Initiating device starts the round */ 1564 if (!hcon->out) 1565 return 0; 1566 1567 BT_DBG("%s Starting passkey round %u", hdev->name, 1568 smp->passkey_round + 1); 1569 1570 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1571 1572 return sc_passkey_send_confirm(smp); 1573 } 1574 1575 return 0; 1576 } 1577 1578 static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey) 1579 { 1580 struct l2cap_conn *conn = smp->conn; 1581 struct hci_conn *hcon = conn->hcon; 1582 u8 smp_op; 1583 1584 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags); 1585 1586 switch (mgmt_op) { 1587 case MGMT_OP_USER_PASSKEY_NEG_REPLY: 1588 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED); 1589 return 0; 1590 case MGMT_OP_USER_CONFIRM_NEG_REPLY: 1591 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED); 1592 return 0; 1593 case MGMT_OP_USER_PASSKEY_REPLY: 1594 hcon->passkey_notify = le32_to_cpu(passkey); 1595 smp->passkey_round = 0; 1596 1597 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) 1598 smp_op = SMP_CMD_PAIRING_CONFIRM; 1599 else 1600 smp_op = 0; 1601 1602 if (sc_passkey_round(smp, smp_op)) 1603 return -EIO; 1604 1605 return 0; 1606 } 1607 1608 /* Initiator sends DHKey check first */ 1609 if (hcon->out) { 1610 sc_dhkey_check(smp); 1611 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1612 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) { 1613 sc_dhkey_check(smp); 1614 sc_add_ltk(smp); 1615 } 1616 1617 return 0; 1618 } 1619 1620 int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey) 1621 { 1622 struct l2cap_conn *conn = hcon->l2cap_data; 1623 struct l2cap_chan *chan; 1624 struct smp_chan *smp; 1625 u32 value; 1626 int err; 1627 1628 BT_DBG(""); 1629 1630 if (!conn) 1631 return -ENOTCONN; 1632 1633 chan = conn->smp; 1634 if (!chan) 1635 return -ENOTCONN; 1636 1637 l2cap_chan_lock(chan); 1638 if (!chan->data) { 1639 err = -ENOTCONN; 1640 goto unlock; 1641 } 1642 1643 smp = chan->data; 1644 1645 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1646 err = sc_user_reply(smp, mgmt_op, passkey); 1647 goto unlock; 1648 } 1649 1650 switch (mgmt_op) { 1651 case MGMT_OP_USER_PASSKEY_REPLY: 1652 value = le32_to_cpu(passkey); 1653 memset(smp->tk, 0, sizeof(smp->tk)); 1654 BT_DBG("PassKey: %d", value); 1655 put_unaligned_le32(value, smp->tk); 1656 /* Fall Through */ 1657 case MGMT_OP_USER_CONFIRM_REPLY: 1658 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 1659 break; 1660 case MGMT_OP_USER_PASSKEY_NEG_REPLY: 1661 case MGMT_OP_USER_CONFIRM_NEG_REPLY: 1662 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); 1663 err = 0; 1664 goto unlock; 1665 default: 1666 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); 1667 err = -EOPNOTSUPP; 1668 goto unlock; 1669 } 1670 1671 err = 0; 1672 1673 /* If it is our turn to send Pairing Confirm, do so now */ 1674 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) { 1675 u8 rsp = smp_confirm(smp); 1676 if (rsp) 1677 smp_failure(conn, rsp); 1678 } 1679 1680 unlock: 1681 l2cap_chan_unlock(chan); 1682 return err; 1683 } 1684 1685 static void build_bredr_pairing_cmd(struct smp_chan *smp, 1686 struct smp_cmd_pairing *req, 1687 struct smp_cmd_pairing *rsp) 1688 { 1689 struct l2cap_conn *conn = smp->conn; 1690 struct hci_dev *hdev = conn->hcon->hdev; 1691 u8 local_dist = 0, remote_dist = 0; 1692 1693 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { 1694 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 1695 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 1696 } 1697 1698 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) 1699 remote_dist |= SMP_DIST_ID_KEY; 1700 1701 if (hci_dev_test_flag(hdev, HCI_PRIVACY)) 1702 local_dist |= SMP_DIST_ID_KEY; 1703 1704 if (!rsp) { 1705 memset(req, 0, sizeof(*req)); 1706 1707 req->auth_req = SMP_AUTH_CT2; 1708 req->init_key_dist = local_dist; 1709 req->resp_key_dist = remote_dist; 1710 req->max_key_size = conn->hcon->enc_key_size; 1711 1712 smp->remote_key_dist = remote_dist; 1713 1714 return; 1715 } 1716 1717 memset(rsp, 0, sizeof(*rsp)); 1718 1719 rsp->auth_req = SMP_AUTH_CT2; 1720 rsp->max_key_size = conn->hcon->enc_key_size; 1721 rsp->init_key_dist = req->init_key_dist & remote_dist; 1722 rsp->resp_key_dist = req->resp_key_dist & local_dist; 1723 1724 smp->remote_key_dist = rsp->init_key_dist; 1725 } 1726 1727 static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) 1728 { 1729 struct smp_cmd_pairing rsp, *req = (void *) skb->data; 1730 struct l2cap_chan *chan = conn->smp; 1731 struct hci_dev *hdev = conn->hcon->hdev; 1732 struct smp_chan *smp; 1733 u8 key_size, auth, sec_level; 1734 int ret; 1735 1736 BT_DBG("conn %p", conn); 1737 1738 if (skb->len < sizeof(*req)) 1739 return SMP_INVALID_PARAMS; 1740 1741 if (conn->hcon->role != HCI_ROLE_SLAVE) 1742 return SMP_CMD_NOTSUPP; 1743 1744 if (!chan->data) 1745 smp = smp_chan_create(conn); 1746 else 1747 smp = chan->data; 1748 1749 if (!smp) 1750 return SMP_UNSPECIFIED; 1751 1752 /* We didn't start the pairing, so match remote */ 1753 auth = req->auth_req & AUTH_REQ_MASK(hdev); 1754 1755 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && 1756 (auth & SMP_AUTH_BONDING)) 1757 return SMP_PAIRING_NOTSUPP; 1758 1759 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 1760 return SMP_AUTH_REQUIREMENTS; 1761 1762 smp->preq[0] = SMP_CMD_PAIRING_REQ; 1763 memcpy(&smp->preq[1], req, sizeof(*req)); 1764 skb_pull(skb, sizeof(*req)); 1765 1766 /* If the remote side's OOB flag is set it means it has 1767 * successfully received our local OOB data - therefore set the 1768 * flag to indicate that local OOB is in use. 1769 */ 1770 if (req->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob) 1771 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); 1772 1773 /* SMP over BR/EDR requires special treatment */ 1774 if (conn->hcon->type == ACL_LINK) { 1775 /* We must have a BR/EDR SC link */ 1776 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) && 1777 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 1778 return SMP_CROSS_TRANSP_NOT_ALLOWED; 1779 1780 set_bit(SMP_FLAG_SC, &smp->flags); 1781 1782 build_bredr_pairing_cmd(smp, req, &rsp); 1783 1784 if (req->auth_req & SMP_AUTH_CT2) 1785 set_bit(SMP_FLAG_CT2, &smp->flags); 1786 1787 key_size = min(req->max_key_size, rsp.max_key_size); 1788 if (check_enc_key_size(conn, key_size)) 1789 return SMP_ENC_KEY_SIZE; 1790 1791 /* Clear bits which are generated but not distributed */ 1792 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1793 1794 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1795 memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); 1796 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); 1797 1798 smp_distribute_keys(smp); 1799 return 0; 1800 } 1801 1802 build_pairing_cmd(conn, req, &rsp, auth); 1803 1804 if (rsp.auth_req & SMP_AUTH_SC) { 1805 set_bit(SMP_FLAG_SC, &smp->flags); 1806 1807 if (rsp.auth_req & SMP_AUTH_CT2) 1808 set_bit(SMP_FLAG_CT2, &smp->flags); 1809 } 1810 1811 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 1812 sec_level = BT_SECURITY_MEDIUM; 1813 else 1814 sec_level = authreq_to_seclevel(auth); 1815 1816 if (sec_level > conn->hcon->pending_sec_level) 1817 conn->hcon->pending_sec_level = sec_level; 1818 1819 /* If we need MITM check that it can be achieved */ 1820 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { 1821 u8 method; 1822 1823 method = get_auth_method(smp, conn->hcon->io_capability, 1824 req->io_capability); 1825 if (method == JUST_WORKS || method == JUST_CFM) 1826 return SMP_AUTH_REQUIREMENTS; 1827 } 1828 1829 key_size = min(req->max_key_size, rsp.max_key_size); 1830 if (check_enc_key_size(conn, key_size)) 1831 return SMP_ENC_KEY_SIZE; 1832 1833 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1834 1835 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1836 memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); 1837 1838 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); 1839 1840 clear_bit(SMP_FLAG_INITIATOR, &smp->flags); 1841 1842 /* Strictly speaking we shouldn't allow Pairing Confirm for the 1843 * SC case, however some implementations incorrectly copy RFU auth 1844 * req bits from our security request, which may create a false 1845 * positive SC enablement. 1846 */ 1847 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1848 1849 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1850 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); 1851 /* Clear bits which are generated but not distributed */ 1852 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1853 /* Wait for Public Key from Initiating Device */ 1854 return 0; 1855 } 1856 1857 /* Request setup of TK */ 1858 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability); 1859 if (ret) 1860 return SMP_UNSPECIFIED; 1861 1862 return 0; 1863 } 1864 1865 static u8 sc_send_public_key(struct smp_chan *smp) 1866 { 1867 struct hci_dev *hdev = smp->conn->hcon->hdev; 1868 1869 BT_DBG(""); 1870 1871 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { 1872 struct l2cap_chan *chan = hdev->smp_data; 1873 struct smp_dev *smp_dev; 1874 1875 if (!chan || !chan->data) 1876 return SMP_UNSPECIFIED; 1877 1878 smp_dev = chan->data; 1879 1880 memcpy(smp->local_pk, smp_dev->local_pk, 64); 1881 memcpy(smp->lr, smp_dev->local_rand, 16); 1882 1883 if (smp_dev->debug_key) 1884 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1885 1886 goto done; 1887 } 1888 1889 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { 1890 BT_DBG("Using debug keys"); 1891 if (set_ecdh_privkey(smp->tfm_ecdh, debug_sk)) 1892 return SMP_UNSPECIFIED; 1893 memcpy(smp->local_pk, debug_pk, 64); 1894 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1895 } else { 1896 while (true) { 1897 /* Generate key pair for Secure Connections */ 1898 if (generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk)) 1899 return SMP_UNSPECIFIED; 1900 1901 /* This is unlikely, but we need to check that 1902 * we didn't accidentially generate a debug key. 1903 */ 1904 if (crypto_memneq(smp->local_pk, debug_pk, 64)) 1905 break; 1906 } 1907 } 1908 1909 done: 1910 SMP_DBG("Local Public Key X: %32phN", smp->local_pk); 1911 SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32); 1912 1913 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk); 1914 1915 return 0; 1916 } 1917 1918 static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) 1919 { 1920 struct smp_cmd_pairing *req, *rsp = (void *) skb->data; 1921 struct l2cap_chan *chan = conn->smp; 1922 struct smp_chan *smp = chan->data; 1923 struct hci_dev *hdev = conn->hcon->hdev; 1924 u8 key_size, auth; 1925 int ret; 1926 1927 BT_DBG("conn %p", conn); 1928 1929 if (skb->len < sizeof(*rsp)) 1930 return SMP_INVALID_PARAMS; 1931 1932 if (conn->hcon->role != HCI_ROLE_MASTER) 1933 return SMP_CMD_NOTSUPP; 1934 1935 skb_pull(skb, sizeof(*rsp)); 1936 1937 req = (void *) &smp->preq[1]; 1938 1939 key_size = min(req->max_key_size, rsp->max_key_size); 1940 if (check_enc_key_size(conn, key_size)) 1941 return SMP_ENC_KEY_SIZE; 1942 1943 auth = rsp->auth_req & AUTH_REQ_MASK(hdev); 1944 1945 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 1946 return SMP_AUTH_REQUIREMENTS; 1947 1948 /* If the remote side's OOB flag is set it means it has 1949 * successfully received our local OOB data - therefore set the 1950 * flag to indicate that local OOB is in use. 1951 */ 1952 if (rsp->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob) 1953 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); 1954 1955 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1956 memcpy(&smp->prsp[1], rsp, sizeof(*rsp)); 1957 1958 /* Update remote key distribution in case the remote cleared 1959 * some bits that we had enabled in our request. 1960 */ 1961 smp->remote_key_dist &= rsp->resp_key_dist; 1962 1963 if ((req->auth_req & SMP_AUTH_CT2) && (auth & SMP_AUTH_CT2)) 1964 set_bit(SMP_FLAG_CT2, &smp->flags); 1965 1966 /* For BR/EDR this means we're done and can start phase 3 */ 1967 if (conn->hcon->type == ACL_LINK) { 1968 /* Clear bits which are generated but not distributed */ 1969 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1970 smp_distribute_keys(smp); 1971 return 0; 1972 } 1973 1974 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC)) 1975 set_bit(SMP_FLAG_SC, &smp->flags); 1976 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH) 1977 conn->hcon->pending_sec_level = BT_SECURITY_HIGH; 1978 1979 /* If we need MITM check that it can be achieved */ 1980 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { 1981 u8 method; 1982 1983 method = get_auth_method(smp, req->io_capability, 1984 rsp->io_capability); 1985 if (method == JUST_WORKS || method == JUST_CFM) 1986 return SMP_AUTH_REQUIREMENTS; 1987 } 1988 1989 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1990 1991 /* Update remote key distribution in case the remote cleared 1992 * some bits that we had enabled in our request. 1993 */ 1994 smp->remote_key_dist &= rsp->resp_key_dist; 1995 1996 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1997 /* Clear bits which are generated but not distributed */ 1998 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1999 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); 2000 return sc_send_public_key(smp); 2001 } 2002 2003 auth |= req->auth_req; 2004 2005 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability); 2006 if (ret) 2007 return SMP_UNSPECIFIED; 2008 2009 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 2010 2011 /* Can't compose response until we have been confirmed */ 2012 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) 2013 return smp_confirm(smp); 2014 2015 return 0; 2016 } 2017 2018 static u8 sc_check_confirm(struct smp_chan *smp) 2019 { 2020 struct l2cap_conn *conn = smp->conn; 2021 2022 BT_DBG(""); 2023 2024 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2025 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM); 2026 2027 if (conn->hcon->out) { 2028 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2029 smp->prnd); 2030 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2031 } 2032 2033 return 0; 2034 } 2035 2036 /* Work-around for some implementations that incorrectly copy RFU bits 2037 * from our security request and thereby create the impression that 2038 * we're doing SC when in fact the remote doesn't support it. 2039 */ 2040 static int fixup_sc_false_positive(struct smp_chan *smp) 2041 { 2042 struct l2cap_conn *conn = smp->conn; 2043 struct hci_conn *hcon = conn->hcon; 2044 struct hci_dev *hdev = hcon->hdev; 2045 struct smp_cmd_pairing *req, *rsp; 2046 u8 auth; 2047 2048 /* The issue is only observed when we're in slave role */ 2049 if (hcon->out) 2050 return SMP_UNSPECIFIED; 2051 2052 if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) { 2053 bt_dev_err(hdev, "refusing legacy fallback in SC-only mode"); 2054 return SMP_UNSPECIFIED; 2055 } 2056 2057 bt_dev_err(hdev, "trying to fall back to legacy SMP"); 2058 2059 req = (void *) &smp->preq[1]; 2060 rsp = (void *) &smp->prsp[1]; 2061 2062 /* Rebuild key dist flags which may have been cleared for SC */ 2063 smp->remote_key_dist = (req->init_key_dist & rsp->resp_key_dist); 2064 2065 auth = req->auth_req & AUTH_REQ_MASK(hdev); 2066 2067 if (tk_request(conn, 0, auth, rsp->io_capability, req->io_capability)) { 2068 bt_dev_err(hdev, "failed to fall back to legacy SMP"); 2069 return SMP_UNSPECIFIED; 2070 } 2071 2072 clear_bit(SMP_FLAG_SC, &smp->flags); 2073 2074 return 0; 2075 } 2076 2077 static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb) 2078 { 2079 struct l2cap_chan *chan = conn->smp; 2080 struct smp_chan *smp = chan->data; 2081 2082 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave"); 2083 2084 if (skb->len < sizeof(smp->pcnf)) 2085 return SMP_INVALID_PARAMS; 2086 2087 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf)); 2088 skb_pull(skb, sizeof(smp->pcnf)); 2089 2090 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 2091 int ret; 2092 2093 /* Public Key exchange must happen before any other steps */ 2094 if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags)) 2095 return sc_check_confirm(smp); 2096 2097 BT_ERR("Unexpected SMP Pairing Confirm"); 2098 2099 ret = fixup_sc_false_positive(smp); 2100 if (ret) 2101 return ret; 2102 } 2103 2104 if (conn->hcon->out) { 2105 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2106 smp->prnd); 2107 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2108 return 0; 2109 } 2110 2111 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) 2112 return smp_confirm(smp); 2113 2114 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 2115 2116 return 0; 2117 } 2118 2119 static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb) 2120 { 2121 struct l2cap_chan *chan = conn->smp; 2122 struct smp_chan *smp = chan->data; 2123 struct hci_conn *hcon = conn->hcon; 2124 u8 *pkax, *pkbx, *na, *nb; 2125 u32 passkey; 2126 int err; 2127 2128 BT_DBG("conn %p", conn); 2129 2130 if (skb->len < sizeof(smp->rrnd)) 2131 return SMP_INVALID_PARAMS; 2132 2133 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd)); 2134 skb_pull(skb, sizeof(smp->rrnd)); 2135 2136 if (!test_bit(SMP_FLAG_SC, &smp->flags)) 2137 return smp_random(smp); 2138 2139 if (hcon->out) { 2140 pkax = smp->local_pk; 2141 pkbx = smp->remote_pk; 2142 na = smp->prnd; 2143 nb = smp->rrnd; 2144 } else { 2145 pkax = smp->remote_pk; 2146 pkbx = smp->local_pk; 2147 na = smp->rrnd; 2148 nb = smp->prnd; 2149 } 2150 2151 if (smp->method == REQ_OOB) { 2152 if (!hcon->out) 2153 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 2154 sizeof(smp->prnd), smp->prnd); 2155 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2156 goto mackey_and_ltk; 2157 } 2158 2159 /* Passkey entry has special treatment */ 2160 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2161 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM); 2162 2163 if (hcon->out) { 2164 u8 cfm[16]; 2165 2166 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, 2167 smp->rrnd, 0, cfm); 2168 if (err) 2169 return SMP_UNSPECIFIED; 2170 2171 if (crypto_memneq(smp->pcnf, cfm, 16)) 2172 return SMP_CONFIRM_FAILED; 2173 } else { 2174 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2175 smp->prnd); 2176 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2177 } 2178 2179 mackey_and_ltk: 2180 /* Generate MacKey and LTK */ 2181 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk); 2182 if (err) 2183 return SMP_UNSPECIFIED; 2184 2185 if (smp->method == JUST_WORKS || smp->method == REQ_OOB) { 2186 if (hcon->out) { 2187 sc_dhkey_check(smp); 2188 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2189 } 2190 return 0; 2191 } 2192 2193 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey); 2194 if (err) 2195 return SMP_UNSPECIFIED; 2196 2197 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type, 2198 hcon->dst_type, passkey, 0); 2199 if (err) 2200 return SMP_UNSPECIFIED; 2201 2202 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 2203 2204 return 0; 2205 } 2206 2207 static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level) 2208 { 2209 struct smp_ltk *key; 2210 struct hci_conn *hcon = conn->hcon; 2211 2212 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role); 2213 if (!key) 2214 return false; 2215 2216 if (smp_ltk_sec_level(key) < sec_level) 2217 return false; 2218 2219 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) 2220 return true; 2221 2222 hci_le_start_enc(hcon, key->ediv, key->rand, key->val, key->enc_size); 2223 hcon->enc_key_size = key->enc_size; 2224 2225 /* We never store STKs for master role, so clear this flag */ 2226 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); 2227 2228 return true; 2229 } 2230 2231 bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level, 2232 enum smp_key_pref key_pref) 2233 { 2234 if (sec_level == BT_SECURITY_LOW) 2235 return true; 2236 2237 /* If we're encrypted with an STK but the caller prefers using 2238 * LTK claim insufficient security. This way we allow the 2239 * connection to be re-encrypted with an LTK, even if the LTK 2240 * provides the same level of security. Only exception is if we 2241 * don't have an LTK (e.g. because of key distribution bits). 2242 */ 2243 if (key_pref == SMP_USE_LTK && 2244 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) && 2245 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role)) 2246 return false; 2247 2248 if (hcon->sec_level >= sec_level) 2249 return true; 2250 2251 return false; 2252 } 2253 2254 static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb) 2255 { 2256 struct smp_cmd_security_req *rp = (void *) skb->data; 2257 struct smp_cmd_pairing cp; 2258 struct hci_conn *hcon = conn->hcon; 2259 struct hci_dev *hdev = hcon->hdev; 2260 struct smp_chan *smp; 2261 u8 sec_level, auth; 2262 2263 BT_DBG("conn %p", conn); 2264 2265 if (skb->len < sizeof(*rp)) 2266 return SMP_INVALID_PARAMS; 2267 2268 if (hcon->role != HCI_ROLE_MASTER) 2269 return SMP_CMD_NOTSUPP; 2270 2271 auth = rp->auth_req & AUTH_REQ_MASK(hdev); 2272 2273 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 2274 return SMP_AUTH_REQUIREMENTS; 2275 2276 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 2277 sec_level = BT_SECURITY_MEDIUM; 2278 else 2279 sec_level = authreq_to_seclevel(auth); 2280 2281 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) { 2282 /* If link is already encrypted with sufficient security we 2283 * still need refresh encryption as per Core Spec 5.0 Vol 3, 2284 * Part H 2.4.6 2285 */ 2286 smp_ltk_encrypt(conn, hcon->sec_level); 2287 return 0; 2288 } 2289 2290 if (sec_level > hcon->pending_sec_level) 2291 hcon->pending_sec_level = sec_level; 2292 2293 if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) 2294 return 0; 2295 2296 smp = smp_chan_create(conn); 2297 if (!smp) 2298 return SMP_UNSPECIFIED; 2299 2300 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && 2301 (auth & SMP_AUTH_BONDING)) 2302 return SMP_PAIRING_NOTSUPP; 2303 2304 skb_pull(skb, sizeof(*rp)); 2305 2306 memset(&cp, 0, sizeof(cp)); 2307 build_pairing_cmd(conn, &cp, NULL, auth); 2308 2309 smp->preq[0] = SMP_CMD_PAIRING_REQ; 2310 memcpy(&smp->preq[1], &cp, sizeof(cp)); 2311 2312 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); 2313 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 2314 2315 return 0; 2316 } 2317 2318 int smp_conn_security(struct hci_conn *hcon, __u8 sec_level) 2319 { 2320 struct l2cap_conn *conn = hcon->l2cap_data; 2321 struct l2cap_chan *chan; 2322 struct smp_chan *smp; 2323 __u8 authreq; 2324 int ret; 2325 2326 BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level); 2327 2328 /* This may be NULL if there's an unexpected disconnection */ 2329 if (!conn) 2330 return 1; 2331 2332 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) 2333 return 1; 2334 2335 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) 2336 return 1; 2337 2338 if (sec_level > hcon->pending_sec_level) 2339 hcon->pending_sec_level = sec_level; 2340 2341 if (hcon->role == HCI_ROLE_MASTER) 2342 if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) 2343 return 0; 2344 2345 chan = conn->smp; 2346 if (!chan) { 2347 bt_dev_err(hcon->hdev, "security requested but not available"); 2348 return 1; 2349 } 2350 2351 l2cap_chan_lock(chan); 2352 2353 /* If SMP is already in progress ignore this request */ 2354 if (chan->data) { 2355 ret = 0; 2356 goto unlock; 2357 } 2358 2359 smp = smp_chan_create(conn); 2360 if (!smp) { 2361 ret = 1; 2362 goto unlock; 2363 } 2364 2365 authreq = seclevel_to_authreq(sec_level); 2366 2367 if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED)) { 2368 authreq |= SMP_AUTH_SC; 2369 if (hci_dev_test_flag(hcon->hdev, HCI_SSP_ENABLED)) 2370 authreq |= SMP_AUTH_CT2; 2371 } 2372 2373 /* Require MITM if IO Capability allows or the security level 2374 * requires it. 2375 */ 2376 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT || 2377 hcon->pending_sec_level > BT_SECURITY_MEDIUM) 2378 authreq |= SMP_AUTH_MITM; 2379 2380 if (hcon->role == HCI_ROLE_MASTER) { 2381 struct smp_cmd_pairing cp; 2382 2383 build_pairing_cmd(conn, &cp, NULL, authreq); 2384 smp->preq[0] = SMP_CMD_PAIRING_REQ; 2385 memcpy(&smp->preq[1], &cp, sizeof(cp)); 2386 2387 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); 2388 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 2389 } else { 2390 struct smp_cmd_security_req cp; 2391 cp.auth_req = authreq; 2392 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp); 2393 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ); 2394 } 2395 2396 set_bit(SMP_FLAG_INITIATOR, &smp->flags); 2397 ret = 0; 2398 2399 unlock: 2400 l2cap_chan_unlock(chan); 2401 return ret; 2402 } 2403 2404 int smp_cancel_and_remove_pairing(struct hci_dev *hdev, bdaddr_t *bdaddr, 2405 u8 addr_type) 2406 { 2407 struct hci_conn *hcon; 2408 struct l2cap_conn *conn; 2409 struct l2cap_chan *chan; 2410 struct smp_chan *smp; 2411 int err; 2412 2413 err = hci_remove_ltk(hdev, bdaddr, addr_type); 2414 hci_remove_irk(hdev, bdaddr, addr_type); 2415 2416 hcon = hci_conn_hash_lookup_le(hdev, bdaddr, addr_type); 2417 if (!hcon) 2418 goto done; 2419 2420 conn = hcon->l2cap_data; 2421 if (!conn) 2422 goto done; 2423 2424 chan = conn->smp; 2425 if (!chan) 2426 goto done; 2427 2428 l2cap_chan_lock(chan); 2429 2430 smp = chan->data; 2431 if (smp) { 2432 /* Set keys to NULL to make sure smp_failure() does not try to 2433 * remove and free already invalidated rcu list entries. */ 2434 smp->ltk = NULL; 2435 smp->slave_ltk = NULL; 2436 smp->remote_irk = NULL; 2437 2438 if (test_bit(SMP_FLAG_COMPLETE, &smp->flags)) 2439 smp_failure(conn, 0); 2440 else 2441 smp_failure(conn, SMP_UNSPECIFIED); 2442 err = 0; 2443 } 2444 2445 l2cap_chan_unlock(chan); 2446 2447 done: 2448 return err; 2449 } 2450 2451 static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb) 2452 { 2453 struct smp_cmd_encrypt_info *rp = (void *) skb->data; 2454 struct l2cap_chan *chan = conn->smp; 2455 struct smp_chan *smp = chan->data; 2456 2457 BT_DBG("conn %p", conn); 2458 2459 if (skb->len < sizeof(*rp)) 2460 return SMP_INVALID_PARAMS; 2461 2462 SMP_ALLOW_CMD(smp, SMP_CMD_MASTER_IDENT); 2463 2464 skb_pull(skb, sizeof(*rp)); 2465 2466 memcpy(smp->tk, rp->ltk, sizeof(smp->tk)); 2467 2468 return 0; 2469 } 2470 2471 static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb) 2472 { 2473 struct smp_cmd_master_ident *rp = (void *) skb->data; 2474 struct l2cap_chan *chan = conn->smp; 2475 struct smp_chan *smp = chan->data; 2476 struct hci_dev *hdev = conn->hcon->hdev; 2477 struct hci_conn *hcon = conn->hcon; 2478 struct smp_ltk *ltk; 2479 u8 authenticated; 2480 2481 BT_DBG("conn %p", conn); 2482 2483 if (skb->len < sizeof(*rp)) 2484 return SMP_INVALID_PARAMS; 2485 2486 /* Mark the information as received */ 2487 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY; 2488 2489 if (smp->remote_key_dist & SMP_DIST_ID_KEY) 2490 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); 2491 else if (smp->remote_key_dist & SMP_DIST_SIGN) 2492 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 2493 2494 skb_pull(skb, sizeof(*rp)); 2495 2496 authenticated = (hcon->sec_level == BT_SECURITY_HIGH); 2497 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK, 2498 authenticated, smp->tk, smp->enc_key_size, 2499 rp->ediv, rp->rand); 2500 smp->ltk = ltk; 2501 if (!(smp->remote_key_dist & KEY_DIST_MASK)) 2502 smp_distribute_keys(smp); 2503 2504 return 0; 2505 } 2506 2507 static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb) 2508 { 2509 struct smp_cmd_ident_info *info = (void *) skb->data; 2510 struct l2cap_chan *chan = conn->smp; 2511 struct smp_chan *smp = chan->data; 2512 2513 BT_DBG(""); 2514 2515 if (skb->len < sizeof(*info)) 2516 return SMP_INVALID_PARAMS; 2517 2518 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO); 2519 2520 skb_pull(skb, sizeof(*info)); 2521 2522 memcpy(smp->irk, info->irk, 16); 2523 2524 return 0; 2525 } 2526 2527 static int smp_cmd_ident_addr_info(struct l2cap_conn *conn, 2528 struct sk_buff *skb) 2529 { 2530 struct smp_cmd_ident_addr_info *info = (void *) skb->data; 2531 struct l2cap_chan *chan = conn->smp; 2532 struct smp_chan *smp = chan->data; 2533 struct hci_conn *hcon = conn->hcon; 2534 bdaddr_t rpa; 2535 2536 BT_DBG(""); 2537 2538 if (skb->len < sizeof(*info)) 2539 return SMP_INVALID_PARAMS; 2540 2541 /* Mark the information as received */ 2542 smp->remote_key_dist &= ~SMP_DIST_ID_KEY; 2543 2544 if (smp->remote_key_dist & SMP_DIST_SIGN) 2545 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 2546 2547 skb_pull(skb, sizeof(*info)); 2548 2549 /* Strictly speaking the Core Specification (4.1) allows sending 2550 * an empty address which would force us to rely on just the IRK 2551 * as "identity information". However, since such 2552 * implementations are not known of and in order to not over 2553 * complicate our implementation, simply pretend that we never 2554 * received an IRK for such a device. 2555 * 2556 * The Identity Address must also be a Static Random or Public 2557 * Address, which hci_is_identity_address() checks for. 2558 */ 2559 if (!bacmp(&info->bdaddr, BDADDR_ANY) || 2560 !hci_is_identity_address(&info->bdaddr, info->addr_type)) { 2561 bt_dev_err(hcon->hdev, "ignoring IRK with no identity address"); 2562 goto distribute; 2563 } 2564 2565 /* Drop IRK if peer is using identity address during pairing but is 2566 * providing different address as identity information. 2567 * 2568 * Microsoft Surface Precision Mouse is known to have this bug. 2569 */ 2570 if (hci_is_identity_address(&hcon->dst, hcon->dst_type) && 2571 (bacmp(&info->bdaddr, &hcon->dst) || 2572 info->addr_type != hcon->dst_type)) { 2573 bt_dev_err(hcon->hdev, 2574 "ignoring IRK with invalid identity address"); 2575 goto distribute; 2576 } 2577 2578 bacpy(&smp->id_addr, &info->bdaddr); 2579 smp->id_addr_type = info->addr_type; 2580 2581 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type)) 2582 bacpy(&rpa, &hcon->dst); 2583 else 2584 bacpy(&rpa, BDADDR_ANY); 2585 2586 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr, 2587 smp->id_addr_type, smp->irk, &rpa); 2588 2589 distribute: 2590 if (!(smp->remote_key_dist & KEY_DIST_MASK)) 2591 smp_distribute_keys(smp); 2592 2593 return 0; 2594 } 2595 2596 static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb) 2597 { 2598 struct smp_cmd_sign_info *rp = (void *) skb->data; 2599 struct l2cap_chan *chan = conn->smp; 2600 struct smp_chan *smp = chan->data; 2601 struct smp_csrk *csrk; 2602 2603 BT_DBG("conn %p", conn); 2604 2605 if (skb->len < sizeof(*rp)) 2606 return SMP_INVALID_PARAMS; 2607 2608 /* Mark the information as received */ 2609 smp->remote_key_dist &= ~SMP_DIST_SIGN; 2610 2611 skb_pull(skb, sizeof(*rp)); 2612 2613 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); 2614 if (csrk) { 2615 if (conn->hcon->sec_level > BT_SECURITY_MEDIUM) 2616 csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED; 2617 else 2618 csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED; 2619 memcpy(csrk->val, rp->csrk, sizeof(csrk->val)); 2620 } 2621 smp->csrk = csrk; 2622 smp_distribute_keys(smp); 2623 2624 return 0; 2625 } 2626 2627 static u8 sc_select_method(struct smp_chan *smp) 2628 { 2629 struct l2cap_conn *conn = smp->conn; 2630 struct hci_conn *hcon = conn->hcon; 2631 struct smp_cmd_pairing *local, *remote; 2632 u8 local_mitm, remote_mitm, local_io, remote_io, method; 2633 2634 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) || 2635 test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) 2636 return REQ_OOB; 2637 2638 /* The preq/prsp contain the raw Pairing Request/Response PDUs 2639 * which are needed as inputs to some crypto functions. To get 2640 * the "struct smp_cmd_pairing" from them we need to skip the 2641 * first byte which contains the opcode. 2642 */ 2643 if (hcon->out) { 2644 local = (void *) &smp->preq[1]; 2645 remote = (void *) &smp->prsp[1]; 2646 } else { 2647 local = (void *) &smp->prsp[1]; 2648 remote = (void *) &smp->preq[1]; 2649 } 2650 2651 local_io = local->io_capability; 2652 remote_io = remote->io_capability; 2653 2654 local_mitm = (local->auth_req & SMP_AUTH_MITM); 2655 remote_mitm = (remote->auth_req & SMP_AUTH_MITM); 2656 2657 /* If either side wants MITM, look up the method from the table, 2658 * otherwise use JUST WORKS. 2659 */ 2660 if (local_mitm || remote_mitm) 2661 method = get_auth_method(smp, local_io, remote_io); 2662 else 2663 method = JUST_WORKS; 2664 2665 /* Don't confirm locally initiated pairing attempts */ 2666 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2667 method = JUST_WORKS; 2668 2669 return method; 2670 } 2671 2672 static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb) 2673 { 2674 struct smp_cmd_public_key *key = (void *) skb->data; 2675 struct hci_conn *hcon = conn->hcon; 2676 struct l2cap_chan *chan = conn->smp; 2677 struct smp_chan *smp = chan->data; 2678 struct hci_dev *hdev = hcon->hdev; 2679 struct crypto_kpp *tfm_ecdh; 2680 struct smp_cmd_pairing_confirm cfm; 2681 int err; 2682 2683 BT_DBG("conn %p", conn); 2684 2685 if (skb->len < sizeof(*key)) 2686 return SMP_INVALID_PARAMS; 2687 2688 memcpy(smp->remote_pk, key, 64); 2689 2690 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) { 2691 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk, 2692 smp->rr, 0, cfm.confirm_val); 2693 if (err) 2694 return SMP_UNSPECIFIED; 2695 2696 if (crypto_memneq(cfm.confirm_val, smp->pcnf, 16)) 2697 return SMP_CONFIRM_FAILED; 2698 } 2699 2700 /* Non-initiating device sends its public key after receiving 2701 * the key from the initiating device. 2702 */ 2703 if (!hcon->out) { 2704 err = sc_send_public_key(smp); 2705 if (err) 2706 return err; 2707 } 2708 2709 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk); 2710 SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32); 2711 2712 /* Compute the shared secret on the same crypto tfm on which the private 2713 * key was set/generated. 2714 */ 2715 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { 2716 struct l2cap_chan *hchan = hdev->smp_data; 2717 struct smp_dev *smp_dev; 2718 2719 if (!hchan || !hchan->data) 2720 return SMP_UNSPECIFIED; 2721 2722 smp_dev = hchan->data; 2723 2724 tfm_ecdh = smp_dev->tfm_ecdh; 2725 } else { 2726 tfm_ecdh = smp->tfm_ecdh; 2727 } 2728 2729 if (compute_ecdh_secret(tfm_ecdh, smp->remote_pk, smp->dhkey)) 2730 return SMP_UNSPECIFIED; 2731 2732 SMP_DBG("DHKey %32phN", smp->dhkey); 2733 2734 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags); 2735 2736 smp->method = sc_select_method(smp); 2737 2738 BT_DBG("%s selected method 0x%02x", hdev->name, smp->method); 2739 2740 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */ 2741 if (smp->method == JUST_WORKS || smp->method == JUST_CFM) 2742 hcon->pending_sec_level = BT_SECURITY_MEDIUM; 2743 else 2744 hcon->pending_sec_level = BT_SECURITY_FIPS; 2745 2746 if (!crypto_memneq(debug_pk, smp->remote_pk, 64)) 2747 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 2748 2749 if (smp->method == DSP_PASSKEY) { 2750 get_random_bytes(&hcon->passkey_notify, 2751 sizeof(hcon->passkey_notify)); 2752 hcon->passkey_notify %= 1000000; 2753 hcon->passkey_entered = 0; 2754 smp->passkey_round = 0; 2755 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type, 2756 hcon->dst_type, 2757 hcon->passkey_notify, 2758 hcon->passkey_entered)) 2759 return SMP_UNSPECIFIED; 2760 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2761 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY); 2762 } 2763 2764 if (smp->method == REQ_OOB) { 2765 if (hcon->out) 2766 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 2767 sizeof(smp->prnd), smp->prnd); 2768 2769 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2770 2771 return 0; 2772 } 2773 2774 if (hcon->out) 2775 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2776 2777 if (smp->method == REQ_PASSKEY) { 2778 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type, 2779 hcon->dst_type)) 2780 return SMP_UNSPECIFIED; 2781 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2782 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 2783 return 0; 2784 } 2785 2786 /* The Initiating device waits for the non-initiating device to 2787 * send the confirm value. 2788 */ 2789 if (conn->hcon->out) 2790 return 0; 2791 2792 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, 2793 0, cfm.confirm_val); 2794 if (err) 2795 return SMP_UNSPECIFIED; 2796 2797 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); 2798 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2799 2800 return 0; 2801 } 2802 2803 static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb) 2804 { 2805 struct smp_cmd_dhkey_check *check = (void *) skb->data; 2806 struct l2cap_chan *chan = conn->smp; 2807 struct hci_conn *hcon = conn->hcon; 2808 struct smp_chan *smp = chan->data; 2809 u8 a[7], b[7], *local_addr, *remote_addr; 2810 u8 io_cap[3], r[16], e[16]; 2811 int err; 2812 2813 BT_DBG("conn %p", conn); 2814 2815 if (skb->len < sizeof(*check)) 2816 return SMP_INVALID_PARAMS; 2817 2818 memcpy(a, &hcon->init_addr, 6); 2819 memcpy(b, &hcon->resp_addr, 6); 2820 a[6] = hcon->init_addr_type; 2821 b[6] = hcon->resp_addr_type; 2822 2823 if (hcon->out) { 2824 local_addr = a; 2825 remote_addr = b; 2826 memcpy(io_cap, &smp->prsp[1], 3); 2827 } else { 2828 local_addr = b; 2829 remote_addr = a; 2830 memcpy(io_cap, &smp->preq[1], 3); 2831 } 2832 2833 memset(r, 0, sizeof(r)); 2834 2835 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2836 put_unaligned_le32(hcon->passkey_notify, r); 2837 else if (smp->method == REQ_OOB) 2838 memcpy(r, smp->lr, 16); 2839 2840 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r, 2841 io_cap, remote_addr, local_addr, e); 2842 if (err) 2843 return SMP_UNSPECIFIED; 2844 2845 if (crypto_memneq(check->e, e, 16)) 2846 return SMP_DHKEY_CHECK_FAILED; 2847 2848 if (!hcon->out) { 2849 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { 2850 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags); 2851 return 0; 2852 } 2853 2854 /* Slave sends DHKey check as response to master */ 2855 sc_dhkey_check(smp); 2856 } 2857 2858 sc_add_ltk(smp); 2859 2860 if (hcon->out) { 2861 hci_le_start_enc(hcon, 0, 0, smp->tk, smp->enc_key_size); 2862 hcon->enc_key_size = smp->enc_key_size; 2863 } 2864 2865 return 0; 2866 } 2867 2868 static int smp_cmd_keypress_notify(struct l2cap_conn *conn, 2869 struct sk_buff *skb) 2870 { 2871 struct smp_cmd_keypress_notify *kp = (void *) skb->data; 2872 2873 BT_DBG("value 0x%02x", kp->value); 2874 2875 return 0; 2876 } 2877 2878 static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb) 2879 { 2880 struct l2cap_conn *conn = chan->conn; 2881 struct hci_conn *hcon = conn->hcon; 2882 struct smp_chan *smp; 2883 __u8 code, reason; 2884 int err = 0; 2885 2886 if (skb->len < 1) 2887 return -EILSEQ; 2888 2889 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) { 2890 reason = SMP_PAIRING_NOTSUPP; 2891 goto done; 2892 } 2893 2894 code = skb->data[0]; 2895 skb_pull(skb, sizeof(code)); 2896 2897 smp = chan->data; 2898 2899 if (code > SMP_CMD_MAX) 2900 goto drop; 2901 2902 if (smp && !test_and_clear_bit(code, &smp->allow_cmd)) 2903 goto drop; 2904 2905 /* If we don't have a context the only allowed commands are 2906 * pairing request and security request. 2907 */ 2908 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ) 2909 goto drop; 2910 2911 switch (code) { 2912 case SMP_CMD_PAIRING_REQ: 2913 reason = smp_cmd_pairing_req(conn, skb); 2914 break; 2915 2916 case SMP_CMD_PAIRING_FAIL: 2917 smp_failure(conn, 0); 2918 err = -EPERM; 2919 break; 2920 2921 case SMP_CMD_PAIRING_RSP: 2922 reason = smp_cmd_pairing_rsp(conn, skb); 2923 break; 2924 2925 case SMP_CMD_SECURITY_REQ: 2926 reason = smp_cmd_security_req(conn, skb); 2927 break; 2928 2929 case SMP_CMD_PAIRING_CONFIRM: 2930 reason = smp_cmd_pairing_confirm(conn, skb); 2931 break; 2932 2933 case SMP_CMD_PAIRING_RANDOM: 2934 reason = smp_cmd_pairing_random(conn, skb); 2935 break; 2936 2937 case SMP_CMD_ENCRYPT_INFO: 2938 reason = smp_cmd_encrypt_info(conn, skb); 2939 break; 2940 2941 case SMP_CMD_MASTER_IDENT: 2942 reason = smp_cmd_master_ident(conn, skb); 2943 break; 2944 2945 case SMP_CMD_IDENT_INFO: 2946 reason = smp_cmd_ident_info(conn, skb); 2947 break; 2948 2949 case SMP_CMD_IDENT_ADDR_INFO: 2950 reason = smp_cmd_ident_addr_info(conn, skb); 2951 break; 2952 2953 case SMP_CMD_SIGN_INFO: 2954 reason = smp_cmd_sign_info(conn, skb); 2955 break; 2956 2957 case SMP_CMD_PUBLIC_KEY: 2958 reason = smp_cmd_public_key(conn, skb); 2959 break; 2960 2961 case SMP_CMD_DHKEY_CHECK: 2962 reason = smp_cmd_dhkey_check(conn, skb); 2963 break; 2964 2965 case SMP_CMD_KEYPRESS_NOTIFY: 2966 reason = smp_cmd_keypress_notify(conn, skb); 2967 break; 2968 2969 default: 2970 BT_DBG("Unknown command code 0x%2.2x", code); 2971 reason = SMP_CMD_NOTSUPP; 2972 goto done; 2973 } 2974 2975 done: 2976 if (!err) { 2977 if (reason) 2978 smp_failure(conn, reason); 2979 kfree_skb(skb); 2980 } 2981 2982 return err; 2983 2984 drop: 2985 bt_dev_err(hcon->hdev, "unexpected SMP command 0x%02x from %pMR", 2986 code, &hcon->dst); 2987 kfree_skb(skb); 2988 return 0; 2989 } 2990 2991 static void smp_teardown_cb(struct l2cap_chan *chan, int err) 2992 { 2993 struct l2cap_conn *conn = chan->conn; 2994 2995 BT_DBG("chan %p", chan); 2996 2997 if (chan->data) 2998 smp_chan_destroy(conn); 2999 3000 conn->smp = NULL; 3001 l2cap_chan_put(chan); 3002 } 3003 3004 static void bredr_pairing(struct l2cap_chan *chan) 3005 { 3006 struct l2cap_conn *conn = chan->conn; 3007 struct hci_conn *hcon = conn->hcon; 3008 struct hci_dev *hdev = hcon->hdev; 3009 struct smp_cmd_pairing req; 3010 struct smp_chan *smp; 3011 3012 BT_DBG("chan %p", chan); 3013 3014 /* Only new pairings are interesting */ 3015 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags)) 3016 return; 3017 3018 /* Don't bother if we're not encrypted */ 3019 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3020 return; 3021 3022 /* Only master may initiate SMP over BR/EDR */ 3023 if (hcon->role != HCI_ROLE_MASTER) 3024 return; 3025 3026 /* Secure Connections support must be enabled */ 3027 if (!hci_dev_test_flag(hdev, HCI_SC_ENABLED)) 3028 return; 3029 3030 /* BR/EDR must use Secure Connections for SMP */ 3031 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) && 3032 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3033 return; 3034 3035 /* If our LE support is not enabled don't do anything */ 3036 if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) 3037 return; 3038 3039 /* Don't bother if remote LE support is not enabled */ 3040 if (!lmp_host_le_capable(hcon)) 3041 return; 3042 3043 /* Remote must support SMP fixed chan for BR/EDR */ 3044 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR)) 3045 return; 3046 3047 /* Don't bother if SMP is already ongoing */ 3048 if (chan->data) 3049 return; 3050 3051 smp = smp_chan_create(conn); 3052 if (!smp) { 3053 bt_dev_err(hdev, "unable to create SMP context for BR/EDR"); 3054 return; 3055 } 3056 3057 set_bit(SMP_FLAG_SC, &smp->flags); 3058 3059 BT_DBG("%s starting SMP over BR/EDR", hdev->name); 3060 3061 /* Prepare and send the BR/EDR SMP Pairing Request */ 3062 build_bredr_pairing_cmd(smp, &req, NULL); 3063 3064 smp->preq[0] = SMP_CMD_PAIRING_REQ; 3065 memcpy(&smp->preq[1], &req, sizeof(req)); 3066 3067 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(req), &req); 3068 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 3069 } 3070 3071 static void smp_resume_cb(struct l2cap_chan *chan) 3072 { 3073 struct smp_chan *smp = chan->data; 3074 struct l2cap_conn *conn = chan->conn; 3075 struct hci_conn *hcon = conn->hcon; 3076 3077 BT_DBG("chan %p", chan); 3078 3079 if (hcon->type == ACL_LINK) { 3080 bredr_pairing(chan); 3081 return; 3082 } 3083 3084 if (!smp) 3085 return; 3086 3087 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3088 return; 3089 3090 cancel_delayed_work(&smp->security_timer); 3091 3092 smp_distribute_keys(smp); 3093 } 3094 3095 static void smp_ready_cb(struct l2cap_chan *chan) 3096 { 3097 struct l2cap_conn *conn = chan->conn; 3098 struct hci_conn *hcon = conn->hcon; 3099 3100 BT_DBG("chan %p", chan); 3101 3102 /* No need to call l2cap_chan_hold() here since we already own 3103 * the reference taken in smp_new_conn_cb(). This is just the 3104 * first time that we tie it to a specific pointer. The code in 3105 * l2cap_core.c ensures that there's no risk this function wont 3106 * get called if smp_new_conn_cb was previously called. 3107 */ 3108 conn->smp = chan; 3109 3110 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3111 bredr_pairing(chan); 3112 } 3113 3114 static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 3115 { 3116 int err; 3117 3118 BT_DBG("chan %p", chan); 3119 3120 err = smp_sig_channel(chan, skb); 3121 if (err) { 3122 struct smp_chan *smp = chan->data; 3123 3124 if (smp) 3125 cancel_delayed_work_sync(&smp->security_timer); 3126 3127 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE); 3128 } 3129 3130 return err; 3131 } 3132 3133 static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan, 3134 unsigned long hdr_len, 3135 unsigned long len, int nb) 3136 { 3137 struct sk_buff *skb; 3138 3139 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL); 3140 if (!skb) 3141 return ERR_PTR(-ENOMEM); 3142 3143 skb->priority = HCI_PRIO_MAX; 3144 bt_cb(skb)->l2cap.chan = chan; 3145 3146 return skb; 3147 } 3148 3149 static const struct l2cap_ops smp_chan_ops = { 3150 .name = "Security Manager", 3151 .ready = smp_ready_cb, 3152 .recv = smp_recv_cb, 3153 .alloc_skb = smp_alloc_skb_cb, 3154 .teardown = smp_teardown_cb, 3155 .resume = smp_resume_cb, 3156 3157 .new_connection = l2cap_chan_no_new_connection, 3158 .state_change = l2cap_chan_no_state_change, 3159 .close = l2cap_chan_no_close, 3160 .defer = l2cap_chan_no_defer, 3161 .suspend = l2cap_chan_no_suspend, 3162 .set_shutdown = l2cap_chan_no_set_shutdown, 3163 .get_sndtimeo = l2cap_chan_no_get_sndtimeo, 3164 }; 3165 3166 static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan) 3167 { 3168 struct l2cap_chan *chan; 3169 3170 BT_DBG("pchan %p", pchan); 3171 3172 chan = l2cap_chan_create(); 3173 if (!chan) 3174 return NULL; 3175 3176 chan->chan_type = pchan->chan_type; 3177 chan->ops = &smp_chan_ops; 3178 chan->scid = pchan->scid; 3179 chan->dcid = chan->scid; 3180 chan->imtu = pchan->imtu; 3181 chan->omtu = pchan->omtu; 3182 chan->mode = pchan->mode; 3183 3184 /* Other L2CAP channels may request SMP routines in order to 3185 * change the security level. This means that the SMP channel 3186 * lock must be considered in its own category to avoid lockdep 3187 * warnings. 3188 */ 3189 atomic_set(&chan->nesting, L2CAP_NESTING_SMP); 3190 3191 BT_DBG("created chan %p", chan); 3192 3193 return chan; 3194 } 3195 3196 static const struct l2cap_ops smp_root_chan_ops = { 3197 .name = "Security Manager Root", 3198 .new_connection = smp_new_conn_cb, 3199 3200 /* None of these are implemented for the root channel */ 3201 .close = l2cap_chan_no_close, 3202 .alloc_skb = l2cap_chan_no_alloc_skb, 3203 .recv = l2cap_chan_no_recv, 3204 .state_change = l2cap_chan_no_state_change, 3205 .teardown = l2cap_chan_no_teardown, 3206 .ready = l2cap_chan_no_ready, 3207 .defer = l2cap_chan_no_defer, 3208 .suspend = l2cap_chan_no_suspend, 3209 .resume = l2cap_chan_no_resume, 3210 .set_shutdown = l2cap_chan_no_set_shutdown, 3211 .get_sndtimeo = l2cap_chan_no_get_sndtimeo, 3212 }; 3213 3214 static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid) 3215 { 3216 struct l2cap_chan *chan; 3217 struct smp_dev *smp; 3218 struct crypto_shash *tfm_cmac; 3219 struct crypto_kpp *tfm_ecdh; 3220 3221 if (cid == L2CAP_CID_SMP_BREDR) { 3222 smp = NULL; 3223 goto create_chan; 3224 } 3225 3226 smp = kzalloc(sizeof(*smp), GFP_KERNEL); 3227 if (!smp) 3228 return ERR_PTR(-ENOMEM); 3229 3230 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 3231 if (IS_ERR(tfm_cmac)) { 3232 BT_ERR("Unable to create CMAC crypto context"); 3233 kzfree(smp); 3234 return ERR_CAST(tfm_cmac); 3235 } 3236 3237 tfm_ecdh = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0); 3238 if (IS_ERR(tfm_ecdh)) { 3239 BT_ERR("Unable to create ECDH crypto context"); 3240 crypto_free_shash(tfm_cmac); 3241 kzfree(smp); 3242 return ERR_CAST(tfm_ecdh); 3243 } 3244 3245 smp->local_oob = false; 3246 smp->tfm_cmac = tfm_cmac; 3247 smp->tfm_ecdh = tfm_ecdh; 3248 3249 create_chan: 3250 chan = l2cap_chan_create(); 3251 if (!chan) { 3252 if (smp) { 3253 crypto_free_shash(smp->tfm_cmac); 3254 crypto_free_kpp(smp->tfm_ecdh); 3255 kzfree(smp); 3256 } 3257 return ERR_PTR(-ENOMEM); 3258 } 3259 3260 chan->data = smp; 3261 3262 l2cap_add_scid(chan, cid); 3263 3264 l2cap_chan_set_defaults(chan); 3265 3266 if (cid == L2CAP_CID_SMP) { 3267 u8 bdaddr_type; 3268 3269 hci_copy_identity_address(hdev, &chan->src, &bdaddr_type); 3270 3271 if (bdaddr_type == ADDR_LE_DEV_PUBLIC) 3272 chan->src_type = BDADDR_LE_PUBLIC; 3273 else 3274 chan->src_type = BDADDR_LE_RANDOM; 3275 } else { 3276 bacpy(&chan->src, &hdev->bdaddr); 3277 chan->src_type = BDADDR_BREDR; 3278 } 3279 3280 chan->state = BT_LISTEN; 3281 chan->mode = L2CAP_MODE_BASIC; 3282 chan->imtu = L2CAP_DEFAULT_MTU; 3283 chan->ops = &smp_root_chan_ops; 3284 3285 /* Set correct nesting level for a parent/listening channel */ 3286 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 3287 3288 return chan; 3289 } 3290 3291 static void smp_del_chan(struct l2cap_chan *chan) 3292 { 3293 struct smp_dev *smp; 3294 3295 BT_DBG("chan %p", chan); 3296 3297 smp = chan->data; 3298 if (smp) { 3299 chan->data = NULL; 3300 crypto_free_shash(smp->tfm_cmac); 3301 crypto_free_kpp(smp->tfm_ecdh); 3302 kzfree(smp); 3303 } 3304 3305 l2cap_chan_put(chan); 3306 } 3307 3308 static ssize_t force_bredr_smp_read(struct file *file, 3309 char __user *user_buf, 3310 size_t count, loff_t *ppos) 3311 { 3312 struct hci_dev *hdev = file->private_data; 3313 char buf[3]; 3314 3315 buf[0] = hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP) ? 'Y': 'N'; 3316 buf[1] = '\n'; 3317 buf[2] = '\0'; 3318 return simple_read_from_buffer(user_buf, count, ppos, buf, 2); 3319 } 3320 3321 static ssize_t force_bredr_smp_write(struct file *file, 3322 const char __user *user_buf, 3323 size_t count, loff_t *ppos) 3324 { 3325 struct hci_dev *hdev = file->private_data; 3326 bool enable; 3327 int err; 3328 3329 err = kstrtobool_from_user(user_buf, count, &enable); 3330 if (err) 3331 return err; 3332 3333 if (enable == hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3334 return -EALREADY; 3335 3336 if (enable) { 3337 struct l2cap_chan *chan; 3338 3339 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); 3340 if (IS_ERR(chan)) 3341 return PTR_ERR(chan); 3342 3343 hdev->smp_bredr_data = chan; 3344 } else { 3345 struct l2cap_chan *chan; 3346 3347 chan = hdev->smp_bredr_data; 3348 hdev->smp_bredr_data = NULL; 3349 smp_del_chan(chan); 3350 } 3351 3352 hci_dev_change_flag(hdev, HCI_FORCE_BREDR_SMP); 3353 3354 return count; 3355 } 3356 3357 static const struct file_operations force_bredr_smp_fops = { 3358 .open = simple_open, 3359 .read = force_bredr_smp_read, 3360 .write = force_bredr_smp_write, 3361 .llseek = default_llseek, 3362 }; 3363 3364 static ssize_t le_min_key_size_read(struct file *file, 3365 char __user *user_buf, 3366 size_t count, loff_t *ppos) 3367 { 3368 struct hci_dev *hdev = file->private_data; 3369 char buf[4]; 3370 3371 snprintf(buf, sizeof(buf), "%2u\n", hdev->le_min_key_size); 3372 3373 return simple_read_from_buffer(user_buf, count, ppos, buf, strlen(buf)); 3374 } 3375 3376 static ssize_t le_min_key_size_write(struct file *file, 3377 const char __user *user_buf, 3378 size_t count, loff_t *ppos) 3379 { 3380 struct hci_dev *hdev = file->private_data; 3381 char buf[32]; 3382 size_t buf_size = min(count, (sizeof(buf) - 1)); 3383 u8 key_size; 3384 3385 if (copy_from_user(buf, user_buf, buf_size)) 3386 return -EFAULT; 3387 3388 buf[buf_size] = '\0'; 3389 3390 sscanf(buf, "%hhu", &key_size); 3391 3392 if (key_size > hdev->le_max_key_size || 3393 key_size < SMP_MIN_ENC_KEY_SIZE) 3394 return -EINVAL; 3395 3396 hdev->le_min_key_size = key_size; 3397 3398 return count; 3399 } 3400 3401 static const struct file_operations le_min_key_size_fops = { 3402 .open = simple_open, 3403 .read = le_min_key_size_read, 3404 .write = le_min_key_size_write, 3405 .llseek = default_llseek, 3406 }; 3407 3408 static ssize_t le_max_key_size_read(struct file *file, 3409 char __user *user_buf, 3410 size_t count, loff_t *ppos) 3411 { 3412 struct hci_dev *hdev = file->private_data; 3413 char buf[4]; 3414 3415 snprintf(buf, sizeof(buf), "%2u\n", hdev->le_max_key_size); 3416 3417 return simple_read_from_buffer(user_buf, count, ppos, buf, strlen(buf)); 3418 } 3419 3420 static ssize_t le_max_key_size_write(struct file *file, 3421 const char __user *user_buf, 3422 size_t count, loff_t *ppos) 3423 { 3424 struct hci_dev *hdev = file->private_data; 3425 char buf[32]; 3426 size_t buf_size = min(count, (sizeof(buf) - 1)); 3427 u8 key_size; 3428 3429 if (copy_from_user(buf, user_buf, buf_size)) 3430 return -EFAULT; 3431 3432 buf[buf_size] = '\0'; 3433 3434 sscanf(buf, "%hhu", &key_size); 3435 3436 if (key_size > SMP_MAX_ENC_KEY_SIZE || 3437 key_size < hdev->le_min_key_size) 3438 return -EINVAL; 3439 3440 hdev->le_max_key_size = key_size; 3441 3442 return count; 3443 } 3444 3445 static const struct file_operations le_max_key_size_fops = { 3446 .open = simple_open, 3447 .read = le_max_key_size_read, 3448 .write = le_max_key_size_write, 3449 .llseek = default_llseek, 3450 }; 3451 3452 int smp_register(struct hci_dev *hdev) 3453 { 3454 struct l2cap_chan *chan; 3455 3456 BT_DBG("%s", hdev->name); 3457 3458 /* If the controller does not support Low Energy operation, then 3459 * there is also no need to register any SMP channel. 3460 */ 3461 if (!lmp_le_capable(hdev)) 3462 return 0; 3463 3464 if (WARN_ON(hdev->smp_data)) { 3465 chan = hdev->smp_data; 3466 hdev->smp_data = NULL; 3467 smp_del_chan(chan); 3468 } 3469 3470 chan = smp_add_cid(hdev, L2CAP_CID_SMP); 3471 if (IS_ERR(chan)) 3472 return PTR_ERR(chan); 3473 3474 hdev->smp_data = chan; 3475 3476 debugfs_create_file("le_min_key_size", 0644, hdev->debugfs, hdev, 3477 &le_min_key_size_fops); 3478 debugfs_create_file("le_max_key_size", 0644, hdev->debugfs, hdev, 3479 &le_max_key_size_fops); 3480 3481 /* If the controller does not support BR/EDR Secure Connections 3482 * feature, then the BR/EDR SMP channel shall not be present. 3483 * 3484 * To test this with Bluetooth 4.0 controllers, create a debugfs 3485 * switch that allows forcing BR/EDR SMP support and accepting 3486 * cross-transport pairing on non-AES encrypted connections. 3487 */ 3488 if (!lmp_sc_capable(hdev)) { 3489 debugfs_create_file("force_bredr_smp", 0644, hdev->debugfs, 3490 hdev, &force_bredr_smp_fops); 3491 3492 /* Flag can be already set here (due to power toggle) */ 3493 if (!hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3494 return 0; 3495 } 3496 3497 if (WARN_ON(hdev->smp_bredr_data)) { 3498 chan = hdev->smp_bredr_data; 3499 hdev->smp_bredr_data = NULL; 3500 smp_del_chan(chan); 3501 } 3502 3503 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); 3504 if (IS_ERR(chan)) { 3505 int err = PTR_ERR(chan); 3506 chan = hdev->smp_data; 3507 hdev->smp_data = NULL; 3508 smp_del_chan(chan); 3509 return err; 3510 } 3511 3512 hdev->smp_bredr_data = chan; 3513 3514 return 0; 3515 } 3516 3517 void smp_unregister(struct hci_dev *hdev) 3518 { 3519 struct l2cap_chan *chan; 3520 3521 if (hdev->smp_bredr_data) { 3522 chan = hdev->smp_bredr_data; 3523 hdev->smp_bredr_data = NULL; 3524 smp_del_chan(chan); 3525 } 3526 3527 if (hdev->smp_data) { 3528 chan = hdev->smp_data; 3529 hdev->smp_data = NULL; 3530 smp_del_chan(chan); 3531 } 3532 } 3533 3534 #if IS_ENABLED(CONFIG_BT_SELFTEST_SMP) 3535 3536 static int __init test_debug_key(struct crypto_kpp *tfm_ecdh) 3537 { 3538 u8 pk[64]; 3539 int err; 3540 3541 err = set_ecdh_privkey(tfm_ecdh, debug_sk); 3542 if (err) 3543 return err; 3544 3545 err = generate_ecdh_public_key(tfm_ecdh, pk); 3546 if (err) 3547 return err; 3548 3549 if (crypto_memneq(pk, debug_pk, 64)) 3550 return -EINVAL; 3551 3552 return 0; 3553 } 3554 3555 static int __init test_ah(void) 3556 { 3557 const u8 irk[16] = { 3558 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3559 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3560 const u8 r[3] = { 0x94, 0x81, 0x70 }; 3561 const u8 exp[3] = { 0xaa, 0xfb, 0x0d }; 3562 u8 res[3]; 3563 int err; 3564 3565 err = smp_ah(irk, r, res); 3566 if (err) 3567 return err; 3568 3569 if (crypto_memneq(res, exp, 3)) 3570 return -EINVAL; 3571 3572 return 0; 3573 } 3574 3575 static int __init test_c1(void) 3576 { 3577 const u8 k[16] = { 3578 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 3579 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; 3580 const u8 r[16] = { 3581 0xe0, 0x2e, 0x70, 0xc6, 0x4e, 0x27, 0x88, 0x63, 3582 0x0e, 0x6f, 0xad, 0x56, 0x21, 0xd5, 0x83, 0x57 }; 3583 const u8 preq[7] = { 0x01, 0x01, 0x00, 0x00, 0x10, 0x07, 0x07 }; 3584 const u8 pres[7] = { 0x02, 0x03, 0x00, 0x00, 0x08, 0x00, 0x05 }; 3585 const u8 _iat = 0x01; 3586 const u8 _rat = 0x00; 3587 const bdaddr_t ra = { { 0xb6, 0xb5, 0xb4, 0xb3, 0xb2, 0xb1 } }; 3588 const bdaddr_t ia = { { 0xa6, 0xa5, 0xa4, 0xa3, 0xa2, 0xa1 } }; 3589 const u8 exp[16] = { 3590 0x86, 0x3b, 0xf1, 0xbe, 0xc5, 0x4d, 0xa7, 0xd2, 3591 0xea, 0x88, 0x89, 0x87, 0xef, 0x3f, 0x1e, 0x1e }; 3592 u8 res[16]; 3593 int err; 3594 3595 err = smp_c1(k, r, preq, pres, _iat, &ia, _rat, &ra, res); 3596 if (err) 3597 return err; 3598 3599 if (crypto_memneq(res, exp, 16)) 3600 return -EINVAL; 3601 3602 return 0; 3603 } 3604 3605 static int __init test_s1(void) 3606 { 3607 const u8 k[16] = { 3608 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 3609 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; 3610 const u8 r1[16] = { 3611 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 }; 3612 const u8 r2[16] = { 3613 0x00, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99 }; 3614 const u8 exp[16] = { 3615 0x62, 0xa0, 0x6d, 0x79, 0xae, 0x16, 0x42, 0x5b, 3616 0x9b, 0xf4, 0xb0, 0xe8, 0xf0, 0xe1, 0x1f, 0x9a }; 3617 u8 res[16]; 3618 int err; 3619 3620 err = smp_s1(k, r1, r2, res); 3621 if (err) 3622 return err; 3623 3624 if (crypto_memneq(res, exp, 16)) 3625 return -EINVAL; 3626 3627 return 0; 3628 } 3629 3630 static int __init test_f4(struct crypto_shash *tfm_cmac) 3631 { 3632 const u8 u[32] = { 3633 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 3634 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 3635 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 3636 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 }; 3637 const u8 v[32] = { 3638 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b, 3639 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59, 3640 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90, 3641 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 }; 3642 const u8 x[16] = { 3643 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3644 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3645 const u8 z = 0x00; 3646 const u8 exp[16] = { 3647 0x2d, 0x87, 0x74, 0xa9, 0xbe, 0xa1, 0xed, 0xf1, 3648 0x1c, 0xbd, 0xa9, 0x07, 0xf1, 0x16, 0xc9, 0xf2 }; 3649 u8 res[16]; 3650 int err; 3651 3652 err = smp_f4(tfm_cmac, u, v, x, z, res); 3653 if (err) 3654 return err; 3655 3656 if (crypto_memneq(res, exp, 16)) 3657 return -EINVAL; 3658 3659 return 0; 3660 } 3661 3662 static int __init test_f5(struct crypto_shash *tfm_cmac) 3663 { 3664 const u8 w[32] = { 3665 0x98, 0xa6, 0xbf, 0x73, 0xf3, 0x34, 0x8d, 0x86, 3666 0xf1, 0x66, 0xf8, 0xb4, 0x13, 0x6b, 0x79, 0x99, 3667 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3668 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3669 const u8 n1[16] = { 3670 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3671 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3672 const u8 n2[16] = { 3673 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3674 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3675 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 }; 3676 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 }; 3677 const u8 exp_ltk[16] = { 3678 0x38, 0x0a, 0x75, 0x94, 0xb5, 0x22, 0x05, 0x98, 3679 0x23, 0xcd, 0xd7, 0x69, 0x11, 0x79, 0x86, 0x69 }; 3680 const u8 exp_mackey[16] = { 3681 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd, 3682 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 }; 3683 u8 mackey[16], ltk[16]; 3684 int err; 3685 3686 err = smp_f5(tfm_cmac, w, n1, n2, a1, a2, mackey, ltk); 3687 if (err) 3688 return err; 3689 3690 if (crypto_memneq(mackey, exp_mackey, 16)) 3691 return -EINVAL; 3692 3693 if (crypto_memneq(ltk, exp_ltk, 16)) 3694 return -EINVAL; 3695 3696 return 0; 3697 } 3698 3699 static int __init test_f6(struct crypto_shash *tfm_cmac) 3700 { 3701 const u8 w[16] = { 3702 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd, 3703 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 }; 3704 const u8 n1[16] = { 3705 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3706 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3707 const u8 n2[16] = { 3708 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3709 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3710 const u8 r[16] = { 3711 0xc8, 0x0f, 0x2d, 0x0c, 0xd2, 0x42, 0xda, 0x08, 3712 0x54, 0xbb, 0x53, 0xb4, 0x3b, 0x34, 0xa3, 0x12 }; 3713 const u8 io_cap[3] = { 0x02, 0x01, 0x01 }; 3714 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 }; 3715 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 }; 3716 const u8 exp[16] = { 3717 0x61, 0x8f, 0x95, 0xda, 0x09, 0x0b, 0x6c, 0xd2, 3718 0xc5, 0xe8, 0xd0, 0x9c, 0x98, 0x73, 0xc4, 0xe3 }; 3719 u8 res[16]; 3720 int err; 3721 3722 err = smp_f6(tfm_cmac, w, n1, n2, r, io_cap, a1, a2, res); 3723 if (err) 3724 return err; 3725 3726 if (crypto_memneq(res, exp, 16)) 3727 return -EINVAL; 3728 3729 return 0; 3730 } 3731 3732 static int __init test_g2(struct crypto_shash *tfm_cmac) 3733 { 3734 const u8 u[32] = { 3735 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 3736 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 3737 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 3738 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 }; 3739 const u8 v[32] = { 3740 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b, 3741 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59, 3742 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90, 3743 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 }; 3744 const u8 x[16] = { 3745 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3746 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3747 const u8 y[16] = { 3748 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3749 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3750 const u32 exp_val = 0x2f9ed5ba % 1000000; 3751 u32 val; 3752 int err; 3753 3754 err = smp_g2(tfm_cmac, u, v, x, y, &val); 3755 if (err) 3756 return err; 3757 3758 if (val != exp_val) 3759 return -EINVAL; 3760 3761 return 0; 3762 } 3763 3764 static int __init test_h6(struct crypto_shash *tfm_cmac) 3765 { 3766 const u8 w[16] = { 3767 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3768 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3769 const u8 key_id[4] = { 0x72, 0x62, 0x65, 0x6c }; 3770 const u8 exp[16] = { 3771 0x99, 0x63, 0xb1, 0x80, 0xe2, 0xa9, 0xd3, 0xe8, 3772 0x1c, 0xc9, 0x6d, 0xe7, 0x02, 0xe1, 0x9a, 0x2d }; 3773 u8 res[16]; 3774 int err; 3775 3776 err = smp_h6(tfm_cmac, w, key_id, res); 3777 if (err) 3778 return err; 3779 3780 if (crypto_memneq(res, exp, 16)) 3781 return -EINVAL; 3782 3783 return 0; 3784 } 3785 3786 static char test_smp_buffer[32]; 3787 3788 static ssize_t test_smp_read(struct file *file, char __user *user_buf, 3789 size_t count, loff_t *ppos) 3790 { 3791 return simple_read_from_buffer(user_buf, count, ppos, test_smp_buffer, 3792 strlen(test_smp_buffer)); 3793 } 3794 3795 static const struct file_operations test_smp_fops = { 3796 .open = simple_open, 3797 .read = test_smp_read, 3798 .llseek = default_llseek, 3799 }; 3800 3801 static int __init run_selftests(struct crypto_shash *tfm_cmac, 3802 struct crypto_kpp *tfm_ecdh) 3803 { 3804 ktime_t calltime, delta, rettime; 3805 unsigned long long duration; 3806 int err; 3807 3808 calltime = ktime_get(); 3809 3810 err = test_debug_key(tfm_ecdh); 3811 if (err) { 3812 BT_ERR("debug_key test failed"); 3813 goto done; 3814 } 3815 3816 err = test_ah(); 3817 if (err) { 3818 BT_ERR("smp_ah test failed"); 3819 goto done; 3820 } 3821 3822 err = test_c1(); 3823 if (err) { 3824 BT_ERR("smp_c1 test failed"); 3825 goto done; 3826 } 3827 3828 err = test_s1(); 3829 if (err) { 3830 BT_ERR("smp_s1 test failed"); 3831 goto done; 3832 } 3833 3834 err = test_f4(tfm_cmac); 3835 if (err) { 3836 BT_ERR("smp_f4 test failed"); 3837 goto done; 3838 } 3839 3840 err = test_f5(tfm_cmac); 3841 if (err) { 3842 BT_ERR("smp_f5 test failed"); 3843 goto done; 3844 } 3845 3846 err = test_f6(tfm_cmac); 3847 if (err) { 3848 BT_ERR("smp_f6 test failed"); 3849 goto done; 3850 } 3851 3852 err = test_g2(tfm_cmac); 3853 if (err) { 3854 BT_ERR("smp_g2 test failed"); 3855 goto done; 3856 } 3857 3858 err = test_h6(tfm_cmac); 3859 if (err) { 3860 BT_ERR("smp_h6 test failed"); 3861 goto done; 3862 } 3863 3864 rettime = ktime_get(); 3865 delta = ktime_sub(rettime, calltime); 3866 duration = (unsigned long long) ktime_to_ns(delta) >> 10; 3867 3868 BT_INFO("SMP test passed in %llu usecs", duration); 3869 3870 done: 3871 if (!err) 3872 snprintf(test_smp_buffer, sizeof(test_smp_buffer), 3873 "PASS (%llu usecs)\n", duration); 3874 else 3875 snprintf(test_smp_buffer, sizeof(test_smp_buffer), "FAIL\n"); 3876 3877 debugfs_create_file("selftest_smp", 0444, bt_debugfs, NULL, 3878 &test_smp_fops); 3879 3880 return err; 3881 } 3882 3883 int __init bt_selftest_smp(void) 3884 { 3885 struct crypto_shash *tfm_cmac; 3886 struct crypto_kpp *tfm_ecdh; 3887 int err; 3888 3889 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 3890 if (IS_ERR(tfm_cmac)) { 3891 BT_ERR("Unable to create CMAC crypto context"); 3892 return PTR_ERR(tfm_cmac); 3893 } 3894 3895 tfm_ecdh = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0); 3896 if (IS_ERR(tfm_ecdh)) { 3897 BT_ERR("Unable to create ECDH crypto context"); 3898 crypto_free_shash(tfm_cmac); 3899 return PTR_ERR(tfm_ecdh); 3900 } 3901 3902 err = run_selftests(tfm_cmac, tfm_ecdh); 3903 3904 crypto_free_shash(tfm_cmac); 3905 crypto_free_kpp(tfm_ecdh); 3906 3907 return err; 3908 } 3909 3910 #endif 3911