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 u8 hash[3]; 506 int err; 507 508 if (!chan || !chan->data) 509 return false; 510 511 BT_DBG("RPA %pMR IRK %*phN", bdaddr, 16, irk); 512 513 err = smp_ah(irk, &bdaddr->b[3], hash); 514 if (err) 515 return false; 516 517 return !crypto_memneq(bdaddr->b, hash, 3); 518 } 519 520 int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa) 521 { 522 struct l2cap_chan *chan = hdev->smp_data; 523 int err; 524 525 if (!chan || !chan->data) 526 return -EOPNOTSUPP; 527 528 get_random_bytes(&rpa->b[3], 3); 529 530 rpa->b[5] &= 0x3f; /* Clear two most significant bits */ 531 rpa->b[5] |= 0x40; /* Set second most significant bit */ 532 533 err = smp_ah(irk, &rpa->b[3], rpa->b); 534 if (err < 0) 535 return err; 536 537 BT_DBG("RPA %pMR", rpa); 538 539 return 0; 540 } 541 542 int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16]) 543 { 544 struct l2cap_chan *chan = hdev->smp_data; 545 struct smp_dev *smp; 546 int err; 547 548 if (!chan || !chan->data) 549 return -EOPNOTSUPP; 550 551 smp = chan->data; 552 553 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { 554 BT_DBG("Using debug keys"); 555 err = set_ecdh_privkey(smp->tfm_ecdh, debug_sk); 556 if (err) 557 return err; 558 memcpy(smp->local_pk, debug_pk, 64); 559 smp->debug_key = true; 560 } else { 561 while (true) { 562 /* Generate key pair for Secure Connections */ 563 err = generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk); 564 if (err) 565 return err; 566 567 /* This is unlikely, but we need to check that 568 * we didn't accidentially generate a debug key. 569 */ 570 if (crypto_memneq(smp->local_pk, debug_pk, 64)) 571 break; 572 } 573 smp->debug_key = false; 574 } 575 576 SMP_DBG("OOB Public Key X: %32phN", smp->local_pk); 577 SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32); 578 579 get_random_bytes(smp->local_rand, 16); 580 581 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->local_pk, 582 smp->local_rand, 0, hash); 583 if (err < 0) 584 return err; 585 586 memcpy(rand, smp->local_rand, 16); 587 588 smp->local_oob = true; 589 590 return 0; 591 } 592 593 static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data) 594 { 595 struct l2cap_chan *chan = conn->smp; 596 struct smp_chan *smp; 597 struct kvec iv[2]; 598 struct msghdr msg; 599 600 if (!chan) 601 return; 602 603 BT_DBG("code 0x%2.2x", code); 604 605 iv[0].iov_base = &code; 606 iv[0].iov_len = 1; 607 608 iv[1].iov_base = data; 609 iv[1].iov_len = len; 610 611 memset(&msg, 0, sizeof(msg)); 612 613 iov_iter_kvec(&msg.msg_iter, WRITE, iv, 2, 1 + len); 614 615 l2cap_chan_send(chan, &msg, 1 + len); 616 617 if (!chan->data) 618 return; 619 620 smp = chan->data; 621 622 cancel_delayed_work_sync(&smp->security_timer); 623 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT); 624 } 625 626 static u8 authreq_to_seclevel(u8 authreq) 627 { 628 if (authreq & SMP_AUTH_MITM) { 629 if (authreq & SMP_AUTH_SC) 630 return BT_SECURITY_FIPS; 631 else 632 return BT_SECURITY_HIGH; 633 } else { 634 return BT_SECURITY_MEDIUM; 635 } 636 } 637 638 static __u8 seclevel_to_authreq(__u8 sec_level) 639 { 640 switch (sec_level) { 641 case BT_SECURITY_FIPS: 642 case BT_SECURITY_HIGH: 643 return SMP_AUTH_MITM | SMP_AUTH_BONDING; 644 case BT_SECURITY_MEDIUM: 645 return SMP_AUTH_BONDING; 646 default: 647 return SMP_AUTH_NONE; 648 } 649 } 650 651 static void build_pairing_cmd(struct l2cap_conn *conn, 652 struct smp_cmd_pairing *req, 653 struct smp_cmd_pairing *rsp, __u8 authreq) 654 { 655 struct l2cap_chan *chan = conn->smp; 656 struct smp_chan *smp = chan->data; 657 struct hci_conn *hcon = conn->hcon; 658 struct hci_dev *hdev = hcon->hdev; 659 u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT; 660 661 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { 662 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 663 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 664 authreq |= SMP_AUTH_BONDING; 665 } else { 666 authreq &= ~SMP_AUTH_BONDING; 667 } 668 669 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) 670 remote_dist |= SMP_DIST_ID_KEY; 671 672 if (hci_dev_test_flag(hdev, HCI_PRIVACY)) 673 local_dist |= SMP_DIST_ID_KEY; 674 675 if (hci_dev_test_flag(hdev, HCI_SC_ENABLED) && 676 (authreq & SMP_AUTH_SC)) { 677 struct oob_data *oob_data; 678 u8 bdaddr_type; 679 680 if (hci_dev_test_flag(hdev, HCI_SSP_ENABLED)) { 681 local_dist |= SMP_DIST_LINK_KEY; 682 remote_dist |= SMP_DIST_LINK_KEY; 683 } 684 685 if (hcon->dst_type == ADDR_LE_DEV_PUBLIC) 686 bdaddr_type = BDADDR_LE_PUBLIC; 687 else 688 bdaddr_type = BDADDR_LE_RANDOM; 689 690 oob_data = hci_find_remote_oob_data(hdev, &hcon->dst, 691 bdaddr_type); 692 if (oob_data && oob_data->present) { 693 set_bit(SMP_FLAG_REMOTE_OOB, &smp->flags); 694 oob_flag = SMP_OOB_PRESENT; 695 memcpy(smp->rr, oob_data->rand256, 16); 696 memcpy(smp->pcnf, oob_data->hash256, 16); 697 SMP_DBG("OOB Remote Confirmation: %16phN", smp->pcnf); 698 SMP_DBG("OOB Remote Random: %16phN", smp->rr); 699 } 700 701 } else { 702 authreq &= ~SMP_AUTH_SC; 703 } 704 705 if (rsp == NULL) { 706 req->io_capability = conn->hcon->io_capability; 707 req->oob_flag = oob_flag; 708 req->max_key_size = hdev->le_max_key_size; 709 req->init_key_dist = local_dist; 710 req->resp_key_dist = remote_dist; 711 req->auth_req = (authreq & AUTH_REQ_MASK(hdev)); 712 713 smp->remote_key_dist = remote_dist; 714 return; 715 } 716 717 rsp->io_capability = conn->hcon->io_capability; 718 rsp->oob_flag = oob_flag; 719 rsp->max_key_size = hdev->le_max_key_size; 720 rsp->init_key_dist = req->init_key_dist & remote_dist; 721 rsp->resp_key_dist = req->resp_key_dist & local_dist; 722 rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev)); 723 724 smp->remote_key_dist = rsp->init_key_dist; 725 } 726 727 static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size) 728 { 729 struct l2cap_chan *chan = conn->smp; 730 struct hci_dev *hdev = conn->hcon->hdev; 731 struct smp_chan *smp = chan->data; 732 733 if (max_key_size > hdev->le_max_key_size || 734 max_key_size < SMP_MIN_ENC_KEY_SIZE) 735 return SMP_ENC_KEY_SIZE; 736 737 smp->enc_key_size = max_key_size; 738 739 return 0; 740 } 741 742 static void smp_chan_destroy(struct l2cap_conn *conn) 743 { 744 struct l2cap_chan *chan = conn->smp; 745 struct smp_chan *smp = chan->data; 746 struct hci_conn *hcon = conn->hcon; 747 bool complete; 748 749 BUG_ON(!smp); 750 751 cancel_delayed_work_sync(&smp->security_timer); 752 753 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags); 754 mgmt_smp_complete(hcon, complete); 755 756 kzfree(smp->csrk); 757 kzfree(smp->slave_csrk); 758 kzfree(smp->link_key); 759 760 crypto_free_shash(smp->tfm_cmac); 761 crypto_free_kpp(smp->tfm_ecdh); 762 763 /* Ensure that we don't leave any debug key around if debug key 764 * support hasn't been explicitly enabled. 765 */ 766 if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG && 767 !hci_dev_test_flag(hcon->hdev, HCI_KEEP_DEBUG_KEYS)) { 768 list_del_rcu(&smp->ltk->list); 769 kfree_rcu(smp->ltk, rcu); 770 smp->ltk = NULL; 771 } 772 773 /* If pairing failed clean up any keys we might have */ 774 if (!complete) { 775 if (smp->ltk) { 776 list_del_rcu(&smp->ltk->list); 777 kfree_rcu(smp->ltk, rcu); 778 } 779 780 if (smp->slave_ltk) { 781 list_del_rcu(&smp->slave_ltk->list); 782 kfree_rcu(smp->slave_ltk, rcu); 783 } 784 785 if (smp->remote_irk) { 786 list_del_rcu(&smp->remote_irk->list); 787 kfree_rcu(smp->remote_irk, rcu); 788 } 789 } 790 791 chan->data = NULL; 792 kzfree(smp); 793 hci_conn_drop(hcon); 794 } 795 796 static void smp_failure(struct l2cap_conn *conn, u8 reason) 797 { 798 struct hci_conn *hcon = conn->hcon; 799 struct l2cap_chan *chan = conn->smp; 800 801 if (reason) 802 smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason), 803 &reason); 804 805 mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE); 806 807 if (chan->data) 808 smp_chan_destroy(conn); 809 } 810 811 #define JUST_WORKS 0x00 812 #define JUST_CFM 0x01 813 #define REQ_PASSKEY 0x02 814 #define CFM_PASSKEY 0x03 815 #define REQ_OOB 0x04 816 #define DSP_PASSKEY 0x05 817 #define OVERLAP 0xFF 818 819 static const u8 gen_method[5][5] = { 820 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 821 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 822 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 823 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM }, 824 { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP }, 825 }; 826 827 static const u8 sc_method[5][5] = { 828 { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, 829 { JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 830 { DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY }, 831 { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM }, 832 { DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, 833 }; 834 835 static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io) 836 { 837 /* If either side has unknown io_caps, use JUST_CFM (which gets 838 * converted later to JUST_WORKS if we're initiators. 839 */ 840 if (local_io > SMP_IO_KEYBOARD_DISPLAY || 841 remote_io > SMP_IO_KEYBOARD_DISPLAY) 842 return JUST_CFM; 843 844 if (test_bit(SMP_FLAG_SC, &smp->flags)) 845 return sc_method[remote_io][local_io]; 846 847 return gen_method[remote_io][local_io]; 848 } 849 850 static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth, 851 u8 local_io, u8 remote_io) 852 { 853 struct hci_conn *hcon = conn->hcon; 854 struct l2cap_chan *chan = conn->smp; 855 struct smp_chan *smp = chan->data; 856 u32 passkey = 0; 857 int ret = 0; 858 859 /* Initialize key for JUST WORKS */ 860 memset(smp->tk, 0, sizeof(smp->tk)); 861 clear_bit(SMP_FLAG_TK_VALID, &smp->flags); 862 863 BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io); 864 865 /* If neither side wants MITM, either "just" confirm an incoming 866 * request or use just-works for outgoing ones. The JUST_CFM 867 * will be converted to JUST_WORKS if necessary later in this 868 * function. If either side has MITM look up the method from the 869 * table. 870 */ 871 if (!(auth & SMP_AUTH_MITM)) 872 smp->method = JUST_CFM; 873 else 874 smp->method = get_auth_method(smp, local_io, remote_io); 875 876 /* Don't confirm locally initiated pairing attempts */ 877 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, 878 &smp->flags)) 879 smp->method = JUST_WORKS; 880 881 /* Don't bother user space with no IO capabilities */ 882 if (smp->method == JUST_CFM && 883 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 884 smp->method = JUST_WORKS; 885 886 /* If Just Works, Continue with Zero TK */ 887 if (smp->method == JUST_WORKS) { 888 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 889 return 0; 890 } 891 892 /* If this function is used for SC -> legacy fallback we 893 * can only recover the just-works case. 894 */ 895 if (test_bit(SMP_FLAG_SC, &smp->flags)) 896 return -EINVAL; 897 898 /* Not Just Works/Confirm results in MITM Authentication */ 899 if (smp->method != JUST_CFM) { 900 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags); 901 if (hcon->pending_sec_level < BT_SECURITY_HIGH) 902 hcon->pending_sec_level = BT_SECURITY_HIGH; 903 } 904 905 /* If both devices have Keyoard-Display I/O, the master 906 * Confirms and the slave Enters the passkey. 907 */ 908 if (smp->method == OVERLAP) { 909 if (hcon->role == HCI_ROLE_MASTER) 910 smp->method = CFM_PASSKEY; 911 else 912 smp->method = REQ_PASSKEY; 913 } 914 915 /* Generate random passkey. */ 916 if (smp->method == CFM_PASSKEY) { 917 memset(smp->tk, 0, sizeof(smp->tk)); 918 get_random_bytes(&passkey, sizeof(passkey)); 919 passkey %= 1000000; 920 put_unaligned_le32(passkey, smp->tk); 921 BT_DBG("PassKey: %d", passkey); 922 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 923 } 924 925 if (smp->method == REQ_PASSKEY) 926 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst, 927 hcon->type, hcon->dst_type); 928 else if (smp->method == JUST_CFM) 929 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, 930 hcon->type, hcon->dst_type, 931 passkey, 1); 932 else 933 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst, 934 hcon->type, hcon->dst_type, 935 passkey, 0); 936 937 return ret; 938 } 939 940 static u8 smp_confirm(struct smp_chan *smp) 941 { 942 struct l2cap_conn *conn = smp->conn; 943 struct smp_cmd_pairing_confirm cp; 944 int ret; 945 946 BT_DBG("conn %p", conn); 947 948 ret = smp_c1(smp->tk, smp->prnd, smp->preq, smp->prsp, 949 conn->hcon->init_addr_type, &conn->hcon->init_addr, 950 conn->hcon->resp_addr_type, &conn->hcon->resp_addr, 951 cp.confirm_val); 952 if (ret) 953 return SMP_UNSPECIFIED; 954 955 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 956 957 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp); 958 959 if (conn->hcon->out) 960 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 961 else 962 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 963 964 return 0; 965 } 966 967 static u8 smp_random(struct smp_chan *smp) 968 { 969 struct l2cap_conn *conn = smp->conn; 970 struct hci_conn *hcon = conn->hcon; 971 u8 confirm[16]; 972 int ret; 973 974 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave"); 975 976 ret = smp_c1(smp->tk, smp->rrnd, smp->preq, smp->prsp, 977 hcon->init_addr_type, &hcon->init_addr, 978 hcon->resp_addr_type, &hcon->resp_addr, confirm); 979 if (ret) 980 return SMP_UNSPECIFIED; 981 982 if (crypto_memneq(smp->pcnf, confirm, sizeof(smp->pcnf))) { 983 bt_dev_err(hcon->hdev, "pairing failed " 984 "(confirmation values mismatch)"); 985 return SMP_CONFIRM_FAILED; 986 } 987 988 if (hcon->out) { 989 u8 stk[16]; 990 __le64 rand = 0; 991 __le16 ediv = 0; 992 993 smp_s1(smp->tk, smp->rrnd, smp->prnd, stk); 994 995 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) 996 return SMP_UNSPECIFIED; 997 998 hci_le_start_enc(hcon, ediv, rand, stk, smp->enc_key_size); 999 hcon->enc_key_size = smp->enc_key_size; 1000 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); 1001 } else { 1002 u8 stk[16], auth; 1003 __le64 rand = 0; 1004 __le16 ediv = 0; 1005 1006 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 1007 smp->prnd); 1008 1009 smp_s1(smp->tk, smp->prnd, smp->rrnd, stk); 1010 1011 if (hcon->pending_sec_level == BT_SECURITY_HIGH) 1012 auth = 1; 1013 else 1014 auth = 0; 1015 1016 /* Even though there's no _SLAVE suffix this is the 1017 * slave STK we're adding for later lookup (the master 1018 * STK never needs to be stored). 1019 */ 1020 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 1021 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand); 1022 } 1023 1024 return 0; 1025 } 1026 1027 static void smp_notify_keys(struct l2cap_conn *conn) 1028 { 1029 struct l2cap_chan *chan = conn->smp; 1030 struct smp_chan *smp = chan->data; 1031 struct hci_conn *hcon = conn->hcon; 1032 struct hci_dev *hdev = hcon->hdev; 1033 struct smp_cmd_pairing *req = (void *) &smp->preq[1]; 1034 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1]; 1035 bool persistent; 1036 1037 if (hcon->type == ACL_LINK) { 1038 if (hcon->key_type == HCI_LK_DEBUG_COMBINATION) 1039 persistent = false; 1040 else 1041 persistent = !test_bit(HCI_CONN_FLUSH_KEY, 1042 &hcon->flags); 1043 } else { 1044 /* The LTKs, IRKs and CSRKs should be persistent only if 1045 * both sides had the bonding bit set in their 1046 * authentication requests. 1047 */ 1048 persistent = !!((req->auth_req & rsp->auth_req) & 1049 SMP_AUTH_BONDING); 1050 } 1051 1052 if (smp->remote_irk) { 1053 mgmt_new_irk(hdev, smp->remote_irk, persistent); 1054 1055 /* Now that user space can be considered to know the 1056 * identity address track the connection based on it 1057 * from now on (assuming this is an LE link). 1058 */ 1059 if (hcon->type == LE_LINK) { 1060 bacpy(&hcon->dst, &smp->remote_irk->bdaddr); 1061 hcon->dst_type = smp->remote_irk->addr_type; 1062 queue_work(hdev->workqueue, &conn->id_addr_update_work); 1063 } 1064 } 1065 1066 if (smp->csrk) { 1067 smp->csrk->bdaddr_type = hcon->dst_type; 1068 bacpy(&smp->csrk->bdaddr, &hcon->dst); 1069 mgmt_new_csrk(hdev, smp->csrk, persistent); 1070 } 1071 1072 if (smp->slave_csrk) { 1073 smp->slave_csrk->bdaddr_type = hcon->dst_type; 1074 bacpy(&smp->slave_csrk->bdaddr, &hcon->dst); 1075 mgmt_new_csrk(hdev, smp->slave_csrk, persistent); 1076 } 1077 1078 if (smp->ltk) { 1079 smp->ltk->bdaddr_type = hcon->dst_type; 1080 bacpy(&smp->ltk->bdaddr, &hcon->dst); 1081 mgmt_new_ltk(hdev, smp->ltk, persistent); 1082 } 1083 1084 if (smp->slave_ltk) { 1085 smp->slave_ltk->bdaddr_type = hcon->dst_type; 1086 bacpy(&smp->slave_ltk->bdaddr, &hcon->dst); 1087 mgmt_new_ltk(hdev, smp->slave_ltk, persistent); 1088 } 1089 1090 if (smp->link_key) { 1091 struct link_key *key; 1092 u8 type; 1093 1094 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags)) 1095 type = HCI_LK_DEBUG_COMBINATION; 1096 else if (hcon->sec_level == BT_SECURITY_FIPS) 1097 type = HCI_LK_AUTH_COMBINATION_P256; 1098 else 1099 type = HCI_LK_UNAUTH_COMBINATION_P256; 1100 1101 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst, 1102 smp->link_key, type, 0, &persistent); 1103 if (key) { 1104 mgmt_new_link_key(hdev, key, persistent); 1105 1106 /* Don't keep debug keys around if the relevant 1107 * flag is not set. 1108 */ 1109 if (!hci_dev_test_flag(hdev, HCI_KEEP_DEBUG_KEYS) && 1110 key->type == HCI_LK_DEBUG_COMBINATION) { 1111 list_del_rcu(&key->list); 1112 kfree_rcu(key, rcu); 1113 } 1114 } 1115 } 1116 } 1117 1118 static void sc_add_ltk(struct smp_chan *smp) 1119 { 1120 struct hci_conn *hcon = smp->conn->hcon; 1121 u8 key_type, auth; 1122 1123 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags)) 1124 key_type = SMP_LTK_P256_DEBUG; 1125 else 1126 key_type = SMP_LTK_P256; 1127 1128 if (hcon->pending_sec_level == BT_SECURITY_FIPS) 1129 auth = 1; 1130 else 1131 auth = 0; 1132 1133 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 1134 key_type, auth, smp->tk, smp->enc_key_size, 1135 0, 0); 1136 } 1137 1138 static void sc_generate_link_key(struct smp_chan *smp) 1139 { 1140 /* From core spec. Spells out in ASCII as 'lebr'. */ 1141 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c }; 1142 1143 smp->link_key = kzalloc(16, GFP_KERNEL); 1144 if (!smp->link_key) 1145 return; 1146 1147 if (test_bit(SMP_FLAG_CT2, &smp->flags)) { 1148 /* SALT = 0x000000000000000000000000746D7031 */ 1149 const u8 salt[16] = { 0x31, 0x70, 0x6d, 0x74 }; 1150 1151 if (smp_h7(smp->tfm_cmac, smp->tk, salt, smp->link_key)) { 1152 kzfree(smp->link_key); 1153 smp->link_key = NULL; 1154 return; 1155 } 1156 } else { 1157 /* From core spec. Spells out in ASCII as 'tmp1'. */ 1158 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 }; 1159 1160 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) { 1161 kzfree(smp->link_key); 1162 smp->link_key = NULL; 1163 return; 1164 } 1165 } 1166 1167 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) { 1168 kzfree(smp->link_key); 1169 smp->link_key = NULL; 1170 return; 1171 } 1172 } 1173 1174 static void smp_allow_key_dist(struct smp_chan *smp) 1175 { 1176 /* Allow the first expected phase 3 PDU. The rest of the PDUs 1177 * will be allowed in each PDU handler to ensure we receive 1178 * them in the correct order. 1179 */ 1180 if (smp->remote_key_dist & SMP_DIST_ENC_KEY) 1181 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO); 1182 else if (smp->remote_key_dist & SMP_DIST_ID_KEY) 1183 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); 1184 else if (smp->remote_key_dist & SMP_DIST_SIGN) 1185 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 1186 } 1187 1188 static void sc_generate_ltk(struct smp_chan *smp) 1189 { 1190 /* From core spec. Spells out in ASCII as 'brle'. */ 1191 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 }; 1192 struct hci_conn *hcon = smp->conn->hcon; 1193 struct hci_dev *hdev = hcon->hdev; 1194 struct link_key *key; 1195 1196 key = hci_find_link_key(hdev, &hcon->dst); 1197 if (!key) { 1198 bt_dev_err(hdev, "no Link Key found to generate LTK"); 1199 return; 1200 } 1201 1202 if (key->type == HCI_LK_DEBUG_COMBINATION) 1203 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1204 1205 if (test_bit(SMP_FLAG_CT2, &smp->flags)) { 1206 /* SALT = 0x000000000000000000000000746D7032 */ 1207 const u8 salt[16] = { 0x32, 0x70, 0x6d, 0x74 }; 1208 1209 if (smp_h7(smp->tfm_cmac, key->val, salt, smp->tk)) 1210 return; 1211 } else { 1212 /* From core spec. Spells out in ASCII as 'tmp2'. */ 1213 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 }; 1214 1215 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk)) 1216 return; 1217 } 1218 1219 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk)) 1220 return; 1221 1222 sc_add_ltk(smp); 1223 } 1224 1225 static void smp_distribute_keys(struct smp_chan *smp) 1226 { 1227 struct smp_cmd_pairing *req, *rsp; 1228 struct l2cap_conn *conn = smp->conn; 1229 struct hci_conn *hcon = conn->hcon; 1230 struct hci_dev *hdev = hcon->hdev; 1231 __u8 *keydist; 1232 1233 BT_DBG("conn %p", conn); 1234 1235 rsp = (void *) &smp->prsp[1]; 1236 1237 /* The responder sends its keys first */ 1238 if (hcon->out && (smp->remote_key_dist & KEY_DIST_MASK)) { 1239 smp_allow_key_dist(smp); 1240 return; 1241 } 1242 1243 req = (void *) &smp->preq[1]; 1244 1245 if (hcon->out) { 1246 keydist = &rsp->init_key_dist; 1247 *keydist &= req->init_key_dist; 1248 } else { 1249 keydist = &rsp->resp_key_dist; 1250 *keydist &= req->resp_key_dist; 1251 } 1252 1253 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1254 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY)) 1255 sc_generate_link_key(smp); 1256 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY)) 1257 sc_generate_ltk(smp); 1258 1259 /* Clear the keys which are generated but not distributed */ 1260 *keydist &= ~SMP_SC_NO_DIST; 1261 } 1262 1263 BT_DBG("keydist 0x%x", *keydist); 1264 1265 if (*keydist & SMP_DIST_ENC_KEY) { 1266 struct smp_cmd_encrypt_info enc; 1267 struct smp_cmd_master_ident ident; 1268 struct smp_ltk *ltk; 1269 u8 authenticated; 1270 __le16 ediv; 1271 __le64 rand; 1272 1273 /* Make sure we generate only the significant amount of 1274 * bytes based on the encryption key size, and set the rest 1275 * of the value to zeroes. 1276 */ 1277 get_random_bytes(enc.ltk, smp->enc_key_size); 1278 memset(enc.ltk + smp->enc_key_size, 0, 1279 sizeof(enc.ltk) - smp->enc_key_size); 1280 1281 get_random_bytes(&ediv, sizeof(ediv)); 1282 get_random_bytes(&rand, sizeof(rand)); 1283 1284 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc); 1285 1286 authenticated = hcon->sec_level == BT_SECURITY_HIGH; 1287 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, 1288 SMP_LTK_SLAVE, authenticated, enc.ltk, 1289 smp->enc_key_size, ediv, rand); 1290 smp->slave_ltk = ltk; 1291 1292 ident.ediv = ediv; 1293 ident.rand = rand; 1294 1295 smp_send_cmd(conn, SMP_CMD_MASTER_IDENT, sizeof(ident), &ident); 1296 1297 *keydist &= ~SMP_DIST_ENC_KEY; 1298 } 1299 1300 if (*keydist & SMP_DIST_ID_KEY) { 1301 struct smp_cmd_ident_addr_info addrinfo; 1302 struct smp_cmd_ident_info idinfo; 1303 1304 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk)); 1305 1306 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo); 1307 1308 /* The hci_conn contains the local identity address 1309 * after the connection has been established. 1310 * 1311 * This is true even when the connection has been 1312 * established using a resolvable random address. 1313 */ 1314 bacpy(&addrinfo.bdaddr, &hcon->src); 1315 addrinfo.addr_type = hcon->src_type; 1316 1317 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo), 1318 &addrinfo); 1319 1320 *keydist &= ~SMP_DIST_ID_KEY; 1321 } 1322 1323 if (*keydist & SMP_DIST_SIGN) { 1324 struct smp_cmd_sign_info sign; 1325 struct smp_csrk *csrk; 1326 1327 /* Generate a new random key */ 1328 get_random_bytes(sign.csrk, sizeof(sign.csrk)); 1329 1330 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); 1331 if (csrk) { 1332 if (hcon->sec_level > BT_SECURITY_MEDIUM) 1333 csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED; 1334 else 1335 csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED; 1336 memcpy(csrk->val, sign.csrk, sizeof(csrk->val)); 1337 } 1338 smp->slave_csrk = csrk; 1339 1340 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign); 1341 1342 *keydist &= ~SMP_DIST_SIGN; 1343 } 1344 1345 /* If there are still keys to be received wait for them */ 1346 if (smp->remote_key_dist & KEY_DIST_MASK) { 1347 smp_allow_key_dist(smp); 1348 return; 1349 } 1350 1351 set_bit(SMP_FLAG_COMPLETE, &smp->flags); 1352 smp_notify_keys(conn); 1353 1354 smp_chan_destroy(conn); 1355 } 1356 1357 static void smp_timeout(struct work_struct *work) 1358 { 1359 struct smp_chan *smp = container_of(work, struct smp_chan, 1360 security_timer.work); 1361 struct l2cap_conn *conn = smp->conn; 1362 1363 BT_DBG("conn %p", conn); 1364 1365 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM); 1366 } 1367 1368 static struct smp_chan *smp_chan_create(struct l2cap_conn *conn) 1369 { 1370 struct l2cap_chan *chan = conn->smp; 1371 struct smp_chan *smp; 1372 1373 smp = kzalloc(sizeof(*smp), GFP_ATOMIC); 1374 if (!smp) 1375 return NULL; 1376 1377 smp->tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 1378 if (IS_ERR(smp->tfm_cmac)) { 1379 BT_ERR("Unable to create CMAC crypto context"); 1380 goto zfree_smp; 1381 } 1382 1383 smp->tfm_ecdh = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0); 1384 if (IS_ERR(smp->tfm_ecdh)) { 1385 BT_ERR("Unable to create ECDH crypto context"); 1386 goto free_shash; 1387 } 1388 1389 smp->conn = conn; 1390 chan->data = smp; 1391 1392 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL); 1393 1394 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout); 1395 1396 hci_conn_hold(conn->hcon); 1397 1398 return smp; 1399 1400 free_shash: 1401 crypto_free_shash(smp->tfm_cmac); 1402 zfree_smp: 1403 kzfree(smp); 1404 return NULL; 1405 } 1406 1407 static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16]) 1408 { 1409 struct hci_conn *hcon = smp->conn->hcon; 1410 u8 *na, *nb, a[7], b[7]; 1411 1412 if (hcon->out) { 1413 na = smp->prnd; 1414 nb = smp->rrnd; 1415 } else { 1416 na = smp->rrnd; 1417 nb = smp->prnd; 1418 } 1419 1420 memcpy(a, &hcon->init_addr, 6); 1421 memcpy(b, &hcon->resp_addr, 6); 1422 a[6] = hcon->init_addr_type; 1423 b[6] = hcon->resp_addr_type; 1424 1425 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk); 1426 } 1427 1428 static void sc_dhkey_check(struct smp_chan *smp) 1429 { 1430 struct hci_conn *hcon = smp->conn->hcon; 1431 struct smp_cmd_dhkey_check check; 1432 u8 a[7], b[7], *local_addr, *remote_addr; 1433 u8 io_cap[3], r[16]; 1434 1435 memcpy(a, &hcon->init_addr, 6); 1436 memcpy(b, &hcon->resp_addr, 6); 1437 a[6] = hcon->init_addr_type; 1438 b[6] = hcon->resp_addr_type; 1439 1440 if (hcon->out) { 1441 local_addr = a; 1442 remote_addr = b; 1443 memcpy(io_cap, &smp->preq[1], 3); 1444 } else { 1445 local_addr = b; 1446 remote_addr = a; 1447 memcpy(io_cap, &smp->prsp[1], 3); 1448 } 1449 1450 memset(r, 0, sizeof(r)); 1451 1452 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 1453 put_unaligned_le32(hcon->passkey_notify, r); 1454 1455 if (smp->method == REQ_OOB) 1456 memcpy(r, smp->rr, 16); 1457 1458 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap, 1459 local_addr, remote_addr, check.e); 1460 1461 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check); 1462 } 1463 1464 static u8 sc_passkey_send_confirm(struct smp_chan *smp) 1465 { 1466 struct l2cap_conn *conn = smp->conn; 1467 struct hci_conn *hcon = conn->hcon; 1468 struct smp_cmd_pairing_confirm cfm; 1469 u8 r; 1470 1471 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); 1472 r |= 0x80; 1473 1474 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1475 1476 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r, 1477 cfm.confirm_val)) 1478 return SMP_UNSPECIFIED; 1479 1480 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); 1481 1482 return 0; 1483 } 1484 1485 static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op) 1486 { 1487 struct l2cap_conn *conn = smp->conn; 1488 struct hci_conn *hcon = conn->hcon; 1489 struct hci_dev *hdev = hcon->hdev; 1490 u8 cfm[16], r; 1491 1492 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */ 1493 if (smp->passkey_round >= 20) 1494 return 0; 1495 1496 switch (smp_op) { 1497 case SMP_CMD_PAIRING_RANDOM: 1498 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); 1499 r |= 0x80; 1500 1501 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, 1502 smp->rrnd, r, cfm)) 1503 return SMP_UNSPECIFIED; 1504 1505 if (crypto_memneq(smp->pcnf, cfm, 16)) 1506 return SMP_CONFIRM_FAILED; 1507 1508 smp->passkey_round++; 1509 1510 if (smp->passkey_round == 20) { 1511 /* Generate MacKey and LTK */ 1512 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk)) 1513 return SMP_UNSPECIFIED; 1514 } 1515 1516 /* The round is only complete when the initiator 1517 * receives pairing random. 1518 */ 1519 if (!hcon->out) { 1520 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 1521 sizeof(smp->prnd), smp->prnd); 1522 if (smp->passkey_round == 20) 1523 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1524 else 1525 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1526 return 0; 1527 } 1528 1529 /* Start the next round */ 1530 if (smp->passkey_round != 20) 1531 return sc_passkey_round(smp, 0); 1532 1533 /* Passkey rounds are complete - start DHKey Check */ 1534 sc_dhkey_check(smp); 1535 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1536 1537 break; 1538 1539 case SMP_CMD_PAIRING_CONFIRM: 1540 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { 1541 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 1542 return 0; 1543 } 1544 1545 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 1546 1547 if (hcon->out) { 1548 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 1549 sizeof(smp->prnd), smp->prnd); 1550 return 0; 1551 } 1552 1553 return sc_passkey_send_confirm(smp); 1554 1555 case SMP_CMD_PUBLIC_KEY: 1556 default: 1557 /* Initiating device starts the round */ 1558 if (!hcon->out) 1559 return 0; 1560 1561 BT_DBG("%s Starting passkey round %u", hdev->name, 1562 smp->passkey_round + 1); 1563 1564 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1565 1566 return sc_passkey_send_confirm(smp); 1567 } 1568 1569 return 0; 1570 } 1571 1572 static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey) 1573 { 1574 struct l2cap_conn *conn = smp->conn; 1575 struct hci_conn *hcon = conn->hcon; 1576 u8 smp_op; 1577 1578 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags); 1579 1580 switch (mgmt_op) { 1581 case MGMT_OP_USER_PASSKEY_NEG_REPLY: 1582 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED); 1583 return 0; 1584 case MGMT_OP_USER_CONFIRM_NEG_REPLY: 1585 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED); 1586 return 0; 1587 case MGMT_OP_USER_PASSKEY_REPLY: 1588 hcon->passkey_notify = le32_to_cpu(passkey); 1589 smp->passkey_round = 0; 1590 1591 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) 1592 smp_op = SMP_CMD_PAIRING_CONFIRM; 1593 else 1594 smp_op = 0; 1595 1596 if (sc_passkey_round(smp, smp_op)) 1597 return -EIO; 1598 1599 return 0; 1600 } 1601 1602 /* Initiator sends DHKey check first */ 1603 if (hcon->out) { 1604 sc_dhkey_check(smp); 1605 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1606 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) { 1607 sc_dhkey_check(smp); 1608 sc_add_ltk(smp); 1609 } 1610 1611 return 0; 1612 } 1613 1614 int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey) 1615 { 1616 struct l2cap_conn *conn = hcon->l2cap_data; 1617 struct l2cap_chan *chan; 1618 struct smp_chan *smp; 1619 u32 value; 1620 int err; 1621 1622 BT_DBG(""); 1623 1624 if (!conn) 1625 return -ENOTCONN; 1626 1627 chan = conn->smp; 1628 if (!chan) 1629 return -ENOTCONN; 1630 1631 l2cap_chan_lock(chan); 1632 if (!chan->data) { 1633 err = -ENOTCONN; 1634 goto unlock; 1635 } 1636 1637 smp = chan->data; 1638 1639 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1640 err = sc_user_reply(smp, mgmt_op, passkey); 1641 goto unlock; 1642 } 1643 1644 switch (mgmt_op) { 1645 case MGMT_OP_USER_PASSKEY_REPLY: 1646 value = le32_to_cpu(passkey); 1647 memset(smp->tk, 0, sizeof(smp->tk)); 1648 BT_DBG("PassKey: %d", value); 1649 put_unaligned_le32(value, smp->tk); 1650 /* Fall Through */ 1651 case MGMT_OP_USER_CONFIRM_REPLY: 1652 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 1653 break; 1654 case MGMT_OP_USER_PASSKEY_NEG_REPLY: 1655 case MGMT_OP_USER_CONFIRM_NEG_REPLY: 1656 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); 1657 err = 0; 1658 goto unlock; 1659 default: 1660 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); 1661 err = -EOPNOTSUPP; 1662 goto unlock; 1663 } 1664 1665 err = 0; 1666 1667 /* If it is our turn to send Pairing Confirm, do so now */ 1668 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) { 1669 u8 rsp = smp_confirm(smp); 1670 if (rsp) 1671 smp_failure(conn, rsp); 1672 } 1673 1674 unlock: 1675 l2cap_chan_unlock(chan); 1676 return err; 1677 } 1678 1679 static void build_bredr_pairing_cmd(struct smp_chan *smp, 1680 struct smp_cmd_pairing *req, 1681 struct smp_cmd_pairing *rsp) 1682 { 1683 struct l2cap_conn *conn = smp->conn; 1684 struct hci_dev *hdev = conn->hcon->hdev; 1685 u8 local_dist = 0, remote_dist = 0; 1686 1687 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { 1688 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 1689 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 1690 } 1691 1692 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) 1693 remote_dist |= SMP_DIST_ID_KEY; 1694 1695 if (hci_dev_test_flag(hdev, HCI_PRIVACY)) 1696 local_dist |= SMP_DIST_ID_KEY; 1697 1698 if (!rsp) { 1699 memset(req, 0, sizeof(*req)); 1700 1701 req->auth_req = SMP_AUTH_CT2; 1702 req->init_key_dist = local_dist; 1703 req->resp_key_dist = remote_dist; 1704 req->max_key_size = conn->hcon->enc_key_size; 1705 1706 smp->remote_key_dist = remote_dist; 1707 1708 return; 1709 } 1710 1711 memset(rsp, 0, sizeof(*rsp)); 1712 1713 rsp->auth_req = SMP_AUTH_CT2; 1714 rsp->max_key_size = conn->hcon->enc_key_size; 1715 rsp->init_key_dist = req->init_key_dist & remote_dist; 1716 rsp->resp_key_dist = req->resp_key_dist & local_dist; 1717 1718 smp->remote_key_dist = rsp->init_key_dist; 1719 } 1720 1721 static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) 1722 { 1723 struct smp_cmd_pairing rsp, *req = (void *) skb->data; 1724 struct l2cap_chan *chan = conn->smp; 1725 struct hci_dev *hdev = conn->hcon->hdev; 1726 struct smp_chan *smp; 1727 u8 key_size, auth, sec_level; 1728 int ret; 1729 1730 BT_DBG("conn %p", conn); 1731 1732 if (skb->len < sizeof(*req)) 1733 return SMP_INVALID_PARAMS; 1734 1735 if (conn->hcon->role != HCI_ROLE_SLAVE) 1736 return SMP_CMD_NOTSUPP; 1737 1738 if (!chan->data) 1739 smp = smp_chan_create(conn); 1740 else 1741 smp = chan->data; 1742 1743 if (!smp) 1744 return SMP_UNSPECIFIED; 1745 1746 /* We didn't start the pairing, so match remote */ 1747 auth = req->auth_req & AUTH_REQ_MASK(hdev); 1748 1749 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && 1750 (auth & SMP_AUTH_BONDING)) 1751 return SMP_PAIRING_NOTSUPP; 1752 1753 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 1754 return SMP_AUTH_REQUIREMENTS; 1755 1756 smp->preq[0] = SMP_CMD_PAIRING_REQ; 1757 memcpy(&smp->preq[1], req, sizeof(*req)); 1758 skb_pull(skb, sizeof(*req)); 1759 1760 /* If the remote side's OOB flag is set it means it has 1761 * successfully received our local OOB data - therefore set the 1762 * flag to indicate that local OOB is in use. 1763 */ 1764 if (req->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob) 1765 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); 1766 1767 /* SMP over BR/EDR requires special treatment */ 1768 if (conn->hcon->type == ACL_LINK) { 1769 /* We must have a BR/EDR SC link */ 1770 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) && 1771 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 1772 return SMP_CROSS_TRANSP_NOT_ALLOWED; 1773 1774 set_bit(SMP_FLAG_SC, &smp->flags); 1775 1776 build_bredr_pairing_cmd(smp, req, &rsp); 1777 1778 if (req->auth_req & SMP_AUTH_CT2) 1779 set_bit(SMP_FLAG_CT2, &smp->flags); 1780 1781 key_size = min(req->max_key_size, rsp.max_key_size); 1782 if (check_enc_key_size(conn, key_size)) 1783 return SMP_ENC_KEY_SIZE; 1784 1785 /* Clear bits which are generated but not distributed */ 1786 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1787 1788 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1789 memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); 1790 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); 1791 1792 smp_distribute_keys(smp); 1793 return 0; 1794 } 1795 1796 build_pairing_cmd(conn, req, &rsp, auth); 1797 1798 if (rsp.auth_req & SMP_AUTH_SC) { 1799 set_bit(SMP_FLAG_SC, &smp->flags); 1800 1801 if (rsp.auth_req & SMP_AUTH_CT2) 1802 set_bit(SMP_FLAG_CT2, &smp->flags); 1803 } 1804 1805 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 1806 sec_level = BT_SECURITY_MEDIUM; 1807 else 1808 sec_level = authreq_to_seclevel(auth); 1809 1810 if (sec_level > conn->hcon->pending_sec_level) 1811 conn->hcon->pending_sec_level = sec_level; 1812 1813 /* If we need MITM check that it can be achieved */ 1814 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { 1815 u8 method; 1816 1817 method = get_auth_method(smp, conn->hcon->io_capability, 1818 req->io_capability); 1819 if (method == JUST_WORKS || method == JUST_CFM) 1820 return SMP_AUTH_REQUIREMENTS; 1821 } 1822 1823 key_size = min(req->max_key_size, rsp.max_key_size); 1824 if (check_enc_key_size(conn, key_size)) 1825 return SMP_ENC_KEY_SIZE; 1826 1827 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1828 1829 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1830 memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); 1831 1832 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); 1833 1834 clear_bit(SMP_FLAG_INITIATOR, &smp->flags); 1835 1836 /* Strictly speaking we shouldn't allow Pairing Confirm for the 1837 * SC case, however some implementations incorrectly copy RFU auth 1838 * req bits from our security request, which may create a false 1839 * positive SC enablement. 1840 */ 1841 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1842 1843 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1844 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); 1845 /* Clear bits which are generated but not distributed */ 1846 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1847 /* Wait for Public Key from Initiating Device */ 1848 return 0; 1849 } 1850 1851 /* Request setup of TK */ 1852 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability); 1853 if (ret) 1854 return SMP_UNSPECIFIED; 1855 1856 return 0; 1857 } 1858 1859 static u8 sc_send_public_key(struct smp_chan *smp) 1860 { 1861 struct hci_dev *hdev = smp->conn->hcon->hdev; 1862 1863 BT_DBG(""); 1864 1865 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { 1866 struct l2cap_chan *chan = hdev->smp_data; 1867 struct smp_dev *smp_dev; 1868 1869 if (!chan || !chan->data) 1870 return SMP_UNSPECIFIED; 1871 1872 smp_dev = chan->data; 1873 1874 memcpy(smp->local_pk, smp_dev->local_pk, 64); 1875 memcpy(smp->lr, smp_dev->local_rand, 16); 1876 1877 if (smp_dev->debug_key) 1878 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1879 1880 goto done; 1881 } 1882 1883 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { 1884 BT_DBG("Using debug keys"); 1885 if (set_ecdh_privkey(smp->tfm_ecdh, debug_sk)) 1886 return SMP_UNSPECIFIED; 1887 memcpy(smp->local_pk, debug_pk, 64); 1888 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1889 } else { 1890 while (true) { 1891 /* Generate key pair for Secure Connections */ 1892 if (generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk)) 1893 return SMP_UNSPECIFIED; 1894 1895 /* This is unlikely, but we need to check that 1896 * we didn't accidentially generate a debug key. 1897 */ 1898 if (crypto_memneq(smp->local_pk, debug_pk, 64)) 1899 break; 1900 } 1901 } 1902 1903 done: 1904 SMP_DBG("Local Public Key X: %32phN", smp->local_pk); 1905 SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32); 1906 1907 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk); 1908 1909 return 0; 1910 } 1911 1912 static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) 1913 { 1914 struct smp_cmd_pairing *req, *rsp = (void *) skb->data; 1915 struct l2cap_chan *chan = conn->smp; 1916 struct smp_chan *smp = chan->data; 1917 struct hci_dev *hdev = conn->hcon->hdev; 1918 u8 key_size, auth; 1919 int ret; 1920 1921 BT_DBG("conn %p", conn); 1922 1923 if (skb->len < sizeof(*rsp)) 1924 return SMP_INVALID_PARAMS; 1925 1926 if (conn->hcon->role != HCI_ROLE_MASTER) 1927 return SMP_CMD_NOTSUPP; 1928 1929 skb_pull(skb, sizeof(*rsp)); 1930 1931 req = (void *) &smp->preq[1]; 1932 1933 key_size = min(req->max_key_size, rsp->max_key_size); 1934 if (check_enc_key_size(conn, key_size)) 1935 return SMP_ENC_KEY_SIZE; 1936 1937 auth = rsp->auth_req & AUTH_REQ_MASK(hdev); 1938 1939 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 1940 return SMP_AUTH_REQUIREMENTS; 1941 1942 /* If the remote side's OOB flag is set it means it has 1943 * successfully received our local OOB data - therefore set the 1944 * flag to indicate that local OOB is in use. 1945 */ 1946 if (rsp->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob) 1947 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); 1948 1949 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1950 memcpy(&smp->prsp[1], rsp, sizeof(*rsp)); 1951 1952 /* Update remote key distribution in case the remote cleared 1953 * some bits that we had enabled in our request. 1954 */ 1955 smp->remote_key_dist &= rsp->resp_key_dist; 1956 1957 if ((req->auth_req & SMP_AUTH_CT2) && (auth & SMP_AUTH_CT2)) 1958 set_bit(SMP_FLAG_CT2, &smp->flags); 1959 1960 /* For BR/EDR this means we're done and can start phase 3 */ 1961 if (conn->hcon->type == ACL_LINK) { 1962 /* Clear bits which are generated but not distributed */ 1963 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1964 smp_distribute_keys(smp); 1965 return 0; 1966 } 1967 1968 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC)) 1969 set_bit(SMP_FLAG_SC, &smp->flags); 1970 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH) 1971 conn->hcon->pending_sec_level = BT_SECURITY_HIGH; 1972 1973 /* If we need MITM check that it can be achieved */ 1974 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { 1975 u8 method; 1976 1977 method = get_auth_method(smp, req->io_capability, 1978 rsp->io_capability); 1979 if (method == JUST_WORKS || method == JUST_CFM) 1980 return SMP_AUTH_REQUIREMENTS; 1981 } 1982 1983 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1984 1985 /* Update remote key distribution in case the remote cleared 1986 * some bits that we had enabled in our request. 1987 */ 1988 smp->remote_key_dist &= rsp->resp_key_dist; 1989 1990 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1991 /* Clear bits which are generated but not distributed */ 1992 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1993 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); 1994 return sc_send_public_key(smp); 1995 } 1996 1997 auth |= req->auth_req; 1998 1999 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability); 2000 if (ret) 2001 return SMP_UNSPECIFIED; 2002 2003 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 2004 2005 /* Can't compose response until we have been confirmed */ 2006 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) 2007 return smp_confirm(smp); 2008 2009 return 0; 2010 } 2011 2012 static u8 sc_check_confirm(struct smp_chan *smp) 2013 { 2014 struct l2cap_conn *conn = smp->conn; 2015 2016 BT_DBG(""); 2017 2018 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2019 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM); 2020 2021 if (conn->hcon->out) { 2022 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2023 smp->prnd); 2024 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2025 } 2026 2027 return 0; 2028 } 2029 2030 /* Work-around for some implementations that incorrectly copy RFU bits 2031 * from our security request and thereby create the impression that 2032 * we're doing SC when in fact the remote doesn't support it. 2033 */ 2034 static int fixup_sc_false_positive(struct smp_chan *smp) 2035 { 2036 struct l2cap_conn *conn = smp->conn; 2037 struct hci_conn *hcon = conn->hcon; 2038 struct hci_dev *hdev = hcon->hdev; 2039 struct smp_cmd_pairing *req, *rsp; 2040 u8 auth; 2041 2042 /* The issue is only observed when we're in slave role */ 2043 if (hcon->out) 2044 return SMP_UNSPECIFIED; 2045 2046 if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) { 2047 bt_dev_err(hdev, "refusing legacy fallback in SC-only mode"); 2048 return SMP_UNSPECIFIED; 2049 } 2050 2051 bt_dev_err(hdev, "trying to fall back to legacy SMP"); 2052 2053 req = (void *) &smp->preq[1]; 2054 rsp = (void *) &smp->prsp[1]; 2055 2056 /* Rebuild key dist flags which may have been cleared for SC */ 2057 smp->remote_key_dist = (req->init_key_dist & rsp->resp_key_dist); 2058 2059 auth = req->auth_req & AUTH_REQ_MASK(hdev); 2060 2061 if (tk_request(conn, 0, auth, rsp->io_capability, req->io_capability)) { 2062 bt_dev_err(hdev, "failed to fall back to legacy SMP"); 2063 return SMP_UNSPECIFIED; 2064 } 2065 2066 clear_bit(SMP_FLAG_SC, &smp->flags); 2067 2068 return 0; 2069 } 2070 2071 static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb) 2072 { 2073 struct l2cap_chan *chan = conn->smp; 2074 struct smp_chan *smp = chan->data; 2075 2076 BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave"); 2077 2078 if (skb->len < sizeof(smp->pcnf)) 2079 return SMP_INVALID_PARAMS; 2080 2081 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf)); 2082 skb_pull(skb, sizeof(smp->pcnf)); 2083 2084 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 2085 int ret; 2086 2087 /* Public Key exchange must happen before any other steps */ 2088 if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags)) 2089 return sc_check_confirm(smp); 2090 2091 BT_ERR("Unexpected SMP Pairing Confirm"); 2092 2093 ret = fixup_sc_false_positive(smp); 2094 if (ret) 2095 return ret; 2096 } 2097 2098 if (conn->hcon->out) { 2099 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2100 smp->prnd); 2101 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2102 return 0; 2103 } 2104 2105 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) 2106 return smp_confirm(smp); 2107 2108 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 2109 2110 return 0; 2111 } 2112 2113 static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb) 2114 { 2115 struct l2cap_chan *chan = conn->smp; 2116 struct smp_chan *smp = chan->data; 2117 struct hci_conn *hcon = conn->hcon; 2118 u8 *pkax, *pkbx, *na, *nb, confirm_hint; 2119 u32 passkey; 2120 int err; 2121 2122 BT_DBG("conn %p", conn); 2123 2124 if (skb->len < sizeof(smp->rrnd)) 2125 return SMP_INVALID_PARAMS; 2126 2127 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd)); 2128 skb_pull(skb, sizeof(smp->rrnd)); 2129 2130 if (!test_bit(SMP_FLAG_SC, &smp->flags)) 2131 return smp_random(smp); 2132 2133 if (hcon->out) { 2134 pkax = smp->local_pk; 2135 pkbx = smp->remote_pk; 2136 na = smp->prnd; 2137 nb = smp->rrnd; 2138 } else { 2139 pkax = smp->remote_pk; 2140 pkbx = smp->local_pk; 2141 na = smp->rrnd; 2142 nb = smp->prnd; 2143 } 2144 2145 if (smp->method == REQ_OOB) { 2146 if (!hcon->out) 2147 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 2148 sizeof(smp->prnd), smp->prnd); 2149 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2150 goto mackey_and_ltk; 2151 } 2152 2153 /* Passkey entry has special treatment */ 2154 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2155 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM); 2156 2157 if (hcon->out) { 2158 u8 cfm[16]; 2159 2160 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, 2161 smp->rrnd, 0, cfm); 2162 if (err) 2163 return SMP_UNSPECIFIED; 2164 2165 if (crypto_memneq(smp->pcnf, cfm, 16)) 2166 return SMP_CONFIRM_FAILED; 2167 } else { 2168 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2169 smp->prnd); 2170 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2171 2172 /* Only Just-Works pairing requires extra checks */ 2173 if (smp->method != JUST_WORKS) 2174 goto mackey_and_ltk; 2175 2176 /* If there already exists long term key in local host, leave 2177 * the decision to user space since the remote device could 2178 * be legitimate or malicious. 2179 */ 2180 if (hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 2181 hcon->role)) { 2182 /* Set passkey to 0. The value can be any number since 2183 * it'll be ignored anyway. 2184 */ 2185 passkey = 0; 2186 confirm_hint = 1; 2187 goto confirm; 2188 } 2189 } 2190 2191 mackey_and_ltk: 2192 /* Generate MacKey and LTK */ 2193 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk); 2194 if (err) 2195 return SMP_UNSPECIFIED; 2196 2197 if (smp->method == JUST_WORKS || smp->method == REQ_OOB) { 2198 if (hcon->out) { 2199 sc_dhkey_check(smp); 2200 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2201 } 2202 return 0; 2203 } 2204 2205 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey); 2206 if (err) 2207 return SMP_UNSPECIFIED; 2208 2209 confirm_hint = 0; 2210 2211 confirm: 2212 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type, 2213 hcon->dst_type, passkey, confirm_hint); 2214 if (err) 2215 return SMP_UNSPECIFIED; 2216 2217 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 2218 2219 return 0; 2220 } 2221 2222 static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level) 2223 { 2224 struct smp_ltk *key; 2225 struct hci_conn *hcon = conn->hcon; 2226 2227 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role); 2228 if (!key) 2229 return false; 2230 2231 if (smp_ltk_sec_level(key) < sec_level) 2232 return false; 2233 2234 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) 2235 return true; 2236 2237 hci_le_start_enc(hcon, key->ediv, key->rand, key->val, key->enc_size); 2238 hcon->enc_key_size = key->enc_size; 2239 2240 /* We never store STKs for master role, so clear this flag */ 2241 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); 2242 2243 return true; 2244 } 2245 2246 bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level, 2247 enum smp_key_pref key_pref) 2248 { 2249 if (sec_level == BT_SECURITY_LOW) 2250 return true; 2251 2252 /* If we're encrypted with an STK but the caller prefers using 2253 * LTK claim insufficient security. This way we allow the 2254 * connection to be re-encrypted with an LTK, even if the LTK 2255 * provides the same level of security. Only exception is if we 2256 * don't have an LTK (e.g. because of key distribution bits). 2257 */ 2258 if (key_pref == SMP_USE_LTK && 2259 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) && 2260 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role)) 2261 return false; 2262 2263 if (hcon->sec_level >= sec_level) 2264 return true; 2265 2266 return false; 2267 } 2268 2269 static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb) 2270 { 2271 struct smp_cmd_security_req *rp = (void *) skb->data; 2272 struct smp_cmd_pairing cp; 2273 struct hci_conn *hcon = conn->hcon; 2274 struct hci_dev *hdev = hcon->hdev; 2275 struct smp_chan *smp; 2276 u8 sec_level, auth; 2277 2278 BT_DBG("conn %p", conn); 2279 2280 if (skb->len < sizeof(*rp)) 2281 return SMP_INVALID_PARAMS; 2282 2283 if (hcon->role != HCI_ROLE_MASTER) 2284 return SMP_CMD_NOTSUPP; 2285 2286 auth = rp->auth_req & AUTH_REQ_MASK(hdev); 2287 2288 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 2289 return SMP_AUTH_REQUIREMENTS; 2290 2291 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 2292 sec_level = BT_SECURITY_MEDIUM; 2293 else 2294 sec_level = authreq_to_seclevel(auth); 2295 2296 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) { 2297 /* If link is already encrypted with sufficient security we 2298 * still need refresh encryption as per Core Spec 5.0 Vol 3, 2299 * Part H 2.4.6 2300 */ 2301 smp_ltk_encrypt(conn, hcon->sec_level); 2302 return 0; 2303 } 2304 2305 if (sec_level > hcon->pending_sec_level) 2306 hcon->pending_sec_level = sec_level; 2307 2308 if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) 2309 return 0; 2310 2311 smp = smp_chan_create(conn); 2312 if (!smp) 2313 return SMP_UNSPECIFIED; 2314 2315 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && 2316 (auth & SMP_AUTH_BONDING)) 2317 return SMP_PAIRING_NOTSUPP; 2318 2319 skb_pull(skb, sizeof(*rp)); 2320 2321 memset(&cp, 0, sizeof(cp)); 2322 build_pairing_cmd(conn, &cp, NULL, auth); 2323 2324 smp->preq[0] = SMP_CMD_PAIRING_REQ; 2325 memcpy(&smp->preq[1], &cp, sizeof(cp)); 2326 2327 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); 2328 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 2329 2330 return 0; 2331 } 2332 2333 int smp_conn_security(struct hci_conn *hcon, __u8 sec_level) 2334 { 2335 struct l2cap_conn *conn = hcon->l2cap_data; 2336 struct l2cap_chan *chan; 2337 struct smp_chan *smp; 2338 __u8 authreq; 2339 int ret; 2340 2341 BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level); 2342 2343 /* This may be NULL if there's an unexpected disconnection */ 2344 if (!conn) 2345 return 1; 2346 2347 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) 2348 return 1; 2349 2350 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) 2351 return 1; 2352 2353 if (sec_level > hcon->pending_sec_level) 2354 hcon->pending_sec_level = sec_level; 2355 2356 if (hcon->role == HCI_ROLE_MASTER) 2357 if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) 2358 return 0; 2359 2360 chan = conn->smp; 2361 if (!chan) { 2362 bt_dev_err(hcon->hdev, "security requested but not available"); 2363 return 1; 2364 } 2365 2366 l2cap_chan_lock(chan); 2367 2368 /* If SMP is already in progress ignore this request */ 2369 if (chan->data) { 2370 ret = 0; 2371 goto unlock; 2372 } 2373 2374 smp = smp_chan_create(conn); 2375 if (!smp) { 2376 ret = 1; 2377 goto unlock; 2378 } 2379 2380 authreq = seclevel_to_authreq(sec_level); 2381 2382 if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED)) { 2383 authreq |= SMP_AUTH_SC; 2384 if (hci_dev_test_flag(hcon->hdev, HCI_SSP_ENABLED)) 2385 authreq |= SMP_AUTH_CT2; 2386 } 2387 2388 /* Require MITM if IO Capability allows or the security level 2389 * requires it. 2390 */ 2391 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT || 2392 hcon->pending_sec_level > BT_SECURITY_MEDIUM) 2393 authreq |= SMP_AUTH_MITM; 2394 2395 if (hcon->role == HCI_ROLE_MASTER) { 2396 struct smp_cmd_pairing cp; 2397 2398 build_pairing_cmd(conn, &cp, NULL, authreq); 2399 smp->preq[0] = SMP_CMD_PAIRING_REQ; 2400 memcpy(&smp->preq[1], &cp, sizeof(cp)); 2401 2402 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); 2403 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 2404 } else { 2405 struct smp_cmd_security_req cp; 2406 cp.auth_req = authreq; 2407 smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp); 2408 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ); 2409 } 2410 2411 set_bit(SMP_FLAG_INITIATOR, &smp->flags); 2412 ret = 0; 2413 2414 unlock: 2415 l2cap_chan_unlock(chan); 2416 return ret; 2417 } 2418 2419 int smp_cancel_and_remove_pairing(struct hci_dev *hdev, bdaddr_t *bdaddr, 2420 u8 addr_type) 2421 { 2422 struct hci_conn *hcon; 2423 struct l2cap_conn *conn; 2424 struct l2cap_chan *chan; 2425 struct smp_chan *smp; 2426 int err; 2427 2428 err = hci_remove_ltk(hdev, bdaddr, addr_type); 2429 hci_remove_irk(hdev, bdaddr, addr_type); 2430 2431 hcon = hci_conn_hash_lookup_le(hdev, bdaddr, addr_type); 2432 if (!hcon) 2433 goto done; 2434 2435 conn = hcon->l2cap_data; 2436 if (!conn) 2437 goto done; 2438 2439 chan = conn->smp; 2440 if (!chan) 2441 goto done; 2442 2443 l2cap_chan_lock(chan); 2444 2445 smp = chan->data; 2446 if (smp) { 2447 /* Set keys to NULL to make sure smp_failure() does not try to 2448 * remove and free already invalidated rcu list entries. */ 2449 smp->ltk = NULL; 2450 smp->slave_ltk = NULL; 2451 smp->remote_irk = NULL; 2452 2453 if (test_bit(SMP_FLAG_COMPLETE, &smp->flags)) 2454 smp_failure(conn, 0); 2455 else 2456 smp_failure(conn, SMP_UNSPECIFIED); 2457 err = 0; 2458 } 2459 2460 l2cap_chan_unlock(chan); 2461 2462 done: 2463 return err; 2464 } 2465 2466 static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb) 2467 { 2468 struct smp_cmd_encrypt_info *rp = (void *) skb->data; 2469 struct l2cap_chan *chan = conn->smp; 2470 struct smp_chan *smp = chan->data; 2471 2472 BT_DBG("conn %p", conn); 2473 2474 if (skb->len < sizeof(*rp)) 2475 return SMP_INVALID_PARAMS; 2476 2477 /* Pairing is aborted if any blocked keys are distributed */ 2478 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_LTK, 2479 rp->ltk)) { 2480 bt_dev_warn_ratelimited(conn->hcon->hdev, 2481 "LTK blocked for %pMR", 2482 &conn->hcon->dst); 2483 return SMP_INVALID_PARAMS; 2484 } 2485 2486 SMP_ALLOW_CMD(smp, SMP_CMD_MASTER_IDENT); 2487 2488 skb_pull(skb, sizeof(*rp)); 2489 2490 memcpy(smp->tk, rp->ltk, sizeof(smp->tk)); 2491 2492 return 0; 2493 } 2494 2495 static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb) 2496 { 2497 struct smp_cmd_master_ident *rp = (void *) skb->data; 2498 struct l2cap_chan *chan = conn->smp; 2499 struct smp_chan *smp = chan->data; 2500 struct hci_dev *hdev = conn->hcon->hdev; 2501 struct hci_conn *hcon = conn->hcon; 2502 struct smp_ltk *ltk; 2503 u8 authenticated; 2504 2505 BT_DBG("conn %p", conn); 2506 2507 if (skb->len < sizeof(*rp)) 2508 return SMP_INVALID_PARAMS; 2509 2510 /* Mark the information as received */ 2511 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY; 2512 2513 if (smp->remote_key_dist & SMP_DIST_ID_KEY) 2514 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); 2515 else if (smp->remote_key_dist & SMP_DIST_SIGN) 2516 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 2517 2518 skb_pull(skb, sizeof(*rp)); 2519 2520 authenticated = (hcon->sec_level == BT_SECURITY_HIGH); 2521 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK, 2522 authenticated, smp->tk, smp->enc_key_size, 2523 rp->ediv, rp->rand); 2524 smp->ltk = ltk; 2525 if (!(smp->remote_key_dist & KEY_DIST_MASK)) 2526 smp_distribute_keys(smp); 2527 2528 return 0; 2529 } 2530 2531 static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb) 2532 { 2533 struct smp_cmd_ident_info *info = (void *) skb->data; 2534 struct l2cap_chan *chan = conn->smp; 2535 struct smp_chan *smp = chan->data; 2536 2537 BT_DBG(""); 2538 2539 if (skb->len < sizeof(*info)) 2540 return SMP_INVALID_PARAMS; 2541 2542 /* Pairing is aborted if any blocked keys are distributed */ 2543 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_IRK, 2544 info->irk)) { 2545 bt_dev_warn_ratelimited(conn->hcon->hdev, 2546 "Identity key blocked for %pMR", 2547 &conn->hcon->dst); 2548 return SMP_INVALID_PARAMS; 2549 } 2550 2551 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO); 2552 2553 skb_pull(skb, sizeof(*info)); 2554 2555 memcpy(smp->irk, info->irk, 16); 2556 2557 return 0; 2558 } 2559 2560 static int smp_cmd_ident_addr_info(struct l2cap_conn *conn, 2561 struct sk_buff *skb) 2562 { 2563 struct smp_cmd_ident_addr_info *info = (void *) skb->data; 2564 struct l2cap_chan *chan = conn->smp; 2565 struct smp_chan *smp = chan->data; 2566 struct hci_conn *hcon = conn->hcon; 2567 bdaddr_t rpa; 2568 2569 BT_DBG(""); 2570 2571 if (skb->len < sizeof(*info)) 2572 return SMP_INVALID_PARAMS; 2573 2574 /* Mark the information as received */ 2575 smp->remote_key_dist &= ~SMP_DIST_ID_KEY; 2576 2577 if (smp->remote_key_dist & SMP_DIST_SIGN) 2578 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 2579 2580 skb_pull(skb, sizeof(*info)); 2581 2582 /* Strictly speaking the Core Specification (4.1) allows sending 2583 * an empty address which would force us to rely on just the IRK 2584 * as "identity information". However, since such 2585 * implementations are not known of and in order to not over 2586 * complicate our implementation, simply pretend that we never 2587 * received an IRK for such a device. 2588 * 2589 * The Identity Address must also be a Static Random or Public 2590 * Address, which hci_is_identity_address() checks for. 2591 */ 2592 if (!bacmp(&info->bdaddr, BDADDR_ANY) || 2593 !hci_is_identity_address(&info->bdaddr, info->addr_type)) { 2594 bt_dev_err(hcon->hdev, "ignoring IRK with no identity address"); 2595 goto distribute; 2596 } 2597 2598 /* Drop IRK if peer is using identity address during pairing but is 2599 * providing different address as identity information. 2600 * 2601 * Microsoft Surface Precision Mouse is known to have this bug. 2602 */ 2603 if (hci_is_identity_address(&hcon->dst, hcon->dst_type) && 2604 (bacmp(&info->bdaddr, &hcon->dst) || 2605 info->addr_type != hcon->dst_type)) { 2606 bt_dev_err(hcon->hdev, 2607 "ignoring IRK with invalid identity address"); 2608 goto distribute; 2609 } 2610 2611 bacpy(&smp->id_addr, &info->bdaddr); 2612 smp->id_addr_type = info->addr_type; 2613 2614 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type)) 2615 bacpy(&rpa, &hcon->dst); 2616 else 2617 bacpy(&rpa, BDADDR_ANY); 2618 2619 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr, 2620 smp->id_addr_type, smp->irk, &rpa); 2621 2622 distribute: 2623 if (!(smp->remote_key_dist & KEY_DIST_MASK)) 2624 smp_distribute_keys(smp); 2625 2626 return 0; 2627 } 2628 2629 static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb) 2630 { 2631 struct smp_cmd_sign_info *rp = (void *) skb->data; 2632 struct l2cap_chan *chan = conn->smp; 2633 struct smp_chan *smp = chan->data; 2634 struct smp_csrk *csrk; 2635 2636 BT_DBG("conn %p", conn); 2637 2638 if (skb->len < sizeof(*rp)) 2639 return SMP_INVALID_PARAMS; 2640 2641 /* Mark the information as received */ 2642 smp->remote_key_dist &= ~SMP_DIST_SIGN; 2643 2644 skb_pull(skb, sizeof(*rp)); 2645 2646 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); 2647 if (csrk) { 2648 if (conn->hcon->sec_level > BT_SECURITY_MEDIUM) 2649 csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED; 2650 else 2651 csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED; 2652 memcpy(csrk->val, rp->csrk, sizeof(csrk->val)); 2653 } 2654 smp->csrk = csrk; 2655 smp_distribute_keys(smp); 2656 2657 return 0; 2658 } 2659 2660 static u8 sc_select_method(struct smp_chan *smp) 2661 { 2662 struct l2cap_conn *conn = smp->conn; 2663 struct hci_conn *hcon = conn->hcon; 2664 struct smp_cmd_pairing *local, *remote; 2665 u8 local_mitm, remote_mitm, local_io, remote_io, method; 2666 2667 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) || 2668 test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) 2669 return REQ_OOB; 2670 2671 /* The preq/prsp contain the raw Pairing Request/Response PDUs 2672 * which are needed as inputs to some crypto functions. To get 2673 * the "struct smp_cmd_pairing" from them we need to skip the 2674 * first byte which contains the opcode. 2675 */ 2676 if (hcon->out) { 2677 local = (void *) &smp->preq[1]; 2678 remote = (void *) &smp->prsp[1]; 2679 } else { 2680 local = (void *) &smp->prsp[1]; 2681 remote = (void *) &smp->preq[1]; 2682 } 2683 2684 local_io = local->io_capability; 2685 remote_io = remote->io_capability; 2686 2687 local_mitm = (local->auth_req & SMP_AUTH_MITM); 2688 remote_mitm = (remote->auth_req & SMP_AUTH_MITM); 2689 2690 /* If either side wants MITM, look up the method from the table, 2691 * otherwise use JUST WORKS. 2692 */ 2693 if (local_mitm || remote_mitm) 2694 method = get_auth_method(smp, local_io, remote_io); 2695 else 2696 method = JUST_WORKS; 2697 2698 /* Don't confirm locally initiated pairing attempts */ 2699 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2700 method = JUST_WORKS; 2701 2702 return method; 2703 } 2704 2705 static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb) 2706 { 2707 struct smp_cmd_public_key *key = (void *) skb->data; 2708 struct hci_conn *hcon = conn->hcon; 2709 struct l2cap_chan *chan = conn->smp; 2710 struct smp_chan *smp = chan->data; 2711 struct hci_dev *hdev = hcon->hdev; 2712 struct crypto_kpp *tfm_ecdh; 2713 struct smp_cmd_pairing_confirm cfm; 2714 int err; 2715 2716 BT_DBG("conn %p", conn); 2717 2718 if (skb->len < sizeof(*key)) 2719 return SMP_INVALID_PARAMS; 2720 2721 memcpy(smp->remote_pk, key, 64); 2722 2723 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) { 2724 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk, 2725 smp->rr, 0, cfm.confirm_val); 2726 if (err) 2727 return SMP_UNSPECIFIED; 2728 2729 if (crypto_memneq(cfm.confirm_val, smp->pcnf, 16)) 2730 return SMP_CONFIRM_FAILED; 2731 } 2732 2733 /* Non-initiating device sends its public key after receiving 2734 * the key from the initiating device. 2735 */ 2736 if (!hcon->out) { 2737 err = sc_send_public_key(smp); 2738 if (err) 2739 return err; 2740 } 2741 2742 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk); 2743 SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32); 2744 2745 /* Compute the shared secret on the same crypto tfm on which the private 2746 * key was set/generated. 2747 */ 2748 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { 2749 struct l2cap_chan *hchan = hdev->smp_data; 2750 struct smp_dev *smp_dev; 2751 2752 if (!hchan || !hchan->data) 2753 return SMP_UNSPECIFIED; 2754 2755 smp_dev = hchan->data; 2756 2757 tfm_ecdh = smp_dev->tfm_ecdh; 2758 } else { 2759 tfm_ecdh = smp->tfm_ecdh; 2760 } 2761 2762 if (compute_ecdh_secret(tfm_ecdh, smp->remote_pk, smp->dhkey)) 2763 return SMP_UNSPECIFIED; 2764 2765 SMP_DBG("DHKey %32phN", smp->dhkey); 2766 2767 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags); 2768 2769 smp->method = sc_select_method(smp); 2770 2771 BT_DBG("%s selected method 0x%02x", hdev->name, smp->method); 2772 2773 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */ 2774 if (smp->method == JUST_WORKS || smp->method == JUST_CFM) 2775 hcon->pending_sec_level = BT_SECURITY_MEDIUM; 2776 else 2777 hcon->pending_sec_level = BT_SECURITY_FIPS; 2778 2779 if (!crypto_memneq(debug_pk, smp->remote_pk, 64)) 2780 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 2781 2782 if (smp->method == DSP_PASSKEY) { 2783 get_random_bytes(&hcon->passkey_notify, 2784 sizeof(hcon->passkey_notify)); 2785 hcon->passkey_notify %= 1000000; 2786 hcon->passkey_entered = 0; 2787 smp->passkey_round = 0; 2788 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type, 2789 hcon->dst_type, 2790 hcon->passkey_notify, 2791 hcon->passkey_entered)) 2792 return SMP_UNSPECIFIED; 2793 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2794 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY); 2795 } 2796 2797 if (smp->method == REQ_OOB) { 2798 if (hcon->out) 2799 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 2800 sizeof(smp->prnd), smp->prnd); 2801 2802 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2803 2804 return 0; 2805 } 2806 2807 if (hcon->out) 2808 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2809 2810 if (smp->method == REQ_PASSKEY) { 2811 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type, 2812 hcon->dst_type)) 2813 return SMP_UNSPECIFIED; 2814 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2815 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 2816 return 0; 2817 } 2818 2819 /* The Initiating device waits for the non-initiating device to 2820 * send the confirm value. 2821 */ 2822 if (conn->hcon->out) 2823 return 0; 2824 2825 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, 2826 0, cfm.confirm_val); 2827 if (err) 2828 return SMP_UNSPECIFIED; 2829 2830 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); 2831 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2832 2833 return 0; 2834 } 2835 2836 static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb) 2837 { 2838 struct smp_cmd_dhkey_check *check = (void *) skb->data; 2839 struct l2cap_chan *chan = conn->smp; 2840 struct hci_conn *hcon = conn->hcon; 2841 struct smp_chan *smp = chan->data; 2842 u8 a[7], b[7], *local_addr, *remote_addr; 2843 u8 io_cap[3], r[16], e[16]; 2844 int err; 2845 2846 BT_DBG("conn %p", conn); 2847 2848 if (skb->len < sizeof(*check)) 2849 return SMP_INVALID_PARAMS; 2850 2851 memcpy(a, &hcon->init_addr, 6); 2852 memcpy(b, &hcon->resp_addr, 6); 2853 a[6] = hcon->init_addr_type; 2854 b[6] = hcon->resp_addr_type; 2855 2856 if (hcon->out) { 2857 local_addr = a; 2858 remote_addr = b; 2859 memcpy(io_cap, &smp->prsp[1], 3); 2860 } else { 2861 local_addr = b; 2862 remote_addr = a; 2863 memcpy(io_cap, &smp->preq[1], 3); 2864 } 2865 2866 memset(r, 0, sizeof(r)); 2867 2868 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2869 put_unaligned_le32(hcon->passkey_notify, r); 2870 else if (smp->method == REQ_OOB) 2871 memcpy(r, smp->lr, 16); 2872 2873 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r, 2874 io_cap, remote_addr, local_addr, e); 2875 if (err) 2876 return SMP_UNSPECIFIED; 2877 2878 if (crypto_memneq(check->e, e, 16)) 2879 return SMP_DHKEY_CHECK_FAILED; 2880 2881 if (!hcon->out) { 2882 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { 2883 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags); 2884 return 0; 2885 } 2886 2887 /* Slave sends DHKey check as response to master */ 2888 sc_dhkey_check(smp); 2889 } 2890 2891 sc_add_ltk(smp); 2892 2893 if (hcon->out) { 2894 hci_le_start_enc(hcon, 0, 0, smp->tk, smp->enc_key_size); 2895 hcon->enc_key_size = smp->enc_key_size; 2896 } 2897 2898 return 0; 2899 } 2900 2901 static int smp_cmd_keypress_notify(struct l2cap_conn *conn, 2902 struct sk_buff *skb) 2903 { 2904 struct smp_cmd_keypress_notify *kp = (void *) skb->data; 2905 2906 BT_DBG("value 0x%02x", kp->value); 2907 2908 return 0; 2909 } 2910 2911 static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb) 2912 { 2913 struct l2cap_conn *conn = chan->conn; 2914 struct hci_conn *hcon = conn->hcon; 2915 struct smp_chan *smp; 2916 __u8 code, reason; 2917 int err = 0; 2918 2919 if (skb->len < 1) 2920 return -EILSEQ; 2921 2922 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) { 2923 reason = SMP_PAIRING_NOTSUPP; 2924 goto done; 2925 } 2926 2927 code = skb->data[0]; 2928 skb_pull(skb, sizeof(code)); 2929 2930 smp = chan->data; 2931 2932 if (code > SMP_CMD_MAX) 2933 goto drop; 2934 2935 if (smp && !test_and_clear_bit(code, &smp->allow_cmd)) 2936 goto drop; 2937 2938 /* If we don't have a context the only allowed commands are 2939 * pairing request and security request. 2940 */ 2941 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ) 2942 goto drop; 2943 2944 switch (code) { 2945 case SMP_CMD_PAIRING_REQ: 2946 reason = smp_cmd_pairing_req(conn, skb); 2947 break; 2948 2949 case SMP_CMD_PAIRING_FAIL: 2950 smp_failure(conn, 0); 2951 err = -EPERM; 2952 break; 2953 2954 case SMP_CMD_PAIRING_RSP: 2955 reason = smp_cmd_pairing_rsp(conn, skb); 2956 break; 2957 2958 case SMP_CMD_SECURITY_REQ: 2959 reason = smp_cmd_security_req(conn, skb); 2960 break; 2961 2962 case SMP_CMD_PAIRING_CONFIRM: 2963 reason = smp_cmd_pairing_confirm(conn, skb); 2964 break; 2965 2966 case SMP_CMD_PAIRING_RANDOM: 2967 reason = smp_cmd_pairing_random(conn, skb); 2968 break; 2969 2970 case SMP_CMD_ENCRYPT_INFO: 2971 reason = smp_cmd_encrypt_info(conn, skb); 2972 break; 2973 2974 case SMP_CMD_MASTER_IDENT: 2975 reason = smp_cmd_master_ident(conn, skb); 2976 break; 2977 2978 case SMP_CMD_IDENT_INFO: 2979 reason = smp_cmd_ident_info(conn, skb); 2980 break; 2981 2982 case SMP_CMD_IDENT_ADDR_INFO: 2983 reason = smp_cmd_ident_addr_info(conn, skb); 2984 break; 2985 2986 case SMP_CMD_SIGN_INFO: 2987 reason = smp_cmd_sign_info(conn, skb); 2988 break; 2989 2990 case SMP_CMD_PUBLIC_KEY: 2991 reason = smp_cmd_public_key(conn, skb); 2992 break; 2993 2994 case SMP_CMD_DHKEY_CHECK: 2995 reason = smp_cmd_dhkey_check(conn, skb); 2996 break; 2997 2998 case SMP_CMD_KEYPRESS_NOTIFY: 2999 reason = smp_cmd_keypress_notify(conn, skb); 3000 break; 3001 3002 default: 3003 BT_DBG("Unknown command code 0x%2.2x", code); 3004 reason = SMP_CMD_NOTSUPP; 3005 goto done; 3006 } 3007 3008 done: 3009 if (!err) { 3010 if (reason) 3011 smp_failure(conn, reason); 3012 kfree_skb(skb); 3013 } 3014 3015 return err; 3016 3017 drop: 3018 bt_dev_err(hcon->hdev, "unexpected SMP command 0x%02x from %pMR", 3019 code, &hcon->dst); 3020 kfree_skb(skb); 3021 return 0; 3022 } 3023 3024 static void smp_teardown_cb(struct l2cap_chan *chan, int err) 3025 { 3026 struct l2cap_conn *conn = chan->conn; 3027 3028 BT_DBG("chan %p", chan); 3029 3030 if (chan->data) 3031 smp_chan_destroy(conn); 3032 3033 conn->smp = NULL; 3034 l2cap_chan_put(chan); 3035 } 3036 3037 static void bredr_pairing(struct l2cap_chan *chan) 3038 { 3039 struct l2cap_conn *conn = chan->conn; 3040 struct hci_conn *hcon = conn->hcon; 3041 struct hci_dev *hdev = hcon->hdev; 3042 struct smp_cmd_pairing req; 3043 struct smp_chan *smp; 3044 3045 BT_DBG("chan %p", chan); 3046 3047 /* Only new pairings are interesting */ 3048 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags)) 3049 return; 3050 3051 /* Don't bother if we're not encrypted */ 3052 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3053 return; 3054 3055 /* Only master may initiate SMP over BR/EDR */ 3056 if (hcon->role != HCI_ROLE_MASTER) 3057 return; 3058 3059 /* Secure Connections support must be enabled */ 3060 if (!hci_dev_test_flag(hdev, HCI_SC_ENABLED)) 3061 return; 3062 3063 /* BR/EDR must use Secure Connections for SMP */ 3064 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) && 3065 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3066 return; 3067 3068 /* If our LE support is not enabled don't do anything */ 3069 if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) 3070 return; 3071 3072 /* Don't bother if remote LE support is not enabled */ 3073 if (!lmp_host_le_capable(hcon)) 3074 return; 3075 3076 /* Remote must support SMP fixed chan for BR/EDR */ 3077 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR)) 3078 return; 3079 3080 /* Don't bother if SMP is already ongoing */ 3081 if (chan->data) 3082 return; 3083 3084 smp = smp_chan_create(conn); 3085 if (!smp) { 3086 bt_dev_err(hdev, "unable to create SMP context for BR/EDR"); 3087 return; 3088 } 3089 3090 set_bit(SMP_FLAG_SC, &smp->flags); 3091 3092 BT_DBG("%s starting SMP over BR/EDR", hdev->name); 3093 3094 /* Prepare and send the BR/EDR SMP Pairing Request */ 3095 build_bredr_pairing_cmd(smp, &req, NULL); 3096 3097 smp->preq[0] = SMP_CMD_PAIRING_REQ; 3098 memcpy(&smp->preq[1], &req, sizeof(req)); 3099 3100 smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(req), &req); 3101 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 3102 } 3103 3104 static void smp_resume_cb(struct l2cap_chan *chan) 3105 { 3106 struct smp_chan *smp = chan->data; 3107 struct l2cap_conn *conn = chan->conn; 3108 struct hci_conn *hcon = conn->hcon; 3109 3110 BT_DBG("chan %p", chan); 3111 3112 if (hcon->type == ACL_LINK) { 3113 bredr_pairing(chan); 3114 return; 3115 } 3116 3117 if (!smp) 3118 return; 3119 3120 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3121 return; 3122 3123 cancel_delayed_work(&smp->security_timer); 3124 3125 smp_distribute_keys(smp); 3126 } 3127 3128 static void smp_ready_cb(struct l2cap_chan *chan) 3129 { 3130 struct l2cap_conn *conn = chan->conn; 3131 struct hci_conn *hcon = conn->hcon; 3132 3133 BT_DBG("chan %p", chan); 3134 3135 /* No need to call l2cap_chan_hold() here since we already own 3136 * the reference taken in smp_new_conn_cb(). This is just the 3137 * first time that we tie it to a specific pointer. The code in 3138 * l2cap_core.c ensures that there's no risk this function wont 3139 * get called if smp_new_conn_cb was previously called. 3140 */ 3141 conn->smp = chan; 3142 3143 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3144 bredr_pairing(chan); 3145 } 3146 3147 static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 3148 { 3149 int err; 3150 3151 BT_DBG("chan %p", chan); 3152 3153 err = smp_sig_channel(chan, skb); 3154 if (err) { 3155 struct smp_chan *smp = chan->data; 3156 3157 if (smp) 3158 cancel_delayed_work_sync(&smp->security_timer); 3159 3160 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE); 3161 } 3162 3163 return err; 3164 } 3165 3166 static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan, 3167 unsigned long hdr_len, 3168 unsigned long len, int nb) 3169 { 3170 struct sk_buff *skb; 3171 3172 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL); 3173 if (!skb) 3174 return ERR_PTR(-ENOMEM); 3175 3176 skb->priority = HCI_PRIO_MAX; 3177 bt_cb(skb)->l2cap.chan = chan; 3178 3179 return skb; 3180 } 3181 3182 static const struct l2cap_ops smp_chan_ops = { 3183 .name = "Security Manager", 3184 .ready = smp_ready_cb, 3185 .recv = smp_recv_cb, 3186 .alloc_skb = smp_alloc_skb_cb, 3187 .teardown = smp_teardown_cb, 3188 .resume = smp_resume_cb, 3189 3190 .new_connection = l2cap_chan_no_new_connection, 3191 .state_change = l2cap_chan_no_state_change, 3192 .close = l2cap_chan_no_close, 3193 .defer = l2cap_chan_no_defer, 3194 .suspend = l2cap_chan_no_suspend, 3195 .set_shutdown = l2cap_chan_no_set_shutdown, 3196 .get_sndtimeo = l2cap_chan_no_get_sndtimeo, 3197 }; 3198 3199 static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan) 3200 { 3201 struct l2cap_chan *chan; 3202 3203 BT_DBG("pchan %p", pchan); 3204 3205 chan = l2cap_chan_create(); 3206 if (!chan) 3207 return NULL; 3208 3209 chan->chan_type = pchan->chan_type; 3210 chan->ops = &smp_chan_ops; 3211 chan->scid = pchan->scid; 3212 chan->dcid = chan->scid; 3213 chan->imtu = pchan->imtu; 3214 chan->omtu = pchan->omtu; 3215 chan->mode = pchan->mode; 3216 3217 /* Other L2CAP channels may request SMP routines in order to 3218 * change the security level. This means that the SMP channel 3219 * lock must be considered in its own category to avoid lockdep 3220 * warnings. 3221 */ 3222 atomic_set(&chan->nesting, L2CAP_NESTING_SMP); 3223 3224 BT_DBG("created chan %p", chan); 3225 3226 return chan; 3227 } 3228 3229 static const struct l2cap_ops smp_root_chan_ops = { 3230 .name = "Security Manager Root", 3231 .new_connection = smp_new_conn_cb, 3232 3233 /* None of these are implemented for the root channel */ 3234 .close = l2cap_chan_no_close, 3235 .alloc_skb = l2cap_chan_no_alloc_skb, 3236 .recv = l2cap_chan_no_recv, 3237 .state_change = l2cap_chan_no_state_change, 3238 .teardown = l2cap_chan_no_teardown, 3239 .ready = l2cap_chan_no_ready, 3240 .defer = l2cap_chan_no_defer, 3241 .suspend = l2cap_chan_no_suspend, 3242 .resume = l2cap_chan_no_resume, 3243 .set_shutdown = l2cap_chan_no_set_shutdown, 3244 .get_sndtimeo = l2cap_chan_no_get_sndtimeo, 3245 }; 3246 3247 static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid) 3248 { 3249 struct l2cap_chan *chan; 3250 struct smp_dev *smp; 3251 struct crypto_shash *tfm_cmac; 3252 struct crypto_kpp *tfm_ecdh; 3253 3254 if (cid == L2CAP_CID_SMP_BREDR) { 3255 smp = NULL; 3256 goto create_chan; 3257 } 3258 3259 smp = kzalloc(sizeof(*smp), GFP_KERNEL); 3260 if (!smp) 3261 return ERR_PTR(-ENOMEM); 3262 3263 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 3264 if (IS_ERR(tfm_cmac)) { 3265 BT_ERR("Unable to create CMAC crypto context"); 3266 kzfree(smp); 3267 return ERR_CAST(tfm_cmac); 3268 } 3269 3270 tfm_ecdh = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0); 3271 if (IS_ERR(tfm_ecdh)) { 3272 BT_ERR("Unable to create ECDH crypto context"); 3273 crypto_free_shash(tfm_cmac); 3274 kzfree(smp); 3275 return ERR_CAST(tfm_ecdh); 3276 } 3277 3278 smp->local_oob = false; 3279 smp->tfm_cmac = tfm_cmac; 3280 smp->tfm_ecdh = tfm_ecdh; 3281 3282 create_chan: 3283 chan = l2cap_chan_create(); 3284 if (!chan) { 3285 if (smp) { 3286 crypto_free_shash(smp->tfm_cmac); 3287 crypto_free_kpp(smp->tfm_ecdh); 3288 kzfree(smp); 3289 } 3290 return ERR_PTR(-ENOMEM); 3291 } 3292 3293 chan->data = smp; 3294 3295 l2cap_add_scid(chan, cid); 3296 3297 l2cap_chan_set_defaults(chan); 3298 3299 if (cid == L2CAP_CID_SMP) { 3300 u8 bdaddr_type; 3301 3302 hci_copy_identity_address(hdev, &chan->src, &bdaddr_type); 3303 3304 if (bdaddr_type == ADDR_LE_DEV_PUBLIC) 3305 chan->src_type = BDADDR_LE_PUBLIC; 3306 else 3307 chan->src_type = BDADDR_LE_RANDOM; 3308 } else { 3309 bacpy(&chan->src, &hdev->bdaddr); 3310 chan->src_type = BDADDR_BREDR; 3311 } 3312 3313 chan->state = BT_LISTEN; 3314 chan->mode = L2CAP_MODE_BASIC; 3315 chan->imtu = L2CAP_DEFAULT_MTU; 3316 chan->ops = &smp_root_chan_ops; 3317 3318 /* Set correct nesting level for a parent/listening channel */ 3319 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 3320 3321 return chan; 3322 } 3323 3324 static void smp_del_chan(struct l2cap_chan *chan) 3325 { 3326 struct smp_dev *smp; 3327 3328 BT_DBG("chan %p", chan); 3329 3330 smp = chan->data; 3331 if (smp) { 3332 chan->data = NULL; 3333 crypto_free_shash(smp->tfm_cmac); 3334 crypto_free_kpp(smp->tfm_ecdh); 3335 kzfree(smp); 3336 } 3337 3338 l2cap_chan_put(chan); 3339 } 3340 3341 static ssize_t force_bredr_smp_read(struct file *file, 3342 char __user *user_buf, 3343 size_t count, loff_t *ppos) 3344 { 3345 struct hci_dev *hdev = file->private_data; 3346 char buf[3]; 3347 3348 buf[0] = hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP) ? 'Y': 'N'; 3349 buf[1] = '\n'; 3350 buf[2] = '\0'; 3351 return simple_read_from_buffer(user_buf, count, ppos, buf, 2); 3352 } 3353 3354 static ssize_t force_bredr_smp_write(struct file *file, 3355 const char __user *user_buf, 3356 size_t count, loff_t *ppos) 3357 { 3358 struct hci_dev *hdev = file->private_data; 3359 bool enable; 3360 int err; 3361 3362 err = kstrtobool_from_user(user_buf, count, &enable); 3363 if (err) 3364 return err; 3365 3366 if (enable == hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3367 return -EALREADY; 3368 3369 if (enable) { 3370 struct l2cap_chan *chan; 3371 3372 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); 3373 if (IS_ERR(chan)) 3374 return PTR_ERR(chan); 3375 3376 hdev->smp_bredr_data = chan; 3377 } else { 3378 struct l2cap_chan *chan; 3379 3380 chan = hdev->smp_bredr_data; 3381 hdev->smp_bredr_data = NULL; 3382 smp_del_chan(chan); 3383 } 3384 3385 hci_dev_change_flag(hdev, HCI_FORCE_BREDR_SMP); 3386 3387 return count; 3388 } 3389 3390 static const struct file_operations force_bredr_smp_fops = { 3391 .open = simple_open, 3392 .read = force_bredr_smp_read, 3393 .write = force_bredr_smp_write, 3394 .llseek = default_llseek, 3395 }; 3396 3397 int smp_register(struct hci_dev *hdev) 3398 { 3399 struct l2cap_chan *chan; 3400 3401 BT_DBG("%s", hdev->name); 3402 3403 /* If the controller does not support Low Energy operation, then 3404 * there is also no need to register any SMP channel. 3405 */ 3406 if (!lmp_le_capable(hdev)) 3407 return 0; 3408 3409 if (WARN_ON(hdev->smp_data)) { 3410 chan = hdev->smp_data; 3411 hdev->smp_data = NULL; 3412 smp_del_chan(chan); 3413 } 3414 3415 chan = smp_add_cid(hdev, L2CAP_CID_SMP); 3416 if (IS_ERR(chan)) 3417 return PTR_ERR(chan); 3418 3419 hdev->smp_data = chan; 3420 3421 /* If the controller does not support BR/EDR Secure Connections 3422 * feature, then the BR/EDR SMP channel shall not be present. 3423 * 3424 * To test this with Bluetooth 4.0 controllers, create a debugfs 3425 * switch that allows forcing BR/EDR SMP support and accepting 3426 * cross-transport pairing on non-AES encrypted connections. 3427 */ 3428 if (!lmp_sc_capable(hdev)) { 3429 debugfs_create_file("force_bredr_smp", 0644, hdev->debugfs, 3430 hdev, &force_bredr_smp_fops); 3431 3432 /* Flag can be already set here (due to power toggle) */ 3433 if (!hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3434 return 0; 3435 } 3436 3437 if (WARN_ON(hdev->smp_bredr_data)) { 3438 chan = hdev->smp_bredr_data; 3439 hdev->smp_bredr_data = NULL; 3440 smp_del_chan(chan); 3441 } 3442 3443 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); 3444 if (IS_ERR(chan)) { 3445 int err = PTR_ERR(chan); 3446 chan = hdev->smp_data; 3447 hdev->smp_data = NULL; 3448 smp_del_chan(chan); 3449 return err; 3450 } 3451 3452 hdev->smp_bredr_data = chan; 3453 3454 return 0; 3455 } 3456 3457 void smp_unregister(struct hci_dev *hdev) 3458 { 3459 struct l2cap_chan *chan; 3460 3461 if (hdev->smp_bredr_data) { 3462 chan = hdev->smp_bredr_data; 3463 hdev->smp_bredr_data = NULL; 3464 smp_del_chan(chan); 3465 } 3466 3467 if (hdev->smp_data) { 3468 chan = hdev->smp_data; 3469 hdev->smp_data = NULL; 3470 smp_del_chan(chan); 3471 } 3472 } 3473 3474 #if IS_ENABLED(CONFIG_BT_SELFTEST_SMP) 3475 3476 static int __init test_debug_key(struct crypto_kpp *tfm_ecdh) 3477 { 3478 u8 pk[64]; 3479 int err; 3480 3481 err = set_ecdh_privkey(tfm_ecdh, debug_sk); 3482 if (err) 3483 return err; 3484 3485 err = generate_ecdh_public_key(tfm_ecdh, pk); 3486 if (err) 3487 return err; 3488 3489 if (crypto_memneq(pk, debug_pk, 64)) 3490 return -EINVAL; 3491 3492 return 0; 3493 } 3494 3495 static int __init test_ah(void) 3496 { 3497 const u8 irk[16] = { 3498 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3499 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3500 const u8 r[3] = { 0x94, 0x81, 0x70 }; 3501 const u8 exp[3] = { 0xaa, 0xfb, 0x0d }; 3502 u8 res[3]; 3503 int err; 3504 3505 err = smp_ah(irk, r, res); 3506 if (err) 3507 return err; 3508 3509 if (crypto_memneq(res, exp, 3)) 3510 return -EINVAL; 3511 3512 return 0; 3513 } 3514 3515 static int __init test_c1(void) 3516 { 3517 const u8 k[16] = { 3518 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 3519 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; 3520 const u8 r[16] = { 3521 0xe0, 0x2e, 0x70, 0xc6, 0x4e, 0x27, 0x88, 0x63, 3522 0x0e, 0x6f, 0xad, 0x56, 0x21, 0xd5, 0x83, 0x57 }; 3523 const u8 preq[7] = { 0x01, 0x01, 0x00, 0x00, 0x10, 0x07, 0x07 }; 3524 const u8 pres[7] = { 0x02, 0x03, 0x00, 0x00, 0x08, 0x00, 0x05 }; 3525 const u8 _iat = 0x01; 3526 const u8 _rat = 0x00; 3527 const bdaddr_t ra = { { 0xb6, 0xb5, 0xb4, 0xb3, 0xb2, 0xb1 } }; 3528 const bdaddr_t ia = { { 0xa6, 0xa5, 0xa4, 0xa3, 0xa2, 0xa1 } }; 3529 const u8 exp[16] = { 3530 0x86, 0x3b, 0xf1, 0xbe, 0xc5, 0x4d, 0xa7, 0xd2, 3531 0xea, 0x88, 0x89, 0x87, 0xef, 0x3f, 0x1e, 0x1e }; 3532 u8 res[16]; 3533 int err; 3534 3535 err = smp_c1(k, r, preq, pres, _iat, &ia, _rat, &ra, res); 3536 if (err) 3537 return err; 3538 3539 if (crypto_memneq(res, exp, 16)) 3540 return -EINVAL; 3541 3542 return 0; 3543 } 3544 3545 static int __init test_s1(void) 3546 { 3547 const u8 k[16] = { 3548 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 3549 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; 3550 const u8 r1[16] = { 3551 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 }; 3552 const u8 r2[16] = { 3553 0x00, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99 }; 3554 const u8 exp[16] = { 3555 0x62, 0xa0, 0x6d, 0x79, 0xae, 0x16, 0x42, 0x5b, 3556 0x9b, 0xf4, 0xb0, 0xe8, 0xf0, 0xe1, 0x1f, 0x9a }; 3557 u8 res[16]; 3558 int err; 3559 3560 err = smp_s1(k, r1, r2, res); 3561 if (err) 3562 return err; 3563 3564 if (crypto_memneq(res, exp, 16)) 3565 return -EINVAL; 3566 3567 return 0; 3568 } 3569 3570 static int __init test_f4(struct crypto_shash *tfm_cmac) 3571 { 3572 const u8 u[32] = { 3573 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 3574 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 3575 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 3576 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 }; 3577 const u8 v[32] = { 3578 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b, 3579 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59, 3580 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90, 3581 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 }; 3582 const u8 x[16] = { 3583 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3584 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3585 const u8 z = 0x00; 3586 const u8 exp[16] = { 3587 0x2d, 0x87, 0x74, 0xa9, 0xbe, 0xa1, 0xed, 0xf1, 3588 0x1c, 0xbd, 0xa9, 0x07, 0xf1, 0x16, 0xc9, 0xf2 }; 3589 u8 res[16]; 3590 int err; 3591 3592 err = smp_f4(tfm_cmac, u, v, x, z, res); 3593 if (err) 3594 return err; 3595 3596 if (crypto_memneq(res, exp, 16)) 3597 return -EINVAL; 3598 3599 return 0; 3600 } 3601 3602 static int __init test_f5(struct crypto_shash *tfm_cmac) 3603 { 3604 const u8 w[32] = { 3605 0x98, 0xa6, 0xbf, 0x73, 0xf3, 0x34, 0x8d, 0x86, 3606 0xf1, 0x66, 0xf8, 0xb4, 0x13, 0x6b, 0x79, 0x99, 3607 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3608 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3609 const u8 n1[16] = { 3610 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3611 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3612 const u8 n2[16] = { 3613 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3614 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3615 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 }; 3616 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 }; 3617 const u8 exp_ltk[16] = { 3618 0x38, 0x0a, 0x75, 0x94, 0xb5, 0x22, 0x05, 0x98, 3619 0x23, 0xcd, 0xd7, 0x69, 0x11, 0x79, 0x86, 0x69 }; 3620 const u8 exp_mackey[16] = { 3621 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd, 3622 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 }; 3623 u8 mackey[16], ltk[16]; 3624 int err; 3625 3626 err = smp_f5(tfm_cmac, w, n1, n2, a1, a2, mackey, ltk); 3627 if (err) 3628 return err; 3629 3630 if (crypto_memneq(mackey, exp_mackey, 16)) 3631 return -EINVAL; 3632 3633 if (crypto_memneq(ltk, exp_ltk, 16)) 3634 return -EINVAL; 3635 3636 return 0; 3637 } 3638 3639 static int __init test_f6(struct crypto_shash *tfm_cmac) 3640 { 3641 const u8 w[16] = { 3642 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd, 3643 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 }; 3644 const u8 n1[16] = { 3645 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3646 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3647 const u8 n2[16] = { 3648 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3649 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3650 const u8 r[16] = { 3651 0xc8, 0x0f, 0x2d, 0x0c, 0xd2, 0x42, 0xda, 0x08, 3652 0x54, 0xbb, 0x53, 0xb4, 0x3b, 0x34, 0xa3, 0x12 }; 3653 const u8 io_cap[3] = { 0x02, 0x01, 0x01 }; 3654 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 }; 3655 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 }; 3656 const u8 exp[16] = { 3657 0x61, 0x8f, 0x95, 0xda, 0x09, 0x0b, 0x6c, 0xd2, 3658 0xc5, 0xe8, 0xd0, 0x9c, 0x98, 0x73, 0xc4, 0xe3 }; 3659 u8 res[16]; 3660 int err; 3661 3662 err = smp_f6(tfm_cmac, w, n1, n2, r, io_cap, a1, a2, res); 3663 if (err) 3664 return err; 3665 3666 if (crypto_memneq(res, exp, 16)) 3667 return -EINVAL; 3668 3669 return 0; 3670 } 3671 3672 static int __init test_g2(struct crypto_shash *tfm_cmac) 3673 { 3674 const u8 u[32] = { 3675 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 3676 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 3677 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 3678 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 }; 3679 const u8 v[32] = { 3680 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b, 3681 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59, 3682 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90, 3683 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 }; 3684 const u8 x[16] = { 3685 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3686 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3687 const u8 y[16] = { 3688 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3689 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3690 const u32 exp_val = 0x2f9ed5ba % 1000000; 3691 u32 val; 3692 int err; 3693 3694 err = smp_g2(tfm_cmac, u, v, x, y, &val); 3695 if (err) 3696 return err; 3697 3698 if (val != exp_val) 3699 return -EINVAL; 3700 3701 return 0; 3702 } 3703 3704 static int __init test_h6(struct crypto_shash *tfm_cmac) 3705 { 3706 const u8 w[16] = { 3707 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3708 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3709 const u8 key_id[4] = { 0x72, 0x62, 0x65, 0x6c }; 3710 const u8 exp[16] = { 3711 0x99, 0x63, 0xb1, 0x80, 0xe2, 0xa9, 0xd3, 0xe8, 3712 0x1c, 0xc9, 0x6d, 0xe7, 0x02, 0xe1, 0x9a, 0x2d }; 3713 u8 res[16]; 3714 int err; 3715 3716 err = smp_h6(tfm_cmac, w, key_id, res); 3717 if (err) 3718 return err; 3719 3720 if (crypto_memneq(res, exp, 16)) 3721 return -EINVAL; 3722 3723 return 0; 3724 } 3725 3726 static char test_smp_buffer[32]; 3727 3728 static ssize_t test_smp_read(struct file *file, char __user *user_buf, 3729 size_t count, loff_t *ppos) 3730 { 3731 return simple_read_from_buffer(user_buf, count, ppos, test_smp_buffer, 3732 strlen(test_smp_buffer)); 3733 } 3734 3735 static const struct file_operations test_smp_fops = { 3736 .open = simple_open, 3737 .read = test_smp_read, 3738 .llseek = default_llseek, 3739 }; 3740 3741 static int __init run_selftests(struct crypto_shash *tfm_cmac, 3742 struct crypto_kpp *tfm_ecdh) 3743 { 3744 ktime_t calltime, delta, rettime; 3745 unsigned long long duration; 3746 int err; 3747 3748 calltime = ktime_get(); 3749 3750 err = test_debug_key(tfm_ecdh); 3751 if (err) { 3752 BT_ERR("debug_key test failed"); 3753 goto done; 3754 } 3755 3756 err = test_ah(); 3757 if (err) { 3758 BT_ERR("smp_ah test failed"); 3759 goto done; 3760 } 3761 3762 err = test_c1(); 3763 if (err) { 3764 BT_ERR("smp_c1 test failed"); 3765 goto done; 3766 } 3767 3768 err = test_s1(); 3769 if (err) { 3770 BT_ERR("smp_s1 test failed"); 3771 goto done; 3772 } 3773 3774 err = test_f4(tfm_cmac); 3775 if (err) { 3776 BT_ERR("smp_f4 test failed"); 3777 goto done; 3778 } 3779 3780 err = test_f5(tfm_cmac); 3781 if (err) { 3782 BT_ERR("smp_f5 test failed"); 3783 goto done; 3784 } 3785 3786 err = test_f6(tfm_cmac); 3787 if (err) { 3788 BT_ERR("smp_f6 test failed"); 3789 goto done; 3790 } 3791 3792 err = test_g2(tfm_cmac); 3793 if (err) { 3794 BT_ERR("smp_g2 test failed"); 3795 goto done; 3796 } 3797 3798 err = test_h6(tfm_cmac); 3799 if (err) { 3800 BT_ERR("smp_h6 test failed"); 3801 goto done; 3802 } 3803 3804 rettime = ktime_get(); 3805 delta = ktime_sub(rettime, calltime); 3806 duration = (unsigned long long) ktime_to_ns(delta) >> 10; 3807 3808 BT_INFO("SMP test passed in %llu usecs", duration); 3809 3810 done: 3811 if (!err) 3812 snprintf(test_smp_buffer, sizeof(test_smp_buffer), 3813 "PASS (%llu usecs)\n", duration); 3814 else 3815 snprintf(test_smp_buffer, sizeof(test_smp_buffer), "FAIL\n"); 3816 3817 debugfs_create_file("selftest_smp", 0444, bt_debugfs, NULL, 3818 &test_smp_fops); 3819 3820 return err; 3821 } 3822 3823 int __init bt_selftest_smp(void) 3824 { 3825 struct crypto_shash *tfm_cmac; 3826 struct crypto_kpp *tfm_ecdh; 3827 int err; 3828 3829 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 3830 if (IS_ERR(tfm_cmac)) { 3831 BT_ERR("Unable to create CMAC crypto context"); 3832 return PTR_ERR(tfm_cmac); 3833 } 3834 3835 tfm_ecdh = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0); 3836 if (IS_ERR(tfm_ecdh)) { 3837 BT_ERR("Unable to create ECDH crypto context"); 3838 crypto_free_shash(tfm_cmac); 3839 return PTR_ERR(tfm_ecdh); 3840 } 3841 3842 err = run_selftests(tfm_cmac, tfm_ecdh); 3843 3844 crypto_free_shash(tfm_cmac); 3845 crypto_free_kpp(tfm_ecdh); 3846 3847 return err; 3848 } 3849 3850 #endif 3851