1 /* 2 BlueZ - Bluetooth protocol stack for Linux 3 Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). 4 5 This program is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License version 2 as 7 published by the Free Software Foundation; 8 9 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 10 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 11 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. 12 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY 13 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES 14 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 18 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS, 19 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS 20 SOFTWARE IS DISCLAIMED. 21 */ 22 23 #include <linux/debugfs.h> 24 #include <linux/scatterlist.h> 25 #include <crypto/aes.h> 26 #include <crypto/hash.h> 27 #include <crypto/kpp.h> 28 #include <crypto/utils.h> 29 30 #include <net/bluetooth/bluetooth.h> 31 #include <net/bluetooth/hci_core.h> 32 #include <net/bluetooth/l2cap.h> 33 #include <net/bluetooth/mgmt.h> 34 35 #include "ecdh_helper.h" 36 #include "smp.h" 37 38 #define SMP_DEV(hdev) \ 39 ((struct smp_dev *)((struct l2cap_chan *)((hdev)->smp_data))->data) 40 41 /* Low-level debug macros to be used for stuff that we don't want 42 * accidentally in dmesg, i.e. the values of the various crypto keys 43 * and the inputs & outputs of crypto functions. 44 */ 45 #ifdef DEBUG 46 #define SMP_DBG(fmt, ...) printk(KERN_DEBUG "%s: " fmt, __func__, \ 47 ##__VA_ARGS__) 48 #else 49 #define SMP_DBG(fmt, ...) no_printk(KERN_DEBUG "%s: " fmt, __func__, \ 50 ##__VA_ARGS__) 51 #endif 52 53 #define SMP_ALLOW_CMD(smp, code) set_bit(code, &smp->allow_cmd) 54 55 /* Keys which are not distributed with Secure Connections */ 56 #define SMP_SC_NO_DIST (SMP_DIST_ENC_KEY | SMP_DIST_LINK_KEY) 57 58 #define SMP_TIMEOUT msecs_to_jiffies(30000) 59 60 #define ID_ADDR_TIMEOUT msecs_to_jiffies(200) 61 62 #define AUTH_REQ_MASK(dev) (hci_dev_test_flag(dev, HCI_SC_ENABLED) ? \ 63 0x3f : 0x07) 64 #define KEY_DIST_MASK 0x07 65 66 /* Maximum message length that can be passed to aes_cmac */ 67 #define CMAC_MSG_MAX 80 68 69 enum { 70 SMP_FLAG_TK_VALID, 71 SMP_FLAG_CFM_PENDING, 72 SMP_FLAG_MITM_AUTH, 73 SMP_FLAG_COMPLETE, 74 SMP_FLAG_INITIATOR, 75 SMP_FLAG_SC, 76 SMP_FLAG_REMOTE_PK, 77 SMP_FLAG_DEBUG_KEY, 78 SMP_FLAG_WAIT_USER, 79 SMP_FLAG_DHKEY_PENDING, 80 SMP_FLAG_REMOTE_OOB, 81 SMP_FLAG_LOCAL_OOB, 82 SMP_FLAG_CT2, 83 }; 84 85 struct smp_dev { 86 /* Secure Connections OOB data */ 87 bool local_oob; 88 u8 local_pk[64]; 89 u8 local_rand[16]; 90 bool debug_key; 91 92 struct crypto_shash *tfm_cmac; 93 struct crypto_kpp *tfm_ecdh; 94 }; 95 96 struct smp_chan { 97 struct l2cap_conn *conn; 98 struct delayed_work security_timer; 99 unsigned long allow_cmd; /* Bitmask of allowed commands */ 100 101 u8 preq[7]; /* SMP Pairing Request */ 102 u8 prsp[7]; /* SMP Pairing Response */ 103 u8 prnd[16]; /* SMP Pairing Random (local) */ 104 u8 rrnd[16]; /* SMP Pairing Random (remote) */ 105 u8 pcnf[16]; /* SMP Pairing Confirm */ 106 u8 tk[16]; /* SMP Temporary Key */ 107 u8 rr[16]; /* Remote OOB ra/rb value */ 108 u8 lr[16]; /* Local OOB ra/rb value */ 109 u8 enc_key_size; 110 u8 remote_key_dist; 111 bdaddr_t id_addr; 112 u8 id_addr_type; 113 u8 irk[16]; 114 struct smp_csrk *csrk; 115 struct smp_csrk *responder_csrk; 116 struct smp_ltk *ltk; 117 struct smp_ltk *responder_ltk; 118 struct smp_irk *remote_irk; 119 u8 *link_key; 120 unsigned long flags; 121 u8 method; 122 u8 passkey_round; 123 124 /* Secure Connections variables */ 125 u8 local_pk[64]; 126 u8 remote_pk[64]; 127 u8 dhkey[32]; 128 u8 mackey[16]; 129 130 struct crypto_shash *tfm_cmac; 131 struct crypto_kpp *tfm_ecdh; 132 }; 133 134 /* These debug key values are defined in the SMP section of the core 135 * specification. debug_pk is the public debug key and debug_sk the 136 * private debug key. 137 */ 138 static const u8 debug_pk[64] = { 139 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 140 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 141 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 142 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20, 143 144 0x8b, 0xd2, 0x89, 0x15, 0xd0, 0x8e, 0x1c, 0x74, 145 0x24, 0x30, 0xed, 0x8f, 0xc2, 0x45, 0x63, 0x76, 146 0x5c, 0x15, 0x52, 0x5a, 0xbf, 0x9a, 0x32, 0x63, 147 0x6d, 0xeb, 0x2a, 0x65, 0x49, 0x9c, 0x80, 0xdc, 148 }; 149 150 static const u8 debug_sk[32] = { 151 0xbd, 0x1a, 0x3c, 0xcd, 0xa6, 0xb8, 0x99, 0x58, 152 0x99, 0xb7, 0x40, 0xeb, 0x7b, 0x60, 0xff, 0x4a, 153 0x50, 0x3f, 0x10, 0xd2, 0xe3, 0xb3, 0xc9, 0x74, 154 0x38, 0x5f, 0xc5, 0xa3, 0xd4, 0xf6, 0x49, 0x3f, 155 }; 156 swap_buf(const u8 * src,u8 * dst,size_t len)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 aes_cmac(struct crypto_shash * tfm,const u8 k[16],const u8 * m,size_t len,u8 mac[16])169 static int aes_cmac(struct crypto_shash *tfm, const u8 k[16], const u8 *m, 170 size_t len, u8 mac[16]) 171 { 172 uint8_t tmp[16], mac_msb[16], msg_msb[CMAC_MSG_MAX]; 173 int err; 174 175 if (len > CMAC_MSG_MAX) 176 return -EFBIG; 177 178 if (!tfm) { 179 BT_ERR("tfm %p", tfm); 180 return -EINVAL; 181 } 182 183 /* Swap key and message from LSB to MSB */ 184 swap_buf(k, tmp, 16); 185 swap_buf(m, msg_msb, len); 186 187 SMP_DBG("msg (len %zu) %*phN", len, (int) len, m); 188 SMP_DBG("key %16phN", k); 189 190 err = crypto_shash_setkey(tfm, tmp, 16); 191 if (err) { 192 BT_ERR("cipher setkey failed: %d", err); 193 return err; 194 } 195 196 err = crypto_shash_tfm_digest(tfm, msg_msb, len, mac_msb); 197 if (err) { 198 BT_ERR("Hash computation error %d", err); 199 return err; 200 } 201 202 swap_buf(mac_msb, mac, 16); 203 204 SMP_DBG("mac %16phN", mac); 205 206 return 0; 207 } 208 smp_f4(struct crypto_shash * tfm_cmac,const u8 u[32],const u8 v[32],const u8 x[16],u8 z,u8 res[16])209 static int smp_f4(struct crypto_shash *tfm_cmac, const u8 u[32], 210 const u8 v[32], const u8 x[16], u8 z, u8 res[16]) 211 { 212 u8 m[65]; 213 int err; 214 215 SMP_DBG("u %32phN", u); 216 SMP_DBG("v %32phN", v); 217 SMP_DBG("x %16phN z %02x", x, z); 218 219 m[0] = z; 220 memcpy(m + 1, v, 32); 221 memcpy(m + 33, u, 32); 222 223 err = aes_cmac(tfm_cmac, x, m, sizeof(m), res); 224 if (err) 225 return err; 226 227 SMP_DBG("res %16phN", res); 228 229 return err; 230 } 231 smp_f5(struct crypto_shash * tfm_cmac,const u8 w[32],const u8 n1[16],const u8 n2[16],const u8 a1[7],const u8 a2[7],u8 mackey[16],u8 ltk[16])232 static int smp_f5(struct crypto_shash *tfm_cmac, const u8 w[32], 233 const u8 n1[16], const u8 n2[16], const u8 a1[7], 234 const u8 a2[7], u8 mackey[16], u8 ltk[16]) 235 { 236 /* The btle, salt and length "magic" values are as defined in 237 * the SMP section of the Bluetooth core specification. In ASCII 238 * the btle value ends up being 'btle'. The salt is just a 239 * random number whereas length is the value 256 in little 240 * endian format. 241 */ 242 const u8 btle[4] = { 0x65, 0x6c, 0x74, 0x62 }; 243 const u8 salt[16] = { 0xbe, 0x83, 0x60, 0x5a, 0xdb, 0x0b, 0x37, 0x60, 244 0x38, 0xa5, 0xf5, 0xaa, 0x91, 0x83, 0x88, 0x6c }; 245 const u8 length[2] = { 0x00, 0x01 }; 246 u8 m[53], t[16]; 247 int err; 248 249 SMP_DBG("w %32phN", w); 250 SMP_DBG("n1 %16phN n2 %16phN", n1, n2); 251 SMP_DBG("a1 %7phN a2 %7phN", a1, a2); 252 253 err = aes_cmac(tfm_cmac, salt, w, 32, t); 254 if (err) 255 return err; 256 257 SMP_DBG("t %16phN", t); 258 259 memcpy(m, length, 2); 260 memcpy(m + 2, a2, 7); 261 memcpy(m + 9, a1, 7); 262 memcpy(m + 16, n2, 16); 263 memcpy(m + 32, n1, 16); 264 memcpy(m + 48, btle, 4); 265 266 m[52] = 0; /* Counter */ 267 268 err = aes_cmac(tfm_cmac, t, m, sizeof(m), mackey); 269 if (err) 270 return err; 271 272 SMP_DBG("mackey %16phN", mackey); 273 274 m[52] = 1; /* Counter */ 275 276 err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk); 277 if (err) 278 return err; 279 280 SMP_DBG("ltk %16phN", ltk); 281 282 return 0; 283 } 284 smp_f6(struct crypto_shash * tfm_cmac,const u8 w[16],const u8 n1[16],const u8 n2[16],const u8 r[16],const u8 io_cap[3],const u8 a1[7],const u8 a2[7],u8 res[16])285 static int smp_f6(struct crypto_shash *tfm_cmac, const u8 w[16], 286 const u8 n1[16], const u8 n2[16], const u8 r[16], 287 const u8 io_cap[3], const u8 a1[7], const u8 a2[7], 288 u8 res[16]) 289 { 290 u8 m[65]; 291 int err; 292 293 SMP_DBG("w %16phN", w); 294 SMP_DBG("n1 %16phN n2 %16phN", n1, n2); 295 SMP_DBG("r %16phN io_cap %3phN a1 %7phN a2 %7phN", r, io_cap, a1, a2); 296 297 memcpy(m, a2, 7); 298 memcpy(m + 7, a1, 7); 299 memcpy(m + 14, io_cap, 3); 300 memcpy(m + 17, r, 16); 301 memcpy(m + 33, n2, 16); 302 memcpy(m + 49, n1, 16); 303 304 err = aes_cmac(tfm_cmac, w, m, sizeof(m), res); 305 if (err) 306 return err; 307 308 SMP_DBG("res %16phN", res); 309 310 return err; 311 } 312 smp_g2(struct crypto_shash * tfm_cmac,const u8 u[32],const u8 v[32],const u8 x[16],const u8 y[16],u32 * val)313 static int smp_g2(struct crypto_shash *tfm_cmac, const u8 u[32], const u8 v[32], 314 const u8 x[16], const u8 y[16], u32 *val) 315 { 316 u8 m[80], tmp[16]; 317 int err; 318 319 SMP_DBG("u %32phN", u); 320 SMP_DBG("v %32phN", v); 321 SMP_DBG("x %16phN y %16phN", x, y); 322 323 memcpy(m, y, 16); 324 memcpy(m + 16, v, 32); 325 memcpy(m + 48, u, 32); 326 327 err = aes_cmac(tfm_cmac, x, m, sizeof(m), tmp); 328 if (err) 329 return err; 330 331 *val = get_unaligned_le32(tmp); 332 *val %= 1000000; 333 334 SMP_DBG("val %06u", *val); 335 336 return 0; 337 } 338 smp_h6(struct crypto_shash * tfm_cmac,const u8 w[16],const u8 key_id[4],u8 res[16])339 static int smp_h6(struct crypto_shash *tfm_cmac, const u8 w[16], 340 const u8 key_id[4], u8 res[16]) 341 { 342 int err; 343 344 SMP_DBG("w %16phN key_id %4phN", w, key_id); 345 346 err = aes_cmac(tfm_cmac, w, key_id, 4, res); 347 if (err) 348 return err; 349 350 SMP_DBG("res %16phN", res); 351 352 return err; 353 } 354 smp_h7(struct crypto_shash * tfm_cmac,const u8 w[16],const u8 salt[16],u8 res[16])355 static int smp_h7(struct crypto_shash *tfm_cmac, const u8 w[16], 356 const u8 salt[16], u8 res[16]) 357 { 358 int err; 359 360 SMP_DBG("w %16phN salt %16phN", w, salt); 361 362 err = aes_cmac(tfm_cmac, salt, w, 16, res); 363 if (err) 364 return err; 365 366 SMP_DBG("res %16phN", res); 367 368 return err; 369 } 370 371 /* The following functions map to the legacy SMP crypto functions e, c1, 372 * s1 and ah. 373 */ 374 smp_e(const u8 * k,u8 * r)375 static int smp_e(const u8 *k, u8 *r) 376 { 377 struct crypto_aes_ctx ctx; 378 uint8_t tmp[16], data[16]; 379 int err; 380 381 SMP_DBG("k %16phN r %16phN", k, r); 382 383 /* The most significant octet of key corresponds to k[0] */ 384 swap_buf(k, tmp, 16); 385 386 err = aes_expandkey(&ctx, tmp, 16); 387 if (err) { 388 BT_ERR("cipher setkey failed: %d", err); 389 return err; 390 } 391 392 /* Most significant octet of plaintextData corresponds to data[0] */ 393 swap_buf(r, data, 16); 394 395 aes_encrypt(&ctx, data, data); 396 397 /* Most significant octet of encryptedData corresponds to data[0] */ 398 swap_buf(data, r, 16); 399 400 SMP_DBG("r %16phN", r); 401 402 memzero_explicit(&ctx, sizeof(ctx)); 403 return err; 404 } 405 smp_c1(const u8 k[16],const u8 r[16],const u8 preq[7],const u8 pres[7],u8 _iat,const bdaddr_t * ia,u8 _rat,const bdaddr_t * ra,u8 res[16])406 static int smp_c1(const u8 k[16], 407 const u8 r[16], const u8 preq[7], const u8 pres[7], u8 _iat, 408 const bdaddr_t *ia, u8 _rat, const bdaddr_t *ra, u8 res[16]) 409 { 410 u8 p1[16], p2[16]; 411 int err; 412 413 SMP_DBG("k %16phN r %16phN", k, r); 414 SMP_DBG("iat %u ia %6phN rat %u ra %6phN", _iat, ia, _rat, ra); 415 SMP_DBG("preq %7phN pres %7phN", preq, pres); 416 417 memset(p1, 0, 16); 418 419 /* p1 = pres || preq || _rat || _iat */ 420 p1[0] = _iat; 421 p1[1] = _rat; 422 memcpy(p1 + 2, preq, 7); 423 memcpy(p1 + 9, pres, 7); 424 425 SMP_DBG("p1 %16phN", p1); 426 427 /* res = r XOR p1 */ 428 crypto_xor_cpy(res, r, p1, sizeof(p1)); 429 430 /* res = e(k, res) */ 431 err = smp_e(k, res); 432 if (err) { 433 BT_ERR("Encrypt data error"); 434 return err; 435 } 436 437 /* p2 = padding || ia || ra */ 438 memcpy(p2, ra, 6); 439 memcpy(p2 + 6, ia, 6); 440 memset(p2 + 12, 0, 4); 441 442 SMP_DBG("p2 %16phN", p2); 443 444 /* res = res XOR p2 */ 445 crypto_xor(res, p2, sizeof(p2)); 446 447 /* res = e(k, res) */ 448 err = smp_e(k, res); 449 if (err) 450 BT_ERR("Encrypt data error"); 451 452 return err; 453 } 454 smp_s1(const u8 k[16],const u8 r1[16],const u8 r2[16],u8 _r[16])455 static int smp_s1(const u8 k[16], 456 const u8 r1[16], const u8 r2[16], u8 _r[16]) 457 { 458 int err; 459 460 /* Just least significant octets from r1 and r2 are considered */ 461 memcpy(_r, r2, 8); 462 memcpy(_r + 8, r1, 8); 463 464 err = smp_e(k, _r); 465 if (err) 466 BT_ERR("Encrypt data error"); 467 468 return err; 469 } 470 smp_ah(const u8 irk[16],const u8 r[3],u8 res[3])471 static int smp_ah(const u8 irk[16], const u8 r[3], u8 res[3]) 472 { 473 u8 _res[16]; 474 int err; 475 476 /* r' = padding || r */ 477 memcpy(_res, r, 3); 478 memset(_res + 3, 0, 13); 479 480 err = smp_e(irk, _res); 481 if (err) { 482 BT_ERR("Encrypt error"); 483 return err; 484 } 485 486 /* The output of the random address function ah is: 487 * ah(k, r) = e(k, r') mod 2^24 488 * The output of the security function e is then truncated to 24 bits 489 * by taking the least significant 24 bits of the output of e as the 490 * result of ah. 491 */ 492 memcpy(res, _res, 3); 493 494 return 0; 495 } 496 smp_irk_matches(struct hci_dev * hdev,const u8 irk[16],const bdaddr_t * bdaddr)497 bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16], 498 const bdaddr_t *bdaddr) 499 { 500 struct l2cap_chan *chan = hdev->smp_data; 501 u8 hash[3]; 502 int err; 503 504 if (!chan || !chan->data) 505 return false; 506 507 bt_dev_dbg(hdev, "RPA %pMR IRK %*phN", bdaddr, 16, irk); 508 509 err = smp_ah(irk, &bdaddr->b[3], hash); 510 if (err) 511 return false; 512 513 return !crypto_memneq(bdaddr->b, hash, 3); 514 } 515 smp_generate_rpa(struct hci_dev * hdev,const u8 irk[16],bdaddr_t * rpa)516 int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa) 517 { 518 struct l2cap_chan *chan = hdev->smp_data; 519 int err; 520 521 if (!chan || !chan->data) 522 return -EOPNOTSUPP; 523 524 get_random_bytes(&rpa->b[3], 3); 525 526 rpa->b[5] &= 0x3f; /* Clear two most significant bits */ 527 rpa->b[5] |= 0x40; /* Set second most significant bit */ 528 529 err = smp_ah(irk, &rpa->b[3], rpa->b); 530 if (err < 0) 531 return err; 532 533 bt_dev_dbg(hdev, "RPA %pMR", rpa); 534 535 return 0; 536 } 537 smp_generate_oob(struct hci_dev * hdev,u8 hash[16],u8 rand[16])538 int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16]) 539 { 540 struct l2cap_chan *chan = hdev->smp_data; 541 struct smp_dev *smp; 542 int err; 543 544 if (!chan || !chan->data) 545 return -EOPNOTSUPP; 546 547 smp = chan->data; 548 549 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { 550 bt_dev_dbg(hdev, "Using debug keys"); 551 err = set_ecdh_privkey(smp->tfm_ecdh, debug_sk); 552 if (err) 553 return err; 554 memcpy(smp->local_pk, debug_pk, 64); 555 smp->debug_key = true; 556 } else { 557 while (true) { 558 /* Generate key pair for Secure Connections */ 559 err = generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk); 560 if (err) 561 return err; 562 563 /* This is unlikely, but we need to check that 564 * we didn't accidentally generate a debug key. 565 */ 566 if (crypto_memneq(smp->local_pk, debug_pk, 64)) 567 break; 568 } 569 smp->debug_key = false; 570 } 571 572 SMP_DBG("OOB Public Key X: %32phN", smp->local_pk); 573 SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32); 574 575 get_random_bytes(smp->local_rand, 16); 576 577 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->local_pk, 578 smp->local_rand, 0, hash); 579 if (err < 0) 580 return err; 581 582 memcpy(rand, smp->local_rand, 16); 583 584 smp->local_oob = true; 585 586 return 0; 587 } 588 smp_send_cmd(struct l2cap_conn * conn,u8 code,u16 len,void * data)589 static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data) 590 { 591 struct l2cap_chan *chan = conn->smp; 592 struct smp_chan *smp; 593 struct kvec iv[2]; 594 struct msghdr msg; 595 596 if (!chan) 597 return; 598 599 bt_dev_dbg(conn->hcon->hdev, "code 0x%2.2x", code); 600 601 iv[0].iov_base = &code; 602 iv[0].iov_len = 1; 603 604 iv[1].iov_base = data; 605 iv[1].iov_len = len; 606 607 memset(&msg, 0, sizeof(msg)); 608 609 iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iv, 2, 1 + len); 610 611 l2cap_chan_send(chan, &msg, 1 + len); 612 613 if (!chan->data) 614 return; 615 616 smp = chan->data; 617 618 cancel_delayed_work_sync(&smp->security_timer); 619 schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT); 620 } 621 authreq_to_seclevel(u8 authreq)622 static u8 authreq_to_seclevel(u8 authreq) 623 { 624 if (authreq & SMP_AUTH_MITM) { 625 if (authreq & SMP_AUTH_SC) 626 return BT_SECURITY_FIPS; 627 else 628 return BT_SECURITY_HIGH; 629 } else { 630 return BT_SECURITY_MEDIUM; 631 } 632 } 633 seclevel_to_authreq(__u8 sec_level)634 static __u8 seclevel_to_authreq(__u8 sec_level) 635 { 636 switch (sec_level) { 637 case BT_SECURITY_FIPS: 638 case BT_SECURITY_HIGH: 639 return SMP_AUTH_MITM | SMP_AUTH_BONDING; 640 case BT_SECURITY_MEDIUM: 641 return SMP_AUTH_BONDING; 642 default: 643 return SMP_AUTH_NONE; 644 } 645 } 646 build_pairing_cmd(struct l2cap_conn * conn,struct smp_cmd_pairing * req,struct smp_cmd_pairing * rsp,__u8 authreq)647 static void build_pairing_cmd(struct l2cap_conn *conn, 648 struct smp_cmd_pairing *req, 649 struct smp_cmd_pairing *rsp, __u8 authreq) 650 { 651 struct l2cap_chan *chan = conn->smp; 652 struct smp_chan *smp = chan->data; 653 struct hci_conn *hcon = conn->hcon; 654 struct hci_dev *hdev = hcon->hdev; 655 u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT; 656 657 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { 658 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 659 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 660 authreq |= SMP_AUTH_BONDING; 661 } else { 662 authreq &= ~SMP_AUTH_BONDING; 663 } 664 665 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) 666 remote_dist |= SMP_DIST_ID_KEY; 667 668 if (hci_dev_test_flag(hdev, HCI_PRIVACY)) 669 local_dist |= SMP_DIST_ID_KEY; 670 671 if (hci_dev_test_flag(hdev, HCI_SC_ENABLED) && 672 (authreq & SMP_AUTH_SC)) { 673 struct oob_data *oob_data; 674 u8 bdaddr_type; 675 676 if (hci_dev_test_flag(hdev, HCI_SSP_ENABLED)) { 677 local_dist |= SMP_DIST_LINK_KEY; 678 remote_dist |= SMP_DIST_LINK_KEY; 679 } 680 681 if (hcon->dst_type == ADDR_LE_DEV_PUBLIC) 682 bdaddr_type = BDADDR_LE_PUBLIC; 683 else 684 bdaddr_type = BDADDR_LE_RANDOM; 685 686 oob_data = hci_find_remote_oob_data(hdev, &hcon->dst, 687 bdaddr_type); 688 if (oob_data && oob_data->present) { 689 set_bit(SMP_FLAG_REMOTE_OOB, &smp->flags); 690 oob_flag = SMP_OOB_PRESENT; 691 memcpy(smp->rr, oob_data->rand256, 16); 692 memcpy(smp->pcnf, oob_data->hash256, 16); 693 SMP_DBG("OOB Remote Confirmation: %16phN", smp->pcnf); 694 SMP_DBG("OOB Remote Random: %16phN", smp->rr); 695 } 696 697 } else { 698 authreq &= ~SMP_AUTH_SC; 699 } 700 701 if (rsp == NULL) { 702 req->io_capability = conn->hcon->io_capability; 703 req->oob_flag = oob_flag; 704 req->max_key_size = hdev->le_max_key_size; 705 req->init_key_dist = local_dist; 706 req->resp_key_dist = remote_dist; 707 req->auth_req = (authreq & AUTH_REQ_MASK(hdev)); 708 709 smp->remote_key_dist = remote_dist; 710 return; 711 } 712 713 rsp->io_capability = conn->hcon->io_capability; 714 rsp->oob_flag = oob_flag; 715 rsp->max_key_size = hdev->le_max_key_size; 716 rsp->init_key_dist = req->init_key_dist & remote_dist; 717 rsp->resp_key_dist = req->resp_key_dist & local_dist; 718 rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev)); 719 720 smp->remote_key_dist = rsp->init_key_dist; 721 } 722 check_enc_key_size(struct l2cap_conn * conn,__u8 max_key_size)723 static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size) 724 { 725 struct l2cap_chan *chan = conn->smp; 726 struct hci_dev *hdev = conn->hcon->hdev; 727 struct smp_chan *smp = chan->data; 728 729 if (conn->hcon->pending_sec_level == BT_SECURITY_FIPS && 730 max_key_size != SMP_MAX_ENC_KEY_SIZE) 731 return SMP_ENC_KEY_SIZE; 732 733 if (max_key_size > hdev->le_max_key_size || 734 max_key_size < SMP_MIN_ENC_KEY_SIZE) 735 return SMP_ENC_KEY_SIZE; 736 737 smp->enc_key_size = max_key_size; 738 739 return 0; 740 } 741 smp_chan_destroy(struct l2cap_conn * conn)742 static void smp_chan_destroy(struct l2cap_conn *conn) 743 { 744 struct l2cap_chan *chan = conn->smp; 745 struct smp_chan *smp = chan->data; 746 struct hci_conn *hcon = conn->hcon; 747 bool complete; 748 749 BUG_ON(!smp); 750 751 cancel_delayed_work_sync(&smp->security_timer); 752 753 complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags); 754 mgmt_smp_complete(hcon, complete); 755 756 kfree_sensitive(smp->csrk); 757 kfree_sensitive(smp->responder_csrk); 758 kfree_sensitive(smp->link_key); 759 760 crypto_free_shash(smp->tfm_cmac); 761 crypto_free_kpp(smp->tfm_ecdh); 762 763 /* Ensure that we don't leave any debug key around if debug key 764 * support hasn't been explicitly enabled. 765 */ 766 if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG && 767 !hci_dev_test_flag(hcon->hdev, HCI_KEEP_DEBUG_KEYS)) { 768 list_del_rcu(&smp->ltk->list); 769 kfree_rcu(smp->ltk, rcu); 770 smp->ltk = NULL; 771 } 772 773 /* If pairing failed clean up any keys we might have */ 774 if (!complete) { 775 if (smp->ltk) { 776 list_del_rcu(&smp->ltk->list); 777 kfree_rcu(smp->ltk, rcu); 778 } 779 780 if (smp->responder_ltk) { 781 list_del_rcu(&smp->responder_ltk->list); 782 kfree_rcu(smp->responder_ltk, rcu); 783 } 784 785 if (smp->remote_irk) { 786 list_del_rcu(&smp->remote_irk->list); 787 kfree_rcu(smp->remote_irk, rcu); 788 } 789 } 790 791 chan->data = NULL; 792 kfree_sensitive(smp); 793 hci_conn_drop(hcon); 794 } 795 smp_failure(struct l2cap_conn * conn,u8 reason)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 get_auth_method(struct smp_chan * smp,u8 local_io,u8 remote_io)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 tk_request(struct l2cap_conn * conn,u8 remote_oob,u8 auth,u8 local_io,u8 remote_io)850 static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth, 851 u8 local_io, u8 remote_io) 852 { 853 struct hci_conn *hcon = conn->hcon; 854 struct l2cap_chan *chan = conn->smp; 855 struct smp_chan *smp = chan->data; 856 u32 passkey = 0; 857 int ret; 858 859 /* Initialize key for JUST WORKS */ 860 memset(smp->tk, 0, sizeof(smp->tk)); 861 clear_bit(SMP_FLAG_TK_VALID, &smp->flags); 862 863 bt_dev_dbg(hcon->hdev, "auth:%u lcl:%u rem:%u", auth, local_io, 864 remote_io); 865 866 /* If neither side wants MITM, either "just" confirm an incoming 867 * request or use just-works for outgoing ones. The JUST_CFM 868 * will be converted to JUST_WORKS if necessary later in this 869 * function. If either side has MITM look up the method from the 870 * table. 871 */ 872 if (!(auth & SMP_AUTH_MITM)) 873 smp->method = JUST_CFM; 874 else 875 smp->method = get_auth_method(smp, local_io, remote_io); 876 877 /* Don't confirm locally initiated pairing attempts */ 878 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, 879 &smp->flags)) 880 smp->method = JUST_WORKS; 881 882 /* Don't bother user space with no IO capabilities */ 883 if (smp->method == JUST_CFM && 884 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 885 smp->method = JUST_WORKS; 886 887 /* If Just Works, Continue with Zero TK and ask user-space for 888 * confirmation */ 889 if (smp->method == JUST_WORKS) { 890 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, 891 hcon->type, 892 hcon->dst_type, 893 passkey, 1); 894 if (ret) 895 return ret; 896 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 897 return 0; 898 } 899 900 /* If this function is used for SC -> legacy fallback we 901 * can only recover the just-works case. 902 */ 903 if (test_bit(SMP_FLAG_SC, &smp->flags)) 904 return -EINVAL; 905 906 /* Not Just Works/Confirm results in MITM Authentication */ 907 if (smp->method != JUST_CFM) { 908 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags); 909 if (hcon->pending_sec_level < BT_SECURITY_HIGH) 910 hcon->pending_sec_level = BT_SECURITY_HIGH; 911 } 912 913 /* If both devices have Keyboard-Display I/O, the initiator 914 * Confirms and the responder Enters the passkey. 915 */ 916 if (smp->method == OVERLAP) { 917 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 918 smp->method = CFM_PASSKEY; 919 else 920 smp->method = REQ_PASSKEY; 921 } 922 923 /* Generate random passkey. */ 924 if (smp->method == CFM_PASSKEY) { 925 memset(smp->tk, 0, sizeof(smp->tk)); 926 get_random_bytes(&passkey, sizeof(passkey)); 927 passkey %= 1000000; 928 put_unaligned_le32(passkey, smp->tk); 929 bt_dev_dbg(hcon->hdev, "PassKey: %u", passkey); 930 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 931 } 932 933 if (smp->method == REQ_PASSKEY) 934 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst, 935 hcon->type, hcon->dst_type); 936 else if (smp->method == JUST_CFM) 937 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, 938 hcon->type, hcon->dst_type, 939 passkey, 1); 940 else 941 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst, 942 hcon->type, hcon->dst_type, 943 passkey, 0); 944 945 return ret; 946 } 947 smp_confirm(struct smp_chan * smp)948 static u8 smp_confirm(struct smp_chan *smp) 949 { 950 struct l2cap_conn *conn = smp->conn; 951 struct smp_cmd_pairing_confirm cp; 952 int ret; 953 954 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 955 956 ret = smp_c1(smp->tk, smp->prnd, smp->preq, smp->prsp, 957 conn->hcon->init_addr_type, &conn->hcon->init_addr, 958 conn->hcon->resp_addr_type, &conn->hcon->resp_addr, 959 cp.confirm_val); 960 if (ret) 961 return SMP_UNSPECIFIED; 962 963 clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 964 965 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp); 966 967 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 968 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 969 else 970 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 971 972 return 0; 973 } 974 smp_random(struct smp_chan * smp)975 static u8 smp_random(struct smp_chan *smp) 976 { 977 struct l2cap_conn *conn = smp->conn; 978 struct hci_conn *hcon = conn->hcon; 979 u8 confirm[16]; 980 int ret; 981 982 bt_dev_dbg(conn->hcon->hdev, "conn %p %s", conn, 983 test_bit(SMP_FLAG_INITIATOR, &smp->flags) ? "initiator" : 984 "responder"); 985 986 ret = smp_c1(smp->tk, smp->rrnd, smp->preq, smp->prsp, 987 hcon->init_addr_type, &hcon->init_addr, 988 hcon->resp_addr_type, &hcon->resp_addr, confirm); 989 if (ret) 990 return SMP_UNSPECIFIED; 991 992 if (crypto_memneq(smp->pcnf, confirm, sizeof(smp->pcnf))) { 993 bt_dev_err(hcon->hdev, "pairing failed " 994 "(confirmation values mismatch)"); 995 return SMP_CONFIRM_FAILED; 996 } 997 998 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 999 u8 stk[16]; 1000 __le64 rand = 0; 1001 __le16 ediv = 0; 1002 1003 smp_s1(smp->tk, smp->rrnd, smp->prnd, stk); 1004 1005 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) 1006 return SMP_UNSPECIFIED; 1007 1008 hci_le_start_enc(hcon, ediv, rand, stk, smp->enc_key_size); 1009 hcon->enc_key_size = smp->enc_key_size; 1010 set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); 1011 } else { 1012 u8 stk[16], auth; 1013 __le64 rand = 0; 1014 __le16 ediv = 0; 1015 1016 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 1017 smp->prnd); 1018 1019 smp_s1(smp->tk, smp->prnd, smp->rrnd, stk); 1020 1021 if (hcon->pending_sec_level == BT_SECURITY_HIGH) 1022 auth = 1; 1023 else 1024 auth = 0; 1025 1026 /* Even though there's no _RESPONDER suffix this is the 1027 * responder STK we're adding for later lookup (the initiator 1028 * STK never needs to be stored). 1029 */ 1030 hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 1031 SMP_STK, auth, stk, smp->enc_key_size, ediv, rand); 1032 } 1033 1034 return 0; 1035 } 1036 smp_notify_keys(struct l2cap_conn * conn)1037 static void smp_notify_keys(struct l2cap_conn *conn) 1038 { 1039 struct l2cap_chan *chan = conn->smp; 1040 struct smp_chan *smp = chan->data; 1041 struct hci_conn *hcon = conn->hcon; 1042 struct hci_dev *hdev = hcon->hdev; 1043 struct smp_cmd_pairing *req = (void *) &smp->preq[1]; 1044 struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1]; 1045 bool persistent; 1046 1047 if (hcon->type == ACL_LINK) { 1048 if (hcon->key_type == HCI_LK_DEBUG_COMBINATION) 1049 persistent = false; 1050 else 1051 persistent = !test_bit(HCI_CONN_FLUSH_KEY, 1052 &hcon->flags); 1053 } else { 1054 /* The LTKs, IRKs and CSRKs should be persistent only if 1055 * both sides had the bonding bit set in their 1056 * authentication requests. 1057 */ 1058 persistent = !!((req->auth_req & rsp->auth_req) & 1059 SMP_AUTH_BONDING); 1060 } 1061 1062 if (smp->remote_irk) { 1063 mgmt_new_irk(hdev, smp->remote_irk, persistent); 1064 1065 /* Now that user space can be considered to know the 1066 * identity address track the connection based on it 1067 * from now on (assuming this is an LE link). 1068 */ 1069 if (hcon->type == LE_LINK) { 1070 bacpy(&hcon->dst, &smp->remote_irk->bdaddr); 1071 hcon->dst_type = smp->remote_irk->addr_type; 1072 /* Use a short delay to make sure the new address is 1073 * propagated _before_ the channels. 1074 */ 1075 queue_delayed_work(hdev->workqueue, 1076 &conn->id_addr_timer, 1077 ID_ADDR_TIMEOUT); 1078 } 1079 } 1080 1081 if (smp->csrk) { 1082 smp->csrk->bdaddr_type = hcon->dst_type; 1083 bacpy(&smp->csrk->bdaddr, &hcon->dst); 1084 mgmt_new_csrk(hdev, smp->csrk, persistent); 1085 } 1086 1087 if (smp->responder_csrk) { 1088 smp->responder_csrk->bdaddr_type = hcon->dst_type; 1089 bacpy(&smp->responder_csrk->bdaddr, &hcon->dst); 1090 mgmt_new_csrk(hdev, smp->responder_csrk, persistent); 1091 } 1092 1093 if (smp->ltk) { 1094 smp->ltk->bdaddr_type = hcon->dst_type; 1095 bacpy(&smp->ltk->bdaddr, &hcon->dst); 1096 mgmt_new_ltk(hdev, smp->ltk, persistent); 1097 } 1098 1099 if (smp->responder_ltk) { 1100 smp->responder_ltk->bdaddr_type = hcon->dst_type; 1101 bacpy(&smp->responder_ltk->bdaddr, &hcon->dst); 1102 mgmt_new_ltk(hdev, smp->responder_ltk, persistent); 1103 } 1104 1105 if (smp->link_key) { 1106 struct link_key *key; 1107 u8 type; 1108 1109 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags)) 1110 type = HCI_LK_DEBUG_COMBINATION; 1111 else if (hcon->sec_level == BT_SECURITY_FIPS) 1112 type = HCI_LK_AUTH_COMBINATION_P256; 1113 else 1114 type = HCI_LK_UNAUTH_COMBINATION_P256; 1115 1116 key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst, 1117 smp->link_key, type, 0, &persistent); 1118 if (key) { 1119 mgmt_new_link_key(hdev, key, persistent); 1120 1121 /* Don't keep debug keys around if the relevant 1122 * flag is not set. 1123 */ 1124 if (!hci_dev_test_flag(hdev, HCI_KEEP_DEBUG_KEYS) && 1125 key->type == HCI_LK_DEBUG_COMBINATION) { 1126 list_del_rcu(&key->list); 1127 kfree_rcu(key, rcu); 1128 } 1129 } 1130 } 1131 } 1132 sc_add_ltk(struct smp_chan * smp)1133 static void sc_add_ltk(struct smp_chan *smp) 1134 { 1135 struct hci_conn *hcon = smp->conn->hcon; 1136 u8 key_type, auth; 1137 1138 if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags)) 1139 key_type = SMP_LTK_P256_DEBUG; 1140 else 1141 key_type = SMP_LTK_P256; 1142 1143 if (hcon->pending_sec_level == BT_SECURITY_FIPS) 1144 auth = 1; 1145 else 1146 auth = 0; 1147 1148 smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 1149 key_type, auth, smp->tk, smp->enc_key_size, 1150 0, 0); 1151 } 1152 sc_generate_link_key(struct smp_chan * smp)1153 static void sc_generate_link_key(struct smp_chan *smp) 1154 { 1155 /* From core spec. Spells out in ASCII as 'lebr'. */ 1156 const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c }; 1157 1158 smp->link_key = kzalloc(16, GFP_KERNEL); 1159 if (!smp->link_key) 1160 return; 1161 1162 if (test_bit(SMP_FLAG_CT2, &smp->flags)) { 1163 /* SALT = 0x000000000000000000000000746D7031 */ 1164 const u8 salt[16] = { 0x31, 0x70, 0x6d, 0x74 }; 1165 1166 if (smp_h7(smp->tfm_cmac, smp->tk, salt, smp->link_key)) { 1167 kfree_sensitive(smp->link_key); 1168 smp->link_key = NULL; 1169 return; 1170 } 1171 } else { 1172 /* From core spec. Spells out in ASCII as 'tmp1'. */ 1173 const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 }; 1174 1175 if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) { 1176 kfree_sensitive(smp->link_key); 1177 smp->link_key = NULL; 1178 return; 1179 } 1180 } 1181 1182 if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) { 1183 kfree_sensitive(smp->link_key); 1184 smp->link_key = NULL; 1185 return; 1186 } 1187 } 1188 smp_allow_key_dist(struct smp_chan * smp)1189 static void smp_allow_key_dist(struct smp_chan *smp) 1190 { 1191 /* Allow the first expected phase 3 PDU. The rest of the PDUs 1192 * will be allowed in each PDU handler to ensure we receive 1193 * them in the correct order. 1194 */ 1195 if (smp->remote_key_dist & SMP_DIST_ENC_KEY) 1196 SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO); 1197 else if (smp->remote_key_dist & SMP_DIST_ID_KEY) 1198 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); 1199 else if (smp->remote_key_dist & SMP_DIST_SIGN) 1200 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 1201 } 1202 sc_generate_ltk(struct smp_chan * smp)1203 static void sc_generate_ltk(struct smp_chan *smp) 1204 { 1205 /* From core spec. Spells out in ASCII as 'brle'. */ 1206 const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 }; 1207 struct hci_conn *hcon = smp->conn->hcon; 1208 struct hci_dev *hdev = hcon->hdev; 1209 struct link_key *key; 1210 1211 key = hci_find_link_key(hdev, &hcon->dst); 1212 if (!key) { 1213 bt_dev_err(hdev, "no Link Key found to generate LTK"); 1214 return; 1215 } 1216 1217 if (key->type == HCI_LK_DEBUG_COMBINATION) 1218 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1219 1220 if (test_bit(SMP_FLAG_CT2, &smp->flags)) { 1221 /* SALT = 0x000000000000000000000000746D7032 */ 1222 const u8 salt[16] = { 0x32, 0x70, 0x6d, 0x74 }; 1223 1224 if (smp_h7(smp->tfm_cmac, key->val, salt, smp->tk)) 1225 return; 1226 } else { 1227 /* From core spec. Spells out in ASCII as 'tmp2'. */ 1228 const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 }; 1229 1230 if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk)) 1231 return; 1232 } 1233 1234 if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk)) 1235 return; 1236 1237 sc_add_ltk(smp); 1238 } 1239 smp_distribute_keys(struct smp_chan * smp)1240 static void smp_distribute_keys(struct smp_chan *smp) 1241 { 1242 struct smp_cmd_pairing *req, *rsp; 1243 struct l2cap_conn *conn = smp->conn; 1244 struct hci_conn *hcon = conn->hcon; 1245 struct hci_dev *hdev = hcon->hdev; 1246 __u8 *keydist; 1247 1248 bt_dev_dbg(hdev, "conn %p", conn); 1249 1250 rsp = (void *) &smp->prsp[1]; 1251 1252 /* The responder sends its keys first */ 1253 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags) && 1254 (smp->remote_key_dist & KEY_DIST_MASK)) { 1255 smp_allow_key_dist(smp); 1256 return; 1257 } 1258 1259 req = (void *) &smp->preq[1]; 1260 1261 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 1262 keydist = &rsp->init_key_dist; 1263 *keydist &= req->init_key_dist; 1264 } else { 1265 keydist = &rsp->resp_key_dist; 1266 *keydist &= req->resp_key_dist; 1267 } 1268 1269 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1270 if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY)) 1271 sc_generate_link_key(smp); 1272 if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY)) 1273 sc_generate_ltk(smp); 1274 1275 /* Clear the keys which are generated but not distributed */ 1276 *keydist &= ~SMP_SC_NO_DIST; 1277 } 1278 1279 bt_dev_dbg(hdev, "keydist 0x%x", *keydist); 1280 1281 if (*keydist & SMP_DIST_ENC_KEY) { 1282 struct smp_cmd_encrypt_info enc; 1283 struct smp_cmd_initiator_ident ident; 1284 struct smp_ltk *ltk; 1285 u8 authenticated; 1286 __le16 ediv; 1287 __le64 rand; 1288 1289 /* Make sure we generate only the significant amount of 1290 * bytes based on the encryption key size, and set the rest 1291 * of the value to zeroes. 1292 */ 1293 get_random_bytes(enc.ltk, smp->enc_key_size); 1294 memset(enc.ltk + smp->enc_key_size, 0, 1295 sizeof(enc.ltk) - smp->enc_key_size); 1296 1297 get_random_bytes(&ediv, sizeof(ediv)); 1298 get_random_bytes(&rand, sizeof(rand)); 1299 1300 smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc); 1301 1302 authenticated = hcon->sec_level == BT_SECURITY_HIGH; 1303 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, 1304 SMP_LTK_RESPONDER, authenticated, enc.ltk, 1305 smp->enc_key_size, ediv, rand); 1306 smp->responder_ltk = ltk; 1307 1308 ident.ediv = ediv; 1309 ident.rand = rand; 1310 1311 smp_send_cmd(conn, SMP_CMD_INITIATOR_IDENT, sizeof(ident), 1312 &ident); 1313 1314 *keydist &= ~SMP_DIST_ENC_KEY; 1315 } 1316 1317 if (*keydist & SMP_DIST_ID_KEY) { 1318 struct smp_cmd_ident_addr_info addrinfo; 1319 struct smp_cmd_ident_info idinfo; 1320 1321 memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk)); 1322 1323 smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo); 1324 1325 /* The hci_conn contains the local identity address 1326 * after the connection has been established. 1327 * 1328 * This is true even when the connection has been 1329 * established using a resolvable random address. 1330 */ 1331 bacpy(&addrinfo.bdaddr, &hcon->src); 1332 addrinfo.addr_type = hcon->src_type; 1333 1334 smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo), 1335 &addrinfo); 1336 1337 *keydist &= ~SMP_DIST_ID_KEY; 1338 } 1339 1340 if (*keydist & SMP_DIST_SIGN) { 1341 struct smp_cmd_sign_info sign; 1342 struct smp_csrk *csrk; 1343 1344 /* Generate a new random key */ 1345 get_random_bytes(sign.csrk, sizeof(sign.csrk)); 1346 1347 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); 1348 if (csrk) { 1349 if (hcon->sec_level > BT_SECURITY_MEDIUM) 1350 csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED; 1351 else 1352 csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED; 1353 memcpy(csrk->val, sign.csrk, sizeof(csrk->val)); 1354 } 1355 smp->responder_csrk = csrk; 1356 1357 smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign); 1358 1359 *keydist &= ~SMP_DIST_SIGN; 1360 } 1361 1362 /* If there are still keys to be received wait for them */ 1363 if (smp->remote_key_dist & KEY_DIST_MASK) { 1364 smp_allow_key_dist(smp); 1365 return; 1366 } 1367 1368 set_bit(SMP_FLAG_COMPLETE, &smp->flags); 1369 smp_notify_keys(conn); 1370 1371 smp_chan_destroy(conn); 1372 } 1373 smp_timeout(struct work_struct * work)1374 static void smp_timeout(struct work_struct *work) 1375 { 1376 struct smp_chan *smp = container_of(work, struct smp_chan, 1377 security_timer.work); 1378 struct l2cap_conn *conn = smp->conn; 1379 1380 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 1381 1382 hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM); 1383 } 1384 smp_chan_create(struct l2cap_conn * conn)1385 static struct smp_chan *smp_chan_create(struct l2cap_conn *conn) 1386 { 1387 struct hci_conn *hcon = conn->hcon; 1388 struct l2cap_chan *chan = conn->smp; 1389 struct smp_chan *smp; 1390 1391 smp = kzalloc(sizeof(*smp), GFP_ATOMIC); 1392 if (!smp) 1393 return NULL; 1394 1395 smp->tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 1396 if (IS_ERR(smp->tfm_cmac)) { 1397 bt_dev_err(hcon->hdev, "Unable to create CMAC crypto context"); 1398 goto zfree_smp; 1399 } 1400 1401 smp->tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0); 1402 if (IS_ERR(smp->tfm_ecdh)) { 1403 bt_dev_err(hcon->hdev, "Unable to create ECDH crypto context"); 1404 goto free_shash; 1405 } 1406 1407 smp->conn = conn; 1408 chan->data = smp; 1409 1410 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL); 1411 1412 INIT_DELAYED_WORK(&smp->security_timer, smp_timeout); 1413 1414 hci_conn_hold(hcon); 1415 1416 return smp; 1417 1418 free_shash: 1419 crypto_free_shash(smp->tfm_cmac); 1420 zfree_smp: 1421 kfree_sensitive(smp); 1422 return NULL; 1423 } 1424 sc_mackey_and_ltk(struct smp_chan * smp,u8 mackey[16],u8 ltk[16])1425 static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16]) 1426 { 1427 struct hci_conn *hcon = smp->conn->hcon; 1428 u8 *na, *nb, a[7], b[7]; 1429 1430 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 1431 na = smp->prnd; 1432 nb = smp->rrnd; 1433 } else { 1434 na = smp->rrnd; 1435 nb = smp->prnd; 1436 } 1437 1438 memcpy(a, &hcon->init_addr, 6); 1439 memcpy(b, &hcon->resp_addr, 6); 1440 a[6] = hcon->init_addr_type; 1441 b[6] = hcon->resp_addr_type; 1442 1443 return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk); 1444 } 1445 sc_dhkey_check(struct smp_chan * smp)1446 static void sc_dhkey_check(struct smp_chan *smp) 1447 { 1448 struct hci_conn *hcon = smp->conn->hcon; 1449 struct smp_cmd_dhkey_check check; 1450 u8 a[7], b[7], *local_addr, *remote_addr; 1451 u8 io_cap[3], r[16]; 1452 1453 memcpy(a, &hcon->init_addr, 6); 1454 memcpy(b, &hcon->resp_addr, 6); 1455 a[6] = hcon->init_addr_type; 1456 b[6] = hcon->resp_addr_type; 1457 1458 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 1459 local_addr = a; 1460 remote_addr = b; 1461 memcpy(io_cap, &smp->preq[1], 3); 1462 } else { 1463 local_addr = b; 1464 remote_addr = a; 1465 memcpy(io_cap, &smp->prsp[1], 3); 1466 } 1467 1468 memset(r, 0, sizeof(r)); 1469 1470 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 1471 put_unaligned_le32(hcon->passkey_notify, r); 1472 1473 if (smp->method == REQ_OOB) 1474 memcpy(r, smp->rr, 16); 1475 1476 smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap, 1477 local_addr, remote_addr, check.e); 1478 1479 smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check); 1480 } 1481 sc_passkey_send_confirm(struct smp_chan * smp)1482 static u8 sc_passkey_send_confirm(struct smp_chan *smp) 1483 { 1484 struct l2cap_conn *conn = smp->conn; 1485 struct hci_conn *hcon = conn->hcon; 1486 struct smp_cmd_pairing_confirm cfm; 1487 u8 r; 1488 1489 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); 1490 r |= 0x80; 1491 1492 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1493 1494 if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r, 1495 cfm.confirm_val)) 1496 return SMP_UNSPECIFIED; 1497 1498 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); 1499 1500 return 0; 1501 } 1502 sc_passkey_round(struct smp_chan * smp,u8 smp_op)1503 static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op) 1504 { 1505 struct l2cap_conn *conn = smp->conn; 1506 struct hci_conn *hcon = conn->hcon; 1507 struct hci_dev *hdev = hcon->hdev; 1508 u8 cfm[16], r; 1509 1510 /* Ignore the PDU if we've already done 20 rounds (0 - 19) */ 1511 if (smp->passkey_round >= 20) 1512 return 0; 1513 1514 switch (smp_op) { 1515 case SMP_CMD_PAIRING_RANDOM: 1516 r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); 1517 r |= 0x80; 1518 1519 if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, 1520 smp->rrnd, r, cfm)) 1521 return SMP_UNSPECIFIED; 1522 1523 if (crypto_memneq(smp->pcnf, cfm, 16)) 1524 return SMP_CONFIRM_FAILED; 1525 1526 smp->passkey_round++; 1527 1528 if (smp->passkey_round == 20) { 1529 /* Generate MacKey and LTK */ 1530 if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk)) 1531 return SMP_UNSPECIFIED; 1532 } 1533 1534 /* The round is only complete when the initiator 1535 * receives pairing random. 1536 */ 1537 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 1538 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 1539 sizeof(smp->prnd), smp->prnd); 1540 if (smp->passkey_round == 20) 1541 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1542 else 1543 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1544 return 0; 1545 } 1546 1547 /* Start the next round */ 1548 if (smp->passkey_round != 20) 1549 return sc_passkey_round(smp, 0); 1550 1551 /* Passkey rounds are complete - start DHKey Check */ 1552 sc_dhkey_check(smp); 1553 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1554 1555 break; 1556 1557 case SMP_CMD_PAIRING_CONFIRM: 1558 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { 1559 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 1560 return 0; 1561 } 1562 1563 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 1564 1565 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 1566 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 1567 sizeof(smp->prnd), smp->prnd); 1568 return 0; 1569 } 1570 1571 return sc_passkey_send_confirm(smp); 1572 1573 case SMP_CMD_PUBLIC_KEY: 1574 default: 1575 /* Initiating device starts the round */ 1576 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 1577 return 0; 1578 1579 bt_dev_dbg(hdev, "Starting passkey round %u", 1580 smp->passkey_round + 1); 1581 1582 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1583 1584 return sc_passkey_send_confirm(smp); 1585 } 1586 1587 return 0; 1588 } 1589 sc_user_reply(struct smp_chan * smp,u16 mgmt_op,__le32 passkey)1590 static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey) 1591 { 1592 struct l2cap_conn *conn = smp->conn; 1593 struct hci_conn *hcon = conn->hcon; 1594 u8 smp_op; 1595 1596 clear_bit(SMP_FLAG_WAIT_USER, &smp->flags); 1597 1598 switch (mgmt_op) { 1599 case MGMT_OP_USER_PASSKEY_NEG_REPLY: 1600 smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED); 1601 return 0; 1602 case MGMT_OP_USER_CONFIRM_NEG_REPLY: 1603 smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED); 1604 return 0; 1605 case MGMT_OP_USER_PASSKEY_REPLY: 1606 hcon->passkey_notify = le32_to_cpu(passkey); 1607 smp->passkey_round = 0; 1608 1609 if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) 1610 smp_op = SMP_CMD_PAIRING_CONFIRM; 1611 else 1612 smp_op = 0; 1613 1614 if (sc_passkey_round(smp, smp_op)) 1615 return -EIO; 1616 1617 return 0; 1618 } 1619 1620 /* Initiator sends DHKey check first */ 1621 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 1622 sc_dhkey_check(smp); 1623 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 1624 } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) { 1625 sc_dhkey_check(smp); 1626 sc_add_ltk(smp); 1627 } 1628 1629 return 0; 1630 } 1631 smp_user_confirm_reply(struct hci_conn * hcon,u16 mgmt_op,__le32 passkey)1632 int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey) 1633 { 1634 struct l2cap_conn *conn = hcon->l2cap_data; 1635 struct l2cap_chan *chan; 1636 struct smp_chan *smp; 1637 u32 value; 1638 int err; 1639 1640 if (!conn) 1641 return -ENOTCONN; 1642 1643 bt_dev_dbg(conn->hcon->hdev, ""); 1644 1645 chan = conn->smp; 1646 if (!chan) 1647 return -ENOTCONN; 1648 1649 l2cap_chan_lock(chan); 1650 if (!chan->data) { 1651 err = -ENOTCONN; 1652 goto unlock; 1653 } 1654 1655 smp = chan->data; 1656 1657 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1658 err = sc_user_reply(smp, mgmt_op, passkey); 1659 goto unlock; 1660 } 1661 1662 switch (mgmt_op) { 1663 case MGMT_OP_USER_PASSKEY_REPLY: 1664 value = le32_to_cpu(passkey); 1665 memset(smp->tk, 0, sizeof(smp->tk)); 1666 bt_dev_dbg(conn->hcon->hdev, "PassKey: %u", value); 1667 put_unaligned_le32(value, smp->tk); 1668 fallthrough; 1669 case MGMT_OP_USER_CONFIRM_REPLY: 1670 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 1671 break; 1672 case MGMT_OP_USER_PASSKEY_NEG_REPLY: 1673 case MGMT_OP_USER_CONFIRM_NEG_REPLY: 1674 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); 1675 err = 0; 1676 goto unlock; 1677 default: 1678 smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); 1679 err = -EOPNOTSUPP; 1680 goto unlock; 1681 } 1682 1683 err = 0; 1684 1685 /* If it is our turn to send Pairing Confirm, do so now */ 1686 if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) { 1687 u8 rsp = smp_confirm(smp); 1688 if (rsp) 1689 smp_failure(conn, rsp); 1690 } 1691 1692 unlock: 1693 l2cap_chan_unlock(chan); 1694 return err; 1695 } 1696 build_bredr_pairing_cmd(struct smp_chan * smp,struct smp_cmd_pairing * req,struct smp_cmd_pairing * rsp)1697 static void build_bredr_pairing_cmd(struct smp_chan *smp, 1698 struct smp_cmd_pairing *req, 1699 struct smp_cmd_pairing *rsp) 1700 { 1701 struct l2cap_conn *conn = smp->conn; 1702 struct hci_dev *hdev = conn->hcon->hdev; 1703 u8 local_dist = 0, remote_dist = 0; 1704 1705 if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { 1706 local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 1707 remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; 1708 } 1709 1710 if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) 1711 remote_dist |= SMP_DIST_ID_KEY; 1712 1713 if (hci_dev_test_flag(hdev, HCI_PRIVACY)) 1714 local_dist |= SMP_DIST_ID_KEY; 1715 1716 if (!rsp) { 1717 memset(req, 0, sizeof(*req)); 1718 1719 req->auth_req = SMP_AUTH_CT2; 1720 req->init_key_dist = local_dist; 1721 req->resp_key_dist = remote_dist; 1722 req->max_key_size = conn->hcon->enc_key_size; 1723 1724 smp->remote_key_dist = remote_dist; 1725 1726 return; 1727 } 1728 1729 memset(rsp, 0, sizeof(*rsp)); 1730 1731 rsp->auth_req = SMP_AUTH_CT2; 1732 rsp->max_key_size = conn->hcon->enc_key_size; 1733 rsp->init_key_dist = req->init_key_dist & remote_dist; 1734 rsp->resp_key_dist = req->resp_key_dist & local_dist; 1735 1736 smp->remote_key_dist = rsp->init_key_dist; 1737 } 1738 smp_cmd_pairing_req(struct l2cap_conn * conn,struct sk_buff * skb)1739 static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) 1740 { 1741 struct smp_cmd_pairing rsp, *req = (void *) skb->data; 1742 struct l2cap_chan *chan = conn->smp; 1743 struct hci_dev *hdev = conn->hcon->hdev; 1744 struct smp_chan *smp = chan->data; 1745 u8 key_size, auth, sec_level; 1746 int ret; 1747 1748 bt_dev_dbg(hdev, "conn %p", conn); 1749 1750 if (skb->len < sizeof(*req)) 1751 return SMP_INVALID_PARAMS; 1752 1753 if (smp && test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 1754 return SMP_CMD_NOTSUPP; 1755 1756 if (!smp) { 1757 smp = smp_chan_create(conn); 1758 if (!smp) 1759 return SMP_UNSPECIFIED; 1760 } 1761 1762 /* We didn't start the pairing, so match remote */ 1763 auth = req->auth_req & AUTH_REQ_MASK(hdev); 1764 1765 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && 1766 (auth & SMP_AUTH_BONDING)) 1767 return SMP_PAIRING_NOTSUPP; 1768 1769 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 1770 return SMP_AUTH_REQUIREMENTS; 1771 1772 smp->preq[0] = SMP_CMD_PAIRING_REQ; 1773 memcpy(&smp->preq[1], req, sizeof(*req)); 1774 skb_pull(skb, sizeof(*req)); 1775 1776 /* If the remote side's OOB flag is set it means it has 1777 * successfully received our local OOB data - therefore set the 1778 * flag to indicate that local OOB is in use. 1779 */ 1780 if (req->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob) 1781 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); 1782 1783 /* SMP over BR/EDR requires special treatment */ 1784 if (conn->hcon->type == ACL_LINK) { 1785 /* We must have a BR/EDR SC link */ 1786 if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) && 1787 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 1788 return SMP_CROSS_TRANSP_NOT_ALLOWED; 1789 1790 set_bit(SMP_FLAG_SC, &smp->flags); 1791 1792 build_bredr_pairing_cmd(smp, req, &rsp); 1793 1794 if (req->auth_req & SMP_AUTH_CT2) 1795 set_bit(SMP_FLAG_CT2, &smp->flags); 1796 1797 key_size = min(req->max_key_size, rsp.max_key_size); 1798 if (check_enc_key_size(conn, key_size)) 1799 return SMP_ENC_KEY_SIZE; 1800 1801 /* Clear bits which are generated but not distributed */ 1802 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1803 1804 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1805 memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); 1806 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); 1807 1808 smp_distribute_keys(smp); 1809 return 0; 1810 } 1811 1812 build_pairing_cmd(conn, req, &rsp, auth); 1813 1814 if (rsp.auth_req & SMP_AUTH_SC) { 1815 set_bit(SMP_FLAG_SC, &smp->flags); 1816 1817 if (rsp.auth_req & SMP_AUTH_CT2) 1818 set_bit(SMP_FLAG_CT2, &smp->flags); 1819 } 1820 1821 if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 1822 sec_level = BT_SECURITY_MEDIUM; 1823 else 1824 sec_level = authreq_to_seclevel(auth); 1825 1826 if (sec_level > conn->hcon->pending_sec_level) 1827 conn->hcon->pending_sec_level = sec_level; 1828 1829 /* If we need MITM check that it can be achieved */ 1830 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { 1831 u8 method; 1832 1833 method = get_auth_method(smp, conn->hcon->io_capability, 1834 req->io_capability); 1835 if (method == JUST_WORKS || method == JUST_CFM) 1836 return SMP_AUTH_REQUIREMENTS; 1837 } 1838 1839 key_size = min(req->max_key_size, rsp.max_key_size); 1840 if (check_enc_key_size(conn, key_size)) 1841 return SMP_ENC_KEY_SIZE; 1842 1843 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 1844 1845 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1846 memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); 1847 1848 smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); 1849 1850 clear_bit(SMP_FLAG_INITIATOR, &smp->flags); 1851 1852 /* Strictly speaking we shouldn't allow Pairing Confirm for the 1853 * SC case, however some implementations incorrectly copy RFU auth 1854 * req bits from our security request, which may create a false 1855 * positive SC enablement. 1856 */ 1857 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 1858 1859 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 1860 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); 1861 /* Clear bits which are generated but not distributed */ 1862 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1863 /* Wait for Public Key from Initiating Device */ 1864 return 0; 1865 } 1866 1867 /* Request setup of TK */ 1868 ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability); 1869 if (ret) 1870 return SMP_UNSPECIFIED; 1871 1872 return 0; 1873 } 1874 sc_send_public_key(struct smp_chan * smp)1875 static u8 sc_send_public_key(struct smp_chan *smp) 1876 { 1877 struct hci_dev *hdev = smp->conn->hcon->hdev; 1878 1879 bt_dev_dbg(hdev, ""); 1880 1881 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { 1882 struct l2cap_chan *chan = hdev->smp_data; 1883 struct smp_dev *smp_dev; 1884 1885 if (!chan || !chan->data) 1886 return SMP_UNSPECIFIED; 1887 1888 smp_dev = chan->data; 1889 1890 memcpy(smp->local_pk, smp_dev->local_pk, 64); 1891 memcpy(smp->lr, smp_dev->local_rand, 16); 1892 1893 if (smp_dev->debug_key) 1894 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1895 1896 goto done; 1897 } 1898 1899 if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { 1900 bt_dev_dbg(hdev, "Using debug keys"); 1901 if (set_ecdh_privkey(smp->tfm_ecdh, debug_sk)) 1902 return SMP_UNSPECIFIED; 1903 memcpy(smp->local_pk, debug_pk, 64); 1904 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 1905 } else { 1906 while (true) { 1907 /* Generate key pair for Secure Connections */ 1908 if (generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk)) 1909 return SMP_UNSPECIFIED; 1910 1911 /* This is unlikely, but we need to check that 1912 * we didn't accidentally generate a debug key. 1913 */ 1914 if (crypto_memneq(smp->local_pk, debug_pk, 64)) 1915 break; 1916 } 1917 } 1918 1919 done: 1920 SMP_DBG("Local Public Key X: %32phN", smp->local_pk); 1921 SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32); 1922 1923 smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk); 1924 1925 return 0; 1926 } 1927 smp_cmd_pairing_rsp(struct l2cap_conn * conn,struct sk_buff * skb)1928 static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) 1929 { 1930 struct smp_cmd_pairing *req, *rsp = (void *) skb->data; 1931 struct l2cap_chan *chan = conn->smp; 1932 struct smp_chan *smp = chan->data; 1933 struct hci_dev *hdev = conn->hcon->hdev; 1934 u8 key_size, auth; 1935 int ret; 1936 1937 bt_dev_dbg(hdev, "conn %p", conn); 1938 1939 if (skb->len < sizeof(*rsp)) 1940 return SMP_INVALID_PARAMS; 1941 1942 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 1943 return SMP_CMD_NOTSUPP; 1944 1945 skb_pull(skb, sizeof(*rsp)); 1946 1947 req = (void *) &smp->preq[1]; 1948 1949 key_size = min(req->max_key_size, rsp->max_key_size); 1950 if (check_enc_key_size(conn, key_size)) 1951 return SMP_ENC_KEY_SIZE; 1952 1953 auth = rsp->auth_req & AUTH_REQ_MASK(hdev); 1954 1955 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 1956 return SMP_AUTH_REQUIREMENTS; 1957 1958 /* If the remote side's OOB flag is set it means it has 1959 * successfully received our local OOB data - therefore set the 1960 * flag to indicate that local OOB is in use. 1961 */ 1962 if (rsp->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob) 1963 set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); 1964 1965 smp->prsp[0] = SMP_CMD_PAIRING_RSP; 1966 memcpy(&smp->prsp[1], rsp, sizeof(*rsp)); 1967 1968 /* Update remote key distribution in case the remote cleared 1969 * some bits that we had enabled in our request. 1970 */ 1971 smp->remote_key_dist &= rsp->resp_key_dist; 1972 1973 if ((req->auth_req & SMP_AUTH_CT2) && (auth & SMP_AUTH_CT2)) 1974 set_bit(SMP_FLAG_CT2, &smp->flags); 1975 1976 /* For BR/EDR this means we're done and can start phase 3 */ 1977 if (conn->hcon->type == ACL_LINK) { 1978 /* Clear bits which are generated but not distributed */ 1979 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 1980 smp_distribute_keys(smp); 1981 return 0; 1982 } 1983 1984 if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC)) 1985 set_bit(SMP_FLAG_SC, &smp->flags); 1986 else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH) 1987 conn->hcon->pending_sec_level = BT_SECURITY_HIGH; 1988 1989 /* If we need MITM check that it can be achieved */ 1990 if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { 1991 u8 method; 1992 1993 method = get_auth_method(smp, req->io_capability, 1994 rsp->io_capability); 1995 if (method == JUST_WORKS || method == JUST_CFM) 1996 return SMP_AUTH_REQUIREMENTS; 1997 } 1998 1999 get_random_bytes(smp->prnd, sizeof(smp->prnd)); 2000 2001 /* Update remote key distribution in case the remote cleared 2002 * some bits that we had enabled in our request. 2003 */ 2004 smp->remote_key_dist &= rsp->resp_key_dist; 2005 2006 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 2007 /* Clear bits which are generated but not distributed */ 2008 smp->remote_key_dist &= ~SMP_SC_NO_DIST; 2009 SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); 2010 return sc_send_public_key(smp); 2011 } 2012 2013 auth |= req->auth_req; 2014 2015 ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability); 2016 if (ret) 2017 return SMP_UNSPECIFIED; 2018 2019 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 2020 2021 /* Can't compose response until we have been confirmed */ 2022 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) 2023 return smp_confirm(smp); 2024 2025 return 0; 2026 } 2027 sc_check_confirm(struct smp_chan * smp)2028 static u8 sc_check_confirm(struct smp_chan *smp) 2029 { 2030 struct l2cap_conn *conn = smp->conn; 2031 2032 bt_dev_dbg(conn->hcon->hdev, ""); 2033 2034 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2035 return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM); 2036 2037 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2038 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2039 smp->prnd); 2040 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2041 } 2042 2043 return 0; 2044 } 2045 2046 /* Work-around for some implementations that incorrectly copy RFU bits 2047 * from our security request and thereby create the impression that 2048 * we're doing SC when in fact the remote doesn't support it. 2049 */ fixup_sc_false_positive(struct smp_chan * smp)2050 static int fixup_sc_false_positive(struct smp_chan *smp) 2051 { 2052 struct l2cap_conn *conn = smp->conn; 2053 struct hci_conn *hcon = conn->hcon; 2054 struct hci_dev *hdev = hcon->hdev; 2055 struct smp_cmd_pairing *req, *rsp; 2056 u8 auth; 2057 2058 /* The issue is only observed when we're in responder role */ 2059 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2060 return SMP_UNSPECIFIED; 2061 2062 if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) { 2063 bt_dev_err(hdev, "refusing legacy fallback in SC-only mode"); 2064 return SMP_UNSPECIFIED; 2065 } 2066 2067 bt_dev_err(hdev, "trying to fall back to legacy SMP"); 2068 2069 req = (void *) &smp->preq[1]; 2070 rsp = (void *) &smp->prsp[1]; 2071 2072 /* Rebuild key dist flags which may have been cleared for SC */ 2073 smp->remote_key_dist = (req->init_key_dist & rsp->resp_key_dist); 2074 2075 auth = req->auth_req & AUTH_REQ_MASK(hdev); 2076 2077 if (tk_request(conn, 0, auth, rsp->io_capability, req->io_capability)) { 2078 bt_dev_err(hdev, "failed to fall back to legacy SMP"); 2079 return SMP_UNSPECIFIED; 2080 } 2081 2082 clear_bit(SMP_FLAG_SC, &smp->flags); 2083 2084 return 0; 2085 } 2086 smp_cmd_pairing_confirm(struct l2cap_conn * conn,struct sk_buff * skb)2087 static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb) 2088 { 2089 struct l2cap_chan *chan = conn->smp; 2090 struct smp_chan *smp = chan->data; 2091 struct hci_conn *hcon = conn->hcon; 2092 struct hci_dev *hdev = hcon->hdev; 2093 2094 bt_dev_dbg(hdev, "conn %p %s", conn, 2095 test_bit(SMP_FLAG_INITIATOR, &smp->flags) ? "initiator" : 2096 "responder"); 2097 2098 if (skb->len < sizeof(smp->pcnf)) 2099 return SMP_INVALID_PARAMS; 2100 2101 memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf)); 2102 skb_pull(skb, sizeof(smp->pcnf)); 2103 2104 if (test_bit(SMP_FLAG_SC, &smp->flags)) { 2105 int ret; 2106 2107 /* Public Key exchange must happen before any other steps */ 2108 if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags)) 2109 return sc_check_confirm(smp); 2110 2111 bt_dev_err(hdev, "Unexpected SMP Pairing Confirm"); 2112 2113 ret = fixup_sc_false_positive(smp); 2114 if (ret) 2115 return ret; 2116 } 2117 2118 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2119 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2120 smp->prnd); 2121 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2122 return 0; 2123 } 2124 2125 if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) 2126 return smp_confirm(smp); 2127 2128 set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); 2129 2130 return 0; 2131 } 2132 smp_cmd_pairing_random(struct l2cap_conn * conn,struct sk_buff * skb)2133 static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb) 2134 { 2135 struct l2cap_chan *chan = conn->smp; 2136 struct smp_chan *smp = chan->data; 2137 struct hci_conn *hcon = conn->hcon; 2138 u8 *pkax, *pkbx, *na, *nb, confirm_hint; 2139 u32 passkey; 2140 int err; 2141 2142 bt_dev_dbg(hcon->hdev, "conn %p", conn); 2143 2144 if (skb->len < sizeof(smp->rrnd)) 2145 return SMP_INVALID_PARAMS; 2146 2147 memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd)); 2148 skb_pull(skb, sizeof(smp->rrnd)); 2149 2150 if (!test_bit(SMP_FLAG_SC, &smp->flags)) 2151 return smp_random(smp); 2152 2153 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2154 pkax = smp->local_pk; 2155 pkbx = smp->remote_pk; 2156 na = smp->prnd; 2157 nb = smp->rrnd; 2158 } else { 2159 pkax = smp->remote_pk; 2160 pkbx = smp->local_pk; 2161 na = smp->rrnd; 2162 nb = smp->prnd; 2163 } 2164 2165 if (smp->method == REQ_OOB) { 2166 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2167 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 2168 sizeof(smp->prnd), smp->prnd); 2169 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2170 goto mackey_and_ltk; 2171 } 2172 2173 /* Passkey entry has special treatment */ 2174 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2175 return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM); 2176 2177 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2178 u8 cfm[16]; 2179 2180 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, 2181 smp->rrnd, 0, cfm); 2182 if (err) 2183 return SMP_UNSPECIFIED; 2184 2185 if (crypto_memneq(smp->pcnf, cfm, 16)) 2186 return SMP_CONFIRM_FAILED; 2187 } else { 2188 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), 2189 smp->prnd); 2190 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2191 2192 /* Only Just-Works pairing requires extra checks */ 2193 if (smp->method != JUST_WORKS) 2194 goto mackey_and_ltk; 2195 2196 /* If there already exists long term key in local host, leave 2197 * the decision to user space since the remote device could 2198 * be legitimate or malicious. 2199 */ 2200 if (hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, 2201 hcon->role)) { 2202 /* Set passkey to 0. The value can be any number since 2203 * it'll be ignored anyway. 2204 */ 2205 passkey = 0; 2206 confirm_hint = 1; 2207 goto confirm; 2208 } 2209 } 2210 2211 mackey_and_ltk: 2212 /* Generate MacKey and LTK */ 2213 err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk); 2214 if (err) 2215 return SMP_UNSPECIFIED; 2216 2217 if (smp->method == REQ_OOB) { 2218 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2219 sc_dhkey_check(smp); 2220 SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); 2221 } 2222 return 0; 2223 } 2224 2225 err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey); 2226 if (err) 2227 return SMP_UNSPECIFIED; 2228 2229 confirm_hint = 0; 2230 2231 confirm: 2232 if (smp->method == JUST_WORKS) 2233 confirm_hint = 1; 2234 2235 err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type, 2236 hcon->dst_type, passkey, confirm_hint); 2237 if (err) 2238 return SMP_UNSPECIFIED; 2239 2240 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 2241 2242 return 0; 2243 } 2244 smp_ltk_encrypt(struct l2cap_conn * conn,u8 sec_level)2245 static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level) 2246 { 2247 struct smp_ltk *key; 2248 struct hci_conn *hcon = conn->hcon; 2249 2250 key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role); 2251 if (!key) 2252 return false; 2253 2254 if (smp_ltk_sec_level(key) < sec_level) 2255 return false; 2256 2257 if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) 2258 return true; 2259 2260 hci_le_start_enc(hcon, key->ediv, key->rand, key->val, key->enc_size); 2261 hcon->enc_key_size = key->enc_size; 2262 2263 /* We never store STKs for initiator role, so clear this flag */ 2264 clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); 2265 2266 return true; 2267 } 2268 smp_sufficient_security(struct hci_conn * hcon,u8 sec_level,enum smp_key_pref key_pref)2269 bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level, 2270 enum smp_key_pref key_pref) 2271 { 2272 if (sec_level == BT_SECURITY_LOW) 2273 return true; 2274 2275 /* If we're encrypted with an STK but the caller prefers using 2276 * LTK claim insufficient security. This way we allow the 2277 * connection to be re-encrypted with an LTK, even if the LTK 2278 * provides the same level of security. Only exception is if we 2279 * don't have an LTK (e.g. because of key distribution bits). 2280 */ 2281 if (key_pref == SMP_USE_LTK && 2282 test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) && 2283 hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role)) 2284 return false; 2285 2286 if (hcon->sec_level >= sec_level) 2287 return true; 2288 2289 return false; 2290 } 2291 smp_send_pairing_req(struct smp_chan * smp,__u8 auth)2292 static void smp_send_pairing_req(struct smp_chan *smp, __u8 auth) 2293 { 2294 struct smp_cmd_pairing cp; 2295 2296 if (smp->conn->hcon->type == ACL_LINK) 2297 build_bredr_pairing_cmd(smp, &cp, NULL); 2298 else 2299 build_pairing_cmd(smp->conn, &cp, NULL, auth); 2300 2301 smp->preq[0] = SMP_CMD_PAIRING_REQ; 2302 memcpy(&smp->preq[1], &cp, sizeof(cp)); 2303 2304 smp_send_cmd(smp->conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); 2305 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); 2306 2307 set_bit(SMP_FLAG_INITIATOR, &smp->flags); 2308 } 2309 smp_cmd_security_req(struct l2cap_conn * conn,struct sk_buff * skb)2310 static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb) 2311 { 2312 struct smp_cmd_security_req *rp = (void *) skb->data; 2313 struct hci_conn *hcon = conn->hcon; 2314 struct hci_dev *hdev = hcon->hdev; 2315 struct smp_chan *smp; 2316 u8 sec_level, auth; 2317 2318 bt_dev_dbg(hdev, "conn %p", conn); 2319 2320 if (skb->len < sizeof(*rp)) 2321 return SMP_INVALID_PARAMS; 2322 2323 if (hcon->role != HCI_ROLE_MASTER) 2324 return SMP_CMD_NOTSUPP; 2325 2326 auth = rp->auth_req & AUTH_REQ_MASK(hdev); 2327 2328 if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) 2329 return SMP_AUTH_REQUIREMENTS; 2330 2331 if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 2332 sec_level = BT_SECURITY_MEDIUM; 2333 else 2334 sec_level = authreq_to_seclevel(auth); 2335 2336 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) { 2337 /* If link is already encrypted with sufficient security we 2338 * still need refresh encryption as per Core Spec 5.0 Vol 3, 2339 * Part H 2.4.6 2340 */ 2341 smp_ltk_encrypt(conn, hcon->sec_level); 2342 return 0; 2343 } 2344 2345 if (sec_level > hcon->pending_sec_level) 2346 hcon->pending_sec_level = sec_level; 2347 2348 if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) 2349 return 0; 2350 2351 smp = smp_chan_create(conn); 2352 if (!smp) 2353 return SMP_UNSPECIFIED; 2354 2355 if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && 2356 (auth & SMP_AUTH_BONDING)) 2357 return SMP_PAIRING_NOTSUPP; 2358 2359 skb_pull(skb, sizeof(*rp)); 2360 2361 smp_send_pairing_req(smp, auth); 2362 2363 return 0; 2364 } 2365 smp_send_security_req(struct smp_chan * smp,__u8 auth)2366 static void smp_send_security_req(struct smp_chan *smp, __u8 auth) 2367 { 2368 struct smp_cmd_security_req cp; 2369 2370 cp.auth_req = auth; 2371 smp_send_cmd(smp->conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp); 2372 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ); 2373 2374 clear_bit(SMP_FLAG_INITIATOR, &smp->flags); 2375 } 2376 smp_conn_security(struct hci_conn * hcon,__u8 sec_level)2377 int smp_conn_security(struct hci_conn *hcon, __u8 sec_level) 2378 { 2379 struct l2cap_conn *conn = hcon->l2cap_data; 2380 struct l2cap_chan *chan; 2381 struct smp_chan *smp; 2382 __u8 authreq; 2383 int ret; 2384 2385 bt_dev_dbg(hcon->hdev, "conn %p hcon %p level 0x%2.2x", conn, hcon, 2386 sec_level); 2387 2388 /* This may be NULL if there's an unexpected disconnection */ 2389 if (!conn) 2390 return 1; 2391 2392 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) 2393 return 1; 2394 2395 if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) 2396 return 1; 2397 2398 if (sec_level > hcon->pending_sec_level) 2399 hcon->pending_sec_level = sec_level; 2400 2401 if (hcon->role == HCI_ROLE_MASTER) 2402 if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) 2403 return 0; 2404 2405 chan = conn->smp; 2406 if (!chan) { 2407 bt_dev_err(hcon->hdev, "security requested but not available"); 2408 return 1; 2409 } 2410 2411 l2cap_chan_lock(chan); 2412 2413 /* If SMP is already in progress ignore this request */ 2414 if (chan->data) { 2415 ret = 0; 2416 goto unlock; 2417 } 2418 2419 smp = smp_chan_create(conn); 2420 if (!smp) { 2421 ret = 1; 2422 goto unlock; 2423 } 2424 2425 authreq = seclevel_to_authreq(sec_level); 2426 2427 if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED)) { 2428 authreq |= SMP_AUTH_SC; 2429 if (hci_dev_test_flag(hcon->hdev, HCI_SSP_ENABLED)) 2430 authreq |= SMP_AUTH_CT2; 2431 } 2432 2433 /* Don't attempt to set MITM if setting is overridden by debugfs 2434 * Needed to pass certification test SM/MAS/PKE/BV-01-C 2435 */ 2436 if (!hci_dev_test_flag(hcon->hdev, HCI_FORCE_NO_MITM)) { 2437 /* Require MITM if IO Capability allows or the security level 2438 * requires it. 2439 */ 2440 if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT || 2441 hcon->pending_sec_level > BT_SECURITY_MEDIUM) 2442 authreq |= SMP_AUTH_MITM; 2443 } 2444 2445 if (hcon->role == HCI_ROLE_MASTER) 2446 smp_send_pairing_req(smp, authreq); 2447 else 2448 smp_send_security_req(smp, authreq); 2449 2450 ret = 0; 2451 2452 unlock: 2453 l2cap_chan_unlock(chan); 2454 return ret; 2455 } 2456 smp_cancel_and_remove_pairing(struct hci_dev * hdev,bdaddr_t * bdaddr,u8 addr_type)2457 int smp_cancel_and_remove_pairing(struct hci_dev *hdev, bdaddr_t *bdaddr, 2458 u8 addr_type) 2459 { 2460 struct hci_conn *hcon; 2461 struct l2cap_conn *conn; 2462 struct l2cap_chan *chan; 2463 struct smp_chan *smp; 2464 int err; 2465 2466 err = hci_remove_ltk(hdev, bdaddr, addr_type); 2467 hci_remove_irk(hdev, bdaddr, addr_type); 2468 2469 hcon = hci_conn_hash_lookup_le(hdev, bdaddr, addr_type); 2470 if (!hcon) 2471 goto done; 2472 2473 conn = hcon->l2cap_data; 2474 if (!conn) 2475 goto done; 2476 2477 chan = conn->smp; 2478 if (!chan) 2479 goto done; 2480 2481 l2cap_chan_lock(chan); 2482 2483 smp = chan->data; 2484 if (smp) { 2485 /* Set keys to NULL to make sure smp_failure() does not try to 2486 * remove and free already invalidated rcu list entries. */ 2487 smp->ltk = NULL; 2488 smp->responder_ltk = NULL; 2489 smp->remote_irk = NULL; 2490 2491 if (test_bit(SMP_FLAG_COMPLETE, &smp->flags)) 2492 smp_failure(conn, 0); 2493 else 2494 smp_failure(conn, SMP_UNSPECIFIED); 2495 err = 0; 2496 } 2497 2498 l2cap_chan_unlock(chan); 2499 2500 done: 2501 return err; 2502 } 2503 smp_cmd_encrypt_info(struct l2cap_conn * conn,struct sk_buff * skb)2504 static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb) 2505 { 2506 struct smp_cmd_encrypt_info *rp = (void *) skb->data; 2507 struct l2cap_chan *chan = conn->smp; 2508 struct smp_chan *smp = chan->data; 2509 2510 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 2511 2512 if (skb->len < sizeof(*rp)) 2513 return SMP_INVALID_PARAMS; 2514 2515 /* Pairing is aborted if any blocked keys are distributed */ 2516 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_LTK, 2517 rp->ltk)) { 2518 bt_dev_warn_ratelimited(conn->hcon->hdev, 2519 "LTK blocked for %pMR", 2520 &conn->hcon->dst); 2521 return SMP_INVALID_PARAMS; 2522 } 2523 2524 SMP_ALLOW_CMD(smp, SMP_CMD_INITIATOR_IDENT); 2525 2526 skb_pull(skb, sizeof(*rp)); 2527 2528 memcpy(smp->tk, rp->ltk, sizeof(smp->tk)); 2529 2530 return 0; 2531 } 2532 smp_cmd_initiator_ident(struct l2cap_conn * conn,struct sk_buff * skb)2533 static int smp_cmd_initiator_ident(struct l2cap_conn *conn, struct sk_buff *skb) 2534 { 2535 struct smp_cmd_initiator_ident *rp = (void *)skb->data; 2536 struct l2cap_chan *chan = conn->smp; 2537 struct smp_chan *smp = chan->data; 2538 struct hci_dev *hdev = conn->hcon->hdev; 2539 struct hci_conn *hcon = conn->hcon; 2540 struct smp_ltk *ltk; 2541 u8 authenticated; 2542 2543 bt_dev_dbg(hdev, "conn %p", conn); 2544 2545 if (skb->len < sizeof(*rp)) 2546 return SMP_INVALID_PARAMS; 2547 2548 /* Mark the information as received */ 2549 smp->remote_key_dist &= ~SMP_DIST_ENC_KEY; 2550 2551 if (smp->remote_key_dist & SMP_DIST_ID_KEY) 2552 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); 2553 else if (smp->remote_key_dist & SMP_DIST_SIGN) 2554 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 2555 2556 skb_pull(skb, sizeof(*rp)); 2557 2558 authenticated = (hcon->sec_level == BT_SECURITY_HIGH); 2559 ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK, 2560 authenticated, smp->tk, smp->enc_key_size, 2561 rp->ediv, rp->rand); 2562 smp->ltk = ltk; 2563 if (!(smp->remote_key_dist & KEY_DIST_MASK)) 2564 smp_distribute_keys(smp); 2565 2566 return 0; 2567 } 2568 smp_cmd_ident_info(struct l2cap_conn * conn,struct sk_buff * skb)2569 static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb) 2570 { 2571 struct smp_cmd_ident_info *info = (void *) skb->data; 2572 struct l2cap_chan *chan = conn->smp; 2573 struct smp_chan *smp = chan->data; 2574 2575 bt_dev_dbg(conn->hcon->hdev, ""); 2576 2577 if (skb->len < sizeof(*info)) 2578 return SMP_INVALID_PARAMS; 2579 2580 /* Pairing is aborted if any blocked keys are distributed */ 2581 if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_IRK, 2582 info->irk)) { 2583 bt_dev_warn_ratelimited(conn->hcon->hdev, 2584 "Identity key blocked for %pMR", 2585 &conn->hcon->dst); 2586 return SMP_INVALID_PARAMS; 2587 } 2588 2589 SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO); 2590 2591 skb_pull(skb, sizeof(*info)); 2592 2593 memcpy(smp->irk, info->irk, 16); 2594 2595 return 0; 2596 } 2597 smp_cmd_ident_addr_info(struct l2cap_conn * conn,struct sk_buff * skb)2598 static int smp_cmd_ident_addr_info(struct l2cap_conn *conn, 2599 struct sk_buff *skb) 2600 { 2601 struct smp_cmd_ident_addr_info *info = (void *) skb->data; 2602 struct l2cap_chan *chan = conn->smp; 2603 struct smp_chan *smp = chan->data; 2604 struct hci_conn *hcon = conn->hcon; 2605 bdaddr_t rpa; 2606 2607 bt_dev_dbg(hcon->hdev, ""); 2608 2609 if (skb->len < sizeof(*info)) 2610 return SMP_INVALID_PARAMS; 2611 2612 /* Mark the information as received */ 2613 smp->remote_key_dist &= ~SMP_DIST_ID_KEY; 2614 2615 if (smp->remote_key_dist & SMP_DIST_SIGN) 2616 SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); 2617 2618 skb_pull(skb, sizeof(*info)); 2619 2620 /* Strictly speaking the Core Specification (4.1) allows sending 2621 * an empty address which would force us to rely on just the IRK 2622 * as "identity information". However, since such 2623 * implementations are not known of and in order to not over 2624 * complicate our implementation, simply pretend that we never 2625 * received an IRK for such a device. 2626 * 2627 * The Identity Address must also be a Static Random or Public 2628 * Address, which hci_is_identity_address() checks for. 2629 */ 2630 if (!bacmp(&info->bdaddr, BDADDR_ANY) || 2631 !hci_is_identity_address(&info->bdaddr, info->addr_type)) { 2632 bt_dev_err(hcon->hdev, "ignoring IRK with no identity address"); 2633 goto distribute; 2634 } 2635 2636 /* Drop IRK if peer is using identity address during pairing but is 2637 * providing different address as identity information. 2638 * 2639 * Microsoft Surface Precision Mouse is known to have this bug. 2640 */ 2641 if (hci_is_identity_address(&hcon->dst, hcon->dst_type) && 2642 (bacmp(&info->bdaddr, &hcon->dst) || 2643 info->addr_type != hcon->dst_type)) { 2644 bt_dev_err(hcon->hdev, 2645 "ignoring IRK with invalid identity address"); 2646 goto distribute; 2647 } 2648 2649 bacpy(&smp->id_addr, &info->bdaddr); 2650 smp->id_addr_type = info->addr_type; 2651 2652 if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type)) 2653 bacpy(&rpa, &hcon->dst); 2654 else 2655 bacpy(&rpa, BDADDR_ANY); 2656 2657 smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr, 2658 smp->id_addr_type, smp->irk, &rpa); 2659 2660 distribute: 2661 if (!(smp->remote_key_dist & KEY_DIST_MASK)) 2662 smp_distribute_keys(smp); 2663 2664 return 0; 2665 } 2666 smp_cmd_sign_info(struct l2cap_conn * conn,struct sk_buff * skb)2667 static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb) 2668 { 2669 struct smp_cmd_sign_info *rp = (void *) skb->data; 2670 struct l2cap_chan *chan = conn->smp; 2671 struct smp_chan *smp = chan->data; 2672 struct smp_csrk *csrk; 2673 2674 bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); 2675 2676 if (skb->len < sizeof(*rp)) 2677 return SMP_INVALID_PARAMS; 2678 2679 /* Mark the information as received */ 2680 smp->remote_key_dist &= ~SMP_DIST_SIGN; 2681 2682 skb_pull(skb, sizeof(*rp)); 2683 2684 csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); 2685 if (csrk) { 2686 if (conn->hcon->sec_level > BT_SECURITY_MEDIUM) 2687 csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED; 2688 else 2689 csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED; 2690 memcpy(csrk->val, rp->csrk, sizeof(csrk->val)); 2691 } 2692 smp->csrk = csrk; 2693 smp_distribute_keys(smp); 2694 2695 return 0; 2696 } 2697 sc_select_method(struct smp_chan * smp)2698 static u8 sc_select_method(struct smp_chan *smp) 2699 { 2700 struct smp_cmd_pairing *local, *remote; 2701 u8 local_mitm, remote_mitm, local_io, remote_io, method; 2702 2703 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) || 2704 test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) 2705 return REQ_OOB; 2706 2707 /* The preq/prsp contain the raw Pairing Request/Response PDUs 2708 * which are needed as inputs to some crypto functions. To get 2709 * the "struct smp_cmd_pairing" from them we need to skip the 2710 * first byte which contains the opcode. 2711 */ 2712 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2713 local = (void *) &smp->preq[1]; 2714 remote = (void *) &smp->prsp[1]; 2715 } else { 2716 local = (void *) &smp->prsp[1]; 2717 remote = (void *) &smp->preq[1]; 2718 } 2719 2720 local_io = local->io_capability; 2721 remote_io = remote->io_capability; 2722 2723 local_mitm = (local->auth_req & SMP_AUTH_MITM); 2724 remote_mitm = (remote->auth_req & SMP_AUTH_MITM); 2725 2726 /* If either side wants MITM, look up the method from the table, 2727 * otherwise use JUST WORKS. 2728 */ 2729 if (local_mitm || remote_mitm) 2730 method = get_auth_method(smp, local_io, remote_io); 2731 else 2732 method = JUST_WORKS; 2733 2734 /* Don't confirm locally initiated pairing attempts */ 2735 if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2736 method = JUST_WORKS; 2737 2738 return method; 2739 } 2740 smp_cmd_public_key(struct l2cap_conn * conn,struct sk_buff * skb)2741 static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb) 2742 { 2743 struct smp_cmd_public_key *key = (void *) skb->data; 2744 struct hci_conn *hcon = conn->hcon; 2745 struct l2cap_chan *chan = conn->smp; 2746 struct smp_chan *smp = chan->data; 2747 struct hci_dev *hdev = hcon->hdev; 2748 struct crypto_kpp *tfm_ecdh; 2749 struct smp_cmd_pairing_confirm cfm; 2750 int err; 2751 2752 bt_dev_dbg(hdev, "conn %p", conn); 2753 2754 if (skb->len < sizeof(*key)) 2755 return SMP_INVALID_PARAMS; 2756 2757 /* Check if remote and local public keys are the same and debug key is 2758 * not in use. 2759 */ 2760 if (!test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags) && 2761 !crypto_memneq(key, smp->local_pk, 64)) { 2762 bt_dev_err(hdev, "Remote and local public keys are identical"); 2763 return SMP_UNSPECIFIED; 2764 } 2765 2766 memcpy(smp->remote_pk, key, 64); 2767 2768 if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) { 2769 err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk, 2770 smp->rr, 0, cfm.confirm_val); 2771 if (err) 2772 return SMP_UNSPECIFIED; 2773 2774 if (crypto_memneq(cfm.confirm_val, smp->pcnf, 16)) 2775 return SMP_CONFIRM_FAILED; 2776 } 2777 2778 /* Non-initiating device sends its public key after receiving 2779 * the key from the initiating device. 2780 */ 2781 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2782 err = sc_send_public_key(smp); 2783 if (err) 2784 return err; 2785 } 2786 2787 SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk); 2788 SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32); 2789 2790 /* Compute the shared secret on the same crypto tfm on which the private 2791 * key was set/generated. 2792 */ 2793 if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { 2794 struct l2cap_chan *hchan = hdev->smp_data; 2795 struct smp_dev *smp_dev; 2796 2797 if (!hchan || !hchan->data) 2798 return SMP_UNSPECIFIED; 2799 2800 smp_dev = hchan->data; 2801 2802 tfm_ecdh = smp_dev->tfm_ecdh; 2803 } else { 2804 tfm_ecdh = smp->tfm_ecdh; 2805 } 2806 2807 if (compute_ecdh_secret(tfm_ecdh, smp->remote_pk, smp->dhkey)) 2808 return SMP_UNSPECIFIED; 2809 2810 SMP_DBG("DHKey %32phN", smp->dhkey); 2811 2812 set_bit(SMP_FLAG_REMOTE_PK, &smp->flags); 2813 2814 smp->method = sc_select_method(smp); 2815 2816 bt_dev_dbg(hdev, "selected method 0x%02x", smp->method); 2817 2818 /* JUST_WORKS and JUST_CFM result in an unauthenticated key */ 2819 if (smp->method == JUST_WORKS || smp->method == JUST_CFM) 2820 hcon->pending_sec_level = BT_SECURITY_MEDIUM; 2821 else 2822 hcon->pending_sec_level = BT_SECURITY_FIPS; 2823 2824 if (!crypto_memneq(debug_pk, smp->remote_pk, 64)) 2825 set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); 2826 2827 if (smp->method == DSP_PASSKEY) { 2828 get_random_bytes(&hcon->passkey_notify, 2829 sizeof(hcon->passkey_notify)); 2830 hcon->passkey_notify %= 1000000; 2831 hcon->passkey_entered = 0; 2832 smp->passkey_round = 0; 2833 if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type, 2834 hcon->dst_type, 2835 hcon->passkey_notify, 2836 hcon->passkey_entered)) 2837 return SMP_UNSPECIFIED; 2838 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2839 return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY); 2840 } 2841 2842 if (smp->method == REQ_OOB) { 2843 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2844 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, 2845 sizeof(smp->prnd), smp->prnd); 2846 2847 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2848 2849 return 0; 2850 } 2851 2852 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2853 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2854 2855 if (smp->method == REQ_PASSKEY) { 2856 if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type, 2857 hcon->dst_type)) 2858 return SMP_UNSPECIFIED; 2859 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); 2860 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 2861 return 0; 2862 } 2863 2864 /* The Initiating device waits for the non-initiating device to 2865 * send the confirm value. 2866 */ 2867 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) 2868 return 0; 2869 2870 err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, 2871 0, cfm.confirm_val); 2872 if (err) 2873 return SMP_UNSPECIFIED; 2874 2875 smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); 2876 SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); 2877 2878 return 0; 2879 } 2880 smp_cmd_dhkey_check(struct l2cap_conn * conn,struct sk_buff * skb)2881 static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb) 2882 { 2883 struct smp_cmd_dhkey_check *check = (void *) skb->data; 2884 struct l2cap_chan *chan = conn->smp; 2885 struct hci_conn *hcon = conn->hcon; 2886 struct smp_chan *smp = chan->data; 2887 u8 a[7], b[7], *local_addr, *remote_addr; 2888 u8 io_cap[3], r[16], e[16]; 2889 int err; 2890 2891 bt_dev_dbg(hcon->hdev, "conn %p", conn); 2892 2893 if (skb->len < sizeof(*check)) 2894 return SMP_INVALID_PARAMS; 2895 2896 memcpy(a, &hcon->init_addr, 6); 2897 memcpy(b, &hcon->resp_addr, 6); 2898 a[6] = hcon->init_addr_type; 2899 b[6] = hcon->resp_addr_type; 2900 2901 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2902 local_addr = a; 2903 remote_addr = b; 2904 memcpy(io_cap, &smp->prsp[1], 3); 2905 } else { 2906 local_addr = b; 2907 remote_addr = a; 2908 memcpy(io_cap, &smp->preq[1], 3); 2909 } 2910 2911 memset(r, 0, sizeof(r)); 2912 2913 if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) 2914 put_unaligned_le32(hcon->passkey_notify, r); 2915 else if (smp->method == REQ_OOB) 2916 memcpy(r, smp->lr, 16); 2917 2918 err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r, 2919 io_cap, remote_addr, local_addr, e); 2920 if (err) 2921 return SMP_UNSPECIFIED; 2922 2923 if (crypto_memneq(check->e, e, 16)) 2924 return SMP_DHKEY_CHECK_FAILED; 2925 2926 if (!test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2927 if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { 2928 set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags); 2929 return 0; 2930 } 2931 2932 /* Responder sends DHKey check as response to initiator */ 2933 sc_dhkey_check(smp); 2934 } 2935 2936 sc_add_ltk(smp); 2937 2938 if (test_bit(SMP_FLAG_INITIATOR, &smp->flags)) { 2939 hci_le_start_enc(hcon, 0, 0, smp->tk, smp->enc_key_size); 2940 hcon->enc_key_size = smp->enc_key_size; 2941 } 2942 2943 return 0; 2944 } 2945 smp_cmd_keypress_notify(struct l2cap_conn * conn,struct sk_buff * skb)2946 static int smp_cmd_keypress_notify(struct l2cap_conn *conn, 2947 struct sk_buff *skb) 2948 { 2949 struct smp_cmd_keypress_notify *kp = (void *) skb->data; 2950 2951 bt_dev_dbg(conn->hcon->hdev, "value 0x%02x", kp->value); 2952 2953 return 0; 2954 } 2955 smp_sig_channel(struct l2cap_chan * chan,struct sk_buff * skb)2956 static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb) 2957 { 2958 struct l2cap_conn *conn = chan->conn; 2959 struct hci_conn *hcon = conn->hcon; 2960 struct smp_chan *smp; 2961 __u8 code, reason; 2962 int err = 0; 2963 2964 if (skb->len < 1) 2965 return -EILSEQ; 2966 2967 if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) { 2968 reason = SMP_PAIRING_NOTSUPP; 2969 goto done; 2970 } 2971 2972 code = skb->data[0]; 2973 skb_pull(skb, sizeof(code)); 2974 2975 smp = chan->data; 2976 2977 if (code > SMP_CMD_MAX) 2978 goto drop; 2979 2980 if (smp && !test_and_clear_bit(code, &smp->allow_cmd)) 2981 goto drop; 2982 2983 /* If we don't have a context the only allowed commands are 2984 * pairing request and security request. 2985 */ 2986 if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ) 2987 goto drop; 2988 2989 switch (code) { 2990 case SMP_CMD_PAIRING_REQ: 2991 reason = smp_cmd_pairing_req(conn, skb); 2992 break; 2993 2994 case SMP_CMD_PAIRING_FAIL: 2995 smp_failure(conn, 0); 2996 err = -EPERM; 2997 break; 2998 2999 case SMP_CMD_PAIRING_RSP: 3000 reason = smp_cmd_pairing_rsp(conn, skb); 3001 break; 3002 3003 case SMP_CMD_SECURITY_REQ: 3004 reason = smp_cmd_security_req(conn, skb); 3005 break; 3006 3007 case SMP_CMD_PAIRING_CONFIRM: 3008 reason = smp_cmd_pairing_confirm(conn, skb); 3009 break; 3010 3011 case SMP_CMD_PAIRING_RANDOM: 3012 reason = smp_cmd_pairing_random(conn, skb); 3013 break; 3014 3015 case SMP_CMD_ENCRYPT_INFO: 3016 reason = smp_cmd_encrypt_info(conn, skb); 3017 break; 3018 3019 case SMP_CMD_INITIATOR_IDENT: 3020 reason = smp_cmd_initiator_ident(conn, skb); 3021 break; 3022 3023 case SMP_CMD_IDENT_INFO: 3024 reason = smp_cmd_ident_info(conn, skb); 3025 break; 3026 3027 case SMP_CMD_IDENT_ADDR_INFO: 3028 reason = smp_cmd_ident_addr_info(conn, skb); 3029 break; 3030 3031 case SMP_CMD_SIGN_INFO: 3032 reason = smp_cmd_sign_info(conn, skb); 3033 break; 3034 3035 case SMP_CMD_PUBLIC_KEY: 3036 reason = smp_cmd_public_key(conn, skb); 3037 break; 3038 3039 case SMP_CMD_DHKEY_CHECK: 3040 reason = smp_cmd_dhkey_check(conn, skb); 3041 break; 3042 3043 case SMP_CMD_KEYPRESS_NOTIFY: 3044 reason = smp_cmd_keypress_notify(conn, skb); 3045 break; 3046 3047 default: 3048 bt_dev_dbg(hcon->hdev, "Unknown command code 0x%2.2x", code); 3049 reason = SMP_CMD_NOTSUPP; 3050 goto done; 3051 } 3052 3053 done: 3054 if (!err) { 3055 if (reason) 3056 smp_failure(conn, reason); 3057 kfree_skb(skb); 3058 } 3059 3060 return err; 3061 3062 drop: 3063 bt_dev_err(hcon->hdev, "unexpected SMP command 0x%02x from %pMR", 3064 code, &hcon->dst); 3065 kfree_skb(skb); 3066 return 0; 3067 } 3068 smp_teardown_cb(struct l2cap_chan * chan,int err)3069 static void smp_teardown_cb(struct l2cap_chan *chan, int err) 3070 { 3071 struct l2cap_conn *conn = chan->conn; 3072 3073 bt_dev_dbg(conn->hcon->hdev, "chan %p", chan); 3074 3075 if (chan->data) 3076 smp_chan_destroy(conn); 3077 3078 conn->smp = NULL; 3079 l2cap_chan_put(chan); 3080 } 3081 bredr_pairing(struct l2cap_chan * chan)3082 static void bredr_pairing(struct l2cap_chan *chan) 3083 { 3084 struct l2cap_conn *conn = chan->conn; 3085 struct hci_conn *hcon = conn->hcon; 3086 struct hci_dev *hdev = hcon->hdev; 3087 struct smp_chan *smp; 3088 3089 bt_dev_dbg(hdev, "chan %p", chan); 3090 3091 /* Only new pairings are interesting */ 3092 if (!test_bit(HCI_CONN_NEW_LINK_KEY, &hcon->flags)) 3093 return; 3094 3095 /* Don't bother if we're not encrypted */ 3096 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3097 return; 3098 3099 /* Only initiator may initiate SMP over BR/EDR */ 3100 if (hcon->role != HCI_ROLE_MASTER) 3101 return; 3102 3103 /* Secure Connections support must be enabled */ 3104 if (!hci_dev_test_flag(hdev, HCI_SC_ENABLED)) 3105 return; 3106 3107 /* BR/EDR must use Secure Connections for SMP */ 3108 if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) && 3109 !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3110 return; 3111 3112 /* If our LE support is not enabled don't do anything */ 3113 if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) 3114 return; 3115 3116 /* Don't bother if remote LE support is not enabled */ 3117 if (!lmp_host_le_capable(hcon)) 3118 return; 3119 3120 /* Remote must support SMP fixed chan for BR/EDR */ 3121 if (!(conn->remote_fixed_chan & L2CAP_FC_SMP_BREDR)) 3122 return; 3123 3124 /* Don't bother if SMP is already ongoing */ 3125 if (chan->data) 3126 return; 3127 3128 smp = smp_chan_create(conn); 3129 if (!smp) { 3130 bt_dev_err(hdev, "unable to create SMP context for BR/EDR"); 3131 return; 3132 } 3133 3134 set_bit(SMP_FLAG_SC, &smp->flags); 3135 3136 bt_dev_dbg(hdev, "starting SMP over BR/EDR"); 3137 3138 smp_send_pairing_req(smp, 0x00); 3139 } 3140 smp_resume_cb(struct l2cap_chan * chan)3141 static void smp_resume_cb(struct l2cap_chan *chan) 3142 { 3143 struct smp_chan *smp = chan->data; 3144 struct l2cap_conn *conn = chan->conn; 3145 struct hci_conn *hcon = conn->hcon; 3146 3147 bt_dev_dbg(hcon->hdev, "chan %p", chan); 3148 3149 if (hcon->type == ACL_LINK) { 3150 bredr_pairing(chan); 3151 return; 3152 } 3153 3154 if (!smp) 3155 return; 3156 3157 if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3158 return; 3159 3160 cancel_delayed_work(&smp->security_timer); 3161 3162 smp_distribute_keys(smp); 3163 } 3164 smp_ready_cb(struct l2cap_chan * chan)3165 static void smp_ready_cb(struct l2cap_chan *chan) 3166 { 3167 struct l2cap_conn *conn = chan->conn; 3168 struct hci_conn *hcon = conn->hcon; 3169 3170 bt_dev_dbg(hcon->hdev, "chan %p", chan); 3171 3172 /* No need to call l2cap_chan_hold() here since we already own 3173 * the reference taken in smp_new_conn_cb(). This is just the 3174 * first time that we tie it to a specific pointer. The code in 3175 * l2cap_core.c ensures that there's no risk this function wont 3176 * get called if smp_new_conn_cb was previously called. 3177 */ 3178 conn->smp = chan; 3179 3180 if (hcon->type == ACL_LINK && test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) 3181 bredr_pairing(chan); 3182 } 3183 smp_recv_cb(struct l2cap_chan * chan,struct sk_buff * skb)3184 static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 3185 { 3186 int err; 3187 3188 bt_dev_dbg(chan->conn->hcon->hdev, "chan %p", chan); 3189 3190 err = smp_sig_channel(chan, skb); 3191 if (err) { 3192 struct smp_chan *smp = chan->data; 3193 3194 if (smp) 3195 cancel_delayed_work_sync(&smp->security_timer); 3196 3197 hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE); 3198 } 3199 3200 return err; 3201 } 3202 smp_alloc_skb_cb(struct l2cap_chan * chan,unsigned long hdr_len,unsigned long len,int nb)3203 static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan, 3204 unsigned long hdr_len, 3205 unsigned long len, int nb) 3206 { 3207 struct sk_buff *skb; 3208 3209 skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL); 3210 if (!skb) 3211 return ERR_PTR(-ENOMEM); 3212 3213 skb->priority = HCI_PRIO_MAX; 3214 bt_cb(skb)->l2cap.chan = chan; 3215 3216 return skb; 3217 } 3218 3219 static const struct l2cap_ops smp_chan_ops = { 3220 .name = "Security Manager", 3221 .ready = smp_ready_cb, 3222 .recv = smp_recv_cb, 3223 .alloc_skb = smp_alloc_skb_cb, 3224 .teardown = smp_teardown_cb, 3225 .resume = smp_resume_cb, 3226 3227 .new_connection = l2cap_chan_no_new_connection, 3228 .state_change = l2cap_chan_no_state_change, 3229 .close = l2cap_chan_no_close, 3230 .defer = l2cap_chan_no_defer, 3231 .suspend = l2cap_chan_no_suspend, 3232 .set_shutdown = l2cap_chan_no_set_shutdown, 3233 .get_sndtimeo = l2cap_chan_no_get_sndtimeo, 3234 }; 3235 smp_new_conn_cb(struct l2cap_chan * pchan)3236 static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan) 3237 { 3238 struct l2cap_chan *chan; 3239 3240 BT_DBG("pchan %p", pchan); 3241 3242 chan = l2cap_chan_create(); 3243 if (!chan) 3244 return NULL; 3245 3246 chan->chan_type = pchan->chan_type; 3247 chan->ops = &smp_chan_ops; 3248 chan->scid = pchan->scid; 3249 chan->dcid = chan->scid; 3250 chan->imtu = pchan->imtu; 3251 chan->omtu = pchan->omtu; 3252 chan->mode = pchan->mode; 3253 3254 /* Other L2CAP channels may request SMP routines in order to 3255 * change the security level. This means that the SMP channel 3256 * lock must be considered in its own category to avoid lockdep 3257 * warnings. 3258 */ 3259 atomic_set(&chan->nesting, L2CAP_NESTING_SMP); 3260 3261 BT_DBG("created chan %p", chan); 3262 3263 return chan; 3264 } 3265 3266 static const struct l2cap_ops smp_root_chan_ops = { 3267 .name = "Security Manager Root", 3268 .new_connection = smp_new_conn_cb, 3269 3270 /* None of these are implemented for the root channel */ 3271 .close = l2cap_chan_no_close, 3272 .alloc_skb = l2cap_chan_no_alloc_skb, 3273 .recv = l2cap_chan_no_recv, 3274 .state_change = l2cap_chan_no_state_change, 3275 .teardown = l2cap_chan_no_teardown, 3276 .ready = l2cap_chan_no_ready, 3277 .defer = l2cap_chan_no_defer, 3278 .suspend = l2cap_chan_no_suspend, 3279 .resume = l2cap_chan_no_resume, 3280 .set_shutdown = l2cap_chan_no_set_shutdown, 3281 .get_sndtimeo = l2cap_chan_no_get_sndtimeo, 3282 }; 3283 smp_add_cid(struct hci_dev * hdev,u16 cid)3284 static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid) 3285 { 3286 struct l2cap_chan *chan; 3287 struct smp_dev *smp; 3288 struct crypto_shash *tfm_cmac; 3289 struct crypto_kpp *tfm_ecdh; 3290 3291 if (cid == L2CAP_CID_SMP_BREDR) { 3292 smp = NULL; 3293 goto create_chan; 3294 } 3295 3296 smp = kzalloc(sizeof(*smp), GFP_KERNEL); 3297 if (!smp) 3298 return ERR_PTR(-ENOMEM); 3299 3300 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 3301 if (IS_ERR(tfm_cmac)) { 3302 bt_dev_err(hdev, "Unable to create CMAC crypto context"); 3303 kfree_sensitive(smp); 3304 return ERR_CAST(tfm_cmac); 3305 } 3306 3307 tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0); 3308 if (IS_ERR(tfm_ecdh)) { 3309 bt_dev_err(hdev, "Unable to create ECDH crypto context"); 3310 crypto_free_shash(tfm_cmac); 3311 kfree_sensitive(smp); 3312 return ERR_CAST(tfm_ecdh); 3313 } 3314 3315 smp->local_oob = false; 3316 smp->tfm_cmac = tfm_cmac; 3317 smp->tfm_ecdh = tfm_ecdh; 3318 3319 create_chan: 3320 chan = l2cap_chan_create(); 3321 if (!chan) { 3322 if (smp) { 3323 crypto_free_shash(smp->tfm_cmac); 3324 crypto_free_kpp(smp->tfm_ecdh); 3325 kfree_sensitive(smp); 3326 } 3327 return ERR_PTR(-ENOMEM); 3328 } 3329 3330 chan->data = smp; 3331 3332 l2cap_add_scid(chan, cid); 3333 3334 l2cap_chan_set_defaults(chan); 3335 3336 if (cid == L2CAP_CID_SMP) { 3337 u8 bdaddr_type; 3338 3339 hci_copy_identity_address(hdev, &chan->src, &bdaddr_type); 3340 3341 if (bdaddr_type == ADDR_LE_DEV_PUBLIC) 3342 chan->src_type = BDADDR_LE_PUBLIC; 3343 else 3344 chan->src_type = BDADDR_LE_RANDOM; 3345 } else { 3346 bacpy(&chan->src, &hdev->bdaddr); 3347 chan->src_type = BDADDR_BREDR; 3348 } 3349 3350 chan->state = BT_LISTEN; 3351 chan->mode = L2CAP_MODE_BASIC; 3352 chan->imtu = L2CAP_DEFAULT_MTU; 3353 chan->ops = &smp_root_chan_ops; 3354 3355 /* Set correct nesting level for a parent/listening channel */ 3356 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 3357 3358 return chan; 3359 } 3360 smp_del_chan(struct l2cap_chan * chan)3361 static void smp_del_chan(struct l2cap_chan *chan) 3362 { 3363 struct smp_dev *smp; 3364 3365 BT_DBG("chan %p", chan); 3366 3367 smp = chan->data; 3368 if (smp) { 3369 chan->data = NULL; 3370 crypto_free_shash(smp->tfm_cmac); 3371 crypto_free_kpp(smp->tfm_ecdh); 3372 kfree_sensitive(smp); 3373 } 3374 3375 l2cap_chan_put(chan); 3376 } 3377 smp_force_bredr(struct hci_dev * hdev,bool enable)3378 int smp_force_bredr(struct hci_dev *hdev, bool enable) 3379 { 3380 if (enable == hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3381 return -EALREADY; 3382 3383 if (enable) { 3384 struct l2cap_chan *chan; 3385 3386 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); 3387 if (IS_ERR(chan)) 3388 return PTR_ERR(chan); 3389 3390 hdev->smp_bredr_data = chan; 3391 } else { 3392 struct l2cap_chan *chan; 3393 3394 chan = hdev->smp_bredr_data; 3395 hdev->smp_bredr_data = NULL; 3396 smp_del_chan(chan); 3397 } 3398 3399 hci_dev_change_flag(hdev, HCI_FORCE_BREDR_SMP); 3400 3401 return 0; 3402 } 3403 smp_register(struct hci_dev * hdev)3404 int smp_register(struct hci_dev *hdev) 3405 { 3406 struct l2cap_chan *chan; 3407 3408 bt_dev_dbg(hdev, ""); 3409 3410 /* If the controller does not support Low Energy operation, then 3411 * there is also no need to register any SMP channel. 3412 */ 3413 if (!lmp_le_capable(hdev)) 3414 return 0; 3415 3416 if (WARN_ON(hdev->smp_data)) { 3417 chan = hdev->smp_data; 3418 hdev->smp_data = NULL; 3419 smp_del_chan(chan); 3420 } 3421 3422 chan = smp_add_cid(hdev, L2CAP_CID_SMP); 3423 if (IS_ERR(chan)) 3424 return PTR_ERR(chan); 3425 3426 hdev->smp_data = chan; 3427 3428 if (!lmp_sc_capable(hdev)) { 3429 /* Flag can be already set here (due to power toggle) */ 3430 if (!hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) 3431 return 0; 3432 } 3433 3434 if (WARN_ON(hdev->smp_bredr_data)) { 3435 chan = hdev->smp_bredr_data; 3436 hdev->smp_bredr_data = NULL; 3437 smp_del_chan(chan); 3438 } 3439 3440 chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); 3441 if (IS_ERR(chan)) { 3442 int err = PTR_ERR(chan); 3443 chan = hdev->smp_data; 3444 hdev->smp_data = NULL; 3445 smp_del_chan(chan); 3446 return err; 3447 } 3448 3449 hdev->smp_bredr_data = chan; 3450 3451 return 0; 3452 } 3453 smp_unregister(struct hci_dev * hdev)3454 void smp_unregister(struct hci_dev *hdev) 3455 { 3456 struct l2cap_chan *chan; 3457 3458 if (hdev->smp_bredr_data) { 3459 chan = hdev->smp_bredr_data; 3460 hdev->smp_bredr_data = NULL; 3461 smp_del_chan(chan); 3462 } 3463 3464 if (hdev->smp_data) { 3465 chan = hdev->smp_data; 3466 hdev->smp_data = NULL; 3467 smp_del_chan(chan); 3468 } 3469 } 3470 3471 #if IS_ENABLED(CONFIG_BT_SELFTEST_SMP) 3472 test_debug_key(struct crypto_kpp * tfm_ecdh)3473 static int __init test_debug_key(struct crypto_kpp *tfm_ecdh) 3474 { 3475 u8 pk[64]; 3476 int err; 3477 3478 err = set_ecdh_privkey(tfm_ecdh, debug_sk); 3479 if (err) 3480 return err; 3481 3482 err = generate_ecdh_public_key(tfm_ecdh, pk); 3483 if (err) 3484 return err; 3485 3486 if (crypto_memneq(pk, debug_pk, 64)) 3487 return -EINVAL; 3488 3489 return 0; 3490 } 3491 test_ah(void)3492 static int __init test_ah(void) 3493 { 3494 const u8 irk[16] = { 3495 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3496 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3497 const u8 r[3] = { 0x94, 0x81, 0x70 }; 3498 const u8 exp[3] = { 0xaa, 0xfb, 0x0d }; 3499 u8 res[3]; 3500 int err; 3501 3502 err = smp_ah(irk, r, res); 3503 if (err) 3504 return err; 3505 3506 if (crypto_memneq(res, exp, 3)) 3507 return -EINVAL; 3508 3509 return 0; 3510 } 3511 test_c1(void)3512 static int __init test_c1(void) 3513 { 3514 const u8 k[16] = { 3515 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 3516 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; 3517 const u8 r[16] = { 3518 0xe0, 0x2e, 0x70, 0xc6, 0x4e, 0x27, 0x88, 0x63, 3519 0x0e, 0x6f, 0xad, 0x56, 0x21, 0xd5, 0x83, 0x57 }; 3520 const u8 preq[7] = { 0x01, 0x01, 0x00, 0x00, 0x10, 0x07, 0x07 }; 3521 const u8 pres[7] = { 0x02, 0x03, 0x00, 0x00, 0x08, 0x00, 0x05 }; 3522 const u8 _iat = 0x01; 3523 const u8 _rat = 0x00; 3524 const bdaddr_t ra = { { 0xb6, 0xb5, 0xb4, 0xb3, 0xb2, 0xb1 } }; 3525 const bdaddr_t ia = { { 0xa6, 0xa5, 0xa4, 0xa3, 0xa2, 0xa1 } }; 3526 const u8 exp[16] = { 3527 0x86, 0x3b, 0xf1, 0xbe, 0xc5, 0x4d, 0xa7, 0xd2, 3528 0xea, 0x88, 0x89, 0x87, 0xef, 0x3f, 0x1e, 0x1e }; 3529 u8 res[16]; 3530 int err; 3531 3532 err = smp_c1(k, r, preq, pres, _iat, &ia, _rat, &ra, res); 3533 if (err) 3534 return err; 3535 3536 if (crypto_memneq(res, exp, 16)) 3537 return -EINVAL; 3538 3539 return 0; 3540 } 3541 test_s1(void)3542 static int __init test_s1(void) 3543 { 3544 const u8 k[16] = { 3545 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 3546 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; 3547 const u8 r1[16] = { 3548 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 }; 3549 const u8 r2[16] = { 3550 0x00, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99 }; 3551 const u8 exp[16] = { 3552 0x62, 0xa0, 0x6d, 0x79, 0xae, 0x16, 0x42, 0x5b, 3553 0x9b, 0xf4, 0xb0, 0xe8, 0xf0, 0xe1, 0x1f, 0x9a }; 3554 u8 res[16]; 3555 int err; 3556 3557 err = smp_s1(k, r1, r2, res); 3558 if (err) 3559 return err; 3560 3561 if (crypto_memneq(res, exp, 16)) 3562 return -EINVAL; 3563 3564 return 0; 3565 } 3566 test_f4(struct crypto_shash * tfm_cmac)3567 static int __init test_f4(struct crypto_shash *tfm_cmac) 3568 { 3569 const u8 u[32] = { 3570 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 3571 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 3572 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 3573 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 }; 3574 const u8 v[32] = { 3575 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b, 3576 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59, 3577 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90, 3578 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 }; 3579 const u8 x[16] = { 3580 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3581 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3582 const u8 z = 0x00; 3583 const u8 exp[16] = { 3584 0x2d, 0x87, 0x74, 0xa9, 0xbe, 0xa1, 0xed, 0xf1, 3585 0x1c, 0xbd, 0xa9, 0x07, 0xf1, 0x16, 0xc9, 0xf2 }; 3586 u8 res[16]; 3587 int err; 3588 3589 err = smp_f4(tfm_cmac, u, v, x, z, res); 3590 if (err) 3591 return err; 3592 3593 if (crypto_memneq(res, exp, 16)) 3594 return -EINVAL; 3595 3596 return 0; 3597 } 3598 test_f5(struct crypto_shash * tfm_cmac)3599 static int __init test_f5(struct crypto_shash *tfm_cmac) 3600 { 3601 const u8 w[32] = { 3602 0x98, 0xa6, 0xbf, 0x73, 0xf3, 0x34, 0x8d, 0x86, 3603 0xf1, 0x66, 0xf8, 0xb4, 0x13, 0x6b, 0x79, 0x99, 3604 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3605 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3606 const u8 n1[16] = { 3607 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3608 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3609 const u8 n2[16] = { 3610 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3611 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3612 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 }; 3613 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 }; 3614 const u8 exp_ltk[16] = { 3615 0x38, 0x0a, 0x75, 0x94, 0xb5, 0x22, 0x05, 0x98, 3616 0x23, 0xcd, 0xd7, 0x69, 0x11, 0x79, 0x86, 0x69 }; 3617 const u8 exp_mackey[16] = { 3618 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd, 3619 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 }; 3620 u8 mackey[16], ltk[16]; 3621 int err; 3622 3623 err = smp_f5(tfm_cmac, w, n1, n2, a1, a2, mackey, ltk); 3624 if (err) 3625 return err; 3626 3627 if (crypto_memneq(mackey, exp_mackey, 16)) 3628 return -EINVAL; 3629 3630 if (crypto_memneq(ltk, exp_ltk, 16)) 3631 return -EINVAL; 3632 3633 return 0; 3634 } 3635 test_f6(struct crypto_shash * tfm_cmac)3636 static int __init test_f6(struct crypto_shash *tfm_cmac) 3637 { 3638 const u8 w[16] = { 3639 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd, 3640 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 }; 3641 const u8 n1[16] = { 3642 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3643 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3644 const u8 n2[16] = { 3645 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3646 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3647 const u8 r[16] = { 3648 0xc8, 0x0f, 0x2d, 0x0c, 0xd2, 0x42, 0xda, 0x08, 3649 0x54, 0xbb, 0x53, 0xb4, 0x3b, 0x34, 0xa3, 0x12 }; 3650 const u8 io_cap[3] = { 0x02, 0x01, 0x01 }; 3651 const u8 a1[7] = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56, 0x00 }; 3652 const u8 a2[7] = { 0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7, 0x00 }; 3653 const u8 exp[16] = { 3654 0x61, 0x8f, 0x95, 0xda, 0x09, 0x0b, 0x6c, 0xd2, 3655 0xc5, 0xe8, 0xd0, 0x9c, 0x98, 0x73, 0xc4, 0xe3 }; 3656 u8 res[16]; 3657 int err; 3658 3659 err = smp_f6(tfm_cmac, w, n1, n2, r, io_cap, a1, a2, res); 3660 if (err) 3661 return err; 3662 3663 if (crypto_memneq(res, exp, 16)) 3664 return -EINVAL; 3665 3666 return 0; 3667 } 3668 test_g2(struct crypto_shash * tfm_cmac)3669 static int __init test_g2(struct crypto_shash *tfm_cmac) 3670 { 3671 const u8 u[32] = { 3672 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, 3673 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, 3674 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, 3675 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 }; 3676 const u8 v[32] = { 3677 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b, 3678 0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59, 3679 0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90, 3680 0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 }; 3681 const u8 x[16] = { 3682 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff, 3683 0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 }; 3684 const u8 y[16] = { 3685 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21, 3686 0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 }; 3687 const u32 exp_val = 0x2f9ed5ba % 1000000; 3688 u32 val; 3689 int err; 3690 3691 err = smp_g2(tfm_cmac, u, v, x, y, &val); 3692 if (err) 3693 return err; 3694 3695 if (val != exp_val) 3696 return -EINVAL; 3697 3698 return 0; 3699 } 3700 test_h6(struct crypto_shash * tfm_cmac)3701 static int __init test_h6(struct crypto_shash *tfm_cmac) 3702 { 3703 const u8 w[16] = { 3704 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34, 3705 0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec }; 3706 const u8 key_id[4] = { 0x72, 0x62, 0x65, 0x6c }; 3707 const u8 exp[16] = { 3708 0x99, 0x63, 0xb1, 0x80, 0xe2, 0xa9, 0xd3, 0xe8, 3709 0x1c, 0xc9, 0x6d, 0xe7, 0x02, 0xe1, 0x9a, 0x2d }; 3710 u8 res[16]; 3711 int err; 3712 3713 err = smp_h6(tfm_cmac, w, key_id, res); 3714 if (err) 3715 return err; 3716 3717 if (crypto_memneq(res, exp, 16)) 3718 return -EINVAL; 3719 3720 return 0; 3721 } 3722 3723 static char test_smp_buffer[32]; 3724 test_smp_read(struct file * file,char __user * user_buf,size_t count,loff_t * ppos)3725 static ssize_t test_smp_read(struct file *file, char __user *user_buf, 3726 size_t count, loff_t *ppos) 3727 { 3728 return simple_read_from_buffer(user_buf, count, ppos, test_smp_buffer, 3729 strlen(test_smp_buffer)); 3730 } 3731 3732 static const struct file_operations test_smp_fops = { 3733 .open = simple_open, 3734 .read = test_smp_read, 3735 .llseek = default_llseek, 3736 }; 3737 run_selftests(struct crypto_shash * tfm_cmac,struct crypto_kpp * tfm_ecdh)3738 static int __init run_selftests(struct crypto_shash *tfm_cmac, 3739 struct crypto_kpp *tfm_ecdh) 3740 { 3741 ktime_t calltime, delta, rettime; 3742 unsigned long long duration; 3743 int err; 3744 3745 calltime = ktime_get(); 3746 3747 err = test_debug_key(tfm_ecdh); 3748 if (err) { 3749 BT_ERR("debug_key test failed"); 3750 goto done; 3751 } 3752 3753 err = test_ah(); 3754 if (err) { 3755 BT_ERR("smp_ah test failed"); 3756 goto done; 3757 } 3758 3759 err = test_c1(); 3760 if (err) { 3761 BT_ERR("smp_c1 test failed"); 3762 goto done; 3763 } 3764 3765 err = test_s1(); 3766 if (err) { 3767 BT_ERR("smp_s1 test failed"); 3768 goto done; 3769 } 3770 3771 err = test_f4(tfm_cmac); 3772 if (err) { 3773 BT_ERR("smp_f4 test failed"); 3774 goto done; 3775 } 3776 3777 err = test_f5(tfm_cmac); 3778 if (err) { 3779 BT_ERR("smp_f5 test failed"); 3780 goto done; 3781 } 3782 3783 err = test_f6(tfm_cmac); 3784 if (err) { 3785 BT_ERR("smp_f6 test failed"); 3786 goto done; 3787 } 3788 3789 err = test_g2(tfm_cmac); 3790 if (err) { 3791 BT_ERR("smp_g2 test failed"); 3792 goto done; 3793 } 3794 3795 err = test_h6(tfm_cmac); 3796 if (err) { 3797 BT_ERR("smp_h6 test failed"); 3798 goto done; 3799 } 3800 3801 rettime = ktime_get(); 3802 delta = ktime_sub(rettime, calltime); 3803 duration = (unsigned long long) ktime_to_ns(delta) >> 10; 3804 3805 BT_INFO("SMP test passed in %llu usecs", duration); 3806 3807 done: 3808 if (!err) 3809 snprintf(test_smp_buffer, sizeof(test_smp_buffer), 3810 "PASS (%llu usecs)\n", duration); 3811 else 3812 snprintf(test_smp_buffer, sizeof(test_smp_buffer), "FAIL\n"); 3813 3814 debugfs_create_file("selftest_smp", 0444, bt_debugfs, NULL, 3815 &test_smp_fops); 3816 3817 return err; 3818 } 3819 bt_selftest_smp(void)3820 int __init bt_selftest_smp(void) 3821 { 3822 struct crypto_shash *tfm_cmac; 3823 struct crypto_kpp *tfm_ecdh; 3824 int err; 3825 3826 tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); 3827 if (IS_ERR(tfm_cmac)) { 3828 BT_ERR("Unable to create CMAC crypto context"); 3829 return PTR_ERR(tfm_cmac); 3830 } 3831 3832 tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0); 3833 if (IS_ERR(tfm_ecdh)) { 3834 BT_ERR("Unable to create ECDH crypto context"); 3835 crypto_free_shash(tfm_cmac); 3836 return PTR_ERR(tfm_ecdh); 3837 } 3838 3839 err = run_selftests(tfm_cmac, tfm_ecdh); 3840 3841 crypto_free_shash(tfm_cmac); 3842 crypto_free_kpp(tfm_ecdh); 3843 3844 return err; 3845 } 3846 3847 #endif 3848