1 // SPDX-License-Identifier: LGPL-2.1 2 /* 3 * 4 * Copyright (C) International Business Machines Corp., 2002, 2011 5 * Etersoft, 2012 6 * Author(s): Steve French (sfrench@us.ibm.com) 7 * Jeremy Allison (jra@samba.org) 2006 8 * Pavel Shilovsky (pshilovsky@samba.org) 2012 9 * 10 */ 11 12 #include <linux/fs.h> 13 #include <linux/list.h> 14 #include <linux/wait.h> 15 #include <linux/net.h> 16 #include <linux/delay.h> 17 #include <linux/uaccess.h> 18 #include <asm/processor.h> 19 #include <linux/mempool.h> 20 #include <linux/highmem.h> 21 #include <crypto/aead.h> 22 #include "cifsglob.h" 23 #include "cifsproto.h" 24 #include "smb2proto.h" 25 #include "cifs_debug.h" 26 #include "smb2status.h" 27 #include "smb2glob.h" 28 29 static int 30 smb3_crypto_shash_allocate(struct TCP_Server_Info *server) 31 { 32 struct cifs_secmech *p = &server->secmech; 33 int rc; 34 35 rc = cifs_alloc_hash("hmac(sha256)", &p->hmacsha256); 36 if (rc) 37 goto err; 38 39 rc = cifs_alloc_hash("cmac(aes)", &p->aes_cmac); 40 if (rc) 41 goto err; 42 43 return 0; 44 err: 45 cifs_free_hash(&p->hmacsha256); 46 return rc; 47 } 48 49 int 50 smb311_crypto_shash_allocate(struct TCP_Server_Info *server) 51 { 52 struct cifs_secmech *p = &server->secmech; 53 int rc = 0; 54 55 rc = cifs_alloc_hash("hmac(sha256)", &p->hmacsha256); 56 if (rc) 57 return rc; 58 59 rc = cifs_alloc_hash("cmac(aes)", &p->aes_cmac); 60 if (rc) 61 goto err; 62 63 rc = cifs_alloc_hash("sha512", &p->sha512); 64 if (rc) 65 goto err; 66 67 return 0; 68 69 err: 70 cifs_free_hash(&p->aes_cmac); 71 cifs_free_hash(&p->hmacsha256); 72 return rc; 73 } 74 75 76 static 77 int smb2_get_sign_key(__u64 ses_id, struct TCP_Server_Info *server, u8 *key) 78 { 79 struct cifs_chan *chan; 80 struct TCP_Server_Info *pserver; 81 struct cifs_ses *ses = NULL; 82 int i; 83 int rc = 0; 84 bool is_binding = false; 85 86 spin_lock(&cifs_tcp_ses_lock); 87 88 /* If server is a channel, select the primary channel */ 89 pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server; 90 91 list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) { 92 if (ses->Suid == ses_id) 93 goto found; 94 } 95 trace_smb3_ses_not_found(ses_id); 96 cifs_server_dbg(FYI, "%s: Could not find session 0x%llx\n", 97 __func__, ses_id); 98 rc = -ENOENT; 99 goto out; 100 101 found: 102 spin_lock(&ses->ses_lock); 103 spin_lock(&ses->chan_lock); 104 105 is_binding = (cifs_chan_needs_reconnect(ses, server) && 106 ses->ses_status == SES_GOOD); 107 if (is_binding) { 108 /* 109 * If we are in the process of binding a new channel 110 * to an existing session, use the master connection 111 * session key 112 */ 113 memcpy(key, ses->smb3signingkey, SMB3_SIGN_KEY_SIZE); 114 spin_unlock(&ses->chan_lock); 115 spin_unlock(&ses->ses_lock); 116 goto out; 117 } 118 119 /* 120 * Otherwise, use the channel key. 121 */ 122 123 for (i = 0; i < ses->chan_count; i++) { 124 chan = ses->chans + i; 125 if (chan->server == server) { 126 memcpy(key, chan->signkey, SMB3_SIGN_KEY_SIZE); 127 spin_unlock(&ses->chan_lock); 128 spin_unlock(&ses->ses_lock); 129 goto out; 130 } 131 } 132 spin_unlock(&ses->chan_lock); 133 spin_unlock(&ses->ses_lock); 134 135 cifs_dbg(VFS, 136 "%s: Could not find channel signing key for session 0x%llx\n", 137 __func__, ses_id); 138 rc = -ENOENT; 139 140 out: 141 spin_unlock(&cifs_tcp_ses_lock); 142 return rc; 143 } 144 145 static struct cifs_ses * 146 smb2_find_smb_ses_unlocked(struct TCP_Server_Info *server, __u64 ses_id) 147 { 148 struct TCP_Server_Info *pserver; 149 struct cifs_ses *ses; 150 151 /* If server is a channel, select the primary channel */ 152 pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server; 153 154 list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) { 155 if (ses->Suid != ses_id) 156 continue; 157 158 spin_lock(&ses->ses_lock); 159 if (ses->ses_status == SES_EXITING) { 160 spin_unlock(&ses->ses_lock); 161 continue; 162 } 163 ++ses->ses_count; 164 spin_unlock(&ses->ses_lock); 165 return ses; 166 } 167 168 return NULL; 169 } 170 171 struct cifs_ses * 172 smb2_find_smb_ses(struct TCP_Server_Info *server, __u64 ses_id) 173 { 174 struct cifs_ses *ses; 175 176 spin_lock(&cifs_tcp_ses_lock); 177 ses = smb2_find_smb_ses_unlocked(server, ses_id); 178 spin_unlock(&cifs_tcp_ses_lock); 179 180 return ses; 181 } 182 183 static struct cifs_tcon * 184 smb2_find_smb_sess_tcon_unlocked(struct cifs_ses *ses, __u32 tid) 185 { 186 struct cifs_tcon *tcon; 187 188 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) { 189 if (tcon->tid != tid) 190 continue; 191 ++tcon->tc_count; 192 return tcon; 193 } 194 195 return NULL; 196 } 197 198 /* 199 * Obtain tcon corresponding to the tid in the given 200 * cifs_ses 201 */ 202 203 struct cifs_tcon * 204 smb2_find_smb_tcon(struct TCP_Server_Info *server, __u64 ses_id, __u32 tid) 205 { 206 struct cifs_ses *ses; 207 struct cifs_tcon *tcon; 208 209 spin_lock(&cifs_tcp_ses_lock); 210 ses = smb2_find_smb_ses_unlocked(server, ses_id); 211 if (!ses) { 212 spin_unlock(&cifs_tcp_ses_lock); 213 return NULL; 214 } 215 tcon = smb2_find_smb_sess_tcon_unlocked(ses, tid); 216 if (!tcon) { 217 cifs_put_smb_ses(ses); 218 spin_unlock(&cifs_tcp_ses_lock); 219 return NULL; 220 } 221 spin_unlock(&cifs_tcp_ses_lock); 222 /* tcon already has a ref to ses, so we don't need ses anymore */ 223 cifs_put_smb_ses(ses); 224 225 return tcon; 226 } 227 228 int 229 smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server, 230 bool allocate_crypto) 231 { 232 int rc; 233 unsigned char smb2_signature[SMB2_HMACSHA256_SIZE]; 234 unsigned char *sigptr = smb2_signature; 235 struct kvec *iov = rqst->rq_iov; 236 struct smb2_hdr *shdr = (struct smb2_hdr *)iov[0].iov_base; 237 struct cifs_ses *ses; 238 struct shash_desc *shash = NULL; 239 struct smb_rqst drqst; 240 241 ses = smb2_find_smb_ses(server, le64_to_cpu(shdr->SessionId)); 242 if (unlikely(!ses)) { 243 cifs_server_dbg(VFS, "%s: Could not find session\n", __func__); 244 return -ENOENT; 245 } 246 247 memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE); 248 memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE); 249 250 if (allocate_crypto) { 251 rc = cifs_alloc_hash("hmac(sha256)", &shash); 252 if (rc) { 253 cifs_server_dbg(VFS, 254 "%s: sha256 alloc failed\n", __func__); 255 goto out; 256 } 257 } else { 258 shash = server->secmech.hmacsha256; 259 } 260 261 rc = crypto_shash_setkey(shash->tfm, ses->auth_key.response, 262 SMB2_NTLMV2_SESSKEY_SIZE); 263 if (rc) { 264 cifs_server_dbg(VFS, 265 "%s: Could not update with response\n", 266 __func__); 267 goto out; 268 } 269 270 rc = crypto_shash_init(shash); 271 if (rc) { 272 cifs_server_dbg(VFS, "%s: Could not init sha256", __func__); 273 goto out; 274 } 275 276 /* 277 * For SMB2+, __cifs_calc_signature() expects to sign only the actual 278 * data, that is, iov[0] should not contain a rfc1002 length. 279 * 280 * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to 281 * __cifs_calc_signature(). 282 */ 283 drqst = *rqst; 284 if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) { 285 rc = crypto_shash_update(shash, iov[0].iov_base, 286 iov[0].iov_len); 287 if (rc) { 288 cifs_server_dbg(VFS, 289 "%s: Could not update with payload\n", 290 __func__); 291 goto out; 292 } 293 drqst.rq_iov++; 294 drqst.rq_nvec--; 295 } 296 297 rc = __cifs_calc_signature(&drqst, server, sigptr, shash); 298 if (!rc) 299 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE); 300 301 out: 302 if (allocate_crypto) 303 cifs_free_hash(&shash); 304 if (ses) 305 cifs_put_smb_ses(ses); 306 return rc; 307 } 308 309 static int generate_key(struct cifs_ses *ses, struct kvec label, 310 struct kvec context, __u8 *key, unsigned int key_size) 311 { 312 unsigned char zero = 0x0; 313 __u8 i[4] = {0, 0, 0, 1}; 314 __u8 L128[4] = {0, 0, 0, 128}; 315 __u8 L256[4] = {0, 0, 1, 0}; 316 int rc = 0; 317 unsigned char prfhash[SMB2_HMACSHA256_SIZE]; 318 unsigned char *hashptr = prfhash; 319 struct TCP_Server_Info *server = ses->server; 320 321 memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE); 322 memset(key, 0x0, key_size); 323 324 rc = smb3_crypto_shash_allocate(server); 325 if (rc) { 326 cifs_server_dbg(VFS, "%s: crypto alloc failed\n", __func__); 327 goto smb3signkey_ret; 328 } 329 330 rc = crypto_shash_setkey(server->secmech.hmacsha256->tfm, 331 ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE); 332 if (rc) { 333 cifs_server_dbg(VFS, "%s: Could not set with session key\n", __func__); 334 goto smb3signkey_ret; 335 } 336 337 rc = crypto_shash_init(server->secmech.hmacsha256); 338 if (rc) { 339 cifs_server_dbg(VFS, "%s: Could not init sign hmac\n", __func__); 340 goto smb3signkey_ret; 341 } 342 343 rc = crypto_shash_update(server->secmech.hmacsha256, i, 4); 344 if (rc) { 345 cifs_server_dbg(VFS, "%s: Could not update with n\n", __func__); 346 goto smb3signkey_ret; 347 } 348 349 rc = crypto_shash_update(server->secmech.hmacsha256, label.iov_base, label.iov_len); 350 if (rc) { 351 cifs_server_dbg(VFS, "%s: Could not update with label\n", __func__); 352 goto smb3signkey_ret; 353 } 354 355 rc = crypto_shash_update(server->secmech.hmacsha256, &zero, 1); 356 if (rc) { 357 cifs_server_dbg(VFS, "%s: Could not update with zero\n", __func__); 358 goto smb3signkey_ret; 359 } 360 361 rc = crypto_shash_update(server->secmech.hmacsha256, context.iov_base, context.iov_len); 362 if (rc) { 363 cifs_server_dbg(VFS, "%s: Could not update with context\n", __func__); 364 goto smb3signkey_ret; 365 } 366 367 if ((server->cipher_type == SMB2_ENCRYPTION_AES256_CCM) || 368 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) { 369 rc = crypto_shash_update(server->secmech.hmacsha256, L256, 4); 370 } else { 371 rc = crypto_shash_update(server->secmech.hmacsha256, L128, 4); 372 } 373 if (rc) { 374 cifs_server_dbg(VFS, "%s: Could not update with L\n", __func__); 375 goto smb3signkey_ret; 376 } 377 378 rc = crypto_shash_final(server->secmech.hmacsha256, hashptr); 379 if (rc) { 380 cifs_server_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__); 381 goto smb3signkey_ret; 382 } 383 384 memcpy(key, hashptr, key_size); 385 386 smb3signkey_ret: 387 return rc; 388 } 389 390 struct derivation { 391 struct kvec label; 392 struct kvec context; 393 }; 394 395 struct derivation_triplet { 396 struct derivation signing; 397 struct derivation encryption; 398 struct derivation decryption; 399 }; 400 401 static int 402 generate_smb3signingkey(struct cifs_ses *ses, 403 struct TCP_Server_Info *server, 404 const struct derivation_triplet *ptriplet) 405 { 406 int rc; 407 bool is_binding = false; 408 int chan_index = 0; 409 410 spin_lock(&ses->ses_lock); 411 spin_lock(&ses->chan_lock); 412 is_binding = (cifs_chan_needs_reconnect(ses, server) && 413 ses->ses_status == SES_GOOD); 414 415 chan_index = cifs_ses_get_chan_index(ses, server); 416 /* TODO: introduce ref counting for channels when the can be freed */ 417 spin_unlock(&ses->chan_lock); 418 spin_unlock(&ses->ses_lock); 419 420 /* 421 * All channels use the same encryption/decryption keys but 422 * they have their own signing key. 423 * 424 * When we generate the keys, check if it is for a new channel 425 * (binding) in which case we only need to generate a signing 426 * key and store it in the channel as to not overwrite the 427 * master connection signing key stored in the session 428 */ 429 430 if (is_binding) { 431 rc = generate_key(ses, ptriplet->signing.label, 432 ptriplet->signing.context, 433 ses->chans[chan_index].signkey, 434 SMB3_SIGN_KEY_SIZE); 435 if (rc) 436 return rc; 437 } else { 438 rc = generate_key(ses, ptriplet->signing.label, 439 ptriplet->signing.context, 440 ses->smb3signingkey, 441 SMB3_SIGN_KEY_SIZE); 442 if (rc) 443 return rc; 444 445 /* safe to access primary channel, since it will never go away */ 446 spin_lock(&ses->chan_lock); 447 memcpy(ses->chans[chan_index].signkey, ses->smb3signingkey, 448 SMB3_SIGN_KEY_SIZE); 449 spin_unlock(&ses->chan_lock); 450 451 rc = generate_key(ses, ptriplet->encryption.label, 452 ptriplet->encryption.context, 453 ses->smb3encryptionkey, 454 SMB3_ENC_DEC_KEY_SIZE); 455 rc = generate_key(ses, ptriplet->decryption.label, 456 ptriplet->decryption.context, 457 ses->smb3decryptionkey, 458 SMB3_ENC_DEC_KEY_SIZE); 459 if (rc) 460 return rc; 461 } 462 463 if (rc) 464 return rc; 465 466 #ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS 467 cifs_dbg(VFS, "%s: dumping generated AES session keys\n", __func__); 468 /* 469 * The session id is opaque in terms of endianness, so we can't 470 * print it as a long long. we dump it as we got it on the wire 471 */ 472 cifs_dbg(VFS, "Session Id %*ph\n", (int)sizeof(ses->Suid), 473 &ses->Suid); 474 cifs_dbg(VFS, "Cipher type %d\n", server->cipher_type); 475 cifs_dbg(VFS, "Session Key %*ph\n", 476 SMB2_NTLMV2_SESSKEY_SIZE, ses->auth_key.response); 477 cifs_dbg(VFS, "Signing Key %*ph\n", 478 SMB3_SIGN_KEY_SIZE, ses->smb3signingkey); 479 if ((server->cipher_type == SMB2_ENCRYPTION_AES256_CCM) || 480 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) { 481 cifs_dbg(VFS, "ServerIn Key %*ph\n", 482 SMB3_GCM256_CRYPTKEY_SIZE, ses->smb3encryptionkey); 483 cifs_dbg(VFS, "ServerOut Key %*ph\n", 484 SMB3_GCM256_CRYPTKEY_SIZE, ses->smb3decryptionkey); 485 } else { 486 cifs_dbg(VFS, "ServerIn Key %*ph\n", 487 SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3encryptionkey); 488 cifs_dbg(VFS, "ServerOut Key %*ph\n", 489 SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3decryptionkey); 490 } 491 #endif 492 return rc; 493 } 494 495 int 496 generate_smb30signingkey(struct cifs_ses *ses, 497 struct TCP_Server_Info *server) 498 499 { 500 struct derivation_triplet triplet; 501 struct derivation *d; 502 503 d = &triplet.signing; 504 d->label.iov_base = "SMB2AESCMAC"; 505 d->label.iov_len = 12; 506 d->context.iov_base = "SmbSign"; 507 d->context.iov_len = 8; 508 509 d = &triplet.encryption; 510 d->label.iov_base = "SMB2AESCCM"; 511 d->label.iov_len = 11; 512 d->context.iov_base = "ServerIn "; 513 d->context.iov_len = 10; 514 515 d = &triplet.decryption; 516 d->label.iov_base = "SMB2AESCCM"; 517 d->label.iov_len = 11; 518 d->context.iov_base = "ServerOut"; 519 d->context.iov_len = 10; 520 521 return generate_smb3signingkey(ses, server, &triplet); 522 } 523 524 int 525 generate_smb311signingkey(struct cifs_ses *ses, 526 struct TCP_Server_Info *server) 527 528 { 529 struct derivation_triplet triplet; 530 struct derivation *d; 531 532 d = &triplet.signing; 533 d->label.iov_base = "SMBSigningKey"; 534 d->label.iov_len = 14; 535 d->context.iov_base = ses->preauth_sha_hash; 536 d->context.iov_len = 64; 537 538 d = &triplet.encryption; 539 d->label.iov_base = "SMBC2SCipherKey"; 540 d->label.iov_len = 16; 541 d->context.iov_base = ses->preauth_sha_hash; 542 d->context.iov_len = 64; 543 544 d = &triplet.decryption; 545 d->label.iov_base = "SMBS2CCipherKey"; 546 d->label.iov_len = 16; 547 d->context.iov_base = ses->preauth_sha_hash; 548 d->context.iov_len = 64; 549 550 return generate_smb3signingkey(ses, server, &triplet); 551 } 552 553 int 554 smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server, 555 bool allocate_crypto) 556 { 557 int rc; 558 unsigned char smb3_signature[SMB2_CMACAES_SIZE]; 559 unsigned char *sigptr = smb3_signature; 560 struct kvec *iov = rqst->rq_iov; 561 struct smb2_hdr *shdr = (struct smb2_hdr *)iov[0].iov_base; 562 struct shash_desc *shash = NULL; 563 struct smb_rqst drqst; 564 u8 key[SMB3_SIGN_KEY_SIZE]; 565 566 rc = smb2_get_sign_key(le64_to_cpu(shdr->SessionId), server, key); 567 if (unlikely(rc)) { 568 cifs_server_dbg(FYI, "%s: Could not get signing key\n", __func__); 569 return rc; 570 } 571 572 if (allocate_crypto) { 573 rc = cifs_alloc_hash("cmac(aes)", &shash); 574 if (rc) 575 return rc; 576 } else { 577 shash = server->secmech.aes_cmac; 578 } 579 580 memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE); 581 memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE); 582 583 rc = crypto_shash_setkey(shash->tfm, key, SMB2_CMACAES_SIZE); 584 if (rc) { 585 cifs_server_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__); 586 goto out; 587 } 588 589 /* 590 * we already allocate aes_cmac when we init smb3 signing key, 591 * so unlike smb2 case we do not have to check here if secmech are 592 * initialized 593 */ 594 rc = crypto_shash_init(shash); 595 if (rc) { 596 cifs_server_dbg(VFS, "%s: Could not init cmac aes\n", __func__); 597 goto out; 598 } 599 600 /* 601 * For SMB2+, __cifs_calc_signature() expects to sign only the actual 602 * data, that is, iov[0] should not contain a rfc1002 length. 603 * 604 * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to 605 * __cifs_calc_signature(). 606 */ 607 drqst = *rqst; 608 if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) { 609 rc = crypto_shash_update(shash, iov[0].iov_base, 610 iov[0].iov_len); 611 if (rc) { 612 cifs_server_dbg(VFS, "%s: Could not update with payload\n", 613 __func__); 614 goto out; 615 } 616 drqst.rq_iov++; 617 drqst.rq_nvec--; 618 } 619 620 rc = __cifs_calc_signature(&drqst, server, sigptr, shash); 621 if (!rc) 622 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE); 623 624 out: 625 if (allocate_crypto) 626 cifs_free_hash(&shash); 627 return rc; 628 } 629 630 /* must be called with server->srv_mutex held */ 631 static int 632 smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server) 633 { 634 int rc = 0; 635 struct smb2_hdr *shdr; 636 struct smb2_sess_setup_req *ssr; 637 bool is_binding; 638 bool is_signed; 639 640 shdr = (struct smb2_hdr *)rqst->rq_iov[0].iov_base; 641 ssr = (struct smb2_sess_setup_req *)shdr; 642 643 is_binding = shdr->Command == SMB2_SESSION_SETUP && 644 (ssr->Flags & SMB2_SESSION_REQ_FLAG_BINDING); 645 is_signed = shdr->Flags & SMB2_FLAGS_SIGNED; 646 647 if (!is_signed) 648 return 0; 649 spin_lock(&server->srv_lock); 650 if (server->ops->need_neg && 651 server->ops->need_neg(server)) { 652 spin_unlock(&server->srv_lock); 653 return 0; 654 } 655 spin_unlock(&server->srv_lock); 656 if (!is_binding && !server->session_estab) { 657 strncpy(shdr->Signature, "BSRSPYL", 8); 658 return 0; 659 } 660 661 rc = server->ops->calc_signature(rqst, server, false); 662 663 return rc; 664 } 665 666 int 667 smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server) 668 { 669 unsigned int rc; 670 char server_response_sig[SMB2_SIGNATURE_SIZE]; 671 struct smb2_hdr *shdr = 672 (struct smb2_hdr *)rqst->rq_iov[0].iov_base; 673 674 if ((shdr->Command == SMB2_NEGOTIATE) || 675 (shdr->Command == SMB2_SESSION_SETUP) || 676 (shdr->Command == SMB2_OPLOCK_BREAK) || 677 server->ignore_signature || 678 (!server->session_estab)) 679 return 0; 680 681 /* 682 * BB what if signatures are supposed to be on for session but 683 * server does not send one? BB 684 */ 685 686 /* Do not need to verify session setups with signature "BSRSPYL " */ 687 if (memcmp(shdr->Signature, "BSRSPYL ", 8) == 0) 688 cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n", 689 shdr->Command); 690 691 /* 692 * Save off the origiginal signature so we can modify the smb and check 693 * our calculated signature against what the server sent. 694 */ 695 memcpy(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE); 696 697 memset(shdr->Signature, 0, SMB2_SIGNATURE_SIZE); 698 699 rc = server->ops->calc_signature(rqst, server, true); 700 701 if (rc) 702 return rc; 703 704 if (memcmp(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE)) { 705 cifs_dbg(VFS, "sign fail cmd 0x%x message id 0x%llx\n", 706 shdr->Command, shdr->MessageId); 707 return -EACCES; 708 } else 709 return 0; 710 } 711 712 /* 713 * Set message id for the request. Should be called after wait_for_free_request 714 * and when srv_mutex is held. 715 */ 716 static inline void 717 smb2_seq_num_into_buf(struct TCP_Server_Info *server, 718 struct smb2_hdr *shdr) 719 { 720 unsigned int i, num = le16_to_cpu(shdr->CreditCharge); 721 722 shdr->MessageId = get_next_mid64(server); 723 /* skip message numbers according to CreditCharge field */ 724 for (i = 1; i < num; i++) 725 get_next_mid(server); 726 } 727 728 static struct mid_q_entry * 729 smb2_mid_entry_alloc(const struct smb2_hdr *shdr, 730 struct TCP_Server_Info *server) 731 { 732 struct mid_q_entry *temp; 733 unsigned int credits = le16_to_cpu(shdr->CreditCharge); 734 735 if (server == NULL) { 736 cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n"); 737 return NULL; 738 } 739 740 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS); 741 memset(temp, 0, sizeof(struct mid_q_entry)); 742 kref_init(&temp->refcount); 743 temp->mid = le64_to_cpu(shdr->MessageId); 744 temp->credits = credits > 0 ? credits : 1; 745 temp->pid = current->pid; 746 temp->command = shdr->Command; /* Always LE */ 747 temp->when_alloc = jiffies; 748 temp->server = server; 749 750 /* 751 * The default is for the mid to be synchronous, so the 752 * default callback just wakes up the current task. 753 */ 754 get_task_struct(current); 755 temp->creator = current; 756 temp->callback = cifs_wake_up_task; 757 temp->callback_data = current; 758 759 atomic_inc(&mid_count); 760 temp->mid_state = MID_REQUEST_ALLOCATED; 761 trace_smb3_cmd_enter(le32_to_cpu(shdr->Id.SyncId.TreeId), 762 le64_to_cpu(shdr->SessionId), 763 le16_to_cpu(shdr->Command), temp->mid); 764 return temp; 765 } 766 767 static int 768 smb2_get_mid_entry(struct cifs_ses *ses, struct TCP_Server_Info *server, 769 struct smb2_hdr *shdr, struct mid_q_entry **mid) 770 { 771 spin_lock(&server->srv_lock); 772 if (server->tcpStatus == CifsExiting) { 773 spin_unlock(&server->srv_lock); 774 return -ENOENT; 775 } 776 777 if (server->tcpStatus == CifsNeedReconnect) { 778 spin_unlock(&server->srv_lock); 779 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n"); 780 return -EAGAIN; 781 } 782 783 if (server->tcpStatus == CifsNeedNegotiate && 784 shdr->Command != SMB2_NEGOTIATE) { 785 spin_unlock(&server->srv_lock); 786 return -EAGAIN; 787 } 788 spin_unlock(&server->srv_lock); 789 790 spin_lock(&ses->ses_lock); 791 if (ses->ses_status == SES_NEW) { 792 if ((shdr->Command != SMB2_SESSION_SETUP) && 793 (shdr->Command != SMB2_NEGOTIATE)) { 794 spin_unlock(&ses->ses_lock); 795 return -EAGAIN; 796 } 797 /* else ok - we are setting up session */ 798 } 799 800 if (ses->ses_status == SES_EXITING) { 801 if (shdr->Command != SMB2_LOGOFF) { 802 spin_unlock(&ses->ses_lock); 803 return -EAGAIN; 804 } 805 /* else ok - we are shutting down the session */ 806 } 807 spin_unlock(&ses->ses_lock); 808 809 *mid = smb2_mid_entry_alloc(shdr, server); 810 if (*mid == NULL) 811 return -ENOMEM; 812 spin_lock(&server->mid_lock); 813 list_add_tail(&(*mid)->qhead, &server->pending_mid_q); 814 spin_unlock(&server->mid_lock); 815 816 return 0; 817 } 818 819 int 820 smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server, 821 bool log_error) 822 { 823 unsigned int len = mid->resp_buf_size; 824 struct kvec iov[1]; 825 struct smb_rqst rqst = { .rq_iov = iov, 826 .rq_nvec = 1 }; 827 828 iov[0].iov_base = (char *)mid->resp_buf; 829 iov[0].iov_len = len; 830 831 dump_smb(mid->resp_buf, min_t(u32, 80, len)); 832 /* convert the length into a more usable form */ 833 if (len > 24 && server->sign && !mid->decrypted) { 834 int rc; 835 836 rc = smb2_verify_signature(&rqst, server); 837 if (rc) 838 cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n", 839 rc); 840 } 841 842 return map_smb2_to_linux_error(mid->resp_buf, log_error); 843 } 844 845 struct mid_q_entry * 846 smb2_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *server, 847 struct smb_rqst *rqst) 848 { 849 int rc; 850 struct smb2_hdr *shdr = 851 (struct smb2_hdr *)rqst->rq_iov[0].iov_base; 852 struct mid_q_entry *mid; 853 854 smb2_seq_num_into_buf(server, shdr); 855 856 rc = smb2_get_mid_entry(ses, server, shdr, &mid); 857 if (rc) { 858 revert_current_mid_from_hdr(server, shdr); 859 return ERR_PTR(rc); 860 } 861 862 rc = smb2_sign_rqst(rqst, server); 863 if (rc) { 864 revert_current_mid_from_hdr(server, shdr); 865 delete_mid(mid); 866 return ERR_PTR(rc); 867 } 868 869 return mid; 870 } 871 872 struct mid_q_entry * 873 smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst) 874 { 875 int rc; 876 struct smb2_hdr *shdr = 877 (struct smb2_hdr *)rqst->rq_iov[0].iov_base; 878 struct mid_q_entry *mid; 879 880 spin_lock(&server->srv_lock); 881 if (server->tcpStatus == CifsNeedNegotiate && 882 shdr->Command != SMB2_NEGOTIATE) { 883 spin_unlock(&server->srv_lock); 884 return ERR_PTR(-EAGAIN); 885 } 886 spin_unlock(&server->srv_lock); 887 888 smb2_seq_num_into_buf(server, shdr); 889 890 mid = smb2_mid_entry_alloc(shdr, server); 891 if (mid == NULL) { 892 revert_current_mid_from_hdr(server, shdr); 893 return ERR_PTR(-ENOMEM); 894 } 895 896 rc = smb2_sign_rqst(rqst, server); 897 if (rc) { 898 revert_current_mid_from_hdr(server, shdr); 899 release_mid(mid); 900 return ERR_PTR(rc); 901 } 902 903 return mid; 904 } 905 906 int 907 smb3_crypto_aead_allocate(struct TCP_Server_Info *server) 908 { 909 struct crypto_aead *tfm; 910 911 if (!server->secmech.enc) { 912 if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) || 913 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) 914 tfm = crypto_alloc_aead("gcm(aes)", 0, 0); 915 else 916 tfm = crypto_alloc_aead("ccm(aes)", 0, 0); 917 if (IS_ERR(tfm)) { 918 cifs_server_dbg(VFS, "%s: Failed alloc encrypt aead\n", 919 __func__); 920 return PTR_ERR(tfm); 921 } 922 server->secmech.enc = tfm; 923 } 924 925 if (!server->secmech.dec) { 926 if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) || 927 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) 928 tfm = crypto_alloc_aead("gcm(aes)", 0, 0); 929 else 930 tfm = crypto_alloc_aead("ccm(aes)", 0, 0); 931 if (IS_ERR(tfm)) { 932 crypto_free_aead(server->secmech.enc); 933 server->secmech.enc = NULL; 934 cifs_server_dbg(VFS, "%s: Failed to alloc decrypt aead\n", 935 __func__); 936 return PTR_ERR(tfm); 937 } 938 server->secmech.dec = tfm; 939 } 940 941 return 0; 942 } 943