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 29static int 30smb3_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; 44err: 45 cifs_free_hash(&p->hmacsha256); 46 return rc; 47} 48 49int 50smb311_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 69err: 70 cifs_free_hash(&p->aes_cmac); 71 cifs_free_hash(&p->hmacsha256); 72 return rc; 73} 74 75 76static 77int 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 = 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 101found: 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 140out: 141 spin_unlock(&cifs_tcp_ses_lock); 142 return rc; 143} 144 145static struct cifs_ses * 146smb2_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 = 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 cifs_smb_ses_inc_refcount(ses); 164 spin_unlock(&ses->ses_lock); 165 return ses; 166 } 167 168 return NULL; 169} 170 171struct cifs_ses * 172smb2_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 183static struct cifs_tcon * 184smb2_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 203struct cifs_tcon * 204smb2_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 228int 229smb2_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 301out: 302 if (allocate_crypto) 303 cifs_free_hash(&shash); 304 if (ses) 305 cifs_put_smb_ses(ses); 306 return rc; 307} 308 309static 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 386smb3signkey_ret: 387 return rc; 388} 389 390struct derivation { 391 struct kvec label; 392 struct kvec context; 393}; 394 395struct derivation_triplet { 396 struct derivation signing; 397 struct derivation encryption; 398 struct derivation decryption; 399}; 400 401static int 402generate_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 if (chan_index == CIFS_INVAL_CHAN_INDEX) { 417 spin_unlock(&ses->chan_lock); 418 spin_unlock(&ses->ses_lock); 419 420 return -EINVAL; 421 } 422 423 spin_unlock(&ses->chan_lock); 424 spin_unlock(&ses->ses_lock); 425 426 /* 427 * All channels use the same encryption/decryption keys but 428 * they have their own signing key. 429 * 430 * When we generate the keys, check if it is for a new channel 431 * (binding) in which case we only need to generate a signing 432 * key and store it in the channel as to not overwrite the 433 * master connection signing key stored in the session 434 */ 435 436 if (is_binding) { 437 rc = generate_key(ses, ptriplet->signing.label, 438 ptriplet->signing.context, 439 ses->chans[chan_index].signkey, 440 SMB3_SIGN_KEY_SIZE); 441 if (rc) 442 return rc; 443 } else { 444 rc = generate_key(ses, ptriplet->signing.label, 445 ptriplet->signing.context, 446 ses->smb3signingkey, 447 SMB3_SIGN_KEY_SIZE); 448 if (rc) 449 return rc; 450 451 /* safe to access primary channel, since it will never go away */ 452 spin_lock(&ses->chan_lock); 453 memcpy(ses->chans[chan_index].signkey, ses->smb3signingkey, 454 SMB3_SIGN_KEY_SIZE); 455 spin_unlock(&ses->chan_lock); 456 457 rc = generate_key(ses, ptriplet->encryption.label, 458 ptriplet->encryption.context, 459 ses->smb3encryptionkey, 460 SMB3_ENC_DEC_KEY_SIZE); 461 if (rc) 462 return rc; 463 rc = generate_key(ses, ptriplet->decryption.label, 464 ptriplet->decryption.context, 465 ses->smb3decryptionkey, 466 SMB3_ENC_DEC_KEY_SIZE); 467 if (rc) 468 return rc; 469 } 470 471#ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS 472 cifs_dbg(VFS, "%s: dumping generated AES session keys\n", __func__); 473 /* 474 * The session id is opaque in terms of endianness, so we can't 475 * print it as a long long. we dump it as we got it on the wire 476 */ 477 cifs_dbg(VFS, "Session Id %*ph\n", (int)sizeof(ses->Suid), 478 &ses->Suid); 479 cifs_dbg(VFS, "Cipher type %d\n", server->cipher_type); 480 cifs_dbg(VFS, "Session Key %*ph\n", 481 SMB2_NTLMV2_SESSKEY_SIZE, ses->auth_key.response); 482 cifs_dbg(VFS, "Signing Key %*ph\n", 483 SMB3_SIGN_KEY_SIZE, ses->smb3signingkey); 484 if ((server->cipher_type == SMB2_ENCRYPTION_AES256_CCM) || 485 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) { 486 cifs_dbg(VFS, "ServerIn Key %*ph\n", 487 SMB3_GCM256_CRYPTKEY_SIZE, ses->smb3encryptionkey); 488 cifs_dbg(VFS, "ServerOut Key %*ph\n", 489 SMB3_GCM256_CRYPTKEY_SIZE, ses->smb3decryptionkey); 490 } else { 491 cifs_dbg(VFS, "ServerIn Key %*ph\n", 492 SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3encryptionkey); 493 cifs_dbg(VFS, "ServerOut Key %*ph\n", 494 SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3decryptionkey); 495 } 496#endif 497 return rc; 498} 499 500int 501generate_smb30signingkey(struct cifs_ses *ses, 502 struct TCP_Server_Info *server) 503 504{ 505 struct derivation_triplet triplet; 506 struct derivation *d; 507 508 d = &triplet.signing; 509 d->label.iov_base = "SMB2AESCMAC"; 510 d->label.iov_len = 12; 511 d->context.iov_base = "SmbSign"; 512 d->context.iov_len = 8; 513 514 d = &triplet.encryption; 515 d->label.iov_base = "SMB2AESCCM"; 516 d->label.iov_len = 11; 517 d->context.iov_base = "ServerIn "; 518 d->context.iov_len = 10; 519 520 d = &triplet.decryption; 521 d->label.iov_base = "SMB2AESCCM"; 522 d->label.iov_len = 11; 523 d->context.iov_base = "ServerOut"; 524 d->context.iov_len = 10; 525 526 return generate_smb3signingkey(ses, server, &triplet); 527} 528 529int 530generate_smb311signingkey(struct cifs_ses *ses, 531 struct TCP_Server_Info *server) 532 533{ 534 struct derivation_triplet triplet; 535 struct derivation *d; 536 537 d = &triplet.signing; 538 d->label.iov_base = "SMBSigningKey"; 539 d->label.iov_len = 14; 540 d->context.iov_base = ses->preauth_sha_hash; 541 d->context.iov_len = 64; 542 543 d = &triplet.encryption; 544 d->label.iov_base = "SMBC2SCipherKey"; 545 d->label.iov_len = 16; 546 d->context.iov_base = ses->preauth_sha_hash; 547 d->context.iov_len = 64; 548 549 d = &triplet.decryption; 550 d->label.iov_base = "SMBS2CCipherKey"; 551 d->label.iov_len = 16; 552 d->context.iov_base = ses->preauth_sha_hash; 553 d->context.iov_len = 64; 554 555 return generate_smb3signingkey(ses, server, &triplet); 556} 557 558int 559smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server, 560 bool allocate_crypto) 561{ 562 int rc; 563 unsigned char smb3_signature[SMB2_CMACAES_SIZE]; 564 unsigned char *sigptr = smb3_signature; 565 struct kvec *iov = rqst->rq_iov; 566 struct smb2_hdr *shdr = (struct smb2_hdr *)iov[0].iov_base; 567 struct shash_desc *shash = NULL; 568 struct smb_rqst drqst; 569 u8 key[SMB3_SIGN_KEY_SIZE]; 570 571 rc = smb2_get_sign_key(le64_to_cpu(shdr->SessionId), server, key); 572 if (unlikely(rc)) { 573 cifs_server_dbg(FYI, "%s: Could not get signing key\n", __func__); 574 return rc; 575 } 576 577 if (allocate_crypto) { 578 rc = cifs_alloc_hash("cmac(aes)", &shash); 579 if (rc) 580 return rc; 581 } else { 582 shash = server->secmech.aes_cmac; 583 } 584 585 memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE); 586 memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE); 587 588 rc = crypto_shash_setkey(shash->tfm, key, SMB2_CMACAES_SIZE); 589 if (rc) { 590 cifs_server_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__); 591 goto out; 592 } 593 594 /* 595 * we already allocate aes_cmac when we init smb3 signing key, 596 * so unlike smb2 case we do not have to check here if secmech are 597 * initialized 598 */ 599 rc = crypto_shash_init(shash); 600 if (rc) { 601 cifs_server_dbg(VFS, "%s: Could not init cmac aes\n", __func__); 602 goto out; 603 } 604 605 /* 606 * For SMB2+, __cifs_calc_signature() expects to sign only the actual 607 * data, that is, iov[0] should not contain a rfc1002 length. 608 * 609 * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to 610 * __cifs_calc_signature(). 611 */ 612 drqst = *rqst; 613 if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) { 614 rc = crypto_shash_update(shash, iov[0].iov_base, 615 iov[0].iov_len); 616 if (rc) { 617 cifs_server_dbg(VFS, "%s: Could not update with payload\n", 618 __func__); 619 goto out; 620 } 621 drqst.rq_iov++; 622 drqst.rq_nvec--; 623 } 624 625 rc = __cifs_calc_signature(&drqst, server, sigptr, shash); 626 if (!rc) 627 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE); 628 629out: 630 if (allocate_crypto) 631 cifs_free_hash(&shash); 632 return rc; 633} 634 635/* must be called with server->srv_mutex held */ 636static int 637smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server) 638{ 639 int rc = 0; 640 struct smb2_hdr *shdr; 641 struct smb2_sess_setup_req *ssr; 642 bool is_binding; 643 bool is_signed; 644 645 shdr = (struct smb2_hdr *)rqst->rq_iov[0].iov_base; 646 ssr = (struct smb2_sess_setup_req *)shdr; 647 648 is_binding = shdr->Command == SMB2_SESSION_SETUP && 649 (ssr->Flags & SMB2_SESSION_REQ_FLAG_BINDING); 650 is_signed = shdr->Flags & SMB2_FLAGS_SIGNED; 651 652 if (!is_signed) 653 return 0; 654 spin_lock(&server->srv_lock); 655 if (server->ops->need_neg && 656 server->ops->need_neg(server)) { 657 spin_unlock(&server->srv_lock); 658 return 0; 659 } 660 spin_unlock(&server->srv_lock); 661 if (!is_binding && !server->session_estab) { 662 strncpy(shdr->Signature, "BSRSPYL", 8); 663 return 0; 664 } 665 666 rc = server->ops->calc_signature(rqst, server, false); 667 668 return rc; 669} 670 671int 672smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server) 673{ 674 unsigned int rc; 675 char server_response_sig[SMB2_SIGNATURE_SIZE]; 676 struct smb2_hdr *shdr = 677 (struct smb2_hdr *)rqst->rq_iov[0].iov_base; 678 679 if ((shdr->Command == SMB2_NEGOTIATE) || 680 (shdr->Command == SMB2_SESSION_SETUP) || 681 (shdr->Command == SMB2_OPLOCK_BREAK) || 682 server->ignore_signature || 683 (!server->session_estab)) 684 return 0; 685 686 /* 687 * BB what if signatures are supposed to be on for session but 688 * server does not send one? BB 689 */ 690 691 /* Do not need to verify session setups with signature "BSRSPYL " */ 692 if (memcmp(shdr->Signature, "BSRSPYL ", 8) == 0) 693 cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n", 694 shdr->Command); 695 696 /* 697 * Save off the origiginal signature so we can modify the smb and check 698 * our calculated signature against what the server sent. 699 */ 700 memcpy(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE); 701 702 memset(shdr->Signature, 0, SMB2_SIGNATURE_SIZE); 703 704 rc = server->ops->calc_signature(rqst, server, true); 705 706 if (rc) 707 return rc; 708 709 if (memcmp(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE)) { 710 cifs_dbg(VFS, "sign fail cmd 0x%x message id 0x%llx\n", 711 shdr->Command, shdr->MessageId); 712 return -EACCES; 713 } else 714 return 0; 715} 716 717/* 718 * Set message id for the request. Should be called after wait_for_free_request 719 * and when srv_mutex is held. 720 */ 721static inline void 722smb2_seq_num_into_buf(struct TCP_Server_Info *server, 723 struct smb2_hdr *shdr) 724{ 725 unsigned int i, num = le16_to_cpu(shdr->CreditCharge); 726 727 shdr->MessageId = get_next_mid64(server); 728 /* skip message numbers according to CreditCharge field */ 729 for (i = 1; i < num; i++) 730 get_next_mid(server); 731} 732 733static struct mid_q_entry * 734smb2_mid_entry_alloc(const struct smb2_hdr *shdr, 735 struct TCP_Server_Info *server) 736{ 737 struct mid_q_entry *temp; 738 unsigned int credits = le16_to_cpu(shdr->CreditCharge); 739 740 if (server == NULL) { 741 cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n"); 742 return NULL; 743 } 744 745 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS); 746 memset(temp, 0, sizeof(struct mid_q_entry)); 747 kref_init(&temp->refcount); 748 temp->mid = le64_to_cpu(shdr->MessageId); 749 temp->credits = credits > 0 ? credits : 1; 750 temp->pid = current->pid; 751 temp->command = shdr->Command; /* Always LE */ 752 temp->when_alloc = jiffies; 753 temp->server = server; 754 755 /* 756 * The default is for the mid to be synchronous, so the 757 * default callback just wakes up the current task. 758 */ 759 get_task_struct(current); 760 temp->creator = current; 761 temp->callback = cifs_wake_up_task; 762 temp->callback_data = current; 763 764 atomic_inc(&mid_count); 765 temp->mid_state = MID_REQUEST_ALLOCATED; 766 trace_smb3_cmd_enter(le32_to_cpu(shdr->Id.SyncId.TreeId), 767 le64_to_cpu(shdr->SessionId), 768 le16_to_cpu(shdr->Command), temp->mid); 769 return temp; 770} 771 772static int 773smb2_get_mid_entry(struct cifs_ses *ses, struct TCP_Server_Info *server, 774 struct smb2_hdr *shdr, struct mid_q_entry **mid) 775{ 776 spin_lock(&server->srv_lock); 777 if (server->tcpStatus == CifsExiting) { 778 spin_unlock(&server->srv_lock); 779 return -ENOENT; 780 } 781 782 if (server->tcpStatus == CifsNeedReconnect) { 783 spin_unlock(&server->srv_lock); 784 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n"); 785 return -EAGAIN; 786 } 787 788 if (server->tcpStatus == CifsNeedNegotiate && 789 shdr->Command != SMB2_NEGOTIATE) { 790 spin_unlock(&server->srv_lock); 791 return -EAGAIN; 792 } 793 spin_unlock(&server->srv_lock); 794 795 spin_lock(&ses->ses_lock); 796 if (ses->ses_status == SES_NEW) { 797 if ((shdr->Command != SMB2_SESSION_SETUP) && 798 (shdr->Command != SMB2_NEGOTIATE)) { 799 spin_unlock(&ses->ses_lock); 800 return -EAGAIN; 801 } 802 /* else ok - we are setting up session */ 803 } 804 805 if (ses->ses_status == SES_EXITING) { 806 if (shdr->Command != SMB2_LOGOFF) { 807 spin_unlock(&ses->ses_lock); 808 return -EAGAIN; 809 } 810 /* else ok - we are shutting down the session */ 811 } 812 spin_unlock(&ses->ses_lock); 813 814 *mid = smb2_mid_entry_alloc(shdr, server); 815 if (*mid == NULL) 816 return -ENOMEM; 817 spin_lock(&server->mid_lock); 818 list_add_tail(&(*mid)->qhead, &server->pending_mid_q); 819 spin_unlock(&server->mid_lock); 820 821 return 0; 822} 823 824int 825smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server, 826 bool log_error) 827{ 828 unsigned int len = mid->resp_buf_size; 829 struct kvec iov[1]; 830 struct smb_rqst rqst = { .rq_iov = iov, 831 .rq_nvec = 1 }; 832 833 iov[0].iov_base = (char *)mid->resp_buf; 834 iov[0].iov_len = len; 835 836 dump_smb(mid->resp_buf, min_t(u32, 80, len)); 837 /* convert the length into a more usable form */ 838 if (len > 24 && server->sign && !mid->decrypted) { 839 int rc; 840 841 rc = smb2_verify_signature(&rqst, server); 842 if (rc) 843 cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n", 844 rc); 845 } 846 847 return map_smb2_to_linux_error(mid->resp_buf, log_error); 848} 849 850struct mid_q_entry * 851smb2_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *server, 852 struct smb_rqst *rqst) 853{ 854 int rc; 855 struct smb2_hdr *shdr = 856 (struct smb2_hdr *)rqst->rq_iov[0].iov_base; 857 struct mid_q_entry *mid; 858 859 smb2_seq_num_into_buf(server, shdr); 860 861 rc = smb2_get_mid_entry(ses, server, shdr, &mid); 862 if (rc) { 863 revert_current_mid_from_hdr(server, shdr); 864 return ERR_PTR(rc); 865 } 866 867 rc = smb2_sign_rqst(rqst, server); 868 if (rc) { 869 revert_current_mid_from_hdr(server, shdr); 870 delete_mid(mid); 871 return ERR_PTR(rc); 872 } 873 874 return mid; 875} 876 877struct mid_q_entry * 878smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst) 879{ 880 int rc; 881 struct smb2_hdr *shdr = 882 (struct smb2_hdr *)rqst->rq_iov[0].iov_base; 883 struct mid_q_entry *mid; 884 885 spin_lock(&server->srv_lock); 886 if (server->tcpStatus == CifsNeedNegotiate && 887 shdr->Command != SMB2_NEGOTIATE) { 888 spin_unlock(&server->srv_lock); 889 return ERR_PTR(-EAGAIN); 890 } 891 spin_unlock(&server->srv_lock); 892 893 smb2_seq_num_into_buf(server, shdr); 894 895 mid = smb2_mid_entry_alloc(shdr, server); 896 if (mid == NULL) { 897 revert_current_mid_from_hdr(server, shdr); 898 return ERR_PTR(-ENOMEM); 899 } 900 901 rc = smb2_sign_rqst(rqst, server); 902 if (rc) { 903 revert_current_mid_from_hdr(server, shdr); 904 release_mid(mid); 905 return ERR_PTR(rc); 906 } 907 908 return mid; 909} 910 911int 912smb3_crypto_aead_allocate(struct TCP_Server_Info *server) 913{ 914 struct crypto_aead *tfm; 915 916 if (!server->secmech.enc) { 917 if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) || 918 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) 919 tfm = crypto_alloc_aead("gcm(aes)", 0, 0); 920 else 921 tfm = crypto_alloc_aead("ccm(aes)", 0, 0); 922 if (IS_ERR(tfm)) { 923 cifs_server_dbg(VFS, "%s: Failed alloc encrypt aead\n", 924 __func__); 925 return PTR_ERR(tfm); 926 } 927 server->secmech.enc = tfm; 928 } 929 930 if (!server->secmech.dec) { 931 if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) || 932 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) 933 tfm = crypto_alloc_aead("gcm(aes)", 0, 0); 934 else 935 tfm = crypto_alloc_aead("ccm(aes)", 0, 0); 936 if (IS_ERR(tfm)) { 937 crypto_free_aead(server->secmech.enc); 938 server->secmech.enc = NULL; 939 cifs_server_dbg(VFS, "%s: Failed to alloc decrypt aead\n", 940 __func__); 941 return PTR_ERR(tfm); 942 } 943 server->secmech.dec = tfm; 944 } 945 946 return 0; 947} 948