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