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 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 rc = generate_key(ses, ptriplet->decryption.label, 462 ptriplet->decryption.context, 463 ses->smb3decryptionkey, 464 SMB3_ENC_DEC_KEY_SIZE); 465 if (rc) 466 return rc; 467 } 468 469 if (rc) 470 return rc; 471 472 #ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS 473 cifs_dbg(VFS, "%s: dumping generated AES session keys\n", __func__); 474 /* 475 * The session id is opaque in terms of endianness, so we can't 476 * print it as a long long. we dump it as we got it on the wire 477 */ 478 cifs_dbg(VFS, "Session Id %*ph\n", (int)sizeof(ses->Suid), 479 &ses->Suid); 480 cifs_dbg(VFS, "Cipher type %d\n", server->cipher_type); 481 cifs_dbg(VFS, "Session Key %*ph\n", 482 SMB2_NTLMV2_SESSKEY_SIZE, ses->auth_key.response); 483 cifs_dbg(VFS, "Signing Key %*ph\n", 484 SMB3_SIGN_KEY_SIZE, ses->smb3signingkey); 485 if ((server->cipher_type == SMB2_ENCRYPTION_AES256_CCM) || 486 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) { 487 cifs_dbg(VFS, "ServerIn Key %*ph\n", 488 SMB3_GCM256_CRYPTKEY_SIZE, ses->smb3encryptionkey); 489 cifs_dbg(VFS, "ServerOut Key %*ph\n", 490 SMB3_GCM256_CRYPTKEY_SIZE, ses->smb3decryptionkey); 491 } else { 492 cifs_dbg(VFS, "ServerIn Key %*ph\n", 493 SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3encryptionkey); 494 cifs_dbg(VFS, "ServerOut Key %*ph\n", 495 SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3decryptionkey); 496 } 497 #endif 498 return rc; 499 } 500 501 int 502 generate_smb30signingkey(struct cifs_ses *ses, 503 struct TCP_Server_Info *server) 504 505 { 506 struct derivation_triplet triplet; 507 struct derivation *d; 508 509 d = &triplet.signing; 510 d->label.iov_base = "SMB2AESCMAC"; 511 d->label.iov_len = 12; 512 d->context.iov_base = "SmbSign"; 513 d->context.iov_len = 8; 514 515 d = &triplet.encryption; 516 d->label.iov_base = "SMB2AESCCM"; 517 d->label.iov_len = 11; 518 d->context.iov_base = "ServerIn "; 519 d->context.iov_len = 10; 520 521 d = &triplet.decryption; 522 d->label.iov_base = "SMB2AESCCM"; 523 d->label.iov_len = 11; 524 d->context.iov_base = "ServerOut"; 525 d->context.iov_len = 10; 526 527 return generate_smb3signingkey(ses, server, &triplet); 528 } 529 530 int 531 generate_smb311signingkey(struct cifs_ses *ses, 532 struct TCP_Server_Info *server) 533 534 { 535 struct derivation_triplet triplet; 536 struct derivation *d; 537 538 d = &triplet.signing; 539 d->label.iov_base = "SMBSigningKey"; 540 d->label.iov_len = 14; 541 d->context.iov_base = ses->preauth_sha_hash; 542 d->context.iov_len = 64; 543 544 d = &triplet.encryption; 545 d->label.iov_base = "SMBC2SCipherKey"; 546 d->label.iov_len = 16; 547 d->context.iov_base = ses->preauth_sha_hash; 548 d->context.iov_len = 64; 549 550 d = &triplet.decryption; 551 d->label.iov_base = "SMBS2CCipherKey"; 552 d->label.iov_len = 16; 553 d->context.iov_base = ses->preauth_sha_hash; 554 d->context.iov_len = 64; 555 556 return generate_smb3signingkey(ses, server, &triplet); 557 } 558 559 int 560 smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server, 561 bool allocate_crypto) 562 { 563 int rc; 564 unsigned char smb3_signature[SMB2_CMACAES_SIZE]; 565 unsigned char *sigptr = smb3_signature; 566 struct kvec *iov = rqst->rq_iov; 567 struct smb2_hdr *shdr = (struct smb2_hdr *)iov[0].iov_base; 568 struct shash_desc *shash = NULL; 569 struct smb_rqst drqst; 570 u8 key[SMB3_SIGN_KEY_SIZE]; 571 572 rc = smb2_get_sign_key(le64_to_cpu(shdr->SessionId), server, key); 573 if (unlikely(rc)) { 574 cifs_server_dbg(FYI, "%s: Could not get signing key\n", __func__); 575 return rc; 576 } 577 578 if (allocate_crypto) { 579 rc = cifs_alloc_hash("cmac(aes)", &shash); 580 if (rc) 581 return rc; 582 } else { 583 shash = server->secmech.aes_cmac; 584 } 585 586 memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE); 587 memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE); 588 589 rc = crypto_shash_setkey(shash->tfm, key, SMB2_CMACAES_SIZE); 590 if (rc) { 591 cifs_server_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__); 592 goto out; 593 } 594 595 /* 596 * we already allocate aes_cmac when we init smb3 signing key, 597 * so unlike smb2 case we do not have to check here if secmech are 598 * initialized 599 */ 600 rc = crypto_shash_init(shash); 601 if (rc) { 602 cifs_server_dbg(VFS, "%s: Could not init cmac aes\n", __func__); 603 goto out; 604 } 605 606 /* 607 * For SMB2+, __cifs_calc_signature() expects to sign only the actual 608 * data, that is, iov[0] should not contain a rfc1002 length. 609 * 610 * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to 611 * __cifs_calc_signature(). 612 */ 613 drqst = *rqst; 614 if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) { 615 rc = crypto_shash_update(shash, iov[0].iov_base, 616 iov[0].iov_len); 617 if (rc) { 618 cifs_server_dbg(VFS, "%s: Could not update with payload\n", 619 __func__); 620 goto out; 621 } 622 drqst.rq_iov++; 623 drqst.rq_nvec--; 624 } 625 626 rc = __cifs_calc_signature(&drqst, server, sigptr, shash); 627 if (!rc) 628 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE); 629 630 out: 631 if (allocate_crypto) 632 cifs_free_hash(&shash); 633 return rc; 634 } 635 636 /* must be called with server->srv_mutex held */ 637 static int 638 smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server) 639 { 640 int rc = 0; 641 struct smb2_hdr *shdr; 642 struct smb2_sess_setup_req *ssr; 643 bool is_binding; 644 bool is_signed; 645 646 shdr = (struct smb2_hdr *)rqst->rq_iov[0].iov_base; 647 ssr = (struct smb2_sess_setup_req *)shdr; 648 649 is_binding = shdr->Command == SMB2_SESSION_SETUP && 650 (ssr->Flags & SMB2_SESSION_REQ_FLAG_BINDING); 651 is_signed = shdr->Flags & SMB2_FLAGS_SIGNED; 652 653 if (!is_signed) 654 return 0; 655 spin_lock(&server->srv_lock); 656 if (server->ops->need_neg && 657 server->ops->need_neg(server)) { 658 spin_unlock(&server->srv_lock); 659 return 0; 660 } 661 spin_unlock(&server->srv_lock); 662 if (!is_binding && !server->session_estab) { 663 strncpy(shdr->Signature, "BSRSPYL", 8); 664 return 0; 665 } 666 667 rc = server->ops->calc_signature(rqst, server, false); 668 669 return rc; 670 } 671 672 int 673 smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server) 674 { 675 unsigned int rc; 676 char server_response_sig[SMB2_SIGNATURE_SIZE]; 677 struct smb2_hdr *shdr = 678 (struct smb2_hdr *)rqst->rq_iov[0].iov_base; 679 680 if ((shdr->Command == SMB2_NEGOTIATE) || 681 (shdr->Command == SMB2_SESSION_SETUP) || 682 (shdr->Command == SMB2_OPLOCK_BREAK) || 683 server->ignore_signature || 684 (!server->session_estab)) 685 return 0; 686 687 /* 688 * BB what if signatures are supposed to be on for session but 689 * server does not send one? BB 690 */ 691 692 /* Do not need to verify session setups with signature "BSRSPYL " */ 693 if (memcmp(shdr->Signature, "BSRSPYL ", 8) == 0) 694 cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n", 695 shdr->Command); 696 697 /* 698 * Save off the origiginal signature so we can modify the smb and check 699 * our calculated signature against what the server sent. 700 */ 701 memcpy(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE); 702 703 memset(shdr->Signature, 0, SMB2_SIGNATURE_SIZE); 704 705 rc = server->ops->calc_signature(rqst, server, true); 706 707 if (rc) 708 return rc; 709 710 if (memcmp(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE)) { 711 cifs_dbg(VFS, "sign fail cmd 0x%x message id 0x%llx\n", 712 shdr->Command, shdr->MessageId); 713 return -EACCES; 714 } else 715 return 0; 716 } 717 718 /* 719 * Set message id for the request. Should be called after wait_for_free_request 720 * and when srv_mutex is held. 721 */ 722 static inline void 723 smb2_seq_num_into_buf(struct TCP_Server_Info *server, 724 struct smb2_hdr *shdr) 725 { 726 unsigned int i, num = le16_to_cpu(shdr->CreditCharge); 727 728 shdr->MessageId = get_next_mid64(server); 729 /* skip message numbers according to CreditCharge field */ 730 for (i = 1; i < num; i++) 731 get_next_mid(server); 732 } 733 734 static struct mid_q_entry * 735 smb2_mid_entry_alloc(const struct smb2_hdr *shdr, 736 struct TCP_Server_Info *server) 737 { 738 struct mid_q_entry *temp; 739 unsigned int credits = le16_to_cpu(shdr->CreditCharge); 740 741 if (server == NULL) { 742 cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n"); 743 return NULL; 744 } 745 746 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS); 747 memset(temp, 0, sizeof(struct mid_q_entry)); 748 kref_init(&temp->refcount); 749 temp->mid = le64_to_cpu(shdr->MessageId); 750 temp->credits = credits > 0 ? credits : 1; 751 temp->pid = current->pid; 752 temp->command = shdr->Command; /* Always LE */ 753 temp->when_alloc = jiffies; 754 temp->server = server; 755 756 /* 757 * The default is for the mid to be synchronous, so the 758 * default callback just wakes up the current task. 759 */ 760 get_task_struct(current); 761 temp->creator = current; 762 temp->callback = cifs_wake_up_task; 763 temp->callback_data = current; 764 765 atomic_inc(&mid_count); 766 temp->mid_state = MID_REQUEST_ALLOCATED; 767 trace_smb3_cmd_enter(le32_to_cpu(shdr->Id.SyncId.TreeId), 768 le64_to_cpu(shdr->SessionId), 769 le16_to_cpu(shdr->Command), temp->mid); 770 return temp; 771 } 772 773 static int 774 smb2_get_mid_entry(struct cifs_ses *ses, struct TCP_Server_Info *server, 775 struct smb2_hdr *shdr, struct mid_q_entry **mid) 776 { 777 spin_lock(&server->srv_lock); 778 if (server->tcpStatus == CifsExiting) { 779 spin_unlock(&server->srv_lock); 780 return -ENOENT; 781 } 782 783 if (server->tcpStatus == CifsNeedReconnect) { 784 spin_unlock(&server->srv_lock); 785 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n"); 786 return -EAGAIN; 787 } 788 789 if (server->tcpStatus == CifsNeedNegotiate && 790 shdr->Command != SMB2_NEGOTIATE) { 791 spin_unlock(&server->srv_lock); 792 return -EAGAIN; 793 } 794 spin_unlock(&server->srv_lock); 795 796 spin_lock(&ses->ses_lock); 797 if (ses->ses_status == SES_NEW) { 798 if ((shdr->Command != SMB2_SESSION_SETUP) && 799 (shdr->Command != SMB2_NEGOTIATE)) { 800 spin_unlock(&ses->ses_lock); 801 return -EAGAIN; 802 } 803 /* else ok - we are setting up session */ 804 } 805 806 if (ses->ses_status == SES_EXITING) { 807 if (shdr->Command != SMB2_LOGOFF) { 808 spin_unlock(&ses->ses_lock); 809 return -EAGAIN; 810 } 811 /* else ok - we are shutting down the session */ 812 } 813 spin_unlock(&ses->ses_lock); 814 815 *mid = smb2_mid_entry_alloc(shdr, server); 816 if (*mid == NULL) 817 return -ENOMEM; 818 spin_lock(&server->mid_lock); 819 list_add_tail(&(*mid)->qhead, &server->pending_mid_q); 820 spin_unlock(&server->mid_lock); 821 822 return 0; 823 } 824 825 int 826 smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server, 827 bool log_error) 828 { 829 unsigned int len = mid->resp_buf_size; 830 struct kvec iov[1]; 831 struct smb_rqst rqst = { .rq_iov = iov, 832 .rq_nvec = 1 }; 833 834 iov[0].iov_base = (char *)mid->resp_buf; 835 iov[0].iov_len = len; 836 837 dump_smb(mid->resp_buf, min_t(u32, 80, len)); 838 /* convert the length into a more usable form */ 839 if (len > 24 && server->sign && !mid->decrypted) { 840 int rc; 841 842 rc = smb2_verify_signature(&rqst, server); 843 if (rc) 844 cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n", 845 rc); 846 } 847 848 return map_smb2_to_linux_error(mid->resp_buf, log_error); 849 } 850 851 struct mid_q_entry * 852 smb2_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *server, 853 struct smb_rqst *rqst) 854 { 855 int rc; 856 struct smb2_hdr *shdr = 857 (struct smb2_hdr *)rqst->rq_iov[0].iov_base; 858 struct mid_q_entry *mid; 859 860 smb2_seq_num_into_buf(server, shdr); 861 862 rc = smb2_get_mid_entry(ses, server, shdr, &mid); 863 if (rc) { 864 revert_current_mid_from_hdr(server, shdr); 865 return ERR_PTR(rc); 866 } 867 868 rc = smb2_sign_rqst(rqst, server); 869 if (rc) { 870 revert_current_mid_from_hdr(server, shdr); 871 delete_mid(mid); 872 return ERR_PTR(rc); 873 } 874 875 return mid; 876 } 877 878 struct mid_q_entry * 879 smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst) 880 { 881 int rc; 882 struct smb2_hdr *shdr = 883 (struct smb2_hdr *)rqst->rq_iov[0].iov_base; 884 struct mid_q_entry *mid; 885 886 spin_lock(&server->srv_lock); 887 if (server->tcpStatus == CifsNeedNegotiate && 888 shdr->Command != SMB2_NEGOTIATE) { 889 spin_unlock(&server->srv_lock); 890 return ERR_PTR(-EAGAIN); 891 } 892 spin_unlock(&server->srv_lock); 893 894 smb2_seq_num_into_buf(server, shdr); 895 896 mid = smb2_mid_entry_alloc(shdr, server); 897 if (mid == NULL) { 898 revert_current_mid_from_hdr(server, shdr); 899 return ERR_PTR(-ENOMEM); 900 } 901 902 rc = smb2_sign_rqst(rqst, server); 903 if (rc) { 904 revert_current_mid_from_hdr(server, shdr); 905 release_mid(mid); 906 return ERR_PTR(rc); 907 } 908 909 return mid; 910 } 911 912 int 913 smb3_crypto_aead_allocate(struct TCP_Server_Info *server) 914 { 915 struct crypto_aead *tfm; 916 917 if (!server->secmech.enc) { 918 if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) || 919 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) 920 tfm = crypto_alloc_aead("gcm(aes)", 0, 0); 921 else 922 tfm = crypto_alloc_aead("ccm(aes)", 0, 0); 923 if (IS_ERR(tfm)) { 924 cifs_server_dbg(VFS, "%s: Failed alloc encrypt aead\n", 925 __func__); 926 return PTR_ERR(tfm); 927 } 928 server->secmech.enc = tfm; 929 } 930 931 if (!server->secmech.dec) { 932 if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) || 933 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) 934 tfm = crypto_alloc_aead("gcm(aes)", 0, 0); 935 else 936 tfm = crypto_alloc_aead("ccm(aes)", 0, 0); 937 if (IS_ERR(tfm)) { 938 crypto_free_aead(server->secmech.enc); 939 server->secmech.enc = NULL; 940 cifs_server_dbg(VFS, "%s: Failed to alloc decrypt aead\n", 941 __func__); 942 return PTR_ERR(tfm); 943 } 944 server->secmech.dec = tfm; 945 } 946 947 return 0; 948 } 949