1 // SPDX-License-Identifier: LGPL-2.1 2 /* 3 * 4 * Encryption and hashing operations relating to NTLM, NTLMv2. See MS-NLMP 5 * for more detailed information 6 * 7 * Copyright (C) International Business Machines Corp., 2005,2013 8 * Author(s): Steve French (sfrench@us.ibm.com) 9 * 10 */ 11 12 #include <linux/fs.h> 13 #include <linux/slab.h> 14 #include "cifsglob.h" 15 #include "cifs_debug.h" 16 #include "cifs_unicode.h" 17 #include "cifsproto.h" 18 #include "ntlmssp.h" 19 #include <linux/ctype.h> 20 #include <linux/random.h> 21 #include <linux/highmem.h> 22 #include <linux/fips.h> 23 #include <linux/iov_iter.h> 24 #include <crypto/aead.h> 25 #include <crypto/aes-cbc-macs.h> 26 #include <crypto/arc4.h> 27 #include <crypto/md5.h> 28 #include <crypto/sha2.h> 29 30 static size_t cifs_sig_step(void *iter_base, size_t progress, size_t len, 31 void *priv, void *priv2) 32 { 33 struct cifs_calc_sig_ctx *ctx = priv; 34 35 if (ctx->md5) 36 md5_update(ctx->md5, iter_base, len); 37 else if (ctx->hmac) 38 hmac_sha256_update(ctx->hmac, iter_base, len); 39 else 40 aes_cmac_update(ctx->cmac, iter_base, len); 41 return 0; /* Return value is length *not* processed, i.e. 0. */ 42 } 43 44 static void cifs_sig_final(struct cifs_calc_sig_ctx *ctx, u8 *out) 45 { 46 if (ctx->md5) 47 md5_final(ctx->md5, out); 48 else if (ctx->hmac) 49 hmac_sha256_final(ctx->hmac, out); 50 else 51 aes_cmac_final(ctx->cmac, out); 52 } 53 54 /* 55 * Pass the data from an iterator into a hash. 56 */ 57 static int cifs_sig_iter(const struct iov_iter *iter, size_t maxsize, 58 struct cifs_calc_sig_ctx *ctx) 59 { 60 struct iov_iter tmp_iter = *iter; 61 size_t did; 62 63 did = iterate_and_advance_kernel(&tmp_iter, maxsize, ctx, NULL, 64 cifs_sig_step); 65 if (did != maxsize) 66 return smb_EIO2(smb_eio_trace_sig_iter, did, maxsize); 67 return 0; 68 } 69 70 int __cifs_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server, 71 char *signature, struct cifs_calc_sig_ctx *ctx) 72 { 73 struct iov_iter iter; 74 ssize_t rc; 75 size_t size = 0; 76 77 for (int i = 0; i < rqst->rq_nvec; i++) 78 size += rqst->rq_iov[i].iov_len; 79 80 iov_iter_kvec(&iter, ITER_SOURCE, rqst->rq_iov, rqst->rq_nvec, size); 81 82 if (iov_iter_count(&iter) <= 4) 83 return smb_EIO2(smb_eio_trace_sig_data_too_small, 84 iov_iter_count(&iter), 4); 85 86 rc = cifs_sig_iter(&iter, iov_iter_count(&iter), ctx); 87 if (rc < 0) 88 return rc; 89 90 rc = cifs_sig_iter(&rqst->rq_iter, iov_iter_count(&rqst->rq_iter), ctx); 91 if (rc < 0) 92 return rc; 93 94 cifs_sig_final(ctx, signature); 95 return 0; 96 } 97 98 /* Build a proper attribute value/target info pairs blob. 99 * Fill in netbios and dns domain name and workstation name 100 * and client time (total five av pairs and + one end of fields indicator. 101 * Allocate domain name which gets freed when session struct is deallocated. 102 */ 103 static int build_avpair_blob(struct cifs_ses *ses) 104 { 105 unsigned int dlen; 106 unsigned int size = 2 * sizeof(struct ntlmssp2_name); 107 char *defdmname = "WORKGROUP"; 108 unsigned char *blobptr; 109 struct ntlmssp2_name *attrptr; 110 111 if (!ses->domainName) { 112 ses->domainName = kstrdup(defdmname, GFP_KERNEL); 113 if (!ses->domainName) 114 return -ENOMEM; 115 } 116 117 dlen = strlen(ses->domainName); 118 119 /* 120 * The length of this blob is two times the size of a 121 * structure (av pair) which holds name/size 122 * ( for NTLMSSP_AV_NB_DOMAIN_NAME followed by NTLMSSP_AV_EOL ) + 123 * unicode length of a netbios domain name 124 */ 125 kfree_sensitive(ses->auth_key.response); 126 ses->auth_key.len = size + 2 * dlen; 127 ses->auth_key.response = kzalloc(ses->auth_key.len, GFP_KERNEL); 128 if (!ses->auth_key.response) { 129 ses->auth_key.len = 0; 130 return -ENOMEM; 131 } 132 133 blobptr = ses->auth_key.response; 134 attrptr = (struct ntlmssp2_name *) blobptr; 135 136 /* 137 * As defined in MS-NTLM 3.3.2, just this av pair field 138 * is sufficient as part of the temp 139 */ 140 attrptr->type = cpu_to_le16(NTLMSSP_AV_NB_DOMAIN_NAME); 141 attrptr->length = cpu_to_le16(2 * dlen); 142 blobptr = (unsigned char *)attrptr + sizeof(struct ntlmssp2_name); 143 cifs_strtoUTF16((__le16 *)blobptr, ses->domainName, dlen, 144 ses->local_nls); 145 146 return 0; 147 } 148 149 #define AV_TYPE(av) (le16_to_cpu(av->type)) 150 #define AV_LEN(av) (le16_to_cpu(av->length)) 151 #define AV_DATA_PTR(av) ((void *)av->data) 152 153 #define av_for_each_entry(ses, av) \ 154 for (av = NULL; (av = find_next_av(ses, av));) 155 156 static struct ntlmssp2_name *find_next_av(struct cifs_ses *ses, 157 struct ntlmssp2_name *av) 158 { 159 u16 len; 160 u8 *end; 161 162 end = (u8 *)ses->auth_key.response + ses->auth_key.len; 163 if (!av) { 164 if (unlikely(!ses->auth_key.response || !ses->auth_key.len)) 165 return NULL; 166 av = (void *)ses->auth_key.response; 167 } else { 168 av = (void *)((u8 *)av + sizeof(*av) + AV_LEN(av)); 169 } 170 171 if ((u8 *)av + sizeof(*av) > end) 172 return NULL; 173 174 len = AV_LEN(av); 175 if (AV_TYPE(av) == NTLMSSP_AV_EOL) 176 return NULL; 177 if ((u8 *)av + sizeof(*av) + len > end) 178 return NULL; 179 return av; 180 } 181 182 /* 183 * Check if server has provided av pair of @type in the NTLMSSP 184 * CHALLENGE_MESSAGE blob. 185 */ 186 static int find_av_name(struct cifs_ses *ses, u16 type, char **name, u16 maxlen) 187 { 188 const struct nls_table *nlsc = ses->local_nls; 189 struct ntlmssp2_name *av; 190 u16 len, nlen; 191 192 if (*name) 193 return 0; 194 195 av_for_each_entry(ses, av) { 196 len = AV_LEN(av); 197 if (AV_TYPE(av) != type || !len) 198 continue; 199 if (!IS_ALIGNED(len, sizeof(__le16))) { 200 cifs_dbg(VFS | ONCE, "%s: bad length(%u) for type %u\n", 201 __func__, len, type); 202 continue; 203 } 204 nlen = len / sizeof(__le16); 205 if (nlen <= maxlen) { 206 ++nlen; 207 *name = kmalloc(nlen, GFP_KERNEL); 208 if (!*name) 209 return -ENOMEM; 210 cifs_from_utf16(*name, AV_DATA_PTR(av), nlen, 211 len, nlsc, NO_MAP_UNI_RSVD); 212 break; 213 } 214 } 215 return 0; 216 } 217 218 /* Server has provided av pairs/target info in the type 2 challenge 219 * packet and we have plucked it and stored within smb session. 220 * We parse that blob here to find the server given timestamp 221 * as part of ntlmv2 authentication (or local current time as 222 * default in case of failure) 223 */ 224 static __le64 find_timestamp(struct cifs_ses *ses) 225 { 226 struct ntlmssp2_name *av; 227 struct timespec64 ts; 228 229 av_for_each_entry(ses, av) { 230 if (AV_TYPE(av) == NTLMSSP_AV_TIMESTAMP && 231 AV_LEN(av) == sizeof(u64)) 232 return *((__le64 *)AV_DATA_PTR(av)); 233 } 234 ktime_get_real_ts64(&ts); 235 return cpu_to_le64(cifs_UnixTimeToNT(ts)); 236 } 237 238 static int calc_ntlmv2_hash(struct cifs_ses *ses, char *ntlmv2_hash) 239 { 240 int len; 241 char nt_hash[CIFS_NTHASH_SIZE]; 242 struct hmac_md5_ctx hmac_ctx; 243 __le16 *user; 244 wchar_t *domain; 245 wchar_t *server; 246 247 /* calculate md4 hash of password */ 248 E_md4hash(ses->password, nt_hash, ses->local_nls); 249 250 hmac_md5_init_usingrawkey(&hmac_ctx, nt_hash, CIFS_NTHASH_SIZE); 251 memzero_explicit(nt_hash, sizeof(nt_hash)); 252 253 /* convert ses->user_name to unicode */ 254 len = ses->user_name ? strlen(ses->user_name) : 0; 255 user = kmalloc(2 + (len * 2), GFP_KERNEL); 256 if (user == NULL) 257 goto out_nomem; 258 259 if (len) { 260 len = cifs_strtoUTF16(user, ses->user_name, len, 261 ses->local_nls); 262 UniStrupr(user); 263 } else { 264 *(u16 *)user = 0; 265 } 266 267 hmac_md5_update(&hmac_ctx, (const u8 *)user, 2 * len); 268 kfree(user); 269 270 /* convert ses->domainName to unicode and uppercase */ 271 if (ses->domainName) { 272 len = strlen(ses->domainName); 273 274 domain = kmalloc(2 + (len * 2), GFP_KERNEL); 275 if (domain == NULL) 276 goto out_nomem; 277 278 len = cifs_strtoUTF16((__le16 *)domain, ses->domainName, len, 279 ses->local_nls); 280 hmac_md5_update(&hmac_ctx, (const u8 *)domain, 2 * len); 281 kfree(domain); 282 } else { 283 /* We use ses->ip_addr if no domain name available */ 284 len = strlen(ses->ip_addr); 285 286 server = kmalloc(2 + (len * 2), GFP_KERNEL); 287 if (server == NULL) 288 goto out_nomem; 289 290 len = cifs_strtoUTF16((__le16 *)server, ses->ip_addr, len, 291 ses->local_nls); 292 hmac_md5_update(&hmac_ctx, (const u8 *)server, 2 * len); 293 kfree(server); 294 } 295 296 hmac_md5_final(&hmac_ctx, ntlmv2_hash); 297 return 0; 298 299 out_nomem: 300 memzero_explicit(&hmac_ctx, sizeof(hmac_ctx)); 301 return -ENOMEM; 302 } 303 304 static void CalcNTLMv2_response(const struct cifs_ses *ses, char *ntlmv2_hash) 305 { 306 struct ntlmv2_resp *ntlmv2 = (struct ntlmv2_resp *) 307 (ses->auth_key.response + CIFS_SESS_KEY_SIZE); 308 unsigned int hash_len; 309 310 /* The MD5 hash starts at challenge_key.key */ 311 hash_len = ses->auth_key.len - (CIFS_SESS_KEY_SIZE + 312 offsetof(struct ntlmv2_resp, challenge.key[0])); 313 314 if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED) 315 memcpy(ntlmv2->challenge.key, ses->ntlmssp->cryptkey, CIFS_SERVER_CHALLENGE_SIZE); 316 else 317 memcpy(ntlmv2->challenge.key, ses->server->cryptkey, CIFS_SERVER_CHALLENGE_SIZE); 318 319 /* Note that the HMAC-MD5 value overwrites ntlmv2->challenge.key */ 320 hmac_md5_usingrawkey(ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE, 321 ntlmv2->challenge.key, hash_len, 322 ntlmv2->ntlmv2_hash); 323 } 324 325 /* 326 * Set up NTLMv2 response blob with SPN (cifs/<hostname>) appended to the 327 * existing list of AV pairs. 328 */ 329 static int set_auth_key_response(struct cifs_ses *ses) 330 { 331 size_t baselen = CIFS_SESS_KEY_SIZE + sizeof(struct ntlmv2_resp); 332 size_t len, spnlen, tilen = 0, num_avs = 2 /* SPN + EOL */; 333 struct TCP_Server_Info *server = ses->server; 334 char *spn __free(kfree) = NULL; 335 struct ntlmssp2_name *av; 336 char *rsp = NULL; 337 int rc; 338 339 spnlen = strlen(server->hostname); 340 len = sizeof("cifs/") + spnlen; 341 spn = kmalloc(len, GFP_KERNEL); 342 if (!spn) { 343 rc = -ENOMEM; 344 goto out; 345 } 346 347 spnlen = scnprintf(spn, len, "cifs/%.*s", 348 (int)spnlen, server->hostname); 349 350 av_for_each_entry(ses, av) 351 tilen += sizeof(*av) + AV_LEN(av); 352 353 len = baselen + tilen + spnlen * sizeof(__le16) + num_avs * sizeof(*av); 354 rsp = kmalloc(len, GFP_KERNEL); 355 if (!rsp) { 356 rc = -ENOMEM; 357 goto out; 358 } 359 360 memcpy(rsp + baselen, ses->auth_key.response, tilen); 361 av = (void *)(rsp + baselen + tilen); 362 av->type = cpu_to_le16(NTLMSSP_AV_TARGET_NAME); 363 av->length = cpu_to_le16(spnlen * sizeof(__le16)); 364 cifs_strtoUTF16((__le16 *)av->data, spn, spnlen, ses->local_nls); 365 av = (void *)((__u8 *)av + sizeof(*av) + AV_LEN(av)); 366 av->type = cpu_to_le16(NTLMSSP_AV_EOL); 367 av->length = 0; 368 369 rc = 0; 370 ses->auth_key.len = len; 371 out: 372 ses->auth_key.response = rsp; 373 return rc; 374 } 375 376 int setup_ntlmv2_rsp(struct cifs_ses *ses) 377 { 378 unsigned char *tiblob = NULL; /* target info blob */ 379 struct ntlmv2_resp *ntlmv2; 380 char ntlmv2_hash[16]; 381 __le64 rsp_timestamp; 382 __u64 cc; 383 int rc; 384 385 if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED) { 386 if (!ses->domainName) { 387 if (ses->domainAuto) { 388 /* 389 * Domain (workgroup) hasn't been specified in 390 * mount options, so try to find it in 391 * CHALLENGE_MESSAGE message and then use it as 392 * part of NTLMv2 authentication. 393 */ 394 rc = find_av_name(ses, NTLMSSP_AV_NB_DOMAIN_NAME, 395 &ses->domainName, 396 CIFS_MAX_DOMAINNAME_LEN); 397 if (rc) 398 goto setup_ntlmv2_rsp_ret; 399 } else { 400 ses->domainName = kstrdup("", GFP_KERNEL); 401 if (!ses->domainName) { 402 rc = -ENOMEM; 403 goto setup_ntlmv2_rsp_ret; 404 } 405 } 406 } 407 rc = find_av_name(ses, NTLMSSP_AV_DNS_DOMAIN_NAME, 408 &ses->dns_dom, CIFS_MAX_DOMAINNAME_LEN); 409 if (rc) 410 goto setup_ntlmv2_rsp_ret; 411 } else { 412 rc = build_avpair_blob(ses); 413 if (rc) { 414 cifs_dbg(VFS, "error %d building av pair blob\n", rc); 415 goto setup_ntlmv2_rsp_ret; 416 } 417 } 418 419 /* Must be within 5 minutes of the server (or in range +/-2h 420 * in case of Mac OS X), so simply carry over server timestamp 421 * (as Windows 7 does) 422 */ 423 rsp_timestamp = find_timestamp(ses); 424 get_random_bytes(&cc, sizeof(cc)); 425 426 cifs_server_lock(ses->server); 427 428 tiblob = ses->auth_key.response; 429 rc = set_auth_key_response(ses); 430 if (rc) { 431 ses->auth_key.len = 0; 432 goto unlock; 433 } 434 435 ntlmv2 = (struct ntlmv2_resp *) 436 (ses->auth_key.response + CIFS_SESS_KEY_SIZE); 437 ntlmv2->blob_signature = cpu_to_le32(0x00000101); 438 ntlmv2->reserved = 0; 439 ntlmv2->time = rsp_timestamp; 440 ntlmv2->client_chal = cc; 441 ntlmv2->reserved2 = 0; 442 443 if (fips_enabled) { 444 cifs_dbg(VFS, "NTLMv2 support is disabled due to FIPS\n"); 445 rc = -EOPNOTSUPP; 446 goto unlock; 447 } 448 449 /* calculate ntlmv2_hash */ 450 rc = calc_ntlmv2_hash(ses, ntlmv2_hash); 451 if (rc) { 452 cifs_dbg(VFS, "Could not get NTLMv2 hash, rc=%d\n", rc); 453 goto unlock; 454 } 455 456 /* calculate first part of the client response (CR1) */ 457 CalcNTLMv2_response(ses, ntlmv2_hash); 458 459 /* now calculate the session key for NTLMv2 */ 460 hmac_md5_usingrawkey(ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE, 461 ntlmv2->ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE, 462 ses->auth_key.response); 463 rc = 0; 464 unlock: 465 cifs_server_unlock(ses->server); 466 memzero_explicit(ntlmv2_hash, sizeof(ntlmv2_hash)); 467 setup_ntlmv2_rsp_ret: 468 kfree_sensitive(tiblob); 469 470 return rc; 471 } 472 473 int 474 calc_seckey(struct cifs_ses *ses) 475 { 476 unsigned char sec_key[CIFS_SESS_KEY_SIZE]; /* a nonce */ 477 struct arc4_ctx *ctx_arc4; 478 479 if (fips_enabled) 480 return -ENODEV; 481 482 get_random_bytes(sec_key, CIFS_SESS_KEY_SIZE); 483 484 ctx_arc4 = kmalloc_obj(*ctx_arc4); 485 if (!ctx_arc4) { 486 cifs_dbg(VFS, "Could not allocate arc4 context\n"); 487 return -ENOMEM; 488 } 489 490 arc4_setkey(ctx_arc4, ses->auth_key.response, CIFS_SESS_KEY_SIZE); 491 arc4_crypt(ctx_arc4, ses->ntlmssp->ciphertext, sec_key, 492 CIFS_CPHTXT_SIZE); 493 494 /* make secondary_key/nonce as session key */ 495 memcpy(ses->auth_key.response, sec_key, CIFS_SESS_KEY_SIZE); 496 /* and make len as that of session key only */ 497 ses->auth_key.len = CIFS_SESS_KEY_SIZE; 498 499 memzero_explicit(sec_key, CIFS_SESS_KEY_SIZE); 500 kfree_sensitive(ctx_arc4); 501 return 0; 502 } 503 504 void 505 cifs_crypto_secmech_release(struct TCP_Server_Info *server) 506 { 507 if (server->secmech.enc) { 508 crypto_free_aead(server->secmech.enc); 509 server->secmech.enc = NULL; 510 } 511 if (server->secmech.dec) { 512 crypto_free_aead(server->secmech.dec); 513 server->secmech.dec = NULL; 514 } 515 } 516