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 104 build_avpair_blob(struct cifs_ses *ses, const struct nls_table *nls_cp) 105 { 106 unsigned int dlen; 107 unsigned int size = 2 * sizeof(struct ntlmssp2_name); 108 char *defdmname = "WORKGROUP"; 109 unsigned char *blobptr; 110 struct ntlmssp2_name *attrptr; 111 112 if (!ses->domainName) { 113 ses->domainName = kstrdup(defdmname, GFP_KERNEL); 114 if (!ses->domainName) 115 return -ENOMEM; 116 } 117 118 dlen = strlen(ses->domainName); 119 120 /* 121 * The length of this blob is two times the size of a 122 * structure (av pair) which holds name/size 123 * ( for NTLMSSP_AV_NB_DOMAIN_NAME followed by NTLMSSP_AV_EOL ) + 124 * unicode length of a netbios domain name 125 */ 126 kfree_sensitive(ses->auth_key.response); 127 ses->auth_key.len = size + 2 * dlen; 128 ses->auth_key.response = kzalloc(ses->auth_key.len, GFP_KERNEL); 129 if (!ses->auth_key.response) { 130 ses->auth_key.len = 0; 131 return -ENOMEM; 132 } 133 134 blobptr = ses->auth_key.response; 135 attrptr = (struct ntlmssp2_name *) blobptr; 136 137 /* 138 * As defined in MS-NTLM 3.3.2, just this av pair field 139 * is sufficient as part of the temp 140 */ 141 attrptr->type = cpu_to_le16(NTLMSSP_AV_NB_DOMAIN_NAME); 142 attrptr->length = cpu_to_le16(2 * dlen); 143 blobptr = (unsigned char *)attrptr + sizeof(struct ntlmssp2_name); 144 cifs_strtoUTF16((__le16 *)blobptr, ses->domainName, dlen, nls_cp); 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 const struct nls_table *nls_cp) 240 { 241 int len; 242 char nt_hash[CIFS_NTHASH_SIZE]; 243 struct hmac_md5_ctx hmac_ctx; 244 __le16 *user; 245 wchar_t *domain; 246 wchar_t *server; 247 248 /* calculate md4 hash of password */ 249 E_md4hash(ses->password, nt_hash, nls_cp); 250 251 hmac_md5_init_usingrawkey(&hmac_ctx, nt_hash, CIFS_NTHASH_SIZE); 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 return -ENOMEM; 258 259 if (len) { 260 len = cifs_strtoUTF16(user, ses->user_name, len, nls_cp); 261 UniStrupr(user); 262 } else { 263 *(u16 *)user = 0; 264 } 265 266 hmac_md5_update(&hmac_ctx, (const u8 *)user, 2 * len); 267 kfree(user); 268 269 /* convert ses->domainName to unicode and uppercase */ 270 if (ses->domainName) { 271 len = strlen(ses->domainName); 272 273 domain = kmalloc(2 + (len * 2), GFP_KERNEL); 274 if (domain == NULL) 275 return -ENOMEM; 276 277 len = cifs_strtoUTF16((__le16 *)domain, ses->domainName, len, 278 nls_cp); 279 hmac_md5_update(&hmac_ctx, (const u8 *)domain, 2 * len); 280 kfree(domain); 281 } else { 282 /* We use ses->ip_addr if no domain name available */ 283 len = strlen(ses->ip_addr); 284 285 server = kmalloc(2 + (len * 2), GFP_KERNEL); 286 if (server == NULL) 287 return -ENOMEM; 288 289 len = cifs_strtoUTF16((__le16 *)server, ses->ip_addr, len, nls_cp); 290 hmac_md5_update(&hmac_ctx, (const u8 *)server, 2 * len); 291 kfree(server); 292 } 293 294 hmac_md5_final(&hmac_ctx, ntlmv2_hash); 295 return 0; 296 } 297 298 static void CalcNTLMv2_response(const struct cifs_ses *ses, char *ntlmv2_hash) 299 { 300 struct ntlmv2_resp *ntlmv2 = (struct ntlmv2_resp *) 301 (ses->auth_key.response + CIFS_SESS_KEY_SIZE); 302 unsigned int hash_len; 303 304 /* The MD5 hash starts at challenge_key.key */ 305 hash_len = ses->auth_key.len - (CIFS_SESS_KEY_SIZE + 306 offsetof(struct ntlmv2_resp, challenge.key[0])); 307 308 if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED) 309 memcpy(ntlmv2->challenge.key, ses->ntlmssp->cryptkey, CIFS_SERVER_CHALLENGE_SIZE); 310 else 311 memcpy(ntlmv2->challenge.key, ses->server->cryptkey, CIFS_SERVER_CHALLENGE_SIZE); 312 313 /* Note that the HMAC-MD5 value overwrites ntlmv2->challenge.key */ 314 hmac_md5_usingrawkey(ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE, 315 ntlmv2->challenge.key, hash_len, 316 ntlmv2->ntlmv2_hash); 317 } 318 319 /* 320 * Set up NTLMv2 response blob with SPN (cifs/<hostname>) appended to the 321 * existing list of AV pairs. 322 */ 323 static int set_auth_key_response(struct cifs_ses *ses) 324 { 325 size_t baselen = CIFS_SESS_KEY_SIZE + sizeof(struct ntlmv2_resp); 326 size_t len, spnlen, tilen = 0, num_avs = 2 /* SPN + EOL */; 327 struct TCP_Server_Info *server = ses->server; 328 char *spn __free(kfree) = NULL; 329 struct ntlmssp2_name *av; 330 char *rsp = NULL; 331 int rc; 332 333 spnlen = strlen(server->hostname); 334 len = sizeof("cifs/") + spnlen; 335 spn = kmalloc(len, GFP_KERNEL); 336 if (!spn) { 337 rc = -ENOMEM; 338 goto out; 339 } 340 341 spnlen = scnprintf(spn, len, "cifs/%.*s", 342 (int)spnlen, server->hostname); 343 344 av_for_each_entry(ses, av) 345 tilen += sizeof(*av) + AV_LEN(av); 346 347 len = baselen + tilen + spnlen * sizeof(__le16) + num_avs * sizeof(*av); 348 rsp = kmalloc(len, GFP_KERNEL); 349 if (!rsp) { 350 rc = -ENOMEM; 351 goto out; 352 } 353 354 memcpy(rsp + baselen, ses->auth_key.response, tilen); 355 av = (void *)(rsp + baselen + tilen); 356 av->type = cpu_to_le16(NTLMSSP_AV_TARGET_NAME); 357 av->length = cpu_to_le16(spnlen * sizeof(__le16)); 358 cifs_strtoUTF16((__le16 *)av->data, spn, spnlen, ses->local_nls); 359 av = (void *)((__u8 *)av + sizeof(*av) + AV_LEN(av)); 360 av->type = cpu_to_le16(NTLMSSP_AV_EOL); 361 av->length = 0; 362 363 rc = 0; 364 ses->auth_key.len = len; 365 out: 366 ses->auth_key.response = rsp; 367 return rc; 368 } 369 370 int 371 setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp) 372 { 373 unsigned char *tiblob = NULL; /* target info blob */ 374 struct ntlmv2_resp *ntlmv2; 375 char ntlmv2_hash[16]; 376 __le64 rsp_timestamp; 377 __u64 cc; 378 int rc; 379 380 if (nls_cp == NULL) { 381 cifs_dbg(VFS, "%s called with nls_cp==NULL\n", __func__); 382 return -EINVAL; 383 } 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, nls_cp); 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, nls_cp); 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 setup_ntlmv2_rsp_ret: 467 kfree_sensitive(tiblob); 468 469 return rc; 470 } 471 472 int 473 calc_seckey(struct cifs_ses *ses) 474 { 475 unsigned char sec_key[CIFS_SESS_KEY_SIZE]; /* a nonce */ 476 struct arc4_ctx *ctx_arc4; 477 478 if (fips_enabled) 479 return -ENODEV; 480 481 get_random_bytes(sec_key, CIFS_SESS_KEY_SIZE); 482 483 ctx_arc4 = kmalloc_obj(*ctx_arc4); 484 if (!ctx_arc4) { 485 cifs_dbg(VFS, "Could not allocate arc4 context\n"); 486 return -ENOMEM; 487 } 488 489 arc4_setkey(ctx_arc4, ses->auth_key.response, CIFS_SESS_KEY_SIZE); 490 arc4_crypt(ctx_arc4, ses->ntlmssp->ciphertext, sec_key, 491 CIFS_CPHTXT_SIZE); 492 493 /* make secondary_key/nonce as session key */ 494 memcpy(ses->auth_key.response, sec_key, CIFS_SESS_KEY_SIZE); 495 /* and make len as that of session key only */ 496 ses->auth_key.len = CIFS_SESS_KEY_SIZE; 497 498 memzero_explicit(sec_key, CIFS_SESS_KEY_SIZE); 499 kfree_sensitive(ctx_arc4); 500 return 0; 501 } 502 503 void 504 cifs_crypto_secmech_release(struct TCP_Server_Info *server) 505 { 506 if (server->secmech.enc) { 507 crypto_free_aead(server->secmech.enc); 508 server->secmech.enc = NULL; 509 } 510 if (server->secmech.dec) { 511 crypto_free_aead(server->secmech.dec); 512 server->secmech.dec = NULL; 513 } 514 } 515