1 /* 2 * WPA Supplicant / shared MSCHAPV2 helper functions / RFC 2433 / RFC 2759 3 * Copyright (c) 2004-2012, Jouni Malinen <j@w1.fi> 4 * 5 * This software may be distributed under the terms of the BSD license. 6 * See README for more details. 7 */ 8 9 #include "includes.h" 10 11 #include "common.h" 12 #include "sha1.h" 13 #include "ms_funcs.h" 14 #include "crypto.h" 15 16 /** 17 * utf8_to_ucs2 - Convert UTF-8 string to UCS-2 encoding 18 * @utf8_string: UTF-8 string (IN) 19 * @utf8_string_len: Length of utf8_string (IN) 20 * @ucs2_buffer: UCS-2 buffer (OUT) 21 * @ucs2_buffer_size: Length of UCS-2 buffer (IN) 22 * @ucs2_string_size: Number of 2-byte words in the resulting UCS-2 string 23 * Returns: 0 on success, -1 on failure 24 */ 25 static int utf8_to_ucs2(const u8 *utf8_string, size_t utf8_string_len, 26 u8 *ucs2_buffer, size_t ucs2_buffer_size, 27 size_t *ucs2_string_size) 28 { 29 size_t i, j; 30 31 for (i = 0, j = 0; i < utf8_string_len; i++) { 32 u8 c = utf8_string[i]; 33 if (j >= ucs2_buffer_size) { 34 /* input too long */ 35 return -1; 36 } 37 if (c <= 0x7F) { 38 WPA_PUT_LE16(ucs2_buffer + j, c); 39 j += 2; 40 } else if (i == utf8_string_len - 1 || 41 j >= ucs2_buffer_size - 1) { 42 /* incomplete surrogate */ 43 return -1; 44 } else { 45 u8 c2 = utf8_string[++i]; 46 if ((c & 0xE0) == 0xC0) { 47 /* two-byte encoding */ 48 WPA_PUT_LE16(ucs2_buffer + j, 49 ((c & 0x1F) << 6) | (c2 & 0x3F)); 50 j += 2; 51 } else if (i == utf8_string_len || 52 j >= ucs2_buffer_size - 1) { 53 /* incomplete surrogate */ 54 return -1; 55 } else { 56 /* three-byte encoding */ 57 u8 c3 = utf8_string[++i]; 58 WPA_PUT_LE16(ucs2_buffer + j, 59 ((c & 0xF) << 12) | 60 ((c2 & 0x3F) << 6) | (c3 & 0x3F)); 61 j += 2; 62 } 63 } 64 } 65 66 if (ucs2_string_size) 67 *ucs2_string_size = j / 2; 68 return 0; 69 } 70 71 72 /** 73 * challenge_hash - ChallengeHash() - RFC 2759, Sect. 8.2 74 * @peer_challenge: 16-octet PeerChallenge (IN) 75 * @auth_challenge: 16-octet AuthenticatorChallenge (IN) 76 * @username: 0-to-256-char UserName (IN) 77 * @username_len: Length of username 78 * @challenge: 8-octet Challenge (OUT) 79 * Returns: 0 on success, -1 on failure 80 */ 81 static int challenge_hash(const u8 *peer_challenge, const u8 *auth_challenge, 82 const u8 *username, size_t username_len, 83 u8 *challenge) 84 { 85 u8 hash[SHA1_MAC_LEN]; 86 const unsigned char *addr[3]; 87 size_t len[3]; 88 89 addr[0] = peer_challenge; 90 len[0] = 16; 91 addr[1] = auth_challenge; 92 len[1] = 16; 93 addr[2] = username; 94 len[2] = username_len; 95 96 if (sha1_vector(3, addr, len, hash)) 97 return -1; 98 os_memcpy(challenge, hash, 8); 99 return 0; 100 } 101 102 103 /** 104 * nt_password_hash - NtPasswordHash() - RFC 2759, Sect. 8.3 105 * @password: 0-to-256-unicode-char Password (IN; UTF-8) 106 * @password_len: Length of password 107 * @password_hash: 16-octet PasswordHash (OUT) 108 * Returns: 0 on success, -1 on failure 109 */ 110 int nt_password_hash(const u8 *password, size_t password_len, 111 u8 *password_hash) 112 { 113 u8 buf[512], *pos; 114 size_t len, max_len; 115 116 max_len = sizeof(buf); 117 if (utf8_to_ucs2(password, password_len, buf, max_len, &len) < 0) 118 return -1; 119 120 len *= 2; 121 pos = buf; 122 return md4_vector(1, (const u8 **) &pos, &len, password_hash); 123 } 124 125 126 /** 127 * hash_nt_password_hash - HashNtPasswordHash() - RFC 2759, Sect. 8.4 128 * @password_hash: 16-octet PasswordHash (IN) 129 * @password_hash_hash: 16-octet PasswordHashHash (OUT) 130 * Returns: 0 on success, -1 on failure 131 */ 132 int hash_nt_password_hash(const u8 *password_hash, u8 *password_hash_hash) 133 { 134 size_t len = 16; 135 return md4_vector(1, &password_hash, &len, password_hash_hash); 136 } 137 138 139 /** 140 * challenge_response - ChallengeResponse() - RFC 2759, Sect. 8.5 141 * @challenge: 8-octet Challenge (IN) 142 * @password_hash: 16-octet PasswordHash (IN) 143 * @response: 24-octet Response (OUT) 144 */ 145 void challenge_response(const u8 *challenge, const u8 *password_hash, 146 u8 *response) 147 { 148 u8 zpwd[7]; 149 des_encrypt(challenge, password_hash, response); 150 des_encrypt(challenge, password_hash + 7, response + 8); 151 zpwd[0] = password_hash[14]; 152 zpwd[1] = password_hash[15]; 153 os_memset(zpwd + 2, 0, 5); 154 des_encrypt(challenge, zpwd, response + 16); 155 } 156 157 158 /** 159 * generate_nt_response - GenerateNTResponse() - RFC 2759, Sect. 8.1 160 * @auth_challenge: 16-octet AuthenticatorChallenge (IN) 161 * @peer_challenge: 16-octet PeerChallenge (IN) 162 * @username: 0-to-256-char UserName (IN) 163 * @username_len: Length of username 164 * @password: 0-to-256-unicode-char Password (IN; UTF-8) 165 * @password_len: Length of password 166 * @response: 24-octet Response (OUT) 167 * Returns: 0 on success, -1 on failure 168 */ 169 int generate_nt_response(const u8 *auth_challenge, const u8 *peer_challenge, 170 const u8 *username, size_t username_len, 171 const u8 *password, size_t password_len, 172 u8 *response) 173 { 174 u8 challenge[8]; 175 u8 password_hash[16]; 176 177 if (challenge_hash(peer_challenge, auth_challenge, username, 178 username_len, challenge)) 179 return -1; 180 if (nt_password_hash(password, password_len, password_hash)) 181 return -1; 182 challenge_response(challenge, password_hash, response); 183 return 0; 184 } 185 186 187 /** 188 * generate_nt_response_pwhash - GenerateNTResponse() - RFC 2759, Sect. 8.1 189 * @auth_challenge: 16-octet AuthenticatorChallenge (IN) 190 * @peer_challenge: 16-octet PeerChallenge (IN) 191 * @username: 0-to-256-char UserName (IN) 192 * @username_len: Length of username 193 * @password_hash: 16-octet PasswordHash (IN) 194 * @response: 24-octet Response (OUT) 195 * Returns: 0 on success, -1 on failure 196 */ 197 int generate_nt_response_pwhash(const u8 *auth_challenge, 198 const u8 *peer_challenge, 199 const u8 *username, size_t username_len, 200 const u8 *password_hash, 201 u8 *response) 202 { 203 u8 challenge[8]; 204 205 if (challenge_hash(peer_challenge, auth_challenge, 206 username, username_len, 207 challenge)) 208 return -1; 209 challenge_response(challenge, password_hash, response); 210 return 0; 211 } 212 213 214 /** 215 * generate_authenticator_response_pwhash - GenerateAuthenticatorResponse() - RFC 2759, Sect. 8.7 216 * @password_hash: 16-octet PasswordHash (IN) 217 * @nt_response: 24-octet NT-Response (IN) 218 * @peer_challenge: 16-octet PeerChallenge (IN) 219 * @auth_challenge: 16-octet AuthenticatorChallenge (IN) 220 * @username: 0-to-256-char UserName (IN) 221 * @username_len: Length of username 222 * @response: 20-octet AuthenticatorResponse (OUT) (note: this value is usually 223 * encoded as a 42-octet ASCII string (S=hexdump_of_response) 224 * Returns: 0 on success, -1 on failure 225 */ 226 int generate_authenticator_response_pwhash( 227 const u8 *password_hash, 228 const u8 *peer_challenge, const u8 *auth_challenge, 229 const u8 *username, size_t username_len, 230 const u8 *nt_response, u8 *response) 231 { 232 static const u8 magic1[39] = { 233 0x4D, 0x61, 0x67, 0x69, 0x63, 0x20, 0x73, 0x65, 0x72, 0x76, 234 0x65, 0x72, 0x20, 0x74, 0x6F, 0x20, 0x63, 0x6C, 0x69, 0x65, 235 0x6E, 0x74, 0x20, 0x73, 0x69, 0x67, 0x6E, 0x69, 0x6E, 0x67, 236 0x20, 0x63, 0x6F, 0x6E, 0x73, 0x74, 0x61, 0x6E, 0x74 237 }; 238 static const u8 magic2[41] = { 239 0x50, 0x61, 0x64, 0x20, 0x74, 0x6F, 0x20, 0x6D, 0x61, 0x6B, 240 0x65, 0x20, 0x69, 0x74, 0x20, 0x64, 0x6F, 0x20, 0x6D, 0x6F, 241 0x72, 0x65, 0x20, 0x74, 0x68, 0x61, 0x6E, 0x20, 0x6F, 0x6E, 242 0x65, 0x20, 0x69, 0x74, 0x65, 0x72, 0x61, 0x74, 0x69, 0x6F, 243 0x6E 244 }; 245 246 u8 password_hash_hash[16], challenge[8]; 247 const unsigned char *addr1[3]; 248 const size_t len1[3] = { 16, 24, sizeof(magic1) }; 249 const unsigned char *addr2[3]; 250 const size_t len2[3] = { SHA1_MAC_LEN, 8, sizeof(magic2) }; 251 252 addr1[0] = password_hash_hash; 253 addr1[1] = nt_response; 254 addr1[2] = magic1; 255 256 addr2[0] = response; 257 addr2[1] = challenge; 258 addr2[2] = magic2; 259 260 if (hash_nt_password_hash(password_hash, password_hash_hash)) 261 return -1; 262 if (sha1_vector(3, addr1, len1, response)) 263 return -1; 264 265 if (challenge_hash(peer_challenge, auth_challenge, username, 266 username_len, challenge)) 267 return -1; 268 return sha1_vector(3, addr2, len2, response); 269 } 270 271 272 /** 273 * generate_authenticator_response - GenerateAuthenticatorResponse() - RFC 2759, Sect. 8.7 274 * @password: 0-to-256-unicode-char Password (IN; UTF-8) 275 * @password_len: Length of password 276 * @nt_response: 24-octet NT-Response (IN) 277 * @peer_challenge: 16-octet PeerChallenge (IN) 278 * @auth_challenge: 16-octet AuthenticatorChallenge (IN) 279 * @username: 0-to-256-char UserName (IN) 280 * @username_len: Length of username 281 * @response: 20-octet AuthenticatorResponse (OUT) (note: this value is usually 282 * encoded as a 42-octet ASCII string (S=hexdump_of_response) 283 * Returns: 0 on success, -1 on failure 284 */ 285 int generate_authenticator_response(const u8 *password, size_t password_len, 286 const u8 *peer_challenge, 287 const u8 *auth_challenge, 288 const u8 *username, size_t username_len, 289 const u8 *nt_response, u8 *response) 290 { 291 u8 password_hash[16]; 292 if (nt_password_hash(password, password_len, password_hash)) 293 return -1; 294 return generate_authenticator_response_pwhash( 295 password_hash, peer_challenge, auth_challenge, 296 username, username_len, nt_response, response); 297 } 298 299 300 /** 301 * nt_challenge_response - NtChallengeResponse() - RFC 2433, Sect. A.5 302 * @challenge: 8-octet Challenge (IN) 303 * @password: 0-to-256-unicode-char Password (IN; UTF-8) 304 * @password_len: Length of password 305 * @response: 24-octet Response (OUT) 306 * Returns: 0 on success, -1 on failure 307 */ 308 int nt_challenge_response(const u8 *challenge, const u8 *password, 309 size_t password_len, u8 *response) 310 { 311 u8 password_hash[16]; 312 if (nt_password_hash(password, password_len, password_hash)) 313 return -1; 314 challenge_response(challenge, password_hash, response); 315 return 0; 316 } 317 318 319 /** 320 * get_master_key - GetMasterKey() - RFC 3079, Sect. 3.4 321 * @password_hash_hash: 16-octet PasswordHashHash (IN) 322 * @nt_response: 24-octet NTResponse (IN) 323 * @master_key: 16-octet MasterKey (OUT) 324 * Returns: 0 on success, -1 on failure 325 */ 326 int get_master_key(const u8 *password_hash_hash, const u8 *nt_response, 327 u8 *master_key) 328 { 329 static const u8 magic1[27] = { 330 0x54, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74, 331 0x68, 0x65, 0x20, 0x4d, 0x50, 0x50, 0x45, 0x20, 0x4d, 332 0x61, 0x73, 0x74, 0x65, 0x72, 0x20, 0x4b, 0x65, 0x79 333 }; 334 const unsigned char *addr[3]; 335 const size_t len[3] = { 16, 24, sizeof(magic1) }; 336 u8 hash[SHA1_MAC_LEN]; 337 338 addr[0] = password_hash_hash; 339 addr[1] = nt_response; 340 addr[2] = magic1; 341 342 if (sha1_vector(3, addr, len, hash)) 343 return -1; 344 os_memcpy(master_key, hash, 16); 345 return 0; 346 } 347 348 349 /** 350 * get_asymetric_start_key - GetAsymetricStartKey() - RFC 3079, Sect. 3.4 351 * @master_key: 16-octet MasterKey (IN) 352 * @session_key: 8-to-16 octet SessionKey (OUT) 353 * @session_key_len: SessionKeyLength (Length of session_key) (IN) 354 * @is_send: IsSend (IN, BOOLEAN) 355 * @is_server: IsServer (IN, BOOLEAN) 356 * Returns: 0 on success, -1 on failure 357 */ 358 int get_asymetric_start_key(const u8 *master_key, u8 *session_key, 359 size_t session_key_len, int is_send, 360 int is_server) 361 { 362 static const u8 magic2[84] = { 363 0x4f, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x69, 364 0x65, 0x6e, 0x74, 0x20, 0x73, 0x69, 0x64, 0x65, 0x2c, 0x20, 365 0x74, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68, 366 0x65, 0x20, 0x73, 0x65, 0x6e, 0x64, 0x20, 0x6b, 0x65, 0x79, 367 0x3b, 0x20, 0x6f, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x73, 368 0x65, 0x72, 0x76, 0x65, 0x72, 0x20, 0x73, 0x69, 0x64, 0x65, 369 0x2c, 0x20, 0x69, 0x74, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68, 370 0x65, 0x20, 0x72, 0x65, 0x63, 0x65, 0x69, 0x76, 0x65, 0x20, 371 0x6b, 0x65, 0x79, 0x2e 372 }; 373 static const u8 magic3[84] = { 374 0x4f, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x69, 375 0x65, 0x6e, 0x74, 0x20, 0x73, 0x69, 0x64, 0x65, 0x2c, 0x20, 376 0x74, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68, 377 0x65, 0x20, 0x72, 0x65, 0x63, 0x65, 0x69, 0x76, 0x65, 0x20, 378 0x6b, 0x65, 0x79, 0x3b, 0x20, 0x6f, 0x6e, 0x20, 0x74, 0x68, 379 0x65, 0x20, 0x73, 0x65, 0x72, 0x76, 0x65, 0x72, 0x20, 0x73, 380 0x69, 0x64, 0x65, 0x2c, 0x20, 0x69, 0x74, 0x20, 0x69, 0x73, 381 0x20, 0x74, 0x68, 0x65, 0x20, 0x73, 0x65, 0x6e, 0x64, 0x20, 382 0x6b, 0x65, 0x79, 0x2e 383 }; 384 static const u8 shs_pad1[40] = { 385 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 386 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 387 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 388 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 389 }; 390 391 static const u8 shs_pad2[40] = { 392 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 393 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 394 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 395 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2 396 }; 397 u8 digest[SHA1_MAC_LEN]; 398 const unsigned char *addr[4]; 399 const size_t len[4] = { 16, 40, 84, 40 }; 400 401 addr[0] = master_key; 402 addr[1] = shs_pad1; 403 if (is_send) { 404 addr[2] = is_server ? magic3 : magic2; 405 } else { 406 addr[2] = is_server ? magic2 : magic3; 407 } 408 addr[3] = shs_pad2; 409 410 if (sha1_vector(4, addr, len, digest)) 411 return -1; 412 413 if (session_key_len > SHA1_MAC_LEN) 414 session_key_len = SHA1_MAC_LEN; 415 os_memcpy(session_key, digest, session_key_len); 416 return 0; 417 } 418 419 420 #define PWBLOCK_LEN 516 421 422 /** 423 * encrypt_pw_block_with_password_hash - EncryptPwBlockWithPasswordHash() - RFC 2759, Sect. 8.10 424 * @password: 0-to-256-unicode-char Password (IN; UTF-8) 425 * @password_len: Length of password 426 * @password_hash: 16-octet PasswordHash (IN) 427 * @pw_block: 516-byte PwBlock (OUT) 428 * Returns: 0 on success, -1 on failure 429 */ 430 int encrypt_pw_block_with_password_hash( 431 const u8 *password, size_t password_len, 432 const u8 *password_hash, u8 *pw_block) 433 { 434 size_t ucs2_len, offset; 435 u8 *pos; 436 437 os_memset(pw_block, 0, PWBLOCK_LEN); 438 439 if (utf8_to_ucs2(password, password_len, pw_block, 512, &ucs2_len) < 0) 440 return -1; 441 442 if (ucs2_len > 256) 443 return -1; 444 445 offset = (256 - ucs2_len) * 2; 446 if (offset != 0) { 447 os_memmove(pw_block + offset, pw_block, ucs2_len * 2); 448 if (os_get_random(pw_block, offset) < 0) 449 return -1; 450 } 451 /* 452 * PasswordLength is 4 octets, but since the maximum password length is 453 * 256, only first two (in little endian byte order) can be non-zero. 454 */ 455 pos = &pw_block[2 * 256]; 456 WPA_PUT_LE16(pos, password_len * 2); 457 rc4_skip(password_hash, 16, 0, pw_block, PWBLOCK_LEN); 458 return 0; 459 } 460 461 462 /** 463 * new_password_encrypted_with_old_nt_password_hash - NewPasswordEncryptedWithOldNtPasswordHash() - RFC 2759, Sect. 8.9 464 * @new_password: 0-to-256-unicode-char NewPassword (IN; UTF-8) 465 * @new_password_len: Length of new_password 466 * @old_password: 0-to-256-unicode-char OldPassword (IN; UTF-8) 467 * @old_password_len: Length of old_password 468 * @encrypted_pw_block: 516-octet EncryptedPwBlock (OUT) 469 * Returns: 0 on success, -1 on failure 470 */ 471 int new_password_encrypted_with_old_nt_password_hash( 472 const u8 *new_password, size_t new_password_len, 473 const u8 *old_password, size_t old_password_len, 474 u8 *encrypted_pw_block) 475 { 476 u8 password_hash[16]; 477 478 if (nt_password_hash(old_password, old_password_len, password_hash)) 479 return -1; 480 if (encrypt_pw_block_with_password_hash(new_password, new_password_len, 481 password_hash, 482 encrypted_pw_block)) 483 return -1; 484 return 0; 485 } 486 487 488 /** 489 * nt_password_hash_encrypted_with_block - NtPasswordHashEncryptedWithBlock() - RFC 2759, Sect 8.13 490 * @password_hash: 16-octer PasswordHash (IN) 491 * @block: 16-octet Block (IN) 492 * @cypher: 16-octer Cypher (OUT) 493 */ 494 void nt_password_hash_encrypted_with_block(const u8 *password_hash, 495 const u8 *block, u8 *cypher) 496 { 497 des_encrypt(password_hash, block, cypher); 498 des_encrypt(password_hash + 8, block + 7, cypher + 8); 499 } 500 501 502 /** 503 * old_nt_password_hash_encrypted_with_new_nt_password_hash - OldNtPasswordHashEncryptedWithNewNtPasswordHash() - RFC 2759, Sect. 8.12 504 * @new_password: 0-to-256-unicode-char NewPassword (IN; UTF-8) 505 * @new_password_len: Length of new_password 506 * @old_password: 0-to-256-unicode-char OldPassword (IN; UTF-8) 507 * @old_password_len: Length of old_password 508 * @encrypted_password_hash: 16-octet EncryptedPasswordHash (OUT) 509 * Returns: 0 on success, -1 on failure 510 */ 511 int old_nt_password_hash_encrypted_with_new_nt_password_hash( 512 const u8 *new_password, size_t new_password_len, 513 const u8 *old_password, size_t old_password_len, 514 u8 *encrypted_password_hash) 515 { 516 u8 old_password_hash[16], new_password_hash[16]; 517 518 if (nt_password_hash(old_password, old_password_len, 519 old_password_hash) || 520 nt_password_hash(new_password, new_password_len, 521 new_password_hash)) 522 return -1; 523 nt_password_hash_encrypted_with_block(old_password_hash, 524 new_password_hash, 525 encrypted_password_hash); 526 return 0; 527 } 528