1 /* 2 * WPA Supplicant / shared MSCHAPV2 helper functions / RFC 2433 / RFC 2759 3 * Copyright (c) 2004-2009, Jouni Malinen <j (at) 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 } 62 } 63 } 64 65 if (ucs2_string_size) 66 *ucs2_string_size = j / 2; 67 return 0; 68 } 69 70 71 /** 72 * challenge_hash - ChallengeHash() - RFC 2759, Sect. 8.2 73 * @peer_challenge: 16-octet PeerChallenge (IN) 74 * @auth_challenge: 16-octet AuthenticatorChallenge (IN) 75 * @username: 0-to-256-char UserName (IN) 76 * @username_len: Length of username 77 * @challenge: 8-octet Challenge (OUT) 78 * Returns: 0 on success, -1 on failure 79 */ 80 static int challenge_hash(const u8 *peer_challenge, const u8 *auth_challenge, 81 const u8 *username, size_t username_len, 82 u8 *challenge) 83 { 84 u8 hash[SHA1_MAC_LEN]; 85 const unsigned char *addr[3]; 86 size_t len[3]; 87 88 addr[0] = peer_challenge; 89 len[0] = 16; 90 addr[1] = auth_challenge; 91 len[1] = 16; 92 addr[2] = username; 93 len[2] = username_len; 94 95 if (sha1_vector(3, addr, len, hash)) 96 return -1; 97 os_memcpy(challenge, hash, 8); 98 return 0; 99 } 100 101 102 /** 103 * nt_password_hash - NtPasswordHash() - RFC 2759, Sect. 8.3 104 * @password: 0-to-256-unicode-char Password (IN; UTF-8) 105 * @password_len: Length of password 106 * @password_hash: 16-octet PasswordHash (OUT) 107 * Returns: 0 on success, -1 on failure 108 */ 109 int nt_password_hash(const u8 *password, size_t password_len, 110 u8 *password_hash) 111 { 112 u8 buf[512], *pos; 113 size_t len, max_len; 114 115 max_len = sizeof(buf); 116 if (utf8_to_ucs2(password, password_len, buf, max_len, &len) < 0) 117 return -1; 118 119 len *= 2; 120 pos = buf; 121 return md4_vector(1, (const u8 **) &pos, &len, password_hash); 122 } 123 124 125 /** 126 * hash_nt_password_hash - HashNtPasswordHash() - RFC 2759, Sect. 8.4 127 * @password_hash: 16-octet PasswordHash (IN) 128 * @password_hash_hash: 16-octet PasswordHashHash (OUT) 129 * Returns: 0 on success, -1 on failure 130 */ 131 int hash_nt_password_hash(const u8 *password_hash, u8 *password_hash_hash) 132 { 133 size_t len = 16; 134 return md4_vector(1, &password_hash, &len, password_hash_hash); 135 } 136 137 138 /** 139 * challenge_response - ChallengeResponse() - RFC 2759, Sect. 8.5 140 * @challenge: 8-octet Challenge (IN) 141 * @password_hash: 16-octet PasswordHash (IN) 142 * @response: 24-octet Response (OUT) 143 */ 144 void challenge_response(const u8 *challenge, const u8 *password_hash, 145 u8 *response) 146 { 147 u8 zpwd[7]; 148 des_encrypt(challenge, password_hash, response); 149 des_encrypt(challenge, password_hash + 7, response + 8); 150 zpwd[0] = password_hash[14]; 151 zpwd[1] = password_hash[15]; 152 os_memset(zpwd + 2, 0, 5); 153 des_encrypt(challenge, zpwd, response + 16); 154 } 155 156 157 /** 158 * generate_nt_response - GenerateNTResponse() - RFC 2759, Sect. 8.1 159 * @auth_challenge: 16-octet AuthenticatorChallenge (IN) 160 * @peer_challenge: 16-octet PeerChallenge (IN) 161 * @username: 0-to-256-char UserName (IN) 162 * @username_len: Length of username 163 * @password: 0-to-256-unicode-char Password (IN; UTF-8) 164 * @password_len: Length of password 165 * @response: 24-octet Response (OUT) 166 * Returns: 0 on success, -1 on failure 167 */ 168 int generate_nt_response(const u8 *auth_challenge, const u8 *peer_challenge, 169 const u8 *username, size_t username_len, 170 const u8 *password, size_t password_len, 171 u8 *response) 172 { 173 u8 challenge[8]; 174 u8 password_hash[16]; 175 176 challenge_hash(peer_challenge, auth_challenge, username, username_len, 177 challenge); 178 if (nt_password_hash(password, password_len, password_hash)) 179 return -1; 180 challenge_response(challenge, password_hash, response); 181 return 0; 182 } 183 184 185 /** 186 * generate_nt_response_pwhash - GenerateNTResponse() - RFC 2759, Sect. 8.1 187 * @auth_challenge: 16-octet AuthenticatorChallenge (IN) 188 * @peer_challenge: 16-octet PeerChallenge (IN) 189 * @username: 0-to-256-char UserName (IN) 190 * @username_len: Length of username 191 * @password_hash: 16-octet PasswordHash (IN) 192 * @response: 24-octet Response (OUT) 193 * Returns: 0 on success, -1 on failure 194 */ 195 int generate_nt_response_pwhash(const u8 *auth_challenge, 196 const u8 *peer_challenge, 197 const u8 *username, size_t username_len, 198 const u8 *password_hash, 199 u8 *response) 200 { 201 u8 challenge[8]; 202 203 if (challenge_hash(peer_challenge, auth_challenge, 204 username, username_len, 205 challenge)) 206 return -1; 207 challenge_response(challenge, password_hash, response); 208 return 0; 209 } 210 211 212 /** 213 * generate_authenticator_response_pwhash - GenerateAuthenticatorResponse() - RFC 2759, Sect. 8.7 214 * @password_hash: 16-octet PasswordHash (IN) 215 * @nt_response: 24-octet NT-Response (IN) 216 * @peer_challenge: 16-octet PeerChallenge (IN) 217 * @auth_challenge: 16-octet AuthenticatorChallenge (IN) 218 * @username: 0-to-256-char UserName (IN) 219 * @username_len: Length of username 220 * @response: 20-octet AuthenticatorResponse (OUT) (note: this value is usually 221 * encoded as a 42-octet ASCII string (S=hexdump_of_response) 222 * Returns: 0 on success, -1 on failure 223 */ 224 int generate_authenticator_response_pwhash( 225 const u8 *password_hash, 226 const u8 *peer_challenge, const u8 *auth_challenge, 227 const u8 *username, size_t username_len, 228 const u8 *nt_response, u8 *response) 229 { 230 static const u8 magic1[39] = { 231 0x4D, 0x61, 0x67, 0x69, 0x63, 0x20, 0x73, 0x65, 0x72, 0x76, 232 0x65, 0x72, 0x20, 0x74, 0x6F, 0x20, 0x63, 0x6C, 0x69, 0x65, 233 0x6E, 0x74, 0x20, 0x73, 0x69, 0x67, 0x6E, 0x69, 0x6E, 0x67, 234 0x20, 0x63, 0x6F, 0x6E, 0x73, 0x74, 0x61, 0x6E, 0x74 235 }; 236 static const u8 magic2[41] = { 237 0x50, 0x61, 0x64, 0x20, 0x74, 0x6F, 0x20, 0x6D, 0x61, 0x6B, 238 0x65, 0x20, 0x69, 0x74, 0x20, 0x64, 0x6F, 0x20, 0x6D, 0x6F, 239 0x72, 0x65, 0x20, 0x74, 0x68, 0x61, 0x6E, 0x20, 0x6F, 0x6E, 240 0x65, 0x20, 0x69, 0x74, 0x65, 0x72, 0x61, 0x74, 0x69, 0x6F, 241 0x6E 242 }; 243 244 u8 password_hash_hash[16], challenge[8]; 245 const unsigned char *addr1[3]; 246 const size_t len1[3] = { 16, 24, sizeof(magic1) }; 247 const unsigned char *addr2[3]; 248 const size_t len2[3] = { SHA1_MAC_LEN, 8, sizeof(magic2) }; 249 250 addr1[0] = password_hash_hash; 251 addr1[1] = nt_response; 252 addr1[2] = magic1; 253 254 addr2[0] = response; 255 addr2[1] = challenge; 256 addr2[2] = magic2; 257 258 if (hash_nt_password_hash(password_hash, password_hash_hash)) 259 return -1; 260 if (sha1_vector(3, addr1, len1, response)) 261 return -1; 262 263 challenge_hash(peer_challenge, auth_challenge, username, username_len, 264 challenge); 265 return sha1_vector(3, addr2, len2, response); 266 } 267 268 269 /** 270 * generate_authenticator_response - GenerateAuthenticatorResponse() - RFC 2759, Sect. 8.7 271 * @password: 0-to-256-unicode-char Password (IN; UTF-8) 272 * @password_len: Length of password 273 * @nt_response: 24-octet NT-Response (IN) 274 * @peer_challenge: 16-octet PeerChallenge (IN) 275 * @auth_challenge: 16-octet AuthenticatorChallenge (IN) 276 * @username: 0-to-256-char UserName (IN) 277 * @username_len: Length of username 278 * @response: 20-octet AuthenticatorResponse (OUT) (note: this value is usually 279 * encoded as a 42-octet ASCII string (S=hexdump_of_response) 280 * Returns: 0 on success, -1 on failure 281 */ 282 int generate_authenticator_response(const u8 *password, size_t password_len, 283 const u8 *peer_challenge, 284 const u8 *auth_challenge, 285 const u8 *username, size_t username_len, 286 const u8 *nt_response, u8 *response) 287 { 288 u8 password_hash[16]; 289 if (nt_password_hash(password, password_len, password_hash)) 290 return -1; 291 return generate_authenticator_response_pwhash( 292 password_hash, peer_challenge, auth_challenge, 293 username, username_len, nt_response, response); 294 } 295 296 297 /** 298 * nt_challenge_response - NtChallengeResponse() - RFC 2433, Sect. A.5 299 * @challenge: 8-octet Challenge (IN) 300 * @password: 0-to-256-unicode-char Password (IN; UTF-8) 301 * @password_len: Length of password 302 * @response: 24-octet Response (OUT) 303 * Returns: 0 on success, -1 on failure 304 */ 305 int nt_challenge_response(const u8 *challenge, const u8 *password, 306 size_t password_len, u8 *response) 307 { 308 u8 password_hash[16]; 309 if (nt_password_hash(password, password_len, password_hash)) 310 return -1; 311 challenge_response(challenge, password_hash, response); 312 return 0; 313 } 314 315 316 /** 317 * get_master_key - GetMasterKey() - RFC 3079, Sect. 3.4 318 * @password_hash_hash: 16-octet PasswordHashHash (IN) 319 * @nt_response: 24-octet NTResponse (IN) 320 * @master_key: 16-octet MasterKey (OUT) 321 * Returns: 0 on success, -1 on failure 322 */ 323 int get_master_key(const u8 *password_hash_hash, const u8 *nt_response, 324 u8 *master_key) 325 { 326 static const u8 magic1[27] = { 327 0x54, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74, 328 0x68, 0x65, 0x20, 0x4d, 0x50, 0x50, 0x45, 0x20, 0x4d, 329 0x61, 0x73, 0x74, 0x65, 0x72, 0x20, 0x4b, 0x65, 0x79 330 }; 331 const unsigned char *addr[3]; 332 const size_t len[3] = { 16, 24, sizeof(magic1) }; 333 u8 hash[SHA1_MAC_LEN]; 334 335 addr[0] = password_hash_hash; 336 addr[1] = nt_response; 337 addr[2] = magic1; 338 339 if (sha1_vector(3, addr, len, hash)) 340 return -1; 341 os_memcpy(master_key, hash, 16); 342 return 0; 343 } 344 345 346 /** 347 * get_asymetric_start_key - GetAsymetricStartKey() - RFC 3079, Sect. 3.4 348 * @master_key: 16-octet MasterKey (IN) 349 * @session_key: 8-to-16 octet SessionKey (OUT) 350 * @session_key_len: SessionKeyLength (Length of session_key) (IN) 351 * @is_send: IsSend (IN, BOOLEAN) 352 * @is_server: IsServer (IN, BOOLEAN) 353 * Returns: 0 on success, -1 on failure 354 */ 355 int get_asymetric_start_key(const u8 *master_key, u8 *session_key, 356 size_t session_key_len, int is_send, 357 int is_server) 358 { 359 static const u8 magic2[84] = { 360 0x4f, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x69, 361 0x65, 0x6e, 0x74, 0x20, 0x73, 0x69, 0x64, 0x65, 0x2c, 0x20, 362 0x74, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68, 363 0x65, 0x20, 0x73, 0x65, 0x6e, 0x64, 0x20, 0x6b, 0x65, 0x79, 364 0x3b, 0x20, 0x6f, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x73, 365 0x65, 0x72, 0x76, 0x65, 0x72, 0x20, 0x73, 0x69, 0x64, 0x65, 366 0x2c, 0x20, 0x69, 0x74, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68, 367 0x65, 0x20, 0x72, 0x65, 0x63, 0x65, 0x69, 0x76, 0x65, 0x20, 368 0x6b, 0x65, 0x79, 0x2e 369 }; 370 static const u8 magic3[84] = { 371 0x4f, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x69, 372 0x65, 0x6e, 0x74, 0x20, 0x73, 0x69, 0x64, 0x65, 0x2c, 0x20, 373 0x74, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68, 374 0x65, 0x20, 0x72, 0x65, 0x63, 0x65, 0x69, 0x76, 0x65, 0x20, 375 0x6b, 0x65, 0x79, 0x3b, 0x20, 0x6f, 0x6e, 0x20, 0x74, 0x68, 376 0x65, 0x20, 0x73, 0x65, 0x72, 0x76, 0x65, 0x72, 0x20, 0x73, 377 0x69, 0x64, 0x65, 0x2c, 0x20, 0x69, 0x74, 0x20, 0x69, 0x73, 378 0x20, 0x74, 0x68, 0x65, 0x20, 0x73, 0x65, 0x6e, 0x64, 0x20, 379 0x6b, 0x65, 0x79, 0x2e 380 }; 381 static const u8 shs_pad1[40] = { 382 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 383 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 384 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 385 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 386 }; 387 388 static const u8 shs_pad2[40] = { 389 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 390 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 391 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 392 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2 393 }; 394 u8 digest[SHA1_MAC_LEN]; 395 const unsigned char *addr[4]; 396 const size_t len[4] = { 16, 40, 84, 40 }; 397 398 addr[0] = master_key; 399 addr[1] = shs_pad1; 400 if (is_send) { 401 addr[2] = is_server ? magic3 : magic2; 402 } else { 403 addr[2] = is_server ? magic2 : magic3; 404 } 405 addr[3] = shs_pad2; 406 407 if (sha1_vector(4, addr, len, digest)) 408 return -1; 409 410 if (session_key_len > SHA1_MAC_LEN) 411 session_key_len = SHA1_MAC_LEN; 412 os_memcpy(session_key, digest, session_key_len); 413 return 0; 414 } 415 416 417 #define PWBLOCK_LEN 516 418 419 /** 420 * encrypt_pw_block_with_password_hash - EncryptPwBlockWithPasswordHash() - RFC 2759, Sect. 8.10 421 * @password: 0-to-256-unicode-char Password (IN; UTF-8) 422 * @password_len: Length of password 423 * @password_hash: 16-octet PasswordHash (IN) 424 * @pw_block: 516-byte PwBlock (OUT) 425 * Returns: 0 on success, -1 on failure 426 */ 427 int encrypt_pw_block_with_password_hash( 428 const u8 *password, size_t password_len, 429 const u8 *password_hash, u8 *pw_block) 430 { 431 size_t ucs2_len, offset; 432 u8 *pos; 433 434 os_memset(pw_block, 0, PWBLOCK_LEN); 435 436 if (utf8_to_ucs2(password, password_len, pw_block, 512, &ucs2_len) < 0) 437 return -1; 438 439 if (ucs2_len > 256) 440 return -1; 441 442 offset = (256 - ucs2_len) * 2; 443 if (offset != 0) { 444 os_memmove(pw_block + offset, pw_block, ucs2_len * 2); 445 if (os_get_random(pw_block, offset) < 0) 446 return -1; 447 } 448 /* 449 * PasswordLength is 4 octets, but since the maximum password length is 450 * 256, only first two (in little endian byte order) can be non-zero. 451 */ 452 pos = &pw_block[2 * 256]; 453 WPA_PUT_LE16(pos, password_len * 2); 454 rc4_skip(password_hash, 16, 0, pw_block, PWBLOCK_LEN); 455 return 0; 456 } 457 458 459 /** 460 * new_password_encrypted_with_old_nt_password_hash - NewPasswordEncryptedWithOldNtPasswordHash() - RFC 2759, Sect. 8.9 461 * @new_password: 0-to-256-unicode-char NewPassword (IN; UTF-8) 462 * @new_password_len: Length of new_password 463 * @old_password: 0-to-256-unicode-char OldPassword (IN; UTF-8) 464 * @old_password_len: Length of old_password 465 * @encrypted_pw_block: 516-octet EncryptedPwBlock (OUT) 466 * Returns: 0 on success, -1 on failure 467 */ 468 int new_password_encrypted_with_old_nt_password_hash( 469 const u8 *new_password, size_t new_password_len, 470 const u8 *old_password, size_t old_password_len, 471 u8 *encrypted_pw_block) 472 { 473 u8 password_hash[16]; 474 475 if (nt_password_hash(old_password, old_password_len, password_hash)) 476 return -1; 477 if (encrypt_pw_block_with_password_hash(new_password, new_password_len, 478 password_hash, 479 encrypted_pw_block)) 480 return -1; 481 return 0; 482 } 483 484 485 /** 486 * nt_password_hash_encrypted_with_block - NtPasswordHashEncryptedWithBlock() - RFC 2759, Sect 8.13 487 * @password_hash: 16-octer PasswordHash (IN) 488 * @block: 16-octet Block (IN) 489 * @cypher: 16-octer Cypher (OUT) 490 */ 491 void nt_password_hash_encrypted_with_block(const u8 *password_hash, 492 const u8 *block, u8 *cypher) 493 { 494 des_encrypt(password_hash, block, cypher); 495 des_encrypt(password_hash + 8, block + 7, cypher + 8); 496 } 497 498 499 /** 500 * old_nt_password_hash_encrypted_with_new_nt_password_hash - OldNtPasswordHashEncryptedWithNewNtPasswordHash() - RFC 2759, Sect. 8.12 501 * @new_password: 0-to-256-unicode-char NewPassword (IN; UTF-8) 502 * @new_password_len: Length of new_password 503 * @old_password: 0-to-256-unicode-char OldPassword (IN; UTF-8) 504 * @old_password_len: Length of old_password 505 * @encrypted_password_hash: 16-octet EncryptedPasswordHash (OUT) 506 * Returns: 0 on success, -1 on failure 507 */ 508 int old_nt_password_hash_encrypted_with_new_nt_password_hash( 509 const u8 *new_password, size_t new_password_len, 510 const u8 *old_password, size_t old_password_len, 511 u8 *encrypted_password_hash) 512 { 513 u8 old_password_hash[16], new_password_hash[16]; 514 515 if (nt_password_hash(old_password, old_password_len, 516 old_password_hash) || 517 nt_password_hash(new_password, new_password_len, 518 new_password_hash)) 519 return -1; 520 nt_password_hash_encrypted_with_block(old_password_hash, 521 new_password_hash, 522 encrypted_password_hash); 523 return 0; 524 } 525
