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 - 1 || 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 int challenge_hash(const u8 *peer_challenge, const u8 *auth_challenge, 82 const u8 *username, size_t username_len, 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 if (challenge_hash(peer_challenge, auth_challenge, username, 177 username_len, challenge) || 178 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 sha1_vector(3, addr1, len1, response) || 260 challenge_hash(peer_challenge, auth_challenge, username, 261 username_len, challenge)) 262 return -1; 263 return sha1_vector(3, addr2, len2, response); 264 } 265 266 267 /** 268 * generate_authenticator_response - GenerateAuthenticatorResponse() - RFC 2759, Sect. 8.7 269 * @password: 0-to-256-unicode-char Password (IN; UTF-8) 270 * @password_len: Length of password 271 * @nt_response: 24-octet NT-Response (IN) 272 * @peer_challenge: 16-octet PeerChallenge (IN) 273 * @auth_challenge: 16-octet AuthenticatorChallenge (IN) 274 * @username: 0-to-256-char UserName (IN) 275 * @username_len: Length of username 276 * @response: 20-octet AuthenticatorResponse (OUT) (note: this value is usually 277 * encoded as a 42-octet ASCII string (S=hexdump_of_response) 278 * Returns: 0 on success, -1 on failure 279 */ 280 int generate_authenticator_response(const u8 *password, size_t password_len, 281 const u8 *peer_challenge, 282 const u8 *auth_challenge, 283 const u8 *username, size_t username_len, 284 const u8 *nt_response, u8 *response) 285 { 286 u8 password_hash[16]; 287 if (nt_password_hash(password, password_len, password_hash)) 288 return -1; 289 return generate_authenticator_response_pwhash( 290 password_hash, peer_challenge, auth_challenge, 291 username, username_len, nt_response, response); 292 } 293 294 295 /** 296 * nt_challenge_response - NtChallengeResponse() - RFC 2433, Sect. A.5 297 * @challenge: 8-octet Challenge (IN) 298 * @password: 0-to-256-unicode-char Password (IN; UTF-8) 299 * @password_len: Length of password 300 * @response: 24-octet Response (OUT) 301 * Returns: 0 on success, -1 on failure 302 */ 303 int nt_challenge_response(const u8 *challenge, const u8 *password, 304 size_t password_len, u8 *response) 305 { 306 u8 password_hash[16]; 307 if (nt_password_hash(password, password_len, password_hash)) 308 return -1; 309 challenge_response(challenge, password_hash, response); 310 return 0; 311 } 312 313 314 /** 315 * get_master_key - GetMasterKey() - RFC 3079, Sect. 3.4 316 * @password_hash_hash: 16-octet PasswordHashHash (IN) 317 * @nt_response: 24-octet NTResponse (IN) 318 * @master_key: 16-octet MasterKey (OUT) 319 * Returns: 0 on success, -1 on failure 320 */ 321 int get_master_key(const u8 *password_hash_hash, const u8 *nt_response, 322 u8 *master_key) 323 { 324 static const u8 magic1[27] = { 325 0x54, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74, 326 0x68, 0x65, 0x20, 0x4d, 0x50, 0x50, 0x45, 0x20, 0x4d, 327 0x61, 0x73, 0x74, 0x65, 0x72, 0x20, 0x4b, 0x65, 0x79 328 }; 329 const unsigned char *addr[3]; 330 const size_t len[3] = { 16, 24, sizeof(magic1) }; 331 u8 hash[SHA1_MAC_LEN]; 332 333 addr[0] = password_hash_hash; 334 addr[1] = nt_response; 335 addr[2] = magic1; 336 337 if (sha1_vector(3, addr, len, hash)) 338 return -1; 339 os_memcpy(master_key, hash, 16); 340 return 0; 341 } 342 343 344 /** 345 * get_asymetric_start_key - GetAsymetricStartKey() - RFC 3079, Sect. 3.4 346 * @master_key: 16-octet MasterKey (IN) 347 * @session_key: 8-to-16 octet SessionKey (OUT) 348 * @session_key_len: SessionKeyLength (Length of session_key) (IN) 349 * @is_send: IsSend (IN, BOOLEAN) 350 * @is_server: IsServer (IN, BOOLEAN) 351 * Returns: 0 on success, -1 on failure 352 */ 353 int get_asymetric_start_key(const u8 *master_key, u8 *session_key, 354 size_t session_key_len, int is_send, 355 int is_server) 356 { 357 static const u8 magic2[84] = { 358 0x4f, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x69, 359 0x65, 0x6e, 0x74, 0x20, 0x73, 0x69, 0x64, 0x65, 0x2c, 0x20, 360 0x74, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68, 361 0x65, 0x20, 0x73, 0x65, 0x6e, 0x64, 0x20, 0x6b, 0x65, 0x79, 362 0x3b, 0x20, 0x6f, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x73, 363 0x65, 0x72, 0x76, 0x65, 0x72, 0x20, 0x73, 0x69, 0x64, 0x65, 364 0x2c, 0x20, 0x69, 0x74, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68, 365 0x65, 0x20, 0x72, 0x65, 0x63, 0x65, 0x69, 0x76, 0x65, 0x20, 366 0x6b, 0x65, 0x79, 0x2e 367 }; 368 static const u8 magic3[84] = { 369 0x4f, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x69, 370 0x65, 0x6e, 0x74, 0x20, 0x73, 0x69, 0x64, 0x65, 0x2c, 0x20, 371 0x74, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68, 372 0x65, 0x20, 0x72, 0x65, 0x63, 0x65, 0x69, 0x76, 0x65, 0x20, 373 0x6b, 0x65, 0x79, 0x3b, 0x20, 0x6f, 0x6e, 0x20, 0x74, 0x68, 374 0x65, 0x20, 0x73, 0x65, 0x72, 0x76, 0x65, 0x72, 0x20, 0x73, 375 0x69, 0x64, 0x65, 0x2c, 0x20, 0x69, 0x74, 0x20, 0x69, 0x73, 376 0x20, 0x74, 0x68, 0x65, 0x20, 0x73, 0x65, 0x6e, 0x64, 0x20, 377 0x6b, 0x65, 0x79, 0x2e 378 }; 379 static const u8 shs_pad1[40] = { 380 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 381 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 382 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 383 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 384 }; 385 386 static const u8 shs_pad2[40] = { 387 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 388 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 389 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 390 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2 391 }; 392 u8 digest[SHA1_MAC_LEN]; 393 const unsigned char *addr[4]; 394 const size_t len[4] = { 16, 40, 84, 40 }; 395 396 addr[0] = master_key; 397 addr[1] = shs_pad1; 398 if (is_send) { 399 addr[2] = is_server ? magic3 : magic2; 400 } else { 401 addr[2] = is_server ? magic2 : magic3; 402 } 403 addr[3] = shs_pad2; 404 405 if (sha1_vector(4, addr, len, digest)) 406 return -1; 407 408 if (session_key_len > SHA1_MAC_LEN) 409 session_key_len = SHA1_MAC_LEN; 410 os_memcpy(session_key, digest, session_key_len); 411 return 0; 412 } 413 414 415 #ifndef CONFIG_NO_RC4 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 || ucs2_len > 256) 438 return -1; 439 440 offset = (256 - ucs2_len) * 2; 441 if (offset != 0) { 442 os_memmove(pw_block + offset, pw_block, ucs2_len * 2); 443 if (os_get_random(pw_block, offset) < 0) 444 return -1; 445 } 446 /* 447 * PasswordLength is 4 octets, but since the maximum password length is 448 * 256, only first two (in little endian byte order) can be non-zero. 449 */ 450 pos = &pw_block[2 * 256]; 451 WPA_PUT_LE16(pos, password_len * 2); 452 rc4_skip(password_hash, 16, 0, pw_block, PWBLOCK_LEN); 453 return 0; 454 } 455 456 457 /** 458 * new_password_encrypted_with_old_nt_password_hash - NewPasswordEncryptedWithOldNtPasswordHash() - RFC 2759, Sect. 8.9 459 * @new_password: 0-to-256-unicode-char NewPassword (IN; UTF-8) 460 * @new_password_len: Length of new_password 461 * @old_password: 0-to-256-unicode-char OldPassword (IN; UTF-8) 462 * @old_password_len: Length of old_password 463 * @encrypted_pw_block: 516-octet EncryptedPwBlock (OUT) 464 * Returns: 0 on success, -1 on failure 465 */ 466 int new_password_encrypted_with_old_nt_password_hash( 467 const u8 *new_password, size_t new_password_len, 468 const u8 *old_password, size_t old_password_len, 469 u8 *encrypted_pw_block) 470 { 471 u8 password_hash[16]; 472 473 if (nt_password_hash(old_password, old_password_len, password_hash)) 474 return -1; 475 if (encrypt_pw_block_with_password_hash(new_password, new_password_len, 476 password_hash, 477 encrypted_pw_block)) 478 return -1; 479 return 0; 480 } 481 482 #endif /* CONFIG_NO_RC4 */ 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