src/crypto/ms_funcs.c

   1 /*
   2  * WPA Supplicant / shared MSCHAPV2 helper functions / RFC 2433 / RFC 2759
   3  * Copyright (c) 2004-2009, 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                         }
  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 }