1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 1997 Gabor Kincses <gabor@acm.org> 5 * 1997 - 2001 Brian Somers <brian@Awfulhak.org> 6 * based on work by Eric Rosenquist 7 * Strata Software Limited. 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $FreeBSD$ 32 */ 33 34 #include <ctype.h> 35 #ifdef __FreeBSD__ 36 #include <openssl/des.h> 37 #include <sha.h> 38 #else 39 #include <sys/types.h> 40 #include <stdlib.h> 41 #ifdef __NetBSD__ 42 #include <openssl/des.h> 43 #else 44 #include <des.h> 45 #endif 46 #include <openssl/sha.h> 47 #endif 48 #include <md4.h> 49 #include <string.h> 50 51 #include "chap_ms.h" 52 53 /* 54 * Documentation & specifications: 55 * 56 * MS-CHAP (CHAP80) rfc2433 57 * MS-CHAP-V2 (CHAP81) rfc2759 58 * MPPE key management draft-ietf-pppext-mppe-keys-02.txt 59 */ 60 61 static char SHA1_Pad1[40] = 62 {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 63 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 64 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 65 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}; 66 67 static char SHA1_Pad2[40] = 68 {0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 69 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 70 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 71 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2}; 72 73 /* unused, for documentation only */ 74 /* only NTResp is filled in for FreeBSD */ 75 struct MS_ChapResponse { 76 u_char LANManResp[24]; 77 u_char NTResp[24]; 78 u_char UseNT; /* If 1, ignore the LANMan response field */ 79 }; 80 81 static u_char 82 Get7Bits(u_char *input, int startBit) 83 { 84 register unsigned int word; 85 86 word = (unsigned)input[startBit / 8] << 8; 87 word |= (unsigned)input[startBit / 8 + 1]; 88 89 word >>= 15 - (startBit % 8 + 7); 90 91 return word & 0xFE; 92 } 93 94 /* IN 56 bit DES key missing parity bits 95 OUT 64 bit DES key with parity bits added */ 96 static void 97 MakeKey(u_char *key, u_char *des_key) 98 { 99 des_key[0] = Get7Bits(key, 0); 100 des_key[1] = Get7Bits(key, 7); 101 des_key[2] = Get7Bits(key, 14); 102 des_key[3] = Get7Bits(key, 21); 103 des_key[4] = Get7Bits(key, 28); 104 des_key[5] = Get7Bits(key, 35); 105 des_key[6] = Get7Bits(key, 42); 106 des_key[7] = Get7Bits(key, 49); 107 108 DES_set_odd_parity((DES_cblock *)des_key); 109 } 110 111 static void /* IN 8 octets IN 7 octest OUT 8 octets */ 112 DesEncrypt(u_char *clear, u_char *key, u_char *cipher) 113 { 114 DES_cblock des_key; 115 DES_key_schedule key_schedule; 116 117 MakeKey(key, des_key); 118 DES_set_key(&des_key, &key_schedule); 119 DES_ecb_encrypt((DES_cblock *)clear, (DES_cblock *)cipher, &key_schedule, 1); 120 } 121 122 static void /* IN 8 octets IN 16 octets OUT 24 octets */ 123 ChallengeResponse(u_char *challenge, u_char *pwHash, u_char *response) 124 { 125 char ZPasswordHash[21]; 126 127 memset(ZPasswordHash, '\0', sizeof ZPasswordHash); 128 memcpy(ZPasswordHash, pwHash, 16); 129 130 DesEncrypt(challenge, ZPasswordHash + 0, response + 0); 131 DesEncrypt(challenge, ZPasswordHash + 7, response + 8); 132 DesEncrypt(challenge, ZPasswordHash + 14, response + 16); 133 } 134 135 void 136 NtPasswordHash(char *key, int keylen, char *hash) 137 { 138 MD4_CTX MD4context; 139 140 MD4Init(&MD4context); 141 MD4Update(&MD4context, key, keylen); 142 MD4Final(hash, &MD4context); 143 } 144 145 void 146 HashNtPasswordHash(char *hash, char *hashhash) 147 { 148 MD4_CTX MD4context; 149 150 MD4Init(&MD4context); 151 MD4Update(&MD4context, hash, 16); 152 MD4Final(hashhash, &MD4context); 153 } 154 155 static void 156 ChallengeHash(char *PeerChallenge, char *AuthenticatorChallenge, 157 char *UserName, char *Challenge) 158 { 159 SHA_CTX Context; 160 char Digest[SHA_DIGEST_LENGTH]; 161 char *Name; 162 163 Name = strrchr(UserName, '\\'); 164 if(NULL == Name) 165 Name = UserName; 166 else 167 Name++; 168 169 SHA1_Init(&Context); 170 171 SHA1_Update(&Context, PeerChallenge, 16); 172 SHA1_Update(&Context, AuthenticatorChallenge, 16); 173 SHA1_Update(&Context, Name, strlen(Name)); 174 175 SHA1_Final(Digest, &Context); 176 memcpy(Challenge, Digest, 8); 177 } 178 179 void 180 GenerateNTResponse(char *AuthenticatorChallenge, char *PeerChallenge, 181 char *UserName, char *Password, 182 int PasswordLen, char *Response) 183 { 184 char Challenge[8]; 185 char PasswordHash[16]; 186 187 ChallengeHash(PeerChallenge, AuthenticatorChallenge, UserName, Challenge); 188 NtPasswordHash(Password, PasswordLen, PasswordHash); 189 ChallengeResponse(Challenge, PasswordHash, Response); 190 } 191 192 #ifndef __FreeBSD__ 193 #define LENGTH 20 194 static char * 195 SHA1_End(SHA_CTX *ctx, char *buf) 196 { 197 int i; 198 unsigned char digest[LENGTH]; 199 static const char hex[]="0123456789abcdef"; 200 201 if (!buf) 202 buf = malloc(2*LENGTH + 1); 203 if (!buf) 204 return 0; 205 SHA1_Final(digest, ctx); 206 for (i = 0; i < LENGTH; i++) { 207 buf[i+i] = hex[digest[i] >> 4]; 208 buf[i+i+1] = hex[digest[i] & 0x0f]; 209 } 210 buf[i+i] = '\0'; 211 return buf; 212 } 213 #endif 214 215 void 216 GenerateAuthenticatorResponse(char *Password, int PasswordLen, 217 char *NTResponse, char *PeerChallenge, 218 char *AuthenticatorChallenge, char *UserName, 219 char *AuthenticatorResponse) 220 { 221 SHA_CTX Context; 222 char PasswordHash[16]; 223 char PasswordHashHash[16]; 224 char Challenge[8]; 225 u_char Digest[SHA_DIGEST_LENGTH]; 226 int i; 227 228 /* 229 * "Magic" constants used in response generation 230 */ 231 char Magic1[39] = 232 {0x4D, 0x61, 0x67, 0x69, 0x63, 0x20, 0x73, 0x65, 0x72, 0x76, 233 0x65, 0x72, 0x20, 0x74, 0x6F, 0x20, 0x63, 0x6C, 0x69, 0x65, 234 0x6E, 0x74, 0x20, 0x73, 0x69, 0x67, 0x6E, 0x69, 0x6E, 0x67, 235 0x20, 0x63, 0x6F, 0x6E, 0x73, 0x74, 0x61, 0x6E, 0x74}; 236 237 238 char 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 * Hash the password with MD4 246 */ 247 NtPasswordHash(Password, PasswordLen, PasswordHash); 248 /* 249 * Now hash the hash 250 */ 251 HashNtPasswordHash(PasswordHash, PasswordHashHash); 252 253 SHA1_Init(&Context); 254 SHA1_Update(&Context, PasswordHashHash, 16); 255 SHA1_Update(&Context, NTResponse, 24); 256 SHA1_Update(&Context, Magic1, 39); 257 SHA1_Final(Digest, &Context); 258 ChallengeHash(PeerChallenge, AuthenticatorChallenge, UserName, Challenge); 259 SHA1_Init(&Context); 260 SHA1_Update(&Context, Digest, 20); 261 SHA1_Update(&Context, Challenge, 8); 262 SHA1_Update(&Context, Magic2, 41); 263 264 /* 265 * Encode the value of 'Digest' as "S=" followed by 266 * 40 ASCII hexadecimal digits and return it in 267 * AuthenticatorResponse. 268 * For example, 269 * "S=0123456789ABCDEF0123456789ABCDEF01234567" 270 */ 271 AuthenticatorResponse[0] = 'S'; 272 AuthenticatorResponse[1] = '='; 273 SHA1_End(&Context, AuthenticatorResponse + 2); 274 for (i=2; i<42; i++) 275 AuthenticatorResponse[i] = toupper(AuthenticatorResponse[i]); 276 277 } 278 279 void 280 GetMasterKey(char *PasswordHashHash, char *NTResponse, char *MasterKey) 281 { 282 char Digest[SHA_DIGEST_LENGTH]; 283 SHA_CTX Context; 284 static char Magic1[27] = 285 {0x54, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74, 286 0x68, 0x65, 0x20, 0x4d, 0x50, 0x50, 0x45, 0x20, 0x4d, 287 0x61, 0x73, 0x74, 0x65, 0x72, 0x20, 0x4b, 0x65, 0x79}; 288 289 SHA1_Init(&Context); 290 SHA1_Update(&Context, PasswordHashHash, 16); 291 SHA1_Update(&Context, NTResponse, 24); 292 SHA1_Update(&Context, Magic1, 27); 293 SHA1_Final(Digest, &Context); 294 memcpy(MasterKey, Digest, 16); 295 } 296 297 void 298 GetAsymetricStartKey(char *MasterKey, char *SessionKey, int SessionKeyLength, 299 int IsSend, int IsServer) 300 { 301 char Digest[SHA_DIGEST_LENGTH]; 302 SHA_CTX Context; 303 char *s; 304 305 static char Magic2[84] = 306 {0x4f, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x69, 307 0x65, 0x6e, 0x74, 0x20, 0x73, 0x69, 0x64, 0x65, 0x2c, 0x20, 308 0x74, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68, 309 0x65, 0x20, 0x73, 0x65, 0x6e, 0x64, 0x20, 0x6b, 0x65, 0x79, 310 0x3b, 0x20, 0x6f, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x73, 311 0x65, 0x72, 0x76, 0x65, 0x72, 0x20, 0x73, 0x69, 0x64, 0x65, 312 0x2c, 0x20, 0x69, 0x74, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68, 313 0x65, 0x20, 0x72, 0x65, 0x63, 0x65, 0x69, 0x76, 0x65, 0x20, 314 0x6b, 0x65, 0x79, 0x2e}; 315 316 static char Magic3[84] = 317 {0x4f, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x69, 318 0x65, 0x6e, 0x74, 0x20, 0x73, 0x69, 0x64, 0x65, 0x2c, 0x20, 319 0x74, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68, 320 0x65, 0x20, 0x72, 0x65, 0x63, 0x65, 0x69, 0x76, 0x65, 0x20, 321 0x6b, 0x65, 0x79, 0x3b, 0x20, 0x6f, 0x6e, 0x20, 0x74, 0x68, 322 0x65, 0x20, 0x73, 0x65, 0x72, 0x76, 0x65, 0x72, 0x20, 0x73, 323 0x69, 0x64, 0x65, 0x2c, 0x20, 0x69, 0x74, 0x20, 0x69, 0x73, 324 0x20, 0x74, 0x68, 0x65, 0x20, 0x73, 0x65, 0x6e, 0x64, 0x20, 325 0x6b, 0x65, 0x79, 0x2e}; 326 327 if (IsSend) { 328 if (IsServer) { 329 s = Magic3; 330 } else { 331 s = Magic2; 332 } 333 } else { 334 if (IsServer) { 335 s = Magic2; 336 } else { 337 s = Magic3; 338 } 339 } 340 341 SHA1_Init(&Context); 342 SHA1_Update(&Context, MasterKey, 16); 343 SHA1_Update(&Context, SHA1_Pad1, 40); 344 SHA1_Update(&Context, s, 84); 345 SHA1_Update(&Context, SHA1_Pad2, 40); 346 SHA1_Final(Digest, &Context); 347 348 memcpy(SessionKey, Digest, SessionKeyLength); 349 } 350 351 void 352 GetNewKeyFromSHA(char *StartKey, char *SessionKey, long SessionKeyLength, 353 char *InterimKey) 354 { 355 SHA_CTX Context; 356 char Digest[SHA_DIGEST_LENGTH]; 357 358 SHA1_Init(&Context); 359 SHA1_Update(&Context, StartKey, SessionKeyLength); 360 SHA1_Update(&Context, SHA1_Pad1, 40); 361 SHA1_Update(&Context, SessionKey, SessionKeyLength); 362 SHA1_Update(&Context, SHA1_Pad2, 40); 363 SHA1_Final(Digest, &Context); 364 365 memcpy(InterimKey, Digest, SessionKeyLength); 366 } 367 368 #if 0 369 static void 370 Get_Key(char *InitialSessionKey, char *CurrentSessionKey, 371 int LengthOfDesiredKey) 372 { 373 SHA_CTX Context; 374 char Digest[SHA_DIGEST_LENGTH]; 375 376 SHA1_Init(&Context); 377 SHA1_Update(&Context, InitialSessionKey, LengthOfDesiredKey); 378 SHA1_Update(&Context, SHA1_Pad1, 40); 379 SHA1_Update(&Context, CurrentSessionKey, LengthOfDesiredKey); 380 SHA1_Update(&Context, SHA1_Pad2, 40); 381 SHA1_Final(Digest, &Context); 382 383 memcpy(CurrentSessionKey, Digest, LengthOfDesiredKey); 384 } 385 #endif 386 387 /* passwordHash 16-bytes MD4 hashed password 388 challenge 8-bytes peer CHAP challenge 389 since passwordHash is in a 24-byte buffer, response is written in there */ 390 void 391 mschap_NT(char *passwordHash, char *challenge) 392 { 393 u_char response[24]; 394 395 ChallengeResponse(challenge, passwordHash, response); 396 memcpy(passwordHash, response, 24); 397 passwordHash[24] = 1; /* NT-style response */ 398 } 399 400 void 401 mschap_LANMan(char *digest, char *challenge, char *secret) 402 { 403 static u_char salt[] = "KGS!@#$%"; /* RASAPI32.dll */ 404 char SECRET[14], *ptr, *end; 405 u_char hash[16]; 406 407 end = SECRET + sizeof SECRET; 408 for (ptr = SECRET; *secret && ptr < end; ptr++, secret++) 409 *ptr = toupper(*secret); 410 if (ptr < end) 411 memset(ptr, '\0', end - ptr); 412 413 DesEncrypt(salt, SECRET, hash); 414 DesEncrypt(salt, SECRET + 7, hash + 8); 415 416 ChallengeResponse(challenge, hash, digest); 417 } 418