1 /*** WARNING - THIS CODE HAS NOT BEEN FINISHED! ***/ 2 /*** The original PPPD code is written in a way to require either the UNIX DES 3 encryption functions encrypt(3) and setkey(3) or the DES library libdes. 4 Since both is not included in lwIP, MSCHAP currently does not work! */ 5 /***************************************************************************** 6 * chpms.c - Network MicroSoft Challenge Handshake Authentication Protocol program file. 7 * 8 * Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc. 9 * Copyright (c) 1997 by Global Election Systems Inc. All rights reserved. 10 * 11 * The authors hereby grant permission to use, copy, modify, distribute, 12 * and license this software and its documentation for any purpose, provided 13 * that existing copyright notices are retained in all copies and that this 14 * notice and the following disclaimer are included verbatim in any 15 * distributions. No written agreement, license, or royalty fee is required 16 * for any of the authorized uses. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 * 29 ****************************************************************************** 30 * REVISION HISTORY 31 * 32 * 03-01-01 Marc Boucher <marc (at) mbsi.ca> 33 * Ported to lwIP. 34 * 97-12-08 Guy Lancaster <lancasterg (at) acm.org>, Global Election Systems Inc. 35 * Original based on BSD chap_ms.c. 36 *****************************************************************************/ 37 /* 38 * chap_ms.c - Microsoft MS-CHAP compatible implementation. 39 * 40 * Copyright (c) 1995 Eric Rosenquist, Strata Software Limited. 41 * http://www.strataware.com/ 42 * 43 * All rights reserved. 44 * 45 * Redistribution and use in source and binary forms are permitted 46 * provided that the above copyright notice and this paragraph are 47 * duplicated in all such forms and that any documentation, 48 * advertising materials, and other materials related to such 49 * distribution and use acknowledge that the software was developed 50 * by Eric Rosenquist. The name of the author may not be used to 51 * endorse or promote products derived from this software without 52 * specific prior written permission. 53 * 54 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 55 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 56 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 57 */ 58 59 /* 60 * Modifications by Lauri Pesonen / lpesonen (at) clinet.fi, april 1997 61 * 62 * Implemented LANManager type password response to MS-CHAP challenges. 63 * Now pppd provides both NT style and LANMan style blocks, and the 64 * prefered is set by option "ms-lanman". Default is to use NT. 65 * The hash text (StdText) was taken from Win95 RASAPI32.DLL. 66 * 67 * You should also use DOMAIN\\USERNAME as described in README.MSCHAP80 68 */ 69 70 #define USE_CRYPT 71 72 #include "lwip/opt.h" 73 74 #if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */ 75 76 #if MSCHAP_SUPPORT /* don't build if not configured for use in lwipopts.h */ 77 78 #include "ppp.h" 79 #include "pppdebug.h" 80 81 #include "md4.h" 82 #ifndef USE_CRYPT 83 #include "des.h" 84 #endif 85 #include "chap.h" 86 #include "chpms.h" 87 88 #include <string.h> 89 90 91 /*************************/ 92 /*** LOCAL DEFINITIONS ***/ 93 /*************************/ 94 95 96 /************************/ 97 /*** LOCAL DATA TYPES ***/ 98 /************************/ 99 typedef struct { 100 u_char LANManResp[24]; 101 u_char NTResp[24]; 102 u_char UseNT; /* If 1, ignore the LANMan response field */ 103 } MS_ChapResponse; 104 /* We use MS_CHAP_RESPONSE_LEN, rather than sizeof(MS_ChapResponse), 105 in case this struct gets padded. */ 106 107 108 109 /***********************************/ 110 /*** LOCAL FUNCTION DECLARATIONS ***/ 111 /***********************************/ 112 113 /* XXX Don't know what to do with these. */ 114 extern void setkey(const char *); 115 extern void encrypt(char *, int); 116 117 static void DesEncrypt (u_char *, u_char *, u_char *); 118 static void MakeKey (u_char *, u_char *); 119 120 #ifdef USE_CRYPT 121 static void Expand (u_char *, u_char *); 122 static void Collapse (u_char *, u_char *); 123 #endif 124 125 static void ChallengeResponse( 126 u_char *challenge, /* IN 8 octets */ 127 u_char *pwHash, /* IN 16 octets */ 128 u_char *response /* OUT 24 octets */ 129 ); 130 static void ChapMS_NT( 131 char *rchallenge, 132 int rchallenge_len, 133 char *secret, 134 int secret_len, 135 MS_ChapResponse *response 136 ); 137 static u_char Get7Bits( 138 u_char *input, 139 int startBit 140 ); 141 142 static void 143 ChallengeResponse( u_char *challenge, /* IN 8 octets */ 144 u_char *pwHash, /* IN 16 octets */ 145 u_char *response /* OUT 24 octets */) 146 { 147 u_char ZPasswordHash[21]; 148 149 BZERO(ZPasswordHash, sizeof(ZPasswordHash)); 150 BCOPY(pwHash, ZPasswordHash, 16); 151 152 #if 0 153 log_packet(ZPasswordHash, sizeof(ZPasswordHash), "ChallengeResponse - ZPasswordHash", LOG_DEBUG); 154 #endif 155 156 DesEncrypt(challenge, ZPasswordHash + 0, response + 0); 157 DesEncrypt(challenge, ZPasswordHash + 7, response + 8); 158 DesEncrypt(challenge, ZPasswordHash + 14, response + 16); 159 160 #if 0 161 log_packet(response, 24, "ChallengeResponse - response", LOG_DEBUG); 162 #endif 163 } 164 165 166 #ifdef USE_CRYPT 167 static void 168 DesEncrypt( u_char *clear, /* IN 8 octets */ 169 u_char *key, /* IN 7 octets */ 170 u_char *cipher /* OUT 8 octets */) 171 { 172 u_char des_key[8]; 173 u_char crypt_key[66]; 174 u_char des_input[66]; 175 176 MakeKey(key, des_key); 177 178 Expand(des_key, crypt_key); 179 setkey((char*)crypt_key); 180 181 #if 0 182 CHAPDEBUG(LOG_INFO, ("DesEncrypt: 8 octet input : %02X%02X%02X%02X%02X%02X%02X%02X\n", 183 clear[0], clear[1], clear[2], clear[3], clear[4], clear[5], clear[6], clear[7])); 184 #endif 185 186 Expand(clear, des_input); 187 encrypt((char*)des_input, 0); 188 Collapse(des_input, cipher); 189 190 #if 0 191 CHAPDEBUG(LOG_INFO, ("DesEncrypt: 8 octet output: %02X%02X%02X%02X%02X%02X%02X%02X\n", 192 cipher[0], cipher[1], cipher[2], cipher[3], cipher[4], cipher[5], cipher[6], cipher[7])); 193 #endif 194 } 195 196 #else /* USE_CRYPT */ 197 198 static void 199 DesEncrypt( u_char *clear, /* IN 8 octets */ 200 u_char *key, /* IN 7 octets */ 201 u_char *cipher /* OUT 8 octets */) 202 { 203 des_cblock des_key; 204 des_key_schedule key_schedule; 205 206 MakeKey(key, des_key); 207 208 des_set_key(&des_key, key_schedule); 209 210 #if 0 211 CHAPDEBUG(LOG_INFO, ("DesEncrypt: 8 octet input : %02X%02X%02X%02X%02X%02X%02X%02X\n", 212 clear[0], clear[1], clear[2], clear[3], clear[4], clear[5], clear[6], clear[7])); 213 #endif 214 215 des_ecb_encrypt((des_cblock *)clear, (des_cblock *)cipher, key_schedule, 1); 216 217 #if 0 218 CHAPDEBUG(LOG_INFO, ("DesEncrypt: 8 octet output: %02X%02X%02X%02X%02X%02X%02X%02X\n", 219 cipher[0], cipher[1], cipher[2], cipher[3], cipher[4], cipher[5], cipher[6], cipher[7])); 220 #endif 221 } 222 223 #endif /* USE_CRYPT */ 224 225 226 static u_char 227 Get7Bits( u_char *input, int startBit) 228 { 229 register unsigned int word; 230 231 word = (unsigned)input[startBit / 8] << 8; 232 word |= (unsigned)input[startBit / 8 + 1]; 233 234 word >>= 15 - (startBit % 8 + 7); 235 236 return word & 0xFE; 237 } 238 239 #ifdef USE_CRYPT 240 241 /* in == 8-byte string (expanded version of the 56-bit key) 242 * out == 64-byte string where each byte is either 1 or 0 243 * Note that the low-order "bit" is always ignored by by setkey() 244 */ 245 static void 246 Expand(u_char *in, u_char *out) 247 { 248 int j, c; 249 int i; 250 251 for(i = 0; i < 64; in++){ 252 c = *in; 253 for(j = 7; j >= 0; j--) { 254 *out++ = (c >> j) & 01; 255 } 256 i += 8; 257 } 258 } 259 260 /* The inverse of Expand 261 */ 262 static void 263 Collapse(u_char *in, u_char *out) 264 { 265 int j; 266 int i; 267 unsigned int c; 268 269 for (i = 0; i < 64; i += 8, out++) { 270 c = 0; 271 for (j = 7; j >= 0; j--, in++) { 272 c |= *in << j; 273 } 274 *out = c & 0xff; 275 } 276 } 277 #endif 278 279 static void 280 MakeKey( u_char *key, /* IN 56 bit DES key missing parity bits */ 281 u_char *des_key /* OUT 64 bit DES key with parity bits added */) 282 { 283 des_key[0] = Get7Bits(key, 0); 284 des_key[1] = Get7Bits(key, 7); 285 des_key[2] = Get7Bits(key, 14); 286 des_key[3] = Get7Bits(key, 21); 287 des_key[4] = Get7Bits(key, 28); 288 des_key[5] = Get7Bits(key, 35); 289 des_key[6] = Get7Bits(key, 42); 290 des_key[7] = Get7Bits(key, 49); 291 292 #ifndef USE_CRYPT 293 des_set_odd_parity((des_cblock *)des_key); 294 #endif 295 296 #if 0 297 CHAPDEBUG(LOG_INFO, ("MakeKey: 56-bit input : %02X%02X%02X%02X%02X%02X%02X\n", 298 key[0], key[1], key[2], key[3], key[4], key[5], key[6])); 299 CHAPDEBUG(LOG_INFO, ("MakeKey: 64-bit output: %02X%02X%02X%02X%02X%02X%02X%02X\n", 300 des_key[0], des_key[1], des_key[2], des_key[3], des_key[4], des_key[5], des_key[6], des_key[7])); 301 #endif 302 } 303 304 static void 305 ChapMS_NT( char *rchallenge, 306 int rchallenge_len, 307 char *secret, 308 int secret_len, 309 MS_ChapResponse *response) 310 { 311 int i; 312 MDstruct md4Context; 313 u_char unicodePassword[MAX_NT_PASSWORD * 2]; 314 static int low_byte_first = -1; 315 316 LWIP_UNUSED_ARG(rchallenge_len); 317 318 /* Initialize the Unicode version of the secret (== password). */ 319 /* This implicitly supports 8-bit ISO8859/1 characters. */ 320 BZERO(unicodePassword, sizeof(unicodePassword)); 321 for (i = 0; i < secret_len; i++) { 322 unicodePassword[i * 2] = (u_char)secret[i]; 323 } 324 MDbegin(&md4Context); 325 MDupdate(&md4Context, unicodePassword, secret_len * 2 * 8); /* Unicode is 2 bytes/char, *8 for bit count */ 326 327 if (low_byte_first == -1) { 328 low_byte_first = (PP_HTONS((unsigned short int)1) != 1); 329 } 330 if (low_byte_first == 0) { 331 /* @todo: arg type - u_long* or u_int* ? */ 332 MDreverse((unsigned int*)&md4Context); /* sfb 961105 */ 333 } 334 335 MDupdate(&md4Context, NULL, 0); /* Tell MD4 we're done */ 336 337 ChallengeResponse((u_char*)rchallenge, (u_char*)md4Context.buffer, response->NTResp); 338 } 339 340 #ifdef MSLANMAN 341 static u_char *StdText = (u_char *)"KGS!@#$%"; /* key from rasapi32.dll */ 342 343 static void 344 ChapMS_LANMan( char *rchallenge, 345 int rchallenge_len, 346 char *secret, 347 int secret_len, 348 MS_ChapResponse *response) 349 { 350 int i; 351 u_char UcasePassword[MAX_NT_PASSWORD]; /* max is actually 14 */ 352 u_char PasswordHash[16]; 353 354 /* LANMan password is case insensitive */ 355 BZERO(UcasePassword, sizeof(UcasePassword)); 356 for (i = 0; i < secret_len; i++) { 357 UcasePassword[i] = (u_char)toupper(secret[i]); 358 } 359 DesEncrypt( StdText, UcasePassword + 0, PasswordHash + 0 ); 360 DesEncrypt( StdText, UcasePassword + 7, PasswordHash + 8 ); 361 ChallengeResponse(rchallenge, PasswordHash, response->LANManResp); 362 } 363 #endif 364 365 void 366 ChapMS( chap_state *cstate, char *rchallenge, int rchallenge_len, char *secret, int secret_len) 367 { 368 MS_ChapResponse response; 369 #ifdef MSLANMAN 370 extern int ms_lanman; 371 #endif 372 373 #if 0 374 CHAPDEBUG(LOG_INFO, ("ChapMS: secret is '%.*s'\n", secret_len, secret)); 375 #endif 376 BZERO(&response, sizeof(response)); 377 378 /* Calculate both always */ 379 ChapMS_NT(rchallenge, rchallenge_len, secret, secret_len, &response); 380 381 #ifdef MSLANMAN 382 ChapMS_LANMan(rchallenge, rchallenge_len, secret, secret_len, &response); 383 384 /* prefered method is set by option */ 385 response.UseNT = !ms_lanman; 386 #else 387 response.UseNT = 1; 388 #endif 389 390 BCOPY(&response, cstate->response, MS_CHAP_RESPONSE_LEN); 391 cstate->resp_length = MS_CHAP_RESPONSE_LEN; 392 } 393 394 #endif /* MSCHAP_SUPPORT */ 395 396 #endif /* PPP_SUPPORT */ 397