lib/liblwip/netif/ppp/chpms.c

   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@mbsi.ca>
  33 *   Ported to lwIP.
  34 * 97-12-08 Guy Lancaster <lancasterg@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@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 */