release/src/router/ppp/pppd/chap_ms.c

   1 /*
   2  * chap_ms.c - Microsoft MS-CHAP compatible implementation.
   3  *
   4  * Copyright (c) 1995 Eric Rosenquist, Strata Software Limited.
   5  * http://www.strataware.com/
   6  *
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms are permitted
  10  * provided that the above copyright notice and this paragraph are
  11  * duplicated in all such forms and that any documentation,
  12  * advertising materials, and other materials related to such
  13  * distribution and use acknowledge that the software was developed
  14  * by Eric Rosenquist.  The name of the author may not be used to
  15  * endorse or promote products derived from this software without
  16  * specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  19  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  20  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  21  */
  22
  23 /*
  24  * Modifications by Lauri Pesonen / lpesonen@clinet.fi, april 1997
  25  *
  26  *   Implemented LANManager type password response to MS-CHAP challenges.
  27  *   Now pppd provides both NT style and LANMan style blocks, and the
  28  *   prefered is set by option "ms-lanman". Default is to use NT.
  29  *   The hash text (StdText) was taken from Win95 RASAPI32.DLL.
  30  *
  31  *   You should also use DOMAIN\\USERNAME as described in README.MSCHAP80
  32  */
  33
  34 #define RCSID   "$Id: chap_ms.c,v 1.1.1.4 2003/10/14 08:09:53 sparq Exp $"
  35
  36 #ifdef CHAPMS
  37
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <string.h>
  41 #include <ctype.h>
  42 #include <sys/types.h>
  43 #include <sys/time.h>
  44 #include <unistd.h>
  45 #ifdef HAVE_CRYPT_H
  46 #include <crypt.h>
  47 #endif
  48
  49 #include "pppd.h"
  50 #include "chap.h"
  51 #include "chap_ms.h"
  52 #include "md4.h"
  53
  54 #ifndef USE_CRYPT
  55 #include <des.h>
  56 #endif
  57
  58 static const char rcsid[] = RCSID;
  59
  60 typedef struct {
  61     u_char LANManResp[24];
  62     u_char NTResp[24];
  63     u_char UseNT;               /* If 1, ignore the LANMan response field */
  64 } MS_ChapResponse;
  65 /* We use MS_CHAP_RESPONSE_LEN, rather than sizeof(MS_ChapResponse),
  66    in case this struct gets padded. */
  67
  68
  69 static void     ChallengeResponse __P((u_char *, u_char *, u_char *));
  70 static void     DesEncrypt __P((u_char *, u_char *, u_char *));
  71 static void     MakeKey __P((u_char *, u_char *));
  72 static u_char   Get7Bits __P((u_char *, int));
  73 static void     ChapMS_NT __P((char *, int, char *, int, MS_ChapResponse *));
  74 #ifdef MSLANMAN
  75 static void     ChapMS_LANMan __P((char *, int, char *, int, MS_ChapResponse *));
  76 #endif
  77
  78 #ifdef USE_CRYPT
  79 static void     Expand __P((u_char *, u_char *));
  80 static void     Collapse __P((u_char *, u_char *));
  81 #endif
  82
  83 #ifdef MSLANMAN
  84 bool    ms_lanman = 0;          /* Use LanMan password instead of NT */
  85                                 /* Has meaning only with MS-CHAP challenges */
  86 #endif
  87
  88 static void
  89 ChallengeResponse(challenge, pwHash, response)
  90     u_char *challenge;  /* IN   8 octets */
  91     u_char *pwHash;     /* IN  16 octets */
  92     u_char *response;   /* OUT 24 octets */
  93 {
  94     char    ZPasswordHash[21];
  95
  96     BZERO(ZPasswordHash, sizeof(ZPasswordHash));
  97     BCOPY(pwHash, ZPasswordHash, MD4_SIGNATURE_SIZE);
  98
  99
 100     DesEncrypt(challenge, ZPasswordHash +  0, response + 0);
 101     DesEncrypt(challenge, ZPasswordHash +  7, response + 8);
 102     DesEncrypt(challenge, ZPasswordHash + 14, response + 16);
 103
 104 }
 105
 106
 107 #ifdef USE_CRYPT
 108 static void
 109 DesEncrypt(clear, key, cipher)
 110     u_char *clear;      /* IN  8 octets */
 111     u_char *key;        /* IN  7 octets */
 112     u_char *cipher;     /* OUT 8 octets */
 113 {
 114     u_char des_key[8];
 115     u_char crypt_key[66];
 116     u_char des_input[66];
 117
 118     MakeKey(key, des_key);
 119
 120     Expand(des_key, crypt_key);
 121     setkey(crypt_key);
 122
 123
 124     Expand(clear, des_input);
 125     encrypt(des_input, 0);
 126     Collapse(des_input, cipher);
 127
 128 }
 129
 130 #else /* USE_CRYPT */
 131
 132 static void
 133 DesEncrypt(clear, key, cipher)
 134     u_char *clear;      /* IN  8 octets */
 135     u_char *key;        /* IN  7 octets */
 136     u_char *cipher;     /* OUT 8 octets */
 137 {
 138     des_cblock          des_key;
 139     des_key_schedule    key_schedule;
 140
 141     MakeKey(key, des_key);
 142
 143     des_set_key(&des_key, key_schedule);
 144
 145
 146     des_ecb_encrypt((des_cblock *)clear, (des_cblock *)cipher, key_schedule, 1);
 147
 148 }
 149
 150 #endif /* USE_CRYPT */
 151
 152
 153 static u_char Get7Bits(input, startBit)
 154     u_char *input;
 155     int startBit;
 156 {
 157     register unsigned int       word;
 158
 159     word  = (unsigned)input[startBit / 8] << 8;
 160     word |= (unsigned)input[startBit / 8 + 1];
 161
 162     word >>= 15 - (startBit % 8 + 7);
 163
 164     return word & 0xFE;
 165 }
 166
 167 #ifdef USE_CRYPT
 168
 169 /* in == 8-byte string (expanded version of the 56-bit key)
 170  * out == 64-byte string where each byte is either 1 or 0
 171  * Note that the low-order "bit" is always ignored by by setkey()
 172  */
 173 static void Expand(in, out)
 174     u_char *in;
 175     u_char *out;
 176 {
 177         int j, c;
 178         int i;
 179
 180         for(i = 0; i < 64; in++){
 181                 c = *in;
 182                 for(j = 7; j >= 0; j--)
 183                         *out++ = (c >> j) & 01;
 184                 i += 8;
 185         }
 186 }
 187
 188 /* The inverse of Expand
 189  */
 190 static void Collapse(in, out)
 191     u_char *in;
 192     u_char *out;
 193 {
 194         int j;
 195         int i;
 196         unsigned int c;
 197
 198         for (i = 0; i < 64; i += 8, out++) {
 199             c = 0;
 200             for (j = 7; j >= 0; j--, in++)
 201                 c |= *in << j;
 202             *out = c & 0xff;
 203         }
 204 }
 205 #endif
 206
 207 static void MakeKey(key, des_key)
 208     u_char *key;        /* IN  56 bit DES key missing parity bits */
 209     u_char *des_key;    /* OUT 64 bit DES key with parity bits added */
 210 {
 211     des_key[0] = Get7Bits(key,  0);
 212     des_key[1] = Get7Bits(key,  7);
 213     des_key[2] = Get7Bits(key, 14);
 214     des_key[3] = Get7Bits(key, 21);
 215     des_key[4] = Get7Bits(key, 28);
 216     des_key[5] = Get7Bits(key, 35);
 217     des_key[6] = Get7Bits(key, 42);
 218     des_key[7] = Get7Bits(key, 49);
 219
 220 #ifndef USE_CRYPT
 221     des_set_odd_parity((des_cblock *)des_key);
 222 #endif
 223
 224 }
 225
 226 static void
 227 ChapMS_NT(rchallenge, rchallenge_len, secret, secret_len, response)
 228     char *rchallenge;
 229     int rchallenge_len;
 230     char *secret;
 231     int secret_len;
 232     MS_ChapResponse    *response;
 233 {
 234     int                 i;
 235 #ifdef __NetBSD__
 236     /* NetBSD uses the libc md4 routines which take bytes instead of bits */
 237     int                 mdlen = secret_len * 2;
 238 #else
 239     int                 mdlen = secret_len * 2 * 8;
 240 #endif
 241     MD4_CTX             md4Context;
 242     u_char              hash[MD4_SIGNATURE_SIZE];
 243     u_char              unicodePassword[MAX_NT_PASSWORD * 2];
 244
 245     /* Initialize the Unicode version of the secret (== password). */
 246     /* This implicitly supports 8-bit ISO8859/1 characters. */
 247     BZERO(unicodePassword, sizeof(unicodePassword));
 248     for (i = 0; i < secret_len; i++)
 249         unicodePassword[i * 2] = (u_char)secret[i];
 250
 251     MD4Init(&md4Context);
 252     MD4Update(&md4Context, unicodePassword, mdlen);
 253
 254     MD4Final(hash, &md4Context);        /* Tell MD4 we're done */
 255
 256     ChallengeResponse(rchallenge, hash, response->NTResp);
 257 }
 258
 259 #ifdef MSLANMAN
 260 static u_char *StdText = (u_char *)"KGS!@#$%"; /* key from rasapi32.dll */
 261
 262 static void
 263 ChapMS_LANMan(rchallenge, rchallenge_len, secret, secret_len, response)
 264     char *rchallenge;
 265     int rchallenge_len;
 266     char *secret;
 267     int secret_len;
 268     MS_ChapResponse     *response;
 269 {
 270     int                 i;
 271     u_char              UcasePassword[MAX_NT_PASSWORD]; /* max is actually 14 */
 272     u_char              PasswordHash[MD4_SIGNATURE_SIZE];
 273
 274     /* LANMan password is case insensitive */
 275     BZERO(UcasePassword, sizeof(UcasePassword));
 276     for (i = 0; i < secret_len; i++)
 277        UcasePassword[i] = (u_char)toupper(secret[i]);
 278     DesEncrypt( StdText, UcasePassword + 0, PasswordHash + 0 );
 279     DesEncrypt( StdText, UcasePassword + 7, PasswordHash + 8 );
 280     ChallengeResponse(rchallenge, PasswordHash, response->LANManResp);
 281 }
 282 #endif
 283
 284 void
 285 ChapMS(cstate, rchallenge, rchallenge_len, secret, secret_len)
 286     chap_state *cstate;
 287     char *rchallenge;
 288     int rchallenge_len;
 289     char *secret;
 290     int secret_len;
 291 {
 292     MS_ChapResponse     response;
 293
 294     BZERO(&response, sizeof(response));
 295
 296     /* Calculate both always */
 297     ChapMS_NT(rchallenge, rchallenge_len, secret, secret_len, &response);
 298
 299 #ifdef MSLANMAN
 300     ChapMS_LANMan(rchallenge, rchallenge_len, secret, secret_len, &response);
 301
 302     /* prefered method is set by option  */
 303     response.UseNT = !ms_lanman;
 304 #else
 305     response.UseNT = 1;
 306 #endif
 307
 308     BCOPY(&response, cstate->response, MS_CHAP_RESPONSE_LEN);
 309     cstate->resp_length = MS_CHAP_RESPONSE_LEN;
 310 }
 311
 312 #endif /* CHAPMS */