2 * chap_ms.c - Microsoft MS-CHAP compatible implementation.
4 * Copyright (c) 1995 Eric Rosenquist, Strata Software Limited.
5 * http://www.strataware.com/
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.
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.
24 * Modifications by Lauri Pesonen / lpesonen@clinet.fi, april 1997
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.
31 * You should also use DOMAIN\\USERNAME as described in README.MSCHAP80
35 static char rcsid[] = "$Id: chap_ms.c,v 1.5 1997/11/27 06:08:10 paulus Exp $";
43 #include <sys/types.h>
58 u_char LANManResp[24];
60 u_char UseNT; /* If 1, ignore the LANMan response field */
62 /* We use MS_CHAP_RESPONSE_LEN, rather than sizeof(MS_ChapResponse),
63 in case this struct gets padded. */
66 static void ChallengeResponse __P((u_char *, u_char *, u_char *));
67 static void DesEncrypt __P((u_char *, u_char *, u_char *));
68 static void MakeKey __P((u_char *, u_char *));
69 static u_char Get7Bits __P((u_char *, int));
70 static void ChapMS_NT __P((char *, int, char *, int, MS_ChapResponse *));
72 static void ChapMS_LANMan __P((char *, int, char *, int, MS_ChapResponse *));
76 static void Expand __P((u_char *, u_char *));
77 static void Collapse __P((u_char *, u_char *));
81 ChallengeResponse(challenge, pwHash, response)
82 u_char *challenge; /* IN 8 octets */
83 u_char *pwHash; /* IN 16 octets */
84 u_char *response; /* OUT 24 octets */
86 char ZPasswordHash[21];
88 BZERO(ZPasswordHash, sizeof(ZPasswordHash));
89 BCOPY(pwHash, ZPasswordHash, MD4_SIGNATURE_SIZE);
92 log_packet(ZPasswordHash, sizeof(ZPasswordHash), "ChallengeResponse - ZPasswordHash", LOG_DEBUG);
95 DesEncrypt(challenge, ZPasswordHash + 0, response + 0);
96 DesEncrypt(challenge, ZPasswordHash + 7, response + 8);
97 DesEncrypt(challenge, ZPasswordHash + 14, response + 16);
100 log_packet(response, 24, "ChallengeResponse - response", LOG_DEBUG);
107 DesEncrypt(clear, key, cipher)
108 u_char *clear; /* IN 8 octets */
109 u_char *key; /* IN 7 octets */
110 u_char *cipher; /* OUT 8 octets */
113 u_char crypt_key[66];
114 u_char des_input[66];
116 MakeKey(key, des_key);
118 Expand(des_key, crypt_key);
122 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet input : %02X%02X%02X%02X%02X%02X%02X%02X",
123 clear[0], clear[1], clear[2], clear[3], clear[4], clear[5], clear[6], clear[7]));
126 Expand(clear, des_input);
127 encrypt(des_input, 0);
128 Collapse(des_input, cipher);
131 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet output: %02X%02X%02X%02X%02X%02X%02X%02X",
132 cipher[0], cipher[1], cipher[2], cipher[3], cipher[4], cipher[5], cipher[6], cipher[7]));
136 #else /* USE_CRYPT */
139 DesEncrypt(clear, key, cipher)
140 u_char *clear; /* IN 8 octets */
141 u_char *key; /* IN 7 octets */
142 u_char *cipher; /* OUT 8 octets */
145 des_key_schedule key_schedule;
147 MakeKey(key, des_key);
149 des_set_key(&des_key, key_schedule);
152 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet input : %02X%02X%02X%02X%02X%02X%02X%02X",
153 clear[0], clear[1], clear[2], clear[3], clear[4], clear[5], clear[6], clear[7]));
156 des_ecb_encrypt((des_cblock *)clear, (des_cblock *)cipher, key_schedule, 1);
159 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet output: %02X%02X%02X%02X%02X%02X%02X%02X",
160 cipher[0], cipher[1], cipher[2], cipher[3], cipher[4], cipher[5], cipher[6], cipher[7]));
164 #endif /* USE_CRYPT */
167 static u_char Get7Bits(input, startBit)
171 register unsigned int word;
173 word = (unsigned)input[startBit / 8] << 8;
174 word |= (unsigned)input[startBit / 8 + 1];
176 word >>= 15 - (startBit % 8 + 7);
183 /* in == 8-byte string (expanded version of the 56-bit key)
184 * out == 64-byte string where each byte is either 1 or 0
185 * Note that the low-order "bit" is always ignored by by setkey()
187 static void Expand(in, out)
194 for(i = 0; i < 64; in++){
196 for(j = 7; j >= 0; j--)
197 *out++ = (c >> j) & 01;
202 /* The inverse of Expand
204 static void Collapse(in, out)
212 for (i = 0; i < 64; i += 8, out++) {
214 for (j = 7; j >= 0; j--, in++)
221 static void MakeKey(key, des_key)
222 u_char *key; /* IN 56 bit DES key missing parity bits */
223 u_char *des_key; /* OUT 64 bit DES key with parity bits added */
225 des_key[0] = Get7Bits(key, 0);
226 des_key[1] = Get7Bits(key, 7);
227 des_key[2] = Get7Bits(key, 14);
228 des_key[3] = Get7Bits(key, 21);
229 des_key[4] = Get7Bits(key, 28);
230 des_key[5] = Get7Bits(key, 35);
231 des_key[6] = Get7Bits(key, 42);
232 des_key[7] = Get7Bits(key, 49);
235 des_set_odd_parity((des_cblock *)des_key);
239 CHAPDEBUG((LOG_INFO, "MakeKey: 56-bit input : %02X%02X%02X%02X%02X%02X%02X",
240 key[0], key[1], key[2], key[3], key[4], key[5], key[6]));
241 CHAPDEBUG((LOG_INFO, "MakeKey: 64-bit output: %02X%02X%02X%02X%02X%02X%02X%02X",
242 des_key[0], des_key[1], des_key[2], des_key[3], des_key[4], des_key[5], des_key[6], des_key[7]));
247 ChapMS_NT(rchallenge, rchallenge_len, secret, secret_len, response)
252 MS_ChapResponse *response;
256 u_short hash[MD4_SIGNATURE_SIZE/sizeof(u_short)];
257 u_char unicodePassword[MAX_NT_PASSWORD * 2];
258 static int low_byte_first = -1;
260 /* Initialize the Unicode version of the secret (== password). */
261 /* This implicitly supports 8-bit ISO8859/1 characters. */
262 BZERO(unicodePassword, sizeof(unicodePassword));
263 for (i = 0; i < secret_len; i++)
264 unicodePassword[i * 2] = (u_char)secret[i];
266 MD4Init(&md4Context);
267 MD4Update(&md4Context, unicodePassword, secret_len * 2 * 8); /* Unicode is 2 bytes/char, *8 for bit count */
269 MD4Final((u_char *) hash, &md4Context); /* Tell MD4 we're done */
271 if (low_byte_first == -1)
272 low_byte_first = (htons((unsigned short int)1) != 1);
273 if (low_byte_first == 0) {
274 for (i = 0; i < MD4_SIGNATURE_SIZE; i += sizeof(u_short))
275 hash[i] = htons(hash[i]);
278 ChallengeResponse(rchallenge, (u_char *)hash, response->NTResp);
282 static u_char *StdText = (u_char *)"KGS!@#$%"; /* key from rasapi32.dll */
285 ChapMS_LANMan(rchallenge, rchallenge_len, secret, secret_len, response)
290 MS_ChapResponse *response;
293 u_char UcasePassword[MAX_NT_PASSWORD]; /* max is actually 14 */
294 u_char PasswordHash[MD4_SIGNATURE_SIZE];
296 /* LANMan password is case insensitive */
297 BZERO(UcasePassword, sizeof(UcasePassword));
298 for (i = 0; i < secret_len; i++)
299 UcasePassword[i] = (u_char)toupper(secret[i]);
300 DesEncrypt( StdText, UcasePassword + 0, PasswordHash + 0 );
301 DesEncrypt( StdText, UcasePassword + 7, PasswordHash + 8 );
302 ChallengeResponse(rchallenge, PasswordHash, response->LANManResp);
307 ChapMS(cstate, rchallenge, rchallenge_len, secret, secret_len)
314 MS_ChapResponse response;
316 extern int ms_lanman;
320 CHAPDEBUG((LOG_INFO, "ChapMS: secret is '%.*s'", secret_len, secret));
322 BZERO(&response, sizeof(response));
324 /* Calculate both always */
325 ChapMS_NT(rchallenge, rchallenge_len, secret, secret_len, &response);
328 ChapMS_LANMan(rchallenge, rchallenge_len, secret, secret_len, &response);
330 /* prefered method is set by option */
331 response.UseNT = !ms_lanman;
336 BCOPY(&response, cstate->response, MS_CHAP_RESPONSE_LEN);
337 cstate->resp_length = MS_CHAP_RESPONSE_LEN;