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 1.3 1997/04/30 05:51:40 paulus Exp $";
41 #include <sys/types.h>
53 u_char LANManResp[24];
55 u_char UseNT; /* If 1, ignore the LANMan response field */
57 /* We use MS_CHAP_RESPONSE_LEN, rather than sizeof(MS_ChapResponse),
58 in case this struct gets padded. */
61 static void DesEncrypt __P((u_char *, u_char *, u_char *));
62 static void MakeKey __P((u_char *, u_char *));
65 static void Expand __P((u_char *, u_char *));
66 static void Collapse __P((u_char *, u_char *));
70 ChallengeResponse(challenge, pwHash, response)
71 u_char *challenge; /* IN 8 octets */
72 u_char *pwHash; /* IN 16 octets */
73 u_char *response; /* OUT 24 octets */
75 char ZPasswordHash[21];
77 BZERO(ZPasswordHash, sizeof(ZPasswordHash));
78 BCOPY(pwHash, ZPasswordHash, 16);
81 log_packet(ZPasswordHash, sizeof(ZPasswordHash), "ChallengeResponse - ZPasswordHash", LOG_DEBUG);
84 DesEncrypt(challenge, ZPasswordHash + 0, response + 0);
85 DesEncrypt(challenge, ZPasswordHash + 7, response + 8);
86 DesEncrypt(challenge, ZPasswordHash + 14, response + 16);
89 log_packet(response, 24, "ChallengeResponse - response", LOG_DEBUG);
96 DesEncrypt(clear, key, cipher)
97 u_char *clear; /* IN 8 octets */
98 u_char *key; /* IN 7 octets */
99 u_char *cipher; /* OUT 8 octets */
102 u_char crypt_key[66];
103 u_char des_input[66];
105 MakeKey(key, des_key);
107 Expand(des_key, crypt_key);
111 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet input : %02X%02X%02X%02X%02X%02X%02X%02X",
112 clear[0], clear[1], clear[2], clear[3], clear[4], clear[5], clear[6], clear[7]));
115 Expand(clear, des_input);
116 encrypt(des_input, 0);
117 Collapse(des_input, cipher);
120 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet output: %02X%02X%02X%02X%02X%02X%02X%02X",
121 cipher[0], cipher[1], cipher[2], cipher[3], cipher[4], cipher[5], cipher[6], cipher[7]));
125 #else /* USE_CRYPT */
128 DesEncrypt(clear, key, cipher)
129 u_char *clear; /* IN 8 octets */
130 u_char *key; /* IN 7 octets */
131 u_char *cipher; /* OUT 8 octets */
134 des_key_schedule key_schedule;
136 MakeKey(key, des_key);
138 des_set_key(&des_key, key_schedule);
141 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet input : %02X%02X%02X%02X%02X%02X%02X%02X",
142 clear[0], clear[1], clear[2], clear[3], clear[4], clear[5], clear[6], clear[7]));
145 des_ecb_encrypt((des_cblock *)clear, (des_cblock *)cipher, key_schedule, 1);
148 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet output: %02X%02X%02X%02X%02X%02X%02X%02X",
149 cipher[0], cipher[1], cipher[2], cipher[3], cipher[4], cipher[5], cipher[6], cipher[7]));
153 #endif /* USE_CRYPT */
156 static u_char Get7Bits(input, startBit)
160 register unsigned int word;
162 word = (unsigned)input[startBit / 8] << 8;
163 word |= (unsigned)input[startBit / 8 + 1];
165 word >>= 15 - (startBit % 8 + 7);
172 /* in == 8-byte string (expanded version of the 56-bit key)
173 * out == 64-byte string where each byte is either 1 or 0
174 * Note that the low-order "bit" is always ignored by by setkey()
176 static void Expand(in, out)
183 for(i = 0; i < 64; in++){
185 for(j = 7; j >= 0; j--)
186 *out++ = (c >> j) & 01;
191 /* The inverse of Expand
193 static void Collapse(in, out)
201 for (i = 0; i < 64; i += 8, out++) {
203 for (j = 7; j >= 0; j--, in++)
210 static void MakeKey(key, des_key)
211 u_char *key; /* IN 56 bit DES key missing parity bits */
212 u_char *des_key; /* OUT 64 bit DES key with parity bits added */
214 des_key[0] = Get7Bits(key, 0);
215 des_key[1] = Get7Bits(key, 7);
216 des_key[2] = Get7Bits(key, 14);
217 des_key[3] = Get7Bits(key, 21);
218 des_key[4] = Get7Bits(key, 28);
219 des_key[5] = Get7Bits(key, 35);
220 des_key[6] = Get7Bits(key, 42);
221 des_key[7] = Get7Bits(key, 49);
224 des_set_odd_parity((des_cblock *)des_key);
228 CHAPDEBUG((LOG_INFO, "MakeKey: 56-bit input : %02X%02X%02X%02X%02X%02X%02X",
229 key[0], key[1], key[2], key[3], key[4], key[5], key[6]));
230 CHAPDEBUG((LOG_INFO, "MakeKey: 64-bit output: %02X%02X%02X%02X%02X%02X%02X%02X",
231 des_key[0], des_key[1], des_key[2], des_key[3], des_key[4], des_key[5], des_key[6], des_key[7]));
236 ChapMS_NT(rchallenge, rchallenge_len, secret, secret_len, response)
241 MS_ChapResponse *response;
245 u_char unicodePassword[MAX_NT_PASSWORD * 2];
246 static int low_byte_first = -1;
248 /* Initialize the Unicode version of the secret (== password). */
249 /* This implicitly supports 8-bit ISO8859/1 characters. */
250 BZERO(unicodePassword, sizeof(unicodePassword));
251 for (i = 0; i < secret_len; i++)
252 unicodePassword[i * 2] = (u_char)secret[i];
254 MDbegin(&md4Context);
255 MDupdate(&md4Context, unicodePassword, secret_len * 2 * 8); /* Unicode is 2 bytes/char, *8 for bit count */
257 if (low_byte_first == -1)
258 low_byte_first = (htons((unsigned short int)1) != 1);
259 if (low_byte_first == 0)
260 MDreverse(&md4Context); /* sfb 961105 */
262 MDupdate(&md4Context, NULL, 0); /* Tell MD4 we're done */
264 ChallengeResponse(rchallenge, (char *)md4Context.buffer, response->NTResp);
267 static u_char *StdText = "KGS!@#$%"; /* key from rasapi32.dll */
269 static ChapMS_LANMan(rchallenge, rchallenge_len, secret, secret_len, response)
274 MS_ChapResponse *response;
277 u_char UcasePassword[MAX_NT_PASSWORD]; /* max is actually 14 */
278 u_char PasswordHash[16];
280 /* LANMan password is case insensitive */
281 BZERO(UcasePassword, sizeof(UcasePassword));
282 for (i = 0; i < secret_len; i++)
283 UcasePassword[i] = (u_char)toupper(secret[i]);
284 DesEncrypt( StdText, UcasePassword + 0, PasswordHash + 0 );
285 DesEncrypt( StdText, UcasePassword + 7, PasswordHash + 8 );
286 ChallengeResponse(rchallenge, PasswordHash, response->LANManResp);
290 ChapMS(cstate, rchallenge, rchallenge_len, secret, secret_len)
297 MS_ChapResponse response;
300 CHAPDEBUG((LOG_INFO, "ChapMS: secret is '%.*s'", secret_len, secret));
302 BZERO(&response, sizeof(response));
304 /* Calculate both always */
305 ChapMS_NT(rchallenge, rchallenge_len, secret, secret_len, &response);
306 ChapMS_LANMan(rchallenge, rchallenge_len, secret, secret_len, &response);
308 /* prefered method is set by option */
309 response.UseNT = !ms_lanman;
311 BCOPY(&response, cstate->response, MS_CHAP_RESPONSE_LEN);
312 cstate->resp_length = MS_CHAP_RESPONSE_LEN;