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
34 #define RCSID "$Id: chap_ms.c,v 1.15 1999/08/13 06:46:12 paulus Exp $"
42 #include <sys/types.h>
58 static const char rcsid[] = RCSID;
61 u_char LANManResp[24];
63 u_char UseNT; /* If 1, ignore the LANMan response field */
65 /* We use MS_CHAP_RESPONSE_LEN, rather than sizeof(MS_ChapResponse),
66 in case this struct gets padded. */
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 *));
75 static void ChapMS_LANMan __P((char *, int, char *, int, MS_ChapResponse *));
79 static void Expand __P((u_char *, u_char *));
80 static void Collapse __P((u_char *, u_char *));
84 bool ms_lanman = 0; /* Use LanMan password instead of NT */
85 /* Has meaning only with MS-CHAP challenges */
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 */
94 char ZPasswordHash[21];
96 BZERO(ZPasswordHash, sizeof(ZPasswordHash));
97 BCOPY(pwHash, ZPasswordHash, MD4_SIGNATURE_SIZE);
100 dbglog("ChallengeResponse - ZPasswordHash %.*B",
101 sizeof(ZPasswordHash), ZPasswordHash);
104 DesEncrypt(challenge, ZPasswordHash + 0, response + 0);
105 DesEncrypt(challenge, ZPasswordHash + 7, response + 8);
106 DesEncrypt(challenge, ZPasswordHash + 14, response + 16);
109 dbglog("ChallengeResponse - response %.24B", response);
116 DesEncrypt(clear, key, cipher)
117 u_char *clear; /* IN 8 octets */
118 u_char *key; /* IN 7 octets */
119 u_char *cipher; /* OUT 8 octets */
122 u_char crypt_key[66];
123 u_char des_input[66];
125 MakeKey(key, des_key);
127 Expand(des_key, crypt_key);
131 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet input : %.8B", clear));
134 Expand(clear, des_input);
135 encrypt(des_input, 0);
136 Collapse(des_input, cipher);
139 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet output: %.8B", cipher));
143 #else /* USE_CRYPT */
146 DesEncrypt(clear, key, cipher)
147 u_char *clear; /* IN 8 octets */
148 u_char *key; /* IN 7 octets */
149 u_char *cipher; /* OUT 8 octets */
152 des_key_schedule key_schedule;
154 MakeKey(key, des_key);
156 des_set_key(&des_key, key_schedule);
159 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet input : %.8B", clear));
162 des_ecb_encrypt((des_cblock *)clear, (des_cblock *)cipher, key_schedule, 1);
165 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet output: %.8B", cipher));
169 #endif /* USE_CRYPT */
172 static u_char Get7Bits(input, startBit)
176 register unsigned int word;
178 word = (unsigned)input[startBit / 8] << 8;
179 word |= (unsigned)input[startBit / 8 + 1];
181 word >>= 15 - (startBit % 8 + 7);
188 /* in == 8-byte string (expanded version of the 56-bit key)
189 * out == 64-byte string where each byte is either 1 or 0
190 * Note that the low-order "bit" is always ignored by by setkey()
192 static void Expand(in, out)
199 for(i = 0; i < 64; in++){
201 for(j = 7; j >= 0; j--)
202 *out++ = (c >> j) & 01;
207 /* The inverse of Expand
209 static void Collapse(in, out)
217 for (i = 0; i < 64; i += 8, out++) {
219 for (j = 7; j >= 0; j--, in++)
226 static void MakeKey(key, des_key)
227 u_char *key; /* IN 56 bit DES key missing parity bits */
228 u_char *des_key; /* OUT 64 bit DES key with parity bits added */
230 des_key[0] = Get7Bits(key, 0);
231 des_key[1] = Get7Bits(key, 7);
232 des_key[2] = Get7Bits(key, 14);
233 des_key[3] = Get7Bits(key, 21);
234 des_key[4] = Get7Bits(key, 28);
235 des_key[5] = Get7Bits(key, 35);
236 des_key[6] = Get7Bits(key, 42);
237 des_key[7] = Get7Bits(key, 49);
240 des_set_odd_parity((des_cblock *)des_key);
244 CHAPDEBUG((LOG_INFO, "MakeKey: 56-bit input : %.7B", key));
245 CHAPDEBUG((LOG_INFO, "MakeKey: 64-bit output: %.8B", des_key));
250 ChapMS_NT(rchallenge, rchallenge_len, secret, secret_len, response)
255 MS_ChapResponse *response;
259 /* NetBSD uses the libc md4 routines which take bytes instead of bits */
260 int mdlen = secret_len * 2;
262 int mdlen = secret_len * 2 * 8;
265 u_char hash[MD4_SIGNATURE_SIZE];
266 u_char unicodePassword[MAX_NT_PASSWORD * 2];
268 /* Initialize the Unicode version of the secret (== password). */
269 /* This implicitly supports 8-bit ISO8859/1 characters. */
270 BZERO(unicodePassword, sizeof(unicodePassword));
271 for (i = 0; i < secret_len; i++)
272 unicodePassword[i * 2] = (u_char)secret[i];
274 MD4Init(&md4Context);
275 MD4Update(&md4Context, unicodePassword, mdlen);
277 MD4Final(hash, &md4Context); /* Tell MD4 we're done */
279 ChallengeResponse(rchallenge, hash, response->NTResp);
283 static u_char *StdText = (u_char *)"KGS!@#$%"; /* key from rasapi32.dll */
286 ChapMS_LANMan(rchallenge, rchallenge_len, secret, secret_len, response)
291 MS_ChapResponse *response;
294 u_char UcasePassword[MAX_NT_PASSWORD]; /* max is actually 14 */
295 u_char PasswordHash[MD4_SIGNATURE_SIZE];
297 /* LANMan password is case insensitive */
298 BZERO(UcasePassword, sizeof(UcasePassword));
299 for (i = 0; i < secret_len; i++)
300 UcasePassword[i] = (u_char)toupper(secret[i]);
301 DesEncrypt( StdText, UcasePassword + 0, PasswordHash + 0 );
302 DesEncrypt( StdText, UcasePassword + 7, PasswordHash + 8 );
303 ChallengeResponse(rchallenge, PasswordHash, response->LANManResp);
308 ChapMS(cstate, rchallenge, rchallenge_len, secret, secret_len)
315 MS_ChapResponse response;
318 CHAPDEBUG((LOG_INFO, "ChapMS: secret is '%.*s'", secret_len, secret));
320 BZERO(&response, sizeof(response));
322 /* Calculate both always */
323 ChapMS_NT(rchallenge, rchallenge_len, secret, secret_len, &response);
326 ChapMS_LANMan(rchallenge, rchallenge_len, secret, secret_len, &response);
328 /* prefered method is set by option */
329 response.UseNT = !ms_lanman;
334 BCOPY(&response, cstate->response, MS_CHAP_RESPONSE_LEN);
335 cstate->resp_length = MS_CHAP_RESPONSE_LEN;