/* $OpenBSD: chap_ms.c,v 1.9 2004/06/29 22:04:44 millert Exp $ */ /* * chap_ms.c - Microsoft MS-CHAP compatible implementation. * * Copyright (c) 1995 Eric Rosenquist. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. The name(s) of the authors of this software must not be used to * endorse or promote products derived from this software without * prior written permission. * * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /* * Modifications by Lauri Pesonen / lpesonen@clinet.fi, april 1997 * * Implemented LANManager type password response to MS-CHAP challenges. * Now pppd provides both NT style and LANMan style blocks, and the * prefered is set by option "ms-lanman". Default is to use NT. * The hash text (StdText) was taken from Win95 RASAPI32.DLL. * * You should also use DOMAIN\\USERNAME as described in README.MSCHAP80 */ #ifndef lint #if 0 static char rcsid[] = "Id: chap_ms.c,v 1.8 1998/04/01 00:15:43 paulus Exp $"; #else static char rcsid[] = "$OpenBSD: chap_ms.c,v 1.9 2004/06/29 22:04:44 millert Exp $"; #endif #endif #ifdef CHAPMS #include #include #include #include #include #include #include #include #ifdef HAVE_CRYPT_H #include #endif #include "pppd.h" #include "chap.h" #include "chap_ms.h" #ifndef USE_CRYPT #include #endif typedef struct { u_char LANManResp[24]; u_char NTResp[24]; u_char UseNT; /* If 1, ignore the LANMan response field */ } MS_ChapResponse; /* We use MS_CHAP_RESPONSE_LEN, rather than sizeof(MS_ChapResponse), in case this struct gets padded. */ static void ChallengeResponse(u_char *, u_char *, u_char *); static void DesEncrypt(u_char *, u_char *, u_char *); static void MakeKey(u_char *, u_char *); static u_char Get7Bits(u_char *, int); static void ChapMS_NT(char *, int, char *, int, MS_ChapResponse *); #ifdef MSLANMAN static void ChapMS_LANMan(char *, int, char *, int, MS_ChapResponse *); #endif #ifdef USE_CRYPT static void Expand(u_char *, u_char *); static void Collapse(u_char *, u_char *); #endif static void ChallengeResponse(challenge, pwHash, response) u_char *challenge; /* IN 8 octets */ u_char *pwHash; /* IN 16 octets */ u_char *response; /* OUT 24 octets */ { char ZPasswordHash[21]; BZERO(ZPasswordHash, sizeof(ZPasswordHash)); BCOPY(pwHash, ZPasswordHash, MD4_SIGNATURE_SIZE); #if 0 log_packet(ZPasswordHash, sizeof(ZPasswordHash), "ChallengeResponse - ZPasswordHash", LOG_DEBUG); #endif DesEncrypt(challenge, ZPasswordHash + 0, response + 0); DesEncrypt(challenge, ZPasswordHash + 7, response + 8); DesEncrypt(challenge, ZPasswordHash + 14, response + 16); #if 0 log_packet(response, 24, "ChallengeResponse - response", LOG_DEBUG); #endif } #ifdef USE_CRYPT static void DesEncrypt(clear, key, cipher) u_char *clear; /* IN 8 octets */ u_char *key; /* IN 7 octets */ u_char *cipher; /* OUT 8 octets */ { u_char des_key[8]; u_char crypt_key[66]; u_char des_input[66]; MakeKey(key, des_key); Expand(des_key, crypt_key); setkey(crypt_key); #if 0 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet input : %02X%02X%02X%02X%02X%02X%02X%02X", clear[0], clear[1], clear[2], clear[3], clear[4], clear[5], clear[6], clear[7])); #endif Expand(clear, des_input); encrypt(des_input, 0); Collapse(des_input, cipher); #if 0 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet output: %02X%02X%02X%02X%02X%02X%02X%02X", cipher[0], cipher[1], cipher[2], cipher[3], cipher[4], cipher[5], cipher[6], cipher[7])); #endif } #else /* USE_CRYPT */ static void DesEncrypt(clear, key, cipher) u_char *clear; /* IN 8 octets */ u_char *key; /* IN 7 octets */ u_char *cipher; /* OUT 8 octets */ { des_cblock des_key; des_key_schedule key_schedule; MakeKey(key, des_key); des_set_key(&des_key, key_schedule); #if 0 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet input : %02X%02X%02X%02X%02X%02X%02X%02X", clear[0], clear[1], clear[2], clear[3], clear[4], clear[5], clear[6], clear[7])); #endif des_ecb_encrypt((des_cblock *)clear, (des_cblock *)cipher, key_schedule, 1); #if 0 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet output: %02X%02X%02X%02X%02X%02X%02X%02X", cipher[0], cipher[1], cipher[2], cipher[3], cipher[4], cipher[5], cipher[6], cipher[7])); #endif } #endif /* USE_CRYPT */ static u_char Get7Bits(input, startBit) u_char *input; int startBit; { unsigned int word; word = (unsigned)input[startBit / 8] << 8; word |= (unsigned)input[startBit / 8 + 1]; word >>= 15 - (startBit % 8 + 7); return word & 0xFE; } #ifdef USE_CRYPT /* in == 8-byte string (expanded version of the 56-bit key) * out == 64-byte string where each byte is either 1 or 0 * Note that the low-order "bit" is always ignored by by setkey() */ static void Expand(in, out) u_char *in; u_char *out; { int j, c; int i; for(i = 0; i < 64; in++){ c = *in; for(j = 7; j >= 0; j--) *out++ = (c >> j) & 01; i += 8; } } /* The inverse of Expand */ static void Collapse(in, out) u_char *in; u_char *out; { int j; int i; unsigned int c; for (i = 0; i < 64; i += 8, out++) { c = 0; for (j = 7; j >= 0; j--, in++) c |= *in << j; *out = c & 0xff; } } #endif static void MakeKey(key, des_key) u_char *key; /* IN 56 bit DES key missing parity bits */ u_char *des_key; /* OUT 64 bit DES key with parity bits added */ { des_key[0] = Get7Bits(key, 0); des_key[1] = Get7Bits(key, 7); des_key[2] = Get7Bits(key, 14); des_key[3] = Get7Bits(key, 21); des_key[4] = Get7Bits(key, 28); des_key[5] = Get7Bits(key, 35); des_key[6] = Get7Bits(key, 42); des_key[7] = Get7Bits(key, 49); #ifndef USE_CRYPT des_set_odd_parity((des_cblock *)des_key); #endif #if 0 CHAPDEBUG((LOG_INFO, "MakeKey: 56-bit input : %02X%02X%02X%02X%02X%02X%02X", key[0], key[1], key[2], key[3], key[4], key[5], key[6])); CHAPDEBUG((LOG_INFO, "MakeKey: 64-bit output: %02X%02X%02X%02X%02X%02X%02X%02X", des_key[0], des_key[1], des_key[2], des_key[3], des_key[4], des_key[5], des_key[6], des_key[7])); #endif } static void ChapMS_NT(rchallenge, rchallenge_len, secret, secret_len, response) char *rchallenge; int rchallenge_len; char *secret; int secret_len; MS_ChapResponse *response; { int i; MD4_CTX md4Context; u_char hash[MD4_SIGNATURE_SIZE]; u_char unicodePassword[MAX_NT_PASSWORD * 2]; /* Initialize the Unicode version of the secret (== password). */ /* This implicitly supports 8-bit ISO8859/1 characters. */ BZERO(unicodePassword, sizeof(unicodePassword)); for (i = 0; i < secret_len; i++) unicodePassword[i * 2] = (u_char)secret[i]; MD4Init(&md4Context); #ifdef __OpenBSD__ MD4Update(&md4Context, unicodePassword, secret_len * 2); /* Unicode is 2 bytes/char */ #else MD4Update(&md4Context, unicodePassword, secret_len * 2 * 8); /* Unicode is 2 bytes/char, *8 for bit count */ #endif MD4Final(hash, &md4Context); /* Tell MD4 we're done */ ChallengeResponse(rchallenge, hash, response->NTResp); } #ifdef MSLANMAN static u_char *StdText = (u_char *)"KGS!@#$%"; /* key from rasapi32.dll */ static void ChapMS_LANMan(rchallenge, rchallenge_len, secret, secret_len, response) char *rchallenge; int rchallenge_len; char *secret; int secret_len; MS_ChapResponse *response; { int i; u_char UcasePassword[MAX_NT_PASSWORD]; /* max is actually 14 */ u_char PasswordHash[MD4_SIGNATURE_SIZE]; /* LANMan password is case insensitive */ BZERO(UcasePassword, sizeof(UcasePassword)); for (i = 0; i < secret_len; i++) UcasePassword[i] = (u_char)toupper(secret[i]); DesEncrypt( StdText, UcasePassword + 0, PasswordHash + 0 ); DesEncrypt( StdText, UcasePassword + 7, PasswordHash + 8 ); ChallengeResponse(rchallenge, PasswordHash, response->LANManResp); } #endif void ChapMS(cstate, rchallenge, rchallenge_len, secret, secret_len) chap_state *cstate; char *rchallenge; int rchallenge_len; char *secret; int secret_len; { MS_ChapResponse response; #ifdef MSLANMAN extern int ms_lanman; #endif #if 0 CHAPDEBUG((LOG_INFO, "ChapMS: secret is '%.*s'", secret_len, secret)); #endif BZERO(&response, sizeof(response)); /* Calculate both always */ ChapMS_NT(rchallenge, rchallenge_len, secret, secret_len, &response); #ifdef MSLANMAN ChapMS_LANMan(rchallenge, rchallenge_len, secret, secret_len, &response); /* prefered method is set by option */ response.UseNT = !ms_lanman; #else response.UseNT = 1; #endif BCOPY(&response, cstate->response, MS_CHAP_RESPONSE_LEN); cstate->resp_length = MS_CHAP_RESPONSE_LEN; } #endif /* CHAPMS */