freebsd-dev/usr.sbin/pppd/chap_ms.c
John Polstra 9836a38f7b Fix the MS-CHAP support. The code was passing a bit count to
MD4Update(), but our version in libmd expects a byte count.

This code is not currently compiled or linked into pppd, so I'm
reasonably sure I didn't break anything. :-)  I added the necessary
statements to the Makefile, but left them commented out because we
are in feature freeze.  When the code is enabled, we must be careful
to build it only if the DES library is available.
1998-10-11 19:40:38 +00:00

336 lines
9.1 KiB
C

/*
* chap_ms.c - Microsoft MS-CHAP compatible implementation.
*
* Copyright (c) 1995 Eric Rosenquist, Strata Software Limited.
* http://www.strataware.com/
*
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by Eric Rosenquist. The name of the author may not be used to
* endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
/*
* 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
static char rcsid[] = "$Id: chap_ms.c,v 1.5 1998/06/20 18:02:09 peter Exp $";
#endif
#ifdef CHAPMS
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/time.h>
#include <syslog.h>
#include <unistd.h>
#ifdef HAVE_CRYPT_H
#include <crypt.h>
#endif
#include "pppd.h"
#include "chap.h"
#include "chap_ms.h"
#include "md4.h"
#ifndef USE_CRYPT
#include <des.h>
#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 __P((u_char *, u_char *, u_char *));
static void DesEncrypt __P((u_char *, u_char *, u_char *));
static void MakeKey __P((u_char *, u_char *));
static u_char Get7Bits __P((u_char *, int));
static void ChapMS_NT __P((char *, int, char *, int, MS_ChapResponse *));
#ifdef MSLANMAN
static void ChapMS_LANMan __P((char *, int, char *, int, MS_ChapResponse *));
#endif
#ifdef USE_CRYPT
static void Expand __P((u_char *, u_char *));
static void Collapse __P((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;
{
register 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);
MD4Update(&md4Context, unicodePassword, secret_len * 2); /* Unicode is 2 bytes/char */
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 */