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/*** WARNING - THIS CODE HAS NOT BEEN FINISHED! ***/
/*** The original PPPD code is written in a way to require either the UNIX DES
encryption functions encrypt(3) and setkey(3) or the DES library libdes.
Since both is not included in lwIP, MSCHAP currently does not work! */
/*****************************************************************************
* chpms.c - Network MicroSoft Challenge Handshake Authentication Protocol program file.
*
* Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
* Copyright (c) 1997 by Global Election Systems Inc. All rights reserved.
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice and the following disclaimer are included verbatim in any
* distributions. No written agreement, license, or royalty fee is required
* for any of the authorized uses.
*
* THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
******************************************************************************
* REVISION HISTORY
*
* 03-01-01 Marc Boucher <marc@mbsi.ca>
* Ported to lwIP.
* 97-12-08 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.
* Original based on BSD chap_ms.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
*/
#define USE_CRYPT
#include "lwip/opt.h"
#if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */
#if MSCHAP_SUPPORT /* don't build if not configured for use in lwipopts.h */
#include "ppp_impl.h"
#include "pppdebug.h"
#include "md4.h"
#ifndef USE_CRYPT
#include "des.h"
#endif
#include "chap.h"
#include "chpms.h"
#include <string.h>
/*************************/
/*** LOCAL DEFINITIONS ***/
/*************************/
/************************/
/*** LOCAL DATA TYPES ***/
/************************/
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. */
/***********************************/
/*** LOCAL FUNCTION DECLARATIONS ***/
/***********************************/
/* XXX Don't know what to do with these. */
extern void setkey(const char *);
extern void encrypt(char *, int);
static void DesEncrypt (u_char *, u_char *, u_char *);
static void MakeKey (u_char *, u_char *);
#ifdef USE_CRYPT
static void Expand (u_char *, u_char *);
static void Collapse (u_char *, u_char *);
#endif
static void ChallengeResponse(
u_char *challenge, /* IN 8 octets */
u_char *pwHash, /* IN 16 octets */
u_char *response /* OUT 24 octets */
);
static void ChapMS_NT(
char *rchallenge,
int rchallenge_len,
char *secret,
int secret_len,
MS_ChapResponse *response
);
static u_char Get7Bits(
u_char *input,
int startBit
);
static void
ChallengeResponse( u_char *challenge, /* IN 8 octets */
u_char *pwHash, /* IN 16 octets */
u_char *response /* OUT 24 octets */)
{
u_char ZPasswordHash[21];
BZERO(ZPasswordHash, sizeof(ZPasswordHash));
BCOPY(pwHash, ZPasswordHash, 16);
#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( 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((char*)crypt_key);
#if 0
CHAPDEBUG(LOG_INFO, ("DesEncrypt: 8 octet input : %02X%02X%02X%02X%02X%02X%02X%02X\n",
clear[0], clear[1], clear[2], clear[3], clear[4], clear[5], clear[6], clear[7]));
#endif
Expand(clear, des_input);
encrypt((char*)des_input, 0);
Collapse(des_input, cipher);
#if 0
CHAPDEBUG(LOG_INFO, ("DesEncrypt: 8 octet output: %02X%02X%02X%02X%02X%02X%02X%02X\n",
cipher[0], cipher[1], cipher[2], cipher[3], cipher[4], cipher[5], cipher[6], cipher[7]));
#endif
}
#else /* USE_CRYPT */
static void
DesEncrypt( 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\n",
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\n",
cipher[0], cipher[1], cipher[2], cipher[3], cipher[4], cipher[5], cipher[6], cipher[7]));
#endif
}
#endif /* USE_CRYPT */
static u_char
Get7Bits( 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(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(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( 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\n",
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\n",
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( char *rchallenge,
int rchallenge_len,
char *secret,
int secret_len,
MS_ChapResponse *response)
{
int i;
MDstruct md4Context;
u_char unicodePassword[MAX_NT_PASSWORD * 2];
static int low_byte_first = -1;
LWIP_UNUSED_ARG(rchallenge_len);
/* 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];
}
MDbegin(&md4Context);
MDupdate(&md4Context, unicodePassword, secret_len * 2 * 8); /* Unicode is 2 bytes/char, *8 for bit count */
if (low_byte_first == -1) {
low_byte_first = (PP_HTONS((unsigned short int)1) != 1);
}
if (low_byte_first == 0) {
/* @todo: arg type - u_long* or u_int* ? */
MDreverse((unsigned int*)&md4Context); /* sfb 961105 */
}
MDupdate(&md4Context, NULL, 0); /* Tell MD4 we're done */
ChallengeResponse((u_char*)rchallenge, (u_char*)md4Context.buffer, response->NTResp);
}
#ifdef MSLANMAN
static u_char *StdText = (u_char *)"KGS!@#$%"; /* key from rasapi32.dll */
static void
ChapMS_LANMan( 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[16];
/* 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( 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'\n", 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 /* MSCHAP_SUPPORT */
#endif /* PPP_SUPPORT */