FreeBSD-5.3/usr.sbin/ppp/chap_ms.c
/*-
* Copyright (c) 1997 Gabor Kincses <gabor@acm.org>
* 1997 - 2001 Brian Somers <brian@Awfulhak.org>
* based on work by Eric Rosenquist
* Strata Software Limited.
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND 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 AUTHOR OR 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.
*
* $FreeBSD: src/usr.sbin/ppp/chap_ms.c,v 1.19 2002/06/15 08:03:29 brian Exp $
*/
#include <ctype.h>
#ifdef __FreeBSD__
#include <openssl/des.h>
#include <sha.h>
#else
#include <sys/types.h>
#include <stdlib.h>
#ifdef __NetBSD__
#include <openssl/des.h>
#else
#include <des.h>
#endif
#include <openssl/sha.h>
#endif
#include <md4.h>
#include <string.h>
#include "chap_ms.h"
/*
* Documentation & specifications:
*
* MS-CHAP (CHAP80) rfc2433
* MS-CHAP-V2 (CHAP81) rfc2759
* MPPE key management draft-ietf-pppext-mppe-keys-02.txt
*/
static char SHA1_Pad1[40] =
{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
static char SHA1_Pad2[40] =
{0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2,
0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2,
0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2,
0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2, 0xF2};
/* unused, for documentation only */
/* only NTResp is filled in for FreeBSD */
struct MS_ChapResponse {
u_char LANManResp[24];
u_char NTResp[24];
u_char UseNT; /* If 1, ignore the LANMan response field */
};
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;
}
/* IN 56 bit DES key missing parity bits
OUT 64 bit DES key with parity bits added */
static void
MakeKey(u_char *key, u_char *des_key)
{
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);
des_set_odd_parity((des_cblock *)des_key);
}
static void /* IN 8 octets IN 7 octest OUT 8 octets */
DesEncrypt(u_char *clear, u_char *key, u_char *cipher)
{
des_cblock des_key;
des_key_schedule key_schedule;
MakeKey(key, des_key);
des_set_key(&des_key, key_schedule);
des_ecb_encrypt((des_cblock *)clear, (des_cblock *)cipher, key_schedule, 1);
}
static void /* IN 8 octets IN 16 octets OUT 24 octets */
ChallengeResponse(u_char *challenge, u_char *pwHash, u_char *response)
{
char ZPasswordHash[21];
memset(ZPasswordHash, '\0', sizeof ZPasswordHash);
memcpy(ZPasswordHash, pwHash, 16);
DesEncrypt(challenge, ZPasswordHash + 0, response + 0);
DesEncrypt(challenge, ZPasswordHash + 7, response + 8);
DesEncrypt(challenge, ZPasswordHash + 14, response + 16);
}
void
NtPasswordHash(char *key, int keylen, char *hash)
{
MD4_CTX MD4context;
MD4Init(&MD4context);
MD4Update(&MD4context, key, keylen);
MD4Final(hash, &MD4context);
}
void
HashNtPasswordHash(char *hash, char *hashhash)
{
MD4_CTX MD4context;
MD4Init(&MD4context);
MD4Update(&MD4context, hash, 16);
MD4Final(hashhash, &MD4context);
}
void
ChallengeHash(char *PeerChallenge, char *AuthenticatorChallenge,
char *UserName, int UserNameLen, char *Challenge)
{
SHA_CTX Context;
char Digest[SHA_DIGEST_LENGTH];
char *Name;
Name = strrchr(UserName, '\\');
if(NULL == Name)
Name = UserName;
else
Name++;
SHA1_Init(&Context);
SHA1_Update(&Context, PeerChallenge, 16);
SHA1_Update(&Context, AuthenticatorChallenge, 16);
SHA1_Update(&Context, Name, strlen(Name));
SHA1_Final(Digest, &Context);
memcpy(Challenge, Digest, 8);
}
void
GenerateNTResponse(char *AuthenticatorChallenge, char *PeerChallenge,
char *UserName, int UserNameLen, char *Password,
int PasswordLen, char *Response)
{
char Challenge[8];
char PasswordHash[16];
ChallengeHash(PeerChallenge, AuthenticatorChallenge, UserName, UserNameLen,
Challenge);
NtPasswordHash(Password, PasswordLen, PasswordHash);
ChallengeResponse(Challenge, PasswordHash, Response);
}
#ifndef __FreeBSD__
#define LENGTH 20
static char *
SHA1_End(SHA_CTX *ctx, char *buf)
{
int i;
unsigned char digest[LENGTH];
static const char hex[]="0123456789abcdef";
if (!buf)
buf = malloc(2*LENGTH + 1);
if (!buf)
return 0;
SHA1_Final(digest, ctx);
for (i = 0; i < LENGTH; i++) {
buf[i+i] = hex[digest[i] >> 4];
buf[i+i+1] = hex[digest[i] & 0x0f];
}
buf[i+i] = '\0';
return buf;
}
#endif
void
GenerateAuthenticatorResponse(char *Password, int PasswordLen,
char *NTResponse, char *PeerChallenge,
char *AuthenticatorChallenge, char *UserName,
int UserNameLen, char *AuthenticatorResponse)
{
SHA_CTX Context;
char PasswordHash[16];
char PasswordHashHash[16];
char Challenge[8];
u_char Digest[SHA_DIGEST_LENGTH];
int i;
/*
* "Magic" constants used in response generation
*/
char Magic1[39] =
{0x4D, 0x61, 0x67, 0x69, 0x63, 0x20, 0x73, 0x65, 0x72, 0x76,
0x65, 0x72, 0x20, 0x74, 0x6F, 0x20, 0x63, 0x6C, 0x69, 0x65,
0x6E, 0x74, 0x20, 0x73, 0x69, 0x67, 0x6E, 0x69, 0x6E, 0x67,
0x20, 0x63, 0x6F, 0x6E, 0x73, 0x74, 0x61, 0x6E, 0x74};
char Magic2[41] =
{0x50, 0x61, 0x64, 0x20, 0x74, 0x6F, 0x20, 0x6D, 0x61, 0x6B,
0x65, 0x20, 0x69, 0x74, 0x20, 0x64, 0x6F, 0x20, 0x6D, 0x6F,
0x72, 0x65, 0x20, 0x74, 0x68, 0x61, 0x6E, 0x20, 0x6F, 0x6E,
0x65, 0x20, 0x69, 0x74, 0x65, 0x72, 0x61, 0x74, 0x69, 0x6F,
0x6E};
/*
* Hash the password with MD4
*/
NtPasswordHash(Password, PasswordLen, PasswordHash);
/*
* Now hash the hash
*/
HashNtPasswordHash(PasswordHash, PasswordHashHash);
SHA1_Init(&Context);
SHA1_Update(&Context, PasswordHashHash, 16);
SHA1_Update(&Context, NTResponse, 24);
SHA1_Update(&Context, Magic1, 39);
SHA1_Final(Digest, &Context);
ChallengeHash(PeerChallenge, AuthenticatorChallenge, UserName, UserNameLen,
Challenge);
SHA1_Init(&Context);
SHA1_Update(&Context, Digest, 20);
SHA1_Update(&Context, Challenge, 8);
SHA1_Update(&Context, Magic2, 41);
/*
* Encode the value of 'Digest' as "S=" followed by
* 40 ASCII hexadecimal digits and return it in
* AuthenticatorResponse.
* For example,
* "S=0123456789ABCDEF0123456789ABCDEF01234567"
*/
AuthenticatorResponse[0] = 'S';
AuthenticatorResponse[1] = '=';
SHA1_End(&Context, AuthenticatorResponse + 2);
for (i=2; i<42; i++)
AuthenticatorResponse[i] = toupper(AuthenticatorResponse[i]);
}
void
GetMasterKey(char *PasswordHashHash, char *NTResponse, char *MasterKey)
{
char Digest[SHA_DIGEST_LENGTH];
SHA_CTX Context;
static char Magic1[27] =
{0x54, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74,
0x68, 0x65, 0x20, 0x4d, 0x50, 0x50, 0x45, 0x20, 0x4d,
0x61, 0x73, 0x74, 0x65, 0x72, 0x20, 0x4b, 0x65, 0x79};
SHA1_Init(&Context);
SHA1_Update(&Context, PasswordHashHash, 16);
SHA1_Update(&Context, NTResponse, 24);
SHA1_Update(&Context, Magic1, 27);
SHA1_Final(Digest, &Context);
memcpy(MasterKey, Digest, 16);
}
void
GetAsymetricStartKey(char *MasterKey, char *SessionKey, int SessionKeyLength,
int IsSend, int IsServer)
{
char Digest[SHA_DIGEST_LENGTH];
SHA_CTX Context;
char *s;
static char Magic2[84] =
{0x4f, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x69,
0x65, 0x6e, 0x74, 0x20, 0x73, 0x69, 0x64, 0x65, 0x2c, 0x20,
0x74, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68,
0x65, 0x20, 0x73, 0x65, 0x6e, 0x64, 0x20, 0x6b, 0x65, 0x79,
0x3b, 0x20, 0x6f, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x73,
0x65, 0x72, 0x76, 0x65, 0x72, 0x20, 0x73, 0x69, 0x64, 0x65,
0x2c, 0x20, 0x69, 0x74, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68,
0x65, 0x20, 0x72, 0x65, 0x63, 0x65, 0x69, 0x76, 0x65, 0x20,
0x6b, 0x65, 0x79, 0x2e};
static char Magic3[84] =
{0x4f, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x69,
0x65, 0x6e, 0x74, 0x20, 0x73, 0x69, 0x64, 0x65, 0x2c, 0x20,
0x74, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68,
0x65, 0x20, 0x72, 0x65, 0x63, 0x65, 0x69, 0x76, 0x65, 0x20,
0x6b, 0x65, 0x79, 0x3b, 0x20, 0x6f, 0x6e, 0x20, 0x74, 0x68,
0x65, 0x20, 0x73, 0x65, 0x72, 0x76, 0x65, 0x72, 0x20, 0x73,
0x69, 0x64, 0x65, 0x2c, 0x20, 0x69, 0x74, 0x20, 0x69, 0x73,
0x20, 0x74, 0x68, 0x65, 0x20, 0x73, 0x65, 0x6e, 0x64, 0x20,
0x6b, 0x65, 0x79, 0x2e};
if (IsSend) {
if (IsServer) {
s = Magic3;
} else {
s = Magic2;
}
} else {
if (IsServer) {
s = Magic2;
} else {
s = Magic3;
}
}
SHA1_Init(&Context);
SHA1_Update(&Context, MasterKey, 16);
SHA1_Update(&Context, SHA1_Pad1, 40);
SHA1_Update(&Context, s, 84);
SHA1_Update(&Context, SHA1_Pad2, 40);
SHA1_Final(Digest, &Context);
memcpy(SessionKey, Digest, SessionKeyLength);
}
void
GetNewKeyFromSHA(char *StartKey, char *SessionKey, long SessionKeyLength,
char *InterimKey)
{
SHA_CTX Context;
char Digest[SHA_DIGEST_LENGTH];
SHA1_Init(&Context);
SHA1_Update(&Context, StartKey, SessionKeyLength);
SHA1_Update(&Context, SHA1_Pad1, 40);
SHA1_Update(&Context, SessionKey, SessionKeyLength);
SHA1_Update(&Context, SHA1_Pad2, 40);
SHA1_Final(Digest, &Context);
memcpy(InterimKey, Digest, SessionKeyLength);
}
#if 0
static void
Get_Key(char *InitialSessionKey, char *CurrentSessionKey,
int LengthOfDesiredKey)
{
SHA_CTX Context;
char Digest[SHA_DIGEST_LENGTH];
SHA1_Init(&Context);
SHA1_Update(&Context, InitialSessionKey, LengthOfDesiredKey);
SHA1_Update(&Context, SHA1_Pad1, 40);
SHA1_Update(&Context, CurrentSessionKey, LengthOfDesiredKey);
SHA1_Update(&Context, SHA1_Pad2, 40);
SHA1_Final(Digest, &Context);
memcpy(CurrentSessionKey, Digest, LengthOfDesiredKey);
}
#endif
/* passwordHash 16-bytes MD4 hashed password
challenge 8-bytes peer CHAP challenge
since passwordHash is in a 24-byte buffer, response is written in there */
void
mschap_NT(char *passwordHash, char *challenge)
{
u_char response[24];
ChallengeResponse(challenge, passwordHash, response);
memcpy(passwordHash, response, 24);
passwordHash[24] = 1; /* NT-style response */
}
void
mschap_LANMan(char *digest, char *challenge, char *secret)
{
static u_char salt[] = "KGS!@#$%"; /* RASAPI32.dll */
char SECRET[14], *ptr, *end;
u_char hash[16];
end = SECRET + sizeof SECRET;
for (ptr = SECRET; *secret && ptr < end; ptr++, secret++)
*ptr = toupper(*secret);
if (ptr < end)
memset(ptr, '\0', end - ptr);
DesEncrypt(salt, SECRET, hash);
DesEncrypt(salt, SECRET + 7, hash + 8);
ChallengeResponse(challenge, hash, digest);
}