/*
* 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
*/
/*
* Modifications by Frank Cusack, frank@google.com, March 2002.
*
* Implemented MS-CHAPv2 functionality, heavily based on sample
* implementation in RFC 2759. Implemented MPPE functionality,
* heavily based on sample implementation in RFC 3079.
*
* Copyright (c) 2002 The Android Open Source Project
*
* 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.
*
*/
#define RCSID "$Id: chap_ms.c,v 1.33 2004/11/12 09:57:43 paulus Exp $"
#ifdef CHAPMS
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/time.h>
#include <unistd.h>
#include "pppd.h"
#include "chap-new.h"
#include "chap_ms.h"
#ifdef ANDROID_CHANGES
#include "openssl-hash.h"
#else
#include "md4.h"
#include "sha1.h"
#endif
#include "pppcrypt.h"
#include "magic.h"
static const char rcsid[] = RCSID;
static void ascii2unicode __P((char[], int, u_char[]));
static void NTPasswordHash __P((char *, int, u_char[MD4_SIGNATURE_SIZE]));
static void ChallengeResponse __P((u_char *, u_char *, u_char[24]));
static void ChapMS_NT __P((u_char *, char *, int, u_char[24]));
static void ChapMS2_NT __P((char *, u_char[16], char *, char *, int,
u_char[24]));
static void GenerateAuthenticatorResponsePlain
__P((char*, int, u_char[24], u_char[16], u_char *,
char *, u_char[41]));
#ifdef MSLANMAN
static void ChapMS_LANMan __P((u_char *, char *, int, MS_ChapResponse *));
#endif
#ifdef MPPE
static void Set_Start_Key __P((u_char *, char *, int));
static void SetMasterKeys __P((char *, int, u_char[24], int));
#endif
#ifdef MSLANMAN
bool ms_lanman = 0; /* Use LanMan password instead of NT */
/* Has meaning only with MS-CHAP challenges */
#endif
#ifdef MPPE
u_char mppe_send_key[MPPE_MAX_KEY_LEN];
u_char mppe_recv_key[MPPE_MAX_KEY_LEN];
int mppe_keys_set = 0; /* Have the MPPE keys been set? */
#ifdef DEBUGMPPEKEY
/* For MPPE debug */
/* Use "[]|}{?/><,`!2&&(" (sans quotes) for RFC 3079 MS-CHAPv2 test value */
static char *mschap_challenge = NULL;
/* Use "!@\#$%^&*()_+:3|~" (sans quotes, backslash is to escape #) for ... */
static char *mschap2_peer_challenge = NULL;
#endif
#include "fsm.h" /* Need to poke MPPE options */
#include "ccp.h"
#include <net/ppp-comp.h>
#endif
/*
* Command-line options.
*/
static option_t chapms_option_list[] = {
#ifdef MSLANMAN
{ "ms-lanman", o_bool, &ms_lanman,
"Use LanMan passwd when using MS-CHAP", 1 },
#endif
#ifdef DEBUGMPPEKEY
{ "mschap-challenge", o_string, &mschap_challenge,
"specify CHAP challenge" },
{ "mschap2-peer-challenge", o_string, &mschap2_peer_challenge,
"specify CHAP peer challenge" },
#endif
{ NULL }
};
/*
* chapms_generate_challenge - generate a challenge for MS-CHAP.
* For MS-CHAP the challenge length is fixed at 8 bytes.
* The length goes in challenge[0] and the actual challenge starts
* at challenge[1].
*/
static void
chapms_generate_challenge(unsigned char *challenge)
{
*challenge++ = 8;
#ifdef DEBUGMPPEKEY
if (mschap_challenge && strlen(mschap_challenge) == 8)
memcpy(challenge, mschap_challenge, 8);
else
#endif
random_bytes(challenge, 8);
}
static void
chapms2_generate_challenge(unsigned char *challenge)
{
*challenge++ = 16;
#ifdef DEBUGMPPEKEY
if (mschap_challenge && strlen(mschap_challenge) == 16)
memcpy(challenge, mschap_challenge, 16);
else
#endif
random_bytes(challenge, 16);
}
static int
chapms_verify_response(int id, char *name,
unsigned char *secret, int secret_len,
unsigned char *challenge, unsigned char *response,
char *message, int message_space)
{
MS_ChapResponse *rmd;
MS_ChapResponse md;
int diff;
int challenge_len, response_len;
challenge_len = *challenge++; /* skip length, is 8 */
response_len = *response++;
if (response_len != MS_CHAP_RESPONSE_LEN)
goto bad;
rmd = (MS_ChapResponse *) response;
#ifndef MSLANMAN
if (!rmd->UseNT[0]) {
/* Should really propagate this into the error packet. */
notice("Peer request for LANMAN auth not supported");
goto bad;
}
#endif
/* Generate the expected response. */
ChapMS(challenge, (char *)secret, secret_len, &md);
#ifdef MSLANMAN
/* Determine which part of response to verify against */
if (!rmd->UseNT[0])
diff = memcmp(&rmd->LANManResp, &md.LANManResp,
sizeof(md.LANManResp));
else
#endif
diff = memcmp(&rmd->NTResp, &md.NTResp, sizeof(md.NTResp));
if (diff == 0) {
slprintf(message, message_space, "Access granted");
return 1;
}
bad:
/* See comments below for MS-CHAP V2 */
slprintf(message, message_space, "E=691 R=1 C=%0.*B V=0",
challenge_len, challenge);
return 0;
}
static int
chapms2_verify_response(int id, char *name,
unsigned char *secret, int secret_len,
unsigned char *challenge, unsigned char *response,
char *message, int message_space)
{
MS_Chap2Response *rmd;
MS_Chap2Response md;
char saresponse[MS_AUTH_RESPONSE_LENGTH+1];
int challenge_len, response_len;
challenge_len = *challenge++; /* skip length, is 16 */
response_len = *response++;
if (response_len != MS_CHAP2_RESPONSE_LEN)
goto bad; /* not even the right length */
rmd = (MS_Chap2Response *) response;
/* Generate the expected response and our mutual auth. */
ChapMS2(challenge, rmd->PeerChallenge, name,
(char *)secret, secret_len, &md,
(unsigned char *)saresponse, MS_CHAP2_AUTHENTICATOR);
/* compare MDs and send the appropriate status */
/*
* Per RFC 2759, success message must be formatted as
* "S=<auth_string> M=<message>"
* where
* <auth_string> is the Authenticator Response (mutual auth)
* <message> is a text message
*
* However, some versions of Windows (win98 tested) do not know
* about the M=<message> part (required per RFC 2759) and flag
* it as an error (reported incorrectly as an encryption error
* to the user). Since the RFC requires it, and it can be
* useful information, we supply it if the peer is a conforming
* system. Luckily (?), win98 sets the Flags field to 0x04
* (contrary to RFC requirements) so we can use that to
* distinguish between conforming and non-conforming systems.
*
* Special thanks to Alex Swiridov <say@real.kharkov.ua> for
* help debugging this.
*/
if (memcmp(md.NTResp, rmd->NTResp, sizeof(md.NTResp)) == 0) {
if (rmd->Flags[0])
slprintf(message, message_space, "S=%s", saresponse);
else
slprintf(message, message_space, "S=%s M=%s",
saresponse, "Access granted");
return 1;
}
bad:
/*
* Failure message must be formatted as
* "E=e R=r C=c V=v M=m"
* where
* e = error code (we use 691, ERROR_AUTHENTICATION_FAILURE)
* r = retry (we use 1, ok to retry)
* c = challenge to use for next response, we reuse previous
* v = Change Password version supported, we use 0
* m = text message
*
* The M=m part is only for MS-CHAPv2. Neither win2k nor
* win98 (others untested) display the message to the user anyway.
* They also both ignore the E=e code.
*
* Note that it's safe to reuse the same challenge as we don't
* actually accept another response based on the error message
* (and no clients try to resend a response anyway).
*
* Basically, this whole bit is useless code, even the small
* implementation here is only because of overspecification.
*/
slprintf(message, message_space, "E=691 R=1 C=%0.*B V=0 M=%s",
challenge_len, challenge, "Access denied");
return 0;
}
static void
chapms_make_response(unsigned char *response, int id, char *our_name,
unsigned char *challenge, char *secret, int secret_len,
unsigned char *private)
{
challenge++; /* skip length, should be 8 */
*response++ = MS_CHAP_RESPONSE_LEN;
ChapMS(challenge, secret, secret_len, (MS_ChapResponse *) response);
}
static void
chapms2_make_response(unsigned char *response, int id, char *our_name,
unsigned char *challenge, char *secret, int secret_len,
unsigned char *private)
{
challenge++; /* skip length, should be 16 */
*response++ = MS_CHAP2_RESPONSE_LEN;
ChapMS2(challenge,
#ifdef DEBUGMPPEKEY
mschap2_peer_challenge,
#else
NULL,
#endif
our_name, secret, secret_len,
(MS_Chap2Response *) response, private,
MS_CHAP2_AUTHENTICATEE);
}
static int
chapms2_check_success(unsigned char *msg, int len, unsigned char *private)
{
if ((len < MS_AUTH_RESPONSE_LENGTH + 2) ||
strncmp((char *)msg, "S=", 2) != 0) {
/* Packet does not start with "S=" */
error("MS-CHAPv2 Success packet is badly formed.");
return 0;
}
msg += 2;
len -= 2;
if (len < MS_AUTH_RESPONSE_LENGTH
|| memcmp(msg, private, MS_AUTH_RESPONSE_LENGTH)) {
/* Authenticator Response did not match expected. */
error("MS-CHAPv2 mutual authentication failed.");
return 0;
}
/* Authenticator Response matches. */
msg += MS_AUTH_RESPONSE_LENGTH; /* Eat it */
len -= MS_AUTH_RESPONSE_LENGTH;
if ((len >= 3) && !strncmp((char *)msg, " M=", 3)) {
msg += 3; /* Eat the delimiter */
} else if (len) {
/* Packet has extra text which does not begin " M=" */
error("MS-CHAPv2 Success packet is badly formed.");
return 0;
}
return 1;
}
static void
chapms_handle_failure(unsigned char *inp, int len)
{
int err;
char *p, *msg;
/* We want a null-terminated string for strxxx(). */
msg = malloc(len + 1);
if (!msg) {
notice("Out of memory in chapms_handle_failure");
return;
}
BCOPY(inp, msg, len);
msg[len] = 0;
p = msg;
/*
* Deal with MS-CHAP formatted failure messages; just print the
* M=<message> part (if any). For MS-CHAP we're not really supposed
* to use M=<message>, but it shouldn't hurt. See
* chapms[2]_verify_response.
*/
if (!strncmp(p, "E=", 2))
err = strtol(p, NULL, 10); /* Remember the error code. */
else
goto print_msg; /* Message is badly formatted. */
if (len && ((p = strstr(p, " M=")) != NULL)) {
/* M=<message> field found. */
p += 3;
} else {
/* No M=<message>; use the error code. */
switch (err) {
case MS_CHAP_ERROR_RESTRICTED_LOGON_HOURS:
p = "E=646 Restricted logon hours";
break;
case MS_CHAP_ERROR_ACCT_DISABLED:
p = "E=647 Account disabled";
break;
case MS_CHAP_ERROR_PASSWD_EXPIRED:
p = "E=648 Password expired";
break;
case MS_CHAP_ERROR_NO_DIALIN_PERMISSION:
p = "E=649 No dialin permission";
break;
case MS_CHAP_ERROR_AUTHENTICATION_FAILURE:
p = "E=691 Authentication failure";
break;
case MS_CHAP_ERROR_CHANGING_PASSWORD:
/* Should never see this, we don't support Change Password. */
p = "E=709 Error changing password";
break;
default:
free(msg);
error("Unknown MS-CHAP authentication failure: %.*v",
len, inp);
return;
}
}
print_msg:
if (p != NULL)
error("MS-CHAP authentication failed: %v", p);
free(msg);
}
static void
ChallengeResponse(u_char *challenge,
u_char PasswordHash[MD4_SIGNATURE_SIZE],
u_char response[24])
{
u_char ZPasswordHash[21];
BZERO(ZPasswordHash, sizeof(ZPasswordHash));
BCOPY(PasswordHash, ZPasswordHash, MD4_SIGNATURE_SIZE);
#if 0
dbglog("ChallengeResponse - ZPasswordHash %.*B",
sizeof(ZPasswordHash), ZPasswordHash);
#endif
(void) DesSetkey(ZPasswordHash + 0);
DesEncrypt(challenge, response + 0);
(void) DesSetkey(ZPasswordHash + 7);
DesEncrypt(challenge, response + 8);
(void) DesSetkey(ZPasswordHash + 14);
DesEncrypt(challenge, response + 16);
#if 0
dbglog("ChallengeResponse - response %.24B", response);
#endif
}
void
ChallengeHash(u_char PeerChallenge[16], u_char *rchallenge,
char *username, u_char Challenge[8])
{
SHA1_CTX sha1Context;
u_char sha1Hash[SHA1_SIGNATURE_SIZE];
char *user;
/* remove domain from "domain\username" */
if ((user = strrchr(username, '\\')) != NULL)
++user;
else
user = username;
SHA1_Init(&sha1Context);
SHA1_Update(&sha1Context, PeerChallenge, 16);
SHA1_Update(&sha1Context, rchallenge, 16);
SHA1_Update(&sha1Context, (unsigned char *)user, strlen(user));
SHA1_Final(sha1Hash, &sha1Context);
BCOPY(sha1Hash, Challenge, 8);
}
/*
* Convert the ASCII version of the password to Unicode.
* This implicitly supports 8-bit ISO8859/1 characters.
* This gives us the little-endian representation, which
* is assumed by all M$ CHAP RFCs. (Unicode byte ordering
* is machine-dependent.)
*/
static void
ascii2unicode(char ascii[], int ascii_len, u_char unicode[])
{
int i;
BZERO(unicode, ascii_len * 2);
for (i = 0; i < ascii_len; i++)
unicode[i * 2] = (u_char) ascii[i];
}
static void
NTPasswordHash(char *secret, int secret_len, u_char hash[MD4_SIGNATURE_SIZE])
{
#ifdef ANDROID_CHANGES
/* We link with MD4 routines in openssl, we have to take bytes instead */
int mdlen = secret_len;
#else
#ifdef __NetBSD__
/* NetBSD uses the libc md4 routines which take bytes instead of bits */
int mdlen = secret_len;
#else
int mdlen = secret_len * 8;
#endif
#endif
MD4_CTX md4Context;
MD4Init(&md4Context);
MD4Update(&md4Context, (unsigned char *)secret, mdlen);
MD4Final(hash, &md4Context);
}
static void
ChapMS_NT(u_char *rchallenge, char *secret, int secret_len,
u_char NTResponse[24])
{
u_char unicodePassword[MAX_NT_PASSWORD * 2];
u_char PasswordHash[MD4_SIGNATURE_SIZE];
/* Hash the Unicode version of the secret (== password). */
ascii2unicode(secret, secret_len, unicodePassword);
NTPasswordHash((char *)unicodePassword, secret_len * 2, PasswordHash);
ChallengeResponse(rchallenge, PasswordHash, NTResponse);
}
static void
ChapMS2_NT(char *rchallenge, u_char PeerChallenge[16], char *username,
char *secret, int secret_len, u_char NTResponse[24])
{
u_char unicodePassword[MAX_NT_PASSWORD * 2];
u_char PasswordHash[MD4_SIGNATURE_SIZE];
u_char Challenge[8];
ChallengeHash(PeerChallenge, (unsigned char *)rchallenge, username,
Challenge);
/* Hash the Unicode version of the secret (== password). */
ascii2unicode(secret, secret_len, unicodePassword);
NTPasswordHash((char *)unicodePassword, secret_len * 2, PasswordHash);
ChallengeResponse(Challenge, PasswordHash, NTResponse);
}
#ifdef MSLANMAN
static u_char *StdText = (u_char *)"KGS!@#$%"; /* key from rasapi32.dll */
static void
ChapMS_LANMan(u_char *rchallenge, 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]);
(void) DesSetkey(UcasePassword + 0);
DesEncrypt( StdText, PasswordHash + 0 );
(void) DesSetkey(UcasePassword + 7);
DesEncrypt( StdText, PasswordHash + 8 );
ChallengeResponse(rchallenge, PasswordHash, response->LANManResp);
}
#endif
void
GenerateAuthenticatorResponse(u_char PasswordHashHash[MD4_SIGNATURE_SIZE],
u_char NTResponse[24], u_char PeerChallenge[16],
u_char *rchallenge, char *username,
u_char authResponse[MS_AUTH_RESPONSE_LENGTH+1])
{
/*
* "Magic" constants used in response generation, from RFC 2759.
*/
u_char Magic1[39] = /* "Magic server to client signing constant" */
{ 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 };
u_char Magic2[41] = /* "Pad to make it do more than one iteration" */
{ 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 };
int i;
SHA1_CTX sha1Context;
u_char Digest[SHA1_SIGNATURE_SIZE];
u_char Challenge[8];
SHA1_Init(&sha1Context);
SHA1_Update(&sha1Context, PasswordHashHash, MD4_SIGNATURE_SIZE);
SHA1_Update(&sha1Context, NTResponse, 24);
SHA1_Update(&sha1Context, Magic1, sizeof(Magic1));
SHA1_Final(Digest, &sha1Context);
ChallengeHash(PeerChallenge, rchallenge, username, Challenge);
SHA1_Init(&sha1Context);
SHA1_Update(&sha1Context, Digest, sizeof(Digest));
SHA1_Update(&sha1Context, Challenge, sizeof(Challenge));
SHA1_Update(&sha1Context, Magic2, sizeof(Magic2));
SHA1_Final(Digest, &sha1Context);
/* Convert to ASCII hex string. */
for (i = 0; i < MAX((MS_AUTH_RESPONSE_LENGTH / 2), sizeof(Digest)); i++)
sprintf((char *)&authResponse[i * 2], "%02X", Digest[i]);
}
static void
GenerateAuthenticatorResponsePlain
(char *secret, int secret_len,
u_char NTResponse[24], u_char PeerChallenge[16],
u_char *rchallenge, char *username,
u_char authResponse[MS_AUTH_RESPONSE_LENGTH+1])
{
u_char unicodePassword[MAX_NT_PASSWORD * 2];
u_char PasswordHash[MD4_SIGNATURE_SIZE];
u_char PasswordHashHash[MD4_SIGNATURE_SIZE];
/* Hash (x2) the Unicode version of the secret (== password). */
ascii2unicode(secret, secret_len, unicodePassword);
NTPasswordHash((char *)unicodePassword, secret_len * 2, PasswordHash);
NTPasswordHash((char *)PasswordHash, sizeof(PasswordHash),
PasswordHashHash);
GenerateAuthenticatorResponse(PasswordHashHash, NTResponse, PeerChallenge,
rchallenge, username, authResponse);
}
#ifdef MPPE
/*
* Set mppe_xxxx_key from the NTPasswordHashHash.
* RFC 2548 (RADIUS support) requires us to export this function (ugh).
*/
void
mppe_set_keys(u_char *rchallenge, u_char PasswordHashHash[MD4_SIGNATURE_SIZE])
{
SHA1_CTX sha1Context;
u_char Digest[SHA1_SIGNATURE_SIZE]; /* >= MPPE_MAX_KEY_LEN */
SHA1_Init(&sha1Context);
SHA1_Update(&sha1Context, PasswordHashHash, MD4_SIGNATURE_SIZE);
SHA1_Update(&sha1Context, PasswordHashHash, MD4_SIGNATURE_SIZE);
SHA1_Update(&sha1Context, rchallenge, 8);
SHA1_Final(Digest, &sha1Context);
/* Same key in both directions. */
BCOPY(Digest, mppe_send_key, sizeof(mppe_send_key));
BCOPY(Digest, mppe_recv_key, sizeof(mppe_recv_key));
mppe_keys_set = 1;
}
/*
* Set mppe_xxxx_key from MS-CHAP credentials. (see RFC 3079)
*/
static void
Set_Start_Key(u_char *rchallenge, char *secret, int secret_len)
{
u_char unicodePassword[MAX_NT_PASSWORD * 2];
u_char PasswordHash[MD4_SIGNATURE_SIZE];
u_char PasswordHashHash[MD4_SIGNATURE_SIZE];
/* Hash (x2) the Unicode version of the secret (== password). */
ascii2unicode(secret, secret_len, unicodePassword);
NTPasswordHash(unicodePassword, secret_len * 2, PasswordHash);
NTPasswordHash(PasswordHash, sizeof(PasswordHash), PasswordHashHash);
mppe_set_keys(rchallenge, PasswordHashHash);
}
/*
* Set mppe_xxxx_key from MS-CHAPv2 credentials. (see RFC 3079)
*
* This helper function used in the Winbind module, which gets the
* NTHashHash from the server.
*/
void
mppe_set_keys2(u_char PasswordHashHash[MD4_SIGNATURE_SIZE],
u_char NTResponse[24], int IsServer)
{
SHA1_CTX sha1Context;
u_char MasterKey[SHA1_SIGNATURE_SIZE]; /* >= MPPE_MAX_KEY_LEN */
u_char Digest[SHA1_SIGNATURE_SIZE]; /* >= MPPE_MAX_KEY_LEN */
u_char SHApad1[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 };
u_char SHApad2[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 };
/* "This is the MPPE Master Key" */
u_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 };
/* "On the client side, this is the send key; "
"on the server side, it is the receive key." */
u_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 };
/* "On the client side, this is the receive key; "
"on the server side, it is the send key." */
u_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 };
u_char *s;
SHA1_Init(&sha1Context);
SHA1_Update(&sha1Context, PasswordHashHash, MD4_SIGNATURE_SIZE);
SHA1_Update(&sha1Context, NTResponse, 24);
SHA1_Update(&sha1Context, Magic1, sizeof(Magic1));
SHA1_Final(MasterKey, &sha1Context);
/*
* generate send key
*/
if (IsServer)
s = Magic3;
else
s = Magic2;
SHA1_Init(&sha1Context);
SHA1_Update(&sha1Context, MasterKey, 16);
SHA1_Update(&sha1Context, SHApad1, sizeof(SHApad1));
SHA1_Update(&sha1Context, s, 84);
SHA1_Update(&sha1Context, SHApad2, sizeof(SHApad2));
SHA1_Final(Digest, &sha1Context);
BCOPY(Digest, mppe_send_key, sizeof(mppe_send_key));
/*
* generate recv key
*/
if (IsServer)
s = Magic2;
else
s = Magic3;
SHA1_Init(&sha1Context);
SHA1_Update(&sha1Context, MasterKey, 16);
SHA1_Update(&sha1Context, SHApad1, sizeof(SHApad1));
SHA1_Update(&sha1Context, s, 84);
SHA1_Update(&sha1Context, SHApad2, sizeof(SHApad2));
SHA1_Final(Digest, &sha1Context);
BCOPY(Digest, mppe_recv_key, sizeof(mppe_recv_key));
mppe_keys_set = 1;
}
/*
* Set mppe_xxxx_key from MS-CHAPv2 credentials. (see RFC 3079)
*/
static void
SetMasterKeys(char *secret, int secret_len, u_char NTResponse[24], int IsServer)
{
u_char unicodePassword[MAX_NT_PASSWORD * 2];
u_char PasswordHash[MD4_SIGNATURE_SIZE];
u_char PasswordHashHash[MD4_SIGNATURE_SIZE];
/* Hash (x2) the Unicode version of the secret (== password). */
ascii2unicode(secret, secret_len, unicodePassword);
NTPasswordHash(unicodePassword, secret_len * 2, PasswordHash);
NTPasswordHash(PasswordHash, sizeof(PasswordHash), PasswordHashHash);
mppe_set_keys2(PasswordHashHash, NTResponse, IsServer);
}
#endif /* MPPE */
void
ChapMS(u_char *rchallenge, char *secret, int secret_len,
MS_ChapResponse *response)
{
BZERO(response, sizeof(*response));
ChapMS_NT(rchallenge, secret, secret_len, response->NTResp);
#ifdef MSLANMAN
ChapMS_LANMan(rchallenge, secret, secret_len, response);
/* preferred method is set by option */
response->UseNT[0] = !ms_lanman;
#else
response->UseNT[0] = 1;
#endif
#ifdef MPPE
Set_Start_Key(rchallenge, secret, secret_len);
#endif
}
/*
* If PeerChallenge is NULL, one is generated and response->PeerChallenge
* is filled in. Call this way when generating a response.
* If PeerChallenge is supplied, it is copied into response->PeerChallenge.
* Call this way when verifying a response (or debugging).
* Do not call with PeerChallenge = response->PeerChallenge.
*
* response->PeerChallenge is then used for calculation of the
* Authenticator Response.
*/
void
ChapMS2(u_char *rchallenge, u_char *PeerChallenge,
char *user, char *secret, int secret_len, MS_Chap2Response *response,
u_char authResponse[], int authenticator)
{
/* ARGSUSED */
u_char *p = response->PeerChallenge;
int i;
BZERO(response, sizeof(*response));
/* Generate the Peer-Challenge if requested, or copy it if supplied. */
if (!PeerChallenge)
for (i = 0; i < sizeof(response->PeerChallenge); i++)
*p++ = (u_char) (drand48() * 0xff);
else
BCOPY(PeerChallenge, response->PeerChallenge,
sizeof(response->PeerChallenge));
/* Generate the NT-Response */
ChapMS2_NT((char *)rchallenge, response->PeerChallenge, user,
secret, secret_len, response->NTResp);
/* Generate the Authenticator Response. */
GenerateAuthenticatorResponsePlain(secret, secret_len, response->NTResp,
response->PeerChallenge, rchallenge,
user, authResponse);
#ifdef MPPE
SetMasterKeys(secret, secret_len, response->NTResp, authenticator);
#endif
}
#ifdef MPPE
/*
* Set MPPE options from plugins.
*/
void
set_mppe_enc_types(int policy, int types)
{
/* Early exit for unknown policies. */
if (policy != MPPE_ENC_POL_ENC_ALLOWED ||
policy != MPPE_ENC_POL_ENC_REQUIRED)
return;
/* Don't modify MPPE if it's optional and wasn't already configured. */
if (policy == MPPE_ENC_POL_ENC_ALLOWED && !ccp_wantoptions[0].mppe)
return;
/*
* Disable undesirable encryption types. Note that we don't ENABLE
* any encryption types, to avoid overriding manual configuration.
*/
switch(types) {
case MPPE_ENC_TYPES_RC4_40:
ccp_wantoptions[0].mppe &= ~MPPE_OPT_128; /* disable 128-bit */
break;
case MPPE_ENC_TYPES_RC4_128:
ccp_wantoptions[0].mppe &= ~MPPE_OPT_40; /* disable 40-bit */
break;
default:
break;
}
}
#endif /* MPPE */
static struct chap_digest_type chapms_digest = {
CHAP_MICROSOFT, /* code */
chapms_generate_challenge,
chapms_verify_response,
chapms_make_response,
NULL, /* check_success */
chapms_handle_failure,
};
static struct chap_digest_type chapms2_digest = {
CHAP_MICROSOFT_V2, /* code */
chapms2_generate_challenge,
chapms2_verify_response,
chapms2_make_response,
chapms2_check_success,
chapms_handle_failure,
};
void
chapms_init(void)
{
chap_register_digest(&chapms_digest);
chap_register_digest(&chapms2_digest);
add_options(chapms_option_list);
}
#endif /* CHAPMS */