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/*
* 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 Google, Inc. 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.
*
*/
#include "netif/ppp/ppp_opts.h"
#if PPP_SUPPORT && MSCHAP_SUPPORT /* don't build if not configured for use in lwipopts.h */
#if 0 /* UNUSED */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/time.h>
#include <unistd.h>
#endif /* UNUSED */
#include "netif/ppp/ppp_impl.h"
#include "netif/ppp/chap-new.h"
#include "netif/ppp/chap_ms.h"
#include "netif/ppp/pppcrypt.h"
#include "netif/ppp/magic.h"
#if MPPE_SUPPORT
#include "netif/ppp/mppe.h" /* For mppe_sha1_pad*, mppe_set_key() */
#endif /* MPPE_SUPPORT */
#define SHA1_SIGNATURE_SIZE 20
#define MD4_SIGNATURE_SIZE 16 /* 16 bytes in a MD4 message digest */
#define MAX_NT_PASSWORD 256 /* Max (Unicode) chars in an NT pass */
#define MS_CHAP_RESPONSE_LEN 49 /* Response length for MS-CHAP */
#define MS_CHAP2_RESPONSE_LEN 49 /* Response length for MS-CHAPv2 */
#define MS_AUTH_RESPONSE_LENGTH 40 /* MS-CHAPv2 authenticator response, */
/* as ASCII */
/* Error codes for MS-CHAP failure messages. */
#define MS_CHAP_ERROR_RESTRICTED_LOGON_HOURS 646
#define MS_CHAP_ERROR_ACCT_DISABLED 647
#define MS_CHAP_ERROR_PASSWD_EXPIRED 648
#define MS_CHAP_ERROR_NO_DIALIN_PERMISSION 649
#define MS_CHAP_ERROR_AUTHENTICATION_FAILURE 691
#define MS_CHAP_ERROR_CHANGING_PASSWORD 709
/*
* Offsets within the response field for MS-CHAP
*/
#define MS_CHAP_LANMANRESP 0
#define MS_CHAP_LANMANRESP_LEN 24
#define MS_CHAP_NTRESP 24
#define MS_CHAP_NTRESP_LEN 24
#define MS_CHAP_USENT 48
/*
* Offsets within the response field for MS-CHAP2
*/
#define MS_CHAP2_PEER_CHALLENGE 0
#define MS_CHAP2_PEER_CHAL_LEN 16
#define MS_CHAP2_RESERVED_LEN 8
#define MS_CHAP2_NTRESP 24
#define MS_CHAP2_NTRESP_LEN 24
#define MS_CHAP2_FLAGS 48
#if MPPE_SUPPORT
#if 0 /* UNUSED */
/* These values are the RADIUS attribute values--see RFC 2548. */
#define MPPE_ENC_POL_ENC_ALLOWED 1
#define MPPE_ENC_POL_ENC_REQUIRED 2
#define MPPE_ENC_TYPES_RC4_40 2
#define MPPE_ENC_TYPES_RC4_128 4
/* used by plugins (using above values) */
extern void set_mppe_enc_types(int, int);
#endif /* UNUSED */
#endif /* MPPE_SUPPORT */
/* Are we the authenticator or authenticatee? For MS-CHAPv2 key derivation. */
#define MS_CHAP2_AUTHENTICATEE 0
#define MS_CHAP2_AUTHENTICATOR 1
static void ascii2unicode (const char[], int, u_char[]);
static void NTPasswordHash (u_char *, int, u_char[MD4_SIGNATURE_SIZE]);
static void ChallengeResponse (const u_char *, const u_char *, u_char[24]);
static void ChallengeHash (const u_char[16], const u_char *, const char *, u_char[8]);
static void ChapMS_NT (const u_char *, const char *, int, u_char[24]);
static void ChapMS2_NT (const u_char *, const u_char[16], const char *, const char *, int,
u_char[24]);
static void GenerateAuthenticatorResponsePlain
(const char*, int, u_char[24], const u_char[16], const u_char *,
const char *, u_char[41]);
#ifdef MSLANMAN
static void ChapMS_LANMan (u_char *, char *, int, u_char *);
#endif
static void GenerateAuthenticatorResponse(const u_char PasswordHashHash[MD4_SIGNATURE_SIZE],
u_char NTResponse[24], const u_char PeerChallenge[16],
const u_char *rchallenge, const char *username,
u_char authResponse[MS_AUTH_RESPONSE_LENGTH+1]);
#if MPPE_SUPPORT
static void Set_Start_Key (ppp_pcb *pcb, const u_char *, const char *, int);
static void SetMasterKeys (ppp_pcb *pcb, const char *, int, u_char[24], int);
#endif /* MPPE_SUPPORT */
static void ChapMS (ppp_pcb *pcb, const u_char *, const char *, int, u_char *);
static void ChapMS2 (ppp_pcb *pcb, const u_char *, const u_char *, const char *, const char *, int,
u_char *, u_char[MS_AUTH_RESPONSE_LENGTH+1], int);
#ifdef MSLANMAN
bool ms_lanman = 0; /* Use LanMan password instead of NT */
/* Has meaning only with MS-CHAP challenges */
#endif
#if MPPE_SUPPORT
#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 "netif/ppp/fsm.h" /* Need to poke MPPE options */
#include "netif/ppp/ccp.h"
#endif /* MPPE_SUPPORT */
#if PPP_OPTIONS
/*
* 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 }
};
#endif /* PPP_OPTIONS */
#if PPP_SERVER
/*
* 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(ppp_pcb *pcb, unsigned char *challenge) {
LWIP_UNUSED_ARG(pcb);
*challenge++ = 8;
#ifdef DEBUGMPPEKEY
if (mschap_challenge && strlen(mschap_challenge) == 8)
memcpy(challenge, mschap_challenge, 8);
else
#endif
magic_random_bytes(challenge, 8);
}
static void chapms2_generate_challenge(ppp_pcb *pcb, unsigned char *challenge) {
LWIP_UNUSED_ARG(pcb);
*challenge++ = 16;
#ifdef DEBUGMPPEKEY
if (mschap_challenge && strlen(mschap_challenge) == 16)
memcpy(challenge, mschap_challenge, 16);
else
#endif
magic_random_bytes(challenge, 16);
}
static int chapms_verify_response(ppp_pcb *pcb, int id, const char *name,
const unsigned char *secret, int secret_len,
const unsigned char *challenge, const unsigned char *response,
char *message, int message_space) {
unsigned char md[MS_CHAP_RESPONSE_LEN];
int diff;
int challenge_len, response_len;
LWIP_UNUSED_ARG(id);
LWIP_UNUSED_ARG(name);
challenge_len = *challenge++; /* skip length, is 8 */
response_len = *response++;
if (response_len != MS_CHAP_RESPONSE_LEN)
goto bad;
#ifndef MSLANMAN
if (!response[MS_CHAP_USENT]) {
/* Should really propagate this into the error packet. */
ppp_notice("Peer request for LANMAN auth not supported");
goto bad;
}
#endif
/* Generate the expected response. */
ChapMS(pcb, (const u_char *)challenge, (const char *)secret, secret_len, md);
#ifdef MSLANMAN
/* Determine which part of response to verify against */
if (!response[MS_CHAP_USENT])
diff = memcmp(&response[MS_CHAP_LANMANRESP],
&md[MS_CHAP_LANMANRESP], MS_CHAP_LANMANRESP_LEN);
else
#endif
diff = memcmp(&response[MS_CHAP_NTRESP], &md[MS_CHAP_NTRESP],
MS_CHAP_NTRESP_LEN);
if (diff == 0) {
ppp_slprintf(message, message_space, "Access granted");
return 1;
}
bad:
/* See comments below for MS-CHAP V2 */
ppp_slprintf(message, message_space, "E=691 R=1 C=%0.*B V=0",
challenge_len, challenge);
return 0;
}
static int chapms2_verify_response(ppp_pcb *pcb, int id, const char *name,
const unsigned char *secret, int secret_len,
const unsigned char *challenge, const unsigned char *response,
char *message, int message_space) {
unsigned char md[MS_CHAP2_RESPONSE_LEN];
char saresponse[MS_AUTH_RESPONSE_LENGTH+1];
int challenge_len, response_len;
LWIP_UNUSED_ARG(id);
challenge_len = *challenge++; /* skip length, is 16 */
response_len = *response++;
if (response_len != MS_CHAP2_RESPONSE_LEN)
goto bad; /* not even the right length */
/* Generate the expected response and our mutual auth. */
ChapMS2(pcb, (const u_char*)challenge, (const u_char*)&response[MS_CHAP2_PEER_CHALLENGE], name,
(const 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[MS_CHAP2_NTRESP], &response[MS_CHAP2_NTRESP],
MS_CHAP2_NTRESP_LEN) == 0) {
if (response[MS_CHAP2_FLAGS])
ppp_slprintf(message, message_space, "S=%s", saresponse);
else
ppp_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.
*/
ppp_slprintf(message, message_space, "E=691 R=1 C=%0.*B V=0 M=%s",
challenge_len, challenge, "Access denied");
return 0;
}
#endif /* PPP_SERVER */
static void chapms_make_response(ppp_pcb *pcb, unsigned char *response, int id, const char *our_name,
const unsigned char *challenge, const char *secret, int secret_len,
unsigned char *private_) {
LWIP_UNUSED_ARG(id);
LWIP_UNUSED_ARG(our_name);
LWIP_UNUSED_ARG(private_);
challenge++; /* skip length, should be 8 */
*response++ = MS_CHAP_RESPONSE_LEN;
ChapMS(pcb, challenge, secret, secret_len, response);
}
static void chapms2_make_response(ppp_pcb *pcb, unsigned char *response, int id, const char *our_name,
const unsigned char *challenge, const char *secret, int secret_len,
unsigned char *private_) {
LWIP_UNUSED_ARG(id);
challenge++; /* skip length, should be 16 */
*response++ = MS_CHAP2_RESPONSE_LEN;
ChapMS2(pcb, challenge,
#ifdef DEBUGMPPEKEY
mschap2_peer_challenge,
#else
NULL,
#endif
our_name, secret, secret_len, response, private_,
MS_CHAP2_AUTHENTICATEE);
}
static int chapms2_check_success(ppp_pcb *pcb, unsigned char *msg, int len, unsigned char *private_) {
LWIP_UNUSED_ARG(pcb);
if ((len < MS_AUTH_RESPONSE_LENGTH + 2) ||
strncmp((char *)msg, "S=", 2) != 0) {
/* Packet does not start with "S=" */
ppp_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. */
ppp_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=" */
ppp_error("MS-CHAPv2 Success packet is badly formed.");
return 0;
}
return 1;
}
static void chapms_handle_failure(ppp_pcb *pcb, unsigned char *inp, int len) {
int err;
const char *p;
char msg[64];
LWIP_UNUSED_ARG(pcb);
/* We want a null-terminated string for strxxx(). */
len = LWIP_MIN(len, 63);
MEMCPY(msg, inp, 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+2, 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:
ppp_error("Unknown MS-CHAP authentication failure: %.*v",
len, inp);
return;
}
}
print_msg:
if (p != NULL)
ppp_error("MS-CHAP authentication failed: %v", p);
}
static void ChallengeResponse(const u_char *challenge,
const u_char PasswordHash[MD4_SIGNATURE_SIZE],
u_char response[24]) {
u_char ZPasswordHash[21];
lwip_des_context des;
u_char des_key[8];
BZERO(ZPasswordHash, sizeof(ZPasswordHash));
MEMCPY(ZPasswordHash, PasswordHash, MD4_SIGNATURE_SIZE);
#if 0
dbglog("ChallengeResponse - ZPasswordHash %.*B",
sizeof(ZPasswordHash), ZPasswordHash);
#endif
pppcrypt_56_to_64_bit_key(ZPasswordHash + 0, des_key);
lwip_des_init(&des);
lwip_des_setkey_enc(&des, des_key);
lwip_des_crypt_ecb(&des, challenge, response +0);
lwip_des_free(&des);
pppcrypt_56_to_64_bit_key(ZPasswordHash + 7, des_key);
lwip_des_init(&des);
lwip_des_setkey_enc(&des, des_key);
lwip_des_crypt_ecb(&des, challenge, response +8);
lwip_des_free(&des);
pppcrypt_56_to_64_bit_key(ZPasswordHash + 14, des_key);
lwip_des_init(&des);
lwip_des_setkey_enc(&des, des_key);
lwip_des_crypt_ecb(&des, challenge, response +16);
lwip_des_free(&des);
#if 0
dbglog("ChallengeResponse - response %.24B", response);
#endif
}
static void ChallengeHash(const u_char PeerChallenge[16], const u_char *rchallenge,
const char *username, u_char Challenge[8]) {
lwip_sha1_context sha1Context;
u_char sha1Hash[SHA1_SIGNATURE_SIZE];
const char *user;
/* remove domain from "domain\username" */
if ((user = strrchr(username, '\\')) != NULL)
++user;
else
user = username;
lwip_sha1_init(&sha1Context);
lwip_sha1_starts(&sha1Context);
lwip_sha1_update(&sha1Context, PeerChallenge, 16);
lwip_sha1_update(&sha1Context, rchallenge, 16);
lwip_sha1_update(&sha1Context, (const unsigned char*)user, strlen(user));
lwip_sha1_finish(&sha1Context, sha1Hash);
lwip_sha1_free(&sha1Context);
MEMCPY(Challenge, sha1Hash, 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(const 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(u_char *secret, int secret_len, u_char hash[MD4_SIGNATURE_SIZE]) {
lwip_md4_context md4Context;
lwip_md4_init(&md4Context);
lwip_md4_starts(&md4Context);
lwip_md4_update(&md4Context, secret, secret_len);
lwip_md4_finish(&md4Context, hash);
lwip_md4_free(&md4Context);
}
static void ChapMS_NT(const u_char *rchallenge, const 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(unicodePassword, secret_len * 2, PasswordHash);
ChallengeResponse(rchallenge, PasswordHash, NTResponse);
}
static void ChapMS2_NT(const u_char *rchallenge, const u_char PeerChallenge[16], const char *username,
const 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, rchallenge, username, Challenge);
/* Hash the Unicode version of the secret (== password). */
ascii2unicode(secret, secret_len, unicodePassword);
NTPasswordHash(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,
unsigned char *response) {
int i;
u_char UcasePassword[MAX_NT_PASSWORD]; /* max is actually 14 */
u_char PasswordHash[MD4_SIGNATURE_SIZE];
lwip_des_context des;
u_char des_key[8];
/* LANMan password is case insensitive */
BZERO(UcasePassword, sizeof(UcasePassword));
for (i = 0; i < secret_len; i++)
UcasePassword[i] = (u_char)toupper(secret[i]);
pppcrypt_56_to_64_bit_key(UcasePassword +0, des_key);
lwip_des_init(&des);
lwip_des_setkey_enc(&des, des_key);
lwip_des_crypt_ecb(&des, StdText, PasswordHash +0);
lwip_des_free(&des);
pppcrypt_56_to_64_bit_key(UcasePassword +7, des_key);
lwip_des_init(&des);
lwip_des_setkey_enc(&des, des_key);
lwip_des_crypt_ecb(&des, StdText, PasswordHash +8);
lwip_des_free(&des);
ChallengeResponse(rchallenge, PasswordHash, &response[MS_CHAP_LANMANRESP]);
}
#endif
static void GenerateAuthenticatorResponse(const u_char PasswordHashHash[MD4_SIGNATURE_SIZE],
u_char NTResponse[24], const u_char PeerChallenge[16],
const u_char *rchallenge, const char *username,
u_char authResponse[MS_AUTH_RESPONSE_LENGTH+1]) {
/*
* "Magic" constants used in response generation, from RFC 2759.
*/
static const 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 };
static const 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;
lwip_sha1_context sha1Context;
u_char Digest[SHA1_SIGNATURE_SIZE];
u_char Challenge[8];
lwip_sha1_init(&sha1Context);
lwip_sha1_starts(&sha1Context);
lwip_sha1_update(&sha1Context, PasswordHashHash, MD4_SIGNATURE_SIZE);
lwip_sha1_update(&sha1Context, NTResponse, 24);
lwip_sha1_update(&sha1Context, Magic1, sizeof(Magic1));
lwip_sha1_finish(&sha1Context, Digest);
lwip_sha1_free(&sha1Context);
ChallengeHash(PeerChallenge, rchallenge, username, Challenge);
lwip_sha1_init(&sha1Context);
lwip_sha1_starts(&sha1Context);
lwip_sha1_update(&sha1Context, Digest, sizeof(Digest));
lwip_sha1_update(&sha1Context, Challenge, sizeof(Challenge));
lwip_sha1_update(&sha1Context, Magic2, sizeof(Magic2));
lwip_sha1_finish(&sha1Context, Digest);
lwip_sha1_free(&sha1Context);
/* Convert to ASCII hex string. */
for (i = 0; i < LWIP_MAX((MS_AUTH_RESPONSE_LENGTH / 2), (int)sizeof(Digest)); i++)
sprintf((char *)&authResponse[i * 2], "%02X", Digest[i]);
}
static void GenerateAuthenticatorResponsePlain(
const char *secret, int secret_len,
u_char NTResponse[24], const u_char PeerChallenge[16],
const u_char *rchallenge, const 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(unicodePassword, secret_len * 2, PasswordHash);
NTPasswordHash(PasswordHash, sizeof(PasswordHash),
PasswordHashHash);
GenerateAuthenticatorResponse(PasswordHashHash, NTResponse, PeerChallenge,
rchallenge, username, authResponse);
}
#if MPPE_SUPPORT
/*
* Set mppe_xxxx_key from MS-CHAP credentials. (see RFC 3079)
*/
static void Set_Start_Key(ppp_pcb *pcb, const u_char *rchallenge, const char *secret, int secret_len) {
u_char unicodePassword[MAX_NT_PASSWORD * 2];
u_char PasswordHash[MD4_SIGNATURE_SIZE];
u_char PasswordHashHash[MD4_SIGNATURE_SIZE];
lwip_sha1_context sha1Context;
u_char Digest[SHA1_SIGNATURE_SIZE]; /* >= MPPE_MAX_KEY_LEN */
/* 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);
lwip_sha1_init(&sha1Context);
lwip_sha1_starts(&sha1Context);
lwip_sha1_update(&sha1Context, PasswordHashHash, MD4_SIGNATURE_SIZE);
lwip_sha1_update(&sha1Context, PasswordHashHash, MD4_SIGNATURE_SIZE);
lwip_sha1_update(&sha1Context, rchallenge, 8);
lwip_sha1_finish(&sha1Context, Digest);
lwip_sha1_free(&sha1Context);
/* Same key in both directions. */
mppe_set_key(pcb, &pcb->mppe_comp, Digest);
mppe_set_key(pcb, &pcb->mppe_decomp, Digest);
pcb->mppe_keys_set = 1;
}
/*
* Set mppe_xxxx_key from MS-CHAPv2 credentials. (see RFC 3079)
*/
static void SetMasterKeys(ppp_pcb *pcb, const 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];
lwip_sha1_context sha1Context;
u_char MasterKey[SHA1_SIGNATURE_SIZE]; /* >= MPPE_MAX_KEY_LEN */
u_char Digest[SHA1_SIGNATURE_SIZE]; /* >= MPPE_MAX_KEY_LEN */
const u_char *s;
/* "This is the MPPE Master Key" */
static const 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." */
static const 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." */
static const 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 };
/* 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);
lwip_sha1_init(&sha1Context);
lwip_sha1_starts(&sha1Context);
lwip_sha1_update(&sha1Context, PasswordHashHash, MD4_SIGNATURE_SIZE);
lwip_sha1_update(&sha1Context, NTResponse, 24);
lwip_sha1_update(&sha1Context, Magic1, sizeof(Magic1));
lwip_sha1_finish(&sha1Context, MasterKey);
lwip_sha1_free(&sha1Context);
/*
* generate send key
*/
if (IsServer)
s = Magic3;
else
s = Magic2;
lwip_sha1_init(&sha1Context);
lwip_sha1_starts(&sha1Context);
lwip_sha1_update(&sha1Context, MasterKey, 16);
lwip_sha1_update(&sha1Context, mppe_sha1_pad1, SHA1_PAD_SIZE);
lwip_sha1_update(&sha1Context, s, 84);
lwip_sha1_update(&sha1Context, mppe_sha1_pad2, SHA1_PAD_SIZE);
lwip_sha1_finish(&sha1Context, Digest);
lwip_sha1_free(&sha1Context);
mppe_set_key(pcb, &pcb->mppe_comp, Digest);
/*
* generate recv key
*/
if (IsServer)
s = Magic2;
else
s = Magic3;
lwip_sha1_init(&sha1Context);
lwip_sha1_starts(&sha1Context);
lwip_sha1_update(&sha1Context, MasterKey, 16);
lwip_sha1_update(&sha1Context, mppe_sha1_pad1, SHA1_PAD_SIZE);
lwip_sha1_update(&sha1Context, s, 84);
lwip_sha1_update(&sha1Context, mppe_sha1_pad2, SHA1_PAD_SIZE);
lwip_sha1_finish(&sha1Context, Digest);
lwip_sha1_free(&sha1Context);
mppe_set_key(pcb, &pcb->mppe_decomp, Digest);
pcb->mppe_keys_set = 1;
}
#endif /* MPPE_SUPPORT */
static void ChapMS(ppp_pcb *pcb, const u_char *rchallenge, const char *secret, int secret_len,
unsigned char *response) {
#if !MPPE_SUPPORT
LWIP_UNUSED_ARG(pcb);
#endif /* !MPPE_SUPPORT */
BZERO(response, MS_CHAP_RESPONSE_LEN);
ChapMS_NT(rchallenge, secret, secret_len, &response[MS_CHAP_NTRESP]);
#ifdef MSLANMAN
ChapMS_LANMan(rchallenge, secret, secret_len,
&response[MS_CHAP_LANMANRESP]);
/* preferred method is set by option */
response[MS_CHAP_USENT] = !ms_lanman;
#else
response[MS_CHAP_USENT] = 1;
#endif
#if MPPE_SUPPORT
Set_Start_Key(pcb, rchallenge, secret, secret_len);
#endif /* MPPE_SUPPORT */
}
/*
* If PeerChallenge is NULL, one is generated and the PeerChallenge
* field of response is filled in. Call this way when generating a response.
* If PeerChallenge is supplied, it is copied into the PeerChallenge field.
* Call this way when verifying a response (or debugging).
* Do not call with PeerChallenge = response.
*
* The PeerChallenge field of response is then used for calculation of the
* Authenticator Response.
*/
static void ChapMS2(ppp_pcb *pcb, const u_char *rchallenge, const u_char *PeerChallenge,
const char *user, const char *secret, int secret_len, unsigned char *response,
u_char authResponse[], int authenticator) {
/* ARGSUSED */
LWIP_UNUSED_ARG(authenticator);
#if !MPPE_SUPPORT
LWIP_UNUSED_ARG(pcb);
#endif /* !MPPE_SUPPORT */
BZERO(response, MS_CHAP2_RESPONSE_LEN);
/* Generate the Peer-Challenge if requested, or copy it if supplied. */
if (!PeerChallenge)
magic_random_bytes(&response[MS_CHAP2_PEER_CHALLENGE], MS_CHAP2_PEER_CHAL_LEN);
else
MEMCPY(&response[MS_CHAP2_PEER_CHALLENGE], PeerChallenge,
MS_CHAP2_PEER_CHAL_LEN);
/* Generate the NT-Response */
ChapMS2_NT(rchallenge, &response[MS_CHAP2_PEER_CHALLENGE], user,
secret, secret_len, &response[MS_CHAP2_NTRESP]);
/* Generate the Authenticator Response. */
GenerateAuthenticatorResponsePlain(secret, secret_len,
&response[MS_CHAP2_NTRESP],
&response[MS_CHAP2_PEER_CHALLENGE],
rchallenge, user, authResponse);
#if MPPE_SUPPORT
SetMasterKeys(pcb, secret, secret_len,
&response[MS_CHAP2_NTRESP], authenticator);
#endif /* MPPE_SUPPORT */
}
#if 0 /* UNUSED */
#if MPPE_SUPPORT
/*
* 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_SUPPORT */
#endif /* UNUSED */
const struct chap_digest_type chapms_digest = {
CHAP_MICROSOFT, /* code */
#if PPP_SERVER
chapms_generate_challenge,
chapms_verify_response,
#endif /* PPP_SERVER */
chapms_make_response,
NULL, /* check_success */
chapms_handle_failure,
};
const struct chap_digest_type chapms2_digest = {
CHAP_MICROSOFT_V2, /* code */
#if PPP_SERVER
chapms2_generate_challenge,
chapms2_verify_response,
#endif /* PPP_SERVER */
chapms2_make_response,
chapms2_check_success,
chapms_handle_failure,
};
#endif /* PPP_SUPPORT && MSCHAP_SUPPORT */