diff options
Diffstat (limited to 'lwip/src/netif/ppp/chap_ms.c')
| -rw-r--r-- | lwip/src/netif/ppp/chap_ms.c | 962 |
1 files changed, 962 insertions, 0 deletions
diff --git a/lwip/src/netif/ppp/chap_ms.c b/lwip/src/netif/ppp/chap_ms.c new file mode 100644 index 0000000..5a989c9 --- /dev/null +++ b/lwip/src/netif/ppp/chap_ms.c @@ -0,0 +1,962 @@ +/* + * 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 */ |