/* * chap_ms.c - Microsoft MS-CHAP compatible implementation. * * Copyright (c) 2000 by Sun Microsystems, Inc. * All rights reserved. * * Copyright (c) 1995 Eric Rosenquist, Strata Software Limited. * http://www.strataware.com/ * * All rights reserved. * * Redistribution and use in source and binary forms are permitted * provided that the above copyright notice and this paragraph are * duplicated in all such forms and that any documentation, * advertising materials, and other materials related to such * distribution and use acknowledge that the software was developed * by Eric Rosenquist. The name of the author may not be used to * endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ /* * This module implements MS-CHAPv1 (RFC 2433) and MS-CHAPv2 (RFC 2759). * * 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 James Carlson / james.d.carlson@sun.com, June 1st, 2000. * * Added MS-CHAPv2 support. */ #pragma ident "%Z%%M% %I% %E% SMI" #define RCSID "$Id: chap_ms.c,v 1.15 1999/08/13 06:46:12 paulus Exp $" #if defined(CHAPMS) || defined(CHAPMSV2) #include #include #include #include #include #include #include #ifdef HAVE_CRYPT_H #include #endif #ifdef CHAPMSV2 #include "sha1.h" #endif #ifndef USE_CRYPT #include #endif #include "pppd.h" #include "chap.h" #include "chap_ms.h" #include "md4.h" #if !defined(lint) && !defined(_lint) static const char rcsid[] = RCSID; #endif typedef struct { u_char LANManResp[24]; u_char NTResp[24]; u_char UseNT; /* If 1, ignore the LANMan response field */ } MS_ChapResponse; /* We use MS_CHAP_RESPONSE_LEN, rather than sizeof(MS_ChapResponse), in case this struct gets padded. */ typedef struct { u_char PeerChallenge[16]; u_char MustBeZero[8]; u_char NTResp[24]; u_char Flags; /* Should be zero (Win98 sends 04) */ } MS_Chapv2Response; /* We use MS_CHAPV2_RESPONSE_LEN, rather than sizeof(MS_Chapv2Response), in case this struct gets padded. */ static void ChallengeResponse __P((u_char *, u_char *, u_char *)); static void DesEncrypt __P((u_char *, u_char *, u_char *)); static void MakeKey __P((u_char *, u_char *)); static u_char Get7Bits __P((u_char *, int)); #ifdef CHAPMS static void ChapMS_NT __P((u_char *, char *, int, MS_ChapResponse *)); #ifdef MSLANMAN static void ChapMS_LANMan __P((u_char *, char *, int, MS_ChapResponse *)); #endif #endif #ifdef CHAPMSV2 static void ChapMSv2_NT __P((char *, u_char *, char *, int, MS_Chapv2Response *)); #endif #ifdef USE_CRYPT static void Expand __P((u_char *, char *)); static void Collapse __P((char *, u_char *)); #endif #if defined(MSLANMAN) && defined(CHAPMS) bool ms_lanman = 0; /* Use LanMan password instead of NT */ /* Has meaning only with MS-CHAP challenges */ #endif #ifdef CHAPMSV2 /* Specially-formatted Microsoft CHAP response message. */ static char status_message[256]; #endif static void ChallengeResponse(challenge, pwHash, response) u_char *challenge; /* IN 8 octets */ u_char *pwHash; /* IN 16 octets */ u_char *response; /* OUT 24 octets */ { u_char ZPasswordHash[21]; BZERO(ZPasswordHash, sizeof(ZPasswordHash)); BCOPY(pwHash, ZPasswordHash, MD4_SIGNATURE_SIZE); #if 0 dbglog("ChallengeResponse - ZPasswordHash %.*B", sizeof(ZPasswordHash), ZPasswordHash); #endif DesEncrypt(challenge, ZPasswordHash + 0, response + 0); DesEncrypt(challenge, ZPasswordHash + 7, response + 8); DesEncrypt(challenge, ZPasswordHash + 14, response + 16); #if 0 dbglog("ChallengeResponse - response %.24B", response); #endif } #ifdef USE_CRYPT static void DesEncrypt(clear, key, cipher) u_char *clear; /* IN 8 octets */ u_char *key; /* IN 7 octets */ u_char *cipher; /* OUT 8 octets */ { u_char des_key[8]; char crypt_key[66]; char des_input[66]; MakeKey(key, des_key); Expand(des_key, crypt_key); setkey(crypt_key); #if 0 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet input : %.8B", clear)); #endif Expand(clear, des_input); encrypt(des_input, 0); Collapse(des_input, cipher); #if 0 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet output: %.8B", cipher)); #endif } #else /* USE_CRYPT */ static void DesEncrypt(clear, key, cipher) u_char *clear; /* IN 8 octets */ u_char *key; /* IN 7 octets */ u_char *cipher; /* OUT 8 octets */ { des_cblock des_key; des_key_schedule key_schedule; MakeKey(key, des_key); des_set_key(&des_key, key_schedule); #if 0 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet input : %.8B", clear)); #endif des_ecb_encrypt((des_cblock *)clear, (des_cblock *)cipher, key_schedule, 1); #if 0 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet output: %.8B", cipher)); #endif } #endif /* USE_CRYPT */ static u_char Get7Bits(input, startBit) u_char *input; int startBit; { register unsigned int word; word = (unsigned)input[startBit / 8] << 8; word |= (unsigned)input[startBit / 8 + 1]; word >>= 15 - (startBit % 8 + 7); return word & 0xFE; } #ifdef USE_CRYPT /* in == 8-byte string (expanded version of the 56-bit key) * out == 64-byte string where each byte is either 1 or 0 * Note that the low-order "bit" is always ignored by by setkey() */ static void Expand(in, out) u_char *in; char *out; { int j, c; int i; for(i = 0; i < 64; in++){ c = *in; for(j = 7; j >= 0; j--) *out++ = (c >> j) & 01; i += 8; } } /* The inverse of Expand */ static void Collapse(in, out) char *in; u_char *out; { int j; int i; unsigned int c; for (i = 0; i < 64; i += 8, out++) { c = 0; for (j = 7; j >= 0; j--, in++) c |= *(u_char *)in << j; *out = c & 0xff; } } #endif static void MakeKey(key, des_key) u_char *key; /* IN 56 bit DES key missing parity bits */ u_char *des_key; /* OUT 64 bit DES key with parity bits added */ { des_key[0] = Get7Bits(key, 0); des_key[1] = Get7Bits(key, 7); des_key[2] = Get7Bits(key, 14); des_key[3] = Get7Bits(key, 21); des_key[4] = Get7Bits(key, 28); des_key[5] = Get7Bits(key, 35); des_key[6] = Get7Bits(key, 42); des_key[7] = Get7Bits(key, 49); #ifndef USE_CRYPT des_set_odd_parity((des_cblock *)des_key); #endif #if 0 CHAPDEBUG((LOG_INFO, "MakeKey: 56-bit input : %.7B", key)); CHAPDEBUG((LOG_INFO, "MakeKey: 64-bit output: %.8B", des_key)); #endif } #ifdef CHAPMS static void ChapMS_NT(rchallenge, secret, secret_len, response) u_char *rchallenge; char *secret; int secret_len; MS_ChapResponse *response; { int i; #ifdef __NetBSD__ /* NetBSD uses the libc md4 routines which take bytes instead of bits */ int mdlen = secret_len * 2; #else int mdlen = secret_len * 2 * 8; #endif MD4_CTX md4Context; u_char hash[MD4_SIGNATURE_SIZE]; u_char unicodePassword[MAX_NT_PASSWORD * 2]; /* Initialize the Unicode version of the secret (== password). */ /* This implicitly supports 8-bit ISO8859/1 characters. */ BZERO(unicodePassword, sizeof(unicodePassword)); for (i = 0; i < secret_len; i++) unicodePassword[i * 2] = (u_char)secret[i]; MD4Init(&md4Context); MD4Update(&md4Context, unicodePassword, mdlen); MD4Final(hash, &md4Context); /* Tell MD4 we're done */ ChallengeResponse(rchallenge, hash, response->NTResp); } #ifdef MSLANMAN static u_char *StdText = (u_char *)"KGS!@#$%"; /* key from rasapi32.dll */ static void ChapMS_LANMan(rchallenge, secret, secret_len, response) 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)( islower(secret[i]) ? toupper(secret[i]) : secret[i]); DesEncrypt( StdText, UcasePassword + 0, PasswordHash + 0 ); DesEncrypt( StdText, UcasePassword + 7, PasswordHash + 8 ); ChallengeResponse(rchallenge, PasswordHash, response->LANManResp); } #endif void ChapMS(cstate, rchallenge, rchallenge_len, secret, secret_len) chap_state *cstate; u_char *rchallenge; int rchallenge_len; char *secret; int secret_len; { MS_ChapResponse response; if (rchallenge_len < 8) { cstate->resp_length = 0; return; } #if 0 CHAPDEBUG((LOG_INFO, "ChapMS: secret is '%.*s'", secret_len, secret)); #endif BZERO(&response, sizeof(response)); /* Calculate both always */ ChapMS_NT(rchallenge, secret, secret_len, &response); #ifdef MSLANMAN ChapMS_LANMan(rchallenge, secret, secret_len, &response); /* prefered method is set by option */ response.UseNT = !ms_lanman; #else response.UseNT = 1; #endif BCOPY(&response, cstate->response, MS_CHAP_RESPONSE_LEN); cstate->resp_length = MS_CHAP_RESPONSE_LEN; } static int ChapMSStatus(cstate, flag) chap_state *cstate; int flag; { if (flag != 0) { cstate->stat_message = NULL; cstate->stat_length = 0; } else { cstate->stat_message = "E=691 R=0 M=\"Authentication failed\""; cstate->stat_length = strlen(cstate->stat_message); } return (flag); } int ChapMSValidate(cstate, response, response_len, secret, secret_len) chap_state *cstate; u_char *response; int response_len; char *secret; int secret_len; { MS_ChapResponse ckresp; if (response_len < MS_CHAP_RESPONSE_LEN || cstate->chal_len < 8) return (0); BZERO(&ckresp, sizeof(ckresp)); if (response[MS_CHAP_RESPONSE_LEN-1]) { ChapMS_NT(cstate->challenge, secret, secret_len, &ckresp); return (ChapMSStatus(cstate, memcmp(ckresp.NTResp, response+24, 24) == 0)); } #ifdef MSLANMAN ChapMS_LANMan(cstate->challenge, secret, secret_len, &ckresp); return (ChapMSStatus(cstate, memcmp(ckresp.LANManResp, response, 24) == 0)); #else return (ChapMSStatus(cstate, 0)); #endif } #endif /* CHAPMS */ #ifdef CHAPMSV2 static void ChallengeHash(peerchallenge, authenticatorchallenge, username, challenge) u_char *peerchallenge, *authenticatorchallenge, *challenge; char *username; { uint8_t digest[20]; SHA1_CTX sha1Context; char *cp; SHA1Init(&sha1Context); SHA1Update(&sha1Context, peerchallenge, 16); SHA1Update(&sha1Context, authenticatorchallenge, 16); /* * Only the user name (as presented by the peer and * excluding any prepended domain name) * is used as input to SHAUpdate(). */ if ((cp = strchr(username,'\\')) != NULL) username = cp; SHA1Update(&sha1Context, (uint8_t *)username, strlen(username)); SHA1Final(digest, &sha1Context); BCOPY(digest, challenge, 8); } static void ChapMSv2_NT(username, rchallenge, secret, secret_len, response) char *username; u_char *rchallenge; char *secret; int secret_len; MS_Chapv2Response *response; { int i; #ifdef __NetBSD__ /* NetBSD uses the libc md4 routines that take bytes instead of bits */ int mdlen = secret_len * 2; #else int mdlen = secret_len * 2 * 8; #endif MD4_CTX md4Context; u_char hash[MD4_SIGNATURE_SIZE]; u_char challenge[8]; u_char unicodePassword[MAX_NT_PASSWORD * 2]; /* Initialize the Unicode version of the secret (== password). */ /* This implicitly supports 8-bit ISO8859/1 characters. */ BZERO(unicodePassword, sizeof(unicodePassword)); for (i = 0; i < secret_len && i < MAX_NT_PASSWORD; i++) if ((unicodePassword[i * 2] = (u_char)secret[i]) == '\0') break; ChallengeHash(response->PeerChallenge, rchallenge, username, challenge); MD4Init(&md4Context); MD4Update(&md4Context, unicodePassword, mdlen); MD4Final(hash, &md4Context); /* Tell MD4 we're done */ ChallengeResponse(challenge, hash, response->NTResp); } void ChapMSv2(cstate, rchallenge, rchallenge_len, secret, secret_len) chap_state *cstate; u_char *rchallenge; int rchallenge_len; char *secret; int secret_len; { MS_Chapv2Response response; u_char *ptr; int i; if (rchallenge_len < 8) { cstate->resp_length = 0; return; } BZERO(&response, sizeof(response)); ptr = response.PeerChallenge; for (i = 0; i < 16; i++) *ptr++ = (u_char) (drand48() * 0xff); ChapMSv2_NT(cstate->resp_name, rchallenge, secret, secret_len, &response); BCOPY(&response, cstate->response, MS_CHAPV2_RESPONSE_LEN); cstate->resp_length = MS_CHAPV2_RESPONSE_LEN; } static void ChapMSv2Success(cstate, msresp, authchall, rhostname, secret, secret_len) chap_state *cstate; MS_Chapv2Response *msresp; u_char *authchall; char *rhostname, *secret; int secret_len; { static const u_char Magic1[39] = "Magic server to client signing constant"; static const u_char Magic2[41] = "Pad to make it do more than one iteration"; #ifdef __NetBSD__ /* NetBSD uses the libc md4 routines that take bytes instead of bits */ int mdlen = 1; #else int mdlen = 8; #endif u_char unicodePassword[MAX_NT_PASSWORD * 2]; MD4_CTX md4Context; u_char hash[MD4_SIGNATURE_SIZE]; u_char hashhash[MD4_SIGNATURE_SIZE]; SHA1_CTX sha1Context; uint8_t digest[20]; u_char challenge[8]; char *cp; static const char hexdig[] = "0123456789ABCDEF"; int i; /* Initialize the Unicode version of the secret (== password). */ /* This implicitly supports 8-bit ISO8859/1 characters. */ BZERO(unicodePassword, sizeof(unicodePassword)); for (i = 0; i < secret_len && i < MAX_NT_PASSWORD; i++) if ((unicodePassword[i * 2] = (u_char)secret[i]) == '\0') break; /* Hash the password with MD4 */ MD4Init(&md4Context); MD4Update(&md4Context, unicodePassword, secret_len * 2 * mdlen); MD4Final(hash, &md4Context); /* Now hash the hash */ MD4Init(&md4Context); MD4Update(&md4Context, hash, MD4_SIGNATURE_SIZE * mdlen); MD4Final(hashhash, &md4Context); SHA1Init(&sha1Context); SHA1Update(&sha1Context, hashhash, MD4_SIGNATURE_SIZE); SHA1Update(&sha1Context, msresp->NTResp, sizeof (msresp->NTResp)); SHA1Update(&sha1Context, Magic1, 39); SHA1Final(digest, &sha1Context); ChallengeHash(msresp->PeerChallenge, authchall, rhostname, challenge); SHA1Init(&sha1Context); SHA1Update(&sha1Context, digest, 20); SHA1Update(&sha1Context, challenge, 8); SHA1Update(&sha1Context, Magic2, 41); SHA1Final(digest, &sha1Context); cp = status_message; *cp++ = 'S'; *cp++ = '='; for (i = 0; i < 20; i++) { *cp++ = hexdig[digest[i]>>4]; *cp++ = hexdig[digest[i]&15]; } /* * RFC 2759 says that a M= greeting message is possible * here. It lies. Any such greeting causes Windoze-98 to give * error number 742, "Dial-Up Networking was unable to complete * the connection. The computer you're dialing in to does not * support the data encryption requirements specified. Please * check your encryption settings in the properties of the * connection. If this problem persists, contact your network * administrator." */ *cp = '\0'; #if 0 slprintf(cp, sizeof (status_message) - (cp-status_message), "M=\"Welcome to %s.\"", hostname); #endif cstate->stat_message = status_message; cstate->stat_length = strlen(status_message); } int ChapMSv2Validate(cstate, rhostname, response, response_len, secret, secret_len) chap_state *cstate; char *rhostname; u_char *response; int response_len; char *secret; int secret_len; { MS_Chapv2Response ckresp; if (response_len < MS_CHAPV2_RESPONSE_LEN || /* response[MS_CHAPV2_RESPONSE_LEN-1] != 0 || */cstate->chal_len < 8) { cstate->stat_message = NULL; cstate->stat_length = 0; return 0; } BZERO(&ckresp, sizeof(ckresp)); BCOPY(response, ckresp.PeerChallenge, 16); ChapMSv2_NT(rhostname, cstate->challenge, secret, secret_len, &ckresp); if (memcmp(ckresp.NTResp, response+24, 24) != 0) { cstate->stat_message = "E=691 R=0 C=11111111111111111111111111111111 V=3 M=\"Authentication failed\""; cstate->stat_length = strlen(cstate->stat_message); return (0); } ChapMSv2Success(cstate, (MS_Chapv2Response *)response, cstate->challenge, rhostname, secret, secret_len); return (1); } #endif /* CHAPMSV2 */ #endif /* CHAPMS or CHAPMSV2 */