X-Git-Url: https://git.ozlabs.org/?p=ppp.git;a=blobdiff_plain;f=pppd%2Fchap_ms.c;h=2dde5ba76b60a3dbb297ffce23480175edecc1ac;hp=1041e0386759b5f9a26b08e80235dafa32bb6cb6;hb=5d490c4106f4a34864c980b925e183cf3bf575e2;hpb=d741a3b912f17d84dc8dc87474e0b989c775de50 diff --git a/pppd/chap_ms.c b/pppd/chap_ms.c index 1041e03..2dde5ba 100644 --- a/pppd/chap_ms.c +++ b/pppd/chap_ms.c @@ -1,23 +1,31 @@ /* * chap_ms.c - Microsoft MS-CHAP compatible implementation. * - * Copyright (c) 1995 Eric Rosenquist, Strata Software Limited. - * http://www.strataware.com/ + * Copyright (c) 1995 Eric Rosenquist. All rights reserved. * - * All rights reserved. + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: * - * 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. + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. * - * 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. + * 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. */ /* @@ -37,10 +45,36 @@ * 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. + * + * 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. + * */ -#define RCSID "$Id: chap_ms.c,v 1.23 2002/11/02 19:48:12 carlsonj Exp $" +#define RCSID "$Id: chap_ms.c,v 1.30 2003/07/10 17:59:33 fcusack Exp $" #ifdef CHAPMS @@ -53,11 +87,12 @@ #include #include "pppd.h" -#include "chap.h" +#include "chap-new.h" #include "chap_ms.h" #include "md4.h" #include "sha1.h" #include "pppcrypt.h" +#include "magic.h" static const char rcsid[] = RCSID; @@ -81,8 +116,6 @@ static void Set_Start_Key __P((u_char *, char *, int)); static void SetMasterKeys __P((char *, int, u_char[24], int)); #endif -extern double drand48 __P((void)); - #ifdef MSLANMAN bool ms_lanman = 0; /* Use LanMan password instead of NT */ /* Has meaning only with MS-CHAP challenges */ @@ -91,7 +124,313 @@ bool ms_lanman = 0; /* Use LanMan password instead of NT */ #ifdef MPPE u_char mppe_send_key[MPPE_MAX_KEY_LEN]; u_char mppe_recv_key[MPPE_MAX_KEY_LEN]; +int mppe_keys_set = 0; /* Have the MPPE keys been set? */ + +/* For MPPE debug */ +/* Use "[]|}{?/><,`!2&&(" (sans quotes) for RFC 3079 MS-CHAPv2 test value */ +static char *mschap_challenge = NULL; +/* Use "!@\#$%^&*()_+:3|~" (sans quotes, backslash is to escape #) for ... */ +static char *mschap2_peer_challenge = NULL; + +#include "fsm.h" /* Need to poke MPPE options */ +#include "ccp.h" +#include +#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; + if (mschap_challenge && strlen(mschap_challenge) == 8) + memcpy(challenge, mschap_challenge, 8); + else + random_bytes(challenge, 8); +} + +static void +chapms2_generate_challenge(unsigned char *challenge) +{ + *challenge++ = 16; + if (mschap_challenge && strlen(mschap_challenge) == 16) + memcpy(challenge, mschap_challenge, 16); + else + 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, 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, + secret, secret_len, &md, + saresponse, MS_CHAP2_AUTHENTICATOR); + + /* compare MDs and send the appropriate status */ + /* + * Per RFC 2759, success message must be formatted as + * "S= M=" + * where + * is the Authenticator Response (mutual auth) + * is a text message + * + * However, some versions of Windows (win98 tested) do not know + * about the M= 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 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, mschap2_peer_challenge, 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(msg, "S=", 2)) { + /* 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(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= part (if any). For MS-CHAP we're not really supposed + * to use M=, 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= field found. */ + p += 3; + } else { + /* No M=; 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, @@ -214,7 +553,7 @@ 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 *LMResponse) + MS_ChapResponse *response) { int i; u_char UcasePassword[MAX_NT_PASSWORD]; /* max is actually 14 */ @@ -228,7 +567,7 @@ ChapMS_LANMan(u_char *rchallenge, char *secret, int secret_len, DesEncrypt( StdText, PasswordHash + 0 ); (void) DesSetkey(UcasePassword + 7); DesEncrypt( StdText, PasswordHash + 8 ); - ChallengeResponse(rchallenge, PasswordHash, LMResponse); + ChallengeResponse(rchallenge, PasswordHash, response->LANManResp); } #endif @@ -430,7 +769,7 @@ SetMasterKeys(char *secret, int secret_len, u_char NTResponse[24], int IsServer) void -ChapMS(chap_state *cstate, u_char *rchallenge, char *secret, int secret_len, +ChapMS(u_char *rchallenge, char *secret, int secret_len, MS_ChapResponse *response) { #if 0 @@ -449,10 +788,9 @@ ChapMS(chap_state *cstate, u_char *rchallenge, char *secret, int secret_len, response->UseNT[0] = 1; #endif - cstate->resp_length = MS_CHAP_RESPONSE_LEN; - #ifdef MPPE Set_Start_Key(rchallenge, secret, secret_len); + mppe_keys_set = 1; #endif } @@ -468,9 +806,9 @@ ChapMS(chap_state *cstate, u_char *rchallenge, char *secret, int secret_len, * Authenticator Response. */ void -ChapMS2(chap_state *cstate, u_char *rchallenge, u_char *PeerChallenge, +ChapMS2(u_char *rchallenge, u_char *PeerChallenge, char *user, char *secret, int secret_len, MS_Chap2Response *response, - u_char authResponse[MS_AUTH_RESPONSE_LENGTH+1], int authenticator) + u_char authResponse[], int authenticator) { /* ARGSUSED */ u_char *p = response->PeerChallenge; @@ -495,12 +833,69 @@ ChapMS2(chap_state *cstate, u_char *rchallenge, u_char *PeerChallenge, response->PeerChallenge, rchallenge, user, authResponse); - cstate->resp_length = MS_CHAP2_RESPONSE_LEN; - #ifdef MPPE SetMasterKeys(secret, secret_len, response->NTResp, authenticator); + mppe_keys_set = 1; #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 */