+++ /dev/null
-/*
- * chap.c - Challenge Handshake Authentication Protocol.
- *
- * Copyright (c) 1993-2002 Paul Mackerras. 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.
- *
- * 4. Redistributions of any form whatsoever must retain the following
- * acknowledgment:
- * "This product includes software developed by Paul Mackerras
- * <paulus@samba.org>".
- *
- * 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.
- *
- * Copyright (c) 1991 Gregory M. Christy.
- * 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 Gregory M. Christy. 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.
- */
-
-#define RCSID "$Id: chap.c,v 1.41 2003/07/28 12:25:41 carlsonj Exp $"
-
-/*
- * TODO:
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/types.h>
-#include <sys/time.h>
-
-#include "pppd.h"
-#include "chap.h"
-#include "md5.h"
-#ifdef CHAPMS
-#include "chap_ms.h"
-#endif
-
-/* Hook for a plugin to validate CHAP challenge */
-int (*chap_auth_hook) __P((char *user,
- u_char *remmd,
- int remmd_len,
- chap_state *cstate)) = NULL;
-
-static const char rcsid[] = RCSID;
-
-#ifdef CHAPMS
-/* For MPPE debug */
-/* Use "[]|}{?/><,`!2&&(" (sans quotes) for RFC 3079 MS-CHAPv2 test value */
-static char *mschap_challenge = NULL;
-/* Use "!@\#$%^&*()_+:3|~" (sans quotes, backslash is to escape #) for ... */
-static char *mschap2_peer_challenge = NULL;
-#endif
-
-/*
- * Command-line options.
- */
-static option_t chap_option_list[] = {
- { "chap-restart", o_int, &chap[0].timeouttime,
- "Set timeout for CHAP", OPT_PRIO },
- { "chap-max-challenge", o_int, &chap[0].max_transmits,
- "Set max #xmits for challenge", OPT_PRIO },
- { "chap-interval", o_int, &chap[0].chal_interval,
- "Set interval for rechallenge", OPT_PRIO },
-#ifdef MSCHAP
-#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
-#endif
- { NULL }
-};
-
-/*
- * Protocol entry points.
- */
-static void ChapInit __P((int));
-static void ChapLowerUp __P((int));
-static void ChapLowerDown __P((int));
-static void ChapInput __P((int, u_char *, int));
-static void ChapProtocolReject __P((int));
-static int ChapPrintPkt __P((u_char *, int,
- void (*) __P((void *, char *, ...)), void *));
-
-struct protent chap_protent = {
- PPP_CHAP,
- ChapInit,
- ChapInput,
- ChapProtocolReject,
- ChapLowerUp,
- ChapLowerDown,
- NULL,
- NULL,
- ChapPrintPkt,
- NULL,
- 1,
- "CHAP",
- NULL,
- chap_option_list,
- NULL,
- NULL,
- NULL
-};
-
-chap_state chap[NUM_PPP]; /* CHAP state; one for each unit */
-
-static void ChapChallengeTimeout __P((void *));
-static void ChapResponseTimeout __P((void *));
-static void ChapReceiveChallenge __P((chap_state *, u_char *, int, int));
-static void ChapRechallenge __P((void *));
-static void ChapReceiveResponse __P((chap_state *, u_char *, int, int));
-static void ChapReceiveSuccess __P((chap_state *, u_char *, int, int));
-static void ChapReceiveFailure __P((chap_state *, u_char *, int, int));
-static void ChapSendStatus __P((chap_state *, int));
-static void ChapSendChallenge __P((chap_state *));
-static void ChapSendResponse __P((chap_state *));
-static void ChapGenChallenge __P((chap_state *));
-
-extern double drand48 __P((void));
-extern void srand48 __P((long));
-
-/*
- * ChapInit - Initialize a CHAP unit.
- */
-static void
-ChapInit(unit)
- int unit;
-{
- chap_state *cstate = &chap[unit];
-
- BZERO(cstate, sizeof(*cstate));
- cstate->unit = unit;
- cstate->clientstate = CHAPCS_INITIAL;
- cstate->serverstate = CHAPSS_INITIAL;
- cstate->timeouttime = CHAP_DEFTIMEOUT;
- cstate->max_transmits = CHAP_DEFTRANSMITS;
- /* random number generator is initialized in magic_init */
-}
-
-
-/*
- * chap_auth_with_peer - Authenticate us with our peer (start client).
- *
- */
-void
-chap_auth_with_peer(int unit, char *our_name, int digest)
-{
- chap_state *cstate = &chap[unit];
-
- cstate->resp_name = our_name;
- cstate->resp_type = digest;
-
- if (cstate->clientstate == CHAPCS_INITIAL ||
- cstate->clientstate == CHAPCS_PENDING) {
- /* lower layer isn't up - wait until later */
- cstate->clientstate = CHAPCS_PENDING;
- return;
- }
-
- /*
- * We get here as a result of LCP coming up.
- * So even if CHAP was open before, we will
- * have to re-authenticate ourselves.
- */
- cstate->clientstate = CHAPCS_LISTEN;
-}
-
-
-/*
- * chap_auth_peer - Authenticate our peer (start server).
- */
-void
-chap_auth_peer(int unit, char *our_name, int digest)
-{
- chap_state *cstate = &chap[unit];
-
- cstate->chal_name = our_name;
- cstate->chal_type = digest;
-
- if (cstate->serverstate == CHAPSS_INITIAL ||
- cstate->serverstate == CHAPSS_PENDING) {
- /* lower layer isn't up - wait until later */
- cstate->serverstate = CHAPSS_PENDING;
- return;
- }
-
- ChapGenChallenge(cstate);
- ChapSendChallenge(cstate); /* crank it up dude! */
- cstate->serverstate = CHAPSS_INITIAL_CHAL;
-}
-
-
-/*
- * ChapChallengeTimeout - Timeout expired on sending challenge.
- */
-static void
-ChapChallengeTimeout(arg)
- void *arg;
-{
- chap_state *cstate = (chap_state *) arg;
-
- /* if we aren't sending challenges, don't worry. then again we */
- /* probably shouldn't be here either */
- if (cstate->serverstate != CHAPSS_INITIAL_CHAL &&
- cstate->serverstate != CHAPSS_RECHALLENGE)
- return;
-
- if (cstate->chal_transmits >= cstate->max_transmits) {
- /* give up on peer */
- error("Peer failed to respond to CHAP challenge");
- cstate->serverstate = CHAPSS_BADAUTH;
- auth_peer_fail(cstate->unit, PPP_CHAP);
- return;
- }
-
- ChapSendChallenge(cstate); /* Re-send challenge */
-}
-
-
-/*
- * ChapResponseTimeout - Timeout expired on sending response.
- */
-static void
-ChapResponseTimeout(arg)
- void *arg;
-{
- chap_state *cstate = (chap_state *) arg;
-
- /* if we aren't sending a response, don't worry. */
- if (cstate->clientstate != CHAPCS_RESPONSE)
- return;
-
- ChapSendResponse(cstate); /* re-send response */
-}
-
-
-/*
- * ChapRechallenge - Time to challenge the peer again.
- */
-static void
-ChapRechallenge(arg)
- void *arg;
-{
- chap_state *cstate = (chap_state *) arg;
-
- /* if we aren't sending a response, don't worry. */
- if (cstate->serverstate != CHAPSS_OPEN)
- return;
-
- ChapGenChallenge(cstate);
- ChapSendChallenge(cstate);
- cstate->serverstate = CHAPSS_RECHALLENGE;
-}
-
-
-/*
- * ChapLowerUp - The lower layer is up.
- *
- * Start up if we have pending requests.
- */
-static void
-ChapLowerUp(unit)
- int unit;
-{
- chap_state *cstate = &chap[unit];
-
- if (cstate->clientstate == CHAPCS_INITIAL)
- cstate->clientstate = CHAPCS_CLOSED;
- else if (cstate->clientstate == CHAPCS_PENDING)
- cstate->clientstate = CHAPCS_LISTEN;
-
- if (cstate->serverstate == CHAPSS_INITIAL)
- cstate->serverstate = CHAPSS_CLOSED;
- else if (cstate->serverstate == CHAPSS_PENDING) {
- ChapGenChallenge(cstate);
- ChapSendChallenge(cstate);
- cstate->serverstate = CHAPSS_INITIAL_CHAL;
- }
-}
-
-
-/*
- * ChapLowerDown - The lower layer is down.
- *
- * Cancel all timeouts.
- */
-static void
-ChapLowerDown(unit)
- int unit;
-{
- chap_state *cstate = &chap[unit];
-
- /* Timeout(s) pending? Cancel if so. */
- if (cstate->serverstate == CHAPSS_INITIAL_CHAL ||
- cstate->serverstate == CHAPSS_RECHALLENGE)
- UNTIMEOUT(ChapChallengeTimeout, cstate);
- else if (cstate->serverstate == CHAPSS_OPEN
- && cstate->chal_interval != 0)
- UNTIMEOUT(ChapRechallenge, cstate);
- if (cstate->clientstate == CHAPCS_RESPONSE)
- UNTIMEOUT(ChapResponseTimeout, cstate);
-
- cstate->clientstate = CHAPCS_INITIAL;
- cstate->serverstate = CHAPSS_INITIAL;
-}
-
-
-/*
- * ChapProtocolReject - Peer doesn't grok CHAP.
- */
-static void
-ChapProtocolReject(unit)
- int unit;
-{
- chap_state *cstate = &chap[unit];
-
- if (cstate->serverstate != CHAPSS_INITIAL &&
- cstate->serverstate != CHAPSS_CLOSED)
- auth_peer_fail(unit, PPP_CHAP);
- if (cstate->clientstate != CHAPCS_INITIAL &&
- cstate->clientstate != CHAPCS_CLOSED)
- auth_withpeer_fail(unit, PPP_CHAP);
- ChapLowerDown(unit); /* shutdown chap */
-}
-
-
-/*
- * ChapInput - Input CHAP packet.
- */
-static void
-ChapInput(unit, inpacket, packet_len)
- int unit;
- u_char *inpacket;
- int packet_len;
-{
- chap_state *cstate = &chap[unit];
- u_char *inp;
- u_char code, id;
- int len;
-
- /*
- * Parse header (code, id and length).
- * If packet too short, drop it.
- */
- inp = inpacket;
- if (packet_len < CHAP_HEADERLEN) {
- CHAPDEBUG(("ChapInput: rcvd short header."));
- return;
- }
- GETCHAR(code, inp);
- GETCHAR(id, inp);
- GETSHORT(len, inp);
- if (len < CHAP_HEADERLEN) {
- CHAPDEBUG(("ChapInput: rcvd illegal length."));
- return;
- }
- if (len > packet_len) {
- CHAPDEBUG(("ChapInput: rcvd short packet."));
- return;
- }
- len -= CHAP_HEADERLEN;
-
- /*
- * Action depends on code (as in fact it usually does :-).
- */
- switch (code) {
- case CHAP_CHALLENGE:
- ChapReceiveChallenge(cstate, inp, id, len);
- break;
-
- case CHAP_RESPONSE:
- ChapReceiveResponse(cstate, inp, id, len);
- break;
-
- case CHAP_FAILURE:
- ChapReceiveFailure(cstate, inp, id, len);
- break;
-
- case CHAP_SUCCESS:
- ChapReceiveSuccess(cstate, inp, id, len);
- break;
-
- default: /* Need code reject? */
- warn("Unknown CHAP code (%d) received.", code);
- break;
- }
-}
-
-
-/*
- * ChapReceiveChallenge - Receive Challenge and send Response.
- */
-static void
-ChapReceiveChallenge(cstate, inp, id, len)
- chap_state *cstate;
- u_char *inp;
- int id;
- int len;
-{
- int rchallenge_len;
- u_char *rchallenge;
- int secret_len;
- char secret[MAXSECRETLEN];
- char rhostname[256];
- MD5_CTX mdContext;
- u_char hash[MD5_SIGNATURE_SIZE];
-
- if (cstate->clientstate == CHAPCS_CLOSED ||
- cstate->clientstate == CHAPCS_PENDING) {
- CHAPDEBUG(("ChapReceiveChallenge: in state %d", cstate->clientstate));
- return;
- }
-
- if (len < 2) {
- CHAPDEBUG(("ChapReceiveChallenge: rcvd short packet."));
- return;
- }
-
- GETCHAR(rchallenge_len, inp);
- len -= sizeof (u_char) + rchallenge_len; /* now name field length */
- if (len < 0) {
- CHAPDEBUG(("ChapReceiveChallenge: rcvd short packet."));
- return;
- }
- rchallenge = inp;
- INCPTR(rchallenge_len, inp);
-
- /* Null terminate and clean remote name. */
- slprintf(rhostname, sizeof(rhostname), "%.*v", len, inp);
-
- /* Microsoft doesn't send their name back in the PPP packet */
- if (explicit_remote || (remote_name[0] != 0 && rhostname[0] == 0)) {
- strlcpy(rhostname, remote_name, sizeof(rhostname));
- CHAPDEBUG(("ChapReceiveChallenge: using '%q' as remote name",
- rhostname));
- }
-
- /* get secret for authenticating ourselves with the specified host */
- if (!get_secret(cstate->unit, cstate->resp_name, rhostname,
- secret, &secret_len, 0)) {
- secret_len = 0; /* assume null secret if can't find one */
- warn("No CHAP secret found for authenticating us to %q", rhostname);
- }
-
- /* cancel response send timeout if necessary */
- if (cstate->clientstate == CHAPCS_RESPONSE)
- UNTIMEOUT(ChapResponseTimeout, cstate);
-
- cstate->resp_id = id;
- cstate->resp_transmits = 0;
-
- /* generate MD based on negotiated type */
- switch (cstate->resp_type) {
-
- case CHAP_DIGEST_MD5:
- MD5Init(&mdContext);
- MD5Update(&mdContext, &cstate->resp_id, 1);
- MD5Update(&mdContext, secret, secret_len);
- MD5Update(&mdContext, rchallenge, rchallenge_len);
- MD5Final(hash, &mdContext);
- BCOPY(hash, cstate->response, MD5_SIGNATURE_SIZE);
- cstate->resp_length = MD5_SIGNATURE_SIZE;
- break;
-
-#ifdef CHAPMS
- case CHAP_MICROSOFT:
- ChapMS(cstate, rchallenge, secret, secret_len,
- (MS_ChapResponse *) cstate->response);
- break;
-
- case CHAP_MICROSOFT_V2:
- ChapMS2(cstate, rchallenge,
- mschap2_peer_challenge? mschap2_peer_challenge: NULL,
- cstate->resp_name, secret, secret_len,
- (MS_Chap2Response *) cstate->response, cstate->earesponse,
- MS_CHAP2_AUTHENTICATEE);
- break;
-#endif /* CHAPMS */
-
- default:
- CHAPDEBUG(("unknown digest type %d", cstate->resp_type));
- return;
- }
-
- BZERO(secret, sizeof(secret));
- ChapSendResponse(cstate);
-}
-
-
-/*
- * ChapReceiveResponse - Receive and process response.
- */
-static void
-ChapReceiveResponse(cstate, inp, id, len)
- chap_state *cstate;
- u_char *inp;
- int id;
- int len;
-{
- u_char *remmd, remmd_len;
- int secret_len, old_state;
- int code;
- char rhostname[256];
- MD5_CTX mdContext;
- char secret[MAXSECRETLEN];
- u_char hash[MD5_SIGNATURE_SIZE];
-
- if (cstate->serverstate == CHAPSS_CLOSED ||
- cstate->serverstate == CHAPSS_PENDING) {
- CHAPDEBUG(("ChapReceiveResponse: in state %d", cstate->serverstate));
- return;
- }
-
- if (id != cstate->chal_id)
- return; /* doesn't match ID of last challenge */
-
- /*
- * If we have received a duplicate or bogus Response,
- * we have to send the same answer (Success/Failure)
- * as we did for the first Response we saw.
- */
- if (cstate->serverstate == CHAPSS_OPEN) {
- ChapSendStatus(cstate, CHAP_SUCCESS);
- return;
- }
- if (cstate->serverstate == CHAPSS_BADAUTH) {
- ChapSendStatus(cstate, CHAP_FAILURE);
- return;
- }
-
- if (len < 2) {
- CHAPDEBUG(("ChapReceiveResponse: rcvd short packet."));
- return;
- }
- GETCHAR(remmd_len, inp); /* get length of MD */
- remmd = inp; /* get pointer to MD */
- INCPTR(remmd_len, inp);
-
- len -= sizeof (u_char) + remmd_len;
- if (len < 0) {
- CHAPDEBUG(("ChapReceiveResponse: rcvd short packet."));
- return;
- }
-
- UNTIMEOUT(ChapChallengeTimeout, cstate);
-
- /* Null terminate and clean remote name. */
- slprintf(rhostname, sizeof(rhostname), "%.*v", len, inp);
-
-#ifdef CHAPMS
- /* copy the flags into cstate for use elsewhere */
- if (cstate->chal_type == CHAP_MICROSOFT_V2)
- cstate->resp_flags = ((MS_Chap2Response *) remmd)->Flags[0];
-#endif /* CHAPMS */
- /*
- * Get secret for authenticating them with us,
- * do the hash ourselves, and compare the result.
- */
- code = CHAP_FAILURE;
-
- /* If a plugin will verify the response, let the plugin do it. */
- if (chap_auth_hook) {
- code = (*chap_auth_hook) ( (explicit_remote ? remote_name : rhostname),
- remmd, (int) remmd_len,
- cstate );
- /*
- * Check remote number authorization. A plugin may have filled in
- * the remote number or added an allowed number, and rather than
- * return an authenticate failure, is leaving it for us to verify.
- */
- if (code == CHAP_SUCCESS) {
- if (!auth_number()) {
- /* We do not want to leak info about the chap result. */
- code = CHAP_FAILURE; /* XXX exit value will be "wrong" */
- warn("calling number %q is not authorized", remote_number);
- }
- }
-
- } else {
- if (!get_secret(cstate->unit, (explicit_remote? remote_name: rhostname),
- cstate->chal_name, secret, &secret_len, 1)) {
- warn("No CHAP secret found for authenticating %q", rhostname);
- } else {
-
- /* generate MD based on negotiated type */
- switch (cstate->chal_type) {
-
- case CHAP_DIGEST_MD5:
- if (remmd_len != MD5_SIGNATURE_SIZE)
- break; /* not even the right length */
- MD5Init(&mdContext);
- MD5Update(&mdContext, &cstate->chal_id, 1);
- MD5Update(&mdContext, secret, secret_len);
- MD5Update(&mdContext, cstate->challenge, cstate->chal_len);
- MD5Final(hash, &mdContext);
-
- /* compare MDs and send the appropriate status */
- if (memcmp(hash, remmd, MD5_SIGNATURE_SIZE) == 0)
- code = CHAP_SUCCESS; /* they are the same! */
- break;
-
-#ifdef CHAPMS
- case CHAP_MICROSOFT:
- {
- int response_offset, response_size;
- MS_ChapResponse *rmd = (MS_ChapResponse *) remmd;
- MS_ChapResponse md;
-
- if (remmd_len != MS_CHAP_RESPONSE_LEN)
- break; /* not even the right length */
-
- /* Determine which part of response to verify against */
- if (rmd->UseNT[0]) {
- response_offset = offsetof(MS_ChapResponse, NTResp);
- response_size = sizeof(rmd->NTResp);
- } else {
-#ifdef MSLANMAN
- response_offset = offsetof(MS_ChapResponse, LANManResp);
- response_size = sizeof(rmd->LANManResp);
-#else
- /* Should really propagate this into the error packet. */
- notice("Peer request for LANMAN auth not supported");
- break;
-#endif /* MSLANMAN */
- }
-
- /* Generate the expected response. */
- ChapMS(cstate, cstate->challenge, secret, secret_len, &md);
-
- /* compare MDs and send the appropriate status */
- if (memcmp((u_char *) &md + response_offset,
- (u_char *) remmd + response_offset,
- response_size) == 0)
- code = CHAP_SUCCESS; /* they are the same! */
- break;
- }
-
- case CHAP_MICROSOFT_V2:
- {
- MS_Chap2Response *rmd = (MS_Chap2Response *) remmd;
- MS_Chap2Response md;
-
- if (remmd_len != MS_CHAP2_RESPONSE_LEN)
- break; /* not even the right length */
-
- /* Generate the expected response and our mutual auth. */
- ChapMS2(cstate, cstate->challenge, rmd->PeerChallenge,
- (explicit_remote? remote_name: rhostname),
- secret, secret_len, &md,
- cstate->saresponse, MS_CHAP2_AUTHENTICATOR);
-
- /* compare MDs and send the appropriate status */
- if (memcmp(md.NTResp, rmd->NTResp, sizeof(md.NTResp)) == 0)
- code = CHAP_SUCCESS; /* yay! */
- break;
- }
-#endif /* CHAPMS */
-
- default:
- CHAPDEBUG(("unknown digest type %d", cstate->chal_type));
- }
- }
-
- BZERO(secret, sizeof(secret));
- }
- ChapSendStatus(cstate, code);
-
- if (code == CHAP_SUCCESS) {
- old_state = cstate->serverstate;
- cstate->serverstate = CHAPSS_OPEN;
- if (old_state == CHAPSS_INITIAL_CHAL) {
- auth_peer_success(cstate->unit, PPP_CHAP, cstate->chal_type,
- rhostname, len);
- }
- if (cstate->chal_interval != 0)
- TIMEOUT(ChapRechallenge, cstate, cstate->chal_interval);
- notice("CHAP peer authentication succeeded for %q", rhostname);
-
- } else {
- warn("CHAP peer authentication failed for %q", rhostname);
- cstate->serverstate = CHAPSS_BADAUTH;
- auth_peer_fail(cstate->unit, PPP_CHAP);
- }
-}
-
-/*
- * ChapReceiveSuccess - Receive Success
- */
-static void
-ChapReceiveSuccess(cstate, inp, id, len)
- chap_state *cstate;
- u_char *inp;
- u_char id;
- int len;
-{
-
- if (cstate->clientstate == CHAPCS_OPEN)
- /* presumably an answer to a duplicate response */
- return;
-
- if (cstate->clientstate != CHAPCS_RESPONSE) {
- /* don't know what this is */
- CHAPDEBUG(("ChapReceiveSuccess: in state %d\n", cstate->clientstate));
- return;
- }
-
- UNTIMEOUT(ChapResponseTimeout, cstate);
-
-#ifdef CHAPMS
- /*
- * For MS-CHAPv2, we must verify that the peer knows our secret.
- */
- if (cstate->resp_type == CHAP_MICROSOFT_V2) {
- if ((len >= MS_AUTH_RESPONSE_LENGTH + 2) && !strncmp(inp, "S=", 2)) {
- inp += 2; len -= 2;
- if (!memcmp(inp, cstate->earesponse, MS_AUTH_RESPONSE_LENGTH)) {
- /* Authenticator Response matches. */
- inp += MS_AUTH_RESPONSE_LENGTH; /* Eat it */
- len -= MS_AUTH_RESPONSE_LENGTH;
- if ((len >= 3) && !strncmp(inp, " M=", 3)) {
- inp += 3; len -= 3; /* Eat the delimiter */
- } else if (len) {
- /* Packet has extra text which does not begin " M=" */
- error("MS-CHAPv2 Success packet is badly formed.");
- auth_withpeer_fail(cstate->unit, PPP_CHAP);
- }
- } else {
- /* Authenticator Response did not match expected. */
- error("MS-CHAPv2 mutual authentication failed.");
- auth_withpeer_fail(cstate->unit, PPP_CHAP);
- }
- } else {
- /* Packet does not start with "S=" */
- error("MS-CHAPv2 Success packet is badly formed.");
- auth_withpeer_fail(cstate->unit, PPP_CHAP);
- }
- }
-#endif
-
- /*
- * Print message.
- */
- if (len > 0)
- PRINTMSG(inp, len);
-
- cstate->clientstate = CHAPCS_OPEN;
-
- notice("CHAP authentication succeeded");
- auth_withpeer_success(cstate->unit, PPP_CHAP, cstate->resp_type);
-}
-
-
-/*
- * ChapReceiveFailure - Receive failure.
- */
-static void
-ChapReceiveFailure(cstate, inp, id, len)
- chap_state *cstate;
- u_char *inp;
- u_char id;
- int len;
-{
-#ifdef CHAPMS
- u_char *msg;
-#endif
- u_char *p = inp;
-
- if (cstate->clientstate != CHAPCS_RESPONSE) {
- /* don't know what this is */
- CHAPDEBUG(("ChapReceiveFailure: in state %d\n", cstate->clientstate));
- return;
- }
-
-#ifdef CHAPMS
- /* We want a null-terminated string for strxxx(). */
- msg = malloc(len + 1);
- if (!msg) {
- p = NULL;
- notice("Out of memory in ChapReceiveFailure");
- goto print_msg;
- }
- BCOPY(inp, msg, len);
- p = msg + len; *p = '\0'; p = msg;
-#endif
-
- UNTIMEOUT(ChapResponseTimeout, cstate);
-
-#ifdef CHAPMS
- if ((cstate->resp_type == CHAP_MICROSOFT_V2) ||
- (cstate->resp_type == CHAP_MICROSOFT)) {
- int error;
-
- /*
- * 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 ChapSendStatus().
- */
- if (!strncmp(p, "E=", 2))
- error = (int) strtol(p, NULL, 10); /* Remember the error code. */
- else
- goto print_msg; /* Message is badly formatted. */
-
- if (len && ((p = strstr(p, " M=")) != NULL)) {
- /* M=<message> field found. */
- p += 3;
- } else {
- /* No M=<message>; use the error code. */
- switch(error) {
- 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);
- p = msg = malloc(len + 33);
- if (!msg) {
- novm("ChapReceiveFailure");
- goto print_msg;
- }
- slprintf(p, len + 33, "Unknown authentication failure: %.*s",
- len, inp);
- break;
- }
- }
- len = strlen(p);
- }
-#endif
-
- /*
- * Print message.
- */
-#ifdef CHAPMS
-print_msg:
-#endif
- if (len > 0 && p != NULL)
- PRINTMSG(p, len);
-
- error("CHAP authentication failed");
- auth_withpeer_fail(cstate->unit, PPP_CHAP);
-#ifdef CHAPMS
- if (msg) free(msg);
-#endif
-}
-
-
-/*
- * ChapSendChallenge - Send an Authenticate challenge.
- */
-static void
-ChapSendChallenge(cstate)
- chap_state *cstate;
-{
- u_char *outp;
- int chal_len, name_len;
- int outlen;
-
- chal_len = cstate->chal_len;
- name_len = strlen(cstate->chal_name);
- outlen = CHAP_HEADERLEN + sizeof (u_char) + chal_len + name_len;
- outp = outpacket_buf;
-
- MAKEHEADER(outp, PPP_CHAP); /* paste in a CHAP header */
-
- PUTCHAR(CHAP_CHALLENGE, outp);
- PUTCHAR(cstate->chal_id, outp);
- PUTSHORT(outlen, outp);
-
- PUTCHAR(chal_len, outp); /* put length of challenge */
- BCOPY(cstate->challenge, outp, chal_len);
- INCPTR(chal_len, outp);
-
- BCOPY(cstate->chal_name, outp, name_len); /* append hostname */
-
- output(cstate->unit, outpacket_buf, outlen + PPP_HDRLEN);
-
- TIMEOUT(ChapChallengeTimeout, cstate, cstate->timeouttime);
- ++cstate->chal_transmits;
-}
-
-
-/*
- * ChapSendStatus - Send a status response (ack or nak).
- * See RFC 2433 and RFC 2759 for MS-CHAP and MS-CHAPv2 message formats.
- */
-static void
-ChapSendStatus(cstate, code)
- chap_state *cstate;
- int code;
-{
- u_char *outp;
- int outlen, msglen;
- char msg[256];
- char *p, *q;
-
- p = msg;
- q = p + sizeof(msg); /* points 1 byte past msg */
-
- if (code == CHAP_SUCCESS) {
-#ifdef CHAPMS
- if (cstate->chal_type == CHAP_MICROSOFT_V2) {
- /*
- * 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.
- */
- slprintf(p, q - p, "S=");
- p += 2;
- slprintf(p, q - p, "%s", cstate->saresponse);
- p += strlen(cstate->saresponse);
- if (cstate->resp_flags != 0)
- goto msgdone;
- slprintf(p, q - p, " M=");
- p += 3;
- }
-#endif /* CHAPMS */
-
- slprintf(p, q - p, "Welcome to %s.", hostname);
- } else {
-#ifdef CHAPMS
- if ((cstate->chal_type == CHAP_MICROSOFT_V2) ||
- (cstate->chal_type == CHAP_MICROSOFT)) {
- /*
- * 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, but MS-CHAP should ignore
- * any extra text according to RFC 2433. So we'll go the easy
- * (read: lazy) route and include it always. 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.
- */
- int i;
-
- slprintf(p, q - p, "E=691 R=1 C=");
- p += 12;
- for (i = 0; i < cstate->chal_len; i++)
- sprintf(p + i * 2, "%02X", cstate->challenge[i]);
- p += cstate->chal_len * 2;
- slprintf(p, q - p, " V=0 M=");
- p += 7;
- }
-#endif /* CHAPMS */
-
- slprintf(p, q - p, "I don't like you. Go 'way.");
- }
-#ifdef CHAPMS
-msgdone:
-#endif
- msglen = strlen(msg);
-
- outlen = CHAP_HEADERLEN + msglen;
- outp = outpacket_buf;
-
- MAKEHEADER(outp, PPP_CHAP); /* paste in a header */
-
- PUTCHAR(code, outp);
- PUTCHAR(cstate->chal_id, outp);
- PUTSHORT(outlen, outp);
- BCOPY(msg, outp, msglen);
- output(cstate->unit, outpacket_buf, outlen + PPP_HDRLEN);
-}
-
-/*
- * ChapGenChallenge is used to generate a pseudo-random challenge string of
- * a pseudo-random length between min_len and max_len. The challenge
- * string and its length are stored in *cstate, and various other fields of
- * *cstate are initialized.
- */
-
-static void
-ChapGenChallenge(cstate)
- chap_state *cstate;
-{
- int chal_len = 0; /* Avoid compiler warning */
- u_char *ptr = cstate->challenge;
- int i;
-
- switch (cstate->chal_type) {
- case CHAP_DIGEST_MD5:
- /*
- * pick a random challenge length between MIN_CHALLENGE_LENGTH and
- * MAX_CHALLENGE_LENGTH
- */
- chal_len = (unsigned) ((drand48() *
- (MAX_CHALLENGE_LENGTH - MIN_CHALLENGE_LENGTH)) +
- MIN_CHALLENGE_LENGTH);
- break;
-
-#ifdef CHAPMS
- case CHAP_MICROSOFT:
- /* MS-CHAP is fixed to an 8 octet challenge. */
- chal_len = 8;
- break;
-
- case CHAP_MICROSOFT_V2:
- /* MS-CHAPv2 is fixed to a 16 octet challenge. */
- chal_len = 16;
- break;
-#endif
- default:
- fatal("ChapGenChallenge: Unsupported challenge type %d",
- (int) cstate->chal_type);
- break;
- }
-
- cstate->chal_len = chal_len;
- cstate->chal_id = ++cstate->id;
- cstate->chal_transmits = 0;
-
-#ifdef CHAPMS
- if (mschap_challenge)
- for (i = 0; i < chal_len; i++)
- *ptr++ = mschap_challenge[i];
- else
-#endif
- /* generate a random string */
- for (i = 0; i < chal_len; i++)
- *ptr++ = (char) (drand48() * 0xff);
-}
-
-/*
- * ChapSendResponse - send a response packet with values as specified
- * in *cstate.
- */
-/* ARGSUSED */
-static void
-ChapSendResponse(cstate)
- chap_state *cstate;
-{
- u_char *outp;
- int outlen, md_len, name_len;
-
- md_len = cstate->resp_length;
- name_len = strlen(cstate->resp_name);
- outlen = CHAP_HEADERLEN + sizeof (u_char) + md_len + name_len;
- outp = outpacket_buf;
-
- MAKEHEADER(outp, PPP_CHAP);
-
- PUTCHAR(CHAP_RESPONSE, outp); /* we are a response */
- PUTCHAR(cstate->resp_id, outp); /* copy id from challenge packet */
- PUTSHORT(outlen, outp); /* packet length */
-
- PUTCHAR(md_len, outp); /* length of MD */
- BCOPY(cstate->response, outp, md_len); /* copy MD to buffer */
- INCPTR(md_len, outp);
-
- BCOPY(cstate->resp_name, outp, name_len); /* append our name */
-
- /* send the packet */
- output(cstate->unit, outpacket_buf, outlen + PPP_HDRLEN);
-
- cstate->clientstate = CHAPCS_RESPONSE;
- TIMEOUT(ChapResponseTimeout, cstate, cstate->timeouttime);
- ++cstate->resp_transmits;
-}
-
-/*
- * ChapPrintPkt - print the contents of a CHAP packet.
- */
-static char *ChapCodenames[] = {
- "Challenge", "Response", "Success", "Failure"
-};
-
-static int
-ChapPrintPkt(p, plen, printer, arg)
- u_char *p;
- int plen;
- void (*printer) __P((void *, char *, ...));
- void *arg;
-{
- int code, id, len;
- int clen, nlen;
- u_char x;
-
- if (plen < CHAP_HEADERLEN)
- return 0;
- GETCHAR(code, p);
- GETCHAR(id, p);
- GETSHORT(len, p);
- if (len < CHAP_HEADERLEN || len > plen)
- return 0;
-
- if (code >= 1 && code <= sizeof(ChapCodenames) / sizeof(char *))
- printer(arg, " %s", ChapCodenames[code-1]);
- else
- printer(arg, " code=0x%x", code);
- printer(arg, " id=0x%x", id);
- len -= CHAP_HEADERLEN;
- switch (code) {
- case CHAP_CHALLENGE:
- case CHAP_RESPONSE:
- if (len < 1)
- break;
- clen = p[0];
- if (len < clen + 1)
- break;
- ++p;
- nlen = len - clen - 1;
- printer(arg, " <");
- for (; clen > 0; --clen) {
- GETCHAR(x, p);
- printer(arg, "%.2x", x);
- }
- printer(arg, ">, name = ");
- print_string((char *)p, nlen, printer, arg);
- break;
- case CHAP_FAILURE:
- case CHAP_SUCCESS:
- printer(arg, " ");
- print_string((char *)p, len, printer, arg);
- break;
- default:
- for (clen = len; clen > 0; --clen) {
- GETCHAR(x, p);
- printer(arg, " %.2x", x);
- }
- }
-
- return len + CHAP_HEADERLEN;
-}
+++ /dev/null
-/*
- * chap.h - Challenge Handshake Authentication Protocol definitions.
- *
- * Copyright (c) 1993-2002 Paul Mackerras. 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.
- *
- * 4. Redistributions of any form whatsoever must retain the following
- * acknowledgment:
- * "This product includes software developed by Paul Mackerras
- * <paulus@samba.org>".
- *
- * 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.
- *
- * Copyright (c) 1991 Gregory M. Christy
- * 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 the author.
- *
- * 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.
- *
- * $Id: chap.h,v 1.15 2002/12/04 23:03:32 paulus Exp $
- */
-
-#ifndef __CHAP_INCLUDE__
-
-/* Code + ID + length */
-#define CHAP_HEADERLEN 4
-
-/*
- * CHAP codes.
- */
-
-#define CHAP_DIGEST_MD5 5 /* use MD5 algorithm */
-#define MD5_SIGNATURE_SIZE 16 /* 16 bytes in a MD5 message digest */
-#define CHAP_MICROSOFT 0x80 /* use Microsoft-compatible alg. */
-#define CHAP_MICROSOFT_V2 0x81 /* use Microsoft-compatible alg. */
-
-/*
- * Digest type and selection.
- */
-
-/* bitmask of supported algorithms */
-#define MDTYPE_MICROSOFT_V2 0x1
-#define MDTYPE_MICROSOFT 0x2
-#define MDTYPE_MD5 0x4
-
-#ifdef CHAPMS
-#define MDTYPE_ALL (MDTYPE_MICROSOFT_V2 | MDTYPE_MICROSOFT | MDTYPE_MD5)
-#else
-#define MDTYPE_ALL (MDTYPE_MD5)
-#endif
-#define MDTYPE_NONE 0
-
-/* Return the digest alg. ID for the most preferred digest type. */
-#define CHAP_DIGEST(mdtype) \
- ((mdtype) & MDTYPE_MICROSOFT_V2)? CHAP_MICROSOFT_V2: \
- ((mdtype) & MDTYPE_MICROSOFT)? CHAP_MICROSOFT: \
- ((mdtype) & MDTYPE_MD5)? CHAP_DIGEST_MD5: \
- 0
-
-/* Return the bit flag (lsb set) for our most preferred digest type. */
-#define CHAP_MDTYPE(mdtype) ((mdtype) ^ ((mdtype) - 1)) & (mdtype)
-
-/* Return the bit flag for a given digest algorithm ID. */
-#define CHAP_MDTYPE_D(digest) \
- ((digest) == CHAP_MICROSOFT_V2)? MDTYPE_MICROSOFT_V2: \
- ((digest) == CHAP_MICROSOFT)? MDTYPE_MICROSOFT: \
- ((digest) == CHAP_DIGEST_MD5)? MDTYPE_MD5: \
- 0
-
-/* Can we do the requested digest? */
-#define CHAP_CANDIGEST(mdtype, digest) \
- ((digest) == CHAP_MICROSOFT_V2)? (mdtype) & MDTYPE_MICROSOFT_V2: \
- ((digest) == CHAP_MICROSOFT)? (mdtype) & MDTYPE_MICROSOFT: \
- ((digest) == CHAP_DIGEST_MD5)? (mdtype) & MDTYPE_MD5: \
- 0
-
-#define CHAP_CHALLENGE 1
-#define CHAP_RESPONSE 2
-#define CHAP_SUCCESS 3
-#define CHAP_FAILURE 4
-
-/*
- * Challenge lengths (for challenges we send) and other limits.
- */
-#define MIN_CHALLENGE_LENGTH 16
-#define MAX_CHALLENGE_LENGTH 24 /* sufficient for MS-CHAP Peer Chal. */
-#define MAX_RESPONSE_LENGTH 64 /* sufficient for MD5 or MS-CHAP */
-#define MS_AUTH_RESPONSE_LENGTH 40 /* MS-CHAPv2 authenticator response, */
- /* as ASCII */
-
-/*
- * Each interface is described by a chap structure.
- */
-
-typedef struct chap_state {
- int unit; /* Interface unit number */
- int clientstate; /* Client state */
- int serverstate; /* Server state */
- u_char challenge[MAX_CHALLENGE_LENGTH]; /* last challenge string sent */
- u_char chal_len; /* challenge length */
- u_char chal_id; /* ID of last challenge */
- u_char chal_type; /* hash algorithm for challenges */
- u_char id; /* Current id */
- char *chal_name; /* Our name to use with challenge */
- int chal_interval; /* Time until we challenge peer again */
- int timeouttime; /* Timeout time in seconds */
- int max_transmits; /* Maximum # of challenge transmissions */
- int chal_transmits; /* Number of transmissions of challenge */
- int resp_transmits; /* Number of transmissions of response */
- u_char response[MAX_RESPONSE_LENGTH]; /* Response to send */
- char saresponse[MS_AUTH_RESPONSE_LENGTH+1]; /* Auth response to send */
- char earesponse[MS_AUTH_RESPONSE_LENGTH+1]; /* Auth response expected */
- /* +1 for null terminator */
- u_char resp_flags; /* flags from MS-CHAPv2 auth response */
- u_char resp_length; /* length of response */
- u_char resp_id; /* ID for response messages */
- u_char resp_type; /* hash algorithm for responses */
- char *resp_name; /* Our name to send with response */
-} chap_state;
-
-/* We need the declaration of chap_state to use this prototype */
-extern int (*chap_auth_hook) __P((char *user, u_char *remmd,
- int remmd_len, chap_state *cstate));
-
-/*
- * Client (peer) states.
- */
-#define CHAPCS_INITIAL 0 /* Lower layer down, not opened */
-#define CHAPCS_CLOSED 1 /* Lower layer up, not opened */
-#define CHAPCS_PENDING 2 /* Auth us to peer when lower up */
-#define CHAPCS_LISTEN 3 /* Listening for a challenge */
-#define CHAPCS_RESPONSE 4 /* Sent response, waiting for status */
-#define CHAPCS_OPEN 5 /* We've received Success */
-
-/*
- * Server (authenticator) states.
- */
-#define CHAPSS_INITIAL 0 /* Lower layer down, not opened */
-#define CHAPSS_CLOSED 1 /* Lower layer up, not opened */
-#define CHAPSS_PENDING 2 /* Auth peer when lower up */
-#define CHAPSS_INITIAL_CHAL 3 /* We've sent the first challenge */
-#define CHAPSS_OPEN 4 /* We've sent a Success msg */
-#define CHAPSS_RECHALLENGE 5 /* We've sent another challenge */
-#define CHAPSS_BADAUTH 6 /* We've sent a Failure msg */
-
-/*
- * Timeouts.
- */
-#define CHAP_DEFTIMEOUT 3 /* Timeout time in seconds */
-#define CHAP_DEFTRANSMITS 10 /* max # times to send challenge */
-
-extern chap_state chap[];
-
-void ChapAuthWithPeer __P((int, char *, int));
-void ChapAuthPeer __P((int, char *, int));
-
-extern struct protent chap_protent;
-
-#define __CHAP_INCLUDE__
-#endif /* __CHAP_INCLUDE__ */
projects / ppp.git / commitdiff