/*** WARNING - THIS HAS NEVER BEEN FINISHED ***//****************************************************************************** chap.c - Network Challenge Handshake Authentication Protocol program file.** Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.* portions Copyright (c) 1997 by Global Election Systems Inc.** The authors hereby grant permission to use, copy, modify, distribute,* and license this software and its documentation for any purpose, provided* that existing copyright notices are retained in all copies and that this* notice and the following disclaimer are included verbatim in any * distributions. No written agreement, license, or royalty fee is required* for any of the authorized uses.** THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.******************************************************************************** REVISION HISTORY** 03-01-01 Marc Boucher <marc@mbsi.ca>*   Ported to lwIP.* 97-12-04 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.*	Original based on BSD chap.c.*****************************************************************************//* * chap.c - Challenge Handshake Authentication Protocol. * * Copyright (c) 1993 The Australian National University. * 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 Australian National University.  The name of the University * 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. * * 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. */#include "ppp.h"#if PPP_SUPPORT > 0#include "magic.h"#if CHAP_SUPPORT > 0#include "randm.h"#include "auth.h"#include "md5.h"#include "chap.h"#include "chpms.h"#include "pppdebug.h"#include "timer.h"/*************************//*** LOCAL DEFINITIONS ***//*************************//************************//*** LOCAL DATA TYPES ***//************************//***********************************//*** LOCAL FUNCTION DECLARATIONS ***//***********************************//* * Protocol entry points. */static void ChapInit (int);static void ChapLowerUp (int);static void ChapLowerDown (int);static void ChapInput (int, u_char *, int);static void ChapProtocolReject (int);static int  ChapPrintPkt (u_char *, int,			      void (*) (void *, char *, ...), void *);static void ChapChallengeTimeout (void *);static void ChapResponseTimeout (void *);static void ChapReceiveChallenge (chap_state *, u_char *, int, int);static void ChapRechallenge (void *);static void ChapReceiveResponse (chap_state *, u_char *, int, int);static void ChapReceiveSuccess(chap_state *cstate, u_char *inp, u_char id, int len);static void ChapReceiveFailure(chap_state *cstate, u_char *inp, u_char id, int len);static void ChapSendStatus (chap_state *, int);static void ChapSendChallenge (chap_state *);static void ChapSendResponse (chap_state *);static void ChapGenChallenge (chap_state *);/******************************//*** PUBLIC DATA STRUCTURES ***//******************************/chap_state chap[NUM_PPP];		/* CHAP state; one for each unit */struct protent chap_protent = {    PPP_CHAP,    ChapInit,    ChapInput,    ChapProtocolReject,    ChapLowerUp,    ChapLowerDown,    NULL,    NULL,#if 0    ChapPrintPkt,    NULL,#endif    1,    "CHAP",#if 0    NULL,    NULL,    NULL#endif};/*****************************//*** LOCAL DATA STRUCTURES ***//*****************************/static char *ChapCodenames[] = {	"Challenge", "Response", "Success", "Failure"};/***********************************//*** PUBLIC FUNCTION DEFINITIONS ***//***********************************//* * ChapAuthWithPeer - Authenticate us with our peer (start client). * */void ChapAuthWithPeer(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;}/* * ChapAuthPeer - Authenticate our peer (start server). */void ChapAuthPeer(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;}/**********************************//*** LOCAL FUNCTION DEFINITIONS ***//**********************************//* * ChapInit - Initialize a CHAP unit. */static void ChapInit(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 */}/* * ChapChallengeTimeout - Timeout expired on sending challenge. */static void ChapChallengeTimeout(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 */		CHAPDEBUG((LOG_ERR, "Peer failed to respond to CHAP challenge\n"));		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(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(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(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(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(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(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((LOG_INFO, "ChapInput: rcvd short header.\n"));		return;	}	GETCHAR(code, inp);	GETCHAR(id, inp);	GETSHORT(len, inp);	if (len < CHAP_HEADERLEN) {		CHAPDEBUG((LOG_INFO, "ChapInput: rcvd illegal length.\n"));		return;	}	if (len > packet_len) {		CHAPDEBUG((LOG_INFO, "ChapInput: rcvd short packet.\n"));		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? */		CHAPDEBUG((LOG_WARNING, "Unknown CHAP code (%d) received.\n", code));		break;	}}/* * ChapReceiveChallenge - Receive Challenge and send Response. */static void ChapReceiveChallenge(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];		CHAPDEBUG((LOG_INFO, "ChapReceiveChallenge: Rcvd id %d.\n", id));	if (cstate->clientstate == CHAPCS_CLOSED ||		cstate->clientstate == CHAPCS_PENDING) {		CHAPDEBUG((LOG_INFO, "ChapReceiveChallenge: in state %d\n",			   cstate->clientstate));		return;	}		if (len < 2) {		CHAPDEBUG((LOG_INFO, "ChapReceiveChallenge: rcvd short packet.\n"));