--- /dev/null
+/*** 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 "lwip/opt.h"
+
+#if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */
+
+#if CHAP_SUPPORT /* don't build if not configured for use in lwipopts.h */
+
+#include "ppp.h"
+#include "pppdebug.h"
+
+#include "magic.h"
+#include "randm.h"
+#include "auth.h"
+#include "md5.h"
+#include "chap.h"
+#include "chpms.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);
+#if 0
+static int ChapPrintPkt (u_char *, int, void (*) (void *, char *, ...), void *);
+#endif
+
+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
+};
+
+
+/***********************************/
+/*** 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"));
+ return;
+ }
+
+ GETCHAR(rchallenge_len, inp);
+ len -= sizeof (u_char) + rchallenge_len; /* now name field length */
+ if (len < 0) {
+ CHAPDEBUG((LOG_INFO, "ChapReceiveChallenge: rcvd short packet.\n"));
+ return;
+ }
+ rchallenge = inp;
+ INCPTR(rchallenge_len, inp);
+
+ if (len >= sizeof(rhostname)) {
+ len = sizeof(rhostname) - 1;
+ }
+ BCOPY(inp, rhostname, len);
+ rhostname[len] = '\000';
+
+ CHAPDEBUG((LOG_INFO, "ChapReceiveChallenge: received name field '%s'\n", rhostname));
+
+ /* Microsoft doesn't send their name back in the PPP packet */
+ if (ppp_settings.remote_name[0] != 0 && (ppp_settings.explicit_remote || rhostname[0] == 0)) {
+ strncpy(rhostname, ppp_settings.remote_name, sizeof(rhostname));
+ rhostname[sizeof(rhostname) - 1] = 0;
+ CHAPDEBUG((LOG_INFO, "ChapReceiveChallenge: using '%s' as remote name\n", 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 */
+ CHAPDEBUG((LOG_WARNING, "No CHAP secret found for authenticating us to %s\n", 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, (u_char*)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, rchallenge_len, secret, secret_len);
+ break;
+#endif
+
+ default:
+ CHAPDEBUG((LOG_INFO, "unknown digest type %d\n", cstate->resp_type));
+ return;
+ }
+
+ BZERO(secret, sizeof(secret));
+ ChapSendResponse(cstate);
+}
+
+
+/*
+ * ChapReceiveResponse - Receive and process response.
+ */
+static void
+ChapReceiveResponse(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];
+
+ CHAPDEBUG((LOG_INFO, "ChapReceiveResponse: Rcvd id %d.\n", id));
+
+ if (cstate->serverstate == CHAPSS_CLOSED ||
+ cstate->serverstate == CHAPSS_PENDING) {
+ CHAPDEBUG((LOG_INFO, "ChapReceiveResponse: in state %d\n",
+ 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((LOG_INFO, "ChapReceiveResponse: rcvd short packet.\n"));
+ 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((LOG_INFO, "ChapReceiveResponse: rcvd short packet.\n"));
+ return;
+ }
+
+ UNTIMEOUT(ChapChallengeTimeout, cstate);
+
+ if (len >= sizeof(rhostname)) {
+ len = sizeof(rhostname) - 1;
+ }
+ BCOPY(inp, rhostname, len);
+ rhostname[len] = '\000';
+
+ CHAPDEBUG((LOG_INFO, "ChapReceiveResponse: received name field: %s\n", rhostname));
+
+ /*
+ * Get secret for authenticating them with us,
+ * do the hash ourselves, and compare the result.
+ */
+ code = CHAP_FAILURE;
+ if (!get_secret(cstate->unit, rhostname, cstate->chal_name, secret, &secret_len, 1)) {
+ /* CHAPDEBUG((LOG_WARNING, TL_CHAP, "No CHAP secret found for authenticating %s\n", rhostname)); */
+ CHAPDEBUG((LOG_WARNING, "No CHAP secret found for authenticating %s\n",
+ rhostname));
+ } else {
+ /* generate MD based on negotiated type */
+ switch (cstate->chal_type) {
+
+ case CHAP_DIGEST_MD5: /* only MD5 is defined for now */
+ if (remmd_len != MD5_SIGNATURE_SIZE) {
+ break; /* it's not even the right length */
+ }
+ MD5Init(&mdContext);
+ MD5Update(&mdContext, &cstate->chal_id, 1);
+ MD5Update(&mdContext, (u_char*)secret, secret_len);
+ MD5Update(&mdContext, cstate->challenge, cstate->chal_len);
+ MD5Final(hash, &mdContext);
+
+ /* compare local and remote MDs and send the appropriate status */
+ if (memcmp (hash, remmd, MD5_SIGNATURE_SIZE) == 0) {
+ code = CHAP_SUCCESS; /* they are the same! */
+ }
+ break;
+
+ default:
+ CHAPDEBUG((LOG_INFO, "unknown digest type %d\n", 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, rhostname, len);
+ }
+ if (cstate->chal_interval != 0) {
+ TIMEOUT(ChapRechallenge, cstate, cstate->chal_interval);
+ }
+ } else {
+ CHAPDEBUG((LOG_ERR, "CHAP peer authentication failed\n"));
+ cstate->serverstate = CHAPSS_BADAUTH;
+ auth_peer_fail(cstate->unit, PPP_CHAP);
+ }
+}
+
+/*
+ * ChapReceiveSuccess - Receive Success
+ */
+static void
+ChapReceiveSuccess(chap_state *cstate, u_char *inp, u_char id, int len)
+{
+ LWIP_UNUSED_ARG(id);
+ LWIP_UNUSED_ARG(inp);
+
+ CHAPDEBUG((LOG_INFO, "ChapReceiveSuccess: Rcvd id %d.\n", id));
+
+ 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((LOG_INFO, "ChapReceiveSuccess: in state %d\n", cstate->clientstate));
+ return;
+ }
+
+ UNTIMEOUT(ChapResponseTimeout, cstate);
+
+ /*
+ * Print message.
+ */
+ if (len > 0) {
+ PRINTMSG(inp, len);
+ }
+
+ cstate->clientstate = CHAPCS_OPEN;
+
+ auth_withpeer_success(cstate->unit, PPP_CHAP);
+}
+
+
+/*
+ * ChapReceiveFailure - Receive failure.
+ */
+static void
+ChapReceiveFailure(chap_state *cstate, u_char *inp, u_char id, int len)
+{
+ LWIP_UNUSED_ARG(id);
+ LWIP_UNUSED_ARG(inp);
+
+ CHAPDEBUG((LOG_INFO, "ChapReceiveFailure: Rcvd id %d.\n", id));
+
+ if (cstate->clientstate != CHAPCS_RESPONSE) {
+ /* don't know what this is */
+ CHAPDEBUG((LOG_INFO, "ChapReceiveFailure: in state %d\n", cstate->clientstate));
+ return;
+ }
+
+ UNTIMEOUT(ChapResponseTimeout, cstate);
+
+ /*
+ * Print message.
+ */
+ if (len > 0) {
+ PRINTMSG(inp, len);
+ }
+
+ CHAPDEBUG((LOG_ERR, "CHAP authentication failed\n"));
+ auth_withpeer_fail(cstate->unit, PPP_CHAP);
+}
+
+
+/*
+ * ChapSendChallenge - Send an Authenticate challenge.
+ */
+static void
+ChapSendChallenge(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[cstate->unit];
+
+ 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 */
+
+ pppWrite(cstate->unit, outpacket_buf[cstate->unit], outlen + PPP_HDRLEN);
+
+ CHAPDEBUG((LOG_INFO, "ChapSendChallenge: Sent id %d.\n", cstate->chal_id));
+
+ TIMEOUT(ChapChallengeTimeout, cstate, cstate->timeouttime);
+ ++cstate->chal_transmits;
+}
+
+
+/*
+ * ChapSendStatus - Send a status response (ack or nak).
+ */
+static void
+ChapSendStatus(chap_state *cstate, int code)
+{
+ u_char *outp;
+ int outlen, msglen;
+ char msg[256];
+
+ if (code == CHAP_SUCCESS) {
+ strcpy(msg, "Welcome!");
+ } else {
+ strcpy(msg, "I don't like you. Go 'way.");
+ }
+ msglen = strlen(msg);
+
+ outlen = CHAP_HEADERLEN + msglen;
+ outp = outpacket_buf[cstate->unit];
+
+ MAKEHEADER(outp, PPP_CHAP); /* paste in a header */
+
+ PUTCHAR(code, outp);
+ PUTCHAR(cstate->chal_id, outp);
+ PUTSHORT(outlen, outp);
+ BCOPY(msg, outp, msglen);
+ pppWrite(cstate->unit, outpacket_buf[cstate->unit], outlen + PPP_HDRLEN);
+
+ CHAPDEBUG((LOG_INFO, "ChapSendStatus: Sent code %d, id %d.\n", code, cstate->chal_id));
+}
+
+/*
+ * 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(chap_state *cstate)
+{
+ int chal_len;
+ u_char *ptr = cstate->challenge;
+ int i;
+
+ /* pick a random challenge length between MIN_CHALLENGE_LENGTH and
+ MAX_CHALLENGE_LENGTH */
+ chal_len = (unsigned)
+ ((((magic() >> 16) *
+ (MAX_CHALLENGE_LENGTH - MIN_CHALLENGE_LENGTH)) >> 16)
+ + MIN_CHALLENGE_LENGTH);
+ cstate->chal_len = chal_len;
+ cstate->chal_id = ++cstate->id;
+ cstate->chal_transmits = 0;
+
+ /* generate a random string */
+ for (i = 0; i < chal_len; i++ ) {
+ *ptr++ = (char) (magic() & 0xff);
+ }
+}
+
+/*
+ * ChapSendResponse - send a response packet with values as specified
+ * in *cstate.
+ */
+/* ARGSUSED */
+static void
+ChapSendResponse(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[cstate->unit];
+
+ 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 */
+ pppWrite(cstate->unit, outpacket_buf[cstate->unit], outlen + PPP_HDRLEN);
+
+ cstate->clientstate = CHAPCS_RESPONSE;
+ TIMEOUT(ChapResponseTimeout, cstate, cstate->timeouttime);
+ ++cstate->resp_transmits;
+}
+
+#if 0
+static char *ChapCodenames[] = {
+ "Challenge", "Response", "Success", "Failure"
+};
+/*
+ * ChapPrintPkt - print the contents of a CHAP packet.
+ */
+static int
+ChapPrintPkt( u_char *p, int plen, void (*printer) (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 = %.*Z", nlen, p);
+ break;
+ case CHAP_FAILURE:
+ case CHAP_SUCCESS:
+ printer(arg, " %.*Z", len, p);
+ break;
+ default:
+ for (clen = len; clen > 0; --clen) {
+ GETCHAR(x, p);
+ printer(arg, " %.2x", x);
+ }
+ }
+
+ return len + CHAP_HEADERLEN;
+}
+#endif
+
+#endif /* CHAP_SUPPORT */
+
+#endif /* PPP_SUPPORT */
