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/*** 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_impl.h"
#include "pppdebug.h"
#include "magic.h"
#include "randm.h"
#include "auth.h"
#include "md5.h"
#include "chap.h"
#include "chpms.h"
#include <string.h>
#if 0 /* UNUSED */
/*
* Command-line options.
*/
static option_t chap_option_list[] = {
{ "chap-restart", o_int, &chap[0].timeouttime,
"Set timeout for CHAP" },
{ "chap-max-challenge", o_int, &chap[0].max_transmits,
"Set max #xmits for challenge" },
{ "chap-interval", o_int, &chap[0].chal_interval,
"Set interval for rechallenge" },
#ifdef MSLANMAN
{ "ms-lanman", o_bool, &ms_lanman,
"Use LanMan passwd when using MS-CHAP", 1 },
#endif
{ NULL }
};
#endif /* UNUSED */
/*
* 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 PPP_ADDITIONAL_CALLBACKS
static int ChapPrintPkt (u_char *, int, void (*) (void *, char *, ...), void *);
#endif
struct protent chap_protent = {
PPP_CHAP,
ChapInit,
ChapInput,
ChapProtocolReject,
ChapLowerUp,
ChapLowerDown,
NULL,
NULL,
#if PPP_ADDITIONAL_CALLBACKS
ChapPrintPkt,
NULL,
#endif /* PPP_ADDITIONAL_CALLBACKS */
1,
"CHAP",
#if PPP_ADDITIONAL_CALLBACKS
NULL,
NULL,
NULL
#endif /* PPP_ADDITIONAL_CALLBACKS */
};
chap_state chap[NUM_PPP]; /* CHAP state; one for each unit */
static void ChapChallengeTimeout (void *);
static void ChapResponseTimeout (void *);
static void ChapReceiveChallenge (chap_state *, u_char *, u_char, 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 *);
/*
* 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 */
}
/*
* ChapAuthWithPeer - Authenticate us with our peer (start client).
*
*/
void
ChapAuthWithPeer(int unit, char *our_name, u_char 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, u_char 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(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); /* lwip: just sets the PPP error code on this unit to PPPERR_AUTHFAIL */
}
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, u_char 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 >= (int)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;
#if MSCHAP_SUPPORT
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 >= (int)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, ("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); /* lwip: just sets the PPP error code on this unit to PPPERR_AUTHFAIL */
}
/*
* 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 = (int)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]; /* @todo: this can be a char*, no strcpy needed */
if (code == CHAP_SUCCESS) {
strcpy(msg, "Welcome!");
} else {
strcpy(msg, "I don't like you. Go 'way.");
}
msglen = (int)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);
LWIP_ASSERT("chal_len <= 0xff", chal_len <= 0xffff);
cstate->chal_len = (u_char)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 = (int)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 PPP_ADDITIONAL_CALLBACKS
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 /* PPP_ADDITIONAL_CALLBACKS */
#endif /* CHAP_SUPPORT */
#endif /* PPP_SUPPORT */
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