310 lines
8.6 KiB
C
310 lines
8.6 KiB
C
/*
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* PPP CHAP Module
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*
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* Written by Toshiharu OHNO (tony-o@iij.ad.jp)
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*
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* Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd.
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*
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* Redistribution and use in source and binary forms are permitted
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* provided that the above copyright notice and this paragraph are
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* duplicated in all such forms and that any documentation,
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* advertising materials, and other materials related to such
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* distribution and use acknowledge that the software was developed
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* by the Internet Initiative Japan, Inc. The name of the
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* IIJ may not be used to endorse or promote products derived
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* from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
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* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*
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* $Id: chap.c,v 1.31 1998/05/21 21:44:25 brian Exp $
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*
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* TODO:
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*/
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#include <sys/types.h>
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#include <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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#include <sys/un.h>
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#include <md4.h>
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#include <md5.h>
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#include <stdlib.h>
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#include <string.h>
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#include <termios.h>
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#include "mbuf.h"
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#include "log.h"
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#include "defs.h"
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#include "timer.h"
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#include "fsm.h"
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#include "lcpproto.h"
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#include "lcp.h"
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#include "lqr.h"
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#include "hdlc.h"
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#include "auth.h"
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#include "chap.h"
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#include "async.h"
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#include "throughput.h"
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#include "descriptor.h"
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#include "iplist.h"
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#include "slcompress.h"
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#include "ipcp.h"
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#include "filter.h"
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#include "ccp.h"
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#include "link.h"
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#include "physical.h"
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#include "mp.h"
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#include "bundle.h"
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#include "chat.h"
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#include "datalink.h"
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#include "chap_ms.h"
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static const char *chapcodes[] = {
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"???", "CHALLENGE", "RESPONSE", "SUCCESS", "FAILURE"
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};
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static void
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ChapOutput(struct physical *physical, u_int code, u_int id,
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const u_char * ptr, int count)
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{
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int plen;
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struct fsmheader lh;
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struct mbuf *bp;
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plen = sizeof(struct fsmheader) + count;
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lh.code = code;
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lh.id = id;
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lh.length = htons(plen);
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bp = mbuf_Alloc(plen, MB_FSM);
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memcpy(MBUF_CTOP(bp), &lh, sizeof(struct fsmheader));
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if (count)
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memcpy(MBUF_CTOP(bp) + sizeof(struct fsmheader), ptr, count);
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log_DumpBp(LogDEBUG, "ChapOutput", bp);
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log_Printf(LogLCP, "ChapOutput: %s\n", chapcodes[code]);
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hdlc_Output(&physical->link, PRI_LINK, PROTO_CHAP, bp);
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}
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void
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chap_SendChallenge(struct authinfo *auth, int chapid, struct physical *physical)
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{
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struct chap *chap = auth2chap(auth);
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int len, i;
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char *cp;
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randinit();
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cp = chap->challenge_data;
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*cp++ = chap->challenge_len = random() % 32 + 16;
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for (i = 0; i < chap->challenge_len; i++)
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*cp++ = random() & 0xff;
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len = strlen(physical->dl->bundle->cfg.auth.name);
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memcpy(cp, physical->dl->bundle->cfg.auth.name, len);
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cp += len;
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ChapOutput(physical, CHAP_CHALLENGE, chapid, chap->challenge_data,
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cp - chap->challenge_data);
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}
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static void
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RecvChapTalk(struct bundle *bundle, struct fsmheader *chp, struct mbuf *bp,
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struct physical *physical)
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{
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int valsize, len;
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int arglen, keylen, namelen;
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char *cp, *argp, *ap, *name, *digest;
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char *keyp;
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MD5_CTX MD5context; /* context for MD5 */
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char answer[100];
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char cdigest[16];
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#ifdef HAVE_DES
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int ix;
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MD4_CTX MD4context; /* context for MD4 */
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#endif
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len = ntohs(chp->length);
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log_Printf(LogDEBUG, "RecvChapTalk: length: %d\n", len);
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arglen = len - sizeof(struct fsmheader);
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cp = (char *) MBUF_CTOP(bp);
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valsize = *cp++ & 255;
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name = cp + valsize;
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namelen = arglen - valsize - 1;
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name[namelen] = 0;
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log_Printf(LogLCP, " Valsize = %d, Name = \"%s\"\n", valsize, name);
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switch (chp->code) {
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case CHAP_CHALLENGE:
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keyp = bundle->cfg.auth.key;
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keylen = strlen(bundle->cfg.auth.key);
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name = bundle->cfg.auth.name;
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namelen = strlen(bundle->cfg.auth.name);
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#ifdef HAVE_DES
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if (physical->dl->chap.using_MSChap)
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argp = malloc(1 + namelen + MS_CHAP_RESPONSE_LEN);
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else
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#endif
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argp = malloc(1 + valsize + namelen + 16);
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if (argp == NULL) {
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ChapOutput(physical, CHAP_FAILURE, chp->id, "Out of memory!", 14);
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return;
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}
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#ifdef HAVE_DES
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if (physical->dl->chap.using_MSChap) {
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digest = argp; /* this is the response */
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*digest++ = MS_CHAP_RESPONSE_LEN; /* 49 */
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memset(digest, '\0', 24);
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digest += 24;
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ap = answer; /* this is the challenge */
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memcpy(ap, keyp, keylen);
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ap += 2 * keylen;
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memcpy(ap, cp, valsize);
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log_DumpBuff(LogDEBUG, "recv", ap, valsize);
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ap += valsize;
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for (ix = keylen; ix > 0 ; ix--) {
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answer[2*ix-2] = answer[ix-1];
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answer[2*ix-1] = 0;
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}
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MD4Init(&MD4context);
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MD4Update(&MD4context, answer, 2 * keylen);
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MD4Final(digest, &MD4context);
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memcpy(digest + 25, name, namelen);
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ap += 2 * keylen;
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chap_MS(digest, answer + 2 * keylen, valsize);
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log_DumpBuff(LogDEBUG, "answer", digest, 24);
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ChapOutput(physical, CHAP_RESPONSE, chp->id, argp,
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namelen + MS_CHAP_RESPONSE_LEN + 1);
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} else {
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#endif
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digest = argp;
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*digest++ = 16; /* value size */
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ap = answer;
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*ap++ = chp->id;
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memcpy(ap, keyp, keylen);
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ap += keylen;
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memcpy(ap, cp, valsize);
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log_DumpBuff(LogDEBUG, "recv", ap, valsize);
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ap += valsize;
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MD5Init(&MD5context);
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MD5Update(&MD5context, answer, ap - answer);
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MD5Final(digest, &MD5context);
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log_DumpBuff(LogDEBUG, "answer", digest, 16);
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memcpy(digest + 16, name, namelen);
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ap += namelen;
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/* Send answer to the peer */
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ChapOutput(physical, CHAP_RESPONSE, chp->id, argp, namelen + 17);
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#ifdef HAVE_DES
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}
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#endif
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free(argp);
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break;
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case CHAP_RESPONSE:
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/*
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* Get a secret key corresponds to the peer
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*/
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keyp = auth_GetSecret(bundle, name, namelen, physical);
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if (keyp) {
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/*
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* Compute correct digest value
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*/
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keylen = strlen(keyp);
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ap = answer;
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*ap++ = chp->id;
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memcpy(ap, keyp, keylen);
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ap += keylen;
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MD5Init(&MD5context);
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MD5Update(&MD5context, answer, ap - answer);
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MD5Update(&MD5context, physical->dl->chap.challenge_data + 1,
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physical->dl->chap.challenge_len);
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MD5Final(cdigest, &MD5context);
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log_DumpBuff(LogDEBUG, "got", cp, 16);
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log_DumpBuff(LogDEBUG, "expect", cdigest, 16);
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/*
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* Compare with the response
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*/
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if (memcmp(cp, cdigest, 16) == 0) {
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datalink_GotAuthname(physical->dl, name, namelen);
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ChapOutput(physical, CHAP_SUCCESS, chp->id, "Welcome!!", 10);
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if (Enabled(bundle, OPT_UTMP))
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physical_Login(physical, name);
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if (physical->link.lcp.auth_iwait == 0)
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/*
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* Either I didn't need to authenticate, or I've already been
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* told that I got the answer right.
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*/
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datalink_AuthOk(physical->dl);
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break;
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}
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}
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/*
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* Peer is not registerd, or response digest is wrong.
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*/
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ChapOutput(physical, CHAP_FAILURE, chp->id, "Invalid!!", 9);
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datalink_AuthNotOk(physical->dl);
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break;
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}
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}
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static void
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RecvChapResult(struct bundle *bundle, struct fsmheader *chp, struct mbuf *bp,
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struct physical *physical)
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{
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int len;
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len = ntohs(chp->length);
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log_Printf(LogDEBUG, "RecvChapResult: length: %d\n", len);
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if (chp->code == CHAP_SUCCESS) {
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if (physical->link.lcp.auth_iwait == PROTO_CHAP) {
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physical->link.lcp.auth_iwait = 0;
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if (physical->link.lcp.auth_ineed == 0)
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/*
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* We've succeeded in our ``login''
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* If we're not expecting the peer to authenticate (or he already
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* has), proceed to network phase.
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*/
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datalink_AuthOk(physical->dl);
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}
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} else {
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/* CHAP failed - it's not going to get any better */
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log_Printf(LogPHASE, "Received CHAP_FAILURE\n");
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datalink_AuthNotOk(physical->dl);
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}
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}
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void
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chap_Input(struct bundle *bundle, struct mbuf *bp, struct physical *physical)
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{
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int len = mbuf_Length(bp);
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struct fsmheader *chp;
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if (len >= sizeof(struct fsmheader)) {
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chp = (struct fsmheader *) MBUF_CTOP(bp);
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if (len >= ntohs(chp->length)) {
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if (chp->code < 1 || chp->code > 4)
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chp->code = 0;
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log_Printf(LogLCP, "chap_Input: %s\n", chapcodes[chp->code]);
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bp->offset += sizeof(struct fsmheader);
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bp->cnt -= sizeof(struct fsmheader);
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switch (chp->code) {
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case CHAP_RESPONSE:
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auth_StopTimer(&physical->dl->chap.auth);
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/* Fall into.. */
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case CHAP_CHALLENGE:
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RecvChapTalk(bundle, chp, bp, physical);
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break;
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case CHAP_SUCCESS:
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case CHAP_FAILURE:
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RecvChapResult(bundle, chp, bp, physical);
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break;
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}
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}
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}
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mbuf_Free(bp);
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}
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