1 files changed, 259 insertions, 0 deletions

diff --git a/usr.sbin/ppp/chap.c b/usr.sbin/ppp/chap.c
new file mode 100644
index 0000000..2b86b40
--- /dev/null
+++ b/usr.sbin/ppp/chap.c
@@ -0,0 +1,259 @@
+/*
+ *			PPP CHAP Module
+ *
+ *	    Written by Toshiharu OHNO (tony-o@iij.ad.jp)
+ *
+ *   Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd.
+ *
+ * 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 Internet Initiative Japan, Inc.  The name of the
+ * IIJ 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.
+ *
+ * $Id:$
+ *
+ *	TODO:
+ *		o Imprement retransmission timer.
+ */
+#include "fsm.h"
+#include "chap.h"
+#include "lcpproto.h"
+#include "lcp.h"
+#include "hdlc.h"
+#include "phase.h"
+#include "vars.h"
+
+static int chapid;
+
+static char *chapcodes[] = {
+  "???", "CHALLENGE", "RESPONCE", "SUCCESS", "FAILURE"
+};
+
+extern char *AuthGetSecret();
+
+void
+ChapOutput(code, id, ptr, count)
+u_int code, id;
+u_char *ptr;
+int count;
+{
+  int plen;
+  struct fsmheader lh;
+  struct mbuf *bp;
+
+  plen =  sizeof(struct fsmheader) + count;
+  lh.code = code;
+  lh.id = id;
+  lh.length = htons(plen);
+  bp = mballoc(plen, MB_FSM);
+  bcopy(&lh, MBUF_CTOP(bp), sizeof(struct fsmheader));
+  if (count)
+    bcopy(ptr, MBUF_CTOP(bp) + sizeof(struct fsmheader), count);
+#ifdef DEBUG
+  DumpBp(bp);
+#endif
+  LogPrintf(LOG_LCP, "ChapOutput: %s\n", chapcodes[code]);
+  HdlcOutput(PRI_NORMAL, PROTO_CHAP, bp);
+}
+
+
+static char challenge_data[80];
+static int  challenge_len;
+
+void
+SendChapChallenge()
+{
+  int keylen, len, i;
+  char *cp;
+
+  srandom(time(NULL));
+  ++chapid;
+
+  cp = challenge_data;
+  *cp++ = challenge_len = random() % 32 + 16;
+  for (i = 0; i < challenge_len; i++)
+    *cp++ = random() & 0xff;
+  len = strlen(VarAuthName);
+  bcopy(VarAuthName, cp, len);
+  cp += len;
+  ChapOutput(CHAP_CHALLENGE, chapid, challenge_data, cp - challenge_data);
+}
+
+#ifdef DEBUG
+void
+DumpDigest(mes, cp, len)
+char *mes;
+char *cp;
+{
+  int i;
+
+  logprintf("%s: ", mes);
+  for (i = 0; i < len; i++) {
+    logprintf(" %02x", *cp++ & 0xff);
+  }
+  logprintf("\n");
+}
+#endif
+
+void
+RecvChapTalk(chp, bp)
+struct fsmheader *chp;
+struct mbuf *bp;
+{
+  int valsize, len;
+  int arglen, keylen, namelen;
+  char *cp, *argp, *ap, *name, *digest;
+  char *keyp;
+  MD5_CTX context;                            /* context */
+  char answer[100];
+  char cdigest[16];
+
+  len = ntohs(chp->length);
+#ifdef DEBUG
+  logprintf("length: %d\n", len);
+#endif
+  arglen = len - sizeof(struct fsmheader);
+  cp = (char *)MBUF_CTOP(bp);
+  valsize = *cp++ & 255;
+  name = cp + valsize;
+  namelen = arglen - valsize - 1;
+  name[namelen] = 0;
+  LogPrintf(LOG_PHASE, " Valsize = %d, Name = %s\n", valsize, name);
+
+  /*
+   * Get a secret key corresponds to the peer
+   */
+  keyp = AuthGetSecret(SECRETFILE, name, namelen, chp->code == CHAP_RESPONSE);
+
+  switch (chp->code) {
+  case CHAP_CHALLENGE:
+    if (keyp) {
+      keylen = strlen(keyp);
+    } else {
+      keylen = strlen(VarAuthKey);
+      keyp = VarAuthKey;
+    }
+    name = VarAuthName;
+    namelen = strlen(VarAuthName);
+    argp = malloc(1 + valsize + namelen);
+    digest = argp;
+    *digest++ = 16;		/* value size */
+    ap = answer;
+    *ap++ = chp->id;
+    bcopy(keyp, ap, keylen);
+    ap += keylen;
+    bcopy(cp, ap, valsize);
+#ifdef DEBUG
+    DumpDigest("recv", ap, valsize);
+#endif
+    ap += valsize;
+    MD5Init(&context);
+    MD5Update(&context, answer, ap - answer);
+    MD5Final(digest, &context);
+#ifdef DEBUG
+    DumpDigest("answer", digest, 16);
+#endif
+    bcopy(name, digest + 16, namelen);
+    ap += namelen;
+    /* Send answer to the peer */
+    ChapOutput(CHAP_RESPONSE, chp->id, argp, namelen + 17);
+    break;
+  case CHAP_RESPONSE:
+    if (keyp) {
+      /*
+       * Compute correct digest value
+       */
+      keylen = strlen(keyp);
+      ap = answer;
+      *ap++ = chp->id;
+      bcopy(keyp, ap, keylen);
+      ap += keylen;
+      MD5Init(&context);
+      MD5Update(&context, answer, ap - answer);
+      MD5Update(&context, challenge_data+1, challenge_len);
+      MD5Final(cdigest, &context);
+#ifdef DEBUG
+      DumpDigest("got", cp, 16);
+      DumpDigest("expect", cdigest, 16);
+#endif
+      /*
+       * Compare with the response
+       */
+      if (bcmp(cp, cdigest, 16) == 0) {
+	ChapOutput(CHAP_SUCCESS, chp->id, "Wellcome!!", 10);
+	NewPhase(PHASE_NETWORK);
+	break;
+      }
+    }
+    /*
+     * Peer is not registerd, or response digest is wrong.
+     */
+    ChapOutput(CHAP_FAILURE, chp->id, "Invalid!!", 9);
+    LcpClose();
+    break;
+  }
+}
+
+void
+RecvChapResult(chp, bp)
+struct fsmheader *chp;
+struct mbuf *bp;
+{
+  int len;
+  struct lcpstate *lcp = &LcpInfo;
+
+  len = ntohs(chp->length);
+#ifdef DEBUG
+  logprintf("length: %d\n", len);
+#endif
+  if (chp->code == CHAP_SUCCESS) {
+    if (lcp->auth_iwait == PROTO_CHAP) {
+      lcp->auth_iwait = 0;
+      if (lcp->auth_ineed == 0)
+	NewPhase(PHASE_NETWORK);
+    }
+  } else {
+    /*
+     * Maybe, we shoud close LCP. Of cause, peer may take close action, too.
+     */
+    ;
+  }
+}
+
+void
+ChapInput(struct mbuf *bp)
+{
+  int len = plength(bp);
+  struct fsmheader *chp;
+
+  if (len >= sizeof(struct fsmheader)) {
+    chp = (struct fsmheader *)MBUF_CTOP(bp);
+    if (len >= ntohs(chp->length)) {
+      if (chp->code < 1 || chp->code > 4)
+	chp->code = 0;
+      LogPrintf(LOG_LCP, "ChapInput: %s\n", chapcodes[chp->code]);
+
+      bp->offset += sizeof(struct fsmheader);
+      bp->cnt -= sizeof(struct fsmheader);
+
+      switch (chp->code) {
+      case CHAP_CHALLENGE:
+      case CHAP_RESPONSE:
+	RecvChapTalk(chp, bp);
+	break;
+      case CHAP_SUCCESS:
+      case CHAP_FAILURE:
+	RecvChapResult(chp, bp);
+	break;
+      }
+    }
+  }
+  pfree(bp);
+}