Allow Microsoft CHAP authentication.

This is a combination of MD4 & DES.
Submitted by:	Gabor Kincses <gabor@acm.org>

9 files changed, 145 insertions, 61 deletions

diff --git a/usr.sbin/ppp/Makefile b/usr.sbin/ppp/Makefile
index b2885c3..3f95b50 100644
--- a/usr.sbin/ppp/Makefile
+++ b/usr.sbin/ppp/Makefile
@@ -1,4 +1,4 @@
-#	$Id: Makefile,v 1.23 1997/08/31 20:18:03 brian Exp $
+#	$Id: Makefile,v 1.24 1997/09/04 00:38:17 brian Exp $
 
 PROG=	ppp
 SRCS=	alias_cmd.c arp.c async.c auth.c ccp.c chap.c chat.c command.c \
@@ -13,4 +13,11 @@ BINMODE=4550
 BINOWN=	root
 BINGRP=	network
 
+.if exists(${DESTDIR}/usr/include/des.h) && !defined(NOSECURE)
+CFLAGS+=-DHAVE_DES
+SRCS+=	chap_ms.c
+LDADD+= -ldes
+DPADD+= ${LIBDES}
+.endif
+
 .include <bsd.prog.mk>
diff --git a/usr.sbin/ppp/chap.c b/usr.sbin/ppp/chap.c
index 35ae17d..3383833 100644
--- a/usr.sbin/ppp/chap.c
+++ b/usr.sbin/ppp/chap.c
@@ -17,15 +17,18 @@
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
- * $Id: chap.c,v 1.21 1997/09/17 23:17:48 brian Exp $
+ * $Id: chap.c,v 1.22 1997/09/22 23:59:13 brian Exp $
  *
  *	TODO:
  */
 #include <sys/types.h>
 #include <time.h>
 #include <utmp.h>
+#include <ctype.h>
+
 #include "fsm.h"
 #include "chap.h"
+#include "chap_ms.h"
 #include "lcpproto.h"
 #include "lcp.h"
 #include "hdlc.h"
@@ -101,10 +104,13 @@ RecvChapTalk(struct fsmheader * chp, struct mbuf * bp)
   int arglen, keylen, namelen;
   char *cp, *argp, *ap, *name, *digest;
   char *keyp;
-  MD4_CTX MD4context;		/* context for MD4 */
   MD5_CTX MD5context;		/* context for MD5 */
   char answer[100];
   char cdigest[16];
+#ifdef HAVE_DES
+  int ix;
+  MD4_CTX MD4context;		/* context for MD4 */
+#endif
 
   len = ntohs(chp->length);
   LogPrintf(LogDEBUG, "RecvChapTalk: length: %d\n", len);
@@ -131,34 +137,64 @@ RecvChapTalk(struct fsmheader * chp, struct mbuf * bp)
     }
     name = VarAuthName;
     namelen = strlen(VarAuthName);
-    argp = malloc(1 + valsize + namelen + 16);
+
+#ifdef HAVE_DES
+    if (VarMSChap)
+      argp = malloc(1 + namelen + MS_CHAP_RESPONSE_LEN);
+    else
+#endif
+      argp = malloc(1 + valsize + namelen + 16);
+
     if (argp == NULL) {
       ChapOutput(CHAP_FAILURE, chp->id, "Out of memory!", 14);
       return;
     }
-    digest = argp;
-    *digest++ = 16;		/* value size */
-    ap = answer;
-    *ap++ = chp->id;
-    bcopy(keyp, ap, keylen);
-    ap += keylen;
-    bcopy(cp, ap, valsize);
-    LogDumpBuff(LogDEBUG, "recv", ap, valsize);
-    ap += valsize;
-    if (VarEncMD4) {
+#ifdef HAVE_DES
+    if (VarMSChap) {
+      digest = argp;     /* this is the response */
+      *digest++ = MS_CHAP_RESPONSE_LEN;   /* 49 */
+      bzero(digest, 24); digest += 24;
+
+      ap = answer;       /* this is the challenge */
+      bcopy(keyp, ap, keylen);
+      ap += 2 * keylen;
+      bcopy(cp, ap, valsize);
+      LogDumpBuff(LogDEBUG, "recv", ap, valsize);
+      ap += valsize;
+      for (ix = keylen; ix > 0 ; ix--) {
+          answer[2*ix-2] = answer[ix-1];
+          answer[2*ix-1] = 0;
+      }
       MD4Init(&MD4context);
-      MD4Update(&MD4context, answer, ap - answer);
+      MD4Update(&MD4context, answer, 2 * keylen);
       MD4Final(digest, &MD4context);
+      bcopy(name, digest + 25, namelen);
+      ap += 2 * keylen;
+      ChapMS(digest, answer + 2 * keylen, valsize);
+      LogDumpBuff(LogDEBUG, "answer", digest, 24);
+      ChapOutput(CHAP_RESPONSE, chp->id, argp, namelen + MS_CHAP_RESPONSE_LEN + 1);
     } else {
+#endif
+      digest = argp;
+      *digest++ = 16;		/* value size */
+      ap = answer;
+      *ap++ = chp->id;
+      bcopy(keyp, ap, keylen);
+      ap += keylen;
+      bcopy(cp, ap, valsize);
+      LogDumpBuff(LogDEBUG, "recv", ap, valsize);
+      ap += valsize;
       MD5Init(&MD5context);
       MD5Update(&MD5context, answer, ap - answer);
       MD5Final(digest, &MD5context);
+      LogDumpBuff(LogDEBUG, "answer", digest, 16);
+      bcopy(name, digest + 16, namelen);
+      ap += namelen;
+      /* Send answer to the peer */
+      ChapOutput(CHAP_RESPONSE, chp->id, argp, namelen + 17);
+#ifdef HAVE_DES
     }
-    LogDumpBuff(LogDEBUG, "answer", digest, 16);
-    bcopy(name, digest + 16, namelen);
-    ap += namelen;
-    /* Send answer to the peer */
-    ChapOutput(CHAP_RESPONSE, chp->id, argp, namelen + 17);
+#endif
     free(argp);
     break;
   case CHAP_RESPONSE:
@@ -172,17 +208,10 @@ RecvChapTalk(struct fsmheader * chp, struct mbuf * bp)
       *ap++ = chp->id;
       bcopy(keyp, ap, keylen);
       ap += keylen;
-      if (VarEncMD4) {
-        MD4Init(&MD4context);
-        MD4Update(&MD4context, answer, ap - answer);
-        MD4Update(&MD4context, challenge_data + 1, challenge_len);
-        MD4Final(cdigest, &MD4context);
-      } else {
-        MD5Init(&MD5context);
-        MD5Update(&MD5context, answer, ap - answer);
-        MD5Update(&MD5context, challenge_data + 1, challenge_len);
-        MD5Final(cdigest, &MD5context);
-      }
+      MD5Init(&MD5context);
+      MD5Update(&MD5context, answer, ap - answer);
+      MD5Update(&MD5context, challenge_data + 1, challenge_len);
+      MD5Final(cdigest, &MD5context);
       LogDumpBuff(LogDEBUG, "got", cp, 16);
       LogDumpBuff(LogDEBUG, "expect", cdigest, 16);
 
diff --git a/usr.sbin/ppp/command.c b/usr.sbin/ppp/command.c
index 483a3bc..c21327f 100644
--- a/usr.sbin/ppp/command.c
+++ b/usr.sbin/ppp/command.c
@@ -17,7 +17,7 @@
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
- * $Id: command.c,v 1.83 1997/09/21 13:07:57 brian Exp $
+ * $Id: command.c,v 1.84 1997/09/22 00:46:51 brian Exp $
  *
  */
 #include <sys/types.h>
@@ -467,7 +467,9 @@ ShowAuthKey()
     return 0;
   fprintf(VarTerm, "AuthName = %s\n", VarAuthName);
   fprintf(VarTerm, "AuthKey  = %s\n", VarAuthKey);
-  fprintf(VarTerm, "Encrypt  = %s\n", VarEncMD4 ? "MD4" : "MD5" );
+#ifdef HAVE_DES
+  fprintf(VarTerm, "Encrypt  = %s\n", VarMSChap ? "MSChap" : "MD5" );
+#endif
   return 1;
 }
 
@@ -1245,9 +1247,11 @@ SetVariable(struct cmdtab const * list, int argc, char **argv, int param)
     strncpy(VarHangupScript, arg, sizeof(VarHangupScript) - 1);
     VarHangupScript[sizeof(VarHangupScript) - 1] = '\0';
     break;
+#ifdef HAVE_DES
   case VAR_ENC:
-    VarEncMD4 = !strcasecmp(arg, "md4");
+    VarMSChap = !strcasecmp(arg, "mschap");
     break;
+#endif
   }
   return 0;
 }
@@ -1302,8 +1306,10 @@ struct cmdtab const SetCommands[] = {
   "Set demand filter", "set dfilter ..."},
   {"dial", NULL, SetVariable, LOCAL_AUTH,
   "Set dialing script", "set dial chat-script", (void *) VAR_DIAL},
+#ifdef HAVE_DES
   {"encrypt", NULL, SetVariable, LOCAL_AUTH,
-  "Set CHAP encryption algorithm", "set encrypt MD4|MD5", (void *) VAR_ENC},
+  "Set CHAP encryption algorithm", "set encrypt MSChap|MD5", (void *) VAR_ENC},
+#endif
   {"escape", NULL, SetEscape, LOCAL_AUTH,
   "Set escape characters", "set escape hex-digit ..."},
   {"hangup", NULL, SetVariable, LOCAL_AUTH,
diff --git a/usr.sbin/ppp/command.h b/usr.sbin/ppp/command.h
index bc9f67f..a64cf6d 100644
--- a/usr.sbin/ppp/command.h
+++ b/usr.sbin/ppp/command.h
@@ -15,7 +15,7 @@
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
- * $Id: command.h,v 1.5 1997/08/25 00:29:09 brian Exp $
+ * $Id: command.h,v 1.6 1997/09/22 00:46:53 brian Exp $
  *
  *	TODO:
  */
@@ -38,6 +38,7 @@ struct cmdtab {
 #define	VAR_ACCMAP	5
 #define	VAR_PHONE	6
 #define	VAR_HANGUP	7
+#ifdef HAVE_DES
 #define	VAR_ENC		8
-
+#endif
 extern int SetVariable(struct cmdtab const *, int, char **, int var_param);
diff --git a/usr.sbin/ppp/lcp.c b/usr.sbin/ppp/lcp.c
index 31fafca..aa6c619 100644
--- a/usr.sbin/ppp/lcp.c
+++ b/usr.sbin/ppp/lcp.c
@@ -17,7 +17,7 @@
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
- * $Id: lcp.c,v 1.33 1997/09/22 23:59:14 brian Exp $
+ * $Id: lcp.c,v 1.34 1997/09/23 19:52:14 brian Exp $
  *
  * TODO:
  *      o Validate magic number received from peer.
@@ -291,7 +291,11 @@ LcpSendConfigReq(struct fsm * fp)
     break;
   case PROTO_CHAP:
     PutConfValue(&cp, cftypes, TY_AUTHPROTO, 5, lcp->want_auth);
-    *cp++ = 5;			/* Use MD4/MD5 */
+#ifdef HAVE_DES
+    *cp++ = VarMSChap ? 0x80 : 0x05;	/* Use MSChap vs. RFC 1994 (MD5) */
+#else
+    *cp++ = 0x05;			/* Use MD5 */
+#endif
     break;
   }
   FsmOutput(fp, CODE_CONFIGREQ, fp->reqid++, ReqBuff, cp - ReqBuff);
@@ -510,10 +514,18 @@ LcpDecodeConfig(u_char * cp, int plen, int mode)
 	    LogPrintf(LogLCP, " %s bad length (%d)\n", request, length);
 	    goto reqreject;
 	  }
-	  if (Acceptable(ConfChap) && cp[4] == 5) {
+#ifdef HAVE_DES
+          if (Acceptable(ConfChap) && (cp[4] == 5 || cp[4] == 0x80))
+#else
+          if (Acceptable(ConfChap) && cp[4] == 5)
+#endif
+	  {
 	    LcpInfo.his_auth = proto;
 	    bcopy(cp, ackp, length);
 	    ackp += length;
+#ifdef HAVE_DES
+            VarMSChap = cp[4] = 0x80;
+#endif
 	  } else if (Acceptable(ConfPap)) {
 	    *nakp++ = *cp;
 	    *nakp++ = 4;
diff --git a/usr.sbin/ppp/main.h b/usr.sbin/ppp/main.h
index 3a97ddc..41d4857 100644
--- a/usr.sbin/ppp/main.h
+++ b/usr.sbin/ppp/main.h
@@ -17,12 +17,13 @@
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
- * $Id: main.h,v 1.4 1997/06/09 03:27:28 brian Exp $
+ * $Id: main.h,v 1.5 1997/08/25 00:29:19 brian Exp $
  *
  */
 
 #ifndef _MAIN_H_
 #define	_MAIN_H_
+
 void Cleanup(int);
 
 #endif
diff --git a/usr.sbin/ppp/ppp.8 b/usr.sbin/ppp/ppp.8
index 5584ecb..0b9cfd9 100644
--- a/usr.sbin/ppp/ppp.8
+++ b/usr.sbin/ppp/ppp.8
@@ -1,4 +1,4 @@
-.\" $Id: ppp.8,v 1.66 1997/09/21 13:06:43 brian Exp $
+.\" $Id: ppp.8,v 1.67 1997/09/22 23:59:15 brian Exp $
 .Dd 20 September 1995
 .Os FreeBSD
 .Dt PPP 8
@@ -1438,7 +1438,7 @@ in
 .Pa ppp.conf .
 CHAP is accepted by default.
 
-Some ppp implementations use MD4 rather than MD5 when encrypting the
+Some ppp implementations use "MS-CHAP" rather than MD5 when encrypting the
 challenge.  Refer to the description of the
 .Dq set encrypt
 command for further details.
@@ -1689,12 +1689,24 @@ This specifies the chat script that will be used to reset the modem
 before it is closed.  It should not normally be necessary, but can
 be used for devices that fail to reset themselves properly on close.
 
-.It set encrypt MD4|MD5
-This specifies the encryption algorithm to use when encrypting the
-CHAP challenge string and defaults to MD5.
-Normally, CHAP authentication is done using MD5, but some ppp
-implementations (notably the RAS on Windows NT 3 & 4) use MD4
-instead.
+.It set encrypt MSChap|MD5
+This specifies the encryption algorithm to request and use when issuing
+the CHAP challenge, and defaults to MD5.  If this is set to MSChap,
+.Nm
+will behave like a Microsoft RAS when sending the CHAP challenge (assuming
+CHAP is enabled).  When responding to a challenge,
+.Nm
+determines how to encrypt the response based on the challenge, so this
+setting is ignored.
+
+.Bl -tag -width NOTE:
+.It NOTE:
+Because the Microsoft encryption algorithm uses a combination of MD4 and DES,
+if you have not installed DES encryption software on your machine
+before building
+.Nm ppp ,
+this option will not be available - only MD5 will be used.
+.El
 
 .It set escape value...
 This option is similar to the
diff --git a/usr.sbin/ppp/ppp.8.m4 b/usr.sbin/ppp/ppp.8.m4
index 5584ecb..0b9cfd9 100644
--- a/usr.sbin/ppp/ppp.8.m4
+++ b/usr.sbin/ppp/ppp.8.m4
@@ -1,4 +1,4 @@
-.\" $Id: ppp.8,v 1.66 1997/09/21 13:06:43 brian Exp $
+.\" $Id: ppp.8,v 1.67 1997/09/22 23:59:15 brian Exp $
 .Dd 20 September 1995
 .Os FreeBSD
 .Dt PPP 8
@@ -1438,7 +1438,7 @@ in
 .Pa ppp.conf .
 CHAP is accepted by default.
 
-Some ppp implementations use MD4 rather than MD5 when encrypting the
+Some ppp implementations use "MS-CHAP" rather than MD5 when encrypting the
 challenge.  Refer to the description of the
 .Dq set encrypt
 command for further details.
@@ -1689,12 +1689,24 @@ This specifies the chat script that will be used to reset the modem
 before it is closed.  It should not normally be necessary, but can
 be used for devices that fail to reset themselves properly on close.
 
-.It set encrypt MD4|MD5
-This specifies the encryption algorithm to use when encrypting the
-CHAP challenge string and defaults to MD5.
-Normally, CHAP authentication is done using MD5, but some ppp
-implementations (notably the RAS on Windows NT 3 & 4) use MD4
-instead.
+.It set encrypt MSChap|MD5
+This specifies the encryption algorithm to request and use when issuing
+the CHAP challenge, and defaults to MD5.  If this is set to MSChap,
+.Nm
+will behave like a Microsoft RAS when sending the CHAP challenge (assuming
+CHAP is enabled).  When responding to a challenge,
+.Nm
+determines how to encrypt the response based on the challenge, so this
+setting is ignored.
+
+.Bl -tag -width NOTE:
+.It NOTE:
+Because the Microsoft encryption algorithm uses a combination of MD4 and DES,
+if you have not installed DES encryption software on your machine
+before building
+.Nm ppp ,
+this option will not be available - only MD5 will be used.
+.El
 
 .It set escape value...
 This option is similar to the
diff --git a/usr.sbin/ppp/vars.h b/usr.sbin/ppp/vars.h
index 6c8ffb3..84040bb 100644
--- a/usr.sbin/ppp/vars.h
+++ b/usr.sbin/ppp/vars.h
@@ -15,7 +15,7 @@
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
- * $Id: vars.h,v 1.27 1997/09/17 23:17:57 brian Exp $
+ * $Id: vars.h,v 1.28 1997/09/22 23:59:16 brian Exp $
  *
  *	TODO:
  */
@@ -85,7 +85,9 @@ struct pppvars {
   char login_script[200];	/* Login script */
   char auth_key[50];		/* PAP/CHAP key */
   char auth_name[50];		/* PAP/CHAP system name */
-  int enc_MD4;			/* Use MD4 for CHAP encryption */
+#ifdef HAVE_DES
+  int use_MSChap;		/* Use MSCHAP encryption */
+#endif
   char phone_numbers[200];	/* Telephone Numbers */
   char phone_copy[200];		/* copy for strsep() */
   char *next_phone;		/* Next phone from the list */
@@ -113,11 +115,13 @@ struct pppvars {
 #define	VarRetryTimeout	pppVars.retry_timeout
 #define	VarAuthKey	pppVars.auth_key
 #define	VarAuthName	pppVars.auth_name
-#define	VarEncMD4	pppVars.enc_MD4
+#ifdef HAVE_DES
+#define	VarMSChap	pppVars.use_MSChap
+#endif
 #define VarPhoneList    pppVars.phone_numbers
 #define VarPhoneCopy    pppVars.phone_copy
 #define VarNextPhone    pppVars.next_phone
-#define VarAltPhone    pppVars.alt_phone
+#define VarAltPhone     pppVars.alt_phone
 #define	VarShortHost	pppVars.shostname
 #define VarReconnectTimer pppVars.reconnect_timer
 #define VarReconnectTries pppVars.reconnect_tries