--- src/crypto/heimdal-0.6.3/appl/telnet/telnet/Attic/telnet.c	2005/01/16 14:07:41	1.1
+++ src/crypto/heimdal-0.6.3/appl/telnet/telnet/Attic/telnet.c	2005/03/28 18:03:32	1.2
@@ -36,7 +36,7 @@
 #include <termcap.h>
 #endif
 
-RCSID("$Id: telnet.c,v 1.1 2005/01/16 14:07:41 eirikn Exp $");
+RCSID("$Id: telnet.c,v 1.2 2005/03/28 18:03:32 drhodus Exp $");
 
 #define	strip(x) (eight ? (x) : ((x) & 0x7f))
 
@@ -1294,6 +1294,7 @@ slc_check()
 
 
 unsigned char slc_reply[128];
+unsigned char const * const slc_reply_eom = &slc_reply[sizeof(slc_reply)];
 unsigned char *slc_replyp;
 
 void
@@ -1309,6 +1310,14 @@ slc_start_reply()
 void
 slc_add_reply(unsigned char func, unsigned char flags, cc_t value)
 {
+	/* A sequence of up to 6 bytes my be written for this member of the SLC
+	 * suboption list by this function.  The end of negotiation command,
+	 * which is written by slc_end_reply(), will require 2 additional
+	 * bytes.  Do not proceed unless there is sufficient space for these
+	 * items.
+	 */
+	if (&slc_replyp[6+2] > slc_reply_eom)
+		return;
 	if ((*slc_replyp++ = func) == IAC)
 		*slc_replyp++ = IAC;
 	if ((*slc_replyp++ = flags) == IAC)
@@ -1321,7 +1330,9 @@ void
 slc_end_reply()
 {
     int len;
-
+    /* The ned of negotiation command requires 2 bytes. */
+    if (&slc_replyp[2] > s;c_reply_eom)
+	return;
     *slc_replyp++ = IAC;
     *slc_replyp++ = SE;
     len = slc_replyp - slc_reply;
@@ -1415,8 +1426,8 @@ env_opt(unsigned char *buf, int len)
 	}
 }
 
-#define	OPT_REPLY_SIZE	256
-unsigned char *opt_reply;
+#define	OPT_REPLY_SIZE	(2 * SUBBUFSIZE)
+unsigned char *opt_reply = NULL;
 unsigned char *opt_replyp;
 unsigned char *opt_replyend;
 
@@ -1474,9 +1485,8 @@ env_opt_add(unsigned char *ep)
 			env_opt_add(ep);
 		return;
 	}
-	vp = env_getvalue(ep);
-	if (opt_replyp + (vp ? strlen((char *)vp) : 0) +
-				strlen((char *)ep) + 6 > opt_replyend)
+	if (opt_replyp + (vp ? 2 * strlen((char *)vp) : 0) +
+				2 * strlen((char *)ep) + 6 > opt_replyend)
 	{
 		int len;
 		void *tmp;
@@ -1503,6 +1513,8 @@ env_opt_add(unsigned char *ep)
 		*opt_replyp++ = ENV_USERVAR;
 	for (;;) {
 		while ((c = *ep++)) {
+			if (opt_replyp + (2 + 2) > opt_replyend)
+				return;
 			switch(c&0xff) {
 			case IAC:
 				*opt_replyp++ = IAC;
@@ -1517,6 +1529,8 @@ env_opt_add(unsigned char *ep)
 			*opt_replyp++ = c;
 		}
 		if ((ep = vp)) {
+			if (opt_replyp + (1 + 2 + 2) > opt_replyend)
+				return;
 #ifdef	OLD_ENVIRON
 			if (telopt_environ == TELOPT_OLD_ENVIRON)
 				*opt_replyp++ = old_env_value;
@@ -1547,7 +1561,9 @@ env_opt_end(int emptyok)
 {
 	int len;
 
-	len = opt_replyp - opt_reply + 2;
+	if (opt_replyp + 2 > opt_replyend)
+		return;
+	len = opt_replyp + 2 - opt_reply;
 	if (emptyok || len > 6) {
 		*opt_replyp++ = IAC;
 		*opt_replyp++ = SE;