===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/clientloop.c,v
retrieving revision 1.180
retrieving revision 1.181
diff -u -r1.180 -r1.181
--- src/usr.bin/ssh/clientloop.c	2007/08/07 07:32:53	1.180
+++ src/usr.bin/ssh/clientloop.c	2007/08/15 08:14:46	1.181
@@ -1,4 +1,4 @@
-/* $OpenBSD: clientloop.c,v 1.180 2007/08/07 07:32:53 djm Exp $ */
+/* $OpenBSD: clientloop.c,v 1.181 2007/08/15 08:14:46 markus Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -282,19 +282,29 @@
 					generated = 1;
 			}
 		}
-		snprintf(cmd, sizeof(cmd),
-		    "%s %s%s list %s 2>" _PATH_DEVNULL,
-		    xauth_path,
-		    generated ? "-f " : "" ,
-		    generated ? xauthfile : "",
-		    display);
-		debug2("x11_get_proto: %s", cmd);
-		f = popen(cmd, "r");
-		if (f && fgets(line, sizeof(line), f) &&
-		    sscanf(line, "%*s %511s %511s", proto, data) == 2)
-			got_data = 1;
-		if (f)
-			pclose(f);
+
+		/*
+		 * When in untrusted mode, we read the cookie only if it was
+		 * successfully generated as an untrusted one in the step
+		 * above.
+		 */
+		if (trusted || generated) {
+			snprintf(cmd, sizeof(cmd),
+			    "%s %s%s list %s 2>" _PATH_DEVNULL,
+			    xauth_path,
+			    generated ? "-f " : "" ,
+			    generated ? xauthfile : "",
+			    display);
+			debug2("x11_get_proto: %s", cmd);
+			f = popen(cmd, "r");
+			if (f && fgets(line, sizeof(line), f) &&
+			    sscanf(line, "%*s %511s %511s", proto, data) == 2)
+				got_data = 1;
+			if (f)
+				pclose(f);
+		} else
+			error("Warning: untrusted X11 forwarding setup failed: "
+			    "xauth key data not generated");
 	}
 
 	if (do_unlink) {