[Bug 338] X11 forwarding no longer works after upgrading from 2.9.9p2 to 3.4p1

[Kevin Steves]

> ------- Additional Comments From jrj at purdue.edu  2002-07-11 05:50 -------
> I figured out the problem.

cool, thanks!

> The real culprit is, of all things, the version of bash that Sun now
> releases.  The ./configure script tries to find a "good" shell to use.
> On one of my machines (2.6) I had stupidly created a /bin/bash symlink
> and it found that ahead of /bin/ksh.  On one of my Solaris 8 machines it
> found the Sun version.  On all the others I had forced ./configure to use
> /bin/ksh or it found it first on its own.  Those mismatches, of course,
> led to all sorts of confusion as it appeared to me xauth was running OK.
> 
> In either case, bash is not capable of finding xauth properly with the
> code that's in ./configure.  I added some debugging code and it does
> something like this:
> 
>   Looking for /bin/xauth
>   Looking for /usr/bin/xauth
>   Looking for /usr/local/bin/xauth
>   ...
>   Looking for /usr/openwin/bin:/bin:/usr/bin:/usr/local/bin:.../xauth
> 
> It's clearly having trouble breaking $PATH apart, and, as luck would
> have it, the problem is with the last element, which is where it puts
> /usr/openwin/bin to look for xauth.  Sigh.

that's a known problem with using autoconf 2.53.  can someone bugzilla
that?  is it a bash problem or autoconf?

> I tried to add some code to ssh.c to detect when xauth was missing,
> which might have speeded up diagnosing this, but it got more complicated
> than I wanted to spend time on.
> 
> You don't appear to have a text file documenting OS specific issues, but I
> suggest a note someplace warning Solaris builders to stay away from bash.

perhaps something like this?

Index: ssh.c
===================================================================
RCS file: /cvs/src/usr.bin/ssh/ssh.c,v
retrieving revision 1.181
diff -u -r1.181 ssh.c
--- ssh.c	3 Jul 2002 14:21:05 -0000	1.181
+++ ssh.c	11 Jul 2002 21:37:07 -0000
@@ -710,11 +710,16 @@
 	FILE *f;
 	int got_data = 0, i;
 	char *display;
+	struct stat st;
 
 	*_proto = proto;
 	*_data = data;
 	proto[0] = data[0] = '\0';
-	if (options.xauth_location && (display = getenv("DISPLAY"))) {
+	if (!options.xauth_location ||
+	    (stat(options.xauth_location, &st) == -1)) {
+		debug("No xauth program.");
+	} else {
+		display = getenv("DISPLAY");
 		/* Try to get Xauthority information for the display. */
 		if (strncmp(display, "localhost:", 10) == 0)
 			/*
@@ -748,6 +753,7 @@
 	if (!got_data) {
 		u_int32_t rand = 0;
 
+		log("Warning: No xauth data; using fake authentication data for X11 forwarding.");
 		strlcpy(proto, "MIT-MAGIC-COOKIE-1", sizeof proto);
 		for (i = 0; i < 16; i++) {
 			if (i % 4 == 0)