Insert two binary NUL bytes (\0) before SSHUTTLE0001 sync string.

...and search for those null bytes before looking for the sync string.

This helps when people have misconfigured .bashrc to print messages even in
non-interactive mode.  (On my Debian Lenny system, .bashrc doesn't seem to
run when you do 'ssh localhost ls', but on MacOS servers, it does.  Hmm...)

2 files changed, 8 insertions, 1 deletions

diff --git a/client.py b/client.py
index 0ff5f2b..449a75a 100644
--- a/client.py
+++ b/client.py
@@ -198,7 +198,14 @@ def _main(listener, fw, ssh_cmd, remotename, python, latency_control,
     handlers.append(mux)
 
     expected = 'SSHUTTLE0001'
+    
     try:
+        v = 'x'
+        while v and v != '\0':
+            v = serversock.recv(1)
+        v = 'x'
+        while v and v != '\0':
+            v = serversock.recv(1)
         initstring = serversock.recv(len(expected))
     except socket.error, e:
         if e.args[0] == errno.ECONNRESET:
diff --git a/server.py b/server.py
index c62c8b5..e1b327d 100644
--- a/server.py
+++ b/server.py
@@ -173,7 +173,7 @@ def main():
         debug1('  %s/%d\n' % r)
         
     # synchronization header
-    sys.stdout.write('SSHUTTLE0001')
+    sys.stdout.write('\0\0SSHUTTLE0001')
     sys.stdout.flush()
 
     handlers = []