commit 838ed3c74d247f9220fedffcc366cddc8b995c13
author Paul Bakker <p.j.bakker@polarssl.org> Tue Jul 08 16:24:56 2014 +0200
committer Paul Bakker <p.j.bakker@polarssl.org> Tue Jul 08 18:28:33 2014 +0200
tree 8bf9aed0cc06520742a0fd2f2dac7a3faba2e8cc
parent 6993284ece8ac0a1945af5a49ede7c5c7e6ecf5b

Improve interop by not writing ext_len in ClientHello when 0

The RFC also indicates that without any extensions, we should write a
struct {} (empty) not an array of length zero.

library/ssl_cli.c

diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 2a15da1..15fc554 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -212,8 +212,11 @@
     SSL_DEBUG_MSG( 3, ( "client hello, total extension length: %d",
                    ext_len ) );
 
-    *p++ = (unsigned char)( ( ext_len >> 8 ) & 0xFF );
-    *p++ = (unsigned char)( ( ext_len      ) & 0xFF );
+    if( ext_len > 0 )
+    {
+        *p++ = (unsigned char)( ( ext_len >> 8 ) & 0xFF );
+        *p++ = (unsigned char)( ( ext_len      ) & 0xFF );
+    }
 
     if ( ssl->hostname != NULL )
     {