From 838ed3c74d247f9220fedffcc366cddc8b995c13 Mon Sep 17 00:00:00 2001 From: Paul Bakker Date: Tue, 8 Jul 2014 16:24:56 +0200 Subject: [PATCH] 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. --- ChangeLog | 2 ++ library/ssl_cli.c | 7 +++++-- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/ChangeLog b/ChangeLog index e24494a61..c4ddcbdc7 100644 --- a/ChangeLog +++ b/ChangeLog @@ -49,6 +49,8 @@ Bugfix * Some example server programs were not sending the close_notify alert. * Potential memory leak in mpi_exp_mod() when error occurs during calculation of RR. + * Improve interoperability by not writing extension length in ClientHello + when no extensions are present (found by Matthew Page) = Version 1.2.10 released 2013-10-07 Changes diff --git a/library/ssl_cli.c b/library/ssl_cli.c index 2a15da1e9..15fc554b9 100644 --- a/library/ssl_cli.c +++ b/library/ssl_cli.c @@ -212,8 +212,11 @@ static int ssl_write_client_hello( ssl_context *ssl ) 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 ) {