Sanity length checks in ssl_read_record() and ssl_fetch_input()
Both are already covered in other places, but not in a clear fashion. So
for instance Coverity thinks the value is still tainted.
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 271bfe6..e9b1024 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -1908,6 +1908,12 @@
SSL_DEBUG_MSG( 2, ( "=> fetch input" ) );
+ if( nb_want > SSL_BUFFER_LEN - 8 )
+ {
+ SSL_DEBUG_MSG( 1, ( "requesting more data than fits" ) );
+ return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
+ }
+
while( ssl->in_left < nb_want )
{
len = nb_want - ssl->in_left;
@@ -2131,13 +2137,20 @@
return( POLARSSL_ERR_SSL_INVALID_RECORD );
}
+ /* Sanity check (outer boundaries) */
+ if( ssl->in_msglen < 1 || ssl->in_msglen > SSL_BUFFER_LEN - 13 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad message length" ) );
+ return( POLARSSL_ERR_SSL_INVALID_RECORD );
+ }
+
/*
- * Make sure the message length is acceptable
+ * Make sure the message length is acceptable for the current transform
+ * and protocol version.
*/
if( ssl->transform_in == NULL )
{
- if( ssl->in_msglen < 1 ||
- ssl->in_msglen > SSL_MAX_CONTENT_LEN )
+ if( ssl->in_msglen > SSL_MAX_CONTENT_LEN )
{
SSL_DEBUG_MSG( 1, ( "bad message length" ) );
return( POLARSSL_ERR_SSL_INVALID_RECORD );