From 29800d2fd177a59de02fc2c1eb1027556b31758f Mon Sep 17 00:00:00 2001
From: Hanno Becker <hanno.becker@arm.com>
Date: Tue, 7 Aug 2018 14:30:18 +0100
Subject: [PATCH] Double check that record expansion is as expected during
 decryption

---
 library/ssl_tls.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 88b39b724..dc6647d78 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -4641,6 +4641,11 @@ static int ssl_prepare_record_content( mbedtls_ssl_context *ssl )
             return( ret );
         }
 
+        if( ssl->in_iv + rec.data_offset != ssl->in_msg )
+        {
+            /* Should never happen */
+            return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+        }
 
         ssl->in_msglen = rec.data_len;
         ssl->in_len[0] = (unsigned char)( rec.data_len >> 8 );