Add a double check to protect from glitch
Check that the encryption has been done for the outbut buffer.
This is to ensure that glitching out the encryption doesn't
result as a unecrypted buffer to be sent.
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index ca5ca6d..d7ad696 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -4490,6 +4490,7 @@
{
unsigned i;
size_t protected_record_size;
+ volatile int encrypted_fi = 0;
/* Skip writing the record content type to after the encryption,
* as it may change when using the CID extension. */
@@ -4544,6 +4545,13 @@
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
ssl->out_msglen = len = rec.data_len;
(void)mbedtls_platform_put_uint16_be( ssl->out_len, rec.data_len );
+ encrypted_fi = 1;
+ }
+
+ //Double check to ensure the encryption has been done
+ if( ssl->transform_out != NULL && encrypted_fi == 0 )
+ {
+ return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
protected_record_size = len + mbedtls_ssl_out_hdr_len( ssl );