incorrect return value in ssl_write_real()

[davidwu2000]

I have a simple fix (below) but could not push to repository

commit f6ac560b040b99b4f9bd120e7477ad85461607d3
Author: David Wu <davidwu@arcturusnetworks.com>
Date:   Tue Mar 7 14:42:21 2017 -0500

    fix the incorrect return value in ssl_write_real()

diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index abad0b3..d680b97 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -6796,8 +6796,8 @@ static int ssl_write_real( mbedtls_ssl_context *ssl,
         if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
         {
             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flush_output", ret );
-            return( ret );
         }
+        return( ret );
     }
     else
     {

[davidwu2000]

here is the function with the fix -

static int ssl_write_real( mbedtls_ssl_context *ssl,
                           const unsigned char *buf, size_t len )
{
    int ret;
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
    size_t max_len = mbedtls_ssl_get_max_frag_len( ssl );

    if( len > max_len )
    {
#if defined(MBEDTLS_SSL_PROTO_DTLS)
        if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
        {
            MBEDTLS_SSL_DEBUG_MSG( 1, ( "fragment larger than the (negotiated) "
                                "maximum fragment length: %d > %d",
                                len, max_len ) );
            return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
        }
        else
#endif
            len = max_len;
    }
#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */

    if( ssl->out_left != 0 )
    {
        if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
        {
            MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flush_output", ret );
        }
        return( ret );
    }
    else
    {
        ssl->out_msglen  = len;
        ssl->out_msgtype = MBEDTLS_SSL_MSG_APPLICATION_DATA;
        memcpy( ssl->out_msg, buf, len );

        if( ( ret = mbedtls_ssl_write_record( ssl ) ) != 0 )
        {
            MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret );
            return( ret );
        }
    }

    return( (int) len );
}

[simonbutcher]

Your fix does look right. Thanks we'll look into this.

[ciarmcom]

ARM Internal Ref: IOTSSL-1255

[simonbutcher]

We've updated the documentation to clarify the correct usage of the API, in PR #1006 for development, and backported it to #1768 for mbedtls-2.7 and #1769 for mbedtls-2.1.

We believe this explains the correct behaviour and therefore I'm closing this issue.