From dc8bfb9001bd0b1acacaf80eeaf17c44d6d66773 Mon Sep 17 00:00:00 2001
From: Hanno Becker <hanno.becker@arm.com>
Date: Mon, 21 May 2018 17:24:27 +0100
Subject: [PATCH] Restructure incoming CliKeyExch: Move key derivation code

This commit moves the generation of the master secret and session keys
from the premaster secret (done in mbedtlsssl_derive_keys()) from the
previous ClientKeyExchange parsing function ssl_parse_client_key_exchange()
to the new postprocessing function ssl_client_key_exchange_postprocess().
---
 library/ssl_srv.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index 5f10e249f..5737411f4 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -4109,6 +4109,14 @@ static int ssl_client_key_exchange_parse( mbedtls_ssl_context *ssl,
 /* Update the handshake state */
 static int ssl_client_key_exchange_postprocess( mbedtls_ssl_context *ssl )
 {
+    int ret;
+
+    if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret );
+        return( ret );
+    }
+
     ssl->state = MBEDTLS_SSL_CERTIFICATE_VERIFY;
     return( 0 );
 }
@@ -4400,11 +4408,11 @@ static int ssl_parse_client_key_exchange( mbedtls_ssl_context *ssl )
         return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
     }
 
-    if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 )
-    {
-        MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret );
-        return( ret );
-    }
+    /* if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 ) */
+    /* { */
+    /*     MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret ); */
+    /*     return( ret ); */
+    /* } */
 
     ssl->state++;