commit 41934dd20a71fc474f0bd4f6cb754b09b48bd52f
author Hanno Becker <hanno.becker@arm.com> Sat Aug 07 19:13:43 2021 +0100
committer Hanno Becker <hanno.becker@arm.com> Sat Aug 07 19:13:43 2021 +0100
tree 7845458d60116086627e797b8d5c7536c89a0e5b
parent 78f6f05778692d25654fbdfafc4cb42fc058843e

Share preparatory code between client and server handshake steps

Signed-off-by: Hanno Becker <hanno.becker@arm.com>

library/ssl_cli.c

diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index e0a1c24..59c5460 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -4210,23 +4210,8 @@
 {
     int ret = 0;
 
-    if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER || ssl->handshake == NULL )
-        return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
-
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "client state: %d", ssl->state ) );
 
-    if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
-        return( ret );
-
-#if defined(MBEDTLS_SSL_PROTO_DTLS)
-    if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
-        ssl->handshake->retransmit_state == MBEDTLS_SSL_RETRANS_SENDING )
-    {
-        if( ( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 )
-            return( ret );
-    }
-#endif /* MBEDTLS_SSL_PROTO_DTLS */
-
     /* Change state now, so that it is right in mbedtls_ssl_read_record(), used
      * by DTLS for dropping out-of-sequence ChangeCipherSpec records */
 #if defined(MBEDTLS_SSL_SESSION_TICKETS)

library/ssl_srv.c

diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index d82ec04..3d67393 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -4258,23 +4258,8 @@
 {
     int ret = 0;
 
-    if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER || ssl->handshake == NULL )
-        return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
-
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "server state: %d", ssl->state ) );
 
-    if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
-        return( ret );
-
-#if defined(MBEDTLS_SSL_PROTO_DTLS)
-    if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
-        ssl->handshake->retransmit_state == MBEDTLS_SSL_RETRANS_SENDING )
-    {
-        if( ( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 )
-            return( ret );
-    }
-#endif /* MBEDTLS_SSL_PROTO_DTLS */
-
     switch( ssl->state )
     {
         case MBEDTLS_SSL_HELLO_REQUEST:

library/ssl_tls.c

diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index bb5ddc4..bf87fe5 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -5076,12 +5076,40 @@
 /*
  * Perform a single step of the SSL handshake
  */
+static int ssl_prepare_handshake_step( mbedtls_ssl_context *ssl )
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+
+    if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
+        return( ret );
+
+#if defined(MBEDTLS_SSL_PROTO_DTLS)
+    if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
+        ssl->handshake->retransmit_state == MBEDTLS_SSL_RETRANS_SENDING )
+    {
+        if( ( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 )
+            return( ret );
+    }
+#endif /* MBEDTLS_SSL_PROTO_DTLS */
+
+    return( ret );
+}
+
 int mbedtls_ssl_handshake_step( mbedtls_ssl_context *ssl )
 {
-    int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 
-    if( ssl == NULL || ssl->conf == NULL )
+    if( ssl            == NULL                       ||
+        ssl->conf      == NULL                       ||
+        ssl->handshake == NULL                       ||
+        ssl->state     == MBEDTLS_SSL_HANDSHAKE_OVER )
+    {
         return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+    }
+
+    ret = ssl_prepare_handshake_step( ssl );
+    if( ret != 0 )
+        return( ret );
 
 #if defined(MBEDTLS_SSL_CLI_C)
     if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )