fix move state to handshake over fail

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
index 239be53..c829635 100644
--- a/library/ssl_tls13_generic.c
+++ b/library/ssl_tls13_generic.c
@@ -1190,13 +1190,15 @@
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse finished message" ) );
 
-    /* Preprocessing step: Compute handshake digest */
-    MBEDTLS_SSL_PROC_CHK( ssl_tls13_preprocess_finished_message( ssl ) );
-
     MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_fetch_handshake_msg( ssl,
                                               MBEDTLS_SSL_HS_FINISHED,
                                               &buf, &buf_len ) );
+
+    /* Preprocessing step: Compute handshake digest */
+    MBEDTLS_SSL_PROC_CHK( ssl_tls13_preprocess_finished_message( ssl ) );
+
     MBEDTLS_SSL_PROC_CHK( ssl_tls13_parse_finished_message( ssl, buf, buf + buf_len ) );
+
     mbedtls_ssl_add_hs_msg_to_checksum( ssl, MBEDTLS_SSL_HS_FINISHED,
                                         buf, buf_len );