tls13: add key exchange modes in handshake params

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 4cbefdb..9f9192f 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -509,6 +509,9 @@
     /*
      * Handshake specific crypto variables
      */
+#if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL)
+    int tls1_3_kex_modes; /*!< key exchange modes for TLS 1.3 */
+#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
 
 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
     defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
@@ -1438,6 +1441,43 @@
                    MBEDTLS_SSL_TLS13_KEY_EXCHANGE_MODE_PSK_ALL ) );
 }
 
+static inline unsigned mbedtls_ssl_tls1_3_check_kex_modes( mbedtls_ssl_context *ssl,
+                                                           int kex_mode_mask )
+{
+    return( ( ssl->handshake->tls1_3_kex_modes & kex_mode_mask ) != 0 );
+}
+
+static inline int mbedtls_ssl_tls1_3_psk_enabled( mbedtls_ssl_context *ssl )
+{
+    return( mbedtls_ssl_tls1_3_check_kex_modes( ssl,
+                   MBEDTLS_SSL_TLS13_KEY_EXCHANGE_MODE_PSK ) );
+}
+
+static inline int mbedtls_ssl_tls1_3_psk_ephemeral_enabled(
+                                                    mbedtls_ssl_context *ssl )
+{
+    return( mbedtls_ssl_tls1_3_check_kex_modes( ssl,
+                   MBEDTLS_SSL_TLS13_KEY_EXCHANGE_MODE_PSK_EPHEMERAL ) );
+}
+
+static inline int mbedtls_ssl_tls1_3_ephemeral_enabled( mbedtls_ssl_context *ssl )
+{
+    return( mbedtls_ssl_tls1_3_check_kex_modes( ssl,
+                   MBEDTLS_SSL_TLS13_KEY_EXCHANGE_MODE_EPHEMERAL ) );
+}
+
+static inline int mbedtls_ssl_tls1_3_some_ephemeral_enabled( mbedtls_ssl_context *ssl )
+{
+    return( mbedtls_ssl_tls1_3_check_kex_modes( ssl,
+                   MBEDTLS_SSL_TLS13_KEY_EXCHANGE_MODE_EPHEMERAL_ALL ) );
+}
+
+static inline int mbedtls_ssl_tls1_3_some_psk_enabled( mbedtls_ssl_context *ssl )
+{
+    return( mbedtls_ssl_tls1_3_check_kex_modes( ssl,
+                   MBEDTLS_SSL_TLS13_KEY_EXCHANGE_MODE_PSK_ALL ) );
+}
+
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
 
 /**