Support different authentication schemes for PT-TLS

src/libpttls/pt_tls.h

@@ -37,6 +37,7 @@
 
 typedef enum pt_tls_message_type_t pt_tls_message_type_t;
 typedef enum pt_tls_sasl_result_t pt_tls_sasl_result_t;
+typedef enum pt_tls_auth_t pt_tls_auth_t;
 
 /**
  * Message types, as defined by NEA PT-TLS
@@ -63,6 +64,22 @@ enum pt_tls_sasl_result_t {
 	PT_TLS_SASL_RESULT_MECH_FAILURE = 3,
 };
 
+/**
+ * Client authentication to require as PT-TLS server.
+ */
+enum pt_tls_auth_t {
+	/** don't require TLS client certificate or request SASL authentication */
+	PT_TLS_AUTH_NONE,
+	/** require TLS certificate authentication, no SASL */
+	PT_TLS_AUTH_TLS,
+	/** do SASL regardless of TLS certificate authentication */
+	PT_TLS_AUTH_SASL,
+	/* if client does not authenticate with a TLS certificate, request SASL */
+	PT_TLS_AUTH_TLS_OR_SASL,
+	/* require both, TLS certificate authentication and SASL */
+	PT_TLS_AUTH_TLS_AND_SASL,
+};
+
 /**
  * Read a PT-TLS message, create reader over Message Value.
  *