extended credential_set_t interface by a cache_cert() method

allows persistent or in-memory caching of fetched certificates

src/charon/credentials/credential_manager.h

@@ -162,9 +162,19 @@ struct credential_manager_t {
 	enumerator_t* (*create_public_enumerator)(credential_manager_t *this,
 					key_type_t type, identification_t *id, auth_info_t *auth);
 	
+	/**
+	 * Cache a certificate by invoking cache_cert() on all registerd sets.
+	 *
+	 * @param cert		certificate to cache
+	 */
+	void (*cache_cert)(credential_manager_t *this, certificate_t *cert);
+	
 	/**
 	 * Flush the certificate cache.
 	 *
+	 * Only the managers local cache is flushed, but not the sets cache filled
+	 * by the cache_cert() method.
+	 *
 	 * @param type		type of certificate to flush, or CERT_ANY
 	 */
 	void (*flush_cache)(credential_manager_t *this, certificate_type_t type);