RNGs' get_bytes and allocate_bytes return boolean

src/libstrongswan/crypto/rngs/rng.h

@@ -1,4 +1,5 @@
 /*
+ * Copyright (C) 2012 Tobias Brunner
  * Copyright (C) 2008 Martin Willi
  * Hochschule fuer Technik Rapperswil
  *
@@ -53,16 +54,20 @@ struct rng_t {
 	 *
 	 * @param len		number of bytes to get
 	 * @param buffer	pointer where the generated bytes will be written
+	 * @return			TRUE if bytes successfully written
 	 */
-	void (*get_bytes) (rng_t *this, size_t len, u_int8_t *buffer);
+	__attribute__((warn_unused_result))
+	bool (*get_bytes) (rng_t *this, size_t len, u_int8_t *buffer);
 
 	/**
 	 * Generates random bytes and allocate space for them.
 	 *
 	 * @param len		number of bytes to get
 	 * @param chunk		chunk which will hold generated bytes
+	 * @return			TRUE if allocation succeeded
 	 */
-	void (*allocate_bytes) (rng_t *this, size_t len, chunk_t *chunk);
+	__attribute__((warn_unused_result))
+	bool (*allocate_bytes) (rng_t *this, size_t len, chunk_t *chunk);
 
 	/**
 	 * Destroys a rng object.