1 files changed, 36 insertions, 3 deletions
diff --git a/src/libstrongswan/crypto/rngs/rng.h b/src/libstrongswan/crypto/rngs/rng.h
index 36ef52bb4..aee829d71 100644
--- a/src/libstrongswan/crypto/rngs/rng.h
+++ b/src/libstrongswan/crypto/rngs/rng.h
@@ -1,4 +1,5 @@
 /*
+ * Copyright (C) 2012 Tobias Brunner
  * Copyright (C) 2008 Martin Willi
  * Hochschule fuer Technik Rapperswil
  *
@@ -53,21 +54,53 @@ 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);
+	bool (*get_bytes)(rng_t *this, size_t len,
+					  u_int8_t *buffer) __attribute__((warn_unused_result));
 
 	/**
 	 * 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);
+	bool (*allocate_bytes)(rng_t *this, size_t len,
+						   chunk_t *chunk) __attribute__((warn_unused_result));
 
 	/**
 	 * Destroys a rng object.
 	 */
-	void (*destroy) (rng_t *this);
+	void (*destroy)(rng_t *this);
 };
 
+/**
+ * Wrapper around rng_t.get_bytes() ensuring that either all bytes or at least
+ * the first byte is not zero.
+ *
+ * @param rng			rng_t object
+ * @param len			number of bytes to get
+ * @param buffer		pointer where the generated bytes will be written
+ * @param all			TRUE if all bytes have to be non-zero, FALSE for first
+ * @return				TRUE if bytes successfully written
+ */
+bool rng_get_bytes_not_zero(rng_t *rng, size_t len, u_int8_t *buffer,
+							bool all) __attribute__((warn_unused_result));
+
+/**
+ * Wrapper around rng_t.allocate_bytes() ensuring that either all bytes or at
+ * least the first byte is not zero.
+ *
+ * @param rng			rng_t object
+ * @param len			number of bytes to get
+ * @param chunk			chunk that stores the generated bytes (allocated)
+ * @param all			TRUE if all bytes have to be non-zero, FALSE for first
+ * @return				TRUE if bytes successfully written
+ */
+bool rng_allocate_bytes_not_zero(rng_t *rng, size_t len, chunk_t *chunk,
+								 bool all) __attribute__((warn_unused_result));
+
+
+
 #endif /** RNG_H_ @}*/