crypto: Add generic interface for IV generators

src/libstrongswan/Makefile.am

@@ -47,7 +47,7 @@ crypto/proposal/proposal_keywords.h crypto/proposal/proposal_keywords_static.h \
 crypto/prfs/prf.h crypto/prfs/mac_prf.h crypto/rngs/rng.h crypto/nonce_gen.h \
 crypto/prf_plus.h crypto/signers/signer.h crypto/signers/mac_signer.h \
 crypto/crypto_factory.h crypto/crypto_tester.h crypto/diffie_hellman.h \
-crypto/aead.h crypto/transform.h crypto/pkcs5.h \
+crypto/aead.h crypto/transform.h crypto/pkcs5.h crypto/iv/iv_gen.h \
 credentials/credential_factory.h credentials/builder.h \
 credentials/cred_encoding.h credentials/keys/private_key.h \
 credentials/keys/public_key.h credentials/keys/shared_key.h \

src/libstrongswan/crypto/iv/iv_gen.h

@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2013 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+/**
+ * @defgroup iv iv
+ * @{ @ingroup crypto
+ */
+
+#ifndef IV_GEN_H_
+#define IV_GEN_H_
+
+typedef struct iv_gen_t iv_gen_t;
+
+#include <library.h>
+
+/**
+ * Generic interface for initialization vector (IV) generators.
+ */
+struct iv_gen_t {
+
+	/**
+	 * Generates an IV and writes it into the buffer.
+	 *
+	 * @param size		size of IV in bytes
+	 * @param buffer	pointer where the generated IV will be written
+	 * @return			TRUE if IV allocation was successful, FALSE otherwise
+	 */
+	bool (*get_iv)(iv_gen_t *this, size_t size,
+				   u_int8_t *buffer) __attribute__((warn_unused_result));
+
+	/**
+	 * Generates an IV and allocates space for it.
+	 *
+	 * @param size		size of IV in bytes
+	 * @param chunk		chunk which will hold the generated IV
+	 * @return			TRUE if IV allocation was successful, FALSE otherwise
+	 */
+	bool (*allocate_iv)(iv_gen_t *this, size_t size,
+						chunk_t *chunk) __attribute__((warn_unused_result));
+
+	/**
+	 * Destroys an IV generator object.
+	 */
+	void (*destroy)(iv_gen_t *this);
+};
+
+#endif /** IV_GEN_H_ @}*/