iv_gen: Add IV generator that allocates IVs randomly

Uses RNG_WEAK as the code currently does elsewhere to allocate IVs.

src/libstrongswan/Android.mk

@@ -13,6 +13,7 @@ crypto/prfs/prf.c crypto/prfs/mac_prf.c crypto/pkcs5.c \
 crypto/rngs/rng.c crypto/prf_plus.c crypto/signers/signer.c \
 crypto/signers/mac_signer.c crypto/crypto_factory.c crypto/crypto_tester.c \
 crypto/diffie_hellman.c crypto/aead.c crypto/transform.c \
+crypto/iv/iv_gen_rand.c \
 credentials/credential_factory.c credentials/builder.c \
 credentials/cred_encoding.c credentials/keys/private_key.c \
 credentials/keys/public_key.c credentials/keys/shared_key.c \

src/libstrongswan/Makefile.am

@@ -11,6 +11,7 @@ crypto/prfs/prf.c crypto/prfs/mac_prf.c crypto/pkcs5.c \
 crypto/rngs/rng.c crypto/prf_plus.c crypto/signers/signer.c \
 crypto/signers/mac_signer.c crypto/crypto_factory.c crypto/crypto_tester.c \
 crypto/diffie_hellman.c crypto/aead.c crypto/transform.c \
+crypto/iv/iv_gen_rand.c \
 credentials/credential_factory.c credentials/builder.c \
 credentials/cred_encoding.c credentials/keys/private_key.c \
 credentials/keys/public_key.c credentials/keys/shared_key.c \

src/libstrongswan/crypto/iv/iv_gen_rand.c

@@ -0,0 +1,79 @@
+/*
+ * 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.
+ */
+
+#include "iv_gen_rand.h"
+
+#include <library.h>
+
+typedef struct private_iv_gen_t private_iv_gen_t;
+
+/**
+ * Private data of an iv_gen_t object.
+ */
+struct private_iv_gen_t {
+
+	/**
+	 * Public iv_gen_t interface.
+	 */
+	iv_gen_t public;
+
+	/**
+	 * rng_t object
+	 */
+	rng_t *rng;
+};
+
+METHOD(iv_gen_t, get_iv, bool,
+	private_iv_gen_t *this, size_t size, u_int8_t *buffer)
+{
+	if (!this->rng)
+	{
+		return FALSE;
+	}
+	return this->rng->get_bytes(this->rng, size, buffer);
+}
+
+METHOD(iv_gen_t, allocate_iv, bool,
+	private_iv_gen_t *this, size_t size, chunk_t *chunk)
+{
+	if (!this->rng)
+	{
+		return FALSE;
+	}
+	return this->rng->allocate_bytes(this->rng, size, chunk);
+}
+
+METHOD(iv_gen_t, destroy, void,
+	private_iv_gen_t *this)
+{
+	DESTROY_IF(this->rng);
+	free(this);
+}
+
+iv_gen_t *iv_gen_rand_create()
+{
+	private_iv_gen_t *this;
+
+	INIT(this,
+		.public = {
+			.get_iv = _get_iv,
+			.allocate_iv = _allocate_iv,
+			.destroy = _destroy,
+		},
+		.rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK),
+	);
+
+	return &this->public;
+}

src/libstrongswan/crypto/iv/iv_gen_rand.h

@@ -0,0 +1,32 @@
+/*
+ * 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.
+ */
+
+/**
+ * @{ @ingroup iv
+ */
+
+#ifndef IV_GEN_RAND_H_
+#define IV_GEN_RAND_H_
+
+#include <crypto/iv/iv_gen.h>
+
+/**
+ * Create an IV generator that generates random IVs.
+ *
+ * @return		IV generator
+ */
+iv_gen_t *iv_gen_rand_create();
+
+#endif /** IV_GEN_RAND_H_ @}*/