1 files changed, 159 insertions, 0 deletions
diff --git a/src/libstrongswan/plugins/cmac/cmac_signer.c b/src/libstrongswan/plugins/cmac/cmac_signer.c
new file mode 100644
index 000000000..82e8885d6
--- /dev/null
+++ b/src/libstrongswan/plugins/cmac/cmac_signer.c
@@ -0,0 +1,159 @@
+/*
+ * Copyright (C) 2012 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 <string.h>
+
+#include "cmac_signer.h"
+#include "cmac.h"
+
+typedef struct private_cmac_signer_t private_cmac_signer_t;
+
+/**
+ * Private data structure with signing context.
+ */
+struct private_cmac_signer_t {
+
+	/**
+	 * Public interface.
+	 */
+	cmac_signer_t public;
+
+	/**
+	 * Assigned cmac function.
+	 */
+	cmac_t *cmac;
+
+	/**
+	 * Block size (truncation of CMAC MAC)
+	 */
+	size_t block_size;
+};
+
+METHOD(signer_t, get_signature, void,
+	private_cmac_signer_t *this, chunk_t data, u_int8_t *buffer)
+{
+	if (buffer == NULL)
+	{	/* append mode */
+		this->cmac->get_mac(this->cmac, data, NULL);
+	}
+	else
+	{
+		u_int8_t mac[this->cmac->get_block_size(this->cmac)];
+
+		this->cmac->get_mac(this->cmac, data, mac);
+		memcpy(buffer, mac, this->block_size);
+	}
+}
+
+METHOD(signer_t, allocate_signature, void,
+	private_cmac_signer_t *this, chunk_t data, chunk_t *chunk)
+{
+	if (chunk == NULL)
+	{	/* append mode */
+		this->cmac->get_mac(this->cmac, data, NULL);
+	}
+	else
+	{
+		u_int8_t mac[this->cmac->get_block_size(this->cmac)];
+
+		this->cmac->get_mac(this->cmac, data, mac);
+
+		chunk->ptr = malloc(this->block_size);
+		chunk->len = this->block_size;
+
+		memcpy(chunk->ptr, mac, this->block_size);
+	}
+}
+
+METHOD(signer_t, verify_signature, bool,
+	private_cmac_signer_t *this, chunk_t data, chunk_t signature)
+{
+	u_int8_t mac[this->cmac->get_block_size(this->cmac)];
+
+	if (signature.len != this->block_size)
+	{
+		return FALSE;
+	}
+
+	this->cmac->get_mac(this->cmac, data, mac);
+	return memeq(signature.ptr, mac, this->block_size);
+}
+
+METHOD(signer_t, get_key_size, size_t,
+	private_cmac_signer_t *this)
+{
+	return this->cmac->get_block_size(this->cmac);
+}
+
+METHOD(signer_t, get_block_size, size_t,
+	private_cmac_signer_t *this)
+{
+	return this->block_size;
+}
+
+METHOD(signer_t, set_key, void,
+	private_cmac_signer_t *this, chunk_t key)
+{
+	this->cmac->set_key(this->cmac, key);
+}
+
+METHOD(signer_t, destroy, void,
+	private_cmac_signer_t *this)
+{
+	this->cmac->destroy(this->cmac);
+	free(this);
+}
+
+/*
+ * Described in header
+ */
+cmac_signer_t *cmac_signer_create(integrity_algorithm_t algo)
+{
+	private_cmac_signer_t *this;
+	size_t truncation;
+	cmac_t *cmac;
+
+	switch (algo)
+	{
+		case AUTH_AES_CMAC_96:
+			cmac = cmac_create(ENCR_AES_CBC, 16);
+			truncation = 12;
+			break;
+		default:
+			return NULL;
+	}
+	if (cmac == NULL)
+	{
+		return NULL;
+	}
+
+	INIT(this,
+		.public = {
+			.signer = {
+				.get_signature = _get_signature,
+				.allocate_signature = _allocate_signature,
+				.verify_signature = _verify_signature,
+				.get_key_size = _get_key_size,
+				.get_block_size = _get_block_size,
+				.set_key = _set_key,
+				.destroy = _destroy,
+			},
+		},
+		.cmac = cmac,
+		.block_size = min(truncation, cmac->get_block_size(cmac)),
+	);
+
+	return &this->public;
+}