1 files changed, 177 insertions, 0 deletions
diff --git a/src/libstrongswan/plugins/xcbc/xcbc_signer.c b/src/libstrongswan/plugins/xcbc/xcbc_signer.c
new file mode 100644
index 000000000..29eb2d25b
--- /dev/null
+++ b/src/libstrongswan/plugins/xcbc/xcbc_signer.c
@@ -0,0 +1,177 @@
+/*
+ * Copyright (C) 2008 Martin Willi
+ * 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.
+ *
+ * $Id$
+ */
+
+#include <string.h>
+
+#include "xcbc_signer.h"
+#include "xcbc.h"
+
+typedef struct private_xcbc_signer_t private_xcbc_signer_t;
+
+/**
+ * Private data structure with signing context.
+ */
+struct private_xcbc_signer_t {
+
+	/**
+	 * Public interface of xcbc_signer_t.
+	 */
+	xcbc_signer_t public;
+	
+	/**
+	 * Assigned xcbc function.
+	 */
+	xcbc_t *xcbc;
+	
+	/**
+	 * Block size (truncation of XCBC MAC)
+	 */
+	size_t block_size;
+};
+
+/**
+ * Implementation of signer_t.get_signature.
+ */
+static void get_signature(private_xcbc_signer_t *this,
+						  chunk_t data, u_int8_t *buffer)
+{
+	if (buffer == NULL)
+	{	/* append mode */
+		this->xcbc->get_mac(this->xcbc, data, NULL);
+	}
+	else
+	{
+		u_int8_t mac[this->xcbc->get_block_size(this->xcbc)];
+		
+		this->xcbc->get_mac(this->xcbc, data, mac);
+		memcpy(buffer, mac, this->block_size);
+	}
+}
+
+/**
+ * Implementation of signer_t.allocate_signature.
+ */
+static void allocate_signature (private_xcbc_signer_t *this,
+								chunk_t data, chunk_t *chunk)
+{
+	if (chunk == NULL)
+	{	/* append mode */
+		this->xcbc->get_mac(this->xcbc, data, NULL);
+	}
+	else
+	{
+		u_int8_t mac[this->xcbc->get_block_size(this->xcbc)];
+		
+		this->xcbc->get_mac(this->xcbc, data, mac);
+
+		chunk->ptr = malloc(this->block_size);
+		chunk->len = this->block_size;
+		
+		memcpy(chunk->ptr, mac, this->block_size);
+	}
+}
+
+/**
+ * Implementation of signer_t.verify_signature.
+ */
+static bool verify_signature(private_xcbc_signer_t *this,
+							 chunk_t data, chunk_t signature)
+{
+	u_int8_t mac[this->xcbc->get_block_size(this->xcbc)];
+	
+	if (signature.len != this->block_size)
+	{
+		return FALSE;
+	}
+	
+	this->xcbc->get_mac(this->xcbc, data, mac);
+	return memeq(signature.ptr, mac, this->block_size);
+}
+
+/**
+ * Implementation of signer_t.get_key_size.
+ */
+static size_t get_key_size(private_xcbc_signer_t *this)
+{
+	return this->xcbc->get_block_size(this->xcbc);
+}
+
+/**
+ * Implementation of signer_t.get_block_size.
+ */
+static size_t get_block_size(private_xcbc_signer_t *this)
+{
+	return this->block_size;
+}
+
+/**
+ * Implementation of signer_t.set_key.
+ */
+static void set_key(private_xcbc_signer_t *this, chunk_t key)
+{
+	this->xcbc->set_key(this->xcbc, key);
+}
+
+/**
+ * Implementation of signer_t.destroy.
+ */
+static status_t destroy(private_xcbc_signer_t *this)
+{
+	this->xcbc->destroy(this->xcbc);
+	free(this);
+	return SUCCESS;
+}
+
+/*
+ * Described in header
+ */
+xcbc_signer_t *xcbc_signer_create(integrity_algorithm_t algo)
+{
+	private_xcbc_signer_t *this;
+	size_t trunc;
+	xcbc_t *xcbc;
+	
+	switch (algo)
+	{
+		case AUTH_AES_XCBC_96:
+			xcbc = xcbc_create(ENCR_AES_CBC, 16);
+			trunc = 12;
+			break;
+		default:
+			return NULL;
+	}
+	if (xcbc == NULL)
+	{
+		return NULL;
+	}
+	
+	this = malloc_thing(private_xcbc_signer_t);
+	this->xcbc = xcbc;
+	this->block_size = min(trunc, xcbc->get_block_size(xcbc));
+	
+	/* interface functions */
+	this->public.signer_interface.get_signature = (void (*) (signer_t*, chunk_t, u_int8_t*))get_signature;
+	this->public.signer_interface.allocate_signature = (void (*) (signer_t*, chunk_t, chunk_t*))allocate_signature;
+	this->public.signer_interface.verify_signature = (bool (*) (signer_t*, chunk_t, chunk_t))verify_signature;
+	this->public.signer_interface.get_key_size = (size_t (*) (signer_t*))get_key_size;
+	this->public.signer_interface.get_block_size = (size_t (*) (signer_t*))get_block_size;
+	this->public.signer_interface.set_key = (void (*) (signer_t*,chunk_t))set_key;
+	this->public.signer_interface.destroy = (void (*) (signer_t*))destroy;
+	
+	return &this->public;
+}
+