Make the hmac_t interface a generic interface for message authentication codes

1 files changed, 72 insertions, 0 deletions

diff --git a/src/libstrongswan/crypto/mac.h b/src/libstrongswan/crypto/mac.h
new file mode 100644
index 000000000..10f09a831
--- /dev/null
+++ b/src/libstrongswan/crypto/mac.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2012 Tobias Brunner
+ * Copyright (C) 2005-2008 Martin Willi
+ * Copyright (C) 2005 Jan Hutter
+ * 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 mac mac
+ * @{ @ingroup crypto
+ */
+
+#ifndef MAC_H_
+#define MAC_H_
+
+typedef struct mac_t mac_t;
+
+#include <library.h>
+
+/**
+ * Generic interface for message authentication codes.
+ *
+ * Classes implementing this interface can use the PRF and signer wrappers.
+ */
+struct mac_t {
+
+	/**
+	 * Generate message authentication code.
+	 *
+	 * If out is NULL, no result is given back.  A next call will
+	 * append the data to already supplied data.  If out is not NULL,
+	 * the mac of all apended data is calculated, written to out and the
+	 * internal state is reset.
+	 *
+	 * @param data		chunk of data to authenticate
+	 * @param out		pointer where the generated bytes will be written
+	 */
+	void (*get_mac)(mac_t *this, chunk_t data, u_int8_t *out);
+
+	/**
+	 * Get the size of the resulting MAC.
+	 *
+	 * @return			block size in bytes
+	 */
+	size_t (*get_mac_size)(mac_t *this);
+
+	/**
+	 * Set the key to be used for the MAC.
+	 *
+	 * Any key length must be accepted.
+	 *
+	 * @param key		key to set
+	 */
+	void (*set_key) (mac_t *this, chunk_t key);
+
+	/**
+	 * Destroys a mac_t object.
+	 */
+	void (*destroy) (mac_t *this);
+};
+
+#endif /** MAC_H_ @}*/