../svn-commit.tmp

2006-04-05 12:10:50 +00:00
parent 3dbbbf3e16
commit 6862128151
171 changed files with 674 additions and 1355 deletions
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+/**
+ * @file hasher.h
+ * 
+ * @brief Interface hasher_t.
+ * 
+ */
+
+/*
+ * Copyright (C) 2005 Jan Hutter, 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.
+ */
+
+#ifndef HASHER_H_
+#define HASHER_H_
+
+
+#include <types.h>
+
+
+typedef enum hash_algorithm_t hash_algorithm_t;
+
+/**
+ * @brief Algorithms to use for hashing.
+ * 
+ * Currently only the following algorithms are implemented and therefore supported:
+ * - HASH_MD5
+ * - HASH_SHA1
+ * 
+ * @ingroup hashers
+ * 
+ */
+enum hash_algorithm_t {
+	HASH_MD2,
+	/**
+	 * Implemented in class md5_hasher_t.
+	 */
+	HASH_MD5,
+	/**
+	 * Implemented in class sha1_hasher_t.
+	 */
+	HASH_SHA1,
+	HASH_SHA256,
+	HASH_SHA384,
+	HASH_SHA512,
+};
+
+/**
+ * String mappings for hash_algorithm_t.
+ */
+extern mapping_t hash_algorithm_m[];
+
+
+typedef struct hasher_t hasher_t;
+
+/**
+ * @brief Generic interface for all hash functions.
+ * 
+ * @b Constructors:
+ *  - hasher_create()
+ *  - md5_hasher_create()
+ *  - sha1_hasher_create()
+ * 
+ * @see		
+ * 			- md5_hasher_t
+ * 			- sha1_hasher_t
+ * 
+ * @todo Implement more hash algorithms
+ * 
+ * @ingroup hashers
+ */
+struct hasher_t {
+	/**
+	 * @brief Hash data and write it in the buffer.
+	 * 
+	 * If the parameter hash is NULL, no result is written back
+	 * an more data can be appended to already hashed data.
+	 * If not, the result is written back and the hasher is reseted.
+	 * 
+	 * @warning: the hash output parameter must hold at least
+	 * hash_t.get_block_size bytes.
+	 * 
+	 * @param this			calling object
+	 * @param data			data to hash
+	 * @param[out] hash		pointer where the hash will be written
+	 */
+	void (*get_hash) (hasher_t *this, chunk_t data, u_int8_t *hash);
+	
+	/**
+	 * @brief Hash data and allocate space for the hash.
+	 * 
+	 * If the parameter hash is NULL, no result is written back
+	 * an more data can be appended to already hashed data.
+	 * If not, the result is written back and the hasher is reseted.
+	 * 
+	 * @param this			calling object
+	 * @param data			chunk with data to hash
+	 * @param[out] hash		chunk which will hold allocated hash
+	 */
+	void (*allocate_hash) (hasher_t *this, chunk_t data, chunk_t *hash);
+	
+	/**
+	 * @brief Get the block size of this hashing function.
+	 * 
+	 * @param this			calling object
+	 * @return				block size in bytes
+	 */
+	size_t (*get_block_size) (hasher_t *this);
+	
+	/**
+	 * @brief Resets the hashers state, which allows
+	 * computation of a completely new hash.
+	 * 
+	 * @param this			calling object
+	 */
+	void (*reset) (hasher_t *this);
+	
+	/**
+	 * @brief Destroys a hasher object.
+	 *
+	 * @param this 	calling object
+	 */
+	void (*destroy) (hasher_t *this);
+};
+
+/**
+ * @brief Generic interface to create a hasher_t.
+ * 
+ * @param hash_algorithm	Algorithm to use for hashing
+ * @return
+ * 							- hasher_t object
+ * 							- NULL if algorithm not supported
+ * 
+ * @ingroup hashers
+ */
+hasher_t *hasher_create(hash_algorithm_t hash_algorithm);
+
+#endif /*HASHER_H_*/