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/**
* @file crypter.h
*
* @brief Interface crypter_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 CRYPTER_H_
#define CRYPTER_H_
#include <types.h>
typedef enum encryption_algorithm_t encryption_algorithm_t;
/**
* @brief Encryption algorithm, as in IKEv2 draft 3.3.2.
*
* Currently only the following algorithms are implemented and therefore supported:
* - ENCR_AES_CBC
*
* @b Constructors:
* - crypter_create()
* - aes_cbc_crypter_create()
*
* @todo Implement more enryption algorithm, especially 3DES
*
* @ingroup crypters
*/
enum encryption_algorithm_t {
ENCR_UNDEFINED = 1024,
ENCR_DES_IV64 = 1,
ENCR_DES = 2,
ENCR_3DES = 3,
ENCR_RC5 = 4,
ENCR_IDEA = 5,
ENCR_CAST = 6,
ENCR_BLOWFISH = 7,
ENCR_3IDEA = 8,
ENCR_DES_IV32 = 9,
ENCR_NULL = 11,
/**
* Implemented in class aes_cbc_crypter_t.
*/
ENCR_AES_CBC = 12,
ENCR_AES_CTR = 13
};
/**
* String mappings for encryption_algorithm_t.
*/
extern mapping_t encryption_algorithm_m[];
typedef struct crypter_t crypter_t;
/**
* @brief Generic interface for symmetric encryption algorithms.
*
* @todo Distinguish between block_size and key_size, since not all
* algorithms use key_size == block_size (e.g. 3DES).
*
* @todo Add a getter which says if an algorithm uses fixed key size, needed for
* tranform_attribute encoding.
*
* @ingroup crypters
*/
struct crypter_t {
/**
* @brief Encrypt a chunk of data and allocate space for
* the encrypted value.
*
* @param this calling object
* @param data data to encrypt
* @param iv initializing vector
* @param[out] encrypted pointer where the encrypted bytes will be written
* @return
* - SUCCESS
* - INVALID_ARG if data size not a multiple of block size
*/
status_t (*encrypt) (crypter_t *this, chunk_t data, chunk_t iv, chunk_t *encrypted);
/**
* @brief Decrypt a chunk of data and allocate space for
* the decrypted value.
*
* @param this calling object
* @param data data to decrypt
* @param iv initializing vector
* @param[out] encrypted pointer where the decrypted bytes will be written
* @return
* - SUCCESS
* - INVALID_ARG if data size not a multiple of block size
*/
status_t (*decrypt) (crypter_t *this, chunk_t data, chunk_t iv, chunk_t *decrypted);
/**
* @brief Get the block size of this crypter_t object.
*
* @param this calling object
* @return block size in bytes
*/
size_t (*get_block_size) (crypter_t *this);
/**
* @brief Set the key for this crypter_t object.
*
* @param this calling object
* @param key key to set
* @return
* - SUCCESS
* - INVALID_ARG if key size != block size
*/
status_t (*set_key) (crypter_t *this, chunk_t key);
/**
* @brief Destroys a crypter_t object.
*
* @param this calling object
*/
void (*destroy) (crypter_t *this);
};
/**
* @brief Generic constructor for crypter_t objects.
*
* Currently only the following algorithms are implemented and therefore supported:
* - ENCR_AES_CBC
*
* @param encryption_algorithm Algorithm to use for crypter
* @param blocksize block size in bytes
* @return
* - crypter_t object
* - NULL if encryption algorithm or blocksize is not supported
*/
crypter_t *crypter_create(encryption_algorithm_t encryption_algorithm, size_t blocksize);
#endif /*CRYPTER_H_*/
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