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/*
* Copyright (C) 2005-2006 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 crypter crypter
* @{ @ingroup crypto
*/
#ifndef CRYPTER_H_
#define CRYPTER_H_
typedef enum encryption_algorithm_t encryption_algorithm_t;
typedef struct crypter_t crypter_t;
#include <library.h>
/**
* Encryption algorithm, as in IKEv2 RFC 3.3.2.
*/
enum encryption_algorithm_t {
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,
ENCR_AES_CBC = 12,
/** CTR as specified for IPsec (RFC5930/RFC3686), nonce appended to key */
ENCR_AES_CTR = 13,
ENCR_AES_CCM_ICV8 = 14,
ENCR_AES_CCM_ICV12 = 15,
ENCR_AES_CCM_ICV16 = 16,
ENCR_AES_GCM_ICV8 = 18,
ENCR_AES_GCM_ICV12 = 19,
ENCR_AES_GCM_ICV16 = 20,
ENCR_NULL_AUTH_AES_GMAC = 21,
ENCR_CAMELLIA_CBC = 23,
/* CTR as specified for IPsec (RFC5529), nonce appended to key */
ENCR_CAMELLIA_CTR = 24,
ENCR_CAMELLIA_CCM_ICV8 = 25,
ENCR_CAMELLIA_CCM_ICV12 = 26,
ENCR_CAMELLIA_CCM_ICV16 = 27,
ENCR_CHACHA20_POLY1305 = 28,
ENCR_UNDEFINED = 1024,
ENCR_DES_ECB = 1025,
ENCR_SERPENT_CBC = 1026,
ENCR_TWOFISH_CBC = 1027,
/* see macros below to handle RC2 (effective) key length */
ENCR_RC2_CBC = 1028,
};
#define DES_BLOCK_SIZE 8
#define BLOWFISH_BLOCK_SIZE 8
#define AES_BLOCK_SIZE 16
#define CAMELLIA_BLOCK_SIZE 16
#define SERPENT_BLOCK_SIZE 16
#define TWOFISH_BLOCK_SIZE 16
/**
* For RC2, if the effective key size in bits is not key_size * 8, it should
* be encoded with the macro below. It can be decoded with the other two macros.
* After decoding the value should be validated.
*/
#define RC2_KEY_SIZE(kl, eff) ((kl) | ((eff) << 8))
#define RC2_EFFECTIVE_KEY_LEN(ks) ((ks) >> 8)
#define RC2_KEY_LEN(ks) ((ks) & 0xff)
/**
* enum name for encryption_algorithm_t.
*/
extern enum_name_t *encryption_algorithm_names;
/**
* Generic interface for symmetric encryption algorithms.
*/
struct crypter_t {
/**
* Encrypt a chunk of data and allocate space for the encrypted value.
*
* The length of the iv must equal to get_iv_size(), while the length
* of data must be a multiple of get_block_size().
* If encrypted is NULL, the encryption is done in-place (overwriting data).
*
* @param data data to encrypt
* @param iv initializing vector
* @param encrypted chunk to allocate encrypted data, or NULL
* @return TRUE if encryption successful
*/
bool (*encrypt)(crypter_t *this, chunk_t data, chunk_t iv,
chunk_t *encrypted) __attribute__((warn_unused_result));
/**
* Decrypt a chunk of data and allocate space for the decrypted value.
*
* The length of the iv must equal to get_iv_size(), while the length
* of data must be a multiple of get_block_size().
* If decrpyted is NULL, the encryption is done in-place (overwriting data).
*
* @param data data to decrypt
* @param iv initializing vector
* @param encrypted chunk to allocate decrypted data, or NULL
* @return TRUE if decryption successful
*/
bool (*decrypt)(crypter_t *this, chunk_t data, chunk_t iv,
chunk_t *decrypted) __attribute__((warn_unused_result));
/**
* Get the block size of the crypto algorithm.
*
* get_block_size() returns the smallest block the crypter can handle,
* not the block size of the underlying crypto algorithm. For counter mode,
* it is usually 1.
*
* @return block size in bytes
*/
size_t (*get_block_size)(crypter_t *this);
/**
* Get the IV size of the crypto algorithm.
*
* @return initialization vector size in bytes
*/
size_t (*get_iv_size)(crypter_t *this);
/**
* Get the key size of the crypto algorithm.
*
* get_key_size() might return a key length different from the key
* size passed to the factory constructor. For Counter Mode, the nonce
* is handled as a part of the key material and is passed to set_key().
*
* @return key size in bytes
*/
size_t (*get_key_size)(crypter_t *this);
/**
* Set the key.
*
* The length of the key must match get_key_size().
*
* @param key key to set
* @return TRUE if key set successfully
*/
bool (*set_key)(crypter_t *this,
chunk_t key) __attribute__((warn_unused_result));
/**
* Destroys a crypter_t object.
*/
void (*destroy)(crypter_t *this);
};
/**
* Conversion of ASN.1 OID to encryption algorithm.
*
* @param oid ASN.1 OID
* @param key_size returns size of encryption key in bits
* @return encryption algorithm, ENCR_UNDEFINED if OID unsupported
*/
encryption_algorithm_t encryption_algorithm_from_oid(int oid, size_t *key_size);
/**
* Conversion of encryption algorithm to ASN.1 OID.
*
* @param alg encryption algorithm
* @param key_size size of encryption key in bits
* @return ASN.1 OID, OID_UNKNOWN if OID is unknown
*/
int encryption_algorithm_to_oid(encryption_algorithm_t alg, size_t key_size);
/**
* Check if an encryption algorithm identifier is an AEAD algorithm.
*
* @param alg algorithm identifier
* @return TRUE if it is an AEAD algorithm
*/
bool encryption_algorithm_is_aead(encryption_algorithm_t alg);
#endif /** CRYPTER_H_ @}*/
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