svn: ecrypt/trunk/submissions/achterbahn/128-80/ref/ecrypt-sync.h
/* ------------------------------------------------------------------------- *
*
* Program: A C H T E R B A H N - 128 / 80
* Version 1.1
*
* Authors: Berndt M. Gammel, Email: gammel@matpack.de
* Rainer Goettfert, Email: rainer.goettfert@gmx.de
* Oliver Kniffler, Email: oliver.kniffler@arcor.de
*
* Language: ANSI C99
*
* Sources: achterbahn128.c
* ecrypt-sync.h
*
* Includes: ecrypt-portable.h,
* ecrypt-config.h,
* ecrypt-machine.h
*
* Makefile: Makefile
*
* Platforms: This program has been tested on the following platforms:
* gcc 3.4.4, Cygwin, Windows 2000
* gcc 4.0.2, S.u.S.E. Linux 10.0
*
* Copyright: (C) 2005-2006 by Berndt M. Gammel, Rainer Goettfert,
* and Oliver Kniffler
*
* ------------------------------------------------------------------------- */
#ifndef ECRYPT_SYNC
#define ECRYPT_SYNC
#include "ecrypt-portable.h"
/* ------------------------------------------------------------------------- */
/* Cipher parameters */
/* ------------------------------------------------------------------------- *
* The name of the cipher.
* ------------------------------------------------------------------------- */
#define ECRYPT_NAME "ACHTERBAHN-128/80"
#define ECRYPT_PROFILE "_____"
#define ECRYPT_AUTHORS "B. M. Gammel, R. Goettfert, O. Kniffler"
/* ------------------------------------------------------------------------- *
* Specify which key and IV sizes are supported by your cipher. A user
* should be able to enumerate the supported sizes by running the
* following code:
*
* for (i = 0; ECRYPT_KEYSIZE(i) <= ECRYPT_MAXKEYSIZE; ++i)
* {
* keysize = ECRYPT_KEYSIZE(i);
*
* ...
* }
*
* All sizes are in bits.
* ------------------------------------------------------------------------- */
#define ECRYPT_MAXKEYSIZE 128U /* constant keysizes 128 or 80 bit */
#define ECRYPT_KEYSIZE(i) (40U+i*8)
#define ECRYPT_MAXIVSIZE 128U /* variable IV sizes */
#define ECRYPT_IVSIZE(i) (i*8) /* 0, 8, 16,..., 128 for keysize 128
0, 8, 16,..., 80 for keysize 80 */
/* ------------------------------------------------------------------------- */
/* Data structures */
/* ------------------------------------------------------------------------- *
* ECRYPT_ctx is the structure containing the representation of the
* internal state of your cipher.
* ------------------------------------------------------------------------- */
typedef struct
{
u32 A0,A1,A2,A3, /* state of 13 driving NLFSR */
A4,A5,A6,A7,
A8,A9,A10,A11;
u64 A12;
u64 key33; /* save key bits 0 to 32 in one word */
u32 keysize; /* save key length in bits */
u32 ivsize; /* save IV length in bits */
u32 iv_setup_done; /* flag to mark that setup is done */
u32 iv[128]; /* save IV - 1 bit/word for fast access */
u32 ky[128]; /* save key - 1 bit/word for fast access */
} ECRYPT_ctx;
/* Mandatory functions */
/* ------------------------------------------------------------------------- *
* Key and message independent initialization. This function will be
* called once when the program starts (e.g., to build expanded S-box
* tables).
* ------------------------------------------------------------------------- */
void ECRYPT_init();
/* ------------------------------------------------------------------------- *
* Key setup. It is the user's responsibility to select the values of
* keysize and ivsize from the set of supported values specified above.
* ------------------------------------------------------------------------- */
void ECRYPT_keysetup(
ECRYPT_ctx* ctx,
const u8* key,
u32 keysize, /* Key size in bits. */
u32 ivsize); /* IV size in bits. */
/* ------------------------------------------------------------------------- *
* IV setup. After having called ECRYPT_keysetup(), the user is
* allowed to call ECRYPT_ivsetup() different times in order to
* encrypt/decrypt different messages with the same key but different IV's.
* ------------------------------------------------------------------------- */
void ECRYPT_ivsetup(
ECRYPT_ctx* ctx,
const u8* iv);
/* ------------------------------------------------------------------------- *
* Encryption/decryption of arbitrary length messages.
*
* For efficiency reasons, the API provides two types of
* encrypt/decrypt functions. The ECRYPT_encrypt_bytes() function
* (declared here) encrypts byte strings of arbitrary length, while
* the ECRYPT_encrypt_blocks() function (defined later) only accepts
* lengths which are multiples of ECRYPT_BLOCKLENGTH.
*
* The user is allowed to make multiple calls to
* ECRYPT_encrypt_blocks() to incrementally encrypt a long message,
* but he is NOT allowed to make additional encryption calls once he
* has called ECRYPT_encrypt_bytes() (unless he starts a new message
* of course). For example, this sequence of calls is acceptable:
*
* ECRYPT_keysetup();
*
* ECRYPT_ivsetup();
* ECRYPT_encrypt_blocks();
* ECRYPT_encrypt_blocks();
* ECRYPT_encrypt_bytes();
*
* ECRYPT_ivsetup();
* ECRYPT_encrypt_blocks();
* ECRYPT_encrypt_blocks();
*
* ECRYPT_ivsetup();
* ECRYPT_encrypt_bytes();
*
* The following sequence is not:
*
* ECRYPT_keysetup();
* ECRYPT_ivsetup();
* ECRYPT_encrypt_blocks();
* ECRYPT_encrypt_bytes();
* ECRYPT_encrypt_blocks();
* ------------------------------------------------------------------------- */
void ECRYPT_encrypt_bytes(
ECRYPT_ctx* ctx,
const u8* plaintext,
u8* ciphertext,
u32 msglen); /* Message length in bytes. */
void ECRYPT_decrypt_bytes(
ECRYPT_ctx* ctx,
const u8* ciphertext,
u8* plaintext,
u32 msglen); /* Message length in bytes. */
/* ------------------------------------------------------------------------- */
/* Optional features */
/* ------------------------------------------------------------------------- *
* For testing purposes it can sometimes be useful to have a function
* which immediately generates keystream without having to provide it
* with a zero plaintext. If your cipher cannot provide this function
* (e.g., because it is not strictly a synchronous cipher), please
* reset the ECRYPT_GENERATES_KEYSTREAM flag.
* ------------------------------------------------------------------------- */
#define ECRYPT_GENERATES_KEYSTREAM
#ifdef ECRYPT_GENERATES_KEYSTREAM
void ECRYPT_keystream_bytes(
ECRYPT_ctx* ctx,
u8* keystream,
u32 length); /* Length of keystream in bytes. */
#endif
/* ------------------------------------------------------------------------- */
/* Optional optimizations */
/* ------------------------------------------------------------------------- *
* By default, the functions in this section are implemented using
* calls to functions declared above. However, you might want to
* implement them differently for performance reasons.
* ------------------------------------------------------------------------- */
/* ------------------------------------------------------------------------- *
* All-in-one encryption/decryption of (short) packets.
*
* The default definitions of these functions can be found in
* "ecrypt-sync.c". If you want to implement them differently, please
* undef the ECRYPT_USES_DEFAULT_ALL_IN_ONE flag.
* ------------------------------------------------------------------------- */
#define ECRYPT_USES_DEFAULT_ALL_IN_ONE
void ECRYPT_encrypt_packet(
ECRYPT_ctx* ctx,
const u8* iv,
const u8* plaintext,
u8* ciphertext,
u32 msglen);
void ECRYPT_decrypt_packet(
ECRYPT_ctx* ctx,
const u8* iv,
const u8* ciphertext,
u8* plaintext,
u32 msglen);
/* ------------------------------------------------------------------------- *
* Encryption/decryption of blocks.
*
* By default, these functions are defined as macros. If you want to
* provide a different implementation, please undef the
* ECRYPT_USES_DEFAULT_BLOCK_MACROS flag and implement the functions
* declared below.
* ------------------------------------------------------------------------- */
#define ECRYPT_BLOCKLENGTH 4
#define ECRYPT_USES_DEFAULT_BLOCK_MACROS
#ifdef ECRYPT_USES_DEFAULT_BLOCK_MACROS
#define ECRYPT_encrypt_blocks(ctx, plaintext, ciphertext, blocks) \
ECRYPT_encrypt_bytes(ctx, plaintext, ciphertext, \
(blocks) * ECRYPT_BLOCKLENGTH)
#define ECRYPT_decrypt_blocks(ctx, ciphertext, plaintext, blocks) \
ECRYPT_decrypt_bytes(ctx, ciphertext, plaintext, \
(blocks) * ECRYPT_BLOCKLENGTH)
#ifdef ECRYPT_GENERATES_KEYSTREAM
#define ECRYPT_keystream_blocks(ctx, keystream, blocks) \
ECRYPT_AE_keystream_bytes(ctx, keystream, \
(blocks) * ECRYPT_BLOCKLENGTH)
#endif
#else
void ECRYPT_encrypt_blocks(
ECRYPT_ctx* ctx,
const u8* plaintext,
u8* ciphertext,
u32 blocks); /* Message length in blocks. */
void ECRYPT_decrypt_blocks(
ECRYPT_ctx* ctx,
const u8* ciphertext,
u8* plaintext,
u32 blocks); /* Message length in blocks. */
#ifdef ECRYPT_GENERATES_KEYSTREAM
void ECRYPT_keystream_blocks(
ECRYPT_AE_ctx* ctx,
const u8* keystream,
u32 blocks); /* Keystream length in blocks. */
#endif
#endif
/*
* If your cipher can be implemented in different ways, you can use
* the ECRYPT_VARIANT parameter to allow the user to choose between
* them at compile time (e.g., gcc -DECRYPT_VARIANT=3 ...). Please
* only use this possibility if you really think it could make a
* significant difference and keep the number of variants
* (ECRYPT_MAXVARIANT) as small as possible (definitely not more than
* 10). Note also that all variants should have exactly the same
* external interface (i.e., the same ECRYPT_BLOCKLENGTH, etc.).
*/
#define ECRYPT_MAXVARIANT 1 /* [edit] */
#ifndef ECRYPT_VARIANT
#define ECRYPT_VARIANT 1
#endif
#if (ECRYPT_VARIANT > ECRYPT_MAXVARIANT)
#error this variant does not exist
#endif
/* ------------------------------------------------------------------------- */
#endif