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| [svn] / ecrypt / trunk / submissions / decim / ecrypt-sync.h |
* imported original ECRYPT submissions after first automatic cleanup.
/* ecrypt-sync.h */
/*
* Header file for synchronous stream ciphers without authentication
* mechanism.
*
* *** Please only edit parts marked with "[edit]". ***
*/
#ifndef ECRYPT_SYNC
#define ECRYPT_SYNC
#include "ecrypt-portable.h"
/* ------------------------------------------------------------------------- */
/* Cipher parameters */
/*
* The name of your cipher.
*/
#define ECRYPT_NAME "DECIM"
/*
* 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 80 /* DECIM is a hardware candidate
* so the key has only 80 bits */
#define ECRYPT_KEYSIZE(i) (80+(i))
#define ECRYPT_MAXIVSIZE 64 /* DECIM is a hardware candidate */
#define ECRYPT_IVSIZE(i) (32 + (i)*32) /* iv has 32 or 64 bits */
/* ------------------------------------------------------------------------- */
/* Data structures */
/*
* ECRYPT_ctx is the structure containing the representation of the
* internal state of your cipher.
*/
typedef struct
{
/*
* the LFSR related
* lfsr_state : state of length 192 bytes
* lfsr_state[192]: next_bit to enter the state
* */
u8 lfsr_state[193];
/*
* ABSG related
* bit_searched : the bit ABSG is currently looking for
* searching : are we searching the bit_searched bit?
* (1=we are, 0=we aren't)
* immediate_finding: did we instantaneously find the bit_searched bit?
* (1=we did, 0=we don't)
*/
u8 searching;
u8 bit_searched;
u8 immediate_finding;
/*
* Filtering related
* is_permute_a : what permutation will we apply?
* (1=permute_a, 0=permute_b)
* */
u8 is_permute_a;
u8 bool_a, bool_b;
u8 out;
/*
* Buffer related
* bits_in_byte : number of bits already packed in the byte
* stream_byte : the byte where bits are packed
* buffer : the array where bits are stored, waiting for being handled
* buffer_end : marker to the end of buffer
* */
u8 bits_in_byte;
u8 stream_byte;
u8 buffer[32];
u8 buffer_end;
/* the size of the iv*/
u8 iv_size;
} 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(void);
/*
* 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();
*/
/*
* By default ECRYPT_encrypt_bytes() and ECRYPT_decrypt_bytes() are
* defined as macros which redirect the call to a single function
* ECRYPT_process_bytes(). If you want to provide separate encryption
* and decryption functions, please undef
* ECRYPT_HAS_SINGLE_BYTE_FUNCTION.
*/
#define ECRYPT_HAS_SINGLE_BYTE_FUNCTION /* [edit] */
#ifdef ECRYPT_HAS_SINGLE_BYTE_FUNCTION
#define ECRYPT_encrypt_bytes(ctx, plaintext, ciphertext, msglen) \
ECRYPT_process_bytes(0, ctx, plaintext, ciphertext, msglen)
#define ECRYPT_decrypt_bytes(ctx, ciphertext, plaintext, msglen) \
ECRYPT_process_bytes(1, ctx, ciphertext, plaintext, msglen)
void ECRYPT_process_bytes(
int action, /* 0 = encrypt; 1 = decrypt; */
ECRYPT_ctx* ctx,
const u8* input,
u8* output,
u32 msglen); /* Message length in bytes. */
#else
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. */
#endif
/* ------------------------------------------------------------------------- */
/* 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 /* [edit] */
/*
* Undef ECRYPT_HAS_SINGLE_PACKET_FUNCTION if you want to provide
* separate packet encryption and decryption functions.
*/
#define ECRYPT_HAS_SINGLE_PACKET_FUNCTION /* [edit] */
#ifdef ECRYPT_HAS_SINGLE_PACKET_FUNCTION
#define ECRYPT_encrypt_packet( \
ctx, iv, plaintext, ciphertext, mglen) \
ECRYPT_process_packet(0, \
ctx, iv, plaintext, ciphertext, mglen)
#define ECRYPT_decrypt_packet( \
ctx, iv, ciphertext, plaintext, mglen) \
ECRYPT_process_packet(1, \
ctx, iv, ciphertext, plaintext, mglen)
void ECRYPT_process_packet(
int action, /* 0 = encrypt; 1 = decrypt; */
ECRYPT_ctx* ctx,
const u8* iv,
const u8* input,
u8* output,
u32 msglen);
#else
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);
#endif
/*
* 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 /* [edit] */
#define ECRYPT_USES_DEFAULT_BLOCK_MACROS /* [edit] */
#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_keystream_bytes(ctx, keystream, \
(blocks) * ECRYPT_BLOCKLENGTH)
#endif
#else
/*
* Undef ECRYPT_HAS_SINGLE_BLOCK_FUNCTION if you want to provide
* separate block encryption and decryption functions.
*/
#define ECRYPT_HAS_SINGLE_BLOCK_FUNCTION /* [edit] */
#ifdef ECRYPT_HAS_SINGLE_BLOCK_FUNCTION
#define ECRYPT_encrypt_blocks(ctx, plaintext, ciphertext, blocks) \
ECRYPT_process_blocks(0, ctx, plaintext, ciphertext, blocks)
#define ECRYPT_decrypt_blocks(ctx, ciphertext, plaintext, blocks) \
ECRYPT_process_blocks(1, ctx, ciphertext, plaintext, blocks)
void ECRYPT_process_blocks(
int action, /* 0 = encrypt; 1 = decrypt; */
ECRYPT_ctx* ctx,
const u8* input,
u8* output,
u32 blocks); /* Message length in blocks. */
#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. */
#endif
#ifdef ECRYPT_GENERATES_KEYSTREAM
void ECRYPT_keystream_blocks(
ECRYPT_ctx* ctx,
u8* keystream,
u32 blocks); /* Keystream length in blocks. */
#endif
#endif
/* ------------------------------------------------------------------------- */
#endif
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