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* added `ECRYPT_PROFILE'. * made makefiles slightly more portable.
/* ecrypt-ssyn.h */
/*
* Header file for self-synchronising stream ciphers without
* authentication mechanism.
*
* *** Please only edit parts marked with "[edit]". ***
*
* Note: while any self-synchronising stream cipher can be implemented
* with the following API, it might not be very suitable for ciphers
* which need a lot of ciphertext to synchronise, and/or have a
* pipelined design. If this is the case, please use the more flexible
* API of 'ecrypt-sync-ae.h'.
*/
#ifndef ECRYPT_SSYN
#define ECRYPT_SSYN
#include "ecrypt-portable.h"
/* ------------------------------------------------------------------------- */
/* Cipher parameters */
/*
* The name of your cipher.
*/
#define ECRYPT_NAME "SSS" /* [edit] */
#define ECRYPT_PROFILE "SW & HW"
/*
* 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 128 /* [edit] */
#define ECRYPT_KEYSIZE(i) (128 + (i)*32) /* [edit] */
#define ECRYPT_MAXIVSIZE 128 /* [edit] */
#define ECRYPT_IVSIZE(i) (32 + (i)*32) /* [edit] */
/*
* Specify the number of consecutive bytes of ciphertext that need to
* to be received correctly in order to synchronise the keystream.
*/
#define ECRYPT_SYNCLENGTH 34 /* [edit] */
/* ------------------------------------------------------------------------- */
/* Data structures */
/*
* ECRYPT_ctx is a structure storing the (expanded) key and iv of the
* cipher.
*/
#include "sss.h"
typedef struct
{
/*
* [edit]
*
* Put here variables representing the (expanded) key and iv. These
* variables are set during the key and iv setup, and are not
* supposed to change during the encryption of a message.
*/
sss_ctx ctx;
u32 ivsize;
} 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. This function also initializes the block of ECRYPT_SYNCLENGTH
* bytes pointed to by 'previous', which will be passed as a parameter
* in the first call to ECRYPT_encrypt_x().
*/
void ECRYPT_ivsetup(
ECRYPT_ctx* ctx,
u8* previous,
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_SYNCLENGTH.
*
* 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. Here is an example (N >= 2):
*
* u8 plaintext[N * ECRYPT_SYNCLENGTH];
* u8 ciphertext[N * ECRYPT_SYNCLENGTH];
*
* u8* previous = ciphertext + (N - 1) * ECRYPT_SYNCLENGTH;
*
* ECRYPT_keysetup(ctx, key, keysize, ...);
* ECRYPT_ivsetup(ctx, previous, iv);
*
* int rest = msglen;
*
* while (rest >= N * ECRYPT_SYNCLENGTH)
* {
* ... [import N new blocks of ECRYPT_SYNCLENGTH bytes in 'plaintext'] ...
*
* ECRYPT_encrypt_blocks(ctx, previous, plaintext, ciphertext, N);
*
* ... [export the N blocks of 'ciphertext'] ...
*
* rest -= N * ECRYPT_SYNCLENGTH;
* }
*
* if (rest > 0)
* {
* ... [import leftover] ...
*
* ECRYPT_encrypt_bytes(ctx, previous, plaintext, ciphertext, rest);
*
* ... [export leftover] ...
* }
*
* Note that the implementation cannot assume anything about the
* relative position of 'previous' and 'ciphertext', except that the
* ECRYPT_SYNCLENGTH bytes pointed to by 'previous' do not overlap
* with the first ECRYPT_SYNCLENGTH bytes of 'ciphertext'. When
* decrypting, 'previous' and 'ciphertext' cannot overlap at all (the
* user will need to switch between two ciphertext buffers).
*/
/*
* 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.
*/
#undef ECRYPT_HAS_SINGLE_BYTE_FUNCTION /* [edit] */
#ifdef ECRYPT_HAS_SINGLE_BYTE_FUNCTION
#define ECRYPT_encrypt_bytes(ctx, previous, plaintext, ciphertext, msglen) \
ECRYPT_process_bytes(0, ctx, previous, plaintext, ciphertext, msglen)
#define ECRYPT_decrypt_bytes(ctx, previous, ciphertext, plaintext, msglen) \
ECRYPT_process_bytes(1, ctx, previous, ciphertext, plaintext, msglen)
void ECRYPT_process_bytes(
int action, /* 0 = encrypt; 1 = decrypt; */
ECRYPT_ctx* ctx,
const u8* previous,
const u8* input,
u8* output,
u32 msglen); /* Message length in bytes. */
#else
void ECRYPT_encrypt_bytes(
ECRYPT_ctx* ctx,
const u8* previous,
const u8* plaintext,
u8* ciphertext,
u32 msglen); /* Message length in bytes. */
void ECRYPT_decrypt_bytes(
ECRYPT_ctx* ctx,
const u8* previous,
const u8* ciphertext,
u8* plaintext,
u32 msglen); /* Message length 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-ssyn.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_USES_DEFAULT_BLOCK_MACROS /* [edit] */
#ifdef ECRYPT_USES_DEFAULT_BLOCK_MACROS
#define ECRYPT_encrypt_blocks(ctx, previous, plaintext, ciphertext, blocks)\
ECRYPT_encrypt_bytes(ctx, previous, plaintext, ciphertext, \
(blocks) * ECRYPT_SYNCLENGTH)
#define ECRYPT_decrypt_blocks(ctx, previous, ciphertext, plaintext, blocks)\
ECRYPT_decrypt_bytes(ctx, previous, ciphertext, plaintext, \
(blocks) * ECRYPT_SYNCLENGTH)
#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, previous, plaintext, ciphertext, blocks) \
ECRYPT_process_blocks(0, ctx, previous, plaintext, ciphertext, blocks)
#define ECRYPT_decrypt_blocks(ctx, previous, ciphertext, plaintext, blocks) \
ECRYPT_process_blocks(1, ctx, previous, ciphertext, plaintext, blocks)
void ECRYPT_process_blocks(
int action, /* 0 = encrypt; 1 = decrypt; */
ECRYPT_ctx* ctx,
const u8* previous,
const u8* input,
u8* output,
u32 blocks); /* Message length in blocks. */
#else
void ECRYPT_encrypt_blocks(
const ECRYPT_ctx* ctx,
const u8* previous,
const u8* plaintext,
u8* ciphertext,
u32 blocks); /* Message length in blocks. */
void ECRYPT_decrypt_blocks(
const ECRYPT_ctx* ctx,
const u8* previous,
const u8* ciphertext,
u8* plaintext,
u32 blocks); /* Message length in blocks. */
#endif
#endif
/* ------------------------------------------------------------------------- */
#endif
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