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| [svn] / ecrypt / trunk / submissions / hermes / hermes8-80 / hermes.c |
* imported API compliant implementation.
/* ----------------------------------------------------------------------------
*
* hermes Algorithm (c) 2005 Dr. Ulrich Kaiser, Germany
*
* UKA 08.Nov.2005 extract for API only
*
* ----------------------------------------------------------------------------
*/
#include "ecrypt-sync.h"
#define K_LENGTH 10
#define X_LENGTH 23
#define O_LENGTH 8
#define INIT_ROUNDS 10
#define STREAM_ROUNDS 3
#define SBOX S
#define KEY_STEP1 3
#define KEY_STEP2 5
#define KEY_STEP3 7
#define K_MOD(p) ((p) < K_LENGTH ? (p) : (p) - K_LENGTH)
#define X_MOD(p) ((p) < X_LENGTH ? (p) : (p) - X_LENGTH)
/* ---------- AES encryption SBOX ----------- */
static const u8 S[256] = {
0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5,
0x30, 0x01, 0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76,
0xCA, 0x82, 0xC9, 0x7D, 0xFA, 0x59, 0x47, 0xF0,
0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4, 0x72, 0xC0,
0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC,
0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15,
0x04, 0xC7, 0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A,
0x07, 0x12, 0x80, 0xE2, 0xEB, 0x27, 0xB2, 0x75,
0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E, 0x5A, 0xA0,
0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84,
0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B,
0x6A, 0xCB, 0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF,
0xD0, 0xEF, 0xAA, 0xFB, 0x43, 0x4D, 0x33, 0x85,
0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C, 0x9F, 0xA8,
0x51, 0xA3, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5,
0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2,
0xCD, 0x0C, 0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17,
0xC4, 0xA7, 0x7E, 0x3D, 0x64, 0x5D, 0x19, 0x73,
0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A, 0x90, 0x88,
0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB,
0xE0, 0x32, 0x3A, 0x0A, 0x49, 0x06, 0x24, 0x5C,
0xC2, 0xD3, 0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79,
0xE7, 0xC8, 0x37, 0x6D, 0x8D, 0xD5, 0x4E, 0xA9,
0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A, 0xAE, 0x08,
0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6,
0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A,
0x70, 0x3E, 0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E,
0x61, 0x35, 0x57, 0xB9, 0x86, 0xC1, 0x1D, 0x9E,
0xE1, 0xF8, 0x98, 0x11, 0x69, 0xD9, 0x8E, 0x94,
0x9B, 0x1E, 0x87, 0xE9, 0xCE, 0x55, 0x28, 0xDF,
0x8C, 0xA1, 0x89, 0x0D, 0xBF, 0xE6, 0x42, 0x68,
0x41, 0x99, 0x2D, 0x0F, 0xB0, 0x54, 0xBB, 0x16};
/*
* DESCRIPTION OF ALGORITHM
*
* accu is one byte
* s-box is a table with 256 bytes, i.e. 8 bit input and 8 bit output
*
* A state byte and a key byte and the previous result (accu)
* are EXORed. Then the s-box function is applied. The output is
* fed into accu and into the oldest state byte.
* Number of initial rounds: >= 4
* Number of sub-rounds : 23 (Hermes8-80) or 37 (Hermes8-128)
*
* Confusion by: S-Box, non-linear boolean function
* Diffusion by: Accu overwriting state byte
*
*
* Notation
*
* Hermes8-80
* State register x consists of 23 bytes x[22]..x[0].
* Key register k consists of 10 bytes k[9]..k[0].
* or
* Hermes8-128
* State register x consists of 37 bytes x[36]..x[0].
* Key register k consists of 16 bytes k[15]..k[0].
*
*/
/* ------------------------------------------------------------------------- */
/* ------------------------------------------------------------------------- */
/* ------------------------------- CORE ---------------------------------- */
/* ------------------------------------------------------------------------- */
/* ------------------------------------------------------------------------- */
#define CORE(ROUNDS) \
do { \
int m; \
\
for(m = 1; m <= ROUNDS; ++m, ++round) \
{ \
int p1; \
\
for(p1 = 0; p1 < X_LENGTH; ++p1) \
{ \
accu ^= ctx->x[p1] ^ ctx->k[p2]; /* linear operation */ \
accu = SBOX[accu]; /* NON-LINEAR OPERATION */ \
ctx->x[p1] = accu; /* overwrite state byte ! */ \
\
/* update the pointers */ \
p2 = K_MOD(p2 + KEY_STEP1); \
\
/* update two key bytes */ \
if (++src >= KEY_STEP3) \
{ \
const int p3 = K_MOD(p2 + 1); /* scratch */ \
const int p4 = K_MOD(p3 + 1); /* scratch */ \
\
u8 tmp; /* scratch */ \
\
tmp = ctx->k[p3] ^ ctx->k[p2]; \
ctx->k[p3] = SBOX[tmp]; \
tmp = ctx->k[p4] ^ ctx->k[p2]; \
ctx->k[p4] = SBOX[tmp]; \
\
src -= KEY_STEP3; \
} \
} /* for j */ \
\
/* key scheduling so that x[] sees different k[] */ \
if(round % KEY_STEP2 == 0) \
p2 = K_MOD(p2 + 1); \
\
} /* for m */ \
} while (0)
/* ------------------------------------------------------------------------- */
/* ------------------------------------------------------------------------- */
/* --------------------------- ECRYPT APIs ------------------------------ */
/* ------------------------------------------------------------------------- */
/* ------------------------------------------------------------------------- */
/**
Empty function, must be provided for the API...
*/
void ECRYPT_init()
{
}
/**
loads key[] into ctx->key[]
stores key size value in record
stores iv size value in record
@param ctx ptr to record
@param key ptr to array with crypto key
@param keysize in bits
@param ivsize in bits
*/
void ECRYPT_keysetup(
ECRYPT_ctx* ctx,
const u8* key,
u32 keysize, /* Key size in bits. */
u32 ivsize ) /* IV size in bits. */
{
int j;
for (j = 0; j < K_LENGTH; ++j)
ctx->key[j] = key[j];
ctx->ni = ivsize / 8;
} /* ECRYPT_keysetup ------------------------------------------------------- */
/**
loads iv[] into x[],
runs initial rounds in order to hide IV and KEY from
first key stream output.
@param ctx ptr to record
@param iv ptr to array with initial value IV
*/
void ECRYPT_ivsetup(
ECRYPT_ctx* ctx,
const u8* iv )
{
const int ni = ctx->ni; /* IV size in bytes. */
u8 accu;
int p1; /* pointer to actual state byte */
int p2; /* pointer to actual key byte */
int src; /* sub-round counter */
int round = 1; /* round counter */
int j;
/* load key */
for (j = 0; j < K_LENGTH; ++j)
ctx->k[j] = ctx->key[j];
p1 = (ctx->k[0] ^ ctx->k[1] ^ ctx->k[2]) % X_LENGTH;
p2 = (ctx->k[3] ^ ctx->k[4] ^ ctx->k[5]) % K_LENGTH;
accu = (ctx->k[6] ^ ctx->k[7] ^ ctx->k[8]);
src = (ctx->k[9] ^ ctx->k[0] ^ ctx->k[3]) % KEY_STEP3;
/* fill IV into state[] and pad */
for (j = 0; j < X_LENGTH; ++j, p1 = X_MOD(p1 + 1))
ctx->x[j] = (p1 < ni ? iv[p1] : 0);
/* ----------------- start of algorithm ----------------- */
CORE(INIT_ROUNDS);
ctx->accu = accu;
ctx->p2 = p2;
ctx->src = src;
ctx->counter = round;
} /* ECRYPT_ivsetup -------------------------------------------------------- */
/**
Encrypts a certain number of bytes of the plaintext.
@param in ctx ptr to record
@param in plaintext ptr to array with plaintext
@param out ciphertext ptr to array with ciphertext
@param in msglen number of bytes to process
*/
void ECRYPT_process_bytes(
int action,
ECRYPT_ctx* ctx,
const u8* input,
u8* output,
u32 msglen) /* Message length in bytes. */
{
/* ----------------- start of algorithm ----------------- */
u8 accu = ctx->accu;
int p2 = ctx->p2; /* pointer to actual key byte */
int src = ctx->src; /* sub-round counter */
int round = ctx->counter;
while ((int)(msglen -= O_LENGTH) >= 0)
{
int po; /* output pointer */
int j;
CORE(STREAM_ROUNDS);
for (j = po = 0; j < O_LENGTH; ++j, po = X_MOD(po + 2))
output[j] = input[j] ^ ctx->x[po];
output += O_LENGTH;
input += O_LENGTH;
}
/* if msglen was not a multile of O_LENGTH, we need one more block */
if ((msglen += O_LENGTH) > 0)
{
int po; /* output pointer */
int j;
CORE(STREAM_ROUNDS);
for (j = po = 0; j < msglen; ++j, po = X_MOD(po + 2))
output[j] = input[j] ^ ctx->x[po];
}
else
{
ctx->accu = accu;
ctx->p2 = p2;
ctx->src = src;
ctx->counter = round;
}
} /* ECRYPT_process_bytes -------------------------------------------------- */
/* ------------------------------------ end -------------------------------- */
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