/* LibTomCrypt, modular cryptographic library -- Tom St Denis
*
* LibTomCrypt is a library that provides various cryptographic
* algorithms in a highly modular and flexible manner.
*
* The library is free for all purposes without any express
* guarantee it works.
*
* Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com
*/
/**
@file noekeon.c
Implementation of the Noekeon block cipher by Tom St Denis
*/
#include "tomcrypt.h"
#ifdef NOEKEON
const struct ltc_cipher_descriptor noekeon_desc =
{
"noekeon",
16,
16, 16, 16, 16,
&noekeon_setup,
&noekeon_ecb_encrypt,
&noekeon_ecb_decrypt,
&noekeon_test,
&noekeon_done,
&noekeon_keysize,
NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
};
static const ulong32 RC[] = {
0x00000080UL, 0x0000001bUL, 0x00000036UL, 0x0000006cUL,
0x000000d8UL, 0x000000abUL, 0x0000004dUL, 0x0000009aUL,
0x0000002fUL, 0x0000005eUL, 0x000000bcUL, 0x00000063UL,
0x000000c6UL, 0x00000097UL, 0x00000035UL, 0x0000006aUL,
0x000000d4UL
};
#define kTHETA(a, b, c, d) \
temp = a^c; temp = temp ^ ROLc(temp, 8) ^ RORc(temp, 8); \
b ^= temp; d ^= temp; \
temp = b^d; temp = temp ^ ROLc(temp, 8) ^ RORc(temp, 8); \
a ^= temp; c ^= temp;
#define THETA(k, a, b, c, d) \
temp = a^c; temp = temp ^ ROLc(temp, 8) ^ RORc(temp, 8); \
b ^= temp ^ k[1]; d ^= temp ^ k[3]; \
temp = b^d; temp = temp ^ ROLc(temp, 8) ^ RORc(temp, 8); \
a ^= temp ^ k[0]; c ^= temp ^ k[2];
#define GAMMA(a, b, c, d) \
b ^= ~(d|c); \
a ^= c&b; \
temp = d; d = a; a = temp;\
c ^= a ^ b ^ d; \
b ^= ~(d|c); \
a ^= c&b;
#define PI1(a, b, c, d) \
a = ROLc(a, 1); c = ROLc(c, 5); d = ROLc(d, 2);
#define PI2(a, b, c, d) \
a = RORc(a, 1); c = RORc(c, 5); d = RORc(d, 2);
/**
Initialize the Noekeon block cipher
@param key The symmetric key you wish to pass
@param keylen The key length in bytes
@param num_rounds The number of rounds desired (0 for default)
@param skey The key in as scheduled by this function.
@return CRYPT_OK if successful
*/
int noekeon_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
{
ulong32 temp;
LTC_ARGCHK(key != NULL);
LTC_ARGCHK(skey != NULL);
if (keylen != 16) {
return CRYPT_INVALID_KEYSIZE;
}
if (num_rounds != 16 && num_rounds != 0) {
return CRYPT_INVALID_ROUNDS;
}
LOAD32H(skey->noekeon.K[0],&key[0]);
LOAD32H(skey->noekeon.K[1],&key[4]);
LOAD32H(skey->noekeon.K[2],&key[8]);
LOAD32H(skey->noekeon.K[3],&key[12]);
LOAD32H(skey->noekeon.dK[0],&key[0]);
LOAD32H(skey->noekeon.dK[1],&key[4]);
LOAD32H(skey->noekeon.dK[2],&key[8]);
LOAD32H(skey->noekeon.dK[3],&key[12]);
kTHETA(skey->noekeon.dK[0], skey->noekeon.dK[1], skey->noekeon.dK[2], skey->noekeon.dK[3]);
return CRYPT_OK;
}
/**
Encrypts a block of text with Noekeon
@param pt The input plaintext (16 bytes)
@param ct The output ciphertext (16 bytes)
@param skey The key as scheduled
@return CRYPT_OK if successful
*/
#ifdef LTC_CLEAN_STACK
static int _noekeon_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey)
#else
int noekeon_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey)
#endif
{
ulong32 a,b,c,d,temp;
int r;
LTC_ARGCHK(skey != NULL);
LTC_ARGCHK(pt != NULL);
LTC_ARGCHK(ct != NULL);
LOAD32H(a,&pt[0]); LOAD32H(b,&pt[4]);
LOAD32H(c,&pt[8]); LOAD32H(d,&pt[12]);
#define ROUND(i) \
a ^= RC[i]; \
THETA(skey->noekeon.K, a,b,c,d); \
PI1(a,b,c,d); \
GAMMA(a,b,c,d); \
PI2(a,b,c,d);
for (r = 0; r < 16; ++r) {
ROUND(r);
}
#undef ROUND
a ^= RC[16];
THETA(skey->noekeon.K, a, b, c, d);
STORE32H(a,&ct[0]); STORE32H(b,&ct[4]);
STORE32H(c,&ct[8]); STORE32H(d,&ct[12]);
return CRYPT_OK;
}
#ifdef LTC_CLEAN_STACK
int noekeon_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey)
{
int err = _noekeon_ecb_encrypt(pt, ct, skey);
burn_stack(sizeof(ulong32) * 5 + sizeof(int));
return CRYPT_OK;
}
#endif
/**
Decrypts a block of text with Noekeon
@param ct The input ciphertext (16 bytes)
@param pt The output plaintext (16 bytes)
@param skey The key as scheduled
@return CRYPT_OK if successful
*/
#ifdef LTC_CLEAN_STACK
static int _noekeon_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey)
#else
int noekeon_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey)
#endif
{
ulong32 a,b,c,d, temp;
int r;
LTC_ARGCHK(skey != NULL);
LTC_ARGCHK(pt != NULL);
LTC_ARGCHK(ct != NULL);
LOAD32H(a,&ct[0]); LOAD32H(b,&ct[4]);
LOAD32H(c,&ct[8]); LOAD32H(d,&ct[12]);
#define ROUND(i) \
THETA(skey->noekeon.dK, a,b,c,d); \
a ^= RC[i]; \
PI1(a,b,c,d); \
GAMMA(a,b,c,d); \
PI2(a,b,c,d);
for (r = 16; r > 0; --r) {
ROUND(r);
}
#undef ROUND
THETA(skey->noekeon.dK, a,b,c,d);
a ^= RC[0];
STORE32H(a,&pt[0]); STORE32H(b, &pt[4]);
STORE32H(c,&pt[8]); STORE32H(d, &pt[12]);
return CRYPT_OK;
}
#ifdef LTC_CLEAN_STACK
int noekeon_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey)
{
int err = _noekeon_ecb_decrypt(ct, pt, skey);
burn_stack(sizeof(ulong32) * 5 + sizeof(int));
return err;
}
#endif
/**
Performs a self-test of the Noekeon block cipher
@return CRYPT_OK if functional, CRYPT_NOP if self-test has been disabled
*/
int noekeon_test(void)
{
#ifndef LTC_TEST
return CRYPT_NOP;
#else
static const struct {
int keylen;
unsigned char key[16], pt[16], ct[16];
} tests[] = {
{
16,
{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 },
{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 },
{ 0x18, 0xa6, 0xec, 0xe5, 0x28, 0xaa, 0x79, 0x73,
0x28, 0xb2, 0xc0, 0x91, 0xa0, 0x2f, 0x54, 0xc5}
}
};
symmetric_key key;
unsigned char tmp[2][16];
int err, i, y;
for (i = 0; i < (int)(sizeof(tests)/sizeof(tests[0])); i++) {
zeromem(&key, sizeof(key));
if ((err = noekeon_setup(tests[i].key, tests[i].keylen, 0, &key)) != CRYPT_OK) {
return err;
}
noekeon_ecb_encrypt(tests[i].pt, tmp[0], &key);
noekeon_ecb_decrypt(tmp[0], tmp[1], &key);
if (XMEMCMP(tmp[0], tests[i].ct, 16) || XMEMCMP(tmp[1], tests[i].pt, 16)) {
#if 0
printf("\n\nTest %d failed\n", i);
if (XMEMCMP(tmp[0], tests[i].ct, 16)) {
printf("CT: ");
for (i = 0; i < 16; i++) {
printf("%02x ", tmp[0][i]);
}
printf("\n");
} else {
printf("PT: ");
for (i = 0; i < 16; i++) {
printf("%02x ", tmp[1][i]);
}
printf("\n");
}
#endif
return CRYPT_FAIL_TESTVECTOR;
}
/* now see if we can encrypt all zero bytes 1000 times, decrypt and come back where we started */
for (y = 0; y < 16; y++) tmp[0][y] = 0;
for (y = 0; y < 1000; y++) noekeon_ecb_encrypt(tmp[0], tmp[0], &key);
for (y = 0; y < 1000; y++) noekeon_ecb_decrypt(tmp[0], tmp[0], &key);
for (y = 0; y < 16; y++) if (tmp[0][y] != 0) return CRYPT_FAIL_TESTVECTOR;
}
return CRYPT_OK;
#endif
}
/** Terminate the context
@param skey The scheduled key
*/
void noekeon_done(symmetric_key *skey)
{
}
/**
Gets suitable key size
@param keysize [in/out] The length of the recommended key (in bytes). This function will store the suitable size back in this variable.
@return CRYPT_OK if the input key size is acceptable.
*/
int noekeon_keysize(int *keysize)
{
LTC_ARGCHK(keysize != NULL);
if (*keysize < 16) {
return CRYPT_INVALID_KEYSIZE;
} else {
*keysize = 16;
return CRYPT_OK;
}
}
#endif
/* $Source: /cvs/libtom/libtomcrypt/src/ciphers/noekeon.c,v $ */
/* $Revision: 1.12 $ */
/* $Date: 2006/11/08 23:01:06 $ */