int safer_ecb_decrypt(const unsigned char *block_in,
unsigned char *block_out,
symmetric_key *skey)
#endif
{ unsigned char a, b, c, d, e, f, g, h, t;
unsigned int round;
unsigned char *key;
LTC_ARGCHK(block_in != NULL);
LTC_ARGCHK(block_out != NULL);
LTC_ARGCHK(skey != NULL);
key = skey->safer.key;
a = block_in[0]; b = block_in[1]; c = block_in[2]; d = block_in[3];
e = block_in[4]; f = block_in[5]; g = block_in[6]; h = block_in[7];
if (LTC_SAFER_MAX_NOF_ROUNDS < (round = *key)) round = LTC_SAFER_MAX_NOF_ROUNDS;
key += LTC_SAFER_BLOCK_LEN * (1 + 2 * round);
h ^= *key; g -= *--key; f -= *--key; e ^= *--key;
d ^= *--key; c -= *--key; b -= *--key; a ^= *--key;
while (round--)
{
t = e; e = b; b = c; c = t; t = f; f = d; d = g; g = t;
IPHT(a, e); IPHT(b, f); IPHT(c, g); IPHT(d, h);
IPHT(a, c); IPHT(e, g); IPHT(b, d); IPHT(f, h);
IPHT(a, b); IPHT(c, d); IPHT(e, f); IPHT(g, h);
h -= *--key; g ^= *--key; f ^= *--key; e -= *--key;
d -= *--key; c ^= *--key; b ^= *--key; a -= *--key;
h = LOG(h) ^ *--key; g = EXP(g) - *--key;
f = EXP(f) - *--key; e = LOG(e) ^ *--key;
d = LOG(d) ^ *--key; c = EXP(c) - *--key;
b = EXP(b) - *--key; a = LOG(a) ^ *--key;
}
block_out[0] = a & 0xFF; block_out[1] = b & 0xFF;
block_out[2] = c & 0xFF; block_out[3] = d & 0xFF;
block_out[4] = e & 0xFF; block_out[5] = f & 0xFF;
block_out[6] = g & 0xFF; block_out[7] = h & 0xFF;
return CRYPT_OK;
}
void SAFER::Decrypt(const byte *block_in, byte *block_out) const
{
byte a, b, c, d, e, f, g, h, t;
unsigned int round = keySchedule[0];
const byte *key = keySchedule + BLOCKSIZE * (1 + 2 * round) - 7;
a = block_in[0];
b = block_in[1];
c = block_in[2];
d = block_in[3];
e = block_in[4];
f = block_in[5];
g = block_in[6];
h = block_in[7];
h ^= key[7];
g -= key[6];
f -= key[5];
e ^= key[4];
d ^= key[3];
c -= key[2];
b -= key[1];
a ^= key[0];
while (round--)
{
key -= 16;
t = e;
e = b;
b = c;
c = t;
t = f;
f = d;
d = g;
g = t;
IPHT(a, e);
IPHT(b, f);
IPHT(c, g);
IPHT(d, h);
IPHT(a, c);
IPHT(e, g);
IPHT(b, d);
IPHT(f, h);
IPHT(a, b);
IPHT(c, d);
IPHT(e, f);
IPHT(g, h);
h -= key[15];
g ^= key[14];
f ^= key[13];
e -= key[12];
d -= key[11];
c ^= key[10];
b ^= key[9];
a -= key[8];
h = LOG(h) ^ key[7];
g = EXP(g) - key[6];
f = EXP(f) - key[5];
e = LOG(e) ^ key[4];
d = LOG(d) ^ key[3];
c = EXP(c) - key[2];
b = EXP(b) - key[1];
a = LOG(a) ^ key[0];
}
block_out[0] = a & 0xFF;
block_out[1] = b & 0xFF;
block_out[2] = c & 0xFF;
block_out[3] = d & 0xFF;
block_out[4] = e & 0xFF;
block_out[5] = f & 0xFF;
block_out[6] = g & 0xFF;
block_out[7] = h & 0xFF;
}
void SAFER::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
byte a, b, c, d, e, f, g, h, t;
unsigned int round = keySchedule[0];
const byte *key = keySchedule + BLOCKSIZE * (1 + 2 * round) - 7;
Block::Get(inBlock)(a)(b)(c)(d)(e)(f)(g)(h);
h ^= key[7]; g -= key[6]; f -= key[5]; e ^= key[4];
d ^= key[3]; c -= key[2]; b -= key[1]; a ^= key[0];
while (round--)
{
key -= 16;
t = e; e = b; b = c; c = t; t = f; f = d; d = g; g = t;
IPHT(a, e); IPHT(b, f); IPHT(c, g); IPHT(d, h);
IPHT(a, c); IPHT(e, g); IPHT(b, d); IPHT(f, h);
IPHT(a, b); IPHT(c, d); IPHT(e, f); IPHT(g, h);
h -= key[15]; g ^= key[14]; f ^= key[13]; e -= key[12];
d -= key[11]; c ^= key[10]; b ^= key[9]; a -= key[8];
h = LOG(h) ^ key[7]; g = EXP(g) - key[6];
f = EXP(f) - key[5]; e = LOG(e) ^ key[4];
d = LOG(d) ^ key[3]; c = EXP(c) - key[2];
b = EXP(b) - key[1]; a = LOG(a) ^ key[0];
}
Block::Put(xorBlock, outBlock)(a)(b)(c)(d)(e)(f)(g)(h);
}
WIN32DLL_DEFINE
void _mcrypt_decrypt(const safer_key_t * key, safer_block_t * block_in)
{
safer_block_t a, b, c, d, e, f, g, h, t;
unsigned int round;
a = block_in[0];
b = block_in[1];
c = block_in[2];
d = block_in[3];
e = block_in[4];
f = block_in[5];
g = block_in[6];
h = block_in[7];
if (SAFER_MAX_NOF_ROUNDS < (round = *key))
round = SAFER_MAX_NOF_ROUNDS;
key += SAFER_BLOCK_LEN * (1 + 2 * round);
h ^= *key;
g -= *--key;
f -= *--key;
e ^= *--key;
d ^= *--key;
c -= *--key;
b -= *--key;
a ^= *--key;
while (round--) {
t = e;
e = b;
b = c;
c = t;
t = f;
f = d;
d = g;
g = t;
IPHT(a, e);
IPHT(b, f);
IPHT(c, g);
IPHT(d, h);
IPHT(a, c);
IPHT(e, g);
IPHT(b, d);
IPHT(f, h);
IPHT(a, b);
IPHT(c, d);
IPHT(e, f);
IPHT(g, h);
h -= *--key;
g ^= *--key;
f ^= *--key;
e -= *--key;
d -= *--key;
c ^= *--key;
b ^= *--key;
a -= *--key;
h = LOG(h) ^ *--key;
g = EXP(g) - *--key;
f = EXP(f) - *--key;
e = LOG(e) ^ *--key;
d = LOG(d) ^ *--key;
c = EXP(c) - *--key;
b = EXP(b) - *--key;
a = LOG(a) ^ *--key;
}
block_in[0] = a & 0xFF;
block_in[1] = b & 0xFF;
block_in[2] = c & 0xFF;
block_in[3] = d & 0xFF;
block_in[4] = e & 0xFF;
block_in[5] = f & 0xFF;
block_in[6] = g & 0xFF;
block_in[7] = h & 0xFF;
} /* Safer_Decrypt_Block */