research-lab/source-code/RingCT/keccak.c

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2016-02-05 20:22:13 +00:00
// keccak.c
// 19-Nov-11 Markku-Juhani O. Saarinen <mjos@iki.fi>
// A baseline Keccak (3rd round) implementation.
//
#include "hash-ops.h"
#include "keccak.h"
const uint64_t keccakf_rndc[24] =
{
0x0000000000000001, 0x0000000000008082, 0x800000000000808a,
0x8000000080008000, 0x000000000000808b, 0x0000000080000001,
0x8000000080008081, 0x8000000000008009, 0x000000000000008a,
0x0000000000000088, 0x0000000080008009, 0x000000008000000a,
0x000000008000808b, 0x800000000000008b, 0x8000000000008089,
0x8000000000008003, 0x8000000000008002, 0x8000000000000080,
0x000000000000800a, 0x800000008000000a, 0x8000000080008081,
0x8000000000008080, 0x0000000080000001, 0x8000000080008008
};
const int keccakf_rotc[24] =
{
1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 2, 14,
27, 41, 56, 8, 25, 43, 62, 18, 39, 61, 20, 44
};
const int keccakf_piln[24] =
{
10, 7, 11, 17, 18, 3, 5, 16, 8, 21, 24, 4,
15, 23, 19, 13, 12, 2, 20, 14, 22, 9, 6, 1
};
// update the state with given number of rounds
void keccakf(uint64_t st[25], int rounds)
{
int i, j, round;
uint64_t t, bc[5];
for (round = 0; round < rounds; round++) {
// Theta
for (i = 0; i < 5; i++)
bc[i] = st[i] ^ st[i + 5] ^ st[i + 10] ^ st[i + 15] ^ st[i + 20];
for (i = 0; i < 5; i++) {
t = bc[(i + 4) % 5] ^ ROTL64(bc[(i + 1) % 5], 1);
for (j = 0; j < 25; j += 5)
st[j + i] ^= t;
}
// Rho Pi
t = st[1];
for (i = 0; i < 24; i++) {
j = keccakf_piln[i];
bc[0] = st[j];
st[j] = ROTL64(t, keccakf_rotc[i]);
t = bc[0];
}
// Chi
for (j = 0; j < 25; j += 5) {
for (i = 0; i < 5; i++)
bc[i] = st[j + i];
for (i = 0; i < 5; i++)
st[j + i] ^= (~bc[(i + 1) % 5]) & bc[(i + 2) % 5];
}
// Iota
st[0] ^= keccakf_rndc[round];
}
}
// compute a keccak hash (md) of given byte length from "in"
typedef uint64_t state_t[25];
//Changed inlen to size_t (s.n. MRL labs)
int keccak(const uint8_t *in, std::size_t inlen, uint8_t *md, int mdlen)
{
state_t st;
uint8_t temp[144];
std::size_t i, rsiz, rsizw;
rsiz = sizeof(state_t) == mdlen ? HASH_DATA_AREA : 200 - 2 * mdlen;
rsizw = rsiz / 8;
memset(st, 0, sizeof(st));
for ( ; inlen >= rsiz; inlen -= rsiz, in += rsiz) {
for (i = 0; i < rsizw; i++)
st[i] ^= ((uint64_t *) in)[i];
keccakf(st, KECCAK_ROUNDS);
}
// last block and padding
memcpy(temp, in, inlen);
temp[inlen++] = 1;
memset(temp + inlen, 0, rsiz - inlen);
temp[rsiz - 1] |= 0x80;
for (i = 0; i < rsizw; i++)
st[i] ^= ((uint64_t *) temp)[i];
keccakf(st, KECCAK_ROUNDS);
memcpy(md, st, mdlen);
return 0;
}
//Changed inlen to size_t (s.n. MRL labs)
void keccak1600(const uint8_t *in, std::size_t inlen, uint8_t *md)
{
keccak(in, inlen, md, sizeof(state_t));
}