experimental/tiny_sha3_bit_interleaved
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This commit is contained in:
Kris Kwiatkowski
2025-05-22 10:03:13 +01:00
parent dcbb319204
commit e948dbbac6
2 changed files with 84 additions and 19 deletions
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99
sha3.c
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@@ -1,12 +1,36 @@
// sha3.c
// 19-Nov-11 Markku-Juhani O. Saarinen <mjos@iki.fi>
// 22-May-25 Kris Kwiatkowski <kris@amongbytes.com>
// Revised 07-Aug-15 to match with official release of FIPS PUB 202 "SHA3"
// Revised 03-Sep-15 for portability + OpenSSL - style API
// Revised 22-May-25 Added bit-interleaved implementation optimized for 32-bit architectures.
#include "sha3.h"
// update the state with given number of rounds
// Interleave even and odd bits into one 64-bit line
uint64_t unshuffle(uint32_t even, uint32_t odd) {
uint64_t result = 0;
for (int i = 0; i < 32; i++) {
result |= ((uint64_t)(even >> i) & 1) << (2 * i);
result |= ((uint64_t)(odd >> i) & 1) << (2 * i + 1);
}
return result;
}
uint32_t shuffle_even(uint64_t x) {
x &= 0x5555555555555555ULL;
x = (x | (x >> 1)) & 0x3333333333333333ULL;
x = (x | (x >> 2)) & 0x0F0F0F0F0F0F0F0FULL;
x = (x | (x >> 4)) & 0x00FF00FF00FF00FFULL;
x = (x | (x >> 8)) & 0x0000FFFF0000FFFFULL;
x = (x | (x >> 16)) & 0x00000000FFFFFFFFULL;
return (uint32_t)x;
}
uint32_t shuffle_odd(uint64_t x) {
return shuffle_even(x >> 1);
}
void sha3_keccakf(uint64_t st[25])
{
@@ -32,7 +56,9 @@ void sha3_keccakf(uint64_t st[25])
// variables
int i, j, r;
uint64_t t, bc[5];
uint32_t t1, t2;
uint32_t even[25], odd[25];
uint32_t bc_even[5], bc_odd[5];
#if __BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__
uint8_t *v;
@@ -47,38 +73,73 @@ void sha3_keccakf(uint64_t st[25])
}
#endif
for (i = 0; i < 25; i++) {
even[i] = shuffle_even(st[i]);
odd[i] = shuffle_odd(st[i]);;
}
// actual iteration
for (r = 0; r < KECCAKF_ROUNDS; r++) {
// 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;
bc_even[i] = even[i] ^ even[i + 5] ^ even[i + 10] ^ even[i + 15] ^ even[i + 20];
bc_odd[i] = odd[i] ^ odd[i + 5] ^ odd[i + 10] ^ odd[i + 15] ^ odd[i + 20];
}
// Chi
for (i = 0; i < 5; i++) {
uint32_t rot32 = ROTL32(bc_odd[(i + 1) % 5], 1);
t1 = bc_even[(i + 4) % 5] ^ rot32;
t2 = bc_odd[(i + 4) % 5] ^ bc_even[(i + 1) % 5];
for (j = 0; j < 25; j += 5) {
even[j + i] ^= t1;
odd[j + i] ^= t2;
}
}
// Rho Pi
t = st[1];
t1 = even[1]; t2 = odd[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];
bc_even[0] = even[j]; bc_odd[0] = odd[j];
int half = keccakf_rotc[i] >> 1;
if (keccakf_rotc[i]&1) {
// U0 = ROT32(U1, tau)
odd[j] = ROTL32(t1, half);
// U1 = ROT32(U0, tau + 1)
even[j] = ROTL32(t2, half + 1);
} else {
// U0 = ROT32(U0, tau)
odd[j] = ROTL32(t2, half);
// U1 = ROT32(U1, tau)
even[j] = ROTL32(t1, half);
}
t1 = bc_even[0]; t2 = bc_odd[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];
for (i = 0; i < 5; i++) {
bc_even[i] = even[j + i];
bc_odd[i] = odd[j + i];
}
for (i = 0; i < 5; i++) {
even[j + i] ^= (~bc_even[(i + 1) % 5]) & bc_even[(i + 2) % 5];
odd[j + i] ^= (~bc_odd[(i + 1) % 5]) & bc_odd[(i + 2) % 5];
}
}
// Iota
st[0] ^= keccakf_rndc[r];
// Iota (can be precomputed)
even[0] ^= shuffle_even(keccakf_rndc[r]);
odd[0] ^= shuffle_odd(keccakf_rndc[r]);
}
for (i = 0; i < 25; i++) {
st[i] = unshuffle(even[i], odd[i]);
}
#if __BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__

4
sha3.h
View File

@@ -15,6 +15,10 @@
#define ROTL64(x, y) (((x) << (y)) | ((x) >> (64 - (y))))
#endif
#ifndef ROTL32
#define ROTL32(x, y) (((x) << (y)) | ((x) >> (32 - (y))))
#endif
// state context
typedef struct {
union { // state: