keccak improvments

This commit is contained in:
bg 2013-09-20 02:14:21 +02:00
parent 7c993b1b86
commit b14938245d
3 changed files with 32 additions and 21 deletions

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@ -34,8 +34,8 @@
/*
typedef struct{
uint64_t a[5][5];
uint16_t r, c;
uint8_t d, bs;
uint16_t r;
uint8_t bs;
} keccak_ctx_t;
*/
.struct 0

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@ -87,14 +87,28 @@ const static uint8_t rc_comp[] PROGMEM = {
0xf1, 0xd0, 0x21, 0x78,
};
const static uint8_t r[5][5] PROGMEM = {
{ ROT_CODE( 0), ROT_CODE(36), ROT_CODE( 3), ROT_CODE(41), ROT_CODE(18) },
{ ROT_CODE( 1), ROT_CODE(44), ROT_CODE(10), ROT_CODE(45), ROT_CODE( 2) },
{ ROT_CODE(62), ROT_CODE( 6), ROT_CODE(43), ROT_CODE(15), ROT_CODE(61) },
{ ROT_CODE(28), ROT_CODE(55), ROT_CODE(25), ROT_CODE(21), ROT_CODE(56) },
{ ROT_CODE(27), ROT_CODE(20), ROT_CODE(39), ROT_CODE( 8), ROT_CODE(14) }
#define RP_IDX(i, j) ((((2 * j + 3 * i) % 5) * 5 + i) * 8)
uint8_t const rho_pi_idx_table[5][5] PROGMEM = {
{ RP_IDX(0, 0), RP_IDX(0, 1), RP_IDX(0, 2), RP_IDX(0, 3), RP_IDX(0, 4) },
{ RP_IDX(1, 0), RP_IDX(1, 1), RP_IDX(1, 2), RP_IDX(1, 3), RP_IDX(1, 4) },
{ RP_IDX(2, 0), RP_IDX(2, 1), RP_IDX(2, 2), RP_IDX(2, 3), RP_IDX(2, 4) },
{ RP_IDX(3, 0), RP_IDX(3, 1), RP_IDX(3, 2), RP_IDX(3, 3), RP_IDX(3, 4) },
{ RP_IDX(4, 0), RP_IDX(4, 1), RP_IDX(4, 2), RP_IDX(4, 3), RP_IDX(4, 4) }
};
#define ROT_BIT(a) (( (a) <= 4) ? ((a) << 1) : (0x01 | ((8 - (a)) << 1)))
#define ROT_CODE(a) ((((a) / 8 + ((((a) % 8) > 4) ? 1 : 0)) << 4) | ROT_BIT(((a) % 8)))
const uint8_t keccak_rotate_codes[5][5] PROGMEM = {
{ ROT_CODE( 0), ROT_CODE( 1), ROT_CODE(62), ROT_CODE(28), ROT_CODE(27) },
{ ROT_CODE(36), ROT_CODE(44), ROT_CODE( 6), ROT_CODE(55), ROT_CODE(20) },
{ ROT_CODE( 3), ROT_CODE(10), ROT_CODE(43), ROT_CODE(25), ROT_CODE(39) },
{ ROT_CODE(41), ROT_CODE(45), ROT_CODE(15), ROT_CODE(21), ROT_CODE( 8) },
{ ROT_CODE(18), ROT_CODE( 2), ROT_CODE(61), ROT_CODE(56), ROT_CODE(14) }
};
static inline
void keccak_round(uint64_t *a, uint8_t rci){
uint64_t b[5][5];
@ -103,11 +117,14 @@ void keccak_round(uint64_t *a, uint8_t rci){
uint64_t v64;
uint8_t v8[8];
} t;
const uint8_t *rot_code = (const uint8_t*)keccak_rotate_codes;
const uint8_t *idx_idx = (const uint8_t*)rho_pi_idx_table;
uint64_t *a_tmp = (uint64_t*)a;
/* theta */
for(i = 0; i < 5; ++i){
b[i][0] = a[i] ^ a[5 + i] ^ a[10 + i] ^ a[15 + i] ^ a[20 + i];
}
for(i = 0; i < 5; ++i){
for(i = 0; i < 5; ++i){
t.v64 = b[(4 + i) % 5][0] ^ rotate64_1bit_left(b[(i + 1) % 5][0]);
for(j = 0; j < 5; ++j){
a[j * 5 + i] ^= t.v64;
@ -118,11 +135,11 @@ void keccak_round(uint64_t *a, uint8_t rci){
keccak_dump_state(a);
#endif
/* rho & pi */
for(i = 0; i < 5; ++i){
for(j = 0; j < 5; ++j){
b[(2 * i + 3 * j) % 5][j] = rotate64left_code(a[j * 5 +i], pgm_read_byte(&(r[i][j])));
}
}
for(i = 0; i < 25; ++i){
*((uint64_t*)(((uint8_t*)b) + pgm_read_byte(idx_idx++))) =
rotate64left_code(*a_tmp++, pgm_read_byte(rot_code++));
}
#if DEBUG
cli_putstr_P(PSTR("\r\n--- after rho & pi ---"));
keccak_dump_state(a);
@ -133,6 +150,7 @@ void keccak_round(uint64_t *a, uint8_t rci){
a[j * 5 + i] = b[j][i] ^ ((~(b[j][(i + 1) % 5])) & (b[j][(i + 2) % 5]));
}
}
#if DEBUG
cli_putstr_P(PSTR("\r\nAfter chi:"));
keccak_dump_state(a);

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@ -33,13 +33,6 @@
#define ROTR_3 (8+3)
#define ROT_BIT(a) (((a) <= 4) ? ((a) << 1) : (0x01 | ((8 - (a)) << 1)))
//#define ROT_CODE(a,b) (((a)<<4) | ((b)&0x0f))
#define ROT_CODE(a) ((((a) / 8 + ((((a) % 8) > 4) ? 1 : 0)) << 4) | ROT_BIT(((a) % 8)))
//#define ROT_CODE(a) ((((a)/8)<<4) | ((a)%8)) /* rotations only to the left */
uint64_t rotate64_1bit_left(uint64_t a);
uint64_t rotate64_1bit_right(uint64_t a);
uint64_t rotate64_nbit_autodir(uint64_t a, int8_t n);