/* See LICENSE file for copyright and license details. */
/**
* 8-bit Keccak-f round constants
*/
static const uint_fast8_t rc8[] = {
UINT8_C(0x01), UINT8_C(0x82), UINT8_C(0x8A), UINT8_C(0x00),
UINT8_C(0x8B), UINT8_C(0x01), UINT8_C(0x81), UINT8_C(0x09),
UINT8_C(0x8A), UINT8_C(0x88), UINT8_C(0x09), UINT8_C(0x0A),
UINT8_C(0x8B), UINT8_C(0x8B), UINT8_C(0x89), UINT8_C(0x03),
UINT8_C(0x02), UINT8_C(0x80)
};
/**
* Rotate a 8-bit word
*
* @param x:uint8_t The value to rotate
* @param n:long int Rotation steps, may not be zero
* @return :uint8_t The value rotated
*/
#define rotate8(x, n) ((uint_fast8_t)(((uint_fast8_t)(x) >> (8L - (n))) | ((uint_fast8_t)(x) << (n))))
/**
* 8-bit word version of `libkeccak_f`
*
* @param state The hashing state
*/
LIBKECCAK_GCC_ONLY(__attribute__((__nonnull__, __nothrow__, __hot__)))
static void
libkeccak_f8(register struct libkeccak_state *state)
{
#define A state->S.w8
uint_fast8_t B[25], C[5], da, db, dc, dd, de;
int i;
for (i = 0; i < 18; i++) {
/* θ step (step 1 of 3). */
#define X(N) C[N] = A[N * 5] ^ A[N * 5 + 1] ^ A[N * 5 + 2] ^ A[N * 5 + 3] ^ A[N * 5 + 4]
LIST_5(X, ;);
#undef X
/* θ step (step 2 of 3). */
da = C[4] ^ rotate8(C[1], 1);
dd = C[2] ^ rotate8(C[4], 1);
db = C[0] ^ rotate8(C[2], 1);
de = C[3] ^ rotate8(C[0], 1);
dc = C[1] ^ rotate8(C[3], 1);
/* ρ and π steps, with last two part of θ. */
#define X(bi, ai, dv, r) B[bi] = rotate8(A[ai] ^ dv, r)
B[0] = A[0] ^ da; X( 1, 15, dd, 4); X( 2, 5, db, 1); X( 3, 20, de, 3); X( 4, 10, dc, 6);
X( 5, 6, db, 4); X( 6, 21, de, 4); X( 7, 11, dc, 6); X( 8, 1, da, 4); X( 9, 16, dd, 7);
X(10, 12, dc, 3); X(11, 2, da, 3); X(12, 17, dd, 1); X(13, 7, db, 2); X(14, 22, de, 7);
X(15, 18, dd, 5); X(16, 8, db, 5); B[17] = A[23]^de; X(18, 13, dc, 7); X(19, 3, da, 1);
X(20, 24, de, 6); X(21, 14, dc, 5); X(22, 4, da, 2); B[23] = A[19]^dd; X(24, 9, db, 2);
#undef X
/* ξ step. */
#define X(N) A[N] = (uint8_t)(B[N] ^ ((~(B[(N + 5) % 25])) & B[(N + 10) % 25]))
LIST_25(X, ;);
#undef X
/* ι step. */
A[0] ^= rc8[i];
}
#undef A
}
/**
* 8-bit lane version of `libkeccak_to_lane`
*
* @param message The message
* @param msglen The length of the message
* @param rr Bitrate in bytes
* @param off The offset in the message
* @return The lane
*/
LIBKECCAK_GCC_ONLY(__attribute__((__nonnull__, __nothrow__, __pure__, __hot__, __warn_unused_result__, __gnu_inline__)))
static inline uint8_t
libkeccak_to_lane8(register const unsigned char *message, register size_t msglen, register long int rr, size_t off)
{
register long int n = (long)((msglen < (size_t)rr ? msglen : (size_t)rr) - off);
if (__builtin_expect(0 < n, 1))
return (uint8_t)message[off];
return 0;
}
