/* See LICENSE file for copyright and license details. */
/**
* 16-bit Keccak-f round constants
*/
static const uint16_t rc16[] = {
UINT16_C(0x0001), UINT16_C(0x8082), UINT16_C(0x808A), UINT16_C(0x8000),
UINT16_C(0x808B), UINT16_C(0x0001), UINT16_C(0x8081), UINT16_C(0x8009),
UINT16_C(0x008A), UINT16_C(0x0088), UINT16_C(0x8009), UINT16_C(0x000A),
UINT16_C(0x808B), UINT16_C(0x008B), UINT16_C(0x8089), UINT16_C(0x8003),
UINT16_C(0x8002), UINT16_C(0x0080), UINT16_C(0x800A), UINT16_C(0x000A)
};
/**
* Rotate a 16-bit word
*
* @param x:uint16_t The value to rotate
* @param n:long int Rotation steps, may not be zero
* @return :uint16_t The value rotated
*/
#define rotate16(x, n) ((uint16_t)(((uint16_t)(x) >> (16L - (n))) | ((uint16_t)(x) << (n))))
/**
* 16-bit word version of `libkeccak_f_round`
*
* @param state The hashing state
* @param rc The round contant for this round
*/
LIBKECCAK_GCC_ONLY(__attribute__((__nonnull__, __nothrow__, __hot__)))
static void
libkeccak_f_round16(register struct libkeccak_state *state, register uint16_t rc)
{
uint16_t *restrict A = state->S.w16;
uint16_t B[25], C[5], da, db, dc, dd, de;
/* 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] ^ rotate16(C[1], 1);
dd = C[2] ^ rotate16(C[4], 1);
db = C[0] ^ rotate16(C[2], 1);
de = C[3] ^ rotate16(C[0], 1);
dc = C[1] ^ rotate16(C[3], 1);
/* ρ and π steps, with last two part of θ. */
#define X(bi, ai, dv, r) B[bi] = rotate16(A[ai] ^ dv, r)
B[0] = A[0] ^ da; X( 1, 15, dd, 12); X( 2, 5, db, 1); X( 3, 20, de, 11); X( 4, 10, dc, 14);
X( 5, 6, db, 12); X( 6, 21, de, 4); X( 7, 11, dc, 6); X( 8, 1, da, 4); X( 9, 16, dd, 7);
X(10, 12, dc, 11); X(11, 2, da, 3); X(12, 17, dd, 9); X(13, 7, db, 10); X(14, 22, de, 7);
X(15, 18, dd, 5); X(16, 8, db, 13); X(17, 23, de, 8); X(18, 13, dc, 15); X(19, 3, da, 9);
X(20, 24, de, 14); X(21, 14, dc, 13); X(22, 4, da, 2); X(23, 19, dd, 8); X(24, 9, db, 2);
#undef X
/* ξ step. */
#define X(N) A[N] = (uint16_t)(B[N] ^ ((~(B[(N + 5) % 25])) & B[(N + 10) % 25]))
LIST_25(X, ;);
#undef X
/* ι step. */
A[0] ^= rc;
}
/**
* 16-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 uint16_t
libkeccak_to_lane16(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);
uint16_t rc = 0;
message += off;
#define X(N) if (__builtin_expect(N < n, 1)) rc |= (uint16_t)message[N] << (N * 8);\
else return rc
LIST_2(X, ;);
#undef X
return rc;
}
