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Diffstat (limited to '')
| -rw-r--r-- | 200.c | 92 |
1 files changed, 92 insertions, 0 deletions
@@ -0,0 +1,92 @@ +/* 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; +} |