diff options
Diffstat (limited to 'siphash.c')
| -rw-r--r-- | siphash.c | 58 |
1 files changed, 28 insertions, 30 deletions
@@ -51,16 +51,16 @@ * */ +#include <stddef.h> #include <stdint.h> #include "siphash.h" #define ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b)))) -#define PREAMBLE(len) \ +#define PREAMBLE \ uint64_t v[4] = { 0x736f6d6570736575ULL, 0x646f72616e646f6dULL, \ 0x6c7967656e657261ULL, 0x7465646279746573ULL }; \ - uint64_t b = (uint64_t)(len) << 56; \ int __i; \ \ do { \ @@ -103,13 +103,21 @@ static inline void siphash_feed(uint64_t *v, uint64_t in) v[0] ^= in; } -#define POSTAMBLE \ - do { \ - siphash_feed(v, b); \ - v[2] ^= 0xff; \ - sipround(v, 4); \ - b = (v[0] ^ v[1]) ^ (v[2] ^ v[3]); \ - } while (0) +/** + * siphash_final - Finalize SipHash calculations + * @v: siphash state (4 x 64-bit integers) + * @len: Total length of input data + * @tail: Final data for the hash (<= 7 bytes) + */ +static inline uint64_t siphash_final(uint64_t *v, size_t len, uint64_t tail) +{ + uint64_t b = (uint64_t)(len) << 56 | tail; + + siphash_feed(v, b); + v[2] ^= 0xff; + sipround(v, 4); + return v[0] ^ v[1] ^ v[2] ^ v[3]; +} /** * siphash_8b() - Table index or timestamp offset for TCP over IPv4 (8 bytes in) @@ -132,11 +140,11 @@ __attribute__((optimize("-fno-strict-aliasing"))) /* cppcheck-suppress unusedFunction */ uint64_t siphash_8b(const uint8_t *in, const uint64_t *k) { - PREAMBLE(8); + PREAMBLE; siphash_feed(v, *(uint64_t *)in); - POSTAMBLE; - return b; + + return siphash_final(v, 8, 0); } /** @@ -153,12 +161,10 @@ uint64_t siphash_12b(const uint8_t *in, const uint64_t *k) { uint32_t *in32 = (uint32_t *)in; - PREAMBLE(12); + PREAMBLE; siphash_feed(v, (uint64_t)(*(in32 + 1)) << 32 | *in32); - b |= *(in32 + 2); - POSTAMBLE; - return b; + return siphash_final(v, 12, *(in32 + 2)); } /** @@ -175,15 +181,12 @@ uint64_t siphash_20b(const uint8_t *in, const uint64_t *k) uint32_t *in32 = (uint32_t *)in; int i; - PREAMBLE(20); + PREAMBLE; for (i = 0; i < 2; i++, in32 += 2) siphash_feed(v, (uint64_t)(*(in32 + 1)) << 32 | *in32); - b |= *in32; - POSTAMBLE; - - return b; + return siphash_final(v, 20, *in32); } /** @@ -201,14 +204,12 @@ uint64_t siphash_32b(const uint8_t *in, const uint64_t *k) uint64_t *in64 = (uint64_t *)in; int i; - PREAMBLE(32); + PREAMBLE; for (i = 0; i < 4; i++, in64++) siphash_feed(v, *in64); - POSTAMBLE; - - return b; + return siphash_final(v, 32, 0); } /** @@ -225,13 +226,10 @@ uint64_t siphash_36b(const uint8_t *in, const uint64_t *k) uint32_t *in32 = (uint32_t *)in; int i; - PREAMBLE(36); + PREAMBLE; for (i = 0; i < 4; i++, in32 += 2) siphash_feed(v, (uint64_t)(*(in32 + 1)) << 32 | *in32); - b |= *in32; - POSTAMBLE; - - return b; + return siphash_final(v, 36, *in32); } |