ParagonIE_Sodium_Core_SipHash::sipHash24( string $in, string $key ): string

163    public static function sipHash24($in, $key)164    {165        $inlen = self::strlen($in);166 167        # /* "somepseudorandomlygeneratedbytes" */168        # u64 v0 = 0x736f6d6570736575ULL;169        # u64 v1 = 0x646f72616e646f6dULL;170        # u64 v2 = 0x6c7967656e657261ULL;171        # u64 v3 = 0x7465646279746573ULL;172        $v = array(173            0x736f6d65, // 0174            0x70736575, // 1175            0x646f7261, // 2176            0x6e646f6d, // 3177            0x6c796765, // 4178            0x6e657261, // 5179            0x74656462, // 6180            0x79746573  // 7181        );182        // v0 => $v[0], $v[1]183        // v1 => $v[2], $v[3]184        // v2 => $v[4], $v[5]185        // v3 => $v[6], $v[7]186 187        # u64 k0 = LOAD64_LE( k );188        # u64 k1 = LOAD64_LE( k + 8 );189        $k = array(190            self::load_4(self::substr($key, 4, 4)),191            self::load_4(self::substr($key, 0, 4)),192            self::load_4(self::substr($key, 12, 4)),193            self::load_4(self::substr($key, 8, 4))194        );195        // k0 => $k[0], $k[1]196        // k1 => $k[2], $k[3]197 198        # b = ( ( u64 )inlen ) << 56;199        $b = array(200            $inlen << 24,201            0202        );203        // See docblock for why the 0th index gets the higher bits.204 205        # v3 ^= k1;206        $v[6] ^= $k[2];207        $v[7] ^= $k[3];208        # v2 ^= k0;209        $v[4] ^= $k[0];210        $v[5] ^= $k[1];211        # v1 ^= k1;212        $v[2] ^= $k[2];213        $v[3] ^= $k[3];214        # v0 ^= k0;215        $v[0] ^= $k[0];216        $v[1] ^= $k[1];217 218        $left = $inlen;219        # for ( ; in != end; in += 8 )220        while ($left >= 8) {221            # m = LOAD64_LE( in );222            $m = array(223                self::load_4(self::substr($in, 4, 4)),224                self::load_4(self::substr($in, 0, 4))225            );226 227            # v3 ^= m;228            $v[6] ^= $m[0];229            $v[7] ^= $m[1];230 231            # SIPROUND;232            # SIPROUND;233            $v = self::sipRound($v);234            $v = self::sipRound($v);235 236            # v0 ^= m;237            $v[0] ^= $m[0];238            $v[1] ^= $m[1];239 240            $in = self::substr($in, 8);241            $left -= 8;242        }