ParagonIE_Sodium_Core32_SipHash::sipHash24( string $in, string $key ): string

76    public static function sipHash24($in, $key)77    {78        $inlen = self::strlen($in);79 80        # /* "somepseudorandomlygeneratedbytes" */81        # u64 v0 = 0x736f6d6570736575ULL;82        # u64 v1 = 0x646f72616e646f6dULL;83        # u64 v2 = 0x6c7967656e657261ULL;84        # u64 v3 = 0x7465646279746573ULL;85        $v = array(86            new ParagonIE_Sodium_Core32_Int64(87                array(0x736f, 0x6d65, 0x7073, 0x6575)88            ),89            new ParagonIE_Sodium_Core32_Int64(90                array(0x646f, 0x7261, 0x6e64, 0x6f6d)91            ),92            new ParagonIE_Sodium_Core32_Int64(93                array(0x6c79, 0x6765, 0x6e65, 0x7261)94            ),95            new ParagonIE_Sodium_Core32_Int64(96                array(0x7465, 0x6462, 0x7974, 0x6573)97            )98        );99 100        # u64 k0 = LOAD64_LE( k );101        # u64 k1 = LOAD64_LE( k + 8 );102        $k = array(103            ParagonIE_Sodium_Core32_Int64::fromReverseString(104                self::substr($key, 0, 8)105            ),106            ParagonIE_Sodium_Core32_Int64::fromReverseString(107                self::substr($key, 8, 8)108            )109        );110 111        # b = ( ( u64 )inlen ) << 56;112        $b = new ParagonIE_Sodium_Core32_Int64(113            array(($inlen << 8) & 0xffff, 0, 0, 0)114        );115 116        # v3 ^= k1;117        $v[3] = $v[3]->xorInt64($k[1]);118        # v2 ^= k0;119        $v[2] = $v[2]->xorInt64($k[0]);120        # v1 ^= k1;121        $v[1] = $v[1]->xorInt64($k[1]);122        # v0 ^= k0;123        $v[0] = $v[0]->xorInt64($k[0]);124 125        $left = $inlen;126        # for ( ; in != end; in += 8 )127        while ($left >= 8) {128            # m = LOAD64_LE( in );129            $m = ParagonIE_Sodium_Core32_Int64::fromReverseString(130                self::substr($in, 0, 8)131            );132 133            # v3 ^= m;134            $v[3] = $v[3]->xorInt64($m);135 136            # SIPROUND;137            # SIPROUND;138            $v = self::sipRound($v);139            $v = self::sipRound($v);140 141            # v0 ^= m;142            $v[0] = $v[0]->xorInt64($m);143 144            $in = self::substr($in, 8);145            $left -= 8;146        }147 148        # switch( left )149        #  {150        #     case 7: b |= ( ( u64 )in[ 6] )  << 48;151        #     case 6: b |= ( ( u64 )in[ 5] )  << 40;152        #     case 5: b |= ( ( u64 )in[ 4] )  << 32;153        #     case 4: b |= ( ( u64 )in[ 3] )  << 24;154        #     case 3: b |= ( ( u64 )in[ 2] )  << 16;155        #     case 2: b |= ( ( u64 )in[ 1] )  <<  8;