ParagonIE_Sodium_Core_Util

10abstract class ParagonIE_Sodium_Core_Util11{12    const U32_MAX = 0xFFFFFFFF;13 14    /**15     * @param int $integer16     * @param int $size (16, 32, 64)17     * @return int18     */19    public static function abs($integer, $size = 0)20    {21        /** @var int $realSize */22        $realSize = (PHP_INT_SIZE << 3) - 1;23        if ($size) {24            --$size;25        } else {26            /** @var int $size */27            $size = $realSize;28        }29 30        $negative = -(($integer >> $size) & 1);31        return (int) (32            ($integer ^ $negative)33                +34            (($negative >> $realSize) & 1)35        );36    }37 38    /**39     * @param string $a40     * @param string $b41     * @return string42     * @throws SodiumException43     */44    public static function andStrings($a, $b)45    {46        /* Type checks: */47        if (!is_string($a)) {48            throw new TypeError('Argument 1 must be a string');49        }50        if (!is_string($b)) {51            throw new TypeError('Argument 2 must be a string');52        }53        $len = self::strlen($a);54        if (self::strlen($b) !== $len) {55            throw new SodiumException('Both strings must be of equal length to combine with bitwise AND');56        }57        return $a & $b;58    }59 60    /**61     * Convert a binary string into a hexadecimal string without cache-timing62     * leaks63     *64     * @internal You should not use this directly from another application65     *66     * @param string $binaryString (raw binary)67     * @return string68     * @throws TypeError69     */70    public static function bin2hex($binaryString)71    {72        /* Type checks: */73        if (!is_string($binaryString)) {74            throw new TypeError('Argument 1 must be a string, ' . gettype($binaryString) . ' given.');75        }76 77        $hex = '';78        $len = self::strlen($binaryString);79        for ($i = 0; $i < $len; ++$i) {80            /** @var array<int, int> $chunk */81            $chunk = unpack('C', $binaryString[$i]);82            /** @var int $c */83            $c = $chunk[1] & 0xf;84            /** @var int $b */85            $b = $chunk[1] >> 4;86            $hex .= pack(87                'CC',88                (87 + $b + ((($b - 10) >> 8) & ~38)),89                (87 + $c + ((($c - 10) >> 8) & ~38))