ParagonIE_Sodium_Core_HChaCha20

10class ParagonIE_Sodium_Core_HChaCha20 extends ParagonIE_Sodium_Core_ChaCha2011{12    /**13     * @param string $in14     * @param string $key15     * @param string|null $c16     * @return string17     *18     * @throws SodiumException19     * @throws TypeError20     */21    public static function hChaCha20($in, $key, $c = null)22    {23        if (self::strlen($in) !== 16) {24            throw new SodiumException('Argument 1 must be 16 bytes');25        }26        if (self::strlen($key) !== 32) {27            throw new SodiumException('Argument 2 must be 32 bytes');28        }29        $ctx = array();30 31        if ($c === null) {32            $ctx[0] = 0x61707865;33            $ctx[1] = 0x3320646e;34            $ctx[2] = 0x79622d32;35            $ctx[3] = 0x6b206574;36        } else {37            $ctx[0] = self::load_4(self::substr($c,  0, 4));38            $ctx[1] = self::load_4(self::substr($c,  4, 4));39            $ctx[2] = self::load_4(self::substr($c,  8, 4));40            $ctx[3] = self::load_4(self::substr($c, 12, 4));41        }42        $ctx[4]  = self::load_4(self::substr($key,  0, 4));43        $ctx[5]  = self::load_4(self::substr($key,  4, 4));44        $ctx[6]  = self::load_4(self::substr($key,  8, 4));45        $ctx[7]  = self::load_4(self::substr($key, 12, 4));46        $ctx[8]  = self::load_4(self::substr($key, 16, 4));47        $ctx[9]  = self::load_4(self::substr($key, 20, 4));48        $ctx[10] = self::load_4(self::substr($key, 24, 4));49        $ctx[11] = self::load_4(self::substr($key, 28, 4));50        $ctx[12] = self::load_4(self::substr($in,   0, 4));51        $ctx[13] = self::load_4(self::substr($in,   4, 4));52        $ctx[14] = self::load_4(self::substr($in,   8, 4));53        $ctx[15] = self::load_4(self::substr($in,  12, 4));54        return self::hChaCha20Bytes($ctx);55    }56 57    /**58     * @param array $ctx59     * @return string60     * @throws TypeError61     */62    protected static function hChaCha20Bytes(array $ctx)63    {64        $x0  = (int) $ctx[0];65        $x1  = (int) $ctx[1];66        $x2  = (int) $ctx[2];67        $x3  = (int) $ctx[3];68        $x4  = (int) $ctx[4];69        $x5  = (int) $ctx[5];70        $x6  = (int) $ctx[6];71        $x7  = (int) $ctx[7];72        $x8  = (int) $ctx[8];73        $x9  = (int) $ctx[9];74        $x10 = (int) $ctx[10];75        $x11 = (int) $ctx[11];76        $x12 = (int) $ctx[12];77        $x13 = (int) $ctx[13];78        $x14 = (int) $ctx[14];79        $x15 = (int) $ctx[15];80 81        for ($i = 0; $i < 10; ++$i) {82            # QUARTERROUND( x0,  x4,  x8,  x12)83            list($x0, $x4, $x8, $x12) = self::quarterRound($x0, $x4, $x8, $x12);84 85            # QUARTERROUND( x1,  x5,  x9,  x13)86            list($x1, $x5, $x9, $x13) = self::quarterRound($x1, $x5, $x9, $x13);87 88            # QUARTERROUND( x2,  x6,  x10,  x14)89            list($x2, $x6, $x10, $x14) = self::quarterRound($x2, $x6, $x10, $x14);