ParagonIE_Sodium_Core32_HChaCha20::hChaCha20

    public static function hChaCha20($in = '', $key = '', $c = null)
    {
        $ctx = array();

        if ($c === null) {
            $ctx[0] = new ParagonIE_Sodium_Core32_Int32(array(0x6170, 0x7865));
            $ctx[1] = new ParagonIE_Sodium_Core32_Int32(array(0x3320, 0x646e));
            $ctx[2] = new ParagonIE_Sodium_Core32_Int32(array(0x7962, 0x2d32));
            $ctx[3] = new ParagonIE_Sodium_Core32_Int32(array(0x6b20, 0x6574));
        } else {
            $ctx[0] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($c, 0, 4));
            $ctx[1] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($c, 4, 4));
            $ctx[2] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($c, 8, 4));
            $ctx[3] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($c, 12, 4));
        }
        $ctx[4]  = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($key, 0, 4));
        $ctx[5]  = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($key, 4, 4));
        $ctx[6]  = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($key, 8, 4));
        $ctx[7]  = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($key, 12, 4));
        $ctx[8]  = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($key, 16, 4));
        $ctx[9]  = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($key, 20, 4));
        $ctx[10] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($key, 24, 4));
        $ctx[11] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($key, 28, 4));
        $ctx[12] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($in, 0, 4));
        $ctx[13] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($in, 4, 4));
        $ctx[14] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($in, 8, 4));
        $ctx[15] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($in, 12, 4));

        return self::hChaCha20Bytes($ctx);
    }