package com.dgut.app.utils;

import java.lang.Byte;

import java.util.UUID;

public class RC4 {

     public static String decry_RC4(byte[] data, String key) {

            if (data == null || key == null) {

                return null;

            }

            return asString(RC4Base(data, key));

        }  

        public static String decry_RC4(String data, String key) {

            if (data == null || key == null) {

                return null;

            }

            return new String(RC4Base(HexString2Bytes(data), key));

        }  

        public static byte[] encry_RC4_byte(String data, String key) {

            if (data == null || key == null) {

                return null;

            }

            byte b_data[] = data.getBytes();

            return RC4Base(b_data, key);

        }  

        public static String encry_RC4_string(String data, String key) {

            if (data == null || key == null) {

                return null;

            }

            return toHexString(asString(encry_RC4_byte(data, key)));

        }  

        private static String asString(byte[] buf) {

            StringBuffer strbuf = new StringBuffer(buf.length);

            for (int i = 0; i < buf.length; i++) {

                strbuf.append((char) buf[i]);

            }

            return strbuf.toString();

        }  

        private static byte[] initKey(String aKey) {

            byte[] b_key = aKey.getBytes();

            byte state[] = new byte[256];  

            for (int i = 0; i < 256; i++) {

                state[i] = (byte) i;

            }

            int index1 = 0;

            int index2 = 0;

            if (b_key == null || b_key.length == 0) {

                return null;

            }

            for (int i = 0; i < 256; i++) {

                index2 = ((b_key[index1] & 0xff) + (state[i] & 0xff) + index2) & 0xff;

                byte tmp = state[i];

                state[i] = state[index2];

                state[index2] = tmp;

                index1 = (index1 + 1) % b_key.length;

            }

            return state;

        }  

        private static String toHexString(String s) {

            String str = "";

            for (int i = 0; i < s.length(); i++) {

                int ch = (int) s.charAt(i);

                String s4 = Integer.toHexString(ch & 0xFF);

                if (s4.length() == 1) {

                    s4 = '0' + s4;

                }

                str = str + s4;

            }

            return str;// 0x表示十六进制

        }  

        private static byte[] HexString2Bytes(String src) {

            int size = src.length();

            byte[] ret = new byte[size / 2];

            byte[] tmp = src.getBytes();

            for (int i = 0; i < size / 2; i++) {

                ret[i] = uniteBytes(tmp[i * 2], tmp[i * 2 + 1]);

            }

            return ret;

        }  

        private static byte uniteBytes(byte src0, byte src1) {

            char _b0 = (char) Byte.decode("0x" + new String(new byte[] { src0 })).byteValue();

            _b0 = (char) (_b0 << 4);

            char _b1 = (char) Byte.decode("0x" + new String(new byte[] { src1 })).byteValue();

            byte ret = (byte) (_b0 ^ _b1);

            return ret;

        }  

        private static byte[] RC4Base(byte[] input, String mKkey) {

            int x = 0;

            int y = 0;

            byte key[] = initKey(mKkey);

            int xorIndex;

            byte[] result = new byte[input.length];  

            for (int i = 0; i < input.length; i++) {

                x = (x + 1) & 0xff;

                y = ((key[x] & 0xff) + y) & 0xff;

                byte tmp = key[x];

                key[x] = key[y];

                key[y] = tmp;

                xorIndex = ((key[x] & 0xff) + (key[y] & 0xff)) & 0xff;

                result[i] = (byte) (input[i] ^ key[xorIndex]);

            }

            return result;

        }  

        public static void main(String[] args) {

            long inputStr = System.currentTimeMillis();

            System.out.println(String.format("%05d", inputStr));

            String str = encry_RC4_string(inputStr+"", UUID.randomUUID().toString().toUpperCase());

            System.out.println(str);

           // System.out.println(decry_RC4(str, UUID.randomUUID().toString().toUpperCase()));

        }

}