Java RC4 加密解密

来源：互联网发布：java 获取网页源代码编辑：程序博客网时间：2024/05/11 01:19

java 代码如下：

import java.io.UnsupportedEncodingException;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 = null;        try        {            tmp = src.getBytes(CHARSET);        }        catch (UnsupportedEncodingException e)        {            e.printStackTrace();        }        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;    }}

测试：

    public static void main(String[] args){        String inputStr = "中国1234";        String key = "3545C7B737D3D3223CA";        String str = encry_RC4_string(inputStr, key);        System.out.println(str);        System.out.println(decry_RC4(str, key));    }

结果如下：

9f5040d88613cf2765a6中国1234

参考：http://blog.sina.com.cn/s/blog_5731c0b301017dxo.html

0 0