十六進制編碼求異或

xmule 2012-07-21

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十六進制編碼求異或

如同消息頭加密一樣：對兩字符串先進行轉碼，再求兩轉碼后的異或，生成新的十六進制編碼：

初步處理如下：

Java代碼

package com.foxconn;
import java.text.ParseException;
public class Aa {
/*
* @author Yujie_Li
*/
private static String hexString = "0123456789ABCDEF";
public static void main(String args[]) throws ParseException{
String code1 = encode("9CE00K00781065");
String code2 = encode("TOX$123FTOX$321");
System.out.println(code1);
System.out.println(code2);
byte [] a = code1.getBytes();
byte [] b = code2.getBytes();
byte [] c = new byte[code1.length()];
//byte類型需要先轉化成字符數(shù)組,，然后才能轉化成字符串
StringBuffer sb = new StringBuffer();
String ret = "";
for(int i =0;i<code1.length();i++){
String hex = Integer.toHexString((a[i]& 0x0f)^(b[i]& 0x0f));
ret += hex.toUpperCase();
System.out.println("=========>>" + hex);
c[i] = (byte) ((a[i]& 0xFF)^(b[i]& 0xFF));
System.out.println(i+"--------"+Integer.toBinaryString(a[i])+
"-------"+Integer.toBinaryString(b[i])+"----"+Integer.toBinaryString((a[i]& 0x0f)^(b[i]& 0x0f)));
sb.append(c[i]&0xFF);
}
String code3 = sb.toString();
System.out.println(code3);
System.out.println(ret);
}
public static String encode(String str) {
// 根據(jù)默認編碼獲取字節(jié)數(shù)組
byte[] bytes = str.getBytes();
String strs = "";
// 將字節(jié)數(shù)組中每個字節(jié)拆解成2位16進制整數(shù)
for (int i = 0; i < bytes.length; i++) {
// 高四位
strs += hexString.charAt((bytes[i] & 0xf0) >> 4);
//System.out.println(i+"--"+bytes[i]+"----"+(bytes[i] & 0xf0)+"----"+hexString.charAt((bytes[i] & 0xf0) >> 4));
// 低四位
strs += hexString.charAt((bytes[i] & 0x0f) >> 0);
}
return strs;
}
}

測試發(fā)現(xiàn)如果轉碼后求異或后某些超過16進制基數(shù)的無法得到正確解,。特做如下修改：

Java代碼

package com.foxconn;
import java.text.ParseException;
public class Aa {
private static String hexStr = "0123456789ABCDEF";
public static void main(String args[]) throws ParseException{
String code1 = encode("9CE00K00781065");
String code2 = encode("TOX$123FTOX$321");
System.out.println(code1);
System.out.println(code2);
System.out.println("7F0C1D14017903767F6814010203");
String result ="";
for(int i=0; i<code1.length();i++){
char c1 = code1.charAt(i);
char c2 = code2.charAt(i);
String a = convertHexToBinary(c1+"");
String b = convertHexToBinary(c2+"");
byte [] aa = a.getBytes();
byte [] bb = b.getBytes();
String cc ="";
for( int j = 0;j<aa.length;j++ ){
cc += aa[j]^bb[j];
}
String tmp =Integer.toHexString(Integer.valueOf(cc,2).intValue()).toString();
result +=tmp;
}
}
public static String convertHexToBinary(String hexString){
long l = Long.parseLong(hexString, 16);
String binaryString = Long.toBinaryString(l);
int shouldBinaryLen = hexString.length()*4;
StringBuffer addZero = new StringBuffer();
int addZeroNum = shouldBinaryLen-binaryString.length();
for(int i=1;i<=addZeroNum;i++){
addZero.append("0");
}
return addZero.toString()+binaryString;
}
public static String encode(String str) {
// 根據(jù)默認編碼獲取字節(jié)數(shù)組
byte[] bytes = str.getBytes();
String strs = "";
// 將字節(jié)數(shù)組中每個字節(jié)拆解成2位16進制整數(shù)
for (int i = 0; i < bytes.length; i++) {
//取得高四位
strs += hexStr.charAt((bytes[i] & 0xf0) >> 4);
// System.out.println(i+"--"+bytes[i]+"----"+(bytes[i] & 0xf0)+"----"+hexString.charAt((bytes[i] & 0xf0) >> 4)+"---"+hexString.charAt((bytes[i] & 0x0f) >> 0));
//取得低四位
strs += hexStr.charAt((bytes[i] & 0x0f) >> 0);
}
return strs;
}
}