关于getBytes()

最近Google上不了很是痛苦，只能一直开着goagent，夏日laptop发热严重，开linux会自动关机。命途多舛。

今天在做逆向时候，源码里面对一个byte[]进行编码成为一串字符串QjI4REM3NTdGQjUxMDk5NTJBMEFBOTMzQzMzMkE2RDM=

.class逆向代码

 1     if (arrayOfByte == null)
 2     {
 3       LogUtil.e(this.TAG, "create signature failed.");
 4       return null;
 5     }
 6     StringBuffer localStringBuffer = new StringBuffer("");
 7     for (int i = 0; i < arrayOfByte.length; i++)
 8     {
 9       int j = arrayOfByte[i];
10       if (j < 0)
11         j += 256;
12       if (j < 16)
13         localStringBuffer.append("0");
14       localStringBuffer.append(Integer.toHexString(j));
15     }
16     return IdentifyApp.base64encode(localStringBuffer.toString().toUpperCase().getBytes());
17   }

求byte[]和decode

1 BASE64Decoder decoder = new BASE64Decoder();
2         byte[] decodedbytes = decoder.decodeBuffer(str);
3         for(int i = 0;i<decodedbytes.length;i++) System.out.print(" "+decodedbytes[i]);
4         System.out.println();
5         System.out.println(new String(decodedbytes));

byte[]>>>  66 50 56 68 67 55 53 55 70 66 53 49 48 57 57 53 50 65 48 65 65 57 51 51 67 51 51 50 65 54 68 51
string>>>B28DC757FB5109952A0AA933C332A6D3

求原数组

 1 package hextooct;
 2
 3 import java.util.ArrayList;
 4
 5 public class Transfer {
 6     public static void main(String[] args)
 7     {
 8         String str = "B28DC757FB5109952A0AA933C332A6D3";
 9         char[] c = str.toCharArray();
10         ArrayList<Integer> al = new ArrayList<Integer>();
11         for(int i = 0; i < c.length; i++)
12         {
13             String s = String.valueOf(c[i]);
14             if(c[i]==‘0‘) continue;
15             if(c[i]>9){
16                 System.out.print(Integer.parseInt(s, 16));
17                 al.add(Integer.parseInt(s,16));
18             }
19             else {System.out.print(c[i]); al.add(Integer.parseInt(s));}
20             System.out.print(" ");
21
22         }
23         System.out.println();
24         System.out.println(al.toString());
25
26     }
27
28 }

跟踪源码：

 public static byte[] md5digest(String paramString)
  {
    monitorenter;
    try
    {
      byte[] arrayOfByte2 = MarkManager.base64decode(MMClientSDK_ForPhone.md5Algorithm(paramString));
      arrayOfByte1 = arrayOfByte2;
      return arrayOfByte1;
    }
    catch (Exception localException)
    {
      while (true)
      {
        LogUtil.w("IdentifyApp", "base64 decrypt license file failure");
        byte[] arrayOfByte1 = null;
      }
    }

解出来string

package com.crack;
import java.io.IOException;
import java.lang.String;

import Decoder.BASE64Decoder;
import Decoder.BASE64Encoder;;
public class Crack {

    public static void main(String[] args) throws IOException
    {
        byte[] arr = {11, 2, 8, 13, 12, 7, 5, 7, 15, 11, 5, 1, 9, 9, 5, 2, 10, 10, 10, 9, 3, 3, 12, 3, 3, 2, 10, 6, 13, 3};
        BASE64Encoder baseencoder = new BASE64Encoder();
        String result = baseencoder.encode(arr);
        System.out.println(result);

        String str="CwIIDQwHBQcPCwUBCQkFAgoKCgkDAwwDAwIKBg0D";
        BASE64Decoder decoder = new BASE64Decoder();
        byte[] decodedbytes = decoder.decodeBuffer(str);
        for(int i = 0;i<decodedbytes.length;i++) System.out.print(" "+decodedbytes[i]);
        System.out.println();
    }
}

CwIIDQwHBQcPCwUBCQkFAgoKCgkDAwwDAwIKBg0D
 11 2 8 13 12 7 5 7 15 11 5 1 9 9 5 2 10 10 10 9 3 3 12 3 3 2 10 6 13 3

关于getBytes()