Question

一个简单的php解密方法，效果很好并正确生成输出。这是代码。

function decryption($Str)
{
  $key = "huasHIYhkasdho1";
  $Newstr="";
  $lenKey=strlen($key);
  $KeyPos=1;
  $LenStr=strlen($Str);
  $str=strrev($Str);
  for ($x=$LenStr; $x>=1; $x--)
  {
    //Step(-1); // WARNING: assuming Step is an external function
    $DecCharNum=ord(substr($str,$x-1,1))-ord(substr($key,$KeyPos-1,1)) + 256;
    $Newstr.=chr($DecCharNum % 256);
    $KeyPos++;
    if ($KeyPos > $lenKey)
    {
      $KeyPos=1;
    }
  }
  $Newstr=strrev($Newstr);
  return $Newstr;
}

但我正在尝试将其转换为java。大多数情况下我已经完成了，但是我遇到的问题是Charset，我无法弄清楚Charset在上述方法中传递的字符串。这是我需要解密的字符串的图像。

此图像是在Windows操作系统（Windows7）中拍摄的实际快照。 http://i41.tinypic.com/w9h2kj.png 相同的Java代码

import java.io.*;

public class FileToArrayOfBytes
{
    public static void main( String[] args )
    {
        FileInputStream fileInputStream=null;

        File file = new File("Report.txt");

        String key = "huasHIYhkasdho1";
        String Newstr = "";
        int lenKey = key.length();
        System.out.println("Key Length : "+lenKey);
        int KeyPos=1;
        byte[] bFile = new byte[(int) file.length()];
        try {
        //convert file into array of bytes
        fileInputStream = new FileInputStream(file);
        fileInputStream.read(bFile);
        fileInputStream.close();
        System.out.println("bFile length : "+bFile.length);
        int LenStr=bFile.length;        
        System.out.println("String Length : "+LenStr);      
        for (int x = bFile.length; x > 0; x--)
        {
            System.out.println("========================================");
        int DecCharNum = ( (int)bFile[x-1] ) - ( (int)key.charAt(KeyPos-1) ) + 256;
            System.out.println("sub 1 = "+ (char)bFile[x-1]);
            System.out.println("sub 2 = " + key.charAt(KeyPos-1));
        System.out.println("ord 1 = " + (int)bFile[x-1]);
        System.out.println("ord 2 = " + (int)key.charAt(KeyPos-1));
        System.out.println("Sub = "+DecCharNum);            
        Newstr += (char) (DecCharNum % 256);
        System.out.println("Dec Value = "+DecCharNum);
        System.out.println("New String = "+ Newstr );

        KeyPos++;
        System.out.println("Position "+KeyPos);

        if (KeyPos > lenKey)
        {
        System.out.println("++++++++++++++++++++++++++++++++++++++");
        KeyPos=1;
            System.out.println("++++++++++++++++++++++++++++++++++++++");
        }
        System.out.println("========================================");
        }

        System.out.println("Done");
        }catch(Exception e){
            e.printStackTrace();
        }
    }
}

以上代码的输出是

Key Length : 15
bFile length : 26
String Length : 26
========================================
sub 1 = 

sub 2 = h
ord 1 = 10
ord 2 = 104
Sub = 162
Dec Value = 162
New String = ¢
Position 2
========================================
========================================
sub 1 = ﾓ
sub 2 = u
ord 1 = -109
ord 2 = 117
Sub = 30
Dec Value = 30
New String = ¢
Position 3
========================================
========================================
sub 1 = ﾛ
sub 2 = a
ord 1 = -101
ord 2 = 97
Sub = 58
Dec Value = 58
New String = ¢:
Position 4
========================================
========================================
sub 1 = ﾙ
sub 2 = s
ord 1 = -103
ord 2 = 115
Sub = 38
Dec Value = 38
New String = ¢:&
Position 5
========================================
========================================
sub 1 = ﾛ
sub 2 = H
ord 1 = -101
ord 2 = 72
Sub = 83
Dec Value = 83
New String = ¢:&S
Position 6
========================================
========================================
sub 1 = ﾏ
sub 2 = I
ord 1 = -113
ord 2 = 73
Sub = 70
Dec Value = 70
New String = ¢:&SF
Position 7
========================================
========================================
sub 1 = z
sub 2 = Y
ord 1 = 122
ord 2 = 89
Sub = 289
Dec Value = 289
New String = ¢:&SF!
Position 8
========================================
========================================
sub 1 = ﾫ
sub 2 = h
ord 1 = -85
ord 2 = 104
Sub = 67
Dec Value = 67
New String = ¢:&SF!C
Position 9
========================================
========================================
sub 1 = ﾒ
sub 2 = k
ord 1 = -110
ord 2 = 107
Sub = 39
Dec Value = 39
New String = ¢:&SF!C'
Position 10
========================================
========================================
sub 1 = ﾦ
sub 2 = a
ord 1 = -90
ord 2 = 97
Sub = 69
Dec Value = 69
New String = ¢:&SF!C'E
Position 11
========================================
========================================
sub 1 = ﾭ
sub 2 = s
ord 1 = -83
ord 2 = 115
Sub = 58
Dec Value = 58
New String = ¢:&SF!C'E:
Position 12
========================================
========================================
sub 1 = s
sub 2 = d
ord 1 = 115
ord 2 = 100
Sub = 271
Dec Value = 271
New String = ¢:&SF!C'E:
Position 13
========================================
========================================
sub 1 = ﾠ
sub 2 = h
ord 1 = -96
ord 2 = 104
Sub = 56
Dec Value = 56
New String = ¢:&SF!C'E:8
Position 14
========================================
========================================
sub 1 = ﾠ
sub 2 = o
ord 1 = -96
ord 2 = 111
Sub = 49
Dec Value = 49
New String = ¢:&SF!C'E:81
Position 15
========================================
========================================
sub 1 = ﾔ
sub 2 = 1
ord 1 = -108
ord 2 = 49
Sub = 99
Dec Value = 99
New String = ¢:&SF!C'E:81c
Position 16
++++++++++++++++++++++++++++++++++++++
++++++++++++++++++++++++++++++++++++++
========================================
========================================
sub 1 = ﾣ
sub 2 = h
ord 1 = -93
ord 2 = 104
Sub = 59
Dec Value = 59
New String = ¢:&SF!C'E:81c;
Position 2
========================================
========================================
sub 1 = ﾗ
sub 2 = u
ord 1 = -105
ord 2 = 117
Sub = 34
Dec Value = 34
New String = ¢:&SF!C'E:81c;"
Position 3
========================================
========================================
sub 1 = ﾱ
sub 2 = a
ord 1 = -79
ord 2 = 97
Sub = 80
Dec Value = 80
New String = ¢:&SF!C'E:81c;"P
Position 4
========================================
========================================
sub 1 = ﾬ
sub 2 = s
ord 1 = -84
ord 2 = 115
Sub = 57
Dec Value = 57
New String = ¢:&SF!C'E:81c;"P9
Position 5
========================================
========================================
sub 1 = ﾋ
sub 2 = H
ord 1 = -117
ord 2 = 72
Sub = 67
Dec Value = 67
New String = ¢:&SF!C'E:81c;"P9C
Position 6
========================================
========================================
sub 1 = y
sub 2 = I
ord 1 = 121
ord 2 = 73
Sub = 304
Dec Value = 304
New String = ¢:&SF!C'E:81c;"P9C0
Position 7
========================================
========================================
sub 1 = y
sub 2 = Y
ord 1 = 121
ord 2 = 89
Sub = 288
Dec Value = 288
New String = ¢:&SF!C'E:81c;"P9C0 
Position 8
========================================
========================================
sub 1 = ﾦ
sub 2 = h
ord 1 = -90
ord 2 = 104
Sub = 62
Dec Value = 62
New String = ¢:&SF!C'E:81c;"P9C0 >
Position 9
========================================
========================================
sub 1 = ﾕ
sub 2 = k
ord 1 = -107
ord 2 = 107
Sub = 42
Dec Value = 42
New String = ¢:&SF!C'E:81c;"P9C0 >*
Position 10
========================================
========================================
sub 1 = ﾪ
sub 2 = a
ord 1 = -86
ord 2 = 97
Sub = 73
Dec Value = 73
New String = ¢:&SF!C'E:81c;"P9C0 >*I
Position 11
========================================
========================================
sub 1 = ﾝ
sub 2 = s
ord 1 = -99
ord 2 = 115
Sub = 42
Dec Value = 42
New String = ¢:&SF!C'E:81c;"P9C0 >*I*
Position 12
========================================
Done

上述代码所需的输出是：201BF2811EB18006FD2013455

请帮我弄清楚问题，我知道问题是Charset使用的，我无法弄明白该怎么做才能正确输出。

Answer 1

此问题与字符集无关。您将输入读取为字节而不是字符，预期输出主要是ASCII。对待它的方式，在byte和char之间进行转换，您将输出作为ISO-8859-1，就像PHP通常那样。

问题的核心是方向。 PHP代码反转字符串，然后从后到前迭代输入，然后反转结果。这与从前到后迭代输入相同。但是你将迭代保持在前面，同时没有移植strrev个调用。将你的循环改为

for (int x = 1; x <= bFile.length; x++)

你应该没事。

Charset让我感到困惑

1 个答案: