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只是爲了好玩，我一直在試圖製作一個文件加密器，它對128位密鑰進行按位異或加密。它似乎適用於使用某些編輯器的純文本文件，但對於其他人和更復雜的文件，我會遇到「損壞的文件」錯誤。如果我在文本文件上進行兩次加密，在Gedit中它會像原來那樣顯示原始文件的內容，但在記事本中，我只是得到了一大堆問號。我的xor加密無法在複雜文件上工作
我已經用Java寫了這段代碼，但是加密部分非常普遍。最關鍵的是在8個16位字符的陣列的形式：
char[] key = {26372, 15219, 53931, 50406, 26072, 23469, 25002, 37812};
要加密文件，我有運行此代碼的循環：
builder.append((char)(bR.read()^key[pos++]));
if(pos == 8) pos = 0; //returns to first position in key
這從讀取下一個字符該文件使用BufferedReader，將其與鍵中的下一個字符對齊並將其附加到StringBuilder。
這裏是整個代碼：
import java.awt.BorderLayout;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;
import javax.swing.SwingWorker;
import javax.swing.UIManager;
public class Encryptor implements Runnable {
/**
* @param args
*/
public static void main(String[] args) {
try {
SwingUtilities.invokeAndWait(new Encryptor());
} catch(Exception e) {
e.printStackTrace();
}
}
JFrame frame;
JButton bCancel, bEncrypt;
JTextArea statusArea;
JScrollPane statusScroll;
JProgressBar progressBar;
String fileContents, fileType, fileName;
EncryptSwingWorker encryptWorker;
char[] key = {
26372, 15219, 53931, 50406, 26072, 23469, 25002, 37812};
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch(Exception e) {}
frame = new JFrame();
statusArea = new JTextArea();
statusArea.setEditable(false);
statusScroll = new JScrollPane(statusArea);
progressBar = new JProgressBar();
progressBar.setValue(0);
bCancel = new JButton("Cancel");
bCancel.setEnabled(false);
bCancel.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
int option = JOptionPane.showOptionDialog(frame,
"Are you sure you want to cancel?",
"Warning", JOptionPane.YES_NO_OPTION,
JOptionPane.QUESTION_MESSAGE, null,
null, null
);
if(option == 0) {
encryptWorker.cancel(true);
statusArea.append("Encryption cancelled\n");
progressBar.setValue(0);
progressBar.setIndeterminate(false);
bCancel.setEnabled(false);
bEncrypt.setEnabled(true);
}
}
});
bEncrypt = new JButton("Encrypt file...");
bEncrypt.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
encryptWorker = Encryptor.this.new EncryptSwingWorker();
encryptWorker.execute();
}
});
JPanel top = new JPanel(new BorderLayout());
top.add(bEncrypt, BorderLayout.CENTER);
top.add(bCancel, BorderLayout.EAST);
frame.getContentPane().add(top, BorderLayout.NORTH);
frame.getContentPane().add(statusScroll, BorderLayout.CENTER);
frame.getContentPane().add(progressBar, BorderLayout.SOUTH);
frame.setSize(200, 150);
frame.setResizable(false);
frame.setTitle("sEncryptor");
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setIconImage(Toolkit.getDefaultToolkit().getImage("encryptor.png"));
}
void encrypt() throws IOException {
JFileChooser fc = new JFileChooser();
int returnVal = fc.showOpenDialog(frame);
if(returnVal == JFileChooser.APPROVE_OPTION) {
if(fc.getSelectedFile() == null) {
JOptionPane.showOptionDialog(frame,
"You did not select a file",
"File Open Error",
JOptionPane.DEFAULT_OPTION,
JOptionPane.WARNING_MESSAGE, null,
null, null
);
encrypt();
return;
}
bCancel.setEnabled(true);
bEncrypt.setEnabled(false);
fileName = fc.getSelectedFile().getPath();
statusArea.append("Calculating size...\n");
progressBar.setIndeterminate(true);
int size = (int)(new File(fileName).length()/32);
progressBar.setIndeterminate(false);
progressBar.setMaximum(size);
BufferedReader bR = new BufferedReader(new FileReader(fc.getSelectedFile()));
StringBuilder builder = new StringBuilder();
statusArea.append("Encrypting...\n");
int pos = 0;
for(double d = 0; bR.ready(); d += 0.03125) {
if(encryptWorker.isCancelled()) return;
progressBar.setValue((int)d);
builder.append((char)(bR.read()^key[pos++]));
if(pos == 8) pos = 0;
}
progressBar.setValue(0);
progressBar.setIndeterminate(true);
fileContents = builder.toString();
bR.close();
statusArea.append("Encryption finished\n");
progressBar.setIndeterminate(false);
}
}
void save(String file) throws IOException {
statusArea.append("Saving...\n");
progressBar.setIndeterminate(true);
BufferedWriter bW = new BufferedWriter(new FileWriter(file));
bW.write(fileContents);
bW.close();
progressBar.setIndeterminate(false);
statusArea.append("Done!\n");
}
void saveAs() throws IOException {
JFileChooser fc = new JFileChooser();
int returnVal = fc.showSaveDialog(frame);
if(returnVal == JFileChooser.APPROVE_OPTION) {
if(fc.getSelectedFile() == null) {
JOptionPane.showOptionDialog(frame,
"You did not select a file",
"File Open Error",
JOptionPane.DEFAULT_OPTION,
JOptionPane.WARNING_MESSAGE, null,
null, null
);
saveAs();
return;
}
save(fc.getSelectedFile().getPath());
}
}
class EncryptSwingWorker extends SwingWorker<Void, Void> {
@Override
protected Void doInBackground() throws Exception {
encrypt();
if(EncryptSwingWorker.this.isCancelled()) return null;
bCancel.setEnabled(false);
while(true) {
Object[] options = {"Override", "Save As...", "Cancel"};
int option = JOptionPane.showOptionDialog(frame,
"Override existing file?",
"Save", JOptionPane.YES_NO_CANCEL_OPTION,
JOptionPane.QUESTION_MESSAGE, null,
options, options[0]
);
if(option == 0)
try {
save(fileName);
} catch(IOException e1) {
e1.printStackTrace();
}
else if(option == 1)
try {
saveAs();
} catch(IOException e1) {
e1.printStackTrace();
}
else {
int option1 = JOptionPane.showOptionDialog(frame,
"The encryption will be lost if you continue\n" +
"Are you sure you want to cancel?",
"Warning", JOptionPane.YES_NO_OPTION,
JOptionPane.QUESTION_MESSAGE, null,
null, null
);
if(option1 == 1) continue;
break;
}
break;
}
fileContents = "";
bEncrypt.setEnabled(true);
return null;
}
}
}
有我丟失的東西在我的代碼，或不異或整個文件造成的問題？
你能*請*只包括能夠證明最小的，其實相關的代碼失敗？ –
聖牛，這是很多未註釋的代碼。請考慮將其發佈在[代碼評論]（http://codereview.stackexchange.com/）上。也就是說，我將它運行在一個文件上，它創建了一個新的'3F'文件_full_（十進制63）字符。你可能會嘗試調試它，一步一步來，並檢查你的邏輯。 –
從嘗試閱讀源代碼，這裏有一些東西作爲未來自我改進的建議 - [enums]（https://www.google.com/search?q=java%20enum）！更不容易出錯，更易讀。 –