java代码加密教程 java最简单的加密方式( 十 )


92A8FD8FEC2F0746 DES密码三
输出:
对输入的文件加密后 , 保存到同一文件夹下增加了".tdes"扩展名的文件中 。
*/
private void encrypt(File fileIn,String sKey){
try{
【java代码加密教程 java最简单的加密方式】if(sKey.length() == 48){
byte[] bytK1 = getKeyByStr(sKey.substring(0,16));
byte[] bytK2 = getKeyByStr(sKey.substring(16,32));
byte[] bytK3 = getKeyByStr(sKey.substring(32,48));
FileInputStream fis = new FileInputStream(fileIn);
byte[] bytIn = new byte[(int)fileIn.length()];
for(int i = 0;iFILEIN.LENGTH();I++){
bytIn[i] = (byte)fis.read();
}
//加密
byte[] bytOut = encryptByDES(encryptByDES(
encryptByDES(bytIn,bytK1),bytK2),bytK3);
String fileOut = fileIn.getPath() + ".tdes";
FileOutputStream fos = new FileOutputStream(fileOut);
for(int i = 0;iBYTOUT.LENGTH;I++){
fos.write((int)bytOut[i]);
}
fos.close();
JOptionPane.showMessageDialog(
this,"加密成功!","提示",JOptionPane.OK_OPTION);
}else
JOptionPane.showMessageDialog(
this,"密码长度必须等于48!","错误信息",JOptionPane.ERROR_MESSAGE);
}catch(Exception e){
e.printStackTrace();
}
}
/**
解密函数
输入:
要解密的文件,密码(由0-F组成,共48个字符,表示3个8位的密码)如:
AD67EA2F3BE6E5ADD368DFE03120B5DF92A8FD8FEC2F0746
其中:
AD67EA2F3BE6E5AD DES密码一
D368DFE03120B5DF DES密码二
92A8FD8FEC2F0746 DES密码三
输出:
对输入的文件解密后 , 保存到用户指定的文件中 。
*/
private void decrypt(File fileIn,String sKey){
try{
if(sKey.length() == 48){
String strPath = fileIn.getPath();
if(strPath.substring(strPath.length()-5).toLowerCase().equals(".tdes"))
strPath = strPath.substring(0,strPath.length()-5);
else{
JOptionPane.showMessageDialog(
this,"不是合法的加密文件!","提示",JOptionPane.OK_OPTION);
return;
}
JFileChooser chooser = new JFileChooser();
chooser.setCurrentDirectory(new File("."));
chooser.setSelectedFile(new File(strPath));
//用户指定要保存的文件
int ret = chooser.showSaveDialog(this);
if(ret==JFileChooser.APPROVE_OPTION){
byte[] bytK1 = getKeyByStr(sKey.substring(0,16));
byte[] bytK2 = getKeyByStr(sKey.substring(16,32));
byte[] bytK3 = getKeyByStr(sKey.substring(32,48));
FileInputStream fis = new FileInputStream(fileIn);
byte[] bytIn = new byte[(int)fileIn.length()];
for(int i = 0;iFILEIN.LENGTH();I++){
bytIn[i] = (byte)fis.read();
}
//解密
byte[] bytOut = decryptByDES(decryptByDES(
decryptByDES(bytIn,bytK3),bytK2),bytK1);
File fileOut = chooser.getSelectedFile();
fileOut.createNewFile();
FileOutputStream fos = new FileOutputStream(fileOut);
for(int i = 0;iBYTOUT.LENGTH;I++){
fos.write((int)bytOut[i]);
}
fos.close();
JOptionPane.showMessageDialog(
this,"解密成功!","提示",JOptionPane.OK_OPTION);
}
}else
JOptionPane.showMessageDialog(
this,"密码长度必须等于48!","错误信息",JOptionPane.ERROR_MESSAGE);
}catch(Exception e){
JOptionPane.showMessageDialog(
this,"解密失败,请核对密码!","提示",JOptionPane.OK_OPTION);
}
}
/**
用DES方法加密输入的字节
bytKey需为8字节长,是加密的密码
*/
private byte[] encryptByDES(byte[] bytP,byte[] bytKey) throws Exception{
DESKeySpec desKS = new DESKeySpec(bytKey);
SecretKeyFactory skf = SecretKeyFactory.getInstance("DES");
SecretKey sk = skf.generateSecret(desKS);
Cipher cip = Cipher.getInstance("DES");
cip.init(Cipher.ENCRYPT_MODE,sk);

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