package com.test;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.security.Key;
import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.KeyGenerator;
class Encrypt { public static void saveDesKey() {
try {
SecureRandom sr = new SecureRandom();
// 为我们选择的DES算法生成一个KeyGenerator对象
KeyGenerator kg = KeyGenerator.getInstance("DES");
kg.init(sr);
// 相对路径 需要新建 conf 文件夹
// String fileName = "conf/DesKey.xml";
// 绝对路径
String fileName = "d:/DesKey.xml";
FileOutputStream fos = new FileOutputStream(fileName);
ObjectOutputStream oos = new ObjectOutputStream(fos);
// 生成密钥
Key key = kg.generateKey();
oos.writeObject(key);
oos.close();
} catch (Exception e) {
e.printStackTrace();
}
} public static Key getKey() {
Key kp = null;
try {
// 相对路径 需要新建 conf 文件夹
// String fileName = "conf/DesKey.xml";
// InputStream is = Encrypt.class.getClassLoader().getResourceAsStream(fileName);
// 绝对路径
String fileName = "d:/DesKey.xml";
FileInputStream is = new FileInputStream(fileName);
ObjectInputStream oos = new ObjectInputStream(is);
kp = (Key) oos.readObject();
oos.close();
} catch (Exception e) {
e.printStackTrace();
}
return kp;
} public static void encrypt(String file, String dest) throws Exception {
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.ENCRYPT_MODE, getKey());
InputStream is = new FileInputStream(file);
OutputStream out = new FileOutputStream(dest);
CipherInputStream cis = new CipherInputStream(is, cipher);
byte[] buffer = new byte[1024];
int r;
while ((r = cis.read(buffer)) > 0) {
out.write(buffer, 0, r);
}
cis.close();
is.close();
out.close();
} public static void decrypt(String file, String dest) throws Exception {
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.DECRYPT_MODE, getKey());
InputStream is = new FileInputStream(file);
OutputStream out = new FileOutputStream(dest);
CipherOutputStream cos = new CipherOutputStream(out, cipher);
byte[] buffer = new byte[1024];
int r;
while ((r = is.read(buffer)) >= 0) {
cos.write(buffer, 0, r);
}
cos.close();
out.close();
is.close();
}
}
public class DES {
public static void main(String[] args) throws Exception {
Encrypt.saveDesKey();
System.out.println("生成key");
Encrypt.getKey();
System.out.println("获取key");
Encrypt.encrypt("d:\\hello.txt", "d:\\encrypt.txt");
System.out.println("加密");
Encrypt.decrypt("d:\\encrypt.txt", "d:\\decrypt.txt");
System.out.println("解密");
}
}