DES加解密文件

</pre><pre name="code" class="java">import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.Key;

import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESedeKeySpec;

/**
* 3DES加密
*
* @version 1.0
* @author
*
*/
public abstract class DesUtil {

/**
* 密钥算法
* @version 1.0
* @author
*/
public static final String KEY_ALGORITHM = "DESede";

/**
* 加密/解密算法/工作模式/填充方式
* @version 1.0
* @author
*/
public static final String CIPHER_ALGORITHM = "DESede/ECB/PKCS5Padding";

/**
* 转换密钥
* @param key 二进制密
* @return key 密钥
*
*/
public static Key toKey(byte[] key) throws Exception{
//实例化DES密钥材料
DESedeKeySpec dks = new DESedeKeySpec(key);
//实例化秘密密钥工
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(KEY_ALGORITHM);
//生成秘密密钥
return keyFactory.generateSecret(dks);
}

/**
* 解密
* @param data 待解密数
* @param key 密钥
* @return byte[] 解密数据
*/
public static byte[] decrypt(byte[] data, byte[] key)throws Exception{
//还原密钥
Key k = toKey(key);
/**
* 实例
* 使用PKCS7Padding填充方式，按如下代码实现
* Cipher.getInstance(CIPHER_ALGORITHM,"BC");
*/
Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
//初始化，设置为解密模
cipher.init(Cipher.DECRYPT_MODE, k);
//执行操作
return cipher.doFinal(data);
}

/**
* 加密
* @param data 待加密数
* @param key 密钥
* @return byte[] 加密数据
*/
public static byte[] encrypt(byte[] data, byte[] key) throws Exception{
//还原密钥
Key k = toKey(key);
/**
* 实例
* 使用PKCS7Padding填充方式，按如下代码实现
* Cipher.getInstance(CIPHER_ALGORITHM,"BC");
*/
Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
//初始化，设置为解密模
cipher.init(Cipher.ENCRYPT_MODE, k);
//执行操作
return cipher.doFinal(data);
}

/**
* 生成密钥
*
* @return byte[] 二进制密
*/
public static byte[] initKey() throws Exception{
/**
* 实例
* 使用128位或192位长度密
* KeyGenerator.getInstance(KEY_ALGORITHM,"BC");
*/
KeyGenerator kg = KeyGenerator.getInstance(KEY_ALGORITHM);
/**
* 初始
*使用128位或192位长度密钥，按如下代码实
*kg.init(128);
*kg.init(192);
*/
kg.init(168);
//生成秘密密钥
SecretKey secretKey = kg.generateKey();
//获得密钥的二进制编码形式
return secretKey.getEncoded();
}

/**
* <p>DES加密文件
* @param file 源文件
* @param destFile 加密后的文件
* @throws Exception
*/
public static void encrypt(byte[] key,String file, String destFile) throws Exception {
Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
//还原密钥
Key k = toKey(key);
cipher.init(Cipher.ENCRYPT_MODE, k);
InputStream is = new FileInputStream(file);
OutputStream out = new FileOutputStream(destFile);
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();
}

/**
* <p> DES解密文件
* @param file 需要解密的文件
* @param dest 解密后的文件
* @throws Exception
*/
public static void decrypt(byte[] key,String file, String dest) throws Exception {
Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
Key k = toKey(key);
cipher.init(Cipher.DECRYPT_MODE, k);
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();
}

/**
*
* @param key 加密私钥
* @param fis 加密的文件输入流(原文件)
* @param out 加密的文件输出流(加密文件文件)
* @throws Exception
*/
public static void encrypt(byte[] key,InputStream fis, OutputStream out) throws Exception {
Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
//还原密钥
Key k = toKey(key);
cipher.init(Cipher.ENCRYPT_MODE, k);
CipherInputStream cis = new CipherInputStream(fis, cipher);
byte[] buffer = new byte[1024];
int r;
while ((r = cis.read(buffer)) > 0) {
out.write(buffer, 0, r);
}
cis.close();
fis.close();
out.close();
}

/**
*
* @param key 加密私钥
* @param fis 加密后的文件输入流(加密后文件)
* @param out 解密的文件输出流(解密后文件)
* @throws Exception
*/
public static void decrypt(byte[] key,FileInputStream fis, OutputStream out) throws Exception {
Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
Key k = toKey(key);
cipher.init(Cipher.DECRYPT_MODE, k);
CipherOutputStream cos = new CipherOutputStream(out, cipher);
byte[] buffer = new byte[1024];
int r;
while ((r = fis.read(buffer)) >= 0) {
cos.write(buffer, 0, r);
}
cos.close();
out.close();
fis.close();
}

public static void main(String[] args) throws Exception {
//    	String key = "DooyI/e/aDRG3PjgwrCYzYCtGQSexNbs";
String key= "MzI5MTQ4NjVhMDE2M2YwOTNkZTQ3ZWM2ZGMyN2JlYzQ=";
//		String key=Base64.encodeBase64String(initKey());
System.out.println(key);
//		System.out.println(key2);
try {
DesUtil.encrypt(key.getBytes(),"D:\\gw.jpg", "D:\\gw1.jpg");
DesUtil.decrypt(key.getBytes(),"D:\\gw1.jpg","D:\\gw2.jpg");
} catch (Exception e) {
e.printStackTrace();
}
}

}

//图片加密
String key=Encodes.decodeBase64String(String.valueOf(CacheUtils.get(CryptUtils.AES_KEY)));
try {
InputStream is = mf.getInputStream();
OutputStream out = new FileOutputStream(tempFilePath);
DesUtil.encrypt(key.getBytes(), is, out);
} catch (Exception e) {
logger.info("图片："+filePath+"加密出错");
e.printStackTrace();
}

@RequestMapping(value = "getImg")
public void getImg(String filePath, HttpServletRequest request, HttpServletResponse response) {
FileInputStream fis = null;
if(filePath.toLowerCase().endsWith(".pdf")){
response.setContentType("application/pdf;charset=UTF-8");
}else{
response.setContentType("application/octet-stream;charset=UTF-8");
}

try {
OutputStream out = response.getOutputStream();
//			filePath="D:\\gw11.jpg";
File file = new File(filePath);
fis = new FileInputStream(file);
//对文件解密
//			String key = "DooyI/e/aDRG3PjgwrCYzYCtGQSexNbs";
String key=Encodes.decodeBase64String(String.valueOf(CacheUtils.get(CryptUtils.AES_KEY)));
DesUtil.decrypt(key.getBytes(),fis,out);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (fis != null) {
try {
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}