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Java AES文件加解密

Posted on 2012-05-19 13:43 IceWee 阅读(11829) 评论(2)  编辑  收藏 所属分类: Java加解密
之前写了DES加解密,AES几乎与之相同,不同的是底层key的位数而已,不过这些对于我们使用者都是透明的。

AESUtils.java
package demo.security;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
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;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

/**
 * <p>
 * AES加密解密工具包
 * </p>
 * 
 * 
@author IceWee
 * @date 2012-5-18
 * 
@version 1.0
 
*/

public class AESUtils {

    
private static final String ALGORITHM = "AES";
    
private static final int KEY_SIZE = 128;
    
private static final int CACHE_SIZE = 1024;
    
    
/**
     * <p>
     * 生成随机密钥
     * </p>
     * 
     * 
@return
     * 
@throws Exception
     
*/

    
public static String getSecretKey() throws Exception {
        
return getSecretKey(null);
    }

    
    
/**
     * <p>
     * 生成密钥
     * </p>
     * 
     * 
@param seed 密钥种子
     * 
@return
     * 
@throws Exception
     
*/

    
public static String getSecretKey(String seed) throws Exception {
        KeyGenerator keyGenerator 
= KeyGenerator.getInstance(ALGORITHM);
        SecureRandom secureRandom;
        
if (seed != null && !"".equals(seed)) {
            secureRandom 
= new SecureRandom(seed.getBytes());
        }
 else {
            secureRandom 
= new SecureRandom();
        }

        keyGenerator.init(KEY_SIZE, secureRandom); 
        SecretKey secretKey 
= keyGenerator.generateKey(); 
        
return Base64Utils.encode(secretKey.getEncoded());
    }

    
    
/**
     * <p>
     * 加密
     * </p>
     * 
     * 
@param data
     * 
@param key
     * 
@return
     * 
@throws Exception
     
*/

    
public static byte[] encrypt(byte[] data, String key) throws Exception {
        Key k 
= toKey(Base64Utils.decode(key));
        
byte[] raw = k.getEncoded(); 
        SecretKeySpec secretKeySpec 
= new SecretKeySpec(raw, ALGORITHM); 
        Cipher cipher 
= Cipher.getInstance(ALGORITHM); 
        cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec);
        
return cipher.doFinal(data);
    }

    
    
/**
     * <p>
     * 文件加密
     * </p>
     * 
     * 
@param key
     * 
@param sourceFilePath
     * 
@param destFilePath
     * 
@throws Exception
     
*/

    
public static void encryptFile(String key, String sourceFilePath, String destFilePath) throws Exception {
        File sourceFile 
= new File(sourceFilePath);
        File destFile 
= new File(destFilePath); 
        
if (sourceFile.exists() && sourceFile.isFile()) {
            
if (!destFile.getParentFile().exists()) {
                destFile.getParentFile().mkdirs();
            }

            destFile.createNewFile();
            InputStream in 
= new FileInputStream(sourceFile);
            OutputStream out 
= new FileOutputStream(destFile);
            Key k 
= toKey(Base64Utils.decode(key));
            
byte[] raw = k.getEncoded(); 
            SecretKeySpec secretKeySpec 
= new SecretKeySpec(raw, ALGORITHM); 
            Cipher cipher 
= Cipher.getInstance(ALGORITHM); 
            cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec);
            CipherInputStream cin 
= new CipherInputStream(in, cipher);
            
byte[] cache = new byte[CACHE_SIZE];
            
int nRead = 0;
            
while ((nRead = cin.read(cache)) != -1{
                out.write(cache, 
0, nRead);
                out.flush();
            }

            out.close();
            cin.close();
            in.close();
        }

    }

    
    
/**
     * <p>
     * 解密
     * </p>
     * 
     * 
@param data
     * 
@param key
     * 
@return
     * 
@throws Exception
     
*/

    
public static byte[] decrypt(byte[] data, String key) throws Exception {
        Key k 
= toKey(Base64Utils.decode(key));
        
byte[] raw = k.getEncoded(); 
        SecretKeySpec secretKeySpec 
= new SecretKeySpec(raw, ALGORITHM); 
        Cipher cipher 
= Cipher.getInstance(ALGORITHM); 
        cipher.init(Cipher.DECRYPT_MODE, secretKeySpec);
        
return cipher.doFinal(data);
    }

    
    
/**
     * <p>
     * 文件解密
     * </p>
     * 
     * 
@param key
     * 
@param sourceFilePath
     * 
@param destFilePath
     * 
@throws Exception
     
*/

    
public static void decryptFile(String key, String sourceFilePath, String destFilePath) throws Exception {
        File sourceFile 
= new File(sourceFilePath);
        File destFile 
= new File(destFilePath); 
        
if (sourceFile.exists() && sourceFile.isFile()) {
            
if (!destFile.getParentFile().exists()) {
                destFile.getParentFile().mkdirs();
            }

            destFile.createNewFile();
            FileInputStream in 
= new FileInputStream(sourceFile);
            FileOutputStream out 
= new FileOutputStream(destFile);
            Key k 
= toKey(Base64Utils.decode(key));
            
byte[] raw = k.getEncoded(); 
            SecretKeySpec secretKeySpec 
= new SecretKeySpec(raw, ALGORITHM); 
            Cipher cipher 
= Cipher.getInstance(ALGORITHM); 
            cipher.init(Cipher.DECRYPT_MODE, secretKeySpec);
            CipherOutputStream cout 
= new CipherOutputStream(out, cipher);
            
byte[] cache = new byte[CACHE_SIZE];
            
int nRead = 0;
            
while ((nRead = in.read(cache)) != -1{
                cout.write(cache, 
0, nRead);
                cout.flush();
            }

            cout.close();
            out.close();
            in.close();
        }

    }

    
    
/**
     * <p>
     * 转换密钥
     * </p>
     * 
     * 
@param key
     * 
@return
     * 
@throws Exception
     
*/

    
private static Key toKey(byte[] key) throws Exception {
        SecretKey secretKey 
= new SecretKeySpec(key, ALGORITHM);
        
return secretKey;
    }

    
}



Base64Utils.java(依赖javabase64-1.3.1.jar)
package demo.security;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;

import it.sauronsoftware.base64.Base64;

/**
* <p>
* BASE64编码解码工具包
* </p>
* <p>
* 依赖javabase64-1.3.1.jar
* </p>
*
*
@author IceWee
* @date 2012-5-19
*
@version 1.0
*/

public class Base64Utils {

   
/**
     * 文件读取缓冲区大小
    
*/

   
private static final int CACHE_SIZE = 1024;
   
   
/**
     * <p>
     * BASE64字符串解码为二进制数据
     * </p>
     *
     *
@param base64
     *
@return
     *
@throws Exception
    
*/

   
public static byte[] decode(String base64) throws Exception {
       
return Base64.decode(base64.getBytes());
    }

   
   
/**
     * <p>
     * 二进制数据编码为BASE64字符串
     * </p>
     *
     *
@param bytes
     *
@return
     *
@throws Exception
    
*/

   
public static String encode(byte[] bytes) throws Exception {
       
return new String(Base64.encode(bytes));
    }

   
   
/**
     * <p>
     * 将文件编码为BASE64字符串
     * </p>
     * <p>
     * 大文件慎用,可能会导致内存溢出
     * </p>
     *
     *
@param filePath 文件绝对路径
     *
@return
     *
@throws Exception
    
*/

   
public static String encodeFile(String filePath) throws Exception {
       
byte[] bytes = fileToByte(filePath);
       
return encode(bytes);
    }

   
   
/**
     * <p>
     * BASE64字符串转回文件
     * </p>
     *
     *
@param filePath 文件绝对路径
     *
@param base64 编码字符串
     *
@throws Exception
    
*/

   
public static void decodeToFile(String filePath, String base64) throws Exception {
       
byte[] bytes = decode(base64);
        byteArrayToFile(bytes, filePath);
    }

   
   
/**
     * <p>
     * 文件转换为二进制数组
     * </p>
     *
     *
@param filePath 文件路径
     *
@return
     *
@throws Exception
    
*/

   
public static byte[] fileToByte(String filePath) throws Exception {
       
byte[] data = new byte[0];
        File file
= new File(filePath);
       
if (file.exists()) {
            FileInputStream in
= new FileInputStream(file);
            ByteArrayOutputStream out
= new ByteArrayOutputStream(2048);
           
byte[] cache = new byte[CACHE_SIZE];
           
int nRead = 0;
           
while ((nRead = in.read(cache)) != -1) {
                out.write(cache,
0, nRead);
                out.flush();
            }

            out.close();
            in.close();
            data
= out.toByteArray();
         }

       
return data;
    }

   
   
/**
     * <p>
     * 二进制数据写文件
     * </p>
     *
     *
@param bytes 二进制数据
     *
@param filePath 文件生成目录
    
*/

   
public static void byteArrayToFile(byte[] bytes, String filePath) throws Exception {
        InputStream in
= new ByteArrayInputStream(bytes);  
        File destFile
= new File(filePath);
       
if (!destFile.getParentFile().exists()) {
            destFile.getParentFile().mkdirs();
        }

        destFile.createNewFile();
        OutputStream out
= new FileOutputStream(destFile);
       
byte[] cache = new byte[CACHE_SIZE];
       
int nRead = 0;
       
while ((nRead = in.read(cache)) != -1) {  
            out.write(cache,
0, nRead);
            out.flush();
        }

        out.close();
        in.close();
    }

   
   
}



AESTester.java
package demo.security;

public class AESTester {
   
   
static String key;
   
   
static {
       
try {
key
= AESUtils.getSecretKey();
        }
catch (Exception e) {
            e.printStackTrace();
        }

    }


   
public static void main(String[] args) throws Exception {
       
long begin = System.currentTimeMillis();
        encryptFile();
        decryptFile();
        test();
       
long end = System.currentTimeMillis();
        System.err.println(
"耗时:" + (end-begin)/1000 + "");
    }

   
   
static void encryptFile() throws Exception {
        String sourceFilePath
= "D:/demo.mp4";
        String destFilePath
= "D:/demo_encrypted.mp4";
        AESUtils.encryptFile(key, sourceFilePath, destFilePath);
    }

   
   
static void decryptFile() throws Exception {
        String sourceFilePath
= "D:/demo_encrypted.mp4";
        String destFilePath
= "D:/demo_decrypted.mp4";
        AESUtils.decryptFile(key, sourceFilePath, destFilePath);
    }

   
   
static void test() throws Exception {
        String source
= "这是一行测试DES加密/解密的文字,你看完也等于没看,是不是啊?!";
        System.err.println(
"原文:\t" + source);
       
byte[] inputData = source.getBytes();
        inputData
= AESUtils.encrypt(inputData, key);
        System.err.println(
"加密后:\t" + Base64Utils.encode(inputData));
       
byte[] outputData = AESUtils.decrypt(inputData, key);
        String outputStr
= new String(outputData);
        System.err.println(
"解密后:\t" + outputStr);
    }


}

Feedback

# re: Java AES文件加解密[未登录]  回复  更多评论   

2015-07-14 16:49 by xxx
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2015-10-10 14:30 by duhai
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