java实现AES加密解密--文件加解密
原文地址：http://www.blogjava.net/icewee/archive/2012/05/19/378556.html
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;
/**
*
* AES加密解密工具包
*
*
* @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;
/**
*
* 生成随机密钥
*
*
* @return
* @throws Exception
*/
public static String getSecretKey() throws Exception {
return getSecretKey(null);
}
/**
*
* 生成密钥
*
*
* @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());
}
/**
*
* 加密
*
*
* @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);
}
/**
*
* 文件加密
*
*
* @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();
}
}
/**
*
* 解密
*
*
* @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);
}
/**
*
* 文件解密
*
*
* @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();
}
}
/**
*
* 转换密钥
*
*
* @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;
/**
*
* BASE64编码解码工具包
*
*
* 依赖javabase64-1.3.1.jar
*
*
* @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;
/**
*
* BASE64字符串解码为二进制数据
*
*
* @param base64
* @return
* @throws Exception
*/
public static byte[] decode(String base64) throws Exception {
return Base64.decode(base64.getBytes());
}
/**
*
* 二进制数据编码为BASE64字符串
*
*
* @param bytes
* @return
* @throws Exception
*/
public static String encode(byte[] bytes) throws Exception {
return new String(Base64.encode(bytes));
}
/**
*
* 将文件编码为BASE64字符串
*
*
* 大文件慎用，可能会导致内存溢出
*
*
* @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);
}
/**
*
* BASE64字符串转回文件
*
*
* @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);
}
/**
*
* 文件转换为二进制数组
*
*
* @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;
}
/**
*
* 二进制数据写文件
*
*
* @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 + "秒");
}
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);
}
}