Java AES文件加解密

jopen 12年前發布 | 74K 次閱讀 Java Java開發
之前寫了DES加解密，AES幾乎與之相同，不同的是底層key的位數而已，不過這些對于我們使用者都是透明的。

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>
生成隨機密鑰
</p>

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

<p>
生成密鑰
</p>

@param seed 密鑰種子
@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>
轉換密鑰
</p>

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



}</pre></span>Base64Utils.java（依賴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編碼解碼工具包
</p>
<p>
依賴javabase64-1.3.1.jar
</p>

@author IceWee
@date 2012-5-19
@version 1.0
*/
public class Base64Utils {
/**

文件讀取緩沖區大小
*/
private static final int CACHE_SIZE = 1024;
/**

<p>
BASE64字符串解碼為二進制數據
</p>

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

<p>
二進制數據編碼為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>
將文件編碼為BASE64字符串
</p>
<p>
大文件慎用，可能會導致內存溢出
</p>

@param filePath 文件絕對路徑
@return
@throws Exception
*/
public static String encodeFile(String filePath) throws Exception {
 byte[] bytes = fileToByte(filePath);
 return encode(bytes);
}
/**

<p>
BASE64字符串轉回文件
</p>

@param filePath 文件絕對路徑
@param base64 編碼字符串
@throws Exception
*/
public static void decodeToFile(String filePath, String base64) throws Exception {
 byte[] bytes = decode(base64);
 byteArrayToFile(bytes, filePath);
}
/**

<p>
文件轉換為二進制數組
</p>

@param filePath 文件路徑
@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>
二進制數據寫文件
</p>

@param bytes 二進制數據
@param filePath 文件生成目錄
*/
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();
}



}</pre>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("耗時：" + (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 = "這是一行測試DES加密/解密的文字，你看完也等于沒看，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);
}


}</pre>轉自：http://www.blogjava.net/icewee/archive/2012/05/19/378556.html
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Java Java開發
Java AES文件加解密

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