public static void crypt(String inFilename, String outFilename, int mode) {
InputStream in = null;
OutputStream out = null;
ObjectInputStream keyin = null;
try {
in = new FileInputStream(inFilename);
out = new FileOutputStream(outFilename);
keyin = new ObjectInputStream(new FileInputStream(keyFilename));
// 获取到密钥
Key key = (Key) keyin.readObject();
// 使用AES算法获取密码对象
Cipher cipher = Cipher.getInstance("AES");
// 通过设置模式和密钥来初始化
cipher.init(mode, key);
// 获取密码块大小，16
int blockSize = cipher.getBlockSize();
// 该密码块对应的输出缓存区大小，用于存放密码对象输出的数据块
int outputSize = cipher.getOutputSize(blockSize);
byte[] inBytes = new byte[blockSize];
byte[] outBytes = new byte[outputSize];
int length = 0;
boolean more = true;
while (more) {
length = in.read(inBytes);
// 如果能读到blockSize大小的块
if (length == blockSize) {
// 数据块存入outBytes
int outLength = cipher.update(inBytes, 0, blockSize, outBytes);
out.write(outBytes, 0, outLength);
} else {
more = false;
}
}
// 如果最后一个输入数据块的字节数小于blockSize，剩下的字节将会自动填充
if (length > 0) {
outBytes = cipher.doFinal(inBytes, 0, length);
} else {
outBytes = cipher.doFinal();
}
out.write(outBytes);
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (GeneralSecurityException e) {
e.printStackTrace();
} finally {
Closer.close(in);
Closer.close(out);
Closer.close(keyin);
}
}
public static void generateKey(String filename) {
ObjectOutputStream out = null;
try {
// 使用AES算法获取密钥的 KeyGenerator对象
KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");
// 用随机源初始化密钥发生器
SecureRandom random = new SecureRandom();
keyGenerator.init(random);
// 生成一个密钥
SecretKey key = keyGenerator.generateKey();
// 把密钥输出到文件
out = new ObjectOutputStream(new FileOutputStream(filename));
out.writeObject(key);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
Closer.close(out);
}
}