AES对称加密实例

Posted 2021-05-22 DataRain

这是一个AES对称加密的实例，主要是用于对文字或者文件进行加密，这个实例不需要引入其他包，只需要使用JDK提供的方法就可以实现对称加解密的功能。记录这个主要是因为有的示例中会使用bcprov-jdk15on这个包中所提供的Provider算法，即引入以下类型包：

<dependency> <groupId>org.bouncycastle</groupId> <artifactId>bcprov-jdk15on</artifactId> <version>1.51</version></dependency>

例如使用这个包里面的算法示例为：

Cipher cipher = Cipher.getInstance(ALGORITHMS , new org.bouncycastle.jce.provider.BouncyCastleProvider());

我在使用这个包里面的算法时候曾经遇到过一种问题，初步估计是由于JDK的版本问题，会引起下面的异常：

java.lang.SecurityException: JCE cannot authenticate the provider BC         at javax.crypto.Cipher.getInstance(Cipher.java:657)

因此为了避免不必要的问题，在简单使用AES加密方法的情况下，不需要采用这个包中的加解密算法，直接使用JDK中的方法即可。

/** * AES加、解密算法工具类 */public class AESUtil {
 /** * 加密算法AES */ private static final String KEY_ALGORITHM = "AES";
 /** * key size: must be equal to 128, 192 or 256 */ private static final Integer KEY_LENGTH = 128;
 /** * 算法名称/加密模式/数据填充方式 */ private static final String ALGORITHMS = "AES/ECB/PKCS5Padding";
 /** * 默认加解密码 */    public static final String DEFAULT_ENCRYPT_PASSWORD = "pass_word";
 private AESUtil() { }
 /** * 加密 * * @param content 加密的字符串 * @param encryptKey key值 */ public static String encrypt(String content, String encryptKey) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { Cipher cipher = Cipher.getInstance(ALGORITHMS); cipher.init(Cipher.ENCRYPT_MODE, generateKey(encryptKey)); byte[] b = cipher.doFinal(content.getBytes(StandardCharsets.UTF_8)); return Base64.encodeBase64String(b); }
 /** * 加密文件 * * @param inFilePath 需要加密的文件路径 * @param outFilePath 加密文件输出路径 * @param encryptKey 加密密钥 * @throws java.io.IOException * @throws javax.crypto.NoSuchPaddingException * @throws java.security.NoSuchAlgorithmException * @throws java.security.InvalidKeyException */ public static void encryptFileToFile(String inFilePath, String outFilePath, String encryptKey) throws IOException, NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException { Cipher cipher = Cipher.getInstance(ALGORITHMS); cipher.init(Cipher.ENCRYPT_MODE, generateKey(encryptKey)); try (InputStream inputStream = new FileInputStream(new File(inFilePath)); InputStream cipherInputStream = new CipherInputStream(inputStream, cipher); OutputStream outputStream = new FileOutputStream(new File(outFilePath))) { int isRead; byte[] cache = new byte[1024]; while ((isRead = cipherInputStream.read(cache, 0, cache.length)) != -1) { outputStream.write(cache, 0, isRead); } } }
 /** * 解密文件 * * @param inFilePath 需要解密的文件路径 * @param encryptKey 解密密钥 * @return 解密后的文件输出流 * @throws NoSuchPaddingException * @throws NoSuchAlgorithmException * @throws InvalidKeyException * @throws IOException */ public static ByteArrayOutputStream decryptFileToStream(String inFilePath, String encryptKey) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, IOException { Cipher cipher = Cipher.getInstance(ALGORITHMS); cipher.init(Cipher.DECRYPT_MODE, generateKey(encryptKey)); try (InputStream inputStream = new FileInputStream(new File(inFilePath)); ByteArrayOutputStream outputStream = new ByteArrayOutputStream(); CipherOutputStream cipherOutputStream = new CipherOutputStream(outputStream, cipher)) { int isRead; byte[] cache = new byte[1024]; while ((isRead = inputStream.read(cache, 0, cache.length)) != -1) { cipherOutputStream.write(cache, 0, isRead); } return outputStream; } }
 /** * 解密 * * @param encryptStr 解密的字符串 * @param decryptKey 解密的key值 */ public static String decrypt(String encryptStr, String decryptKey) throws NoSuchPaddingException, NoSuchAlgorithmException, BadPaddingException, IllegalBlockSizeException, InvalidKeyException { byte[] decodeBase64 = Base64.decodeBase64(encryptStr); Cipher cipher = Cipher.getInstance(ALGORITHMS); cipher.init(Cipher.DECRYPT_MODE, generateKey(decryptKey)); byte[] decryptBytes = cipher.doFinal(decodeBase64); return new String(decryptBytes); }
 /** * create the secret key with the password * * @param password user define password * @return the secret key object * @throws java.security.NoSuchAlgorithmException */ private static SecretKey generateKey(String password) throws NoSuchAlgorithmException { SecureRandom random = SecureRandom.getInstance("SHA1PRNG"); random.setSeed(password.getBytes(StandardCharsets.UTF_8)); KeyGenerator gen = KeyGenerator.getInstance(KEY_ALGORITHM); gen.init(KEY_LENGTH, random); return gen.generateKey(); }
}