AES加密解密

 

 1、生成秘钥

private static SecretKeySpec getKey(String key) {
        //指定秘钥生成算法
        byte[] arrBTmp = key.getBytes();
        // 创建一个空的16位字节数组（默认值为0）
        //TODO 秘钥只能是16位或32位，有待处理
        byte[] arrB = new byte[16];
        for (int i = 0; i < arrBTmp.length && i < arrB.length; i++) {
            arrB[i] = arrBTmp[i];
        }
        SecretKeySpec secretKey = new SecretKeySpec(arrB, "AES");
        return secretKey;
    }

 2、加密

private static String encrypt(String content , SecretKeySpec secretKey) {
        try {
            //实例化密码器AES算法
            Cipher cipher = Cipher.getInstance("AES");
            //初始化密码器类型-加密类型
            cipher.init(Cipher.ENCRYPT_MODE, secretKey);
            //明文字节长度 length/16=n，如果不是整除的 n=n+1
            byte [] byte_encode = content.getBytes("utf-8");
            //密文字节长度是16*n
            byte [] byte_aes = cipher.doFinal(byte_encode);
            //密文字节数组转字符串
            String aes_encode = new BASE64Encoder().encode(byte_aes);
            return aes_encode;
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        }
        return null;
    }

 3、解密

private static String decrypt(String encryptText,SecretKeySpec secretKey) {
        try {
            //实例化密码器AES算法
            Cipher cipher=Cipher.getInstance("AES");
            //初始化密码器类型-解密类型
            cipher.init(Cipher.DECRYPT_MODE,secretKey);
            //密文转字节数组
            byte[] byte_decode = new BASE64Decoder().decodeBuffer(encryptText);
            //解密
            byte[] byte_aes = cipher.doFinal(byte_decode);
            //还原明文字符串
            String plainText = new String(byte_aes,"utf-8");
            return plainText;
        } catch (IOException e) {
            e.printStackTrace();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        }
        return null;
    }