Java中如何实现AES+Base64加解密

发布时间: 2020-07-09

问题

人人都说Java好，要学Java得趁早。 我年近三十才痛悟要学Java，希望能有所得。

因为一些原因，我们需要在客户端到服务端的消息体中针对某个字段加密。

这里有一个AES Encryption and Decryption Online Tool(Calculator)。

折腾了一番终于搞定。有一个坑是需要将密文中的-和_替换一下才能正常解密：

    return new String(cipher.doFinal(Base64.getDecoder().decode(strToDecrypt.replace('-', '+').replace('_', '/'))));

解答

Base64+AES解密类：

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.util.Arrays;
import java.util.Base64;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

public class AES {

    private static SecretKeySpec secretKey;
    private static byte[] key;

    public static void setKey(String myKey)
    {
        MessageDigest sha = null;
        try {
            key = myKey.getBytes("UTF-8");
            key = Arrays.copyOf(key, 16);
            secretKey = new SecretKeySpec(key, "AES");
        }
        catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
    }

    public static String encrypt(String strToEncrypt, String secret)
    {
        try
        {
            setKey(secret);
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
            cipher.init(Cipher.ENCRYPT_MODE, secretKey);
            return Base64.getEncoder().encodeToString(cipher.doFinal(strToEncrypt.getBytes("UTF-8")));
        }
        catch (Exception e)
        {
            System.out.println("Error while encrypting: " + e.toString());
        }
        return null;
    }

    public static String decrypt(String strToDecrypt, String secret)
    {
        try
        {
            setKey(secret);
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
            cipher.init(Cipher.DECRYPT_MODE, secretKey);
            return new String(cipher.doFinal(Base64.getDecoder().decode(strToDecrypt.replace('-', '+').replace('_', '/'))));
        }
        catch (Exception e)
        {
            System.out.println("Error while decrypting: " + e.toString());
            e.printStackTrace();
        }
        return null;
    }
}

如何用起来：

import helpers.AES

object AesTest {
  def main(args: Array[String]): Unit = {

    val secretKey = "1234567890123456"
    val originalString = "52da75d04e948704"
    val encryptedString = "A5qtKZ3nJRRgMS2Yc2oVYppNJTIDuJfra6lBf_pQIpY"

    val decryptedString: String = AES.decrypt(encryptedString, secretKey)

    println(originalString)
    println(decryptedString)

  }
}