JAVA AES CBC 加密 解密

AES 256 , KEY 的长度为 32字节（32*8=256bit）.

AES 128 , KEY 的长度为 16字节（16*8=128bit）

 

CBC 模式需要IV， IV的值是固定写死，还是当参数传入，自己看情况。IV的长度没研究，这里用的是16字符。

java PKCS5Padding 对应 C#.NET 的 PKCS7 。

明文，KEY和IV 三者 string 转 byte[] 时要统一编码，如UTF-8。

加密后 cipher.doFinal() 得到密文byte[] ，是直接转string,还是转为base64编码的string ，要统一。

 

Base64Utils :

package com.company;

import org.apache.commons.codec.binary.Base64;

public class Base64Utils {

    public static final String _charset = "UTF-8";


    /**
     * BASE64字符串解码为二进制数据
     * @param str
     * @return
     * @throws Exception
     */
    public static byte[] decode(String str) throws Exception {
        Base64 _base64 = new Base64();
        return _base64.decodeBase64(str.getBytes(_charset));
    }


    /**
     * 二进制数据编码为BASE64字符串
     * @param bytes
     * @return
     * @throws Exception
     */
    public static String encode(byte[] bytes) throws Exception {
        Base64 _base64 = new Base64();
        return new String(_base64.encodeBase64Chunked(bytes));
    }

}

 

AesUtil:

package com.company;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;


/**
 * AES CBC PKCS5 模式加密解密
 */
public class AesUtil {

    private static final String charset = "UTF-8";

    /**
     * 加密
     * @param content
     * @param key
     * @param iv
     * @return
     * @throws Exception
     */
    public static String encrypt(String content, String key, String iv)
            throws Exception {

        //明文
        byte[] contentBytes = content.getBytes(charset);

        //AES KEY
        byte[] keyBytes = key.getBytes(charset);
        SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "AES");

        //AES IV
        byte[] initParam = iv.getBytes(charset);
        IvParameterSpec ivParameterSpec = new IvParameterSpec(initParam);

        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivParameterSpec);
        byte[] byEnd = cipher.doFinal(contentBytes);

        //加密后的byte数组转BASE64字符串
        String strEnd = Base64Utils.encode(byEnd);
        return strEnd;
    }

    /**
     * 解密
     * @param content
     * @param key
     * @param iv
     * @return
     * @throws Exception
     */
    public static String decrypt(String content, String key, String iv)
            throws Exception {
        //反向解析BASE64字符串为byte数组
        byte[] encryptedBytes = Base64Utils.decode(content);

        //AES KEY
        byte[] keyBytes = key.getBytes(charset);
        SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "AES");

        //AES IV
        byte[] initParam = iv.getBytes(charset);
        IvParameterSpec ivParameterSpec = new IvParameterSpec(initParam);

        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        cipher.init(Cipher.DECRYPT_MODE, keySpec, ivParameterSpec);
        byte[] byEnd = cipher.doFinal(encryptedBytes);

        //加密后的byte数组直接转字符串
        String strEnd = new String(byEnd, charset);
        return strEnd;
    }

}

 

 

 

 

AesUtil:base 64 编码引用了 org.apache.commons.codec.binary.Base64，可以从网上下载。http://commons.apache.org/proper/commons-codec/download_codec.cgi

名字：commons-codec-1.12.jar

--

 

测试代码 main:

 

package com.company;


public class Main {

    private static final String IV_STRING = "abcdefghABCDEFGH";

    public static void main(String[] args) {

        try {

            String cc = "中华 HELLO~！@#￥%……&*（）——+1";
            System.out.println("明文：\r\n" + cc);

            System.out.println("AES 256 -------：\r\n");
            String aesKey = "12345678901234567890123456789012";

            String aa = AesUtil.encrypt(cc, aesKey, IV_STRING);
            System.out.println("密文：\r\n" + aa);
            String dd = AesUtil.decrypt(aa, aesKey, IV_STRING);
            System.out.println("解密后明文：\r\n" + dd);


        } catch (Exception ex) {

            System.out.println("ex：\r\n" + ex.getMessage());
        }
    }
}

 

 

 

end