Java版AES加密/解密工具，含微信平台(小程序/开放平台)加密数据解密
在信息安全越来越重要的今天，数据加密尤其为重要，在密码学中常见的加密算法有对称加密（AES、DES、SM4）、非对称加密（RSA、SM2）、信息摘要算法（严格来说信息摘要算法不属于加解密算法，主要有md5、sha1、SHA-256、sha3、sm3）等，其中数据对称加密用的比较广泛的是AES，非对称加密用的比较广泛的是RSA，万恶的勒索病毒的加密算法就是AES+RSA。
最近在弄微信小程序，其中就有隐私数据的解密，就牵涉到AES，故而整理了下，特记之。
AESUtils类如下：
package utils;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.security.AlgorithmParameters;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.Security;
import java.util.Arrays;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.codec.binary.Base64;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
/**
* AES加密/解密工具，含微信平台(小程序/开放平台)加密数据解密
* @author hlinfo.net
* @Remarks 微信平台(小程序/开放平台)加密数据解密依赖org.bouncycastle:bcprov-jdk16及commons-codec:commons-codec
* @Example
*
* //微信平台(小程序/开放平台)加密数据解密
* String encryptedData = "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";
* String sessionKey = "tiihtNczf5v6AKRyjwEUhQ==";
* String iv = "r7BXXKkLb8qrSNn05n0qiA==";
* System.out.println("微信数据解密："+AESUtils.wxDecrypt(encryptedData, sessionKey, iv));
* //普通 加密/解密
* String key = getKey();
* System.out.println("密钥:"+key);
* String encData = encrypt("Hello Word", key);
* System.out.println("加密密文:"+encData);
* System.out.println("解密原文："+decrypt(encData, key));
*
*/
public class AESUtils {
//CipherMode：算法/模式/填充
private static final String CipherMode = "AES/ECB/PKCS5Padding";
//CipherModeForWX：算法/模式/填充 微信平台要求算法为：AES-128-CBC，数据采用PKCS#7填充
private static final String CipherModeForWX = "AES/CBC/PKCS7Padding";
//密钥长度 可以是128、256等
private static final int keysize = 128;
//是否导入provider
public static boolean initialized = true;
private static final Charset CHARSET = Charset.forName("utf-8");
//填充的位数
private static final int BLOCK_SIZE = 32;
/**
* 导入provider
*/
public static boolean initialize() {
if (!initialized) {return false;}
Security.addProvider(new BouncyCastleProvider());
initialized = true;
return initialized;
}
/**
* 生成一个AES密钥对象
* @return
*/
public static SecretKeySpec generateKey(){
try {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
kgen.init(keysize, new SecureRandom());
SecretKey secretKey = kgen.generateKey();
byte[] enCodeFormat = secretKey.getEncoded();
SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
return key;
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
return null;
}
/**
* 生成一个AES密钥字符串
* @return
*/
public static String generateKeyString(){
return byte2hex(generateKey().getEncoded());
}
/**
* 加密字节数据
* @param content
* @param key
* @return
*/
public static byte[] encrypt(byte[] content,byte[] key) {
try {
Cipher cipher = Cipher.getInstance(CipherMode);
cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key, "AES"));
byte[] result = cipher.doFinal(content);
return result;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 通过byte[]类型的密钥加密String
* @param content
* @param key
* @return 16进制密文字符串
*/
public static String encrypt(String content,byte[] key) {
try {
Cipher cipher = Cipher.getInstance(CipherMode);
cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key, "AES"));
byte[] data = cipher.doFinal(content.getBytes("UTF-8"));
String result = byte2hex(data);
return result;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 通过String类型的密钥加密String
* @param content
* @param key
* @return 16进制密文字符串
*/
public static String encrypt(String content,String key) {
byte[] data = null;
try {
data = content.getBytes("UTF-8");
} catch (Exception e) {
e.printStackTrace();
}
data = encrypt(data,new SecretKeySpec(hex2byte(key), "AES").getEncoded());
String result = byte2hex(data);
return result;
}
/**
* 通过byte[]类型的密钥解密byte[]
* @param content
* @param key
* @return
*/
public static byte[] decrypt(byte[] content,byte[] key) {
try {
Cipher cipher = Cipher.getInstance(CipherMode);
cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(key, "AES"));
byte[] result = cipher.doFinal(content);
return result;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
// 生成iv
public static AlgorithmParameters generateIV(byte[] iv) throws Exception {
AlgorithmParameters params = AlgorithmParameters.getInstance("AES");
params.init(new IvParameterSpec(iv));
return params;
}
/**
* 通过String类型的密钥 解密String类型的密文
* @param content
* @param key
* @return
*/
public static String decrypt(String content, String key) {
byte[] data = null;
try {
data = hex2byte(content);
} catch (Exception e) {
e.printStackTrace();
}
data = decrypt(data, hex2byte(key));
if (data == null)
return null;
String result = null;
try {
result = new String(data, "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return result;
}
/**
* 通过byte[]类型的密钥解密byte[]，主要用于微信平台(小程序/开放平台)数据解密
* @param content
* @param key
* @return
*/
public static byte[] wxDecrypt(byte[] content,byte[] key,byte[] iv) {
initialize();
try {
Cipher cipher = Cipher.getInstance(CipherModeForWX);
cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(key, "AES"), generateIV(iv));// 初始化
byte[] result = cipher.doFinal(content);
return result;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 微信平台(小程序/开放平台)数据解密
* @param content
* @param sessionKey
* @param iv
* @return
*/
public static String wxDecrypt(String content, String sessionKey,String iv) {
String result = "";
try {
byte[] resultByte = wxDecrypt(Base64.decodeBase64(content), Base64.decodeBase64(sessionKey), Base64.decodeBase64(iv));
if(null != resultByte && resultByte.length > 0){
result = new String(PKCS7Decode(resultByte));
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return result;
}
/**
* 通过byte[]类型的密钥 解密String类型的密文
* @param content
* @param key
* @return
*/
public static String decrypt(String content,byte[] key) {
try {
Cipher cipher = Cipher.getInstance(CipherMode);
cipher.init(Cipher.DECRYPT_MODE,new SecretKeySpec(key, "AES"));
byte[] data = cipher.doFinal(hex2byte(content));
return new String(data, "UTF-8");
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 字节数组转成16进制字符串
* @param b
* @return
*/
public static String byte2hex(byte[] b) { // 一个字节的数，
StringBuffer sb = new StringBuffer(b.length * 2);
String tmp;
for (int n = 0; n < b.length; n++) {
// 整数转成十六进制表示
tmp = (Integer.toHexString(b[n] & 0XFF));
if (tmp.length() == 1) {
sb.append("0");
}
sb.append(tmp);
}
return sb.toString().toUpperCase(); // 转成大写
}
/**
* byte数组转化为16进制字符串
*
* @param bytes
* @return
*/
private static String byteToHexString(byte[] bytes) {
StringBuffer sb = new StringBuffer();
for (int i = 0; i < bytes.length; i++) {
String strHex = Integer.toHexString(bytes[i]);
if (strHex.length() > 3) {
sb.append(strHex.substring(6));
} else {
if (strHex.length() < 2) {
sb.append("0" + strHex);
} else {
sb.append(strHex);
}
}
}
return sb.toString();
}
/**
* 将hex字符串转换成字节数组
* @param inputString
* @return
*/
private static byte[] hex2byte(String inputString) {
if (inputString == null || inputString.length() < 2) {
return new byte[0];
}
inputString = inputString.toLowerCase();
int l = inputString.length() / 2;
byte[] result = new byte[l];
for (int i = 0; i < l; ++i) {
String tmp = inputString.substring(2 * i, 2 * i + 2);
result[i] = (byte) (Integer.parseInt(tmp, 16) & 0xFF);
}
return result;
}
/****
* 获取对称加密随机生成的秘钥串
*
* @return
*/
public static String getKey() {
try {
KeyGenerator kg = KeyGenerator.getInstance("AES");
kg.init(keysize);
SecretKey sk = kg.generateKey();
byte[] b = sk.getEncoded();
String s = byteToHexString(b);
return s;
}
catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* 获得对明文进行补位填充的字节.
*
* @param count 需要进行填充补位操作的明文字节个数
* @return 补齐用的字节数组
*/
public static byte[] PKCS7Encode(int count) {
// 计算需要填充的位数
int amountToPad = BLOCK_SIZE - (count % BLOCK_SIZE);
if (amountToPad == 0) {
amountToPad = BLOCK_SIZE;
}
// 获得补位所用的字符
char padChr = PKCS7Chr(amountToPad);
String tmp = new String();
for (int index = 0; index < amountToPad; index++) {
tmp += padChr;
}
return tmp.getBytes(CHARSET);
}
/**
* 删除解密后明文的补位字符
*
* @param decrypted
* 解密后的明文
* @return 删除补位字符后的明文
*/
public static byte[] PKCS7Decode(byte[] decrypted) {
int pad = decrypted[decrypted.length - 1];
if (pad < 1 || pad > 32) {
pad = 0;
}
return Arrays.copyOfRange(decrypted, 0, decrypted.length - pad);
}
/**
* 将数字转化成ASCII码对应的字符，用于对明文进行补码
*
* @param a
* 需要转化的数字
* @return 转化得到的字符
*/
public static char PKCS7Chr(int a) {
byte target = (byte) (a & 0xFF);
return (char) target;
}
}
示例：
public static void main(String[] args) {
//微信平台(小程序/开放平台)加密数据解密
String encryptedData = "CiyLU1Aw2KjvrjMdj8YKliAjtP4gsMZMQmRzooG2xrDcvSnxIMXFufNstNGTyaGS9uT5geRa0W4oTOb1WT7fJlAC+oNPdbB+3hVbJSRgv+4lGOETKUQz6OYStslQ142dNCuabNPGBzlooOmB231qMM85d2/fV6ChevvXvQP8Hkue1poOFtnEtpyxVLW1zAo6/1Xx1COxFvrc2d7UL/lmHInNlxuacJXwu0fjpXfz/YqYzBIBzD6WUfTIF9GRHpOn/Hz7saL8xz+W//FRAUid1OksQaQx4CMs8LOddcQhULW4ucetDf96JcR3g0gfRK4PC7E/r7Z6xNrXd2UIeorGj5Ef7b1pJAYB6Y5anaHqZ9J6nKEBvB4DnNLIVWSgARns/8wR2SiRS7MNACwTyrGvt9ts8p12PKFdlqYTopNHR1Vf7XjfhQlVsAJdNiKdYmYVoKlaRv85IfVunYzO0IKXsyl7JCUjCpoG20f0a04COwfneQAGGwd5oa+T8yO5hzuyDb/XcxxmK01EpqOyuxINew==";
String sessionKey = "tiihtNczf5v6AKRyjwEUhQ==";
String iv = "r7BXXKkLb8qrSNn05n0qiA==";
System.out.println("微信数据解密："+AESUtils.wxDecrypt(encryptedData, sessionKey, iv));
//普通 加密/解密
String key = getKey();
System.out.println("密钥:"+key);
String encData = encrypt("Hello Word", key);
System.out.println("加密密文:"+encData);
System.out.println("解密原文："+decrypt(encData, key));
}
输出：
微信数据解密：{"openId":"oGZUI0egBJY1zhBYw2KhdUfwVJJE","nickName":"Band","gender":1,"language":"zh_CN","city":"Guangzhou","province":"Guangdong","country":"CN","avatarUrl":"http://wx.qlogo.cn/mmopen/vi_32/aSKcBBPpibyKNicHNTMM0qJVh8Kjgiak2AHWr8MHM4WgMEm7GFhsf8OYrySdbvAMvTsw3mo8ibKicsnfN5pRjl1p8HQ/0","unionId":"ocMvos6NjeKLIBqg5Mr9QjxrP1FA","watermark":{"timestamp":1477314187,"appid":"wx4f4bc4dec97d474b"}}
密钥:4a7c12c0eb0fc1b0481d3b9a6653029d
加密密文:2788DFA79229947C4E9EDF0A72532504
解密原文：Hello Word
备注：
本工具由于包含微信平台(小程序/开放平台)加密数据解密方法，所有依赖了org.bouncycastle:bcprov-jdk16及commons-codec:commons-codec两个jar包，maven坐标为：
<dependency>
<groupId>org.bouncycastlegroupId>
<artifactId>bcprov-jdk16artifactId>
<version>1.46version>
dependency>
<dependency>
<groupId>commons-codecgroupId>
<artifactId>commons-codecartifactId>
<version>1.15version>
dependency>
如果不需要微信平台(小程序/开放平台)加密数据解密方法，注释掉wxDecrypt(String content, String sessionKey,String iv) 和initialize()两个方法即可，这样就不用导入上面的两个依赖jar包了。