premise:
Three parameters,
1.sessionKey (available when you take openId)
2.encryptedData (provided by the front end)
3.iv (provided by the front end)
One class and one method.
1. Class:
import java.nio.charset.Charset;
import java.util.Arrays;
/**
* 微信小程序加解密
* @author liuyazhuang
*
*/
public class WxPKCS7Encoder {
private static final Charset CHARSET = Charset.forName("utf-8");
private static final int BLOCK_SIZE = 32;
/**
* 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[] encode(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 = chr(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[] decode(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 chr(int a) {
byte target = (byte) (a & 0xFF);
return (char) target;
}
}
2. Method:
import java.io.UnsupportedEncodingException;
import java.security.AlgorithmParameters;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.Security;
import java.security.spec.InvalidParameterSpecException;
import java.util.HashMap;
import javax.annotation.Resource;
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 org.apache.commons.codec.binary.Base64;
import org.apache.commons.lang3.StringUtils;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import lombok.extern.slf4j.Slf4j;
@Slf4j
public class AesCbcUtil {
static {
//BouncyCastle是一个开源的加解密解决方案，主页在http://www.bouncycastle.org/
Security.addProvider(new BouncyCastleProvider());
}
/**
* AES解密
*
* @param data //密文，被加密的数据
* @param key //秘钥
* @param iv //偏移量
* @param encodingFormat //解密后的结果需要进行的编码
* @param type //0 是其他 1是微信步数
* @return
* @throws Exception
*/
public static String decrypt(String data, String key, String iv, String encodingFormat,Integer type) throws Exception {
// initialize();
if(StringUtils.isEmpty(data)||StringUtils.isEmpty(key)||StringUtils.isEmpty(iv))
throw new SkyParamNullException("小程序获取用户信息参数不能为空");
//被加密的数据
byte[] dataByte = Base64.decodeBase64(data);
//加密秘钥
byte[] keyByte = Base64.decodeBase64(key);
//偏移量
byte[] ivByte = Base64.decodeBase64(iv);
try {
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");
AlgorithmParameters parameters = AlgorithmParameters.getInstance("AES");
parameters.init(new IvParameterSpec(ivByte));
cipher.init(Cipher.DECRYPT_MODE, spec, parameters);// 初始化
byte[] resultByte = cipher.doFinal(dataByte);
if (null != resultByte && resultByte.length > 0) {
if (type==1){
return new String(WxPKCS7Encoder.decode(resultByte));
}else {
return new String(resultByte, encodingFormat);
}
}
return null;
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
log.error("小程序解析出错1{}",e.getMessage());
} catch (NoSuchPaddingException e) {
e.printStackTrace();
log.error("小程序解析出错2{}",e.getMessage());
} catch (InvalidParameterSpecException e) {
e.printStackTrace();
log.error("小程序解析出错3{}",e.getMessage());
} catch (InvalidKeyException e) {
e.printStackTrace();
log.error("小程序解析出错4{}",e.getMessage());
} catch (InvalidAlgorithmParameterException e) {
e.printStackTrace();
log.error("小程序解析出错5{}",e.getMessage());
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
log.error("小程序解析出错6{}",e.getMessage());
} catch (BadPaddingException e) {
e.printStackTrace();
log.error("小程序解析出错7{}",e.getMessage());
}
catch (UnsupportedEncodingException e) {
e.printStackTrace();
log.error("小程序解析出错8{}",e.getMessage());
}
return null;
}
}
achieve
@ApiOperation(value = "wx步数解密")
@PostMapping(value = "/decode")
public ResultModel<Object> questionList(@RequestBody WxSportParam param) throws Exception {
HashMap<String, Object> map = wxXiaoChenXuUtil.getWxOpenId(//这个方法网上很多，没有就用binarywang的
param.getCode()//前端提供的code
,sysProperties.getWxAppId()//appID
,sysProperties.getWxAppSecret());//secret
String sessionKey = map.get("session_key").toString();
String result = AesCbcUtil.decrypt(param.getData(), sessionKey,param.getIv(), "UTF-8",1);
return ResultModel.success(result);
}
Data coming out:
{ “stepInfoList”: [
{
“timestamp”: 1445866601,
“step”: 100
},
{
“timestamp”: 1445876601,
“step”: 120
} ] }、
tips: If you are parsing user information, use the same method, pass 0 in the parameter type in decrypt. The difference between the two is that the byte decode method is different.
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