java接口鑒權之sign簽名校驗與JWT驗證
需求描述：
項目里的幾個Webapi接口需要進行鑒權，同接口可被小程序或網頁調用，小程序里沒有用戶登錄的概念，網頁里有用戶登錄的概念，對於調用方來源是小程序的情況下進行放權，其他情況下需要有身份驗證。也就是說給所有小程序請求進行放行，給網頁請求進行jwt身份驗證。由於我的小程序沒有用戶登錄的功能，所以要針對小程序和網頁設計出兩套完全不同的鑒權方式。
鑒權流程設計：
查閱相關資料，最終決定的鑒權方式：
- 小程序采用sign簽名檢驗
- 網頁采用目前比較流行的JWT的token校驗
通過AOP的思想使用.Net的Attribute進行攔截請求
代碼實現
主要是服務端寫一個Attribute，判斷是小程序還是網頁，然后采用不同的兩種不同的鑒權方式。
- Attribute代碼：
public class WxAllowFilterAttribute : BaseActionFilter
{
private static readonly int _errorCode = 401;
public override void OnActionExecuting(HttpActionContext filterContext)
{
var iswx = filterContext.iswx();//判斷是否是小程序發來的請求
if (iswx)
{
//小程序的簽名校驗
if (!filterContext.checkwx()) {
filterContext.Response = Error("小程序簽名驗證失敗", _errorCode);
};
}
else
{
//JWT的token校驗
string token = filterContext.GetToken();
if (string.IsNullOrEmpty(token))
{
filterContext.Response = Error("缺少token", _errorCode);
return;
}
if (!JWTHelper.CheckToken(token, JWTHelper.JWTSecret))
{
filterContext.Response = Error("token校驗失敗!", _errorCode);
return;
}
var payload = JWTHelper.GetPayload<JWTPayload>(token);
if (payload.Expire < DateTime.Now)
{
filterContext.Response = Error("token過期!", _errorCode);
return;
}
base.OnActionExecuting(filterContext);
}
}
}
- 擴展類
public static class HttpRequest
{
public static readonly string wx_secret = ConfigurationManager.AppSettings["wx_secret"];
/// <summary>
/// 獲取Token
/// </summary>
/// <param name="req">請求</param>
/// <returns></returns>
public static string GetToken(this HttpActionContext req)
{
string tokenHeader = req.Request.Headers.Authorization == null ? "" : req.Request.Headers.Authorization.Parameter;
if (string.IsNullOrEmpty(tokenHeader))
return null;
string pattern = "^Bearer (.*?)$";
if (!Regex.IsMatch(tokenHeader, pattern))
throw new Exception("token格式不對!格式為:Bearer {token}");
string token = Regex.Match(tokenHeader, pattern).Groups[1].ToString();
if (string.IsNullOrEmpty(token))
throw new Exception("token不能為空!");
return token;
}
/// <summary>
/// 判斷是否微信
/// </summary>
/// <param name="req"></param>
/// <returns></returns>
public static bool iswx(this HttpActionContext req)
{
var queryList = req.Request.RequestUri.Query.Split('&').ToList<string>();
Dictionary<String, String> pList = new Dictionary<String, String>();
if (queryList.Count < 2)
{
return false;
}
else
{
queryList.ForEach(x =>
{
var a = x.Split('=');
if (a.Count() >= 2)
{
pList.Add(a[0], a[1]);
}
});
var iswx = pList.Any(x => x.Key == "app_key" && x.Value == "wx");//判斷是否有微信標識的字段
return iswx;
}
}
/// <summary>
/// 檢驗微信sign是否合法
/// </summary>
/// <param name="req"></param>
/// <returns></returns>
public static bool checkwx(this HttpActionContext req)
{
var queryList = req.Request.RequestUri.Query.Split('&').ToList<string>();
Dictionary<String, String> pList = new Dictionary<String, String>();
queryList.ForEach(x =>
{
var a = x.Split('=');
if (a.Count() >= 2)
{
pList.Add(a[0], a[1]);
}
});
var app_key = pList["app_key"];
var app_secret = wx_secret;
var timetamp = pList["timestamp"];
var sign = pList["sign"];
if (!string.IsNullOrEmpty(timetamp)) {
var tamp=Convert.ToInt64(timetamp);
var nowtamp = ToTimestamp(DateTime.Now);
var a = nowtamp-tamp;
if (a >= 15) {
return false;
}
}
StringBuilder sb = new StringBuilder();
sb.Append(app_key);
sb.Append(app_secret);
sb.Append(timetamp);
var newsign = GetMD5(sb.ToString());
return newsign == sign;
}
public static string GetMD5(string sDataIn)
{
MD5CryptoServiceProvider provider = new MD5CryptoServiceProvider();
byte[] bytes = Encoding.UTF8.GetBytes(sDataIn);
byte[] buffer2 = provider.ComputeHash(bytes);
provider.Clear();
string str = "";
for (int i = 0; i < buffer2.Length; i++)
{
str = str + buffer2[i].ToString("X").PadLeft(2, '0');
}
return str.ToLower();
}
public static long ToTimestamp(this DateTime target)
{
return (target.ToUniversalTime().Ticks - 621355968000000000) / 10000000;
}
}
- Filter基類
public class BaseActionFilter : ActionFilterAttribute
{
//public virtual void OnActionExecuting(HttpActionContext filterContext)
//{
//}
//public virtual void OnActionExecuted(HttpActionContext filterContext)
//{
//}
/// <summary>
/// 返回JSON
/// </summary>
/// <param name="json">json字符串</param>
/// <returns></returns>
public HttpResponseMessage JsonContent(string json)
{
var content = new StringContent(json, Encoding.UTF8, "application/json");
return new HttpResponseMessage { Content = content, StatusCode = HttpStatusCode.OK };
}
public HttpResponseMessage IsSuccess()
{
AjaxResult res = new AjaxResult
{
IsSuccess = true,
Msg = "請求成功！"
};
return JsonContent(JsonHelper.SerializeObject(res));
}
/// <summary>
/// 返回成功
/// </summary>
/// <param name="msg">消息</param>
/// <returns></returns>
public HttpResponseMessage IsSuccess(string msg)
{
AjaxResult res = new AjaxResult
{
IsSuccess = true,
Msg = msg
};
return JsonContent(JsonHelper.SerializeObject(res));
}
/// <summary>
/// 返回成功
/// </summary>
/// <param name="data">返回的數據</param>
/// <returns></returns>
public HttpResponseMessage IsSuccess<T>(T data)
{
AjaxResult<T> res = new AjaxResult<T>
{
IsSuccess = true,
Msg = "請求成功！",
Data = data
};
return JsonContent(JsonHelper.SerializeObject(res));
}
/// <summary>
/// 返回錯誤
/// </summary>
/// <returns></returns>
public HttpResponseMessage Error()
{
AjaxResult res = new AjaxResult
{
IsSuccess = false,
Msg = "請求失敗！"
};
return JsonContent(JsonHelper.SerializeObject(res));
}
/// <summary>
/// 返回錯誤
/// </summary>
/// <param name="msg">錯誤提示</param>
/// <returns></returns>
public HttpResponseMessage Error(string msg)
{
AjaxResult res = new AjaxResult
{
IsSuccess = false,
Msg = msg,
};
return JsonContent(JsonHelper.SerializeObject(res));
}
/// <summary>
/// 返回錯誤
/// </summary>
/// <param name="msg">錯誤提示</param>
/// <param name="errorCode">錯誤代碼</param>
/// <returns></returns>
public HttpResponseMessage Error(string msg, int errorCode)
{
AjaxResult res = new AjaxResult
{
IsSuccess = false,
Msg = msg,
StatusCode = errorCode
};
return JsonContent(JsonHelper.SerializeObject(res));
}
}
- JWT擴展類
public class JWTHelper
{
private static readonly string _headerBase64Url = "{\"alg\":\"HS256\",\"typ\":\"JWT\"}".Base64UrlEncode();
public static readonly string JWTSecret = ConfigurationManager.AppSettings["JWTSecret"];
/// <summary>
/// 生成Token
/// </summary>
/// <param name="payloadJsonStr">數據JSON字符串</param>
/// <param name="secret">密鑰</param>
/// <returns></returns>
public static string GetToken(string payloadJsonStr, string secret)
{
string payloadBase64Url = payloadJsonStr.Base64UrlEncode();
StringBuilder sb = new StringBuilder();
StringBuilder sb1 = new StringBuilder();
sb.AppendFormat("{0}", _headerBase64Url);
sb.Append(".");
sb.AppendFormat("{0}", payloadBase64Url);
sb1 = sb;
string sign = sb.ToString().ToHMACSHA256String(secret);
string token = sb1.AppendFormat(".{0}", sign).ToString();
return token;
}
/// <summary>
/// 獲取Token中的數據
/// </summary>
/// <typeparam name="T">泛型</typeparam>
/// <param name="token">token</param>
/// <returns></returns>
public static T GetPayload<T>(string token)
{
if (string.IsNullOrEmpty(token))
{
return default(T);
}
return token.Split('.')[1].Base64UrlDecode().ToObject<T>();
}
/// <summary>
/// 校驗Token
/// </summary>
/// <param name="token">token</param>
/// <param name="secret">密鑰</param>
/// <returns></returns>
public static bool CheckToken(string token, string secret)
{
var items = token.Split('.');
var oldSign = items[2];
StringBuilder sb = new StringBuilder();
sb.AppendFormat("{0}", items[0]);
sb.AppendFormat(".{0}", items[1]);
string newSign = sb.ToString().ToHMACSHA256String(secret);
return oldSign == newSign;
}
}
檢驗用戶名密碼是否正確的業務接口代碼這里不貼了..
網頁客戶端的代碼還沒寫完，主要思路就是判斷緩存里是否有token，沒有就去把用戶名密碼去調用服務端的登錄接口拿到token后存到緩存里，之后的所有請求都在頭部帶上這個token。
小程序客戶端代碼 :
在app.js中定義一個公共的promise請求方法，並帶上請求的參數(app_key,時間戳,md5加密后的sign等)，這里要注意區分get和post請求的區別，get是放在url后的,post是放在body里的，要對傳參的格式要稍加處理
request(params) {
reqTime++;
//加載彈框
wx.showLoading({
title: '加載中...',
mask: true
});
//返回
return new Promise((resolve, reject) => {
var data = {
app_key: this.globalData.app_key,
timestamp: Math.round(new Date() / 1000),
sign: ''
}
data.sign = utilMd5.hexMD5(`${this.globalData.app_key}${this.globalData.app_secret}${data.timestamp}`)
if (params.method.toUpperCase() == 'POST') {
if (!params.url.includes('?')) {
params.url += '?'
}
var url = `&app_key=${this.globalData.app_key}×tamp=${data.timestamp}&sign=${data.sign}`
params = {
...params,
url: params.url + url
}
data = params.data
} else {
data = {
...params.data,
...data
}
}
params = {
...params,
data: {
...data
}
}
wx.request({
//解構params獲取請求參數
...params,
success: (result) => {
resolve(result);
},
fail: (err) => {
reject(err);
},
complete: () => {
reqTime--;
//停止加載
if (!reqTime)
wx.hideLoading();
}
});
});
}
這邊說明下，我的app_key和app_secret都是寫在app.js里的公共變量中的，app_key在url里是暴露的，但是app_secret是絕不能被暴露的。光知道app_key是無法生成正確的sign的，必須app_key,app_secret和timestap三者的加密才能生成正確的sign。我把app_secret寫在app.js中可能不是安全的做法，但是通過請求服務器去獲取app.secret又要面臨網絡請求的安全問題，最多對字符串進行加密解密，但也不能說絕對安全了。app_secret怎么處理最安全我目前也沒想到很好的辦法。。
好了，以上就是小程序的鑒權方法，小程序客戶端在請求時只需要調用這個公共方法就行。
鑒權測試結果
- 給控制器或者方法前面加上鑒權的特性[WxAllowFilter]
- PostMan直接調用不帶任何sign等參數
- 偽造小程序參數簽名驗證失敗或者時間戳超過10秒
- 小程序內調用
轉載