在很多项目中,因为webapi是对外开放的,这个时候,我们就要得考虑接口交换数据的安全性。

安全机制也比较多,如andriod与webapi 交换数据的时候,可以走双向证书方法,但是开发成本比较大,

今天我们不打算介绍这方面的知识,我们说说一个较简单也较常见的安全交换机制

在这里要提醒读者,目前所有的加密机制都不是绝对的安全

我们的目标是,任何用户或者软件获取到我们的webapi接口url后用来再次访问该地址都是无效的!

达到这种目标的话,我们必须要在url中增加一个时间戳,但是仅仅如此还是不够,用户可以修改我们的时间戳!

因此我们可以对时间戳 进行MD5加密,但是这样依然不够,用户可以直接对我们的时间戳md5的哦,因些需要引入一个绝对安全

的双方约定的key,并同时加入其它参数进行混淆!

注意:这个key要在app里和我们的webapi里各保存相同的一份!

于是我们约定公式: 加密结果=md5(时间戳+随机数+key+post或者get的参数)

下面我们开始通过上述公式写代码:

于由我的环境是asp.net mvc 的,所以重写一个加密类ApiSecurityFilter

1、获取参数

if (request.Headers.Contains("timestamp"))
    timestamp = HttpUtility.UrlDecode(request.Headers.GetValues("timestamp").FirstOrDefault());

   if (request.Headers.Contains("nonce"))
    nonce = HttpUtility.UrlDecode(request.Headers.GetValues("nonce").FirstOrDefault());

   if (request.Headers.Contains("signature"))
    signature = HttpUtility.UrlDecode(request.Headers.GetValues("signature").FirstOrDefault());

   if (string.IsNullOrEmpty(timestamp) || string.IsNullOrEmpty(nonce) || string.IsNullOrEmpty(signature))
    throw new SecurityException();

2、判断时间戳是否超过指定时间

 double ts = 0;
   bool timespanvalidate = double.TryParse(timestamp, out ts);

   bool falg = (DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0)).TotalMilliseconds - ts > 60 * 1000;

   if (falg || (!timespanvalidate))
    throw new SecurityException();

3、POST/DELETE/UPDATE 三种方式提取参数

 case "POST":
    case "PUT":
    case "DELETE":

     Stream stream = HttpContext.Current.Request.InputStream;
     StreamReader streamReader = new StreamReader(stream);
     sortedParams = new SortedDictionary<string, string>(new JsonSerializer().Deserialize<Dictionary<string, string>>(new JsonTextReader(streamReader)));

     break;

4、GET 方式提取参数

case "GET":

     IDictionary<string, string> parameters = new Dictionary<string, string>();

     foreach (string key in HttpContext.Current.Request.QueryString)
     {
      if (!string.IsNullOrEmpty(key))
      {
       parameters.Add(key, HttpContext.Current.Request.QueryString[key]);
      }
     }

     sortedParams = new SortedDictionary<string, string>(parameters);

     break;

5、排序上述参数并拼接,形成我们要参与md5的约定公式中的第四个参数

   StringBuilder query = new StringBuilder();

   if (sortedParams != null)
   {
    foreach (var sort in sortedParams.OrderBy(k => k.Key))
    {
     if (!string.IsNullOrEmpty(sort.Key))
     {
      query.Append(sort.Key).Append(sort.Value);
     }
    }

    data = query.ToString().Replace(" ", "");
   }

6、开始约定公式计算结果并对比传过的结果是否一致

 var md5Staff = Seedwork.Utils.CharHelper.MD5(string.Concat(timestamp + nonce + staffId + data), 32);

   if (!md5Staff.Equals(signature))
    throw new SecurityException();

完整的代码如下:

public class ApiSecurityFilter : ActionFilterAttribute
 {
  public override void OnActionExecuting(HttpActionContext actionContext)
  {
   var request = actionContext.Request;

   var method = request.Method.Method;
   var staffId = "^***********************************$";

   string timestamp = string.Empty, nonce = string.Empty, signature = string.Empty;

   if (request.Headers.Contains("timestamp"))
    timestamp = request.Headers.GetValues("timestamp").FirstOrDefault();

   if (request.Headers.Contains("nonce"))
    nonce = request.Headers.GetValues("nonce").FirstOrDefault();

   if (request.Headers.Contains("signature"))
    signature = request.Headers.GetValues("signature").FirstOrDefault();

   if (string.IsNullOrEmpty(timestamp) || string.IsNullOrEmpty(nonce) || string.IsNullOrEmpty(signature))
    throw new SecurityException();

   double ts = 0;
   bool timespanvalidate = double.TryParse(timestamp, out ts);

   bool falg = (DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0)).TotalMilliseconds - ts > 60 * 1000;

   if (falg || (!timespanvalidate))
    throw new SecurityException("timeSpanValidate");

   var data = string.Empty;
   IDictionary<string, string> sortedParams = null;

   switch (method.ToUpper())
   {
    case "POST":
    case "PUT":
    case "DELETE":

     Stream stream = HttpContext.Current.Request.InputStream;
     StreamReader streamReader = new StreamReader(stream);
     sortedParams = new SortedDictionary<string, string>(new JsonSerializer().Deserialize<Dictionary<string, string>>(new JsonTextReader(streamReader)));

     break;
     
    case "GET":

     IDictionary<string, string> parameters = new Dictionary<string, string>();

     foreach (string key in HttpContext.Current.Request.QueryString)
     {
      if (!string.IsNullOrEmpty(key))
      {
       parameters.Add(key, HttpContext.Current.Request.QueryString[key]);
      }
     }

     sortedParams = new SortedDictionary<string, string>(parameters);

     break;

    default:
     throw new SecurityException("defaultOptions");
   }

   StringBuilder query = new StringBuilder();

   if (sortedParams != null)
   {
    foreach (var sort in sortedParams.OrderBy(k => k.Key))
    {
     if (!string.IsNullOrEmpty(sort.Key))
     {
      query.Append(sort.Key).Append(sort.Value);
     }
    }

    data = query.ToString().Replace(" ", "");
   }
  
   var md5Staff = Seedwork.Utils.CharHelper.MD5(string.Concat(timestamp + nonce + staffId + data), 32);

   if (!md5Staff.Equals(signature))
    throw new SecurityException("md5Staff");

   base.OnActionExecuting(actionContext);
  }

  public override void OnActionExecuted(HttpActionExecutedContext actionExecutedContext)
  {
   base.OnActionExecuted(actionExecutedContext);
  }
 }

7、最后在asp.net mvc 里加入配置上述类

 public static class WebApiConfig
 {
  public static void Register(HttpConfiguration config)
  {
   // Web API configuration and services
   config.Filters.Add(new ApiSecurityFilter());

   config.Filters.Add(new ApiHandleErrorAttribute());

   // Web API routes
   config.MapHttpAttributeRoutes();

   config.Routes.MapHttpRoute(
    name: "DefaultApi",
    routeTemplate: "api/{controller}/{id}",
    defaults: new { id = RouteParameter.Optional }
   );
  }
 }

8、添加写入日志类

 public class ApiHandleErrorAttribute: ExceptionFilterAttribute
 {
  /// <summary>
  /// add by laiyunba 
  /// </summary>
  /// <param name="filterContext">context oop</param>
  public override void OnException(HttpActionExecutedContext filterContext)
  {
   LoggerFactory.CreateLog().LogError(Messages.error_unmanagederror, filterContext.Exception);
  }
 }

9、利用微信小程序测试接口

 var data = {
  UserName: username,
  Password: password,
  Action: 'Mobile',
  Sms: ''
  };

  var timestamp = util.gettimestamp();
  var nonce = util.getnonce();

  if (username && password) {
  wx.request({
   url: rootUrl + '/api/login',
   method: "POST",
   data: data,
   header: {
   'content-type': 'application/json',
   'timestamp': timestamp,
   'nonce': nonce,
   'signature': util.getMD5Staff(data, timestamp, nonce)
   },
   success: function (res) {
   if (res.data) {

1)其中getMD5Staff函数:

function getMD5Staff(queryData, timestamp, nonce) {

 var staffId = getstaffId();//保存的key与webapi同步
 var data = dictionaryOrderWithData(queryData);
 return md5.md5(timestamp + nonce + staffId + data);
}

2)dictionaryOrderWithData函数:

function dictionaryOrderWithData(dic) {
 //eg {x:2,y:3,z:1}
 var result = "";
 var sdic = Object.keys(dic).sort(function (a, b) { return a.localeCompare(b) });
 var value = "";

 for (var ki in sdic) {
 if (dic[sdic[ki]] == null) {
  value = ""
 }
 else {
  value = dic[sdic[ki]];
 }
 result += sdic[ki] + value;
 }

 return result.replace(/\s/g, "");
}

10、测试日志

LaiyunbaApp Error: 2 : 2017-10-18 09:15:25 Unmanaged error in aplication, the exception information is Exception:System.Security.SecurityException: 安全性错误。
 在 DistributedServices.MainBoundedContext.FilterAttribute.ApiSecurityFilter.OnActionExecuting(HttpActionContext actionContext)
 在 System.Web.Http.Filters.ActionFilterAttribute.OnActionExecutingAsync(HttpActionContext actionContext, CancellationToken cancellationToken)
--- 引发异常的上一位置中堆栈跟踪的末尾 ---
 在 System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
 在 System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
 在 System.Web.Http.Filters.ActionFilterAttribute.<ExecuteActionFilterAsyncCore>d__0.MoveNext()
--- 引发异常的上一位置中堆栈跟踪的末尾 ---
 在 System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
 在 System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
 在 System.Web.Http.Controllers.ActionFilterResult.<ExecuteAsync>d__2.MoveNext()
--- 引发异常的上一位置中堆栈跟踪的末尾 ---
 在 System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
 在 System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
 在 System.Web.Http.Controllers.ExceptionFilterResult.<ExecuteAsync>d__0.MoveNext()
失败的程序集的区域是:
MyComputer
LogicalOperationStack=2017-10-18 09:15:25 
2017-10-18 09:15:25 DateTime=2017-10-18T01:15:25.1000017Z
2017-10-18 09:15:25 Callstack= 在 System.Environment.GetStackTrace(Exception e, Boolean needFileInfo)
 在 System.Environment.get_StackTrace()
 在 System.Diagnostics.TraceEventCache.get_Callstack()
 在 System.Diagnostics.TraceListener.WriteFooter(TraceEventCache eventCache)
 在 System.Diagnostics.TraceSource.TraceEvent(TraceEventType eventType, Int32 id, String message)
 在 Infrastructure.Crosscutting.NetFramework.Logging.TraceSourceLog.TraceInternal(TraceEventType eventType, String message)
 在 Infrastructure.Crosscutting.NetFramework.Logging.TraceSourceLog.LogError(String message, Exception exception, Object[] args)
 在 System.Web.Http.Filters.ExceptionFilterAttribute.OnExceptionAsync(HttpActionExecutedContext actionExecutedContext, CancellationToken cancellationToken)
 在 System.Web.Http.Filters.ExceptionFilterAttribute.<ExecuteExceptionFilterAsyncCore>d__0.MoveNext()
 在 System.Runtime.CompilerServices.AsyncTaskMethodBuilder.Start[TStateMachine](TStateMachine& stateMachine)
 在 System.Web.Http.Filters.ExceptionFilterAttribute.ExecuteExceptionFilterAsyncCore(HttpActionExecutedContext actionExecutedContext, CancellationToken cancellationToken)
 在 System.Web.Http.Filters.ExceptionFilterAttribute.System.Web.Http.Filters.IExceptionFilter.ExecuteExceptionFilterAsync(HttpActionExecutedContext actionExecutedContext, CancellationToken cancellationToken)
 在 System.Web.Http.Controllers.ExceptionFilterResult.<ExecuteAsync>d__0.MoveNext()
 在 System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.Start[TStateMachine](TStateMachine& stateMachine)
 在 System.Web.Http.Controllers.ExceptionFilterResult.ExecuteAsync(CancellationToken cancellationToken)
 在 System.Web.Http.ApiController.ExecuteAsync(HttpControllerContext controllerContext, CancellationToken cancellationToken)
 在 System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()
 在 System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.Start[TStateMachine](TStateMachine& stateMachine)
 在 System.Web.Http.Dispatcher.HttpControllerDispatcher.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
 在 System.Net.Http.HttpMessageInvoker.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
 在 System.Web.Http.Dispatcher.HttpRoutingDispatcher.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)

至此,webapi加密工作已经全部完成,上述异常是直接访问url报的错误,必须在app环境下才可以正常访问。

 总结:webapi加密机密很多,像微信小程序,用户很难拿到客户端app的源码,想知道我们的key也是无从说起。当然,我们也得定期更新app版本。

像app for andriod or ios 可以使用双向证书,或者使用我们上述的方式,然后加固app,防止不怀好意的人破解得到key,当然不管如何,我们首先要走的都是https协议!

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持脚本之家。

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