Using Delegatinghandler to implement API key validation for Web APIs

• Providing API key based on QueryString

  http://localhost:57967/Api/Values?key=12345

• Request header-based Decency API key

New Uri (URL), client. DefaultRequestHeaders.Accept.Clear (); client. DEFAULTREQUESTHEADERS.ACCEPT.ADD (new mediatypewithqualityheadervalue ("application/ JSON"), client. Defaultrequestheaders.add ("x-apikey","00000") ;

Writing Apikeyhandler

 Public classApikeyhandler:delegatinghandler { Public stringKey {Get;Set; }  PublicApikeyhandler (stringkey,httpconfiguration httpconfiguration) {             This. Key =key; Innerhandler=NewHttpcontrollerdispatcher (httpconfiguration); }        protected OverrideTaskSendAsync (httprequestmessage request, CancellationToken CancellationToken) {if(!Validatekey (Request)) {                varResponse =Newhttpresponsemessage (Httpstatuscode.forbidden); varTSC =NewTaskcompletionsource(); Tsc.                Setresult (response); returnTSC.            Task; }            return Base.        SendAsync (Request, CancellationToken); }        Private BOOLValidatekey (Httprequestmessage message) {IEnumerable<string> apikeyheadervalues =NULL; if(Message. Headers.trygetvalues ("X-apikey", outapikeyheadervalues)) {                varApikeyheadervalue =Apikeyheadervalues.first (); return(Apikeyheadervalue = = This. Key)//... your authentication logic here ...                /*var username = (Apikeyheadervalue = = "00000"?)               "Maarten": "OtherUser");                var usernameclaim = new Claim (claimtypes.name, username);                var identity = new Claimsidentity (new[] {usernameclaim}, "ApiKey");                var principal = new ClaimsPrincipal (identity);             Thread.CurrentPrincipal = Principal; */            }            /*var query = message.            Requesturi.parsequerystring ();            string key = query["Key"]; return (key = = this.            Key); */        }

Configure to a specific route up

 config. Routes.maphttproute (name:   " default Api   , Routetemplate:   " api/{controller}/{id}   "  new  {ID = routeparameter.optional}, constraints:  null   new  Apik Eyhandler ( " 12345   "  

Using Delegatinghandler to implement API key validation for Web APIs