c# - Authorization Header is null when making jQuery Ajax request -

i have went through pretty of articles can find , followed suggested , somehow when processing request on server side authorization header null.

the back-end asp.net mvc web api , i've implemented filter authentication. i've tried using postman , setup authorization header , have verified back-end code works.

however, can't seem make work via ajax call in jquery.

here jquery ajax request:

//do ajax call api     $.ajax({         url: "http://localhost:55602/api/evaluatetableexpression?callback=?",         type: "get",         data: "json=" + escape(json.stringify({             "fdml": "hr.employee emp { emp.id, emp.firstname, emp.prsname }"         })),         datatype: "jsonp",         beforesend: function(request) {             request.setrequestheader("authorization", "basic " + btoa("master:servant"));         },         success: function(data, status) {              console.log(data);              if (!data.errorsoccurred) {                 var header = data.value.header.columns;                 var records = processrecords(header, data.value.rows.rows);                 rendergrid(header, records, $("#employeegrid"));             }         },         error: function(xhr, textstatus, errorthrown){             console.log(errorthrown);         }     }); 

and below snippet of code processes request...

public override void onauthorization(httpactioncontext actioncontext)     {         // in case user authorized using forms authentication         // check header basic authentication         if (thread.currentprincipal.identity.isauthenticated) return;          var authheader = actioncontext.request.headers.authorization;         if (authheader != null)         {             if (authheader.scheme.equals("basic", stringcomparison.ordinalignorecase) &&                 !string.isnullorwhitespace(authheader.parameter))                  if (authenticateuser(authheader)) return;         }          handleunauthorizedrequest(actioncontext);     } 

when inspect actioncontext.request.header, can see authorization value null.

what doing wrong here? in advance.

edit: including settings in web.config file might figure out what's causing problem.

<httpprotocol>   <customheaders>     <add name="access-control-allow-origin" value="*" />     <add name="access-control-request-headers" value="authorization, content-type"/>     <add name="access-control-allow-headers" value="content-type, authorization" />     <add name="access-control-allow-methods" value="post, get, options" />   </customheaders> </httpprotocol>  <authentication mode="forms" /> 

edit: below raw http request

get /api/evaluatetableexpression?callback=jquery21109280835636891425_1403905133542&j‌​son=%7b%22fdml%22%3a%22hr.employee%20as%20emp%20%7b%20emp.id%2c%20emp.firstname%2‌​c%20emp.prsname%20%7d%22%7d&_=1403905133544  http/1.1 host: localhost:55602  connection: keep-alive  accept: / user-agent: mozilla/5.0 (windows nt 6.3; wow64) applewebkit/537.36 (khtml, gecko) chrome/35.0.1916.153 safari/537.36 referer: localhost/fdmweb accept-encoding: gzip,deflate,sdch accept-language: en-us,en;q=0.8 

edit: seems has doing cross origin request. when comment out datatype: "jsonp" attribute on ajax call, can see authorization header being set. problem is, how set header when expecting jsonp result or doing cors?

to solve problem need this

1. remove custom headers web.config
2. add reference in web api project:

   system.web.http.cors

3. add following line code inside register method of webapiconfig class.

   config.enablecors();

4. add following attribute in controller(s)

   [enablecors(origins: "", headers: "", methods: "*", supportscredentials = true)]