server_aspnet.html

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layout: default
title: enable cross-origin resource sharing
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	<div class="container">
		<section>
		<h1>CORS on ASP.NET</h1>

<p>
				If you don't have access to configure IIS, you can still add the header through ASP.NET by adding the following line to your source pages:
			</p>
			<pre class="code">Response.AppendHeader("Access-Control-Allow-Origin", "*");</pre>
			<p class="note">
				Note: this approach is compatible with IIS6, IIS7 Classic Mode, and IIS7 Integrated Mode.
			</p>

<h2>ASP.NET Web API</h2>

<p>ASP.NET Web API 2 supports CORS.</p>

<p>To enable CORS support, add the <a href="http://www.nuget.org/packages/Microsoft.AspNet.WebApi.Cors">Microsoft.AspNet.WebApi.Cors</a> NuGet package to your project.</p>

<p>Add this code to your configuration:</p>

<pre class="code">
public static void Register(HttpConfiguration config)
{
    // New code
    config.EnableCors();
}
</pre>

<p>To enable cross-origin requests, add the [EnableCors] attribute to your Web API controller or controller method:</p>

<pre class="code">
[EnableCors(origins: "http://example.com", headers: "*", methods: "*")]
public class TestController : ApiController
{
    // Controller methods not shown...
}
</pre>

<h3>Enabling Globally</h3>

<p>The method described above can also be used to enable CORS across the API without annotating each controller:</p>
<pre class="code">
public static void Register(HttpConfiguration config)
{
    var corsAttr = new EnableCorsAttribute("http://example.com", "*", "*");
    config.EnableCors(corsAttr);
}
</pre>

<p>For more information, see the official <a href="http://www.asp.net/web-api/overview/security/enabling-cross-origin-requests-in-web-api">Web API documentation</a>.</p>

<h2>Libraries</h2>
		<ul><li>The open source Thinktecture.IdentityModel security library contains a full-featured CORS implementation. Here is the <a href="http://brockallen.com/2012/06/28/cors-support-in-webapi-mvc-and-iis-with-thinktecture-identitymodel/">announcement page</a> with some samples. Here is the source for <a href="https://github.com/thinktecture/Thinktecture.IdentityModel.45">.NET 4.5</a> and for <a href="https://github.com/thinktecture/Thinktecture.IdentityModel.40">.NET 4.0</a>. Both are packaged into a <a href="http://nuget.org/packages/Thinktecture.IdentityModel">Nuget package</a> downloadable from Visual Studio.</li></ul>
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