asp.net-mvc Force HTTPS using Rewrite rule


Example

This example shows how you can use IIS Rewrite rules to force HTTPS by making all HTTP requests return a 301 (Permanent) Redirect to the HTTPS page.

This is usually better than using the [RequireHttps] attribute because the attribute uses a 302 redirect, and being in the MVC pipeline it is much slower than doing it at the IIS level.

   <rewrite xdt:Transform="Insert">
      <rules>
        <rule name="Enforce HTTPS WWW" stopProcessing="true">
          <match url=".*" />
          <conditions logicalGrouping="MatchAll" trackAllCaptures="true">
            <add input="{HTTP_HOST}" pattern="^(?!www)(.*)"/>
            <add input="{URL}" pattern="^(.*)"/>
            <!-- {URL} Gives the base portion of the URL, without any querystring or extra path information, for example, "/vdir/default.asp". -->
          </conditions>
          <action type="Redirect" url="https://www.{C:1}{C:2}" appendQueryString="true" redirectType="Permanent" />
        </rule>
      </rules>
    </rewrite>