web.config redirect non-www to www

Question

I need to redirect non-www urls to www url for both http and https urls. I tried following rules in web.config.

<rule name="Redirect to WWW" stopProcessing="true"> <match url=".*" /> <conditions>     <add input="{HTTP_HOST}" pattern="^domain.com$" /> </conditions> <action type="Redirect" url="http://www.domain.com/{R:0}" redirectType="Permanent" /> 

<rule name="Redirect to WWW https" stopProcessing="true"> <match url=".*" /> <conditions>     <add input="{HTTPS}" pattern="^domain.com$" /> </conditions> <action type="Redirect" url="https://www.domain.com/{R:0}" redirectType="Permanent" /> 

It works perfectly for non-ssl url but in case of ssl it redirect from https://domain.com to http://www.domain.com

Please help me to correct my rules.

Answer 1

For a safer rule that works for both Match Any and Match All situations, you can use the Rewrite Map solution. It’s a perfectly good solution with the only drawback being the ever so slight extra effort to set it up since you need to create a rewrite map before you create the rule. In other words, if you choose to use this as your sole method of handling the protocol, you’ll be safe.

You can create a Rewrite Map called MapProtocol, you can use {MapProtocol:{HTTPS}} for the protocol within any rule action.

<rewrite>   <rules>     <rule name="Redirect to www" stopProcessing="true">       <match url="(.*)" />       <conditions trackAllCaptures="false">         <add input="{HTTP_HOST}" pattern="^domain.com$" />       </conditions>       <action type="Redirect"          url="{MapProtocol:{HTTPS}}://www.domain.com/{R:1}" />     </rule>   </rules>   <rewriteMaps>     <rewriteMap name="MapProtocol">       <add key="on" value="https" />       <add key="off" value="http" />     </rewriteMap>   </rewriteMaps> </rewrite> 

Reference

Answer 2

Other answers here are unnecessary long, here's the rule i use (just copy and paste) :

<rule name="ensurewww" stopProcessing="true">   <match url=".*" />   <conditions>     <add input="{CACHE_URL}" pattern="^(.+)://(?!www)(.*)" />   </conditions>   <action type="Redirect" url="{C:1}://www.{C:2}" redirectType="Permanent" /> </rule> 

This will redirect to the www version while preserving the HTTP and HTTPS protocol

Hope this helps.