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IIS rewrite URL from .htaccess: match all files and folders starting with . and deny access

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Last Modified: 2017-04-20
On  IIS and trying to translate into it the following Apache rule:

# prevent httpd from serving dotfiles (.htaccess, .svn, .git, etc.) 
# - except let's encrypt challenge
RedirectMatch 403 ^/?\.(?!/well-known/acme-challenge/[\w-]{43}$)

RewriteCond %{REQUEST_URI}::$1 ^(/.+)/(.*)::\2$
RewriteRule ^(.*) - [E=BASE:%1]

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The idea of the rule is prevent IIS from serving:

    Any file than starts with “.”, or

    Any folder that starts with “.” but the folder “./well-known/acme-challenge”

Thanks in advance ;)
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Dan McFaddenTechnical Lead - Active Directory
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Commented:
First, I'd like to see the how you would create a URL path with a "dot" as the first character.  To me, the uri-stem "./well-known/acme-challenge/*" seems to indicate that somewhere there is a directory named "." which is not allowed.

Or is there an application that utilizes URL routing rules (something like an MVC structure) that handles URL routing/mapping?

Not everything doable in Apache is doable in IIS and visa-versa.

Typically you can import the .htaccess rules using the URL Rewrite feature (if it is installed on the IIS Server).  The issue with the Apache rewrite rule is that is uses a flag that URL Rewrite does not support, that being the "[E=BASE:%1] statement on the rewrite.  Which is trying to dynamically update the CGI environment variable named BASE.

You can setup static CGI environment variables in IIS, but the URL Rewrite feature does not support an interface for setting/updating environment variables (for CGI or FastCGI).

So, unfortunately, this rule is not compatible with the URL Rewrite feature in IIS.

Dan

Author

Commented:
Hi Dan,

Easily CMD and  md .demo

In the case of ./well-known/acme-challenge is created by a certifcate intaller (Certify).

Well, there is no way to deny files or folder staring with "." on IIS?

Thanks!
Dan McFaddenTechnical Lead - Active Directory
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Commented:
OK, something re-learned today.  Wasn't thinking of command line create.

Either way, the issue in the rule is not the dot in the path, it is the environment variable assignment in the htaccess rule.  There is no facility for IIS (no API available for IIS) to modify  the user environment variables.  Essentially making this rewrite rule incompatible with IIS URL Rewrite feature.

If you remove the line "RewriteRule ^(.*) - [E=BASE:%1]" you can import the htaccess file into the URL Rewrite feature directly.

Dan

Author

Commented:
Maybe  [E=BASE:%1] cannot be translated to IIS

the 1st part
# prevent httpd from serving dotfiles (.htaccess, .svn, .git, etc.) 
# - except let's encrypt challenge
RedirectMatch 403 ^/?\.(?!/well-known/acme-challenge/[\w-]{43}$)

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this will translated onto web.config as

<rule name="Deny files and folderd starting with . but allow folder .well-known" patternSyntax="ECMAScript" stopProcessing="true">
   <match url="(^\.|\/\.(?!well-known))" ignoreCase="true" negate="false" />
   <conditions logicalGrouping="MatchAll">
   </conditions>
   <action type="AbortRequest" />
</rule>

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Dan McFaddenTechnical Lead - Active Directory
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Commented:
Which is what I had mentioned in my previous post.

Dan

Author

Commented:
Sorry did not see it, where did you mention it?

If you are referring to the rule that is generated by importing the .htaccess into IIS is not even close to it.
If you import the above .htaccess to IIS you get this:
.htaccess to IIS y
Dan McFaddenTechnical Lead - Active Directory
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Commented:
I mentionedI mentioned it here.

If you remove the line "RewriteRule ^(.*) - [E=BASE:%1]" you can import the htaccess file into the URL Rewrite feature directly.

Dan

Author

Commented:
Yes, it can be imported but it does not work.

The rule is what you see on above image without the red dots lines.

So, it does not work as the .htaccess it does not “match all files and folders starting with . and deny access” as asked.
Technical Lead - Active Directory
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Commented:
This problem has been solved!
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