Certificate with "<%" cannot be regocnized in IIS

Question

Hello,

Currently we put a certificate into an IIS and try to download it by Invoke-WebRequest.
The download failed and turns out to be due to the certificate contains "<%".

Manually read by http also failed with 500:

Other certificate without this "<%" can be downloaded.
Any suggestion on this issue?

Thanks in advance.

Chu Ling Rui

Answer 1

The problem is that IIS's default handler mapping for .cer files is asp.dll. IIS is trying to "run" your cer file. You need to have .cer files treated as a StaticFile.

At the web site level, rename .cer to .cer-save or something like that.

Then in the mime type definitions, add an entry for .cer files for application/octet-stream.

Note: I don't know why the default IIS config is defined like that. Do this on a test server first to verify that it doesn't impact HTTPS sites.

PS C:\> Invoke-WebRequest localhost/test.cer  
  
  
StatusCode        : 200  
StatusDescription : OK  
Content           : {60, 37, 32, 32...}  
RawContent        : HTTP/1.1 200 OK  
                    Accept-Ranges: bytes  
                    Content-Length: 343  
                    Content-Type: application/octet-stream  
                    Date: Fri, 16 Sep 2022 13:06:47 GMT  
                    ETag: "6d1e2cb1c2c9d81:0"  
                    Last-Modified: Fri, 16 Sep 2022 11:5...  
Headers           : {[Accept-Ranges, bytes], [Content-Length, 343], [Content-Type, application/octet-stream], [Date,  
                    Fri, 16 Sep 2022 13:06:47 GMT]...}  
RawContentLength  : 343  
  

Answer 2

Just an update:
If we regenerate a certificate on the same system, certificate with <% will still be generated.

Answer 3

Hello,

This 3C 25 is static IP on the site, no way to change it.
Any good way to fix this issue?

Thanks in advance.
ChuLingRui

Answer 4

Hello there,

The first thing that has to be checked is whether the website is accessible over http. You will need to have the website working on http first before continuing with this troubleshooter.

There could be many reasons. We will follow a step-by-step approach to solve this problem.

Troubleshooting SSL related issues (Server Certificate) https://learn.microsoft.com/en-us/iis/troubleshoot/security-issues/troubleshooting-ssl-related-issues-server-certificate

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