Re: STL file extension for "Certificate Trust List" ?

From: Delft Spline Systems (
Date: Wed May 15 2002 - 19:30:54 EEST

Dear list,

Thanks for the help that was given, on how to again associate
the extension STL to one's favorite RP application.

This being solved, the real question was for the real meaning of
such "Certificate Trust List". Changing the association might
result in some Windows application that no longer functions
correctly, and I do not want to be responsible for that on our
client's computers.

By now I have found some background information on:

Such list is made by the Microsoft application MakeCTL
and saved as STL file. Here is an excerpt:
The MakeCTL utility creates a certificate trust list (CTL) and saves the
encoded CTL to a certificate store or to a file. MakeCTL is only supported
with Internet Explorer 4.0 or later. A CryptoAPI Tool wizard is available
with Internet Explorer 5.0 or later and Windows NT 4.0 SP4 or later.
MakeCTL [-u subjectUsageID] [-s [-r registryLocation]]
        store1 [-s [-r registryLocation]] store2 … [-s [-r
        storeN output.stl
output Name of the output file to contain the CTL.

Note the file-extension STL for the output file.
Use of such Certificate is related to secure encrypted communication
with your browser.

The good part is that repairing the STL extension to be again associated
with an RP utility is possible, and does not appear to cause any problems.

The bad part is that in my experience after some time the association
may be reset to "Certificate Trust List" by some Microsoft application,
perhaps when downloading a secure documnent using MS Explorer.
Unfortunately I have no solution for that.

Best Regards,

Lex Lennings.

On May 14, I wrote to rp-ml:
> Does anyone have some clue about the meaning and use
> of a Certificate Trust List file, about how to redefine the
> file type to be a Stereo Lithography file, and if such redefinition
> will disable any important Windows functionality ?

Delft Spline Systems, The Netherlands.
We offer DeskProto: affordable Rapid Prototyping using CNC milling. --- website:

For more information about the rp-ml, see

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