From: roy@sendai.scytale.com (Roy M. Silvernail)
Date: Tue, 24 Dec 1996 12:12:09 -0800 (PST)
To: blake@bcdev.com (Blake Coverett)
Subject: Re: [NOT NOISE] Microsoft Crypto Service Provider API
In-Reply-To: <01BBF127.ACD7C120@bcdev.com>
Message-ID: <961224.113652.8U1.rnr.w165w@sendai.scytale.com>
MIME-Version: 1.0
Content-Type: text


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In list.cypherpunks, blake@bcdev.com writes of the MS CSPAPI and
signatures:

> More interesting would be the OS patch that allows an unsigned 
> (or signed by someone other than MS) CSP to be loaded...

Agreed.

> Hmm, logically the patch must be built in and only need to be 
> switched on as it would be too annoying to debug a CSP if you
> needed to get it signed every time you built a new version.

Not quite.  The API comes with a program SIGN.EXE that will create a
"debugging signature" for your CSP, and a new ADVAPI32.DLL, described as
a "Modified advapi32.dll to load providers that are signed with
sign.exe."  So the patch point is a bit more accessable than inside the
kernel.  Maybe the "Modified advapi32.dll" should find its way offshore?

> Microsoft's Authenticode system had such a patch at one time
> for just that purpose, and all it required was a registry setting.

Interestingly enough, CSP signatures are held in the registry instead of
the binary, necessitating some install procedure for a given CSP.  Not
to start rumors, but NT 4.0 does use threads to watch some registry
entries that control the version (workstation/server).  Not much of a
stretch to imagine a thread that tracks (reports?) changes to
HKEY_LOCAL_MACHINE
    SOFTWARE
        Microsoft
            Cryptography
                Defaults
                    Provider
                        ...
- -- 
           Roy M. Silvernail     [ ]      roy@scytale.com
DNRC Minister Plenipotentiary of All Things Confusing, Software Division
PGP Public Key fingerprint =  31 86 EC B9 DB 76 A7 54  13 0B 6A 6B CC 09 18 B6
                Key available from pubkey@scytale.com

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