[DUG] Calculations affected by login

[Myles Penlington]

Well, it looks like you have identified the source of the issue already.
To me it smells of a security issue.

 

My best guess (and perhaps only one)

Does the app use temp files? If so where does it write them?

Does it access the registry, in particular the local machine hive?

If this is the case, use process monitor to check where. 

 

Does it use COM? Or .NET or COM via .NET?

 

You should be able to duplicate on your own machine, if you create a
plain user with access to nothing but their own local settings. And Read
only access to program files folder.

 

Myles.

 

 

From: delphi-bounces at delphi.org.nz [mailto:delphi-bounces at delphi.org.nz]
On Behalf Of John Davys
Sent: Wednesday, 28 May 2008 4:26 p.m.
To: 'NZ Borland Developers Group - Delphi List'
Subject: [DUG] Calculations affected by login

 

This is an odd one but I have had the problem demonstrated to me today
as I found it hard to believe.

 

I'm using BDS 2006, Delphi personality plus the TMS component set. The
application uses a mathematical model to simulate heat transfer and does
millions of calculations solving differential equations numerically to
generate temperatures over time etc. The results are displayed in a TMS
grid and a TeeChart component draws a graph of them.

 

The strange thing is that the calculations & graph come out fine if the
user is logged into the pc as a local user but not if the user is logged
into the pc as a domain user. The numbers calculated are garbage in the
second case. So that's the same app, on the same hardware, only
difference being the logged in user. No exceptions are generated, it
runs without apparent error.

 

When logged into the network, the user is part of a large company
network (Microsoft Active Directory) that has a strict lockdown policy
where most users are severely restricted in what they can do or see.
When logged in as a local user he is in the Administrators group whereas
logged in as a domain user he won't be.

 

This is running under XP, SP2. It is recent hardware, an HP laptop.

 

I can't duplicate the problem on any of my development or test machines.
I'm on a different network but it's still MS active directory and I'm
logged in as a network user.

 

A further point of interest is that a tester, in a different
organisation, reports the same issue i.e. it doesn't produce the correct
answers as a network user but does on a standalone pc. In this case the
standalone pc is a physically different machine.

 

I'm struggling to come up with any kind of mechanism that could account
for this behaviour. Any ideas?

 

Cheers

John

 

------------------------------------------------------------------------
--------

John Davys

Senior Consultant - Database Systems

Rezare Systems Limited

Hamilton, New Zealand

ph: (07) 857 0824

mobile: (027) 557 0824

http://www.rezare.co.nz <http://www.rezare.co.nz/> 

 

 



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