[A-List] How NSA access was built into Windows

[Bill Totten <shimogamo@xxxxxxxxxxxxx>]

by Duncan Campbell (September 04 1999)

via digglicious.blogspot.com (January 01 2007)


A careless mistake by Microsoft programmers has revealed that special access
codes prepared by the US National Security Agency have been secretly built 
into Windows. The NSA access system is built into every version of the Windows
operating system now in use, except early releases of Windows 95 (and its
predecessors). The discovery comes close on the heels of the revelations earlier
this year that another US software giant, Lotus, had built an NSA "help
information" trapdoor into its Notes system, and that security functions on
other software systems had been deliberately crippled.

The first discovery of the new NSA access system was made two years ago by
British researcher Dr Nicko van Someren. But it was only a few weeks ago when a
second researcher rediscovered the access system. With it, he found the evidence
linking it to NSA.

Computer security specialists have been aware for two years that unusual
features are contained inside a standard Windows software "driver" used for
security and encryption functions. The driver, called ADVAPI.DLL, enables and
controls a range of security functions. If you use Windows, you will find it 
in the C:\Windows\system directory of your computer.

ADVAPI.DLL works closely with Microsoft Internet Explorer, but will only run
crypographic functions that the US governments allows Microsoft to export. That
information is bad enough news, from a European point of view. Now, it turns out
that ADVAPI will run special programmes inserted and controlled by NSA. As yet,
no-one knows what these programmes are, or what they do.

Dr Nicko van Someren reported at last year's Crypto 98 conference that he had
disassembled the ADVADPI driver. He found it contained two different keys. One
was used by Microsoft to control the cryptographic functions enabled in Windows,
in compliance with US export regulations. But the reason for building in a
second key, or who owned it, remained a mystery.


A second key

Two weeks ago, a US security company came up with conclusive evidence that 
the second key belongs to NSA. Like Dr van Someren, Andrew Fernandez, chief
scientist with Cryptonym of Morrisville, North Carolina, had been probing the
presence and significance of the two keys. Then he checked the latest Service
Pack release for Windows NT4, Service Pack 5 {2}. He found that Microsoft's
developers had failed to remove or "strip" the debugging symbols used to test
this software before they released it. Inside the code were the labels for the
two keys. One was called "KEY". The other was called "NSAKEY".

Fernandes reported his re-discovery of the two CAPI keys, and their secret
meaning, to "Advances in Cryptology, Crypto 99" conference held in Santa Barbara.
According to those present at the conference, Windows developers attending 
the conference did not deny that the "NSA" key was built into their software.
But they refused to talk about what the key did, or why it had been put there
without users' knowledge.


A third key?!

But according to two witnesses attending the conference, even Microsoft's top
crypto programmers were astonished to learn that the version of ADVAPI.DLL
shipping with Windows 2000 contains not two, but three keys. Brian LaMachia,
head of CAPI development at Microsoft was "stunned" to learn of these
discoveries, by outsiders. The latest discovery by Dr van Someren is based on
advanced search methods which test and report on the "entropy" of programming
code.

Within the Microsoft organisation, access to Windows source code is said to 
be highly compartmentalized, making it easy for modifications to be inserted
without the knowledge of even the respective product managers.

Researchers are divided about whether the NSA key could be intended to let US
government users of Windows run classified cryptosystems on their machines or
whether it is intended to open up anyone's and everyone's Windows computer to
intelligence gathering techniques deployed by NSA's burgeoning corps of
"information warriors".

According to Fernandez of Cryptonym, the result of having the secret key inside
your Windows operating system "is that it is tremendously easier for the NSA to
load unauthorized security services on all copies of Microsoft Windows, and once
these security services are loaded, they can effectively compromise your entire
operating system". The NSA key is contained inside all versions of Windows from
Windows 95 OSR2 onwards.

"For non-American IT managers relying on Windows NT to operate highly secure
data centres, this find is worrying", he added. "The US government is currently
making it as difficult as possible for "strong" crypto to be used outside of the
US. That they have also installed a cryptographic back-door in the world's most
abundant operating system should send a strong message to foreign IT managers".

"How is an IT manager to feel when they learn that in every copy of Windows sold,
Microsoft has a 'back door' for NSA - making it orders of magnitude easier for
the US government to access your computer?" he asked.


Can the loophole be turned round against the snoopers?

Dr van Someren feels that the primary purpose of the NSA key inside Windows 
may be for legitimate US government use. But he says that there cannot be a
legitimate explanation for the third key in Windows 2000 CAPI. "It looks more
fishy", he said.

Fernandez believes that NSA's built-in loophole can be turned round against the
snoopers. The NSA key inside CAPI can be replaced by your own key, and used to
sign cryptographic security modules from overseas or unauthorised third parties,
unapproved by Microsoft or the NSA. This is exactly what the US government has
been trying to prevent. A demonstration "how to do it" program that replaces the
NSA key can be found on Cryptonym's website {3}.

According to one leading US cryptographer, the IT world should be thankful 
that the subversion of Windows by NSA has come to light before the arrival 
of CPUs that handles encrypted instruction sets. These would make the type 
of discoveries made this month impossible. "Had the next-generation CPU's 
with encrypted instruction sets already been deployed, we would have never 
found out about NSAKEY".


Notes:

{1} http://www.heise.de/tp/r4/artikel/2/2898/1.html

{2} http://www.microsoft.com/technet/archive/downloads/winnt.mspx?mfr=true

{3} http://www.cryptonym.com/hottopics/msft-nsa/ReplaceNsaKey.zip


http://www.techweb.com/wire/story/TWB19990903S0014

http://digglicious.blogspot.com/2007/01/how-nsa-access-was-built-into-windows.html



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