Question

So I enabled this group policy and the first time I tried to compile my solution I get this error. The funny thing is that I only use cryptographic function in one place but what I am seeing this on is all my Silverlight ResourceDictionary files and WPF userControl files. Everything else seems to compile fine.

Why am I seeing the error on only xaml files where I do nothing with encryption? I know I can disable the FIPS group policy but I do want to support it. Any idea why specific XAML files are throwing this error during compile?

Answer 1

After some research I found this answer which makes sense:

WPF and FIPS

Here are the contents of the link just in case it is removed:

The following is the reply I got from the WPF XAML team:

We didn’t fix it because this issue was discovered days (June 2, 2008) before the release.

I still have the BBPack I didn’t checkin.  Here is the comment from the code.



            // The Federal Information Processing Standard mandates that

            // MD5 is obsolete and not safe for cryptographic checksums.

            // We are using it to coordinating source files for debugging

            // not authenticating so MD5 use is OK here.

            // But, on a OS with the FIPS compliant switch ON, the managed

            // MD5CryptoServiceProvider Ctor will throw.  So we can't use it.

            //

            // Currently we use a PInvoke wrapper to the Native layer;

            // which still works, even on a FIPS compliant machine.  A Better

            // fix would be to move to the approved SHA checksums, but that

            // will require co-ordination with VS and the Debugger groups etc.



The MSI builder and a few other tools also threw on a FIPS=1 machine.

So even we if we fixed our part (in 3.5sp1), the customer’s end-to-end solution was still broken.



General FIPS info:

http://support.microsoft.com/kb/811833/en-us