Please do not use the .NET 2.0 HMACSHA512 and HMACSHA384 Classes

Microsoft informa sobre un bug en las clases HMACSHA512 y HMACSHA384

Jorge Serrano - MVP Visual Developer - Visual Basic — Wed, 31 Jan 2007 23:45:47 GMT

Microsoft ha informado públicamente de un bug detectado hace poco en sus clases de criptografía HMACSHA512

.Net Security Blog : Please do not use the .NET 2.0 HMACSHA512 and HMA

SecurityKicks.com — Thu, 01 Feb 2007 00:24:43 GMT

You've been kicked (a good thing) - Trackback from SecurityKicks.com

Inconsistencias en HMACSHA512 y HMACSHA384

[ punto net ] — Thu, 01 Feb 2007 23:37:32 GMT

El equipo de Seguridad del CLR del Microsoft .NET Framework ha anunciado que existen ciertas inconsistencias...

.NET 2.0 : Bug dans les classes HMACSHA512 et HMACSHA384 (System.Security.Cryptography)

CoqBlog — Sat, 03 Feb 2007 01:40:05 GMT

Un bug a été découvert dans le Framework .NET 2.0 : les classes HMACSHA512 et HMACSHA384 sont susceptible

deploying an asmx webservice on a fips windows 2003 server

webstudy — Fri, 16 Feb 2007 19:26:32 GMT

I get this error when I publish my asmx webservice file to a windows 2003 server with FIPS enabled:

This implementation is not part of the Windows Platform FIPS validated cryptographic algorithms

Is there a document that describes how to host a webservice on a FIPS compliant webserver?

re: Please do not use the .NET 2.0 HMACSHA512 and HMACSHA384 Classes

Nytewolf — Tue, 20 Feb 2007 09:17:07 GMT

Now I wonder why this wasn't found sooner....

MSDN Flash Ireland - International Resources - 21 Feb 2007

Robert Burke's Weblog — Tue, 20 Feb 2007 17:05:40 GMT

[Default] Spotlight on: Windows Vista Innovate on Windows Vista Innovate on Windows Vista helps fast-track

re: Please do not use the .NET 2.0 HMACSHA512 and HMACSHA384 Classes

Omri — Tue, 20 Feb 2007 19:27:19 GMT

"The next service pack to the .NET Framework will contain a fix for this bug..."

There is a release date for the next SP?

re: Please do not use the .NET 2.0 HMACSHA512 and HMACSHA384 Classes

shawnfa — Tue, 20 Feb 2007 22:19:42 GMT

I don't believe that we have announced a date for that service pack. You should start to see this change appear in future CTPs of Orcas and other pre-release versions of the framework until the service pack is released however.

-Shawn

re: Please do not use the .NET 2.0 HMACSHA512 and HMACSHA384 Classes

required — Wed, 28 Feb 2007 20:14:20 GMT

I would suggest to keep away from the buggedHMACMode otherwise you'll be incompatible in the real world.

re: Please do not use the .NET 2.0 HMACSHA512 and HMACSHA384 Classes

kurtrus — Tue, 20 Mar 2007 20:50:47 GMT

We're using System.Security.Cryptography.SHA256Managed as a way to encrypt passwords stored in our application database. Is that affected as well?

re: Please do not use the .NET 2.0 HMACSHA512 and HMACSHA384 Classes

shawnfa — Thu, 29 Mar 2007 20:27:07 GMT

SHA256Managed is not affected, only the HMACSHA384 and HMACSHA512 algorithms are affected by the bug.

-Shawn

re: Please do not use the .NET 2.0 HMACSHA512 and HMACSHA384 Classes

David Taylor — Sun, 22 Apr 2007 05:23:55 GMT

Hi Shawn,

A few months ago I found another bug with .NET 2 when using the XML Serializer under a certain condition.

The bug is when deserializing XML that has elements referencing other inline elements by ID and when the element is a nillable primitive.

I found this when integrating to web services on BEA WebLogic because it uses the specific type of encoding by default which triggers the bug on the .NET side. You would not have picked this bug up when testing .NET against .NET because ASMX web services and the XML Serializer do not serialize out this particular way.

I am *very* sure this bug is a runtime bug introduced by the new Nullable primitive support (ie Nullable<int>) and the mapping done when the XML is supplied in this specific format.

Note that if you use the .NET 2 WSDL.exe utility (or VS 2005) to generate the proxy you see this bug; however if you use the .NET 1.1 WSDL.exe utility and them import the generated proxy into the VS 2005 project you do not see the bug. This is because only the .NET 2 wsdl.exe tool uses the new nullable<T> feature rather than doing the prior (ie adding an additional boolean field to note if the value was supplied).

Sorry for the long winded explanation - but I have not had enough time to follow this up with Microsoft; and if you are really doing a service pack to the v2 libraries you should include this.

If you want more information ping me at: davidandrewtaylor [at] hotmail.com

re: Please do not use the .NET 2.0 HMACSHA512 and HMACSHA384 Classes

David Taylor — Sun, 22 Apr 2007 05:26:31 GMT

BTW Shawn: Our solution to the bug I just posted was quite ugly -> A SoapExtension to intercept and reformat the incoming XML to reformat the incoming XML so the referenced IDs are not used; which gets around the specific bug in the .NET 2 deserializer.

re: Please do not use the .NET 2.0 HMACSHA512 and HMACSHA384 Classes

shawnfa — Mon, 07 May 2007 22:05:41 GMT

Hi David,

You can file your bug report on the MSDN Product Feedback Center (http://connect.microsoft.com/site/sitehome.aspx?SiteID=210) in order to see if the XML team has fixed that bug already or to get it on their radar.

-Shawn

re: Please do not use the .NET 2.0 HMACSHA512 and HMACSHA384 Classes

Rich — Sun, 01 Feb 2009 15:03:36 GMT

I happened to browsing the event log now in 2009 and noticed this error message. I have a PhD in computer science but am a general Windows XP user. The error message said I should come here for more information. But this information is lousy. I have no idea what I am supposed to actually *do*. I'm not really interested in spending two hours figuring out if (1) I need to do something (2) what I have to do (3) what file I actually need to edit. Could you add a pointer for poor suckers like me who land on this page, for some actual information?

re: Please do not use the .NET 2.0 HMACSHA512 and HMACSHA384 Classes

shawnfa — Mon, 02 Feb 2009 21:49:36 GMT

Hi Rich,

If your application does not need to interact with HMAC-SHA-384 or HMAC-SHA-512 data that was created with the .NET framework v2.0 RTM, then you can ignore this message. In order to suppress the event log message, you can use a .exe.config file for your application using with the legacyHMACWarning switch set to 0 (you can see an example in the blog post).

-Shawn

re: Please do not use the .NET 2.0 HMACSHA512 and HMACSHA384 Classes

Rich — Wed, 10 Jun 2009 17:19:07 GMT

Still not satisfied. I'm not writing an application. I'm using standard Microsoft applications and other 3rd party software.

I suspect it is Microsoft Dynamics CRM that is triggering the events, since Dynamics CRM is pretty fragile in general.