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Signing the Assembly

We have decided not to ship a strong named assembly through our Codeplex release. Our final release to be included in the .net 4.0 will be signed and we believe we should avoid having two signed assemblies out there.

However, nothing stops you from signing it if you want to use MEF in an existing project that is signed. The following are the steps to required to sign it.

Creating a key

  • Open the MEF.sln solution in Microsoft Visual Studio 2008
  • Right click the ComponentModel project and select Properties...
  • Click on the Signing tab

  • Enter a name for your key and uncheck the "Protect my key file with a password"

The key will be generated and included in your project.
  • On the ComponentModel project, open the AssemblyInfo.cs file
  • Comment the InternalsVisibleTo declarations
  • Right click the project and select Build

The build should succeed and you'll have a signed assembly. In order to have the whole solution building and run the tests, you need to take a few steps further.

Extracting the public key

  • Open a Visual Studio Command Prompt
  • Type the following command to extract the public keys from the assembly you just built:
C:\dev\MEF_Drop_2009_01_23\bin>sn -Tp System.ComponentModel.Composition.dll

Microsoft (R) .NET Framework Strong Name Utility  Version 3.5.30718.1
Copyright (c) Microsoft Corporation.  All rights reserved.

Public key is

Public key token is XXXXXXXXXXXXXXX

Take note of the public key as it will be used on further steps.

Associate the key you created with the test projects

The test project and test framework needs to be signed too and instead of generating a new key, we will use the key created in the previous step.
  • Right click the ComponentModelUnitTest project and select Properties
  • Click on the Signing tab
  • Make sure the Sign the assembly is checked
  • Select <Browse...> and pick the key created for the ComponentModel

Repeat the same steps for the project UnitTestFramework

Change the InternalsVisibleTo attribute declarations.

The assembly level attribute InternalsVisibleToAttribute now needs to be changed to include the public key portion of the key you created.
  • On the ComponentModel project, open the AssemblyInfo.cs file
  • Uncomment the InternalsVisibleTo attribute declarations
  • Add the public key that you collected previously to each InternalsVisibleTo declaration. They will look like the following

[assembly: System.Runtime.CompilerServices.InternalsVisibleTo(
"System.ComponentModel.Composition.UnitTests, PublicKey=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX" + 
[assembly: System.Runtime.CompilerServices.InternalsVisibleTo(
"System.ComponentModel.Composition.UnitTestFramework, PublicKey=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX" +

Where the XXXXX is a really long string.

Repeat the same step for the project UnitTestFramework

By now your solution should be compiling without any problems.

Last edited Jan 27, 2009 at 11:09 PM by haveriss, version 5


pspidey Feb 3, 2009 at 10:41 PM 
Unless I misread this, you missed out a step at the end -

the AssemblyInfo.cs for the UnitTestFramework project also needs to be updated to include the public key for the internalvisibleto reference to the UnitTests assembly.

Other than that - thanks I'd previously removed the unit tests because of problems with the strong naming.