How I do a sign an assembly that has already been built into a dll specifically flute.dll

After a little searching, I found this post that explains one way of doing it.

Exerpt:

From a VS.NET command prompt, enter the following:

1. Generate a KeyFile: sn -k keyPair.snk
2. Obtain the MSIL for the provided assembly: ildasm providedAssembly.dll /out:providedAssembly.il
3. Rename/move the original assembly: ren providedAssembly.dll providedAssembly.dll.orig
4. Create a new assembly from the MSIL output and your assembly KeyFile: ilasm providedAssembly.il /dll /key=keyPair.snk

Step 1: Dis-assemble the assembly

ildasm myTest.dll /out:myTest.il 

Step 2: Re-Assemble using your strong-name key

ilasm myTest.il /res:myTest.res /dll /key:myTest.snk /out:myTestSN.dll 

For verification you can use following command:

sn -vf myTestSN.dll

Hope this helps!

This link also shows how to do it, including when one of the 3rd party assemblies you're signing has a reference to another unsigned assembly that you're signing:

http://buffered.io/posts/net-fu-signing-an-unsigned-assembly-without-delay-signing

Edit: sorry, link is busted.