Signing the Patterns and Practices Enterprise Library
We recently ran into an issue where a Windows
Forms application was consuming the Enterprise Library's Caching and Exception
Handling block. The Windows Forms
assembly was configured to be signed with a specified .snk file, which was the
same .snk which we were planning to use to sign the Enterprise Library
assemblies. The first step was to
open each project in the Enterprise Library and specify the .snk file. We then had to update the assembly
information to represent the internal hex private key which we extracted from
the .snk. See Tom Hollander's blog
for specific instructions.
Once the library was signed (the library projects,
test projects and designer projects too) we then replaced the .dlls that were
unsigned with the newly signed .dll files.
The challenge was that we were getting an assembly manifest exception
from the Configuration Manager.
"An error occurred creating the configuration section
handler for cachingConfiguration: Could not load file or assembly
'Microsoft.Practices.EnterpriseLibrary.Caching, Version=2.0.0.0,
Culture=neutral, PublicKeyToken=null' or one of its dependencies. The located
assembly's manifest definition does not match the assembly reference. (Exception
from HRESULT: 0x80131040)
If you take note, the PublicKeyToken argument
is null. This is because the EntLib
configuration tool was used prior to the signing of the assemblies. Thus, this error was happening when the
configuration manager tried to reconcile the signed referenced assembly for the
EntLib in the project and the specification of the assembly in the
app.config. The above error is the
result. The quick fix is to place
the public key token into the app.config for each specification of the EntLib
.dll files. This will cause the
manifest and the app.config to agree and code execution to launch. The long term fix is to place the signed
assemblies for the Enterprise Library into the directory that the EntLib config
tool lives. Then when configuring a
new application in this tool, the public key token will be written into the
app.config.
When manually doing this to remediate, use sn -t
assemblyname.dll to extract the public key token.
Thanks to Tom Hollander who provided the
solution!
