IIS Medium Trust

Anyone know if CB's client dlls were compiled in managed code; and if so, does it allow partially trusted callers, i.e. AllowPartiallyTrustedCallers attribute? Am using ASP.NET MVC3 C# 4.0 CLR and IIS 7.5 and would like to use CB as a session state store provider. I may still have to create a wrapper project using the 3.5 CLR; since the 4.0 CLR does not allow net tcp bindings. Thanks.