Will PackageDigitalSignatureManager.VerifySignatures() lead to a call outside the network?

Will PackageDigitalSignatureManager.VerifySignatures() lead to a call
outside the network?

I have a business requirement to check the digital signature on an Open
Packaging Conventions Package (it's a Word document) prior to continuing
to process the document. The package is signed by me prior to delivering
it to the client, so my code needs to verify at runtime that the file came
from me and also has not been altered. I have working code that does this
properly:
public static bool VerifySignature(Package package)
{
bool verified = true;
PackageDigitalSignatureManager dsm = new
PackageDigitalSignatureManager(package);
VerifyResult verifyResult = dsm.VerifySignatures(false);
verified &= verifyResult == VerifyResult.Success;
var signature = dsm.Signatures.Where(s =>
s.Signer.Subject.Equals("MyCompanyName")).FirstOrDefault();
verified &= !ReferenceEquals(signature, null) &&
signature.Signer.Issuer.Equals("NameOfCA");
return verified;
}
My question relates to what actually happens when
PackageDigitalSignatureManager.VerifySignatures() is called. I am
concerned that during the certificate validation a CRL check, or some
other call outside the network, will be made. I have some clients who run
my application on machines with absolutely no internet access. If the code
relies on internet access, it's basically a showstopper for me.
I want to know two things:
Will my code lead to a CRL check or something else which could result in a
call outside the network?
If so, is there a way to prevent it, or perhaps a different way to
validate the signature reliably using a different mechanism?