I posted about this on the hub few days ago, figured it might be beneficial to do so here as well
The issue is that the "allow untrusted" options as they are now are honest to a fault, ie. they also disable all KEYP checks when turned on. The attached patch fixes this. The ConnectionManager and UserConnection changes are just a micro-optimization not to lookup the user twice if we already have it.
In theory we could also avoid verifying KEYP twice in such scenario (ie. just include the checkKeyprint() call to under the added if statement as well, because if it fails in the first place the execution never reaches this point, for outgoing connections).
Also, while this is more of a request it would be nice if someone would come up with a way to reflect the verify_callback error "KeyPrint mismatch" in HubFrame.
poy: Please verify this patch.