dr8/yubico-pam — comment on commit d705f429bc972f85a50f0b2f96703cbdc28b744f
File:  line 0
By dr8:

In retrospect, there is an error here in that if the client_key is not specified in the pam config file, the test in line 689 still passes, even though cfg->client_key is NULL - and then the client will always refuse server signatures.

Presumably we want to allow users not to specify the key if they wish.