A question came up on the Unix & Linux SE site: Checking if passwordless ssh authorization is possible without permission for sshd_config?.
I immediately thought you could possibly infer this using the commands:
ssh-keyscan -t rsa <server> and
ssh-keyscan -t dsa <server>.
My logic is that if a server is returning either key, then it must support that type of key for users' use as well.
Is this assumption incorrect?