SSH Key: “Permissions 0644 for 'id_rsa.pub' are too open.” on mac

Question

I generate a ssh key pair on my mac and add the public key to my ubuntu server(in fact, it is a virtual machine on my mac),but when I try to login the ubuntu server,it says:

Answer 1

If youre using a .ssh/config file try to

chmod 0400 .ssh/config

then:

chmod 0400 .ssh/<>