“Key is invalid” message on GitHub

Question

I have generated SSH keys for a new server installation according to the procedure outlined here. However, when I copy the contents of id_rsa.pub to my keys list on

Answer 1

I was having the same issue, despite copying the public key from cat output directly from the terminal (Cmder/ConEmu). It seems that the method that you use to copy the public key seems to make a difference. Here is a way to check:

$ ssh-keygen -l -f ~/.ssh/id_rsa.pub
4096 SHA256:...

Then paste the key that fails into a new file, and try to verify that:

$ ssh-keygen -l -f test.pub
test.pub is not a public key file.

In my case I had been copying the key from terminal output using cat; instead getting the key from vim worked. Here is way to open the key in vim with word wrap enabled:

$ vim "+set wrap" ~/.ssh/id_rsa.pub

I suspect that the terminal emulator may have something to do with it as I haven't had this issue with Terminal.app.