I need to send a public key to my bank. I'm using CoreFTP which allows the generation of keys using RSA. It says that it generates "OpenSSH compatible certificates [sic]" when you press the generate keys button.
The keys it generates have
-----BEGIN RSA PUBLIC KEY-----
at the start (and then the key and then an end marker).
My bank rejects my public key and says it should begin
I suspect "RSA" and "OpenSSH" have variations that neither end are being clear about what they generate/expect.
How can I convert my key from the format the CoreFTP is providing to the format my bank wants?