Does anybody know a way of either converting (on android) a putty key to something I can use in ConnectBot, or a good android SSH app that can use Putty keys natively?
I am away from home without my laptop, which I would usually use. I only have my android phone with me.
A few months ago I tried creating RSA key pairs to use with Putty on my laptop and ConnectBot but for some reason I just could not crack it so gave up. I also used puttygen to create an RSA key but it would not work on ConnectBot
If you want to stick with that “one key” approach - get a hardware token like a Nitrokey or a Yubikey. That should also work with most Android SSH clients.
This is actually quite handy, I’ve got a yubikey already and didn’t know they could be used for ssh
Unless you have one of the dumbed down Fido or whatever only versions yubikey is just a smartcard with key storage, and multiple different applications for interfacing with the keys - and as everybody (at least everybody sane) uses the same crypto algorithms those can be shared for whatever needs that.
For SSH you’ll have at least two options - if you have a GPG key on that thing just use the auth-key on there (create one if you don’t have that yet) for SSH, if not maybe adding a PIV key is the better option, that should be available via PKCS#11 then. There might be additional options as well, though.