[I-19] SSH key priority option?

I also need support for IdentityFile, or at least an alternative solution. With ssh-agent, it's the only way I've found to have both work and personal accounts on Bitbucket that require distinct private keys. My ~/.ssh/config file is full of configs to know which keys are preferred on which hosts.

For example:

```
Host bitbucket.org
IdentityFile ~/.ssh/id_ed25519 # Used for Work account

Host personal.bitbucket.org
HostName bitbucket.org
User git
IdentityFile ~/.ssh/id_ecdsa # Used for Personal account
```

This has also helped me keep track of which public keys are with which services, because not everything supported Ed25519 when I set up the keys.

Maybe you can use Match Key with Host?

That works. But since it doesn't support ECDSA, I generated an alternate Ed25519 key and used:


Host personal.bitbucket.org
HostName bitbucket.org
User git
IdentityAgent ~/.1password/agent.sock
IdentityFile ~/.ssh/id_ed25519-alternate.pub


Now I only have one remaining service using that ECDSA key because they still don't support Ed25519.

Despite setting up an IdentityFile with a public key instead of a private one, 1Password is still unlocking the RSA key first.

Are you SSH'ing from the terminal or if not, what SSH client are you using?

I am using the terminal.

Could you share (the relevant bits of) your SSH config and SSH_AUTH_SOCK=~/.1password/agent.sock ssh-add -l output?

SSH config:
```
IdentityFile ~/.ssh/id_ed25519.pub
IdentityFile ~/.ssh/id_rsa.pub

Host *
IdentityAgent ~/.1password/agent.sock

Host aur.archlinux.org
IdentityFile ~/.ssh/aur.pub
User aur

[repeating below for different servers]
Host [server-alias]
HostName [ip address]
User [username]


4096 SHA256:Gu0EFgYpwVbLsqX5nDEL5V1jUfryMTe7FR8AUUsg4+E (RSA)
256 SHA256:WdVfgHlD0C2HEq9y60mYiah/4lY8xhitK1wY1pvYKjk (ED25519)
3072 SHA256:S9scRLenmjLjv4srb9n5dIkYu9MM2ihZDXVbLxW4KNg (RSA)
```

For that host specific AUR configuration, it works perfectly and unlocks the aur key first.
The global configuration doesn't work and just uses the RSA key first anyway.

I'm guessing that that's because you've specified multiple keys as IdentityFile. If you want control over which key is used, your SSH config should be more explicit. For example:

```
IdentityFile ~/.ssh/id_ed25519.pub

Host host-that-uses-the-rsa-key
IdentityFile ~/.ssh/id_rsa.pub
```

Or even more explicit:
```
Host host-that-uses-the-rsa-key
IdentityFile ~/.ssh/id_rsa.pub

Host host-that-uses-the-ed25519-key
IdentityFile ~/.ssh/id_ed25519.pub
```

SSH by default uses the keys in the order specified. I could go and mark which key to use for each host, but it would be far more convenient to have them apply globally apart from a few exceptions.

Specifying the order to try keys in would be a small quality of life feature. It could be used to demote a key to be a fallback that's used only when necessary and to just optimize the authentication speed to not waste time trying less frequently used keys.