I don't know if this is a hack or not: we run a git command and increment the pending action
count to 1 but at some point the command requests a username or password, so we need to prompt
the user to enter that. At that point we don't want to say that there is a pending action,
so we decrement the action count before prompting the user and then re-increment it again afterward.
Given that we panic when the counter goes below zero, it's important that it's not zero
when we run the git command (should be impossible anyway).
I toyed with a different approach using channels and a long-running goroutine that
handles all commands that request credentials but it feels over-engineered compared to this
commit's approach.
The 8.2 release of OpenSSH added support for FIDO/U2F hardware
authenticators, which manifests in being able to create new types of SSH
key, named `ecdsa-sk` nad `ed25519-sk`. This is relevant to lazygit,
as those SSH keys can be used to authorise git operations over SSH, as
well as signing git commits. Actual code changes are required for
correct support, as the authentication process for these types of keys
is different than the process for types supported previously.
When an operation requiring credentials is initialised with a U2F
authenticator-backed key, the first prompt is:
Enter PIN for ${key_type} key ${path_to_key}:
at which point the user is supposed to enter a numeric (and secret) PIN,
specific to the particular FIDO/U2F authenticator using which the SSH
keypair was generated. Upon entering the correct key, the user is
supposed to physically interact with the authenticator to confirm
presence. Sometimes this is accompanied by the following text prompt:
Confirm user presence for key ${key_type} ${key_fingerprint}
This second prompt does not always occur and it is presumed that the
user will know to perform this step even if not prompted specifically.
At this stage some authenticator devices may also begin to blink a LED
to indicate that they're waiting for input.
To facilitate lazygit's interoperability with these types of keys, add
support for the first PIN prompt, which allows "fetch", "pull", and
"push" git operations to complete.
