This is the dual of 1f3c8c5b3d
where we output more detail when signapi fails to validate.
Extend the API to return a string for success, which we output
to stdout.
This will help the test suite *and* end users validate that the expected
thing is happening.
In order to make this cleaner, split the "verified commit" set
in the pull code into GPG and signapi verified sets, and have
the signapi verified set contain the verification string.
We're not doing anything with the verification string in the
pull code *yet* but I plan to add something like
`ostree pull --verbose` which would finally print this.
The goal here is to move the code towards a model
where the *client* can explicitly specify which signature types
are acceptable.
We retain support for `sign-verify=true` for backwards compatibility.
But in that configuration, a missing public key is just "no signatures found".
With `sign-verify=ed25519` and no key configured, we can
explicitly say `No keys found for required signapi type ed25519`
which is much, much clearer.
Implementation side, rather than maintaining `gboolean sign_verify` *and*
`GPtrArray sign_verifiers`, just have the array. If it's `NULL` that means
not to verify.
Note that currently, an explicit list is an OR of signatures, not AND.
In practice...I think most people are going to be using a single entry
anyways.
Previously in the pull code, every time we went to verify
a commit we would re-initialize an `OstreeSign` instance
of each time, re-parse the remote configuration
and re-load its public keys etc.
In most cases this doesn't matter really because we're
pulling one commit, but if e.g. pulling a commit with
history would get a bit silly.
This changes things so that the pull code initializes the
verifiers once, and reuses them thereafter.
This is continuing towards changing the code to support
explicitly configured verifiers, xref
https://github.com/ostreedev/ostree/issues/2080
This cleans up the verification code; it was weird how
we'd get the list of known names and then try to create
an instance from it (and throw an error if that failed, which
couldn't happen).
Colin Walters