This will perform updates with all currently present metadata.
It is "intended" for usage with local metadata repositories referring
to local files.
fwupdtool however does also support fetching a file from the web
and if the metadata refers to the file on the web it should also work
for that.
If a remote like LVFS outputs <location>foo.cab</location> without a prepended
hostname and path then we should use the metadata URI hostname and path instead.
This allows us to trivially mirror a firmware repository, although clients using
older versions of libfwupd will not work without this patch. We should encourage
people to use `FirmwareBaseURI` for a long time yet.
We can use this as an alternative for GPG. No PKCS7 certificates are currently
installed by fwupd and it's expected that the LVFS will still only provide GPG
detached signatures.
If an OEM distributor wants to sign firmware with a PKCS7 and the corresponding
certificate is provided then the firmware will be marked as valid.
Only firmware shipping with a .p7b file will use the PKCS7 functionality,
similarly remote metadata validation will default to GPG unless Keyring=pkcs7
is specified in the config file.
In this mode, both the metadata and firmware is stored on the local filesystem
and distributed using a distribution system like OSTree.
Fixes https://github.com/hughsie/fwupd/issues/162
