This ignores several different combinations of errnos which are returned
if the storage destination is not able to fsync correctly.
See also https://github.com/restic/restic/pull/4021
This stores a hash of the username + password in map which is indexed by
the username. Indexing by username avoids accidentally introducing a
timing side-channel as a successful/failed lookup only provides
information on whether a cache entry exists for a username or not.
Hashing the username and password together makes it simple to get a
constant-time string comparison as we no longer have to worry about
string length differences.
Expriy is done by a goroutine which every few seconds checks for expired
cache entries and removes those.
A upload is now first saved to a temporary file before it gets renamed
to the final filename. This ensures that incomplete uploads don't leave
broken files behind (at least not under their real filename).
In addition, removing failed uploads is no longer prone to a race
condition with a retried upload. That scenario could occur when the
first upload fails partway and the server doesn't notice that
immediately. A later retry by restic will then delete the broken upload
and upload the file again. If the server notices now that the initial
upload has failed, then it will delete the correctly uploaded file.
This has been fixed by only ever deleting the temporary file during
upload.
Restic uses the sha256 hash to calculate filenames based on the file
content. Check on the rest-server side that the uploaded file is intact
and reject it otherwise.
The rest server is normally shutdown via a SIGINT signal. The http
handle calls are endless loops and don't return in the normal case. Thus
add a signal handler to shutdown the profiler.
Michael Eischer