Compression filter named in a backup header is executed in restore
environment (commonly dom0). While this field is properly authenticated,
there may be cases where backup archive comes from less
trusted source, like migrating from potentially compromised
system.
Modify backup header parsing code to add field specific validators.
Whitelist only know crypto, hmac and compression algorithms.
Based on a patch by Jean-Philippe Ouellet <jpo@vt.edu>
Reported-by: Jean-Philippe Ouellet <jpo@vt.edu>
For various reasons, decryption may be slower than initial encryption
(different hardware, different system load etc). Do not fail the restore
operation if scrypt anticipate it will take considerably more time or
memory, than while creating the backup (where the scrypt parameters were
originally set).
Thanks to @jharveyb for the report and suggested solution.
FixesQubesOS/qubes-issues#4683
When both threads and processes are used, logging module can deadlock.
Workaround this by re-initializating locks in logging module.
See https://bugs.python.org/issue6721 for details.
Revert this commit when the python issue is fixed (in the python version
used for backup restore).
This is specifically the case on Travis-CI. But since dom0 backup is
restored into separate directory now, instead of directly overriding
user home, this check is much less relevant now.
If EOF is reached on tar's stderr, stop reading it, even if didn't found
expected data. Log this event.
This may happen when tar output some fatal error, instead of filelist.
os.path.splitext fails on path without proper file base name, like
'/something/..000'. Use plain string methods (rsplit).
FixesQubesOS/qubes-issues#3167
Very few calls at client side really needs VM class name. So, even in
non-blind mode use just QubesVM class, to avoid strange cases depending
on blind mode being enabled or not. Then, have VM class name in 'klass'
property. If known at object creation time, cache it, otherwise query
qubesd at first access.
Abort tar process after extracting requested files - do not parse the
archive until the end (possibly tens of GB later).
FixesQubesOS/qubes-issues#2986
