Even with the new keyed hash table journal feature: if an attacker
manages to get access to the journal file id it could synthesize records
that result in hash collisions. Let's rotate automatically when we
notice that, so that a new journal file ID is generated, our performance
is restored and the attacker has to guess a new file ID before being
able to trigger the issue again.
That said, untrusted peers should never get access to journal files in
the first case...
This adds a new (incompatible) feature to journal files: if enabled the
hash function used for the hash tables is no longer jenkins hash with a
zero key, but siphash keyed by the file uuid that is included in the
file header anyway. This should make our hash tables more robust against
collision attacks, as long as the attacker has no read access to the
journal files. We switch from jenkins to siphash simply because it's
more well-known and we standardize for the rest of our codebase onto it.
This is hardening in order to make collision attacks harder for clients
that can forge log messages but have no read access to the logs. It has
no effect on clients that have read access.
Let's prefix this with "jenkins_" since it wraps the jenkins hash. We
want to add support for other hash functions to journald soon, hence
better be clear with what this is. In particular as all other symbols
defined by lookup3.h actually are prefixed "jenkins_".
Let's clean this up a bit, following our usual nomenclature to name
return parameters ret-xyz.
This is mostly a bit of renaming, but there's also some minor other
changes: if we return a pointer to a mmap'ed object plus its offset, in
almost all cases we are happy if either parameter is NULL in case the
caller is not interested in it. Let's fix the remaining case to do this
too, to minimize surprises.
The object flags field is a bitmask, hence don't sloppily define
_OBJECT_COMPRESSED_MAX as one mor than the previous flag. That worked OK
as long as we only had two flags, but will fall apart as soon as we have
three. Let's fix this.
(It's kinda sloppy how the string table is built here, as it will be
quite sparse as soon as we have more enum entries, but let's keep it for
now.)
Instead of reading these files at startup and never again, let's read
them when we need them. As an optimization (in particular as some of
these files contain the data for many fields at once) let's cache the
results as long as the stat data (i.e. mtime) remains stable.
Also, while we are at it, if we can't read any of these props, let's not
fail everything, but continue without the data.
Since cryptsetup 2.3.0 a new API to verify dm-verity volumes by a
pkcs7 signature, with the public key in the kernel keyring,
is available. Use it if libcryptsetup supports it.
Since cryptsetup 2.3.0 a new API to verify dm-verity volumes by a
pkcs7 signature, with the public key in the kernel keyring,
is available. Use it if libcryptsetup supports it in the
veritysetup helper binary.
This way journalctl can make use of libqrencode if it's there, but will
quietly not use it if it isn't.
This means libqrencode remains a build-time dep, but not a strict
runtime dependency.
I figure we should do something similar for a bunch of other "leaf"
libraries we only use few symbols of. Specifically the following are
probably good candidates:
* pcre2
* libpwquality
* p11kit
* elfutils
and possibly:
* libcryptsetup (only in some parts. i.e. building systemd-cryptsetup
without it makes no sense. However building the dissect option with
libcryptsetup as optional dep does make sense)
* possibly the compression libraries (at least the ones we never use for
compression, but only as alternative ones for decompression)
Already covered like this is:
* libxkcommon
https://tools.ietf.org/html/draft-knodel-terminology-02https://lwn.net/Articles/823224/
This gets rid of most but not occasions of these loaded terms:
1. scsi_id and friends are something that is supposed to be removed from
our tree (see #7594)
2. The test suite defines an API used by the ubuntu CI. We can remove
this too later, but this needs to be done in sync with the ubuntu CI.
3. In some cases the terms are part of APIs we call or where we expose
concepts the kernel names the way it names them. (In particular all
remaining uses of the word "slave" in our codebase are like this,
it's used by the POSIX PTY layer, by the network subsystem, the mount
API and the block device subsystem). Getting rid of the term in these
contexts would mean doing some major fixes of the kernel ABI first.
Regarding the replacements: when whitelist/blacklist is used as noun we
replace with with allow list/deny list, and when used as verb with
allow-list/deny-list.
Zbigniew Jędrzejewski-Szmek
Lennart Poettering
Evgeny Vereshchagin
Yu Watanabe
Luca Boccassi
Michal Koutný