Currently, if the libmount feature is disabled, we don't build
libshared and as a result skip building every other executable as
well. Among other things, this makes our nodeps CI builds kind of
pointless since hardly any code will be compiled.
Let's improve on the situation by making libmount properly optional
in libshared. Then, we only skip building the executables that
actually need libmount.
Before:
$ build/systemd-creds --uid=asdf
Failed to resolve user 'asdf': No such process
Now:
$ build/systemd-creds --uid=asdf
Failed to resolve user 'asdf': Unknown user
This reworkds TPM2 based creds a bit. Instead of mapping the key type
"tpm2" directly to a TPM2 key without PK, let's map it to an "automatic"
key type that either picks PK or doesn't, depending on what's available.
That should make things easier to grok for people, as the nitty gritty
details of PK or not PK are made autmatic. Moreover it gives us more
leverage to change the TPM2 enrollment types later (for example, we
definitely want to start pinning SRK, and hook up pcrlock too, for
creds, which we currently don't).
This hence adds a new _CRED_AUTO_TPM2
pseudo-type we automatically maps to CRED_AES256_GCM_BY_TPM2_HMAC_WITH_PK
or CRED_AES256_GCM_BY_TPM2_HMAC depending if PK as available. Similar,
_CRED_AUTO_HOST_AND_TPM2 is added, which does the same for the
host/nonhost cred type.
This does not introduce any new type on the wire, it just changes how we
select the right key type.
To make the code more readable this also adds some categorization macros
for the keys, instead of repeating the list of key types at multiple
places.
The ability to encrypt/authenticate encryption with a null key was
originally just a fallback concept for cases where during early boot we
have no host key, but the local system has no TPM2. Nowadays it is used
for other stuff as well, such as pcrlock data propagation (i.e. data
that needs no protection itself and required to properly to TPM key
derivation).
Let's give better, explicit control over null key usage, i.e. let's make
it a tristate both on the systemd-creds command line and in the Varlink
IPC to control three cases:
- the default that we allow it only if SecureBoot is off
- explicitly allowed
- explicitly refused (this is new)
Ideally systemd-creds --allow-null switch would take a boolean argument
to control this as a tristate. Alas, that would be a compat break, hence
I added --refuse-null instead (which also maps to the low-level flag for
this).
This also normalizes that the null key is always called "null key" in
messages, and not sometimes "empty key" or "fallback key".
Let's make some specific condition more recognizable via error codes of
their own, and in particular remove confusion between EREMOTE as
returned by tpm2_unseal() and by us.
This commit cleans up the includes for all the small tools across
the tree.
A few cases of returning EXIT_SUCCESS are replaced with returning
0 to avoid including <stdlib.h>.
Split out of #37344.
Let's move some more implementation logic into functions. We keep
the logic that requires the macro in the macro and move the rest into
functions.
While we're at it, let's also make the parameter declarations of
all the string table macros less clausthrophobic.
Let's move some logic from _DEFINE_MAIN_FUNCTION() and other places
in main-func.h into functions that we implement in main-func.c to
allow moving some included headers from the header to the .c file.
Now that the necessary functions from log.h have been moved to macro.h,
we can stop including log.h in macro.h. This requires modifying source
files all over the tree to include log.h instead.
PCR 7 covers the SecureBoot policy, in particular "dbx", i.e. the
denylist of bad actors. That list is pretty much as frequently updated
as firmware these days (as fwupd took over automatic updating). This
means literal PCR 7 policies are problematic: they likely break soon,
and are as brittle as any other literal PCR policies.
hence, pick safer defaults, i.e. exclude PCR 7 from the default mask.
This means the mask is now empty.
Generally, people should really switch to signed PCR policies covering
PCR 11, in combination with systemd-pcrlock for the other PCRs.
The values that were previously hardcoded in sd-varlink.c are now defined
in new varlink_set_info_systemd() and that function is called everywhere
where we create a server.
We often used a pattern like if (!FLAGS_SET(flags, SD_JSON_FORMAT_OFF)),
which is rather verbose and also contains a double negative, which we try
to avoid. Add a little helper to avoid an explicit bit check.
This change clarifies an aditional thing: in some cases we treated
SD_JSON_FORMAT_OFF as a flag (flags & SD_JSON_FORMAT_OFF), while in other cases
we treated it as an independent enum value (flags == SD_JSON_FORMAT_OFF).
In the first form, flags like SD_JSON_FORMAT_SSE do _not_ turn the json
output on, while in the second form they do. Let's use the first form
everywhere.
No functional change intended.
Initially I wasn't sure if this helper should be made public or just internal,
but it seems such a common pattern that if we expose the flags, we might just
as well expose it too, to make life easier for any consumers.
The verb s not really specific to credential management, it was always a
bit misplaced. Hence move it to systemd-analyze, where we already have
some general TPM related verbs such as "srk" and "pcrs"
It's time. sd-json was already done earlier in this cycle, let's now
make sd-varlink public too.
This is mostly just a search/replace job of epical proportions.
I left some functions internal (mostly IDL handling), and I turned some
static inline calls into regular calls.
This is preparation for making our Varlink API a public API. Since our
Varlink API is built on top of our JSON API we need to make that public
first (it's a nice API, but JSON APIs there are already enough, this is
purely about the Varlink angle).
I made most of the json.h APIs public, and just placed them in
sd-json.h. Sometimes I wasn't so sure however, since the underlying data
structures would have to be made public too. If in doubt I didn#t risk
it, and moved the relevant API to src/libsystemd/sd-json/json-util.h
instead (without any sd_* symbol prefixes).
This is mostly a giant search/replace patch.
When we display passed credentials we show a brief safety level based on
how the credential is pass in: if it's backed by swappable memory we
give it a "weak" level. This check was so far done by checking if the
file is backed by ramfs. However, since
1155f44f48 we actually prefer tmpfs with
the new "noswap" option for this.
Hence, fix this, and explicitly look for "noswap" among the mount
options in case we detect tmpfs.
- drop unnecessary SYNTHETIC_ERRNO() when the logger does not propagate
error code,
- drop unnecessary '%m' in error message when the error code is
specified with SYNTHETIC_ERRNO(),
- add missing full stop at the end of log message,
- use RET_GATHER(),
- add missing ", ignoring.",
- upeercase the first letter, etc., etc...
This adds for both the D-Bus and the Varlink flavours of our polkit
client api a flags parameter. And then folds the "bool interactive" flag
that the D-Bus version so far had, into a flag, and also adds support
for it in the Varlink API.
Since this means the Varlink API gained another parameter, let's do what
we already did for the D-Bus API and add a _full() version of the API
that has the flags and the good_uid parameter, and one without both.
Daan De Meyer
Zbigniew Jędrzejewski-Szmek
Lennart Poettering
Antonio Alvarez Feijoo
Mike Yuan
Yu Watanabe
Simon Pilkington
Ludwig Nussel
Luca Boccassi