This adds a two new values to --private-users-ownership=: "map" and
"auto".
"map" exposes the kernel 5.12 idmap feature pretty much 1:1. It fails if
the kernel or used file system doesn't support ID mapping.
"auto" is a bit smarter: if we can make ID mapping work, we'll use it,
otherwise revert back to classic chown()ing. We'll also use chown()ing
if we detect that an image is already ID shifted, both to increase
compatibility with the status quo ante, and to simplify our codepaths,
since the mappings become a lot simpler if we only have to map from zero
to something else, instead of from anything to anything else.
The short -U switch, and --private-users=pick will now imply
--private-users-ownership=auto instead of
--private-users-ownership=chown, since the new logic should be the much
better choice.
This makes use of the new kernel 5.12 APIs to add an idmap to a mount
point. It does so by cloning the mountpoint, changing it, and then
unmounting the old mountpoint, replacing it later with the new one.
This replaces --private-user-chown by an enum value
--private-user-ownership=off|chown. Changes otherwise very little.
This is mostly preparation for a follow-up commit adding a new "map"
mode, using kernel 5.12 UID mapping mounts.
Note that this does alter codeflow a bit: the new enum already knows
three different values instead of the old true/false pair. Besides "off"
and "chown" it knows -EINVAL, i.e. whenever the value wsn't set
explicitly. This value is changed to "off" or "chown" before use, thus
retaining compat to the status quo before, except it won't override
explicit configuration anymore. Thus, if you explicitly request
--private-user=pick you can now combine it wiht an explicit
--private-user-ownership=off if you like, which will give you a
container that runs under its own UID set, but the files will be owned
by the original image. Makes not much sense besids maybe debugging, but
if requested explicitly I think it's OK to implement.
userns identity 1:1 mapping is a pretty useful concept since it isolates
capability sets between containers and hosts, even if it doesn't map
any uid ranges. Let's support it with an explicit concept.
(Note that this is identical to --private-users=0:65536 (which in turn
is identical to --private-users=0), but I think it makes to emphasize
this concept as a high-level one that makes sense to support.)
Some tokens support authorization via fingerprint or other biometric
ID. Add support for "user verification" to cryptenroll and cryptsetup.
Disable by default, as it is still quite uncommon.
In some cases user presence might not be required to get _a_
secret out of a FIDO2 device, but it might be required to
the get actual secret that was used to lock the volume.
Record whether we used it in the LUKS header JSON metadata.
Let the cryptenroll user ask for the feature, but bail out if it is
required by the token and the user disabled it.
Enabled by default.
Closes: https://github.com/systemd/systemd/issues/19246
Some FIDO2 devices allow the user to choose whether to use a PIN or not
and will HMAC with a different secret depending on the choice.
Some other devices (or some device-specific configuration) can instead
make it mandatory.
Allow the cryptenroll user to choose whether to use a PIN or not, but
fail immediately if it is a hard requirement.
Record the choice in the JSON-encoded LUKS header metadata so that the
right set of options can be used on unlock.
On headless setups, in case other methods fail, asking for a password/pin
is not useful as there are no users on the terminal, and generates
unwanted noise. Add a parameter to /etc/crypttab to skip it.
So far we basically had two ways to iterate through NSS records: one via
the varlink IPC and one via the userdb.[ch] infra, with slightly
different implementations.
Let's clean this up, and always use userdb.[ch] also when resolving via
userdbd. The different codepaths for the NameServiceSwitch and the
Multiplexer varlink service now differ only in the different flags
passed to the userdb lookup.
Behaviour shouldn't change by this. This is mostly refactoring, reducing
redundant codepaths.
Let's use "exclude" for flags that really exclude records from our
lookup. Let's use "avoid" referring to concepts that when flag is set
we'll not use but we have a fallback path for that should yield the same
result. Let' use "suppress" for suppressing partial info, even if we
return the record otherwise.
So far we used "avoid" for all these cases, which was confusing.
Whiel we are at it, let's reassign the bits a bit, leaving some space
for bits follow-up commits are going to add.
This fixes the following error:
```
In file included from ../src/basic/af-list.h:6,
from ../src/basic/af-list.c:7:
../src/basic/string-util.h: In function 'char_is_cc':
../src/basic/string-util.h:133:19: error: comparison is always true due to limited range of data type [-Werror=type-limits]
133 | return (p >= 0 && p < ' ') || p == 127;
| ^~
cc1: all warnings being treated as errors
```
Fixes#19543.
userdbd listens on "two" sockets, that are actually the same: one is a
real AF_UNIX socket in the fs, and the other is a symlink to it.
So far, when userdbd was started from the command line it would make one
a symlink and the other a real socket, but when invoked via unit files
they'd be swapped, i.e. the other would be a symlink and the one a real
socket.
Let's bring this in line.
Since the "io.systemd.Multiplexer" is our main interface, let's make it
the one exposed as socket, and then make "io.systemd.NameServiceSwitch"
a symlink to it. Or in other words, let's adjust the C code to match the
unit file.
Add SBAT support, when -Dsbat-distro value is specified. One can use
-Dsbat-distro=auto for autodetection of all sbat options. Many meson configure
options added to customize SBAT CSV values, but sensible defaults are auto
detected by default. SBAT support is required if shim v15+ is used to load
systemd-boot binary or kernel.efi (Type II BootLoaderSpec).
Fixes#19247
When we are queried for membership lists on a system that has exactly
zero, then we'll return ESRCH immediately instead of at EOF. Which is
OK, but we need to handle this in various places, and not get confused
by it.
It's not going to be efficient if called in inner loops, but it's oh so
handy, and we have some code that does this:
asprintf(&p, "%s…", b, …);
free(b);
b = TAKE_PTR(p);
which can now be replaced by the quicker and easier to read:
strextendf(&p, "…", …);
Let's add three defines for the 3 special cases of passwords.
Some of our tools used different values for the "locked"/"invalid" case,
let's settle on using "!*" which means the password is both locked *and*
invalid.
Other tools like to use "!!" for this case, which however is less than
ideal I think, since the this could also be a considered an entry with
an empty password, that can be enabled again by unlocking it twice.
If ":" was the last char in the string, we would call access() on ".../drivers/", which
would pass. It probably doesn't matter, but let's reject this anyway.
Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=33881.
Not only we would duplicate unknown input on the stack, we would do it
over and over. So let's first check that the input has reasonable length,
but also allocate just one fixed size buffer.
Lennart Poettering
Luca Boccassi
Yu Watanabe
Zbigniew Jędrzejewski-Szmek
Dimitri John Ledkov
Mike Kazantsev