The PolicyPCR digest is not always the complete input to an offline
signature. PolicyAuthorize also includes the hashed policy reference.
This is now required for NVPCRs to work in the initrd.
Expose the complete data as "tbs" (to-be-signed) and use it when ukify
matches offline signatures. Keep "pol" as the compatibility fallback.
Fixes: https://github.com/systemd/systemd/issues/43635
Follow-up for f0f3687700
systemd-measure can produce multiple signed policies for different
phases. However, a policy for a TPM resource that includes these signed
policies can currently be satisfied by any policy that is signed
with the same key.
It can be desirable to bind a resource's policy to one or more
specific phases. One way to do this could be to sign policies for
different phases or phase combinations with different keys. Another
approach is to limit the scope of signed policies using a policy
reference.
Using a policy reference works because:
- The reference is included along with the approved policy digest in the
digest that is signed.
- The reference argument is included in the authorization policy for a
resource via the TPM2_PolicyAuthorize assertion.
- During execution of the TPM2_PolicyAuthorize assertion, the TPM checks
that the session's current policy digest is the approved policy digest,
computes a digest from the approved policy digest and the supplied policy
reference, and checks that the resulting digest is the one that was
verified by TPM2_VerifySignature (via the returned ticket).
This adds a new --policyref argument to systemd-measure which binds all
of the signed policies to the specified policy reference. I did consider
making this more intelligent by auto-generating policy references for each
phase, but this approach provides the most flexibility for now. By making
use of the existing --append argument, a signer can produce multiple
signed policies with the same key that are bound to any individual phases
or combinations of phases.
The policy reference is a string without the NULL terminator. It is
supplied to the TPM via the TPM2B_NONCE type, which has a maximum size
equivalent to the size of the largest digest supported by the TPM. As
the signer doesn't know the capabilities of the target TPM,
systemd-measure limits the size of the policy reference to 32 bytes, to
fit within the size of a SHA256 digest.
This also includes the corresponding changes to systemd-cryptenroll and
systemd-repart (to add an equivalent --tpm2-public-key-policyref argument
so that the policy can be bound to the desired corresponding phase, and to
ensure that the policy reference is included in the LUKS2 token metadata),
and systemd-cryptsetup (to handle the policy reference stored in the LUKS2
token metadata).
This doesn't include policy reference support for credentials yet
because it requires a change to the credential headers.
When doing offline signing we need to know the exact payload
to sign, and the 'calculate' verb doesn't really show that, it
shows the PCR values. But what we sign is the hash of the policy.
So add a new verb that outputs the json payload that goes in the
.pcrsig section, without the .sig object, so that we can take them
and give the .pol object to an offline and asynchronous signing
service, such as SUSE's Open Build Service, and then add the .sig
object to the json and attach it to a UKI.
Let's gather generic key/certificate operations in a new tool
systemd-keyutil instead of spreading them across various special purpose
tools.
Fixes#35087
Let's gather generic key/certificate operations in a new tool
systemd-keyutil instead of spreading them across various special
purpose tools.
Fixes#35087
In the troff output, this doesn't seem to make any difference. But in the
html output, the whitespace is sometimes preserved, creating an additional
gap before the following content. Drop it everywhere to avoid this.
This verb writes a public key to stdout extracted from either a public key
path, from a certificate (path or provider) or from a private key (path,
engine, provider). We'll use this in ukify to get rid of the use of the
python cryptography module to convert a private key or certificate to a
public key.
This allows loading the X.509 certificate from an OpenSSL provider
instead of a file system path. This allows loading certficates directly
from hardware tokens instead of having to export them to a file on
disk first.
systemd-stub provides the signing key for TPM2 signed PCR policies in a
file tpm2-pcr-public-key.pem to userspace. Hence, to clarify that this
is the same key as used when signing via "systemd-measure", let's rename
it in the docs like that.
Also rename the private key to tpm2-pcr-private-key.pem, to keep the
symmetry.
With this we should universally stick to this nomenclature:
1. tpm2-pcr-public-key.pem ← public part of signing key
2. tpm2-pcr-private-key.pem ← private part of signing key
3. tpm2-pcr-signature.json ← signature file made with key pair
Inspired by: #34069
At this point we have a clearer model:
* systemd-measure should be used for measuring UKIs on vendor build
systems, i.e. only cover stuff predictable by the OS vendor, and
identical on all systems. And that is pretty much only PCR 11.
* systemd-pcrlock should cover the other PCRs, which carry inherently
local information, and can only be predicted locally and not already
on vendor build systems.
Because of that, let's not bother with any PCRs except for 11 in
systemd-measure. This was added at a time where systemd-pcrlock didn't
exist yet, and hence it wasn't clear how this will play out in the end.
Allow signing with an OpenSSL engine/provider, such as PKCS11. A public key is
not enough, a full certificate is needed for PKCS11, so a new parameter is
added for that too.
The binaries are built and installed if HAVE_TPM2 is set, and ignore ENABLE_BOOTLOADER,
so do the same for the manpages.
For the sd-pcrlock case this also installs the manpage aliases for the units, which
are not installed with -Dbootloader=disabled, but there's no way to conditionalize
the aliases, so on balance it's better to have too much documentation rather than
too little.
Fixes https://github.com/systemd/systemd/issues/30588
This was requested, though I think an issue was never filed. If people are
supposed to invoke it, even for testing, then it's reasonable to make it
"public".
The tool initially just measured the boot phase, but was subsequently
extended to measure file system and machine IDs, too. At AllSystemsGo
there were request to add more, and make the tool generically
accessible.
Hence, let's rename the binary (but not the pcrphase services), to make
clear the tool is not just measureing the boot phase, but a lot of other
things too.
The tool is located in /usr/lib/ and still relatively new, hence let's
just rename the binary and be done with it, while keeping the unit names
stable.
While we are at it, also move the tool out of src/boot/ and into its own
src/pcrextend/ dir, since it's not really doing boot related stuff
anymore.
As I noticed a lot of missing information when trying to implement checking
for missing info. I reimplemented the version information script to be more
robust, and here is the result.
Follow up to ec07c3c80b
This tries to add information about when each option was added. It goes
back to version 183.
The version info is included from a separate file to allow generating it,
which would allow more control on the formatting of the final output.
ukify supports signing with multiple keys, so show an example of this, and just
let ukify print the calls to systemd-measure that will be done.
This also does other small cleanups:
- Use more realistic names in examples
- Use $ as the prompt for commands that don't require root (most don't).
Once we switch to operations that don't require a TPM, we should be able to get
rid of the remaining calls that require root.
- Ellipsize or linebreak various parts
- Use --uname. We warn if it is not specified and we have to do autodetection, so
let's nudge people towards including it rather than not.
Follow-up for e069c57f06.
This drops all mentions of gnu-efi and its manual build machinery. A
future commit will bring bootloader builds back. A new bootloader meson
option is now used to control whether to build sd-boot and its userspace
tooling.
(The one case that is left unchanged is '< <(subcommand)'.)
This way, the style with no gap was already dominant. This way, the reader
immediately knows that ' < ' is a comparison operator and ' << ' is a shift.
In a few cases, replace custom EOF replacement by just EOF. There is no point
in using someting like "_EOL" unless "EOF" appears in the text.
Fixes#25780.
> Man page: crypttab.5
> Issue 1: Missing fullstop
> Issue 2: I<cipher=>, I<hash=>, I<size=> → B<cipher=>, B<hash=>, B<size=>
>
> "Force LUKS mode\\&. When this mode is used, the following options are "
> "ignored since they are provided by the LUKS header on the device: "
> "I<cipher=>, I<hash=>, I<size=>"
Seems OK to me. The full stop is there and has been for at least a few years. And we use <option> for the markup, which is appropriate here.
> Man page: crypttab.5
> Issue 1: Missing fullstop
> Issue 2: I<cipher=>, I<hash=>, I<keyfile-offset=>, I<keyfile-size=>, I<size=> → B<cipher=>, B<hash=>, B<keyfile-offset=>, B<keyfile-size=>, B<size=>
>
> "Use TrueCrypt encryption mode\\&. When this mode is used, the following "
> "options are ignored since they are provided by the TrueCrypt header on the "
> "device or do not apply: I<cipher=>, I<hash=>, I<keyfile-offset=>, I<keyfile-"
> "size=>, I<size=>"
Same.
> Man page: journalctl.1
> Issue 1: make be → may be
Fixed.
> Issue 2: below\\&. → below:
Fixed.
> Man page: journalctl.1
> Issue: Colon at the end?
>
> "The following commands are understood\\&. If none is specified the default "
> "is to display journal records\\&."
> msgstr ""
> "Die folgenden Befehle werden verstanden\\&. Falls keiner festgelegt ist, ist "
> "die Anzeige von Journal-Datensätzen die Vorgabe\\&."
This is a bit awkward, but I'm not sure how to fix it.
> Man page: kernel-install.8
> Issue: methods a fallback → methods fallback
It was correct, but I added a comma to make the sense clearer.
> Man page: loader.conf.5
> Issue 1: secure boot variables → Secure Boot variables
> Issue 2: one → one for (multiple times)
>
> "Supported secure boot variables are one database for authorized images, one "
> "key exchange key (KEK) and one platform key (PK)\\&. For more information, "
> "refer to the \\m[blue]B<UEFI specification>\\m[]\\&\\s-2\\u[2]\\d\\s+2, "
> "under Secure Boot and Driver Signing\\&. Another resource that describe the "
> "interplay of the different variables is the \\m[blue]B<EDK2 "
> "documentation>\\m[]\\&\\s-2\\u[3]\\d\\s+2\\&."
"one of" would sound strange. "One this and one that" is OK.
> Man page: loader.conf.5
> Issue: systemd-boot → B<systemd-boot>(7)
Fixed.
> Man page: logind.conf.5
> Issue: systemd-logind → B<systemd-logind>(8)
We use <filename>systemd-logind</> on subsequent references… I think that's good enough.
> Man page: nss-myhostname.8
> Issue: B<getent> → B<getent>(1)
Fixed.
> Man page: nss-resolve.8
> Issue: B<systemd-resolved> → B<systemd-resolved>(8)
The first reference does this, subsequent are shorter.
> Man page: os-release.5
> Issue: Portable Services → Portable Services Documentation?
Updated.
> Man page: pam_systemd_home.8
> Issue: auth and account use "reason", while session and password do not?
Reworded.
> Man page: portablectl.1
> Issue: In systemd-portabled.service(8): Portable Services Documentation
Updated.
> Man page: repart.d.5
> Issue: The partition → the partition
Fixed.
> Man page: repart.d.5
> Issue: B<systemd-repart> → B<systemd-repart>(8)
The first reference does this. I also change this one, because it's pretty far down in the text.
> Man page: systemd.1
> Issue: kernel command line twice?
>
> "Takes a boolean argument\\&. If false disables importing credentials from "
> "the kernel command line, qemu_fw_cfg subsystem or the kernel command line\\&."
Apparently this was fixed already.
> Man page: systemd-boot.7
> Issue: enrollement → enrollment
Fixed.
> Man page: systemd-cryptenroll.1
> Issue: multiple cases: any specified → the specified
Reworded.
> Man page: systemd-cryptenroll.1
> Issue: If this this → If this
Fixed tree-wide.
> Man page: systemd-cryptsetup-generator.8
> Issue: and the initrd → and in the initrd
"Is honoured by the initrd" is OK, because we often speak about the initrd as a single unit. But in the same paragraph we also used "in the initrd", which makes the other use look sloppy. I changed it to "in the initrd" everywhere in that file.
> Man page: systemd.directives.7
> Issue: Why are these two quoted (but not others)?
>
> "B<\\*(Aqh\\*(Aq>"
>
> B<\\*(Aqs\\*(Aq>"
>
> "B<\\*(Aqy\\*(Aq>"
This is autogenerated from files… We use slightly different markup in different files, and it's just too hard to make it consistent. We gave up on this.
> Man page: systemd.exec.5
> Issue 1: B<at>(1p) → B<at>(1)
> Issue 2: B<crontab>(1p) → B<crontab>(1)
Fixed.
> Man page: systemd.exec.5
> Issue: B<select()> → B<select>(2)
Fixed.
> Man page: systemd.exec.5
> Issue: qemu → B<qemu>(1)
The man page doesn't seem to be in any of the canonical places on the web.
I added a link to online docs.
> Man page: systemd.exec.5
> Issue: variable → variables
Seems to be fixed already.
> Man page: systemd-integritysetup-generator.8
> Issue: systemd-integritysetup-generator → B<systemd-integritysetup-generator>
I changed <filename> to <command>.
> Man page: systemd-integritysetup-generator.8
> Issue: superfluous comma at the end
Already fixed.
> Man page: systemd-measure.1
> Issue: (see B<--pcr-bank=>) below → (see B<--pcr-bank=> below)
Reworded.
> Man page: systemd-measure.1
> Issue: =PATH> → =>I<PATH>
Fixed.
> Man page: systemd-measure.1.po
> Issue: B<--bank=DIGEST> → B<--bank=>I<DIGEST>
Fixed.
> Man page: systemd.netdev.5
> Issue: os the → on the
Appears to have been fixed already.
> Man page: systemd.netdev.5
> Issue: Onboard → On-board (as in previous string)
Updated.
> Man page: systemd.network.5
> Issue: B<systemd-networkd> -> B<systemd-networkd>(8)
First reference does this, subsequent do not.
> Man page: systemd.network.5
> Issue: B<netlabelctl> → B<netlabelctl>(8)
First reference does this, subsequent do not.
> Man page: systemd.network.5
> Issue: Missing verb (aquired? configured?) in the half sentence starting with "or by a "
I dropped the comma.
> Man page: systemd-nspawn.1
> Issue: All host users outside of that range → All other host users
Reworded.
> # FIXME no effect → no effect\\&.
> #. type: Plain text
> #: archlinux debian-unstable fedora-rawhide mageia-cauldron opensuse-tumbleweed
> msgid ""
> "Whichever ID mapping option is used, the same mapping will be used for users "
> "and groups IDs\\&. If B<rootidmap> is used, the group owning the bind "
> "mounted directory will have no effect"
A period is added. Not sure if there's some other issue.
> Man page: systemd-oomd.service.8
> Issue: B<systemd> → B<systemd>(1)
Done.
> Man page: systemd.path.5
> Issue 1: B<systemd.exec>(1) → B<systemd.exec>(5)
> Issue 2: This section does not (yet?) exist
Fixed.
> Man page: systemd-pcrphase.service.8
> Issue 1: indicate phases into TPM2 PCR 11 ??
> Issue 2: Colon at the end of the paragraph?
Fixed.
> Man page: systemd-pcrphase.service.8
> Issue: final boot phase → final shutdown phase?
Updated.
> Man page: systemd-pcrphase.service.8
> Issue: for the the → for the
Fixed tree-wide.
> Man page: systemd-portabled.service.8
> Issue: In systemd-portabled.service(8): Portable Services Documentation
Updated.
> Man page: systemd-pstore.service.8
> Issue: Here and the following paragraphs: . → \\&. // Upstream: What does this comment mean? // You normally write \\&. for a full dot (full stop etc.); here you write only "." (i.e. a plain dot).
>
> "and we look up \"localhost\", nss-dns will send the following queries to "
> "systemd-resolved listening on 127.0.0.53:53: first \"localhost.foobar.com\", "
> "then \"localhost.barbar.com\", and finally \"localhost\". If (hopefully) the "
> "first two queries fail, systemd-resolved will synthesize an answer for the "
> "third query."
Looks all OK to me.
> Man page: systemd.resource-control.5
> Issue: Missing closing bracket after link to Control Groups version 1
Fixed.
> Man page: systemd-sysext.8
> Issue: In systemd-portabled.service(8): Portable Services Documentation
Updated.
> Man page: systemd.timer.5
> Issue 1: B<systemd.exec>(1) → B<systemd.exec>(5)
> Issue 2: This section does not (yet?) exist
Fixed.
> Man page: systemd.unit.5
> Issue: that is → that are
Fixed.
> Man page: systemd-veritysetup-generator.8
> Issue: systemd-veritysetup-generator → B<systemd-veritysetup-generator>
>
> "systemd-veritysetup-generator implements B<systemd.generator>(7)\\&."
>
> "systemd-veritysetup-generator understands the following kernel command line "
> "parameters:"
Updated.
> Man page: systemd-volatile-root.service.8
> Issue: initrdyes → Initrd
Fixed.
> Man page: sysupdate.d.5
> Issue: : → \\&. (As above in TRANSFER)
Updated.
> Man page: sysupdate.d.5
> Issue: some → certain
Updated.
> Man page: sysupdate.d.5
> Issue 1: i\\&.e\\& → I\\&.e\\&
Fixed.
> Issue 2: the image → the system
"image" seems correct.
> Man page: tmpfiles.d.5
> Issue: systemd-tmpfiles → B<systemd-tmpfiles>(8)
Updated.
Often it's useful to add multiple signatures in the signature JSON file
to embedd in a single .pcrsig. (For example, a signature by key X for
boot phase "enter-initrd" and one by key Y for
"enter-initrd:leave-initrd" or so). Make this easy, by adding the
ability to append signatures to a previously generated JSON file.
Luca Boccassi
Chris Coulson
Lennart Poettering
cvlc12
Jan Engelhardt
Zbigniew Jędrzejewski-Szmek
Daan De Meyer
anonymix007
Tobias Fleig
Sam Leonard
Luca Boccassi
David Tardon
Yu Watanabe
Antonio Alvarez Feijoo
Abderrahim Kitouni
nikstur
Morten Linderud
Jan Janssen