Until now OpenSSL was linked into every binary and library that needed
cryptography, pulling libcrypto (and, for resolved, libssl) into the
address space of services that never touch them at runtime. This commit
moves all OpenSSL usage behind the same dlopen helper pattern that we
already use for other optional libraries (libpam, libseccomp, libxz, …)
so libcrypto/libssl are only loaded on demand.
The bulk of the work lives in src/shared/crypto-util.{c,h} (libcrypto)
and src/shared/ssl-util.{c,h} (libssl), which replace the previous
src/shared/openssl-util.{c,h}:
- crypto-util.{c,h} declares every libcrypto function we call via
DLSYM_PROTOTYPE() and resolves them inside dlopen_libcrypto().
- ssl-util.{c,h} holds the libssl-specific DLSYM_PROTOTYPEs,
dlopen_libssl(), and the SSL_freep cleanup helper, so translation
units that only need libcrypto do not pull in libssl declarations.
- Callers refer to the symbols through sym_* aliases rather than the
original names.
- Convenience macros that used to be provided by the OpenSSL headers
(OPENSSL_free, BN_num_bytes, the sk_TYPE_* helpers, …) are
reimplemented as sym_* wrappers so no code path needs to fall back
to the linker-resolved symbols.
- All _cleanup_ helpers are redefined in terms of the sym_* variants
(EVP_PKEY_freep, X509_freep, BIO_freep, …) so cleanup attributes
keep working without pulling in libcrypto symbols at link time.
- The public crypto-util.c entry points (openssl_pubkey_from_pem,
openssl_digest_many, openssl_hmac_many, openssl_cipher_many,
kdf_ss_derive, kdf_kb_hmac_derive, rsa_* / ecc_* helpers,
pubkey_fingerprint, digest_and_sign, pkcs7_new, x509_fingerprint,
openssl_extract_public_key, pkey_generate_volume_keys, the load_*
helpers, …) now call dlopen_libcrypto() at entry before touching any
sym_* pointer.
The call sites across the tree have been converted to call
dlopen_libcrypto()/dlopen_libssl() at the appropriate entry point
before their first sym_* use, and to use sym_* variants throughout:
- bootctl, sbsign, measure, pcrlock, pcrextend, tpm2-setup, repart,
cryptsetup, cryptenroll, homectl, homed, homework, keyutil,
sysupdate, creds, import, dissect-image, pe-binary, pkcs11-util,
pkcs7-util, tpm2-util, creds-util. resolved additionally dlopens
libssl for DoT.
The meson build files are updated to depend on libopenssl_cflags (a
new partial dependency that exposes include paths and compile flags
only, not the linker flags) instead of libopenssl for every target that
previously linked against OpenSSL. Nothing links against libcrypto or
libssl directly anymore.
A new src/sbsign/authenticode.c hosts the Authenticode ASN.1 type
definitions that used to live inline in sbsign.c. The OpenSSL
ASN1_SEQUENCE / ASN1_CHOICE / IMPLEMENT_ASN1_FUNCTIONS macros expand to
code that references libcrypto symbols directly, so to keep this
translation unit unlinked from libcrypto we redirect ASN1_item_* to
the sym_* variants via #define and wrap the ASN1_*_it() getters (which
appear as constant function pointers in static initializers) in small
trampoline functions that forward to the sym_* pointers at runtime.
test-dlopen-so gains assertions for dlopen_libcrypto and dlopen_libssl
so the dlopen contract is exercised in CI, and the openssl-specific
test was renamed from test-openssl.c to test-crypto-util.c to match
the new header naming.
Convert systemd-cryptsetup, systemd-cryptenroll, systemd-veritysetup
and systemd-integritysetup to go through the existing dlopen wrapper
for libcryptsetup instead of linking the library directly. Each binary
calls dlopen_cryptsetup() at the start of its run() and uses the sym_*
variants for every libcryptsetup entry point.
Extend cryptsetup-util.{h,c} to cover the libcryptsetup symbols that
these binaries use and that the wrapper was missing:
crypt_activate_by_token_pin, crypt_deactivate, crypt_init_data_device,
crypt_keyslot_status, crypt_set_keyring_to_link (conditional on
HAVE_CRYPT_SET_KEYRING_TO_LINK), crypt_status and
crypt_token_external_path.
With no direct callers of crypt_free() left, drop the non-sym
crypt_freep cleanup variant and rename sym_crypt_freep back to
crypt_freep via DEFINE_TRIVIAL_CLEANUP_FUNC_FULL_RENAME, matching the
naming convention used by other dlopen wrappers (acl_freep,
xkb_context_unrefp, ...). Update the remaining users in src/shared,
src/repart, src/home and src/growfs to the new name.
The four affected meson targets switch from libcryptsetup to
libcryptsetup_cflags so they no longer record a DT_NEEDED entry for
libcryptsetup.so.12.
I promised in https://github.com/systemd/systemd/pull/41426 that its the
final update for coccinelle pointer deref checks. However it turned out
there is this coccinelle/parsing_hacks.h that I wasn't aware of. The
file missed some important things like _cleanup_(x) that prevented
coccinelle to check a bunch of functions.
This PR adds some missing defines to the parsing_hacks.h and fixes the
missing asserts(). I apologize that its a bit long (and frankly boring)
and that I missed this earlier.
The last commit contains one small behavior change (ret in
sd_varlink_idl_parse() is now really optional) but the big one is very
mechanical.
The updated parsing_hacks.h file uncovered a bunch of extra
things that the check-pointer-deref coccinelle script flags.
This commit fixes them to make the tree check-pointer-deref clean.
We generally want to print an error message if table_print()
fails. Add a helper function for this and use it consistently.
This does one of the three things depending on the call site:
- a no-change reformatting of the code
- change from a custom message to the generic one
- addition of the error message where previously none was printed
In the third case, the actual use impact is very small, since the
table formatting is very unlikely to fail. But if it did, we would
often return an error without any message whatsoever, which we
never want to do.
Almost all callers of table_print() specify stdout or NULL (equivalent
to stdout) as the output stream. Simplify things by not requiring the
the stream to be specified.
In almost all cases, the printing of the table is surrounded by normal
printfs() that don't do explicit flushing and for which we don't check
the output stream status. Let's simplify most callers and skip this
step. The reason is not so much to avoid the extra step itself, but
instead to avoid the _handling_ of the potential failure. We generally
only want to print an error message for ENOMEM and other "internal"
errors, so strictly speaking we should filter out the errors from the
stream. By skipping the flush&check step we implicitly do this.
Add the libfido2 dependency to cryptenroll and cryptsetup's
meson files. If libfido2's not installed in the default path
the build wasn't finding its headers correctly.
'tpm2-primary-alg' field is currently unset in LUKS JSON token both for the
case when SRK was used for enrolling (--tpm2-device-key=) and for the case when
SRK was obtained/generated (--tpm2-device=). While this information is not
really needed for unsealing (the sealed object itself has key type in it), it
may be convenient to see key type in e.g. 'cryptsetup luksDump' in the
situations where key type matters. Since 'tpm2-primary-alg' is already defined,
just set it properly in all cases.
Originating device lookups currently use separate entry points and
callers must decide between the single-step helper and manual looping.
Add a recursive flag to block_device_get_originating() and
block_get_originating(), and update callers to pass an explicit value.
Calling mlockall in an unprivileged process most notably had the effect
of making systemd-cryptenroll OOM while trying to open a normal-sized
argon2 keyslot due to it hitting RLIMIT_MEMLOCK.
When employing MCL_FUTURE we don't actually want it to impose
immediate population of malloc()-ed pages. Hence let's set
MCL_ONFAULT everywhere.
Additionally, specify MCL_CURRENT to ensure future memory allocations
on already mapped pages are covered too. (Addresses
https://github.com/systemd/systemd/pull/40319#discussion_r2693726196)
Note that in shutdown the mlockall() is done to avoid keeping swap space
busy, hence a dedicated call w/ MCL_CURRENT and w/o MCL_ONFAULT is made.
Let's introduce these for the following two reasons:
- Using them makes sure the parameter names match between declaration
and definition (if both use the corresponding macros).
- They make sure developers can't forget the _const_ and _pure_
attributes for the declarations.
This commit also includes some include sorting fixes
Let's not leak details from src/shared and src/libsystemd into
src/basic, even though you can't actually do anything useful with
just forward declarations from src/shared.
The sd-forward.h header is put in src/libsystemd/sd-common as we
don't have a directory for shared internal headers for libsystemd
yet.
Let's also rename forward.h to basic-forward.h to keep things
self-explanatory.
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.
Admittedly, some of our glyphs _are_ special, e.g. "O=" for SPECIAL_GLYPH_TOUCH ;)
But we don't need this in the name. The very long names make some invocations
very wordy, e.g. special_glyph(SPECIAL_GLYPH_SLIGHTLY_UNHAPPY_SMILEY).
Also, I want to add GLYPH_SPACE, which is not special at all.
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.
This new field allows specification of an fd on which the password
prompt logic will look for POLLHUP events for, and if seen will abort
the query.
The usecase for this is that when we query for a pw on behalf of a
Varlink client we can abort the query automatically if the client dies.
```
$ systemd-cryptenroll /dev/vda3
SLOT TYPE
0 password
$ systemd-cryptenroll --wipe-slot 1 /dev/vda3
Failed to wipe slot 1, continuing: No such file or directory
```
Users will generally know what a qrcode is, so let's not treat them as dumb and
explain that it can be scanned. OTOH, we should say what the qrcode contains
and it is useful to give a hint why the users would want to scan it. Reword
messages accordingly.
(Also, don't say "to your phone", when somebody might be using a stolen phone,
or something else then a phone.)
If we operate in "offline" mode, i.e. know the device key, then we will
not have a TPM2 connection, hence don't try to read the PCR bank to use form
it.
We don't need it anyway because we are not going to test unseal things.
Fixes: #33855
So far you had to pick:
1. Use a signed PCR TPM2 policy to lock your disk to (i.e. UKI vendor
blesses your setup via signature)
or
2. Use a pcrlock policy (i.e. local system blesses your setup via
dynamic local policy stored in NV index)
It was not possible combine these two, because TPM2 access policies do
not allow the combination of PolicyAuthorize (used to implement #1
above) and PolicyAuthorizeNV (used to implement #2) in a single policy,
unless one is "further upstream" (and can simply remove the other from
the policy freely).
This is quite limiting of course, since we actually do want to enforce
on each TPM object that both the OS vendor policy and the local policy
must be fulfilled, without the chance for the vendor or the local system
to disable the other.
This patch addresses this: instead of trying to find a way to come up
with some adventurous scheme to combine both policy into one TPM2
policy, we simply shard the symmetric LUKS decryption key: one half we
protect via the signed PCR policy, and the other we protect via the
pcrlock policy. Only if both halves can be acquired the disk can be
decrypted.
This means:
1. we simply double the unlock key in length in case both policies shall
be used.
2. We store two resulting TPM policy hashes in the LUKS token JSON, one
for each policy
3. We store two sealed TPM policy key blobs in the LUKS token JSON, for
both halves of the LUKS unlock key.
This patch keeps the "sharding" logic relatively generic (i.e. the low
level logic is actually fine with more than 2 shards), because I figure
sooner or later we might have to encode more shards, for example if we
add further TPM2-based access policies, for example when combining FIDO2
with TPM2, or implementing TOTP for this.
Daan De Meyer
Lennart Poettering
Yu Watanabe
Zbigniew Jędrzejewski-Szmek
Michael Vogt
Dan McGregor
Mike Yuan
Vitaly Kuznetsov
Zbigniew Jędrzejewski-Szmek
Chris Down
cyclopentane
Daan De Meyer
Jelle van der Waa
Lennart Poettering
Jelle van der Waa
Antonio Alvarez Feijoo