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.
This reverts commit 526f1594daec073269c3e70ee7914f6dd8740d5c.
This revert is necessary because the change breaks mDNS hostname stability
whenever a DNS-SD service calls UnregisterService. When a service
unregisters (e.g. on process restart), manager_refresh_rrs() clears and
re-adds all RRs in PROBING state, which sends a multicast announcement
(QR=1). The kernel reflects this back to resolved's own socket. Because
the local-address check was moved inside the query-only branch by the
reverted commit, the reply path in on_mdns_packet() is now unguarded.
The looped-back announcement matches the pending probe transaction and
completes it with DNS_TRANSACTION_SUCCESS. Since the zone item is still
in PROBING state (not ESTABLISHED), dns_zone_item_notify() sets
we_lost=true and calls dns_zone_item_conflict(), which invokes
manager_next_hostname() and renames the hostname (e.g. foo.local →
foo4.local). This happens reliably on every restart of any service using
RegisterService/UnregisterService (homebridge, avahi-compat wrappers,
etc.).
The top-level local-address check in on_mdns_packet() suppresses all
looped-back multicast traffic before the reply/query split. Restoring it
there is consistent with the overall design: dns_scope_check_conflicts()
already has its own manager_packet_from_local_address() guard and is
unaffected.
A more targeted long-term fix (e.g. guarding dns_transaction_process_reply()
for mDNS, or avoiding unnecessary re-probing of already-established records
in manager_refresh_rrs()) can be pursued separately.
Every dlopen_xxx() helper now takes an int log_level argument. It is
passed through to dlopen_many_sym_or_warn() (which in turn propagates it
to dlopen_verbose() for the library-not-installed case), and is used by
the fallback stub when support for the library is not compiled in to
emit a "<lib> support is not compiled in." message at the caller's level.
Callers pass LOG_DEBUG when gracefully degrading, or a higher level when
the failure should surface, and no longer need to log redundantly at the
call site.
As part of this, dlopen_bpf_full() (which already took a log_level) is
merged into dlopen_bpf() rather than keeping both.
The static inline fallbacks used to live in the headers, which required
pulling log.h in from every header that declared a dlopen_xxx(). Move
them into the .c files instead: the declaration is always outside the
#if HAVE_XXX block, the impl sits outside the outer #if HAVE_XXX wrap
with its own internal #if HAVE_XXX/#else/#endif, and apparmor-util.c,
idn-util.c, libmount-util.c and pam-util.c are now always compiled so
they can host their stubs.
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.
As mentioned in the grandfather commit, I want to use the _many
suffix for freeing of the contents of an array, so the functions
to free the array to get the suffix _array.
dnssec_rsa_verify_raw() asserts that RSA_size(key) matches the RRSIG
signature size, and dnssec_ecdsa_verify_raw() asserts that
EC_KEY_check_key() succeeds. Both conditions depend on parsed DNS
record content. Replace with proper error returns.
The actual crypto verify calls (EVP_PKEY_verify / ECDSA_do_verify)
handle mismatches fine on their own, so the asserts were also redundant.
While at it, fix the misleading "EC_POINT_bn2point failed" log message
that actually refers to an EC_KEY_set_public_key() failure.
Fixes: https://github.com/systemd/systemd/issues/41569
manager_set_dns_server() and dns_server_flush_cache() call dns_cache_flush()
unconditionally, wiping the entire cache even when StaleRetentionSec is
configured. This defeats serve-stale by discarding cached records that should
remain available during server switches and feature-level re-probes.
The original serve-stale commit (5ed91481ab) added a stale_retention_usec
guard to link_set_dns_server(), and a later commit (7928c0e0a1) added the
same guard to dns_delegate_set_dns_server(), but these two call sites in
resolved-dns-server.c were missed.
This is particularly visible with DNSOverTLS, where TLS handshake failures
trigger frequent feature-level downgrades and re-probes via
dns_server_flush_cache(), flushing the cache each time.
Add the same stale_retention_usec guard to both call sites so that cache
entries are allowed to expire naturally via dns_cache_prune() when
serve-stale is enabled.
Fixes: #40781
This commit was prepared with assistance from an AI coding agent (GitHub
Copilot). All changes have been reviewed for correctness and adherence to the
systemd coding style.
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.
Trivial ordering/modernizing change that got highlighted by
claude and refined by keszybz to move to the modern systemd
style.
Thanks to keszybz for suggesting this.
This addresses
https://github.com/systemd/systemd/pull/41213#pullrequestreview-4002247053
which I somehow missed earlier.
Claude found a real issue for the case of manager_etc_hosts_flush().
We'll do the equivalent change in manager_static_records_flush() too,
even though it's not really necessary there, simply to keep things
nicely mirrored.
sd-resolved does dnssec "backwards" compared to most resolvers.
A typical strategy is to start from the DNS root and gather the
requisite keys on the way down, but sd-resolved requests the final
answer it wants and then goes searching for the requisite keys later.
We don't know in advance under which names we should expect to find
those keys, because we don't know the zone cuts a priori, but we can use
what we have found in prior responses to make an educated guess. This
was more or less the intent of 47690634f1, but it was partially
regressed in d840783db5 while fixing a bug handling totally empty
responses.
Fixes#37472
Ref: 47690634f1 ("resolved: don't request the SOA for every dns label")
Fixes: d840783db5 ("resolved: always progress DS queries")
sd-resolved does not support all the permissible DNSSEC signature
algorithms, and some are intentionally unsupported as a matter of
policy. Answers that can only be validated via unsupported algorithms
should be treated as if they were unsigned, per RFC4035 § 5.2.
Previously, sd-resolved tried to properly record insecure answers for
unsupported algortihms, but did not record this status for each of the
auxilliary DNSSEC transactions, so the primary transaction had no way to
know if there was a plausible DNSKEY with an unsupported signature
algorithm in the chain of trust.
This commit adds the insecure DNSKEYs that use unsupported algorithms to
the list of validated keys for each transaction, so that dependent
transactions can learn that a plausible chain of trust exists, even if
no authenticated one does, and report the insecure answer.
This should improve the situation in #35126.
This is an extension of the /etc/hosts concept, but can provide any kind
of RRs (well, actually, we only parse A/AAAA/PTR for now, but the
concept is open for more).
Fixes: #17791
When we are told to reload our configuration also flush out /etc/hosts
explicitly. This is particularly relevant since we suppress too frequent
reloads, and hence a synchronous way to force a reload is very useful.
sd-resolved does not support all the permissible DNSSEC signature
algorithms, and some are intentionally unsupported as a matter of
policy. Answers that can only be validated via unsupported algorithms
should be treated as if they were unsigned, per RFC4035§5.2.
Previously, sd-resolved tried to properly record insecure answers for
unsupported algortihms, but did not record this status for each of the
auxilliary DNSSEC transactions, so the primary transaction had no way to
know if there was a plausible DNSKEY with an unsupported signature
algorithm in the chain of trust.
This commit adds the insecure DNSKEYs that use unsupported algorithms to
the list of validated keys for each transaction, so that dependent
transactions can learn that a plausible chain of trust exists, even if
no authenticated one does, and report the insecure answer.
We often have a pattern where the same verb function is used for
multiple actions. This leads to an antipattern where we figure out what
action needs to be taken from argv[0] multiple times: often once in
parse_argv() to figure out what options are allowed, then once again
implicitly in dispatch_verb(), and then again in the action verb itself.
Let's allow passing a parameter into the verb to simplify this.
This matches a pattern we have in conf-parser.h, where we have both
void *userdata (more global) and void *data (per-config item). Here,
I opted for uintptr_t userdata. It seems that most of the time we'll
want to just pass an enum value. This works OK with no casts. I also
tried a void* and union. In both cases, much more boilerplate is needed:
either a cast or a macro to help avoid compiler warnings. uintptr_t
seems generic enough to cover foreseeable usecases with no fuss.
This is a noop refactoring. See next commit for an example.
Fix typo: DNS_TYPE_DNSKEY should be used instead of DNS_TYPE_KEY.
- DNS_TYPE_KEY is deprecated
- Source code at resolved-dns-trust-anchor.c#L313 handles
DNS_TYPE_DNSKEY records, but not DNS_TYPE_KEY
So DNS_TYPE_KEY is not referenced anywhere
Avahi provides AVAHI_IF_UNSPEC (-1) to browse mDNS services on all
interfaces simultaneously. Currently, systemd-resolved's BrowseServices
varlink API requires a specific interface index and lacks the ability to browse on
all available interfaces.
This change adds support for ifindex = 0 to mean \"browse on all mDNS-enabled
interfaces\" to match the Avahi API.
When ifindex = 0 is specified the browser will now iterate all mDNS scopes
instead of a single interface.
This enables applications to discover services on any network interface
without needing to know the specific interface index in advance.
Assisted-by: Claude Opus 4.6 (Eclipse Theia IDE AI)
The interface where each service was discovered needs to be remembered
so it can be correctly reported when the service is later removed.
Previously, service removal would use sb->ifindex, losing the actual
interface information from the original discovery.
This change:
- Adds an ifindex field to DnssdDiscoveredService struct
- Stores the discovered interface index when adding new services,
preferring the per-item ifindex from DnsAnswerItem over the service
browser's ifindex
- Uses the stored ifindex when reporting service removal events
This ensures that service removal notifications include the correct
interface index where the service was originally discovered, matching
the behavior of the corresponding service addition notifications.
Assisted-by: Claude Opus 4.6 (Eclipse Theia IDE AI)
This makes it possible to have DNS requests for certain domains routed
differently than normal requests, which is for instance useful when
using policy routing to route traffic over a VPN but DNS requests for
the VPN endpoint itself, should be routed differently.
It doesn't make much sense to configure a firewall mark at the level of
a network interface, but at the level of a DNS delegate it can be very
useful.
If the IDL declares the method requires 'more' yet the call doesn't
have it set, varlink_idl_validate_method_call() should have rejected
it and the callback shouldn't be reached.
Historically, resolvectl status has not included the interface
specification for DNS servers with an IPv6 link-local address, since it
is technically somewhat redundant. But, adding this extra bit of
information makes it easier to copy-and-paste to use elsewhere, etc.
For example, the previous output:
Link 2 (enp34s0)
Current Scopes: DNS LLMNR/IPv4 LLMNR/IPv6
Protocols: +DefaultRoute LLMNR=resolve -mDNS -DNSOverTLS DNSSEC=no/unsupported
Current DNS Server: fe80::861e:a3ff:feb1:f8e7
DNS Servers: 192.168.1.12 192.168.1.13 fe80::861e:a3ff:feb1:f8e7
DNS Domain: lan
now becomes:
Link 2 (enp34s0)
Current Scopes: DNS LLMNR/IPv4 LLMNR/IPv6
Protocols: +DefaultRoute LLMNR=resolve -mDNS -DNSOverTLS DNSSEC=no/unsupported
Current DNS Server: fe80::861e:a3ff:feb1:f8e7%2
DNS Servers: 192.168.1.12 192.168.1.13 fe80::861e:a3ff:feb1:f8e7%2
DNS Domain: lan
There is a lot of duplication across the functions for printing global,
link, and delegate output. Since these all use a common DNSConfiguration
type now, the logic can be consolidated.
Adapt printing and format helper functions to accept a DNSConfiguration
parameter to appropriately format output. Then, add print_configuration(),
a single function that prints the appropriate status output based on the
contents of DNSConfiguration.
Now that varlink is always used for status output, consolidate the JSON
and regular status code paths. Add status_full(), which is the single
point that calls DumpDNSConfiguration, filters based on link names and
mode if needed, and prints the output in the appropriate format.
This simplifies status_ifindex(), and removes the need for a separate
status_json().
Daan De Meyer
Lennart Poettering
Bret Comnes
Yu Watanabe
Luca Boccassi
Michael Vogt
Zbigniew Jędrzejewski-Szmek
Milan Kyselica
azureuser
Ronan Pigott
Frantisek Sumsal
Mike Yuan
Anton Tiurin
Christian Glombek
r-vdp
Carlos Peón Costa
Zbigniew Jędrzejewski-Szmek
Nick Rosbrook