Daan De Meyer
8c3f64e61f
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.
System and Service Manager
Details
Most documentation is available on systemd's web site.
Assorted, older, general information about systemd can be found in the systemd Wiki.
Information about build requirements is provided in the README file.
Consult our NEWS file for information about what's new in the most recent systemd versions.
Please see the Code Map for information about this repository's layout and content.
Please see the Hacking guide for information on how to hack on systemd and test your modifications.
Please see our Contribution Guidelines for more information about filing GitHub Issues and posting GitHub Pull Requests.
When preparing patches for systemd, please follow our Coding Style Guidelines.
If you are looking for support, please contact our mailing list, join our IRC channel #systemd on libera.chat or Matrix channel
Stable branches with backported patches are available in the stable repo.
We have a security bug bounty program sponsored by the Sovereign Tech Fund hosted on YesWeHack
Repositories with distribution packages built from git main are available on OBS, and also repositories with packages built from the latest stable release