CI:
- ci/ci.sh: new CHILLDKG environment variable, passed to configure as
--enable-module-chilldkg (mirroring FROST).
- .github/workflows/ci.yml: default CHILLDKG: 'no' and CHILLDKG: 'yes'
in every job that enables FROST, except the x86_64 matrix entry that
deliberately builds without the ecdh module (chilldkg requires
schnorrsig + ecdh; the configure-time dependency error would fire
there). YAML validity and per-job dependency presence checked
programmatically.
ctime_tests:
- src/ctime_tests.c: run a full ChillDKG session (n = 2, t = 2) through
the public API under the memory checker: hostpubkey_gen, params_hash,
participant_step1, coordinator_step1, participant_step2,
coordinator_finalize, participant_finalize, participant_recover and
recovery_ack_sign. Host secret keys, session randomness, aux
randomness and the resulting secret shares are undefined (secret);
all protocol messages, the certificate, threshold public key, public
shares, recovery data, ack signature and the secret-free state1
objects are defined (public). state2 stays secret (contains the
secret share).
Constant-time fixes found by running the new block under
MemorySanitizer (valgrind unavailable locally; MSan build via clang +
CMake). All are missing declassifications of secret-derived but public
(or public-outcome) values, following the frost module's
secp256k1_declassify pattern with justification comments; no real
constant-time bugs were found:
- hostpubkey_gen: declassify the computed host public key before
serialization (public output).
- participant_step1: declassify the zero-randomness check result (only
reveals "the RNG returned 32 zero bytes", which aborts the session).
- encpedpop participant_step1: declassify the pubnonce point before
serialization (public, part of pmsg1).
- chilldkg_schnorrsig_sign: declassify the signer public key before
normalization/parity branch, and declassify the return value (a
failure only reveals a zero derived nonce, negligible probability).
- vss_commit: declassify the VSS commitments before serialization
(public, part of pmsg1).
- vss_verify_secshare: declassify secshare*G before the infinity/eq
checks (equals the public pubshare in honest runs; the discrete log
is not revealed).
- simplpedpop_participant_investigate (proactive audit; not reached by
ctime_tests): declassify the secshare-sum comparison result (the
public fault code reveals it anyway).
Verified: MSan ctime_tests exits 0; autotools make check 10/10 (the
local tree is configured without --enable-ctime-tests because neither
valgrind nor an MSan-instrumented gcc build is available; CI runs
ctime_tests under valgrind as before); CMake ctest 428/428;
./tests --target=chilldkg and ./chilldkg_example pass.
3b68633f59