0f088ec112 Rename CTIMETEST -> CTIMETESTS (Pieter Wuille)
74b026f05d Add runtime checking for DECLASSIFY flag (Pieter Wuille)
5e2e6fcfc0 Run ctime test in Linux MSan CI job (Pieter Wuille)
18974061a3 Make ctime tests building configurable (Pieter Wuille)
5048be17e9 Rename valgrind_ctime_test -> ctime_tests (Pieter Wuille)
6eed6c18de Update error messages to suggest msan as well (Pieter Wuille)
8e11f89a68 Add support for msan integration to checkmem.h (Pieter Wuille)
8dc64079eb Add compile-time error to valgrind_ctime_test (Pieter Wuille)
0db05a770e Abstract interactions with valgrind behind new checkmem.h (Pieter Wuille)
4f1a54e41d Move valgrind CPPFLAGS into SECP_CONFIG_DEFINES (Pieter Wuille)
Pull request description:
This introduces an abstraction layer `src/checkmem.h`, which defines macros for interacting with memory checking tools. Depending on the environment, they're mapped to MemorySanitizer builtins, Valgrind integration macros, or nothing at all.
This means that msan builds immediately benefit from existing undefined memory checks in the tests. It also means those builds result in a `ctime_tests` (new name for `valgrind_ctime_test`) binary that can usefully test constant-timeness (not inside Valgrind, and with the downside that it's not running against a production library build, but it's faster and available on more platforms).
Such an msan-ctime test is added to the Linux x86_64 msan CI job, as an example. More CI cases could be added (e.g. for MacOs or ARM Linux) later.
ACKs for top commit:
real-or-random:
ACK 0f088ec112
hebasto:
ACK 0f088ec112, I have reviewed the code and it looks OK. Able to build `ctime_tests` using MSan.
Tree-SHA512: f4ffcc0c2ea794894662d9797b3a349770a4b361996f967f33d7d14b332171de5d525f50bcebaeaf7d0624957083380962079c75e490d1b7d71f8f9eb6211590
This uses AM_PROG_AR to discover ar, which is the recommended way to do
so. Among other advantages, it honors the AR environment variable (as
set from the outside). The macro has been around since automake 1.11.2
(Dec 2011).
This commit also removes code that discovers ranlib and strip. ranlib
has been obsolete for decades (ar does its task now automatically), and
anyway LT_INIT takes care of discovering it. The code we used to set
STRIP was last mentioned in the automake 1.5 manual. Since automake 1.6
(Mar 2002), strip is discovered automatically when necessary (look for
the *private* macro AM_PROG_INSTALL_STRIP in the automake manual).
- Improve Makefile.am for both prebuilt tables files
- On the way, tidy EXTRA_DIST: Move the header files to noinst_HEADERS,
where they conceptually belong, and add missing SECURITY.md to EXTRA_DIST
This header contains a static array that replaces the ecmult_context pre_g and pre_g_128 tables.
The gen_ecmult_static_pre_g program generates this header file.
This removes the ununsed `obj` directory. It also suggests in the README
to create the "coverage" files in a separate directory and adds the
coverage files to .gitignore.
readme: Improve instructions for coverage reports
f431b3f28a valgrind_ctime_test: Add schnorrsig_sign (Jonas Nick)
16ffa9d97c schnorrsig: Add taproot test case (Jonas Nick)
8dfd53ee3f schnorrsig: Add benchmark for sign and verify (Jonas Nick)
4e43520026 schnorrsig: Add BIP-340 compatible signing and verification (Jonas Nick)
7332d2db6b schnorrsig: Add BIP-340 nonce function (Jonas Nick)
7a703fd97d schnorrsig: Init empty experimental module (Jonas Nick)
eabd9bc46a Allow initializing tagged sha256 (Jonas Nick)
6fcb5b845d extrakeys: Add keypair_xonly_tweak_add (Jonas Nick)
58254463f9 extrakeys: Add keypair struct with create, pub and pub_xonly (Jonas Nick)
f0010349b8 Separate helper functions for pubkey_create and seckey_tweak_add (Jonas Nick)
910d9c284c extrakeys: Add xonly_pubkey_tweak_add & xonly_pubkey_tweak_add_test (Jonas Nick)
176bfb1110 Separate helper function for ec_pubkey_tweak_add (Jonas Nick)
4cd2ee474d extrakeys: Add xonly_pubkey with serialize, parse and from_pubkey (Jonas Nick)
47e6618e11 extrakeys: Init empty experimental module (Jonas Nick)
3e08b02e2a Make the secp256k1_declassify argument constant (Jonas Nick)
Pull request description:
This PR implements signing, verification and batch verification as described in [BIP-340](https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki) in an experimental module named `schnorrsig`. It includes the test vectors and a benchmarking tool.
This PR also adds a module `extrakeys` that allows [BIP-341](https://github.com/bitcoin/bips/blob/master/bip-0341.mediawiki)-style key tweaking.
(Adding ChaCha20 as a CSPRNG and batch verification was moved to PR #760).
In order to enable the module run `./configure` with `--enable-experimental --enable-module-schnorrsig`.
Based on apoelstra's work.
ACKs for top commit:
gmaxwell:
ACK f431b3f28a (exactly matches the previous post-fixup version which I have already reviewed and tested)
sipa:
ACK f431b3f28a
real-or-random:
ACK f431b3f28a careful code review
Tree-SHA512: e15e849c7bb65cdc5d7b1d6874678e275a71e4514de9d5432ec1700de3ba92aa9f381915813f4729057af152d90eea26aabb976ed297019c5767e59cf0bbc693
Valgrind does bit-level tracking of the "uninitialized" status of memory,
property tracks memory which is tainted by any uninitialized memory, and
warns if any branch or array access depends on an uninitialized bit.
That is exactly the verification we need on secret data to test for
constant-time behaviour. All we need to do is tell valgrind our
secret key is actually uninitialized memory.
This adds a valgrind_ctime_test which is compiled if valgrind is installed:
Run it with libtool --mode=execute:
$ libtool --mode=execute valgrind ./valgrind_ctime_test
We observe that when changing the b-value in the elliptic curve formula
`y^2 = x^3 + ax + b`, the group law is unchanged. Therefore our functions
for secp256k1 will be correct if and only if they are correct when applied
to the curve defined by `y^2 = x^3 + 4` defined over the same field. This
curve has a point P of order 199.
This commit adds a test which computes the subgroup generated by P and
exhaustively checks that addition of every pair of points gives the correct
result.
Unfortunately we cannot test const-time scalar multiplication by the same
mechanism. The reason is that these ecmult functions both compute a wNAF
representation of the scalar, and this representation is tied to the order
of the group.
Testing with the incomplete version of gej_add_ge (found in 5de4c5dff^)
shows that this detects the incompleteness when adding P - 106P, which
is exactly what we expected since 106 is a cube root of 1 mod 199.
This vastly shrinks the size of the context required for signing on devices with
memory-mapped Flash.
Tables are generated by the new gen_context tool into a header.
Hennadii Stepanov
Tim Ruffing
Pieter Wuille
Elichai Turkel
siv2r
Russell O'Connor
Jonas Nick
Jake Rawsthorne
Gregory Maxwell
Tony Rizko
Andrew Poelstra
upgradeadvice
Pieter Wuille
Thomas Daede
Pavel Janík
Phillip Mienk
Cory Fields