Lightweight unit testing framework, providing a structured way to define,
execute, and report tests. It includes a central test registry, a flexible
command-line argument parser of the form "--key=value" / "-k=value" /
"-key=value" (facilitating future framework extensions), ability to run
tests in parallel and accumulated test time logging reports.
So far the supported command-line args are:
- "--jobs=<num>" or "-j=<num>" to specify the number of parallel workers.
- "--seed=<hex>" to specify the RNG seed (random if not set).
- "--iterations=<num>" or "-i=<num>" to specify the number of iterations.
Compatibility Note:
To stay compatible with previous versions, the framework also supports
the two original positional arguments: the iterations count and the
RNG seed (in that order).
Relocate the clock time getter to tests_common.h to
make it easily reusable across test programs. This
will be useful for the upcoming unit test framework.
Context - why not placing it inside testutil.h?:
The bench program links against the production-compiled library,
not its own compiled version. Therefore, `gettime_i64()` cannot
be moved to testutil.h, because testutil.h calls
`secp256k1_pubkey_save()`, which exists only in the internal
secp256k1.c and not in the public API.
This should hopefully be useful as orientation for users implementing
the key exchange part of BIP324. Conceptually the example is not very
different to the ECDH one, so a lot of code/comments are just copied
(e.g. context creation, secret key generation, shared secret comparison,
console output, cleanup with secret key clearing).
Widely available versions of GCC and Clang beat our field asm on -O2.
In particular, GCC 10.5.0, which is Bitcoin Core's current compiler
for official x86_64 builds, produces code that is > 20% faster for
fe_mul and > 10% faster for signature verification (see #726).
These are the alternatives to this PR:
We could replace our current asm with the fastest compiler output
that we can find. This is potentially faster, but it has multiple
drawbacks:
- It's more coding work because it needs detailed benchmarks (e.g.,
with many compiler/options).
- It's more review work because we need to deal with inline asm
(including clobbers etc.) and there's a lack of experts reviewers
in this area.
- It's not unlikely that we'll fall behind again in a few compiler
versions, and then we have to deal with this again, i.e., redo the
benchmarks. Given our history here, I doubt that we'll revolve
this timely.
We could change the default of the asm build option to off. But this
will also disable the scalar asm, which is still faster.
We could split the build option into two separate options for field
and scalar asm and only disable the field asm by default. But this
adds complexity to the build and to the test matrix.
My conclusion is that this PR gets the low-hanging fruit in terms of
performance. It simplifies our code significantly. It's clearly an
improvement, and it's very easy to review. Whether re-introducing
better asm (whether from a compiler or from CryptOpt) is worth the
hassle can be evaluated separately, and should not hold up this
improvement.
Solves #726.
It is a non-Libtool-specific way to explicitly specify the user's
intention to consume a static `libseck256k1`.
This change allows to get rid of MSVC linker warnings LNK4217 and
LNK4286. Also, it makes possible to merge the `SECP256K1_API` and
`SECP256K1_API_VAR` into one.
The scheme implemented is described below, and largely follows the paper
"SwiftEC: Shallue–van de Woestijne Indifferentiable Function To Elliptic Curves",
by Chavez-Saab, Rodriguez-Henriquez, and Tibouchi
(https://eprint.iacr.org/2022/759).
A new 64-byte public key format is introduced, with the property that *every*
64-byte array is an encoding for a non-infinite curve point. Each curve point
has roughly 2^256 distinct encodings. This permits disguising public keys as
uniformly random bytes.
The new API functions:
* secp256k1_ellswift_encode: convert a normal public key to an ellswift 64-byte
public key, using additional entropy to pick among the many possible
encodings.
* secp256k1_ellswift_decode: convert an ellswift 64-byte public key to a normal
public key.
* secp256k1_ellswift_create: a faster and safer equivalent to calling
secp256k1_ec_pubkey_create + secp256k1_ellswift_encode.
* secp256k1_ellswift_xdh: x-only ECDH directly on ellswift 64-byte public keys,
where the key encodings are fed to the hash function.
The scheme itself is documented in secp256k1_ellswift.h.
Adds a test using the Wycheproof vectors as outlined in #1106. The
vectors are taken from the Wycheproof repo. We use a python script
to convert the JSON-formatted vectors into C code.
Co-authored-by: Sean Andersen <6730974+andozw@users.noreply.github.com>
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
