The secp256k1_ellswift_xdh function uses overflow = secp256k1_scalar_is_zero(&s) which overwrites the overflow flag from the preceding secp256k1_scalar_set_b32 call. This means secret keys >= the curve order are silently accepted (reduced mod n) instead of being rejected.
The fix changes = to |=, matching the correct pattern already used in secp256k1_ecdh (main_impl.h, line 51).
The ECDH module's test suite explicitly tests overflow rejection (passes secp256k1_group_order_bytes as a key and checks the function returns 0). The ellswift test suite has no corresponding test, which is why this went undetected.
In the bench and bench_internal help functions argv was not being
passed, in this change we pass in argv[0] and use it in the help text.
Additionally instead of passing all of argv in bench_ecmult we now
just pass argv[0] and is used as the executable_path variable.
2cb2e312e9 extrakeys: Migrate to bitcoin-core/secp256k1#1518 secp256k1_ec_pubkey_sort (DarkWindman)
7d2591ce12 Add secp256k1_pubkey_sort (Jonas Nick)
Pull request description:
Merge bitcoin-core/secp256k1#1518: Add secp256k1_pubkey_sort
This PR can be recreated with `./contrib/sync-upstream.sh -b master range bb528cf`.
Tip: Use `git show --remerge-diff` to show the changes manually added to the merge commit.
ACKs for top commit:
real-or-random:
ACK 2cb2e312e9
Tree-SHA512: dbdb6c5df2195d2ece9574367e0f684a651ea199806a80232c85b0ffd0ba6b930b108bd97385d9fab656754a85fa6de223a93b945046b043aab20ad7bb3d1bff
f47bbc07f0 test: add unit tests for secp256k1_scalar_check_overflow (Rohit Yadav)
Pull request description:
This Pull Request improves the tests for `secp256k1_scalar_check_overflow` as requested in #1812.
### Changes:
- Removed the redundant "all ones" check from `run_scalar_tests`.
- Added a new dedicated test function `test_scalar_check_overflow`.
- Added static checks for edge cases: `0`, `N-1`, `N`, `N+1`, and `MAX`.
- Added random input tests that verify `check_overflow` against a manual byte comparison.
Fixes#1812.
ACKs for top commit:
theStack:
re-ACK f47bbc07f0
real-or-random:
utACK f47bbc07f0
Tree-SHA512: dad3aa31ecf3f296843c907ac3d9aa5a9b9cb839b36aa3b59e49c853c60c58291412e70dff37dc15f8e14023a8f1e1aba87395065607612d5f6cfa92e14e73b5
97b3c47849 refactor: remove unnecessary `malloc` result casts (Sebastian Falbesoner)
Pull request description:
While working on benchmark code for #1765, I noticed that in some instances we explicitly cast `malloc` results in the codebase. It seems that there is no good reason to do this in C, and it's even considered bad practice, see e.g. https://stackoverflow.com/a/605858.
This commit touches mostly test code, the only two functions used in production are `secp256k1_context_{create,clone}`. Instances were found manually via `$ git grep "malloc("`.
ACKs for top commit:
real-or-random:
Weak Concept ACK && Code Review ACK 97b3c47849
w0xlt:
ACK 97b3c47849
Tree-SHA512: 74aa9f47eb52b7f2a6fcb69deb6aef0c0daa136c5deedfba1228218ef178c722212d8e9936fd2946d2035df932637ca4df49c98ddde488c6b009a74c4d5df316
1bc74a22f8 test: show both Autotools and CMake usage for ctime_tests (8144225309)
Pull request description:
When building with CMake and running `ctime_tests` outside valgrind, users see:
```
Usage: libtool --mode=execute valgrind ./ctime_tests
```
CMake users don't have libtool. Show both commands.
### Before
```
$ ./build/bin/ctime_tests
This test can only usefully be run inside valgrind because it was not compiled under msan.
Usage: libtool --mode=execute valgrind ./ctime_tests
```
### After
```
$ ./build/bin/ctime_tests
This test can only usefully be run inside valgrind because it was not compiled under msan.
Usage: valgrind ./ctime_tests (or with Autotools: libtool --mode=execute valgrind ./ctime_tests)
```
Fixes#1697
ACKs for top commit:
real-or-random:
utACK 1bc74a22f8
Tree-SHA512: d35c332c75fe3df66928cb8b137e11995c67a57744985a50a539d1d9f24cf39ee46f17c6f6a501664a62f67e11b7bb041ba0e1eed6632bf7dccdb57a2c88f9bc
It seems that there is no good reason to do this and it's even
considered bad practice, see e.g. https://stackoverflow.com/a/605858
This commit touches mostly test code, the only two functions used
in production are `secp256k1_context_{create,clone}`.
Instances were found manually via `$ git grep "malloc("`
748c0fdd67 Add CMake build directory patterns to `.gitignore` (Hennadii Stepanov)
7eb86bdb01 autotools: Rename `build-aux` to `autotools-aux` (Hennadii Stepanov)
Pull request description:
Whenever I work on changes that require comparison, such as benchmarking, I end up with two or more build directories that provide different binary variants simultaneously. Adding these build directories to `.gitignore` makes the workflow a bit easier.
Additionally, a trivial refactoring is included to reduce the code.
ACKs for top commit:
real-or-random:
utACK 748c0fdd67
furszy:
ACK 748c0fdd67
Tree-SHA512: 948917dcdc2ec6d5a2227f35ef9208fdbc62c56047db1c60b39f6da632642847aefa18f136986f9f15f08e0b2385964afe9a311346b728536323c54b4f0e3f04
47eb70959a ecmult: Use size_t for array indices in _odd_multiplies_table (Tim Ruffing)
bb1d199de5 ecmult: Use size_t for array indices into tables (Tim Ruffing)
Pull request description:
I don't think the current code is incorrect, but using `size_t` improves readability because the type makes it clear that we're dealing with array indices.
Also, making the result of the `ECMULT_TABLE_SIZE` macro (hopefully) a `size_t` fixes a compiler warning on MSVC, see #1791.
ACKs for top commit:
hebasto:
re-ACK 47eb70959a.
jonasnick:
ACK 47eb70959a
theStack:
ACK 47eb70959a
Tree-SHA512: e484fd610d50e972021c0184a683993364290eb58e09b65f9521b4507ec8d0639b402c67002005630b389bc863a7aa05b75f7224524dbcbafbfa5f9a4812b4a5
In this change the get_iters function was updated to print an error
message and then return 0. In the functions that use get_iters they
print the help text and then EXIT_FAILURE
bd5ced1fe1 doc/bench: added help text for SECP256K1_BENCH_ITERS env var for bench_ecmult (kevkevinpal)
Pull request description:
ACKs for top commit:
real-or-random:
utACK bd5ced1fe1
hebasto:
ACK bd5ced1fe1, I have reviewed the code and it looks OK. Tested on Ubuntu 25.10.
jonasnick:
ACK bd5ced1fe1
Tree-SHA512: 7cfc1a8915717bdfe2901f20f578e23368ece9937a40f36805a0a5b741f97a0502a085c973f6912b96c2bca921ef1654908cfe2c90c0601a7ffa92de4415dc62
2f73e5281d group: Avoid using infinity field directly in other modules (Tim Ruffing)
Pull request description:
Minor refactoring to make the abstraction cleaner
ACKs for top commit:
hebasto:
ACK 2f73e5281d, I have reviewed the code and it looks OK.
theStack:
ACK 2f73e5281d
Tree-SHA512: eae5ad1ce81f491adb48ab1cbf04211f8d43e41255abcacc958fa3dcb1de5021707d56ed1b009a6f3f6c45cd8f20c1f2677891690a3c0a467fc7e064af2512a8
ae00c552df Add VERIFY_CHECKs that flags are 0 or 1 (John Moffett)
Pull request description:
Flags for constant-time masking rely on the values being exactly `0` or `1` rather than `0` or true (any nonzero). One function, `secp256k1_fe_cmov` [documents](e7f7083b53/src/field.h (L315)) and [`VERIFY_CHECK`s](e7f7083b53/src/field_impl.h (L365)) this, but most don't.
This updates the documentation and adds `VERIFY_CHECK`s enforcing `flag == 0 || flag == 1` for:
`secp256k1_fe_storage_cmov`
`secp256k1_gej_cmov`
`secp256k1_ge_storage_cmov`
`secp256k1_scalar_cadd_bit`
`secp256k1_scalar_cond_negate`
`secp256k1_scalar_cmov`
`secp256k1_int_cmov`
ACKs for top commit:
furszy:
ACK ae00c55
hebasto:
re-ACK ae00c552df.
Tree-SHA512: c9d358929d39d93b0aea602d318429f7e82af96bf601f048a1cdeb0621b8adc6d1204648d352aa2060cb0f63db6dcf0da863854375ed313cea44dfad61c19a18
3b5b03f301 doc/bench: Added cmake build options to bench error messages (kevkevinpal)
Pull request description:
## Motivation
I wanted to try and run the benchmarking scripts and I noticed the recovery benchmark in `bench.c`. I wanted to run but I was using `cmake` and the error message telling me to use `./configure -enable-module-recovery` wasn't sufficient.
I figure rather than forcing users to look into the `CMakeLists.txt` file or anywhere else we should add this to the output
## Solution
I appended to the message to include the `-DSECP256K1_ENABLE_MODULE_...=ON` in the message.
ACKs for top commit:
real-or-random:
utACK 3b5b03f301
hebasto:
ACK 3b5b03f301, I have reviewed the code and it looks OK.
Tree-SHA512: 3a6c966b65ab3f0d6dda81e5dd95529087db3f2901f2686af68c16079ec5b323568f3c9acb155d92a6d50b4102faf0844d0d87216df001adbf69cab4ce86dabc
No behavior changes.
Refactors the previously monolithic ElligatorSwift test into isolated,
independent test cases. Doing so allows the test suite to execute
these cases in parallel rather than sequentially.
Overall, seen 35-40% tests time reduction locally.
This is quite useful for the Debug build with no optimizations,
which is noticeably slow.
#### Local Debug-build Results (7 jobs):
- master: 138.0 seconds.
- this PR: 89.3 seconds.
(~1.55× speedup, ~35% reduction)
#### Local Release-build Results (7 jobs):
- master: 9.5 seconds.
- this PR: 5.9 seconds.
(~1.61× speedup, ~38% reduction)
Flags for constant-time masking rely
on the values being exactly 0 or 1 rather
than 0 or true. Add VERIFY_CHECKs to enforce
in VERIFY builds as a preventative
measure and add documentation where relevant.
3daab83a60 refactor: remove ret from secp256k1_ec_pubkey_serialize (kevkevinpal)
Pull request description:
This is a follow-up to https://github.com/bitcoin-core/secp256k1/pull/1774#discussion_r2539737079
It is pretty straightforward to remove `ret` and to just return either `0` or `1`
ACKs for top commit:
real-or-random:
utACK 3daab83a60
theStack:
ACK 3daab83a60
Tree-SHA512: ce598d917455a2d25297436bf2b900a9e88a638617cb79ca22e467135035c334b6815911fe4429ff44dbd877e6d10a346d0b37f2e5a7459e5b35854023832d27
f5e815f430 remove secp256k1_eckey_pubkey_serialize function (Sebastian Falbesoner)
0d3659c547 use new `_eckey_pubkey_serialize{33,65}` functions in modules (ellswift,musig) (Sebastian Falbesoner)
adb76f82ea use new `_eckey_pubkey_serialize{33,65}` functions in public API (Sebastian Falbesoner)
fc7458ca3e introduce `secp256k1_eckey_pubkey_serialize{33,65}` functions (Sebastian Falbesoner)
Pull request description:
This PR splits up the pubkey serialization function `secp256k1_eckey_pubkey_serialize` into two variants for the compressed (33 bytes) and uncompressed (65 bytes) public key output format each, where only non-infinity group elements as input are allowed. The motivation is to simplify call-sites significantly, as they currently need to introduce two variables and a VERIFY_CHECKs on the return value and the in/out size parameter within a pre-processor block, typically leading to 8 lines of code. By using the new functions, the code is reduced to a single line of code that just calls the function (see #1773). This is helpful for already existing modules on master (ellswift, musig) and upcoming ones (silentpayments, see #1765).
One drawback is that the public API function `secp256k1_ec_pubkey_serialize` is now slightly more complex (we now call one of two functions instead of a single one, depending on whether the compressed flag is set or not), but that should hopefully not be a problem.
The commits are intentionally kept small to ease review, happy to squash them if that is preferred.
(Kudos to w0xlt for the initial idea (https://github.com/bitcoin-core/secp256k1/pull/1765#pullrequestreview-3462461331) and to real-or-random for the suggestion to split the already existing function (https://github.com/bitcoin-core/secp256k1/issues/1773#issuecomment-3540461718).)
ACKs for top commit:
real-or-random:
utACK f5e815f430
w0xlt:
ACK f5e815f430
Tree-SHA512: da576bbeae477f31ba76c0001f8df08b51fe5e31d67b422a238348ead3341bf37f0c1509ad9d0a93b63e6d61c152707c85beabd02f4eac3b3bdcff129e0ea750
This change improves separation from CMake build directories, which
typically use the "build" prefix.
Additionally, corresponding `.gitignore` entries have been refactored.
26166c4f5f ecmult_multi: reduce strauss memory usage by 30% (Jonas Nick)
Pull request description:
This is a draft because I'm not sure about the cleanest way to implement it.
ACKs for top commit:
real-or-random:
ACK 26166c4f5f benchmarks show no significant difference (only tried low point counts)
siv2r:
tACK 26166c4
hebasto:
ACK 26166c4f5f, I have reviewed the code and it looks OK.
Tree-SHA512: f289daee0b0b51451331eefdd99200a78bd83539365d38465c038dc0e6ad940daf821119f7161b08a2390cf046e3859a8f950f2fe881a427aba16353031def7d
