Kgothatso Ngako a7d4337778 build: wire the frost_enrollment module into both build systems
Second of six commits adding the frost_enrollment module. This one is
scaffolding only: the five entry points are stubs that validate their
pointer arguments, zero their outputs and return 0. What is being
verified here is that the module configures, compiles, links, exports
its symbols and registers its test module in both build systems -- so
that the next commit changes nothing but arithmetic.

Ordering is the one thing in this commit that can go silently wrong, and
it goes wrong in opposite directions in the two build systems:

- configure.ac executes its `if` blocks in file order, and
  enable_module_frost defaults to no (configure.ac:243). A block placed
  after the frost block at :601 that sets enable_module_frost=yes flips
  the variable too late: AM_CONDITIONAL goes true, so the header is
  installed and the Makefile fragment is pulled in, but
  -DENABLE_MODULE_FROST=1 is never appended, so src/secp256k1.c never
  includes frost's implementation and every secp256k1_frost_* symbol
  fails to link. The new block therefore goes ahead of both the frost
  block and prefractal's, which documents the same trap.

- src/CMakeLists.txt processes dependents FIRST, so the same block goes
  above the FROST block there, beside prefractal's.

Verified rather than assumed: configuring with ONLY
--enable-module-frost-enrollment emits -DENABLE_MODULE_FROST=1
alongside -DENABLE_MODULE_FROST_ENROLLMENT=1, and the CMake summary
prints "frost ON" for the same configuration -- the latter is what the
PARENT_SCOPE lift buys, since the summary runs after
add_subdirectory(src) and would otherwise report a module it is
compiling in as OFF.

The dependency guard is prefractal's implies-frost idiom, copied
verbatim along with its reasoning. frost is default-OFF, so the
`test x"$enable_module_frost" = x"no"` / `DEFINED X AND NOT X` guard
every other module uses -- which reads as "the user disabled it
explicitly" for a default-ON dependency -- is true by default here and
cannot tell an explicit --disable-module-frost from the default once
both are in the cache. Enabling frost-enrollment simply implies frost,
with no error.

The one frost-module change in the whole series is in this commit:
src/modules/frost/session.h gains a declaration for
secp256k1_frost_sort_ids, which is defined at session_impl.h:517 and
declared nowhere. The params hash needs it to canonicalize identifier
order. Prefractal reaches frost's statics through translation-unit
ordering alone; rather than inherit reuse-by-link-order, this declares
the function where keygen.h:48 already declares derive_pubshare_at, so
the reuse goes through an interface. No behavior change: it is a
declaration for an existing static definition in the same TU.

CI wiring is two files, and skipping either half fails quietly:

- ci/ci.sh gets FROST_ENROLLMENT in the reproduction header's variable
  list and --enable-module-frost-enrollment="$FROST_ENROLLMENT" after
  the prefractal line.
- .github/workflows/ci.yml gets FROST_ENROLLMENT at every PREFRACTAL
  site: the global default, 11 inline matrix entries and 10 job-level
  env blocks. Without the default, ci.sh runs under set -eux with an
  empty $FROST_ENROLLMENT, passes --enable-module-frost-enrollment="",
  `test x"" = x"yes"` is false, and the module is off in all of CI while
  ci.sh visibly has the plumbing.

Verified programmatically over the parsed workflow: across the 106
effective job contexts, PREFRACTAL and FROST_ENROLLMENT now agree in
every single one (45 set to yes, no mismatches), no context sets
FROST_ENROLLMENT without FROST or without EXPERIMENTAL, and no context
leaves it undefined. ci.sh passes sh -n.

The stub test is not a placeholder that has to be deleted later: every
entry point must reject an empty helper set and leave its output zeroed,
which is true of the stubs and stays true of the finished
implementation, so it doubles as the check that all five symbols are
reachable from the test binary.

Verification. Autotools: ./autogen.sh, then a frost-enrollment-only
configure and a full configure with frost, chilldkg, iceberg, prefractal
and frost-enrollment all on -- both build with zero warnings under the
project's -Werror-grade flag set, ./tests and ./exhaustive_tests exit 0,
and `./tests -l` lists the frost_enrollment module. CMake: configure with
-DSECP256K1_EXPERIMENTAL=ON -DSECP256K1_ENABLE_MODULE_FROST_ENROLLMENT=ON
builds clean and ctest passes 391 tests. nm shows the five new symbols
exported from libsecp256k1.so; tools/symbol-check.py could not be run
here because python3-lief is not installed in this environment, but all
five carry the required secp256k1_ prefix. make dist succeeds and the
tarball carries src/modules/frost_enrollment/frost_enrollment.md
alongside the other module documents.

One unrelated observation from this build: a stale
src/ctime_tests-ctime_tests.o left over from an earlier configure with a
different module set will fail to link, because automake does not track
CPPFLAGS changes across reconfigures. make clean between configurations
with different module sets, not a fault in this change.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-04 03:53:03 +02:00
2026-09-04 02:56:23 +02:00
2026-08-31 12:25:09 +02:00
2013-05-09 15:24:32 +02:00

libsecp256k1-zkp

Dependencies: None

A fork of libsecp256k1 with support for advanced and experimental features

Added features:

  • Experimental module for ECDSA adaptor signatures.
  • Experimental module for ECDSA sign-to-contract.
  • Experimental modules for Confidential Assets (Pedersen commitments, range proofs, and surjection proofs).
  • Experimental module for address whitelisting.
  • Experimental module for Schnorr signature half-aggregation.
  • Experimental module for FROST (BIP 445).
  • Experimental module for ChillDKG, distributed key generation for FROST (bip-frost-dkg draft).
  • Experimental module for Iceberg, a threshold scheme that lets a group of parties stand in for a single MuSig2 (BIP 327) participant.
  • Experimental module for Prefractal, a nested FROST+MuSig2 signer that lets a FROST group occupy one participant slot of an ordinary MuSig2 (BIP 327) session.

Experimental features are made available for testing and review by the community. The APIs of these features should not be considered stable.

Build steps

Obtaining and verifying

The git tag for each release (e.g. v0.6.0) is GPG-signed by one of the maintainers. For a fully verified build of this project, it is recommended to obtain this repository via git, obtain the GPG keys of the signing maintainer(s), and then verify the release tag's signature using git.

This can be done with the following steps:

  1. Obtain the GPG keys listed in SECURITY.md.
  2. If possible, cross-reference these key IDs with another source controlled by its owner (e.g. social media, personal website). This is to mitigate the unlikely case that incorrect content is being presented by this repository.
  3. Clone the repository:
    git clone https://github.com/bitcoin-core/secp256k1
    
  4. Check out the latest release tag, e.g.
    git checkout v0.7.1
    
  5. Use git to verify the GPG signature:
    % git tag -v v0.7.1 | grep -C 3 'Good signature'
    
    gpg: Signature made Mon 26 Jan 2026 07:42:46 PM UTC
    gpg:                using RSA key 2840EAABF4BC9F0FFD716AFAFBAFCC46DE2D3FE2
    gpg: Good signature from "Pieter Wuille <pieter@wuille.net>" [unknown]
    gpg:                 aka "Pieter Wuille <pieter.wuille@gmail.com>" [full]
    gpg:                 aka "[jpeg image of size 5996]" [undefined]
    gpg: WARNING: This key is not certified with a trusted signature!
    gpg:          There is no indication that the signature belongs to the owner.
    Primary key fingerprint: 133E AC17 9436 F14A 5CF1  B794 860F EB80 4E66 9320
         Subkey fingerprint: 2840 EAAB F4BC 9F0F FD71  6AFA FBAF CC46 DE2D 3FE2
    

Building with Autotools

$ ./autogen.sh       # Generate a ./configure script
$ ./configure        # Generate a build system
$ make               # Run the actual build process
$ make check         # Run the test suite
$ sudo make install  # Install the library into the system (optional)

To compile optional modules (such as Schnorr signatures), you need to run ./configure with additional flags (such as --enable-module-schnorrsig). Run ./configure --help to see the full list of available flags. For experimental modules, you will also need --enable-experimental as well as a flag for each individual module, e.g. --enable-module-rangeproof.

Building with CMake

To maintain a pristine source tree, CMake encourages to perform an out-of-source build by using a separate dedicated build tree.

Building on POSIX systems

$ cmake -B build              # Generate a build system in subdirectory "build"
$ cmake --build build         # Run the actual build process
$ ctest --test-dir build      # Run the test suite
$ sudo cmake --install build  # Install the library into the system (optional)

To compile optional modules (such as Schnorr signatures), you need to run cmake with additional flags (such as -DSECP256K1_ENABLE_MODULE_SCHNORRSIG=ON). Run cmake -B build -LH or ccmake -B build to see the full list of available flags.

Cross compiling

To alleviate issues with cross compiling, preconfigured toolchain files are available in the cmake directory. For example, to cross compile for Windows:

$ cmake -B build -DCMAKE_TOOLCHAIN_FILE=cmake/x86_64-w64-mingw32.toolchain.cmake

To cross compile for Android with NDK (using NDK's toolchain file, and assuming the ANDROID_NDK_ROOT environment variable has been set):

$ cmake -B build -DCMAKE_TOOLCHAIN_FILE="${ANDROID_NDK_ROOT}/build/cmake/android.toolchain.cmake" -DANDROID_ABI=arm64-v8a -DANDROID_PLATFORM=28

Building on Windows

The following example assumes Visual Studio 2022. Using clang-cl is recommended.

In "Developer Command Prompt for VS 2022":

>cmake -B build -T ClangCL
>cmake --build build --config RelWithDebInfo

Usage examples

Usage examples can be found in the examples directory. To compile them you need to configure with --enable-examples.

To compile the examples, make sure the corresponding modules are enabled.

Benchmark

If configured with --enable-benchmark (which is the default), binaries for benchmarking the libsecp256k1-zkp functions will be present in the root directory after the build.

To print the benchmark result to the command line:

$ ./bench_name

To create a CSV file for the benchmark result :

$ ./bench_name | sed '2d;s/ \{1,\}//g' > bench_name.csv

Reporting a vulnerability

See SECURITY.md

Contributing to libsecp256k1

See CONTRIBUTING.md

Description
Experimental fork of libsecp256k1 with support for pedersen commitments and range proofs.
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