All notable changes to this project will be documented in this file.
The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.
0.3.2 - 2023-05-13
We strongly recommend updating to 0.3.2 if you use or plan to use GCC >=13 to compile libsecp256k1. When in doubt, check the GCC version using gcc -v
.
- Module
ecdh
: Fix "constant-timeness" issue with GCC 13.1 (and potentially future versions of GCC) that could leave applications using libsecp256k1's ECDH module vulnerable to a timing side-channel attack. The fix avoids secret-dependent control flow during ECDH computations when libsecp256k1 is compiled with GCC 13.1.
- Fixed an old bug that permitted compilers to potentially output bad assembly code on x86_64. In theory, it could lead to a crash or a read of unrelated memory, but this has never been observed on any compilers so far.
- Various improvements and changes to CMake builds. CMake builds remain experimental.
- Made API versioning consistent with GNU Autotools builds.
- Switched to
BUILD_SHARED_LIBS
variable for controlling whether to build a static or a shared library. - Added
SECP256K1_INSTALL
variable for the controlling whether to install the build artefacts.
- Renamed asm build option
arm
toarm32
. Use--with-asm=arm32
instead of--with-asm=arm
(GNU Autotools), and-DSECP256K1_ASM=arm32
instead of-DSECP256K1_ASM=arm
(CMake).
The ABI is compatible with versions 0.3.0 and 0.3.1.
0.3.1 - 2023-04-10
We strongly recommend updating to 0.3.1 if you use or plan to use Clang >=14 to compile libsecp256k1, e.g., Xcode >=14 on macOS has Clang >=14. When in doubt, check the Clang version using clang -v
.
- Fix "constant-timeness" issue with Clang >=14 that could leave applications using libsecp256k1 vulnerable to a timing side-channel attack. The fix avoids secret-dependent control flow and secret-dependent memory accesses in conditional moves of memory objects when libsecp256k1 is compiled with Clang >=14.
- Added tests against Project Wycheproof's set of ECDSA test vectors (Bitcoin "low-S" variant), a fixed set of test cases designed to trigger various edge cases.
- Increased minimum required CMake version to 3.13. CMake builds remain experimental.
The ABI is compatible with version 0.3.0.
0.3.0 - 2023-03-08
- Added experimental support for CMake builds. Traditional GNU Autotools builds (
./configure
andmake
) remain fully supported. - Usage examples: Added a recommended method for securely clearing sensitive data, e.g., secret keys, from memory.
- Tests: Added a new test binary
noverify_tests
. This binary runs the tests without some additional checks present in the ordinarytests
binary and is thereby closer to production binaries. Thenoverify_tests
binary is automatically run as part of themake check
target.
- Fixed declarations of API variables for MSVC (
__declspec(dllimport)
). This fixes MSVC builds of programs which link against a libsecp256k1 DLL dynamically and use API variables (and not only API functions). Unfortunately, the MSVC linker now will emit warningLNK4217
when trying to link against libsecp256k1 statically. Pass/ignore:4217
to the linker to suppress this warning.
- Forbade cloning or destroying
secp256k1_context_static
. Create a new context instead of cloning the static context. (If this change breaks your code, your code is probably wrong.) - Forbade randomizing (copies of)
secp256k1_context_static
. Randomizing a copy ofsecp256k1_context_static
did not have any effect and did not provide defense-in-depth protection against side-channel attacks. Create a new context if you want to benefit from randomization.
- Removed the configuration header
src/libsecp256k1-config.h
. We recommend passing flags to./configure
orcmake
to set configuration options (see./configure --help
orcmake -LH
). If you cannot or do not want to use one of the supported build systems, pass configuration flags such as-DSECP256K1_ENABLE_MODULE_SCHNORRSIG
manually to the compiler (see the fileconfigure.ac
for supported flags).
Due to changes in the API regarding secp256k1_context_static
described above, the ABI is not compatible with previous versions.
0.2.0 - 2022-12-12
- Added usage examples for common use cases in a new
examples/
directory. - Added
secp256k1_selftest
, to be used in conjunction withsecp256k1_context_static
. - Added support for 128-bit wide multiplication on MSVC for x86_64 and arm64, giving roughly a 20% speedup on those platforms.
- Enabled modules
schnorrsig
,extrakeys
andecdh
by default in./configure
. - The
secp256k1_nonce_function_rfc6979
nonce function, used by default bysecp256k1_ecdsa_sign
, now reduces the message hash modulo the group order to match the specification. This only affects improper use of ECDSA signing API.
- Deprecated context flags
SECP256K1_CONTEXT_VERIFY
andSECP256K1_CONTEXT_SIGN
. UseSECP256K1_CONTEXT_NONE
instead. - Renamed
secp256k1_context_no_precomp
tosecp256k1_context_static
. - Module
schnorrsig
: renamedsecp256k1_schnorrsig_sign
tosecp256k1_schnorrsig_sign32
.
Since this is the first release, we do not compare application binary interfaces. However, there are earlier unreleased versions of libsecp256k1 that are not ABI compatible with this version.
0.1.0 - 2013-03-05 to 2021-12-25
This version was in fact never released. The number was given by the build system since the introduction of autotools in Jan 2014 (ea0fe5a5bf0c04f9cc955b2966b614f5f378c6f6). Therefore, this version number does not uniquely identify a set of source files.