This package provides bindings (using cgo) to the upstream https://github.com/bitcoin-core/secp256k1 C library.
It exposes several high level functions for elliptic curve operations over the secp256k1 curve, namely ECDSA, point & scalar operations, ECDH, and recoverable signatures.
It should be mentioned that the upstream library is still experimental and has yet to be formally released. As such, you should think twice before installing this package.
The currently targeted version of libsecp256k1 is the latest master commit.
Currently two experimental libraries are also included and supported: ECDH and signature recovery. These are included with the default installation, and may eventually be discontinued by the same (as has happened with Schnorr).
To start developing, clone the package from github, and from the source directory, run the following to install the package.
git submodule update --init
make install
Tests can be run by calling make test
Coverage can be build by calling make coverage
To display a HTML code coverage report, call make coverage-html
Please make sure to include tests for new features.
There have been some slight changes to the API exposed by libsecp256k1. This section will document conventions adopted in the design.
There are some functions which return more than one error code, indicating the specific failure which occurred. With this in mind, the raw error code is always returned as the first return value.
To help provide some meaning to the error codes, the last parameter will be used to return reasonable error messages.
In functions like EcPrivkeyTweakAdd, libsecp256k1 will take a pointer to the private key, tweaking the value in place (overwriting the original value)
To avoid making copies of secrets in memory, we allow upstream to overwrite the original values. If the to-be-written value is a new object, it is returned with the other return values (example: EcdsaSign)