This library provides well-tested Python CFFI bindings for libsecp256k1, the heavily optimized C library used by Bitcoin Core for operations on elliptic curve secp256k1.
- Fastest available implementation (more than 10x faster than OpenSSL)
- Clean, easy to use API
- Frequent updates from libsecp256k1 master
- Linux, macOS, and Windows all have binary packages for both 64 and 32-bit architectures
- Linux & macOS use GMP for faster computation
- Deterministic signatures via RFC 6979
- Non-malleable signatures (lower-S form) by default
- Secure, non-malleable ECDH implementation
- Implements a fix for https://bugs.python.org/issue28150 to support Python 3.6+ on macOS
- https://www.ethereum.org
- https://lbry.io
- https://libp2p.io
- https://zeronet.io
- https://ark.io
- https://www.augur.net
- https://www.nucypher.com
- https://raiden.network
- https://golem.network
- https://omisego.network
and many more
Coincurve is distributed on PyPI and is available on Linux/macOS and Windows and supports Python 2.7/3.5+ and PyPy3.5-v5.8.1+.
$ pip install coincurve
If you are on a system that doesn't have a precompiled binary wheel (e.g. FreeBSD) then pip will fetch source to build yourself. You must have the necessary packages.
On Debian/Ubuntu the necessary system packages are:
build-essential
automake
pkg-config
libtool
libffi-dev
python3-dev
(orpython-dev
for Python 2)libgmp-dev
(optional)
On macOS the necessary Homebrew packages are:
automake
pkg-config
libtool
libffi
gmp
(optional)
Coincurve provides a simple API.
verify_signature(signature, message, public_key, hasher=sha256, context=GLOBAL_CONTEXT)
Verifies some message was signed by the owner of a public key.
Parameters:
- signature (
bytes
) - The signature to verify. - message (
bytes
) - The message that was supposedly signed. - public_key (
bytes
) - A public key in compressed or uncompressed form. - hasher - The hash function to use, can be
None
. hasher(message) must return 32 bytes. - context (
coincurve.Context
)
- signature (
Returns:
bool
All instances have a public_key
of type coincurve.PublicKey
PrivateKey(secret=None, context=GLOBAL_CONTEXT)
Parameters:
- secret (
bytes
) - The secret to use. - context (
coincurve.Context
)
- secret (
Methods:
classmethod from_hex(hexed, context=GLOBAL_CONTEXT)
classmethod from_int(num, context=GLOBAL_CONTEXT)
classmethod from_pem(pem, context=GLOBAL_CONTEXT)
classmethod from_der(der, context=GLOBAL_CONTEXT)
sign(message, hasher=sha256, custom_nonce=None)
Parameters:
- message (
bytes
) - The message to sign. - hasher - The hash function to use, can be
None
. hasher(message) must return 32 bytes. - custom_nonce - A tuple of arity 2 in the form of
(nonce_fn, nonce_data)
. Refer to: secp256k1.h
- message (
Returns:
bytes
. 68 <= len(signature) <= 71
sign_recoverable(message, hasher=sha256)
Parameters:
- message (
bytes
) - The message to sign. - hasher - The hash function to use, can be
None
. hasher(message) must return 32 bytes.
- message (
Returns:
bytes
ecdh(public_key)
Computes a Diffie-Hellman secret in constant time. Note: This prevents malleability by returning
sha256(compressed_public_key)
instead of the x
coordinate directly. See ofek#9.
Parameters:
- public_key (
bytes
) - Another party's public key in compressed or uncompressed form.
- public_key (
Returns:
bytes
add(scalar, update=False)
Parameters:
- scalar (
bytes
) - The scalar to add. - update (
bool
) - IfTrue
, will update and returnself
.
- scalar (
Returns:
coincurve.PrivateKey
multiply(scalar, update=False)
Parameters:
- scalar (
bytes
) - The scalar to multiply. - update (
bool
) - IfTrue
, will update and returnself
.
- scalar (
Returns:
coincurve.PrivateKey
to_hex()
to_int()
to_pem()
to_der()
PublicKey(data, context=GLOBAL_CONTEXT)
Parameters:
- data (
bytes
) - The public key in compressed or uncompressed form. - context (
coincurve.Context
)
- data (
Methods:
classmethod from_secret(secret, context=GLOBAL_CONTEXT)
classmethod from_valid_secret(secret, context=GLOBAL_CONTEXT)
classmethod from_point(x, y, context=GLOBAL_CONTEXT)
classmethod from_signature_and_message(serialized_sig, message, hasher=sha256, context=GLOBAL_CONTEXT)
classmethod combine_keys(public_keys, context=GLOBAL_CONTEXT)
Parameters:
- public_keys (
list
) - Alist
ofcoincurve.PublicKey
to add. - context (
coincurve.Context
)
- public_keys (
Returns:
coincurve.PublicKey
format(compressed=True)
Parameters:
- compressed (
bool
)
- compressed (
Returns: The public key serialized to
bytes
.
point()
- Returns: (x, y)
verify(signature, message, hasher=sha256)
Verifies some message was signed by the owner of this public key.
Parameters:
- signature (
bytes
) - The signature to verify. - message (
bytes
) - The message that was supposedly signed. - hasher - The hash function to use, can be
None
. hasher(message) must return 32 bytes.
- signature (
Returns:
bool
add(scalar, update=False)
Parameters:
- scalar (
bytes
) - The scalar to add. - update (
bool
) - IfTrue
, will update and returnself
.
- scalar (
Returns:
coincurve.PublicKey
multiply(scalar, update=False)
Parameters:
- scalar (
bytes
) - The scalar to multiply. - update (
bool
) - IfTrue
, will update and returnself
.
- scalar (
Returns:
coincurve.PublicKey
combine(public_keys, update=False)
Parameters:
- public_keys (
list
) - Alist
ofcoincurve.PublicKey
to add. - update (
bool
) - IfTrue
, will update and returnself
.
- public_keys (
Returns:
coincurve.PublicKey
Coincurve is distributed under the terms of both
at your option.
- Contributors of libsecp256k1.
- Contributors of secp256k1-py. While Coincurve is nearly a complete rewrite, much of the build system provided by ulope remains.
Important changes are emphasized.
- New: Binary wheels for Python 3.8!
- Support building on OpenBSD
- Improve handling of PEM private key deserialization
- Improve ECDH documentation
- Improvements from libsecp256k1 master
- New: Binary wheels on Linux for PyPy3.6 v7.1.1-beta!
- New: Binary wheels on macOS for Python 3.8.0-alpha.3!
- New: Binary wheels on Linux are now also built with the new manylinux2010 spec for 64-bit platforms!
- Improvements from libsecp256k1 master
- Fix some linking scenarios by placing bundled libsecp256k1 dir first in path
- Allow override of system libsecp256k1 with environment variable
- Add benchmarks
- Use Codecov to track coverage
- Use black for code formatting
- Support tox for testing
- Compatibility with latest libsecp256k1 ECDH API
- Make libgmp optional when building from source
- Fixed wheels for macOS
- Breaking: Drop support for 32-bit macOS
View all history