import ctypes
import os
import warnings
from ctypes import (
byref, c_byte, c_int, c_uint, c_char_p, c_size_t, c_void_p, create_string_buffer, CFUNCTYPE, POINTER
)
from pycoin.encoding.bytes32 import from_bytes_32, to_bytes_32
from pycoin.intbytes import iterbytes
SECP256K1_FLAGS_TYPE_MASK = ((1 << 8) - 1)
SECP256K1_FLAGS_TYPE_CONTEXT = (1 << 0)
SECP256K1_FLAGS_TYPE_COMPRESSION = (1 << 1)
# /** The higher bits contain the actual data. Do not use directly. */
SECP256K1_FLAGS_BIT_CONTEXT_VERIFY = (1 << 8)
SECP256K1_FLAGS_BIT_CONTEXT_SIGN = (1 << 9)
SECP256K1_FLAGS_BIT_COMPRESSION = (1 << 8)
# /** Flags to pass to secp256k1_context_create. */
SECP256K1_CONTEXT_VERIFY = (SECP256K1_FLAGS_TYPE_CONTEXT | SECP256K1_FLAGS_BIT_CONTEXT_VERIFY)
SECP256K1_CONTEXT_SIGN = (SECP256K1_FLAGS_TYPE_CONTEXT | SECP256K1_FLAGS_BIT_CONTEXT_SIGN)
SECP256K1_CONTEXT_NONE = (SECP256K1_FLAGS_TYPE_CONTEXT)
SECP256K1_FLAGS_BIT_COMPRESSION = (1 << 8)
SECP256K1_EC_COMPRESSED = (SECP256K1_FLAGS_TYPE_COMPRESSION | SECP256K1_FLAGS_BIT_COMPRESSION)
SECP256K1_EC_UNCOMPRESSED = (SECP256K1_FLAGS_TYPE_COMPRESSION)
[docs]def load_library():
try:
PYCOIN_LIBSECP256K1_PATH = os.getenv("PYCOIN_LIBSECP256K1_PATH")
library_path = PYCOIN_LIBSECP256K1_PATH or ctypes.util.find_library('libsecp256k1')
secp256k1 = ctypes.cdll.LoadLibrary(library_path)
secp256k1.secp256k1_context_create.argtypes = [c_uint]
secp256k1.secp256k1_context_create.restype = c_void_p
secp256k1.secp256k1_context_randomize.argtypes = [c_void_p, c_char_p]
secp256k1.secp256k1_context_randomize.restype = c_int
secp256k1.secp256k1_ec_pubkey_create.argtypes = [c_void_p, c_void_p, c_char_p]
secp256k1.secp256k1_ec_pubkey_create.restype = c_int
secp256k1.secp256k1_ecdsa_sign.argtypes = [c_void_p, c_char_p, c_char_p, c_char_p, c_void_p, c_void_p]
secp256k1.secp256k1_ecdsa_sign.restype = c_int
secp256k1.secp256k1_ecdsa_verify.argtypes = [c_void_p, c_char_p, c_char_p, c_char_p]
secp256k1.secp256k1_ecdsa_verify.restype = c_int
secp256k1.secp256k1_ec_pubkey_parse.argtypes = [c_void_p, c_char_p, c_char_p, c_int]
secp256k1.secp256k1_ec_pubkey_parse.restype = c_int
secp256k1.secp256k1_ec_pubkey_serialize.argtypes = [c_void_p, c_char_p, c_void_p, c_char_p, c_uint]
secp256k1.secp256k1_ec_pubkey_serialize.restype = c_int
secp256k1.secp256k1_ecdsa_signature_parse_compact.argtypes = [c_void_p, c_char_p, c_char_p]
secp256k1.secp256k1_ecdsa_signature_parse_compact.restype = c_int
secp256k1.secp256k1_ecdsa_signature_serialize_compact.argtypes = [c_void_p, c_char_p, c_char_p]
secp256k1.secp256k1_ecdsa_signature_serialize_compact.restype = c_int
secp256k1.secp256k1_ec_pubkey_tweak_mul.argtypes = [c_void_p, c_char_p, c_char_p]
secp256k1.secp256k1_ec_pubkey_tweak_mul.restype = c_int
secp256k1.ctx = secp256k1.secp256k1_context_create(SECP256K1_CONTEXT_SIGN | SECP256K1_CONTEXT_VERIFY)
r = secp256k1.secp256k1_context_randomize(secp256k1.ctx, os.urandom(32))
if r:
return secp256k1
except (OSError, AttributeError):
if PYCOIN_LIBSECP256K1_PATH:
warnings.warn("PYCOIN_LIBSECP256K1_PATH set but libsecp256k1 optimizations not loaded")
return None
libsecp256k1 = load_library()
[docs]class Optimizations:
def __mul__(self, e):
e %= self.order()
if e == 0:
return self._infinity
pubkey = create_string_buffer(65)
libsecp256k1.secp256k1_ec_pubkey_create(libsecp256k1.ctx, pubkey, c_char_p(to_bytes_32(e)))
pubkey_size = c_size_t(65)
pubkey_serialized = create_string_buffer(65)
libsecp256k1.secp256k1_ec_pubkey_serialize(
libsecp256k1.ctx, pubkey_serialized, byref(pubkey_size), pubkey, SECP256K1_EC_UNCOMPRESSED)
x = from_bytes_32(pubkey_serialized[1:33])
y = from_bytes_32(pubkey_serialized[33:])
return self.Point(x, y)
[docs] def sign(self, secret_exponent, val, gen_k=None):
nonce_function = None
if gen_k is not None:
k_as_bytes = to_bytes_32(gen_k(self.order(), secret_exponent, val))
def adaptor(nonce32_p, msg32_p, key32_p, algo16_p, data, attempt):
nonce32_p.contents[:] = list(iterbytes(k_as_bytes))
return 1
p_b32 = POINTER(c_byte*32)
nonce_function = CFUNCTYPE(c_int, p_b32, p_b32, p_b32, POINTER(c_byte*16), c_void_p, c_uint)(adaptor)
sig = create_string_buffer(64)
sig_hash_bytes = to_bytes_32(val)
libsecp256k1.secp256k1_ecdsa_sign(
libsecp256k1.ctx, sig, sig_hash_bytes, to_bytes_32(secret_exponent), nonce_function, None)
compact_signature = create_string_buffer(64)
libsecp256k1.secp256k1_ecdsa_signature_serialize_compact(libsecp256k1.ctx, compact_signature, sig)
r = from_bytes_32(compact_signature[:32])
s = from_bytes_32(compact_signature[32:])
return (r, s)
[docs] def verify(self, public_pair, val, signature_pair):
sig = create_string_buffer(64)
input64 = to_bytes_32(signature_pair[0]) + to_bytes_32(signature_pair[1])
r = libsecp256k1.secp256k1_ecdsa_signature_parse_compact(libsecp256k1.ctx, sig, input64)
if not r:
return False
r = libsecp256k1.secp256k1_ecdsa_signature_normalize(libsecp256k1.ctx, sig, sig)
public_pair_bytes = b'\4' + to_bytes_32(public_pair[0]) + to_bytes_32(public_pair[1])
pubkey = create_string_buffer(64)
r = libsecp256k1.secp256k1_ec_pubkey_parse(
libsecp256k1.ctx, pubkey, public_pair_bytes, len(public_pair_bytes))
if not r:
return False
return 1 == libsecp256k1.secp256k1_ecdsa_verify(libsecp256k1.ctx, sig, to_bytes_32(val), pubkey)
[docs] def multiply(self, p, e):
"""Multiply a point by an integer."""
e %= self.order()
if p == self._infinity or e == 0:
return self._infinity
pubkey = create_string_buffer(64)
public_pair_bytes = b'\4' + to_bytes_32(p[0]) + to_bytes_32(p[1])
r = libsecp256k1.secp256k1_ec_pubkey_parse(
libsecp256k1.ctx, pubkey, public_pair_bytes, len(public_pair_bytes))
if not r:
return False
r = libsecp256k1.secp256k1_ec_pubkey_tweak_mul(libsecp256k1.ctx, pubkey, to_bytes_32(e))
if not r:
return self._infinity
pubkey_serialized = create_string_buffer(65)
pubkey_size = c_size_t(65)
libsecp256k1.secp256k1_ec_pubkey_serialize(
libsecp256k1.ctx, pubkey_serialized, byref(pubkey_size), pubkey, SECP256K1_EC_UNCOMPRESSED)
x = from_bytes_32(pubkey_serialized[1:33])
y = from_bytes_32(pubkey_serialized[33:])
return self.Point(x, y)
[docs]def create_LibSECP256K1Optimizations():
class noop:
pass
native = os.getenv("PYCOIN_NATIVE")
if native and native.lower() != "secp256k1":
return noop
if not libsecp256k1:
return noop
return Optimizations
LibSECP256K1Optimizations = create_LibSECP256K1Optimizations()