def sec(self, compressed=True):
'''returns the binary version of the SEC format'''
if compressed:
if not self.csec:
serialized = ffi.new('unsigned char [33]')
output_len = ffi.new('size_t *', 33)
lib.secp256k1_ec_pubkey_serialize(
GLOBAL_CTX,
serialized,
output_len,
self.c,
lib.SECP256K1_EC_COMPRESSED,
)
self.csec = bytes(ffi.buffer(serialized, 33))
return self.csec
else:
if not self.usec:
serialized = ffi.new('unsigned char [65]')
output_len = ffi.new('size_t *', 65)
lib.secp256k1_ec_pubkey_serialize(
GLOBAL_CTX,
serialized,
output_len,
self.c,
lib.SECP256K1_EC_UNCOMPRESSED,
)
self.usec = bytes(ffi.buffer(serialized, 65))
return self.usec
def der(self):
if not self.der_cache:
der = ffi.new('unsigned char[72]')
der_length = ffi.new('size_t *', 72)
lib.secp256k1_ecdsa_signature_serialize_der(
GLOBAL_CTX, der, der_length, self.c)
self.der_cache = bytes(ffi.buffer(der, der_length[0]))
return self.der_cache
def __rmul__(self, coefficient):
coef = coefficient % N
new_key = ffi.new('secp256k1_pubkey *')
s = self.sec(compressed=False)
lib.secp256k1_ec_pubkey_parse(GLOBAL_CTX, new_key, s, len(s))
lib.secp256k1_ec_pubkey_tweak_mul(GLOBAL_CTX, new_key,
coef.to_bytes(32, 'big'))
serialized = ffi.new('unsigned char [65]')
output_len = ffi.new('size_t *', 65)
lib.secp256k1_ec_pubkey_serialize(GLOBAL_CTX, serialized, output_len,
new_key,
lib.SECP256K1_EC_UNCOMPRESSED)
return self.__class__(usec=bytes(serialized))
def __add__(self, scalar):
'''Multiplies scalar by generator, adds result to current point'''
coef = scalar % N
new_key = ffi.new('secp256k1_pubkey *')
s = self.sec(compressed=False)
lib.secp256k1_ec_pubkey_parse(GLOBAL_CTX, new_key, s, len(s))
lib.secp256k1_ec_pubkey_tweak_add(GLOBAL_CTX, new_key,
coef.to_bytes(32, 'big'))
serialized = ffi.new('unsigned char [65]')
output_len = ffi.new('size_t *', 65)
lib.secp256k1_ec_pubkey_serialize(GLOBAL_CTX, serialized, output_len,
new_key,
lib.SECP256K1_EC_UNCOMPRESSED)
return self.__class__(usec=bytes(serialized))
def sign(self, z):
secret = self.secret.to_bytes(32, 'big')
msg = z.to_bytes(32, 'big')
csig = ffi.new('secp256k1_ecdsa_signature *')
if not lib.secp256k1_ecdsa_sign(GLOBAL_CTX, csig, msg, secret,
ffi.NULL, ffi.NULL):
raise RuntimeError('something went wrong with c signing')
sig = Signature(c=csig)
if not self.point.verify(z, sig):
raise RuntimeError('something went wrong with signing')
return sig
def __init__(self, der: Optional[bytes] = None, c: None = None) -> None:
if der:
self.der_cache = der
self.c = ffi.new('secp256k1_ecdsa_signature *')
if not lib.secp256k1_ecdsa_signature_parse_der(
GLOBAL_CTX, self.c, der, len(der)):
raise RuntimeError(f'badly formatted signature {der.hex()}')
elif c:
self.c = c
self.der_cache = None
else:
raise RuntimeError('need der or c object')
def __init__(self, der=None, c=None):
if der:
self.der_cache = der
self.c = ffi.new('secp256k1_ecdsa_signature *')
if not lib.secp256k1_ecdsa_signature_parse_der(
GLOBAL_CTX, self.c, der, len(der)):
raise RuntimeError('badly formatted signature {}'.format(
der.hex()))
elif c:
self.c = c
self.der_cache = None
else:
raise RuntimeError('need der or c object')
def __init__(self, csec=None, usec=None):
if usec:
self.usec = usec
self.csec = None
sec_cache = usec
elif csec:
self.csec = csec
self.usec = None
sec_cache = csec
else:
raise RuntimeError('need a serialization')
self.c = ffi.new('secp256k1_pubkey *')
if not lib.secp256k1_ec_pubkey_parse(GLOBAL_CTX, self.c, sec_cache,
len(sec_cache)):
raise RuntimeError('libsecp256k1 produced error')