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 __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')