def _CKD_pub(cK, c, s):
I = hmac_oneshot(c, cK + s, hashlib.sha512)
pubkey = ecc.ECPrivkey(I[0:32]) + ecc.ECPubkey(cK)
if pubkey.is_at_infinity():
raise ecc.InvalidECPointException()
cK_n = pubkey.get_public_key_bytes(compressed=True)
c_n = I[32:]
return cK_n, c_n
def is_old_mpk(mpk: str) -> bool:
try:
int(mpk, 16)
except:
return False
if len(mpk) != 128:
return False
try:
ecc.ECPubkey(bfh('04' + mpk))
except:
return False
return True
def get_pubkey_from_mpk(self, mpk, for_change, n):
z = self.get_sequence(mpk, for_change, n)
master_public_key = ecc.ECPubkey(bfh('04' + mpk))
public_key = master_public_key + z * ecc.generator()
return public_key.get_public_key_hex(compressed=False)
def _CKD_pub(cK, c, s):
I = hmac.new(c, cK + s, hashlib.sha512).digest()
pubkey = ecc.ECPrivkey(I[0:32]) + ecc.ECPubkey(cK)
cK_n = pubkey.get_public_key_bytes(compressed=True)
c_n = I[32:]
return cK_n, c_n