def verify_lrs_signature(self, client_msg, client_sig):
"""Verifies whether the LRS signature is valid."""
# modify copy of stp_array to prevent duplicate voting
stp_array = list(self.stp_array)
stp_array.append(msg_hash(client_msg, sha1))
return lrs.verify(client_msg, stp_array, *client_sig, g=self.generator)
def lrs_sign(self, msg):
"""Sign for LRS."""
ltp_array = sendrecv(self.server_addr, [Constants.GET_LTP_ARRAY])
ltp_idx = ltp_array.index(self.pub_key)
# modify stp_array to prevent duplicate voting
ltp_array.append(msg_hash(msg, sha1))
return lrs.sign(msg, self.pri_key, ltp_idx, ltp_array)
def lrs_sign(self, msg):
"""Sign for LRS."""
generator = sendrecv(self.server_addr, [Constants.GET_GENERATOR])
stp_array = sendrecv(self.server_addr, [Constants.GET_STP_ARRAY])
stp = powm(generator, self.pri_key)
stp_idx = stp_array.index(stp)
# modify stp_array to prevent duplicate voting
stp_array.append(msg_hash(msg, sha1))
return lrs.sign(msg, self.pri_key, stp_idx, stp_array, g=generator)
def sign(self, msg, generator):
"""Sign with ElGamal signature."""
r, s = 0, 0
while s == 0:
k = randkeyRP(1, Constants.P - 2)
r = powm(generator, k)
s = (msg_hash(msg, sha1) - self.pri_key * r) * modinv(
k, Constants.P - 1)
s %= Constants.P - 1
return (r, s)
def verify_signature(self, msg, stp, sig):
"""Verifies signature in message posting.
msg: The message to verify
stp: The public key of the user
sig: The signature
Returns whether the signature is valid or not.
"""
r, s = sig
u = powm(self.generator, msg_hash(msg, sha1))
v = (powm(stp, r) * powm(r, s)) % Constants.P
return u == v
def verify_lrs_signature(self, client_msg, client_sig): # modify copy of ltp_array to prevent duplicate voting ltp_array = list(self.ltp_list.keys()) ltp_array.append(msg_hash(client_msg, sha1)) return lrs.verify(client_msg, ltp_array, *client_sig)