def _generateRandomID(
self,
c1 = constants.CRYPTO_CHALLENGE_C1,
c2 = constants.CRYPTO_CHALLENGE_C2):
"""Generates the NodeID by solving two cryptographic puzzles."""
# Solve the static cryptographic puzzle.
rsaKey = None
p = 0x1 # non-zero value
pub = None
randomStream = Crypto.Random.new().read
while not util.hasNZeroBitPrefix(p, c1):
rsaKey = Crypto.PublicKey.RSA.generate(constants.RSA_BITS, randomStream)
pub = str(rsaKey.n) + str(rsaKey.e)
p = util.hsh2int(Crypto.Hash.SHA.new(Crypto.Hash.SHA.new(pub).digest()))
# created correct NodeID
self.rsaKey = rsaKey
nodeID = Crypto.Hash.SHA.new(pub)
# Solve the dynamic cryptographic puzzle.
p, x = 0x1, None
while not util.hasNZeroBitPrefix(p, c2):
x = util.bin2int(util.generateRandomString(constants.ID_LENGTH))
# This is madness!
p = util.hsh2int(
Crypto.Hash.SHA.new(
util.int2bin(
(util.hsh2int(nodeID) ^ x))))
# Found a correct value of X and nodeID
self.x = x
return nodeID.digest()
def _verifyID(self, nodeID, x):
'''Verifies if a user's ID has been generated using the '''
p1 = util.hsh2int(Crypto.Hash.SHA.new(nodeID))
p2 = util.hsh2int(Crypto.Hash.SHA.new(
util.int2bin((util.bin2int(nodeID) ^ x))))
# check preceeding c_i bits in P1 and P2 using sharesXPrefices.
return (
util.hasNZeroBitPrefix(p1, constants.CRYPTO_CHALLENGE_C1) and
util.hasNZeroBitPrefix(p2, constants.CRYPTO_CHALLENGE_C2))