PyBitmessage-2021-04-27/src/pyelliptic/eccblindchain.py
Peter Surda ff1f451691
Blind signature updates
- added serializing and deserializing
- added a signature chain class `ECCBlindSigChain`
- added more tests
2020-03-31 14:13:32 +08:00

53 lines
1.6 KiB
Python

"""
Blind signature chain with a top level CA
"""
from .eccblind import ECCBlind
class ECCBlindChain(object): # pylint: disable=too-few-public-methods
"""
# Class for ECC Blind Chain signature functionality
"""
def __init__(self, ca=None, chain=None):
self.chain = []
self.ca = []
if ca:
for i in range(0, len(ca), 35):
self.ca.append(ca[i:i + 35])
if chain:
self.chain.append(chain[0:35])
for i in range(35, len(chain), 100):
if len(chain[i:]) == 65:
self.chain.append(chain[i:i + 65])
else:
self.chain.append(chain[i:i + 100])
def verify(self, msg, value):
"""Verify a chain provides supplied message and value"""
parent = None
l_ = 0
for level in self.chain:
l_ += 1
pubkey = None
signature = None
if len(level) == 100:
pubkey, signature = (level[0:35], level[35:])
elif len(level) == 35:
if level not in self.ca:
return False
parent = level
continue
else:
signature = level
verifier_obj = ECCBlind(pubkey=parent)
if pubkey:
if not verifier_obj.verify(pubkey, signature, value):
return False
parent = pubkey
else:
return verifier_obj.verify(msg=msg, signature=signature,
value=value)
return None