'''
Base class for identity-based signatures
Notes: This class implements an interface for a standard identity-based signatures scheme.
Identity-based signatures consists of four algorithms: (setup, keygen, sign and verify).
'''
from charm.toolbox.schemebase import *
ibsigBaseSecDefs = Enum('EU_CMA', 'wEU_CMA', 'sEU_CMA')
EU_CMA,wEU_CMA,sEU_CMA="EU_CMA","wEU_CMA","sEU_CMA"
ibsigSchemeType='ibsigScheme'
[docs]class IBSig(SchemeBase):
def __init__(self):
SchemeBase.__init__(self)
SchemeBase._setProperty(self, scheme='IBSig')
[docs] def setProperty(self, secDef=None, assumption=None, messageSpace=None, secModel=None, **kwargs):
assert secDef is not None and secDef in ibsigBaseSecDefs.getList(), "not a valid security definition for this scheme type."
SchemeBase._setProperty(self, None, ibsigBaseSecDefs[secDef], str(assumption), messageSpace, str(secModel), **kwargs)
return True
[docs] def getProperty(self):
baseProp = SchemeBase._getProperty(self)
return baseProp
[docs] def checkProperty(self, schemeObj, _reqProps):
reqProps = [ (str(k), str(v)) for k,v in _reqProps ]
result = SchemeBase._checkProperty(self, schemeObj, reqProps)
if result == True:
self.setScheme(schemeObj)
return result
[docs] def updateProperty(self, scheme, secDef=None, assumption=None, messageSpace=None, secModel=None, **kwargs):
# 1. inherit the scheme's properties
assert hasattr(scheme, 'properties'), "schemeObj does not have getProperty() method."
self.properties.update(scheme.getProperty())
# 2. make sure things are consistent, then update to new properties
assert self.properties[schemeType] is not None, "scheme type wasn't specified on initialization"
assert secDef is not None and secDef in ibsigBaseSecDefs.getList(), "not a valid security definition for this scheme type."
SchemeBase._setProperty(self, None, ibsigBaseSecDefs[secDef], str(assumption), messageSpace, str(secModel), **kwargs)
return
[docs] def printProperties(self):
name = str(self.__class__).split("'")[-2].split(".")[-1]
print("<=== %s Properties ===>" % name)
for k,v in self.properties.items():
print(k, ":", v)
print("<=== %s Properties ===>" % name)
return
[docs] def setup(self):
raise NotImplementedError
[docs] def keygen(self, msk, ID):
raise NotImplementedError
[docs] def sign(self, pk, sk, M):
raise NotImplementedError
[docs] def verify(self, pk, M, sig):
raise NotImplementedError