def verify_chain(self, trusted_certs = None): # do the normal certificate verification stuff trusted_root = Certificate.verify_chain(self, trusted_certs) if self.parent: # make sure the parent's hrn is a prefix of the child's hrn if not hrn_authfor_hrn(self.parent.get_hrn(), self.get_hrn()): raise GidParentHrn("This cert HRN %s isn't in the namespace for parent HRN %s" % (self.get_hrn(), self.parent.get_hrn())) # Parent must also be an authority (of some type) to sign a GID # There are multiple types of authority - accept them all here if not self.parent.get_type().find('authority') == 0: raise GidInvalidParentHrn("This cert %s's parent %s is not an authority (is a %s)" % (self.get_hrn(), self.parent.get_hrn(), self.parent.get_type())) # Then recurse up the chain - ensure the parent is a trusted # root or is in the namespace of a trusted root self.parent.verify_chain(trusted_certs) else: # make sure that the trusted root's hrn is a prefix of the child's trusted_gid = GID(string=trusted_root.save_to_string()) trusted_type = trusted_gid.get_type() trusted_hrn = trusted_gid.get_hrn() #if trusted_type == 'authority': # trusted_hrn = trusted_hrn[:trusted_hrn.rindex('.')] cur_hrn = self.get_hrn() if not hrn_authfor_hrn(trusted_hrn, cur_hrn): raise GidParentHrn("Trusted root with HRN %s isn't a namespace authority for this cert: %s" % (trusted_hrn, cur_hrn)) # There are multiple types of authority - accept them all here if not trusted_type.find('authority') == 0: raise GidInvalidParentHrn("This cert %s's trusted root signer %s is not an authority (is a %s)" % (self.get_hrn(), trusted_hrn, trusted_type)) return
def verify_issuer(self, trusted_gids): root_cred = self.get_credential_list()[-1] root_target_gid = root_cred.get_gid_object() root_cred_signer = root_cred.get_signature().get_issuer_gid() # Case 1: # Allow non authority to sign target and cred about target. # # Why do we need to allow non authorities to sign? # If in the target gid validation step we correctly # checked that the target is only signed by an authority, # then this is just a special case of case 3. # This short-circuit is the common case currently - # and cause GID validation doesn't check 'authority', # this allows users to generate valid slice credentials. if root_target_gid.is_signed_by_cert(root_cred_signer): # cred signer matches target signer, return success return # Case 2: # Allow someone to sign credential about themeselves. Used? # If not, remove this. #root_target_gid_str = root_target_gid.save_to_string() #root_cred_signer_str = root_cred_signer.save_to_string() #if root_target_gid_str == root_cred_signer_str: # # cred signer is target, return success # return # Case 3: # root_cred_signer is not the target_gid # So this is a different gid that we have not verified. # xmlsec1 verified the cert chain on this already, but # it hasn't verified that the gid meets the HRN namespace # requirements. # Below we'll ensure that it is an authority. # But we haven't verified that it is _signed by_ an authority # We also don't know if xmlsec1 requires that cert signers # are marked as CAs. # Note that if verify() gave us no trusted_gids then this # call will fail. So skip it if we have no trusted_gids if trusted_gids and len(trusted_gids) > 0: root_cred_signer.verify_chain(trusted_gids) else: print "No trusted gids. Cannot verify that cred signer is signed by a trusted authority. Skipping that check." # See if the signer is an authority over the domain of the target. # There are multiple types of authority - accept them all here # Maybe should be (hrn, type) = urn_to_hrn(root_cred_signer.get_urn()) root_cred_signer_type = root_cred_signer.get_type() if (root_cred_signer_type.find('authority') == 0): #logger.debug('Cred signer is an authority') # signer is an authority, see if target is in authority's domain signerhrn = root_cred_signer.get_hrn() if hrn_authfor_hrn(signerhrn, root_target_gid.get_hrn()): return # We've required that the credential be signed by an authority # for that domain. Reasonable and probably correct. # A looser model would also allow the signer to be an authority # in my control framework - eg My CA or CH. Even if it is not # the CH that issued these, eg, user credentials. # Give up, credential does not pass issuer verification raise CredentialNotVerifiable("Could not verify credential owned by %s for object %s. Cred signer %s not the trusted authority for Cred target %s" % (self.gidCaller.get_urn(), self.gidObject.get_urn(), root_cred_signer.get_hrn(), root_target_gid.get_hrn()))
def verify_issuer(self, trusted_gids): root_cred = self.get_credential_list()[-1] root_target_gid = root_cred.get_gid_object() root_cred_signer = root_cred.get_signature().get_issuer_gid() # Case 1: # Allow non authority to sign target and cred about target. # # Why do we need to allow non authorities to sign? # If in the target gid validation step we correctly # checked that the target is only signed by an authority, # then this is just a special case of case 3. # This short-circuit is the common case currently - # and cause GID validation doesn't check 'authority', # this allows users to generate valid slice credentials. if root_target_gid.is_signed_by_cert(root_cred_signer): # cred signer matches target signer, return success return # Case 2: # Allow someone to sign credential about themeselves. Used? # If not, remove this. #root_target_gid_str = root_target_gid.save_to_string() #root_cred_signer_str = root_cred_signer.save_to_string() #if root_target_gid_str == root_cred_signer_str: # # cred signer is target, return success # return # Case 3: # root_cred_signer is not the target_gid # So this is a different gid that we have not verified. # xmlsec1 verified the cert chain on this already, but # it hasn't verified that the gid meets the HRN namespace # requirements. # Below we'll ensure that it is an authority. # But we haven't verified that it is _signed by_ an authority # We also don't know if xmlsec1 requires that cert signers # are marked as CAs. # Note that if verify() gave us no trusted_gids then this # call will fail. So skip it if we have no trusted_gids if trusted_gids and len(trusted_gids) > 0: root_cred_signer.verify_chain(trusted_gids) else: print "No trusted gids. Cannot verify that cred signer is signed by a trusted authority. Skipping that check." # See if the signer is an authority over the domain of the target. # There are multiple types of authority - accept them all here # Maybe should be (hrn, type) = urn_to_hrn(root_cred_signer.get_urn()) root_cred_signer_type = root_cred_signer.get_type() if (root_cred_signer_type.find('authority') == 0): #logger.debug('Cred signer is an authority') # signer is an authority, see if target is in authority's domain signerhrn = root_cred_signer.get_hrn() if hrn_authfor_hrn(signerhrn, root_target_gid.get_hrn()): return # We've required that the credential be signed by an authority # for that domain. Reasonable and probably correct. # A looser model would also allow the signer to be an authority # in my control framework - eg My CA or CH. Even if it is not # the CH that issued these, eg, user credentials. # Give up, credential does not pass issuer verification raise CredentialNotVerifiable( "Could not verify credential owned by %s for object %s. Cred signer %s not the trusted authority for Cred target %s" % (self.gidCaller.get_urn(), self.gidObject.get_urn(), root_cred_signer.get_hrn(), root_target_gid.get_hrn()))