Zope Subversion Repository

Zope: zope.security/trunk/src/zope/security/examples/sandbox_security.py

Drop support for Python 2.4 and 2.5.

Replace deprecated 'zope.component.adapts' usage with equivalent
'zope.component.adapter' decorator.

Replace deprecated 'zope.interface.classProvides' usage with equivalent
'zope.interface.provider' decorator.

Replace deprecated 'zope.interface.implements' usage with equivalent
'zope.interface.implementer' decorator.

##############################################################################
#
# Copyright (c) 2003 Zope Foundation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
"""A small, secure sandbox application.

This module is responsible of securing the sandbox application and run it in a
secure mode. There are several steps that are taken to set up the security

  1. map permissions to actions
  
  2. map authentication tokens/principals onto permissions
  
  3. implement checker and security policies that affect 1,2
  
  4. bind checkers to classes/instances
  
  5. proxy wrap as necessary
"""
import sandbox
from zope.security.interfaces import IParticipation
from zope.security import checker, management, simplepolicies
from zope.interface import implementer


# Define all permissions that will be available 
NotAllowed = 'Not Allowed'
Public = checker.CheckerPublic
TransportAgent = 'Transport Agent'
AccessServices = 'Access Services'
AccessAgents = 'Access Agents'
AccessTimeService = 'Access Time Services'
AccessAgentService = 'Access Agent Service'
AccessHomeService = 'Access Home Service'

AddAgent = 'Add Agent'
ALL='All'

NoSetAttr = lambda name: NotAllowed


class SimulationSecurityDatabase(object):
    """Security Database

    In the database, locations are mapped to authentication tokens to
    permissions.
    """
    origin = {
        'any' : [ALL]
        }

    jail = {
        'norse legend' : [TransportAgent, AccessServices, AccessAgentService,
                          AccessHomeService, TransportAgent, AccessAgents],
        'any' : [AccessTimeService, AddAgent]
        }

    valhalla = {
        'norse legend' : [AddAgent],
        'any' : [AccessServices, AccessTimeService, AccessAgentService,
                 AccessHomeService, TransportAgent, AccessAgents]
        }


class SimulationSecurityPolicy(simplepolicies.ParanoidSecurityPolicy):
    """Security Policy during the Simulation.

    A very simple security policy that is specific to the simulations.
    """

    def checkPermission(self, permission, object):
        """See zope.security.interfaces.ISecurityPolicy"""
        home = object.getHome()
        db = getattr(SimulationSecurityDatabase, home.getId(), None)

        if db is None:
            return False

        allowed = db.get('any', ())
        if permission in allowed or ALL in allowed:
            return True

        if not self.participations:
            return False

        for participation in self.participations:
            token = participation.principal.getAuthenticationToken()
            allowed = db.get(token, ())
            if permission not in allowed:
                return False

        return True


@implementer(IParticipation)
class AgentParticipation(object):
    """Agent Participation during the Simulation.

    A very simple participation that is specific to the simulations.
    """


    def __init__(self, agent):
        self.principal = agent
        self.interaction = None


def PermissionMapChecker(permissions_map=None, set_permissions=None):
    """Create a checker from using the 'permission_map.'"""
    if permissions_map is None:
        permissions_map = {}
    if set_permissions is None:
        set_permissions = {}
    res = {}
    for key, value in permissions_map.items():
        for method in value:
            res[method] = key
    return checker.Checker(res, set_permissions)


#################################
# sandbox security settings
sandbox_security = {
    AccessServices : ['getService', 'addService', 'getServiceIds'],
    AccessAgents : ['getAgentsIds', 'getAgents'],
    AddAgent : ['addAgent'],
    TransportAgent : ['transportAgent'],
    Public : ['getId','getHome']
    }
sandbox_checker = PermissionMapChecker(sandbox_security)

#################################
# service security settings

# time service
tservice_security = { AccessTimeService:['getTime'] }
time_service_checker = PermissionMapChecker(tservice_security)

# home service
hservice_security = { AccessHomeService:['getAvailableHomes'] }
home_service_checker = PermissionMapChecker(hservice_security)

# agent service
aservice_security = { AccessAgentService:['getLocalAgents'] }
agent_service_checker = PermissionMapChecker(aservice_security)


def wire_security():

    management.setSecurityPolicy(SimulationSecurityPolicy)

    checker.defineChecker(sandbox.Sandbox, sandbox_checker)
    checker.defineChecker(sandbox.TimeService, time_service_checker)
    checker.defineChecker(sandbox.AgentDiscoveryService, agent_service_checker)
    checker.defineChecker(sandbox.HomeDiscoveryService, home_service_checker)

    def addAgent(self, agent):
        if not self._agents.has_key(agent.getId()) \
           and sandbox.IAgent.providedBy(agent):
            self._agents[agent.getId()]=agent
            agentChecker = checker.selectChecker(self)
            wrapped_home = agentChecker.proxy(self)
            agent.setHome(wrapped_home)
        else:
            raise sandbox.SandboxError("couldn't add agent %s" %agent)

    sandbox.Sandbox.addAgent = addAgent

    def setupAgent(self, agent):
        management.newInteraction(AgentParticipation(agent))

    sandbox.TimeGenerator.setupAgent = setupAgent

    def teardownAgent(self, agent):
        management.endInteraction()

    sandbox.TimeGenerator.teardownAgent = teardownAgent

    def GreenerPastures(agent):
        """ where do they want to go today """
        import random
        _homes = sandbox._homes
        possible_homes = _homes.keys()
        possible_homes.remove(agent.getHome().getId())
        new_home =  _homes.get(random.choice(possible_homes))
        return checker.selectChecker(new_home).proxy(new_home)

    sandbox.GreenerPastures = GreenerPastures


if __name__ == '__main__':
    wire_security()
    sandbox.main()

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