Hallo zusammen,
bin jetzt selbst auf die Lösung gekommen … folgender Eintrag in der /etc/postfix/main.conf verursacht die EMail-Rückweisung:
smtpd_data_restrictions = check_policy_service unix:private/[color=#00BF00]sender_policy_incoming[/color]
was genau bewirkt in diesem Zusammenhang der Eintrag in der /etc/postfix/master.cf –verify-sender --allow-unauthenticated ?
sender_policy_incoming unix - n n - - spawn
user=listener argv=/usr/lib/postfix/kolab_smtp_access_policy--verify-sender --allow-unauthenticated
… hier das file kolab_smtp_access_policy
[code]#!/usr/bin/python
Jeroen van Meeuwen (Kolab Systems)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
import datetime
import os
import sys
import time
from optparse import OptionParser
from ConfigParser import SafeConfigParser
cache = None
import sqlalchemy
from sqlalchemy import Boolean
from sqlalchemy import Column
from sqlalchemy import Date
from sqlalchemy import DateTime
from sqlalchemy import Integer
from sqlalchemy import MetaData
from sqlalchemy import String
from sqlalchemy import Table
from sqlalchemy import Sequence
from sqlalchemy import create_engine
from sqlalchemy.orm import mapper
try:
from sqlalchemy.orm import sessionmaker
except:
from sqlalchemy.orm import create_session
from sqlalchemy.schema import Index
from sqlalchemy.schema import UniqueConstraint
sys.path = [’…’,’.’] + sys.path
import pykolab
from pykolab import utils
from pykolab.auth import Auth
from pykolab.constants import *
from pykolab.translate import _
TODO: Figure out how to make our logger do some syslogging as well.
log = pykolab.getLogger(‘pykolab.smtp_access_policy’)
TODO: Removing the stdout handler would mean one can no longer test by
means of manual execution in debug mode.
#log.remove_stdout_handler()
conf = pykolab.getConf()
auth = None
mydomains = None
Caching routines using SQLAlchemy.
If creating the cache fails, we continue without any caching, significantly
increasing the load on LDAP.
cache_expire = 86400
try:
metadata = MetaData()
except:
cache = False
session = None
policy_result_table = Table(
‘policy_result’, metadata,
Column(‘id’, Integer, Sequence(‘seq_id_result’), primary_key=True),
Column(‘key’, String(16), nullable=False),
Column(‘value’, Boolean, nullable=False),
Column(‘sender’, String(64), nullable=False),
Column(‘recipient’, String(64), nullable=False),
Column(‘sasl_username’, String(64)),
Column(‘sasl_sender’, String(64)),
Column(‘created’, Integer, nullable=False),
)
Index(
‘fsrss’,
policy_result_table.c.key,
policy_result_table.c.sender,
policy_result_table.c.recipient,
policy_result_table.c.sasl_username,
policy_result_table.c.sasl_sender,
unique=True
)
class PolicyResult(object):
def init(
self,
key=None,
value=None,
sender=None,
recipient=None,
sasl_username=None,
sasl_sender=None
):
self.key = key
self.value = value
self.sender = sender
self.sasl_username = sasl_username
self.sasl_sender = sasl_sender
self.recipient = recipient
self.created = (int)(time.time())
mapper(PolicyResult, policy_result_table)
statistic_table = Table(
‘statistic’, metadata,
Column(‘id’, Integer, Sequence(‘seq_id_statistic’), primary_key=True),
Column(‘sender’, String(64), nullable=False),
Column(‘recipient’, String(64), nullable=False),
Column(‘date’, Date, nullable=False),
Column(‘count’, Integer, nullable=False),
)
Index(
‘srd’,
statistic_table.c.sender,
statistic_table.c.recipient,
statistic_table.c.date,
unique=True
)
class Statistic(object):
def init(self, sender, recipient, date=datetime.date.today(), count=0):
self.sender = sender
self.recipient = recipient
self.date = date
self.count = count
mapper(Statistic, statistic_table)
class PolicyRequest(object):
email_address_keys = [ ‘sender’, ‘recipient’ ]
recipients = []
auth = None
sasl_domain = None
sasl_user = None
sender_domain = None
sender_user = None
sasl_user_uses_alias = False
sasl_user_is_delegate = False
def __init__(self, policy_request={}):
"""
Creates a new policy request object. Pass it a policy_request
dictionary as described in the Postfix documentation on:
http://www.postfix.org/SMTPD_POLICY_README.html
"""
for key in policy_request.keys():
# Normalize email addresses (they may contain recipient delimiters)
if key in self.email_address_keys:
policy_request[key] = normalize_address(policy_request[key])
if not key == 'recipient':
if policy_request[key] == '':
setattr(self, key, None)
else:
setattr(self, key, policy_request[key])
else:
if not policy_request['recipient'].strip() == '':
self.recipients = list(set(self.recipients + [policy_request['recipient']]))
def add_request(self, policy_request={}):
"""
Add subsequent policy requests to the existing policy request.
All data in the request should be the same as the initial policy
request, but for the recipient - with destination limits set over
1, Postfix may attempt to deliver messages to more then one
recipient during a single delivery attempt, and during submission,
the policy will receive one policy request per recipient.
"""
# Check instance. Not sure what to do if the instance is not the same.
if hasattr(self, 'instance'):
if not policy_request['instance'] == self.instance:
# TODO: We need to empty our pockets
pass
log.debug(
_("Adding policy request to instance %s") % (self.instance),
level=8
)
# Normalize email addresses (they may contain recipient delimiters)
if policy_request.has_key('recipient'):
policy_request['recipient'] = normalize_address(
policy_request['recipient']
)
if not policy_request['recipient'].strip() == '':
self.recipients = list(set(self.recipients + [policy_request['recipient']]))
def parse_ldap_dn(self, dn):
"""
See if parameter 'dn' is a basestring LDAP dn, and if so, return
the results we can obtain from said DN. Return a list of relevant
attribute values.
If not a DN, return None.
"""
values = []
try:
import ldap.dn
ldap_dn = ldap.dn.explode_dn(dn)
except ldap.DECODING_ERROR:
# This is not a DN.
return None
if len(ldap_dn) > 0:
search_attrs = conf.get_list(
'kolab_smtp_access_policy',
'address_search_attrs'
)
rule_subject = self.auth.get_user_attributes(
self.sasl_domain,
{ 'dn': dn },
search_attrs + [ 'objectclass' ]
)
for search_attr in search_attrs:
if rule_subject.has_key(search_attr):
if isinstance(rule_subject[search_attr], basestring):
values.append(rule_subject[search_attr])
else:
values.extend(rule_subject[search_attr])
return values
else:
# ldap.dn.explode_dn didn't error out, but it also didn't split
# the DN properly.
return None
def parse_ldap_uri(self, uri):
values = []
parsed_uri = utils.parse_ldap_uri(uri)
if parsed_uri == None:
return None
(_protocol, _server, _port, _base_dn, _attrs, _scope, _filter) = \
parsed_uri
if len(_attrs) == 0:
search_attrs = conf.get_list(
'kolab_smtp_access_policy',
'address_search_attrs'
)
else:
search_attrs = [ _attrs ]
users = []
self.auth._auth._bind()
_users = self.auth._auth._search(
_base_dn,
scope=LDAP_SCOPE[_scope],
filterstr=_filter,
attrlist=search_attrs + [ 'objectclass' ],
override_search="_regular_search"
)
for _user in _users:
for search_attr in search_attrs:
values.extend(_user[1][search_attr])
return values
def parse_policy(self, _subject, _object, policy):
"""
Parse policy to apply on _subject, for object _object.
The policy is a list of rules.
The _subject is a sender for kolabAllowSMTPRecipient checks, and
a recipient for kolabAllowSMTPSender checks.
The _object is a recipient for kolabAllowSMTPRecipient checks, and
a sender for kolabAllowSMTPSender checks.
"""
special_rule_values = {
'$mydomains': expand_mydomains
}
rules = { 'allow': [], 'deny': [] }
if isinstance(policy, basestring):
policy = [policy]
for rule in policy:
# Find rules that are actually special values, simply by
# mapping the rule onto a key in "special_rule_values", a
# dictionary with the corresponding value set to a function to
# execute.
if rule in special_rule_values.keys():
special_rules = special_rule_values[rule]()
if rule.startswith("-"):
rules['deny'].extend(special_rules)
else:
rules['allow'].extend(special_rules)
continue
# Lower-case the rule
rule = rule.lower()
# Also note the '-' cannot be passed on to the functions that
# follow, so store the rule separately from the prefix that is
# prepended to deny rules.
if rule.startswith("-"):
_prefix = '-'
_rule = rule[1:]
else:
_prefix = ''
_rule = rule
# See if the value is an LDAP DN
ldap_dn = self.parse_ldap_dn(_rule)
if not ldap_dn == None and len(ldap_dn) > 0:
if _prefix == '-':
rules['deny'].extend(ldap_dn)
else:
rules['allow'].extend(ldap_dn)
else:
ldap_uri = self.parse_ldap_uri(_rule)
if not ldap_uri == None and len(ldap_uri) > 0:
if _prefix == '-':
rules['deny'].extend(ldap_uri)
else:
rules['allow'].extend(ldap_uri)
else:
if rule.startswith("-"):
rules['deny'].append(rule[1:])
else:
rules['allow'].append(rule)
allowed = False
for rule in rules['allow']:
deny_override = False
if _object.endswith(rule):
for deny_rule in rules['deny']:
if deny_rule.endswith(rule):
deny_override = True
if not deny_override:
allowed = True
denied = False
for rule in rules['deny']:
allow_override = False
if _object.endswith(rule):
if not allowed:
denied = True
continue
else:
for allow_rule in rules['allow']:
if allow_rule.endswith(rule):
allow_override = True
if not allow_override:
denied = True
if not denied:
allowed = True
return allowed
def verify_alias(self):
"""
Verify whether the user authenticated for this policy request is
using an alias of its primary authentication ID / attribute.
John.Doe@example.org (mail) for example could be sending with
envelope sender jdoe@example.org (mailAlternateAddress, alias).
"""
search_attrs = conf.get_list(self.sasl_domain, 'address_search_attrs')
if search_attrs == None or \
(isinstance(search_attrs, list) and len(search_attrs) == 0):
search_attrs = conf.get_list(self.sasl_domain, 'mail_attributes')
if search_attrs == None or \
(isinstance(search_attrs, list) and len(search_attrs) == 0):
search_attrs = conf.get_list(
'kolab_smtp_access_policy',
'address_search_attrs'
)
if search_attrs == None or \
(isinstance(search_attrs, list) and len(search_attrs) == 0):
search_attrs = conf.get_list(
conf.get('kolab', 'auth_mechanism'),
'mail_attributes'
)
want_attrs = []
for search_attr in search_attrs:
if not self.sasl_user.has_key(search_attr):
want_attrs.append(search_attr)
if len(want_attrs) > 0:
self.sasl_user.update(
self.auth.get_user_attributes(
self.sasl_domain,
self.sasl_user,
want_attrs
)
)
# Catch a user using one of its own alias addresses.
for search_attr in search_attrs:
if self.sasl_user.has_key(search_attr):
if isinstance(self.sasl_user[search_attr], list):
if self.sender.lower() in [x.lower() for x in self.sasl_user[search_attr]]:
return True
elif self.sasl_user[search_attr].lower() == self.sender.lower():
return True
return False
def verify_authenticity(self):
"""
Verify that the SASL username or lack thereof corresponds with
allowing or disallowing authenticated users.
If an SASL username is supplied, use it to obtain the authentication
database user object including all attributes we may find ourselves
interested in.
"""
if self.sasl_username == None:
if not conf.allow_unauthenticated:
reject(_("Unauthorized access not allowed"))
else:
# If unauthenticated is allowed, I have nothing to do here.
return True
sasl_username = self.sasl_username
# If we have an sasl_username, find the user object in the
# authentication database, along with the attributes we are
# interested in.
if self.sasl_domain == None:
if len(self.sasl_username.split('@')) > 1:
self.sasl_domain = self.sasl_username.split('@')[1]
else:
self.sasl_domain = conf.get('kolab', 'primary_domain')
sasl_username = "%s@%s" % (self.sasl_username, self.sasl_domain)
if self.auth == None:
self.auth = Auth(self.sasl_domain)
elif not self.auth.domain == self.sasl_domain:
self.auth = Auth(self.sasl_domain)
sasl_users = self.auth.find_recipient(
sasl_username,
domain=self.sasl_domain
)
if isinstance(sasl_users, list):
if len(sasl_users) == 0:
log.error(_("Could not find recipient"))
return False
else:
self.sasl_user = { 'dn': sasl_users[0] }
elif isinstance(sasl_users, basestring):
self.sasl_user = { 'dn': sasl_users }
if not self.sasl_user['dn']:
# Got a final answer here, do the caching thing.
cache_update(
function='verify_sender',
sender=self.sender,
recipients=self.recipients,
result=(int)(False),
sasl_username=self.sasl_username,
sasl_sender=self.sasl_sender
)
reject(
_("Could not find envelope sender user %s (511)") % (
self.sasl_username
)
)
attrs = conf.get_list(self.sasl_domain, 'auth_attributes')
if attrs == None or (isinstance(attrs, list) and len(attrs) == 0):
attrs = conf.get_list(
conf.get('kolab', 'auth_mechanism'),
'auth_attributes'
)
mail_attrs = conf.get_list(self.sasl_domain, 'mail_attributes')
if mail_attrs == None or \
(isinstance(mail_attrs, list) and len(mail_attrs) == 0):
mail_attrs = conf.get_list(
conf.get('kolab', 'auth_mechanism'),
'mail_attributes'
)
if not mail_attrs == None:
attrs.extend(mail_attrs)
attrs.extend(
[
'kolabAllowSMTPRecipient',
'kolabAllowSMTPSender'
]
)
attrs = list(set(attrs))
user_attrs = self.auth.get_user_attributes(
self.sasl_domain,
self.sasl_user,
attrs
)
user_attrs['dn'] = self.sasl_user['dn']
self.sasl_user = utils.normalize(user_attrs)
log.debug(
_("Obtained authenticated user details for %r: %r") % (
self.sasl_user['dn'],
self.sasl_user.keys()
),
level=8
)
def verify_delegate(self):
"""
Verify whether the authenticated user is a delegate of the envelope
sender.
"""
if self.sender_domain == None:
if len(self.sender.split('@')) > 1:
self.sender_domain = self.sender.split('@')[1]
else:
self.sender_domain = conf.get('kolab', 'primary_domain')
if self.sender == self.sasl_username:
return True
search_attrs = conf.get_list(self.sender_domain, 'mail_attributes')
if search_attrs == None:
search_attrs = conf.get_list(
conf.get('kolab', 'auth_mechanism'),
'mail_attributes'
)
sender_users = self.auth.find_recipient(
self.sender,
domain=self.sender_domain
)
if isinstance(sender_users, list):
if len(sender_users) > 1:
# More then one sender user with this recipient address.
# TODO: check each of the sender users found.
self.sender_user = { 'dn': sender_users[0] }
elif len(sender_users) == 1:
self.sender_user = { 'dn': sender_users }
else:
self.sender_user = { 'dn': False }
elif isinstance(sender_users, basestring):
self.sender_user = { 'dn': sender_users }
if not self.sender_user['dn']:
cache_update(
function='verify_sender',
sender=self.sender,
recipients=self.recipients,
result=(int)(False),
sasl_username=self.sasl_username,
sasl_sender=self.sasl_sender
)
reject(_("Could not find envelope sender user %s") % (self.sender))
attrs = search_attrs
attrs.extend(
[
'kolabAllowSMTPRecipient',
'kolabAllowSMTPSender',
'kolabDelegate'
]
)
user_attrs = self.auth.get_user_attributes(
self.sender_domain,
self.sender_user,
attrs
)
user_attrs['dn'] = self.sender_user['dn']
self.sender_user = utils.normalize(user_attrs)
if not self.sender_user.has_key('kolabdelegate'):
reject(
_("%s is unauthorized to send on behalf of %s") % (
self.sasl_user['dn'],
self.sender_user['dn']
)
)
elif self.sender_user['kolabdelegate'] == None:
# No delegates for this sender could be found. The user is
# definitely NOT a delegate of the sender.
log.warning(
_("User %s attempted to use envelope sender address %s without authorization") % (
policy_request["sasl_username"],
policy_request["sender"]
)
)
# Got a final answer here, do the caching thing.
if not cache == False:
record_id = cache_update(
function='verify_sender',
sender=self.sender,
recipients=self.recipients,
result=(int)(False),
sasl_username=self.sasl_username,
sasl_sender=self.sasl_sender
)
sender_is_delegate = False
else:
# See if we can match the value of the envelope sender delegates to
# the actual sender sasl_username
if self.sasl_user == None:
sasl_users = self.auth.find_recipient(
self.sasl_username,
domain=self.sasl_domain
)
if isinstance(sasl_users, list):
if len(sasl_users) == 0:
log.error(_("Could not find recipient"))
return False
else:
self.sasl_user = { 'dn': sasl_users[0] }
elif isinstance(sasl_users, basestring):
self.sasl_user = { 'dn': sasl_users }
# Possible values for the kolabDelegate attribute are:
# a 'uid', a 'dn'.
if not self.sasl_user.has_key('uid'):
self.sasl_user['uid'] = self.auth.get_user_attribute(
self.sasl_domain,
self.sasl_user,
'uid'
)
sender_delegates = self.sender_user['kolabdelegate']
if not type(sender_delegates) == list:
sender_delegates = [ sender_delegates ]
for sender_delegate in sender_delegates:
if self.sasl_user['dn'] == sender_delegate:
log.debug(
_("Found user %s to be a delegate user of %s") % (
policy_request["sasl_username"],
policy_request["sender"]
),
level=8
)
sender_is_delegate = True
elif self.sasl_user['uid'] == sender_delegate:
log.debug(
_("Found user %s to be a delegate user of %s") % (
policy_request["sasl_username"],
policy_request["sender"]
),
level=8
)
sender_is_delegate = True
# If nothing matches sender_is_delegate is still None.
if not sender_is_delegate == True:
sender_is_delegate = False
return sender_is_delegate
def verify_recipient(self, recipient):
"""
Verify whether the sender is allowed send to this recipient, using
the recipient's kolabAllowSMTPSender.
"""
self.recipient = recipient
if not self.sasl_username == '' and not self.sasl_username == None:
log.debug(_("Verifying authenticated sender '%(sender)s' with sasl_username '%(sasl_username)s' for recipient '%(recipient)s'") % (self.__dict__)
)
else:
log.debug(_("Verifying unauthenticated sender '%(sender)s' for recipient '%(recipient)s'") % (self.__dict__)
)
recipient_verified = False
if not cache == False:
records = cache_select(
function='verify_recipient',
sender=self.sender,
recipient=recipient,
sasl_username=self.sasl_username,
sasl_sender=self.sasl_sender,
)
if not records == None and len(records) == 1:
log.info(
_("Reproducing verify_recipient(%s, %s) from cache") % (
self.sender,
recipient
)
)
return records[0].value
# TODO: Under some conditions, the recipient may not be fully qualified.
# We'll cross that bridge when we get there, though.
if len(recipient.split('@')) > 1:
sasl_domain = recipient.split('@')[1]
else:
sasl_domain = conf.get('kolab', 'primary_domain')
recipient = "%s@%s" % (recipient,sasl_domain)
if not verify_domain(sasl_domain):
if not cache == False:
cache_update(
function='verify_recipient',
sender=self.sender,
recipient=recipient,
result=(int)(True),
sasl_username=self.sasl_username,
sasl_sender=self.sasl_sender
)
return True
if self.auth == None:
self.auth = Auth(sasl_domain)
elif not self.auth.domain == sasl_domain:
self.auth = Auth(sasl_domain)
if verify_domain(sasl_domain):
if not self.auth.domains == None and self.auth.domains.has_key(sasl_domain):
log.debug(
_("Using authentication domain %s instead of %s") % (
self.auth.domains[sasl_domain],
sasl_domain
),
level=8
)
sasl_domain = self.auth.domains[sasl_domain]
else:
log.debug(
_("Domain %s is a primary domain") % (
sasl_domain
),
level=8
)
else:
log.warning(
_("Checking the recipient for domain %s that is not ours. This is probably a configuration error.") % (
sasl_domain
)
)
return True
recipients = self.auth.find_recipient(
normalize_address(recipient),
domain=sasl_domain,
)
if isinstance(recipients, list):
if len(recipients) > 1:
log.info(
_("This recipient address is related to multiple object entries and the SMTP Access Policy can therefore not restrict message flow")
)
cache_update(
function='verify_recipient',
sender=self.sender,
recipient=normalize_address(recipient),
result=(int)(True),
sasl_username=self.sasl_username,
sasl_sender=self.sasl_sender
)
return True
elif len(recipients) == 1:
_recipient = { 'dn': recipients[0] }
else:
log.debug(
_("Recipient address %r not found. Allowing since the MTA was configured to accept the recipient.") % (
normalize_address(recipient)
),
level=3
)
cache_update(
function='verify_recipient',
sender=self.sender,
recipient=normalize_address(recipient),
result=(int)(True),
sasl_username=self.sasl_username,
sasl_sender=self.sasl_sender
)
return True
elif isinstance(recipients, basestring):
_recipient = {
'dn': recipients
}
# We have gotten an invalid recipient. We need to catch this case,
# because testing can input invalid recipients, and so can faulty
# applications, or misconfigured servers.
if not _recipient['dn']:
if not conf.allow_unauthenticated:
cache_update(
function='verify_recipient',
sender=self.sender,
recipient=normalize_address(recipient),
result=(int)(False),
sasl_username=self.sasl_username,
sasl_sender=self.sasl_sender
)
reject(_("Invalid recipient"))
else:
cache_update(
function='verify_recipient',
sender=self.sender,
recipient=normalize_address(recipient),
result=(int)(True),
sasl_username=self.sasl_username,
sasl_sender=self.sasl_sender
)
log.debug(_("Could not find this user, accepting"), level=8)
return True
if not _recipient['dn'] == False:
recipient_policy = self.auth.get_entry_attribute(
sasl_domain,
_recipient['dn'],
'kolabAllowSMTPSender'
)
# If no such attribute has been specified, allow
if recipient_policy == None:
cache_update(
function='verify_recipient',
sender=self.sender,
recipient=normalize_address(recipient),
result=(int)(True),
sasl_username=self.sasl_username,
sasl_sender=self.sasl_sender
)
recipient_verified = True
# Otherwise, parse the policy obtained with the subject of the policy
# being the recipient, and the object to apply the policy to being the
# sender.
else:
recipient_verified = self.parse_policy(
recipient,
self.sender,
recipient_policy
)
cache_update(
function='verify_recipient',
sender=self.sender,
recipient=normalize_address(recipient),
result=(int)(recipient_verified),
sasl_username=self.sasl_username,
sasl_sender=self.sasl_sender
)
return recipient_verified
def verify_recipients(self):
"""
Verify whether the sender is allowed send to the recipients in this
policy request, using each recipient's kolabAllowSMTPSender.
Note there may be multiple recipients in this policy request, and
therefor self.recipients is a list - walk through that list.
"""
recipients_verified = True
if not cache == False:
records = cache_select(
function='verify_recipient',
sender=self.sender,
recipients=self.recipients,
sasl_username=self.sasl_username,
sasl_sender=self.sasl_sender,
)
if not records == None and len(records) == len(self.recipients):
log.debug("Euh, what am I doing here?")
for record in records:
recipient_found = False
for recipient in self.recipients:
if recipient == record.recipient:
recipient_found = True
if not recipient_found:
reject(_("Sender %s is not allowed to send to recipient %s") % (self.sender,recipient))
for recipient in self.recipients:
recipient_verified = self.verify_recipient(recipient)
if not recipient_verified:
recipients_verified = False
return recipients_verified
def verify_sender(self):
"""
Verify the sender's access policy.
1) Verify whether the sasl_username is allowed to send using the
envelope sender address, with the kolabDelegate attribute
associated with the LDAP object that has the envelope sender
address.
2) Verify whether the sender is allowed to send to recipient(s)
listed on the sender's object.
A third potential action could be to check the recipient object to
see if the sender is allowed to send to the recipient by the
recipient's kolabAllowSMTPSender, but this is done in
verify_recipients().
"""
sender_verified = False
if self.sender == None:
# Trusted host?
if not hasattr(self, 'client_address') or \
self.client_address == "" or \
self.client_address == None:
# Nothing to compare to.
return False
try:
import netaddr
networks = conf.get_list(
'kolab_smtp_access_policy',
'empty_sender_hosts'
)
trusted = False
for network in networks:
if netaddr.IPNetwork(self.client_address) in netaddr.IPNetwork(network):
return True
except ImportError, errmsg:
return False
if not cache == False:
records = cache_select(
sender=self.sender,
recipients=self.recipients,
sasl_username=self.sasl_username,
sasl_sender=self.sasl_sender,
function='verify_sender'
)
if not records == None and len(records) == len(self.recipients):
log.info(_("Reproducing verify_sender(%r) from cache") % (
self.__dict__
)
)
for record in records:
recipient_found = False
for recipient in self.recipients:
if recipient == record.recipient:
recipient_found = True
if recipient_found and not record.value:
reject(_("Sender %s is not allowed to send to recipient %s") % (self.sender,recipient))
return True
if self.verify_authenticity() == False:
reject(_("Unverifiable sender."))
self.sasl_user_uses_alias = self.verify_alias()
if not self.sasl_user_uses_alias:
log.debug(_("Sender is not using an alias"), level=8)
self.sasl_user_is_delegate = self.verify_delegate()
# If the authenticated user is using delegate functionality, apply the
# recipient policy attribute for the envelope sender.
if self.sasl_user_is_delegate == False and \
self.sasl_user_uses_alias == False:
reject(_("Sender uses unauthorized envelope sender address"))
elif self.sasl_user_is_delegate:
# Apply the recipient policy for the sender using the envelope
# sender user object.
recipient_policy_domain = self.sender_domain
recipient_policy_sender = self.sender
recipient_policy_user = self.sender_user
elif not self.sasl_user == None:
# Apply the recipient policy from the authenticated user.
recipient_policy_domain = self.sasl_domain
recipient_policy_sender = self.sasl_username
recipient_policy_user = self.sasl_user
else:
if not conf.allow_unauthenticated:
reject(_("Could not verify sender"))
else:
recipient_policy_domain = self.sender_domain
recipient_policy_sender = self.sender
recipient_policy_user = self.sender_user
log.debug(
_("Verifying whether sender is allowed to send to recipient using sender policy"),
level=8
)
if recipient_policy_user.has_key('kolaballowsmtprecipient'):
recipient_policy = recipient_policy_user['kolaballowsmtprecipient']
else:
recipient_policy = self.auth.get_user_attribute(
recipient_policy_domain,
recipient_policy_user,
'kolabAllowSMTPRecipient'
)
log.debug(_("Result is %r") % (recipient_policy), level=8)
# If no such attribute has been specified, allow
if recipient_policy == None:
log.debug(
_("No recipient policy restrictions exist for this sender"),
level=8
)
sender_verified = True
# Otherwise,parse the policy obtained.
else:
log.debug(
_("Found a recipient policy to apply for this sender."),
level=8
)
recipient_allowed = None
for recipient in self.recipients:
recipient_allowed = self.parse_policy(
recipient_policy_sender,
recipient,
recipient_policy
)
if not recipient_allowed:
reject(
_("Sender %s not allowed to send to recipient %s") % (recipient_policy_user['dn'],recipient)
)
sender_verified = True
if not cache == False:
record_id = cache_update(
function='verify_sender',
sender=self.sender,
recipients=self.recipients,
result=(int)(sender_verified),
sasl_username=self.sasl_username,
sasl_sender=self.sasl_sender
)
return sender_verified
def cache_cleanup():
if not cache == True:
return
log.debug(_("Cleaning up the cache"), level=8)
session.query(
PolicyResult
).filter(
PolicyResult.created < ((int)(time.time()) - cache_expire)
).delete()
session.commit()
def cache_init():
global cache, cache_expire, session
if conf.has_section('kolab_smtp_access_policy'):
if conf.has_option('kolab_smtp_access_policy', 'cache_uri'):
cache_uri = conf.get('kolab_smtp_access_policy', 'cache_uri')
cache = True
if conf.has_option('kolab_smtp_access_policy', 'retention'):
cache_expire = (int)(
conf.get(
'kolab_smtp_access_policy',
'retention'
)
)
elif conf.has_option('kolab_smtp_access_policy', 'uri'):
log.warning(_("The 'uri' setting in the kolab_smtp_access_policy section is soon going to be deprecated in favor of 'cache_uri'"))
cache_uri = conf.get('kolab_smtp_access_policy', 'uri')
cache = True
else:
return False
else:
return False
if conf.debuglevel > 8:
engine = create_engine(cache_uri, echo=True)
else:
engine = create_engine(cache_uri, echo=False)
try:
metadata.create_all(engine)
except sqlalchemy.exc.OperationalError, e:
log.error(_("Operational Error in caching: %s" % (e)))
return False
Session = sessionmaker(bind=engine)
session = Session()
cache_cleanup()
return cache
def cache_select(
function,
sender,
recipient=’’,
recipients=[],
sasl_username=’’,
sasl_sender=’’
):
if not cache == True:
return None
if not recipient == '' and recipients == []:
recipients = [recipient]
return session.query(
PolicyResult
).filter_by(
key=function,
sender=sender,
sasl_username=sasl_username,
sasl_sender=sasl_sender
).filter(
PolicyResult.recipient.in_(recipients)
).filter(
PolicyResult.created >= \
((int)(time.time()) - cache_expire)
).all()
def cache_insert(
function,
sender,
recipient=’’,
recipients=[],
result=None,
sasl_username=’’,
sasl_sender=’’
):
if not cache == True:
return []
log.debug(
_("Caching the policy result with timestamp %d") % (
(int)(time.time())
),
level=8
)
if not recipient == '' and recipients == []:
recipients = [recipient]
for recipient in recipients:
session.add(
PolicyResult(
key=function,
value=result,
sender=sender,
recipient=recipient,
sasl_username=sasl_username,
sasl_sender=sasl_sender
)
)
session.commit()
def cache_update(
function,
sender,
recipient=’’,
recipients=[],
result=None,
sasl_username=’’,
sasl_sender=’’
):
"""
Insert an updated set of rows into the cache depending on the necessity
"""
if not cache == True:
return
records = []
_records = cache_select(
function,
sender,
recipient,
recipients,
sasl_username,
sasl_sender
)
for record in _records:
if record.value == (int)(result):
records.append(record)
if not recipient == '' and recipients == []:
recipients = [recipient]
for recipient in recipients:
recipient_found = False
for record in records:
if record.recipient == recipient:
recipient_found = True
if not recipient_found:
cache_insert(
function=function,
sender=sender,
recipient=recipient,
result=result,
sasl_username=sasl_username,
sasl_sender=sasl_sender
)
def defer_if_permit(message, policy_request=None):
log.info(_(“Returning action DEFER_IF_PERMIT: %s”) % (message))
print “action=DEFER_IF_PERMIT %s\n\n” % (message)
sys.exit(0)
def dunno(message, policy_request=None):
log.info(_(“Returning action DUNNO: %s”) % (message))
print “action=DUNNO %s\n\n” % (message)
sys.exit(0)
def hold(message, policy_request=None):
log.info(_(“Returning action HOLD: %s”) % (message))
print “action=HOLD %s\n\n” % (message)
sys.exit(0)
def permit(message, policy_request=None):
log.info(_(“Returning action PERMIT: %s”) % (message))
# If we have no policy request, we have been called for a reason,
# and everything relevant has been figured out already.
if policy_request == None:
print "action=PERMIT\n\n"
sys.exit(0)
# If the user is not authenticated, there's no reason to do
# extra checks here -- to have been performed already.
if not hasattr(policy_request, 'sasl_username'):
print "action=PERMIT\n\n"
sys.exit(0)
# Same here.
if policy_request.sasl_username == None:
print "action=PERMIT\n\n"
sys.exit(0)
delegate_sender_header = None
alias_sender_header = None
# If the sender is a delegate of the envelope sender address, take into
# account the preferred domain policy for appending the Sender and/or
# X-Sender headers.
#
# Note that a delegatee by very definition is not using an alias.
#
if policy_request.sasl_user_is_delegate:
# Domain-specific setting?
if not policy_request.sender_domain == None:
delegate_sender_header = conf.get(policy_request.sender_domain, 'delegate_sender_header')
# Global setting?
if delegate_sender_header == None:
delegate_sender_header = conf.get('kolab_smtp_access_policy', 'delegate_sender_header')
# Default
if delegate_sender_header == None:
delegate_sender_header = True
# If the sender is using an alias as the envelope sender address, take
# into account the preferred domain policy for appending the Sender
# and/or X-Sender headers.
elif policy_request.sasl_user_uses_alias:
# Domain-specific setting?
if not policy_request.sender_domain == None:
alias_sender_header = conf.get(policy_request.sender_domain, 'alias_sender_header')
# Global setting?
if alias_sender_header == None:
alias_sender_header = conf.get('kolab_smtp_access_policy', 'alias_sender_header')
# Default
if alias_sender_header == None:
alias_sender_header = True
# Make the values booleans
delegate_sender_header = utils.true_or_false(delegate_sender_header)
alias_sender_header = utils.true_or_false(alias_sender_header)
# Do we use a (simple) encryption key to obscure the headers' contents?
# Note that using an encryption key voids the actual use of proper Sender
# and X-Sender headers such as they could be interpreted by a client
# application.
enc_key = conf.get(policy_request.sender_domain, 'sender_header_enc_key')
if enc_key == None:
enc_key = conf.get('kolab_smtp_access_policy', 'sender_header_enc_key')
sender_header = None
xsender_header = None
if delegate_sender_header or alias_sender_header:
# Domain specific?
sender_header = conf.get(policy_request.sender_domain, 'sender_header')
# Global setting?
if sender_header == None:
sender_header = conf.get('kolab_smtp_access_policy', 'sender_header')
# Default
if sender_header == None:
sender_header = True
# Domain specific?
xsender_header = conf.get(policy_request.sender_domain, 'xsender_header')
# Global setting?
if xsender_header == None:
xsender_header = conf.get('kolab_smtp_access_policy', 'xsender_header')
# Default
if xsender_header == None:
xsender_header = True
# Note that if the user is not a delegatee, and not using an alias, the sender
# address is the envelope sender address, and the defaults for sender_header
# and xsender_header being None, ultimately evaluating to False seems
# appropriate.
# Make the values booleans
sender_header = utils.true_or_false(sender_header)
xsender_header = utils.true_or_false(xsender_header)
if sender_header or xsender_header:
# Do the encoding, if any
if not enc_key == None:
header = 'X-Authenticated-As'
xheader = None
sender = utils.encode(enc_key, policy_request.sasl_username)
else:
header = 'Sender'
xheader = 'X-Sender'
sender = policy_request.sasl_username
if sender_header:
print "action=PREPEND %s: %s" % (header, sender)
if xsender_header and not xheader == None:
print "action=PREPEND %s: %s" % (xheader, sender)
print "action=PERMIT\n\n"
sys.exit(0)
def reject(message, policy_request=None):
log.info(_(“Returning action REJECT: %s”) % (message))
print “action=REJECT %s\n\n” % (message)
sys.exit(0)
def expand_mydomains():
“”"
Return a list of my domains.
“”"
global auth,mydomains
if not mydomains == None:
return mydomains
auth.connect()
mydomains = auth.list_domains()
return mydomains.keys()
def normalize_address(email_address):
“”"
Parse an address; Strip off anything after a recipient delimiter.
“”"
# TODO: Recipient delimiter is configurable.
if len(email_address.split("+")) > 1:
# Take the first part split by recipient delimiter and the last part
# split by '@'.
return "%s@%s" % (
email_address.split("+")[0].lower(),
# TODO: Under some conditions, the recipient may not be fully
# qualified. We'll cross that bridge when we get there, though.
email_address.split('@')[1].lower()
)
else:
return email_address.lower()
def read_request_input():
“”"
Read a single policy request from sys.stdin, and return a dictionary
containing the request.
“”"
start_time = time.time()
log.debug(_("Starting to loop for new request"))
policy_request = {}
end_of_request = False
while not end_of_request:
if (time.time()-start_time) >= conf.timeout:
log.warning(_("Timeout for policy request reading exceeded"))
sys.exit(0)
request_line = sys.stdin.readline()
if request_line.strip() == '':
if policy_request.has_key('request'):
log.debug(_("End of current request"), level=8)
end_of_request = True
else:
request_line = request_line.strip()
log.debug(_("Getting line: %s") % (request_line), level=8)
policy_request[request_line.split('=')[0]] = \
'='.join(request_line.split('=')[1:]).lower()
log.debug(_("Returning request"))
return policy_request
def verify_domain(domain):
“”"
Verify whether the domain is internal (mine) or external.
“”"
global auth,mydomains
if not mydomains == None:
return domain in mydomains.keys()
auth.connect()
domain_verified = False
mydomains = auth.list_domains()
if not mydomains == None and mydomains.has_key(domain):
domain_verified = True
else:
domain_verified = False
return domain_verified
if name == “main”:
access_policy_group = conf.add_cli_parser_option_group(
_(“Access Policy Options”)
)
access_policy_group.add_option( "--timeout",
dest = "timeout",
action = "store",
default = 10,
help = _("SMTP Policy request timeout."))
access_policy_group.add_option( "--verify-recipient",
dest = "verify_recipient",
action = "store_true",
default = False,
help = _("Verify the recipient access policy."))
access_policy_group.add_option( "--verify-sender",
dest = "verify_sender",
action = "store_true",
default = False,
help = _("Verify the sender access policy."))
access_policy_group.add_option( "--allow-unauthenticated",
dest = "allow_unauthenticated",
action = "store_true",
default = False,
help = _("Allow unauthenticated senders."))
conf.finalize_conf()
auth = Auth()
cache = cache_init()
policy_requests = {}
# Start the work
while True:
policy_request = read_request_input()
instance = policy_request['instance']
log.debug(_("Got request instance %s") % (instance))
if policy_requests.has_key(instance):
policy_requests[instance].add_request(policy_request)
else:
policy_requests[instance] = PolicyRequest(policy_request)
protocol_state = policy_request['protocol_state'].strip().lower()
log.debug(
_("Request instance %s is in state %s") % (
instance,
protocol_state
)
)
if not protocol_state == 'data':
log.debug(
_("Request instance %s is not yet in DATA state") % (
instance
)
)
print "action=DUNNO\n\n"
sys.stdout.flush()
# We can recognize being in the DATA part by the recipient_count being
# set to a non-zero value and the protocol_state being set to 'data'.
# Note that the input we're getting is a string, not an integer.
else:
log.debug(_("Request instance %s reached DATA state") % (instance))
sender_allowed = False
recipient_allowed = False
try:
if conf.verify_sender:
sender_allowed = policy_requests[instance].verify_sender()
else:
sender_allowed = True
if conf.verify_recipient:
recipient_allowed = \
policy_requests[instance].verify_recipients()
else:
recipient_allowed = True
except Exception, errmsg:
import traceback
log.error(_("Unhandled exception caught: %r") % (errmsg))
log.error(traceback.format_exc())
if not sender_allowed:
reject(_("Sender access denied"))
elif not recipient_allowed:
reject(_("Recipient access denied"))
else:
permit(_("No objections"), policy_requests[instance])
[/code]
Wenn ich das File richtig interpretiere werden die LDAP Attribute kolabAllowSMTPRecipient und kolabAllowSMTPSender verarbeitet.
Siehe hierzu auch: https://wiki.kolab.org/User:Kanarip/Draft:Kolab_SMTP_Access_Policy#PERMIT.2C_REJECT_and_OTHER
Können diese beiden Attribute in den UMC Benutzereinstellungen zur Zeit bereits verändert werden ?
BG,
Hermann
