freeipa/ipalib/aci.py
Rob Crittenden 0d70c68395 Fix aci plugin, enhance aci parsing capabilities, add user group support
- The aci plugin didn't quite work with the new ldap2 backend.
- We already walk through the target part of the ACI syntax so skip that
  in the regex altogether. This now lets us handle all current ACIs in IPA
  (some used to be ignored/skipped)
- Add support for user groups so one can do v1-style delegation (group A
  can write attributes x,y,z in group B). It is actually quite a lot more
  flexible than that but you get the idea)
- Improve error messages in the aci library
- Add a bit of documentation to the aci plugin
2009-09-28 22:27:42 -06:00

327 lines
14 KiB
Python
Executable File

# Authors:
# Rob Crittenden <rcritten@redhat.com>
#
# Copyright (C) 2008 Red Hat
# see file 'COPYING' for use and warranty information
#
# 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; version 2 only
#
# 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
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
import shlex
import re
import ldap
# The Python re module doesn't do nested parenthesis
# Break the ACI into 3 pieces: target, name, permissions/bind_rules
ACIPat = re.compile(r'\(version\s+3.0\s*;\s*acl\s+\"([^\"]*)\"\s*;\s*([^;]*);\s*\)', re.UNICODE)
# Break the permissions/bind_rules out
PermPat = re.compile(r'(\w+)\s*\((.*)\)\s+(.*)', re.UNICODE)
# Break the bind rule out
BindPat = re.compile(r'([a-zA-Z0-9;\.]+)\s*(\!?=)\s*(.*)', re.UNICODE)
ACTIONS = ["allow", "deny"]
PERMISSIONS = ["read", "write", "add", "delete", "search", "compare",
"selfwrite", "proxy", "all"]
class ACI:
"""
Holds the basic data for an ACI entry, as stored in the cn=accounts
entry in LDAP. Has methods to parse an ACI string and export to an
ACI String.
"""
def __init__(self,acistr=None):
self.name = None
self.orig_acistr = acistr
self.target = {}
self.action = "allow"
self.permissions = ["write"]
self.bindrule = {}
if acistr is not None:
self._parse_acistr(acistr)
def __getitem__(self,key):
"""Fake getting attributes by key for sorting"""
if key == 0:
return self.name
if key == 1:
return self.source_group
if key == 2:
return self.dest_group
raise TypeError("Unknown key value %s" % key)
def __repr__(self):
"""An alias for export_to_string()"""
return self.export_to_string()
def export_to_string(self):
"""Output a Directory Server-compatible ACI string"""
self.validate()
aci = ""
for t in self.target:
op = self.target[t]['operator']
if type(self.target[t]['expression']) in (tuple, list):
target = ""
for l in self.target[t]['expression']:
target = target + l + " || "
target = target[:-4]
aci = aci + "(%s %s \"%s\")" % (t, op, target)
else:
aci = aci + "(%s %s \"%s\")" % (t, op, self.target[t]['expression'])
aci = aci + "(version 3.0;acl \"%s\";%s (%s) %s %s \"%s\"" % (self.name, self.action, ",".join(self.permissions), self.bindrule['keyword'], self.bindrule['operator'], self.bindrule['expression']) + ";)"
return aci
def _remove_quotes(self, s):
# Remove leading and trailing quotes
if s.startswith('"'):
s = s[1:]
if s.endswith('"'):
s = s[:-1]
return s
def _parse_target(self, aci):
lexer = shlex.shlex(aci.encode('utf-8'))
lexer.wordchars = lexer.wordchars + "."
l = []
var = False
op = "="
for token in lexer:
# We should have the form (a = b)(a = b)...
if token == "(":
var = lexer.next().strip()
operator = lexer.next()
if operator != "=" and operator != "!=":
# Peek at the next char before giving up
operator = operator + lexer.next()
if operator != "=" and operator != "!=":
raise SyntaxError("No operator in target, got '%s'" % operator)
op = operator
val = lexer.next().strip()
val = self._remove_quotes(val)
end = lexer.next()
if end != ")":
raise SyntaxError('No end parenthesis in target, got %s' % end)
if var == 'targetattr':
# Make a string of the form attr || attr || ... into a list
t = re.split('[^a-zA-Z0-9;\*]+', val)
self.target[var] = {}
self.target[var]['operator'] = op
self.target[var]['expression'] = t
else:
self.target[var] = {}
self.target[var]['operator'] = op
self.target[var]['expression'] = val
def _parse_acistr(self, acistr):
vstart = acistr.find('version')
if vstart < 0:
raise SyntaxError, "malformed ACI, unable to find version %s" % acistr
acimatch = ACIPat.match(acistr[vstart-1:])
if not acimatch or len(acimatch.groups()) < 2:
raise SyntaxError, "malformed ACI, match for version and bind rule failed %s" % acistr
self._parse_target(acistr[:vstart-1])
self.name = acimatch.group(1)
bindperms = PermPat.match(acimatch.group(2))
if not bindperms or len(bindperms.groups()) < 3:
raise SyntaxError, "malformed ACI, permissions match failed %s" % acistr
self.action = bindperms.group(1)
self.permissions = bindperms.group(2).replace(' ','').split(',')
self.set_bindrule(bindperms.group(3))
def validate(self):
"""Do some basic verification that this will produce a
valid LDAP ACI.
returns True if valid
"""
if not type(self.permissions) in (tuple, list):
raise SyntaxError, "permissions must be a list"
for p in self.permissions:
if not p.lower() in PERMISSIONS:
raise SyntaxError, "invalid permission: '%s'" % p
if not self.name:
raise SyntaxError, "name must be set"
if not isinstance(self.name, basestring):
raise SyntaxError, "name must be a string"
if not isinstance(self.target, dict) or len(self.target) == 0:
raise SyntaxError, "target must be a non-empty dictionary"
if not isinstance(self.bindrule, dict):
raise SyntaxError, "bindrule must be a dictionary"
if not self.bindrule.get('operator') or not self.bindrule.get('keyword') or not self.bindrule.get('expression'):
raise SyntaxError, "bindrule is missing a component"
return True
def set_target_filter(self, filter, operator="="):
self.target['targetfilter'] = {}
if not filter.startswith("("):
filter = "(" + filter + ")"
self.target['targetfilter']['expression'] = filter
self.target['targetfilter']['operator'] = operator
def set_target_attr(self, attr, operator="="):
if not type(attr) in (tuple, list):
attr = [attr]
self.target['targetattr'] = {}
self.target['targetattr']['expression'] = attr
self.target['targetattr']['operator'] = operator
def set_target(self, target, operator="="):
assert target.startswith("ldap:///")
self.target['target'] = {}
self.target['target']['expression'] = target
self.target['target']['operator'] = operator
def set_bindrule(self, bindrule):
match = BindPat.match(bindrule)
if not match or len(match.groups()) < 3:
raise SyntaxError, "malformed bind rule"
self.set_bindrule_keyword(match.group(1))
self.set_bindrule_operator(match.group(2))
self.set_bindrule_expression(match.group(3).replace('"',''))
def set_bindrule_keyword(self, keyword):
self.bindrule['keyword'] = keyword
def set_bindrule_operator(self, operator):
self.bindrule['operator'] = operator
def set_bindrule_expression(self, expression):
self.bindrule['expression'] = expression
def isequal(self, b):
"""
Compare the current ACI to another one to see if they are
the same.
returns True if equal, False if not.
"""
assert isinstance(b, ACI)
try:
if self.name.lower() != b.name.lower():
return False
if set(self.permissions) != set(b.permissions):
return False
if self.bindrule.get('keyword') != b.bindrule.get('keyword'):
return False
if self.bindrule.get('operator') != b.bindrule.get('operator'):
return False
if self.bindrule.get('expression') != b.bindrule.get('expression'):
return False
if self.target.get('targetfilter',{}).get('expression') != b.target.get('targetfilter',{}).get('expression'):
return False
if self.target.get('targetfilter',{}).get('operator') != b.target.get('targetfilter',{}).get('operator'):
return False
if set(self.target.get('targetattr',{}).get('expression')) != set(b.target.get('targetattr',{}).get('expression')):
return False
if self.target.get('targetattr',{}).get('operator') != b.target.get('targetattr',{}).get('operator'):
return False
if self.target.get('target',{}).get('expression') != b.target.get('target',{}).get('expression'):
return False
if self.target.get('target',{}).get('operator') != b.target.get('target',{}).get('operator'):
return False
except Exception:
# If anything throws up then they are not equal
return False
# We got this far so lets declare them the same
return True
def extract_group_cns(aci_list, client):
"""
Extracts all the cn's from a list of aci's and returns them as a hash
from group_dn to group_cn.
It first tries to cheat by looking at the first rdn for the
group dn. If that's not cn for some reason, it looks up the group.
"""
group_dn_to_cn = {}
for aci in aci_list:
for dn in (aci.source_group, aci.dest_group):
if not group_dn_to_cn.has_key(dn):
rdn_list = ldap.explode_dn(dn, 0)
first_rdn = rdn_list[0]
(type,value) = first_rdn.split('=')
if type == "cn":
group_dn_to_cn[dn] = value
else:
try:
group = client.get_entry_by_dn(dn, ['cn'])
group_dn_to_cn[dn] = group.getValue('cn')
except Exception:
group_dn_to_cn[dn] = 'unknown'
return group_dn_to_cn
if __name__ == '__main__':
# a = ACI('(targetattr="title")(targetfilter="(memberOf=cn=bar,cn=groups,cn=accounts ,dc=example,dc=com)")(version 3.0;acl "foobar";allow (write) groupdn="ldap:///cn=foo,cn=groups,cn=accounts,dc=example,dc=com";)')
# print a
# a = ACI('(target="ldap:///uid=bjensen,dc=example,dc=com")(targetattr=*) (version 3.0;acl "aci1";allow (write) userdn="ldap:///self";)')
# print a
# a = ACI(' (targetattr = "givenName || sn || cn || displayName || title || initials || loginShell || gecos || homePhone || mobile || pager || facsimileTelephoneNumber || telephoneNumber || street || roomNumber || l || st || postalCode || manager || secretary || description || carLicense || labeledURI || inetUserHTTPURL || seeAlso || employeeType || businessCategory || ou")(version 3.0;acl "Self service";allow (write) userdn = "ldap:///self";)')
# print a
a = ACI('(target="ldap:///uid=*,cn=users,cn=accounts,dc=example,dc=com")(version 3.0;acl "add_user";allow (add) groupdn="ldap:///cn=add_user,cn=taskgroups,dc=example,dc=com";)')
print a
print "---"
a = ACI('(targetattr=member)(target="ldap:///cn=ipausers,cn=groups,cn=accounts,dc=example,dc=com")(version 3.0;acl "add_user_to_default_group";allow (write) groupdn="ldap:///cn=add_user_to_default_group,cn=taskgroups,dc=example,dc=com";)')
print a
print "---"
a = ACI('(targetattr!=member)(target="ldap:///cn=ipausers,cn=groups,cn=accounts,dc=example,dc=com")(version 3.0;acl "add_user_to_default_group";allow (write) groupdn="ldap:///cn=add_user_to_default_group,cn=taskgroups,dc=example,dc=com";)')
print a
print "---"
a = ACI('(targetattr = "userPassword || krbPrincipalKey || sambaLMPassword || sambaNTPassword || passwordHistory")(version 3.0; acl "change_password"; allow (write) groupdn = "ldap:///cn=change_password,cn=taskgroups,dc=example,dc=com";)')
print a
print "---"
a = ACI()
a.name ="foo"
a.set_target_attr(['title','givenname'], "!=")
# a.set_bindrule("groupdn = \"ldap:///cn=foo,cn=groups,cn=accounts,dc=example,dc=com\"")
a.set_bindrule_keyword("groupdn")
a.set_bindrule_operator("=")
a.set_bindrule_expression ("\"ldap:///cn=foo,cn=groups,cn=accounts,dc=example,dc=com\"")
a.permissions = ['read','write','add']
print a
b = ACI()
b.name ="foo"
b.set_target_attr(['givenname','title'], "!=")
b.set_bindrule_keyword("groupdn")
b.set_bindrule_operator("=")
b.set_bindrule_expression ("\"ldap:///cn=foo,cn=groups,cn=accounts,dc=example,dc=com\"")
b.permissions = ['add','read','write']
print b
print a.isequal(b)
a = ACI('(targetattr != "userPassword || krbPrincipalKey || sambaLMPassword || sambaNTPassword || passwordHistory || krbMKey")(version 3.0; acl "Enable Anonymous access"; allow (read, search, compare) userdn = "ldap:///anyone";)')
print a
a = ACI('(targetfilter = "(|(objectClass=person)(objectClass=krbPrincipalAux)(objectClass=posixAccount)(objectClass=groupOfNames)(objectClass=posixGroup))")(targetattr != "aci || userPassword || krbPrincipalKey || sambaLMPassword || sambaNTPassword || passwordHistory")(version 3.0; acl "Account Admins can manage Users and Groups"; allow (add, delete, read, write) groupdn = "ldap:///cn=admins,cn=groups,cn=accounts,dc=greyoak,dc=com";)')
print a