pyceo/pylib/csc/backends/ldapi.py

898 lines
26 KiB
Python

"""
LDAP Backend Interface
This module is intended to be a thin wrapper around LDAP operations.
Methods on the connection object correspond in a straightforward way
to LDAP queries and updates.
A LDAP entry is the most important component of a CSC UNIX account.
The entry contains the username, user id number, real name, shell,
and other important information. All non-local UNIX accounts must
have an LDAP entry, even if the account does not log in directly.
This module makes use of python-ldap, a Python module with bindings
to libldap, OpenLDAP's native C client library.
"""
import ldap.modlist, ipc, os
class LDAPException(Exception):
"""Exception class for LDAP-related errors."""
class LDAPConnection(object):
"""
Connection to the LDAP directory. All directory
queries and updates are made via this class.
Exceptions: (all methods)
LDAPException - on directory query failure
Example:
connection = LDAPConnection()
connection.connect(...)
# make queries and updates, e.g.
connection.user_delete('mspang')
connection.disconnect()
"""
def __init__(self):
self.ldap = None
def connect_anon(self, uri, user_base, group_base):
"""
Establish a connection to the LDAP Server.
Parameters:
uri - connection string (e.g. ldap://foo.com, ldaps://bar.com)
user_base - base of the users subtree
group_base - baes of the group subtree
Example: connect('ldaps:///', 'cn=ceo,dc=csclub,dc=uwaterloo,dc=ca',
'secret', 'ou=People,dc=csclub,dc=uwaterloo,dc=ca',
'ou=Group,dc=csclub,dc=uwaterloo,dc=ca')
"""
# open the connection
self.ldap = ldap.initialize(uri)
# authenticate
self.ldap.simple_bind_s('', '')
self.user_base = user_base
self.group_base = group_base
def connect_sasl(self, uri, bind_dn, mech, realm, userid, password, user_base, group_base):
# open the connection
self.ldap = ldap.initialize(uri)
# authenticate
sasl = Sasl(mech, realm, userid, password)
self.ldap.sasl_interactive_bind_s(bind_dn, sasl)
self.user_base = user_base
self.group_base = group_base
def disconnect(self):
"""Close the connection to the LDAP server."""
if self.ldap:
# close connection
try:
self.ldap.unbind_s()
self.ldap = None
except ldap.LDAPError, e:
raise LDAPException("unable to disconnect: %s" % e)
def connected(self):
"""Determine whether the connection has been established."""
return self.ldap is not None
### Helper Methods ###
def lookup(self, dn, objectClass=None):
"""
Helper method to retrieve the attributes of an entry.
Parameters:
dn - the distinguished name of the directory entry
Returns: a dictionary of attributes of the matched dn, or
None of the dn does not exist in the directory
"""
if not self.connected(): raise LDAPException("Not connected!")
# search for the specified dn
try:
if objectClass:
search_filter = '(objectClass=%s)' % self.escape(objectClass)
matches = self.ldap.search_s(dn, ldap.SCOPE_BASE, search_filter)
else:
matches = self.ldap.search_s(dn, ldap.SCOPE_BASE)
except ldap.NO_SUCH_OBJECT:
return None
except ldap.LDAPError, e:
raise LDAPException("unable to lookup dn %s: %s" % (dn, e))
# this should never happen due to the nature of DNs
if len(matches) > 1:
raise LDAPException("duplicate dn in ldap: " + dn)
# dn was found, but didn't match the objectClass filter
elif len(matches) < 1:
return None
# return the attributes of the single successful match
match = matches[0]
match_dn, match_attributes = match
return match_attributes
### User-related Methods ###
def user_lookup(self, uid, objectClass=None):
"""
Retrieve the attributes of a user.
Parameters:
uid - the uid to look up
Returns: attributes of user with uid
"""
dn = 'uid=' + uid + ',' + self.user_base
return self.lookup(dn, objectClass)
def user_search(self, search_filter, params):
"""
Search for users with a filter.
Parameters:
search_filter - LDAP filter string to match users against
Returns: a dictionary mapping uids to attributes
"""
if not self.connected(): raise LDAPException("Not connected!")
search_filter = search_filter % tuple(self.escape(x) for x in params)
# search for entries that match the filter
try:
matches = self.ldap.search_s(self.user_base, ldap.SCOPE_SUBTREE, search_filter)
except ldap.LDAPError, e:
raise LDAPException("user search failed: %s" % e)
results = {}
for match in matches:
dn, attrs = match
uid = attrs['uid'][0]
results[uid] = attrs
return results
def user_modify(self, uid, attrs):
"""
Update user attributes in the directory.
Parameters:
uid - username of the user to modify
attrs - dictionary as returned by user_lookup() with changes to make.
omitted attributes are DELETED.
Example: user = user_lookup('mspang')
user['uidNumber'] = [ '0' ]
connection.user_modify('mspang', user)
"""
# distinguished name of the entry to modify
dn = 'uid=' + uid + ',' + self.user_base
# retrieve current state of user
old_user = self.user_lookup(uid)
try:
# build list of modifications to make
changes = ldap.modlist.modifyModlist(old_user, attrs)
# apply changes
self.ldap.modify_s(dn, changes)
except ldap.LDAPError, e:
raise LDAPException("unable to modify: %s" % e)
def user_delete(self, uid):
"""
Removes a user from the directory.
Example: connection.user_delete('mspang')
"""
try:
dn = 'uid=' + uid + ',' + self.user_base
self.ldap.delete_s(dn)
except ldap.LDAPError, e:
raise LDAPException("unable to delete: %s" % e)
### Account-related Methods ###
def account_lookup(self, uid):
"""
Retrieve the attributes of an account.
Parameters:
uid - the uid to look up
Returns: attributes of user with uid
"""
return self.user_lookup(uid, 'posixAccount')
def account_search_id(self, uidNumber):
"""
Retrieves a list of accounts with a certain UNIX uid number.
LDAP (or passwd for that matter) does not enforce any restriction on
the number of accounts that can have a certain UID number. Therefore
this method returns a list of matches.
Parameters:
uidNumber - the user id of the accounts desired
Returns: a dictionary mapping uids to attributes
Example: connection.account_search_id(21292) -> {'mspang': { ... }}
"""
search_filter = '(&(objectClass=posixAccount)(uidNumber=%s))'
return self.user_search(search_filter, [ uidNumber ])
def account_search_gid(self, gidNumber):
"""
Retrieves a list of accounts with a certain UNIX gid
number (search by default group).
Returns: a dictionary mapping uids to attributes
"""
search_filter = '(&(objectClass=posixAccount)(gidNumber=%s))'
return self.user_search(search_filter, [ gidNumber ])
def account_add(self, uid, cn, uidNumber, gidNumber, homeDirectory, loginShell=None, gecos=None, description=None, update=False):
"""
Adds a user account to the directory.
Parameters:
uid - the UNIX username for the account
cn - the real name of the member
uidNumber - the UNIX user id number
gidNumber - the UNIX group id number (default group)
homeDirectory - home directory for the user
loginShell - login shell for the user
gecos - comment field (usually stores name etc)
description - description field (optional and unimportant)
update - if True, will update existing entries
Example: connection.user_add('mspang', 'Michael Spang',
21292, 100, '/users/mspang', '/bin/bash',
'Michael Spang,,,')
"""
if not self.connected(): raise LDAPException("Not connected!")
dn = 'uid=' + uid + ',' + self.user_base
attrs = {
'objectClass': [ 'top', 'account', 'posixAccount', 'shadowAccount' ],
'uid': [ uid ],
'cn': [ cn ],
'loginShell': [ loginShell ],
'uidNumber': [ str(uidNumber) ],
'gidNumber': [ str(gidNumber) ],
'homeDirectory': [ homeDirectory ],
'gecos': [ gecos ],
}
if loginShell:
attrs['loginShell'] = [ loginShell ]
if description:
attrs['description'] = [ description ]
try:
old_entry = self.user_lookup(uid)
if old_entry and 'posixAccount' not in old_entry['objectClass'] and update:
attrs.update(old_entry)
attrs['objectClass'] = list(attrs['objectClass'])
attrs['objectClass'].append('posixAccount')
if not 'shadowAccount' in attrs['objectClass']:
attrs['objectClass'].append('shadowAccount')
modlist = ldap.modlist.modifyModlist(old_entry, attrs)
self.ldap.modify_s(dn, modlist)
else:
modlist = ldap.modlist.addModlist(attrs)
self.ldap.add_s(dn, modlist)
except ldap.LDAPError, e:
raise LDAPException("unable to add: %s" % e)
### Group-related Methods ###
def group_lookup(self, cn):
"""
Retrieves the attributes of a group.
Parameters:
cn - the UNIX group name to lookup
Returns: attributes of the group's LDAP entry
Example: connection.group_lookup('office') -> {
'cn': 'office',
'gidNumber', '1001',
...
}
"""
dn = 'cn=' + cn + ',' + self.group_base
return self.lookup(dn, 'posixGroup')
def group_search_id(self, gidNumber):
"""
Retrieves a list of groups with the specified UNIX group number.
Returns: a list of groups with gid gidNumber
Example: connection.group_search_id(1001) -> ['office']
"""
if not self.connected(): raise LDAPException("Not connected!")
# search for posixAccount entries with the specified uidNumber
try:
search_filter = '(&(objectClass=posixGroup)(gidNumber=%d))' % gidNumber
matches = self.ldap.search_s(self.group_base, ldap.SCOPE_SUBTREE, search_filter)
except ldap.LDAPError, e:
raise LDAPException("group search failed: %s" % e)
# list for groups found
group_cns = []
results = {}
for match in matches:
dn, attrs = match
uid = attrs['cn'][0]
results[uid] = attrs
return results
def group_add(self, cn, gidNumber, description=None):
"""
Adds a group to the directory.
Example: connection.group_add('office', 1001, 'Office Staff')
"""
if not self.connected(): raise LDAPException("Not connected!")
dn = 'cn=' + cn + ',' + self.group_base
attrs = {
'objectClass': [ 'top', 'posixGroup', 'group' ],
'cn': [ cn ],
'gidNumber': [ str(gidNumber) ],
}
if description:
attrs['description'] = description
try:
modlist = ldap.modlist.addModlist(attrs)
self.ldap.add_s(dn, modlist)
except ldap.LDAPError, e:
raise LDAPException("unable to add group: %s" % e)
def group_modify(self, cn, attrs):
"""
Update group attributes in the directory.
The only available updates are fairly destructive (rename or renumber)
but this method is provided for completeness.
Parameters:
cn - name of the group to modify
entry - dictionary as returned by group_lookup() with changes to make.
omitted attributes are DELETED.
Example: group = group_lookup('office')
group['gidNumber'] = [ str(connection.first_id(20000, 40000)) ]
del group['memberUid']
connection.group_modify('office', group)
"""
if not self.connected(): raise LDAPException("Not connected!")
# distinguished name of the entry to modify
dn = 'cn=' + cn + ',' + self.group_base
# retrieve current state of group
old_group = self.group_lookup(cn)
try:
# build list of modifications to make
changes = ldap.modlist.modifyModlist(old_group, attrs)
# apply changes
self.ldap.modify_s(dn, changes)
except ldap.LDAPError, e:
raise LDAPException("unable to modify: %s" % e)
def group_delete(self, cn):
"""
Removes a group from the directory."
Example: connection.group_delete('office')
"""
if not self.connected(): raise LDAPException("Not connected!")
try:
dn = 'cn=' + cn + ',' + self.group_base
self.ldap.delete_s(dn)
except ldap.LDAPError, e:
raise LDAPException("unable to delete group: %s" % e)
### Member-related Methods ###
def member_lookup(self, uid):
"""
Retrieve the attributes of a member. This method will only return
results that have the objectClass 'member'.
Parameters:
uid - the username to look up
Returns: attributes of member with uid
Example: connection.member_lookup('mspang') ->
{ 'uid': 'mspang', 'uidNumber': 21292 ...}
"""
if not self.connected(): raise LDAPException("Not connected!")
dn = 'uid=' + uid + ',' + self.user_base
return self.lookup(dn, 'member')
def member_search_name(self, name):
"""
Retrieves a list of members with the specified name (fuzzy).
Returns: a dictionary mapping uids to attributes
"""
search_filter = '(&(objectClass=member)(cn~=%s))'
return self.user_search(search_filter, [ name ] )
def member_search_term(self, term):
"""
Retrieves a list of members who were registered in a certain term.
Returns: a dictionary mapping uids to attributes
"""
search_filter = '(&(objectClass=member)(term=%s))'
return self.user_search(search_filter, [ term ])
def member_search_program(self, program):
"""
Retrieves a list of members in a certain program (fuzzy).
Returns: a dictionary mapping uids to attributes
"""
search_filter = '(&(objectClass=member)(program~=%s))'
return self.user_search(search_filter, [ program ])
def member_add(self, uid, cn, program=None, description=None):
"""
Adds a member to the directory.
Parameters:
uid - the UNIX username for the member
cn - the real name of the member
program - the member's program of study
description - a description for the entry
"""
dn = 'uid=' + uid + ',' + self.user_base
attrs = {
'objectClass': [ 'top', 'account', 'member' ],
'uid': [ uid ],
'cn': [ cn ],
}
if program:
attrs['program'] = [ program ]
if description:
attrs['description'] = [ description ]
try:
modlist = ldap.modlist.addModlist(attrs)
self.ldap.add_s(dn, modlist)
except ldap.LDAPError, e:
raise LDAPException("unable to add: %s" % e)
def member_add_account(self, uid, uidNumber, gidNumber, homeDirectory, loginShell=None, gecos=None):
"""
Adds login privileges to a member.
"""
return self.account_add(uid, None, uidNumber, gidNumber, homeDirectory, loginShell, gecos, None, True)
### Miscellaneous Methods ###
def escape(self, value):
"""
Escapes special characters in a value so that it may be safely inserted
into an LDAP search filter.
"""
value = str(value)
value = value.replace('\\', '\\5c').replace('*', '\\2a')
value = value.replace('(', '\\28').replace(')', '\\29')
value = value.replace('\x00', '\\00')
return value
def used_uids(self, minimum=None, maximum=None):
"""
Compiles a list of used UIDs in a range.
Parameters:
minimum - smallest uid to return in the list
maximum - largest uid to return in the list
Returns: list of integer uids
Example: connection.used_uids(20000, 40000) -> [20000, 20001, ...]
"""
if not self.connected(): raise LDAPException("Not connected!")
try:
users = self.ldap.search_s(self.user_base, ldap.SCOPE_SUBTREE, '(objectClass=posixAccount)', ['uidNumber'])
except ldap.LDAPError, e:
raise LDAPException("search for uids failed: %s" % e)
uids = []
for user in users:
dn, attrs = user
uid = int(attrs['uidNumber'][0])
if (not minimum or uid >= minimum) and (not maximum or uid <= maximum):
uids.append(uid)
return uids
def used_gids(self, minimum=None, maximum=None):
"""
Compiles a list of used GIDs in a range.
Parameters:
minimum - smallest gid to return in the list
maximum - largest gid to return in the list
Returns: list of integer gids
Example: connection.used_gids(20000, 40000) -> [20000, 20001, ...]
"""
if not self.connected(): raise LDAPException("Not connected!")
try:
users = self.ldap.search_s(self.user_base, ldap.SCOPE_SUBTREE, '(objectClass=posixAccount)', ['gidNumber'])
except ldap.LDAPError, e:
raise LDAPException("search for gids failed: %s" % e)
gids = []
for user in users:
dn, attrs = user
gid = int(attrs['gidNumber'][0])
if (not minimum or gid >= minimum) and (not maximum or gid <= maximum):
gids.append(gid)
return gids
def make_modlist(self, old, new):
keys = set(old.keys()).union(set(new))
mlist = []
for key in keys:
if key in old and not key in new:
mlist.append((ldap.MOD_DELETE, key, list(set(old[key]))))
elif key in new and not key in old:
mlist.append((ldap.MOD_ADD, key, list(set(new[key]))))
else:
to_add = list(set(new[key]) - set(old[key]))
if len(to_add) > 0:
mlist.append((ldap.MOD_ADD, key, to_add))
to_del = list(set(old[key]) - set(new[key]))
if len(to_del) > 0:
mlist.append((ldap.MOD_DELETE, key, to_del))
return mlist
class Sasl:
CB_USER = 0x4001
bind_dn = 'dn:uid=%s,cn=%s,cn=%s,cn=auth'
def __init__(self, mech, realm, userid, password):
self.mech = mech
self.bind_dn = self.bind_dn % (userid, realm, mech)
if mech == 'GSSAPI':
type, arg = password
kinit = '/usr/bin/kinit'
kinit_args = [ 'kinit', '%s@%s' % (userid, realm) ]
if type == 'keytab':
kinit_args += [ '-k', '-t', arg ]
pid, kinit_out, kinit_in = ipc.popeni(kinit, kinit_args)
os.waitpid(pid, 0)
def callback(self, id, challenge, prompt, defresult):
if id == self.CB_USER:
return self.bind_dn
else:
return None
### Tests ###
if __name__ == '__main__':
from csc.common.test import *
conffile = '/etc/csc/ldap.cf'
cfg = dict([map(str.strip, a.split("=", 1)) for a in map(str.strip, open(conffile).read().split("\n")) if "=" in a ])
srvurl = cfg['server_url'][1:-1]
binddn = cfg['admin_bind_dn'][1:-1]
bindpw = cfg['admin_bind_pw'][1:-1]
ubase = cfg['users_base'][1:-1]
gbase = cfg['groups_base'][1:-1]
minid = 99999000
maxid = 100000000
# t=test u=user g=group c=changed r=real e=expected
tuname = 'testuser'
turname = 'Test User'
tuhome = '/home/testuser'
tushell = '/bin/false'
tugecos = 'Test User,,,'
tgname = 'testgroup'
tmname = 'testmember'
tmrname = 'Test Member'
tmprogram = 'UBW'
tmdesc = 'Test Description'
cushell = '/bin/true'
cuhome = '/home/changed'
curname = 'Test Modified User'
cmhome = '/home/testmember'
cmshell = '/bin/false'
cmgecos = 'Test Member,,,'
test(LDAPConnection)
connection = LDAPConnection()
success()
test(LDAPConnection.disconnect)
connection.disconnect()
success()
test(LDAPConnection.connect)
connection.connect(srvurl, binddn, bindpw, ubase, gbase)
if not connection.connected():
fail("not connected")
success()
try:
connection.user_delete(tuname)
connection.user_delete(tmname)
connection.group_delete(tgname)
except LDAPException:
pass
test(LDAPConnection.used_uids)
uids = connection.used_uids(minid, maxid)
if type(uids) is not list:
fail("list not returned")
success()
test(LDAPConnection.used_gids)
gids = connection.used_gids(minid, maxid)
if type(gids) is not list:
fail("list not returned")
success()
unusedids = []
for idnum in xrange(minid, maxid):
if not idnum in uids and not idnum in gids:
unusedids.append(idnum)
tuuid = unusedids.pop()
tugid = unusedids.pop()
eudata = {
'uid': [ tuname ],
'loginShell': [ tushell ],
'uidNumber': [ str(tuuid) ],
'gidNumber': [ str(tugid) ],
'gecos': [ tugecos ],
'homeDirectory': [ tuhome ],
'cn': [ turname ]
}
test(LDAPConnection.account_add)
connection.account_add(tuname, turname, tuuid, tugid, tuhome, tushell, tugecos)
success()
emdata = {
'uid': [ tmname ],
'cn': [ tmrname ],
'program': [ tmprogram ],
'description': [ tmdesc ],
}
test(LDAPConnection.member_add)
connection.member_add(tmname, tmrname, tmprogram, tmdesc)
success()
tggid = unusedids.pop()
egdata = {
'cn': [ tgname ],
'gidNumber': [ str(tggid) ]
}
test(LDAPConnection.group_add)
connection.group_add(tgname, tggid)
success()
test(LDAPConnection.account_lookup)
udata = connection.account_lookup(tuname)
if udata: del udata['objectClass']
assert_equal(eudata, udata)
success()
test(LDAPConnection.member_lookup)
mdata = connection.member_lookup(tmname)
if mdata: del mdata['objectClass']
assert_equal(emdata, mdata)
success()
test(LDAPConnection.user_lookup)
udata = connection.user_lookup(tuname)
mdata = connection.user_lookup(tmname)
if udata: del udata['objectClass']
if mdata: del mdata['objectClass']
assert_equal(eudata, udata)
assert_equal(emdata, mdata)
success()
test(LDAPConnection.group_lookup)
gdata = connection.group_lookup(tgname)
if gdata: del gdata['objectClass']
assert_equal(egdata, gdata)
success()
test(LDAPConnection.account_search_id)
eulist = [ tuname ]
ulist = connection.account_search_id(tuuid).keys()
assert_equal(eulist, ulist)
success()
test(LDAPConnection.account_search_gid)
ulist = connection.account_search_gid(tugid)
if tuname not in ulist:
fail("%s not in %s" % (tuname, ulist))
success()
test(LDAPConnection.member_search_name)
mlist = connection.member_search_name(tmrname)
if tmname not in mlist:
fail("%s not in %s" % (tmname, mlist))
success()
test(LDAPConnection.member_search_program)
mlist = connection.member_search_program(tmprogram)
if tmname not in mlist:
fail("%s not in %s" % (tmname, mlist))
success()
test(LDAPConnection.group_search_id)
glist = connection.group_search_id(tggid).keys()
eglist = [ tgname ]
assert_equal(eglist, glist)
success()
ecudata = connection.account_lookup(tuname)
ecudata['loginShell'] = [ cushell ]
ecudata['homeDirectory'] = [ cuhome ]
ecudata['cn'] = [ curname ]
test(LDAPConnection.user_modify)
connection.user_modify(tuname, ecudata)
cudata = connection.account_lookup(tuname)
assert_equal(ecudata, cudata)
success()
tmuid = unusedids.pop()
tmgid = unusedids.pop()
emadata = emdata.copy()
emadata.update({
'loginShell': [ cmshell ],
'uidNumber': [ str(tmuid) ],
'gidNumber': [ str(tmgid) ],
'gecos': [ cmgecos ],
'homeDirectory': [ cmhome ],
})
test(LDAPConnection.member_add_account)
connection.member_add_account(tmname, tmuid, tmuid, cmhome, cmshell, cmgecos)
success()
ecgdata = connection.group_lookup(tgname)
ecgdata['memberUid'] = [ tuname ]
test(LDAPConnection.group_modify)
connection.group_modify(tgname, ecgdata)
cgdata = connection.group_lookup(tgname)
assert_equal(ecgdata, cgdata)
success()
test(LDAPConnection.group_delete)
connection.group_delete(tgname)
success()
test(LDAPConnection.disconnect)
connection.disconnect()
success()