freeipa/ipa-client/ipaclient/ipadiscovery.py
Marko Myllynen 6c9b6548cc Don't remove /tmp when removing temp cert dir
If /tmp happens to be empty os.removedirs() happily removes it...

https://fedorahosted.org/freeipa/ticket/1843
2011-09-22 22:02:54 -04:00

346 lines
11 KiB
Python

# Authors: Simo Sorce <ssorce@redhat.com>
#
# Copyright (C) 2007 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, 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
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
import socket
import os
import logging
import ipapython.dnsclient
import tempfile
import ldap
from ldap import LDAPError
from ipapython.ipautil import run, CalledProcessError, valid_ip
NOT_FQDN = -1
NO_LDAP_SERVER = -2
REALM_NOT_FOUND = -3
NOT_IPA_SERVER = -4
BAD_HOST_CONFIG = -10
class IPADiscovery:
def __init__(self):
self.realm = None
self.domain = None
self.server = None
self.basedn = None
def __get_resolver_domains(self):
"""
Read /etc/resolv.conf and return all the domains found in domain and
search.
Returns a list
"""
domains = []
domain = None
try:
fp = open('/etc/resolv.conf', 'r')
lines = fp.readlines()
fp.close()
for line in lines:
if line.lower().startswith('domain'):
domain = line.split(None)[-1]
elif line.lower().startswith('search'):
domains = domains + line.split(None)[1:]
except:
pass
if domain and not domain in domains:
domains = [domain] + domains
return domains
def getServerName(self):
return self.server
def getDomainName(self):
return self.domain
def getRealmName(self):
return self.realm
def getKDCName(self):
return self.kdc
def getBaseDN(self):
return self.basedn
def check_domain(self, domain):
"""
Given a domain search it for SRV records, breaking it down to search
all subdomains too.
Returns a tuple (server, domain) or (None,None) if a SRV record
isn't found.
"""
server = None
while not server:
logging.debug("[ipadnssearchldap("+domain+")]")
server = self.ipadnssearchldap(domain)
if server:
return (server, domain)
else:
p = domain.find(".")
if p == -1: #no ldap server found and last component of the domain already tested
return (None, None)
domain = domain[p+1:]
return (None, None)
def search(self, domain = "", server = "", hostname=None):
qname = ""
results = []
result = []
krbret = []
ldapret = []
if not server:
if not domain: #domain not provided do full DNS discovery
# get the local host name
if not hostname:
hostname = socket.getfqdn()
if not hostname:
return BAD_HOST_CONFIG
if valid_ip(hostname):
return NOT_FQDN
# first, check for an LDAP server for the local domain
p = hostname.find(".")
if p == -1: #no domain name
return NOT_FQDN
domain = hostname[p+1:]
# Get the list of domains from /etc/resolv.conf, we'll search
# them all. We search the domain of our hostname first though,
# even if that means searching it twice. This is to avoid the
# situation where domain isn't set in /etc/resolv.conf and
# the search list has the hostname domain not first. We could
# end up with the wrong SRV record.
domains = self.__get_resolver_domains()
domains = [domain] + domains
for domain in domains:
(server, domain) = self.check_domain(domain)
if server:
self.server = server
self.domain = domain
break
if not self.domain: #no ldap server found
return NO_LDAP_SERVER
else:
logging.debug("[ipadnssearchldap]")
self.server = self.ipadnssearchldap(domain)
if self.server:
self.domain = domain
else:
return NO_LDAP_SERVER
else: #server forced on us, this means DNS doesn't work :/
self.domain = domain
self.server = server
#search for kerberos
logging.debug("[ipadnssearchkrb]")
krbret = self.ipadnssearchkrb(self.domain)
if not server and not krbret[0]:
return REALM_NOT_FOUND
self.realm = krbret[0]
self.kdc = krbret[1]
logging.debug("[ipacheckldap]")
# check ldap now
ldapret = self.ipacheckldap(self.server, self.realm)
if not ldapret:
return NOT_IPA_SERVER
self.server = ldapret[0]
self.realm = ldapret[1]
return 0
def ipacheckldap(self, thost, trealm):
"""
Given a host and kerberos realm verify that it is an IPA LDAP
server hosting the realm. The connection is an SSL connection
so the remote IPA CA cert must be available at
http://HOST/ipa/config/ca.crt
Returns a list [host, realm] or an empty list on error.
"""
lret = []
lres = []
lattr = ""
linfo = ""
lrealms = []
i = 0
# Get the CA certificate
try:
# Create TempDir
temp_ca_dir = tempfile.mkdtemp()
except OSError, e:
raise RuntimeError("Creating temporary directory failed: %s" % str(e))
try:
run(["/usr/bin/wget", "-O", "%s/ca.crt" % temp_ca_dir, "http://%s/ipa/config/ca.crt" % thost])
except CalledProcessError, e:
logging.debug('Retrieving CA from %s failed.\n%s' % (thost, str(e)))
return []
#now verify the server is really an IPA server
try:
logging.debug("Init ldap with: ldap://"+thost+":389")
lh = ldap.initialize("ldap://"+thost+":389")
ldap.set_option(ldap.OPT_X_TLS_REQUIRE_CERT, True)
ldap.set_option(ldap.OPT_X_TLS_CACERTFILE, "%s/ca.crt" % temp_ca_dir)
lh.set_option(ldap.OPT_PROTOCOL_VERSION, 3)
lh.set_option(ldap.OPT_X_TLS_DEMAND, True)
lh.start_tls_s()
lh.simple_bind_s("","")
logging.debug("Search rootdse")
lret = lh.search_s("", ldap.SCOPE_BASE, "(objectClass=*)")
for lattr in lret[0][1]:
if lattr.lower() == "namingcontexts":
self.basedn = lret[0][1][lattr][0]
logging.debug("Search for (info=*) in "+self.basedn+"(base)")
lret = lh.search_s(self.basedn, ldap.SCOPE_BASE, "(info=IPA*)")
if not lret:
return []
logging.debug("Found: "+str(lret))
for lattr in lret[0][1]:
if lattr.lower() == "info":
linfo = lret[0][1][lattr][0].lower()
break
if not linfo or linfo.lower() != 'ipa v2.0':
return []
#search and return known realms
logging.debug("Search for (objectClass=krbRealmContainer) in "+self.basedn+"(sub)")
lret = lh.search_s("cn=kerberos,"+self.basedn, ldap.SCOPE_SUBTREE, "(objectClass=krbRealmContainer)")
if not lret:
#something very wrong
return []
logging.debug("Found: "+str(lret))
for lres in lret:
for lattr in lres[1]:
if lattr.lower() == "cn":
lrealms.append(lres[1][lattr][0])
if trealm:
for r in lrealms:
if trealm == r:
return [thost, trealm]
# must match or something is very wrong
return []
else:
if len(lrealms) != 1:
#which one? we can't attach to a multi-realm server without DNS working
return []
else:
return [thost, lrealms[0]]
#we shouldn't get here
return []
except LDAPError, err:
if not isinstance(err, ldap.TIMEOUT):
logging.error("LDAP Error: %s: %s" %
(err.args[0]['desc'], err.args[0].get('info', '')))
else:
logging.error("LDAP Error: timeout")
return []
finally:
os.remove("%s/ca.crt" % temp_ca_dir)
os.rmdir(temp_ca_dir)
def ipadnssearchldap(self, tdomain):
servers = ""
rserver = ""
qname = "_ldap._tcp."+tdomain
# terminate the name
if not qname.endswith("."):
qname += "."
results = ipapython.dnsclient.query(qname, ipapython.dnsclient.DNS_C_IN, ipapython.dnsclient.DNS_T_SRV)
for result in results:
if result.dns_type == ipapython.dnsclient.DNS_T_SRV:
rserver = result.rdata.server.rstrip(".")
if result.rdata.port and result.rdata.port != 389:
rserver += ":" + str(result.rdata.port)
if servers:
servers += "," + rserver
else:
servers = rserver
break
return servers
def ipadnssearchkrb(self, tdomain):
realm = ""
kdc = ""
# now, check for a Kerberos realm the local host or domain is in
qname = "_kerberos." + tdomain
# terminate the name
if not qname.endswith("."):
qname += "."
results = ipapython.dnsclient.query(qname, ipapython.dnsclient.DNS_C_IN, ipapython.dnsclient.DNS_T_TXT)
for result in results:
if result.dns_type == ipapython.dnsclient.DNS_T_TXT:
realm = result.rdata.data
if realm:
break
if realm:
# now fetch server information for the realm
qname = "_kerberos._udp." + realm.lower()
# terminate the name
if not qname.endswith("."):
qname += "."
results = ipapython.dnsclient.query(qname, ipapython.dnsclient.DNS_C_IN, ipapython.dnsclient.DNS_T_SRV)
for result in results:
if result.dns_type == ipapython.dnsclient.DNS_T_SRV:
qname = result.rdata.server.rstrip(".")
if result.rdata.port and result.rdata.port != 88:
qname += ":" + str(result.rdata.port)
if kdc:
kdc += "," + qname
else:
kdc = qname
if not kdc:
logging.debug("SRV record for KDC not found! Realm: %s, SRV record: %s" % (realm, qname))
return [realm, kdc]