Coverage for ipalib/rpc: 51%

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# Authors:

# Jason Gerard DeRose <jderose@redhat.com>

# Rob Crittenden <rcritten@redhat.com>

# 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/>.

"""

RPC client and shared RPC client/server functionality.

This module adds some additional functionality on top of the ``xmlrpclib``

module in the Python standard library. For documentation on the

``xmlrpclib`` module, see:

http://docs.python.org/library/xmlrpclib.html

Also see the `ipaserver.rpcserver` module.

"""

from types import NoneType

from decimal import Decimal

import threading

import sys

import os

import errno

import locale

import datetime

from xmlrpclib import (Binary, Fault, dumps, loads, ServerProxy, Transport,

ProtocolError, MININT, MAXINT)

import kerberos

from dns import resolver, rdatatype

from dns.exception import DNSException

from ipalib.backend import Connectible

from ipalib.errors import public_errors, PublicError, UnknownError, NetworkError, KerberosError, XMLRPCMarshallError

from ipalib import errors

from ipalib.request import context, Connection

from ipalib.util import get_current_principal

from ipapython.ipa_log_manager import root_logger

from ipapython import ipautil

from ipapython import kernel_keyring

from ipapython.cookie import Cookie

from ipalib.text import _

import httplib

import socket

from ipapython.nsslib import NSSHTTPS, NSSConnection

from nss.error import NSPRError

from urllib2 import urlparse

from ipalib.krb_utils import KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN, KRB5KRB_AP_ERR_TKT_EXPIRED, \

KRB5_FCC_PERM, KRB5_FCC_NOFILE, KRB5_CC_FORMAT, KRB5_REALM_CANT_RESOLVE

from ipapython.dn import DN

COOKIE_NAME = 'ipa_session'

KEYRING_COOKIE_NAME = '%s_cookie:%%s' % COOKIE_NAME

def client_session_keyring_keyname(principal):

'''

Return the key name used for storing the client session data for

the given principal.

'''

return KEYRING_COOKIE_NAME % principal

def update_persistent_client_session_data(principal, data):

'''

Given a principal create or update the session data for that

principal in the persistent secure storage.

Raises ValueError if unable to perform the action for any reason.

'''

try:

keyname = client_session_keyring_keyname(principal)

except Exception, e:

raise ValueError(str(e))

# kernel_keyring only raises ValueError (why??)

kernel_keyring.update_key(keyname, data)

def read_persistent_client_session_data(principal):

'''

Given a principal return the stored session data for that

principal from the persistent secure storage.

Raises ValueError if unable to perform the action for any reason.

'''

try:

keyname = client_session_keyring_keyname(principal)

except Exception, e:

raise ValueError(str(e))

# kernel_keyring only raises ValueError (why??)

return kernel_keyring.read_key(keyname)

def delete_persistent_client_session_data(principal):

'''

Given a principal remove the session data for that

principal from the persistent secure storage.

Raises ValueError if unable to perform the action for any reason.

'''

try:

keyname = client_session_keyring_keyname(principal)

except Exception, e:

raise ValueError(str(e))

# kernel_keyring only raises ValueError (why??)

kernel_keyring.del_key(keyname)

def xml_wrap(value):

"""

Wrap all ``str`` in ``xmlrpclib.Binary``.

Because ``xmlrpclib.dumps()`` will itself convert all ``unicode`` instances

into UTF-8 encoded ``str`` instances, we don't do it here.

So in total, when encoding data for an XML-RPC packet, the following

transformations occur:

* All ``str`` instances are treated as binary data and are wrapped in

an ``xmlrpclib.Binary()`` instance.

* Only ``unicode`` instances are treated as character data. They get

converted to UTF-8 encoded ``str`` instances (although as mentioned,

not by this function).

Also see `xml_unwrap()`.

:param value: The simple scalar or simple compound value to wrap.

"""

if type(value) in (list, tuple):

return tuple(xml_wrap(v) for v in value)

if isinstance(value, dict):

return dict(

(k, xml_wrap(v)) for (k, v) in value.iteritems()

)

if type(value) is str:

return Binary(value)

if type(value) is Decimal:

# transfer Decimal as a string

return unicode(value)

if isinstance(value, (int, long)) and (value < MININT or value > MAXINT):

return unicode(value)

if isinstance(value, DN):

return str(value)

assert type(value) in (unicode, int, long, float, bool, NoneType)

return value

def xml_unwrap(value, encoding='UTF-8'):

"""

Unwrap all ``xmlrpc.Binary``, decode all ``str`` into ``unicode``.

When decoding data from an XML-RPC packet, the following transformations

occur:

* The binary payloads of all ``xmlrpclib.Binary`` instances are

returned as ``str`` instances.

* All ``str`` instances are treated as UTF-8 encoded Unicode strings.

They are decoded and the resulting ``unicode`` instance is returned.

Also see `xml_wrap()`.

:param value: The value to unwrap.

:param encoding: The Unicode encoding to use (defaults to ``'UTF-8'``).

"""

if type(value) in (list, tuple):

return tuple(xml_unwrap(v, encoding) for v in value)

if type(value) is dict:

return dict(

(k, xml_unwrap(v, encoding)) for (k, v) in value.iteritems()

)

if type(value) is str:

return value.decode(encoding)

if isinstance(value, Binary):

assert type(value.data) is str

return value.data

assert type(value) in (unicode, int, float, bool, NoneType)

return value

def xml_dumps(params, methodname=None, methodresponse=False, encoding='UTF-8'):

"""

Encode an XML-RPC data packet, transparently wraping ``params``.

This function will wrap ``params`` using `xml_wrap()` and will

then encode the XML-RPC data packet using ``xmlrpclib.dumps()`` (from the

Python standard library).

For documentation on the ``xmlrpclib.dumps()`` function, see:

http://docs.python.org/library/xmlrpclib.html#convenience-functions

Also see `xml_loads()`.

:param params: A ``tuple`` or an ``xmlrpclib.Fault`` instance.

:param methodname: The name of the method to call if this is a request.

:param methodresponse: Set this to ``True`` if this is a response.

:param encoding: The Unicode encoding to use (defaults to ``'UTF-8'``).

"""

if type(params) is tuple:

params = xml_wrap(params)

else:

assert isinstance(params, Fault)

return dumps(params,

methodname=methodname,

methodresponse=methodresponse,

encoding=encoding,

allow_none=True,

)

def decode_fault(e, encoding='UTF-8'):

assert isinstance(e, Fault)

if type(e.faultString) is str:

return Fault(e.faultCode, e.faultString.decode(encoding))

return e

def xml_loads(data, encoding='UTF-8'):

"""

Decode the XML-RPC packet in ``data``, transparently unwrapping its params.

This function will decode the XML-RPC packet in ``data`` using

``xmlrpclib.loads()`` (from the Python standard library). If ``data``

contains a fault, ``xmlrpclib.loads()`` will itself raise an

``xmlrpclib.Fault`` exception.

Assuming an exception is not raised, this function will then unwrap the

params in ``data`` using `xml_unwrap()`. Finally, a

``(params, methodname)`` tuple is returned containing the unwrapped params

and the name of the method being called. If the packet contains no method

name, ``methodname`` will be ``None``.

For documentation on the ``xmlrpclib.loads()`` function, see:

http://docs.python.org/library/xmlrpclib.html#convenience-functions

Also see `xml_dumps()`.

:param data: The XML-RPC packet to decode.

"""

try:

(params, method) = loads(data)

return (xml_unwrap(params), method)

except Fault, e:

raise decode_fault(e)

class LanguageAwareTransport(Transport):

"""Transport sending Accept-Language header"""

def get_host_info(self, host):

(host, extra_headers, x509) = Transport.get_host_info(self, host)

try:

lang = locale.setlocale(locale.LC_ALL, '').split('.')[0].lower()

except locale.Error:

# fallback to default locale

lang = 'en_us'

if not isinstance(extra_headers, list):

extra_headers = []

extra_headers.append(

('Accept-Language', lang.replace('_', '-'))

)

extra_headers.append(

('Referer', 'https://%s/ipa/xml' % str(host))

)

return (host, extra_headers, x509)

class SSLTransport(LanguageAwareTransport):

"""Handles an HTTPS transaction to an XML-RPC server."""

def __nss_initialized(self, dbdir):

"""

If there is another connections open it may have already

initialized NSS. This is likely to lead to an NSS shutdown

failure. One way to mitigate this is to tell NSS to not

initialize if it has already been done in another open connection.

Returns True if another connection is using the same db.

"""

for value in context.__dict__.values():

if not isinstance(value, Connection):

continue

if not isinstance(value.conn._ServerProxy__transport, SSLTransport):

continue

if hasattr(value.conn._ServerProxy__transport, 'dbdir') and \

value.conn._ServerProxy__transport.dbdir == dbdir:

return True

return False

def make_connection(self, host):

host, self._extra_headers, x509 = self.get_host_info(host)

# Python 2.7 changed the internal class used in xmlrpclib from

# HTTP to HTTPConnection. We need to use the proper subclass

# If we an existing connection exists using the same NSS database

# there is no need to re-initialize. Pass thsi into the NSS

# connection creator.

if sys.version_info >= (2, 7):

if self._connection and host == self._connection[0]:

return self._connection[1]

dbdir = '/etc/pki/nssdb'

no_init = self.__nss_initialized(dbdir)

if sys.version_info < (2, 7):

conn = NSSHTTPS(host, 443, dbdir=dbdir, no_init=no_init)

else:

conn = NSSConnection(host, 443, dbdir=dbdir, no_init=no_init)

self.dbdir=dbdir

conn.connect()

if sys.version_info < (2, 7):

return conn

else:

self._connection = host, conn

return self._connection[1]

class KerbTransport(SSLTransport):

"""

Handles Kerberos Negotiation authentication to an XML-RPC server.

"""

flags = kerberos.GSS_C_MUTUAL_FLAG | kerberos.GSS_C_SEQUENCE_FLAG

def _handle_exception(self, e, service=None):

(major, minor) = ipautil.get_gsserror(e)

if minor[1] == KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:

raise errors.ServiceError(service=service)

elif minor[1] == KRB5_FCC_NOFILE:

raise errors.NoCCacheError()

elif minor[1] == KRB5KRB_AP_ERR_TKT_EXPIRED:

raise errors.TicketExpired()

elif minor[1] == KRB5_FCC_PERM:

raise errors.BadCCachePerms()

elif minor[1] == KRB5_CC_FORMAT:

raise errors.BadCCacheFormat()

elif minor[1] == KRB5_REALM_CANT_RESOLVE:

raise errors.CannotResolveKDC()

else:

raise errors.KerberosError(major=major, minor=minor)

def get_host_info(self, host):

"""

Two things can happen here. If we have a session we will add

a cookie for that. If not we will set an Authorization header.

"""

(host, extra_headers, x509) = SSLTransport.get_host_info(self, host)

if not isinstance(extra_headers, list):

extra_headers = []

session_cookie = getattr(context, 'session_cookie', None)

if session_cookie:

extra_headers.append(('Cookie', session_cookie))

return (host, extra_headers, x509)

# Set the remote host principal

service = "HTTP@" + host.split(':')[0]

try:

(rc, vc) = kerberos.authGSSClientInit(service, self.flags)

except kerberos.GSSError, e:

self._handle_exception(e)

try:

kerberos.authGSSClientStep(vc, "")

except kerberos.GSSError, e:

self._handle_exception(e, service=service)

for (h, v) in extra_headers:

if h == 'Authorization':

extra_headers.remove((h, v))

break

extra_headers.append(

('Authorization', 'negotiate %s' % kerberos.authGSSClientResponse(vc))

)

return (host, extra_headers, x509)

def single_request(self, host, handler, request_body, verbose=0):

try:

return SSLTransport.single_request(self, host, handler, request_body, verbose)

finally:

self.close()

def store_session_cookie(self, cookie_header):

'''

Given the contents of a Set-Cookie header scan the header and

extract each cookie contained within until the session cookie

is located. Examine the session cookie if the domain and path

are specified, if not update the cookie with those values from

the request URL. Then write the session cookie into the key

store for the principal. If the cookie header is None or the

session cookie is not present in the header no action is

taken.

Context Dependencies:

The per thread context is expected to contain:

principal

The current pricipal the HTTP request was issued for.

request_url

The URL of the HTTP request.

'''

if cookie_header is None:

return

principal = getattr(context, 'principal', None)

request_url = getattr(context, 'request_url', None)

root_logger.debug("received Set-Cookie '%s'", cookie_header)

# Search for the session cookie

try:

session_cookie = Cookie.get_named_cookie_from_string(cookie_header,

COOKIE_NAME, request_url)

except Exception, e:

root_logger.error("unable to parse cookie header '%s': %s", cookie_header, e)

return

if session_cookie is None:

return

cookie_string = str(session_cookie)

root_logger.debug("storing cookie '%s' for principal %s", cookie_string, principal)

try:

update_persistent_client_session_data(principal, cookie_string)

except Exception, e:

# Not fatal, we just can't use the session cookie we were sent.

pass

def parse_response(self, response):

self.store_session_cookie(response.getheader('Set-Cookie'))

return SSLTransport.parse_response(self, response)

class DelegatedKerbTransport(KerbTransport):

"""

Handles Kerberos Negotiation authentication and TGT delegation to an

XML-RPC server.

"""

flags = kerberos.GSS_C_DELEG_FLAG | kerberos.GSS_C_MUTUAL_FLAG | \

kerberos.GSS_C_SEQUENCE_FLAG

class xmlclient(Connectible):

"""

Forwarding backend plugin for XML-RPC client.

Also see the `ipaserver.rpcserver.xmlserver` plugin.

"""

def __init__(self):

super(xmlclient, self).__init__()

self.__errors = dict((e.errno, e) for e in public_errors)

def get_url_list(self, xmlrpc_uri):

"""

Create a list of urls consisting of the available IPA servers.

"""

# the configured URL defines what we use for the discovered servers

(scheme, netloc, path, params, query, fragment) = urlparse.urlparse(xmlrpc_uri)

servers = []

name = '_ldap._tcp.%s.' % self.env.domain

try:

answers = resolver.query(name, rdatatype.SRV)

except DNSException, e:

answers = []

for answer in answers:

server = str(answer.target).rstrip(".")

servers.append('https://%s%s' % (ipautil.format_netloc(server), path))

servers = list(set(servers))

# the list/set conversion won't preserve order so stick in the

# local config file version here.

cfg_server = xmlrpc_uri

if cfg_server in servers:

# make sure the configured master server is there just once and

# it is the first one

servers.remove(cfg_server)

servers.insert(0, cfg_server)

else:

servers.insert(0, cfg_server)

return servers

def get_session_cookie_from_persistent_storage(self, principal):

'''

Retrieves the session cookie for the given principal from the

persistent secure storage. Returns None if not found or unable

to retrieve the session cookie for any reason, otherwise

returns a Cookie object containing the session cookie.

'''

# Get the session data, it should contain a cookie string

# (possibly with more than one cookie).

try:

cookie_string = read_persistent_client_session_data(principal)

except Exception, e:

return None

# Search for the session cookie within the cookie string

try:

session_cookie = Cookie.get_named_cookie_from_string(cookie_string, COOKIE_NAME)

except Exception, e:

return None

return session_cookie

def apply_session_cookie(self, url):

'''

Attempt to load a session cookie for the current principal

from the persistent secure storage. If the cookie is

successfully loaded adjust the input url's to point to the

session path and insert the session cookie into the per thread

context for later insertion into the HTTP request. If the

cookie is not successfully loaded then the original url is

returned and the per thread context is not modified.

Context Dependencies:

The per thread context is expected to contain:

principal

The current pricipal the HTTP request was issued for.

The per thread context will be updated with:

session_cookie

A cookie string to be inserted into the Cookie header

of the HTPP request.

'''

original_url = url

principal = getattr(context, 'principal', None)

session_cookie = self.get_session_cookie_from_persistent_storage(principal)

if session_cookie is None:

self.log.debug("failed to find session_cookie in persistent storage for principal '%s'",

principal)

return original_url

else:

self.debug("found session_cookie in persistent storage for principal '%s', cookie: '%s'",

principal, session_cookie)

# Decide if we should send the cookie to the server

try:

session_cookie.http_return_ok(original_url)

except Cookie.Expired, e:

self.debug("deleting session data for principal '%s': %s", principal, e)

try:

delete_persistent_client_session_data(principal)

except Exception, e:

pass

return original_url

except Cookie.URLMismatch, e:

self.debug("not sending session cookie, URL mismatch: %s", e)

return original_url

except Exception, e:

self.error("not sending session cookie, unknown error: %s", e)

return original_url

# O.K. session_cookie is valid to be returned, stash it away where it will will

# get included in a HTTP Cookie headed sent to the server.

self.log.debug("setting session_cookie into context '%s'", session_cookie.http_cookie())

setattr(context, 'session_cookie', session_cookie.http_cookie())

# Form the session URL by substituting the session path into the original URL

scheme, netloc, path, params, query, fragment = urlparse.urlparse(original_url)

path = '/ipa/session/xml'

session_url = urlparse.urlunparse((scheme, netloc, path, params, query, fragment))

return session_url

def create_connection(self, ccache=None, verbose=False, fallback=True,

delegate=False):

try:

xmlrpc_uri = self.env.xmlrpc_uri

principal = get_current_principal()

setattr(context, 'principal', principal)

# We have a session cookie, try using the session URI to see if it

# is still valid

if not delegate:

xmlrpc_uri = self.apply_session_cookie(xmlrpc_uri)

except ValueError:

# No session key, do full Kerberos auth

pass

urls = self.get_url_list(xmlrpc_uri)

serverproxy = None

for url in urls:

kw = dict(allow_none=True, encoding='UTF-8')

kw['verbose'] = verbose

if url.startswith('https://'):

if delegate:

kw['transport'] = DelegatedKerbTransport()

else:

kw['transport'] = KerbTransport()

else:

kw['transport'] = LanguageAwareTransport()

self.log.info('trying %s' % url)

setattr(context, 'request_url', url)

serverproxy = ServerProxy(url, **kw)

if len(urls) == 1:

# if we have only 1 server and then let the

# main requester handle any errors. This also means it

# must handle a 401 but we save a ping.

return serverproxy

try:

command = getattr(serverproxy, 'ping')

try:

response = command()

except Fault, e:

e = decode_fault(e)

if e.faultCode in self.__errors:

error = self.__errors[e.faultCode]

raise error(message=e.faultString)

else:

raise UnknownError(

code=e.faultCode,

error=e.faultString,

server=url,

)

# We don't care about the response, just that we got one

break

except KerberosError, krberr:

# kerberos error on one server is likely on all

raise errors.KerberosError(major=str(krberr), minor='')

except ProtocolError, e:

if hasattr(context, 'session_cookie') and e.errcode == 401:

# Unauthorized. Remove the session and try again.

delattr(context, 'session_cookie')

try:

delete_persistent_client_session_data(principal)

except Exception, e:

# This shouldn't happen if we have a session but it isn't fatal.

pass

return self.create_connection(ccache, verbose, fallback, delegate)

if not fallback:

raise

serverproxy = None

except Exception, e:

if not fallback:

raise

else:

self.log.info('Connection to %s failed with %s', url, e)

serverproxy = None

if serverproxy is None:

raise NetworkError(uri=_('any of the configured servers'),

error=', '.join(urls))

return serverproxy

def destroy_connection(self):

if sys.version_info >= (2, 7):

conn = getattr(context, self.id, None)

if conn is not None:

conn = conn.conn._ServerProxy__transport

conn.close()

def forward(self, name, *args, **kw):

"""

Forward call to command named ``name`` over XML-RPC.

This method will encode and forward an XML-RPC request, and will then

decode and return the corresponding XML-RPC response.

:param command: The name of the command being forwarded.

:param args: Positional arguments to pass to remote command.

:param kw: Keyword arguments to pass to remote command.

"""

if name not in self.Command:

raise ValueError(

'%s.forward(): %r not in api.Command' % (self.name, name)

)

server = getattr(context, 'request_url', None)

self.info('Forwarding %r to server %r', name, server)

command = getattr(self.conn, name)

params = [args, kw]

try:

response = command(*xml_wrap(params))

return xml_unwrap(response)

except Fault, e:

e = decode_fault(e)

self.debug('Caught fault %d from server %s: %s', e.faultCode,

server, e.faultString)

if e.faultCode in self.__errors:

error = self.__errors[e.faultCode]

raise error(message=e.faultString)

raise UnknownError(

code=e.faultCode,

error=e.faultString,

server=server,

)

except NSPRError, e:

raise NetworkError(uri=server, error=str(e))

except ProtocolError, e:

# By catching a 401 here we can detect the case where we have

# a single IPA server and the session is invalid. Otherwise

# we always have to do a ping().

session_cookie = getattr(context, 'session_cookie', None)

if session_cookie and e.errcode == 401:

# Unauthorized. Remove the session and try again.

delattr(context, 'session_cookie')

try:

principal = getattr(context, 'principal', None)

delete_persistent_client_session_data(principal)

except Exception, e:

# This shouldn't happen if we have a session but it isn't fatal.

pass

# Create a new serverproxy with the non-session URI. If there

# is an existing connection we need to save the NSS dbdir so

# we can skip an unnecessary NSS_Initialize() and avoid

# NSS_Shutdown issues.

serverproxy = self.create_connection(os.environ.get('KRB5CCNAME'), self.env.verbose, self.env.fallback, self.env.delegate)

dbdir = None

current_conn = getattr(context, self.id, None)

if current_conn is not None:

dbdir = getattr(current_conn.conn._ServerProxy__transport, 'dbdir', None)

if dbdir is not None:

self.debug('Using dbdir %s' % dbdir)

setattr(context, self.id, Connection(serverproxy, self.disconnect))

if dbdir is not None:

current_conn = getattr(context, self.id, None)

current_conn.conn._ServerProxy__transport.dbdir = dbdir

return self.forward(name, *args, **kw)

raise NetworkError(uri=server, error=e.errmsg)

except socket.error, e:

raise NetworkError(uri=server, error=str(e))

except (OverflowError, TypeError), e:

raise XMLRPCMarshallError(error=str(e))

Coverage for ipalib/rpc : 51%

369 statements 188 run 181 missing 0 excluded