docker-offlineimap/offlineimap/repository/IMAP.py
Eygene Ryabinkin f69613965f Make OS-default CA certificate file to be requested explicitely
This simplifies logics for the user, especially if he uses both
fingerprint and certificate validation: it is hard to maintain
the compatibility with the prior behaviour and to avoid getting
default CA bundle to be disabled when fingerprint verification
is requested.

See
  http://thread.gmane.org/gmane.mail.imap.offlineimap.general/6695
for discussion about this change.

Default CA bundle is requested via 'sslcertfile = OS-DEFAULT'.

I had also enforced all cases where explicitely-requested CA bundles
are non-existent to be hard errors: when users asks us to use CA
bundle (and, thus, certificate validation), but we can't find one,
we must error out rather than happily continue and downgrade to
no validation.

Reported-By: Edd Barrett <edd@theunixzoo.co.uk>
Reviewed-By: Nicolas Sebrecht <nicolas.s-dev@laposte.net>
Signed-off-by: Eygene Ryabinkin <rea@codelabs.ru>
2015-01-18 22:05:49 +03:00

443 lines
17 KiB
Python

# IMAP repository support
# Copyright (C) 2002-2015 John Goerzen & contributors
#
# 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 2 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, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
from threading import Event
import os
from sys import exc_info
import netrc
import errno
from offlineimap.repository.Base import BaseRepository
from offlineimap import folder, imaputil, imapserver, OfflineImapError
from offlineimap.folder.UIDMaps import MappedIMAPFolder
from offlineimap.threadutil import ExitNotifyThread
from offlineimap.utils.distro import get_os_sslcertfile, get_os_sslcertfile_searchpath
class IMAPRepository(BaseRepository):
def __init__(self, reposname, account):
"""Initialize an IMAPRepository object."""
BaseRepository.__init__(self, reposname, account)
# self.ui is being set by the BaseRepository
self._host = None
self.imapserver = imapserver.IMAPServer(self)
self.folders = None
if self.getconf('sep', None):
self.ui.info("The 'sep' setting is being ignored for IMAP "
"repository '%s' (it's autodetected)" % self)
def startkeepalive(self):
keepalivetime = self.getkeepalive()
if not keepalivetime: return
self.kaevent = Event()
self.kathread = ExitNotifyThread(target = self.imapserver.keepalive,
name = "Keep alive " + self.getname(),
args = (keepalivetime, self.kaevent))
self.kathread.setDaemon(1)
self.kathread.start()
def stopkeepalive(self):
if not hasattr(self, 'kaevent'):
# Keepalive is not active.
return
self.kaevent.set()
del self.kathread
del self.kaevent
def holdordropconnections(self):
if not self.getholdconnectionopen():
self.dropconnections()
def dropconnections(self):
self.imapserver.close()
def getholdconnectionopen(self):
if self.getidlefolders():
return 1
return self.getconfboolean("holdconnectionopen", 0)
def getkeepalive(self):
num = self.getconfint("keepalive", 0)
if num == 0 and self.getidlefolders():
return 29*60
else:
return num
def getsep(self):
"""Return the folder separator for the IMAP repository
This requires that self.imapserver has been initialized with an
acquireconnection() or it will still be `None`"""
assert self.imapserver.delim != None, "'%s' " \
"repository called getsep() before the folder separator was " \
"queried from the server" % self
return self.imapserver.delim
def gethost(self):
"""Return the configured hostname to connect to
:returns: hostname as string or throws Exception"""
if self._host: # use cached value if possible
return self._host
# 1) check for remotehosteval setting
if self.config.has_option(self.getsection(), 'remotehosteval'):
host = self.getconf('remotehosteval')
try:
host = self.localeval.eval(host)
except Exception as e:
raise OfflineImapError("remotehosteval option for repository "\
"'%s' failed:\n%s" % (self, e),
OfflineImapError.ERROR.REPO), \
None, exc_info()[2]
if host:
self._host = host
return self._host
# 2) check for plain remotehost setting
host = self.getconf('remotehost', None)
if host != None:
self._host = host
return self._host
# no success
raise OfflineImapError("No remote host for repository "\
"'%s' specified." % self,
OfflineImapError.ERROR.REPO)
def get_remote_identity(self):
"""Remote identity is used for certain SASL mechanisms
(currently -- PLAIN) to inform server about the ID
we want to authorize as instead of our login name."""
return self.getconf('remote_identity', default=None)
def get_auth_mechanisms(self):
supported = ["GSSAPI", "CRAM-MD5", "PLAIN", "LOGIN"]
# Mechanisms are ranged from the strongest to the
# weakest ones.
# TODO: we need DIGEST-MD5, it must come before CRAM-MD5
# TODO: due to the chosen-plaintext resistance.
default = ["GSSAPI", "CRAM-MD5", "PLAIN", "LOGIN"]
mechs = self.getconflist('auth_mechanisms', r',\s*',
default)
for m in mechs:
if m not in supported:
raise OfflineImapError("Repository %s: " % self + \
"unknown authentication mechanism '%s'" % m,
OfflineImapError.ERROR.REPO)
self.ui.debug('imap', "Using authentication mechanisms %s" % mechs)
return mechs
def getuser(self):
user = None
localeval = self.localeval
if self.config.has_option(self.getsection(), 'remoteusereval'):
user = self.getconf('remoteusereval')
if user != None:
return localeval.eval(user)
user = self.getconf('remoteuser')
if user != None:
return user
try:
netrcentry = netrc.netrc().authenticators(self.gethost())
except IOError as inst:
if inst.errno != errno.ENOENT:
raise
else:
if netrcentry:
return netrcentry[0]
try:
netrcentry = netrc.netrc('/etc/netrc').authenticators(self.gethost())
except IOError as inst:
if inst.errno not in (errno.ENOENT, errno.EACCES):
raise
else:
if netrcentry:
return netrcentry[0]
def getport(self):
port = None
if self.config.has_option(self.getsection(), 'remoteporteval'):
port = self.getconf('remoteporteval')
if port != None:
return self.localeval.eval(port)
return self.getconfint('remoteport', None)
def getssl(self):
return self.getconfboolean('ssl', 0)
def getsslclientcert(self):
xforms = [os.path.expanduser, os.path.expandvars, os.path.abspath]
return self.getconf_xform('sslclientcert', xforms, None)
def getsslclientkey(self):
xforms = [os.path.expanduser, os.path.expandvars, os.path.abspath]
return self.getconf_xform('sslclientkey', xforms, None)
def getsslcacertfile(self):
"""Determines CA bundle.
Returns path to the CA bundle. It is either explicitely specified
or requested via "OS-DEFAULT" value (and we will search known
locations for the current OS and distribution).
If search via "OS-DEFAULT" route yields nothing, we will throw an
exception to make our callers distinguish between not specified
value and non-existent default CA bundle.
It is also an error to specify non-existent file via configuration:
it will error out later, but, perhaps, with less verbose explanation,
so we will also throw an exception. It is consistent with
the above behaviour, so any explicitely-requested configuration
that doesn't result in an existing file will give an exception.
"""
xforms = [os.path.expanduser, os.path.expandvars, os.path.abspath]
cacertfile = self.getconf_xform('sslcacertfile', xforms, None)
if self.getconf('sslcacertfile', None) == "OS-DEFAULT":
cacertfile = get_os_sslcertfile()
if cacertfile == None:
searchpath = get_os_sslcertfile_searchpath()
if searchpath:
reason = "Default CA bundle was requested, "\
"but no existing locations available. "\
"Tried %s." % (", ".join(searchpath))
else:
reason = "Default CA bundle was requested, "\
"but OfflineIMAP doesn't know any for your "\
"current operating system."
raise OfflineImapError(reason, OfflineImapError.ERROR.REPO)
if cacertfile is None:
return None
if not os.path.isfile(cacertfile):
reason = "CA certfile for repository '%s' couldn't be found. "\
"No such file: '%s'" % (self.name, cacertfile)
raise OfflineImapError(reason, OfflineImapError.ERROR.REPO)
return cacertfile
def getsslversion(self):
return self.getconf('ssl_version', None)
def get_ssl_fingerprint(self):
"""Return array of possible certificate fingerprints.
Configuration item cert_fingerprint can contain multiple
comma-separated fingerprints in hex form."""
value = self.getconf('cert_fingerprint', "")
return [f.strip().lower() for f in value.split(',') if f]
def getpreauthtunnel(self):
return self.getconf('preauthtunnel', None)
def gettransporttunnel(self):
return self.getconf('transporttunnel', None)
def getreference(self):
return self.getconf('reference', '')
def getidlefolders(self):
localeval = self.localeval
return localeval.eval(self.getconf('idlefolders', '[]'))
def getmaxconnections(self):
num1 = len(self.getidlefolders())
num2 = self.getconfint('maxconnections', 1)
return max(num1, num2)
def getexpunge(self):
return self.getconfboolean('expunge', 1)
def getpassword(self):
"""Return the IMAP password for this repository.
It tries to get passwords in the following order:
1. evaluate Repository 'remotepasseval'
2. read password from Repository 'remotepass'
3. read password from file specified in Repository 'remotepassfile'
4. read password from ~/.netrc
5. read password from /etc/netrc
On success we return the password.
If all strategies fail we return None."""
# 1. evaluate Repository 'remotepasseval'
passwd = self.getconf('remotepasseval', None)
if passwd != None:
return self.localeval.eval(passwd)
# 2. read password from Repository 'remotepass'
password = self.getconf('remotepass', None)
if password != None:
return password
# 3. read password from file specified in Repository 'remotepassfile'
passfile = self.getconf('remotepassfile', None)
if passfile != None:
fd = open(os.path.expanduser(passfile))
password = fd.readline().strip()
fd.close()
return password
# 4. read password from ~/.netrc
try:
netrcentry = netrc.netrc().authenticators(self.gethost())
except IOError as inst:
if inst.errno != errno.ENOENT:
raise
else:
if netrcentry:
user = self.getconf('remoteuser')
if user == None or user == netrcentry[0]:
return netrcentry[2]
# 5. read password from /etc/netrc
try:
netrcentry = netrc.netrc('/etc/netrc').authenticators(self.gethost())
except IOError as inst:
if inst.errno not in (errno.ENOENT, errno.EACCES):
raise
else:
if netrcentry:
user = self.getconf('remoteuser')
if user == None or user == netrcentry[0]:
return netrcentry[2]
# no strategy yielded a password!
return None
def getfolder(self, foldername):
"""Return instance of OfflineIMAP representative folder."""
return self.getfoldertype()(self.imapserver, foldername, self)
def getfoldertype(self):
return folder.IMAP.IMAPFolder
def connect(self):
imapobj = self.imapserver.acquireconnection()
self.imapserver.releaseconnection(imapobj)
def forgetfolders(self):
self.folders = None
def getfolders(self):
"""Return a list of instances of OfflineIMAP representative folder."""
if self.folders != None:
return self.folders
retval = []
imapobj = self.imapserver.acquireconnection()
# check whether to list all folders, or subscribed only
listfunction = imapobj.list
if self.getconfboolean('subscribedonly', False):
listfunction = imapobj.lsub
try:
listresult = listfunction(directory = self.imapserver.reference)[1]
finally:
self.imapserver.releaseconnection(imapobj)
for s in listresult:
if s == None or \
(isinstance(s, basestring) and s == ''):
# Bug in imaplib: empty strings in results from
# literals. TODO: still relevant?
continue
flags, delim, name = imaputil.imapsplit(s)
flaglist = [x.lower() for x in imaputil.flagsplit(flags)]
if '\\noselect' in flaglist:
continue
foldername = imaputil.dequote(name)
retval.append(self.getfoldertype()(self.imapserver, foldername,
self))
# Add all folderincludes
if len(self.folderincludes):
imapobj = self.imapserver.acquireconnection()
try:
for foldername in self.folderincludes:
try:
imapobj.select(foldername, readonly = True)
except OfflineImapError as e:
# couldn't select this folderinclude, so ignore folder.
if e.severity > OfflineImapError.ERROR.FOLDER:
raise
self.ui.error(e, exc_info()[2],
'Invalid folderinclude:')
continue
retval.append(self.getfoldertype()(
self.imapserver, foldername, self))
finally:
self.imapserver.releaseconnection(imapobj)
if self.foldersort is None:
# default sorting by case insensitive transposed name
retval.sort(key=lambda x: str.lower(x.getvisiblename()))
else:
# do foldersort in a python3-compatible way
# http://bytes.com/topic/python/answers/844614-python-3-sorting-comparison-function
def cmp2key(mycmp):
"""Converts a cmp= function into a key= function
We need to keep cmp functions for backward compatibility"""
class K:
def __init__(self, obj, *args):
self.obj = obj
def __cmp__(self, other):
return mycmp(self.obj.getvisiblename(), other.obj.getvisiblename())
return K
retval.sort(key=cmp2key(self.foldersort))
self.folders = retval
return self.folders
def makefolder(self, foldername):
"""Create a folder on the IMAP server
This will not update the list cached in :meth:`getfolders`. You
will need to invoke :meth:`forgetfolders` to force new caching
when you are done creating folders yourself.
:param foldername: Full path of the folder to be created."""
if self.getreference():
foldername = self.getreference() + self.getsep() + foldername
if not foldername: # Create top level folder as folder separator
foldername = self.getsep()
self.ui.makefolder(self, foldername)
if self.account.dryrun:
return
imapobj = self.imapserver.acquireconnection()
try:
result = imapobj.create(foldername)
if result[0] != 'OK':
raise OfflineImapError("Folder '%s'[%s] could not be created. "
"Server responded: %s" % \
(foldername, self, str(result)),
OfflineImapError.ERROR.FOLDER)
finally:
self.imapserver.releaseconnection(imapobj)
class MappedIMAPRepository(IMAPRepository):
def getfoldertype(self):
return MappedIMAPFolder