Scott Kitterman
116 lines
3.6 KiB
Python
116 lines
3.6 KiB
Python
# drop_priviledges (from https://github.com/nigelb/Static-UPnP)
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# Copyright (C) 2016 NigelB
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# Copyright (C) 2018 Scott Kitterman
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License along
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# with this program; if not, write to the Free Software Foundation, Inc.,
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# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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def drop_privileges(milterconfig):
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import os
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import grp
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import pwd
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import syslog
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if os.getuid() != 0:
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if milterconfig.get('Syslog'):
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syslog.syslog('drop_privileges: Not running as root. Cannot drop permissions.')
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return
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# Figure out if user and group are specified
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userstr = milterconfig.get('UserID')
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userlist = userstr.split(':')
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if len(userlist) == 1:
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gidname = userlist[0]
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else:
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gidname = userlist[1]
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uidname = userlist[0]
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# Get the uid/gid from the name
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running_uid = pwd.getpwnam(uidname).pw_uid
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running_gid = grp.getgrnam(gidname).gr_gid
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# Remove group privileges
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os.setgroups([])
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# Try setting the new uid/gid
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os.setgid(running_gid)
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os.setuid(running_uid)
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# Set umask
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old_umask = os.umask(milterconfig.get('UMask'))
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#################
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class ExceptHook:
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def __init__(self, useSyslog = 1, useStderr = 0):
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self.useSyslog = useSyslog
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self.useStderr = useStderr
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def __call__(self, etype, evalue, etb):
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import traceback
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import sys
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tb = traceback.format_exception(*(etype, evalue, etb))
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for line in tb:
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if self.useSyslog:
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import syslog
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syslog.syslog(line)
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if self.useStderr:
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sys.stderr.write(line)
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####################
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def setExceptHook():
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import sys
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sys.excepthook = ExceptHook(useSyslog = 1, useStderr = 1)
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####################
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def write_pid(milterconfig):
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"""Write PID in pidfile. Will not overwrite an existing file."""
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import os
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import syslog
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if not os.path.isfile(milterconfig.get('PidFile')):
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pid = str(os.getpid())
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try:
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f = open(milterconfig.get('PidFile'), 'w')
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except IOError as e:
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if milterconfig.get('Syslog'):
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syslog.syslog('Unable to write pidfle {0}. IOError: {1}'.format(milterconfig.get('PidFile'), e))
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raise
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f.write(pid)
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f.close()
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else:
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if milterconfig.get('Syslog'):
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syslog.syslog('Unable to write pidfle {0}. File exists.'.format(milterconfig.get('PidFile')))
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raise RuntimeError('Unable to write pidfle {0}. File exists.'.format(milterconfig.get('PidFile')))
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####################
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def read_keyfile(milterconfig, keytype):
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"""Read private key from file."""
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import syslog
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if keytype == "RSA":
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keyfile = milterconfig.get('KeyFile')
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if keytype == "Ed25519":
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keyfile = milterconfig.get('KeyFileEd25519')
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try:
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f = open(keyfile, 'r')
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keylist = f.readlines()
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except IOError as e:
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if milterconfig.get('Syslog'):
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syslog.syslog('Unable to read keyfile {0}. IOError: {1}'.format(keyfile, e))
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raise
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f.close()
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key = ''
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for line in keylist:
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key += line
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return key
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