#!/usr/bin/env python # # Copyright (C) 2001-2007 Jason R. Mastaler # # This file is part of TMDA. # # TMDA 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. A copy of this license should # be included in the file COPYING. # # TMDA 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 TMDA; if not, write to the Free Software Foundation, Inc., # 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA # Based on code from Python's (undocumented) smtpd module # Copyright (C) 2001,2002 Python Software Foundation. from optparse import OptionGroup, OptionParser import os import signal import socket import sys try: import paths except ImportError: # Prepend /usr/lib/python2.x/site-packages/TMDA/pythonlib sitedir = os.path.join(sys.prefix, 'lib', 'python'+sys.version[:3], 'site-packages', 'TMDA', 'pythonlib') sys.path.insert(0, sitedir) from TMDA import Util from TMDA import Version class Devnull: def write(self, msg): pass def flush(self): pass program = sys.argv[0] FQDN = socket.getfqdn() if FQDN == 'localhost': FQDN = socket.gethostname() if os.getuid() == 0: running_as_root = True else: running_as_root = False remoteauth = { 'proto': None, 'host': 'localhost', 'port': None, 'dn': '', 'enable': 0, } defaultauthports = { 'imap': 143, 'imaps': 993, 'apop': 110, 'pop3': 110, 'ldap': 389, # 'pop3s': 995, } # option parsing opt_desc = \ """An authenticated ofmip proxy for TMDA that allows you to 'tag' your mail client's outgoing mail through SMTP. For more information, including setup and usage instructions, see http://wiki.tmda.net/TmdaOfmipdHowto""" parser = OptionParser(description=opt_desc, version=Version.TMDA) parser.add_option("-V", action="store_true", default=False, dest="full_version", help="show full TMDA version information and exit.") # option groups gengroup = OptionGroup(parser, "General") congroup = OptionGroup(parser, "Connection") authgroup = OptionGroup(parser, "Authentication") virtgroup = OptionGroup(parser, "Virtual Domains") # general gengroup.add_option("-d", "--debug", action="store_true", default=False, dest="debug", help="Turn on debugging prints.") gengroup.add_option("-L", "--log", action="store_true", default=False, dest="log", help= \ """Turn on logging prints. This option logs everything that -d logs, except for the raw SMTP protocol data. Hence, it is useful if you want to leave logging enabled permanently, but don't want your logs bloated with AUTH data and/or the content of large attachments.""") gengroup.add_option("-b", "--background", action="store_false", dest="foreground", help="Detach and run in the background (default).") gengroup.add_option("-f", "--foreground", action="store_true", default=False, dest="foreground", help="Don't detach; run in the foreground.") gengroup.add_option("-u", "--username", dest="username", help= \ """The username that this program should run under. The default is to run as the user who starts the program unless that is root, in which case an attempt to seteuid user 'tofmipd' will be made. Use this option to override these defaults.""") gengroup.add_option("-c", "--configdir", metavar="DIR", dest="configdir", help= \ """DIR is the base directory to search for the authenticated user's TMDA configuration file in. This might be useful if you wish to maintain TMDA files outside the user's home directory. 'username/config' will be appended to form the path; e.g, `-c /var/tmda' will have tmda-ofmipd search for `/var/tmda/bobby/config'. If this option is not used, `~user/.tmda/config' will be assumed, but see the --vhome-script option for qmail virtual domain users.""") # connection congroup.add_option("-p", "--proxyport", default="%s:%s" % (FQDN, 8025), metavar="HOST:PORT", dest="proxyport", help= \ """The HOST:PORT to listen for incoming connections on. The default is FQDN:8025 (i.e, port 8025 on the fully qualified domain name for the local host). Use '0.0.0.0:PORT' to listen on all available interfaces.""") congroup.add_option("-C", "--connections", type="int", default="20", metavar="NUM", dest="connections", help= \ """Do not handle more than NUM simultaneous connections. If there are NUM active connections, defer acceptance of new connections until one finishes. NUM must be a positive integer. Default: 20""") congroup.add_option("-1", "--one-session", action="store_true", default=False, dest="one_session", help= \ """Don't bind to a port and accept new connections; Process a single SMTP session on stdin (used both for input & output). This is useful when started from tcpserver or stunnel.""") congroup.add_option("-P", "--pure-proxy", action="store_true", default=False, dest="pure_proxy", help= \ """Proxy the message straight through to the mail transport system unaltered if the user's TMDA config file is missing. The /usr/sbin/sendmail program on the system is used to inject the message. You can override this by setting $TMDA_SENDMAIL_PROGRAM in the environment. This option might be useful when serving a mixed environment of TMDA and non-TMDA users.""") congroup.add_option("-t", "--throttle-script", metavar="/PATH/TO/SCRIPT", dest="throttlescript", help= \ """Full pathname of a script which can meter how much mail any user sends. The script is passed a login name whenever a user tries to send mail. If the script returns a 0, the message is allowed. For any other value, the message is rejected.""") # authentication authgroup.add_option("-R", "--remoteauth", metavar="PROTO://HOST[:PORT][/DN]", dest="remoteauth", help= \ """Protocol and host to check username and password. PROTO can be one of the following: 'imap' (IMAP4 server), 'imaps' (IMAP4 server over SSL), 'pop3' (POP3 server), 'apop' (POP3 server with APOP authentication), 'ldap' (LDAP server). Optional :PORT defaults to the standard port for the specified protocol (143 for imap, 993 for imaps, 110 for pop3/apop, and 389 for ldap). /DN is mandatory for ldap and should contain a '%%s' identifying the username. Examples: '-R imaps://myimapserver.net', '-R pop3://mypopserver.net:2110', '-R ldap://example.com/cn=%%s,dc=host,dc=com'""") authgroup.add_option("-A", "--authprog", metavar="PROGRAM", dest="authprog", help= \ """A checkpassword compatible command used to check username/password. Examples: '-A "/usr/sbin/checkpassword-pam -s id -- /bin/true"', '-A "/usr/local/vpopmail/bin/vchkpw /usr/bin/true"'. The program must be able to receive the username/password pair on descriptor 3 and in the following format: `username\\0password\\0' Any program claiming to be checkpassword-compatible should be able to do this. If you can tell the program to accept input on another descriptor, such as stdin, don't. It won't work, because TMDA follows the standard (http://cr.yp.to/checkpwd/interface.html) exactly. Also, checkpassword-type programs expect to find the name of another program to run on their command line. For tmda-ofmipd's purpose, /bin/true is perfectly fine. Note the position of the quotes in the Examples, which cause the the whole string following the -A to be passed as a single argument.""") authgroup.add_option("-a", "--authfile", metavar="FILE", dest="authfile", help= \ """Path to the file holding authentication information for this proxy. Default location is /etc/tofmipd if running as root/tofmipd, otherwise ~user/.tmda/tofmipd. Use this option to override these defaults.""") authgroup.add_option("-F", "--fallback", action="store_true", default=False, dest="fallback", help= \ """When used with -R or -A, fallback to authenticate against the authfile if remote authentication fails. Note: this flag has no effect on -R to -A fallback. If you specify both -R and -A methods, then authprog will be tried after remoteauth has failed.""") # virtual domains virtgroup.add_option("-S", "--vhome-script", metavar="/PATH/TO/SCRIPT", dest="vhomescript", help= \ """Full pathname of a script that prints a virtual email user's home directory on standard output. tmda-ofmipd will read that and use it to build the path to the user's config file instead of '~user/.tmda'. The script must take two arguments, the user name and the domain, on its command line. This option is for use only with the VPopMail and VMailMgr add-ons to qmail. See the contrib directory for sample scripts.""") virtgroup.add_option("-v", "--vdomains-path", default="/var/qmail/control/virtualdomains", metavar="/PATH/TO/FILE", dest="vdomainspath", help= \ """Full pathname to qmail's virtualdomains file. The default is /var/qmail/control/virtualdomains. This is also tmda-ofmipd's default, so you normally won't need to set this parameter. If you have installed qmail somewhere other than /var/qmail, you will need to set this so tmda-ofmipd can find the virtualdomains file. NOTE: This is only used when you have a qmail installation with virtual domains using the VMailMgr add-on. It implies that you will also set the '--vhome-script' option above.""") for g in (gengroup, congroup, authgroup, virtgroup): parser.add_option_group(g) (opts, args) = parser.parse_args() if opts.full_version: print Version.ALL sys.exit() if opts.vhomescript and opts.configdir: parser.error("options '--vhome-script' and '--configdir' are incompatible!") if opts.debug or opts.log: DEBUGSTREAM = sys.stderr else: DEBUGSTREAM = Devnull() if opts.remoteauth: # arg is like: imap://host:port autharg = opts.remoteauth try: authproto, autharg = autharg.split('://', 1) except ValueError: authproto, autharg = autharg, None if authproto not in defaultauthports.keys(): raise ValueError, 'Protocol not supported: ' + authproto + \ '\nPlease pick one of ' + repr(defaultauthports.keys()) remoteauth['proto'] = authproto remoteauth['port'] = defaultauthports[authproto] if autharg: try: autharg, dn = autharg.split('/', 1) remoteauth['dn'] = dn except ValueError: dn = '' try: authhost, authport = autharg.split(':', 1) except ValueError: authhost = autharg authport = defaultauthports[authproto] if authhost: remoteauth['host'] = authhost if authport: remoteauth['port'] = authport print >> DEBUGSTREAM, "auth method: %s://%s:%s/%s" % \ (remoteauth['proto'], remoteauth['host'], remoteauth['port'], remoteauth['dn']) remoteauth['enable'] = 1 if running_as_root: if not opts.username: opts.username = 'tofmipd' if not opts.authfile: opts.authfile = '/etc/tofmipd' ipauthmapfile = '/etc/ipauthmap' else: tmda_path = os.path.join(os.path.expanduser('~'), '.tmda') ipauthmapfile = os.path.join(tmda_path, 'ipauthmap') if not opts.authfile: opts.authfile = os.path.join(tmda_path, 'tofmipd') def warning(msg='', exit=1): delimiter = '*' * 70 if msg: msg = Util.wraptext(msg) print >> sys.stderr, '\n', delimiter, '\n', msg, '\n', delimiter, '\n' if exit: sys.exit() # provide disclaimer if running as root if running_as_root: msg = 'WARNING: The security implications and risks of running ' + \ program + ' in "seteuid" mode have not been fully evaluated. ' + \ 'If you are uncomfortable with this, quit now and instead run ' + \ program + ' under your non-privileged TMDA user account.' warning(msg, exit=0) import asynchat import asyncore import base64 import hmac import imaplib import md5 import popen2 import poplib import random import time __version__ = Version.TMDA NEWLINE = '\n' EMPTYSTRING = '' COMMASPACE = ', ' if remoteauth['proto'] == 'ldap': try: import ldap except ImportError: raise ImportError, \ 'python-ldap (http://python-ldap.sf.net/) required.' if remoteauth['dn'] == '': print >> DEBUGSTREAM, "Error: Missing ldap dn\n" raise ValueError try: remoteauth['dn'].index('%s') except: print >> DEBUGSTREAM, "Error: Invalid ldap dn\n" raise ValueError # Utility functions def pipecmd(command, *strings): popen2._cleanup() cmd = popen2.Popen3(command, 1, bufsize=-1) cmdout, cmdin, cmderr = cmd.fromchild, cmd.tochild, cmd.childerr if strings: # Write to the tochild file object. for s in strings: cmdin.write(s) cmdin.flush() cmdin.close() # Read from the childerr object; command will block until exit. err = cmderr.read().strip() cmderr.close() # Read from the fromchild object. out = cmdout.read().strip() cmdout.close() # Get exit status from the wait() member function. return cmd.wait() def run_authprog(username, password): """authprog should return 0 for auth ok, and a positive integer in case of a problem.""" print >> DEBUGSTREAM, "Trying authprog method" cmd = "/bin/sh -c 'exec %s 3<&0'" % (opts.authprog,) return pipecmd(cmd, '%s\0%s\0' % (username, password)) def run_remoteauth(username, password, localip): """Authenticate username/password combination against a remote resource. Return 1 upon successful authentication, and 0 otherwise.""" authhost = remoteauth['host'] authport = remoteauth['port'] if authhost == '0.0.0.0': ipauthmap = ipauthmap2dict(ipauthmapfile) if len(ipauthmap) == 0: authhost = localip else: authdata = ipauthmap.get(localip, '127.0.0.1').split(':') authhost = authdata[0] if len(authdata) > 1: authport = authdata[1] else: authport = remoteauth['port'] print >> DEBUGSTREAM, "trying %s authentication for %s@%s:%s" % \ (remoteauth['proto'], username, authhost, authport) if remoteauth['proto'] == 'imap': M = imaplib.IMAP4(authhost, int(authport)) try: M.login(username, password) M.logout() return 1 except: print >> DEBUGSTREAM, "imap authentication for %s@%s failed" % \ (username, authhost) return 0 elif remoteauth['proto'] == 'imaps': M = imaplib.IMAP4_SSL(authhost, int(authport)) try: M.login(username, password) M.logout() return 1 except: print >> DEBUGSTREAM, "imaps authentication for %s@%s failed" % \ (username, authhost) return 0 elif remoteauth['proto'] in ('pop3', 'apop'): M = poplib.POP3(authhost, int(authport)) try: if remoteauth['proto'] == 'pop3': M.user(username) M.pass_(password) M.quit() return 1 else: M.apop(username, password) M.quit() return 1 except: print >> DEBUGSTREAM, "%s authentication for %s@%s failed" % \ (remoteauth['proto'], username, authhost) return 0 elif remoteauth['proto'] == 'ldap': import ldap try: M = ldap.initialize("ldap://%s:%s" % (authhost, authport)) M.simple_bind_s(remoteauth['dn'] % username, password) M.unbind_s() return 1 except: print >> DEBUGSTREAM, "ldap authentication for %s@%s failed" % \ (username, authhost) return 0 # proto not implemented print >> DEBUGSTREAM, "Error: protocol %s not implemented" % \ remoteauth['proto'] return 0 def authfile2dict(authfile): """Iterate over a tmda-ofmipd authentication file, and return a dictionary containing username:password pairs. Username is returned in lowercase.""" authdict = {} fp = file(authfile, 'r') for line in fp: line = line.strip() if line == '': continue else: fields = line.split(':', 1) authdict[fields[0].lower().strip()] = fields[1].strip() fp.close() return authdict def ipauthmap2dict(ipauthmapfile): """Iterate 'ipauthmapfile' (IP1:IP2:port) and return a dictionary containing IP1 -> IP2:port hashes.""" ipauthmap = {} try: fp = file(ipauthmapfile, 'r') for line in fp: line = line.strip() if line == '': continue ipdata = line.split(':', 1) ipauthmap[ipdata[0].strip()] = ipdata[1].strip() fp.close() except IOError: pass return ipauthmap def b64_encode(s): """base64 encoding without the trailing newline.""" return base64.encodestring(s)[:-1] def b64_decode(s): """base64 decoding.""" return base64.decodestring(s) # Classes class SMTPChannel(asynchat.async_chat): COMMAND = 0 DATA = 1 AUTH = 2 def __init__(self, server, conn): asynchat.async_chat.__init__(self, conn) # SMTP AUTH self.__smtpauth = 0 self.__auth_resp1 = None self.__auth_resp2 = None self.__auth_username = None self.__auth_password = None self.__auth_sasl = None self.__sasl_types = ['login', 'cram-md5', 'plain'] # Remove CRAM-MD5 from the published SASL types if using the # `--authprog' or `--remoteauth' options. See FAQ 5.8. if remoteauth['enable'] or opts.authprog: self.__sasl_types.remove('cram-md5') self.__auth_cram_md5_ticket = '<%s.%s@%s>' % (random.randrange(10000), int(time.time()), FQDN) self.__server = server self.__conn = conn self.__line = [] self.__state = self.COMMAND #self.__greeting = 0 self.__mailfrom = None self.__rcpttos = [] self.__data = '' self.__fqdn = FQDN # If we're running under tcpserver, then it sets up a bunch of # environment variables that give socket address information. # We always use this, rather than e.g. calling getsockname on # conn, because the tcpserver socket might not be passed directly # to tmda-ofmipd. For example, stunnel might terminate the socket, # decrypt the data and send it here over a pipe... # Note: Whilst tcpserver does provide these variables, the # xinetd/stunnel combination does not. if opts.one_session and os.environ.has_key('TCPREMOTEIP'): self.__peerip = os.environ['TCPREMOTEIP'] self.__peername = os.environ.get('TCPREMOTEHOST', None) if not self.__peername: self.__peername = socket.getfqdn(self.__peerip) self.__peerport = os.environ['TCPREMOTEPORT'] self.__peer = (self.__peerip, self.__peerport) self._localip = os.environ['TCPLOCALIP'] self._localname = os.environ.get('TCPLOCALHOST', None) if not self._localname: self._localname = socket.getfqdn(self._localip) self._localport = os.environ['TCPLOCALPORT'] self._local = (self._localip, self._localport) else: # xinetd (or stunnel?) does at least provide REMOTE_HOST. if opts.one_session and os.environ.has_key('REMOTE_HOST'): self.__peerip = os.environ['REMOTE_HOST'] self.__peerport = '' self.__peer = (self.__peerip, self.__peerport) else: self.__peer = conn.getpeername() self.__peerip = self.__peer[0] self.__peerport = self.__peer[1] self.__peername = socket.getfqdn(self.__peerip) self._local = conn.getsockname() self._localip = self._local[0] self._localname = socket.getfqdn(self._localip) self._localport = self._local[1] print >> DEBUGSTREAM, 'Incoming connection from:', repr(self.__peer) print >> DEBUGSTREAM, 'Incoming connection to:', repr(self._local) self.push('220 %s ESMTP tmda-ofmipd' % (self.__fqdn)) self.set_terminator('\r\n') # Overrides base class for convenience def push(self, msg): asynchat.async_chat.push(self, msg + '\r\n') # Implementation of base class abstract method def collect_incoming_data(self, data): self.__line.append(data) def verify_login(self, b64username, b64password): """The LOGIN SMTP authentication method is an undocumented, unstandardized Microsoft invention. Needed to support MS Outlook clients.""" try: username = b64_decode(b64username) password = b64_decode(b64password) except: return 501 self.__auth_username = username.lower() self.__auth_password = password os.environ['TCPLOCALIP'] = self._localip if remoteauth['enable']: # Try first with the remote auth if run_remoteauth(username, password, self._localip): return 1 if opts.authprog: # Then with the authprog if run_authprog(username, password) == 0: return 1 # Now can we fall back on the authfile if (not opts.fallback) and (remoteauth['enable'] or opts.authprog): return 0 authdict = authfile2dict(opts.authfile) if authdict.get(username.lower(), 0) <> password: return 0 else: return 1 def verify_plain(self, response): """PLAIN is described in RFC 2595.""" try: response = b64_decode(response) except: return 501 try: username, username, password = response.split('\0') except ValueError: return 0 self.__auth_username = username.lower() self.__auth_password = password os.environ['TCPLOCALIP'] = self._localip if remoteauth['enable']: # Try first with the remote auth if run_remoteauth(username, password, self._localip): return 1 if opts.authprog: # Then with the authprog if run_authprog(username, password) == 0: return 1 # Now can we fall back on the authfile if (not opts.fallback) and (remoteauth['enable'] or opts.authprog): return 0 authdict = authfile2dict(opts.authfile) if authdict.get(username.lower(), 0) <> password: return 0 else: return 1 def verify_cram_md5(self, response, ticket): """CRAM-MD5 is described in RFC 2195.""" try: response = b64_decode(response) except: return 501 try: username, hexdigest = response.split() except ValueError: return 0 authdict = authfile2dict(opts.authfile) password = authdict.get(username.lower(), 0) self.__auth_username = username.lower() self.__auth_password = password if password == 0: return 0 newhexdigest = hmac.HMAC(password, ticket, digestmod=md5).hexdigest() if newhexdigest <> hexdigest: return 0 else: return 1 def auth_reset_state(self): """As per RFC 2554, the SMTP state is reset if the AUTH fails, and once it succeeds.""" self.__auth_sasl = None self.__auth_resp1 = None self.__auth_resp2 = None self.__state = self.COMMAND def auth_notify_required(self): """Send a 530 reply. RFC 2554 says this response may be returned by any command other than AUTH, EHLO, HELO, NOOP, RSET, or QUIT. It indicates that server policy requires authentication in order to perform the requested action.""" self.push('530 Error: Authentication required') def auth_notify_fail(self, failcode=0): if failcode == 501: # base64 decoding failed self.push('501 malformed AUTH input') else: self.push('535 AUTH failed') print >> DEBUGSTREAM, 'Auth: ', 'failed for user', \ "'%s'" % self.__auth_username self.__smtpauth = 0 def auth_notify_succeed(self): self.push('235 AUTH successful') print >> DEBUGSTREAM, 'Auth: ', 'succeeded for user', \ "'%s'" % self.__auth_username os.environ['LOGIN'] = self.__auth_username self.__smtpauth = 1 def auth_verify(self, sasl=None): if sasl is None: sasl = self.__auth_sasl verify = 0 if sasl == 'plain': verify = self.verify_plain(self.__auth_resp1) elif sasl == 'cram-md5': verify = self.verify_cram_md5(self.__auth_resp1, self.__auth_cram_md5_ticket) elif sasl == 'login': verify = self.verify_login(self.__auth_resp1, self.__auth_resp2) if verify == 1: self.auth_notify_succeed() else: self.auth_notify_fail(verify) self.auth_reset_state() def auth_challenge(self): line = EMPTYSTRING.join(self.__line) if not self.__auth_resp1: # No initial response, issue first server challenge if self.__auth_sasl == 'plain': self.push('334 ') elif self.__auth_sasl == 'cram-md5': self.push('334 ' + b64_encode(self.__auth_cram_md5_ticket)) elif self.__auth_sasl == 'login': self.push('334 VXNlcm5hbWU6') return if self.__auth_resp1 and not self.__auth_resp2: # Client sent an initial response if self.__auth_sasl == 'plain': # Perform authentication self.auth_verify() elif self.__auth_sasl == 'cram-md5': # Perform authentication self.auth_verify() elif self.__auth_sasl == 'login': # Issue second server challenge self.push('334 UGFzc3dvcmQ6') return if self.__auth_resp1 and self.__auth_resp2: # Client sent a second response (only if AUTH=LOGIN), # perform authentication self.auth_verify() return # Implementation of base class abstract method def found_terminator(self): line = EMPTYSTRING.join(self.__line) if opts.debug: print >> DEBUGSTREAM, 'Data:', repr(line) self.__line = [] if self.__state == self.COMMAND: if not line: self.push('500 Error: bad syntax') return method = None i = line.find(' ') if i < 0: command = line.upper() arg = None else: command = line[:i].upper() arg = line[i+1:].strip() method = getattr(self, 'smtp_' + command, None) if not method: self.push('502 Error: command "%s" not implemented' % command) return method(arg) return elif self.__state == self.DATA: # Remove extraneous carriage returns and de-transparency according # to RFC 2821, Section 4.5.2. data = [] for text in line.split('\r\n'): if text and text[0] == '.': data.append(text[1:]) else: data.append(text) self.__data = NEWLINE.join(data) if not opts.throttlescript or not os.system("%s %s" % (opts.throttlescript, self.__auth_username)): try: status = self.__server.process_message(self.__peer, self.__mailfrom, self.__rcpttos, self.__data, self.__auth_username) except: print >>DEBUGSTREAM, "process_message raised an exception:" import traceback traceback.print_exc(DEBUGSTREAM) raise else: status = self.push('450 Outgoing mail quota exceeded') self.__rcpttos = [] self.__mailfrom = None self.__state = self.COMMAND self.set_terminator('\r\n') if not status: self.push('250 Ok') else: self.push(status) elif self.__state == self.AUTH: if line == '*': # client canceled the authentication attempt self.push('501 AUTH exchange cancelled') self.auth_reset_state() return if not self.__auth_resp1: self.__auth_resp1 = line else: self.__auth_resp2 = line self.auth_challenge() else: self.push('451 Internal confusion') return # ESMTP/SMTP commands def smtp_EHLO(self, arg): if not arg: self.push('501 Syntax: EHLO hostname') return #self.__greeting = arg self.push('250-%s' % self.__fqdn) self.push('250 AUTH %s' % (' '.join(map(lambda s: s.upper(), self.__sasl_types)))) # Put a Received header string in the environment for tmda-inject # to add later. rh = [] rh.append('from %s' % (arg)) if ((arg.lower() <> self.__peername.lower()) and (self.__peername.lower() <> self.__peerip)): rh.append('(%s [%s])' % (self.__peername, self.__peerip)) else: rh.append('(%s)' % (self.__peerip)) rh.append('by %s (tmda-ofmipd) with ESMTP;' % (self.__fqdn)) rh.append(Util.make_date()) os.environ['TMDA_OFMIPD_RECEIVED'] = ' '.join(rh) def smtp_NOOP(self, arg): if arg: self.push('501 Syntax: NOOP') else: self.push('250 Ok') def smtp_QUIT(self, arg): # args is ignored self.push('221 Bye') self.close_when_done() # factored def __getaddr(self, keyword, arg): address = None keylen = len(keyword) if arg[:keylen].upper() == keyword: address = arg[keylen:].strip() if not address: pass elif address[0] == '<' and address[-1] == '>' and address <> '<>': # Addresses can be in the form but watch out # for null address, e.g. <> address = address[1:-1] return address def smtp_MAIL(self, arg): # Authentication required first if not self.__smtpauth: self.auth_notify_required() return print >> DEBUGSTREAM, '===> MAIL', arg address = self.__getaddr('FROM:', arg) if not address: self.push('501 Syntax: MAIL FROM:
') return if self.__mailfrom: self.push('503 Error: nested MAIL command') return self.__mailfrom = address print >> DEBUGSTREAM, 'sender:', self.__mailfrom self.push('250 Ok') def smtp_RCPT(self, arg): print >> DEBUGSTREAM, '===> RCPT', arg if not self.__mailfrom: self.push('503 Error: need MAIL command') return address = self.__getaddr('TO:', arg) if not address: self.push('501 Syntax: RCPT TO:
') return self.__rcpttos.append(address) print >> DEBUGSTREAM, 'recips:', self.__rcpttos self.push('250 Ok') def smtp_RSET(self, arg): if arg: self.push('501 Syntax: RSET') return # Resets the sender, recipients, and data, but not the greeting self.__mailfrom = None self.__rcpttos = [] self.__data = '' self.__state = self.COMMAND self.push('250 Ok') def smtp_DATA(self, arg): if not self.__rcpttos: self.push('503 Error: need RCPT command') return if arg: self.push('501 Syntax: DATA') return self.__state = self.DATA self.set_terminator('\r\n.\r\n') self.push('354 End data with .') def smtp_AUTH(self, arg): """RFC 2554 - SMTP Service Extension for Authentication""" if self.__smtpauth: # After an successful AUTH, no more AUTH commands may be # issued in the same session. self.push('503 Duplicate AUTH') return if arg: args = arg.split() if len(args) == 2: self.__auth_sasl = args[0] self.__auth_resp1 = args[1] else: self.__auth_sasl = args[0] if self.__auth_sasl: self.__auth_sasl = self.__auth_sasl.lower() if not arg or self.__auth_sasl not in self.__sasl_types: self.push('504 AUTH type unimplemented') return self.__state = self.AUTH self.auth_challenge() class MessageProcessor: """Base 'pure' SMTP message processing class. Raises NotImplementedError if you try to use it.""" # API for "doing something useful with the message" def process_message(self, peer, mailfrom, rcpttos, data): """Override this abstract method to handle messages from the client. peer is a tuple containing (ipaddr, port) of the client that made the socket connection to our smtp port. mailfrom is the raw address the client claims the message is coming from. rcpttos is a list of raw addresses the client wishes to deliver the message to. data is a string containing the entire full text of the message, headers (if supplied) and all. It has been `de-transparencied' according to RFC 821, Section 4.5.2. In other words, a line containing a `.' followed by other text has had the leading dot removed. This function should return None, for a normal `250 Ok' response; otherwise it returns the desired response string in RFC 821 format. """ raise NotImplementedError class DebuggingMessageProcessor(MessageProcessor): """Simply prints each message it receives on stdout.""" # Do something with the gathered message def process_message(self, peer, mailfrom, rcpttos, data): inheaders = 1 lines = data.split('\n') print '---------- MESSAGE FOLLOWS ----------' for line in lines: # headers first if inheaders and not line: print 'X-Peer:', peer[0] inheaders = 0 print line print '------------ END MESSAGE ------------' class SMTPServer(asyncore.dispatcher, MessageProcessor): """Run an SMTP server daemon - accept new socket connections and process SMTP sessions on each conneciton.""" def __init__(self, localaddr, remoteaddr): self._localaddr = localaddr self._remoteaddr = remoteaddr asyncore.dispatcher.__init__(self) self.create_socket(socket.AF_INET, socket.SOCK_STREAM) # try to re-use a server port if possible self.set_reuse_addr() self.bind(localaddr) self.listen(5) print >> DEBUGSTREAM, \ 'tmda-ofmipd started at %s\n\tListening on %s' % \ (Util.make_date(), opts.proxyport) def readable(self): if len(asyncore.socket_map) > opts.connections: # too many simultaneous connections return 0 else: return 1 def handle_accept(self): conn = self.accept()[0] self._channel = SMTPChannel(self, conn) class SMTPProcessor(asyncore.dispatcher, MessageProcessor): """Run a single SMTP session, on the stdin file descriptor.""" def __init__(self): asyncore.dispatcher.__init__(self) conn = socket.fromfd(0, socket.AF_INET, socket.SOCK_STREAM) self._channel = SMTPChannel(self, conn) class PureProxy(MessageProcessor): """Proxies all messages to a real smtpd which does final delivery. Used solely as a base class.""" def process_message(self, peer, mailfrom, rcpttos, data): lines = data.split('\n') # Look for the last header i = 0 for line in lines: if not line: break i += 1 lines.insert(i, 'X-Peer: %s' % peer[0]) data = NEWLINE.join(lines) refused = self._deliver(mailfrom, rcpttos, data) # TBD: what to do with refused addresses? print >> DEBUGSTREAM, 'we got some refusals:', refused def _deliver(self, mailfrom, rcpttos, data): import smtplib refused = {} try: s = smtplib.SMTP() s.connect(self._remoteaddr[0], self._remoteaddr[1]) try: refused = s.sendmail(mailfrom, rcpttos, data) finally: s.quit() except smtplib.SMTPRecipientsRefused, e: print >> DEBUGSTREAM, 'got SMTPRecipientsRefused' refused = e.recipients except (socket.error, smtplib.SMTPException), e: print >> DEBUGSTREAM, 'got', e.__class__ # All recipients were refused. If the exception had an associated # error code, use it. Otherwise,fake it with a non-triggering # exception code. errcode = getattr(e, 'smtp_code', -1) errmsg = getattr(e, 'smtp_error', 'ignore') for r in rcpttos: refused[r] = (errcode, errmsg) return refused class VDomainProxy(PureProxy): """This proxy is used only for virtual domain support in a qmail + (VPopMail or VMailMgr) environment. It needs to behave differently from the standard TMDA proxy in that authenticated users are not system (/etc/passwd) users.""" def process_message(self, peer, mailfrom, rcpttos, data, auth_username): # Set the TCPLOCALIP environment variable to support VPopMail's reverse # IP domain mapping. os.environ['TCPLOCALIP'] = self._channel._localip # Set up partial tmda-inject command line. execdir = os.path.dirname(os.path.abspath(program)) inject_cmd = [os.path.join(execdir, 'tmda-inject')] + rcpttos userinfo = auth_username.split('@', 1) user = userinfo[0] if len(userinfo) > 1: domain = userinfo[1] else: domain = '' # If running as uid 0, fork in preparation for running the tmda-inject # process and change UID and GID to the virtual domain user. This is # for VMailMgr, where each virtual domain is a system (/etc/passwd) # user. if running_as_root: pid = os.fork() if pid <> 0: rpid, status = os.wait() # Did tmda-inject succeed? if status <> 0: raise IOError, 'tmda-inject failed!' return else: # The 'prepend' is the system user in charge of this virtual # domain. prepend = Util.getvdomainprepend(auth_username, opts.vdomainspath) if not prepend: err = 'Error: "%s" is not a virtual domain' % (domain,) print >> DEBUGSTREAM, err os._exit(-1) os.seteuid(0) os.setgid(Util.getgid(prepend)) os.setgroups(Util.getgrouplist(prepend)) os.setuid(Util.getuid(prepend)) # For VMailMgr's utilities. os.environ['HOME'] = Util.gethomedir(prepend) # From here on, we're either in the child (pid == 0) or we're not # running as root, so we haven't forked. vhomedir = Util.getvuserhomedir(user, domain, opts.vhomescript) print >> DEBUGSTREAM, 'vuser homedir: "%s"' % (vhomedir,) # This is so "~" will work in the .tmda/* files. os.environ['HOME'] = vhomedir # change inject_cmd to pass the message through if # --pure-proxy was specified and the .tmda/config file is # missing. if opts.pure_proxy and not os.path.exists(os.path.join (vhomedir, '.tmda', 'config')): sendmail_program = os.environ.get('TMDA_SENDMAIL_PROGRAM') \ or '/usr/sbin/sendmail' inject_cmd = [sendmail_program, '-f', mailfrom, '-i', '--'] + rcpttos try: Util.pipecmd(inject_cmd, data) except Exception, err: print >> DEBUGSTREAM, 'Error:', err if running_as_root: os._exit(-1) if running_as_root: # Should never get here! os._exit(0) class TMDAProxy(PureProxy): """Using this server for outgoing smtpd, the authenticated user will have his mail tagged using his TMDA config file.""" def process_message(self, peer, mailfrom, rcpttos, data, auth_username): if opts.configdir is None: # ~user/.tmda/ tmda_configdir = os.path.join(os.path.expanduser ('~' + auth_username), '.tmda') else: tmda_configdir = os.path.join(os.path.expanduser (opts.configdir), auth_username) tmda_configfile = os.path.join(tmda_configdir, 'config') if opts.pure_proxy and not os.path.exists(tmda_configfile): sendmail_program = os.environ.get('TMDA_SENDMAIL_PROGRAM') \ or '/usr/sbin/sendmail' inject_cmd = [sendmail_program, '-f', mailfrom, '-i', '--'] + rcpttos else: execdir = os.path.dirname(os.path.abspath(program)) inject_path = os.path.join(execdir, 'tmda-inject') inject_cmd = [inject_path, '-c', tmda_configfile] + rcpttos # This is so "~" will always work in the .tmda/* files. os.environ['HOME'] = Util.gethomedir(auth_username) # If running as uid 0, fork the tmda-inject process, and # then change UID and GID to the authenticated user. if running_as_root: pid = os.fork() if pid == 0: os.seteuid(0) os.setgid(Util.getgid(auth_username)) os.setgroups(Util.getgrouplist(auth_username)) os.setuid(Util.getuid(auth_username)) try: Util.pipecmd(inject_cmd, data) except Exception, err: print >> DEBUGSTREAM, 'Error:', err os._exit(-1) os._exit(0) else: rpid, status = os.wait() # Did tmda-inject succeed? if status <> 0: raise IOError, 'tmda-inject failed!' else: # no need to fork Util.pipecmd(inject_cmd, data) class VDomainProxyServer(VDomainProxy, SMTPServer): """A proxy server class that binds to the server port, accepts new connections, and processes them as necessary for a qmail virtual user environment. All implementation is inherited from superclasses.""" pass class VDomainProxyProcessor(VDomainProxy, SMTPProcessor): """A proxy server class that handles an SMTP session on a previously created socket, and performs processing as necessary for a qmail virtual user environment. All implementation is inherited from superclasses.""" pass class TMDAProxyServer(TMDAProxy, SMTPServer): """A proxy server class that binds to the server port, accepts new connections, and processes them as necessary for a system user environment. All implementation is inherited from superclasses.""" pass class TMDAProxyProcessor(TMDAProxy, SMTPProcessor): """A proxy server class that handles an SMTP session on a previously created socket, and performs processing as necessary for a system user environment. All implementation is inherited from superclasses.""" pass def main(): # check permissions of authfile if using only remote # authentication. if not (remoteauth['enable'] or opts.authprog) or opts.fallback: authfile_mode = Util.getfilemode(opts.authfile) if authfile_mode not in (400, 600): raise IOError, \ opts.authfile + ' must be chmod 400 or 600!' # try binding to the specified host:port host, port = opts.proxyport.split(':', 1) if opts.vhomescript: if opts.one_session: proxy = VDomainProxyProcessor() else: proxy = VDomainProxyServer((host, int(port)), ('localhost', 25)) else: if opts.one_session: proxy = TMDAProxyProcessor() else: proxy = TMDAProxyServer((host, int(port)), ('localhost', 25)) if running_as_root: pw_uid = Util.getuid(opts.username) # check ownership of authfile if using only remote # authentication. if not (remoteauth['enable'] or opts.authprog) or opts.fallback: if Util.getfileuid(opts.authfile) <> pw_uid: raise IOError, \ opts.authfile + ' must be owned by UID ' + str(pw_uid) # try setegid() os.setegid(Util.getgid(opts.username)) # try setting the supplemental group ids os.setgroups(Util.getgrouplist(opts.username)) # try seteuid() os.seteuid(pw_uid) if not (opts.foreground or opts.one_session): signal.signal(signal.SIGHUP, signal.SIG_IGN) # ignore SIGHUP if os.fork() <> 0: sys.exit() # Start the event loop try: asyncore.loop() except KeyboardInterrupt: pass # This is the end my friend. if __name__ == '__main__': main()