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Author SHA1 Message Date
cvs2svn 65c73f61c2 This commit was manufactured by cvs2svn to create tag 'milter-0_8_3'.
Sprout from master 2005-10-12 17:21:13 UTC Stuart Gathman <stuart@gathman.org> 'Release 0.8.3'
Cherrypick from bmsi 2005-05-31 18:23:49 UTC Stuart Gathman <stuart@gathman.org> 'Development changes since 0.7.2':
    README
    cid2spf.py
    milter.rc
    milter.rc7
    rejects.py
    rhsbl.m4
    sample.py
    test.py
    test/amazon
    test/big5
    test/bounce
    test/bounce1
    test/bound
    test/honey
    test/missingboundary
    test/samp1
    test/spam44
    test/spam7
    test/spam8
    test/test1
    test/test8
    test/virus1
    test/virus13
    test/virus2
    test/virus3
    test/virus4
    test/virus5
    test/virus6
    test/virus7
    testsample.py
2005-10-12 17:21:14 +00:00
Stuart Gathman a50194d07f Release 0.8.3 2005-10-12 17:21:13 +00:00
Stuart Gathman 1cf272ceb0 Release 0.8.3 2005-10-12 16:45:58 +00:00
Stuart Gathman d2dc09f979 Release 0.8.3 2005-10-12 16:43:14 +00:00
Stuart Gathman ea82d6d608 Release 0.8.3 2005-10-12 16:36:30 +00:00
Stuart Gathman ace3e13685 Always check HELO except for SPF pass, temperror. 2005-10-11 22:50:07 +00:00
Stuart Gathman 78ea2e2263 Use logging module to make logging threadsafe (avoid splitting log lines) 2005-10-10 23:50:20 +00:00
Stuart Gathman d34efa39bb Configure SPF policy via sendmail access file. 2005-10-10 20:15:33 +00:00
Stuart Gathman 36b5b4e6d4 Milter.py moved to Milter subpackage. 2005-10-07 03:25:24 +00:00
Stuart Gathman 04874d6e35 Banned users option. Experimental feature to supply Sender when
missing and MFROM domain doesn't match From.  Log cipher bits for
SMTP AUTH.  Sketch access file feature.
2005-10-07 03:23:40 +00:00
Stuart Gathman 073f87dcc7 Handle perverse MFROM quoting. 2005-09-08 03:55:09 +00:00
Stuart Gathman 7ab5ddf053 Getting ready for 0.8.3 2005-08-18 04:19:26 +00:00
Stuart Gathman d6ef1a4007 Don't innoculate with SCREENED mail. 2005-08-18 03:36:54 +00:00
Stuart Gathman 2a4ab4e87c Send DSN before adding message to quarantine. 2005-08-17 19:35:28 +00:00
Stuart Gathman 241717b0e2 quarantine template 2005-08-16 22:46:33 +00:00
Stuart Gathman bd8fabae0f Example of wiretap with multiple destinations. 2005-08-16 22:46:10 +00:00
Stuart Gathman d119af1a3e Trean non-existant include as no match in "lax" mode. 2005-08-12 17:36:51 +00:00
Stuart Gathman f1f082fe8a Consider SMTP AUTH connections internal. 2005-08-11 22:17:59 +00:00
Stuart Gathman b0286bff22 Treat fail like softfail for selected (braindead) domains.
Treat mail according to extended processing results, but
report any PermError that would officially result via DSN.
2005-08-04 21:21:33 +00:00
Stuart Gathman a9663a23d7 Keep screened honeypot mail, but optionally discard honeypot only mail. 2005-08-02 18:04:36 +00:00
Stuart Gathman 8df5cd026e Limit CNAME chains independently of DNS lookup limit 2005-07-22 16:00:23 +00:00
Stuart Gathman 0cbfc0d249 Limit CNAME lookups. 2005-07-21 17:59:46 +00:00
Stuart Gathman 46ad2794f1 Handle corrupt ZIP attachments 2005-07-20 14:56:38 +00:00
Stuart Gathman 8fef702522 Handle corrupt and empty ZIP files. 2005-07-20 14:49:45 +00:00
Stuart Gathman 62b33bd964 Check pydspam version for honeypot, include latest pyspf changes. 2005-07-20 03:30:04 +00:00
Stuart Gathman ffcadf6c01 Remove debug print 2005-07-18 14:36:23 +00:00
Stuart Gathman 9f7d52118a Release 0.8.2 2005-07-17 01:33:13 +00:00
Stuart Gathman 95b24f7663 Log as well as use extended result for best guess. 2005-07-17 01:25:44 +00:00
Stuart Gathman db0f1095e5 Release 0.8.2 2005-07-15 22:24:10 +00:00
Stuart Gathman f749b6f2cd Support callback exception policy 2005-07-15 22:18:17 +00:00
Stuart Gathman 23485978fc Latest pyspf updates 2005-07-15 22:17:41 +00:00
Stuart Gathman e1f4744a22 Use extended results processing for best_guess. 2005-07-15 20:25:36 +00:00
Stuart Gathman ef413913d0 Allow extended processing for MX count. 2005-07-15 20:00:35 +00:00
Stuart Gathman 8ad4b16156 Import bug fixes from pyspf module. CID xml support removed. 2005-07-14 03:47:40 +00:00
Stuart Gathman b28a56ea37 Make SES package optional. Initial honeypot support. 2005-07-14 03:23:33 +00:00
Stuart Gathman e3b18d61c9 Initial SES integration. 2005-07-06 04:05:40 +00:00
Stuart Gathman 5335e18925 Questions from email answered. 2005-07-04 21:06:31 +00:00
Stuart Gathman e2f1587832 Don't match hostnames for internal connects. 2005-07-02 23:27:31 +00:00
Stuart Gathman febf56b031 Always log trusted Received and Received-SPF headers. 2005-07-01 16:30:24 +00:00
Stuart Gathman e9f6773096 Report context allocation error. 2005-06-24 04:20:07 +00:00
Stuart Gathman 2276762c52 Remove unused name argument to generic wrappers. 2005-06-24 04:12:43 +00:00
Stuart Gathman a142fefb19 Handle close called before connect. 2005-06-24 03:57:35 +00:00
Stuart Gathman 900b7ef3fb Setreply for rejectvirus. 2005-06-20 22:35:35 +00:00
Stuart Gathman d07e536f44 Release 0.8.1 2005-06-17 02:23:34 +00:00
Stuart Gathman 2d291d35f6 Release 0.8.1 2005-06-17 02:07:20 +00:00
Stuart Gathman a94f82d8f3 Handle zip within zip. 2005-06-17 01:49:39 +00:00
Stuart Gathman 124747c309 Update faq. 2005-06-17 00:46:29 +00:00
Stuart Gathman 4c659c7f87 Acknowlege that current env callback protocol is entrenched. 2005-06-17 00:45:10 +00:00
Stuart Gathman 3e47952438 Change more info page back to spf.pobox.com which is now maintained. 2005-06-17 00:38:39 +00:00
Stuart Gathman a01c5d31f1 Ignore HeaderParseError decoding header 2005-06-16 18:35:51 +00:00
Stuart Gathman 493741c81e Return consistent tuple on error. 2005-06-15 19:45:47 +00:00
Stuart Gathman 9a969e8f60 Release 0.8.0 2005-06-14 22:02:46 +00:00
Stuart Gathman 3d7003a638 Web site updates. 2005-06-14 22:02:09 +00:00
Stuart Gathman f643cafc04 Check internal_domains for outgoing mail. 2005-06-14 21:55:30 +00:00
Stuart Gathman 09582a2e86 fix pychecker nits 2005-06-14 20:31:26 +00:00
Stuart Gathman 7eb2fb09ef Properly log exceptions from pydspam 2005-06-06 18:24:59 +00:00
Stuart Gathman 07c56ce667 include DSN templates 2005-06-05 02:44:41 +00:00
Stuart Gathman ecb870acaa Fix bugs from testing RPM 2005-06-04 19:41:17 +00:00
Stuart Gathman e99117e8f6 Organize config reader by section. Create defang section. 2005-06-03 04:57:05 +00:00
Stuart Gathman 0283c20eef Configure banned extensions. Scan zipfile option with test case. 2005-06-02 15:00:17 +00:00
Stuart Gathman bdc6b71845 Update copyright notices after reading article on /. 2005-06-02 04:18:55 +00:00
Stuart Gathman 053734d435 Record timestamp in send_dsn.log 2005-06-02 02:09:00 +00:00
Stuart Gathman 56f1f58be8 Reject on PermErr 2005-06-02 02:08:12 +00:00
Stuart Gathman 5d6ceaefe4 Support configurable templates for DSNs. 2005-06-02 01:00:37 +00:00
Stuart Gathman 1d10bb172f Create Milter package. 2005-05-31 20:39:16 +00:00
Stuart Gathman 8e93d4be38 Move development to sourceforge. 2005-05-31 20:34:40 +00:00
Stuart Gathman ea81a31044 Clear unknown mechanism list at proper time. 2005-05-31 18:57:59 +00:00
Stuart Gathman 2ad3e1cd6e This commit was generated by cvs2svn to track changes on a CVS vendor
branch.
2005-05-31 18:23:49 +00:00
Stuart Gathman b056551e16 This commit was generated by cvs2svn to track changes on a CVS vendor
branch.
2005-05-31 18:10:47 +00:00
Stuart Gathman 6277f05e6a This commit was generated by cvs2svn to track changes on a CVS vendor
branch.
2005-05-31 18:09:06 +00:00
Stuart Gathman 19ad88b6b2 This commit was generated by cvs2svn to track changes on a CVS vendor
branch.
2005-05-31 18:08:20 +00:00
Stuart Gathman e688112eed This commit was generated by cvs2svn to track changes on a CVS vendor
branch.
2005-05-31 18:07:19 +00:00
Stuart Gathman c510c4576f This commit was generated by cvs2svn to track changes on a CVS vendor
branch.
2005-05-31 18:04:05 +00:00
21 changed files with 1038 additions and 423 deletions
+136
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@@ -0,0 +1,136 @@
Step one. Which DSPAM is right for you?
The DSPAM project makes dspam part of the LDA (Local Delivery Agent).
Pydspam puts dspam into the MTA (Mail Transfer Agent - sendmail with pymilter).
The advantage of doing dspam in the LDA is that any aliasing has already been
resolved. You need only configure mailboxes.
The advantage of doing dspam in the MTA is it can screen an entire
company as a gateway with multiple domains. Unfortunately, this
means you have to tell it about all the aliases that comprise each
account. (Also, pydspam is still uses dspam-2.6.5.2 - the Dspam API
has changed for newer versions.)
If the LDA is right for you, you'll want to use the official Dspam
package. http://www.nuclearelephant.com/projects/dspam/
If the MTA approach is what you want, then pydspam is what you want.
In either case, you will still want pymilter to block forgeries, Windows
executables, etc.
So, lets assume you want to install pymilter, and may or may not
wish to install pydspam.
Step two. Obtaining RPMS.
For basic pymilter you'll need:
python-2.4
milter-0.8.2 (the RH9 rpm should work on Fedora Core - let me know)
sendmail-8.13.x (with milter support enabled)
and for SPF you'll need:
pydns-2.3.0-2.4
and for SRS you'll need:
pysrs-0.30.9-1.py24
I'm pretty sure you will want to have SPF and SRS available.
Step three. Activate basic milter.
Activate the basic milter by editing /etc/mail/sendmail.mc and adding:
INPUT_MAIL_FILTER(`pythonfilter', `S=local:/var/run/milter/pythonsock, F=T, T=C:5m;S:20s;R:5m;E:5m')
You can then "make sendmail.cf" and restart sendmail.
Tail /var/log/milter/milter.log while SMTP clients connect to your
sendmail instance. This should show you what the milter is doing.
By default, milter-0.8.2 rejects on SPF fail, except for listed domains
(that are known to be broken). Some admins don't like that, and 0.8.3 will use
the /etc/mail/access database to configure SPF responses. For now,
if you don't like SPF, you can disable spf by replacing "import spf"
with "spf = None" around line 285 in /var/log/milter/bms.py.
Step four. Tweaking the basic config.
Most pymilter configuration is in /etc/mail/pymilter.cfg.
By default, milter scans attachments for executable extensions. You can
turn this off by setting banned_exts to the empty list. There are options
to scan ZIP attachments and rfc822 attachments. When it finds a banned
file type, milter saves the original message in /var/log/milter/save,
and replaces the attachment with a plain text warning message.
Configure hello_blacklist with your own helo name and domains - which
you know cannot legitimately be used by external MTAs.
Configure trusted_relay with your secondary MX servers, if any. These
should also run pymilter with similar policies. (But this isn't
needed for initial testing.)
Configure internal_connect with subnets of your internal SMTP clients.
Internal connections skip SPF testing and other policies.
Configure internal_domains with domains used by your internal SMTP clients.
If they attempt to use any other domain, the attempt is blocked and the
client is logged as a "zombie". Conversely, any attempt by an external
MTA to use one of your internal domains is treated as a forgery and
blocked (a simplified form of local SPF).
Adjust porn_words and spam_words - these block emails with a Subject
containing the listed strings. They can be empty to disable Subject
string blocking.
Advanced SPF configuration.
The sendmail access file, or another readonly database with that
format, can be used for detail spf policy. SPF access policy
record are tagged with "SPF-{Result}:". Results are
Pass, Neutral, Softfail, Fail, PermError. Currently supported
policy keywords are OK, CBV, REJECT. Currently, TempError always
results in TEMPFAIL.
The default policies are set in pymilter.cfg. The defaults
if none of the config options are set are as follows:
SPF-Fail: REJECT
SPF-Softfail: CBV
SPF-Neutral: OK
SPF-PermError: REJECT
SPF-Pass: OK
The tag may be followed by a specific domain. For instance, to
require a Pass from aol.com:
SPF-Neutral:aol.com REJECT
SPF-Softfail:aol.com REJECT
The CBV policy requires a valid HELO name. If the EHLO name is
RFC2822 compliant, then a DSN is sent to the alleged sender. The
template for the DSN is selected according to the SPF result:
Fail: softfail.txt
SoftFail: softfail.txt
Neutral: neutral.txt
PermError: permerror.txt
None: strike3.txt
An SPF-Pass is always accepted by the milter. Domains can be blacklisted
via sendmail in the access file or via a RHS DNS blacklist.
To be continued.
Forthcoming topics:
SRS config
pydspam config
wiretap config
+3 -2
View File
@@ -1,6 +1,7 @@
include COPYING
include TODO
include NEWS
include HOWTO
include CREDITS
include README
include MANIFEST.in
@@ -23,5 +24,5 @@ include milter.rc
include milter.rc7
include milter.cfg
include rhsbl.m4
include softfail.txt
include strike3.txt
include *.txt
include *.html
-203
View File
@@ -1,203 +0,0 @@
# Author: Stuart D. Gathman <stuart@bmsi.com>
# Copyright 2001 Business Management Systems, Inc.
# This code is under GPL. See COPYING for details.
import os
import milter
import thread
from milter import ACCEPT,CONTINUE,REJECT,DISCARD,TEMPFAIL, \
set_flags, setdbg, setbacklog, settimeout, \
ADDHDRS, CHGBODY, ADDRCPT, DELRCPT, CHGHDRS, \
V1_ACTS, V2_ACTS, CURR_ACTS
try: from milter import QUARANTINE
except: pass
_seq_lock = thread.allocate_lock()
_seq = 0
def uniqueID():
"""Return a sequence number unique to this process.
"""
global _seq
_seq_lock.acquire()
seqno = _seq = _seq + 1
_seq_lock.release()
return seqno
class Milter:
"""A simple class interface to the milter module.
"""
def _setctx(self,ctx):
self.__ctx = ctx
if ctx:
ctx.setpriv(self)
# user replaceable callbacks
def log(self,*msg):
print 'Milter:',
for i in msg: print i,
print
def connect(self,hostname,unused,hostaddr):
"Called for each connection to sendmail."
self.log("connect from %s at %s" % (hostname,hostaddr))
return CONTINUE
def hello(self,hostname):
"Called after the HELO command."
self.log("hello from %s" % hostname)
return CONTINUE
def envfrom(self,f,*str):
"""Called to begin each message.
f -> string message sender
str -> tuple additional ESMTP parameters
"""
self.log("mail from",f,str)
return CONTINUE
def envrcpt(self,to,*str):
"Called for each message recipient."
self.log("rcpt to",to,str)
return CONTINUE
def header(self,field,value):
"Called for each message header."
self.log("%s: %s" % (field,value))
return CONTINUE
def eoh(self):
"Called after all headers are processed."
self.log("eoh")
return CONTINUE
def body(self,unused):
"Called to transfer the message body."
return CONTINUE
def eom(self):
"Called at the end of message."
self.log("eom")
return CONTINUE
def abort(self):
"Called if the connection is terminated abnormally."
self.log("abort")
return CONTINUE
def close(self):
"Called at the end of connection, even if aborted."
self.log("close")
return CONTINUE
# Milter methods which can be invoked from callbacks
def getsymval(self,sym):
return self.__ctx.getsymval(sym)
# If sendmail does not support setmlreply, then only the
# first msg line is used.
def setreply(self,rcode,xcode=None,msg=None,*ml):
return self.__ctx.setreply(rcode,xcode,msg,*ml)
# Milter methods which can only be called from eom callback.
def addheader(self,field,value):
return self.__ctx.addheader(field,value)
def chgheader(self,field,idx,value):
return self.__ctx.chgheader(field,idx,value)
def addrcpt(self,rcpt):
return self.__ctx.addrcpt(rcpt)
def delrcpt(self,rcpt):
return self.__ctx.delrcpt(rcpt)
def replacebody(self,body):
return self.__ctx.replacebody(body)
# When quarantined, a message goes into the mailq as if to be delivered,
# but delivery is deferred until the message is unquarantined.
def quarantine(self,reason):
return self.__ctx.quarantine(reason)
def progress(self):
return self.__ctx.progress()
factory = Milter
def connectcallback(ctx,hostname,family,hostaddr):
m = factory()
m._setctx(ctx)
return m.connect(hostname,family,hostaddr)
def closecallback(ctx):
m = ctx.getpriv()
if not m: return CONTINUE
rc = m.close()
m._setctx(None) # release milterContext
return rc
def envcallback(c,args):
"""Convert ESMTP parms to keyword parameters.
Can be used in the envfrom and/or envrcpt callbacks to process
ESMTP parameters as python keyword parameters."""
kw = {}
for s in args[1:]:
pos = s.find('=')
if pos > 0:
kw[s[:pos]] = s[pos+1:]
return apply(c,args,kw)
def runmilter(name,socketname,timeout = 0):
# This bit is here on the assumption that you will be starting this filter
# before sendmail. If sendmail is not running and the socket already exists,
# libmilter will throw a warning. If sendmail is running, this is still
# safe if there are no messages currently being processed. It's safer to
# shutdown sendmail, kill the filter process, restart the filter, and then
# restart sendmail.
pos = socketname.find(':')
if pos > 1:
s = socketname[:pos]
fname = socketname[pos+1:]
else:
s = "unix"
fname = socketname
if s == "unix" or s == "local":
print "Removing %s" % fname
try:
os.unlink(fname)
except:
pass
# The default flags set include everything
# milter.set_flags(milter.ADDHDRS)
milter.set_connect_callback(connectcallback)
milter.set_helo_callback(lambda ctx, host: ctx.getpriv().hello(host))
milter.set_envfrom_callback(lambda ctx,*str:
ctx.getpriv().envfrom(*str))
# envcallback(ctx.getpriv().envfrom,str))
milter.set_envrcpt_callback(lambda ctx,*str:
ctx.getpriv().envrcpt(*str))
# envcallback(ctx.getpriv().envrcpt,str))
milter.set_header_callback(lambda ctx,fld,val:
ctx.getpriv().header(fld,val))
milter.set_eoh_callback(lambda ctx: ctx.getpriv().eoh())
milter.set_body_callback(lambda ctx,chunk: ctx.getpriv().body(chunk))
milter.set_eom_callback(lambda ctx: ctx.getpriv().eom())
milter.set_abort_callback(lambda ctx: ctx.getpriv().abort())
milter.set_close_callback(closecallback)
milter.setconn(socketname)
if timeout > 0: milter.settimeout(timeout)
# The name *must* match the X line in sendmail.cf (supposedly)
milter.register(name)
start_seq = _seq
try:
milter.main()
except milter.error:
if start_seq == _seq: raise # couldn't start
# milter has been running for a while, but now it can't start new threads
raise milter.error("out of thread resources")
+3 -1
View File
@@ -16,6 +16,8 @@ from milter import ACCEPT,CONTINUE,REJECT,DISCARD,TEMPFAIL, \
try: from milter import QUARANTINE
except: pass
__version__ = '0.8.3'
_seq_lock = thread.allocate_lock()
_seq = 0
@@ -215,6 +217,6 @@ def runmilter(name,socketname,timeout = 0):
raise milter.error("out of thread resources")
__all__ = globals().copy()
for priv in ('os','milter','thread','factory','_seq','_seq_lock'):
for priv in ('os','milter','thread','factory','_seq','_seq_lock','__version__'):
del __all__[priv]
__all__ = __all__.keys()
+14 -7
View File
@@ -9,6 +9,7 @@ import smtplib
import spf
import socket
from email.Message import Message
import Milter
nospf_msg = """Subject: Critical mail server configuration error
@@ -103,7 +104,7 @@ def send_dsn(mailfrom,receiver,msg=None):
q = spf.query(None,None,None)
mxlist = q.dns(domain,'MX')
if not mxlist:
mxlist = (0,domain),
mxlist = (0,domain), # fallback to A record when no MX
else:
mxlist.sort()
smtp = smtplib.SMTP()
@@ -112,8 +113,11 @@ def send_dsn(mailfrom,receiver,msg=None):
smtp.connect(host)
code,resp = smtp.helo(receiver)
# some wiley spammers have MX records that resolve to 127.0.0.1
if resp.split()[0] == receiver:
return (553,'Fraudulent MX for %s' % domain)
a = resp.split()
if not a:
return (553,'MX for %s has no hostname in banner: %s' % (domain,host))
if a[0] == receiver:
return (553,'Fraudulent MX for %s: %s' % (domain,host))
if not (200 <= code <= 299):
raise smtplib.SMTPHeloError(code, resp)
if msg:
@@ -151,13 +155,13 @@ def create_msg(q,rcptlist,origmsg=None,template=None):
connectip = q.i
receiver = q.r
sender_domain = q.o
result = q.result
perm_error = q.perm_error
rcpt = '\n\t'.join(rcptlist)
try: subject = origmsg['Subject']
except: subject = '(none)'
try:
spf_result = origmsg['Received-SPF']
if not spf_result.startswith('softfail'):
spf_result = None
except: spf_result = None
msg = Message()
@@ -165,11 +169,14 @@ def create_msg(q,rcptlist,origmsg=None,template=None):
msg.add_header('To',sender)
msg.add_header('From','postmaster@%s'%receiver)
msg.add_header('Auto-Submitted','auto-generated (configuration error)')
msg.add_header('X-Mailer','PyMilter-'+Milter.__version__)
msg.set_type('text/plain')
if not template:
if spf_result: template = softfail_msg
else: template = nospf_msg
if spf_result and spf_result.startswith('softfail'):
template = softfail_msg
else:
template = nospf_msg
hdrs,body = template.split('\n',1)
for ln in hdrs.splitlines():
name,val = ln.split(':',1)
+9
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@@ -1,5 +1,14 @@
Here is a history of user visible changes to Python milter.
0.8.3 Keep screened honeypot mail, but optionally discard honeypot only mail.
spf_accept_fail option for braindead SPF senders
(treats fail like softfail)
Option to set SPF policy via sendmail access map.
Option to supply Sender header from MAIL FROM when missing.
Consider SMTP AUTH connections internal.
Send DSN for SPF errors corrected by extended processing.
Send DSN before SCREENED mail is quarantined
Use logging package to keep log lines atomic.
0.8.2 Strict processing limits per SPF RFC
Fixed several parsing bugs under RFC
Support official IANA SPF record (type99)
+12 -29
View File
@@ -1,41 +1,32 @@
Find rfc2822 policy for MFROM quoting.
Use /etc/mail/access for domain specific SPF policies.
SPF-Fail: REJECT
SPF-Softfail: OK
SPF-Neutral: OK
SPF-Neutral:aol.com ERROR:"550 AOL mail must get SPF PASS"
Defer TEMPERROR in SPF evaluation - give precedence to security
(only defer for PASS mechanisms).
Option to add Received-SPF header, but never reject on SPF.
I think the above will handle this.
Create null config that does nothing - except maybe add Received-SPF
headers. Many admins would like to turn features on one at a time.
Checking in mime.py;
/bms/cvs/milter/mime.py,v <-- mime.py
new revision: 1.56; previous revision: 1.55
done
Checking in spf.py;
/bms/cvs/milter/spf.py,v <-- spf.py
new revision: 1.18; previous revision: 1.17
done
Checking in testmime.py;
/bms/cvs/milter/testmime.py,v <-- testmime.py
new revision: 1.19; previous revision: 1.18
Auto whitelist based on outgoing email - perhaps with magic subject
or recipient prefix.
Can't output messages with malformed rfc822 attachments.
Example malformed SPF:
onvunvuvvx.usafisnews.org text "v=spf1 mx ptr ip4:207.44.199.970 -all"
Move milter,Milter,mime,spf modules to pymilter
milter package will have bms.py application
Support SMTP AUTH and disable SPF checks when connection is authorized.
Web admin interface
Check valid domains allowed by internal senders to detect PCs infected
with spam trojans.
Do CBV (callback verification) for mail with no published SPF record.
message log for automated stats and blacklisting
Skip dspam when SPF pass?
Skip dspam when SPF pass? NO
Report 551 with rcpt on SPF fail?
check spam keywords with character classes, e.g.
{a}=[a@ãä], {i}=[i1í], {e}=[eë], {o}=[o0ö]
@@ -46,9 +37,6 @@ user to give to the forwarder. Alias only works for mail from that
forwarder. Milter gets forwarder domain from alias and uses it to
SPF check forwarder.
Another special dspam user, 'honeypot', can be listed in innoculations.
All email to those addresses is treated as known spam.
Framework for modular Python milter components within a single VM.
Python milters can be already be composed through sendmail by running each in
a separate process. However, a significant amount of memory is wasted
@@ -57,8 +45,7 @@ is cumbersome (e.g., adding mail headers, writing external files).
Backup copies for outgoing/incoming mail.
Allow multiple wiretap groups, each with its own destination. Perhaps
also copy incoming wiretap mail, even though sendmail alias works perfectly
Copy incoming wiretap mail, even though sendmail alias works perfectly
for the purpose, to avoid having to change two configs for a wiretap.
Provide a way to reload milter.cfg without stopping/restarting milter.
@@ -72,10 +59,6 @@ Keep separate ismodified flag for headers and body. This is important
when rejecting outgoing mail with viruses removed (so as not to
embarrass yourself), and also removing Received headers with hidepath.
Wrap smfi_setbacklog(int) - but it is only available in sendmail >= 8.12.3,
so how can we detect whether to wrap it?
Need a test module to feed sample messages to a milter though a live
sendmail and SMTP. The mockup currently used is probably not very accurate,
and doesn't test the threading code.
+352 -95
View File
@@ -1,6 +1,43 @@
#!/usr/bin/env python
# A simple milter that has grown quite a bit.
# $Log$
# Revision 1.29 2005/10/11 22:50:07 customdesigned
# Always check HELO except for SPF pass, temperror.
#
# Revision 1.28 2005/10/10 23:50:20 customdesigned
# Use logging module to make logging threadsafe (avoid splitting log lines)
#
# Revision 1.27 2005/10/10 20:15:33 customdesigned
# Configure SPF policy via sendmail access file.
#
# Revision 1.26 2005/10/07 03:23:40 customdesigned
# Banned users option. Experimental feature to supply Sender when
# missing and MFROM domain doesn't match From. Log cipher bits for
# SMTP AUTH. Sketch access file feature.
#
# Revision 1.25 2005/09/08 03:55:08 customdesigned
# Handle perverse MFROM quoting.
#
# Revision 1.24 2005/08/18 03:36:54 customdesigned
# Don't innoculate with SCREENED mail.
#
# Revision 1.23 2005/08/17 19:35:27 customdesigned
# Send DSN before adding message to quarantine.
#
# Revision 1.22 2005/08/11 22:17:58 customdesigned
# Consider SMTP AUTH connections internal.
#
# Revision 1.21 2005/08/04 21:21:31 customdesigned
# Treat fail like softfail for selected (braindead) domains.
# Treat mail according to extended processing results, but
# report any PermError that would officially result via DSN.
#
# Revision 1.20 2005/08/02 18:04:35 customdesigned
# Keep screened honeypot mail, but optionally discard honeypot only mail.
#
# Revision 1.19 2005/07/20 03:30:04 customdesigned
# Check pydspam version for honeypot, include latest pyspf changes.
#
# Revision 1.18 2005/07/17 01:25:44 customdesigned
# Log as well as use extended result for best guess.
#
@@ -246,6 +283,7 @@ import traceback
import ConfigParser
import time
import re
import anydbm
import Milter.dsn as dsn
from Milter.dynip import is_dynip as dynip
@@ -266,8 +304,7 @@ try: import spf
except: spf = None
ip4re = re.compile(r'^[1-9][0-9]*\.[1-9][0-9]*\.[1-9][0-9]*\.[1-9][0-9]*$')
#import syslog
#syslog.openlog('milter')
import logging
# Thanks to Chris Liechti for config parsing suggestions
@@ -292,6 +329,7 @@ scan_rfc822 = True
internal_connect = ()
trusted_relay = ()
internal_domains = ()
banned_users = ()
hello_blacklist = ()
smart_alias = {}
dspam_dict = None
@@ -309,14 +347,24 @@ srs_reject_spoofed = False
srs_domain = None
spf_reject_neutral = ()
spf_accept_softfail = ()
spf_accept_fail = ()
spf_best_guess = False
spf_reject_noptr = False
multiple_bounce_recipients = True
supply_sender = False
access_file = None
time_format = '%Y%b%d %H:%M:%S %Z'
timeout = 600
cbv_cache = {}
logging.basicConfig(
stream=sys.stdout,
level=logging.INFO,
format='%(asctime)s %(message)s',
datefmt='%Y%b%d %H:%M:%S'
)
milter_log = logging.getLogger('milter')
try:
too_old = time.time() - 30*24*60*60 # 30 days
too_old = time.time() - 7*24*60*60 # 7 days
for ln in open('send_dsn.log'):
try:
rcpt,ts = ln.strip().split(None,1)
@@ -388,6 +436,7 @@ def read_config(list):
'hashlength': '8',
'reject_spoofed': 'no',
'reject_noptr': 'no',
'supply_sender': 'no',
'best_guess': 'no',
'dspam_internal': 'yes'
})
@@ -441,7 +490,7 @@ def read_config(list):
for sa in cp.getlist('wiretap','smart_alias'):
sm = cp.getlist('wiretap',sa)
if len(sm) < 2:
print 'malformed smart alias:',sa
milter_log.warning('malformed smart alias: %s',sa)
continue
if len(sm) == 2: sm.append(sa)
key = (sm[0],sm[1])
@@ -463,18 +512,21 @@ def read_config(list):
# spf section
global spf_reject_neutral,spf_best_guess,SRS,spf_reject_noptr
global spf_accept_softfail
global spf_accept_softfail,spf_accept_fail,supply_sender,access_file
if spf:
spf.DELEGATE = cp.getdefault('spf','delegate')
spf_reject_neutral = cp.getlist('spf','reject_neutral')
spf_accept_softfail = cp.getlist('spf','accept_softfail')
spf_accept_fail = cp.getlist('spf','accept_fail')
spf_best_guess = cp.getboolean('spf','best_guess')
spf_reject_noptr = cp.getboolean('spf','reject_noptr')
supply_sender = cp.getboolean('spf','supply_sender')
access_file = cp.getdefault('spf','access_file')
srs_config = cp.getdefault('srs','config')
if srs_config: cp.read([srs_config])
srs_secret = cp.getdefault('srs','secret')
if SRS and srs_secret:
global ses,srs,srs_reject_spoofed,srs_domain
global ses,srs,srs_reject_spoofed,srs_domain,banned_users
database = cp.getdefault('srs','database')
srs_reject_spoofed = cp.getboolean('srs','reject_spoofed')
maxage = cp.getint('srs','maxage')
@@ -493,13 +545,31 @@ def read_config(list):
else:
srs_domain = []
srs_domain.append(cp.getdefault('srs','fwdomain'))
banned_users = cp.getlist('srs','banned_users')
#print srs_domain
def parse_addr(t):
"""Split email into user,domain.
>>> parse_addr('user@example.com')
['user', 'example.com']
>>> parse_addr('"user@example.com"')
['user@example.com']
>>> parse_addr('"user@bar"@example.com')
['user@bar', 'example.com']
>>> parse_addr('foo')
['foo']
"""
if t.startswith('<') and t.endswith('>'): t = t[1:-1]
if t.startswith('"'):
if t.endswith('"'): return [t[1:-1]]
pos = t.find('"@')
if pos > 0: return [t[1:pos],t[pos+2:]]
return t.split('@')
def parse_header(val):
"""Decode headers gratuitously encoded to hide the content.
"""
try:
h = decode_header(val)
if not len(h) or (not h[0][1] and len(h) == 1): return val
@@ -522,15 +592,83 @@ def parse_header(val):
except email.Errors.HeaderParseError: pass
return val
class SPFPolicy(object):
"Get SPF policy by result, defaulting to classic policy from pymilter.cfg"
def __init__(self,domain):
self.domain = domain.lower()
if access_file:
try: acf = anydbm.open(access_file,'r')
except: acf = None
else: acf = None
self.acf = acf
def getPolicy(self,pfx):
acf = self.acf
if not acf: return None
try:
return acf[pfx + self.domain]
except KeyError:
try:
return acf[pfx]
except KeyError:
return None
def getFailPolicy(self):
policy = self.getPolicy('SPF-Fail:')
if not policy:
if self.domain in spf_accept_fail:
policy = 'CBV'
else:
policy = 'REJECT'
return policy
def getNonePolicy(self):
policy = self.getPolicy('SPF-None:')
if not policy:
if spf_reject_noptr:
policy = 'REJECT'
else:
policy = 'CBV'
return policy
def getSoftfailPolicy(self):
policy = self.getPolicy('SPF-Softfail:')
if not policy:
if self.domain in spf_accept_softfail:
policy = 'OK'
elif self.domain in spf_reject_neutral:
policy = 'REJECT'
else:
policy = 'CBV'
return policy
def getNeutralPolicy(self):
policy = self.getPolicy('SPF-Neutral:')
if not policy:
if self.domain in spf_reject_neutral:
policy = 'REJECT'
policy = 'OK'
return policy
def getPermErrorPolicy(self):
policy = self.getPolicy('SPF-PermError:')
if not policy:
policy = 'REJECT'
return policy
def getPassPolicy(self):
policy = self.getPolicy('SPF-Pass:')
if not policy:
policy = 'OK'
return policy
class bmsMilter(Milter.Milter):
"""Milter to replace attachments poisonous to Windows with a WARNING message,
check SPF, and other anti-forgery features, and implement wiretapping
and smart alias redirection."""
def log(self,*msg):
print "%s [%d]" % (time.strftime('%Y%b%d %H:%M:%S'),self.id),
for i in msg: print i,
print
milter_log.info('[%d] %s',self.id,' '.join([str(m) for m in msg]))
def __init__(self):
self.tempname = None
@@ -649,8 +787,41 @@ class bmsMilter(Milter.Milter):
self.new_headers = []
self.recipients = []
self.cbv_needed = None
t = parse_addr(f.lower())
t = parse_addr(f)
if len(t) == 2: t[1] = t[1].lower()
self.canon_from = '@'.join(t)
# Some braindead MTAs can't be relied upon to properly flag DSNs.
# This heuristic tries to recognize such.
self.is_bounce = (f == '<>' or t[0].lower() in banned_users
#and t[1] == self.hello_name
)
# Check SMTP AUTH, also available:
# auth_authen authenticated user
# auth_author (ESMTP AUTH= param)
# auth_ssf (connection security, 0 = unencrypted)
# auth_type (authentication method, CRAM-MD5, DIGEST-MD5, PLAIN, etc)
# cipher_bits SSL encryption strength
# cert_subject SSL cert subject
# verify SSL cert verified
self.user = self.getsymval('{auth_authen}')
if self.user:
# Very simple SMTP AUTH policy by defaul:
# any successful authentication is considered INTERNAL
# FIXME: configure allowed MAIL FROM by user
self.internal_connection = True
self.log(
"SMTP AUTH:",self.user, self.getsymval('{auth_type}'),
"sslbits =",self.getsymval('{cipher_bits}'),
"ssf =",self.getsymval('{auth_ssf}'), "INTERNAL"
)
if self.getsymval('{verify}'):
self.log("SSL AUTH:",
self.getsymval('{cert_subject}'),
"verify =",self.getsymval('{verify}')
)
self.fp.write('From %s %s\n' % (self.canon_from,time.ctime()))
if len(t) == 2:
user,domain = t
@@ -689,19 +860,25 @@ class bmsMilter(Milter.Milter):
if not (self.internal_connection or self.trusted_relay) \
and self.connectip and spf:
return self.check_spf()
self.spf = None
return Milter.CONTINUE
def check_spf(self):
t = parse_addr(self.mailfrom)
if len(t) == 2: t[1] = t[1].lower()
receiver = self.receiver
q = spf.query(self.connectip,'@'.join(t),self.hello_name,receiver=receiver)
q = spf.query(self.connectip,self.canon_from,self.hello_name,
receiver=receiver,strict=False)
q.set_default_explanation(
'SPF fail: see http://spf.pobox.com/why.html?sender=%s&ip=%s' % (q.s,q.i))
'SPF fail: see http://openspf.com/why.html?sender=%s&ip=%s' % (q.s,q.i))
res,code,txt = q.check()
if res in ('none', 'softfail'):
q.result = res
if res in ('unknown','permerror') and q.perm_error and q.perm_error.ext:
self.cbv_needed = q # report SPF syntax error to sender
res,code,txt = q.perm_error.ext # extended (lax processing) result
txt = 'EXT: ' + txt
p = SPFPolicy(q.o)
if res not in ('pass','error','temperror'):
if self.mailfrom != '<>':
# check hello name via spf
# check hello name via spf unless spf pass
h = spf.query(self.connectip,'',self.hello_name,receiver=receiver)
hres,hcode,htxt = h.check()
if hres in ('deny','fail','neutral','softfail'):
@@ -717,11 +894,11 @@ class bmsMilter(Milter.Milter):
and not dynip(self.hello_name,self.connectip):
hres,hcode,htxt = h.best_guess()
else: hres = res
ores = res
if spf_best_guess and res == 'none':
#self.log('SPF: no record published, guessing')
q.set_default_explanation(
'SPF guess: see http://spf.pobox.com/why.html')
q.strict = False
# best_guess should not result in fail
if self.missing_ptr:
# ignore dynamic PTR for best guess
@@ -729,32 +906,43 @@ class bmsMilter(Milter.Milter):
else:
res,code,txt = q.best_guess()
receiver += ': guessing'
if q.perm_error:
if q.perm_error: # FIXME: should never happen?
res,code,txt = q.perm_error.ext # extended result
txt = 'EXT: ' + txt
if self.missing_ptr and res in ('neutral', 'none') and hres != 'pass':
if spf_reject_noptr:
if self.missing_ptr and ores == 'none' and res != 'pass' \
and hres != 'pass':
policy = p.getNonePolicy()
if policy == 'CBV':
if self.mailfrom != '<>':
q.result = ores
self.cbv_needed = q # accept, but inform sender via DSN
elif policy != 'OK':
self.log('REJECT: no PTR, HELO or SPF')
self.setreply('550','5.7.1',
'You must have a reverse lookup or publish SPF: http://spf.pobox.com',
'Contact your mail administrator IMMEDIATELY! Your mail server is',
'severely misconfigured. It has no PTR record (dynamic PTR records',
"You must have a reverse lookup or publish SPF: http://spf.pobox.com",
"Contact your mail administrator IMMEDIATELY! Your mail server is",
"severely misconfigured. It has no PTR record (dynamic PTR records",
"that contain your IP don't count), an invalid HELO, and no SPF record."
)
return Milter.REJECT
if self.mailfrom != '<>':
q.result = res
self.cbv_needed = q
if res in ('deny', 'fail'):
policy = p.getFailPolicy()
if hres == 'pass' and policy == 'CBV':
if self.mailfrom != '<>':
self.cbv_needed = q
elif policy != 'OK':
self.log('REJECT: SPF %s %i %s' % (res,code,txt))
self.setreply(str(code),'5.7.1',txt)
# A proper SPF fail error message would read:
# forger.biz [1.2.3.4] is not allowed to send mail with the domain
# "forged.org" in the sender address. Contact <postmaster@forged.org>.
return Milter.REJECT
if res == 'softfail' and not q.o in spf_accept_softfail:
if self.missing_ptr and hres != 'pass':
if spf_reject_noptr or q.o in spf_reject_neutral:
if res == 'softfail':
policy = p.getSoftfailPolicy()
if policy == 'CBV' and hres == 'pass':
if self.mailfrom != '<>':
self.cbv_needed = q
elif policy != 'OK':
self.log('REJECT: SPF %s %i %s' % (res,code,txt))
self.setreply('550','5.7.1',
'SPF softfail: If you get this Delivery Status Notice, your email',
@@ -764,10 +952,12 @@ class bmsMilter(Milter.Milter):
'notify your administrator of the problem immediately.'
)
return Milter.REJECT
if self.mailfrom != '<>':
q.result = res
self.cbv_needed = q
if res == 'neutral' and q.o in spf_reject_neutral:
policy = p.getNeutralPolicy()
if policy == 'CBV' and hres == 'pass':
if self.mailfrom != '<>':
self.cbv_needed = q
elif policy != 'OK':
self.log('REJECT: SPF neutral for',q.s)
self.setreply('550','5.7.1',
'mail from %s must pass SPF: http://spf.pobox.com/why.html' % q.o,
@@ -778,16 +968,25 @@ class bmsMilter(Milter.Milter):
'servers for %s should accomplish this.' % q.o
)
return Milter.REJECT
if res == 'unknown':
if res in ('unknown','permerror'):
policy = p.getPermErrorPolicy()
if policy == 'CBV' and hres == 'pass':
if self.mailfrom != '<>':
self.cbv_needed = q
elif policy != 'OK':
self.log('REJECT: SPF %s %i %s' % (res,code,txt))
# latest SPF draft recommends 5.5.2 instead of 5.7.1
self.setreply(str(code),'5.5.2',txt)
self.setreply(str(code),'5.5.2',txt,
'There is a fatal syntax error in the SPF record for %s' % q.o,
'We cannot accept mail from %s until this is corrected.' % q.o
)
return Milter.REJECT
if res == 'error':
if res in ('error','temperror'):
self.log('TEMPFAIL: SPF %s %i %s' % (res,code,txt))
self.setreply(str(code),'4.3.0',txt)
return Milter.TEMPFAIL
self.add_header('Received-SPF',q.get_header(res,receiver))
self.spf = q
return Milter.CONTINUE
# hide_path causes a copy of the message to be saved - until we
@@ -802,11 +1001,7 @@ class bmsMilter(Milter.Milter):
t = parse_addr(to.lower())
if len(t) == 2:
user,domain = t
if self.mailfrom == '<>' or self.canon_from.startswith('postmaster@') \
or self.canon_from.startswith('mailer-daemon@'):
if self.recipients and not multiple_bounce_recipients:
self.data_allowed = False
if srs and domain in srs_domain:
if self.is_bounce and srs and domain in srs_domain:
oldaddr = '@'.join(parse_addr(to))
try:
if ses:
@@ -830,6 +1025,7 @@ class bmsMilter(Milter.Milter):
self.setreply('550','5.7.1','Invalid SES signature')
return Milter.REJECT
self.data_allowed = not srs_reject_spoofed
# non DSN mail to SRS address will bounce due to invalid local part
self.recipients.append('@'.join(t))
users = check_user.get(domain)
@@ -907,14 +1103,19 @@ class bmsMilter(Milter.Milter):
return Milter.CONTINUE
def forged_bounce(self):
if len(self.recipients) > 1:
self.log('REJECT: Multiple bounce recipients')
self.setreply('550','5.7.1','Multiple bounce recipients')
if self.mailfrom != '<>':
self.log("REJECT: bogus DSN")
self.setreply('550','5.7.1',
"I do not accept mail from postmaster, mailer-daemon, or clamav.",
"All such mail has turned out to be Delivery Status Notifications",
"which failed to be marked as such. Please send a real DSN if",
"you need to. Use another MAIL FROM if you need to send me mail."
)
else:
self.log('REJECT: bounce with no SRS encoding')
self.setreply('550','5.7.1',
"I did not send you that message. Please consider implementing SPF",
"(http://spf.pobox.com) to avoid bouncing mail to spoofed senders.",
"(http://openspf.com) to avoid bouncing mail to spoofed senders.",
"Thank you."
)
return Milter.REJECT
@@ -959,8 +1160,28 @@ class bmsMilter(Milter.Milter):
for name,val in self.new_headers:
self.fp.write("%s: %s\n" % (name,val)) # add new headers to buffer
self.fp.write("\n") # terminate headers
# log when neither sender nor from domains matches mail from domain
if supply_sender and self.mailfrom != '<>':
mf_domain = self.canon_from.split('@')[-1]
self.fp.seek(0)
msg = rfc822.Message(self.fp)
for rn,hf in msg.getaddrlist('from')+msg.getaddrlist('sender'):
t = parse_addr(hf)
if len(t) == 2 and t[1].lower() == mf_domain:
break
else:
for f in msg.getallmatchingheaders('from'):
self.log(f)
sender = msg.getallmatchingheaders('sender')
if sender:
for f in sender:
self.log(f)
else:
self.log("NOTE: Supplying MFROM as Sender");
self.add_header('Sender',self.mailfrom)
del msg
# copy headers to a temp file for scanning the body
self.fp.seek(0)
headers = self.fp.getvalue()
self.fp.close()
fd,fname = tempfile.mkstemp(".defang")
@@ -1040,6 +1261,7 @@ class bmsMilter(Milter.Milter):
# this will give a fast start to stats
def check_spam(self):
"return True/False if self.fp, else return Milter.REJECT/TEMPFAIL/etc"
if not dspam_userdir: return False
ds = Dspam.DSpamDirectory(dspam_userdir)
ds.log = self.log
@@ -1059,7 +1281,7 @@ class bmsMilter(Milter.Milter):
ds.add_spam(sender,txt)
txt = None
self.fp = None
return False
return Milter.DISCARD
elif user == 'falsepositive' and self.internal_connection:
sender = dspam_users.get(self.canon_from)
if sender:
@@ -1075,10 +1297,24 @@ class bmsMilter(Milter.Milter):
self.log("Large message:",len(txt))
return False
if user == 'honeypot' and Dspam.VERSION >= '1.1.9':
ds.check_spam(user,txt,force_result=dspam.DSR_ISSPAM)
self.log("HONEYPOT:",rcpt)
keep = False # keep honeypot mail
self.fp = None
return False
if len(self.recipients) > 1:
self.log("HONEYPOT:",rcpt,'SCREENED')
if self.spf:
# check that sender accepts quarantine DSN
msg = mime.message_from_file(StringIO.StringIO(txt))
rc = self.send_dsn(self.spf,msg,'quarantine.txt')
del msg
if rc != Milter.CONTINUE:
return rc
ds.check_spam(user,txt,self.recipients,quarantine=True,
force_result=dspam.DSR_ISSPAM)
else:
ds.check_spam(user,txt,self.recipients,quarantine=keep,
force_result=dspam.DSR_ISSPAM)
self.log("HONEYPOT:",rcpt)
return Milter.DISCARD
txt = ds.check_spam(user,txt,self.recipients)
if not txt:
# DISCARD if quarrantined for any recipient. It
@@ -1086,12 +1322,12 @@ class bmsMilter(Milter.Milter):
# as a false positive.
self.log("DSPAM:",user,rcpt)
self.fp = None
return False
return Milter.DISCARD
self.fp = StringIO.StringIO(txt)
modified = True
except Exception,x:
self.log("check_spam:",x)
traceback.print_exc()
milter_log.error("check_spam: %s",x,exc_info=True)
# screen if no recipients are dspam_users
if not modified and dspam_screener and not self.internal_connection \
and self.dspam:
@@ -1102,14 +1338,27 @@ class bmsMilter(Milter.Milter):
return False
screener = dspam_screener[self.id % len(dspam_screener)]
if not ds.check_spam(screener,txt,self.recipients,
classify=True,quarantine=not self.reject_spam):
self.fp = None
classify=True,quarantine=False):
if self.reject_spam:
self.log("DSPAM:",screener,
'REJECT: X-DSpam-Score: %f' % ds.probability)
self.setreply('550','5.7.1','Your Message looks spammy')
return True
self.fp = None
return Milter.REJECT
self.log("DSPAM:",screener,"SCREENED")
if self.spf:
# check that sender accepts quarantine DSN
self.fp.seek(0)
msg = mime.message_from_file(self.fp)
rc = self.send_dsn(self.spf,msg,'quarantine.txt')
if rc != Milter.CONTINUE:
self.fp = None
return rc
del msg
if not ds.check_spam(screener,txt,self.recipients,classify=True):
self.fp = None
return Milter.DISCARD
# Message no longer looks spammy, deliver normally. We lied in the DSN.
return modified
def eom(self):
@@ -1120,8 +1369,7 @@ class bmsMilter(Milter.Milter):
# analyze external mail for spam
spam_checked = self.check_spam() # tag or quarantine for spam
if not self.fp:
if spam_checked: return Milter.REJECT
return Milter.DISCARD # message quarantined for all recipients
return spam_checked
# analyze all mail for dangerous attachments and scripts
self.fp.seek(0)
@@ -1139,7 +1387,7 @@ class bmsMilter(Milter.Milter):
if not exc_value.strerror:
exc_value.strerror = exc_value.args[0]
if exc_value.strerror == 'Lock failed':
self.log("LOCK: BUSY") # log filename
milter_log.warn("LOCK: BUSY") # log filename
self.setreply('450','4.2.0',
'Too busy discarding spam. Please try again later.')
return Milter.TEMPFAIL
@@ -1147,7 +1395,7 @@ class bmsMilter(Milter.Milter):
os.rename(self.tempname,fname)
self.tempname = None
if exc_type == email.Errors.BoundaryError:
self.log("MALFORMED: %s" % fname) # log filename
milter_log.warn("MALFORMED: %s",fname) # log filename
if self.internal_connection:
# accept anyway for now
return Milter.ACCEPT
@@ -1155,12 +1403,12 @@ class bmsMilter(Milter.Milter):
'Boundary error in your message, are you a spammer?')
return Milter.REJECT
if exc_type == email.Errors.HeaderParseError:
self.log("MALFORMED: %s" % fname) # log filename
milter_log.warn("MALFORMED: %s",fname) # log filename
self.setreply('554','5.7.7',
'Header parse error in your message, are you a spammer?')
return Milter.REJECT
milter_log.error("FAIL: %s",fname) # log filename
# let default exception handler print traceback and return 451 code
self.log("FAIL: %s" % fname) # log filename
raise
if rc == Milter.REJECT: return rc;
if rc == Milter.DISCARD: return rc;
@@ -1188,39 +1436,17 @@ class bmsMilter(Milter.Milter):
if self.cbv_needed:
q = self.cbv_needed
sender = q.s
cached = cbv_cache.has_key(sender)
if cached:
self.log('CBV:',sender,'(cached)')
res = cbv_cache[sender]
if q.result in ('softfail','fail','deny'):
template_name = 'softfail.txt'
elif q.result in ('unknown','permerror'):
template_name = 'permerror.txt'
elif q.result == 'neutral':
template_name = 'neutral.txt'
else:
self.log('CBV:',sender)
try:
if q.result == 'softfail':
template = file('softfail.txt').read()
else:
template = file('strike3.txt').read()
except IOError: template = None
m = dsn.create_msg(q,self.recipients,msg,template)
m = m.as_string()
print >>open('last_dsn','w'),m
res = dsn.send_dsn(sender,self.receiver,m)
if res:
desc = "CBV: %d %s" % res[:2]
if 400 <= res[0] < 500:
self.log('TEMPFAIL:',desc)
self.setreply('450','4.2.0',*desc.splitlines())
return Milter.TEMPFAIL
if len(res) < 3: res += time.time(),
cbv_cache[sender] = res
self.log('REJECT:',desc)
self.setreply('550','5.7.1',*desc.splitlines())
return Milter.REJECT
cbv_cache[sender] = res
if not cached:
s = time.strftime(time_format,time.localtime())
print >>open('send_dsn.log','a'),sender,s # log who we sent DSNs to
template_name = 'strike3.txt'
rc = self.send_dsn(q,msg,template_name)
self.cbv_needed = None
if rc != Milter.CONTINUE: return rc
if not defanged and not spam_checked:
os.remove(self.tempname)
@@ -1254,13 +1480,44 @@ class bmsMilter(Milter.Milter):
out.close()
return Milter.TEMPFAIL
def send_dsn(self,q,msg,template_name):
sender = q.s
cached = cbv_cache.has_key(sender)
if cached:
self.log('CBV:',sender,'(cached)')
res = cbv_cache[sender]
else:
self.log('CBV:',sender)
try:
template = file(template_name).read()
except IOError: template = None
m = dsn.create_msg(q,self.recipients,msg,template)
m = m.as_string()
print >>open('last_dsn','w'),m
res = dsn.send_dsn(sender,self.receiver,m)
if res:
desc = "CBV: %d %s" % res[:2]
if 400 <= res[0] < 500:
self.log('TEMPFAIL:',desc)
self.setreply('450','4.2.0',*desc.splitlines())
return Milter.TEMPFAIL
if len(res) < 3: res += time.time(),
cbv_cache[sender] = res
self.log('REJECT:',desc)
self.setreply('550','5.7.1',*desc.splitlines())
return Milter.REJECT
cbv_cache[sender] = res
if not cached:
s = time.strftime(time_format,time.localtime())
print >>open('send_dsn.log','a'),sender,s # log who we sent DSNs to
return Milter.CONTINUE
def close(self):
sys.stdout.flush() # make log messages visible
if self.tempname:
os.remove(self.tempname) # remove in case session aborted
if self.fp:
self.fp.close()
sys.stdout.flush()
return Milter.CONTINUE
def abort(self):
@@ -1275,10 +1532,10 @@ def main():
if srs or len(discard_users) > 0 or smart_alias or dspam_userdir:
flags = flags + Milter.DELRCPT
Milter.set_flags(flags)
print "%s bms milter startup" % time.strftime('%Y%b%d %H:%M:%S')
milter_log.info("bms milter startup")
sys.stdout.flush()
Milter.runmilter("pythonfilter",socketname,timeout)
print "%s bms milter shutdown" % time.strftime('%Y%b%d %H:%M:%S')
milter_log.info("bms milter shutdown")
if __name__ == "__main__":
read_config(["/etc/mail/pymilter.cfg","milter.cfg"])
+1
View File
@@ -194,4 +194,5 @@ everything up for you. For other systems:
</ol>
</ol>
</body>
</html>
+19 -1
View File
@@ -70,6 +70,10 @@ config=/etc/mail/pysrs.cfg
;fwdomain = mydomain.com
# turn this on after a grace period to reject spoofed DSNs
reject_spoofed = 0
# Many braindead MTAs send DSNs with a non-DSN MFROM (e.g. to report that
# some virus claiming to be sent by you). This heuristic
# refuses mail from user names commonly abused in that way.
;banned_users = postmaster, mailer-daemon, clamav
# See http://spf.pobox.com for more info on SPF.
[spf]
@@ -85,6 +89,16 @@ reject_spoofed = 0
;reject_noptr = 0
# always accept softfail from these domains, or send DSN otherwise
;accept_softfail = bounces.amazon.com
# Treat fail from these domains like softfail: because their SPF record
# or an important sender is screwed up. Must have valid HELO, however.
;accept_fail = custhelp.com
# Use sendmail access map or similar format for detailed spf policy.
# SPF entries in the access map will override any defaults set above.
;access_file = /etc/mail/access.db
# Add MAIL FROM as Sender when Sender is missing and From domain
# doesn't match MAIL FROM. Outlook and other email clients will then display
# something like: "Sent by sender@domain.com on behalf of from@example.com"
;supply_sender = 0
# features intended to clean up outgoing mail
[scrub]
@@ -101,6 +115,7 @@ blind = 1
# (sendmail aliases let you monitor incoming mail)
#
;users = disloyal@bigcorp.com, bigmouth@bigcorp.com
# multiple destinations can use smart_alias
;dest = spy@bigcorp.com
# discard outgoing mail without alerting sender
# can be used in conjunction with wiretap to censor outgoing mail
@@ -108,7 +123,10 @@ blind = 1
#
# smart aliases trigger on both sender and recipient
#
;smart_alias = copycust,walter
;smart_alias = copycust,walter,spy1,spy2
# multiple wiretap monitors
;spy1 = disloyal@bigcorp.com,spy@bigcorp.com
;spy2 = bigmouth@bigcorp.com,spy@bigcorp.com
# mail from client@clientcorp.com to sue@bigcorp.com is redirected to
# local alias copycust
;copycust = client@clientcorp.com,sue@bigcorp.com
+10 -2
View File
@@ -24,7 +24,7 @@ ALT="Viewable With Any Browser" BORDER="0"></A>
Stuart D. Gathman</a><br>
This web page is written by Stuart D. Gathman<br>and<br>sponsored by
<a href="http://www.bmsi.com">Business Management Systems, Inc.</a> <br>
Last updated Jun 09, 2005</h4>
Last updated Aug 28, 2005</h4>
See the <a href="faq.html">FAQ</a> | <a href="http://sourceforge.net/project/showfiles.php?group_id=139894">Download now</a> |
<a href="/mailman/listinfo/pymilter">Subscribe to mailing list</a> |
@@ -49,7 +49,15 @@ efficient and secure. I recommend upgrading.
Python milter is being moved to
<a href="http://sourceforge.net/projects/pymilter/">pymilter Sourceforge
project</a> for development.
project</a> for development and release downloads.
<p>
Release 0.8.2 has changes to <a href="http://openspf.net">SPF</a> to bring it
in line with the newly official RFC. It adds
<a href="http://ses.codeshare.ca/">SES</a>
support (the original SES without body hash) for pysrs-0.30.10, and honeypot
support for pydspam-1.1.9. There is a new method in the base milter module.
milter.set_exception_policy(i) lets you choose a policy of CONTINUE, REJECT, or
TEMPFAIL (default) for untrapped exceptions encountered in a milter callback.
<p>
Release 0.8.0 is the first <a href="http://sourceforge.net/">Sourceforge</a>
release. It supports Python-2.4, and provides an option to accept mail
+24 -7
View File
@@ -1,6 +1,6 @@
%define name milter
%define version 0.8.2
%define release 2.RH7
%define version 0.8.3
%define release 1.RH7
# what version of RH are we building for?
%define redhat9 0
%define redhat7 1
@@ -63,7 +63,7 @@ rm -rf $RPM_BUILD_ROOT
mkdir -p $RPM_BUILD_ROOT/var/log/milter
mkdir -p $RPM_BUILD_ROOT/etc/mail
mkdir $RPM_BUILD_ROOT/var/log/milter/save
cp bms.py strike3.txt softfail.txt $RPM_BUILD_ROOT/var/log/milter
cp bms.py *.txt $RPM_BUILD_ROOT/var/log/milter
cp milter.cfg $RPM_BUILD_ROOT/etc/mail/pymilter.cfg
# logfile rotation
@@ -146,7 +146,7 @@ rm -rf $RPM_BUILD_ROOT
%files -f INSTALLED_FILES
%defattr(-,root,root)
%doc README NEWS TODO CREDITS sample.py
%doc README HOWTO NEWS TODO CREDITS sample.py
/etc/logrotate.d/milter
/etc/cron.daily/milter
%ifos aix4.1
@@ -160,12 +160,30 @@ rm -rf $RPM_BUILD_ROOT
%dir /var/log/milter/save
%config /var/log/milter/start.sh
%config /var/log/milter/bms.py
%config /var/log/milter/strike3.txt
%config /var/log/milter/softfail.txt
%config(noreplace) /var/log/milter/strike3.txt
%config(noreplace) /var/log/milter/softfail.txt
%config(noreplace) /var/log/milter/neutral.txt
%config(noreplace) /var/log/milter/quarantine.txt
%config(noreplace) /var/log/milter/permerror.txt
%config(noreplace) /etc/mail/pymilter.cfg
/usr/share/sendmail-cf/hack/rhsbl.m4
%changelog
* Fri Jul 15 2005 Stuart Gathman <stuart@bmsi.com> 0.8.3-1
- Keep screened honeypot mail, but optionally discard honeypot only mail.
- spf_accept_fail option for braindead SPF senders (treats fail like softfail)
- Consider SMTP AUTH connections internal.
- Send DSN for SPF errors corrected by extended processing.
- Send DSN before SCREENED mail is quarantined
- Option to set SPF policy via sendmail access map.
- Option to supply Sender header from MAIL FROM when missing.
- Use logging package to keep log lines atomic.
* Fri Jul 15 2005 Stuart Gathman <stuart@bmsi.com> 0.8.2-4
- Limit each CNAME chain independently like PTR and MX
* Fri Jul 15 2005 Stuart Gathman <stuart@bmsi.com> 0.8.2-3
- Limit CNAME lookups (regression)
* Fri Jul 15 2005 Stuart Gathman <stuart@bmsi.com> 0.8.2-2
- Handle corrupt ZIP attachments
* Fri Jul 15 2005 Stuart Gathman <stuart@bmsi.com> 0.8.2-1
- Strict processing limits per SPF RFC
- Fixed several parsing bugs under RFC
@@ -174,7 +192,6 @@ rm -rf $RPM_BUILD_ROOT
- Extended SPF processing results beyond strict RFC limits
- Support original SES for local bounce protection (requires pysrs-0.30.10)
- Callback exception processing option in milter module
- Handle corrupt ZIP attachments
* Thu Jun 16 2005 Stuart Gathman <stuart@bmsi.com> 0.8.1-1
- Fix zip in zip loop in mime.py
- Fix HeaderParseError in bms.py header callback
+34
View File
@@ -0,0 +1,34 @@
Subject: SPF %(result)s (POSSIBLE FORGERY)
This is an automatically generated Delivery Status Notification.
THIS IS A WARNING MESSAGE ONLY.
YOU DO *NOT* NEED TO RESEND YOUR MESSAGE.
Delivery to the following recipients has been delayed.
%(rcpt)s
Subject: %(subject)s
Received-SPF: %(spf_result)s
Your sender policy (or lack thereof) indicated that the above email was not
sent via an authorized SMTP server, but may still be legitimate. Since there
is no positive confirmation that the message is really from you, we have
to give it extra scrutiny - including verifying that the sender really
exists by sending you this DSN. We will remember this sender and not
bother you again for while. You can avoid this message entirely for
legitimate mail by using an authorized SMTP server. Contact your mail
administrator and ask how to configure your email client to use an
authorized server.
If you never sent the above message, then your domain has been forged.
Your mail admin needs to publish a strict SPF record so that I can reject
those forgeries instead of bugging you about them.
If you need further assistance, please do not hesitate to contact me.
Kind regards,
postmaster@%(receiver)s
+31
View File
@@ -0,0 +1,31 @@
Subject: Critical SPF configuration error
This is an automatically generated Delivery Status Notification.
THIS IS A WARNING MESSAGE ONLY.
YOU DO *NOT* NEED TO RESEND YOUR MESSAGE.
Delivery to the following recipients has been delayed.
%(rcpt)s
Subject: %(subject)s
Your spf record has a permanent error. The error was:
%(perm_error)s
We will reinterpret your record using "lax" processing heuristics
which may result in your mail being accepted anyway. But you or your
mail administrator need to fix your SPF record as soon as possible.
We are sending you this message to alert you to the fact that
you have problems with your email configuration.
If you need further assistance, please do not hesitate to
contact me again.
Kind regards,
postmaster@%(receiver)s
+237
View File
@@ -0,0 +1,237 @@
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<html>
<head>
<title>Python Milter Mail Policy </title>
</head><body>
<h1> Python Milter Mail Policy </h1>
<h3> Classify connection </h3>
When the SMTP client connects, the connection IP address is
saved for later verification, and the connection
is classified as INTERNAL or EXTERNAL by matching the ip
address against the <code>internal_connect</code> configuration.
IP addresses with no PTR, and PTR names that look like
the kind assigned to dynamic IPs (as determined by a heuristic
algorithm) are flagged as DYNAMIC. IPs that match the
<code>trusted_relay</code> configuration are flagged as TRUSTED.
<p>
Examples from the log file (<i>not</i> the SMTP error message returned):
<pre>
2005Jul29 13:56:53 [71207] connect from p50863492.dip0.t-ipconnect.de at ('80.134.52.146', 1858) EXTERNAL DYN
2005Jul29 18:10:15 [74511] connect from foopub at ('1.2.3.4', 46513) EXTERNAL TRUSTED
2005Jul29 14:41:00 [71805] connect from foobar at ('192.168.0.1', 41205) INTERNAL
2005Jul29 14:41:15 [71806] connect from cncln.online.ln.cn at ('218.25.240.137', 35992) EXTERNAL
</pre>
<p>
Certain obviously evil PTR names are blocked at this point:
"localhost" (when IP is not 127.*) and ".".
<pre>
2005Jul29 14:49:50 [71918] connect from localhost at ('221.132.0.6', 50507) EXTERNAL
2005Jul29 14:49:50 [71918] REJECT: PTR is localhost
</pre>
<h3> HELO Check </h3>
The HELO name provided by the client is saved for later verification
(for example by SPF). We could validate the HELO at this point
by verifying that an A record for the HELO name matches the connect ip.
However, currently we only block certain obvious problems.
HELO names that look like an IP4 address
and ones that match the <code>hello_blacklist</code> configuration
are immediately rejected. The hello_blacklist typically contains
the current MTAs own HELO name or email domains.
Clients that attempt to skip HELO are immediately rejected.
<pre>
2005Jul29 18:10:15 [74512] hello from example.com
2005Jul29 18:10:15 [74512] REJECT: spam from self: example.com
2005Jul29 18:17:09 [74581] hello from 80.191.244.69
2005Jul29 18:17:09 [74581] REJECT: numeric hello name: 80.191.244.69
</pre>
<h3> MAIL FROM Check </h3>
Before calling our milter, sendmail checks a DNS blacklist to
block banned sender domains. We never see a blocked domain.
<p>
The MAIL FROM address is saved for possible use by the smart-alias
feature. First, the <code>internal_domains</code> is used for
a simple screening if defined. If the MAIL FROM for an INTERNAL connection
is NOT in <code>internal_domains</code>, then it is rejected (the
PC is most likely infected and attempting to send out spam).
If the MAIL FROM for an EXTERNAL connection IS in
<code>internal_domains</code>, then the message is immediately rejected.
This is quick and effective for most small company MTAs. For more
complex mail networks, it is too simplistic, and should not be defined.
SPF will handle the complex cases.
<h4> wiretap </h4>
The wiretap feature can screen and/or monitor mail to/from certain
users. If the MAIL FROM is being wiretapped, the recipients are
altered accordingly.
<h4> SPF check </h4>
Finally, the MAIL FROM, connect IP, and HELO name are checked against
any SPF records published via DNS for the alleged sender (MAIL FROM).
If there is no SPF record, we check for a local substitute under the
domain defined in the <code>[spf]delegate</code> configuration.
Further checks depend on the result.
<table border=1>
<tr><th>NONE</th><td>
If there is no SPF record (official or delegated), then we
initiate a "three strikes and your out" regime, which looks for
<b>some</b> form of validated identification.
<ol>
<li>We try a "best guess" SPF record of "v=spf1 a/24 mx/24 ptr". If this
passes, good.
<li> We try to validate the HELO name. First check for an SPF record.
Otherwise, check whether the connect IP matches any A record for
the HELO name, or any A record for any MX name for the HELO name,
or is at least in the same /24 subnet as any of the above.
(In other words, a HELO SPF "best guess" of "v=spf1 a/24 mx/24".)
If so, good. We consider the HELO validated. If the HELO SPF
check fails, we reject the email.
</ol>
<pre>
2005Jul30 19:45:16 [93991] connect from [221.200.41.54] at ('221.200.41.54', 3581) EXTERNAL DYN
2005Jul30 19:45:18 [93991] hello from adelphia.net
2005Jul30 19:45:19 [93991] mail from <wendy.stubbsua@link-it.com> ()
2005Jul30 19:45:19 [93991] REJECT: hello SPF: fail 550 access denied
</pre>
<ol>
<li> If there is a validated PTR name, and it doesn't look
like a dynamic name, good. We consider the connection validated.
</ol>
If any of the above can be validated, we continue on.
If none of the above can be validated, and the <code>[SPF]reject_noptr</code>
option is true, we reject the message immediately with the explanation
that we need some form of valid identification before we accept an email.
If <code>[SPF]reject_noptr</code> is false, we flag the message as
needing Call Back Validation.
The Call Back Valildation sends a DSN to the purported sender informing
them of the lack of identification. If the message is legitimate, the
sender needs to know that their email setup is broken and should be corrected.
If the message is forged, the sender is informed of the forgery,
and their need to publish an SPF record or at least use a valid HELO name.
If the purported sender does not accept the DSN,
then the message is rejected. The CBV status is cached to avoid
annoying the purported sender with too many DSNs. Currently, the DSN
is repeated to the same sender once per month.
<p>
In this example, although 3com.com has no SPF record, we assume that
any legitimate mail from them will at least have a valid HELO or PTR.
<pre>
2005Jul30 23:52:03 [96777] connect from [222.252.233.200] at ('222.252.233.200', 29934) EXTERNAL DYN
2005Jul30 23:52:03 [96777] hello from 3mail.3com.com
2005Jul30 23:52:04 [96777] mail from <etec_nic_family@3mail.3com.com> ()
2005Jul30 23:52:04 [96777] REJECT: no PTR, HELO or SPF
</pre>
</td></tr>
<tr><th>PASS</th><td>
A pass result normally lets the email continue on, but the domain is
tracked for reputation (and may be blocked), and may skip content scanning if
it matches a whitelist.
<pre>
2005Jul24 17:44:26 [2104] mail from <gnucash-devel-bounces@gnucash.org> ('SIZE=4410',)
2005Jul24 17:44:26 [2104] Received-SPF: pass (mail.bmsi.com: domain of gnucash.org
designates 204.107.200.65 as permitted sender)
client-ip=204.107.200.65; envelope-from=gnucash-devel-bounces@gnucash.org; helo=cvs.gnucash.org;
</pre>
</td></tr>
<tr><th>NEUTRAL</th><td>
A neutral result normally lets the email continue on, but the domain is not
tracked for reputation or matched against any whitelists.
Highly forged domains listed in <code>[SPF]reject_neutral</code> are
rejected.
<pre>
2005Jul24 17:41:37 [2070] connect from cp500627-a.dbsch1.nb.home.nl at ('84.27.225.3', 3465) EXTERNAL
2005Jul24 17:41:37 [2070] hello from cp500627-a.dbsch1.nb.home.nl
2005Jul24 17:41:38 [2070] mail from <nwarjejkw@yahoo.com> ()
2005Jul24 17:41:38 [2070] REJECT: SPF neutral for nwarjejkw@yahoo.com
</pre>
</td></tr>
<tr><th>SOFTFAIL</th><td>
A softfail result normally lets the email continue on, but the domain is not
tracked for reputation or matched against any whitelists. Furthermore,
the message is flagged as needing Call Back Validation,
and the highly forged domains listed in <code>[SPF]reject_neutral</code> are
rejected as well.
<p>
At present, we also require a valid HELO or PTR to avoid rejecting
a softfail. But this should probably change to only require a
successful CBV.
<p>
The Call Back Valildation sends a DSN to the purported sender informing
them of the softfail. If the message is legitimate, the sender needs
to know about the softfail so that their email setup can be corrected.
If the message is forged, the sender is informed of the forgery, confirming
that SPF is protecting their reputation and encouraging a rapid transition
to a strict policy. If the purported sender does not accept the DSN,
then the message is rejected. The CBV status is cached to avoid
annoying the purported sender with too many DSNs. Currently, the DSN
is repeated to the same sender once per month.
<pre>
2005Jul24 15:41:33 [801] mail from <Aitp@horafeliz.com> ()
2005Jul24 15:41:33 [801] Received-SPF: softfail (mail.bmsi.com: transitioning domain of horafeliz.com
does not designate 221.184.83.185 as permitted sender)
client-ip=221.184.83.185; envelope-from=Aitp@horafeliz.com;
helo=p8185-ipad30funabasi.chiba.ocn.ne.jp;
2005Jul24 15:41:33 [801] rcpt to <david@example.com> ()
2005Jul24 15:41:35 [801] Subject: Microsoft, Adobe, Macromedia, Corel software. Up to 80% discount.
2005Jul24 15:41:35 [801] X-Mailer: Microsoft Outlook, Build 10.0.2605
2005Jul24 15:41:35 [801] CBV: Aitp@horafeliz.com
2005Jul24 15:41:38 [801] REJECT: CBV: 550 <Aitp@horafeliz.com>: User unknown
</pre>
</td></tr>
<tr><th>FAIL</th><td>
The message is rejected with a reference the SPF why page.
<pre>
2005Jul30 19:53:27 [94070] connect from [212.70.52.16] at ('212.70.52.16', 3192) EXTERNAL DYN
2005Jul30 19:53:27 [94070] hello from winzip.com
2005Jul30 19:53:27 [94070] mail from <dan@winzip.com> ()
2005Jul30 19:53:27 [94070] REJECT: SPF fail 550 SPF fail:
see http://openspf.com/why.html?sender=dan@winzip.com&ip=212.70.52.16
</pre>
</td></tr>
<tr><th>PERMERROR</th><td>
Permanent errors were called "unknown", and are still show that way
in the log. The message is rejected. Previously, we enabled "lax" parsing
of the SPF record, but rejecting is better because it informs the
sender about their problem. The next milter version will
look for a local substitute SPF record (as for a missing SPF record)
before rejecting. This will inform the sender of their problem, but
also let the receiver install a temporary workaround.
<pre>
2005Jul24 18:05:37 [2312] mail from <b-mihdbcgaacaa-becibijh-000-@msg.euxiphipops.com> ()
2005Jul24 18:05:37 [2312] REJECT: SPF unknown 550 SPF Permanent Error:
include mechanism missing domain: include
</pre>
The SPF record for msg.euxiphipops.com looked like this at the time of the
above error:
<pre>
msg.euxiphipops.com TXT "v=spf1 mx ptr a include"
</pre>
</td></tr>
<tr><th>TEMPERROR</th><td>
Temporary errors result in a 451 "Try again later" response. The sender
should retry the message at a later time.
<pre>
2005Jul24 07:33:13 [29846] mail from <quickenloans@rate.quicken.com> ('SIZE=73775', 'BODY=8BITMIME')
2005Jul24 07:33:43 [29846] TEMPFAIL: SPF error 450 SPF Temporary Error: DNS Timeout
</pre>
</td></tr>
</table>
</body>
</html>
+26
View File
@@ -0,0 +1,26 @@
Subject: DELIVERY STATUS (POSSIBLE SPAM)
This is an automatically generated Delivery Status Notification.
THIS IS A WARNING MESSAGE ONLY.
YOU DO *NOT* NEED TO RESEND YOUR MESSAGE.
Delivery to the following recipients has been delayed.
%(rcpt)s
Subject: %(subject)s
Received-SPF: %(spf_result)s
A statistical analysis of your message has classified it as junk mail,
and it has been quarantined. Eventually, the recipients will review
their quarantined mail and may notice your message. If your message is
important, please contact them via other means. You may also try sending
them a simple plain text message.
If you need further assistance, please do not hesitate to contact me.
Kind regards,
postmaster@%(receiver)s
+2 -2
View File
@@ -1,5 +1,5 @@
[bdist_rpm]
python=python2
python=python2.4
doc_files=README NEWS TODO
packager=Stuart D. Gathman <stuart@bmsi.com>
release=2.4
release=1
+2 -1
View File
@@ -1,6 +1,7 @@
import os
import sys
from distutils.core import setup, Extension
import Milter
# FIXME: on some versions of sendmail, smutil is renamed to sm
libs = ["milter", "smutil"]
@@ -12,7 +13,7 @@ if sys.version < '2.2.3':
DistributionMetadata.classifiers = None
DistributionMetadata.download_url = None
setup(name = "milter", version = "0.8.2",
setup(name = "milter", version = Milter.__version__,
description="Python interface to sendmail milter API",
long_description="""\
This is a python extension module to enable python scripts to
+4 -2
View File
@@ -1,4 +1,4 @@
Subject: SPF softfail (POSSIBLE FORGERY)
Subject: SPF %(result)s (POSSIBLE FORGERY)
This is an automatically generated Delivery Status Notification.
@@ -14,7 +14,9 @@ Subject: %(subject)s
Received-SPF: %(spf_result)s
Your sender policy indicated that the above email was likely forged and that
feedback was desired.
feedback was desired. If you are sending from a foreign ISP,
then you may need to follow your home ISPs instructions for configuring
your outgoing mail server.
If you need further assistance, please do not hesitate to contact me.
+53 -10
View File
@@ -47,6 +47,28 @@ For news, bugfixes, etc. visit the home page for this implementation at
# Terrence is not responding to email.
#
# $Log$
# Revision 1.13 2005/07/22 16:00:23 customdesigned
# Limit CNAME chains independently of DNS lookup limit
#
# Revision 1.31 2005/07/22 02:11:50 customdesigned
# Use dictionary to check for CNAME loops. Check limit independently for
# each top level name, just like for PTR.
#
# Revision 1.30 2005/07/21 20:07:31 customdesigned
# Translate DNS error in DNSLookup. This completely isolates DNS
# dependencies to the DNSLookup method.
#
# Revision 1.29 2005/07/21 17:49:39 customdesigned
# My best guess at what RFC intended for limiting CNAME loops.
#
# Revision 1.28 2005/07/21 17:37:08 customdesigned
# Break out external DNSLookup method so that test suite can
# duplicate CNAME loop bug. Test zone data dictionary now
# mirrors structure of real DNS.
#
# Revision 1.27 2005/07/21 15:26:06 customdesigned
# First cut at updating docs. Test suite is obsolete.
#
# Revision 1.26 2005/07/20 03:12:40 customdesigned
# When not in strict mode, don't give PermErr for bad mechanism until
# encountered during evaluation.
@@ -253,6 +275,16 @@ if not hasattr(DNS.Type,'SPF'):
DNS.Type.typemap[99] = 'SPF'
DNS.Lib.RRunpacker.getSPFdata = DNS.Lib.RRunpacker.getTXTdata
def DNSLookup(name,qtype):
try:
req = DNS.DnsRequest(name, qtype=qtype)
resp = req.req()
#resp.show()
# key k: ('wayforward.net', 'A'), value v
return [((a['name'], a['typename']), a['data']) for a in resp.answers]
except DNS.DNSError,x:
raise TempError,'DNS ' + str(x)
# 32-bit IPv4 address mask
MASK = 0xFFFFFFFFL
@@ -305,6 +337,7 @@ DEFAULT_SPF = 'v=spf1 a/24 mx/24 ptr'
MAX_LOOKUP = 10 #draft-schlitt-spf-classic-02 Para 10.1
MAX_MX = 10 #draft-schlitt-spf-classic-02 Para 10.1
MAX_PTR = 10 #draft-schlitt-spf-classic-02 Para 10.1
MAX_CNAME = 10 # analogous interpretation to MAX_PTR
MAX_RECURSION = 20
ALL_MECHANISMS = ('a', 'mx', 'ptr', 'exists', 'include', 'ip4', 'ip6', 'all')
COMMON_MISTAKES = { 'prt': 'ptr', 'ip': 'ip4', 'ipv4': 'ip4', 'ipv6': 'ip6' }
@@ -409,6 +442,9 @@ class query(object):
>>> q.check(spf='v=spf1 ip4:192.0.0.0/8 ?all moo')
('unknown', 550, 'SPF Permanent Error: Unknown mechanism found: moo')
>>> q.check(spf='v=spf1 =a ?all moo')
('unknown', 550, 'SPF Permanent Error: Unknown qualifier, IETF draft para 4.6.1, found in: =a')
>>> q.check(spf='v=spf1 ip4:192.0.0.0/8 ~all')
('pass', 250, 'sender SPF verified')
@@ -450,8 +486,6 @@ class query(object):
self.perm_error.ext = rc
raise self.perm_error
return rc
except DNS.DNSError,x:
return ('error', 450, 'SPF DNS Error: ' + str(x))
except TempError,x:
return ('error', 450, 'SPF Temporary Error: ' + str(x))
except PermError,x:
@@ -601,9 +635,15 @@ class query(object):
if res == 'pass':
break
if res == 'none':
try:
if self.strict or not self.perm_error:
raise PermError(
'No valid SPF record for included domain: %s'%arg,
mech)
except PermError,x:
if self.strict:
raise x
self.perm_error = x
continue
elif m == 'all':
break
@@ -844,7 +884,7 @@ class query(object):
"""Get a list of domain names for an IP address."""
return self.dns(reverse_dots(i) + ".in-addr.arpa", 'PTR')
def dns(self, name, qtype):
def dns(self, name, qtype, cnames=None):
"""DNS query.
If the result is in cache, return that. Otherwise pull the
@@ -861,18 +901,21 @@ class query(object):
result = self.cache.get( (name, qtype) )
cname = None
if not result:
req = DNS.DnsRequest(name, qtype=qtype)
resp = req.req()
#resp.show()
for a in resp.answers:
# key k: ('wayforward.net', 'A'), value v
k, v = (a['name'], a['typename']), a['data']
for k,v in DNSLookup(name,qtype):
if k == (name, 'CNAME'):
cname = v
self.cache.setdefault(k, []).append(v)
result = self.cache.get( (name, qtype), [])
if not result and cname:
result = self.dns(cname, qtype)
if not cnames:
cnames = {}
elif len(cnames) >= MAX_CNAME:
raise PermError(
'Length of CNAME chain exceeds %d' % MAX_CNAME)
cnames[name] = cname
if cname in cnames:
raise PermError,'CNAME loop'
result = self.dns(cname, qtype, cnames=cnames)
return result
def get_header(self,res,receiver=None):
+8 -3
View File
@@ -1,4 +1,5 @@
import unittest
import doctest
import Milter
import bms
import mime
@@ -22,7 +23,7 @@ class TestMilter(bms.bmsMilter):
def getsymval(self,name):
if name == 'j': return 'test.milter.org'
return bms.bmsMilter.getsymval(self,name)
return ''
def replacebody(self,chunk):
if self._body:
@@ -284,7 +285,10 @@ class BMSMilterTestCase(unittest.TestCase):
# self.failUnless(rc == Milter.REJECT)
# milter.close();
def suite(): return unittest.makeSuite(BMSMilterTestCase,'test')
def suite():
s = unittest.makeSuite(BMSMilterTestCase,'test')
s.addTest(doctest.DocTestSuite(bms))
return s
if __name__ == '__main__':
if len(sys.argv) > 1:
@@ -296,4 +300,5 @@ if __name__ == '__main__':
fp = milter._body
sys.stdout.write(fp.getvalue())
else:
unittest.main()
#unittest.main()
unittest.TextTestRunner().run(suite())