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GNU GENERAL PUBLIC LICENSE
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recursive-include docs *
recursive-include misc *

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# pyquarantine-milter
A pymilter based sendmail/postfix pre-queue filter with the ability to quarantine e-mails, sending notifications
to recipients and respond with a milter-action (ACCEPT, DISCARD or REJECT).
It is useful in many cases because of its felxible configuration and the ability to handle any number of quarantines.
The MTA can check e-mail headers using regular expressions to determine if and which quarantine to use.
Each quarantine can be configured with a quarantine type, notification type, whitelist and an action to respond with.
The project is currently in alpha status, but will soon be used in a productive enterprise environment and possibly existing bugs will be fixed.
## Requirements
* pymilter <https://pythonhosted.org/pymilter/>
* peewee <https://github.com/coleifer/peewee/>
* BeautifulSoup <https://www.crummy.com/software/BeautifulSoup/>
## Configuration
The pyquarantine module uses an INI-style configuration file. The sections are described below.
### Section "global"
Any available configuration option can be set in the global section as default instead of in a quarantine section.
The following configuration options are mandatory in the global section:
* **quarantines**
Comma-separated, ordered list of active quarantines. For each, there must be a section of the same name in the configuration.
* **smtp_host**
SMTP host to inject original e-mails. This is needed if not all recipients of an e-mail are whitelisted
* **smtp_port**
SMTP port
### Quarantine sections
The following configuration options are mandatory in each quarantine section:
* **regex**
Regular expression to filter e-mail headers.
* **type**
One of the quarantine-types described below.
* **action**
One of the actions described below.
* **notification**
One of the notification types described below.
* **whitelist**
Database connection string (e.g. mysql://user:password@host:port) or NONE to disable whitelist.
### Quarantine types
* **NONE**
Original e-mails scrapped, sent to nirvana, black-holed or however you want to call it.
* **FILE**
Original e-mails are stored on the filesystem with a unique filename. The filename is available as a
template variable used in notifiaction templates.
The following configuration options are mandatory for this quarantine type:
* **directory**
The directory in which quarantined e-mails are stored.
### Notification types
* **NONE**
No quarantine notifications will be sent.
* **EMAIL**
Quarantine e-mail notifications are sent to recipients. The SMTP host and port, E-mail template, from-address and the subject are configurable for each quarantine. The templates must contain the notification e-mail text in HTML form.
The following template variables are available:
* **{EMAIL_FROM}**
E-mail from-address received by the milter (envelope-from).
* **{EMAIL_TO}**
E-mail recipient address of this notification.
* **{EMAIL_SUBJECT}**
Configured e-mail subject.
* **{EMAIL_QUARANTINE_ID}**
Quarantine-ID of the original e-mail if available, empty otherwise.
The following configuration options are mandatory for this notification type:
* **notification_email_from**
Notification e-mail from-address.
* **notification_email_subject**
Notification e-mail subject.
* **notification_email_template**
Notification e-mail template to use.
* **notification_email_replacement_img**
An image to replace images in e-mail.
### Actions
Every quarantine responds with a milter-action if an e-mail header matches the configured regular expression.
The following actions are available:
* **ACCEPT**
Continue processing e-mails.
* **DISCARD**
Silently discard e-mails.
* **REJECT**
Reject e-mails.
### Whitelist
If a whitelist database connection string is configured, the following configuration options are mandatory:
* **whitelist_table**
Database table to use.
## Developer information
Everyone who wants to improve or extend this project is very welcome.

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# This is an example /etc/pyquarantine/pyquarantine.conf file.
# Copy it into place before use.
#
# Comments: use '#' for comment lines and ';' (following a space) for inline comments.
#
# If an option is not present in a quarantine section, it will be read from
# the global section.
#
[global]
# Option: quarantines
# Notes: Set active quarantines (comma-separated).
# Each active quarantine must have a section with the same name below.
# The quarantine name 'global' is forbidden and will be ignored.
# Quarantine names must be unique.
# Values: [ ACTIVE ]
#
quarantines = spam
# Option: smtp_host
# Notes: Set the SMTP host. It will be used to (re-)inject emails.
# Values: [ HOSTNAME | IP_ADDRESS ]
#
smtp_host = 127.0.0.1
# Option: smtp_port
# Notes: Set the SMTP port.
# Values: [ PORT ]
#
smtp_port = 25
[spam]
# Option: regex
# Notes: Set the regular expression to match against email headers.
# If the regex matches any of the email headers, the email
# will be processed by this quarantine.
# Values: [ REGEX ]
#
regex = ^X-Spam-Flag: YES
# Option: type
# Notes: Set the quarantine type.
# Values: [ file | none ]
#
type = file
# Option: directory
# Notes: Set the directory to store quarantined emails.
# This option is needed by quarantine type 'file'.
# Values: [ DIRECTORY ]
#
directory = /var/lib/pyquarantine/spam
# Option: action
# Notes: Set the milter action to perform if email is processed by this quarantine.
# Values: [ accept | discard | reject ]
#
action = discard
# Option: notification
# Notes: Set the notification type.
# Values: [ email | none ]
#
notification = email
# Option: notification_email_from
# Notes: Set the from address used when sending notification emails.
# This option is needed by notification type 'email'.
# Values: [ FROM_ADDRESS ]
#
notification_email_from = notification@domain.tld
# Option: notification_email_usbject
# Notes: Set the subject used when sending notification emails.
# This option is needed by notification type 'email'.
# Values: [ SUBJECT ]
#
notification_email_subject = Spam Quarantine Notification
# Option: notification_email_template
# Notes: Set the template used when sending notification emails.
# A relative path to this config file can be used.
# This option is needed by notification type 'email'.
# Values: [ TEMPLATE_FILE ]
#
notification_email_template = templates/notification.template
# Option: notification_email_replacement_img
# Notes: Set the replacement image for images within emails.
# A relative path to this config file can be used.
# This option is needed by notification type 'email'.
# Values: [ IMAGE_FILE ]
#
notification_email_replacement_img = templates/removed.png
# Option: whitelist
# Notes: Set the whitelist of this quarantine.
# If a whitelist is used, the configured user must have
# read/write access to the table configured below.
# Values: [ DB_CONNECTION_STRING | none ]
#
whitelist = mysql://user:password@localhost/database
# Option: whitelist_table
# Notes: Set the database table name.
# This option is needed if a whitelist is configured.
# Values: [ DATABASE_TABLE]
#
whitelist_table = whitelist

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<html>
<body>
<h1>This is a spam notification mail</h1>
<b>From:</b> {EMAIL_FROM}<br/>
<b>To:</b> {EMAIL_TO}<br/>
<b>Subject:</b> {EMAIL_SUBJECT}<br/>
<b>Quarantine-ID:</b> {EMAIL_QUARANTINE_ID}<br/><br/><br/>
{EMAIL_HTML_TEXT}
</body>
</html>

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# /etc/conf.d/pyquarantine-milter: config file for /etc/init.d/pyquarantine-milter
# Set the socket used to communicate with the MTA.
# Examples:
# unix:/path/to/socket a named pipe
# inet:8899 listen on ANY interface
# inet:8899@localhost listen on a specific interface
# inet6:8899 listen on ANY interface
# inet6:8899@[2001:db8:1234::1] listen on a specific interface
SOCKET="inet:8899@127.0.0.1"
# Start the daemon as the user. You can optionally append a group name here also.
# USER="daemon"
# USER="daemon:nobody"
# Optional parameters for pyquarantine-milter
# MILTER_OPTS=""

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#!/sbin/openrc-run
user=${USER:-daemon:nobody}
socket="${SOCKET:-}"
milter_opts="${MILTER_OPTS:-}"
pidfile="/run/${RC_SVCNAME}.pid"
command="/usr/bin/pyquarantine-milter"
command_args="-s ${socket} ${milter_opts}"
command_background=true
start_stop_daemon_args="--user ${user}"
extra_commands="configtest"
depend() {
need net
before mta
}
checkconfig() {
if [ -z "${socket}" ]; then
eerror "No socket specified in config!"
fi
OUTPUT=$( ${command} ${command_args} -t 2>&1 )
ret=$?
if [ $ret -ne 0 ]; then
eerror "${SVCNAME} has detected an error in your configuration:"
printf "%s\n" "${OUTPUT}"
fi
return $ret
}
configtest() {
ebegin "Checking ${SVCNAME} configuration"
checkconfig
eend $?
}
start_pre() {
if [ "${RC_CMD}" != "restart" ]; then
checkconfig || return $?
fi
}
stop_pre() {
if [ "${RC_CMD}" != "restart" ]; then
checkconfig || return $?
fi
}

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#!/usr/bin/env python2
#
# PyQuarantine-Milter is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# PyQuarantine-Milter 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 PyQuarantineMilter. If not, see <http://www.gnu.org/licenses/>.
#
__all__ = ["QuarantineMilter", "generate_milter_config", "reload_config", "mailer", "notifications", "run", "quarantines", "whitelists"]
import ConfigParser
import Milter
import StringIO
import logging
import os
import re
import sys
import mailer
import quarantines
import notifications
import whitelists
from Milter.utils import parse_addr
class QuarantineMilter(Milter.Base):
"""QuarantineMilter based on Milter.Base to implement milter communication
The class variable config needs to be filled with the result of the generate_milter_config function.
"""
config = None
# list of default config files
_config_files = ["/etc/pyquarantine/pyquarantine.conf", os.path.expanduser('~/pyquarantine.conf'), "pyquarantine.conf"]
# list of possible actions
_actions = {"ACCEPT": Milter.ACCEPT, "REJECT": Milter.REJECT, "DISCARD": Milter.DISCARD}
def __init__(self):
self.logger = logging.getLogger(__name__)
# save config, it must not change during runtime
self.config = QuarantineMilter.config
@staticmethod
def get_configfiles():
return QuarantineMilter._config_files
@staticmethod
def get_actions():
return QuarantineMilter._actions
@staticmethod
def set_configfiles(config_files):
QuarantineMilter._config_files = config_files
@Milter.noreply
def envfrom(self, mailfrom, *str):
self.mailfrom = "@".join(parse_addr(mailfrom)).lower()
self.recipients = set()
return Milter.CONTINUE
@Milter.noreply
def envrcpt(self, to, *str):
self.recipients.add("@".join(parse_addr(to)).lower())
return Milter.CONTINUE
@Milter.noreply
def data(self):
self.queueid = self.getsymval('i')
self.logger.debug("{}: received queue-id from MTA".format(self.queueid))
self.recipients = list(self.recipients)
self.headers = []
self.subject = ""
return Milter.CONTINUE
@Milter.noreply
def header(self, name, value):
self.headers.append("{}: {}".format(name, value))
if name.lower() == "subject":
self.subject = value
return Milter.CONTINUE
def eoh(self):
self.matched = None
self.whitelist = whitelists.WhitelistCache()
# iterate email headers
for header in self.headers:
self.logger.debug("{}: checking header '{}' against regex of every configured quarantine".format(self.queueid, header))
# iterate quarantines
for name, quarantine in self.config.items():
if self.matched != None and quarantine["index"] == self.matched["index"]:
# a quarantine with higher precedence already matched, skip checks of quarantines with lower precedence
self.logger.debug("{}: quarantine '{}' matched already, skip further checks of this header".format(self.queueid, name))
break
self.logger.debug("{}: checking header against quarantine '{}'".format(self.queueid, name))
# check if header matches regex
if quarantine["regex_compiled"].match(header):
if quarantine["whitelist"] != None and \
len(self.whitelist.get_whitelisted_recipients(quarantine["whitelist"], self.mailfrom, self.recipients)) == len(self.recipients):
# all recipients are whitelisted, continue with header checks
self.logger.debug("{}: header matched regex, but all recipients are whitelisted in quarantine '{}', continue checking this header".format(self.queueid, name))
continue
self.matched = quarantine
# skip checks of this header with quarantines with lower precedence
self.logger.debug("{}: header matched regex in quarantine '{}', further checks of this header will be skipped".format(self.queueid, name))
break
if self.matched != None and self.matched["index"] == 0:
self.logger.debug("{}: skipping checks of remaining headers, the quarantine with highest precedence matched already".format(self.queueid))
break
if self.matched != None:
self.logger.info("{}: email matched quarantine '{}'".format(self.queueid, self.matched["name"]))
# one of the configured quarantines matched
if self.matched["quarantine"] != None or self.matched["notification"] != None:
self.logger.debug("{}: initializing memory buffer to save email data".format(self.queueid))
# quarantine or notification configured, initialize memory buffer to save mail
self.fp = StringIO.StringIO()
# write email headers to memory buffer
self.fp.write("{}\n".format("\n".join(self.headers)))
else:
# quarantine and notification disabled, return configured action
self.logger.debug("{}: ".format(self.queueid))
self.logger.info("{}: quarantine and notification disabled, responding with configured action: {}".format(self.queueid, self.matched["action"].upper()))
return self.matched["milter_action"]
else:
# no quarantine matched, accept mail
self.logger.info("{}: email passed clean".format(self.queueid))
return Milter.ACCEPT
return Milter.CONTINUE
def body(self, chunk):
# save received body chunk
self.fp.write(chunk)
return Milter.CONTINUE
def eom(self):
if self.matched["whitelist"] != None:
whitelisted_recipients = self.whitelist.get_whitelisted_recipients(self.matched["whitelist"], self.mailfrom, self.recipients)
if len(whitelisted_recipients) > 0:
for recipient in whitelisted_recipients:
self.recipients.remove(recipient)
self.fp.seek(0)
self.logger.info("{}: sending original email to whitelisted recipient(s): {}".format(self.queueid, "<{}>".format(">,<".join(whitelisted_recipients))))
try:
mailer.sendmail(self.matched["smtp_host"], self.matched["smtp_port"], self.queueid, self.mailfrom, whitelisted_recipients, self.fp.read())
except Exception as e:
self.logger.error("{}: unable to send original email: {}".format(self.queueid, e))
return Milter.TEMPFAIL
if len(self.recipients) > 0:
quarantine_id = ""
if self.matched["quarantine"] != None:
# add email to quarantine
self.fp.seek(0)
try:
quarantine_id = self.matched["quarantine"].add(self.queueid, self.mailfrom, self.recipients, fp=self.fp)
except Exception as e:
self.logger.error("{}: unable to add email to quarantine: {}".format(self.queueid, e))
return Milter.TEMPFAIL
else:
self.logger.info("{}: added email to quarantine of recipient(s): {}".format(self.queueid, "<{}>".format(">,<".join(self.recipients))))
if self.matched["notification"] != None:
# notify
self.fp.seek(0)
try:
self.matched["notification"].notify(self.queueid, quarantine_id, self.subject, self.mailfrom, self.recipients, fp=self.fp)
except Exception as e:
self.logger.error("{}: unable to send notification(s): {}".format(self.queueid, e))
return Milter.TEMPFAIL
else:
self.logger.info("{}: sent notification(s) to: {}".format(self.queueid, "<{}>".format(">,<".join(self.recipients))))
self.fp.close()
# return configured action
self.logger.info("{}: responding with configured action: {}".format(self.queueid, self.matched["action"].upper()))
return self.matched["milter_action"]
def generate_milter_config(configtest=False):
"Generate the configuration for QuarantineMilter class."
logger = logging.getLogger(__name__)
# read config file
parser = ConfigParser.ConfigParser()
config_files = parser.read(QuarantineMilter.get_configfiles())
if len(config_files) == 0:
raise RuntimeError("config file not found")
QuarantineMilter.set_configfiles(config_files)
os.chdir(os.path.dirname(config_files[0]))
# check if mandatory config options in global section are present
if "global" not in parser.sections():
raise RuntimeError("mandatory section 'global' not present in config file")
for option in ["quarantines"]:
if not parser.has_option("global", option):
raise RuntimeError("mandatory option '{}' not present in config section 'global'".format(option))
config = {}
config["global"] = dict(parser.items("global"))
# iterate configured quarantines
quarantine_names = list(set(map(str.strip, parser.get("global", "quarantines").split(","))))
if "global" in quarantine_names:
logger.warning("removed illegal quarantine name 'global' from list of active quarantines")
del(quarantine_names["global"])
if len(quarantine_names) == 0:
raise RuntimeError("no quarantines configured")
idx = 0
for name in quarantine_names:
name = name.strip()
# check if config section for current quarantine is present
if name not in parser.sections():
raise RuntimeError("config section '{}' is not present".format(name))
config[name] = dict(parser.items(name))
config[name]["name"] = name
# check if mandatory config options are present in config
for option in ["regex", "type", "notification", "action", "whitelist", "smtp_host", "smtp_port"]:
if option not in config[name].keys() and \
option in config["global"].keys():
config[name][option] = config["global"][option]
if option not in config[name].keys():
raise RuntimeError("mandatory option '{}' not present in config section '{}' or 'global'".format(option, name))
logger.debug("preparing configuration for quarantine '{}' ...".format(name))
## add the index
config[name]["index"] = idx
idx += 1
# compile regex
regex = config[name]["regex"]
logger.debug("=> compiling regex '{}'".format(regex))
config[name]["regex_compiled"] = re.compile(regex)
# create quarantine instance
quarantine_type = config[name]["type"].lower()
if quarantine_type in quarantines.quarantine_types.keys():
logger.debug("=> initializing quarantine type '{}'".format(quarantine_type))
quarantine = quarantines.quarantine_types[quarantine_type](name, config, configtest)
elif quarantine_type == "none":
logger.debug("=> setting quarantine to NONE")
quarantine = None
else:
raise RuntimeError("unknown quarantine_type '{}'".format(quarantine_type))
config[name]["quarantine"] = quarantine
# create whitelist instance
whitelist = config[name]["whitelist"]
if whitelist.lower() == "none":
logger.debug("=> setting whitelist to NONE")
config[name]["whitelist"] = None
else:
logger.debug("=> initializing whitelist database")
config[name]["whitelist"] = whitelists.Whitelist(name, config, configtest)
# create notification instance
notification_type = config[name]["notification"].lower()
if notification_type in notifications.notification_types.keys():
logger.debug("=> initializing notification type '{}'".format(notification_type))
notification = notifications.notification_types[notification_type](name, config, configtest)
elif notification_type == "none":
logger.debug("=> setting notification to NONE")
notification = None
else:
raise RuntimeError("unknown notification type '{}'".format(notification_type))
config[name]["notification"] = notification
# determining milter action for this quarantine
action = config[name]["action"].upper()
if action in QuarantineMilter.get_actions().keys():
logger.debug("=> setting action to {}".format(action))
config[name]["milter_action"] = QuarantineMilter.get_actions()[action]
else:
raise RuntimeError("unknown action '{}' configured for quarantine '{}'".format(action, name))
# remove global section from config, every section should be a quarantine
del(config["global"])
if configtest:
print("Configuration ok")
return config
def reload_config():
"Reload the configuration of QuarantineMilter class."
logger = logging.getLogger(__name__)
logger.debug("received SIGUSR1")
try:
config = generate_milter_config()
except RuntimeError as e:
logger.info(e)
logger.info("daemon is still running with previous configuration")
else:
logger.info("reloading configuration")
QuarantineMilter.config = config

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#!/usr/bin/env python2
#
# PyQuarantine-Milter is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# PyQuarantine-Milter 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 PyQuarantineMilter. If not, see <http://www.gnu.org/licenses/>.
#
import logging
import smtplib
import sys
from multiprocessing import Process, Queue
logger = logging.getLogger(__name__)
queue = Queue(maxsize=50)
process = None
def mailprocess():
"Mailer process to send emails asynchronously."
global logger
global queue
try:
while True:
m = queue.get()
if not m: break
smtp_host, smtp_port, queueid, mailfrom, recipient, mail = m
try:
s = smtplib.SMTP(host=smtp_host, port=smtp_port)
s.sendmail(mailfrom, [recipient], mail)
except Exception as e:
logger.error("{}: error while sending email to <{}> via {}: {}".format(queueid, recipient, smtp_host, e))
else:
logger.info("{}: email to <{}> sent successfully".format(queueid, recipient))
s.quit()
except KeyboardInterrupt:
pass
logger.debug("mailer process terminated")
def sendmail(smtp_host, smtp_port, queueid, mailfrom, recipients, mail):
"Send an email."
global logger
global process
global queue
if type(recipients) == str:
recipients = [recipients]
# start mailprocess if it is not started yet
if process == None:
process = Process(target=mailprocess)
process.daemon = True
logger.debug("starting mailer process")
process.start()
for recipient in recipients:
queue.put((smtp_host, smtp_port, queueid, mailfrom, recipient, mail))

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#!/usr/bin/env python2
#
# PyQuarantine-Milter is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# PyQuarantine-Milter 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 PyQuarantineMilter. If not, see <http://www.gnu.org/licenses/>.
#
import email
import logging
import mailer
import re
from bs4 import BeautifulSoup
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.image import MIMEImage
class BaseNotification(object):
"Notification base class"
def __init__(self, quarantine_name, config, configtest=False):
self.quarantine_name = quarantine_name
self.config = config[quarantine_name]
self.global_config = config["global"]
self.logger = logging.getLogger(__name__)
def notify(self, queueid, quarantine_id, subject, mailfrom, recipients, fp):
pass
class EMailNotification(BaseNotification):
"Notification class to send notifications via mail."
_html_text = "text/html"
_plain_text = "text/plain"
_bad_tags = [
"applet",
"embed",
"frame",
"frameset",
"head",
"iframe",
"script"
]
_good_tags = [
"a",
"b",
"br",
"center",
"div",
"font",
"h1",
"h2",
"h3",
"h4",
"h5",
"h6",
"i",
"img",
"li",
"span",
"table",
"td",
"th",
"tr",
"tt",
"u",
"ul"
]
good_attributes = [
"align",
"alt",
"bgcolor",
"border",
"cellpadding",
"cellspacing",
"colspan",
"dir",
"headers",
"height",
"name",
"rowspan",
"size",
"src",
"style",
"title",
"type",
"value",
"width"
]
def __init__(self, quarantine_name, config, configtest=False):
super(EMailNotification, self).__init__(quarantine_name, config, configtest)
# check if mandatory options are present in config
for option in ["smtp_host", "smtp_port", "notification_email_from", "notification_email_subject", "notification_email_template", "notification_email_replacement_img"]:
if option not in self.config.keys() and option in self.global_config.keys():
self.config[option] = self.global_config[option]
if option not in self.config.keys():
raise RuntimeError("mandatory option '{}' not present in config section '{}' or 'global'".format(option, self.quarantine_name))
self.smtp_host = self.config["smtp_host"]
self.smtp_port = self.config["smtp_port"]
self.mailfrom = self.config["notification_email_from"]
self.subject = self.config["notification_email_subject"]
try:
self.template = open(self.config["notification_email_template"], "rb").read()
except Exception as e:
raise RuntimeError("error reading email template: {}".format(e))
try:
self.replacement_img = MIMEImage(open(self.config["notification_email_replacement_img"], "rb").read())
except Exception as e:
raise RuntimeError("error reading email replacement image: {}".format(e))
else:
self.replacement_img.add_header("Content-ID", "<removed_for_security_reasons>")
def get_text(self, part):
"Get the mail text in html form from email part."
mimetype = part.get_content_type()
text = part.get_payload(decode=True)
if mimetype == EMailNotification._plain_text:
text = re.sub(r"^(.*)$", r"\1<br/>\n", text, flags=re.MULTILINE)
soup = BeautifulSoup(text, "lxml", from_encoding=part.get_content_charset())
return soup
def get_text_multipart(self, msg, preferred=_html_text):
"Get the mail text of a multipart email in html form."
soup = None
for part in msg.get_payload():
mimetype = part.get_content_type()
if mimetype in [EMailNotification._plain_text, EMailNotification._html_text]:
soup = self.get_text(part)
elif mimetype.startswith("multipart"):
soup = self.get_text_multipart(part, preferred)
if soup != None and mimetype == preferred:
break
return soup
def sanitize(self, soup):
"Sanitize mail html text."
# completly remove bad elements
for element in soup(EMailNotification._bad_tags):
element.extract()
# remove not whitelisted elements, but keep their content
for element in soup.find_all(True):
if element.name not in EMailNotification._good_tags:
element.replaceWithChildren()
# remove not whitelisted attributes
for element in soup.find_all(True):
for attribute in element.attrs.keys():
if attribute not in EMailNotification.good_attributes:
del(element.attrs[attribute])
# set href attribute for all a-tags to #
for element in soup("a"):
element["href"] = "#"
return soup
def get_html_text_part(self, msg):
"Get the mail text of an email in html form."
soup = None
mimetype = msg.get_content_type()
if mimetype in [EMailNotification._plain_text, EMailNotification._html_text]:
soup = self.get_text(msg)
elif mimetype.startswith("multipart"):
soup = self.get_text_multipart(msg)
if soup == None:
text = "ERROR: unable to extract text from email body"
soup = BeautifulSoup(text, "lxml", "UTF-8")
return soup
def notify(self, queueid, quarantine_id, subject, mailfrom, recipients, fp):
"Notify recipients via email."
super(EMailNotification, self).notify(queueid, quarantine_id, subject, mailfrom, recipients, fp)
self.logger.debug("{}: generating notification email".format(queueid))
# extract html text from email
self.logger.debug("{}: extraction email text from original email".format(queueid))
soup = self.get_html_text_part(email.message_from_file(fp))
# replace picture sources
picture_replaced = False
for element in soup("img"):
if "src" in element:
self.logger.debug("{}: replacing image: {}".format(queueid, element["src"]))
element["src"] = "cid:removed_for_security_reasons"
picture_replaced = True
for recipient in recipients:
self.logger.debug("{}: sending notification to <{}>".format(queueid, recipient))
self.logger.debug("{}: parsing email template".format(queueid))
htmltext = self.template.format( \
EMAIL_HTML_TEXT=self.sanitize(soup), \
EMAIL_FROM=mailfrom, \
EMAIL_TO=recipient, \
EMAIL_SUBJECT=subject, \
EMAIL_QUARANTINE_ID=quarantine_id
)
msg = MIMEMultipart('alternative')
msg["Subject"] = self.subject
msg["From"] = "<{}>".format(self.mailfrom)
msg["To"] = "<{}>".format(recipient)
msg["Date"] = email.utils.formatdate()
msg.attach(MIMEText(htmltext, "html", 'UTF-8'))
if picture_replaced:
msg.attach(self.replacement_img)
mailer.sendmail(self.smtp_host, self.smtp_port, queueid, self.mailfrom, recipient, msg.as_string())
# list of notification types and their related notification classes
notification_types = {"email": EMailNotification}

74
pyquarantine/quarantines.py Normal file
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#!/usr/bin/env python2
#
# PyQuarantine-Milter is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# PyQuarantine-Milter 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 PyQuarantineMilter. If not, see <http://www.gnu.org/licenses/>.
#
import datetime
import json
import logging
import os
from shutil import copyfileobj
class BaseQuarantine(object):
"Quarantine base class"
def __init__(self, name, config, configtest=False):
self.name = name
self.config = config[name]
self.global_config = config["global"]
self.logger = logging.getLogger(__name__)
def add(self, queueid, mailfrom, recipients, fp):
"Add mail to quarantine."
return ""
class FileQuarantine(BaseQuarantine):
"Quarantine class to store mails on filesystem."
def __init__(self, name, config, configtest=False):
super(FileQuarantine, self).__init__(name, config, configtest)
# check if mandatory options are present in config
for option in ["directory"]:
if option not in self.config.keys() and option in self.global_config.keys():
self.config[option] = self.global_config[option]
if option not in self.config.keys():
raise RuntimeError("mandatory option '{}' not present in config section '{}' or 'global'".format(option, self.name))
self.directory = self.config["directory"]
# check if quarantine directory exists and is writable
if not os.path.isdir(self.directory) or not os.access(self.directory, os.W_OK):
raise RuntimeError("file quarantine directory '{}' does not exist or is not writable".format(self.directory))
def add(self, queueid, mailfrom, recipients, fp):
"Add mail to file quarantine and return quarantine-id."
super(FileQuarantine, self).add(queueid, mailfrom, recipients, fp)
quarantine_id = "{}_{}".format(datetime.datetime.now().strftime("%Y-%m-%d_%H%M%S"), queueid)
# save mail
with open(os.path.join(self.directory, quarantine_id), "wb") as f:
copyfileobj(fp, f)
# save metadata
metadata = {
"from": mailfrom,
"recipients": recipients
}
with open(os.path.join(self.directory, "{}.metadata".format(quarantine_id)), "wb") as f:
json.dump(metadata, f, indent=2)
return quarantine_id
# list of quarantine types and their related quarantine classes
quarantine_types = {"file": FileQuarantine}

98
pyquarantine/run.py Normal file
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#!/usr/bin/env python2
#
# PyQuarantine-Milter is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# PyQuarantine-Milter 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 PyQuarantineMilter. If not, see <http://www.gnu.org/licenses/>.
#
import Milter
import argparse
import logging
import logging.handlers
import sys
import pyquarantine
def main():
"Run PyQuarantine-Milter."
# parse command line
parser = argparse.ArgumentParser(description="Quarantine milter daemon",
formatter_class=lambda prog: argparse.HelpFormatter(prog, max_help_position=45, width=140))
parser.add_argument('-c', '--config', help='list of config files', nargs='+',
default=pyquarantine.QuarantineMilter.get_configfiles())
parser.add_argument('-s', '--socket', help='socket used to communicatewith the MTA', required=True)
parser.add_argument('-d', '--debug', help='log debugging messages', action='store_true')
parser.add_argument('-t', '--test', help='check configuration', action='store_true')
args = parser.parse_args()
# setup logging
loglevel = logging.INFO
logname = "pyquarantine-milter"
syslog_name = logname
if args.debug:
loglevel = logging.DEBUG
logname = "{}[%(name)s]".format(logname)
syslog_name = "{}: [%(name)s] %(levelname)s".format(syslog_name)
# set config files for milter class
pyquarantine.QuarantineMilter.set_configfiles(args.config)
logger = logging.getLogger()
logger.setLevel(loglevel)
# setup console log
stdouthandler = logging.StreamHandler(sys.stdout)
stdouthandler.setLevel(logging.DEBUG)
formatter = logging.Formatter("%(message)s".format(logname))
stdouthandler.setFormatter(formatter)
logger.addHandler(stdouthandler)
logger = logging.getLogger(__name__)
if args.test:
try:
pyquarantine.generate_milter_config(args.test)
except RuntimeError as e:
logger.error(e)
sys.exit(255)
else:
sys.exit(0)
formatter = logging.Formatter("%(asctime)s {}: %(levelname)s - %(message)s".format(logname), datefmt="%Y-%m-%d %H:%M:%S")
stdouthandler.setFormatter(formatter)
# setup syslog
sysloghandler = logging.handlers.SysLogHandler(address="/dev/log", facility=logging.handlers.SysLogHandler.LOG_MAIL)
sysloghandler.setLevel(loglevel)
formatter = logging.Formatter("{}: %(message)s".format(syslog_name))
sysloghandler.setFormatter(formatter)
logger.addHandler(sysloghandler)
logger.info("PyQuarantine-Milter starting")
try:
# generate milter config
pyquarantine.QuarantineMilter.config = pyquarantine.generate_milter_config()
except RuntimeError as e:
logger.error(e)
sys.exit(255)
# register to have the Milter factory create instances of your class:
Milter.factory = pyquarantine.QuarantineMilter
Milter.set_exception_policy(Milter.TEMPFAIL)
#Milter.set_flags(0) # tell sendmail which features we use
# run milter
rc = 0
try:
Milter.runmilter("pyquarantine-milter", socketname=args.socket, timeout=300)
except Milter.milter.error as e:
logger.error(e)
rc = 255
pyquarantine.mailer.queue.put(None)
logger.info("PyQuarantine-Milter terminated")
sys.exit(rc)
if __name__ == "__main__":
main()

141
pyquarantine/whitelists.py Normal file
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#!/usr/bin/env python2
#
# PyQuarantine-Milter is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# PyQuarantine-Milter 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 PyQuarantineMilter. If not, see <http://www.gnu.org/licenses/>.
#
import datetime
import logging
import peewee
import re
import sys
from playhouse.db_url import connect
class WhitelistModel(peewee.Model):
mailfrom = peewee.CharField()
recipient = peewee.CharField()
created = peewee.DateTimeField(default=datetime.datetime.now)
last_used = peewee.DateTimeField(default=datetime.datetime.now)
comment = peewee.TextField(default="")
permanent = peewee.BooleanField(default=False)
class Meta(object):
indexes = (
(('mailfrom', 'recipient'), True), # trailing comma is mandatory if only one index should be created
)
class Whitelist(object):
"Whitelist base class"
_whitelists = {}
def __init__(self, name, config, configtest=False):
self.name = name
self.config = config[name]
self.global_config = config["global"]
self.logger = logging.getLogger(__name__)
# check if mandatory options are present in config
for option in ["whitelist_table"]:
if option not in self.config.keys() and option in self.global_config.keys():
self.config[option] = self.global_config[option]
if option not in self.config.keys():
raise RuntimeError("mandatory option '{}' not present in config section '{}' or 'global'".format(option, self.name))
self.tablename = self.config["whitelist_table"]
connection_string = self.config["whitelist"]
if connection_string in Whitelist._whitelists.keys():
self.db = Whitelist._whitelists[connection_string]
return
try:
# connect to database
self.logger.debug("connecting to database '{}'".format(re.sub(r"(.*?://.*?):.*?(@.*)", r"\1:<PASSWORD>\2", connection_string)))
self.db = connect(connection_string)
except Exception as e:
raise RuntimeError("unable to connect to database: {}".format(e))
else:
Whitelist._whitelists[connection_string] = self.db
if configtest: return
self.Meta = Meta
self.Meta.database = self.db
self.Meta.table_name = self.tablename
self.Whitelist = type("WhitelistModel_{}".format(name), (WhitelistModel,), {
"Meta": self.Meta
})
try:
self.db.create_tables([self.Whitelist])
except Exception as e:
raise RuntimeError("unable to initialize table '{}': {}".format(self.tablename, e))
def get_weight(self, entry):
value = 0
for address in [entry.mailfrom, entry.recipient]:
if address == "":
value += 2
elif address[0] == "@":
value += 1
return value
def check(self, mailfrom, recipient):
# generate list of possible mailfroms
self.logger.debug("query database for whitelist entries from <{}> to <{}>".format(mailfrom, recipient))
mailfroms = [""]
if "@" in mailfrom:
mailfroms.append("@{}".format(mailfrom.split("@")[1]))
mailfroms.append(mailfrom)
# generate list of possible recipients
recipients = [""]
if "@" in recipient:
recipients.append("@{}".format(recipient.split("@")[1]))
recipients.append(recipient)
# query the database
try:
entries = list(self.Whitelist.select().where(self.Whitelist.mailfrom.in_(mailfroms), self.Whitelist.recipient.in_(recipients)))
except Exception as e:
entries = []
self.logger.error("unable to query whitelist database: {}".format(e))
if len(entries) == 0:
# no whitelist entry found
return False
print(entries)
if len(entries) > 1:
entries.sort(key=lambda x: self.get_weight(x))
# use entry with the highest weight
entry = entries[-1]
entry.last_used = datetime.datetime.now()
entry.save()
return True
class WhitelistCache(object):
def __init__(self):
self.cache = {}
def load(self, whitelist, mailfrom, recipients):
for recipient in recipients:
self.check(whitelist, mailfrom, recipient)
def check(self, whitelist, mailfrom, recipient):
if whitelist not in self.cache.keys(): self.cache[whitelist] = {}
if recipient not in self.cache[whitelist].keys(): self.cache[whitelist][recipient] = None
if self.cache[whitelist][recipient] == None:
self.cache[whitelist][recipient] = whitelist.check(mailfrom, recipient)
return self.cache[whitelist][recipient]
def get_whitelisted_recipients(self, whitelist, mailfrom, recipients):
self.load(whitelist, mailfrom, recipients)
return filter(lambda x: self.cache[whitelist][x] == True, self.cache[whitelist].keys())

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setup.py Normal file
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from setuptools import setup
def read_file(fname):
with open(fname, 'r') as f:
return f.read()
setup(name = "pyquarantine",
version = "1.0.0",
author = "Thomas Oettli",
author_email = "spacefreak86@gmx.ch",
description = "A milter to handle multiple quarantines.",
license = "GPL 3",
keywords = "quarantine milter",
url = "https://github.com/spacefreak86/pyquarantine-milter",
packages = ["pyquarantine"],
long_description = read_file("README.md"),
classifiers = [
# 3 - Alpha
# 4 - Beta
# 5 - Production/Stable
"Development Status :: 3 - Alpha",
"License :: OSI Approved :: GNU General Public License v3 or later (GPLv3+)",
"Operating System :: OS Independent",
"Programming Language :: Python",
"Programming Language :: Python :: 2.7",
"Topic :: Communications :: Email :: Quarantine"
],
entry_points = {
"console_scripts": [
"pyquarantine-milter=pyquarantine.run:main"
]
},
install_requires = ["pymilter", "peewee"],
python_requires = ">=2.7,<3"
)