Initial commit of source code and docs

This commit is contained in:
2019-03-03 22:22:56 +01:00
commit e41f8bba2a
15 changed files with 1888 additions and 0 deletions

View File

@@ -0,0 +1,216 @@
#!/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}