Merge pull request #798 from mail-in-a-box/fail2banjails

add fail2ban jails for ownCloud, postfix submission, roundcube, and the Mail-in-a-Box management daemon

CHANGELOG.md

@@ -9,6 +9,10 @@ Mail:
 * Roundcube is updated to version 1.2.0.
 * SSLv3 and RC4 are now no longer supported in incoming and outgoing mail (SMTP port 25).
 
+System:
+
+* fail2ban jails added for SMTP submission, Roundcube, ownCloud, the control panel, and munin.
+
 v0.18c (June 2, 2016)
 ---------------------
 

conf/fail2ban/filter.d/miab-management-daemon.conf

@@ -0,0 +1,12 @@
+# Fail2Ban filter Mail-in-a-Box management daemon
+
+[INCLUDES]
+
+before = common.conf
+
+[Definition]
+
+_daemon = mailinabox
+
+failregex = Mail-in-a-Box Management Daemon: Failed login attempt from ip <HOST> - timestamp .*
+ignoreregex =

conf/fail2ban/filter.d/miab-munin.conf

@@ -0,0 +1,7 @@
+[INCLUDES]
+
+before = common.conf
+
+[Definition]
+failregex=<HOST> - .*GET /admin/munin/.* HTTP/1.1\" 401.*
+ignoreregex =

conf/fail2ban/filter.d/miab-owncloud.conf

@@ -0,0 +1,7 @@
+[INCLUDES]
+
+before = common.conf
+
+[Definition]
+failregex=Login failed: .*Remote IP: '<HOST>[\)']
+ignoreregex =

conf/fail2ban/filter.d/miab-postfix-submission.conf

@@ -0,0 +1,7 @@
+[INCLUDES]
+
+before = common.conf
+
+[Definition]
+failregex=postfix/submission/smtpd.*warning.*\[<HOST>\]: .* authentication (failed|aborted)
+ignoreregex =

conf/fail2ban/filter.d/miab-roundcube.conf

@@ -0,0 +1,9 @@
+[INCLUDES]
+
+before = common.conf
+
+[Definition]
+
+failregex = IMAP Error: Login failed for .*? from <HOST>\. AUTHENTICATE.*
+
+ignoreregex = 

conf/fail2ban/jails.conf

@@ -1,4 +1,5 @@
-# Fail2Ban configuration file for Mail-in-a-Box
+# Fail2Ban configuration file for Mail-in-a-Box. Do not edit.
+# This file is re-generated on updates.
 
 [DEFAULT]
 # Whitelist our own IP addresses. 127.0.0.1/8 is the default. But our status checks
@@ -6,24 +7,52 @@
 # ours too. The string is substituted during installation.
 ignoreip = 127.0.0.1/8 PUBLIC_IP
 
-# JAILS
-
-[ssh]
-maxretry = 7
-bantime = 3600
-
-[ssh-ddos]
-enabled  = true
-
-[sasl]
-enabled  = true
-
 [dovecot]
 enabled = true
 filter  = dovecotimap
+logpath = /var/log/mail.log
 findtime = 30
 maxretry = 20
+
+[miab-management]
+enabled = true
+filter = miab-management-daemon
+port = http,https
+logpath = /var/log/syslog
+maxretry = 20
+findtime = 30
+
+[miab-munin]
+enabled  = true
+port     = http,https
+filter   = miab-munin
+logpath  = /var/log/nginx/access.log
+maxretry = 20
+findtime = 30
+
+[miab-owncloud]
+enabled  = true
+port     = http,https
+filter   = miab-owncloud
+logpath  = STORAGE_ROOT/owncloud/owncloud.log
+maxretry = 20
+findtime = 120
+
+[miab-postfix587]
+enabled  = true
+port     = 587
+filter   = miab-postfix-submission
 logpath  = /var/log/mail.log
+maxretry = 20
+findtime = 30
+
+[miab-roundcube]
+enabled  = true
+port     = http,https
+filter   = miab-roundcube
+logpath  = /var/log/roundcubemail/errors
+maxretry = 20
+findtime = 30
 
 [recidive]
 enabled  = true
@@ -39,3 +68,13 @@ action   = iptables-allports[name=recidive]
 # By default we don't configure this address and no action is required from the admin anyway.
 # So the notification is ommited. This will prevent message appearing in the mail.log that mail
 # can't be delivered to fail2ban@$HOSTNAME.
+
+[sasl]
+enabled  = true
+
+[ssh]
+maxretry = 7
+bantime = 3600
+
+[ssh-ddos]
+enabled  = true

management/daemon.py

@@ -1,7 +1,8 @@
 #!/usr/bin/python3
 
-import os, os.path, re, json
+import os, os.path, re, json, time
 import subprocess
+
 from functools import wraps
 
 from flask import Flask, request, render_template, abort, Response, send_from_directory, make_response
@@ -45,6 +46,9 @@ def authorized_personnel_only(viewfunc):
 			privs = []
 			error = "Incorrect username or password"
 
+			# Write a line in the log recording the failed login
+			log_failed_login(request)
+
 		# Authorized to access an API view?
 		if "admin" in privs:
 			# Call view func.
@@ -117,6 +121,9 @@ def me():
 	try:
 		email, privs = auth_service.authenticate(request, env)
 	except ValueError as e:
+		# Log the failed login
+		log_failed_login(request)
+
 		return json_response({
 			"status": "invalid",
 			"reason": "Incorrect username or password",
@@ -583,6 +590,22 @@ def munin_cgi(filename):
 		app.logger.warning("munin_cgi: munin-cgi-graph returned 404 status code. PATH_INFO=%s", env['PATH_INFO'])
 	return response
 
+def log_failed_login(request):
+	# We need to figure out the ip to list in the message, all our calls are routed
+	# through nginx who will put the original ip in X-Forwarded-For.
+	# During setup we call the management interface directly to determine the user
+	# status. So we can't always use X-Forwarded-For because during setup that header
+	# will not be present.
+	if request.headers.getlist("X-Forwarded-For"):
+		ip = request.headers.getlist("X-Forwarded-For")[0]
+	else:
+		ip = request.remote_addr
+
+	# We need to add a timestamp to the log message, otherwise /dev/log will eat the "duplicate"
+	# message.
+	app.logger.warning( "Mail-in-a-Box Management Daemon: Failed login attempt from ip %s - timestamp %s" % (ip, time.time()))
+
+
 # APP
 
 if __name__ == '__main__':

setup/owncloud.sh

@@ -92,7 +92,6 @@ if [ ! -f $STORAGE_ROOT/owncloud/owncloud.db ]; then
 	mkdir -p $STORAGE_ROOT/owncloud
 
 	# Create an initial configuration file.
-	TIMEZONE=$(cat /etc/timezone)
 	instanceid=oc$(echo $PRIMARY_HOSTNAME | sha1sum | fold -w 10 | head -n 1)
 	cat > $STORAGE_ROOT/owncloud/config.php <<EOF;
 <?php
@@ -125,7 +124,6 @@ if [ ! -f $STORAGE_ROOT/owncloud/owncloud.db ]; then
   'mail_smtppassword' => '',
   'mail_from_address' => 'owncloud',
   'mail_domain' => '$PRIMARY_HOSTNAME',
-  'logtimezone' => '$TIMEZONE',
 );
 ?>
 EOF
@@ -163,7 +161,11 @@ fi
 #   so set it here. It also can change if the box's PRIMARY_HOSTNAME changes, so
 #   this will make sure it has the right value.
 # * Some settings weren't included in previous versions of Mail-in-a-Box.
+# * We need to set the timezone to the system timezone to allow fail2ban to ban
+#   users within the proper timeframe
+# * We need to set the logdateformat to something that will work correctly with fail2ban
 # Use PHP to read the settings file, modify it, and write out the new settings array.
+TIMEZONE=$(cat /etc/timezone)
 CONFIG_TEMP=$(/bin/mktemp)
 php <<EOF > $CONFIG_TEMP && mv $CONFIG_TEMP $STORAGE_ROOT/owncloud/config.php;
 <?php
@@ -175,6 +177,9 @@ include("$STORAGE_ROOT/owncloud/config.php");
 \$CONFIG['overwrite.cli.url'] = '/cloud';
 \$CONFIG['mail_from_address'] = 'administrator'; # just the local part, matches our master administrator address
 
+\$CONFIG['logtimezone'] = '$TIMEZONE';
+\$CONFIG['logdateformat'] = 'Y-m-d H:i:s';
+
 echo "<?php\n\\\$CONFIG = ";
 var_export(\$CONFIG);
 echo ";";

setup/system.sh

@@ -291,10 +291,12 @@ restart_service resolvconf
 
 # ### Fail2Ban Service
 
-# Configure the Fail2Ban installation to prevent dumb bruce-force attacks against dovecot, postfix and ssh
+# Configure the Fail2Ban installation to prevent dumb bruce-force attacks against dovecot, postfix, ssh, etc.
-cat conf/fail2ban/jail.local \
+rm -f /etc/fail2ban/jail.local # we used to use this file but don't anymore
+cat conf/fail2ban/jails.conf \
 	| sed "s/PUBLIC_IP/$PUBLIC_IP/g" \
-	> /etc/fail2ban/jail.local
+	| sed "s#STORAGE_ROOT#$STORAGE_ROOT#" \
-cp conf/fail2ban/dovecotimap.conf /etc/fail2ban/filter.d/dovecotimap.conf
+	> /etc/fail2ban/jail.d/mailinabox.conf
+cp -f conf/fail2ban/filter.d/* /etc/fail2ban/filter.d/
 
 restart_service fail2ban

tests/fail2ban.py

@@ -0,0 +1,195 @@
+# Test that a box's fail2ban setting are working
+# correctly by attempting a bunch of failed logins.
+# Specify SSH login information the command line -
+# we use that to reset fail2ban after each test,
+# and we extract the hostname from that to open
+# connections to.
+######################################################################
+
+import sys, os, time, functools
+
+# parse command line
+
+if len(sys.argv) < 2:
+	print("Usage: tests/fail2ban.py user@hostname")
+	sys.exit(1)
+
+ssh_user, hostname = sys.argv[1].split("@", 1)
+
+# define some test types
+
+import socket
+socket.setdefaulttimeout(10)
+
+class IsBlocked(Exception):
+	"""Tests raise this exception when it appears that a fail2ban
+	jail is in effect, i.e. on a connection refused error."""
+	pass
+
+def smtp_test():
+	import smtplib
+
+	try:
+		server = smtplib.SMTP(hostname, 587)
+	except ConnectionRefusedError:
+		# looks like fail2ban worked
+		raise IsBlocked()
+	server.starttls()
+	server.ehlo_or_helo_if_needed()
+
+	try:
+		server.login("fakeuser", "fakepassword")
+		raise Exception("authentication didn't fail")
+	except smtplib.SMTPAuthenticationError:
+		# athentication should fail
+		pass
+
+	try:
+		server.quit()
+	except:
+		# ignore errors here
+		pass
+
+def imap_test():
+	import imaplib
+
+	try:
+		M = imaplib.IMAP4_SSL(hostname)
+	except ConnectionRefusedError:
+		# looks like fail2ban worked
+		raise IsBlocked()
+
+	try:
+		M.login("fakeuser", "fakepassword")
+		raise Exception("authentication didn't fail")
+	except imaplib.IMAP4.error:
+		# authentication should fail
+		pass
+	finally:
+		M.logout() # shuts down connection, has nothing to do with login()
+
+def http_test(url, expected_status, postdata=None, qsargs=None, auth=None):
+	import urllib.parse
+	import requests
+	from requests.auth import HTTPBasicAuth
+
+	# form request
+	url = urllib.parse.urljoin("https://" + hostname, url)
+	if qsargs: url += "?" + urllib.parse.urlencode(qsargs)
+	urlopen = requests.get if not postdata else requests.post
+
+	try:
+		# issue request
+		r = urlopen(
+			url,
+			auth=HTTPBasicAuth(*auth) if auth else None,
+			data=postdata,
+			headers={'User-Agent': 'Mail-in-a-Box fail2ban tester'},
+			timeout=8)
+	except requests.exceptions.ConnectTimeout as e:
+		raise IsBlocked()
+	except requests.exceptions.ConnectionError as e:
+		if "Connection refused" in str(e):
+			raise IsBlocked()
+		raise # some other unexpected condition
+
+	# return response status code
+	if r.status_code != expected_status:
+		r.raise_for_status() # anything but 200
+		raise IOError("Got unexpected status code %s." % r.status_code)
+
+# define how to run a test
+
+def restart_fail2ban_service(final=False):
+	# Log in over SSH to restart fail2ban.
+	command = "sudo fail2ban-client reload"
+	if not final:
+		# Stop recidive jails during testing.
+		command += " && sudo fail2ban-client stop recidive"
+	os.system("ssh %s@%s \"%s\"" % (ssh_user, hostname, command))
+
+def testfunc_runner(i, testfunc, *args):
+	print(i+1, end=" ", flush=True)
+	testfunc(*args)
+
+def run_test(testfunc, args, count, within_seconds, parallel):
+	# Run testfunc count times in within_seconds seconds (and actually
+	# within a little less time so we're sure we're under the limit).
+	#
+	# Because some services are slow, like IMAP, we can't necessarily
+	# run testfunc sequentially and still get to count requests within
+	# the required time. So we split the requests across threads.
+
+	import requests.exceptions
+	from multiprocessing import Pool
+
+	restart_fail2ban_service()
+
+	# Log.
+	print(testfunc.__name__, " ".join(str(a) for a in args), "...")
+
+	# Record the start time so we can know how to evenly space our
+	# calls to testfunc.
+	start_time = time.time()
+
+	with Pool(parallel) as p:
+		# Distribute the requests across the pool.
+		asyncresults = []
+		for i in range(count):
+			ar = p.apply_async(testfunc_runner, [i, testfunc] + list(args))
+			asyncresults.append(ar)
+
+		# Wait for all runs to finish.
+		p.close()
+		p.join()
+
+		# Check for errors.
+		for ar in asyncresults:
+			try:
+				ar.get()
+			except IsBlocked:
+				print("Test machine prematurely blocked!")
+				return False
+
+	# Did we make enough requests within the limit?
+	if (time.time()-start_time) > within_seconds:
+		raise Exception("Test failed to make %s requests in %d seconds." % (count, within_seconds))
+
+	# Wait a moment for the block to be put into place.
+	time.sleep(4)
+
+	# The next call should fail.
+	print("*", end=" ", flush=True)
+	try:
+		testfunc(*args)
+	except IsBlocked:
+		# Success -- this one is supposed to be refused.
+		print("blocked [OK]")
+		return True # OK
+
+	print("not blocked!")
+	return False
+
+######################################################################
+
+if __name__ == "__main__":
+	# run tests
+
+	# SMTP bans at 10 even though we say 20 in the config because we get
+	# doubled-up warnings in the logs, we'll let that be for now
+	run_test(smtp_test, [], 10, 30, 8)
+
+	# IMAP
+	run_test(imap_test, [], 20, 30, 4)
+
+	# Mail-in-a-Box control panel
+	run_test(http_test, ["/admin/me", 200], 20, 30, 1)
+
+	# Munin via the Mail-in-a-Box control panel
+	run_test(http_test, ["/admin/munin/", 401], 20, 30, 1)
+
+	# ownCloud
+	run_test(http_test, ["/cloud/remote.php/webdav", 401, None, None, ["aa", "aa"]], 20, 120, 1)
+
+	# restart fail2ban so that this client machine is no longer blocked
+	restart_fail2ban_service(final=True)