Commit Graph

63 Commits

Author SHA1 Message Date
d8d8a01a5f
roles/common: Remove SSH rate limiting from firewalld
Rather than a simple rate limit, I'm now using fail2ban to ban IPs
that actually fail to login.
2019-10-26 16:41:42 +02:00
0605f70f2e
roles/common: Add support for fail2ban
This is active banning of IPs that are brute forcing login attempts
to SSH, versus the passive banning of 10,000 abusive IPs from the
abuseipdb.com blacklist. For now I am banning IPs that fail to log
in successfully more than twelve times in a one-hour period, but
these settings might change, and I can override them at the group
and host level if needed.

Currently this works for CentOS 7, Ubuntu 16.04, and Ubuntu 18.04,
with minor differences in the systemd configuration due to older
versions on some distributions.

You can see the status of the jail like this:

    # fail2ban-client status sshd
    Status for the jail: sshd
    |- Filter
    |  |- Currently failed: 0
    |  |- Total failed:     0
    |  `- Journal matches:  _SYSTEMD_UNIT=sshd.service + _COMM=sshd
    `- Actions
       |- Currently banned: 1
       |- Total banned:     1
       `- Banned IP list:   106.13.112.20

You can unban IPs like this:

    # fail2ban-client set sshd unbanip 106.13.112.20
2019-10-26 16:36:07 +02:00
f3614d4ad4
roles/common: Remove buster-backports
I was using it to get iptables 1.8.3 to work around an issue with
firewalld, but I've solved that another way.
2019-10-18 22:56:52 +03:00
d030827f12
roles/common: Relax SSH rate limit in firewalld
Now that I'm blocking ~10,000 malicious IPs from AbuseIPDB I feel
more comfortable using a more relaxed rate limit for SSH. A limit
of 12 per minute is about one every five seconds.
2019-10-06 18:27:45 +03:00
6ebf900960
roles/common: Add missing rules for abusers ipsets
I had forgotten to add these when porting these rules from another
repository.
2019-10-05 13:01:51 +03:00
2740f050fc
roles/common: Increase ssh MaxAuthTries from 3 to 4
If a user has RSA, ECDSA, and ED25519 private keys present on their
system then the ssh client will offer all of these to the server
and they may not get a chance to try password auth before it fails.
2019-09-15 15:17:00 +03:00
cf16264f53
roles/common: Update sshd_config template for Debian 10
It seems I had imported the stock one from a default install, but I
never configured it.
2019-09-15 15:15:30 +03:00
43715dd392
roles/common: Use stable tarsnap 2019-09-13 22:14:49 +03:00
7551b803f6
roles/common: Use iptables 1.8.3 on Debian Buster
There is a bug in iptables 1.8.2 in Debian 10 "Buster" that causes
firewalld to fail when restoring rules. The bug has been fixed in
iptables 1.8.3, which is currently in buster-backports.

See: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=914694
2019-08-01 15:36:15 +03:00
c148da73e7
roles/common: Use experimental Tarsnap on Debian buster
Tarsnap currently provides experimental packages for Debian Buster.

See: https://www.tarsnap.com/pkg-deb.html#experimental
2019-07-19 12:07:27 +03:00
39622077cd roles/common: Use Debian 9 tarsnap packages
There are no tarsnap binaries for Debian 10 yet.
2019-07-06 21:16:19 +03:00
b79001f97a roles/common: Update security.sources.list for cron-apt
We need to make sure to get security updates for packages that are
not in main!
2019-07-06 21:16:19 +03:00
207296b1f8 roles/common: Update Debian security apt repository
See: https://www.debian.org/security/
2019-07-06 21:16:19 +03:00
dd5662911e roles/common: Import sshd_config from Debian 10
OpenSSH version is 7.9p1-10.
2019-07-06 21:16:19 +03:00
18ee583261
roles/common: Don't log brute force SSH attempts
This is nice to see that the throttling is working, but the logs are
completely full of this useless crap now.
2019-02-26 10:30:03 -08:00
329edaee87
roles/common: Rate limit SSH connections in firewalld
I think 5 connections per minute is more than enough. Any over this
and it will be logged to the systemd journal as a warning.

See: https://www.win.tue.nl/~vincenth/ssh_rate_limit_firewalld.htm
See: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/security_guide/configuring_complex_firewall_rules_with_the_rich-language_syntax
2019-01-28 14:09:18 +02:00
963bf65099
roles/common: Limit number of SSH authentication attempts
The default in later OpenSSH is 6, which seems too high. If you can't
get your password correct after 3 tries then I think you need help.

Eventually I'd like an easy way to enable blocking of repeated login
attempts at the firewall level. I think it's possible in firewalld.
2018-07-23 13:14:54 +03:00
1a9033dece
roles/common: Use bionic tarsnap builds on Ubuntu 18.04
Tarsnap finally published builds for Ubuntu 18.04 "bionic" so we don't
need to use the 17.10 "artful" ones anymore.
2018-05-09 00:05:42 +03:00
9445541f51
roles/common: Always use security.ubuntu.com
Vanilla Ubuntu (and Debian actually) defaults to using the official
mirror for security updates rather than country or regional mirrors.

Also, for what it's worth, Ubuntu mirrors didn't always sync these
security archives. I'd prefer to stay closer to vanilla Ubuntu but
also it kinda makes sense to get security updates from the official
source than a mirror (in case of delay or errors).
2018-04-25 18:09:11 +03:00
832573acc5
roles/common: Remove comments from sources.list
I want this file to be more like what comes from the stock Ubuntu.
2018-04-25 18:07:55 +03:00
f3403cc79a
roles/common: Remove Ubuntu partner repo from apt sources
I haven't used this in years, and it looks to only be proprietary things
like Adobe, Skype, etc.
2018-04-25 17:49:38 +03:00
632aa1cf14 Fix a few more Jinja2 filters used as tests
I had created these earlier in this branch before rebasing it on top
of the Ansible 2.5.0 readiness branch.

See: https://docs.ansible.com/ansible/devel/porting_guides/porting_guide_2.5.html
2018-04-05 12:17:26 +03:00
d1ba60e15d Use version_compare to test for Ubuntu 18.04 "bionic"
It just feels more correct, plus I usually forget the release code
name from time to time.
2018-04-05 12:17:26 +03:00
c5bebf0336 roles/common: Use Ubuntu 17.10's tarsnap packages on Ubuntu 18.04
There are no tarsnap packages for Ubuntu 18.04 "bionic" yet so we
should use Ubuntu 17.10 "artful".
2018-04-05 12:17:25 +03:00
19414041e7 roles/common: Add sshd config for Ubuntu 18.04
From the default sshd_config with some cipher settings from the Debian
9 template.
2018-04-05 12:17:25 +03:00
52b4efd3b0
roles/common: Use HTTPS for tarsnap package mirror 2018-03-17 11:51:45 +02:00
fec081d40a
roles/common: Use deb.debian.org instead of httpredir
Seems to be the evolution of httpredir.
2017-11-05 01:31:16 +02:00
5f8820bf9f
roles/common: Remove Ubuntu 14.04 logic
We're only supporting Ubuntu 16.04 now.
2017-11-05 01:11:37 +02:00
f76fc64afa
roles/common: Remove unused sshd_config templates
We're not supporting Ubuntu 14.04 or 15.04 anymore so we don't need
these templates.
2017-11-05 00:59:19 +02:00
77a3b1cff7
roles/common: Remove Debian 8 sshd_config template 2017-11-05 00:58:03 +02:00
620e8258ac
roles/common: Remove duplicate option in sshd_config 2017-11-01 13:22:18 +02:00
b945240756
roles/common: Harden sshd_config template for Debian 9 and Ubuntu 16.04
From: https://wiki.mozilla.org/Security/Guidelines/OpenSSH
2017-06-19 10:13:24 +03:00
d766c3dbbe
roles/common: Add tasks to install tarsnap
Now that Tarsnap has official packages this is one less thing that
needs to be manually installed from source after bringing a machine
up.

See: http://mail.tarsnap.com/tarsnap-announce/msg00037.html
2017-02-07 07:28:35 -08:00
1fef5c9b5a roles/common: Add sshd_config for Debian 9 (stretch)
Taken from base install and diffed against the current Ubuntu 16.04
and Debian 8 config templates.
2017-01-30 14:56:27 +02:00
9ca685a6af
roles/common: Adjust allowed user logic for Ubuntu 16.04 sshd_config 2017-01-30 12:54:35 +02:00
50536af990
Use Ansible's version_compare instead of doing math on strings
I'm surprised this worked all these years actually. Since Ansible
version 1.6 it has been possible to use the version_compare filter
instead of doing math logic on strings.

See: https://docs.ansible.com/ansible/playbooks_tests.html
2016-12-20 15:04:47 +02:00
b7c92e4dc1
roles/common: Remove 128-bit Ciphers and MACs from sshd_config
I had removed them from Debian 8 and Ubuntu 14.04 configs last year
when the NSA's Suite B crypto guidelines dropped 128-bit algorithms
but those changes didn't make it to my new Ubuntu 16.04 config.

It is probably overkill and paranoid, but this server is mine, so I
can make those decisions (and I only connect from modern clients).
2016-08-16 14:28:58 +03:00
33cdcc9ad1
roles/common: Add a few SHA-2 MACs to sshd_config
Fixes a problem with Paramiko, which Ansible uses for transport.

See: http://www.paramiko.org/changelog.html#1.16.0
See: https://github.com/ilri/rmg-ansible-public/issues/37
2016-08-16 14:24:53 +03:00
33f22b32a4
roles/common: Update sources for cron-apt
The system's apt configuration is using restricted and multiverse
so the security sources list should as well.
2016-05-05 12:16:37 +03:00
a0bb4c2f57 roles/common: Add sshd_config for Ubuntu 16.04 2016-04-22 11:25:35 +03:00
5f71991259
roles/common: Use httpredir.debian.org as default Debian mirror
Automatically uses the best mirror for your location, see:

    http://httpredir.debian.org/demo.html

Should be much better than any hardcoded default for most hosts.

Signed-off-by: Alan Orth <alan.orth@gmail.com>
2015-11-30 09:34:16 +02:00
973b37be4e
roles/common: Tweak sshd_config to match NSA Suite B recommendations
NSA stopped recommending AES-128 in August, 2015...

Before: https://web.archive.org/web/20150403110658/https://www.nsa.gov/ia/programs/suiteb_cryptography/index.shtml
After: https://web.archive.org/web/20150815072948/https://www.nsa.gov/ia/programs/suiteb_cryptography/index.shtml

I don't see why we shouldn't follow suit; maybe they know something
we don't!

Signed-off-by: Alan Orth <alan.orth@gmail.com>
2015-09-02 16:55:51 +03:00
8b336352d7
roles/common: Only allow ssh access by provisioning user
Signed-off-by: Alan Orth <alan.orth@gmail.com>
2015-09-02 12:24:11 +03:00
c480075789
roles/common: Use "interface" instead of "alias" to get interface name in firewalld template
Signed-off-by: Alan Orth <alan.orth@gmail.com>
2015-08-23 12:06:47 +03:00
18ca44193d
roles/common: Add sysctl template for Debian hosts
Note: I've only tested this on a Debian container, and you can't
set these sysctls on containers (the host controls them). To make
matters worse, there is no fact to make ansible skip this on hosts
that are running in containers. For now I will just skip it on
hosts that are "virtualization" servers... even though we actually
do have KVM running on Debian on real hardware. *sigh*

Signed-off-by: Alan Orth <alan.orth@gmail.com>
2015-08-23 00:12:17 +03:00
96fe209843 roles/common: Fix mode on Debian 8 sshd_config
Accidentally added it with 777.

Signed-off-by: Alan Orth <alan.orth@gmail.com>
2015-08-23 00:02:39 +03:00
7519995153 roles/common: Add Debian 8 sshd_config
Signed-off-by: Alan Orth <alan.orth@gmail.com>
2015-08-23 00:02:39 +03:00
dc24285ec6 roles/common: Use apt_mirror variable in Debian sources
Signed-off-by: Alan Orth <alan.orth@gmail.com>
2015-08-23 00:02:39 +03:00
28f61d589e roles/common: Add Debian support to sources.list template
Signed-off-by: Alan Orth <alan.orth@gmail.com>
2015-08-23 00:02:39 +03:00
1fc2453703 roles/common: Add firewalld support
Needed in Ubuntu 15.04 where iptables-persistent is going away. I
have added translations of the current IPv4 and IPv6 iptables rules.

Signed-off-by: Alan Orth <alan.orth@gmail.com>
2015-08-23 00:02:39 +03:00