Commit Graph

185 Commits

Author SHA1 Message Date
2631f76c6d
roles/common: Use iptables backend for firewalld on Debian
For some reason the nftables set support in firewalld doesn't seem
to be working. I see that sets (aka ipsets in nftables lingo) are
created, but they are empty. For now I will just leave these tasks
as they are to revert the behavior on current hosts (should do no
change on new installed, as the regexp won't match).
2019-10-26 19:34:25 +02:00
919fbbbcd9
roles/common: Make sure fail2ban is started 2019-10-26 17:14:28 +02:00
9f27cda97b
roles/common: Update list of abusive IP addresses
This comes from the AbuseIPDB with a confidence level of 95%. I use
the following command to download and sort the IPs:

$ curl -G https://api.abuseipdb.com/api/v2/blacklist -d confidenceMinimum=95 -H "Key: $ABUSEIPDB_API_KEY" -H "Accept: text/plain" | sort > /tmp/ips.txt

I manually remove the IPv6 addresses and save them to a different
filr, then I add the XML formatting to files and run them through
tidy.
2019-10-26 17:09:18 +02:00
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
4710ee6f07
roles/common: Bump version checks to Ubuntu 16.04 2019-10-26 16:40:14 +02:00
9db104efa6
roles/common: Bump version checks to Debian 9 2019-10-26 16:37:27 +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
25e0fd3557
roles/common: Use individual calls with firewalld
Seems to work around an issue when firewalld is using the nftables
backend with iptables 1.8.2 on Debian 10. Alternatively I could go
back to using the iptables backend... hmm.

See: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=914694
2019-10-18 22:49:29 +03:00
cac38af09b
roles/common: Use nftables firewalld backend on Debian 10
nftables is the iptables replacement. There is support for nftables
in firewalld since v0.6.0.

See: https://firewalld.org/2018/07/nftables-backend
2019-10-18 19:02:17 +03:00
7c0b458bc1
roles/common: Don't use iptables from buster-backports
This causes problems every time I re-run the Ansible tag because the
nightly apt security uses a different sources.list and the indexes
are then missing buster-backports. I could add a cache update to the
task, but actually I think the original bug I was trying to solve is
finally fixed, and I'm going to switch to nftables anyways.
2019-10-18 18:53:21 +03:00
1b0a6703b6
roles/common: Update list of abusive IPv4 addresses
This comes from the AbuseIPDB with a confidence level of 95%. I use
the following command to download and sort the IPs:

$ curl -G https://api.abuseipdb.com/api/v2/blacklist -d confidenceMinimum=95 -H "Key: $ABUSEIPDB_API_KEY" -H "Accept: text/plain" | sort > /tmp/ips.txt

Then I add the XML formatting to the file and run it through tidy.
2019-10-18 13:45:59 +03:00
6244530929
roles/common: Fix short name of abusers-ipv6 ipset 2019-10-17 22:04:00 +03:00
68ec9f0467
roles/common: Update list of abusive IPv4 addresses
This comes from the AbuseIPDB with a confidence level of 95%. I use
the following command to download and sort the IPs:

$ curl -G https://api.abuseipdb.com/api/v2/blacklist -d confidenceMinimum=95 -H "Key: $ABUSEIPDB_API_KEY" -H "Accept: text/plain" | sort > /tmp/ips.txt

Then I add the XML formatting to the file and run it through tidy.
2019-10-14 00:24:48 +03:00
a8efe97a02
roles/common: Update list of abusive IPv4 addresses
This comes from the AbuseIPDB with a confidence level of 95%. I use
the following command to download and sort the IPs:

$ curl -G https://api.abuseipdb.com/api/v2/blacklist -d confidenceMinimum=95 -H "Key: $ABUSEIPDB_API_KEY" -H "Accept: text/plain" | sort > /tmp/ips.txt

Then I add the XML formatting to the file and run it through tidy.
2019-10-09 14:52:41 +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
8b28a65bf0
roles/common/files/abusers-ipv4.xml: Top 10,000 abusers from abuseipdb
These are the top 10,000 abusers with 95% confidence from abuseipdb.
2019-10-05 23:56:24 +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
ef3c5c200e
roles/common: Update list of abusive IPv4 addresses
I updated the list with a few dozen more hosts that we brute forcing
SSH but failed to even negotiate a connection because they are using
old ciphers. I will still block them because they attempted 100+ co-
nnections.
2019-10-05 12:46:06 +03:00
80df220602
roles/common: Restart firewalld instead of reload
I'm having problems with reload hanging on Debian 10 so I will just
revert to the older behavior of restarting.
2019-10-05 12:29:30 +03:00
c2a92269e4
roles/common: Add ipsets of abusive IPs to firewalld
This uses the ipsets feature of the Linux kernel to create lists of
IPs (though could be MACs, IP:port, etc) that we can block via the
existing firewalld zone we are already using. In my testing it works
on CentOS 7, Ubuntu 16.04, and Ubuntu 18.04.

The list of abusive IPs currently comes from HPC's systemd journal,
where I filtered for hosts that had attempted and failed to log in
over 100 times. The list is formatted with tidy, for example:

    $ tidy -xml -iq -m -w 0 roles/common/files/abusers-ipv4.xml

See: https://firewalld.org/2015/12/ipset-support
2019-10-05 12:28:30 +03:00
532b533516
roles/common: Update apt in firewall task
Otherwise the buster-backports source might not be available, as
the nightly security upates use a different apt sources.list.
2019-10-05 12:00:08 +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
cbdd779af0
roles/common: Remove lzop and lrzip from packages
zstd is a much better all-purpose compression utility.
2019-09-15 13:23:52 +03:00
4faeb79b5c
roles/common: Add zstd to base packages 2019-09-14 20:36:40 +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
7d8457e5b3
roles/common: Remove old SSH public key 2019-07-23 16:07:39 +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
03e2abc4fb roles/common: Install gnupg2 on Debian
Needed by Ansible to add and verify apt package signing keys.
2019-07-07 15:52:25 +03:00
12b6f3aaa2
roles/common: Don't ignore errors on Tarsnap key add
It turns out that I had the wrong key ID so it's no wonder this was
failing...
2019-07-07 15:51:04 +03:00
704b02ce0a
roles/common: Fix tarsnap package key
For some reason the key ID I had here was wrong. According to the
Tarsnap website the key ID is 0x6D97F5A4CA38CF33.

ee: https://www.tarsnap.com/pkg-deb.html
2019-07-07 15:49:45 +03:00
709a947987
Merge branch 'debian10' 2019-07-06 21:43:41 +03:00
3b95730417
roles/common: Synchronize Debian package task with Ubuntu 2019-07-06 21:36:04 +03:00
10200e52ab
roles/common: Use a fact for base packages on Debian
This is safer and ends up being faster because all packages get in-
stalled in one apt transaction.
2019-07-06 21:31:59 +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
1b4e9ae87c roles/common: Install Python 3 version of pycurl on Debian 10
Debian 10 comes with Python 2 and Python 3 (at least from the ISO),
so we should prefer the Python 3 version of pycurl. We'll see whet-
her cloud providers like Linode and Digital Ocean ship with Python
3 or not in their default image.
2019-07-06 21:16:19 +03:00
da4a6660fb roles/common: Update comment in tasks/ntp.yml 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
5957f5f2c5
roles: The apt cache_valid_time implies update_cache
See: https://docs.ansible.com/ansible/latest/modules/apt_module.html
2019-03-17 17:29:28 +02:00
c5b5cda3d3
Smarter updating of apt index during playbook execution
We can register changes when adding repositories and keys and then
update the apt package index conditionally. This should make it be
more consistent between initial host setup and subsequent re-runs.
2019-03-17 17:29:15 +02:00
bec79f18d1
roles/common: Ignore tarsnap key errors
Ansible errors on adding the tarsnap signing key because it is not
valid (expired a month ago). I contacted Colin Percival about this
on Twitter but he did not seem worried for some reason.
2019-03-13 12:36:47 +02:00
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
9921a40c19
roles/common: Update comment 2018-12-20 10:31:18 +02:00
91356ab364
roles/common: Disable Canonical spam in MOTD 2018-12-20 10:27:52 +02:00
49cfbc4c47
roles/common: Add missing systemd-journald config
I apparently forgot to add this when I committed the systemd-journald
changes a few weeks ago.
2018-12-20 09:59:13 +02:00