Commit Graph

268 Commits

Author SHA1 Message Date
2961578a54
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 | sed -e '/:/w /tmp/ipv6.txt' \
    -e '/:/d' > /tmp/ipv4.txt

I manually add the XML formatting to each file and run them through
tidy:

  $ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv4.xml
  $ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv6.xml

Then I formatted the nftables files manually. Meh...
2022-02-28 18:51:35 +03:00
9e737466c5
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 | sed -e '/:/w /tmp/ipv6.txt' \
    -e '/:/d' > /tmp/ipv4.txt

I manually add the XML formatting to each file and run them through
tidy:

  $ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv4.xml
  $ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv6.xml

Then I formatted the nftables files manually. Meh...
2022-02-04 21:47:37 +03:00
0ffb1b1a36
roles/common: use pyinotify backend for nginx fail2ban jail
This seems to be automatically selected, but on some other servers
I notice it is not. I will set it here explicitly so fail2ban does
not fall back to the inefficient "polling" or incorrect "systemd"
backends.
2022-01-04 15:10:02 +02:00
ebbde530d2
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 | sed -e '/:/w /tmp/ipv6.txt' \
    -e '/:/d' > /tmp/ipv4.txt

I manually add the XML formatting to each file and run them through
tidy:

  $ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv4.xml
  $ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv6.xml

Then I created the nftables files manually. Meh...
2021-12-22 11:40:27 +02:00
f070fd9a64
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 | sed -e '/:/w /tmp/ipv6.txt' \
    -e '/:/d' > /tmp/ipv4.txt

I manually add the XML formatting to each file and run them through
tidy:

  $ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv4.xml
  $ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv6.xml
2021-11-07 10:12:43 +02:00
ebd8b0632b
roles/common: Disable unsafe Diffie-Hellman SSH moduli
The WeakDH team showed (in 2015) that Diffie-Hellman key exchange
with prime number groups of 1024 bits or less were weaker than we
previously thought, and well within the reach of nation states. They
recommended (in 2015) using 2048-bit or higher prime groups.

The SSH audit project recommends that we should use 3072-bit now.

See: https://weakdh.org/
See: https://github.com/jtesta/ssh-audit/
2021-10-10 16:57:05 +03:00
df26b6c17e
roles/common: notify fail2ban after updating firewall
We should always restart fail2ban after updating the firewall. Also
note that the order of execution of handlers depends on how they are
defined in the handler config, not on the order they are listed in
the task's notify statement.

See: https://docs.ansible.com/ansible/latest/user_guide/playbooks_handlers.html
2021-09-28 10:45:51 +03:00
d92151b8a6
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 | sed -e '/:/w /tmp/ipv6.txt' \
    -e '/:/d' > /tmp/ipv4.txt

I manually add the XML formatting to each file and run them through
tidy:

  $ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv4.xml
  $ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv6.xml

Note: there were no IPv6 addresses in the top 10,000 this time so I
used a dummy address for the nftables set so the syntax was valid.
2021-09-28 10:28:02 +03:00
b13ead0657
roles/common: use a range for mosh ports in nftables
This is better than a loop in Jinja (though that is useful!).
2021-09-28 07:34:25 +03:00
65e6dd34cd
roles/common: Add missing section to Debian 11 sshd_config
We need to be able to configure the list of SSH users.
2021-09-27 12:59:27 +03:00
170e591701
roles/common: Install rsync and lsof 2021-09-27 11:36:40 +03:00
a4acc85704
roles/common: Remove iptables on newer Debian 2021-09-27 10:35:38 +03:00
f7b9aa67f5
roles/common: Fix comment about Debian 10 firewall 2021-09-27 10:31:31 +03:00
20cd6f213c
roles/common: cache_valid_time explicitly sets update_cache
See: https://docs.ansible.com/ansible/latest/collections/ansible/builtin/apt_module.html
2021-09-08 21:59:51 +03:00
34a30c4d13
roles/common: Don't update apt cache when removing packages 2021-09-08 17:05:48 +03:00
c03e75d736
roles/common: explicitly install systemd-timesyncd
It is a standalone package on (at least) Ubuntu 20.04 and Debian 11
and some cloud images do not have it installed by default (for exa-
mple Scaleway).
2021-09-08 17:04:46 +03:00
d08f10f9c8
roles/common: Fix comment in ntp playbook 2021-09-08 17:04:20 +03:00
635bb5234d
roles/common: fix logic for copying AbuseIPDB.com nft sets
We have to force these because they are not updated on the host like
the other lists (API limit of five requests per day!). We update the
list periodically here in git.
2021-09-08 09:58:13 +03:00
37901da5b5
roles/common: update AbuseIPDB lists for nftables 2021-09-08 09:57:58 +03:00
e36ae3b11e
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 | sed -e '/:/w /tmp/ipv6.txt' \
    -e '/:/d' > /tmp/ipv4.txt

I manually add the XML formatting to each file and run them through
tidy:

  $ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv4.xml
  $ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv6.xml
2021-09-08 09:35:36 +03:00
15208241d3
roles/common: Add git-lfs to base packages 2021-09-07 17:51:33 +03:00
479127a5e4
roles/common: Fix nftables handler in Debian firewall
We used to use reload, but now the idempotent thing to do is to use
restart instead of reload.
2021-09-07 15:43:33 +03:00
575a9fdfe6
roles/common: Add mosh ports to common
These have been in each hosts's "extra" rules lists forever and I
use them on every single host so they might as well be in the base
rules.
2021-09-05 16:23:42 +03:00
35fa3b0d72
roles/common: Fix typo in handlers 2021-09-05 16:19:31 +03:00
f7e87ea7be
roles/common: Fix fail2ban ignoreip
According to jail.conf we actually need to separate multiple values
with spaces instead of commas. On some versions of fail2ban this is
a fatal error:

> CRITICAL Unhandled exception in Fail2Ban:
> Traceback (most recent call last):
>   File "/usr/lib/python3/dist-packages/fail2ban/server/jailthread.py", line 66, in run_with_except_hook
>     run(*args, **kwargs)
>   File "/usr/lib/python3/dist-packages/fail2ban/server/filtersystemd.py", line 246, in run
>     *self.formatJournalEntry(logentry))
>   File "/usr/lib/python3/dist-packages/fail2ban/server/filter.py", line 432, in processLineAndAdd
>     if self.inIgnoreIPList(ip, log_ignore=True):
>   File "/usr/lib/python3/dist-packages/fail2ban/server/filter.py", line 371, in inIgnoreIPList
>     "(?<=b)1+", bin(DNSUtils.addr2bin(s[1]))).group())
>   File "/usr/lib/python3/dist-packages/fail2ban/server/filter.py", line 928, in addr2bin
>     return struct.unpack("!L", socket.inet_aton(ipstring))[0]
> OSError: illegal IP address string passed to inet_aton

This affects (at least) fail2ban 0.9.3 on Ubuntu 16.04, but I never
noticed.
2021-08-12 15:24:50 +03:00
b5ea575d8d
roles/common: Always restart nftables service
The "reload" capability only exists on Ubuntu, and it is exactly
the same as the "restart" functionality.
2021-08-01 14:23:00 +03:00
98cc3a8c2e
Add nginx filter for fail2ban
Some hosts can use fail2ban's nginx-botsearch filter to ban anyone
making requests to non-existent files like wp-login.php. There is
no reason to request such files naively and anyone found doing so
can be banned immediately.

In theory I should report them to AbuseIPDB.com, but that will take
a little more wiring up.
2021-08-01 09:56:43 +03:00
a67d901641
roles/common: Use AbuseIPDB.com list in nftables
For now I am still manually updating this, as we can only hit their
API five times per day, so it is not possible to have each host get
the list themselves every day with our one API key.
2021-07-31 21:46:50 +03:00
7ae100faeb
roles/common: Add comments to nftables.conf 2021-07-30 09:37:30 +03:00
debcb21161
roles/common: Install curl for Abuse.ch update scripts 2021-07-29 10:24:32 +03:00
8dd7663b3c
roles/common: Use Abuse.ch's SSL Blacklist in nftables
This adds Abuse.sh's list of IPs using blacklisted SSL certificates
to nftables. These IPs are high confidence indicators of compromise
and we should not route them. The list is updated daily by a systemd
timer.

See: https://sslbl.abuse.ch/blacklist/
2021-07-29 10:16:00 +03:00
cba2a7a996
roles/common: Fix nftables in Debian firewall
The previous commit meant to move the service start, not the config
copying task.
2021-07-29 10:10:04 +03:00
197bdf7666
roles/common: Start nftables service later
We should only try to start the nftables service after we finish
copying all the config files just in case there is some unclean
state in one of them. On a first run this shouldn't matter, but
after nftables and some abuse list update scripts have run this
can happen (mostly in testing!).
2021-07-29 10:05:15 +03:00
46fc2ce3d4
roles/common: Move cleanup to a one-off play
We only need to run this once on existing hosts that are using the
old firewalld/ipsets setup before applying the new nftables config.
2021-07-29 10:00:30 +03:00
b4d50166f4
roles/common: Fix loop in firewall cleanup 2021-07-28 23:46:53 +03:00
af6c3dd12a
roles/common: Update cache in firewall playbook
cron-apt updates the system against the security-only databases at
night so many packages are "missing" unless you run apt update. We
need to update the cache on all apt tasks actually because I might
be running them by their tag and they currently only get updated at
the beginning of the playbook.
2021-07-28 14:46:58 +03:00
b66c724109
roles/common: Use nftables on Ubuntu 20.04 as well
This mostly copies the Debian 11 nftables setup and includes a play
to clean up the old firewalld settings, timers, etc.
2021-07-28 14:18:41 +03:00
8bc2b6f493
roles/common: Retab nftables.conf.j2 2021-07-27 22:03:23 +03:00
a74d6dfc08
roles/common: Don't overwrite spamhaus nft sets
The ones in this repo are only placeholders that get updated by the
update-spamhaus-nftables service, so we shouldn't overwrite them if
they exist.
2021-07-27 22:01:57 +03:00
d3922e7878
roles/common: Port configurable firewall logic to nftables
This opens TCP port 22 on all hosts, TCP ports 80 and 443 on hosts
in the web group, and allows configuration of "extra" rules in the
host or group vars.
2021-07-27 21:22:32 +03:00
14814aa5d9
roles/common: Wire up fail2ban
The nftables support works easily and creates the table, chains, and
sets on demand.
2021-07-26 22:07:31 +03:00
3b053167b1
roles/common: Fix sources.list for Debian 11 Bullseye
Seems the path to the security updates repo changed.
2021-07-26 21:12:05 +03:00
9bba0d96bb
roles/common: Add initial support for nftables on Debian 11
I will try using nftables directly instead of via firewalld as of
Debian 11 as it is the replacement for the iptables/ipset stack in
recent years and is easier to work with.

This also includes a systemd service, timer, and script to update
the spamhaus DROP lists as nftables sets.

Still need to add fail2ban support.
2021-07-26 13:09:41 +03:00
38c333045b
roles/common: bring Ubuntu firewall changes to Debian 11
Note that there is currently an issue loading the spamhaus rules on
Debian 11 when using ipsets with firewalld and the nftables backend.
The bug is apparently caused by overlapping CIDR segments, and the
solution appears to be that we need to manually aggregate them with
a tool like aggregate6 (Python).

See: https://bugzilla.redhat.com/show_bug.cgi?id=1836571
See: https://wiki.fysik.dtu.dk/it/Linux_firewall_configuration#using-ipsets-in-firewalld-on-rhel-centos-8
See: https://github.com/job/aggregate6
2021-07-24 23:09:33 +03:00
d4ede33099
roles/common: Don't configure apt sources on ARM
I was using this on Ubuntu, but might as well bring it here too so
that I can run Debian on Scaleway's ARM instances, for example.
2021-07-24 22:32:20 +03:00
0bad75788d
roles/common: Add encryption settings to Debian 11 sshd_config
Mostly based on the ssh-audit policy for OpenSSH 8.4, but with any
algorithms using less than 256 bits removed. NSA's Suite B removed
these long ago, and the new CNSA suite only uses 256 and up.

See: https://github.com/jtesta/ssh-audit/blob/master/src/ssh_audit/policy.py
See: https://en.wikipedia.org/wiki/Commercial_National_Security_Algorithm_Suite
2021-07-24 22:28:59 +03:00
892033b880
roles/common: port common settings to Debian 11 sshd_config
Still need to add the encryption settings.
2021-07-22 14:16:20 +03:00
7c6ab2a652 roles/common: Add sshd_config from Debian 11 RC2 2021-07-22 14:15:00 +03:00
1c95c1faa8
roles/common: Update KexAlgorithms in Ubuntu 20.04 sshd_config
Recommended by ssh-audit. Note that curve25519-sha256 is the new name
for the previously private implementation in libssh.
2021-07-22 12:57:31 +03:00
9ea14de6f5
roles/common: Remove Encrypt-and-MAC modes from Ubuntu 20.04 sshd_config
Recommended by ssh-audit, but also generally the concensus for a few
years that Encrypt-and-MAC is hard to get right. OpenSSH has several
Encrypt-then-MAC schemes available so we can use those.

See: https://www.daemonology.net/blog/2009-06-24-encrypt-then-mac.html
2021-07-22 12:48:12 +03:00