mirror of
https://github.com/mail-in-a-box/mailinabox.git
synced 2024-11-25 02:47:04 +00:00
a7dded8182
Having a log file can help debugging when something goes wrong and NSD doesn't fail or MiaB doesn't notify you. See https://discourse.mailinabox.email/t/dns-email-domain-becomes-inaccessible-every-few-hours/3770
150 lines
4.8 KiB
Bash
Executable File
150 lines
4.8 KiB
Bash
Executable File
#!/bin/bash
|
|
# DNS
|
|
# -----------------------------------------------
|
|
|
|
# This script installs packages, but the DNS zone files are only
|
|
# created by the /dns/update API in the management server because
|
|
# the set of zones (domains) hosted by the server depends on the
|
|
# mail users & aliases created by the user later.
|
|
|
|
source setup/functions.sh # load our functions
|
|
source /etc/mailinabox.conf # load global vars
|
|
|
|
# Install the packages.
|
|
#
|
|
# * nsd: The non-recursive nameserver that publishes our DNS records.
|
|
# * ldnsutils: Helper utilities for signing DNSSEC zones.
|
|
# * openssh-client: Provides ssh-keyscan which we use to create SSHFP records.
|
|
echo "Installing nsd (DNS server)..."
|
|
apt_install nsd ldnsutils openssh-client
|
|
|
|
# Prepare nsd's configuration.
|
|
|
|
mkdir -p /var/run/nsd
|
|
|
|
cat > /etc/nsd/nsd.conf << EOF;
|
|
# Do not edit. Overwritten by Mail-in-a-Box setup.
|
|
server:
|
|
hide-version: yes
|
|
logfile: "/var/log/nsd.log"
|
|
|
|
# identify the server (CH TXT ID.SERVER entry).
|
|
identity: ""
|
|
|
|
# The directory for zonefile: files.
|
|
zonesdir: "/etc/nsd/zones"
|
|
|
|
# Allows NSD to bind to IP addresses that are not (yet) added to the
|
|
# network interface. This allows nsd to start even if the network stack
|
|
# isn't fully ready, which apparently happens in some cases.
|
|
# See https://www.nlnetlabs.nl/projects/nsd/nsd.conf.5.html.
|
|
ip-transparent: yes
|
|
|
|
EOF
|
|
|
|
# Add log rotation
|
|
cat > /etc/logrotate.d/nsd <<EOF;
|
|
/var/log/nsd.log {
|
|
weekly
|
|
missingok
|
|
rotate 12
|
|
compress
|
|
delaycompress
|
|
notifempty
|
|
}
|
|
EOF
|
|
|
|
# Since we have bind9 listening on localhost for locally-generated
|
|
# DNS queries that require a recursive nameserver, and the system
|
|
# might have other network interfaces for e.g. tunnelling, we have
|
|
# to be specific about the network interfaces that nsd binds to.
|
|
for ip in $PRIVATE_IP $PRIVATE_IPV6; do
|
|
echo " ip-address: $ip" >> /etc/nsd/nsd.conf;
|
|
done
|
|
|
|
echo "include: /etc/nsd/zones.conf" >> /etc/nsd/nsd.conf;
|
|
|
|
# Create DNSSEC signing keys.
|
|
|
|
mkdir -p "$STORAGE_ROOT/dns/dnssec";
|
|
|
|
# TLDs don't all support the same algorithms, so we'll generate keys using a few
|
|
# different algorithms. RSASHA1-NSEC3-SHA1 was possibly the first widely used
|
|
# algorithm that supported NSEC3, which is a security best practice. However TLDs
|
|
# will probably be moving away from it to a a SHA256-based algorithm.
|
|
#
|
|
# Supports `RSASHA1-NSEC3-SHA1` (didn't test with `RSASHA256`):
|
|
#
|
|
# * .info
|
|
# * .me
|
|
#
|
|
# Requires `RSASHA256`
|
|
#
|
|
# * .email
|
|
# * .guide
|
|
#
|
|
# Supports `RSASHA256` (and defaulting to this)
|
|
#
|
|
# * .fund
|
|
|
|
FIRST=1 #NODOC
|
|
for algo in RSASHA1-NSEC3-SHA1 RSASHA256; do
|
|
if [ ! -f "$STORAGE_ROOT/dns/dnssec/$algo.conf" ]; then
|
|
if [ $FIRST == 1 ]; then
|
|
echo "Generating DNSSEC signing keys..."
|
|
FIRST=0 #NODOC
|
|
fi
|
|
|
|
# Create the Key-Signing Key (KSK) (with `-k`) which is the so-called
|
|
# Secure Entry Point. The domain name we provide ("_domain_") doesn't
|
|
# matter -- we'll use the same keys for all our domains.
|
|
#
|
|
# `ldns-keygen` outputs the new key's filename to stdout, which
|
|
# we're capturing into the `KSK` variable.
|
|
#
|
|
# ldns-keygen uses /dev/random for generating random numbers by default.
|
|
# This is slow and unecessary if we ensure /dev/urandom is seeded properly,
|
|
# so we use /dev/urandom. See system.sh for an explanation. See #596, #115.
|
|
KSK=$(umask 077; cd $STORAGE_ROOT/dns/dnssec; ldns-keygen -r /dev/urandom -a $algo -b 2048 -k _domain_);
|
|
|
|
# Now create a Zone-Signing Key (ZSK) which is expected to be
|
|
# rotated more often than a KSK, although we have no plans to
|
|
# rotate it (and doing so would be difficult to do without
|
|
# disturbing DNS availability.) Omit `-k` and use a shorter key length.
|
|
ZSK=$(umask 077; cd $STORAGE_ROOT/dns/dnssec; ldns-keygen -r /dev/urandom -a $algo -b 1024 _domain_);
|
|
|
|
# These generate two sets of files like:
|
|
#
|
|
# * `K_domain_.+007+08882.ds`: DS record normally provided to domain name registrar (but it's actually invalid with `_domain_`)
|
|
# * `K_domain_.+007+08882.key`: public key
|
|
# * `K_domain_.+007+08882.private`: private key (secret!)
|
|
|
|
# The filenames are unpredictable and encode the key generation
|
|
# options. So we'll store the names of the files we just generated.
|
|
# We might have multiple keys down the road. This will identify
|
|
# what keys are the current keys.
|
|
cat > $STORAGE_ROOT/dns/dnssec/$algo.conf << EOF;
|
|
KSK=$KSK
|
|
ZSK=$ZSK
|
|
EOF
|
|
fi
|
|
|
|
# And loop to do the next algorithm...
|
|
done
|
|
|
|
# Force the dns_update script to be run every day to re-sign zones for DNSSEC
|
|
# before they expire. When we sign zones (in `dns_update.py`) we specify a
|
|
# 30-day validation window, so we had better re-sign before then.
|
|
cat > /etc/cron.daily/mailinabox-dnssec << EOF;
|
|
#!/bin/bash
|
|
# Mail-in-a-Box
|
|
# Re-sign any DNS zones with DNSSEC because the signatures expire periodically.
|
|
`pwd`/tools/dns_update
|
|
EOF
|
|
chmod +x /etc/cron.daily/mailinabox-dnssec
|
|
|
|
# Permit DNS queries on TCP/UDP in the firewall.
|
|
|
|
ufw_allow domain
|
|
|