Category Archives: CLI

Wireguard on a USG Pro 4

I ran into some issues when trying to configure an OpenVPN tunnel between my Ubiquiti USG Pro 4 and a Debian VPS. I was very disappointed to discover that the version of OpenVPN on the USG only supports TLS 1.0! My issue was the Debian side rejecting that as insecure.

Thankfully, it was fairly painless to get Wireguard configured on the USG Pro 4. I was hesitant to do so at first because I knew every time my USG was updated I would lose the wireguard pacakge. Fortunately that can be resolved by configuring a post-install script. Thanks to ilar.in and calypte.cc and this github gist for the steps on how to do so.

curl -O https://raw.githubusercontent.com/britannic/install-edgeos-packages/master/install-pkgs
sudo install -o root -g root -m 0755 install-pkgs /config/scripts/post-config.d/install-pkgs
  • Add wireguard DEB package to persistent storage that the script will look for:
sudo mkdir -p /config/data/install-packages
cd /config/data/install-packages
curl -fLSs https://github.com/WireGuard/wireguard-vyatta-ubnt/releases/download/1.0.20200729-1/ugw4-v1-v1.0.20200729-v1.0.20200513.deb
  • Generate a public/private keypair for USG use
cd /config/auth
umask 077
wg genkey > wg_private.key
wg pubkey < wg_private.key > wg_public.key
  • Generate config.gateway.json config to use wireguard
    "interfaces": {
 ...
        "wireguard": {
            "wg0": {
                "address": "<IP_OF_USG_ON_WG_CLIENT_SUBNET>",
                "listen-port": "<WG_LISTEN_PORT>",
                "peer": {
                    "<ENDPOINT_CLIENT_PUBLIC_KEY>": {
                        "allowed-ips": "0.0.0.0/0",
                        "endpoint":  "<ENDPOINT_CLIENT_ADDRESS>:<ENDPOINT_CLIENT_PORT>
"
                    }
                },
                "private-key": "/config/auth/priv.key",
                "route-allowed-ips": false
            },
            "wg1": {
                "address": "<IP_OF_USG_ON_WG_SERVER_SUBNET",
                "firewall": {
                    "in": {
                        "name": "LAN_IN"
                    },
                    "local": {
                        "name": "LAN_LOCAL"
                    },
                    "out": {
                        "name": "LAN_OUT"
                    }
                },
                "listen-port": "<USG_WG_SERVER_LISTEN_PORT>",
                "mtu": "1352",
                "peer": {
                    "<PUBLIC_KEY_OF_WG_CONNECTING_CLIENT": {
                        "allowed-ips": "<SUBNETS_ON_REMOTE_HOST>"
                    }
                },
                "private-key": "/config/auth/wg-server.priv",
                "route-allowed-ips": true
            }
        }
    },

I have two different wireguard interfaces configured – wg0 to be a client to another server, and wg1 to be a server accepting other clients (site-to-site VPN.)

If you want to have multiple peers defined on a single wireguard interface, encapsulate the peers with brackets like so:

"peer": [{
						"--pubkey--": {
							"allowed-ips": [
								"172.255.252.2/32"
							],
							"persistent-keepalive": 60
						}
					},
					{
						"--pubkey--": {
							"allowed-ips": [
								"172.255.252.3/32"
							],
							"persistent-keepalive": 60
						}
					}
				],

Test configuration first

Before committing your config.gateway.json code, test it line by line by SSHing into the USG-Pro 4 and entering config mode. Then type out your JSON lines one at a time, with each key being a new argument separated by a space. The first section above would look like this:

configure
edit interfaces
set wireguard wg0 address WIREGUARD_ADDRESS
set wireguard wg0 listen-port WG_LISTEN_PORT
set wireguard wg0 peer ENDPOINT_CLIENT_PUBLIC_KEY allowed-ips 0.0.0.0/0
set wireguard wg0 peer ENDPOINT_CLIENT_PUBLIC_KEY endpoint ENDPOINT_ADDRESS:ENDPOINT_PORT
set wireguard wg0 private-key /config/auth/priv.key
set wireguard wg0 route-allowed-ips false
commit

If the commit works without error, you can then drop out of the configure section and look at your wireguard config:

exit
sudo wg show

If all looks well, then copy your config.gateway.json to your controller and trigger a reprovision.

Verify after provisioning: 

sudo netstat -npl | grep <WIREGUARD_PORT> | grep udp

Troubleshooting

USG not connecting to changed endpoint address

If you change the address of the wireguard endpoint, USG pro will not connect to that new address. You have to delete and re-create the interface (thanks to https://github.com/Lochnair/vyatta-wireguard/issues/72#issuecomment-423840448 for the information)

Fix this by deleting the wireguard interface

admin@Firewall:~$ configure
[edit]
admin@Firewall# delete interfaces wireguard
[edit]
admin@Firewall# commit


Then reprovision by making a small change, force provision, then change back, and force another provision (annoying) or alternatively reboot firewall.

Wireguard shows established but ping doesn’t work

Example error:

From 10.99.13.1 icmp_seq=5 Destination Host Unreachable
ping: sendmsg: Required key not available

To figure out what’s going on, enable logging to kernel buffer (dmesg) Thanks to procustodibus.com for the info.

echo module wireguard +p > /sys/kernel/debug/dynamic_debug/control

With debug on, ping again and check kernel messages (dmesg)

[Tue Dec 21 22:16:12 2021] wireguard: wg0: No peer has allowed IPs matching 10.99.13.2

This showed I didn’t have my access control properly configured. Modify /etc/wireguard/wg0.conf on your client config and make sure your AllowedIPs are properly letting traffic through.

AllowedIPs = 10.99.13.0/24

USG not allowing connections

Clients unable to connect to USG despite having a good config. Double check your firewall rules. I had neglected to create a WAN LOCAL rule allowing UDP packets on my wireguard port. Once that was configured, handshakes completed successfully.

Firewalls can’t ping each other

I had an issue where the firewalls would pass traffic through, but they couldn’t ping each other. The solution was to add the VPN subnet you created to allowed-ips on both sides of the connection.

Site to site Wireguard VPN between OPNSense & Debian Linux server

I have a Debian linode box acting as a wireguard server. I wanted to join my opnsense firewall to it to allow devices behind it to access the box through the wireguard tunnel. It was not as straightforward as I had hoped, but thankfully I got it all working.

OPNSense side

Documentation link

Install wireguard via GUI

Install the os-wireguard package. Manually drop to the CLI and install the wireguard package as well:
sudo pkg install wireguard

Configure Local instance

  • Name and listen port can be random. Tunnel address is the subnet you wish to expose to the other end (the subnet you wish to have access to the tunnel.)
  • Leave everything else blank and hit save
  • Edit your new connection and copy the Public key, this will need to be sent to the Debian server

Configure Endpoint

  • Name: hostname of Debian server
  • Public Key: Public key of server (can be obtained by running wg show on the server)
  • Shared Secret: blank (unless you’ve configured it on the server)
  • Allowed IPs: IPs or subnets on the Debian server you wish to expose to the client side (the OPNSense box)
  • Endpoint address: DNS name of Debian server
  • Endpoint port: Port Debian wireguard instance is listening on

Enable the VPN

General tab / Enable wireguard checkbox and hit apply.

Debian side

Take down the tunnel

sudo wg-quick down wg0

Edit wireguard config to add peer

sudo vim /etc/wireguard/wg0.conf

[Peer]
PublicKey = <PUBLIC_KEY_YOU_COPIED_IN_LOCAL_INSTANCE_STEP>
AllowedIPs = <IPs or Subnets behind the OPNSense side you wish to be exposed to the Debian side> 

Restart wireguard

sudo wg-quick up wg0

Check connections

Example wg show output below with dummy IPs:

sudo wg show
interface: wg0
  public key: f+/J4JO0aL6kwOaudAvZVa1H2mDzR8Nh3Vfeqq+anF8=
  private key: (hidden)
  listening port: 12345

peer: TuUW7diXcWlaV97z3cQ1/92Zal2Pm9Qz/W2OMN+v20g=
  endpoint: 10.0.0.1:54137
  allowed ips: 10.0.0.2/32
  latest handshake: 17 seconds ago
  transfer: 5.14 KiB received, 3.81 KiB sent

peer: CZuC/+wxvzj9+TiGeyZtcT/lMGZnXsfSs/h5Jtw2VSE=
  endpoint: 8.8.8.8:12345
  allowed ips: 192.168.1.1/32
  latest handshake: 7 minutes, 8 seconds ago
  transfer: 5.89 MiB received, 952.20 MiB sent

The endpoint: line gets populated when a successful VPN connection is made. If it’s missing, the tunnel was not established.

Troubleshooting

OPNSense box

Nothing happens after saving information and enabling tunnel

Make sure latest wireguard package is installed

sudo pkg install wireguard

Get more log output by opening a shell on your OPNSense box and running

sudo /usr/local/etc/rc.d/wireguard start

In my case I was getting this interesting message

[!] Missing WireGuard kernel support (ifconfig: SIOCIFCREATE2: Invalid argument). Falling back to slow userspace implementation.
[#] wireguard-go wg0
┌──────────────────────────────────────────────────────┐
│                                                                                                                                                   │
│   Running wireguard-go is not required because this                                                     │
│   kernel has first class support for WireGuard. For                                                          │
│   information on installing the kernel module,                                                                 │
│   please visit                                                                                                                             │
│         https://www.wireguard.com/install/                                                                           │
└──────────────────────────────────────────────────────┘

I fixed this problem by manually installing wireguard with the pkg install command above.

Debian box

Wireguard config not saving

make sure to stop the tunnel first, otherwise your changes get overwritten by the daemon.

sudo wg-quick down wg0
<make changes>
sudo wg-quick up wg0

Self host postfix SMTP relay for Zimbra Mail Server

My notes for spinning up a small Debian linode server to act as an SMTP relay for my home network (note you will have to engage with linode support to enable mail ports for new accounts.)

Relay server configuration

Install postfix

sudo apt install postfix

Modify main.cf

sudo vim /etc/postfix/main.cf

Under TLS parameters, add TLS security to enable secure transfer of mail

smtp_tls_security_level = may
I decided not to open up postfix to the internet but instead my relay has a wireguard tunnel and postfix is allowed to relay only from that VPN subnet.

Add your subnets and relay restrictions further down:

mynetworks = 127.0.0.0/8 <YOUR_SERVER_SUBNET>
smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated check_relay_domains
relay_domains = <MY_DOMAIN_NAME>
myhostname = <RELAYSERVER_HOSTNAME>
inet_interfaces = 127.0.0.1, <IP_OF_WIREGUARD_VPN_INTERFACE>

Zimbra configuration

In Zimmbra admin panel, edit your mail server

Configure / Servers / your_mail_server

MTA section

Add the DNS name and port of the relay system next to “Relay MTA for external deliverability”

If it won’t let you save, saying ::1 is required, you can add ::1 to MTA Trusted networks, however, on my Zimbra server this broke postfix. The symptoms were e-mails hanging and not sending. To fix, log into the Zimbra mail server and run as the zimbra user:

zmprov ms YOUR_MAIL_DOMAIN_NAME zimbraMtaMyNetworks ‘127.0.0.1 192.168.0.0/16’ (list of networks you had before but excluding ::1)

Then, issue postfix reload

That was it. A simple postfix SMTP relay which only accepts mail from my internal VPN (it doesn’t listen on the external interface at all.)

Troubleshooting

Realyed mail shows red unlock icon in Gmail (mail getting sent unencrypted)

Per postfix documentation I needed to enable secure transfer of mail by adding

smtp_tls_security_level = may

to main.cf

Mail does not send after adding ::1 to MTA Trusted Networks

Remove it via the CLI and reload postfix:

zmprov ms YOUR_MAIL_DOMAIN_NAME zimbraMtaMyNetworks '127.0.0.1 192.168.0.0/16' (list of networks you had before but excluding ::1)
postfix reload

piKVM pushover startup script

I’ve had an issue where I wasn’t sure if my dynamic DNS provider registered properly. I then realized that I have a piKVM attached to one of my servers that boots on powerup, even if the server does not. I could utilize this piKVM to help me out.

Thanks to inspiration from Chris Dzombak I was able to whip up a little script that runs on startup. This script waits 5 minutes to allow for my firewall and modem to boot up, then sends a pushover notification to let me know the piKVM is online and what its external IP address is.

To get it working on the piKVM I had to enter into RW mode, write and save the script, add execute permissions to the script, then configure a systemd service to run the script at startup.

Here is the script, saved under /root/boot-pushover.sh

#!/usr/bin/env bash
set -eu

#Wait 5 minutes to allow router bootup
sleep 300

TOKEN="PUSHOVER_APPLICATION_TOKEN"
USER="PUSHOVER_USER_TOKEN"
EXTERNAL_IP="$(curl ifconfig.me)"
MESSAGE="$(hostname) is online. External IP: $EXTERNAL_IP"

#Send pushover command to alert it's up and send its external IP
curl -s \
  --form-string "token=$TOKEN" \
  --form-string "user=$USER" \
  --form-string "message=$MESSAGE" \
  https://api.pushover.net/1/messages.json

Set executable: chmod +x /root/boot-pushover.sh

Here is the systemd service, saved under /etc/systemd/system/boot-pushover-notification.service

[Service]
Type=oneshot
ExecStart=/root/boot-pushover.sh
RemainAfterExit=yes
User=root
Group=root
RestartSec=15
Restart=on-failure

[Unit]
Wants=network.target
After=network.target nss-lookup.target

[Install]
WantedBy=multi-user.target

Reload daemons & enable startup:

systemctl daemon-reload
systemctl enable boot-pushover-notification.service

Test by exiting rw mode and rebooting the piKVM:

ro
reboot

It works really well!

Saltstack JINJA set variables within set parameter

It took me a while to understand how to insert variables into a JINJA set statement. I read this tutorial which was helpful but still didn’t get me what I wanted. I wanted to be able to set a variable within a {% set %} parameter, something like this:

{% set variable = salt['vault'].read_secret('super/secret/path/{{ variable }}/more/secret/path/{{ another_variable}}', 'username') %}

Except that didn’t work. It simply rendered the brackets instead of inserting the variable.

I finally came across this stackoverflow page which outlined what I needed to do – a lot like in C, I needed to quote things I wanted to be taken literally, then add a + sign to insert the variable, then another + sign for the rest of the parameter. The correct syntax is as follows:

{% set variable = salt['vault'].read_secret('super/secret/path/' + variable + '/more/secret/path/' + another_variable', 'username') %}

This worked beautifully.

rsync create directory tree on remote host

I ran into an issue where I want to use rsync to copy a folder to a remote host into a destination directory that doesn’t yet exist. I was frustrated to find that rsync doesn’t appear to be able to create a remote directory tree. It would keep erroring out with this message:

rsync: mkdir "/opt/splunk/var/run/searchpeers" failed: No such file or directory (2)

I discovered this workaround which allowed me to finally accomplish what I wanted in one line: create the remote directory structure first, then synchronize into it. This is done with the --rsync-path option. You can specify the mkdir -p command beforehand, then add the rsync command after double ampersand (&&)

My specific use case was to copy a Splunk search peer bundle from one indexer to another. This was my working one liner:

rsync -aP --rsync-path="sudo mkdir -p /opt/splunk/var/run/searchpeers && sudo rsync" /opt/splunk/var/run/searchpeers splunk-idx2.jeppson.org:/opt/splunk/var/run/searchpeers

Success.

Restore files from remote borg repository disk image

My off-site backup involves sending borgbackup archives of VM images to a remote synology server. I recently needed to restore a single file from one of the VM images stored within this borg backup repository on the remote server. My connection to this server is not very fast so I didn’t want to wait to download the entire image file to mount it locally.

My solution was to mount the remote borgbackup repository on my local machine over SSH so I could poke around for and copy the specific file I wanted. This requires the borgbackup binary to be present on the remote machine. Since it’s a synology, I simply copied the standalone binary over.

The restore process was complicated by the fact that the VM disk image is owned by root, so in order to access the file I needed to mount the remote repository as root.

This is the process:

  1. Set BORG_REMOTE_PATH
    1. export BORG_REMOTE_PATH=<PATH_TO_BORG_BINARY_ON_REMOTE_SYSTEM>
  2. (Arch Linux): install python-llfuse
  3. Mount repository over SSH:
    1. borg mount <USER>@<REMOTE_SYSTEM>:<PATH_TO_REMOTE_BORGBACKUP_REPOSITORY>::<BACKUP_NAME> <MOUNT_FOLDER>
  4. Follow disk image mounting process
    1. losetup -Pr -f <PATH_TO_MOUNTED_BORGBACKUP>/<FILENAME_OF_VM_IMAGE>
    2. mount -o ro /dev/loop0p2 /mnt/loop0/
  5. Follow reverse to unmount when done:
    1. umount /mnt/loop0
    2. losetup -d /dev/loop0
    3. borg umount <MOUNT_FOLDER>

Success! I was able to restore an individual file within a raw VM image backup on a remote Borgbackup repository using this method.

Access idrac6 java console in mac OS

I needed to access my aging Dell PowerEdge R610 iDRAC console on my shiny new 13″ Macbook Pro M1. Unfortunately just like in Linux I ran into the “Connection failed” problem described in this post.

It was actually pretty easy to do for Mac. I installed the latest java for Mac from Oracle’s website. Once installed, I needed to find the location of the Java home directory for my mac. I found this stackoverflow discussion which directed me to use the /usr/libexec/java_home command.

Armed with that command in a subshell I was able to get to the file I wanted to edit:

sudo vim "$(/usr/libexec/java_home)/lib/security/java.security"

Once there I removed RC4 from the

jdk.tls.disabledAlgorithms

line. It worked! It was an easier process than on Linux or Windows.

Guacamole docker quick and easy

Apache Guacamole as an awesome HTML5 remote access gateway. Unfortunately it can be very frustrating to set up. They have docker images that are supposed to make the process easier, but I still ran into a lot of problems trying to get everything configured and linked.

Fortunately, a docker compose file exists to make Guacamole much easier to set up. Simply follow the instructions as laid out in the github readme:

  • Install docker & docker-compose
  • Clone their repository, run the initial prep script (for SSL keys & database initialization), and bring it up with docker-compose:
git clone "https://github.com/boschkundendienst/guacamole-docker-compose.git"
cd guacamole-docker-compose
sudo ./prepare.sh
sudo docker-compose up -d

Done! If you didn’t change anything in the docker-compose.yml file, you will have a new instance of Guacamole running on HTTPS port 8443 of your docker host. If you need to make changes (or if you forgot to run the prepare.sh file with sudo), you can run the reset.sh script which will destroy everything. You can then modify docker-compose.yml to suit your needs:

  • Whether to use nginx for HTTPS or just expose guacamole on port 8080 non-https (in case you already have a reverse proxy set up)
  • postgres password

Config files for each container are located within various folders in your guacamole-docker-compose folder. This can all be changed by editing the docker-compose.yml file.

Note this does configuration does not work with WOL, but as I do not use this feature I don’t mind.

Troubleshooting

docker ps will show running containers (docker ps -a shows all containers) If one is not running that should be, docker logs <container name> gives valuable insight as to why. In my case guacd was erroring out because I hadn’t initialized the database properly. Running the reset.sh script and starting over, this time running as sudo, did the trick.

Mount LVM partitions in FreeBSD

I’ve been playing around with helloSystem, an up and coming FreeBSD desktop environment that mirrors the MacOS experience quite well. Since it’s based in FreeBSD I’ve had to brush up on a few FreeBSD-isms that are distinctly different from Linux.

Since I’m dual booting this helloSystem BSD system alongside my Arch Linux install, I want to be able to access files on my Arch system from the BSD system. My Arch system uses LVM, which posed a challenge as LVM is a distinctly Linux thing.

To get it to work I needed to load a couple modules (thanks to the FreeBSD forums for help)

  • fuse
  • geom_linux_lvm

You can do this at runtime by using the kldload command

kldload fuse
kldload /boot/kernel/geom_linux_lvm.ko

To make the kernel module loading survive a reboot, add them to /boot/loader.conf

geom_linux_lvm_load="YES"
fuse_load="YES"

You can now scan your BSD system for LVM partitions:

geom linux_lvm list

The LVM partitions are listed under /dev/linux_lvm. The last step is to mount them with FUSE:

fuse-ext2 -o rw+ /dev/linux_lvm/NAME_OF_LVM_PARTITION /mnt/DESIRED_MOUNT_FOLDER

rw+ indicates a read/write mount.