signal-cli

First and foremost a big thank you to AsamK(https://github.com/AsamK) most of this guide is copied from AsamK's signal-cli repo modified to fit my own needs.

This guide is for installing and running signal-cli as a daemon and setting up a system-wide dbus. signal-cli is a commandline interface for the Signal messenger. It supports registering, verifying, sending and receiving messages. signal-cli uses a patched libsignal-service-java, extracted from the Signal-Android source code. For registering you need a phone number where you can receive SMS or incoming calls.

Installation

System requirements:

• at least Java Runtime Environment (JRE) 17
• wget

debian: $ sudo apt install wget openjdk-17-jre

Install system-wide on Linux

See latest version.

export VERSION=<latest version, format "x.y.z">
wget https://github.com/AsamK/signal-cli/releases/download/v"${VERSION}"/signal-cli-"${VERSION}"-Linux.tar.gz
sudo tar xf signal-cli-"${VERSION}"-Linux.tar.gz -C /opt
sudo ln -sf /opt/signal-cli-"${VERSION}"/bin/signal-cli /usr/local/bin/

Initial Setup

Create user for running the service, --systen creates a system user without home dir and password. :

# adduser --system --group signal-cli

Create a folder for signal account configs:

# mkdir /var/lib/signal-cli
# chown signal-cli: /var/lib/signal-cli

Register Account

# su signal-cli -s /bin/bash
$ /usr/local/bin/signal-cli --config /var/lib/signal-cli -u <PHONE NUMBER> register

Registering may require solving a CAPTCHA challenge: Registration with captcha

Verify the number using the code received via SMS or voice, optionally add --pin PIN_CODE if you've added a pin code to your account:

signal-cli$ /usr/local/bin/signal-cli --config /var/lib/signal-cli -u <PHONE NUMBER> verify <CODE>

Setup systemd service and dbus

To run on the system bus you need to take some additional steps. It’s advisable to run signal-cli as a separate unix user, the following steps assume you created a user named signal-cli. To run a service on the system bus, a config file is needed to allow the signal-cli user to take a name on the system bus. An example config file can be found in data/org.asamk.Signal.conf. This file also configures that any user can talk with the signal-cli daemon. The data/org.asamk.Signal.service and data/signal-cli.service files configure a dbus activated systemd service for signal-cli, so the service is automatically started when the dbus service is requested.

These steps, executed as root, should work on all distributions using systemd.

Git clone this repo as you will need files from the data folder.

git clone https://git.data.coop/sune/Signal-cli.git

move the files:

# mv data/org.asamk.Signal.conf /etc/dbus-1/system.d/
# mv data/org.asamk.Signal.service /usr/share/dbus-1/system-services/
# mv data/signal-cli.service /etc/systemd/system/

edit service file to match phone number and enable systemd service:

# sed -i -e "s|%number%|<PHONE NUMBER>|" /etc/systemd/system/signal-cli.service
# systemctl daemon-reload
# systemctl enable signal-cli.service
# systemctl reload dbus.service
# systemctl start signal-cli.service

Test

Send a message:

$ signal-cli --dbus-system send -m "hey test" <RECIPIENT>