signal-cli

signal-cli is a commandline interface for libsignal-service-java. It supports registering, verifying, sending and receiving messages. To be able to link to an existing Signal-Android/signal-cli instance, signal-cli uses a patched libsignal-service-java, because libsignal-service-java does not yet support provisioning as a slave device. For registering you need a phone number where you can receive SMS or incoming calls. signal-cli is primarily intended to be used on servers to notify admins of important events. For this use-case, it has a dbus interface, that can be used to send messages from any programming language that has dbus bindings.

Installation

You can build signal-cli yourself, or use the provided binary files, which should work on Linux, macOS and Windows. For Arch Linux there is also a package in AUR and there is a FreeBSD port available as well. You need to have at least JRE 11 installed, to run signal-cli.

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}".tar.gz
sudo tar xf signal-cli-"${VERSION}".tar.gz -C /opt
sudo ln -sf /opt/signal-cli-"${VERSION}"/bin/signal-cli /usr/local/bin/

You can find further instructions on the Wiki:

• Quickstart
• DBus Service

Usage

For a complete usage overview please read the man page and the wiki.

Important: The USERNAME is your phone number in international format and must include the country calling code. Hence it should start with a "+" sign. (See Wikipedia for a list of all country codes.)

• Register a number (with SMS verification)

    signal-cli -u USERNAME register
  

  You can register Signal using a land line number. In this case you can skip SMS verification process and jump directly to the voice call verification by adding the --voice switch at the end of above register command.

• 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 -u USERNAME verify CODE
  

• Send a message

    signal-cli -u USERNAME send -m "This is a message" RECIPIENT
  

• Pipe the message content from another process.

    uname -a | signal-cli -u USERNAME send RECIPIENT
  

• Receive messages

    signal-cli -u USERNAME receive
  

Storage

The password and cryptographic keys are created when registering and stored in the current users home directory:

$XDG_DATA_HOME/signal-cli/data/ ($HOME/.local/share/signal-cli/data/)

For legacy users, the old config directories are used as a fallback:

    $HOME/.config/signal/data/

    $HOME/.config/textsecure/data/

Building

This project uses Gradle for building and maintaining dependencies. If you have a recent gradle version installed, you can replace ./gradlew with gradle in the following steps.

1. Checkout the source somewhere on your filesystem with

    git clone https://github.com/AsamK/signal-cli.git
   

2. Execute Gradle:

    ./gradlew build
   

3. Create shell wrapper in build/install/signal-cli/bin:

    ./gradlew installDist
   

4. Create tar file in build/distributions:

    ./gradlew distTar
   

Building a native binary with GraalVM (EXPERIMENTAL)

It is possible to build a native binary with GraalVM. This is still experimental and will not work in all situations.

1. Install GraalVM and setup the enviroment

2. Install prerequisites

3. Execute Gradle:

    ./gradlew assembleNativeImage
   

   The binary is available at build/native-image/signal-cli

Troubleshooting

If you use a version of the Oracle JRE and get an InvalidKeyException you need to enable unlimited strength crypto. See https://stackoverflow.com/questions/6481627/java-security-illegal-key-size-or-default-parameters for instructions.

License

This project uses libsignal-service-java from Open Whisper Systems:

https://github.com/WhisperSystems/libsignal-service-java

Licensed under the GPLv3: http://www.gnu.org/licenses/gpl-3.0.html