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Hosting your own SMP Server

| Updated 12.10.2024 | Languages: EN, FR, CZ, PL |

Table of Contents

Overview

SMP server is the relay server used to pass messages in SimpleX network. SimpleX Chat apps have preset servers (for mobile apps these are smp11, smp12 and smp14.simplex.im), but you can easily change app configuration to use other servers.

SimpleX clients only determine which server is used to receive the messages, separately for each contact (or group connection with a group member), and these servers are only temporary, as the delivery address can change.

To create SMP server, you'll need:

  1. VPS or any other server.
  2. Your own domain, pointed at the server (smp.example.com)
  3. A basic Linux knowledge.

Please note: when you change the servers in the app configuration, it only affects which servers will be used for the new contacts, the existing contacts will not automatically move to the new servers, but you can move them manually using "Change receiving address" button in contact/member information pages – it will be automated in the future.

Quick start

To create SMP server as a systemd service, you'll need:

  • VPS or any other server.
  • Your server domain, with A and AAAA records specifying server IPv4 and IPv6 addresses (smp1.example.com)
  • A basic Linux knowledge.

Please note: while you can run an SMP server without a domain name, in the near future client applications will start using server domain name in the invitation links (instead of simplex.chat domain they use now). In case a server does not have domain name and server pages (see below), the clients will be generaing the links with simplex: scheme that cannot be opened in the browsers.

  1. Install server with Installation script.

  2. Adjust firewall:

    ufw allow 80/tcp &&\
ufw allow 443/tcp &&\
ufw allow 5223/tcp

  3. Init server:

    Replace smp1.example.com with your actual server domain.

    su smp -c 'smp-server init --yes \
                        --store-log \
                        --no-password \
                        --control-port \
                        --socks-proxy \
                        --source-code \
                        --fqdn=smp1.example.com

  4. Install tor:

    CODENAME="$(lsb_release -c | awk '{print $2}')"

echo "deb [signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org ${CODENAME} main
deb-src [signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org ${CODENAME} main" > /etc/apt/sources.list.d/tor.list &&\
curl --proto '=https' --tlsv1.2 -sSf https://deb.torproject.org/torproject.org/A3C4F0F979CAA22CDBA8F512EE8CBC9E886DDD89.asc | gpg --dearmor | tee /usr/share/keyrings/tor-archive-keyring.gpg >/dev/null &&\
apt update && apt install -y tor deb.torproject.org-keyring

  5. Configure tor:

    tor-instance-create tor2 &&\
mkdir /var/lib/tor/simplex-smp/ &&\
chown debian-tor:debian-tor /var/lib/tor/simplex-smp/ &&\
chmod 700 /var/lib/tor/simplex-smp/

    vim /etc/tor/torrc

    Paste the following:

    # Enable log (otherwise, tor doesn't seem to deploy onion address)
Log notice file /var/log/tor/notices.log
# Enable single hop routing (2 options below are dependencies of the third) - It will reduce the latency at the cost of lower anonimity of the server - as SMP-server onion address is used in the clients together with public address, this is ok. If you deploy SMP-server with onion-only address, keep standard configuration.
SOCKSPort 0
HiddenServiceNonAnonymousMode 1
HiddenServiceSingleHopMode 1
# smp-server hidden service host directory and port mappings
HiddenServiceDir /var/lib/tor/simplex-smp/
HiddenServicePort 5223 localhost:5223
HiddenServicePort 443 localhost:443

    vim /etc/tor/instances/tor2/torrc

    Paste the following:

    # Log tor to systemd daemon
Log notice syslog
# Listen to local 9050 port for socks proxy
SocksPort 9050

  6. Start tor:

    systemctl enable tor &&\
systemctl start tor &&\
systemctl restart tor &&\
systemctl enable --now tor@tor2

  7. Install Caddy:

    sudo apt install -y debian-keyring debian-archive-keyring apt-transport-https curl &&\
curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/gpg.key' | sudo gpg --dearmor -o /usr/share/keyrings/caddy-stable-archive-keyring.gpg &&\
curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/debian.deb.txt' | sudo tee /etc/apt/sources.list.d/caddy-stable.list &&\
sudo apt update && sudo apt install caddy

  8. Configure Caddy:

    vim /etc/caddy/Caddyfile

    Replace smp1.example.com with your actual server domain. Paste the following:

    http://smp1.example.com {
   redir https://smp1.example.com{uri} permanent
}

smp1.example.com:8443 {
   tls {
      key_type rsa4096
   }
}

    vim /usr/local/bin/simplex-servers-certs

    Replace smp1.example.com with your actual server domain. Paste the following:

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

user='smp'
group="$user"

domain='smp1.example.com'
folder_in="/var/lib/caddy/.local/share/caddy/certificates/acme-v02.api.letsencrypt.org-directory/${domain}"
folder_out='/etc/opt/simplex'
key_name='web.key'
cert_name='web.crt'

# Copy certifiacte from Caddy directory to smp-server directory
cp "${folder_in}/${domain}.crt" "${folder_out}/${cert_name}"
# Assign correct permissions
chown "$user":"$group" "${folder_out}/${cert_name}"

# Copy certifiacte key from Caddy directory to smp-server directory
cp "${folder_in}/${domain}.key" "${folder_out}/${key_name}"
# Assign correct permissions
chown "$user":"$group" "${folder_out}/${key_name}"

    chmod +x /usr/local/bin/simplex-servers-certs

    sudo crontab -e

    Paste the following:

    # Every week on 00:20 sunday
20 0 * * 0 /usr/local/bin/simplex-servers-certs

  9. Enable and start Caddy service:

    Wait until "good to go" has been printed.

    systemctl enable --now caddy &&\
sleep 10 &&\
/usr/local/bin/simplex-servers-certs &&\
echo 'good to go'

  10. Enable and start smp-server:

    systemctl enable --now smp-server.service

  11. Print your address:

    smp="$(journalctl --output cat -q _SYSTEMD_INVOCATION_ID="$(systemctl show -p InvocationID --value smp-server)" | grep -m1 'Server address:' | awk '{print $NF}' | sed 's/:443.*//')"
tor="$(cat /var/lib/tor/simplex-smp/hostname)"

echo "$smp,$tor"

Installation options

You can install SMP server in one of the following ways:

systemd service

Installation script

This installation script will automatically install binaries, systemd services and additional scripts that will manage backups, updates and uninstallation. This is the recommended option due to its flexibility, easy updating, and being battle tested on our servers.

Please note that currently only Ubuntu distribution is supported.

Run the following script on the server:

curl --proto '=https' --tlsv1.2 -sSf https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/install.sh -o simplex-server-install.sh &&\
if echo '53fcdb4ceab324316e2c4cda7e84dbbb344f32550a65975a7895425e5a1be757 simplex-server-install.sh' | sha256sum -c; then
  chmod +x ./simplex-server-install.sh
  ./simplex-server-install.sh
  rm ./simplex-server-install.sh
else
  echo "SHA-256 checksum is incorrect!"
  rm ./simplex-server-install.sh
fi

Type 1 and hit enter to install smp-server.

Manual deployment

Manual installation is the most advanced deployment that provides the most flexibility. Generally recommended only for advanced users.

  1. Install binary:

    • Using pre-compiled binaries:

      curl -L https://github.com/simplex-chat/simplexmq/releases/latest/download/smp-server-ubuntu-20_04-x86-64 -o /usr/local/bin/smp-server && chmod +x /usr/local/bin/smp-server

    • Compiling from source:

      Please refer to Build from source: Using your distribution

  2. Create user and group for smp-server:

    sudo useradd -m smp

  3. Create necessary directories and assign permissions:

    sudo mkdir -p /var/opt/simplex /etc/opt/simplex
sudo chown smp:smp /var/opt/simplex /etc/opt/simplex

  4. Allow smp-server port in firewall:

    # For Ubuntu
sudo ufw allow 5223/tcp
sudo ufw allow 443/tcp
sudo ufw allow 80/tcp
# For Fedora
sudo firewall-cmd --permanent --add-port=5223/tcp --add-port=443/tcp --add-port=80/tcp && \
sudo firewall-cmd --reload

  5. Optional — If you're using distribution with systemd, create /etc/systemd/system/smp-server.service file with the following content:

    [Unit]
Description=SMP server systemd service

[Service]
User=smp
Group=smp
Type=simple
ExecStart=/usr/local/bin/smp-server start +RTS -N -RTS
ExecStopPost=/usr/bin/env sh -c '[ -e "/var/opt/simplex/smp-server-store.log" ] && cp "/var/opt/simplex/smp-server-store.log" "/var/opt/simplex/smp-server-store.log.bak"'
LimitNOFILE=65535
KillSignal=SIGINT
TimeoutStopSec=infinity
AmbientCapabilities=CAP_NET_BIND_SERVICE

[Install]
WantedBy=multi-user.target

    And execute sudo systemctl daemon-reload.

Docker container

You can deploy smp-server using Docker Compose. This is second recommended option due to its popularity and relatively easy deployment.

This deployment provides two Docker Compose files: the automatic one and manual. If you're not sure, choose automatic.

This will download images from Docker Hub.

Docker: Automatic setup

This configuration provides quick and easy way to setup your SMP server: Caddy will automatically manage Let's Encrypt certificates and redirect HTTP to HTTPS, while smp-server will serve both server information page and SMP Protocol by 443 port. 5223 port is used as fallback.

Please note that you must have 80 and 443 ports unallocated by other servers.

  1. Create smp-server directory and switch to it:
mkdir smp-server && cd smp-server
  1. Create docker-compose.yml file with the following content:

You can also grab it from here - docker-compose-smp-complete.yml. Don't forget to rename it to docker-compose.yml.

name: SimpleX Chat - smp-server

services:
  oneshot:
    image: ubuntu:latest
    environment:
      CADDYCONF: |
        ${CADDY_OPTS:-}

        http://{$$ADDR} {
            redir https://{$$ADDR}{uri} permanent
        }

        {$$ADDR}:8443 {
            tls {
                key_type rsa4096
            }
        }
    command: sh -c 'if [ ! -f /etc/caddy/Caddyfile ]; then printf "$${CADDYCONF}" > /etc/caddy/Caddyfile; fi'
    volumes:
      - ./caddy_conf:/etc/caddy

  caddy:
    image: caddy:latest
    depends_on:
      oneshot:
        condition: service_completed_successfully
    cap_add:
      - NET_ADMIN
    environment:
      ADDR: ${ADDR?"Please specify the domain."}
    volumes:
      - ./caddy_conf:/etc/caddy
      - caddy_data:/data
      - caddy_config:/config
    ports:
      - 80:80
    restart: unless-stopped
    healthcheck:
      test: "test -d /data/caddy/certificates/${CERT_PATH:-acme-v02.api.letsencrypt.org-directory}/${ADDR} || exit 1"
      interval: 1s
      retries: 60

  smp-server:
    image: ${SIMPLEX_IMAGE:-simplexchat/smp-server:latest}
    depends_on:
      caddy:
        condition: service_healthy
    environment:
      ADDR: ${ADDR?"Please specify the domain."}
      PASS: ${PASS:-}
    volumes:
      - ./smp_configs:/etc/opt/simplex
      - ./smp_state:/var/opt/simplex
      - type: volume
        source: caddy_data
        target: /certificates
        volume:
          subpath: "caddy/certificates/${CERT_PATH:-acme-v02.api.letsencrypt.org-directory}/${ADDR}"
    ports:
      - 443:443
      - 5223:5223
    restart: unless-stopped

volumes:
  caddy_data:
  caddy_config:
  1. In the same directory, create .env file with the following content:

You can also grab it from here - docker-compose-smp-complete.env. Don't forget to rename it to .env.

Change variables according to your preferences.

# Mandatory
ADDR=your_ip_or_addr

# Optional
#PASS='123123'
  1. Start your containers:
docker compose up

Docker: Manual setup

If you know what you are doing, this configuration provides bare SMP server setup without automatically managed Let's Encrypt certificates by Caddy to serve server information page with 5223 port set as primary.

This configuration allows you to retain the ability to manage 80 and 443 ports yourself. As a downside, SMP server *can not be served to 443 port.

  1. Create smp-server directory and switch to it:
mkdir smp-server && cd smp-server
  1. Create docker-compose.yml file with the following content:

You can also grab it from here - docker-compose-smp-manual.yml. Don't forget to rename it to docker-compose.yml.

name: SimpleX Chat - smp-server

services:
  smp-server:
    image: ${SIMPLEX_IMAGE:-simplexchat/smp-server:latest}
    environment:
      WEB_MANUAL: ${WEB_MANUAL:-1}
      ADDR: ${ADDR?"Please specify the domain."}
      PASS: ${PASS:-}
    volumes:
      - ./smp_configs:/etc/opt/simplex
      - ./smp_state:/var/opt/simplex
    ports:
      - 5223:5223
    restart: unless-stopped
  1. In the same directory, create .env file with the following content:

You can also grab it from here - docker-compose-smp-manual.env. Don't forget to rename it to .env.

Change variables according to your preferences.

# Mandatory
ADDR=your_ip_or_addr

# Optional
#PASS='123123'
WEB_MANUAL=1
  1. Start your containers:
docker compose up

Linode marketplace

You can deploy smp-server upon creating new Linode VM. Please refer to: Linode Marketplace

Verifying server binaries

Starting from v6.3 server builds are reproducible.

That also allows us to sign server releases, confirming the integrity of GitHub builds.

To verify server binaries after you downloaded them:

  1. Download _sha256sums (hashes of all server binaries) and _sha256sums.asc (signature).

  2. Download our key FB44AF81A45BDE327319797C85107E357D4A17FC from openpgp.org

  3. Import the key with gpg --import FB44AF81A45BDE327319797C85107E357D4A17FC. Key filename should be the same as its fingerprint, but please change it if necessary.

  4. Run gpg --verify _sha256sums.asc _sha256sums. It should print:

Good signature from "SimpleX Chat chat@simplex.chat"

  1. Compute the hashes of the binaries you plan to use with shu256sum <file> or with openssl sha256 <file> and compare them with the hashes in the file _sha256sums - they must be the same.

That is it - you now verified authenticity of our GitHub server binaries.

Configuration

To see which options are available, execute smp-server without flags:

sudo su smp -c smp-server

...
Available commands:
  init                     Initialize server - creates /etc/opt/simplex and
                           /var/opt/simplex directories and configuration files
  start                    Start server (configuration:
                           /etc/opt/simplex/smp-server.ini)
  delete                   Delete configuration and log files

You can get further help by executing sudo su smp -c "smp-server <command> -h"

After that, we need to configure smp-server:

Interactively

Execute the following command:

sudo su smp -c "smp-server init"

There are several options to consider:

  • Enable store log to restore queues and messages on server restart (Yn):

    Enter y to enable saving and restoring connections and messages when the server is restarted.

    Please note: it is important to use SIGINT to restart the server, as otherwise the undelivered messages will not be restored. The connections will be restored irrespective of how the server is restarted, as unlike messages they are added to append-only log on every change.

  • Enable logging daily statistics (yN):

    Enter y to enable logging statistics in CSV format, e.g. they can be used to show aggregate usage charts in Grafana.

These statistics include daily counts of created, secured and deleted queues, sent and received messages, and also daily, weekly, and monthly counts of active queues (that is, the queues that were used for any messages). We believe that this information does not include anything that would allow correlating different queues as belonging to the same users, but please let us know, confidentially, if you believe that this can be exploited in any way.

  • Require a password to create new messaging queues?

    Press Enter or enter your arbitrary password to password-protect smp-server, or n to disable password protection.

  • Enter server FQDN or IP address for certificate (127.0.0.1):

    Enter your domain or ip address that your smp-server is running on - it will be included in server certificates and also printed as part of server address.

Via command line options

Execute the following command:

sudo su smp -c "smp-server init -h"

...
Available options:
  -l,--store-log           Enable store log for persistence
  -s,--daily-stats         Enable logging daily server statistics
  -a,--sign-algorithm ALG  Signature algorithm used for TLS certificates:
                           ED25519, ED448 (default: ED448)
  --ip IP                  Server IP address, used as Common Name for TLS online
                           certificate if FQDN is not supplied
                           (default: "127.0.0.1")
  -n,--fqdn FQDN           Server FQDN used as Common Name for TLS online
                           certificate
  --no-password            Allow creating new queues without password
  --password PASSWORD      Set password to create new messaging queues
  -y,--yes                 Non-interactive initialization using command-line
                           options
  -h,--help                Show this help text

You should determine which flags are needed for your use-case and then execute smp-server init with -y flag for non-interactive initialization:

sudo su smp -c "smp-server init -y -<your flag> <your option>"

For example, run:

sudo su smp -c "smp-server init -y -l --ip 192.168.1.5 --password test"

to initialize your smp-server configuration with:

  • restoring connections and messages when the server is restarted (-l flag),
  • IP address 192.168.1.5,
  • protect smp-server with a password test.

After that, your installation is complete and you should see in your teminal output something like this:

Certificate request self-signature ok
subject=CN = 127.0.0.1
Server initialized, you can modify configuration in /etc/opt/simplex/smp-server.ini.
Run `smp-server start` to start server.
----------
You should store CA private key securely and delete it from the server.
If server TLS credential is compromised this key can be used to sign a new one, keeping the same server identity and established connections.
CA private key location: /etc/opt/simplex/ca.key
----------
SMP server v3.4.0
Fingerprint: d5fcsc7hhtPpexYUbI2XPxDbyU2d3WsVmROimcL90ss=
Server address: smp://d5fcsc7hhtPpexYUbI2XPxDbyU2d3WsVmROimcL90ss=:V8ONoJ6ICwnrZnTC_QuSHfCEYq53uLaJKQ_oIC6-ve8=@<hostnames>

The server address above should be used in your client configuration, and if you added server password it should only be shared with the other people who you want to allow using your server to receive the messages (all your contacts will be able to send messages - it does not require a password). If you passed IP address or hostnames during the initialisation, they will be printed as part of server address, otherwise replace <hostnames> with the actual server hostnames.

Further configuration

All generated configuration, along with a description for each parameter, is available inside configuration file in /etc/opt/simplex/smp-server.ini for further customization. Depending on the smp-server version, the configuration file looks something like this:

[INFORMATION]
# AGPLv3 license requires that you make any source code modifications
# available to the end users of the server.
# LICENSE: https://github.com/simplex-chat/simplexmq/blob/stable/LICENSE
# Include correct source code URI in case the server source code is modified in any way.
# If any other information fields are present, source code property also MUST be present.

source_code: https://github.com/simplex-chat/simplexmq

# Declaring all below information is optional, any of these fields can be omitted.

# Server usage conditions and amendments.
# It is recommended to use standard conditions with any amendments in a separate document.
# usage_conditions: https://github.com/simplex-chat/simplex-chat/blob/stable/PRIVACY.md
# condition_amendments: link

# Server location and operator.
# server_country: ISO-3166 2-letter code
# operator: entity (organization or person name)
# operator_country: ISO-3166 2-letter code
# website:

# Administrative contacts.
# admin_simplex: SimpleX address
# admin_email:
# admin_pgp:
# admin_pgp_fingerprint:

# Contacts for complaints and feedback.
# complaints_simplex: SimpleX address
# complaints_email:
# complaints_pgp:
# complaints_pgp_fingerprint:

# Hosting provider.
# hosting: entity (organization or person name)
# hosting_country: ISO-3166 2-letter code

[STORE_LOG]
# The server uses STM memory for persistence,
# that will be lost on restart (e.g., as with redis).
# This option enables saving memory to append only log,
# and restoring it when the server is started.
# Log is compacted on start (deleted objects are removed).
enable: on

# Undelivered messages are optionally saved and restored when the server restarts,
# they are preserved in the .bak file until the next restart.
restore_messages: on
expire_messages_days: 21
expire_ntfs_hours: 24

# Log daily server statistics to CSV file
log_stats: on

[AUTH]
# Set new_queues option to off to completely prohibit creating new messaging queues.
# This can be useful when you want to decommission the server, but not all connections are switched yet.
new_queues: on

# Use create_password option to enable basic auth to create new messaging queues.
# The password should be used as part of server address in client configuration:
# smp://fingerprint:password@host1,host2
# The password will not be shared with the connecting contacts, you must share it only
# with the users who you want to allow creating messaging queues on your server.
# create_password: password to create new queues (any printable ASCII characters without whitespace, '@', ':' and '/')

# control_port_admin_password:
# control_port_user_password:

[TRANSPORT]
# Host is only used to print server address on start.
# You can specify multiple server ports.
host: <domain/ip>
port: 5223,443
log_tls_errors: off

# Use `websockets: 443` to run websockets server in addition to plain TLS.
websockets: off
# control_port: 5224

[PROXY]
# Network configuration for SMP proxy client.
# `host_mode` can be 'public' (default) or 'onion'.
# It defines prefferred hostname for destination servers with multiple hostnames.
# host_mode: public
# required_host_mode: off

# The domain suffixes of the relays you operate (space-separated) to count as separate proxy statistics.
# own_server_domains: 

# SOCKS proxy port for forwarding messages to destination servers.
# You may need a separate instance of SOCKS proxy for incoming single-hop requests.
# socks_proxy: localhost:9050

# `socks_mode` can be 'onion' for SOCKS proxy to be used for .onion destination hosts only (default)
# or 'always' to be used for all destination hosts (can be used if it is an .onion server).
# socks_mode: onion

# Limit number of threads a client can spawn to process proxy commands in parrallel.
# client_concurrency: 32

[INACTIVE_CLIENTS]
# TTL and interval to check inactive clients
disconnect: off
# ttl: 21600
# check_interval: 3600

[WEB]
# Set path to generate static mini-site for server information and qr codes/links
static_path: /var/opt/simplex/www

# Run an embedded server on this port
# Onion sites can use any port and register it in the hidden service config.
# Running on a port 80 may require setting process capabilities.
#http: 8000

# You can run an embedded TLS web server too if you provide port and cert and key files.
# Not required for running relay on onion address.
https: 443
cert: /etc/opt/simplex/web.crt
key: /etc/opt/simplex/web.key

Server security

Initialization

Although it's convenient to initialize smp-server configuration directly on the server, operators ARE ADVISED to initialize smp-server fully offline to protect your SMP server CA private key.

Follow the steps to quickly initialize the server offline:

  1. Install Docker on your system.

  2. Deploy smp-server locally.

  3. Destroy the container. All relevant configuration files and keys will be available at $HOME/simplex/smp/config.

  4. Move your CA private key (ca.key) to the safe place. For further explanation, see the next section: Server security: Private keys.

  5. Copy all other configuration files except the CA key to the server:

    rsync -hzasP $HOME/simplex/smp/config/ <server_user>@<server_address>:/etc/opt/simplex/

Private keys

Connection to the smp server occurs via a TLS connection. During the TLS handshake, the client verifies smp-server CA and server certificates by comparing its fingerprint with the one included in server address. If server TLS credential is compromised, this key can be used to sign a new one, keeping the same server identity and established connections. In order to protect your smp-server from bad actors, operators ARE ADVISED to move CA private key to a safe place. That could be:

Follow the steps to secure your CA keys:

  1. Login to your server via SSH.

  2. Copy the CA key to a safe place from this file:

    /etc/opt/simplex/ca.key

  3. Delete the CA key from the server. Please make sure you've saved you CA key somewhere safe. Otherwise, you would lose the ability to rotate the online certificate:

    rm /etc/opt/simplex/ca.key

Online certificate rotation

Operators of smp servers ARE ADVISED to rotate online certificate regularly (e.g., every 3 months). In order to do this, follow the steps:

  1. Create relevant folders:

    mkdir -p $HOME/simplex/smp/config

  2. Copy the configuration files from the server to the local machine (if not yet):

    rsync -hzasP <server_user>@<server_address>:/etc/opt/simplex/ $HOME/simplex/smp/config/

  3. Copy your CA private key from a safe place to the local machine and name it ca.key.

  4. Download latest smp-server binary from Github releases:

    curl -L 'https://github.com/simplex-chat/simplexmq/releases/latest/download/smp-server-ubuntu-20_04-x86-64' -o smp-server

  5. Put the smp-server binary to your $PATH and make it executable:

    sudo mv smp-server /usr/local/bin/ && chmod +x /usr/local/bin/smp-server

  6. Export a variable to configure your path to smp-server configuration:

    export SMP_SERVER_CFG_PATH=$HOME/simplex/smp/config

  7. Execute the following command:

    smp-server cert

    This command should print:

    Certificate request self-signature ok
subject=CN = <your domain or IP>
Generated new server credentials
----------
You should store CA private key securely and delete it from the server.
If server TLS credential is compromised this key can be used to sign a new one, keeping the same server identity and established connections.
CA private key location:
$HOME/simplex/smp/config/ca.key
----------

  8. Remove the CA key from the config folder (make sure you have a backup!):

    rm $HOME/simplex/smp/config/ca.key

  9. Upload new certificates to the server:

    rsync -hzasP $HOME/simplex/smp/config/ <server_user>@<server_address>:/etc/opt/simplex/

  10. Connect to the server via SSH and restart the service:

    ssh <server_user>@<server_address> "systemctl restart smp-server"

  11. Done!

Tor: installation and configuration

Installation for onion address

SMP-server can also be deployed to be available via Tor network. Run the following commands as root user.

  1. Install tor:

    We're assuming you're using Ubuntu/Debian based distributions. If not, please refer to offical tor documentation or your distribution guide.

    • Configure offical Tor PPA repository:

      CODENAME="$(lsb_release -c | awk '{print $2}')"
echo "deb [signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org ${CODENAME} main
deb-src [signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org ${CODENAME} main" > /etc/apt/sources.list.d/tor.list

    • Import repository key:

      curl --proto '=https' --tlsv1.2 -sSf https://deb.torproject.org/torproject.org/A3C4F0F979CAA22CDBA8F512EE8CBC9E886DDD89.asc | gpg --dearmor | tee /usr/share/keyrings/tor-archive-keyring.gpg >/dev/null

    • Update repository index:

      apt update

    • Install tor package:

      apt install -y tor deb.torproject.org-keyring

  2. Configure tor:

    • File configuration:

      Open tor configuration with your editor of choice (nano,vim,emacs,etc.):

      vim /etc/tor/torrc

      And insert the following lines to the bottom of configuration. Please note lines starting with #: this is comments about each individual options.

      # Enable log (otherwise, tor doesn't seem to deploy onion address)
Log notice file /var/log/tor/notices.log
# Enable single hop routing (2 options below are dependencies of the third) - It will reduce the latency at the cost of lower anonimity of the server - as SMP-server onion address is used in the clients together with public address, this is ok. If you deploy SMP-server with onion-only address, you may want to keep standard configuration instead.
SOCKSPort 0
HiddenServiceNonAnonymousMode 1
HiddenServiceSingleHopMode 1
# smp-server hidden service host directory and port mappings
HiddenServiceDir /var/lib/tor/simplex-smp/
HiddenServicePort 5223 localhost:5223
HiddenServicePort 443 localhost:443

    • Create directories:

      mkdir /var/lib/tor/simplex-smp/ && chown debian-tor:debian-tor /var/lib/tor/simplex-smp/ && chmod 700 /var/lib/tor/simplex-smp/

  3. Start tor:

    Enable systemd service and start tor. Offical tor is a bit flaky on the first start and may not create onion host address, so we're restarting it just in case.

    systemctl enable --now tor && systemctl restart tor

  4. Display onion host:

    Execute the following command to display your onion host address:

    cat /var/lib/tor/simplex-smp/hostname

SOCKS port for SMP PROXY

SMP-server versions starting from v5.8.0-beta.0 can be configured to PROXY smp servers available exclusively through Tor network to be accessible to the clients that do not use Tor. Run the following commands as root user.

  1. Install tor as described in the previous section.

  2. Execute the following command to creatae a new Tor daemon instance:

    tor-instance-create tor2

  3. Open the tor2 configuration and replace its content with the following lines:

    vim /etc/tor/instances/tor2/torrc

    # Log tor to systemd daemon
Log notice syslog
# Listen to local 9050 port for socks proxy
SocksPort 9050

  4. Enable service at startup and start the daemon:

    systemctl enable --now tor@tor2

    You can check tor2 logs with the following command:

    journalctl -u tor@tor2

  5. After server initialization, configure the PROXY section like so:

    ...
[PROXY]
socks_proxy: 127.0.0.1:9050
own_server_domains: <your domain suffixes if using `log_stats: on`>
...

Server information page

SMP server SHOULD be configured to serve Web page with server information that can include admin info, server info, provider info, etc. It will also serve connection links, generated using the mobile/desktop apps. Run the following commands as root user.

Please note: this configuration is supported since v6.1.0-beta.2.

  1. Add the following to your smp-server configuration (please modify fields in [INFORMATION] section to include relevant information):

    vim /etc/opt/simplex/smp-server.ini

    [TRANSPORT]
# host is only used to print server address on start
host: <domain/ip>
port: 443,5223
websockets: off
log_tls_errors: off
control_port: 5224

[WEB]
https: 443
static_path: /var/opt/simplex/www
cert: /etc/opt/simplex/web.crt
key: /etc/opt/simplex/web.key

[INFORMATION]
# AGPLv3 license requires that you make any source code modifications
# available to the end users of the server.
# LICENSE: https://github.com/simplex-chat/simplexmq/blob/stable/LICENSE
# Include correct source code URI in case the server source code is modified in any way.
# If any other information fields are present, source code property also MUST be present.

source_code: https://github.com/simplex-chat/simplexmq

# Declaring all below information is optional, any of these fields can be omitted.

# Server usage conditions and amendments.
# It is recommended to use standard conditions with any amendments in a separate document.
# usage_conditions: https://github.com/simplex-chat/simplex-chat/blob/stable/PRIVACY.md
# condition_amendments: link

# Server location and operator.
server_country: <YOUR_SERVER_LOCATION>
operator: <YOUR_NAME>
operator_country: <YOUR_LOCATION>
website: <WEBSITE_IF_AVAILABLE>

# Administrative contacts.
#admin_simplex: SimpleX address
admin_email: <EMAIL>
# admin_pgp:
# admin_pgp_fingerprint:

# Contacts for complaints and feedback.
# complaints_simplex: SimpleX address
complaints_email: <COMPLAINTS_EMAIL>
# complaints_pgp:
# complaints_pgp_fingerprint:

# Hosting provider.
hosting: <HOSTING_PROVIDER_NAME>
hosting_country: <HOSTING_PROVIDER_LOCATION>

  2. Install the webserver. For easy deployment we'll describe the installtion process of Caddy webserver on Ubuntu server:

    1. Install the packages:

      sudo apt install -y debian-keyring debian-archive-keyring apt-transport-https curl

    2. Install caddy gpg key for repository:

      curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/gpg.key' | sudo gpg --dearmor -o /usr/share/keyrings/caddy-stable-archive-keyring.gpg

    3. Install Caddy repository:

      curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/debian.deb.txt' | sudo tee /etc/apt/sources.list.d/caddy-stable.list

    4. Install Caddy:

      sudo apt update && sudo apt install caddy

    Full Caddy instllation instructions

  3. Replace Caddy configuration with the following:

    Please replace YOUR_DOMAIN with your actual domain (smp.example.com).

    vim /etc/caddy/Caddyfile

    http://YOUR_DOMAIN {
   redir https://YOUR_DOMAIN{uri} permanent
}

YOUR_DOMAIN:8443 {
   tls {
      key_type rsa4096
   }
}

  4. Enable and start Caddy service:

    systemctl enable --now caddy

  5. Create script to copy certificates to your smp directory:

    Please replace YOUR_DOMAIN with your actual domain (smp.example.com).

    vim /usr/local/bin/simplex-servers-certs

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

user='smp'
group="$user"

domain='HOST'
folder_in="/var/lib/caddy/.local/share/caddy/certificates/acme-v02.api.letsencrypt.org-directory/${domain}"
folder_out='/etc/opt/simplex'
key_name='web.key'
cert_name='web.crt'

# Copy certifiacte from Caddy directory to smp-server directory
cp "${folder_in}/${domain}.crt" "${folder_out}/${cert_name}"
# Assign correct permissions
chown "$user":"$group" "${folder_out}/${cert_name}"

# Copy certifiacte key from Caddy directory to smp-server directory
cp "${folder_in}/${domain}.key" "${folder_out}/${key_name}"
# Assign correct permissions
chown "$user":"$group" "${folder_out}/${key_name}"

  6. Make the script executable and execute it:

    chmod +x /usr/local/bin/simplex-servers-certs && /usr/local/bin/simplex-servers-certs

  7. Check if certificates were copied:

    ls -haltr /etc/opt/simplex/web*

  8. Create cronjob to copy certificates to smp directory in timely manner:

    sudo crontab -e

    # Every week on 00:20 sunday
20 0 * * 0 /usr/local/bin/simplex-servers-certs

  9. Then:

  10. Access the webpage you've deployed from your browser (https://smp.example.org). You should see the smp-server information that you've provided in your ini file.

Documentation

All necessary files for smp-server are located in /etc/opt/simplex/ folder.

Stored messages, connections, statistics and server log are located in /var/opt/simplex/ folder.

SMP server address

SMP server address has the following format:

smp://<fingerprint>[:<password>]@<public_hostname>[,<onion_hostname>]

  • <fingerprint>

    Your smp-server fingerprint of certificate. You can check your certificate fingerprint in /etc/opt/simplex/fingerprint.

  • optional <password>

    Your configured password of smp-server. You can check your configured pasword in /etc/opt/simplex/smp-server.ini, under [AUTH] section in create_password: field.

  • <public_hostname>, optional <onion_hostname>

    Your configured hostname(s) of smp-server. You can check your configured hosts in /etc/opt/simplex/smp-server.ini, under [TRANSPORT] section in host: field.

Systemd commands

To start smp-server on host boot, run:

sudo systemctl enable smp-server.service

Created symlink /etc/systemd/system/multi-user.target.wants/smp-server.service → /etc/systemd/system/smp-server.service.

To start smp-server, run:

sudo systemctl start smp-server.service

To check status of smp-server, run:

sudo systemctl status smp-server.service

● smp-server.service - SMP server
     Loaded: loaded (/etc/systemd/system/smp-server.service; enabled; vendor preset: enabled)
     Active: active (running) since Sat 2022-11-23 19:23:21 UTC; 1min 48s ago
   Main PID: 30878 (smp-server)
     CGroup: /docker/5588ab759e80546b4296a7c50ffebbb1fb7b55b8401300e9201313b720989aa8/system.slice/smp-server.service
             └─30878 smp-server start

Nov 23 19:23:21 5588ab759e80 systemd[1]: Started SMP server.
Nov 23 19:23:21 5588ab759e80 smp-server[30878]: SMP server v3.4.0
Nov 23 19:23:21 5588ab759e80 smp-server[30878]: Fingerprint: d5fcsc7hhtPpexYUbI2XPxDbyU2d3WsVmROimcL90ss=
Nov 23 19:23:21 5588ab759e80 smp-server[30878]: Server address: smp://d5fcsc7hhtPpexYUbI2XPxDbyU2d3WsVmROimcL90ss=:V8ONoJ6ICwnrZnTC_QuSHfCEYq53uLaJKQ_oIC6-ve8=@<hostnames>
Nov 23 19:23:21 5588ab759e80 smp-server[30878]: Store log: /var/opt/simplex/smp-server-store.log
Nov 23 19:23:21 5588ab759e80 smp-server[30878]: Listening on port 5223 (TLS)...
Nov 23 19:23:21 5588ab759e80 smp-server[30878]: not expiring inactive clients
Nov 23 19:23:21 5588ab759e80 smp-server[30878]: creating new queues requires password

To stop smp-server, run:

sudo systemctl stop smp-server.service

To check tail of smp-server log, run:

sudo journalctl -fu smp-server.service

Nov 23 19:23:21 5588ab759e80 systemd[1]: Started SMP server.
Nov 23 19:23:21 5588ab759e80 smp-server[30878]: SMP server v3.4.0
Nov 23 19:23:21 5588ab759e80 smp-server[30878]: Fingerprint: d5fcsc7hhtPpexYUbI2XPxDbyU2d3WsVmROimcL90ss=
Nov 23 19:23:21 5588ab759e80 smp-server[30878]: Server address: smp://d5fcsc7hhtPpexYUbI2XPxDbyU2d3WsVmROimcL90ss=:V8ONoJ6ICwnrZnTC_QuSHfCEYq53uLaJKQ_oIC6-ve8=@<hostnames>
Nov 23 19:23:21 5588ab759e80 smp-server[30878]: Store log: /var/opt/simplex/smp-server-store.log
Nov 23 19:23:21 5588ab759e80 smp-server[30878]: Listening on port 5223 (TLS)...
Nov 23 19:23:21 5588ab759e80 smp-server[30878]: not expiring inactive clients
Nov 23 19:23:21 5588ab759e80 smp-server[30878]: creating new queues requires password

Control port

Enabling control port in the configuration allows administrator to see information about the smp-server in real-time. Additionally, it allows to delete queues for content moderation and see the debug info about the clients, sockets, etc. Enabling the control port requires setting the admin and user passwords.

  1. Generate two passwords for each user:

    tr -dc A-Za-z0-9 </dev/urandom | head -c 20; echo

  2. Open the configuration file:

    vim /etc/opt/simplex/smp-server.ini

  3. Configure the control port and replace the passwords:

    [AUTH]
control_port_admin_password: <your_randomly_generated_admin_password>
control_port_user_password: <your_randomly_generated_user_password>

[TRANSPORT]
control_port: 5224

  4. Restart the server:

    systemctl restart smp-server

To access the control port, use:

nc 127.0.0.1 5224

or:

telnet 127.0.0.1 5224

Upon connecting, the control port should print:

SMP server control port
'help' for supported commands

To authenticate, type the following and hit enter. Change the my_generated_password with the user or admin password from the configuration:

auth my_generated_password

Here's the full list of commands, their descriptions and who can access them.

Command Description Requires admin role
stats Real-time statistics. Fields described in Daily statistics -
stats-rts GHC/Haskell statistics. Can be enabled with +RTS -T -RTS option -
clients Clients information. Useful for debugging. yes
sockets General sockets information. -
socket-threads Thread infomation per socket. Useful for debugging. yes
threads Threads information. Useful for debugging. yes
server-info Aggregated server infomation. -
delete Delete known queue. Useful for content moderation. -
save Save queues/messages from memory. yes
help Help menu. -
quit Exit the control port. -

Daily statistics

You can enable smp-server statistics for Grafana dashboard by setting value on in /etc/opt/simplex/smp-server.ini, under [STORE_LOG] section in log_stats: field.

Logs will be stored as csv file in /var/opt/simplex/smp-server-stats.daily.log. Fields for the csv file are:

fromTime,qCreated,qSecured,qDeleted,msgSent,msgRecv,dayMsgQueues,weekMsgQueues,monthMsgQueues,msgSentNtf,msgRecvNtf,dayCountNtf,weekCountNtf,monthCountNtf,qCount,msgCount,msgExpired,qDeletedNew,qDeletedSecured,pRelays_pRequests,pRelays_pSuccesses,pRelays_pErrorsConnect,pRelays_pErrorsCompat,pRelays_pErrorsOther,pRelaysOwn_pRequests,pRelaysOwn_pSuccesses,pRelaysOwn_pErrorsConnect,pRelaysOwn_pErrorsCompat,pRelaysOwn_pErrorsOther,pMsgFwds_pRequests,pMsgFwds_pSuccesses,pMsgFwds_pErrorsConnect,pMsgFwds_pErrorsCompat,pMsgFwds_pErrorsOther,pMsgFwdsOwn_pRequests,pMsgFwdsOwn_pSuccesses,pMsgFwdsOwn_pErrorsConnect,pMsgFwdsOwn_pErrorsCompat,pMsgFwdsOwn_pErrorsOther,pMsgFwdsRecv,qSub,qSubAuth,qSubDuplicate,qSubProhibited,msgSentAuth,msgSentQuota,msgSentLarge,msgNtfs,msgNtfNoSub,msgNtfLost,qSubNoMsg,msgRecvGet,msgGet,msgGetNoMsg,msgGetAuth,msgGetDuplicate,msgGetProhibited,psSubDaily,psSubWeekly,psSubMonthly,qCount2,ntfCreated,ntfDeleted,ntfSub,ntfSubAuth,ntfSubDuplicate,ntfCount,qDeletedAllB,qSubAllB,qSubEnd,qSubEndB,ntfDeletedB,ntfSubB,msgNtfsB,msgNtfExpired

Fields description

Field number Field name Field Description
1 fromTime Date of statistics
Messaging queue:
2 qCreated Created
3 qSecured Established
4 qDeleted Deleted
Messages:
5 msgSent Sent
6 msgRecv Received
7 dayMsgQueues Active queues in a day
8 weekMsgQueues Active queues in a week
9 monthMsgQueues Active queues in a month
Messages with "notification" flag
10 msgSentNtf Sent
11 msgRecvNtf Received
12 dayCountNtf Active queues in a day
13 weekCountNtf Active queues in a week
14 monthCountNtf Active queues in a month
Additional statistics:
15 qCount Stored queues
16 msgCount Stored messages
17 msgExpired Expired messages
18 qDeletedNew New deleted queues
19 qDeletedSecured Secured deleted queues
Requested sessions with all relays:
20 pRelays_pRequests - requests
21 pRelays_pSuccesses - successes
22 pRelays_pErrorsConnect - connection errors
23 pRelays_pErrorsCompat - compatability errors
24 pRelays_pErrorsOther - other errors
Requested sessions with own relays:
25 pRelaysOwn_pRequests - requests
26 pRelaysOwn_pSuccesses - successes
27 pRelaysOwn_pErrorsConnect - connection errors
28 pRelaysOwn_pErrorsCompat - compatability errors
29 pRelaysOwn_pErrorsOther - other errors
Message forwards to all relays:
30 pMsgFwds_pRequests - requests
31 pMsgFwds_pSuccesses - successes
32 pMsgFwds_pErrorsConnect - connection errors
33 pMsgFwds_pErrorsCompat - compatability errors
34 pMsgFwds_pErrorsOther - other errors
Message forward to own relays:
35 pMsgFwdsOwn_pRequests - requests
36 pMsgFwdsOwn_pSuccesses - successes
37 pMsgFwdsOwn_pErrorsConnect - connection errors
38 pMsgFwdsOwn_pErrorsCompat - compatability errors
39 pMsgFwdsOwn_pErrorsOther - other errors
Received message forwards:
40 pMsgFwdsRecv
Message queue subscribtion errors:
41 qSub All
42 qSubAuth Authentication erorrs
43 qSubDuplicate Duplicate SUB errors
44 qSubProhibited Prohibited SUB errors
Message errors:
45 msgSentAuth Authentication errors
46 msgSentQuota Quota errors
47 msgSentLarge Large message errors
48 msgNtfs XXXXXXXXXXXXXXXXXXXX
49 msgNtfNoSub XXXXXXXXXXXXXXXXXXXX
50 msgNtfLost XXXXXXXXXXXXXXXXXXXX
51 qSubNoMsg Removed, always 0
52 msgRecvGet XXXXXXXXXXXXXXXXX
53 msgGet XXXXXXXXXXXXXXXXX
54 msgGetNoMsg XXXXXXXXXXXXXXXXX
55 msgGetAuth XXXXXXXXXXXXXXXXX
56 msgGetDuplicate XXXXXXXXXXXXXXXXX
57 msgGetProhibited XXXXXXXXXXXXXXXXX
58 psSub_dayCount Removed, always 0
59 psSub_weekCount Removed, always 0
60 psSub_monthCount Removed, always 0
61 qCount XXXXXXXXXXXXXXXXX
62 ntfCreated XXXXXXXXXXXXXXXXX
63 ntfDeleted XXXXXXXXXXXXXXXXX
64 ntfSub XXXXXXXXXXXXXXXXX
65 ntfSubAuth XXXXXXXXXXXXXXXXX
66 ntfSubDuplicate XXXXXXXXXXXXXXXXX
67 ntfCount XXXXXXXXXXXXXXXXX
68 qDeletedAllB XXXXXXXXXXXXXXXXX
69 qSubAllB XXXXXXXXXXXXXXXXX
70 qSubEnd XXXXXXXXXXXXXXXXX
71 qSubEndB XXXXXXXXXXXXXXXXX
72 ntfDeletedB XXXXXXXXXXXXXXXXX
73 ntfSubB XXXXXXXXXXXXXXXXX
74 msgNtfsB XXXXXXXXXXXXXXXXX
75 msgNtfExpired XXXXXXXXXXXXXXXXX

To import csv to Grafana one should:

  1. Install Grafana plugin: Grafana - CSV datasource

  2. Allow local mode by appending following:

    [plugin.marcusolsson-csv-datasource]
allow_local_mode = true

    ... to /etc/grafana/grafana.ini

  3. Add a CSV data source:

    • In the side menu, click the Configuration tab (cog icon)
    • Click Add data source in the top-right corner of the Data Sources tab
    • Enter "CSV" in the search box to find the CSV data source
    • Click the search result that says "CSV"
    • In URL, enter a file that points to CSV content

  4. You're done! You should be able to create your own dashboard with statistics.

For further documentation, see: CSV Data Source for Grafana - Documentation

Updating your SMP server

To update your smp-server to latest version, choose your installation method and follow the steps:

  • Manual deployment

    1. Stop the server:

      sudo systemctl stop smp-server

    2. Update the binary:

       curl -L https://github.com/simplex-chat/simplexmq/releases/latest/download/smp-server-ubuntu-20_04-x86-64 -o /usr/local/bin/smp-server && chmod +x /usr/local/bin/smp-server

    3. Start the server:

      sudo systemctl start smp-server

  • Offical installation script

    1. Execute the followin command:

      sudo simplex-servers-update

      To install specific version, run:

      export VER=<version_from_github_releases> &&\
sudo -E simplex-servers-update

    2. Done!

  • Docker container

    1. Stop and remove the container:

      docker rm $(docker stop $(docker ps -a -q --filter ancestor=simplexchat/smp-server --format="\{\{.ID\}\}"))

    2. Pull latest image:

      docker pull simplexchat/smp-server:latest

    3. Start new container:

      docker run -d \
  -p 5223:5223 \
  -p 443:443 \
  -v $HOME/simplex/smp/config:/etc/opt/simplex:z \
  -v $HOME/simplex/smp/logs:/var/opt/simplex:z \
  simplexchat/smp-server:latest

  • Linode Marketplace

    1. Pull latest images:

      docker-compose --project-directory /etc/docker/compose/simplex pull

    2. Restart the containers:

      docker-compose --project-directory /etc/docker/compose/simplex up -d --remove-orphans

    3. Remove obsolete images:

      docker image prune

Reproduce builds

You can locally reproduce server binaries, following these instructions.

If you are a security expert or researcher, you can help SimpleX network and users community by signing the release checksums – we will publish your signature. Please reach out to us!

To reproduce the build you must have:

  • Linux machine
  • x86-64 architecture
  • Installed docker, curl and git

  1. Download script:

    curl -LO 'https://raw.githubusercontent.com/simplex-chat/simplexmq/refs/heads/master/scripts/simplexmq-reproduce-builds.sh'

  2. Make it executable:

    chmod +x simplexmq-reproduce-builds.sh

  3. Execute the script with the required tag:

    ./simplexmq-reproduce-builds.sh 'v6.3.1'

    The script executes these steps (please review the script to confirm):

    1. builds all server binaries for the release in docker container.
    2. downloads binaries from the same GitHub release and compares them with the built binaries.
    3. if they all match, generates _sha256sums file with their checksums.

    This will take a while.

  4. After compilation, you should see the folder named as the tag (e.g., v6.3.1) with two subfolders:

    ls v6.3.1

    from-source  prebuilt  _sha256sums

    The file _sha256sums contains the hashes of all builds - you can compare it with the same file in GitHub release.

Configuring the app to use the server

To configure the app to use your messaging server copy it's full address, including password, and add it to the app. You have an option to use your server together with preset servers or without them - you can remove or disable them.

It is also possible to share the address of your server with your friends by letting them scan QR code from server settings - it will include server password, so they will be able to receive messages via your server as well.

Please note: you need SMP server version 4.0 to have password support. If you already have a deployed server, you can add password by adding it to server INI file.

     

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