bashbot

A Telegram bot written in bash.

Written by Drew (@topkecleon), Daniil Gentili (@danogentili), and Kay M (@gnadelwartz).

Contributions by JuanPotato, BigNerd95, TiagoDanin, and iicc1.

Released to the public domain wherever applicable. Elsewhere, consider it released under the WTFPLv2.

Prerequisites

Depends on tmux. Uses JSON.sh.

Most complete UTF-8 support for bashbot is availible if phyton is installed (optional).

Bashbot Documentation and Downloads are availible on www.github.com

Install bashbot

1. Go to the directory you want to install bashbot, e.g.

   • your $HOME directory (install and run with your user-ID)
   • /usr/local if you want to run as service

2. Download latest release archive from github and extract all files.

   As an alternative you can clone the github repository to get the latest, but possible unstable improvements.

   git clone https://github.com/topkecleon/telegram-bot-bash
   

3. Go to directory telegram-bot-bash, run ./bashbot.sh init and follow the instructions. At this point you are asked for your Bots token given by botfather.

Update bashbot

1. Download latest update zip from github
2. Extract all files and copy them to your bashbot dir
3. Run sudo ./bashbot.sh init to setup your environment after the update

Documentation

• Create a new Telegram Bot with botfather
• Getting Started
  • Managing your Bot
  • Recieve data
  • Send messages
  • Send files, locations, keyboards
• Advanced Features
  • Access Control
  • Interactive Chats
  • Background Jobs
  • Inline queries
• Expert Use
  • Handling UTF-8 character sets
  • Run as other user or system service
  • Scedule bashbot from Cron
• Best Practices
  • Customize commands.sh
  • Seperate logic from commands
  • Test your Bot with shellcheck
• Bashbot function reference
• Notes for bashbot developers

Note on Keyboards

From Version 0.60 on keybord format for send_keyboard and send_message "mykeyboardstartshere ..." was changed. Keybords are now defined in JSON Array notation e.g. "[ \"yes\" , \"no\" ]". This has the advantage that you can create any type of keyboard supported by Telegram. The old format is supported for backward compatibility, but may fail for corner cases.

Example Keyboards:

• yes no in two rows:
  • OLD format: 'yes' 'no' (two strings)
  • NEW format: '[ "yes" ] , [ "no" ]' (two arrays with a string)
• new layouts made easy with NEW format:
  • Yes No in one row: '[ "yes" , "no" ]'
  • Yes No plus Maybe in 2.row: '[ "yes" , "no" ] , [ "maybe" ]'
  • numpad style keyboard: '[ "1" , "2" , "3" ] , [ "4" , "5" , "6" ] , [ "7" , "8" , "9" ] , [ "0" ]'

Security Considerations

Running a Telegram Bot means it is connected to the public and you never know whats send to your Bot.

Bash scripts in general are not designed to be bullet proof, so consider this Bot as a proof of concept. More concret examples of security problems are: bash's 'quoting hell' and globbing. Implications of wrong quoting

Whenever you are processing input from from untrusted sources (messages, files, network) you must be as carefull as possible, e.g. set IFS appropriate, disable globbing (set -f) and quote everthing. In addition disable not used Bot commands and delete unused scripts from your Bot, e.g. example scripts 'notify', 'calc', 'question',

A powerful tool to improve your scripts robustness is shellcheck. You can use it online or install shellcheck locally. All bashbot scripts are checked by shellcheck.

Run your Bot as a restricted user

I recommend to run your bot as a user, with almost no access rights. All files your Bot have write access to are in danger to be overwritten/deleted if your bot is hacked. For the same reason ervery file your Bot can read is in danger to be disclosed. Restict your Bots access rigths to the absolute minimum.

Never run your Bot as root, this is the most dangerous you can do! Usually the user 'nobody' has almost no rights on Unix/Linux systems. See Expert use on how to run your Bot as an other user.

Secure your Bot installation

Your Bot configuration must no be readable from other users. Everyone who can read your Bots token can act as your Bot and has access to all chats your Bot is in!

Everyone with read access to your Bot files can extract your Bots data. Especially your Bot Token in token must be protected against other users. No one exept you must have write access to the Bot files. The Bot must be restricted to have write access to count and tmp-bot-bash only, all other files must be write protected.

To set access rights for your bashbot installation to a reasonable default run sudo ./bashbot.sh init after every update or change to your installation directory.

Is this Bot insecure?

Bashbot is not more (in)secure as any other Bot written in any other language, we have done our best to make it as secure as possible. But YOU are responsible for the bot commands you wrote and you should know about the risks ...

That's it!

If you feel that there's something missing or if you found a bug, feel free to submit a pull request!

$$VERSION$$ v0.62-0-g5d5dbae