Dead Drop Service

Send One-Time Secrets in a secure way

A Dead Drop service written in Kotlin / KTor.

This service uses sjcl on client-side to encrypt the data, stores the encrypted data on the server (while never sharing the password with the server), and generates a link to get the data (once) again.

This is the source-code of drop.moetz.dev.

Setup

The docker image can be found here: hub.docker.com/r/flowmo7/dead-drop.

Possible environment variables:

• PORT: The port the server listens on. Defaults to 8080.
• DOMAIN: The domain this application is available at, e.g. drop.example.org.
• IS_HTTPS: Whether this application is available as HTTPS / behind an HTTPS reverse proxy (which it should be). Default to true.
• PATH_PREFIX: When the application is available on a sub-path of the given domain (routed by a reverse proxy, e.g.), the path needs to be set here. Defaults to no path.
• FILE_KEEP_TIME_IN_HOURS: The number of hours to keep a drop-record. Defaults to 24.
• SHOW_GITHUB_LINK_IN_FOOTER: Whether the GitHub link should be visible in the footer. Defaults to true.
• COLOR_CODE: The hex-color-code the page should be styled in. Only colors on which white text is readable are supported yet. Without the leading '#'. Defaults to ff9800.
• SITE_TITLE: The title of the site. Defaults to Dead-Drop: Send secure information.
• SITE_TITLE_SHORT: The title of the site in short. Defaults to Dead-Drop.

Data persistence

If you want to persist the encrypted storage, and map it out of the docker container, the following mounting points are available:

• /var/dead-drop/data: Is the directory that contains the encrypted data (for at most 24 hours)
• /var/dead-drop/key/key.secret: Is the file that contains the key for the server-side encryption (the data stored in the data directory is encrypted another time before persisted in the given path).

Example docker-compose.yml

services:
  dead-drop:
    image: "flowmo7/dead-drop:master"
    restart: unless-stopped
    ports:
      - 8080:8080 #Should be behind an SSL reverse proxy
    volumes:
      - /srv/docker/dead-drop/data:/var/dead-drop/data:rw
      - /srv/docker/dead-drop/key:/var/dead-drop/key:rw

Acknowledgments

This project is heavily inspired by BillKeenan/dead-drop-python, which I used (self-hosted) before creating this service.

LICENSE

Copyright 2021 Florian Mötz

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.