cupcakearmy/cryptgeon

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About?

cryptgeon is a secure, open source sharing note or file service inspired by PrivNote. It includes a server, a web page and a CLI client.

🌍 If you want to translate the project feel free to reach out to me.

Thanks to Lokalise for providing free access to their platform.

Live Service / Demo

Web

Check out the live service / demo and see for yourself cryptgeon.org

CLI

npx cryptgeon send text "This is a secret note"

For more documentation about the CLI see the readme.

Raycast Extension

There is an official Raycast extension.

Features

• send text or files
• server cannot decrypt contents due to client side encryption
• view or time constraints
• in memory, no persistence
• obligatory dark mode support

How does it work?

each note has a generated id (256bit) and key 256(bit). The id is used to save & retrieve the note. the note is then encrypted with aes in gcm mode on the client side with the key and then sent to the server. data is stored in memory and never persisted to disk. the server never sees the encryption key and cannot decrypt the contents of the notes even if it tried to.

View counts are guaranteed with one running instance of cryptgeon. Multiple instances connected to the same Redis instance can run into race conditions, where a note might be retrieved more than the view count allows.

Screenshot

Environment Variables

Deployment

ℹ️ https is required otherwise browsers will not support the cryptographic functions.

ℹ️ There is a health endpoint available at /api/health/. It returns either 200 or 503.

Docker

Docker is the easiest way. There is the official image here.

# docker-compose.yml

version: "3.8"

services:
  redis:
    image: redis:7-alpine
    # This is required to stay in RAM only.
    command: redis-server --save "" --appendonly no
    # Set a size limit. See link below on how to customise.
    # https://redis.io/docs/latest/operate/rs/databases/memory-performance/eviction-policy/
    # --maxmemory 1gb --maxmemory-policy allkeys-lrulpine
    # This prevents the creation of an anonymous volume.
    tmpfs:
      - /data

  app:
    image: cupcakearmy/cryptgeon:latest
    depends_on:
      - redis
    environment:
      # Size limit for a single note.
      SIZE_LIMIT: 4 MiB
    ports:
      - 80:8000

    # Optional health checks
    # healthcheck:
    #   test: ["CMD", "curl", "--fail", "http://127.0.0.1:8000/api/live/"]
    #   interval: 1m
    #   timeout: 3s
    #   retries: 2
    #   start_period: 5s

NGINX Proxy

See the examples/nginx folder. There an example with a simple proxy, and one with https. You need to specify the server names and certificates.

Traefik 2

See the examples/traefik folder.

Scratch

See the examples/scratch folder. There you'll find a guide how to setup a server and install cryptgeon from scratch.

Synology

There is a guide you can follow.

YouTube Guides

• English by Webnestify
• English by DB Tech Previous Video
• German by ApfelCast

Written Guides

• French by zarevskaya
• Italian by @nicfab
• English by @nicfab

Contributing

See CONTRIBUTING.md.

Security

Please refer to the security section here.

Attributions

• Test data:
  • Text for tests Nietzsche Ipsum
  • AES Paper
  • Unsplash Pictures
• Loading animation by Nikhil Krishnan
• Icons made by freepik from www.flaticon.com