Here To There

Here To There is a small self-hosted file handoff app. Upload a file on one device, share a short code, and download it on another device.

What It Does

• Browser upload and download flow
• Short retrieval code format: ID-CHECKSUM (example: 12-ABCD)
• Files encrypted at rest with Fernet
• QR code generation for quick mobile retrieval
• Automatic cleanup of old uploads

Important Security Notes

This project is for personal or trusted-network use.

• Anyone with a valid code can download the file.
• Run behind HTTPS if exposed outside your LAN.
• Use a strong random CHECKSUM_SECRET.
• Use a valid Fernet ENCRYPTION_KEY.
• For sensitive files, consider additional client-side encryption before upload.

Requirements

• Python 3.10+
• Dependencies from requirements.txt

Configuration (.env)

Create .env in the project root (or copy .env.example):

DOMAIN=http://localhost:8170
PORT=8170
CLEAR_TIME_MINUTES=10
MAX_FILE_SIZE_MB=100
CHECKSUM_SECRET=REPLACE_WITH_LONG_RANDOM_SECRET
ENCRYPTION_KEY=REPLACE_WITH_VALID_FERNET_KEY
TITLE=Here to There

Config Fields

• DOMAIN: Public base URL used to generate download links.
• PORT: Flask server port.
• CLEAR_TIME_MINUTES: Minutes before old upload folders are deleted.
• MAX_FILE_SIZE_MB: Maximum allowed upload size in MB.
• CHECKSUM_SECRET: Secret used to generate and validate code checksums.
• ENCRYPTION_KEY: Fernet key used to encrypt/decrypt file contents.
• TITLE: App title shown on the homepage.

Generate a Fernet key for the ENCRYPTION_KEY:

python -c "from cryptography.fernet import Fernet; print(Fernet.generate_key().decode())"

Run Locally

python -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
python start.py

Open http://localhost:8170.

Run With Docker

1. Pull the image:

docker pull git.carsonmayn.com/carson/heretothere:latest

2. Generate a Fernet key for the ENCRYPTION_KEY:

pip install cryptography
python -c "from cryptography.fernet import Fernet; print(Fernet.generate_key().decode())"

3. Set config fields in the enviromental variables.

docker run git.carsonmayn.com/carson/heretothere:latest \
-e DOMAIN="example.com" \
-e PORT="8080" \
-e CLEAR_TIME_MINUTES="10" \
-e MAX_FILE_SIZE_MB="100" \
-e CHECKSUM_SECRET = "jriohgeoihhwyvshdv" \
-e ENCRYPTION_KEY = "wouvuwudvowuvcosyudv" \
-e TITLE = "My Heretothere Instance"

The container reads config from environment variables and persists files in ./uploads.

How Storage Works

Uploads are stored under uploads/<id>/:

• data.enc: Encrypted file payload
• meta.json: Metadata (currently filename)

Older plaintext upload folders are still downloadable for backward compatibility.

Project Structure

• start.py: Flask app and upload/download logic
• webpage/: HTML templates
• uploads/: Runtime file storage
• .env.example: Config template
• dockerfile, docker-compose.yml: Container setup

Troubleshooting

• Invalid ENCRYPTION_KEY:
  • Set ENCRYPTION_KEY to a valid Fernet key.
• Upload rejected as too large:
  • Increase MAX_FILE_SIZE_MB in .env.
• QR endpoint returns invalid domain:
  • Ensure DOMAIN matches the URL users actually access.