Lock it in a Cista. Only you hold the key.
匣中剑气，唯你可启。
Cista is an open-source, self-hosted web application for secure end-to-end encrypted file sharing. Files are encrypted in your browser before upload — the server never sees your plaintext data.
No terminal, no OpenSSL, no technical skills required. If you can use a website, you can use Cista.
Generate RSA-4096 or RSA-2048 key pairs directly in your browser using the Web Crypto API. No command line, no technical knowledge required. Your private key never leaves your device.
- AES-256-GCM encrypts each file with a unique random key (DEK)
- RSA-4096 or RSA-2048 encrypts the DEK with the recipient's public key
- Files are encrypted in the browser before upload — server stores only ciphertext
- Decryption happens in the browser after download
- Generate 6-8 character alphanumeric share codes (uppercase + digits, excluding confusing chars)
- Two sharing modes:
- Registered users — uses recipient's public key for maximum security
- Unregistered users (one-time) — generates a temporary key pair; no login required to download
- Download page accessible to anyone via the homepage or header "Redeem Code" link
- Configurable expiry dates and download limits
- Revoke share codes at any time
Email-based registration and login, password reset flow, account deletion with all data cleanup, admin panel.
English and Chinese (中文) supported. Easy to add more languages.
| Layer | Technology |
|---|---|
| Frontend | TypeScript, HTMX, Alpine.js, Tailwind CSS |
| Backend | TypeScript (Node.js), Express.js |
| Database | SQLite (dev) / PostgreSQL (prod) — via abstraction layer |
| Encryption | Web Crypto API (browser), bcrypt (server) |
| File Storage | Local filesystem (dev) / S3-compatible (prod) |
| Auth | JWT (HTTP-only cookies) |
- Node.js 18+
- npm
git clone https://github.com/your-org/cista.git
cd cista
bash scripts/setup.sh# Install dependencies
cd server && npm install && cd ..
cd client && npm install && cd ..
# Create data directories
mkdir -p server/data
# Run database migrations
cd server && npx tsx src/db/migrate.ts && cd ..
# Seed admin user (default: admin@cista.local / Admin123!)
cd server && npx tsx src/db/seed.ts && cd ..
# Start the server
cd server && npx tsx src/index.tsThe server runs at http://localhost:3000.
| Variable | Default | Description |
|---|---|---|
PORT |
3000 |
Server port |
HOST |
0.0.0.0 |
Server host |
NODE_ENV |
development |
Environment |
DATABASE_URL |
./data/cista.db |
SQLite database path |
JWT_SECRET |
auto-generated | JWT signing secret |
STORAGE_TYPE |
local |
File storage backend |
MAX_FILE_SIZE |
1073741824 (1GB) |
Max upload size |
ADMIN_EMAIL |
admin@cista.local |
Seed admin email |
ADMIN_PASSWORD |
Admin123! |
Seed admin password |
cista/
├── server/ # Backend (Express.js)
│ ├── src/
│ │ ├── index.ts # Entry point
│ │ ├── config.ts # Configuration
│ │ ├── db/ # Database layer
│ │ │ ├── index.ts # sql.js helper functions
│ │ │ ├── migrate.ts # Table creation
│ │ │ └── seed.ts # Admin user seeding
│ │ ├── routes/ # API & page routes
│ │ │ ├── auth.ts # Authentication endpoints
│ │ │ ├── keys.ts # Public key management
│ │ │ ├── files.ts # File CRUD & upload
│ │ │ ├── shares.ts # Share code management
│ │ │ ├── admin.ts # Admin endpoints
│ │ │ └── pages.ts # HTML page rendering
│ │ ├── middleware/ # Express middleware
│ │ ├── storage/ # File storage abstraction
│ │ ├── i18n/ # Internationalization
│ │ └── views/ # EJS templates
│ └── data/ # SQLite DB & uploaded files
├── client/ # Frontend build
│ ├── src/
│ │ ├── main.ts # Entry point
│ │ └── crypto/ # Web Crypto API helpers
│ └── vite.config.ts
├── scripts/
│ └── setup.sh # One-click setup
└── package.json # Root workspace
- users — User accounts with password hashes and roles
- user_keys — RSA public keys with fingerprints
- files — Encrypted file metadata and storage paths
- share_codes — Share codes with encrypted DEKs and access controls
- password_reset_tokens — Time-limited password reset tokens
- system_config — Key-value system configuration
┌─────────────────────┐ ┌──────────────────────┐
│ Sender's │ │ Server │
│ Browser │ │ │
│ │ │ Stores only: │
│ 1. Generates DEK │ ──────► │ • Encrypted file │
│ 2. Encrypts file │ Upload │ • Encrypted DEK │
│ with AES-256-GCM│ │ • Public keys │
│ 3. Encrypts DEK │ │ • Hashed passwords │
│ with recipient's│ │ │
│ public key │ │ Cannot decrypt: │
│ 4. Deletes plain- │ │ • Files ✗ │
│ text & DEK │ │ • DEKs ✗ │
│ │ │ • Private keys ✗ │
└─────────────────────┘ └──────────────────────┘
│ │
│ Share Code │
▼ ▼
┌─────────────────────┐ ┌──────────────────────┐
│ Recipient's │◄─────────│ (or share code │
│ Browser │ Download│ via URL) │
│ │ │ │
│ 1. Downloads │ │ │
│ encrypted file │ │ │
│ 2. Decrypts DEK │ │ │
│ with private key│ │ │
│ 3. Decrypts file │ │ │
│ with DEK │ │ │
└─────────────────────┘ └──────────────────────┘
| Purpose | Algorithm |
|---|---|
| File encryption | AES-256-GCM (random IV per file) |
| Key encryption | RSA-OAEP (SHA-256) |
| Key generation | RSA-4096 / RSA-2048 |
| Key derivation | PBKDF2 (600,000 iterations) |
| Password hashing | bcrypt (cost 10) |
- All private keys generated and stored exclusively in the browser (IndexedDB)
- Private keys encrypted at rest with a key derived from the user's password
- Server stores zero knowledge: no plaintext files, no private keys, no passwords
- HTTP-only cookies for JWT tokens (not accessible via JavaScript)
- Rate limiting on auth endpoints
- Password strength enforcement
- System is fully auditable — all source code open
| Feature | Cista | Vellaris | Privipod | Yopass |
|---|---|---|---|---|
| One-click key generation | ✅ Browser-based | ❌ Manual CLI | ❌ Manual CLI | ❌ Manual CLI |
| Share with unregistered users | ✅ "One-time share" | ❌ | ✅ | ✅ |
| File management dashboard | ✅ Full CRUD | ✅ | ❌ | ❌ |
| Share code management | ✅ Revoke, expiry, limits | ❌ | Limited | Limited |
| Self-hosted | ✅ Open source | ✅ | ✅ | ✅ |
| E2E encryption | ✅ AES-256-GCM + RSA | ✅ AES-256 + RSA-4096 | ✅ Browser-based | ✅ OpenPGP |
| Zero-knowledge | ✅ | ✅ | ✅ | ✅ |
| Admin panel | ✅ User & system management | ❌ | ❌ | ❌ |
| i18n | ✅ Chinese & English | ❌ English only | ❌ English only | ❌ English only |
| License | BSL 1.1 (4yr → Apache 2.0) | — | AGPL v3 | GPL v3 |
# Run tests
cd server && npm test
# Start in development mode
npm run dev- 12 unit tests for database operations
- 62 API integration tests covering all endpoints
- All tests:
cd server && npm test
Business Source License 1.1
Additional Use Grant: You may use the Licensed Work in development, testing, and personal non-production environments. For production deployments, please contact the author for commercial licensing.
Change Date: 4 years from the release date of each version (e.g., versions released July 2026 change to Apache 2.0 in July 2030).
Change License: Apache License 2.0
See the LICENSE file for the full license text.
如果你觉得这个项目有帮助，欢迎赞助支持持续开发。
If you find this project helpful, please consider sponsoring its development.
感谢所有支持者！ 🙏
Thank you to all supporters! 🙏
This software is provided for educational and lawful purposes only. The authors assume no liability for any misuse or damages. Always conduct your own security audit before deploying to production.