OSTP - Ospab Stealth Transport Protocol

Русский язык · Wiki · Contributing · Releases

A fast, custom encrypted transport protocol written in Rust.

OSTP (Ospab Stealth Transport Protocol) is a high-performance transport protocol. It implements a custom ARQ transport over UDP, as well as a UoT (UDP-over-TCP) mode. Every byte on the wire - including packet headers - is cryptographically indistinguishable from random noise, making it highly resistant to Deep Packet Inspection (DPI).

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Quick Install

Linux

bash <(curl -Ls https://raw.githubusercontent.com/ospab/ostp/master/scripts/install.sh)

Windows (PowerShell, run as Administrator)

irm https://raw.githubusercontent.com/ospab/ostp/master/scripts/install.ps1 | iex

Manual Download

Download pre-built binaries for your platform from GitHub Releases.

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Key Features

Feature	Description
Full Traffic Obfuscation	Every packet - including headers - is indistinguishable from random noise. Session IDs and nonces are masked with per-packet HMAC-derived keys.
Noise Protocol Handshake	Noise_NNpsk0_25519_ChaChaPoly_BLAKE2s - PSK-authenticated, forward-secret key exchange with no static identity exposure.
Reliable UDP (ARQ)	Selective ACK/NACK with rate-limited retransmission, configurable reorder buffer, and exponential backoff.
Multiplexed Streams	Multiple logical TCP streams over a single encrypted UDP session with per-stream flow control.
Seamless Roaming	Clients can switch networks (WiFi ↔ LTE) without session interruption - tracked by session-ID, not IP.
Management API	Built-in REST API for third-party panels (3x-ui, custom dashboards). Per-user stats, traffic limits, key CRUD.
Fallback Server	TCP fallback proxy to a web server - makes OSTP indistinguishable from nginx during active probing.
Multi-Listener	Bind to multiple addresses simultaneously (dual-stack IPv4/IPv6, multi-port).
TUN Mode	Full-system VPN via native smoltcp network stack without external dependencies. All traffic transparently routed through the tunnel.
xHTTP Stealth (UoT)	UDP-over-TCP tunnel that completely hides traffic. Since all data is fully encrypted and length-prefixed, it bypasses DPI filters that block unknown UDP traffic by riding over a plain TCP connection.
Mobile & Web Apps	Beautiful cross-platform mobile client (Flutter) and a modern Web Control Panel (React/Vite) for effortless server and client management.
TURN Relay	RFC 5766 TURN support for environments where direct UDP is blocked.
Hot-Reload	Runtime config reload without restart (access keys, exclusions, mux settings).
Structured Logging	tracing-based logging with RUST_LOG filtering. JSON/file/syslog output support.
Cross-Platform	Windows, Linux, macOS, Android, FreeBSD, MIPS, RISC-V. Single binary, no runtime dependencies.

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Architecture

graph TD
    subgraph Client ["Client"]
        A[Browser / Apps] -->|SOCKS5 / HTTP| B(Bridge Multiplexer)
        TUN[TUN Interface] -->|IP Packets| B
        
        subgraph OSTPCoreClient ["OSTP Core Protocol"]
            B --> C{Protocol Machine}
            C -->|Noise Handshake| D[ChaCha20Poly1305 AEAD]
            D -->|Obfuscated UDP Payload| E((UDP Socket))
        end
    end

    E <==>|Encrypted & Obfuscated UDP Tunnel| F

    subgraph Server ["Server"]
        F((UDP Socket)) --> G{Dispatcher}
        
        subgraph OSTPCoreServer ["OSTP Core Backend"]
            G -->|Auth & Decrypt| H[Session & State Guard]
            H -->|TCP Stream| I[Relay Loop]
        end
        
        G -->|Active Probing / Unauth| FB[TCP Fallback Proxy]
        FB -->|Forward| NGINX[nginx / Caddy]
        
        H -->|Stats & Traffic| API[Management API]
        
        I -->|Outbound| WWW((Internet))
    end

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Quick Start

1. Generate config

# On your VPS (server):
./ostp init server

# On your machine (client):
./ostp init client

2. Edit config

Server - set your access keys:

{
  "mode": "server",
  "listen": "0.0.0.0:50000",
  "access_keys": ["YOUR_SECRET_KEY"],
  "api": { "enabled": true, "bind": "127.0.0.1:9090", "token": "admin-token" },
  "fallback": { "enabled": false, "listen": "0.0.0.0:443", "target": "127.0.0.1:8080" }
}

Client - point to your server:

{
  "mode": "client",
  "server": "YOUR_SERVER_IP:50000",
  "access_key": "YOUR_SECRET_KEY",
  "socks5_bind": "127.0.0.1:1088",
  "transport": { "mode": "udp", "stealth_sni": "vk.com" },
  "tun": { "enable": false, "dns": "1.1.1.1" }
}

3. Run

./ostp                         # Uses config.json in current directory
./ostp --config /path/to.json  # Custom config path
./ostp check                   # Validate config without running
./ostp gk                      # Generate a new access key
./ostp links                   # Print client share links

4. Connect via share link (one-liner)

./ostp connect "ostp://ACCESS_KEY@server.com:50000?..."

[!WARNING] Always wrap the ostp://... link in quotes (") so your terminal doesn't misinterpret special characters like & or ?.

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Management API

Built-in REST API for building panels and dashboards.

# Server status
curl -H "Authorization: Bearer mytoken" http://127.0.0.1:9090/api/server/status

# List all users with traffic stats  
curl -H "Authorization: Bearer mytoken" http://127.0.0.1:9090/api/users

# Create a user with 10GB traffic limit
curl -X POST -H "Authorization: Bearer mytoken" \
  -H "Content-Type: application/json" \
  -d '{"limit_bytes": 10737418240}' \
  http://127.0.0.1:9090/api/users

Full API reference: Management API

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CLI Reference

ostp [--config <PATH>] [COMMAND]

Commands:
  run                    Run the daemon using the config file (default when no command is given)
  connect <URL>          Connect once using a share link: ostp://KEY@HOST:PORT
  setup                  Interactive setup wizard
  init <MODE>            Generate a template config (server/client/relay)
  check                  Validate the configuration file and exit
  gk                     Generate a secure access key (alias: generate-key)
    --format <FMT>         Key format: hex, base64 (default: hex)
    -n, --count <N>        Number of keys to generate (default: 1)
  links                  Print client share links from the server config
  import <URL>           Import a share link into the config file
  update                 Update OSTP to the latest release
    -b, --branch <NAME>    Release channel: stable, pre-release, alpha (default: stable)
    -v, --version <VER>    Update to an exact version instead of the channel's latest
  migrate                Force-migrate the configuration file to the current format
  prober                 Run the DNS-transport resolver prober
  proxy-env               Print shell export commands for the local SOCKS proxy
  proxy-env-clear         Print shell export commands to unset it
  uninstall              Stop the service and remove the binary and config

Global options:
  --config <PATH>        Config file path (default: config.json)

Every subcommand also accepts -h/--help for its own option list.

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Protocol Summary

Layer	Mechanism
Key Exchange	Noise NNpsk0 (X25519 + ChaChaPoly + BLAKE2s) zero-RTT
Encryption	ChaCha20-Poly1305 AEAD per-packet
Header Obfuscation	HMAC-SHA256 derived per-packet mask
Reliability	Selective ACK with cumulative + SACK ranges
Retransmission	Rate-limited NACK + exponential backoff RTO
Keepalive	Ping/Pong with RTT measurement every 5s

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Building from Source

# Prerequisites: Rust 1.75+
cargo build --release

# Cross-compile for Linux
cross build --release --target x86_64-unknown-linux-gnu

# Run tests
cargo test -p ostp-core -p ostp-server

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Documentation

• Wiki - Full documentation
• Installation
• Configuration Reference
• Management API
• Protocol Design
• Building from Source
• FAQ

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License

GNU Affero General Public License v3.0 (AGPL-3.0). See LICENSE for the full text.

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Contact

• Telegram: @ospab0
• Email: gvoprgrg@gmail.com