278cbf4fb4
Same audit as konduit-public (c61664c), applied to koridor. The conclusion is the opposite: there is no server binary and no config format, so nothing can be documented wrongly. The source backs the README - ffi/src/ssh.rs:389 uses per-flow channel_open_direct_tcpip, with no streamlocal, remote TUN or forwarded-tcpip anywhere in the crate. No contradictions found; the gap was thinness. Added docs/server-quickstart.md. The whole server story was previously one clause in the README: - The real requirement (AllowTcpForwarding yes), and that it is already the OpenSSH default, so most servers need no configuration at all. - What you do NOT need: ip_forward, masquerade rules, /dev/net/tun, root. Anyone who has set up a VPN server before assumes all four are required. - Keypair generation, since the user supplies the key; koridor does not generate one for the tunnel. - Host key trust on first connect. The connect is refused until the fingerprint is accepted, and a later change is fatal rather than retried. The finding that justified the work: UDP forwarding provisions itself on the user's server on first enable - it writes ~/.koridor/udp-relay.sh, appends a forced-command line to ~/.ssh/authorized_keys marked # koridor-udp-relay, and requires socat (hardcoded in ffi/src/udp_relay/script.rs:12). So "No special server-side software required" is true for TCP and false once that toggle is on. Nothing public said so. It is off by default and idempotent, and remove_marked_line strips only koridor's own line, leaving every other key untouched - but a user's authorized_keys and home directory are modified without them being told. The README now carries that caveat inline. #k-ops/#6/#212
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4.2 KiB
Markdown
97 lines
4.2 KiB
Markdown
<div align="center">
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<img src="images/feature-graphic.png" alt="koridor" width="512"/>
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# koridor
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**VPN over your own SSH server.**
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[](#about)
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[]()
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[]()
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</div>
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---
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koridor is a full-device VPN client built around a single idea: **you already have a server you trust — just tunnel through it.**
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Instead of operating its own VPN infrastructure, koridor routes your device's traffic through a plain SSH server you configure yourself. There's no koridor-operated backend, no account, and no third party in the middle.
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## Why koridor?
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Most VPN apps ask you to trust the app vendor's servers. koridor doesn't have any — it connects to a server you already own or personally trust, using nothing more exotic than standard SSH port forwarding on the wire. If you can run `sshd`, you can run a koridor server.
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## Features
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- **Full-device tunnel** — a TUN-based VPN, not just an app-aware SOCKS proxy. Every app on the device is covered, with no per-app setup.
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- **Bring your own server** — connects to any SSH server with `AllowTcpForwarding yes`. No special server-side software required. (One opt-in exception: UDP port forwarding provisions a relay script and an `authorized_keys` line on your server — see the [Server Quickstart](docs/server-quickstart.md#6-optional-udp-port-forwarding).)
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- **Simple onboarding** — set up a connection profile, toggle on, done.
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- **Fail-closed reconnects** — transient drops are retried with exponential backoff; if the tunnel can't recover, the route is torn down rather than silently leaking traffic in the open.
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- **Tunnel-only DNS** — lookups are resolved through the server's own resolver over the tunnel, never leaked to a third-party DNS provider.
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- **No telemetry** — no analytics, crash reporting, or usage tracking of any kind.
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- **Cross-platform** — Linux, Windows, Android (macOS and iOS planned).
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## Download
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### Android
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<a href="https://play.google.com/store/apps/details?id=eu.k_ops.koridor">
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<img src="https://play.google.com/intl/en_us/badges/static/images/badges/en_badge_web_generic.png" alt="Get it on Google Play" height="60"/>
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</a>
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### Linux · Windows
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Releases are published on the [Releases](../../releases) page.
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### macOS · iOS
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Coming soon.
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## Setup
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- [Server Quickstart](docs/server-quickstart.md) — what your SSH server needs, the
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keypair, host-key trust, and what UDP forwarding provisions on your box
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## Architecture
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```
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Flutter UI (Dart)
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│
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FFI (cdylib)
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│
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koridor engine (Rust)
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├── TUN device
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├── smoltcp netstack (packets → TCP flows)
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├── russh SSH client (direct-tcpip per flow)
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└── Route manager
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```
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Each TCP flow captured off the TUN device is proxied over its own SSH `direct-tcpip` channel — the same kind of traffic an ordinary SSH port-forward produces, indistinguishable on the wire from routine SSH use.
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The TUN device and OS route management layer is shared with [Konduit](https://konduit.k-ops.eu), other VPN client from [K-Ops Oy](https://k-ops.eu) , and is published for transparency and audit as [`konduit-platform`](https://git.k-ops.eu/konduit/konduit-public/src/branch/master/konduit-platform).
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## Security
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- Your SSH private key and passphrase are stored only in the OS secure credential store (Android Keystore / platform-equivalent) and are only ever sent to the server you configure, as part of establishing the tunnel.
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- All traffic between client and server is carried inside the SSH transport.
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See the [Privacy Policy](privacy-policy.md) for full details on what koridor does and does not process.
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## Support & Contributing
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**Bug reports:** file an issue on [Gitea Issues](https://git.k-ops.eu/koridor/koridor-public/issues).
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**Vulnerabilities:** report directly to koridor@k-ops.eu.
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**Contributing:** core development is handled internally. We do not currently accept external pull requests.
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---
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## About
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Created by **Eugen Kaparulin**.
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Official binaries distributed by **[K-Ops Oy](https://k-ops.eu)**.
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© Eugen Kaparulin. All rights reserved.
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[Privacy Policy](privacy-policy.md)
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