# DragonSSH XHTTP Public Example

A deliberately small Android reference client for the DragonSSH XHTTP-SSH transport.
It contains one home screen, the XHTTP split-stream transport, SSH password authentication,
an Android `VpnService`, a local SOCKS relay, and BadVPN tun2socks with UDPGW.

## Public scope

Included:

- XHTTP over TLS/HTTP/2
- streamed downlink: `GET {path}/{sessionId}`
- ordered packet uplink: `POST {path}/{sessionId}/{sequence}`
- simple Server, Port, SNI, XHTTP Host, and XHTTP Path configuration
- SSH username/password authentication
- silent SSH/XHTTP transport reconnect while the Android VPN remains established
- configurable VPN DNS resolvers
- UDPGW forwarding through BadVPN tun2socks
- separate Home, Settings, VPN/UDPGW, and Logs screens

Not included:

- paid application screens, branding, panel URLs, certificates, signing fingerprints, or secrets
- remote/online configuration
- config import/export or config protection
- Xray, DNSTT/SlowDNS, SSL payload modes, ads, analytics, accounts, profiles, or reseller features
- production server addresses or credentials

The large `com.trilead`, `com.jcraft`, `org.spongycastle`, and `badvpn` trees are vendored
transport dependencies. The native build compiles only `libancillary`, the socket-protection
bridge, and the UDPGW-enabled `tun2socks` executable.

## Dependency note

The ConnectBot bcrypt fork is resolved from Maven Central as `org.connectbot:jbcrypt:1.0.2`. The former relocated coordinate `org.connectbot.jbcrypt:jbcrypt:1.0.0` is intentionally not used.

## Build fix in 1.0.7

- Corrected the password storage notice so it compiles with Android AAPT2.
- Updated the password storage notice and its resource reference.
- No tunnel behavior or saved-password behavior changed.

## Build

1. Open the root folder in Android Studio.
2. Install Android SDK 36 and an Android NDK compatible with Gradle's `ndkBuild` integration.
3. Let Android Studio create `local.properties` with your SDK path.
4. Build and install the `app` module.

The minimum Android version is API 26. Four ABIs are enabled: ARMv7, ARM64, x86, and x86_64.

## System-bar behavior

The sample handles Android edge-to-edge window insets explicitly. The configuration screen adds
safe padding for the status bar, display cutouts, gesture navigation, three-button navigation,
and the on-screen keyboard, so controls remain visible on Android 15/16 and earlier versions.

## Configuration mapping

The app uses the same names as SocksRevive VOID:

- **Server**: the XHTTP proxy IP address or hostname.
- **Port**: the XHTTP listener port, normally `443`.
- **User name / Password**: SSH credentials carried inside the XHTTP stream.
- **SNI**: the hostname sent during the TLS handshake.
- **XHTTP Host**: the CDN or reverse-proxy routing hostname.
- **XHTTP Path**: the base path, such as `/ssh`.
- **XHTTP TLS**: enables TLS and HTTP/2 for the XHTTP connection.

There is no separate SSH destination. **Server is the XHTTP proxy**, and the XHTTP session exposes the SSH byte stream used for authentication.

## TLS certificate behavior

To match the original SocksRevive VOID implementation, XHTTP TLS intentionally accepts every server certificate and skips hostname verification. Self-signed, expired, mismatched, and otherwise untrusted certificates are accepted. SNI is still sent for CDN/fronting routing, but it is not used to validate the certificate.

This is intentionally insecure against man-in-the-middle attacks and is included only because it is required by this transport example. There is no certificate-validation toggle in the sample.

## Log viewer

The sample log is structured rather than rendered as one large text block:

- timestamp per entry
- INFO, WARNING, ERROR, DEBUG, or VERBOSE badge
- color-coded rows
- DEBUG/VERBOSE filter
- follow-newest toggle
- copy and clear actions

Passwords are never written to the log.

## Protocol behavior

The SSH library receives a virtual duplex socket:

- its input stream is the body of one long-lived XHTTP GET response;
- its output stream is buffered and sent as strictly ordered POST requests;
- only one POST is in flight at a time, preserving sequence order;
- bounded buffering applies backpressure instead of creating an unbounded HTTP request queue;
- control sockets are excluded from the Android VPN to prevent routing loops.

See [`docs/XHTTP_PROTOCOL.md`](docs/XHTTP_PROTOCOL.md) for the request contract.

## License

The combined sample is distributed under GPL-3.0-or-later because its VPN layer contains
GPL-covered source. Third-party components retain their own notices; see
[`THIRD_PARTY_NOTICES.md`](THIRD_PARTY_NOTICES.md) and license files kept beside native sources.