rustunnel/droid-wiki/reference/data-models.md

Data models

ConnectionKey

pub struct ConnectionKey {
    pub version: u8,          // must be 1
    pub target: String,       // listener address
    pub ca_cert_pem: String,
    pub server_cert_pem: String,
    pub server_key_pem: String,
    pub client_cert_pem: String,
    pub client_key_pem: String,
    pub auth_token: String,
}

Encoded as: rtun1. + base64url(JSON) — no padding.

Config

pub struct Config {
    pub listen_address: String,
    pub listen_port: u16,
    pub socks_address: String,
    pub socks_port: u16,
    pub ca_cert_path: String,
    pub server_cert_path: String,
    pub server_key_path: String,
    pub client_cert_path: String,
    pub client_key_path: String,
    pub auth_token_path: String,
}

Frame

pub struct Frame {
    pub frame_type: u8,   // 0x01 CONNECT, 0x02 CONNECT_REPLY, 0x03 DATA, 0x04 CLOSE, 0x05 ERROR
    pub stream_id: u64,   // odd for client-initiated
    pub flags: u8,        // reserved (0x00)
    pub payload: Bytes,
}

Wire format: 1 byte type + 8 bytes stream_id (big-endian) + 4 bytes len (big-endian) + 1 byte flags + len bytes payload.

Max payload: 4 MiB.

Socks5Target

pub enum Socks5Target {
    Ipv4(std::net::Ipv4Addr, u16),
    Domain { domain: String, port: u16 },
}

GeneratedMaterial

pub struct GeneratedMaterial {
    pub ca_cert_pem: String,
    pub ca_key_pem: String,
    pub server_cert_pem: String,
    pub server_key_pem: String,
    pub client_cert_pem: String,
    pub client_key_pem: String,
    pub auth_token: String,
}

Error enums

• TlsError — missing/invalid certificates, identity mismatch, expiration, verification failure
• AuthError — missing or invalid token
• TunnelError — TLS error, auth error, bind error, connection refused, port in use, protocol error
• HostError — DNS resolution failure, invalid hostname, no addresses
• Socks5Error — invalid version, unsupported auth/command/addr type, parse errors
• FrameError — frame too short, payload overflow, I/O error, protocol error

Key source files

File	Purpose
src/connkey.rs	ConnectionKey
src/config.rs	Config
src/framing.rs	Frame, FrameReader, FrameWriter
src/socks5.rs	Socks5Target, Socks5State, Socks5Error
src/generate.rs	GeneratedMaterial
src/errors.rs	TlsError, AuthError, TunnelError, HostError