ferogram-connect 0.6.5

/*
 * Copyright (c) 2026 Ankit Chaubey <ankitchaubey.dev@gmail.com>
 * https://github.com/ankit-chaubey
 *
 * Project: ferogram
 * Website: https://ferogram.dev
 *
 * Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
 * https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
 * <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
 * This file may not be copied, modified, or distributed except according
 * to those terms.
 */

/// Which MTProto wire framing to use for a connection.
///
/// | Variant | Init bytes | Notes |
/// |---------|-----------|-------|
/// | `Abridged` | `0xEF` | Lightest framing |
/// | `Intermediate` | `0xEEEEEEEE` | 4-byte length prefix |
/// | `Full` | none | length + seqno + CRC32: **default** |
/// | `Obfuscated` | random 64B | Bypasses DPI / MTProxy |
/// | `PaddedIntermediate` | random 64B (`0xDDDDDDDD` tag) | Required for `0xDD` MTProxy secrets |
/// | `FakeTls` | TLS 1.3 ClientHello | Most DPI-resistant; required for `0xEE` MTProxy secrets |
#[derive(Clone, Debug, Default)]
pub enum TransportKind {
    /// MTProto Abridged transport: length prefix is 1 or 4 bytes.
    Abridged,
    /// MTProto Intermediate transport: 4-byte LE length prefix.
    Intermediate,
    /// MTProto Full transport: 4-byte length + seqno + CRC32.
    ///
    /// No init byte is sent. Provides CRC32 integrity and sequence number
    /// validation on every frame. **Default** transport.
    #[default]
    Full,
    /// Obfuscated2 transport: AES-256-CTR over Abridged framing.
    /// Required for MTProxy and networks with deep-packet inspection.
    ///
    /// `secret` is the 16-byte MTProxy secret, or `None` for keyless obfuscation.
    Obfuscated { secret: Option<[u8; 16]> },
    /// Obfuscated PaddedIntermediate transport (`0xDDDDDDDD` tag in nonce).
    ///
    /// Same AES-256-CTR obfuscation as `Obfuscated`, but uses Intermediate
    /// framing and appends 0-15 random padding bytes to each frame.
    /// Required for `0xDD` MTProxy secrets.
    PaddedIntermediate { secret: Option<[u8; 16]> },
    /// FakeTLS transport (`0xEE` prefix in MTProxy secret).
    ///
    /// Wraps all MTProto data in fake TLS 1.3 records.
    FakeTls { secret: [u8; 16], domain: String },
    /// Not real HTTP - falls back to `Abridged` framing on the same port.
    /// Use `Abridged` directly instead.
    Http,
}