From 0ec0ed34ec0c5bce6f40e96f6d53b42a0947d045 Mon Sep 17 00:00:00 2001
From: Joshua Goins <josh@redstrate.com>
Date: Sat, 8 Mar 2025 14:38:31 -0500
Subject: [PATCH] Parse the encryption initialization packet

---
 src/bin/kawari-lobby.rs |  9 +++----
 src/lib.rs              |  2 +-
 src/packet.rs           | 56 ++++++++++++++++++++++++++++++++++++-----
 3 files changed, 55 insertions(+), 12 deletions(-)

diff --git a/src/bin/kawari-lobby.rs b/src/bin/kawari-lobby.rs
index 16cff15..34033a9 100644
--- a/src/bin/kawari-lobby.rs
+++ b/src/bin/kawari-lobby.rs
@@ -17,12 +17,11 @@ async fn main() {
         tokio::spawn(async move {
             let mut buf = [0; 2056];
             loop {
-                let n = read
-                .read(&mut buf)
-                .await
-                .expect("Failed to read data!");
+                let n = read.read(&mut buf).await.expect("Failed to read data!");
 
-                parse_packet(&buf[..n]);
+                if n != 0 {
+                    parse_packet(&buf[..n]);
+                }
             }
         });
     }
diff --git a/src/lib.rs b/src/lib.rs
index 554165a..6b4a37c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -3,8 +3,8 @@ use rand::Rng;
 use rand::distributions::Alphanumeric;
 
 pub mod config;
-pub mod patchlist;
 pub mod packet;
+pub mod patchlist;
 
 pub fn generate_sid() -> String {
     let random_id: String = rand::thread_rng()
diff --git a/src/packet.rs b/src/packet.rs
index 362f517..0acf63b 100644
--- a/src/packet.rs
+++ b/src/packet.rs
@@ -1,6 +1,6 @@
 use std::{fs::write, io::Cursor};
 
-use binrw::{binrw, BinRead};
+use binrw::{BinRead, binrw, helpers::until_eof};
 
 pub(crate) fn read_bool_from<T: std::convert::From<u8> + std::cmp::PartialEq>(x: T) -> bool {
     x == T::from(1u8)
@@ -10,6 +10,11 @@ pub(crate) fn write_bool_as<T: std::convert::From<u8>>(x: &bool) -> T {
     if *x { T::from(1u8) } else { T::from(0u8) }
 }
 
+pub(crate) fn read_string(byte_stream: Vec<u8>) -> String {
+    let str = String::from_utf8(byte_stream).unwrap();
+    str.trim_matches(char::from(0)).to_string() // trim \0 from the end of strings
+}
+
 #[binrw]
 #[brw(repr = u16)]
 #[derive(Debug)]
@@ -17,6 +22,22 @@ enum ConnectionType {
     Lobby = 0x3,
 }
 
+#[binrw]
+#[derive(Debug)]
+enum SegmentType {
+    #[brw(magic = 0x9u32)]
+    InitializeEncryption {
+        #[br(pad_before = 36)] // empty
+        #[br(count = 64)]
+        #[br(map = read_string)]
+        #[bw(ignore)]
+        phrase: String,
+
+        #[br(pad_after = 512)] // empty
+        key: u32,
+    },
+}
+
 #[binrw]
 #[derive(Debug)]
 struct PacketHeader {
@@ -25,12 +46,30 @@ struct PacketHeader {
     timestamp: u64,
     size: u32,
     connection_type: ConnectionType,
-    count: u16,
+    segment_count: u16,
     unk3: u8,
     #[br(map = read_bool_from::<u8>)]
     #[bw(map = write_bool_as::<u8>)]
     compressed: bool,
-    unk4: u32,
+    unk4: u16,
+    unk5: u32, // iolite says the size after oodle decompression
+}
+
+#[binrw]
+#[derive(Debug)]
+struct PacketSegment {
+    size: u32,
+    source_actor: u32,
+    target_actor: u32,
+    segment_type: SegmentType,
+}
+
+#[binrw]
+#[derive(Debug)]
+struct Packet {
+    header: PacketHeader,
+    #[br(count = header.segment_count)]
+    segments: Vec<PacketSegment>,
 }
 
 fn dump(msg: &str, data: &[u8]) {
@@ -41,12 +80,17 @@ fn dump(msg: &str, data: &[u8]) {
 pub fn parse_packet(data: &[u8]) {
     let mut cursor = Cursor::new(data);
 
-    if let Ok(packet) = PacketHeader::read_le(&mut cursor) {
+    if let Ok(packet) = Packet::read_le(&mut cursor) {
         println!("{:#?}", packet);
 
-        if packet.size as usize != data.len() {
-            dump("Packet size mismatch between what we're given and the header!", data);
+        if packet.header.size as usize != data.len() {
+            dump(
+                "Packet size mismatch between what we're given and the header!",
+                data,
+            );
         }
+
+        dump("nothing", data);
     } else {
         dump("Failed to parse packet!", data);
     }