From 612b3b5e108c6c09be1860aca0804754951a7970 Mon Sep 17 00:00:00 2001
From: arnaucube <root@arnaucube.com>
Date: Sat, 13 Jun 2020 13:11:26 +0200
Subject: [PATCH] Add conn_req_msg & ann_req_msg contructors, torrent.size() &
 .info_hash()

---
 Cargo.toml |  3 +++
 src/lib.rs | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/Cargo.toml b/Cargo.toml
index 29243ad..790e680 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,3 +10,6 @@ serde_bencode = "^0.2.1"
 serde = "^1.0.0"
 serde_derive = "^1.0.0"
 serde_bytes = "0.10.0"
+byteorder = "1.3.4"
+rand = "0.7"
+sha-1 = "0.9.0"
diff --git a/src/lib.rs b/src/lib.rs
index ba98ef0..b0eeb26 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,7 @@
+use byteorder::{BigEndian, ByteOrder};
+use rand::Rng;
+use sha1::{Digest, Sha1};
+
 extern crate serde;
 extern crate serde_bencode;
 #[macro_use]
@@ -68,6 +72,55 @@ impl Torrent {
         let b = std::fs::read(path).unwrap();
         de::from_bytes::<Torrent>(&b).unwrap()
     }
+    pub fn size(&self) -> u64 {
+        let files = self.info.files.as_ref().unwrap();
+        let mut size: u64 = 0;
+        for i in 0..files.len() {
+            size = size + files[i].length as u64;
+        }
+        size
+    }
+    pub fn info_hash(&self) -> Vec<u8> {
+        let info_bytes: Vec<u8> = ser::to_bytes(&self.info).unwrap();
+        let mut hasher = Sha1::new();
+        hasher.update(info_bytes);
+        let result = hasher.finalize();
+        result.to_vec()
+    }
+}
+
+const CONNECT_MSG: u32 = 0;
+const ANNOUNCE_MSG: u32 = 1;
+
+fn conn_req_msg() -> [u8; 16] {
+    let mut b: [u8; 16] = [0; 16];
+    BigEndian::write_u64(&mut b[0..8], 0x41727101980); // connection_id
+    let random_bytes = rand::thread_rng().gen::<[u8; 4]>();
+    b[12..16].clone_from_slice(&random_bytes[..]);
+    b
+}
+
+fn ann_req_msg(connection_id: u64, torrent: &Torrent, port: u16) -> Vec<u8> {
+    let mut b: [u8; 98] = [0; 98];
+    BigEndian::write_u64(&mut b[0..8], connection_id);
+    BigEndian::write_u32(&mut b[8..12], CONNECT_MSG); // action
+    let random_bytes = rand::thread_rng().gen::<[u8; 4]>();
+    b[12..16].clone_from_slice(&random_bytes[..]);
+    // println!("md5sum {:?}", torrent);
+    b[16..36].clone_from_slice(&torrent.info_hash()[..]);
+    println!("info_hash: {:?}", &b[16..36]);
+    // TODO [36..56] peerId b[36..56].clone_from_slice("todo".as_bytes());
+    // TODO [56..64] downloaded
+    println!("torrent.size(): {:?}", torrent.size());
+    BigEndian::write_u64(&mut b[64..72], torrent.size()); // [64..72] left
+                                                          // TODO [72..80] uploaded
+                                                          // TODO [80..84] event (0:none, 1:completed, 2:started, 3:stopped)
+                                                          // TODO [84..88] ip address
+    let random_bytes = rand::thread_rng().gen::<[u8; 4]>();
+    b[88..92].clone_from_slice(&random_bytes[..]); // [88..92] key (random)
+    BigEndian::write_i32(&mut b[92..96], -1); // [92..96] num_want (default: -1)
+    BigEndian::write_u16(&mut b[96..98], port); // [96..98] port
+    b.to_vec()
 }
 
 #[cfg(test)]
@@ -77,6 +130,9 @@ mod tests {
     #[test]
     fn test_read() {
         let t = Torrent::open("test.torrent");
-        println!("{:?}", t);
+        println!("torrent: {:?}", t.info.name);
+        println!("announce: {:?}", t.announce.clone().unwrap());
+
+        println!("conn_req_msg: {:?}", conn_req_msg());
     }
 }