Improved encryption implementation

src/netmd/encryption.rs

@@ -9,9 +9,25 @@ use super::interface::DataEncryptorInput;
 type DesEcbEnc = ecb::Decryptor<des::Des>;
 type DesCbcEnc = cbc::Encryptor<des::Des>;
 
-pub fn threaded_encryptor(
-    input: DataEncryptorInput,
-) -> UnboundedReceiver<(Vec<u8>, Vec<u8>, Vec<u8>)> {
+pub struct Encryptor {
+    channel: Option<UnboundedReceiver<(Vec<u8>, Vec<u8>, Vec<u8>)>>,
+    state: Option<EncryptorState>,
+}
+
+struct EncryptorState {
+    input_data: Vec<u8>,
+    iv: [u8; 8],
+    random_key: [u8; 8],
+    encrypted_random_key: [u8; 8],
+    default_chunk_size: usize,
+    current_chunk_size: usize,
+    offset: usize,
+    packet_count: usize,
+    closed: bool,
+}
+
+impl Encryptor {
+    pub fn new_threaded(input: DataEncryptorInput) -> Self {
         let (tx, rx) = unbounded_channel::<(Vec<u8>, Vec<u8>, Vec<u8>)>();
 
         thread::spawn(move || {
@@ -73,22 +89,12 @@ pub fn threaded_encryptor(
             }
         });
 
-    rx
+        Self {
+            channel: Some(rx),
+            state: None
+        }
     }
 
-pub struct Encryptor {
-    input_data: Vec<u8>,
-    iv: [u8; 8],
-    random_key: [u8; 8],
-    encrypted_random_key: [u8; 8],
-    default_chunk_size: usize,
-    current_chunk_size: usize,
-    offset: usize,
-    packet_count: usize,
-    closed: bool,
-}
-
-impl Encryptor {
     pub fn new(input: DataEncryptorInput) -> Self {
         let iv = [0u8; 8];
 
@@ -120,7 +126,9 @@ impl Encryptor {
 
         let offset: usize = 0;
 
-        Self {
+        Encryptor {
+            channel: None,
+            state: Some(EncryptorState {
                 input_data,
                 iv,
                 random_key,
@@ -130,48 +138,59 @@ impl Encryptor {
                 default_chunk_size,
                 packet_count,
                 closed: false,
+            })
         }
     }
 
     /// Get the next encrypted value
     pub async fn next(&mut self) -> Option<(Vec<u8>, Vec<u8>, Vec<u8>)> {
-        if self.closed {
+        let output;
+
+        if let Some(state) = self.state.as_mut() {
+            if state.closed {
                 return None
             }
 
-        if self.packet_count > 0 {
-            self.current_chunk_size = self.default_chunk_size;
+            if state.packet_count > 0 {
+                state.current_chunk_size = state.default_chunk_size;
             } else {
-            self.current_chunk_size = self.default_chunk_size - 24;
+                state.current_chunk_size = state.default_chunk_size - 24;
             }
 
-        self.current_chunk_size = std::cmp::min(self.current_chunk_size, self.input_data.len() - self.offset);
+            state.current_chunk_size = std::cmp::min(state.current_chunk_size, state.input_data.len() - state.offset);
 
-        let this_data_chunk = &mut self.input_data[self.offset..self.offset + self.current_chunk_size];
-        DesCbcEnc::new(&self.random_key.into(), &self.iv.into())
-            .encrypt_padded_mut::<NoPadding>(this_data_chunk, self.current_chunk_size)
+            let this_data_chunk = &mut state.input_data[state.offset..state.offset + state.current_chunk_size];
+            DesCbcEnc::new(&state.random_key.into(), &state.iv.into())
+                .encrypt_padded_mut::<NoPadding>(this_data_chunk, state.current_chunk_size)
                 .unwrap();
 
-        let output = (
-            self.encrypted_random_key.to_vec(),
-            self.iv.to_vec(),
+            output = Some((
+                state.encrypted_random_key.to_vec(),
+                state.iv.to_vec(),
                 this_data_chunk.to_vec(),
-        );
+            ));
 
-        self.iv.copy_from_slice(&this_data_chunk[this_data_chunk.len() - 8..]);
+            state.iv.copy_from_slice(&this_data_chunk[this_data_chunk.len() - 8..]);
 
-        self.packet_count += 1;
-        self.offset += self.current_chunk_size;
+            state.packet_count += 1;
+            state.offset += state.current_chunk_size;
+        } else if let Some(channel) = self.channel.as_mut() {
+            output = channel.recv().await
+        } else {
+            unreachable!("If you got here, this is bad!");
+        }
 
-        Some(output)
+        output
     }
 
     /// Call close to return none from subsequent calls
     pub fn close(&mut self) {
-        self.closed = true;
+        if let Some(state) = self.state.as_mut() {
+            state.closed = true;
+        } else if let Some(channel) = self.channel.as_mut() {
+            channel.close()
+        } else {
+            unreachable!("If you got here, this is bad!");
         }
     }
-
-pub fn encryptor() {
-
 }

src/netmd/interface.rs

@@ -17,7 +17,7 @@ use std::time::Duration;
 use thiserror::Error;
 
 use super::base::NetMD;
-use super::encryption::{threaded_encryptor, EncryptorState};
+use super::encryption::Encryptor;
 use super::utils::{cross_sleep, to_sjis};
 
 /// An action to take on the player
@@ -1690,11 +1690,7 @@ impl NetMDInterface {
         discformat: u8,
         frames: u32,
         pkt_size: u32,
-        // key, iv, data
-        #[cfg(not(target_family = "wasm"))]
-        mut packets: UnboundedReceiver<(Vec<u8>, Vec<u8>, Vec<u8>)>,
-        #[cfg(target_family = "wasm")]
-        mut packets: EncryptorState,
+        mut packets: Encryptor,
         hex_session_key: &[u8],
         progress_callback: F,
     ) -> Result<(u16, Vec<u8>, Vec<u8>), InterfaceError>
@@ -1733,7 +1729,7 @@ impl NetMDInterface {
         let mut written_bytes = 0;
         let mut packet_count = 0;
 
-        while let Some((key, iv, data)) = packets.recv().await {
+        while let Some((key, iv, data)) = packets.next().await {
             let binpack = if packet_count == 0 {
                 let packed_length: Vec<u8> = pkt_size.to_be_bytes().to_vec();
                 [vec![0, 0, 0, 0], packed_length, key, iv, data].concat()
@@ -1921,8 +1917,8 @@ impl MDTrack {
     }
 
     #[cfg(not(target_family = "wasm"))]
-    pub fn get_encrypting_iterator(&mut self) -> UnboundedReceiver<(Vec<u8>, Vec<u8>, Vec<u8>)> {
-        threaded_encryptor(DataEncryptorInput {
+    pub fn get_encrypting_iterator(&mut self) -> Encryptor {
+        Encryptor::new_threaded(DataEncryptorInput {
             kek: self.get_kek(),
             frame_size: self.frame_size(),
             chunk_size: self.chunk_size(),
@@ -1931,8 +1927,8 @@ impl MDTrack {
     }
 
     #[cfg(target_family = "wasm")]
-    pub fn get_encrypting_iterator(&mut self) -> EncryptorState {
-        EncryptorState::new(DataEncryptorInput {
+    pub fn get_encrypting_iterator(&mut self) -> Encryptor {
+        Encryptor::new(DataEncryptorInput {
             kek: self.get_kek(),
             frame_size: self.frame_size(),
             chunk_size: self.chunk_size(),