somewhat (not work) poly1305 MAC

Cargo.lock

@@ -113,6 +113,7 @@ dependencies = [
  "blake3",
  "chacha",
  "diffie-hellman",
+ "poly1305",
  "rand",
 ]
 
@@ -131,6 +132,13 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "poly1305"
+version = "0.1.0"
+dependencies = [
+ "crypto-bigint",
+]
+
 [[package]]
 name = "ppv-lite86"
 version = "0.2.21"

Cargo.toml

@@ -6,5 +6,6 @@ edition = "2024"
 [dependencies]
 diffie-hellman = { path = "../diffie-hellman", features = ["rand"] }
 chacha = { path = "../chacha" }
+poly1305 = { path = "../poly1305" }
 rand = "0.9.2"
 blake3 = "1.8.2"

src/lib.rs

@@ -17,7 +17,8 @@ pub struct EncryptedStream {
     block: Block,
 }
 
-const KEY_DERIVATION_CONTEXT: &str = concat!(env!("CARGO_PKG_NAME"), "/", env!("CARGO_PKG_VERSION"));
+const KEY_DERIVATION_CONTEXT: &str =
+    concat!(env!("CARGO_PKG_NAME"), "/", env!("CARGO_PKG_VERSION"));
 
 impl EncryptedStream {
     /// connect and negotiate an encrypted stream as a client
@@ -39,7 +40,8 @@ impl EncryptedStream {
         let mut nonce_bytes = [0u8; 12];
         socket.read_exact(&mut nonce_bytes)?;
 
-        let key = shared_secret.derive_key(|bytes| blake3::derive_key(KEY_DERIVATION_CONTEXT, &bytes));
+        let key =
+            shared_secret.derive_key(|bytes| blake3::derive_key(KEY_DERIVATION_CONTEXT, &bytes));
 
         Ok(EncryptedStream::wrap(socket, key, nonce_bytes))
     }
@@ -64,6 +66,28 @@ impl EncryptedStream {
     pub fn reset(&mut self, next_nonce: [u32; 3]) {
         self.block.reset(next_nonce)
     }
+
+    pub fn read_packet(&mut self) -> Result<Vec<u8>, Error> {
+        // the first bytes should be the nonce
+        let mut nonce_bytes = [0u8; 12];
+        self.socket.read(&mut nonce_bytes)?;
+
+        let mut nonce = [0u32; 3];
+        u8_to_u32(&mut nonce, &nonce_bytes);
+
+        self.block.reset(nonce);
+
+        let poly_key = self.block.get_bytes();
+        self.block.advance();
+
+        let mut len_bytes = [0u8; 4];
+        self.read(&mut len_bytes)?;
+
+        let len = u32::from_le_bytes(len_bytes);
+
+        let mut buf = vec![0u8; len as usize];
+
+    }
 }
 
 impl TryFrom<TcpStream> for EncryptedStream {
@@ -88,7 +112,8 @@ impl TryFrom<TcpStream> for EncryptedStream {
 
         socket.write(&nonce_bytes)?;
 
-        let key = shared_secret.derive_key(|bytes| blake3::derive_key(KEY_DERIVATION_CONTEXT, &bytes));
+        let key =
+            shared_secret.derive_key(|bytes| blake3::derive_key(KEY_DERIVATION_CONTEXT, &bytes));
 
         Ok(EncryptedStream::wrap(socket, key, nonce_bytes))
     }