skeleton for new communications module

src/comms.rs

@@ -0,0 +1,36 @@
+use super::crypto;
+use aes_gcm::{aead::consts::U12, aes::Aes256, AesGcm};
+use rand::rngs::OsRng;
+use std::error::Error;
+use tokio::{
+    io::{AsyncBufReadExt, AsyncWriteExt, BufReader, BufWriter},
+    net::tcp::{ReadHalf, WriteHalf},
+};
+
+pub async fn send_bytes(
+    writer: &mut BufWriter<WriteHalf<'_>>,
+    enc: Option<(&mut AesGcm<Aes256, U12>, &mut OsRng)>,
+    data: &Vec<u8>,
+) -> Result<(), Box<dyn Error + Send + Sync>> {
+    let processed = enc.map_or(Ok(data.clone()), |enc| {
+        crypto::aes_encrypt(data, enc.0, enc.1)
+    })?;
+    writer.write_all(&processed).await?;
+    writer.flush().await?;
+
+    Ok(())
+}
+
+pub async fn recv_bytes(
+    reader: &mut BufReader<ReadHalf<'_>>,
+    cipher: Option<&mut AesGcm<Aes256, U12>>,
+    buf: &mut Vec<u8>,
+) -> Result<(), Box<dyn Error + Send + Sync>> {
+    let recv_bytes = reader.read_until(b'\n', buf).await?;
+    *buf = cipher.map_or(Ok(buf.clone()), |c| crypto::aes_decrypt(&buf, c))?;
+    if recv_bytes == 0 {
+        todo!("ERROR: No message received or client <xyz> crashed");
+    }
+
+    Ok(())
+}