feat(project): Establish initial IRTT workspace and protocol definitions

crates/irtt-proto/src/close.rs

@@ -0,0 +1,46 @@
+use crate::{
+    flags::{FLAG_CLOSE, FLAG_HMAC},
+    hmac, write_header, Result, HMAC_SIZE,
+};
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct CloseRequest {
+    pub token: u64,
+}
+
+pub fn encode_close_request(request: &CloseRequest, hmac_key: Option<&[u8]>) -> Result<Vec<u8>> {
+    let mut flags = FLAG_CLOSE;
+    if hmac_key.is_some() {
+        flags |= FLAG_HMAC;
+    }
+
+    let mut out = Vec::new();
+    write_header(&mut out, flags);
+    if hmac_key.is_some() {
+        out.extend_from_slice(&[0; HMAC_SIZE]);
+    }
+    out.extend_from_slice(&request.token.to_le_bytes());
+    if let Some(key) = hmac_key {
+        hmac::compute_hmac_in_place(key, &mut out, hmac::hmac_offset())?;
+    }
+    Ok(out)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn close_request_sizes() {
+        let request = CloseRequest {
+            token: 0x7896_b6ab_8771_5213,
+        };
+        assert_eq!(encode_close_request(&request, None).unwrap().len(), 12);
+        assert_eq!(
+            encode_close_request(&request, Some(b"testkey"))
+                .unwrap()
+                .len(),
+            28
+        );
+    }
+}