Function read_envelope

nodedb-cluster/src/transport/server.rs:361–393

Read a complete authenticated envelope from a QUIC receive stream. Reads the fixed envelope pre-header (version + from_node_id + seq + inner_len), then the inner frame, then the MAC tag. Returns the full envelope bytes for caller-side parsing.

(recv: &mut quinn::RecvStream)

/// inner_len), then the inner frame, then the MAC tag. Returns the full
/// envelope bytes for caller-side parsing.
pub(crate) async fn read_envelope(recv: &mut quinn::RecvStream) -> Result<Vec<u8>> {
    // Envelope header is version(1) + from_node_id(8) + seq(8) + inner_len(4).
    const ENV_HDR_LEN: usize = 21;

    let mut hdr = [0u8; ENV_HDR_LEN];
    recv.read_exact(&mut hdr)
        .await
        .map_err(|e| ClusterError::Transport {
            detail: format!("read envelope header: {e}"),
        })?;

    let inner_len = u32::from_le_bytes([hdr[17], hdr[18], hdr[19], hdr[20]]);
    if inner_len > MAX_RPC_PAYLOAD_SIZE {
        return Err(ClusterError::Codec {
            detail: format!(
                "envelope inner length {inner_len} exceeds maximum {MAX_RPC_PAYLOAD_SIZE}"
            ),
        });
    }

    let total = ENV_HDR_LEN + inner_len as usize + rpc_codec::MAC_LEN;
    let mut buf = vec![0u8; total];
    buf[..ENV_HDR_LEN].copy_from_slice(&hdr);
    if total > ENV_HDR_LEN {
        recv.read_exact(&mut buf[ENV_HDR_LEN..])
            .await
            .map_err(|e| ClusterError::Transport {
                detail: format!("read envelope payload+mac: {e}"),
            })?;
    }

    Ok(buf)
}