From 128aba164d096fb86c608029480d14016ca22203 Mon Sep 17 00:00:00 2001
From: Belma Gutlic <belma.dzi@gmail.com>
Date: Tue, 24 Dec 2019 13:46:50 +0100
Subject: [PATCH] Encrypt stream in chunks

---
 src/crypto.ts | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/src/crypto.ts b/src/crypto.ts
index 5d583d2..81b1121 100644
--- a/src/crypto.ts
+++ b/src/crypto.ts
@@ -1,22 +1,35 @@
-import { Handshake } from "./handshake";
 import { Buffer } from "buffer";
+import { Handshake } from "./handshake";
 
 interface ReturnEncryptionWrapper {
   (source: Iterable<Uint8Array>): AsyncIterableIterator<Uint8Array>;
 }
 
+const maxPlaintextLength = 65519;
+
+
 // Returns generator that encrypts payload from the user
 export function encryptStream(handshake: Handshake): ReturnEncryptionWrapper {
   return async function * (source) {
     for await (const chunk of source) {
       const chunkBuffer = Buffer.from(chunk);
-      const data = await handshake.encrypt(chunkBuffer, handshake.session);
-      yield data;
+
+
+      for (let i = 0; i < chunkBuffer.length; i += maxPlaintextLength) {
+        let end = i + maxPlaintextLength;
+        if (end > chunkBuffer.length) {
+          end = chunkBuffer.length;
+        }
+
+        const data = handshake.encrypt(chunkBuffer.slice(i, end), handshake.session);
+        yield data;
+      }
     }
   }
 }
 
 
+
 // Decrypt received payload to the user
 export function decryptStream(handshake: Handshake): ReturnEncryptionWrapper {
   return async function * (source) {