From 9dae5168fc182701fc299b505db5b3ed858fcd57 Mon Sep 17 00:00:00 2001
From: Franck Royer <franck@status.im>
Date: Mon, 7 Mar 2022 07:48:02 +1100
Subject: [PATCH] Use browser (subtle) implementation for all env

---
 src/lib/waku_message/symmetric/index.ts | 63 ++++++++++++-------------
 src/lib/waku_message/version_1.ts       |  6 +--
 2 files changed, 34 insertions(+), 35 deletions(-)

diff --git a/src/lib/waku_message/symmetric/index.ts b/src/lib/waku_message/symmetric/index.ts
index 925c08aaec..d29e2cb9b9 100644
--- a/src/lib/waku_message/symmetric/index.ts
+++ b/src/lib/waku_message/symmetric/index.ts
@@ -1,38 +1,37 @@
-export const SymmetricKeySize = 32;
+import { randomBytes, subtle } from "../../crypto";
+
+export const KeySize = 32;
 export const IvSize = 12;
 export const TagSize = 16;
 
-export interface Symmetric {
-  /**
-   * Proceed with symmetric encryption of `clearText` value.
-   */
-  encrypt: (
-    iv: Buffer | Uint8Array,
-    key: Buffer,
-    clearText: Buffer
-  ) => Promise<Buffer>;
-  /**
-   * Proceed with symmetric decryption of `cipherText` value.
-   */
-  decrypt: (iv: Buffer, key: Buffer, cipherText: Buffer) => Promise<Buffer>;
-  /**
-   * Generate an Initialization Vector (iv) for for Symmetric encryption purposes.
-   */
-  generateIv: () => Uint8Array;
+const Algorithm = { name: "AES-GCM", length: 128 };
+
+export async function encrypt(
+  iv: Buffer | Uint8Array,
+  key: Buffer,
+  clearText: Buffer
+): Promise<Buffer> {
+  return subtle
+    .importKey("raw", key, Algorithm, false, ["encrypt"])
+    .then((cryptoKey) =>
+      subtle.encrypt({ iv, ...Algorithm }, cryptoKey, clearText)
+    )
+    .then(Buffer.from);
 }
 
-export let symmetric: Symmetric = {} as unknown as Symmetric;
+export async function decrypt(
+  iv: Buffer,
+  key: Buffer,
+  cipherText: Buffer
+): Promise<Buffer> {
+  return subtle
+    .importKey("raw", key, Algorithm, false, ["decrypt"])
+    .then((cryptoKey) =>
+      subtle.decrypt({ iv, ...Algorithm }, cryptoKey, cipherText)
+    )
+    .then(Buffer.from);
+}
 
-import("./browser")
-  .then((mod) => {
-    symmetric = mod;
-  })
-  .catch((eBrowser) => {
-    import("./node")
-      .then((mod) => {
-        symmetric = mod;
-      })
-      .catch((eNode) => {
-        throw `Could not load any symmetric crypto modules: ${eBrowser}, ${eNode}`;
-      });
-  });
+export function generateIv(): Uint8Array {
+  return randomBytes(IvSize);
+}
diff --git a/src/lib/waku_message/version_1.ts b/src/lib/waku_message/version_1.ts
index 4972410f16..535c232484 100644
--- a/src/lib/waku_message/version_1.ts
+++ b/src/lib/waku_message/version_1.ts
@@ -7,7 +7,7 @@ import * as secp256k1 from "secp256k1";
 import { hexToBytes } from "../utils";
 
 import * as ecies from "./ecies";
-import { IvSize, symmetric, SymmetricKeySize } from "./symmetric";
+import * as symmetric from "./symmetric";
 
 const FlagsLength = 1;
 const FlagMask = 3; // 0011
@@ -170,7 +170,7 @@ export async function decryptSymmetric(
   key: Uint8Array | Buffer | string
 ): Promise<Uint8Array> {
   const data = Buffer.from(payload);
-  const ivStart = data.length - IvSize;
+  const ivStart = data.length - symmetric.IvSize;
   const cipher = data.slice(0, ivStart);
   const iv = data.slice(ivStart);
 
@@ -190,7 +190,7 @@ export function generatePrivateKey(): Uint8Array {
  * Generate a new symmetric key to be used for symmetric encryption.
  */
 export function generateSymmetricKey(): Uint8Array {
-  return randomBytes(SymmetricKeySize);
+  return randomBytes(symmetric.KeySize);
 }
 
 /**