crypto: use secret directly instead of deriving key

src/modules/stream/manage.js

@@ -20,7 +20,7 @@ const hmacSalt = randomBytes(64).toString('hex');
 export function createStream(obj) {
     const streamID = nanoid(),
         iv = randomBytes(16).toString('base64url'),
-        secret = randomBytes(256).toString('base64url'),
+        secret = randomBytes(32).toString('base64url'),
         exp = new Date().getTime() + streamLifespan,
         hmac = generateHmac(`${streamID},${exp},${iv},${secret}`, hmacSalt),
         streamData = {

src/modules/sub/crypto.js

@@ -1,25 +1,22 @@
 import { createHmac, createCipheriv, createDecipheriv, scryptSync } from "crypto";
 
 const algorithm = "aes256"
-const keyLength = 32;
 
 export function generateHmac(str, salt) {
     return createHmac("sha256", salt).update(str).digest("base64url");
 }
 
 export function encryptStream(plaintext, iv, secret) {
-    const buff = Buffer.from(JSON.stringify(plaintext), "utf-8");
-
-    const key = scryptSync(Buffer.from(secret, "base64url"), "salt", keyLength);
+    const buff = Buffer.from(JSON.stringify(plaintext));
+    const key = Buffer.from(secret, "base64url");
     const cipher = createCipheriv(algorithm, key, Buffer.from(iv, "base64url"));
 
     return Buffer.concat([ cipher.update(buff), cipher.final() ])
 }
 
 export function decryptStream(ciphertext, iv, secret) {
-    const buff = Buffer.from(ciphertext, "binary");
-
-    const key = scryptSync(Buffer.from(secret, "base64url"), "salt", keyLength);
+    const buff = Buffer.from(ciphertext);
+    const key = Buffer.from(secret, "base64url");
     const decipher = createDecipheriv(algorithm, key, Buffer.from(iv, "base64url"));
 
     return Buffer.concat([ decipher.update(buff), decipher.final() ])