api: move hmac secrets to single file

api/src/misc/crypto.js

@@ -1,15 +1,7 @@
-import { createHmac, createCipheriv, createDecipheriv, randomBytes } from "crypto";
+import { createCipheriv, createDecipheriv } from "crypto";
 
 const algorithm = "aes256";
 
-export function generateSalt() {
-    return randomBytes(64);
-}
-
-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));
     const key = Buffer.from(secret, "base64url");