api: flatten code directories, better filenames, remove old files

api/src/misc/crypto.js

@@ -0,0 +1,27 @@
+import { createHmac, createCipheriv, createDecipheriv, randomBytes } from "crypto";
+
+const algorithm = "aes256";
+
+export function generateSalt() {
+    return randomBytes(64).toString('hex');
+}
+
+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");
+    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);
+    const key = Buffer.from(secret, "base64url");
+    const decipher = createDecipheriv(algorithm, key, Buffer.from(iv, "base64url"));
+
+    return Buffer.concat([ decipher.update(buff), decipher.final() ])
+}