encryption code separated into its own file

static/js/utils.js

@@ -12,4 +12,22 @@ function error(str) {
     error.show();
     error.html(str);
     error.fadeOut(10000);
+}
+
+function uint8ToBase64(u8Arr) {
+    const CHUNK_SIZE = 0x8000; //arbitrary number
+    const length = u8Arr.length;
+    let index = 0;
+    let result = '';
+    let slice;
+    while (index < length) {
+        slice = u8Arr.subarray(index, Math.min(index + CHUNK_SIZE, length));
+        result += String.fromCharCode.apply(null, slice);
+        index += CHUNK_SIZE;
+    }
+    return btoa(result);
+}
+
+function base64ToUint8Array(base64encoded) {
+    return new Uint8Array(atob(base64encoded).split("").map(function(c) { return c.charCodeAt(0); }));
 }