[ticket/17010] Clean up code and move some functions to core js

PHPBB3-17010

phpBB/assets/javascript/core.js

@@ -1677,6 +1677,33 @@ phpbb.getFunctionByName = function (functionName) {
 	return context[func];
 };
 
+/**
+ * Convert raw key ArrayBuffer to base64 string.
+ *
+ * @param {ArrayBuffer} rawKey Raw key array buffer as exported by SubtleCrypto exportKey()
+ * @returns {string} Base64 encoded raw key string
+ */
+phpbb.rawKeyToBase64 = (rawKey) => {
+	const keyBuffer = new Uint8Array(rawKey);
+	let keyText = '';
+	const keyLength = keyBuffer.byteLength;
+	for (let i = 0; i < keyLength; i++) {
+		keyText += String.fromCharCode(keyBuffer[i]);
+	}
+
+	return window.btoa(keyText);
+};
+
+/**
+ * Base64URL encode base64 encoded string
+ *
+ * @param {string} base64String Base64 encoded string
+ * @returns {string} Base64URL encoded string
+ */
+phpbb.base64UrlEncode = (base64String) => {
+	return base64String.replace(/\+/g, '-').replace(/\//g, '_').replace(/=+$/, '');
+};
+
 /**
 * Register page dropdowns.
 */