프론트엔드 암호 모듈 리팩토링

src/lib/modules/crypto/util.ts

@@ -0,0 +1,19 @@
+export const encodeToBase64 = (data: ArrayBuffer) => {
+  return btoa(String.fromCharCode(...new Uint8Array(data)));
+};
+
+export const decodeFromBase64 = (data: string) => {
+  return Uint8Array.from(atob(data), (c) => c.charCodeAt(0)).buffer;
+};
+
+export const concatenateBuffers = (...buffers: ArrayBuffer[]) => {
+  const arrays = buffers.map((buffer) => new Uint8Array(buffer));
+  const totalLength = arrays.reduce((acc, array) => acc + array.length, 0);
+  const result = new Uint8Array(totalLength);
+
+  arrays.reduce((offset, array) => {
+    result.set(array, offset);
+    return offset + array.length;
+  }, 0);
+  return result;
+};