Add key generation

src/core/utils/x25519.ts

@@ -0,0 +1,9 @@
+import { x25519 } from "@noble/curves/ed25519";
+
+export function getX25519PrivateKey(): Uint8Array {
+  return x25519.utils.randomPrivateKey();
+}
+
+export function getX25519PublicKey(privateKey: Uint8Array): Uint8Array {
+  return x25519.getPublicKey(privateKey);
+}