implemented frontend including separate message system; started to implement backend

yjs-poll/node_modules/lib0/crypto/common.js

@@ -0,0 +1,19 @@
+import * as webcrypto from 'lib0/webcrypto'
+
+/**
+ * @param {CryptoKey} key
+ */
+export const exportKeyJwk = async key => {
+  const jwk = await webcrypto.subtle.exportKey('jwk', key)
+  jwk.key_ops = key.usages
+  return jwk
+}
+
+/**
+ * Only suited for exporting public keys.
+ *
+ * @param {CryptoKey} key
+ * @return {Promise<Uint8Array<ArrayBuffer>>}
+ */
+export const exportKeyRaw = key =>
+  webcrypto.subtle.exportKey('raw', key).then(key => new Uint8Array(key))