implemented frontend including separate message system; started to implement backend

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

@@ -0,0 +1,70 @@
+import * as error from '../error.js'
+import * as buffer from '../buffer.js'
+import * as string from '../string.js'
+import * as json from '../json.js'
+import * as ecdsa from '../crypto/ecdsa.js'
+import * as time from '../time.js'
+
+/**
+ * @param {Object} data
+ */
+const _stringify = data => buffer.toBase64UrlEncoded(string.encodeUtf8(json.stringify(data)))
+
+/**
+ * @param {string} base64url
+ */
+const _parse = base64url => json.parse(string.decodeUtf8(buffer.fromBase64UrlEncoded(base64url)))
+
+/**
+ * @param {CryptoKey} privateKey
+ * @param {Object} payload
+ */
+export const encodeJwt = (privateKey, payload) => {
+  const { name: algName, namedCurve: algCurve } = /** @type {any} */ (privateKey.algorithm)
+  /* c8 ignore next 3 */
+  if (algName !== 'ECDSA' || algCurve !== 'P-384') {
+    error.unexpectedCase()
+  }
+  const header = {
+    alg: 'ES384',
+    typ: 'JWT'
+  }
+  const jwt = _stringify(header) + '.' + _stringify(payload)
+  return ecdsa.sign(privateKey, string.encodeUtf8(jwt)).then(signature =>
+    jwt + '.' + buffer.toBase64UrlEncoded(signature)
+  )
+}
+
+/**
+ * @param {CryptoKey} publicKey
+ * @param {string} jwt
+ */
+export const verifyJwt = async (publicKey, jwt) => {
+  const [headerBase64, payloadBase64, signatureBase64] = jwt.split('.')
+  const verified = await ecdsa.verify(publicKey, buffer.fromBase64UrlEncoded(signatureBase64), string.encodeUtf8(headerBase64 + '.' + payloadBase64))
+  /* c8 ignore next 3 */
+  if (!verified) {
+    throw new Error('Invalid JWT')
+  }
+  const payload = _parse(payloadBase64)
+  if (payload.exp != null && time.getUnixTime() > payload.exp) {
+    throw new Error('Expired JWT')
+  }
+  return {
+    header: _parse(headerBase64),
+    payload
+  }
+}
+
+/**
+ * Decode a jwt without verifying it. Probably a bad idea to use this. Only use if you know the jwt was already verified!
+ *
+ * @param {string} jwt
+ */
+export const unsafeDecode = jwt => {
+  const [headerBase64, payloadBase64] = jwt.split('.')
+  return {
+    header: _parse(headerBase64),
+    payload: _parse(payloadBase64)
+  }
+}