decodeJwt function

Map decodeJwt(String jwt)

Implementation

Map decodeJwt(String jwt) {
  List<String> parts = jwt.split('.');
  if (parts.length == 5) {
    throw 'Only JWTs using Compact JWS serialization can be decoded';
  }
  if (parts.length != 3) {
    throw 'Invalid JWT';
  }

  String payload = parts[1];
  if (payload.isEmpty) {
    throw 'JWTs must contain a payload';
  }

  Uint8List decoded;
  try {
    decoded = base64Url.decode(base64Url.normalize(payload));
  } catch (_) {
    throw 'Failed to base64url decode the payload';
  }

  try {
    String jsonPayload = utf8.decode(decoded);
    Map<String, dynamic> result = jsonDecode(jsonPayload);
    return result;
  } catch (e) {
    throw 'Failed to decode JWT: $e';
  }
}