FIDO U2F Enroll Operation - iOS Example

Below is the code related to processing a FIDO U2F enroll operation.
SurePassIdU2F *u2f;

U2FClientSettings *settings = [[U2FClientSettings alloc]
                               initWithNavigationController:self.navigationController
                               fidoEndpointURL:serverUrl];

u2f = [[SurePassIdU2F alloc] initWithSettings:settings];

[u2f signUsername:usernameOrSessionToken
  fidoSignResultHandler:^(enum U2FResult result, NSString * _Nullable token) {
  switch (result) {
    case SUCCESS: {
      // FIDO Authentication succeeded.
      break;
    }
      
    case FALLBACK_AUTHENTICATION: {
      // The user wants to use fallback authentication instead of FIDO.
      // This will only happen if U2FClientSettings.allowFallbackAuthentication
      // is set to YES.
      break;
    }

    case CANCELED: {
      // The user canceled FIDO Authentication.
      break;
    }
  }
} fidoClientErrorHandler:^(NSString * _Nullable errorMessage) {
  // Handle FIDO Client errors.
} fidoServerErrorHandler:^(NSString * _Nullable errorMessage, int errorCode) {
  // Handle FIDO Server errors.
}];