Function validate

src/common/roles.cpp:85–141

Option<Error> validate(const string& role)
{
  // We check * explicitly first as a performance improvement.
  static const string* star = new string("*");
  if (role == *star) {
    return None();
  }

  if (strings::startsWith(role, '/')) {
    return Error("Role '" + role + "' cannot start with a slash");
  }

  if (strings::endsWith(role, '/')) {
    return Error("Role '" + role + "' cannot end with a slash");
  }

  if (strings::contains(role, "//")) {
    return Error("Role '" + role + "' cannot contain two adjacent slashes");
  }

  // Validate each component in the role path.
  vector<string> components = strings::tokenize(role, "/");
  if (components.empty()) {
    return Error("Role names cannot be the empty string");
  }

  static const string* dot = new string(".");
  static const string* dotdot = new string("..");

  foreach (const string& component, components) {
    CHECK(!component.empty()); // `tokenize` does not return empty tokens.

    if (component == *dot) {
      return Error("Role '" + role + "' cannot include '.' as a component");
    }

    if (component == *dotdot) {
      return Error("Role '" + role + "' cannot include '..' as a component");
    }

    if (component == *star) {
      return Error("Role '" + role + "' cannot include '*' as a component");
    }

    if (strings::startsWith(component, '-')) {
      return Error("Role component '" + component + "' is invalid "
                   "because it starts with a dash");
    }

    if (component.find_first_of(*INVALID_CHARACTERS) != string::npos) {
      return Error("Role component '" + component + "' is invalid "
                   "because it contains backspace or whitespace");
    }
  }

  return None();
}