package main import ( "errors" "fmt" "net/http" "sync" log "github.com/sirupsen/logrus" ) type authenticator interface { // AuthenticatorID needs to return an unique string to identify // this special authenticator AuthenticatorID() (id string) // Configure loads the configuration for the Authenticator from the // global config.yaml file which is passed as a byte-slice. // If no configuration for the Authenticator is supplied the function // needs to return the errAuthenticatorUnconfigured Configure(yamlSource []byte) (err error) // DetectUser is used to detect a user without a login form from // a cookie, header or other methods // If no user was detected the errNoValidUserFound needs to be // returned DetectUser(res http.ResponseWriter, r *http.Request) (user string, groups []string, err error) // Login is called when the user submits the login form and needs // to authenticate the user or throw an error. If the user has // successfully logged in the persistent cookie should be written // in order to use DetectUser for the next login. // If the user did not login correctly the errNoValidUserFound // needs to be returned Login(res http.ResponseWriter, r *http.Request) (err error) // LoginFields needs to return the fields required for this login // method. If no login using this method is possible the function // needs to return nil. LoginFields() (fields []loginField) // Logout is called when the user visits the logout endpoint and // needs to destroy any persistent stored cookies Logout(res http.ResponseWriter, r *http.Request) (err error) } type loginField struct { Label string Name string Placeholder string Type string } var ( errAuthenticatorUnconfigured = errors.New("No valid configuration found for this authenticator") errNoValidUserFound = errors.New("No valid users found") authenticatorRegistry = []authenticator{} authenticatorRegistryMutex sync.RWMutex activeAuthenticators = []authenticator{} ) func registerAuthenticator(a authenticator) { authenticatorRegistryMutex.Lock() defer authenticatorRegistryMutex.Unlock() authenticatorRegistry = append(authenticatorRegistry, a) } func initializeAuthenticators(yamlSource []byte) error { authenticatorRegistryMutex.Lock() defer authenticatorRegistryMutex.Unlock() for _, a := range authenticatorRegistry { err := a.Configure(yamlSource) switch err { case nil: activeAuthenticators = append(activeAuthenticators, a) log.WithFields(log.Fields{"authenticator": a.AuthenticatorID()}).Debug("Activated authenticator") case errAuthenticatorUnconfigured: log.WithFields(log.Fields{"authenticator": a.AuthenticatorID()}).Debug("Authenticator unconfigured") // This is okay. default: return fmt.Errorf("Authenticator configuration caused an error: %s", err) } } if len(activeAuthenticators) == 0 { return fmt.Errorf("No authenticator configurations supplied") } return nil } func detectUser(res http.ResponseWriter, r *http.Request) (string, []string, error) { authenticatorRegistryMutex.RLock() defer authenticatorRegistryMutex.RUnlock() for _, a := range activeAuthenticators { user, groups, err := a.DetectUser(res, r) switch err { case nil: return user, groups, err case errNoValidUserFound: // This is okay. default: return "", nil, err } } return "", nil, errNoValidUserFound } func loginUser(res http.ResponseWriter, r *http.Request) error { authenticatorRegistryMutex.RLock() defer authenticatorRegistryMutex.RUnlock() for _, a := range activeAuthenticators { err := a.Login(res, r) switch err { case nil: return nil case errNoValidUserFound: // This is okay. default: return err } } return errNoValidUserFound } func logoutUser(res http.ResponseWriter, r *http.Request) error { authenticatorRegistryMutex.RLock() defer authenticatorRegistryMutex.RUnlock() for _, a := range activeAuthenticators { if err := a.Logout(res, r); err != nil { return err } } return nil } func getFrontendAuthenticators() map[string][]loginField { authenticatorRegistryMutex.RLock() defer authenticatorRegistryMutex.RUnlock() output := map[string][]loginField{} for _, a := range activeAuthenticators { if len(a.LoginFields()) == 0 { continue } output[a.AuthenticatorID()] = a.LoginFields() } return output }