Custom Authentication Module

public class CustomLoginModule implements javax.security.auth.spi.LoginModule {
  private Subject mySubject;
  private CallbackHandler myCallbackHandler;
  private Callback[] myCallbacks;
  private NameCallback myNameCallback;
  private PasswordCallback myPasswordCallback;

  public void initialize(Subject subject, CallbackHandler callbackHandler, Map<String, ?> sharedState, Map<String, ?> options) {
    // We should remember callback handler and create our own callbacks.
    // TeamCity authorization scheme supports two callbacks only: NameCallback and PasswordCallback.
    // From these callbacks you will receive username and password entered on the login page.
    myCallbackHandler = callbackHandler;
    myNameCallback = new NameCallback("login:");
    myPasswordCallback = new PasswordCallback("password:", false);
    // remember references to newly created callbacks
    myCallbacks = new Callback[]{myNameCallback, myPasswordCallback};

    // Subject is a place where authorized entity credentials are stored.
    // When user is successfully authorized, the jetbrains.buildServer.serverSide.auth.ServerPrincipal
    // instance should be added to the subject. Based on this information the principal server will know a real name of
    // the authorized entity and realm where this entity was authorized.
    mySubject = subject;
  }

  public boolean login() throws LoginException {
    // invoke callback handler so that username and password were added
    // to the name and password callbacks
    try {
      myCallbackHandler.handle(myCallbacks);
    }
    catch (Throwable t) {
      throw new jetbrains.buildServer.serverSide.auth.TeamCityLoginException(t);
    }

    // retrieve login and password
    final String login = myNameCallback.getName();
    final String password = new String(myPasswordCallback.getPassword());

    // perform authentication
    if (checkPassword(login, password)) {
    // create ServerPrincipal and put it in the subject
      mySubject.getPrincipals().add(new ServerPrincipal(null, login));
      return true;
    }

    throw new jetbrains.buildServer.serverSide.auth.TeamCityFailedLoginException();
  }

  private boolean checkPassword(final String login, final String password) {
    return true;
  }

  public boolean commit() throws LoginException {
    // simply return true
    return true;
  }

  public boolean abort() throws LoginException {
    return true;
  }

  public boolean logout() throws LoginException {
    return true;
  }
}

public class CustomLoginModuleDescriptor extends jetbrains.buildServer.serverSide.auth.LoginModuleDescriptorAdapter {
  // Spring framework will provide reference to LoginConfiguration when
  // the CustomLoginModuleDescriptor is instantiated
  public CustomLoginModuleDescriptor(LoginConfiguration loginConfiguration) {
    // register this descriptor in the login configuration
    loginConfiguration.registerLoginModule(this);
  }

  public String getName() {
    // return unique name of this module type. e.g. a derivative id will then be used in "auth-config.xml" file
    return "custom";
  }

  @Override
  public String getDisplayName() {
    // return presentable name of this plugin
    return "My custom authentication plugin";
  }

  @Override
  public String getDescription() {
    // return human-readable description of this module type
    return "Authentication via custom login module";
  }

  public Class<? extends LoginModule> getLoginModuleClass() {
    // return our custom login module class
    return CustomLoginModule.class;
  }

  @Override
  public Map<String, ?> getJAASOptions(final Map<String, String> properties) {
    // return options which can be passed to our custom login module
    // for example, we could store reference to SBuildServer instance here
    return null;
  }
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans default-autowire="constructor">
  <bean id="customLoginModuleDescriptor" class="some.package.CustomLoginModuleDescriptor"/>
</beans>

public class CustomHttpAuthenticationScheme extends jetbrains.buildServer.controllers.interceptors.auth.HttpAuthenticationSchemeAdapter {
  // Spring framework will provide reference to LoginConfiguration when
  // the CustomLoginModuleDescriptor is instantiated
  public CustomHttpAuthenticationScheme(final LoginConfiguration loginConfiguration) {
    // register this scheme in the login configuration
    loginConfiguration.registerAuthModuleType(this);
  }

  @Override
  protected String doGetName() {
    // return unique name of this module type. e.g. a derivative id will then be used in "auth-config.xml" file
    return "custom";
  }

  @Override
  public String getDisplayName() {
    // return presentable name of this plugin
    return "My custom HTTP authentication plugin";
  }

  @Override
  public String getDescription() {
    // return human-readable description of this module type
    return "Authentication via custom HTTP scheme";
  }

  // main method to process HTTP authentication
  @Override
  public HttpAuthenticationResult processAuthenticationRequest(final HttpServletRequest request,
                                                               final HttpServletResponse response,
                                                               final Map<String, String> properties) throws IOException {
    if (!isAttemptToAuthenticateViaThisHTTPScheme(request)) {
      return HttpAuthenticationResult.notApplicable();
    }

    // perform authentication
    final String username = authenticate(request);
    if (username == null) {
      return HttpAuthUtil.sendUnauthorized(request, response, "Failed to authenticate user", this, properties);
    }

    return HttpAuthenticationResult.authenticated(new ServerPrincipal(null, username), true);
  }
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans default-autowire="constructor">
  <bean id="customHttpAuthenticationScheme" class="some.package.CustomHttpAuthenticationScheme"/>
</beans>