AuthenticatorBase (Apache Tomcat 9.0.111 API Documentation)
Description: declaration: package: org.apache.catalina.authenticator, class: AuthenticatorBase

# Class AuthenticatorBase

java.lang.Object
org.apache.catalina.util.LifecycleBase
org.apache.catalina.util.LifecycleMBeanBase
org.apache.catalina.valves.ValveBase
org.apache.catalina.authenticator.AuthenticatorBase

All Implemented Interfaces:
  `MBeanRegistration, RegistrationListener, Authenticator, Contained, JmxEnabled, Lifecycle, Valve`

Direct Known Subclasses:
  `BasicAuthenticator, DigestAuthenticator, FormAuthenticator, NonLoginAuthenticator, SpnegoAuthenticator, SSLAuthenticator`

public abstract class AuthenticatorBase extends ValveBase implements Authenticator, RegistrationListener
Basic implementation of the Valve interface that enforces the `<security-constraint>` elements in the web application deployment descriptor. This functionality is implemented as a Valve so that it can be omitted in environments that do not require these features. Individual implementations of each supported authentication method can subclass this base class as required.

USAGE CONSTRAINT: When this class is utilized, the Context to which it is attached (or a parent Container in a hierarchy) must have an associated Realm that can be used for authenticating users and enumerating the roles to which they have been assigned.

USAGE CONSTRAINT: This Valve is only useful when processing HTTP requests. Requests of any other type will simply be passed through.

- ## Nested Class Summary

  Nested Classes
  Modifier and Type
  Class
  Description
  `protected static enum`
  `AuthenticatorBase.AllowCorsPreflight`

  ### Nested classes/interfaces inherited from interface Lifecycle

  `Lifecycle.SingleUse`

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `protected boolean`
  `alwaysUseSession`
  Should a session always be used once a user is authenticated?
  `protected static final String`
  `AUTH_HEADER_NAME`
  Authentication header
  `protected boolean`
  `cache`
  Should we cache authenticated Principals if the request is part of an HTTP session?
  `protected boolean`
  `changeSessionIdOnAuthentication`
  Should the session ID, if any, be changed upon a successful authentication to prevent a session fixation attack?
  `protected Context`
  `context`
  The Context to which this Valve is attached.
  `protected boolean`
  `disableProxyCaching`
  Flag to determine if we disable proxy caching, or leave the issue up to the webapp developer.
  `protected String`
  `jaspicCallbackHandlerClass`
  The name of the JASPIC callback handler class.
  `protected static final String`
  `REALM_NAME`
  Default authentication realm name.
  `protected boolean`
  `securePagesWithPragma`
  Flag to determine if we disable proxy caching with headers incompatible with IE.
  `protected String`
  `secureRandomAlgorithm`
  The name of the algorithm to use to create instances of `SecureRandom` which are used to generate SSO session IDs.
  `protected String`
  `secureRandomClass`
  The Java class name of the secure random number generator class to be used when generating SSO session identifiers.
  `protected String`
  `secureRandomProvider`
  The name of the provider to use to create instances of `SecureRandom` which are used to generate session SSO IDs.
  `protected boolean`
  `sendAuthInfoResponseHeaders`
  Should the auth information (remote user and auth type) be returned as response headers for a forwarded/proxied request?
  `protected SessionIdGeneratorBase`
  `sessionIdGenerator`
  `protected static final StringManager`
  `sm`
  The string manager for this package.
  `protected SingleSignOn`
  `sso`
  The SingleSignOn implementation in our request processing chain, if there is one.

  ### Fields inherited from class ValveBase

  `asyncSupported, container, containerLog, next`

  ### Fields inherited from class LifecycleMBeanBase

  `mserver`

  ### Fields inherited from interface Lifecycle

  `AFTER_DESTROY_EVENT, AFTER_INIT_EVENT, AFTER_START_EVENT, AFTER_STOP_EVENT, BEFORE_DESTROY_EVENT, BEFORE_INIT_EVENT, BEFORE_START_EVENT, BEFORE_STOP_EVENT, CONFIGURE_START_EVENT, CONFIGURE_STOP_EVENT, PERIODIC_EVENT, START_EVENT, STOP_EVENT`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `AuthenticatorBase()`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `protected boolean`
  `allowCorsPreflightBypass(Request request)`
  `protected void`
  `associate(String ssoId, Session session)`
  Associate the specified single sign on identifier with the specified Session.
  `boolean`
  `authenticate(Request request, HttpServletResponse httpResponse)`
  Authenticate the user making this request, based on the login configuration of the `Context` with which this Authenticator is associated.
  `protected String`
  `changeSessionID(Request request, Session session)`
  `protected boolean`
  `checkForCachedAuthentication(Request request, HttpServletResponse response, boolean useSSO)`
  Check to see if the user has already been authenticated earlier in the processing chain or if there is enough information available to authenticate the user without requiring further user interaction.
  `protected abstract boolean`
  `doAuthenticate(Request request, HttpServletResponse response)`
  Provided for subclasses to implement their specific authentication mechanism.
  `protected Principal`
  `doLogin(Request request, String username, String password)`
  Process the login request.
  `String`
  `getAllowCorsPreflight()`
  `boolean`
  `getAlwaysUseSession()`
  `protected abstract String`
  `getAuthMethod()`
  Return the authentication method, which is vendor-specific and not defined by HttpServletRequest.
  `boolean`
  `getCache()`
  Return the cache authenticated Principals flag.
  `boolean`
  `getChangeSessionIdOnAuthentication()`
  Return the flag that states if we should change the session ID of an existing session upon successful authentication.
  `Container`
  `getContainer()`
  Get the `Container` with which this instance is associated.
  `boolean`
  `getDisableProxyCaching()`
  Return the flag that states if we add headers to disable caching by proxies.
  `String`
  `getJaspicCallbackHandlerClass()`
  Return the JASPIC callback handler class name
  `protected static String`
  `getRealmName(Context context)`
  `boolean`
  `getSecurePagesWithPragma()`
  Return the flag that states, if proxy caching is disabled, what headers we add to disable the caching.
  `String`
  `getSecureRandomAlgorithm()`
  Return the secure random number generator algorithm name.
  `String`
  `getSecureRandomClass()`
  Return the secure random number generator class name.
  `String`
  `getSecureRandomProvider()`
  Return the secure random number generator provider name.
  `void`
  `invoke(Request request, Response response)`
  Enforce the security restrictions in the web application deployment descriptor of our associated Context.
  `protected boolean`
  `isContinuationRequired(Request request)`
  Does this authenticator require that `authenticate(Request, HttpServletResponse)` is called to continue an authentication process that started in a previous request?
  `protected boolean`
  `isPreemptiveAuthPossible(Request request)`
  Can the authenticator perform preemptive authentication for the given request?
  `boolean`
  `isSendAuthInfoResponseHeaders()`
  Returns the flag whether authentication information will be sent to a reverse proxy on a forwarded request.
  `void`
  `login(String username, String password, Request request)`
  `void`
  `logout(Request request)`
  `void`
  `notify(String layer, String appContext)`
  `protected boolean`
  `reauthenticateFromSSO(String ssoId, Request request)`
  Attempts reauthentication to the `Realm` using the credentials included in argument `entry`.
  `void`
  `register(Request request, HttpServletResponse response, Principal principal, String authType, String username, String password)`
  Register an authenticated Principal and authentication type in our request, in the current session (if there is one), and with our SingleSignOn valve, if there is one.
  `protected void`
  `register(Request request, HttpServletResponse response, Principal principal, String authType, String username, String password, boolean alwaysUseSession, boolean cache)`
  Register an authenticated Principal and authentication type in our request, in the current session (if there is one), and with our SingleSignOn valve, if there is one.
  `void`
  `setAllowCorsPreflight(String allowCorsPreflight)`
  `void`
  `setAlwaysUseSession(boolean alwaysUseSession)`
  `void`
  `setCache(boolean cache)`
  Set the cache authenticated Principals flag.
  `void`
  `setChangeSessionIdOnAuthentication(boolean changeSessionIdOnAuthentication)`
  Set the value of the flag that states if we should change the session ID of an existing session upon successful authentication.
  `void`
  `setContainer(Container container)`
  Set the `Container` with which this instance is associated.
  `void`
  `setDisableProxyCaching(boolean nocache)`
  Set the value of the flag that states if we add headers to disable caching by proxies.
  `void`
  `setJaspicCallbackHandlerClass(String jaspicCallbackHandlerClass)`
  Set the JASPIC callback handler class name
  `void`
  `setSecurePagesWithPragma(boolean securePagesWithPragma)`
  Set the value of the flag that states what headers we add to disable proxy caching.
  `void`
  `setSecureRandomAlgorithm(String secureRandomAlgorithm)`
  Set the secure random number generator algorithm name.
  `void`
  `setSecureRandomClass(String secureRandomClass)`
  Set the secure random number generator class name.
  `void`
  `setSecureRandomProvider(String secureRandomProvider)`
  Set the secure random number generator provider name.
  `void`
  `setSendAuthInfoResponseHeaders(boolean sendAuthInfoResponseHeaders)`
  Sets the flag whether authentication information will be sent to a reverse proxy on a forwarded request.
  `protected void`
  `startInternal()`
  Start this component and implement the requirements of `LifecycleBase.startInternal()`.
  `protected void`
  `stopInternal()`
  Stop this component and implement the requirements of `LifecycleBase.stopInternal()`.

  ### Methods inherited from class ValveBase

  `backgroundProcess, getDomainInternal, getNext, getObjectNameKeyProperties, initInternal, isAsyncSupported, setAsyncSupported, setNext, toString`

  ### Methods inherited from class LifecycleMBeanBase

  `destroyInternal, getDomain, getObjectName, postDeregister, postRegister, preDeregister, preRegister, register, setDomain, unregister, unregister`

  ### Methods inherited from class LifecycleBase

  `addLifecycleListener, destroy, findLifecycleListeners, fireLifecycleEvent, getState, getStateName, getThrowOnFailure, init, removeLifecycleListener, setState, setState, setThrowOnFailure, start, stop`

  ### Methods inherited from class Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- ## Field Details

  - ### sm

    protected static final StringManager sm
    The string manager for this package.

  - ### AUTH_HEADER_NAME

    protected static final String AUTH_HEADER_NAME
    Authentication header
    See Also:
      - Constant Field Values

  - ### REALM_NAME

    protected static final String REALM_NAME
    Default authentication realm name.
    See Also:
      - Constant Field Values

  - ### alwaysUseSession

    protected boolean alwaysUseSession
    Should a session always be used once a user is authenticated? This may offer some performance benefits since the session can then be used to cache the authenticated Principal, hence removing the need to authenticate the user via the Realm on every request. This may be of help for combinations such as BASIC authentication used with the JNDIRealm or DataSourceRealms. However, there will also be the performance cost of creating and GC'ing the session. By default, a session will not be created.

  - ### cache

    protected boolean cache
    Should we cache authenticated Principals if the request is part of an HTTP session?

  - ### changeSessionIdOnAuthentication

    protected boolean changeSessionIdOnAuthentication
    Should the session ID, if any, be changed upon a successful authentication to prevent a session fixation attack?

  - ### context

    protected Context context
    The Context to which this Valve is attached.

  - ### disableProxyCaching

    protected boolean disableProxyCaching
    Flag to determine if we disable proxy caching, or leave the issue up to the webapp developer.

  - ### securePagesWithPragma

    protected boolean securePagesWithPragma
    Flag to determine if we disable proxy caching with headers incompatible with IE.

  - ### secureRandomClass

    protected String secureRandomClass
    The Java class name of the secure random number generator class to be used when generating SSO session identifiers. The random number generator class must be self-seeding and have a zero-argument constructor. If not specified, an instance of `SecureRandom` will be generated.

  - ### secureRandomAlgorithm

    protected String secureRandomAlgorithm
    The name of the algorithm to use to create instances of `SecureRandom` which are used to generate SSO session IDs. If no algorithm is specified, SHA1PRNG is used. If SHA1PRNG is not available, the platform default will be used. To use the platform default (which may be SHA1PRNG), specify the empty string. If an invalid algorithm and/or provider is specified the SecureRandom instances will be created using the defaults. If that fails, the SecureRandom instances will be created using platform defaults.

  - ### secureRandomProvider

    protected String secureRandomProvider
    The name of the provider to use to create instances of `SecureRandom` which are used to generate session SSO IDs. If no provider is specified the platform default is used. If an invalid algorithm and/or provider is specified the SecureRandom instances will be created using the defaults. If that fails, the SecureRandom instances will be created using platform defaults.

  - ### jaspicCallbackHandlerClass

    protected String jaspicCallbackHandlerClass
    The name of the JASPIC callback handler class. If none is specified the default `CallbackHandlerImpl` will be used.

  - ### sendAuthInfoResponseHeaders

    protected boolean sendAuthInfoResponseHeaders
    Should the auth information (remote user and auth type) be returned as response headers for a forwarded/proxied request? When the `RemoteIpValve` or `RemoteIpFilter` mark a forwarded request with the `Globals.REQUEST_FORWARDED_ATTRIBUTE` this authenticator can return the values of `HttpServletRequest.getRemoteUser()` and `HttpServletRequest.getAuthType()` as response headers `remote-user` and `auth-type` to a reverse proxy. This is useful, e.g., for access log consistency or other decisions to make.

  - ### sessionIdGenerator

    protected SessionIdGeneratorBase sessionIdGenerator

  - ### sso

    protected SingleSignOn sso
    The SingleSignOn implementation in our request processing chain, if there is one.

- ## Constructor Details

  - ### AuthenticatorBase

    public AuthenticatorBase()

- ## Method Details

  - ### getRealmName

    protected static String getRealmName(Context context)

  - ### getAllowCorsPreflight

    public String getAllowCorsPreflight()

  - ### setAllowCorsPreflight

    public void setAllowCorsPreflight(String allowCorsPreflight)

  - ### getAlwaysUseSession

    public boolean getAlwaysUseSession()

  - ### setAlwaysUseSession

    public void setAlwaysUseSession(boolean alwaysUseSession)

  - ### getCache

    public boolean getCache()
    Return the cache authenticated Principals flag.
    Returns:
      `true` if authenticated Principals will be cached, otherwise `false`

  - ### setCache

    public void setCache(boolean cache)
    Set the cache authenticated Principals flag.
    Parameters:
      `cache` - The new cache flag

  - ### getContainer

    public Container getContainer()
    Description copied from interface: `Contained`
    Get the `Container` with which this instance is associated.
    Specified by:
      `getContainer` in interface `Contained`
    Overrides:
      `getContainer` in class `ValveBase`
    Returns:
      The Container with which this instance is associated or `null` if not associated with a Container

  - ### setContainer

    public void setContainer(Container container)
    Description copied from interface: `Contained`
    Set the `Container` with which this instance is associated.
    Specified by:
      `setContainer` in interface `Contained`
    Overrides:
      `setContainer` in class `ValveBase`
    Parameters:
      `container` - The Container instance with which this instance is to be associated, or `null` to disassociate this instance from any Container

  - ### getDisableProxyCaching

    public boolean getDisableProxyCaching()
    Return the flag that states if we add headers to disable caching by proxies.
    Returns:
      `true` if the headers will be added, otherwise `false`

  - ### setDisableProxyCaching

    public void setDisableProxyCaching(boolean nocache)
    Set the value of the flag that states if we add headers to disable caching by proxies.
    Parameters:
      `nocache` - `true` if we add headers to disable proxy caching, `false` if we leave the headers alone.

  - ### getSecurePagesWithPragma

    public boolean getSecurePagesWithPragma()
    Return the flag that states, if proxy caching is disabled, what headers we add to disable the caching.
    Returns:
      `true` if a Pragma header should be used, otherwise `false`

  - ### setSecurePagesWithPragma

    public void setSecurePagesWithPragma(boolean securePagesWithPragma)
    Set the value of the flag that states what headers we add to disable proxy caching.
    Parameters:
      `securePagesWithPragma` - `true` if we add headers which are incompatible with downloading office documents in IE under SSL but which fix a caching problem in Mozilla.

  - ### getChangeSessionIdOnAuthentication

    public boolean getChangeSessionIdOnAuthentication()
    Return the flag that states if we should change the session ID of an existing session upon successful authentication.
    Returns:
      `true` to change session ID upon successful authentication, `false` to do not perform the change.

  - ### setChangeSessionIdOnAuthentication

    public void setChangeSessionIdOnAuthentication(boolean changeSessionIdOnAuthentication)
    Set the value of the flag that states if we should change the session ID of an existing session upon successful authentication.
    Parameters:
      `changeSessionIdOnAuthentication` - `true` to change session ID upon successful authentication, `false` to do not perform the change.

  - ### getSecureRandomClass

    public String getSecureRandomClass()
    Return the secure random number generator class name.
    Returns:
      The fully qualified name of the SecureRandom implementation to use

  - ### setSecureRandomClass

    public void setSecureRandomClass(String secureRandomClass)
    Set the secure random number generator class name.
    Parameters:
      `secureRandomClass` - The new secure random number generator class name

  - ### getSecureRandomAlgorithm

    public String getSecureRandomAlgorithm()
    Return the secure random number generator algorithm name.
    Returns:
      The name of the SecureRandom algorithm used

  - ### setSecureRandomAlgorithm

    public void setSecureRandomAlgorithm(String secureRandomAlgorithm)
    Set the secure random number generator algorithm name.
    Parameters:
      `secureRandomAlgorithm` - The new secure random number generator algorithm name

  - ### getSecureRandomProvider

    public String getSecureRandomProvider()
    Return the secure random number generator provider name.
    Returns:
      The name of the SecureRandom provider

  - ### setSecureRandomProvider

    public void setSecureRandomProvider(String secureRandomProvider)
    Set the secure random number generator provider name.
    Parameters:
      `secureRandomProvider` - The new secure random number generator provider name

  - ### getJaspicCallbackHandlerClass

    public String getJaspicCallbackHandlerClass()
    Return the JASPIC callback handler class name
    Returns:
      The name of the JASPIC callback handler

  - ### setJaspicCallbackHandlerClass

    public void setJaspicCallbackHandlerClass(String jaspicCallbackHandlerClass)
    Set the JASPIC callback handler class name
    Parameters:
      `jaspicCallbackHandlerClass` - The new JASPIC callback handler class name

  - ### isSendAuthInfoResponseHeaders

    public boolean isSendAuthInfoResponseHeaders()
    Returns the flag whether authentication information will be sent to a reverse proxy on a forwarded request.
    Returns:
      `true` if response headers shall be sent, `false` otherwise

  - ### setSendAuthInfoResponseHeaders

    public void setSendAuthInfoResponseHeaders(boolean sendAuthInfoResponseHeaders)
    Sets the flag whether authentication information will be sent to a reverse proxy on a forwarded request.
    Parameters:
      `sendAuthInfoResponseHeaders` - `true` if response headers shall be sent, `false` otherwise

  - ### invoke

    public void invoke(Request request, Response response) throws IOException, ServletException
    Enforce the security restrictions in the web application deployment descriptor of our associated Context.
    Specified by:
      `invoke` in interface `Valve`
    Parameters:
      `request` - Request to be processed
      `response` - Response to be processed
    Throws:
      `IOException` - if an input/output error occurs
      `ServletException` - if thrown by a processing element

  - ### allowCorsPreflightBypass

    protected boolean allowCorsPreflightBypass(Request request)

  - ### authenticate

    public boolean authenticate(Request request, HttpServletResponse httpResponse) throws IOException
    Description copied from interface: `Authenticator`
    Authenticate the user making this request, based on the login configuration of the `Context` with which this Authenticator is associated.
    Specified by:
      `authenticate` in interface `Authenticator`
    Parameters:
      `request` - Request we are processing
      `httpResponse` - Response we are populating
    Returns:
      `true` if any specified constraints have been satisfied, or `false` if one more constraints were not satisfied (in which case an authentication challenge will have been written to the response).
    Throws:
      `IOException` - if an input/output error occurs

  - ### doAuthenticate

    protected abstract boolean doAuthenticate(Request request, HttpServletResponse response) throws IOException
    Provided for subclasses to implement their specific authentication mechanism.
    Parameters:
      `request` - The request that triggered the authentication
      `response` - The response associated with the request
    Returns:
      `true` if the user was authenticated, otherwise `false`, in which case an authentication challenge will have been written to the response
    Throws:
      `IOException` - If an I/O problem occurred during the authentication process

  - ### isContinuationRequired

    protected boolean isContinuationRequired(Request request)
    Does this authenticator require that `authenticate(Request, HttpServletResponse)` is called to continue an authentication process that started in a previous request?
    Parameters:
      `request` - The request currently being processed
    Returns:
      `true` if authenticate() must be called, otherwise `false`

  - ### associate

    protected void associate(String ssoId, Session session)
    Associate the specified single sign on identifier with the specified Session.
    Parameters:
      `ssoId` - Single sign on identifier
      `session` - Session to be associated

  - ### checkForCachedAuthentication

    protected boolean checkForCachedAuthentication(Request request, HttpServletResponse response, boolean useSSO)
    Check to see if the user has already been authenticated earlier in the processing chain or if there is enough information available to authenticate the user without requiring further user interaction.
    Parameters:
      `request` - The current request
      `response` - The current response
      `useSSO` - Should information available from SSO be used to attempt to authenticate the current user?
    Returns:
      `true` if the user was authenticated via the cache, otherwise `false`

  - ### reauthenticateFromSSO

    protected boolean reauthenticateFromSSO(String ssoId, Request request)
    Attempts reauthentication to the `Realm` using the credentials included in argument `entry`.
    Parameters:
      `ssoId` - identifier of SingleSignOn session with which the caller is associated
      `request` - the request that needs to be authenticated
    Returns:
      `true` if the reauthentication from SSL occurred

  - ### register

    public void register(Request request, HttpServletResponse response, Principal principal, String authType, String username, String password)
    Register an authenticated Principal and authentication type in our request, in the current session (if there is one), and with our SingleSignOn valve, if there is one. Set the appropriate cookie to be returned.
    Parameters:
      `request` - The servlet request we are processing
      `response` - The servlet response we are generating
      `principal` - The authenticated Principal to be registered
      `authType` - The authentication type to be registered
      `username` - Username used to authenticate (if any)
      `password` - Password used to authenticate (if any)

  - ### register

    protected void register(Request request, HttpServletResponse response, Principal principal, String authType, String username, String password, boolean alwaysUseSession, boolean cache)
    Register an authenticated Principal and authentication type in our request, in the current session (if there is one), and with our SingleSignOn valve, if there is one. Set the appropriate cookie to be returned.
    Parameters:
      `request` - The servlet request we are processing
      `response` - The servlet response we are generating
      `principal` - The authenticated Principal to be registered
      `authType` - The authentication type to be registered
      `username` - Username used to authenticate (if any)
      `password` - Password used to authenticate (if any)
      `alwaysUseSession` - Should a session always be used once a user is authenticated?
      `cache` - Should we cache authenticated Principals if the request is part of an HTTP session?

  - ### changeSessionID

    protected String changeSessionID(Request request, Session session)

  - ### login

    public void login(String username, String password, Request request) throws ServletException
    Specified by:
      `login` in interface `Authenticator`
    Throws:
      `ServletException`

  - ### getAuthMethod

    protected abstract String getAuthMethod()
    Return the authentication method, which is vendor-specific and not defined by HttpServletRequest.
    Returns:
      the authentication method, which is vendor-specific and not defined by HttpServletRequest.

  - ### doLogin

    protected Principal doLogin(Request request, String username, String password) throws ServletException
    Process the login request.
    Parameters:
      `request` - Associated request
      `username` - The user
      `password` - The password
    Returns:
      The authenticated Principal
    Throws:
      `ServletException` - No principal was authenticated with the specified credentials

  - ### logout

    public void logout(Request request)
    Specified by:
      `logout` in interface `Authenticator`

  - ### startInternal

    protected void startInternal() throws LifecycleException
    Description copied from class: `ValveBase`
    Start this component and implement the requirements of `LifecycleBase.startInternal()`.
    Overrides:
      `startInternal` in class `ValveBase`
    Throws:
      `LifecycleException` - if this component detects a fatal error that prevents this component from being used

  - ### stopInternal

    protected void stopInternal() throws LifecycleException
    Description copied from class: `ValveBase`
    Stop this component and implement the requirements of `LifecycleBase.stopInternal()`.
    Overrides:
      `stopInternal` in class `ValveBase`
    Throws:
      `LifecycleException` - if this component detects a fatal error that prevents this component from being used

  - ### isPreemptiveAuthPossible

    protected boolean isPreemptiveAuthPossible(Request request)
    Can the authenticator perform preemptive authentication for the given request?
    Parameters:
      `request` - The request to check for credentials
    Returns:
      `true` if preemptive authentication is possible, otherwise `false`

  - ### notify

    public void notify(String layer, String appContext)
    Specified by:
      `notify` in interface `RegistrationListener`