# Class BasicAuthenticator

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

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

public class BasicAuthenticator extends AuthenticatorBase
An Authenticator and Valve implementation of HTTP BASIC Authentication, as outlined in RFC 7617: "The 'Basic' HTTP Authentication Scheme"

- ## Nested Class Summary

  Nested Classes
  Modifier and Type
  Class
  Description
  `static class`
  `BasicAuthenticator.BasicCredentials`
  Parser for an HTTP Authorization header for BASIC authentication as per RFC 2617 section 2, and the Base64 encoded credentials as per RFC 2045 section 6.8.

  ### Nested classes/interfaces inherited from class AuthenticatorBase

  `AuthenticatorBase.AllowCorsPreflight, AuthenticatorBase.SsoReauthenticationMode`

  ### Nested classes/interfaces inherited from interface Lifecycle

  `Lifecycle.SingleUse`

- ## Field Summary

  ### Fields inherited from class AuthenticatorBase

  `alwaysUseSession, AUTH_HEADER_NAME, cache, changeSessionIdOnAuthentication, context, disableProxyCaching, jaspicCallbackHandlerClass, REALM_NAME, securePagesWithPragma, secureRandomAlgorithm, secureRandomClass, secureRandomProvider, sendAuthInfoResponseHeaders, sessionIdGenerator, sm, sso`

  ### 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
  `BasicAuthenticator()`
  Default constructor.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `protected boolean`
  `doAuthenticate(Request request, HttpServletResponse response)`
  Provided for subclasses to implement their specific authentication mechanism.
  `protected String`
  `getAuthMethod()`
  Return the authentication method, which is vendor-specific and not defined by HttpServletRequest.
  `String`
  `getCharset()`
  Returns the character set used for encoding credentials, as set by the user.
  `boolean`
  `getTrimCredentials()`
  Deprecated.
  Will be removed in Tomcat 11 onwards.
  `protected boolean`
  `isPreemptiveAuthPossible(Request request)`
  Can the authenticator perform preemptive authentication for the given request?
  `void`
  `setCharset(String charsetString)`
  Sets the character set used for encoding credentials.
  `void`
  `setTrimCredentials(boolean trimCredentials)`
  Deprecated.
  Will be removed in Tomcat 11 onwards.

  ### Methods inherited from class AuthenticatorBase

  `allowCorsPreflightBypass, associate, authenticate, changeSessionID, checkForCachedAuthentication, doLogin, getAllowCorsPreflight, getAlwaysUseSession, getCache, getChangeSessionIdOnAuthentication, getContainer, getDisableProxyCaching, getJaspicCallbackHandlerClass, getRealmName, getSecurePagesWithPragma, getSecureRandomAlgorithm, getSecureRandomClass, getSecureRandomProvider, getSsoReauthenticationMode, invoke, isContinuationRequired, isSendAuthInfoResponseHeaders, login, logout, notify, reauthenticateFromSSO, register, register, setAllowCorsPreflight, setAlwaysUseSession, setCache, setChangeSessionIdOnAuthentication, setContainer, setDisableProxyCaching, setJaspicCallbackHandlerClass, setSecurePagesWithPragma, setSecureRandomAlgorithm, setSecureRandomClass, setSecureRandomProvider, setSendAuthInfoResponseHeaders, setSsoReauthenticationMode, startInternal, 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`

- ## Constructor Details

  - ### BasicAuthenticator

    public BasicAuthenticator()
    Default constructor.

- ## Method Details

  - ### getCharset

    public String getCharset()
    Returns the character set used for encoding credentials, as set by the user.
    Returns:
      the character set name, the default value is "UTF-8"

  - ### setCharset

    public void setCharset(String charsetString)
    Sets the character set used for encoding credentials. Empty charsets will set ISO-8859-1.
    Parameters:
      `charsetString` - the character set name
    Throws:
      `IllegalArgumentException` - if the charset is not supported

  - ### getTrimCredentials

    @Deprecated public boolean getTrimCredentials()
    Deprecated.
    Will be removed in Tomcat 11 onwards.
    Obtain the current setting for the removal of whitespace around the decoded user name and password.
    Returns:
      `true` if white space will be removed around the decoded user name and password

  - ### setTrimCredentials

    @Deprecated public void setTrimCredentials(boolean trimCredentials)
    Deprecated.
    Will be removed in Tomcat 11 onwards.
    Configures trimming of whitespace around the decoded user name and password.
    Parameters:
      `trimCredentials` - `true` to remove white space around the decoded user name and password

  - ### doAuthenticate

    protected boolean doAuthenticate(Request request, HttpServletResponse response) throws IOException
    Description copied from class: `AuthenticatorBase`
    Provided for subclasses to implement their specific authentication mechanism.
    Specified by:
      `doAuthenticate` in class `AuthenticatorBase`
    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

  - ### getAuthMethod

    protected String getAuthMethod()
    Description copied from class: `AuthenticatorBase`
    Return the authentication method, which is vendor-specific and not defined by HttpServletRequest.
    Specified by:
      `getAuthMethod` in class `AuthenticatorBase`
    Returns:
      the authentication method, which is vendor-specific and not defined by HttpServletRequest.

  - ### isPreemptiveAuthPossible

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