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package com.sun.enterprise.security.jauth;

/**
 * This ClientAuthContext class manages AuthModules that may be used
 * to secure requests made as a client.  A caller typically uses this class
 * in the following manner:
 *
 * <ol>
 * <li> Retrieve an instance of this class via AuthConfig.getClientAuthContext.
 * <li> Invoke <i>secureRequest</i>.
 *	<br>
 *	ClientAuthContext implementation invokes configured plug-in modules.
 *	Modules attach credentials to initial request object
 *	(for example, a username and password), and/or secure the request
 *      (for example, sign and encrypt the request).
 * <li> Issue request.
 * <li> Receive response and pass it to <i>validateResponse</i>.
 *	<br>
 *	ClientAuthContext implementation invokes configured plug-in modules.
 *	Modules verify or decrypt response as necessary.
 * <li> The <i>disposeSubject</i> method may be invoked if necessary
 *	to clean up any authentication state in the Subject.
 * </ol>
 * 
 * <p> An instance may reuse module instances it
 * previously created. As a result a single module instance may be used
 * to issue different requests as different clients.
 * It is the module implementation's responsibility to properly
 * store and restore any necessary state.  A module that does not need
 * to do so may remain completely stateless.
 *
 * <p> Instances of this class have custom logic to determine
 * what modules to invoke, and in what order.  In addition,
 * this custom logic may control whether subsequent modules are invoked
 * based on the success or failure of previously invoked modules.
 *
 * <p> The caller is responsible for passing in a state Map
 * that can be used by underlying modules to save state across
 * a sequence of calls from <code>secureRequest</code>
 * to <code>validateResponse</code> to <code>disposeSubject</code>.
 * The same Map instance must be passed to all methods in the call sequence.
 * Furthermore, each call sequence should be passed its own unique
 * shared state Map instance.
 *
 * @version %I%, %G%
 * @see AuthConfig
 * @see SOAPAuthParam
 */
public interface ClientAuthContext {

    /**
     * Secure a request message.
     *
     * <p> Attach authentication credentials to an initial request,
     * sign/encrypt a request, or respond to a server challenge, for example.
     *
     * <p> This method invokes configured modules to secure the request.
     *
     * @param param an authentication parameter that encapsulates the
     *		client request and server response objects.
     *
     * @param subject the subject may be used by configured modules
     *		to obtain Principals and credentials necessary to
     *		secure the request, or null.  If null, the module may
     *		use a CallbackHandler to obtain any information necessary
     *		to secure the request.
     *
     * @param sharedState a Map for modules to save state across
     *		a sequence of calls from <code>secureRequest</code>
     *		to <code>validateResponse</code> to <code>disposeSubject</code>.
     *
     * @exception AuthException if the operation failed.
     */
    void secureRequest(AuthParam param,
			javax.security.auth.Subject subject,
			java.util.Map sharedState)
		throws AuthException;

    /**
     * Validate received response.
     *
     * <p> Validation may include verifying signature in response,
     * or decrypting response contents, for example.
     * 
     * <p> This method invokes configured modules to validate the response.
     *
     * @param param an authentication parameter that encapsulates the
     *		client request and server response objects.
     *
     * @param subject the subject may be used by configured modules
     *		to store the Principals and credentials related
     *		to the identity validated in the response.
     *
     * @param sharedState a Map for modules to save state across
     *		a sequence of calls from <code>secureRequest</code>
     *		to <code>validateResponse</code> to <code>disposeSubject</code>.
     *
     * @exception AuthException if the operation failed.
     */
    void validateResponse(AuthParam param,
			javax.security.auth.Subject subject,
			java.util.Map sharedState)
		throws AuthException;

    /**
     * Dispose of the Subject
     * (remove Principals or credentials from the Subject object
     * that were stored during <code>validateResponse</code>).
     *
     * <p> This method invokes configured modules to dispose the Subject.
     *
     * @param subject the subject to be disposed.
     *
     * @param sharedState a Map for modules to save state across
     *		a sequence of calls from <code>secureRequest</code>
     *		to <code>validateResponse</code> to <code>disposeSubject</code>.
     *
     * @exception AuthException if the operation failed.
     */
    void disposeSubject(javax.security.auth.Subject subject,
			java.util.Map sharedState)
		throws AuthException;
}