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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

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 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

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package javax.security.sasl;

import java.util.Map;

import javax.security.auth.callback.CallbackHandler;

/**

 * An interface for creating instances of {@code SaslClient}.

 * A class that implements this interface

 * must be thread-safe and handle multiple simultaneous

 * requests. It must also have a public constructor that accepts no

 * argument.

 *<p>

 * This interface is not normally accessed directly by a client, which will use the

 * {@code Sasl} static methods

 * instead. However, a particular environment may provide and install a

 * new or different {@code SaslClientFactory}.

 *

 * @since 1.5

 *

 * @see SaslClient

 * @see Sasl

 *

 * @author Rosanna Lee

 * @author Rob Weltman

 */

public abstract interface SaslClientFactory {

    /**

     * Creates a SaslClient using the parameters supplied.

     *

     * @param mechanisms The non-null list of mechanism names to try. Each is the

     * IANA-registered name of a SASL mechanism. (e.g. "GSSAPI", "CRAM-MD5").

     * @param authorizationId The possibly null protocol-dependent

     * identification to be used for authorization.

     * If null or empty, the server derives an authorization

     * ID from the client's authentication credentials.

     * When the SASL authentication completes successfully,

     * the specified entity is granted access.

     * @param protocol The non-null string name of the protocol for which

     * the authentication is being performed (e.g., "ldap").

     * @param serverName The non-null fully qualified host name

     * of the server to authenticate to.

     * @param props The possibly null set of properties used to select the SASL

     * mechanism and to configure the authentication exchange of the selected

     * mechanism. See the {@code Sasl} class for a list of standard properties.

     * Other, possibly mechanism-specific, properties can be included.

     * Properties not relevant to the selected mechanism are ignored,

     * including any map entries with non-String keys.

     *

     * @param cbh The possibly null callback handler to used by the SASL

     * mechanisms to get further information from the application/library

     * to complete the authentication. For example, a SASL mechanism might

     * require the authentication ID, password and realm from the caller.

     * The authentication ID is requested by using a {@code NameCallback}.

     * The password is requested by using a {@code PasswordCallback}.

     * The realm is requested by using a {@code RealmChoiceCallback} if there is a list

     * of realms to choose from, and by using a {@code RealmCallback} if

     * the realm must be entered.

     *

     *@return A possibly null {@code SaslClient} created using the parameters

     * supplied. If null, this factory cannot produce a {@code SaslClient}

     * using the parameters supplied.

     *@exception SaslException If cannot create a {@code SaslClient} because

     * of an error.

     */

    public abstract SaslClient createSaslClient(

        String[] mechanisms,

        String authorizationId,

        String protocol,

        String serverName,

        Map<String,?> props,

        CallbackHandler cbh) throws SaslException;

    /**

     * Returns an array of names of mechanisms that match the specified

     * mechanism selection policies.

     * @param props The possibly null set of properties used to specify the

     * security policy of the SASL mechanisms. For example, if {@code props}

     * contains the {@code Sasl.POLICY_NOPLAINTEXT} property with the value

     * {@code "true"}, then the factory must not return any SASL mechanisms

     * that are susceptible to simple plain passive attacks.

     * See the {@code Sasl} class for a complete list of policy properties.

     * Non-policy related properties, if present in {@code props}, are ignored,

     * including any map entries with non-String keys.

     * @return A non-null array containing a IANA-registered SASL mechanism names.

     */

    public abstract String[] getMechanismNames(Map<String,?> props);

}