/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.karaf.webconsole;

import java.io.IOException;
import java.security.GeneralSecurityException;

import javax.security.auth.Subject;
import javax.security.auth.callback.Callback;
import javax.security.auth.callback.CallbackHandler;
import javax.security.auth.callback.NameCallback;
import javax.security.auth.callback.PasswordCallback;
import javax.security.auth.callback.UnsupportedCallbackException;
import javax.security.auth.login.AccountException;
import javax.security.auth.login.FailedLoginException;
import javax.security.auth.login.LoginContext;

import org.apache.felix.webconsole.WebConsoleSecurityProvider;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class JaasSecurityProvider implements WebConsoleSecurityProvider {

	private static final Logger LOG = LoggerFactory.getLogger(WebConsoleSecurityProvider.class);

    private String realm;

    public String getRealm() {
        return realm;
    }

    public void setRealm(String realm) {
        this.realm = realm;
    }

    public Object authenticate(final String username, final String password) {
        try {
            Subject subject = new Subject();
            LoginContext loginContext = new LoginContext(realm, subject, new CallbackHandler() {
                public void handle(Callback[] callbacks) throws IOException, UnsupportedCallbackException {
                    for (int i = 0; i < callbacks.length; i++) {
                        if (callbacks[i] instanceof NameCallback) {
                            ((NameCallback) callbacks[i]).setName(username);
                        } else if (callbacks[i] instanceof PasswordCallback) {
                            ((PasswordCallback) callbacks[i]).setPassword(password.toCharArray());
                        } else {
                            throw new UnsupportedCallbackException(callbacks[i]);
                        }
                    }
                }
            });
            loginContext.login();
            return subject;
        } catch (FailedLoginException e) {
            LOG.debug("Login failed", e);
            return null;
        } catch (AccountException e) {
            LOG.warn("Account failure", e);
            return null;
        } catch (GeneralSecurityException e) {
            LOG.error("General Security Exception", e);
            return null;
        }
    }

    public boolean authorize(Object o, String s) {
        return true;
    }
}
