/*

 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.

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

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

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

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package sun.net.www.protocol.http;

import java.net.URL;

import java.net.URI;

import java.net.URISyntaxException;

import java.net.PasswordAuthentication;

import java.nio.ByteBuffer;

import java.nio.CharBuffer;

import java.nio.charset.Charset;

import java.io.IOException;

import java.io.OutputStream;

import java.util.Arrays;

import java.util.Base64;

import java.util.Objects;

import sun.net.www.HeaderParser;

import sun.nio.cs.ISO_8859_1;

import sun.nio.cs.UTF_8;

/**

 * BasicAuthentication: Encapsulate an http server authentication using

 * the "basic" scheme.

 *

 * @author Bill Foote

 */

class BasicAuthentication extends AuthenticationInfo {

    @java.io.Serial

    private static final long serialVersionUID = 100L;

    /** The authentication string for this host, port, and realm.  This is

        a simple BASE64 encoding of "login:password".    */

    final String auth;

    /**

     * Create a BasicAuthentication

     */

    public BasicAuthentication(boolean isProxy, String host, int port,

                               String realm, PasswordAuthentication pw,

                               boolean isUTF8, String authenticatorKey) {

        super(isProxy ? PROXY_AUTHENTICATION : SERVER_AUTHENTICATION,

              AuthScheme.BASIC, host, port, realm,

              Objects.requireNonNull(authenticatorKey));

        this.auth = authValueFrom(pw, isUTF8);

        this.pw = pw;

    }

    /**

     * Create a BasicAuthentication

     */

    public BasicAuthentication(boolean isProxy, String host, int port,

                               String realm, String auth,

                               String authenticatorKey) {

        super(isProxy ? PROXY_AUTHENTICATION : SERVER_AUTHENTICATION,

              AuthScheme.BASIC, host, port, realm,

              Objects.requireNonNull(authenticatorKey));

        this.auth = "Basic " + auth;

    }

    /**

     * Create a BasicAuthentication

     */

    public BasicAuthentication(boolean isProxy, URL url, String realm,

                               PasswordAuthentication pw, boolean isUTF8,

                               String authenticatorKey) {

        super(isProxy ? PROXY_AUTHENTICATION : SERVER_AUTHENTICATION,

              AuthScheme.BASIC, url, realm,

              Objects.requireNonNull(authenticatorKey));

        this.auth = authValueFrom(pw, isUTF8);

        this.pw = pw;

    }

    private static String authValueFrom(PasswordAuthentication pw, boolean isUTF8) {

        String plain = pw.getUserName() + ":";

        char[] password = pw.getPassword();

        CharBuffer cbuf = CharBuffer.allocate(plain.length() + password.length);

        cbuf.put(plain).put(password).flip();

        Charset charset = isUTF8 ? UTF_8.INSTANCE : ISO_8859_1.INSTANCE;

        ByteBuffer buf = charset.encode(cbuf);

        ByteBuffer enc = Base64.getEncoder().encode(buf);

        String ret = "Basic " + new String(enc.array(), enc.position(), enc.remaining(),

                ISO_8859_1.INSTANCE);

        Arrays.fill(buf.array(), (byte) 0);

        Arrays.fill(enc.array(), (byte) 0);

        Arrays.fill(cbuf.array(), (char) 0);

        return ret;

    }

    /**

     * Create a BasicAuthentication

     */

    public BasicAuthentication(boolean isProxy, URL url, String realm,

                               String auth, String authenticatorKey) {

        super(isProxy ? PROXY_AUTHENTICATION : SERVER_AUTHENTICATION,

              AuthScheme.BASIC, url, realm,

              Objects.requireNonNull(authenticatorKey));

        this.auth = "Basic " + auth;

    }

    /**

     * @return true if this authentication supports preemptive authorization

     */

    @Override

    public boolean supportsPreemptiveAuthorization() {

        return true;

    }

    /**

     * Set header(s) on the given connection. This will only be called for

     * definitive (i.e. non-preemptive) authorization.

     * @param conn The connection to apply the header(s) to

     * @param p A source of header values for this connection, if needed.

     * @param raw The raw header values for this connection, if needed.

     * @return true if all goes well, false if no headers were set.

     */

    @Override

    public boolean setHeaders(HttpURLConnection conn, HeaderParser p, String raw) {

        // no need to synchronize here:

        //   already locked by s.n.w.p.h.HttpURLConnection

        assert conn.isLockHeldByCurrentThread();

        conn.setAuthenticationProperty(getHeaderName(), getHeaderValue(null,null));

        return true;

    }

    /**

     * @return the value of the HTTP header this authentication wants set

     */

    @Override

    public String getHeaderValue(URL url, String method) {

        /* For Basic the authorization string does not depend on the request URL

         * or the request method

         */

        return auth;

    }

    /**

     * For Basic Authentication, the security parameters can never be stale.

     * In other words there is no possibility to reuse the credentials.

     * They are always either valid or invalid.

     */

    @Override

    public boolean isAuthorizationStale (String header) {

        return false;

    }

    /**

     * @return the common root path between npath and path.

     * This is used to detect when we have an authentication for two

     * paths and the root of th authentication space is the common root.

     */

    static String getRootPath(String npath, String opath) {

        int index = 0;

        int toindex;

        /* Must normalize so we don't get confused by ../ and ./ segments */

        try {

            npath = new URI (npath).normalize().getPath();

            opath = new URI (opath).normalize().getPath();

        } catch (URISyntaxException e) {

            /* ignore error and use the old value */

        }

        while (index < opath.length()) {

            toindex = opath.indexOf('/', index+1);

            if (toindex != -1 && opath.regionMatches(0, npath, 0, toindex+1))

                index = toindex;

            else

                return opath.substring(0, index+1);

        }

        /*should not reach here. If we do simply return npath*/

        return npath;

    }

}