/*

 * 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package sun.security.ssl;

import java.math.BigInteger;

import java.util.*;

import java.util.regex.Pattern;

import javax.net.ssl.*;

import sun.net.util.IPAddressUtil;

import sun.security.action.GetPropertyAction;

/**

 * A utility class to share the static methods.

 */

final class Utilities {

    static final char[] hexDigits = "0123456789ABCDEF".toCharArray();

    private static final String indent = "  ";

    private static final Pattern lineBreakPatern =

                Pattern.compile("\\r\\n|\\n|\\r");

    /**

     * Puts {@code hostname} into the {@code serverNames} list.

     * <P>

     * If the {@code serverNames} does not look like a legal FQDN, it will

     * not be put into the returned list.

     * <P>

     * Note that the returned list does not allow duplicated name type.

     *

     * @return a list of {@link SNIServerName}

     */

    static List<SNIServerName> addToSNIServerNameList(

            List<SNIServerName> serverNames, String hostname) {

        SNIHostName sniHostName = rawToSNIHostName(hostname);

        if (sniHostName == null) {

            return serverNames;

        }

        int size = serverNames.size();

        List<SNIServerName> sniList = (size != 0) ?

        boolean reset = false;

        for (int i = 0; i < size; i++) {

            SNIServerName serverName = sniList.get(i);

            if (serverName.getType() == StandardConstants.SNI_HOST_NAME) {

                sniList.set(i, sniHostName);

                if (SSLLogger.isOn && SSLLogger.isOn("ssl")) {

                     SSLLogger.fine(

                        "the previous server name in SNI (" + serverName +

                        ") was replaced with (" + sniHostName + ")");

                }

                reset = true;

                break;

            }

        }

        if (!reset) {

            sniList.add(sniHostName);

        }

        return Collections.<SNIServerName>unmodifiableList(sniList);

    }

    /**

     * Converts string hostname to {@code SNIHostName}.

     * <P>

     * Note that to check whether a hostname is a valid domain name, we cannot

     * use the hostname resolved from name services.  For virtual hosting,

     * multiple hostnames may be bound to the same IP address, so the hostname

     * resolved from name services is not always reliable.

     *

     * @param  hostname

     *         the raw hostname

     * @return an instance of {@link SNIHostName}, or null if the hostname does

     *         not look like a FQDN

     */

    private static SNIHostName rawToSNIHostName(String hostname) {

        SNIHostName sniHostName = null;

        if (hostname != null && hostname.indexOf('.') > 0 &&

                !hostname.endsWith(".") &&

                !IPAddressUtil.isIPv4LiteralAddress(hostname) &&

                !IPAddressUtil.isIPv6LiteralAddress(hostname)) {

            try {

                sniHostName = new SNIHostName(hostname);

            } catch (IllegalArgumentException iae) {

                // don't bother to handle illegal host_name

                if (SSLLogger.isOn && SSLLogger.isOn("ssl")) {

                     SSLLogger.fine(hostname + "\" " +

                        "is not a legal HostName for  server name indication");

                }

            }

        }

        return sniHostName;

    }

    /**

     * Return the value of the boolean System property propName.

     *

     * Note use of privileged action. Do NOT make accessible to applications.

     */

    static boolean getBooleanProperty(String propName, boolean defaultValue) {

        // if set, require value of either true or false

        String b = GetPropertyAction.privilegedGetProperty(propName);

        if (b == null) {

            return defaultValue;

        } else if (b.equalsIgnoreCase("false")) {

            return false;

        } else if (b.equalsIgnoreCase("true")) {

            return true;

        } else {

            throw new RuntimeException("Value of " + propName

                + " must either be 'true' or 'false'");

        }

    }

    static String indent(String source) {

        return Utilities.indent(source, indent);

    }

    static String indent(String source, String prefix) {

        StringBuilder builder = new StringBuilder();

        if (source == null) {

        } else {

            String[] lines = lineBreakPatern.split(source);

            boolean isFirst = true;

            for (String line : lines) {

                if (isFirst) {

                    isFirst = false;

                } else {

                    builder.append("\n");

                }

                builder.append(prefix).append(line);

            }

        }

        return builder.toString();

    }

    static String toHexString(byte b) {

        return String.valueOf(hexDigits[(b >> 4) & 0x0F]) +

                String.valueOf(hexDigits[b & 0x0F]);

    }

    static String byte16HexString(int id) {

        return "0x" +

                hexDigits[(id >> 12) & 0x0F] + hexDigits[(id >> 8) & 0x0F] +

                hexDigits[(id >> 4) & 0x0F] + hexDigits[id & 0x0F];

    }

    static String toHexString(byte[] bytes) {

        if (bytes == null || bytes.length == 0) {

            return "";

        }

        StringBuilder builder = new StringBuilder(bytes.length * 3);

        boolean isFirst = true;

        for (byte b : bytes) {

            if (isFirst) {

                isFirst = false;

            } else {

                builder.append(' ');

            }

            builder.append(hexDigits[(b >> 4) & 0x0F]);

            builder.append(hexDigits[b & 0x0F]);

        }

        return builder.toString();

    }

    static String toHexString(long lv) {

        StringBuilder builder = new StringBuilder(128);

        boolean isFirst = true;

        do {

            if (isFirst) {

                isFirst = false;

            } else {

                builder.append(' ');

            }

            builder.append(hexDigits[(int)(lv & 0x0F)]);

            lv >>>= 4;

            builder.append(hexDigits[(int)(lv & 0x0F)]);

            lv >>>= 4;

        } while (lv != 0);

        builder.reverse();

        return builder.toString();

    }

    /**

     * Utility method to convert a BigInteger to a byte array in unsigned

     * format as needed in the handshake messages. BigInteger uses

     * 2's complement format, i.e. it prepends an extra zero if the MSB

     * is set. We remove that.

     */

    static byte[] toByteArray(BigInteger bi) {

        byte[] b = bi.toByteArray();

        if ((b.length > 1) && (b[0] == 0)) {

            int n = b.length - 1;

            byte[] newarray = new byte[n];

            System.arraycopy(b, 1, newarray, 0, n);

            b = newarray;

        }

        return b;

    }

}