001/**
002 *
003 * Copyright © 2014-2019 Florian Schmaus
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.jivesoftware.smack.util.stringencoder;
018
019import java.nio.charset.StandardCharsets;
020
021import org.jivesoftware.smack.util.Objects;
022import org.jivesoftware.smack.util.StringUtils;
023
024public class Base64 {
025
026    private static Base64.Encoder base64encoder;
027
028    public static void setEncoder(Base64.Encoder encoder) {
029        Objects.requireNonNull(encoder, "encoder must no be null");
030        base64encoder = encoder;
031    }
032
033    public static final String encode(String string) {
034        return encodeToString(string.getBytes(StandardCharsets.UTF_8));
035    }
036
037    public static final String encodeToString(byte[] input) {
038        return base64encoder.encodeToString(input);
039    }
040
041    public static final String encodeToString(byte[] input, int offset, int len) {
042        return encodeToString(slice(input, offset, len));
043    }
044
045    public static final String encodeToStringWithoutPadding(byte[] input) {
046        return base64encoder.encodeToStringWithoutPadding(input);
047    }
048
049    public static final byte[] encode(byte[] input) {
050        return base64encoder.encode(input);
051    }
052
053    public static final String decodeToString(String string) {
054        byte[] bytes = decode(string);
055        return new String(bytes, StandardCharsets.UTF_8);
056    }
057
058    // TODO: We really should not mask the IllegalArgumentException. But some unit test depend on this behavior, like
059    // ibb.packet.DataPacketExtension.shouldReturnNullIfDataIsInvalid().
060    public static final byte[] decode(String string) {
061        // xs:base64Binary may include XML whitespace which we need to delete before feeding the string into the Base64
062        // decoder. See also XML Schema Part 2: Datatypes Second Edition § 3.2.16.
063        string = StringUtils.deleteXmlWhitespace(string);
064        try {
065            return base64encoder.decode(string);
066        } catch (IllegalArgumentException e) {
067            return null;
068        }
069    }
070
071    public static final byte[] decode(byte[] input) {
072        String string = new String(input, StandardCharsets.US_ASCII);
073        return decode(string);
074    }
075
076    private static byte[] slice(byte[] input, int offset, int len) {
077        if (offset == 0 && len == input.length) {
078            return input;
079        }
080
081        byte[] res = new byte[len];
082        System.arraycopy(input, offset, res, 0, len);
083        return res;
084    }
085
086    public interface Encoder {
087        byte[] decode(String string);
088
089        String encodeToString(byte[] input);
090
091        String encodeToStringWithoutPadding(byte[] input);
092
093        byte[] encode(byte[] input);
094    }
095}