Base64.java revision f33eae7e84eb6d3b0f4e86b59605bb3de73009f3
1adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project/* 2adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Licensed to the Apache Software Foundation (ASF) under one or more 3adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * contributor license agreements. See the NOTICE file distributed with 4adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * this work for additional information regarding copyright ownership. 5adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * The ASF licenses this file to You under the Apache License, Version 2.0 6adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * (the "License"); you may not use this file except in compliance with 7adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * the License. You may obtain a copy of the License at 8adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * 9adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * http://www.apache.org/licenses/LICENSE-2.0 10adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * 11adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Unless required by applicable law or agreed to in writing, software 12adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * distributed under the License is distributed on an "AS IS" BASIS, 13adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * See the License for the specific language governing permissions and 15adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * limitations under the License. 16adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 17adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 18adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project/** 19adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project* @author Alexander Y. Kleymenov 20adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project*/ 21adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 22adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectpackage org.apache.harmony.luni.util; 23adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 24adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectimport java.io.UnsupportedEncodingException; 25adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 26adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project/** 27adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * This class implements Base64 encoding/decoding functionality 28adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * as specified in RFC 2045 (http://www.ietf.org/rfc/rfc2045.txt). 29adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 30adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectpublic class Base64 { 31f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes 32adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public static byte[] decode(byte[] in) { 33adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return decode(in, in.length); 34adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 35f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes 36adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public static byte[] decode(byte[] in, int len) { 37adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // approximate output length 38adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int length = len / 4 * 3; 39adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // return an empty array on emtpy or short input without padding 40adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (length == 0) { 41adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return new byte[0]; 42adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 43adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // temporary array 44adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project byte[] out = new byte[length]; 45adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // number of padding characters ('=') 46adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int pad = 0; 47adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project byte chr; 48adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // compute the number of the padding characters 49adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // and adjust the length of the input 50adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project for (;;len--) { 51adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project chr = in[len-1]; 52adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // skip the neutral characters 53f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes if ((chr == '\n') || (chr == '\r') || 54adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project (chr == ' ') || (chr == '\t')) { 55adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project continue; 56adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 57adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (chr == '=') { 58adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project pad++; 59adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } else { 60adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project break; 61adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 62adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 63adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // index in the output array 64adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int out_index = 0; 65adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // index in the input array 66adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int in_index = 0; 67adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // holds the value of the input character 68adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int bits = 0; 69adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // holds the value of the input quantum 70adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int quantum = 0; 71adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project for (int i=0; i<len; i++) { 72adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project chr = in[i]; 73adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // skip the neutral characters 74f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes if ((chr == '\n') || (chr == '\r') || 75adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project (chr == ' ') || (chr == '\t')) { 76adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project continue; 77adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 78adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if ((chr >= 'A') && (chr <= 'Z')) { 79adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // char ASCII value 80adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // A 65 0 81adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // Z 90 25 (ASCII - 65) 82adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project bits = chr - 65; 83adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } else if ((chr >= 'a') && (chr <= 'z')) { 84adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // char ASCII value 85adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // a 97 26 86adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // z 122 51 (ASCII - 71) 87adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project bits = chr - 71; 88adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } else if ((chr >= '0') && (chr <= '9')) { 89adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // char ASCII value 90adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // 0 48 52 91adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // 9 57 61 (ASCII + 4) 92adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project bits = chr + 4; 93adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } else if (chr == '+') { 94adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project bits = 62; 95adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } else if (chr == '/') { 96adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project bits = 63; 97adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } else { 98adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return null; 99adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 100adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // append the value to the quantum 101adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project quantum = (quantum << 6) | (byte) bits; 102adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (in_index%4 == 3) { 103adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // 4 characters were read, so make the output: 104adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[out_index++] = (byte) ((quantum & 0x00FF0000) >> 16); 105adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[out_index++] = (byte) ((quantum & 0x0000FF00) >> 8); 106adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[out_index++] = (byte) (quantum & 0x000000FF); 107adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 108adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project in_index++; 109adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 110adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (pad > 0) { 111adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // adjust the quantum value according to the padding 112adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project quantum = quantum << (6*pad); 113adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // make output 114adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[out_index++] = (byte) ((quantum & 0x00FF0000) >> 16); 115adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (pad == 1) { 116adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[out_index++] = (byte) ((quantum & 0x0000FF00) >> 8); 117adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 118adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 119adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // create the resulting array 120adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project byte[] result = new byte[out_index]; 121adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project System.arraycopy(out, 0, result, 0, out_index); 122adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return result; 123adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 124adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 125adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project private static final byte[] map = new byte[] 126f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 127f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 128f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 129f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', 130adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project '4', '5', '6', '7', '8', '9', '+', '/'}; 131adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 132adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public static String encode(byte[] in, String charsetName) throws UnsupportedEncodingException { 133adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int length = in.length * 4 / 3; 134adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project length += length / 76 + 3; // for crlr 135adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project byte[] out = new byte[length]; 136adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int index = 0, i, crlr = 0, end = in.length - in.length%3; 137adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project for (i=0; i<end; i+=3) { 138adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[index++] = map[(in[i] & 0xff) >> 2]; 139f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes out[index++] = map[((in[i] & 0x03) << 4) 140adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project | ((in[i+1] & 0xff) >> 4)]; 141f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes out[index++] = map[((in[i+1] & 0x0f) << 2) 142adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project | ((in[i+2] & 0xff) >> 6)]; 143adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[index++] = map[(in[i+2] & 0x3f)]; 144adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (((index - crlr)%76 == 0) && (index != 0)) { 145adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[index++] = '\n'; 146adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project crlr++; 147adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project //out[index++] = '\r'; 148adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project //crlr++; 149adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 150adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 151adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project switch (in.length % 3) { 152adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project case 1: 153adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[index++] = map[(in[end] & 0xff) >> 2]; 154adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[index++] = map[(in[end] & 0x03) << 4]; 155adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[index++] = '='; 156adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[index++] = '='; 157adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project break; 158adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project case 2: 159adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[index++] = map[(in[end] & 0xff) >> 2]; 160f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes out[index++] = map[((in[end] & 0x03) << 4) 161adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project | ((in[end+1] & 0xff) >> 4)]; 162f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes out[index++] = map[((in[end+1] & 0x0f) << 2)]; 163adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[index++] = '='; 164adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project break; 165adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 166adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return new String(out, 0, index, charsetName); 167adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 168adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project} 169adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 170