Base64.java revision b1b8fbeeae579e9f49c41166bb5d9b2e60b75438
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; 25b1b8fbeeae579e9f49c41166bb5d9b2e60b75438Elliott Hughesimport java.nio.charset.Charset; 26adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 27adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project/** 28adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * This class implements Base64 encoding/decoding functionality 29adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * as specified in RFC 2045 (http://www.ietf.org/rfc/rfc2045.txt). 30adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 31adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectpublic class Base64 { 32b1b8fbeeae579e9f49c41166bb5d9b2e60b75438Elliott Hughes private Base64() { 33b1b8fbeeae579e9f49c41166bb5d9b2e60b75438Elliott Hughes } 34f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes 35adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public static byte[] decode(byte[] in) { 36adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return decode(in, in.length); 37adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 38f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes 39adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public static byte[] decode(byte[] in, int len) { 40adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // approximate output length 41adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int length = len / 4 * 3; 42b1b8fbeeae579e9f49c41166bb5d9b2e60b75438Elliott Hughes // return an empty array on empty or short input without padding 43adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (length == 0) { 44adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return new byte[0]; 45adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 46adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // temporary array 47adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project byte[] out = new byte[length]; 48adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // number of padding characters ('=') 49adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int pad = 0; 50adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project byte chr; 51adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // compute the number of the padding characters 52adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // and adjust the length of the input 53adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project for (;;len--) { 54adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project chr = in[len-1]; 55adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // skip the neutral characters 56f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes if ((chr == '\n') || (chr == '\r') || 57adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project (chr == ' ') || (chr == '\t')) { 58adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project continue; 59adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 60adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (chr == '=') { 61adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project pad++; 62adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } else { 63adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project break; 64adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 65adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 66adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // index in the output array 67adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int out_index = 0; 68adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // index in the input array 69adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int in_index = 0; 70adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // holds the value of the input character 71adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int bits = 0; 72adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // holds the value of the input quantum 73adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int quantum = 0; 74adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project for (int i=0; i<len; i++) { 75adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project chr = in[i]; 76adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // skip the neutral characters 77f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes if ((chr == '\n') || (chr == '\r') || 78adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project (chr == ' ') || (chr == '\t')) { 79adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project continue; 80adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 81adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if ((chr >= 'A') && (chr <= 'Z')) { 82adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // char ASCII value 83adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // A 65 0 84adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // Z 90 25 (ASCII - 65) 85adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project bits = chr - 65; 86adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } else if ((chr >= 'a') && (chr <= 'z')) { 87adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // char ASCII value 88adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // a 97 26 89adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // z 122 51 (ASCII - 71) 90adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project bits = chr - 71; 91adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } else if ((chr >= '0') && (chr <= '9')) { 92adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // char ASCII value 93adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // 0 48 52 94adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // 9 57 61 (ASCII + 4) 95adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project bits = chr + 4; 96adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } else if (chr == '+') { 97adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project bits = 62; 98adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } else if (chr == '/') { 99adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project bits = 63; 100adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } else { 101adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return null; 102adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 103adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // append the value to the quantum 104adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project quantum = (quantum << 6) | (byte) bits; 105adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (in_index%4 == 3) { 106adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // 4 characters were read, so make the output: 107adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[out_index++] = (byte) ((quantum & 0x00FF0000) >> 16); 108adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[out_index++] = (byte) ((quantum & 0x0000FF00) >> 8); 109adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[out_index++] = (byte) (quantum & 0x000000FF); 110adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 111adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project in_index++; 112adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 113adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (pad > 0) { 114adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // adjust the quantum value according to the padding 115adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project quantum = quantum << (6*pad); 116adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // make output 117adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[out_index++] = (byte) ((quantum & 0x00FF0000) >> 16); 118adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (pad == 1) { 119adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[out_index++] = (byte) ((quantum & 0x0000FF00) >> 8); 120adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 121adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 122adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // create the resulting array 123adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project byte[] result = new byte[out_index]; 124adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project System.arraycopy(out, 0, result, 0, out_index); 125adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return result; 126adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 127adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 128adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project private static final byte[] map = new byte[] 129f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 130f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 131f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 132f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', 133adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project '4', '5', '6', '7', '8', '9', '+', '/'}; 134adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 135b1b8fbeeae579e9f49c41166bb5d9b2e60b75438Elliott Hughes public static String encode(byte[] in, Charset charset) { 136adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int length = in.length * 4 / 3; 137adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project length += length / 76 + 3; // for crlr 138adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project byte[] out = new byte[length]; 139adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int index = 0, i, crlr = 0, end = in.length - in.length%3; 140adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project for (i=0; i<end; i+=3) { 141adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[index++] = map[(in[i] & 0xff) >> 2]; 142f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes out[index++] = map[((in[i] & 0x03) << 4) 143adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project | ((in[i+1] & 0xff) >> 4)]; 144f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes out[index++] = map[((in[i+1] & 0x0f) << 2) 145adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project | ((in[i+2] & 0xff) >> 6)]; 146adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[index++] = map[(in[i+2] & 0x3f)]; 147adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (((index - crlr)%76 == 0) && (index != 0)) { 148adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[index++] = '\n'; 149adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project crlr++; 150adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project //out[index++] = '\r'; 151adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project //crlr++; 152adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 153adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 154adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project switch (in.length % 3) { 155adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project case 1: 156adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[index++] = map[(in[end] & 0xff) >> 2]; 157adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[index++] = map[(in[end] & 0x03) << 4]; 158adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[index++] = '='; 159adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[index++] = '='; 160adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project break; 161adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project case 2: 162adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[index++] = map[(in[end] & 0xff) >> 2]; 163f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes out[index++] = map[((in[end] & 0x03) << 4) 164adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project | ((in[end+1] & 0xff) >> 4)]; 165f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes out[index++] = map[((in[end+1] & 0x0f) << 2)]; 166adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project out[index++] = '='; 167adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project break; 168adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 169b1b8fbeeae579e9f49c41166bb5d9b2e60b75438Elliott Hughes return new String(out, 0, index, charset); 170adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 171adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project} 172