| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| package org.apache.tools.ant.util; |
| |
| /** |
| * BASE 64 encoding of a String or an array of bytes. |
| * |
| * Based on RFC 1421. |
| * |
| **/ |
| public class Base64Converter { |
| |
| private static final int BYTE = 8; |
| private static final int WORD = 16; |
| private static final int BYTE_MASK = 0xFF; |
| private static final int POS_0_MASK = 0x0000003F; |
| private static final int POS_1_MASK = 0x00000FC0; |
| private static final int POS_1_SHIFT = 6; |
| private static final int POS_2_MASK = 0x0003F000; |
| private static final int POS_2_SHIFT = 12; |
| private static final int POS_3_MASK = 0x00FC0000; |
| private static final int POS_3_SHIFT = 18; |
| |
| |
| private static final char[] ALPHABET = { |
| 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', // 0 to 7 |
| 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', // 8 to 15 |
| 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', // 16 to 23 |
| 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', // 24 to 31 |
| 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', // 32 to 39 |
| 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', // 40 to 47 |
| 'w', 'x', 'y', 'z', '0', '1', '2', '3', // 48 to 55 |
| '4', '5', '6', '7', '8', '9', '+', '/'}; // 56 to 63 |
| |
| // CheckStyle:ConstantNameCheck OFF - bc |
| /** Provided for BC purposes */ |
| public static final char[] alphabet = ALPHABET; |
| // CheckStyle:ConstantNameCheck ON |
| |
| |
| /** |
| * Encode a string into base64 encoding. |
| * @param s the string to encode. |
| * @return the encoded string. |
| */ |
| public String encode(String s) { |
| return encode(s.getBytes()); |
| } |
| |
| /** |
| * Encode a byte array into base64 encoding. |
| * @param octetString the byte array to encode. |
| * @return the encoded string. |
| */ |
| public String encode(byte[] octetString) { |
| int bits24; |
| int bits6; |
| |
| // CheckStyle:MagicNumber OFF |
| char[] out = new char[((octetString.length - 1) / 3 + 1) * 4]; |
| // CheckStyle:MagicNumber ON |
| int outIndex = 0; |
| int i = 0; |
| |
| // CheckStyle:MagicNumber OFF |
| while ((i + 3) <= octetString.length) { |
| // CheckStyle:MagicNumber ON |
| // store the octets |
| bits24 = (octetString[i++] & BYTE_MASK) << WORD; |
| bits24 |= (octetString[i++] & BYTE_MASK) << BYTE; |
| bits24 |= octetString[i++]; |
| |
| bits6 = (bits24 & POS_3_MASK) >> POS_3_SHIFT; |
| out[outIndex++] = ALPHABET[bits6]; |
| bits6 = (bits24 & POS_2_MASK) >> POS_2_SHIFT; |
| out[outIndex++] = ALPHABET[bits6]; |
| bits6 = (bits24 & POS_1_MASK) >> POS_1_SHIFT; |
| out[outIndex++] = ALPHABET[bits6]; |
| bits6 = (bits24 & POS_0_MASK); |
| out[outIndex++] = ALPHABET[bits6]; |
| } |
| if (octetString.length - i == 2) { |
| // store the octets |
| bits24 = (octetString[i] & BYTE_MASK) << WORD; |
| bits24 |= (octetString[i + 1] & BYTE_MASK) << BYTE; |
| bits6 = (bits24 & POS_3_MASK) >> POS_3_SHIFT; |
| out[outIndex++] = ALPHABET[bits6]; |
| bits6 = (bits24 & POS_2_MASK) >> POS_2_SHIFT; |
| out[outIndex++] = ALPHABET[bits6]; |
| bits6 = (bits24 & POS_1_MASK) >> POS_1_SHIFT; |
| out[outIndex++] = ALPHABET[bits6]; |
| |
| // padding |
| out[outIndex++] = '='; |
| } else if (octetString.length - i == 1) { |
| // store the octets |
| bits24 = (octetString[i] & BYTE_MASK) << WORD; |
| bits6 = (bits24 & POS_3_MASK) >> POS_3_SHIFT; |
| out[outIndex++] = ALPHABET[bits6]; |
| bits6 = (bits24 & POS_2_MASK) >> POS_2_SHIFT; |
| out[outIndex++] = ALPHABET[bits6]; |
| |
| // padding |
| out[outIndex++] = '='; |
| out[outIndex++] = '='; |
| } |
| return new String(out); |
| } |
| } |