| /** |
| * 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.hadoop.fs.azurebfs.utils; |
| |
| /** |
| * Base64 |
| */ |
| public final class Base64 { |
| /** |
| * The Base 64 Characters. |
| */ |
| private static final String BASE_64_CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; |
| |
| /** |
| * Decoded values, -1 is invalid character, -2 is = pad character. |
| */ |
| private static final byte[] DECODE_64 = { |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0-15 |
| |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* |
| * 16- 31 |
| */ |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, /* |
| * 32- 47 |
| */ |
| 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -2, -1, -1, /* |
| * 48- 63 |
| */ |
| -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, /* 64-79 */ |
| 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, /* |
| * 80- 95 |
| */ |
| -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, /* |
| * 96- 111 |
| */ |
| 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1 /* |
| * 112- 127 |
| */ |
| }; |
| |
| /** |
| * Decodes a given Base64 string into its corresponding byte array. |
| * |
| * @param data |
| * the Base64 string, as a <code>String</code> object, to decode |
| * |
| * @return the corresponding decoded byte array |
| * @throws IllegalArgumentException |
| * If the string is not a valid base64 encoded string |
| */ |
| public static byte[] decode(final String data) { |
| if (data == null) { |
| throw new IllegalArgumentException("The data parameter is not a valid base64-encoded string."); |
| } |
| |
| int byteArrayLength = 3 * data.length() / 4; |
| |
| if (data.endsWith("==")) { |
| byteArrayLength -= 2; |
| } |
| else if (data.endsWith("=")) { |
| byteArrayLength -= 1; |
| } |
| |
| final byte[] retArray = new byte[byteArrayLength]; |
| int byteDex = 0; |
| int charDex = 0; |
| |
| for (; charDex < data.length(); charDex += 4) { |
| // get 4 chars, convert to 3 bytes |
| final int char1 = DECODE_64[(byte) data.charAt(charDex)]; |
| final int char2 = DECODE_64[(byte) data.charAt(charDex + 1)]; |
| final int char3 = DECODE_64[(byte) data.charAt(charDex + 2)]; |
| final int char4 = DECODE_64[(byte) data.charAt(charDex + 3)]; |
| |
| if (char1 < 0 || char2 < 0 || char3 == -1 || char4 == -1) { |
| // invalid character(-1), or bad padding (-2) |
| throw new IllegalArgumentException("The data parameter is not a valid base64-encoded string."); |
| } |
| |
| int tVal = char1 << 18; |
| tVal += char2 << 12; |
| tVal += (char3 & 0xff) << 6; |
| tVal += char4 & 0xff; |
| |
| if (char3 == -2) { |
| // two "==" pad chars, check bits 12-24 |
| tVal &= 0x00FFF000; |
| retArray[byteDex++] = (byte) (tVal >> 16 & 0xFF); |
| } |
| else if (char4 == -2) { |
| // one pad char "=" , check bits 6-24. |
| tVal &= 0x00FFFFC0; |
| retArray[byteDex++] = (byte) (tVal >> 16 & 0xFF); |
| retArray[byteDex++] = (byte) (tVal >> 8 & 0xFF); |
| |
| } |
| else { |
| // No pads take all 3 bytes, bits 0-24 |
| retArray[byteDex++] = (byte) (tVal >> 16 & 0xFF); |
| retArray[byteDex++] = (byte) (tVal >> 8 & 0xFF); |
| retArray[byteDex++] = (byte) (tVal & 0xFF); |
| } |
| } |
| return retArray; |
| } |
| |
| /** |
| * Decodes a given Base64 string into its corresponding byte array. |
| * |
| * @param data |
| * the Base64 string, as a <code>String</code> object, to decode |
| * |
| * @return the corresponding decoded byte array |
| * @throws IllegalArgumentException |
| * If the string is not a valid base64 encoded string |
| */ |
| public static Byte[] decodeAsByteObjectArray(final String data) { |
| int byteArrayLength = 3 * data.length() / 4; |
| |
| if (data.endsWith("==")) { |
| byteArrayLength -= 2; |
| } |
| else if (data.endsWith("=")) { |
| byteArrayLength -= 1; |
| } |
| |
| final Byte[] retArray = new Byte[byteArrayLength]; |
| int byteDex = 0; |
| int charDex = 0; |
| |
| for (; charDex < data.length(); charDex += 4) { |
| // get 4 chars, convert to 3 bytes |
| final int char1 = DECODE_64[(byte) data.charAt(charDex)]; |
| final int char2 = DECODE_64[(byte) data.charAt(charDex + 1)]; |
| final int char3 = DECODE_64[(byte) data.charAt(charDex + 2)]; |
| final int char4 = DECODE_64[(byte) data.charAt(charDex + 3)]; |
| |
| if (char1 < 0 || char2 < 0 || char3 == -1 || char4 == -1) { |
| // invalid character(-1), or bad padding (-2) |
| throw new IllegalArgumentException("The data parameter is not a valid base64-encoded string."); |
| } |
| |
| int tVal = char1 << 18; |
| tVal += char2 << 12; |
| tVal += (char3 & 0xff) << 6; |
| tVal += char4 & 0xff; |
| |
| if (char3 == -2) { |
| // two "==" pad chars, check bits 12-24 |
| tVal &= 0x00FFF000; |
| retArray[byteDex++] = (byte) (tVal >> 16 & 0xFF); |
| } |
| else if (char4 == -2) { |
| // one pad char "=" , check bits 6-24. |
| tVal &= 0x00FFFFC0; |
| retArray[byteDex++] = (byte) (tVal >> 16 & 0xFF); |
| retArray[byteDex++] = (byte) (tVal >> 8 & 0xFF); |
| |
| } |
| else { |
| // No pads take all 3 bytes, bits 0-24 |
| retArray[byteDex++] = (byte) (tVal >> 16 & 0xFF); |
| retArray[byteDex++] = (byte) (tVal >> 8 & 0xFF); |
| retArray[byteDex++] = (byte) (tVal & 0xFF); |
| } |
| } |
| return retArray; |
| } |
| |
| /** |
| * Encodes a byte array as a Base64 string. |
| * |
| * @param data |
| * the byte array to encode |
| * @return the Base64-encoded string, as a <code>String</code> object |
| */ |
| public static String encode(final byte[] data) { |
| final StringBuilder builder = new StringBuilder(); |
| final int dataRemainder = data.length % 3; |
| |
| int j = 0; |
| int n = 0; |
| for (; j < data.length; j += 3) { |
| |
| if (j < data.length - dataRemainder) { |
| n = ((data[j] & 0xFF) << 16) + ((data[j + 1] & 0xFF) << 8) + (data[j + 2] & 0xFF); |
| } |
| else { |
| if (dataRemainder == 1) { |
| n = (data[j] & 0xFF) << 16; |
| } |
| else if (dataRemainder == 2) { |
| n = ((data[j] & 0xFF) << 16) + ((data[j + 1] & 0xFF) << 8); |
| } |
| } |
| |
| // Left here for readability |
| // byte char1 = (byte) ((n >>> 18) & 0x3F); |
| // byte char2 = (byte) ((n >>> 12) & 0x3F); |
| // byte char3 = (byte) ((n >>> 6) & 0x3F); |
| // byte char4 = (byte) (n & 0x3F); |
| builder.append(BASE_64_CHARS.charAt((byte) ((n >>> 18) & 0x3F))); |
| builder.append(BASE_64_CHARS.charAt((byte) ((n >>> 12) & 0x3F))); |
| builder.append(BASE_64_CHARS.charAt((byte) ((n >>> 6) & 0x3F))); |
| builder.append(BASE_64_CHARS.charAt((byte) (n & 0x3F))); |
| } |
| |
| final int bLength = builder.length(); |
| |
| // append '=' to pad |
| if (data.length % 3 == 1) { |
| builder.replace(bLength - 2, bLength, "=="); |
| } |
| else if (data.length % 3 == 2) { |
| builder.replace(bLength - 1, bLength, "="); |
| } |
| |
| return builder.toString(); |
| } |
| |
| /** |
| * Encodes a byte array as a Base64 string. |
| * |
| * @param data |
| * the byte array to encode |
| * @return the Base64-encoded string, as a <code>String</code> object |
| */ |
| public static String encode(final Byte[] data) { |
| final StringBuilder builder = new StringBuilder(); |
| final int dataRemainder = data.length % 3; |
| |
| int j = 0; |
| int n = 0; |
| for (; j < data.length; j += 3) { |
| |
| if (j < data.length - dataRemainder) { |
| n = ((data[j] & 0xFF) << 16) + ((data[j + 1] & 0xFF) << 8) + (data[j + 2] & 0xFF); |
| } |
| else { |
| if (dataRemainder == 1) { |
| n = (data[j] & 0xFF) << 16; |
| } |
| else if (dataRemainder == 2) { |
| n = ((data[j] & 0xFF) << 16) + ((data[j + 1] & 0xFF) << 8); |
| } |
| } |
| |
| // Left here for readability |
| // byte char1 = (byte) ((n >>> 18) & 0x3F); |
| // byte char2 = (byte) ((n >>> 12) & 0x3F); |
| // byte char3 = (byte) ((n >>> 6) & 0x3F); |
| // byte char4 = (byte) (n & 0x3F); |
| builder.append(BASE_64_CHARS.charAt((byte) ((n >>> 18) & 0x3F))); |
| builder.append(BASE_64_CHARS.charAt((byte) ((n >>> 12) & 0x3F))); |
| builder.append(BASE_64_CHARS.charAt((byte) ((n >>> 6) & 0x3F))); |
| builder.append(BASE_64_CHARS.charAt((byte) (n & 0x3F))); |
| } |
| |
| final int bLength = builder.length(); |
| |
| // append '=' to pad |
| if (data.length % 3 == 1) { |
| builder.replace(bLength - 2, bLength, "=="); |
| } |
| else if (data.length % 3 == 2) { |
| builder.replace(bLength - 1, bLength, "="); |
| } |
| |
| return builder.toString(); |
| } |
| |
| /** |
| * Determines whether the given string contains only Base64 characters. |
| * |
| * @param data |
| * the string, as a <code>String</code> object, to validate |
| * @return <code>true</code> if <code>data</code> is a valid Base64 string, otherwise <code>false</code> |
| */ |
| public static boolean validateIsBase64String(final String data) { |
| |
| if (data == null || data.length() % 4 != 0) { |
| return false; |
| } |
| |
| for (int m = 0; m < data.length(); m++) { |
| final byte charByte = (byte) data.charAt(m); |
| |
| // pad char detected |
| if (DECODE_64[charByte] == -2) { |
| if (m < data.length() - 2) { |
| return false; |
| } |
| else if (m == data.length() - 2 && DECODE_64[(byte) data.charAt(m + 1)] != -2) { |
| return false; |
| } |
| } |
| |
| if (charByte < 0 || DECODE_64[charByte] == -1) { |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| /** |
| * Private Default Ctor. |
| */ |
| private Base64() { |
| // No op |
| } |
| } |