All Downloads are FREE. Search and download functionalities are using the official Maven repository.

com.unboundid.util.Base32 Maven / Gradle / Ivy

/*
 * Copyright 2012-2019 Ping Identity Corporation
 * All Rights Reserved.
 */
/*
 * Copyright (C) 2012-2019 Ping Identity Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License (GPLv2 only)
 * or the terms of the GNU Lesser General Public License (LGPLv2.1 only)
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see .
 */
package com.unboundid.util;



import java.io.IOException;
import java.text.ParseException;

import static com.unboundid.util.UtilityMessages.*;



/**
 * This class provides methods for encoding and decoding data in base32 as
 * defined in RFC 4648.  It
 * provides a somewhat compact way of representing binary data using only
 * printable characters (a subset of ASCII letters and numeric digits selected
 * to avoid ambiguity, like confusion between the number 1 and the uppercase
 * letter I, and between the number 0 and the uppercase letter O).  It uses a
 * five-bit encoding mechanism in which every five bytes of raw data is
 * converted into eight bytes of base32-encoded data.
 * 

*

Example

* The following examples demonstrate the process for base32-encoding raw data, * and for decoding a string containing base32-encoded data back to the raw * data used to create it: *
 * // Base32-encode some raw data:
 * String base32String = Base32.encode(rawDataBytes);
 *
 * // Decode a base32 string back to raw data:
 * byte[] decodedRawDataBytes;
 * try
 * {
 *   decodedRawDataBytes = Base32.decode(base32String);
 * }
 * catch (ParseException pe)
 * {
 *   // The string did not represent a valid base32 encoding.
 *   decodedRawDataBytes = null;
 * }
 * 
*/ @ThreadSafety(level=ThreadSafetyLevel.COMPLETELY_THREADSAFE) public final class Base32 { /** * The set of characters in the base32 alphabet. */ private static final char[] BASE32_ALPHABET = ("ABCDEFGHIJKLMNOPQRSTUVWXYZ234567").toCharArray(); /** * Prevent this class from being instantiated. */ private Base32() { // No implementation is required. } /** * Encodes the UTF-8 representation of the provided string in base32 format. * * @param data The raw data to be encoded. It must not be {@code null}. * * @return The base32-encoded representation of the provided data. */ public static String encode(final String data) { Validator.ensureNotNull(data); return encode(StaticUtils.getBytes(data)); } /** * Encodes the provided data in base32 format. * * @param data The raw data to be encoded. It must not be {@code null}. * * @return The base32-encoded representation of the provided data. */ public static String encode(final byte[] data) { Validator.ensureNotNull(data); final StringBuilder buffer = new StringBuilder(4*data.length/3+1); encodeInternal(data, 0, data.length, buffer); return buffer.toString(); } /** * Appends a base32-encoded version of the contents of the provided buffer * (using a UTF-8 representation) to the given buffer. * * @param data The raw data to be encoded. It must not be {@code null}. * @param buffer The buffer to which the base32-encoded data is to be * written. */ public static void encode(final String data, final StringBuilder buffer) { Validator.ensureNotNull(data); encode(StaticUtils.getBytes(data), buffer); } /** * Appends a base32-encoded version of the contents of the provided buffer * (using a UTF-8 representation) to the given buffer. * * @param data The raw data to be encoded. It must not be {@code null}. * @param buffer The buffer to which the base32-encoded data is to be * written. */ public static void encode(final String data, final ByteStringBuffer buffer) { Validator.ensureNotNull(data); encode(StaticUtils.getBytes(data), buffer); } /** * Appends a base32-encoded representation of the provided data to the given * buffer. * * @param data The raw data to be encoded. It must not be {@code null}. * @param buffer The buffer to which the base32-encoded data is to be * written. */ public static void encode(final byte[] data, final StringBuilder buffer) { encodeInternal(data, 0, data.length, buffer); } /** * Appends a base32-encoded representation of the provided data to the given * buffer. * * @param data The array containing the raw data to be encoded. It must * not be {@code null}. * @param off The offset in the array at which the data to encode begins. * @param length The number of bytes to be encoded. * @param buffer The buffer to which the base32-encoded data is to be * written. */ public static void encode(final byte[] data, final int off, final int length, final StringBuilder buffer) { encodeInternal(data, off, length, buffer); } /** * Appends a base32-encoded representation of the provided data to the given * buffer. * * @param data The raw data to be encoded. It must not be {@code null}. * @param buffer The buffer to which the base32-encoded data is to be * written. */ public static void encode(final byte[] data, final ByteStringBuffer buffer) { encodeInternal(data, 0, data.length, buffer); } /** * Appends a base32-encoded representation of the provided data to the given * buffer. * * @param data The raw data to be encoded. It must not be {@code null}. * @param off The offset in the array at which the data to encode begins. * @param length The number of bytes to be encoded. * @param buffer The buffer to which the base32-encoded data is to be * written. */ public static void encode(final byte[] data, final int off, final int length, final ByteStringBuffer buffer) { encodeInternal(data, off, length, buffer); } /** * Appends a base32-encoded representation of the provided data to the given * buffer. * * @param data The raw data to be encoded. It must not be {@code null}. * @param off The offset in the array at which the data to encode begins. * @param length The number of bytes to be encoded. * @param buffer The buffer to which the base32-encoded data is to be * written. */ private static void encodeInternal(final byte[] data, final int off, final int length, final Appendable buffer) { Validator.ensureNotNull(data); Validator.ensureTrue(data.length >= off); Validator.ensureTrue(data.length >= (off+length)); if (length == 0) { return; } try { int pos = off; for (int i=0; i < (length / 5); i++) { final long longValue = (((data[pos++] & 0xFFL) << 32) | ((data[pos++] & 0xFFL) << 24) | ((data[pos++] & 0xFFL) << 16) | ((data[pos++] & 0xFFL) << 8) | (data[pos++] & 0xFFL)); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 35) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 30) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 25) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 20) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 15) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 10) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 5) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) (longValue & 0x1FL)]); } switch ((off+length) - pos) { case 1: long longValue = ((data[pos] & 0xFFL) << 32); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 35) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 30) & 0x1FL)]); buffer.append("======"); return; case 2: longValue = (((data[pos++] & 0xFFL) << 32) | ((data[pos] & 0xFFL) << 24)); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 35) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 30) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 25) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 20) & 0x1FL)]); buffer.append("===="); return; case 3: longValue = (((data[pos++] & 0xFFL) << 32) | ((data[pos++] & 0xFFL) << 24) | ((data[pos] & 0xFFL) << 16)); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 35) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 30) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 25) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 20) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 15) & 0x1FL)]); buffer.append("==="); return; case 4: longValue = (((data[pos++] & 0xFFL) << 32) | ((data[pos++] & 0xFFL) << 24) | ((data[pos++] & 0xFFL) << 16) | ((data[pos] & 0xFFL) << 8)); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 35) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 30) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 25) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 20) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 15) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 10) & 0x1FL)]); buffer.append(BASE32_ALPHABET[(int) ((longValue >> 5) & 0x1FL)]); buffer.append("="); return; } } catch (final IOException ioe) { Debug.debugException(ioe); // This should never happen. throw new RuntimeException(ioe.getMessage(), ioe); } } /** * Decodes the contents of the provided base32-encoded string. * * @param data The base32-encoded string to decode. It must not be * {@code null}. * * @return A byte array containing the decoded data. * * @throws ParseException If the contents of the provided string cannot be * parsed as base32-encoded data. */ public static byte[] decode(final String data) throws ParseException { Validator.ensureNotNull(data); final int length = data.length(); if (length == 0) { return StaticUtils.NO_BYTES; } if ((length % 8) != 0) { throw new ParseException(ERR_BASE32_DECODE_INVALID_LENGTH.get(), length); } final ByteStringBuffer buffer = new ByteStringBuffer(5 * (length / 8)); int stringPos = 0; while (stringPos < length) { long longValue = 0x00; for (int i=0; i < 8; i++) { longValue <<= 5; switch (data.charAt(stringPos++)) { case 'A': case 'a': longValue |= 0x00L; break; case 'B': case 'b': longValue |= 0x01L; break; case 'C': case 'c': longValue |= 0x02L; break; case 'D': case 'd': longValue |= 0x03L; break; case 'E': case 'e': longValue |= 0x04L; break; case 'F': case 'f': longValue |= 0x05L; break; case 'G': case 'g': longValue |= 0x06L; break; case 'H': case 'h': longValue |= 0x07L; break; case 'I': case 'i': longValue |= 0x08L; break; case 'J': case 'j': longValue |= 0x09L; break; case 'K': case 'k': longValue |= 0x0AL; break; case 'L': case 'l': longValue |= 0x0BL; break; case 'M': case 'm': longValue |= 0x0CL; break; case 'N': case 'n': longValue |= 0x0DL; break; case 'O': case 'o': longValue |= 0x0EL; break; case 'P': case 'p': longValue |= 0x0FL; break; case 'Q': case 'q': longValue |= 0x10L; break; case 'R': case 'r': longValue |= 0x11L; break; case 'S': case 's': longValue |= 0x12L; break; case 'T': case 't': longValue |= 0x13L; break; case 'U': case 'u': longValue |= 0x14L; break; case 'V': case 'v': longValue |= 0x15L; break; case 'W': case 'w': longValue |= 0x16L; break; case 'X': case 'x': longValue |= 0x17L; break; case 'Y': case 'y': longValue |= 0x18L; break; case 'Z': case 'z': longValue |= 0x19L; break; case '2': longValue |= 0x1AL; break; case '3': longValue |= 0x1BL; break; case '4': longValue |= 0x1CL; break; case '5': longValue |= 0x1DL; break; case '6': longValue |= 0x1EL; break; case '7': longValue |= 0x1FL; break; case '=': switch (length - stringPos) { case 0: // The string ended with a single equal sign, so there are // four bytes left. buffer.append((byte) ((longValue >> 32) & 0xFFL)); buffer.append((byte) ((longValue >> 24) & 0xFFL)); buffer.append((byte) ((longValue >> 16) & 0xFFL)); buffer.append((byte) ((longValue >> 8) & 0xFFL)); return buffer.toByteArray(); case 2: // The string ended with three equal signs, so there are three // bytes left. longValue <<= 10; buffer.append((byte) ((longValue >> 32) & 0xFFL)); buffer.append((byte) ((longValue >> 24) & 0xFFL)); buffer.append((byte) ((longValue >> 16) & 0xFFL)); return buffer.toByteArray(); case 3: // The string ended with four equal signs, so there are two // bytes left. longValue <<= 15; buffer.append((byte) ((longValue >> 32) & 0xFFL)); buffer.append((byte) ((longValue >> 24) & 0xFFL)); return buffer.toByteArray(); case 5: // The string ended with six equal signs, so there is one byte // left. longValue <<= 25; buffer.append((byte) ((longValue >> 32) & 0xFFL)); return buffer.toByteArray(); default: throw new ParseException( ERR_BASE32_DECODE_UNEXPECTED_EQUAL.get((stringPos-1)), (stringPos-1)); } default: throw new ParseException( ERR_BASE32_DECODE_UNEXPECTED_CHAR.get( data.charAt(stringPos-1)), (stringPos-1)); } } buffer.append((byte) ((longValue >> 32) & 0xFFL)); buffer.append((byte) ((longValue >> 24) & 0xFFL)); buffer.append((byte) ((longValue >> 16) & 0xFFL)); buffer.append((byte) ((longValue >> 8) & 0xFFL)); buffer.append((byte) (longValue & 0xFFL)); } return buffer.toByteArray(); } /** * Decodes the contents of the provided base32-encoded string to a string * containing the raw data using the UTF-8 encoding. * * @param data The base32-encoded string to decode. It must not be * {@code null}. * * @return A string containing the decoded data. * * @throws ParseException If the contents of the provided string cannot be * parsed as base32-encoded data using the UTF-8 * encoding. */ public static String decodeToString(final String data) throws ParseException { Validator.ensureNotNull(data); final byte[] decodedBytes = decode(data); return StaticUtils.toUTF8String(decodedBytes); } }




© 2015 - 2024 Weber Informatics LLC | Privacy Policy