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The UnboundID LDAP SDK for Java is a fast, comprehensive, and easy-to-use
Java API for communicating with LDAP directory servers and performing
related tasks like reading and writing LDIF, encoding and decoding data
using base64 and ASN.1 BER, and performing secure communication. This
package contains the Standard Edition of the LDAP SDK, which is a
complete, general-purpose library for communicating with LDAPv3 directory
servers.
/*
* Copyright 2012-2018 Ping Identity Corporation
* All Rights Reserved.
*/
/*
* Copyright (C) 2012-2018 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);
}
}