/*
* Copyright (c) 2014 The APN-PROXY Project
*
* The APN-PROXY Project 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 com.xx_dev.apn.proxy.utils;
import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
/**
* @author xmx
* @version $Id: com.xx_dev.apn.proxy.utils.Base64 14-1-8 16:13 (xmx) Exp $
*/
public class Base64 {
/**
* Holds thread context so classes can be thread-safe.
* <p/>
* This class is not itself thread-safe; each thread must allocate its own
* copy.
*
* @since 1.7
*/
static class Context {
/**
* Place holder for the bytes we're dealing with for our based logic.
* Bitwise operations store and extract the encoding or decoding from
* this variable.
*/
int ibitWorkArea;
/**
* Place holder for the bytes we're dealing with for our based logic.
* Bitwise operations store and extract the encoding or decoding from
* this variable.
*/
long lbitWorkArea;
/**
* Buffer for streaming.
*/
byte[] buffer;
/**
* Position where next character should be written in the buffer.
*/
int pos;
/**
* Position where next character should be read from the buffer.
*/
int readPos;
/**
* Boolean flag to indicate the EOF has been reached. Once EOF has been
* reached, this object becomes useless, and must be thrown away.
*/
boolean eof;
/**
* Variable tracks how many characters have been written to the current
* line. Only used when encoding. We use it to make sure each encoded
* line never goes beyond lineLength (if lineLength > 0).
*/
int currentLinePos;
/**
* Writes to the buffer only occur after every 3/5 reads when encoding,
* and every 4/8 reads when decoding. This variable helps track that.
*/
int modulus;
Context() {
}
/**
* Returns a String useful for debugging (especially within a debugger.)
*
* @return a String useful for debugging.
*/
@SuppressWarnings("boxing")
// OK to ignore boxing here
@Override
public String toString() {
return String.format(
"%s[buffer=%s, currentLinePos=%s, eof=%s, ibitWorkArea=%s, lbitWorkArea=%s, "
+ "modulus=%s, pos=%s, readPos=%s]", this.getClass().getSimpleName(),
buffer, currentLinePos, eof, ibitWorkArea, lbitWorkArea, modulus, pos, readPos);
}
}
/**
* EOF
*
* @since 1.7
*/
static final int EOF = -1;
/**
* MIME chunk size per RFC 2045 section 6.8.
* <p/>
* <p>
* The {@value} character limit does not count the trailing CRLF, but counts
* all other characters, including any equal signs.
* </p>
*
* @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section
* 6.8</a>
*/
public static final int MIME_CHUNK_SIZE = 76;
/**
* PEM chunk size per RFC 1421 section 4.3.2.4.
* <p/>
* <p>
* The {@value} character limit does not count the trailing CRLF, but counts
* all other characters, including any equal signs.
* </p>
*
* @see <a href="http://tools.ietf.org/html/rfc1421">RFC 1421 section
* 4.3.2.4</a>
*/
public static final int PEM_CHUNK_SIZE = 64;
private static final int DEFAULT_BUFFER_RESIZE_FACTOR = 2;
/**
* Defines the default buffer size - currently {@value} - must be large
* enough for at least one encoded block+separator
*/
private static final int DEFAULT_BUFFER_SIZE = 8192;
/**
* Mask used to extract 8 bits, used in decoding bytes
*/
protected static final int MASK_8BITS = 0xff;
/**
* Byte used to pad output.
*/
protected static final byte PAD_DEFAULT = '='; // Allow static access to
// default
protected final byte PAD = PAD_DEFAULT; // instance variable just in case it
// needs to vary later
/**
* Number of bytes in each full block of unencoded data, e.g. 4 for Base64
* and 5 for Base32
*/
private final int unencodedBlockSize;
/**
* Number of bytes in each full block of encoded data, e.g. 3 for Base64 and
* 8 for Base32
*/
private final int encodedBlockSize;
/**
* Chunksize for encoding. Not used when decoding. A value of zero or less
* implies no chunking of the encoded data. Rounded down to nearest multiple
* of encodedBlockSize.
*/
protected final int lineLength;
/**
* Size of chunk separator. Not used unless {@link #lineLength} > 0.
*/
private final int chunkSeparatorLength;
/**
* BASE32 characters are 6 bits in length. They are formed by taking a block
* of 3 octets to form a 24-bit string, which is converted into 4 BASE64
* characters.
*/
private static final int BITS_PER_ENCODED_BYTE = 6;
private static final int BYTES_PER_UNENCODED_BLOCK = 3;
private static final int BYTES_PER_ENCODED_BLOCK = 4;
/**
* Chunk separator per RFC 2045 section 2.1.
* <p/>
* <p>
* N.B. The next major release may break compatibility and make this field
* private.
* </p>
*
* @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section
* 2.1</a>
*/
static final byte[] CHUNK_SEPARATOR = {'\r', '\n'};
/**
* This array is a lookup table that translates 6-bit positive integer index
* values into their "Base64 Alphabet" equivalents as specified in Table 1
* of RFC 2045.
* <p/>
* Thanks to "commons" project in ws.apache.org for this code.
* http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/
*/
private static final byte[] STANDARD_ENCODE_TABLE = {'A', 'B', 'C', 'D', 'E', 'F', 'G',
'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5',
'6', '7', '8', '9', '+', '/'};
/**
* This is a copy of the STANDARD_ENCODE_TABLE above, but with + and /
* changed to - and _ to make the encoded Base64 results more URL-SAFE. This
* table is only used when the Base64's mode is set to URL-SAFE.
*/
private static final byte[] URL_SAFE_ENCODE_TABLE = {'A', 'B', 'C', 'D', 'E', 'F', 'G',
'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5',
'6', '7', '8', '9', '-', '_'};
/**
* This array is a lookup table that translates Unicode characters drawn
* from the "Base64 Alphabet" (as specified in Table 1 of RFC 2045) into
* their 6-bit positive integer equivalents. Characters that are not in the
* Base64 alphabet but fall within the bounds of the array are translated to
* -1.
* <p/>
* Note: '+' and '-' both decode to 62. '/' and '_' both decode to 63. This
* means decoder seamlessly handles both URL_SAFE and STANDARD base64. (The
* encoder, on the other hand, needs to know ahead of time what to emit).
* <p/>
* Thanks to "commons" project in ws.apache.org for this code.
* http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/
*/
private static final byte[] DECODE_TABLE = {-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, 62, -1, 63, 52, 53, 54, 55,
56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, 63, -1, 26,
27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48,
49, 50, 51};
/**
* Base64 uses 6-bit fields.
*/
/**
* Mask used to extract 6 bits, used when encoding
*/
private static final int MASK_6BITS = 0x3f;
// The static final fields above are used for the original static byte[]
// methods on Base64.
// The private member fields below are used with the new streaming approach,
// which requires
// some state be preserved between calls of encode() and decode().
/**
* Encode table to use: either STANDARD or URL_SAFE. Note: the DECODE_TABLE
* above remains static because it is able to decode both STANDARD and
* URL_SAFE streams, but the encodeTable must be a member variable so we can
* switch between the two modes.
*/
private final byte[] encodeTable;
// Only one decode table currently; keep for consistency with Base32 code
private final byte[] decodeTable = DECODE_TABLE;
/**
* Line separator for encoding. Not used when decoding. Only used if
* lineLength > 0.
*/
private final byte[] lineSeparator;
/**
* Convenience variable to help us determine when our buffer is going to run
* out of room and needs resizing.
* <code>decodeSize = 3 + lineSeparator.length;</code>
*/
private final int decodeSize;
/**
* Convenience variable to help us determine when our buffer is going to run
* out of room and needs resizing.
* <code>encodeSize = 4 + lineSeparator.length;</code>
*/
private final int encodeSize;
/**
* Creates a Base64 codec used for decoding (all modes) and encoding in
* URL-unsafe mode.
* <p>
* When encoding the line length is 0 (no chunking), and the encoding table
* is STANDARD_ENCODE_TABLE.
* </p>
* <p/>
* <p>
* When decoding all variants are supported.
* </p>
*/
public Base64() {
this(0);
}
/**
* Creates a Base64 codec used for decoding (all modes) and encoding in the
* given URL-safe mode.
* <p>
* When encoding the line length is 76, the line separator is CRLF, and the
* encoding table is STANDARD_ENCODE_TABLE.
* </p>
* <p/>
* <p>
* When decoding all variants are supported.
* </p>
*
* @param urlSafe if {@code true}, URL-safe encoding is used. In most cases this
* should be set to {@code false}.
* @since 1.4
*/
public Base64(boolean urlSafe) {
this(MIME_CHUNK_SIZE, CHUNK_SEPARATOR, urlSafe);
}
/**
* Creates a Base64 codec used for decoding (all modes) and encoding in
* URL-unsafe mode.
* <p>
* When encoding the line length is given in the constructor, the line
* separator is CRLF, and the encoding table is STANDARD_ENCODE_TABLE.
* </p>
* <p>
* Line lengths that aren't multiples of 4 will still essentially end up
* being multiples of 4 in the encoded data.
* </p>
* <p>
* When decoding all variants are supported.
* </p>
*
* @param lineLength Each line of encoded data will be at most of the given length
* (rounded down to nearest multiple of 4). If lineLength <= 0,
* then the output will not be divided into lines (chunks).
* Ignored when decoding.
* @since 1.4
*/
public Base64(int lineLength) {
this(lineLength, CHUNK_SEPARATOR);
}
/**
* Creates a Base64 codec used for decoding (all modes) and encoding in
* URL-unsafe mode.
* <p>
* When encoding the line length and line separator are given in the
* constructor, and the encoding table is STANDARD_ENCODE_TABLE.
* </p>
* <p>
* Line lengths that aren't multiples of 4 will still essentially end up
* being multiples of 4 in the encoded data.
* </p>
* <p>
* When decoding all variants are supported.
* </p>
*
* @param lineLength Each line of encoded data will be at most of the given length
* (rounded down to nearest multiple of 4). If lineLength <= 0,
* then the output will not be divided into lines (chunks).
* Ignored when decoding.
* @param lineSeparator Each line of encoded data will end with this sequence of
* bytes.
* @throws IllegalArgumentException Thrown when the provided lineSeparator included some base64
* characters.
* @since 1.4
*/
public Base64(int lineLength, byte[] lineSeparator) {
this(lineLength, lineSeparator, false);
}
/**
* Creates a Base64 codec used for decoding (all modes) and encoding in
* URL-unsafe mode.
* <p>
* When encoding the line length and line separator are given in the
* constructor, and the encoding table is STANDARD_ENCODE_TABLE.
* </p>
* <p>
* Line lengths that aren't multiples of 4 will still essentially end up
* being multiples of 4 in the encoded data.
* </p>
* <p>
* When decoding all variants are supported.
* </p>
*
* @param lineLength Each line of encoded data will be at most of the given length
* (rounded down to nearest multiple of 4). If lineLength <= 0,
* then the output will not be divided into lines (chunks).
* Ignored when decoding.
* @param lineSeparator Each line of encoded data will end with this sequence of
* bytes.
* @param urlSafe Instead of emitting '+' and '/' we emit '-' and '_'
* respectively. urlSafe is only applied to encode operations.
* Decoding seamlessly handles both modes.
* @throws IllegalArgumentException The provided lineSeparator included some base64 characters.
* That's not going to work!
* @since 1.4
*/
public Base64(int lineLength, byte[] lineSeparator, boolean urlSafe) {
this.unencodedBlockSize = BYTES_PER_UNENCODED_BLOCK;
this.encodedBlockSize = BYTES_PER_ENCODED_BLOCK;
int chunkSeparatorLength = lineSeparator == null ? 0 : lineSeparator.length;
final boolean useChunking = lineLength > 0 && chunkSeparatorLength > 0;
this.lineLength = useChunking ? (lineLength / encodedBlockSize) * encodedBlockSize : 0;
this.chunkSeparatorLength = chunkSeparatorLength;
// could be simplified if there is no requirement to reject invalid
// line sep when length <=0
// @see test case Base64Test.testConstructors()
if (lineSeparator != null) {
if (containsAlphabetOrPad(lineSeparator)) {
String sep = newStringUtf8(lineSeparator);
throw new IllegalArgumentException(
"lineSeparator must not contain base64 characters: [" + sep + "]");
}
if (lineLength > 0) { // null line-sep forces no chunking rather
// than throwing IAE
this.encodeSize = BYTES_PER_ENCODED_BLOCK + lineSeparator.length;
this.lineSeparator = new byte[lineSeparator.length];
System.arraycopy(lineSeparator, 0, this.lineSeparator, 0, lineSeparator.length);
} else {
this.encodeSize = BYTES_PER_ENCODED_BLOCK;
this.lineSeparator = null;
}
} else {
this.encodeSize = BYTES_PER_ENCODED_BLOCK;
this.lineSeparator = null;
}
this.decodeSize = this.encodeSize - 1;
this.encodeTable = urlSafe ? URL_SAFE_ENCODE_TABLE : STANDARD_ENCODE_TABLE;
}
/**
* Returns true if this object has buffered data for reading.
*
* @param context the context to be used
* @return true if there is data still available for reading.
*/
boolean hasData(Context context) { // package protected for access from I/O
// streams
return context.buffer != null;
}
/**
* Returns the amount of buffered data available for reading.
*
* @param context the context to be used
* @return The amount of buffered data available for reading.
*/
int available(Context context) { // package protected for access from I/O
// streams
return context.buffer != null ? context.pos - context.readPos : 0;
}
/**
* Get the default buffer size. Can be overridden.
*
* @return {@link #DEFAULT_BUFFER_SIZE}
*/
protected int getDefaultBufferSize() {
return DEFAULT_BUFFER_SIZE;
}
/**
* Increases our buffer by the {@link #DEFAULT_BUFFER_RESIZE_FACTOR}.
*
* @param context the context to be used
*/
private byte[] resizeBuffer(Context context) {
if (context.buffer == null) {
context.buffer = new byte[getDefaultBufferSize()];
context.pos = 0;
context.readPos = 0;
} else {
byte[] b = new byte[context.buffer.length * DEFAULT_BUFFER_RESIZE_FACTOR];
System.arraycopy(context.buffer, 0, b, 0, context.buffer.length);
context.buffer = b;
}
return context.buffer;
}
/**
* Ensure that the buffer has room for <code>size</code> bytes
*
* @param size minimum spare space required
* @param context the context to be used
*/
protected byte[] ensureBufferSize(int size, Context context) {
if ((context.buffer == null) || (context.buffer.length < context.pos + size)) {
return resizeBuffer(context);
}
return context.buffer;
}
/**
* Extracts buffered data into the provided byte[] array, starting at
* position bPos, up to a maximum of bAvail bytes. Returns how many bytes
* were actually extracted.
* <p/>
* Package protected for access from I/O streams.
*
* @param b byte[] array to extract the buffered data into.
* @param bPos position in byte[] array to start extraction at.
* @param bAvail amount of bytes we're allowed to extract. We may extract fewer
* (if fewer are available).
* @param context the context to be used
* @return The number of bytes successfully extracted into the provided
* byte[] array.
*/
int readResults(byte[] b, int bPos, int bAvail, Context context) {
if (context.buffer != null) {
int len = Math.min(available(context), bAvail);
System.arraycopy(context.buffer, context.readPos, b, bPos, len);
context.readPos += len;
if (context.readPos >= context.pos) {
context.buffer = null; // so hasData() will return false, and
// this method can return -1
}
return len;
}
return context.eof ? EOF : 0;
}
/**
* Checks if a byte value is whitespace or not. Whitespace is taken to mean:
* space, tab, CR, LF
*
* @param byteToCheck the byte to check
* @return true if byte is whitespace, false otherwise
*/
protected static boolean isWhiteSpace(byte byteToCheck) {
switch (byteToCheck) {
case ' ':
case '\n':
case '\r':
case '\t':
return true;
default:
return false;
}
}
/**
* Encodes an Object using the Base-N algorithm. This method is provided in
* order to satisfy the requirements of the Encoder interface, and will
* throw an EncoderException if the supplied object is not of type byte[].
*
* @param obj Object to encode
* @return An object (of type byte[]) containing the Base-N encoded data
* which corresponds to the byte[] supplied.
* @throws Exception if the parameter supplied is not of type byte[]
*/
public Object encode(Object obj) throws Exception {
if (!(obj instanceof byte[])) {
throw new Exception("Parameter supplied to Base-N encode is not a byte[]");
}
return encode((byte[]) obj);
}
/**
* Encodes a byte[] containing binary data, into a String containing
* characters in the Base-N alphabet. Uses UTF8 encoding.
*
* @param pArray a byte array containing binary data
* @return A String containing only Base-N character data
*/
public String encodeToString(byte[] pArray) {
return newStringUtf8(encode(pArray));
}
/**
* Encodes a byte[] containing binary data, into a String containing
* characters in the appropriate alphabet. Uses UTF8 encoding.
*
* @param pArray a byte array containing binary data
* @return String containing only character data in the appropriate
* alphabet.
*/
public String encodeAsString(byte[] pArray) {
return newStringUtf8(encode(pArray));
}
/**
* Decodes an Object using the Base-N algorithm. This method is provided in
* order to satisfy the requirements of the Decoder interface, and will
* throw a DecoderException if the supplied object is not of type byte[] or
* String.
*
* @param obj Object to decode
* @return An object (of type byte[]) containing the binary data which
* corresponds to the byte[] or String supplied.
* @throws Exception if the parameter supplied is not of type byte[]
*/
public Object decode(Object obj) throws Exception {
if (obj instanceof byte[]) {
return decode((byte[]) obj);
} else if (obj instanceof String) {
return decode((String) obj);
} else {
throw new Exception("Parameter supplied to Base-N decode is not a byte[] or a String");
}
}
/**
* Decodes a String containing characters in the Base-N alphabet.
*
* @param pArray A String containing Base-N character data
* @return a byte array containing binary data
*/
public byte[] decode(String pArray) {
return decode(getBytesUtf8(pArray));
}
/**
* Decodes a byte[] containing characters in the Base-N alphabet.
*
* @param pArray A byte array containing Base-N character data
* @return a byte array containing binary data
*/
public byte[] decode(byte[] pArray) {
if (pArray == null || pArray.length == 0) {
return pArray;
}
Context context = new Context();
decode(pArray, 0, pArray.length, context);
decode(pArray, 0, EOF, context); // Notify decoder of EOF.
byte[] result = new byte[context.pos];
readResults(result, 0, result.length, context);
return result;
}
/**
* Encodes a byte[] containing binary data, into a byte[] containing
* characters in the alphabet.
*
* @param pArray a byte array containing binary data
* @return A byte array containing only the basen alphabetic character data
*/
public byte[] encode(byte[] pArray) {
if (pArray == null || pArray.length == 0) {
return pArray;
}
Context context = new Context();
encode(pArray, 0, pArray.length, context);
encode(pArray, 0, EOF, context); // Notify encoder of EOF.
byte[] buf = new byte[context.pos - context.readPos];
readResults(buf, 0, buf.length, context);
return buf;
}
/**
* Tests a given byte array to see if it contains only valid characters
* within the alphabet. The method optionally treats whitespace and pad as
* valid.
*
* @param arrayOctet byte array to test
* @param allowWSPad if {@code true}, then whitespace and PAD are also allowed
* @return {@code true} if all bytes are valid characters in the alphabet or
* if the byte array is empty; {@code false}, otherwise
*/
public boolean isInAlphabet(byte[] arrayOctet, boolean allowWSPad) {
for (int i = 0; i < arrayOctet.length; i++) {
if (!isInAlphabet(arrayOctet[i])
&& (!allowWSPad || (arrayOctet[i] != PAD) && !isWhiteSpace(arrayOctet[i]))) {
return false;
}
}
return true;
}
/**
* Tests a given String to see if it contains only valid characters within
* the alphabet. The method treats whitespace and PAD as valid.
*
* @param basen String to test
* @return {@code true} if all characters in the String are valid characters
* in the alphabet or if the String is empty; {@code false},
* otherwise
* @see #isInAlphabet(byte[], boolean)
*/
public boolean isInAlphabet(String basen) {
return isInAlphabet(getBytesUtf8(basen), true);
}
/**
* Tests a given byte array to see if it contains any characters within the
* alphabet or PAD.
* <p/>
* Intended for use in checking line-ending arrays
*
* @param arrayOctet byte array to test
* @return {@code true} if any byte is a valid character in the alphabet or
* PAD; {@code false} otherwise
*/
protected boolean containsAlphabetOrPad(byte[] arrayOctet) {
if (arrayOctet == null) {
return false;
}
for (byte element : arrayOctet) {
if (PAD == element || isInAlphabet(element)) {
return true;
}
}
return false;
}
/**
* Calculates the amount of space needed to encode the supplied array.
*
* @param pArray byte[] array which will later be encoded
* @return amount of space needed to encoded the supplied array. Returns a
* long since a max-len array will require > Integer.MAX_VALUE
*/
public long getEncodedLength(byte[] pArray) {
// Calculate non-chunked size - rounded up to allow for padding
// cast to long is needed to avoid possibility of overflow
long len = ((pArray.length + unencodedBlockSize - 1) / unencodedBlockSize)
* (long) encodedBlockSize;
if (lineLength > 0) { // We're using chunking
// Round up to nearest multiple
len += ((len + lineLength - 1) / lineLength) * chunkSeparatorLength;
}
return len;
}
/**
* Returns our current encode mode. True if we're URL-SAFE, false otherwise.
*
* @return true if we're in URL-SAFE mode, false otherwise.
* @since 1.4
*/
public boolean isUrlSafe() {
return this.encodeTable == URL_SAFE_ENCODE_TABLE;
}
/**
* <p>
* Encodes all of the provided data, starting at inPos, for inAvail bytes.
* Must be called at least twice: once with the data to encode, and once
* with inAvail set to "-1" to alert encoder that EOF has been reached, so
* flush last remaining bytes (if not multiple of 3).
* </p>
* <p>
* Thanks to "commons" project in ws.apache.org for the bitwise operations,
* and general approach.
* http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/
* </p>
*
* @param in byte[] array of binary data to base64 encode.
* @param inPos Position to start reading data from.
* @param inAvail Amount of bytes available from input for encoding.
* @param context the context to be used
*/
void encode(byte[] in, int inPos, int inAvail, Context context) {
if (context.eof) {
return;
}
// inAvail < 0 is how we're informed of EOF in the underlying data we're
// encoding.
if (inAvail < 0) {
context.eof = true;
if (0 == context.modulus && lineLength == 0) {
return; // no leftovers to process and not using chunking
}
final byte[] buffer = ensureBufferSize(encodeSize, context);
final int savedPos = context.pos;
switch (context.modulus) { // 0-2
case 0: // nothing to do here
break;
case 1: // 8 bits = 6 + 2
// top 6 bits:
buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 2) & MASK_6BITS];
// remaining 2:
buffer[context.pos++] = encodeTable[(context.ibitWorkArea << 4) & MASK_6BITS];
// URL-SAFE skips the padding to further reduce size.
if (encodeTable == STANDARD_ENCODE_TABLE) {
buffer[context.pos++] = PAD;
buffer[context.pos++] = PAD;
}
break;
case 2: // 16 bits = 6 + 6 + 4
buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 10) & MASK_6BITS];
buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 4) & MASK_6BITS];
buffer[context.pos++] = encodeTable[(context.ibitWorkArea << 2) & MASK_6BITS];
// URL-SAFE skips the padding to further reduce size.
if (encodeTable == STANDARD_ENCODE_TABLE) {
buffer[context.pos++] = PAD;
}
break;
default:
throw new IllegalStateException("Impossible modulus " + context.modulus);
}
context.currentLinePos += context.pos - savedPos; // keep track of
// current line
// position
// if currentPos == 0 we are at the start of a line, so don't add
// CRLF
if (lineLength > 0 && context.currentLinePos > 0) {
System.arraycopy(lineSeparator, 0, buffer, context.pos, lineSeparator.length);
context.pos += lineSeparator.length;
}
} else {
for (int i = 0; i < inAvail; i++) {
final byte[] buffer = ensureBufferSize(encodeSize, context);
context.modulus = (context.modulus + 1) % BYTES_PER_UNENCODED_BLOCK;
int b = in[inPos++];
if (b < 0) {
b += 256;
}
context.ibitWorkArea = (context.ibitWorkArea << 8) + b; // BITS_PER_BYTE
if (0 == context.modulus) { // 3 bytes = 24 bits = 4 * 6 bits to
// extract
buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 18) & MASK_6BITS];
buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 12) & MASK_6BITS];
buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 6) & MASK_6BITS];
buffer[context.pos++] = encodeTable[context.ibitWorkArea & MASK_6BITS];
context.currentLinePos += BYTES_PER_ENCODED_BLOCK;
if (lineLength > 0 && lineLength <= context.currentLinePos) {
System.arraycopy(lineSeparator, 0, buffer, context.pos,
lineSeparator.length);
context.pos += lineSeparator.length;
context.currentLinePos = 0;
}
}
}
}
}
/**
* <p>
* Decodes all of the provided data, starting at inPos, for inAvail bytes.
* Should be called at least twice: once with the data to decode, and once
* with inAvail set to "-1" to alert decoder that EOF has been reached. The
* "-1" call is not necessary when decoding, but it doesn't hurt, either.
* </p>
* <p>
* Ignores all non-base64 characters. This is how chunked (e.g. 76
* character) data is handled, since CR and LF are silently ignored, but has
* implications for other bytes, too. This method subscribes to the
* garbage-in, garbage-out philosophy: it will not check the provided data
* for validity.
* </p>
* <p>
* Thanks to "commons" project in ws.apache.org for the bitwise operations,
* and general approach.
* http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/
* </p>
*
* @param in byte[] array of ascii data to base64 decode.
* @param inPos Position to start reading data from.
* @param inAvail Amount of bytes available from input for encoding.
* @param context the context to be used
*/
void decode(byte[] in, int inPos, int inAvail, Context context) {
if (context.eof) {
return;
}
if (inAvail < 0) {
context.eof = true;
}
for (int i = 0; i < inAvail; i++) {
final byte[] buffer = ensureBufferSize(decodeSize, context);
final byte b = in[inPos++];
if (b == PAD) {
// We're done.
context.eof = true;
break;
} else {
if (b >= 0 && b < DECODE_TABLE.length) {
final int result = DECODE_TABLE[b];
if (result >= 0) {
context.modulus = (context.modulus + 1) % BYTES_PER_ENCODED_BLOCK;
context.ibitWorkArea = (context.ibitWorkArea << BITS_PER_ENCODED_BYTE)
+ result;
if (context.modulus == 0) {
buffer[context.pos++] = (byte) ((context.ibitWorkArea >> 16) & MASK_8BITS);
buffer[context.pos++] = (byte) ((context.ibitWorkArea >> 8) & MASK_8BITS);
buffer[context.pos++] = (byte) (context.ibitWorkArea & MASK_8BITS);
}
}
}
}
}
// Two forms of EOF as far as base64 decoder is concerned: actual
// EOF (-1) and first time '=' character is encountered in stream.
// This approach makes the '=' padding characters completely optional.
if (context.eof && context.modulus != 0) {
final byte[] buffer = ensureBufferSize(decodeSize, context);
// We have some spare bits remaining
// Output all whole multiples of 8 bits and ignore the rest
switch (context.modulus) {
// case 0 : // impossible, as excluded above
case 1: // 6 bits - ignore entirely
// not currently tested; perhaps it is impossible?
break;
case 2: // 12 bits = 8 + 4
context.ibitWorkArea = context.ibitWorkArea >> 4; // dump the
// extra 4
// bits
buffer[context.pos++] = (byte) ((context.ibitWorkArea) & MASK_8BITS);
break;
case 3: // 18 bits = 8 + 8 + 2
context.ibitWorkArea = context.ibitWorkArea >> 2; // dump 2 bits
buffer[context.pos++] = (byte) ((context.ibitWorkArea >> 8) & MASK_8BITS);
buffer[context.pos++] = (byte) ((context.ibitWorkArea) & MASK_8BITS);
break;
default:
throw new IllegalStateException("Impossible modulus " + context.modulus);
}
}
}
/**
* Tests a given byte array to see if it contains only valid characters
* within the Base64 alphabet. Currently the method treats whitespace as
* valid.
*
* @param arrayOctet byte array to test
* @return {@code true} if all bytes are valid characters in the Base64
* alphabet or if the byte array is empty; {@code false}, otherwise
* @deprecated 1.5 Use {@link #isBase64(byte[])}, will be removed in 2.0.
*/
@Deprecated
public static boolean isArrayByteBase64(byte[] arrayOctet) {
return isBase64(arrayOctet);
}
/**
* Returns whether or not the <code>octet</code> is in the base 64 alphabet.
*
* @param octet The value to test
* @return {@code true} if the value is defined in the the base 64 alphabet,
* {@code false} otherwise.
* @since 1.4
*/
public static boolean isBase64(byte octet) {
return octet == PAD_DEFAULT
|| (octet >= 0 && octet < DECODE_TABLE.length && DECODE_TABLE[octet] != -1);
}
/**
* Tests a given String to see if it contains only valid characters within
* the Base64 alphabet. Currently the method treats whitespace as valid.
*
* @param base64 String to test
* @return {@code true} if all characters in the String are valid characters
* in the Base64 alphabet or if the String is empty; {@code false},
* otherwise
* @since 1.5
*/
public static boolean isBase64(String base64) {
return isBase64(getBytesUtf8(base64));
}
/**
* Tests a given byte array to see if it contains only valid characters
* within the Base64 alphabet. Currently the method treats whitespace as
* valid.
*
* @param arrayOctet byte array to test
* @return {@code true} if all bytes are valid characters in the Base64
* alphabet or if the byte array is empty; {@code false}, otherwise
* @since 1.5
*/
public static boolean isBase64(byte[] arrayOctet) {
for (int i = 0; i < arrayOctet.length; i++) {
if (!isBase64(arrayOctet[i]) && !isWhiteSpace(arrayOctet[i])) {
return false;
}
}
return true;
}
/**
* Encodes binary data using the base64 algorithm but does not chunk the
* output.
*
* @param binaryData binary data to encode
* @return byte[] containing Base64 characters in their UTF-8
* representation.
*/
public static byte[] encodeBase64(byte[] binaryData) {
return encodeBase64(binaryData, false);
}
/**
* Encodes binary data using the base64 algorithm but does not chunk the
* output.
* <p/>
* NOTE: We changed the behaviour of this method from multi-line chunking
* (commons-codec-1.4) to single-line non-chunking (commons-codec-1.5).
*
* @param binaryData binary data to encode
* @return String containing Base64 characters.
* @since 1.4 (NOTE: 1.4 chunked the output, whereas 1.5 does not).
*/
public static String encodeBase64String(byte[] binaryData) {
return newStringUtf8(encodeBase64(binaryData, false));
}
/**
* Encodes binary data using a URL-safe variation of the base64 algorithm
* but does not chunk the output. The url-safe variation emits - and _
* instead of + and / characters.
*
* @param binaryData binary data to encode
* @return byte[] containing Base64 characters in their UTF-8
* representation.
* @since 1.4
*/
public static byte[] encodeBase64URLSafe(byte[] binaryData) {
return encodeBase64(binaryData, false, true);
}
/**
* Encodes binary data using a URL-safe variation of the base64 algorithm
* but does not chunk the output. The url-safe variation emits - and _
* instead of + and / characters.
*
* @param binaryData binary data to encode
* @return String containing Base64 characters
* @since 1.4
*/
public static String encodeBase64URLSafeString(byte[] binaryData) {
return newStringUtf8(encodeBase64(binaryData, false, true));
}
private static String newStringUtf8(byte bytes[]) {
try {
return new String(bytes, "UTF-8");
} catch (UnsupportedEncodingException e) {
return new String(bytes);
}
}
private static byte[] getBytesUtf8(String s) {
try {
return s.getBytes("UTF-8");
} catch (UnsupportedEncodingException e) {
return s.getBytes();
}
}
/**
* Encodes binary data using the base64 algorithm and chunks the encoded
* output into 76 character blocks
*
* @param binaryData binary data to encode
* @return Base64 characters chunked in 76 character blocks
*/
public static byte[] encodeBase64Chunked(byte[] binaryData) {
return encodeBase64(binaryData, true);
}
/**
* Encodes binary data using the base64 algorithm, optionally chunking the
* output into 76 character blocks.
*
* @param binaryData Array containing binary data to encode.
* @param isChunked if {@code true} this encoder will chunk the base64 output into
* 76 character blocks
* @return Base64-encoded data.
* @throws IllegalArgumentException Thrown when the input array needs an output array bigger than
* {@link Integer#MAX_VALUE}
*/
public static byte[] encodeBase64(byte[] binaryData, boolean isChunked) {
return encodeBase64(binaryData, isChunked, false);
}
/**
* Encodes binary data using the base64 algorithm, optionally chunking the
* output into 76 character blocks.
*
* @param binaryData Array containing binary data to encode.
* @param isChunked if {@code true} this encoder will chunk the base64 output into
* 76 character blocks
* @param urlSafe if {@code true} this encoder will emit - and _ instead of the
* usual + and / characters.
* @return Base64-encoded data.
* @throws IllegalArgumentException Thrown when the input array needs an output array bigger than
* {@link Integer#MAX_VALUE}
* @since 1.4
*/
public static byte[] encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe) {
return encodeBase64(binaryData, isChunked, urlSafe, Integer.MAX_VALUE);
}
/**
* Encodes binary data using the base64 algorithm, optionally chunking the
* output into 76 character blocks.
*
* @param binaryData Array containing binary data to encode.
* @param isChunked if {@code true} this encoder will chunk the base64 output into
* 76 character blocks
* @param urlSafe if {@code true} this encoder will emit - and _ instead of the
* usual + and / characters.
* @param maxResultSize The maximum result size to accept.
* @return Base64-encoded data.
* @throws IllegalArgumentException Thrown when the input array needs an output array bigger than
* maxResultSize
* @since 1.4
*/
public static byte[] encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe,
int maxResultSize) {
if (binaryData == null || binaryData.length == 0) {
return binaryData;
}
// Create this so can use the super-class method
// Also ensures that the same roundings are performed by the ctor and
// the code
Base64 b64 = isChunked ? new Base64(urlSafe) : new Base64(0, CHUNK_SEPARATOR, urlSafe);
long len = b64.getEncodedLength(binaryData);
if (len > maxResultSize) {
throw new IllegalArgumentException(
"Input array too big, the output array would be bigger (" + len
+ ") than the specified maximum size of " + maxResultSize);
}
return b64.encode(binaryData);
}
/**
* Decodes a Base64 String into octets
*
* @param base64String String containing Base64 data
* @return Array containing decoded data.
* @since 1.4
*/
public static byte[] decodeBase64(String base64String) {
return new Base64().decode(base64String);
}
/**
* Decodes Base64 data into octets
*
* @param base64Data Byte array containing Base64 data
* @return Array containing decoded data.
*/
public static byte[] decodeBase64(byte[] base64Data) {
return new Base64().decode(base64Data);
}
// Implementation of the Encoder Interface
// Implementation of integer encoding used for crypto
/**
* Decodes a byte64-encoded integer according to crypto standards such as
* W3C's XML-Signature
*
* @param pArray a byte array containing base64 character data
* @return A BigInteger
* @since 1.4
*/
public static BigInteger decodeInteger(byte[] pArray) {
return new BigInteger(1, decodeBase64(pArray));
}
/**
* Encodes to a byte64-encoded integer according to crypto standards such as
* W3C's XML-Signature
*
* @param bigInt a BigInteger
* @return A byte array containing base64 character data
* @throws NullPointerException if null is passed in
* @since 1.4
*/
public static byte[] encodeInteger(BigInteger bigInt) {
if (bigInt == null) {
throw new NullPointerException("encodeInteger called with null parameter");
}
return encodeBase64(toIntegerBytes(bigInt), false);
}
/**
* Returns a byte-array representation of a <code>BigInteger</code> without
* sign bit.
*
* @param bigInt <code>BigInteger</code> to be converted
* @return a byte array representation of the BigInteger parameter
*/
static byte[] toIntegerBytes(BigInteger bigInt) {
int bitlen = bigInt.bitLength();
// round bitlen
bitlen = ((bitlen + 7) >> 3) << 3;
byte[] bigBytes = bigInt.toByteArray();
if (((bigInt.bitLength() % 8) != 0) && (((bigInt.bitLength() / 8) + 1) == (bitlen / 8))) {
return bigBytes;
}
// set up params for copying everything but sign bit
int startSrc = 0;
int len = bigBytes.length;
// if bigInt is exactly byte-aligned, just skip signbit in copy
if ((bigInt.bitLength() % 8) == 0) {
startSrc = 1;
len--;
}
int startDst = bitlen / 8 - len; // to pad w/ nulls as per spec
byte[] resizedBytes = new byte[bitlen / 8];
System.arraycopy(bigBytes, startSrc, resizedBytes, startDst, len);
return resizedBytes;
}
/**
* Returns whether or not the <code>octet</code> is in the Base32 alphabet.
*
* @param octet The value to test
* @return {@code true} if the value is defined in the the Base32 alphabet
* {@code false} otherwise.
*/
protected boolean isInAlphabet(byte octet) {
return octet >= 0 && octet < decodeTable.length && decodeTable[octet] != -1;
}
}