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/*
* 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 com.feilong.lib.net.util;
import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
/**
* Provides Base64 encoding and decoding as defined by RFC 2045.
*
*
* This class implements section 6.8. Base64 Content-Transfer-Encoding from RFC 2045 Multipurpose
* Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies by Freed and Borenstein.
*
*
* The class can be parameterized in the following manner with various constructors:
*
* - URL-safe mode: Default off.
* - Line length: Default 76. Line length that aren't multiples of 4 will still essentially end up being multiples of
* 4 in the encoded data.
*
- Line separator: Default is CRLF ("\r\n")
*
*
* Since this class operates directly on byte streams, and not character streams, it is hard-coded to only encode/decode
* character encodings which are compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc).
*
*
* @see RFC 2045
* @since 2.2
* @version $Id$
*/
public class Base64{
private static final int DEFAULT_BUFFER_RESIZE_FACTOR = 2;
private static final int DEFAULT_BUFFER_SIZE = 8192;
/**
* Chunk size per RFC 2045 section 6.8.
*
*
* The {@value} character limit does not count the trailing CRLF, but counts all other characters, including any
* equal signs.
*
*
* @see RFC 2045 section 6.8
*/
static final int CHUNK_SIZE = 76;
/**
* Chunk separator per RFC 2045 section 2.1.
*
* @see RFC 2045 section 2.1
*/
private static final byte[] CHUNK_SEPARATOR = { '\r', '\n' };
private static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
/**
* 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.
*
* 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',
'-',
'_' };
/**
* Byte used to pad output.
*/
private static final byte PAD = '=';
/**
* 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.
*
* 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).
*
* 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 };
/** Mask used to extract 6 bits, used when encoding */
private static final int MASK_6BITS = 0x3f;
/** Mask used to extract 8 bits, used in decoding base64 bytes */
private static final int MASK_8BITS = 0xff;
// 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;
/**
* Line length for encoding. Not used when decoding. A value of zero or less implies no chunking of the base64
* encoded data.
*/
private final int lineLength;
/**
* 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.
* decodeSize = 3 + lineSeparator.length;
*/
private final int decodeSize;
/**
* Convenience variable to help us determine when our buffer is going to run out of room and needs resizing.
* encodeSize = 4 + lineSeparator.length;
*/
private final int encodeSize;
/**
* Buffer for streaming.
*/
private byte[] buffer;
/**
* Position where next character should be written in the buffer.
*/
private int pos;
/**
* Position where next character should be read from the buffer.
*/
private int readPos;
/**
* 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).
*/
private int currentLinePos;
/**
* Writes to the buffer only occur after every 3 reads when encoding, an every 4 reads when decoding. This variable
* helps track that.
*/
private int modulus;
/**
* Boolean flag to indicate the EOF has been reached. Once EOF has been reached, this Base64 object becomes useless,
* and must be thrown away.
*/
private boolean eof;
/**
* Place holder for the 3 bytes we're dealing with for our base64 logic. Bitwise operations store and extract the
* base64 encoding or decoding from this variable.
*/
private int x;
/**
* Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
*
* When encoding the line length is 76, the line separator is CRLF, and the encoding table is STANDARD_ENCODE_TABLE.
*
*
*
* When decoding all variants are supported.
*
*/
public Base64(){
this(false);
}
/**
* Creates a Base64 codec used for decoding (all modes) and encoding in the given URL-safe mode.
*
* When encoding the line length is 76, the line separator is CRLF, and the encoding table is STANDARD_ENCODE_TABLE.
*
*
*
* When decoding all variants are supported.
*
*
* @param urlSafe
* if true, URL-safe encoding is used. In most cases this should be set to
* false.
* @since 1.4
*/
public Base64(boolean urlSafe){
this(CHUNK_SIZE, CHUNK_SEPARATOR, urlSafe);
}
/**
* Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
*
* When encoding the line length is given in the constructor, the line separator is CRLF, and the encoding table is
* STANDARD_ENCODE_TABLE.
*
*
* Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.
*
*
* When decoding all variants are supported.
*
*
* @param lineLength
* Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4).
* If {@code 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.
*
* When encoding the line length and line separator are given in the constructor, and the encoding table is
* STANDARD_ENCODE_TABLE.
*
*
* Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.
*
*
* When decoding all variants are supported.
*
*
* @param lineLength
* Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4).
* If {@code 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.
*
* When encoding the line length and line separator are given in the constructor, and the encoding table is
* STANDARD_ENCODE_TABLE.
*
*
* Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.
*
*
* When decoding all variants are supported.
*
*
* @param lineLength
* Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4).
* If {@code 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){
if (lineSeparator == null){
lineLength = 0; // disable chunk-separating
lineSeparator = EMPTY_BYTE_ARRAY; // this just gets ignored
}
this.lineLength = lineLength > 0 ? (lineLength / 4) * 4 : 0;
this.lineSeparator = new byte[lineSeparator.length];
System.arraycopy(lineSeparator, 0, this.lineSeparator, 0, lineSeparator.length);
if (lineLength > 0){
this.encodeSize = 4 + lineSeparator.length;
}else{
this.encodeSize = 4;
}
this.decodeSize = this.encodeSize - 1;
if (containsBase64Byte(lineSeparator)){
String sep = newStringUtf8(lineSeparator);
throw new IllegalArgumentException("lineSeperator must not contain base64 characters: [" + sep + "]");
}
this.encodeTable = urlSafe ? URL_SAFE_ENCODE_TABLE : STANDARD_ENCODE_TABLE;
}
/**
* 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;
}
/**
* Returns true if this Base64 object has buffered data for reading.
*
* @return true if there is Base64 object still available for reading.
*/
boolean hasData(){
return this.buffer != null;
}
/**
* Returns the amount of buffered data available for reading.
*
* @return The amount of buffered data available for reading.
*/
int avail(){
return buffer != null ? pos - readPos : 0;
}
/** Doubles our buffer. */
private void resizeBuffer(){
if (buffer == null){
buffer = new byte[DEFAULT_BUFFER_SIZE];
pos = 0;
readPos = 0;
}else{
byte[] b = new byte[buffer.length * DEFAULT_BUFFER_RESIZE_FACTOR];
System.arraycopy(buffer, 0, b, 0, buffer.length);
buffer = b;
}
}
/**
* 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.
*
* @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).
* @return The number of bytes successfully extracted into the provided byte[] array.
*/
int readResults(byte[] b,int bPos,int bAvail){
if (buffer != null){
int len = Math.min(avail(), bAvail);
if (buffer != b){
System.arraycopy(buffer, readPos, b, bPos, len);
readPos += len;
if (readPos >= pos){
buffer = null;
}
}else{
// Re-using the original consumer's output array is only
// allowed for one round.
buffer = null;
}
return len;
}
return eof ? -1 : 0;
}
/**
* Sets the streaming buffer. This is a small optimization where we try to buffer directly to the consumer's output
* array for one round (if the consumer calls this method first) instead of starting our own buffer.
*
* @param out
* byte[] array to buffer directly to.
* @param outPos
* Position to start buffering into.
* @param outAvail
* Amount of bytes available for direct buffering.
*/
void setInitialBuffer(byte[] out,int outPos,int outAvail){
// We can re-use consumer's original output array under
// special circumstances, saving on some System.arraycopy().
if (out != null && out.length == outAvail){
buffer = out;
pos = outPos;
readPos = outPos;
}
}
/**
*
* 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).
*
*
* 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/
*
*
* @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.
*/
void encode(byte[] in,int inPos,int inAvail){
if (eof){
return;
}
// inAvail < 0 is how we're informed of EOF in the underlying data we're
// encoding.
if (inAvail < 0){
eof = true;
if (buffer == null || buffer.length - pos < encodeSize){
resizeBuffer();
}
switch (modulus) {
case 1:
buffer[pos++] = encodeTable[(x >> 2) & MASK_6BITS];
buffer[pos++] = encodeTable[(x << 4) & MASK_6BITS];
// URL-SAFE skips the padding to further reduce size.
if (encodeTable == STANDARD_ENCODE_TABLE){
buffer[pos++] = PAD;
buffer[pos++] = PAD;
}
break;
case 2:
buffer[pos++] = encodeTable[(x >> 10) & MASK_6BITS];
buffer[pos++] = encodeTable[(x >> 4) & MASK_6BITS];
buffer[pos++] = encodeTable[(x << 2) & MASK_6BITS];
// URL-SAFE skips the padding to further reduce size.
if (encodeTable == STANDARD_ENCODE_TABLE){
buffer[pos++] = PAD;
}
break;
default:
break; // other values ignored
}
if (lineLength > 0 && pos > 0){
System.arraycopy(lineSeparator, 0, buffer, pos, lineSeparator.length);
pos += lineSeparator.length;
}
}else{
for (int i = 0; i < inAvail; i++){
if (buffer == null || buffer.length - pos < encodeSize){
resizeBuffer();
}
modulus = (++modulus) % 3;
int b = in[inPos++];
if (b < 0){
b += 256;
}
x = (x << 8) + b;
if (0 == modulus){
buffer[pos++] = encodeTable[(x >> 18) & MASK_6BITS];
buffer[pos++] = encodeTable[(x >> 12) & MASK_6BITS];
buffer[pos++] = encodeTable[(x >> 6) & MASK_6BITS];
buffer[pos++] = encodeTable[x & MASK_6BITS];
currentLinePos += 4;
if (lineLength > 0 && lineLength <= currentLinePos){
System.arraycopy(lineSeparator, 0, buffer, pos, lineSeparator.length);
pos += lineSeparator.length;
currentLinePos = 0;
}
}
}
}
}
/**
*
* 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.
*
*
* 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.
*
*
* 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/
*
*
* @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.
*/
void decode(byte[] in,int inPos,int inAvail){
if (eof){
return;
}
if (inAvail < 0){
eof = true;
}
for (int i = 0; i < inAvail; i++){
if (buffer == null || buffer.length - pos < decodeSize){
resizeBuffer();
}
byte b = in[inPos++];
if (b == PAD){
// We're done.
eof = true;
break;
}
if (b >= 0 && b < DECODE_TABLE.length){
int result = DECODE_TABLE[b];
if (result >= 0){
modulus = (++modulus) % 4;
x = (x << 6) + result;
if (modulus == 0){
buffer[pos++] = (byte) ((x >> 16) & MASK_8BITS);
buffer[pos++] = (byte) ((x >> 8) & MASK_8BITS);
buffer[pos++] = (byte) (x & 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 (eof && modulus != 0){
x = x << 6;
switch (modulus) {
case 2:
x = x << 6;
buffer[pos++] = (byte) ((x >> 16) & MASK_8BITS);
break;
case 3:
buffer[pos++] = (byte) ((x >> 16) & MASK_8BITS);
buffer[pos++] = (byte) ((x >> 8) & MASK_8BITS);
break;
default:
break; // other values ignored
}
}
}
/**
* Returns whether or not the octet is in the base 64 alphabet.
*
* @param octet
* The value to test
* @return true if the value is defined in the the base 64 alphabet, false otherwise.
* @since 1.4
*/
public static boolean isBase64(byte octet){
return octet == PAD || (octet >= 0 && octet < DECODE_TABLE.length && DECODE_TABLE[octet] != -1);
}
/**
* 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 true if all bytes are valid characters in the Base64 alphabet or if the byte array is empty;
* false, otherwise
*/
public static boolean isArrayByteBase64(byte[] arrayOctet){
for (byte element : arrayOctet){
if (!isBase64(element) && !isWhiteSpace(element)){
return false;
}
}
return true;
}
/**
* Tests a given byte array to see if it contains only valid characters within the Base64 alphabet.
*
* @param arrayOctet
* byte array to test
* @return true if any byte is a valid character in the Base64 alphabet; false herwise
*/
private static boolean containsBase64Byte(byte[] arrayOctet){
for (byte element : arrayOctet){
if (isBase64(element)){
return true;
}
}
return false;
}
/**
* 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 into 76 character blocks separated by CRLF.
*
* For a non-chunking version, see {@link #encodeBase64StringUnChunked(byte[])}.
*
* @param binaryData
* binary data to encode
* @return String containing Base64 characters.
* @since 1.4
*/
public static String encodeBase64String(byte[] binaryData){
return newStringUtf8(encodeBase64(binaryData, true));
}
/**
* Encodes binary data using the base64 algorithm, without using chunking.
*
* For a chunking version, see {@link #encodeBase64String(byte[])}.
*
* @param binaryData
* binary data to encode
* @return String containing Base64 characters.
* @since 3.2
*/
public static String encodeBase64StringUnChunked(byte[] binaryData){
return newStringUtf8(encodeBase64(binaryData, false));
}
/**
* Encodes binary data using the base64 algorithm.
*
* @param binaryData
* binary data to encode
* @param useChunking
* whether to split the output into chunks
* @return String containing Base64 characters.
* @since 3.2
*/
public static String encodeBase64String(byte[] binaryData,boolean useChunking){
return newStringUtf8(encodeBase64(binaryData, useChunking));
}
/**
* 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));
}
/**
* 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);
}
/**
* Decodes a String containing containing characters in the Base64 alphabet.
*
* @param pArray
* A String containing Base64 character data
* @return a byte array containing binary data
* @since 1.4
*/
public byte[] decode(String pArray){
return decode(getBytesUtf8(pArray));
}
private static byte[] getBytesUtf8(String pArray){
try{
return pArray.getBytes("UTF8");
}catch (UnsupportedEncodingException e){
throw new RuntimeException(e);
}
}
/**
* Decodes a byte[] containing containing characters in the Base64 alphabet.
*
* @param pArray
* A byte array containing Base64 character data
* @return a byte array containing binary data
*/
public byte[] decode(byte[] pArray){
reset();
if (pArray == null || pArray.length == 0){
return pArray;
}
long len = (pArray.length * 3) / 4;
byte[] buf = new byte[(int) len];
setInitialBuffer(buf, 0, buf.length);
decode(pArray, 0, pArray.length);
decode(pArray, 0, -1); // Notify decoder of EOF.
// Would be nice to just return buf (like we sometimes do in the encode
// logic), but we have no idea what the line-length was (could even be
// variable). So we cannot determine ahead of time exactly how big an
// array is necessary. Hence the need to construct a 2nd byte array to
// hold the final result:
byte[] result = new byte[pos];
readResults(result, 0, result.length);
return result;
}
/**
* 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 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 true this encoder will chunk the base64 output into 76 character blocks
* @param urlSafe
* if 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 true this encoder will chunk the base64 output into 76 character blocks
* @param urlSafe
* if 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;
}
long len = getEncodeLength(binaryData, isChunked ? CHUNK_SIZE : 0, isChunked ? CHUNK_SEPARATOR : EMPTY_BYTE_ARRAY);
if (len > maxResultSize){
throw new IllegalArgumentException(
"Input array too big, the output array would be bigger (" + len + ") than the specified maxium size of "
+ maxResultSize);
}
Base64 b64 = isChunked ? new Base64(urlSafe) : new Base64(0, CHUNK_SEPARATOR, urlSafe);
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);
}
/**
* Checks if a byte value is whitespace or not.
*
* @param byteToCheck
* the byte to check
* @return true if byte is whitespace, false otherwise
*/
private static boolean isWhiteSpace(byte byteToCheck){
switch (byteToCheck) {
case ' ':
case '\n':
case '\r':
case '\t':
return true;
default:
return false;
}
}
/**
* Encodes a byte[] containing binary data, into a String containing characters in the Base64 alphabet.
*
* @param pArray
* a byte array containing binary data
* @return A String containing only Base64 character data
* @since 1.4
*/
public String encodeToString(byte[] pArray){
return newStringUtf8(encode(pArray));
}
private static String newStringUtf8(byte[] encode){
String str = null;
try{
str = new String(encode, "UTF8");
}catch (UnsupportedEncodingException ue){
throw new RuntimeException(ue);
}
return str;
}
/**
* Encodes a byte[] containing binary data, into a byte[] containing characters in the Base64 alphabet.
*
* @param pArray
* a byte array containing binary data
* @return A byte array containing only Base64 character data
*/
public byte[] encode(byte[] pArray){
reset();
if (pArray == null || pArray.length == 0){
return pArray;
}
long len = getEncodeLength(pArray, lineLength, lineSeparator);
byte[] buf = new byte[(int) len];
setInitialBuffer(buf, 0, buf.length);
encode(pArray, 0, pArray.length);
encode(pArray, 0, -1); // Notify encoder of EOF.
// Encoder might have resized, even though it was unnecessary.
if (buffer != buf){
readResults(buf, 0, buf.length);
}
// In URL-SAFE mode we skip the padding characters, so sometimes our
// final length is a bit smaller.
if (isUrlSafe() && pos < buf.length){
byte[] smallerBuf = new byte[pos];
System.arraycopy(buf, 0, smallerBuf, 0, pos);
buf = smallerBuf;
}
return buf;
}
/**
* Pre-calculates the amount of space needed to base64-encode the supplied array.
*
* @param pArray
* byte[] array which will later be encoded
* @param chunkSize
* line-length of the output (<= 0 means no chunking) between each
* chunkSeparator (e.g. CRLF).
* @param chunkSeparator
* the sequence of bytes used to separate chunks of output (e.g. CRLF).
*
* @return amount of space needed to encoded the supplied array. Returns
* a long since a max-len array will require Integer.MAX_VALUE + 33%.
*/
private static long getEncodeLength(byte[] pArray,int chunkSize,byte[] chunkSeparator){
// base64 always encodes to multiples of 4.
chunkSize = (chunkSize / 4) * 4;
long len = (pArray.length * 4) / 3;
long mod = len % 4;
if (mod != 0){
len += 4 - mod;
}
if (chunkSize > 0){
boolean lenChunksPerfectly = len % chunkSize == 0;
len += (len / chunkSize) * chunkSeparator.length;
if (!lenChunksPerfectly){
len += chunkSeparator.length;
}
}
return len;
}
// 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 BigInteger without sign bit.
*
* @param bigInt
* BigInteger 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;
}
/**
* Resets this Base64 object to its initial newly constructed state.
*/
private void reset(){
buffer = null;
pos = 0;
readPos = 0;
currentLinePos = 0;
modulus = 0;
eof = false;
}
// Getters for use in testing
int getLineLength(){
return lineLength;
}
byte[] getLineSeparator(){
return lineSeparator.clone();
}
}