org.apache.wicket.util.crypt.Base64 Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.wicket.util.crypt;
import java.math.BigInteger;
/**
* Provides Base64 encoding and decoding with URL and filename safe alphabet as defined by RFC 3548,
* section 4.
*
* This Base64 encoder is modified to meet URL requirements. The changes are: '+' => '*', '/' =>
* '-', and no padding.
*
* This class is taken from the Apache commons-codec, and adjusted to fit the Wicket framework's
* needs, especially external dependencies have been removed.
*
*
* This class implements section 4. Base 64 Encoding with URL and Filename Safe
* Alphabet from RFC 3548 The Base16, Base32, and Base64 Data Encodings by Simon
* Josefsson.
*
*
* @author Apache Software Foundation
* @author Juergen Donnerstag
*
* @since 1.2
*/
// TODO Wicket 8: consider to deprecate this class in Wicket 7 and replace it with standard Java 8 {@code java.util.Base64}
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.
*
*
* N.B. The next major release may break compatibility and make this field private.
*
*
* @see RFC 2045 section 2.1
*/
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.
*
* 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(final 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 lineLength <= 0, then the output will not be divided
* into lines (chunks). Ignored when decoding.
* @since 1.4
*/
public Base64(final 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 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(final int lineLength, final 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 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, final boolean urlSafe)
{
if (lineSeparator == null)
{
lineLength = 0; // disable chunk-separating
lineSeparator = CHUNK_SEPARATOR; // 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)
{
encodeSize = 4 + lineSeparator.length;
}
else
{
encodeSize = 4;
}
decodeSize = encodeSize - 1;
if (containsBase64Byte(lineSeparator))
{
String sep = StringUtils.newStringUtf8(lineSeparator);
throw new IllegalArgumentException(
"lineSeperator must not contain base64 characters: [" + sep + "]");
}
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 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 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(final byte[] b, final int bPos, final 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(final byte[] out, final int outPos, final 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(final byte[] in, int inPos, final 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;
}
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(final byte[] in, int inPos, final 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;
}
else
{
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;
}
}
}
/**
* 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(final 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(final byte[] arrayOctet)
{
for (byte octet : arrayOctet)
{
if (!isBase64(octet) && !isWhiteSpace(octet))
{
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(final byte[] arrayOctet)
{
for (byte octet : arrayOctet)
{
if (isBase64(octet))
{
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(final byte[] binaryData)
{
return encodeBase64(binaryData, false);
}
/**
* Encodes binary data using the base64 algorithm into 76 character blocks separated by CRLF.
*
* @param binaryData
* binary data to encode
* @return String containing Base64 characters.
* @since 1.4
*/
public static String encodeBase64String(final byte[] binaryData)
{
return StringUtils.newStringUtf8(encodeBase64(binaryData, 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 byte[] containing Base64 characters in their UTF-8 representation.
* @since 1.4
*/
public static byte[] encodeBase64URLSafe(final 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(final byte[] binaryData)
{
return StringUtils.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(final 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(final String pArray)
{
return decode(StringUtils.getBytesUtf8(pArray));
}
/**
* 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(final byte[] pArray)
{
reset();
if ((pArray == null) || (pArray.length == 0))
{
return pArray;
}
long len = Math.max(1, (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(final byte[] binaryData, final 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(final byte[] binaryData, final boolean isChunked,
final 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(final byte[] binaryData, final boolean isChunked,
final boolean urlSafe, final int maxResultSize)
{
if ((binaryData == null) || (binaryData.length == 0))
{
return binaryData;
}
long len = getEncodeLength(binaryData, CHUNK_SIZE, CHUNK_SEPARATOR);
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(final 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(final 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(final byte byteToCheck)
{
switch (byteToCheck)
{
case ' ' :
case '\n' :
case '\r' :
case '\t' :
return true;
default :
return false;
}
}
// Implementation of the Encoder Interface
/**
* 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(final byte[] pArray)
{
return StringUtils.newStringUtf8(encode(pArray));
}
/**
* 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(final 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(final byte[] pArray, int chunkSize,
final 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(final 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(final 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(final 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;
}
}