org.kin.stellarfork.codec.Base64.kt 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.kin.stellarfork.codec
import java.math.BigInteger
/*
* 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.
*/ /**
* Provides Base64 encoding and decoding as defined by [RFC 2045](http://www.ietf.org/rfc/rfc2045.txt).
*
*
*
* 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).
*
*
*
* This class is not thread-safe. Each thread should use its own instance.
*
*
* @author Apache Software Foundation
* @version $Revision$
* @see [RFC 2045](http://www.ietf.org/rfc/rfc2045.txt)
*
* @since 1.0
*/
class Base64 @JvmOverloads constructor(
lineLength: Int = 0,
lineSeparator: ByteArray? = CHUNK_SEPARATOR,
urlSafe: Boolean = false
) : BaseNCodec(
BYTES_PER_UNENCODED_BLOCK,
BYTES_PER_ENCODED_BLOCK,
lineLength,
lineSeparator?.size ?: 0
) {
// 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 val encodeTable: ByteArray
// Only one decode table currently; keep for consistency with Base32 code
private val decodeTable = DECODE_TABLE
/**
* Line separator for encoding. Not used when decoding. Only used if lineLength > 0.
*/
private var lineSeparator: ByteArray? = null
/**
* Convenience variable to help us determine when our buffer is going to run out of room and needs resizing.
* `decodeSize = 3 + lineSeparator.length;`
*/
private val decodeSize: Int
/**
* Convenience variable to help us determine when our buffer is going to run out of room and needs resizing.
* `encodeSize = 4 + lineSeparator.length;`
*/
private var encodeSize = 0
/**
* 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.
*/
private var bitWorkArea = 0
/**
* 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
*/
constructor(urlSafe: Boolean) : this(
MIME_CHUNK_SIZE,
CHUNK_SEPARATOR,
urlSafe
) {
}
/**
* 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
*/
val isUrlSafe: Boolean
get() = encodeTable == URL_SAFE_ENCODE_TABLE
/**
*
*
* 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 pArray byte[] array of binary data to base64 encode.
* @param i Position to start reading data from.
* @param length Amount of bytes available from input for encoding.
*/
override fun encode(pArray: ByteArray, i: Int, length: Int) {
var inPos = i
if (eof) {
return
}
// inAvail < 0 is how we're informed of EOF in the underlying data we're
// encoding.
if (length < 0) {
eof = true
if (0 == modulus && lineLength == 0) {
return // no leftovers to process and not using chunking
}
ensureBufferSize(encodeSize)
val savedPos = pos
buffer?.let { buffer ->
when (modulus) {
1 -> {
buffer[pos++] = encodeTable[bitWorkArea shr 2 and MASK_6BITS] // top 6 bits
buffer[pos++] = encodeTable[bitWorkArea shl 4 and MASK_6BITS] // remaining 2
// URL-SAFE skips the padding to further reduce size.
if (encodeTable.contentEquals(STANDARD_ENCODE_TABLE)) {
buffer[pos++] = PAD
buffer[pos++] = PAD
}
}
2 -> {
buffer[pos++] = encodeTable[bitWorkArea shr 10 and MASK_6BITS]
buffer[pos++] = encodeTable[bitWorkArea shr 4 and MASK_6BITS]
buffer[pos++] = encodeTable[bitWorkArea shl 2 and MASK_6BITS]
// URL-SAFE skips the padding to further reduce size.
if (encodeTable.contentEquals(STANDARD_ENCODE_TABLE)) {
buffer[pos++] = PAD
}
}
}
}
currentLinePos += pos - savedPos // keep track of current line position
// if currentPos == 0 we are at the start of a line, so don't add CRLF
lineSeparator?.let { lineSeparator ->
if (lineLength > 0 && currentLinePos > 0) {
System.arraycopy(lineSeparator, 0, buffer, pos, lineSeparator.size)
pos += lineSeparator.size
}
}
} else {
for (n in 0 until length) {
ensureBufferSize(encodeSize)
modulus =
(modulus + 1) % BYTES_PER_UNENCODED_BLOCK
var b = pArray[inPos++].toInt()
if (b < 0) {
b += 256
}
bitWorkArea = (bitWorkArea shl 8) + b // BITS_PER_BYTE
if (0 == modulus) { // 3 bytes = 24 bits = 4 * 6 bits to extract
buffer?.let { buffer ->
buffer[pos++] =
encodeTable[bitWorkArea shr 18 and MASK_6BITS]
buffer[pos++] =
encodeTable[bitWorkArea shr 12 and MASK_6BITS]
buffer[pos++] =
encodeTable[bitWorkArea shr 6 and MASK_6BITS]
buffer[pos++] =
encodeTable[bitWorkArea and MASK_6BITS]
currentLinePos += BYTES_PER_ENCODED_BLOCK
lineSeparator?.let { lineSeparator ->
if (lineLength in 1..currentLinePos) {
System.arraycopy(
lineSeparator,
0,
buffer,
pos,
lineSeparator.size
)
pos += lineSeparator.size
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 pArray byte[] array of ascii data to base64 decode.
* @param i Position to start reading data from.
* @param length Amount of bytes available from input for encoding.
*/
override fun decode(pArray: ByteArray, i: Int, length: Int) {
var inPos = i
if (eof) {
return
}
if (length < 0) {
eof = true
}
for (n in 0 until length) {
ensureBufferSize(decodeSize)
val b = pArray[inPos++]
if (b == PAD) { // We're done.
eof = true
break
} else {
if (b >= 0 && b < DECODE_TABLE.size) {
val result =
DECODE_TABLE[b.toInt()].toInt()
if (result >= 0) {
modulus = (modulus + 1) % BYTES_PER_ENCODED_BLOCK
bitWorkArea = (bitWorkArea shl BITS_PER_ENCODED_BYTE) + result
if (modulus == 0) {
buffer?.let { buffer ->
buffer[pos++] = (bitWorkArea shr 16 and MASK_8BITS).toByte()
buffer[pos++] = (bitWorkArea shr 8 and MASK_8BITS).toByte()
buffer[pos++] = (bitWorkArea and MASK_8BITS).toByte()
}
}
}
}
}
}
// 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) {
ensureBufferSize(decodeSize)
buffer?.let { buffer ->
when (modulus) {
2 -> {
bitWorkArea = bitWorkArea shr 4 // dump the extra 4 bits
buffer[pos++] =
(bitWorkArea and MASK_8BITS).toByte()
}
3 -> {
bitWorkArea = bitWorkArea shr 2 // dump 2 bits
buffer[pos++] = (bitWorkArea shr 8 and MASK_8BITS).toByte()
buffer[pos++] = (bitWorkArea and MASK_8BITS).toByte()
}
}
}
}
}
/**
* Returns whether or not the `octet` is in the Base32 alphabet.
*
* @param value The value to test
* @return `true` if the value is defined in the the Base32 alphabet `false` otherwise.
*/
override fun isInAlphabet(value: Byte): Boolean {
return value >= 0 && value < decodeTable.size && decodeTable[value.toInt()].toInt() != -1
}
companion object {
/**
* 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 const val BITS_PER_ENCODED_BYTE = 6
private const val BYTES_PER_UNENCODED_BLOCK = 3
private const val BYTES_PER_ENCODED_BLOCK = 4
/**
* 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](http://www.ietf.org/rfc/rfc2045.txt)
*/
@JvmField
val CHUNK_SEPARATOR: ByteArray = byteArrayFromChars('\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 val STANDARD_ENCODE_TABLE = byteArrayFromChars(
'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 val URL_SAFE_ENCODE_TABLE = byteArrayFromChars(
'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.
*
*
* 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 val DECODE_TABLE = byteArrayOf(
-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 const val MASK_6BITS = 0x3f
/**
* 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
*/
@JvmStatic
fun isBase64(octet: Byte): Boolean {
return octet == PAD_DEFAULT || octet >= 0 && octet < DECODE_TABLE.size && DECODE_TABLE[octet.toInt()].toInt() != -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 `true` if all characters in the String are valid characters in the Base64 alphabet or if
* the String is empty; `false`, otherwise
* @since 1.5
*/
@JvmStatic
fun isBase64(base64: String): Boolean {
return isBase64(StringUtils.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 `true` if all bytes are valid characters in the Base64 alphabet or if the byte array is empty;
* `false`, otherwise
*/
@JvmStatic
@Deprecated("1.5 Use {@link #isBase64(byte[])}, will be removed in 2.0.", ReplaceWith(
"isBase64(arrayOctet)",
"org.kin.stellarfork.codec.Base64.Companion.isBase64"
)
)
fun isArrayByteBase64(arrayOctet: ByteArray): Boolean {
return isBase64(arrayOctet)
}
/**
* 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
* @since 1.5
*/
@JvmStatic
fun isBase64(arrayOctet: ByteArray): Boolean {
for (i in arrayOctet.indices) {
if (!isBase64(arrayOctet[i]) && !isWhiteSpace(
arrayOctet[i]
)
) {
return false
}
}
return true
}
/**
* Encodes binary data using the base64 algorithm but does not chunk the output.
*
*
* 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).
*/
@JvmStatic
fun encodeBase64String(binaryData: ByteArray?): String? {
return StringUtils.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
*/
@JvmStatic
fun encodeBase64URLSafe(binaryData: ByteArray?): ByteArray? {
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
*/
@JvmStatic
fun encodeBase64URLSafeString(binaryData: ByteArray?): String {
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
*/
@JvmStatic
fun encodeBase64Chunked(binaryData: ByteArray?): ByteArray? {
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 `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
*/
/**
* 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 [Integer.MAX_VALUE]
* @since 1.4
*/
/**
* 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 [Integer.MAX_VALUE]
*/
/**
* 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.
*/
@JvmOverloads
@JvmStatic
fun encodeBase64(
binaryData: ByteArray?,
isChunked: Boolean = false,
urlSafe: Boolean = false,
maxResultSize: Int = Int.MAX_VALUE
): ByteArray? {
if (binaryData == null || binaryData.isEmpty()) {
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
val b64 =
if (isChunked) Base64(urlSafe) else Base64(
0,
CHUNK_SEPARATOR,
urlSafe
)
val len = b64.getEncodedLength(binaryData)
require(len <= maxResultSize) {
"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
*/
@JvmStatic
fun decodeBase64(base64String: String?): ByteArray? {
return Base64().decode(base64String)
}
/**
* Decodes Base64 data into octets
*
* @param base64Data Byte array containing Base64 data
* @return Array containing decoded data.
*/
@JvmStatic
fun decodeBase64(base64Data: ByteArray?): ByteArray? {
return 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
*/
@JvmStatic
fun decodeInteger(pArray: ByteArray): BigInteger {
return 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
*/
@JvmStatic
fun encodeInteger(bigInt: BigInteger?): ByteArray? {
if (bigInt == null) {
throw 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
*/
@JvmStatic
fun toIntegerBytes(bigInt: BigInteger): ByteArray {
var bitlen = bigInt.bitLength()
// round bitlen
bitlen = bitlen + 7 shr 3 shl 3
val 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
var startSrc = 0
var len = bigBytes.size
// if bigInt is exactly byte-aligned, just skip signbit in copy
if (bigInt.bitLength() % 8 == 0) {
startSrc = 1
len--
}
val startDst = bitlen / 8 - len // to pad w/ nulls as per spec
val resizedBytes = ByteArray(bitlen / 8)
System.arraycopy(bigBytes, startSrc, resizedBytes, startDst, len)
return resizedBytes
}
}
/**
* 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
*/
/**
* 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
*/
/**
* 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
*/
/**
* Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
*
*
* When encoding the line length is 0 (no chunking), and the encoding table is STANDARD_ENCODE_TABLE.
*
*
*
*
* When decoding all variants are supported.
*
*/
init {
// TODO 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)) {
val sep =
StringUtils.newStringUtf8(lineSeparator)
throw IllegalArgumentException("lineSeparator must not contain base64 characters: [$sep]")
}
if (lineLength > 0) { // null line-sep forces no chunking rather than throwing IAE
encodeSize =
BYTES_PER_ENCODED_BLOCK + lineSeparator.size
this.lineSeparator = ByteArray(lineSeparator.size)
System.arraycopy(
lineSeparator,
0,
this.lineSeparator,
0,
lineSeparator.size
)
} else {
encodeSize = BYTES_PER_ENCODED_BLOCK
this.lineSeparator = null
}
} else {
encodeSize = BYTES_PER_ENCODED_BLOCK
this.lineSeparator = null
}
decodeSize = encodeSize - 1
encodeTable =
if (urlSafe) URL_SAFE_ENCODE_TABLE else STANDARD_ENCODE_TABLE
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy