All Downloads are FREE. Search and download functionalities are using the official Maven repository.

io.logspace.agent.shaded.apache.commons.codec.binary.Base64 Maven / Gradle / Ivy

There is a newer version: 0.3.2
Show newest version
/*
 * 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 io.logspace.agent.shaded.apache.commons.codec.binary;

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). *

*

* This class is not thread-safe. Each thread should use its own instance. *

* * @see RFC 2045 * @author Apache Software Foundation * @since 1.0 * @version $Revision: 1201529 $ */ public class Base64 extends BaseNCodec { /** * 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. * *

* 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', '-', '_' }; /** * 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 }; /** * 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. * 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; /** * 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 int bitWorkArea; /** * 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. *

*/ public Base64() { this(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 */ 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. *

* 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(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(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 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) { super(BYTES_PER_UNENCODED_BLOCK, BYTES_PER_ENCODED_BLOCK, lineLength, lineSeparator == null ? 0 : lineSeparator.length); // 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)) { String sep = StringUtils.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 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; } /** *

* 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. */ @Override 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 (0 == modulus && lineLength == 0) { return; // no leftovers to process and not using chunking } ensureBufferSize(encodeSize); int savedPos = pos; switch (modulus) { // 0-2 case 1 : // 8 bits = 6 + 2 buffer[pos++] = encodeTable[(bitWorkArea >> 2) & MASK_6BITS]; // top 6 bits buffer[pos++] = encodeTable[(bitWorkArea << 4) & MASK_6BITS]; // remaining 2 // URL-SAFE skips the padding to further reduce size. if (encodeTable == STANDARD_ENCODE_TABLE) { buffer[pos++] = PAD; buffer[pos++] = PAD; } break; case 2 : // 16 bits = 6 + 6 + 4 buffer[pos++] = encodeTable[(bitWorkArea >> 10) & MASK_6BITS]; buffer[pos++] = encodeTable[(bitWorkArea >> 4) & MASK_6BITS]; buffer[pos++] = encodeTable[(bitWorkArea << 2) & MASK_6BITS]; // URL-SAFE skips the padding to further reduce size. if (encodeTable == STANDARD_ENCODE_TABLE) { buffer[pos++] = PAD; } break; } 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 if (lineLength > 0 && currentLinePos > 0) { System.arraycopy(lineSeparator, 0, buffer, pos, lineSeparator.length); pos += lineSeparator.length; } } else { for (int i = 0; i < inAvail; i++) { ensureBufferSize(encodeSize); modulus = (modulus+1) % BYTES_PER_UNENCODED_BLOCK; int b = in[inPos++]; if (b < 0) { b += 256; } bitWorkArea = (bitWorkArea << 8) + b; // BITS_PER_BYTE if (0 == modulus) { // 3 bytes = 24 bits = 4 * 6 bits to extract buffer[pos++] = encodeTable[(bitWorkArea >> 18) & MASK_6BITS]; buffer[pos++] = encodeTable[(bitWorkArea >> 12) & MASK_6BITS]; buffer[pos++] = encodeTable[(bitWorkArea >> 6) & MASK_6BITS]; buffer[pos++] = encodeTable[bitWorkArea & MASK_6BITS]; currentLinePos += BYTES_PER_ENCODED_BLOCK; 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. */ @Override void decode(byte[] in, int inPos, int inAvail) { if (eof) { return; } if (inAvail < 0) { eof = true; } for (int i = 0; i < inAvail; i++) { ensureBufferSize(decodeSize); 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+1) % BYTES_PER_ENCODED_BLOCK; bitWorkArea = (bitWorkArea << BITS_PER_ENCODED_BYTE) + result; if (modulus == 0) { buffer[pos++] = (byte) ((bitWorkArea >> 16) & MASK_8BITS); buffer[pos++] = (byte) ((bitWorkArea >> 8) & MASK_8BITS); buffer[pos++] = (byte) (bitWorkArea & 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) { ensureBufferSize(decodeSize); // We have some spare bits remaining // Output all whole multiples of 8 bits and ignore the rest switch (modulus) { // case 1: // 6 bits - ignore entirely // break; case 2 : // 12 bits = 8 + 4 bitWorkArea = bitWorkArea >> 4; // dump the extra 4 bits buffer[pos++] = (byte) ((bitWorkArea) & MASK_8BITS); break; case 3 : // 18 bits = 8 + 8 + 2 bitWorkArea = bitWorkArea >> 2; // dump 2 bits buffer[pos++] = (byte) ((bitWorkArea >> 8) & MASK_8BITS); buffer[pos++] = (byte) ((bitWorkArea) & MASK_8BITS); break; } } } /** * 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 * @deprecated 1.5 Use {@link #isBase64(byte[])}, will be removed in 2.0. */ public static boolean isArrayByteBase64(byte[] arrayOctet) { return isBase64(arrayOctet); } /** * 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_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 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 */ public static boolean isBase64(String base64) { 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 * @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. * * 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 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 */ 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 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(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 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; } // 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 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; } /** * Returns whether or not the octet is in the Base32 alphabet. * * @param octet * The value to test * @return true if the value is defined in the the Base32 alphabet false otherwise. */ @Override protected boolean isInAlphabet(byte octet) { return octet >= 0 && octet < decodeTable.length && decodeTable[octet] != -1; } }




© 2015 - 2024 Weber Informatics LLC | Privacy Policy