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Java sdk for Dapps interact with cwv blockchain node
package org.brewchain.sdk.contract.rlp.util;
/**
* If you find the code useful or you find a bug, please send me a note at base64 @ miginfocom . com.
*
* Licence (BSD):
* ==============
*
* Copyright (c) 2004, Mikael Grev, MiG InfoCom AB. (base64 @ miginfocom . com)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice, this list
* of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice, this
* list of conditions and the following disclaimer in the documentation and/or other
* materials provided with the distribution.
* Neither the name of the MiG InfoCom AB nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* @version 2.2
* @author Mikael Grev
* Date: 2004-aug-02
* Time: 11:31:11
*/
public final class Base64 /* Modified by Evan Saulpaugh */ {
public static final int NO_FLAGS = 0;
public static final int NO_PADDING = 1;
public static final int NO_LINE_SEP = 2; // No "\r\n" after 76 characters
public static final int URL_SAFE_CHARS = 4;
private static final char[] TABLE_STANDARD = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray();
private static final char[] TABLE_URL_SAFE = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_".toCharArray();
/**
* Encodes a raw byte array into a Base64 String.
* @param buffer buffer containing the input. If length 0, an empty array will be returned.
* @param off the offset into the buffer of the input bytes
* @param len the length of the input, in bytes
* @param flags indicating the desired encoding options
* @return a Base64-encoded String. Never null.
*/
@SuppressWarnings("deprecation")
public static String encodeToString(byte[] buffer, int off, int len, int flags) {
byte[] enc = encodeToBytes(buffer, off, len, flags);
return new String(enc, 0, 0, enc.length);
}
/**
* Encodes a raw byte array into a Base64 byte[].
* @param buffer buffer containing the input. If length 0, an empty array will be returned.
* @param bytesOff the offset into the buffer of the input bytes
* @param bytesLen the length of the input, in bytes
* @param flags indicating the desired encoding options
* @return a Base64-encoded array. Never null.
*/
public static byte[] encodeToBytes(final byte[] buffer, final int bytesOff, final int bytesLen, final int flags) {
final boolean noPad = (flags & NO_PADDING) != 0;
final boolean noLineSep = (flags & NO_LINE_SEP) != 0;
final char[] table = (flags & URL_SAFE_CHARS) != 0 ? TABLE_URL_SAFE : TABLE_STANDARD;
final int bytesChunks = bytesLen / 3;
final int bytesEvenLen = bytesChunks * 3;
final int bytesRemainder = bytesLen - bytesEvenLen; // bytesLen % 3; // [0,2]
final int charsRemainder = bytesRemainder == 1 ? 2 : bytesRemainder == 2 ? 3 : 0;
final int rawLen = (bytesChunks << 2) + (noPad ? charsRemainder : (charsRemainder != 0) ? 4 : 0);
final int outLen = noLineSep ? rawLen : rawLen + (((rawLen - 1) / 76) << 1);
final byte[] out = new byte[outLen];
final int lineSepLim = outLen - 2;
final int endEvenBytes = bytesOff + bytesEvenLen; // End of even 24-bits chunks
for (int i = bytesOff, o = 0, chungus = 0; i < endEvenBytes; ) {
final int v = (buffer[i++] & 0xff) << 16 | (buffer[i++] & 0xff) << 8 | (buffer[i++] & 0xff);
out[o++] = (byte) table[v >>> 18]; // (v >>> 18) & 0x3f
out[o++] = (byte) table[(v >>> 12) & 0x3f];
out[o++] = (byte) table[(v >>> 6) & 0x3f];
out[o++] = (byte) table[v & 0x3f];
if (!noLineSep && ++chungus == 19 /* big */ && o < lineSepLim) {
out[o++] = '\r';
out[o++] = '\n';
chungus = 0;
}
}
// Encode remaining bytes (if any)
if(bytesRemainder > 0) {
boolean twoBytesLeft = false;
int v = 0;
switch (bytesRemainder) { /* cases fall through */
case 2: v |= (buffer[endEvenBytes + 1] & 0xff) << 2; twoBytesLeft = true;
case 1: v |= (buffer[endEvenBytes] & 0xff) << 10;
}
final int charsLeft = noPad ? charsRemainder : charsRemainder + (twoBytesLeft ? 1 : 2); // plus equals signs
final int charsIdx = outLen - charsLeft;
switch (charsLeft) { /* cases fall through */
case 4: out[charsIdx + 3] = (byte) '=';
case 3: out[charsIdx + 2] = (byte) (twoBytesLeft ? table[v & 0x3f] : '=');
case 2: out[charsIdx + 1] = (byte) table[(v >> 6) & 0x3f];
default: out[charsIdx] = (byte) table[v >> 12]; // (v >> 12) & 0x3f
}
}
return out;
}
}