cn.bif.utils.base.Base58 Maven / Gradle / Ivy
The 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.
* © COPYRIGHT 2021 Corporation CAICT All rights reserved.
* http://www.caict.ac.cn
*/
package cn.bif.utils.base;
import java.io.UnsupportedEncodingException;
public class Base58 {
private static final char[] ALPHABET = "123456789AbCDEFGHJKLMNPQRSTuVWXYZaBcdefghijkmnopqrstUvwxyz"
.toCharArray();
private static final int BASE_58 = ALPHABET.length;
private static final int BASE_256 = 256;
private static final int[] INDEXES = new int[128];
// 字符编码类型关键字
public static final byte BASE_58_VALUE = 'f';
static {
for (int i = 0; i < INDEXES.length; i++) {
INDEXES[i] = -1;
}
for (int i = 0; i < ALPHABET.length; i++) {
INDEXES[ALPHABET[i]] = i;
}
}
public static String encode(byte[] input) {
if (input.length == 0) {
// paying with the same coin
return "";
}
//
// Make a copy of the input since we are going to modify it.
//
input = copyOfRange(input, 0, input.length);
//
// Count leading zeroes
//
int zeroCount = 0;
while (zeroCount < input.length && input[zeroCount] == 0) {
++zeroCount;
}
//
// The actual encoding
//
byte[] temp = new byte[input.length * 2];
int j = temp.length;
int startAt = zeroCount;
while (startAt < input.length) {
byte mod = divmod58(input, startAt);
if (input[startAt] == 0) {
++startAt;
}
temp[--j] = (byte) ALPHABET[mod];
}
//
// Strip extra '1' if any
//
while (j < temp.length && temp[j] == ALPHABET[0]) {
++j;
}
//
// Add as many leading '1' as there were leading zeros.
//
while (--zeroCount >= 0) {
temp[--j] = (byte) ALPHABET[0];
}
byte[] output = copyOfRange(temp, j, temp.length);
return new String(output);
}
public static byte[] decode(String input) {
if (input.length() == 0) {
// paying with the same coin
return new byte[0];
}
byte[] input58 = new byte[input.length()];
//
// Transform the String to a base58 byte sequence
//
for (int i = 0; i < input.length(); ++i) {
char c = input.charAt(i);
int digit58 = -1;
if (c >= 0 && c < 128) {
digit58 = INDEXES[c];
}
if (digit58 < 0) {
throw new RuntimeException("Not a Base58 input: " + input);
}
input58[i] = (byte) digit58;
}
//
// Count leading zeroes
//
int zeroCount = 0;
while (zeroCount < input58.length && input58[zeroCount] == 0) {
++zeroCount;
}
//
// The encoding
//
byte[] temp = new byte[input.length()];
int j = temp.length;
int startAt = zeroCount;
while (startAt < input58.length) {
byte mod = divmod256(input58, startAt);
if (input58[startAt] == 0) {
++startAt;
}
temp[--j] = mod;
}
//
// Do no add extra leading zeroes, move j to first non null byte.
//
while (j < temp.length && temp[j] == 0) {
++j;
}
return copyOfRange(temp, j - zeroCount, temp.length);
}
private static byte divmod58(byte[] number, int startAt) {
int remainder = 0;
for (int i = startAt; i < number.length; i++) {
int digit256 = (int) number[i] & 0xFF;
int temp = remainder * BASE_256 + digit256;
number[i] = (byte) (temp / BASE_58);
remainder = temp % BASE_58;
}
return (byte) remainder;
}
private static byte divmod256(byte[] number58, int startAt) {
int remainder = 0;
for (int i = startAt; i < number58.length; i++) {
int digit58 = (int) number58[i] & 0xFF;
int temp = remainder * BASE_58 + digit58;
number58[i] = (byte) (temp / BASE_256);
remainder = temp % BASE_256;
}
return (byte) remainder;
}
private static byte[] copyOfRange(byte[] source, int from, int to) {
byte[] range = new byte[to - from];
System.arraycopy(source, from, range, 0, range.length);
return range;
}
/**
* string to base58
*
* @param srcStr Source string
* @return Base58 string
*/
public static String str2Base58(String srcStr) throws UnsupportedEncodingException {
return Base58.encode(srcStr.getBytes("utf-8"));
}
/**
* base58 to string
*
* @param srcStr Base58 string
* @return Source string
*/
public static String base582Str(String base58Str) throws UnsupportedEncodingException {
return new String(Base58.decode(base58Str));
}
public static void main(String[] args) throws UnsupportedEncodingException {
String src = "5jfRuasbj3QYDrLaKhp2TsWS2AWpokFYgH5Jh1FtuHeuvW7g97gHWiUFcyq1eiTdHAaG73939vyoX3ubMjje1Uc8yVJTmFhg2hUr4yUyoTkkFKq";
System.out.println(Base58.base582Str(src));
System.out.println(Base58.str2Base58("V8ibeWYXYbCro17hPe2M9u7jQC7HTkTNtqWD_51ea28eacc5f34591fb95a72544b7e787c17ca7da4e3f7f2494aa6fc70a40d71"));
}
}