Merge pull request #2162 from CherryRum/v5-dev

添加Base58工具类

hutool-core/src/main/java/cn/hutool/core/codec/Base58.java

@@ -0,0 +1,151 @@
+package cn.hutool.core.codec;
+
+import java.math.BigInteger;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Arrays;
+
+
+/**
+ * @author lin
+ * Inspired from https://github.com/adamcaudill/Base58Check/blob/master/src/Base58Check/Base58CheckEncoding.cs
+ * Base58工具类，提供Base58的编码和解码方案<br>
+ * @since 5.7.22
+ */
+public class Base58 {
+
+
+	private static final String ALPHABET = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
+	private static final char[] ALPHABET_ARRAY = ALPHABET.toCharArray();
+	private static final BigInteger BASE_SIZE = BigInteger.valueOf(ALPHABET_ARRAY.length);
+	private static final int CHECKSUM_SIZE = 4;
+
+	// -------------------------------------------------------------------- encode
+
+	/**
+	 * Base58编码
+	 *
+	 * @param data 被编码的数组，添加校验和。
+	 * @return 编码后的字符串
+	 * @since 5.7.22
+	 */
+	public static String encode(byte[] data) throws NoSuchAlgorithmException {
+		return encodePlain(addChecksum(data));
+	}
+
+	/**
+	 * Base58编码
+	 *
+	 * @param data 被编码的数据，不带校验和。
+	 * @return 编码后的字符串
+	 * @since 5.7.22
+	 */
+	public static String encodePlain(byte[] data) {
+		BigInteger intData;
+		try {
+			intData = new BigInteger(1, data);
+		} catch (NumberFormatException e) {
+			return "";
+		}
+		StringBuilder result = new StringBuilder();
+		while (intData.compareTo(BigInteger.ZERO) > 0) {
+			BigInteger[] quotientAndRemainder = intData.divideAndRemainder(BASE_SIZE);
+			BigInteger quotient = quotientAndRemainder[0];
+			BigInteger remainder = quotientAndRemainder[1];
+			intData = quotient;
+			result.insert(0, ALPHABET_ARRAY[remainder.intValue()]);
+		}
+		for (int i = 0; i < data.length && data[i] == 0; i++) {
+			result.insert(0, '1');
+		}
+		return result.toString();
+	}
+	// -------------------------------------------------------------------- decode
+
+	/**
+	 * Base58编码
+	 *
+	 * @param encoded 被解码的base58字符串
+	 * @return 解码后的bytes
+	 * @since 5.7.22
+	 */
+	public static byte[] decode(String encoded) throws NoSuchAlgorithmException {
+		byte[] valueWithChecksum = decodePlain(encoded);
+		byte[] value = verifyAndRemoveChecksum(valueWithChecksum);
+		if (value == null) {
+			throw new IllegalArgumentException("Base58 checksum is invalid");
+		}
+		return value;
+	}
+
+	/**
+	 * Base58编码
+	 *
+	 * @param encoded 被解码的base58字符串
+	 * @return 解码后的bytes
+	 * @since 5.7.22
+	 */
+	public static byte[] decodePlain(String encoded) {
+		if (encoded.length() == 0) {
+			return new byte[0];
+		}
+		BigInteger intData = BigInteger.ZERO;
+		int leadingZeros = 0;
+		for (int i = 0; i < encoded.length(); i++) {
+			char current = encoded.charAt(i);
+			int digit = ALPHABET.indexOf(current);
+			if (digit == -1) {
+				throw new IllegalArgumentException(String.format("Invalid Base58 character `%c` at position %d", current, i));
+			}
+			intData = (intData.multiply(BASE_SIZE)).add(BigInteger.valueOf(digit));
+		}
+
+		for (int i = 0; i < encoded.length(); i++) {
+			char current = encoded.charAt(i);
+			if (current == '1') {
+				leadingZeros++;
+			} else {
+				break;
+			}
+		}
+		byte[] bytesData;
+		if (intData.equals(BigInteger.ZERO)) {
+			bytesData = new byte[0];
+		} else {
+			bytesData = intData.toByteArray();
+		}
+		//Should we cut the sign byte ? - https://bitcoinj.googlecode.com/git-history/216deb2d35d1a128a7f617b91f2ca35438aae546/lib/src/com/google/bitcoin/core/Base58.java
+		boolean stripSignByte = bytesData.length > 1 && bytesData[0] == 0 && bytesData[1] < 0;
+		byte[] decoded = new byte[bytesData.length - (stripSignByte ? 1 : 0) + leadingZeros];
+		System.arraycopy(bytesData, stripSignByte ? 1 : 0, decoded, leadingZeros, decoded.length - leadingZeros);
+		return decoded;
+	}
+
+	private static byte[] verifyAndRemoveChecksum(byte[] data) throws NoSuchAlgorithmException {
+		byte[] value = Arrays.copyOfRange(data, 0, data.length - CHECKSUM_SIZE);
+		byte[] checksum = Arrays.copyOfRange(data, data.length - CHECKSUM_SIZE, data.length);
+		byte[] expectedChecksum = getChecksum(value);
+		return Arrays.equals(checksum, expectedChecksum) ? value : null;
+	}
+
+	private static byte[] addChecksum(byte[] data) throws NoSuchAlgorithmException {
+		byte[] checksum = getChecksum(data);
+		byte[] result = new byte[data.length + checksum.length];
+		System.arraycopy(data, 0, result, 0, data.length);
+		System.arraycopy(checksum, 0, result, data.length, checksum.length);
+		return result;
+	}
+
+	private static byte[] getChecksum(byte[] data) throws NoSuchAlgorithmException {
+		byte[] hash = hash256(data);
+		hash = hash256(hash);
+		return Arrays.copyOfRange(hash, 0, CHECKSUM_SIZE);
+	}
+
+	private static byte[] hash256(byte[] data) throws NoSuchAlgorithmException {
+		MessageDigest md = MessageDigest.getInstance("SHA-256");
+		md.update(data);
+		return md.digest();
+	}
+
+}

hutool-core/src/test/java/cn/hutool/core/codec/Base58Test.java

@@ -0,0 +1,34 @@
+package cn.hutool.core.codec;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.nio.charset.StandardCharsets;
+import java.security.NoSuchAlgorithmException;
+
+public class Base58Test {
+	@Test
+	public void testEncode() throws NoSuchAlgorithmException {
+		String a = "hello world";
+		String encode = Base58.encode(a.getBytes(StandardCharsets.UTF_8));
+		Assert.assertEquals("3vQB7B6MrGQZaxCuFg4oh", encode);
+	}
+	@Test
+	public void testEncodePlain() {
+		String a = "hello world";
+		String encode = Base58.encodePlain(a.getBytes(StandardCharsets.UTF_8));
+		Assert.assertEquals("StV1DL6CwTryKyV", encode);
+	}
+	@Test
+	public void testDecode() throws NoSuchAlgorithmException {
+		String a = "3vQB7B6MrGQZaxCuFg4oh";
+		byte[] decode = Base58.decode(a);
+		Assert.assertArrayEquals("hello world".getBytes(StandardCharsets.UTF_8),decode);
+	}
+	@Test
+	public void testDecodePlain()  {
+		String a = "StV1DL6CwTryKyV";
+		byte[] decode = Base58.decodePlain(a);
+		Assert.assertArrayEquals("hello world".getBytes(StandardCharsets.UTF_8),decode);
+	}
+}