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- package com.simple.utils;
-
- import java.security.MessageDigest;
-
- /**
- * @author Stormeye
- * @since 2018.08.09
- */
- public class HashUtil {
- private static final java.security.SecureRandom random = new java.security.SecureRandom();
- private static final char[] HEX_DIGITS = "0123456789abcdef".toCharArray();
- private static final char[] CHAR_ARRAY = "_-0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
- .toCharArray();
-
- public static String md5(String srcStr) {
- return hash("MD5", srcStr);
- }
-
- public static String sha1(String srcStr) {
- return hash("SHA-1", srcStr);
- }
-
- public static String sha256(String srcStr) {
- return hash("SHA-256", srcStr);
- }
-
- public static String sha384(String srcStr) {
- return hash("SHA-384", srcStr);
- }
-
- public static String sha512(String srcStr) {
- return hash("SHA-512", srcStr);
- }
-
- public static String hash(String algorithm, String srcStr) {
- try {
- MessageDigest md = MessageDigest.getInstance(algorithm);
- byte[] bytes = md.digest(srcStr.getBytes("utf-8"));
- return toHex(bytes);
- } catch (Exception e) {
- throw new RuntimeException(e);
- }
- }
-
- private static String toHex(byte[] bytes) {
- StringBuilder ret = new StringBuilder(bytes.length * 2);
- for (int i = 0; i < bytes.length; i++) {
- ret.append(HEX_DIGITS[(bytes[i] >> 4) & 0x0f]);
- ret.append(HEX_DIGITS[bytes[i] & 0x0f]);
- }
- return ret.toString();
- }
-
- /**
- * md5 128bit 16bytes sha1 160bit 20bytes sha256 256bit 32bytes sha384
- * 384bit 48bytes sha512 512bit 64bytes
- */
- public static String generateSalt(int saltLength) {
- StringBuilder salt = new StringBuilder();
- for (int i = 0; i < saltLength; i++) {
- salt.append(CHAR_ARRAY[random.nextInt(CHAR_ARRAY.length)]);
- }
- return salt.toString();
- }
-
- public static String generateSaltForSha256() {
- return generateSalt(32);
- }
-
- public static String generateSaltForSha512() {
- return generateSalt(64);
- }
-
- public static boolean slowEquals(byte[] a, byte[] b) {
- if (a == null || b == null) {
- return false;
- }
-
- int diff = a.length ^ b.length;
- for (int i = 0; i < a.length && i < b.length; i++) {
- diff |= a[i] ^ b[i];
- }
- return diff == 0;
- }
- }
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