From 9a48a4cfc42b1a08881eb80d965df398f7b9224c Mon Sep 17 00:00:00 2001
From: FatttSnake <fatttsnake@gmail.com>
Date: Mon, 6 Jun 2022 23:56:07 +0800
Subject: [PATCH] Add PBKDF2Util

---
 .../library/database/util/PBKDF2Util.java     | 98 +++++++++++++++++++
 .../library/database/PBKDF2UtilTest.java      | 29 ++++++
 2 files changed, 127 insertions(+)
 create mode 100644 Library/src/main/java/com/cfive/classroom/library/database/util/PBKDF2Util.java
 create mode 100644 Library/src/test/java/com/cfive/classroom/library/database/PBKDF2UtilTest.java

diff --git a/Library/src/main/java/com/cfive/classroom/library/database/util/PBKDF2Util.java b/Library/src/main/java/com/cfive/classroom/library/database/util/PBKDF2Util.java
new file mode 100644
index 0000000..a052954
--- /dev/null
+++ b/Library/src/main/java/com/cfive/classroom/library/database/util/PBKDF2Util.java
@@ -0,0 +1,98 @@
+package com.cfive.classroom.library.database.util;
+
+import javax.crypto.SecretKeyFactory;
+import javax.crypto.spec.PBEKeySpec;
+import java.math.BigInteger;
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+import java.security.spec.InvalidKeySpecException;
+import java.security.spec.KeySpec;
+
+public class PBKDF2Util {
+    public static final String PBKDF2_ALGORITHM = "PBKDF2WithHmacSHA1";
+
+    public static final int SALT_BYTE_SIZE = 32 / 2;         //盐的长度
+    public static final int HASH_BIT_SIZE = 128 * 4;         //生成密文的长度
+    public static final int PBKDF2_ITERATIONS = 1000;        //迭代次数
+
+    /**
+     * @auther: Ragty
+     * @describe: 对输入的密码进行验证
+     * @param: [attemptedPassword(待验证密码), encryptedPassword(密文), salt(盐值)]
+     * @return: boolean
+     * @date: 2018/11/2
+     */
+    public boolean authenticate(String attemptedPassword, String encryptedPassword, String salt)
+            throws NoSuchAlgorithmException, InvalidKeySpecException {
+        // 用相同的盐值对用户输入的密码进行加密
+        String encryptedAttemptedPassword = getEncryptedPassword(attemptedPassword, salt);
+        // 把加密后的密文和原密文进行比较，相同则验证成功，否则失败
+        return encryptedAttemptedPassword.equals(encryptedPassword);
+    }
+
+
+    /**
+     * @auther: Ragty
+     * @describe: 生成密文
+     * @param: [password(明文密码), salt(盐值)]
+     * @return: java.lang.String
+     * @date: 2018/11/2
+     */
+    public String getEncryptedPassword(String password, String salt) throws NoSuchAlgorithmException,
+            InvalidKeySpecException {
+
+        KeySpec spec = new PBEKeySpec(password.toCharArray(), fromHex(salt), PBKDF2_ITERATIONS, HASH_BIT_SIZE);
+        SecretKeyFactory f = SecretKeyFactory.getInstance(PBKDF2_ALGORITHM);
+        return toHex(f.generateSecret(spec).getEncoded());
+    }
+
+
+    /**
+     * @auther: Ragty
+     * @describe: 通过加密的强随机数生成盐(最后转换为16进制)
+     * @param: []
+     * @return: java.lang.String
+     * @date: 2018/11/2
+     */
+    public String generateSalt() throws NoSuchAlgorithmException {
+        SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
+        byte[] salt = new byte[SALT_BYTE_SIZE];
+        random.nextBytes(salt);
+
+        return toHex(salt);
+    }
+
+
+    /**
+     * @auther: Ragty
+     * @describe: 十六进制字符串转二进制字符串
+     * @param: [hex]
+     * @return: byte[]
+     * @date: 2018/11/2
+     */
+    private static byte[] fromHex(String hex) {
+        byte[] binary = new byte[hex.length() / 2];
+        for (int i = 0; i < binary.length; i++) {
+            binary[i] = (byte) Integer.parseInt(hex.substring(2 * i, 2 * i + 2), 16);
+        }
+        return binary;
+    }
+
+
+    /**
+     * @auther: Ragty
+     * @describe: 二进制字符串转十六进制字符串
+     * @param: [array]
+     * @return: java.lang.String
+     * @date: 2018/11/2
+     */
+    private static String toHex(byte[] array) {
+        BigInteger bi = new BigInteger(1, array);
+        String hex = bi.toString(16);
+        int paddingLength = (array.length * 2) - hex.length();
+        if (paddingLength > 0)
+            return String.format("%0" + paddingLength + "d", 0) + hex;
+        else
+            return hex;
+    }
+}
\ No newline at end of file
diff --git a/Library/src/test/java/com/cfive/classroom/library/database/PBKDF2UtilTest.java b/Library/src/test/java/com/cfive/classroom/library/database/PBKDF2UtilTest.java
new file mode 100644
index 0000000..918ecae
--- /dev/null
+++ b/Library/src/test/java/com/cfive/classroom/library/database/PBKDF2UtilTest.java
@@ -0,0 +1,29 @@
+package com.cfive.classroom.library.database;
+
+import com.cfive.classroom.library.database.util.PBKDF2Util;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.junit.jupiter.api.Test;
+
+import java.security.NoSuchAlgorithmException;
+import java.security.spec.InvalidKeySpecException;
+
+class PBKDF2UtilTest {
+    private static final Logger LOGGER = LogManager.getLogger();
+    private final PBKDF2Util pbkdf2Util = new PBKDF2Util();
+
+    @Test
+    void testPassword() throws NoSuchAlgorithmException, InvalidKeySpecException {
+        String password = "123456";
+
+        String salt = pbkdf2Util.generateSalt();
+        String pbkdf2 = pbkdf2Util.getEncryptedPassword(password, salt);
+//        String md5 = md5Util.digest(password);
+
+        LOGGER.debug("原始密码:" + password);
+//        System.out.println("MD5加密后的密码:"+md5);
+        LOGGER.debug("盐值:" + salt);
+        LOGGER.debug("PBKDF2加盐后的密码:" + pbkdf2);
+        LOGGER.debug("Test success");
+    }
+}
\ No newline at end of file