Spring MVC项目中如何用AES256 对DB 密码加密

在Spring MVC项目中，对数据库密码进行AES256加密通常包含以下几个步骤：

1. **添加依赖**:
首先，在项目的pom.xml文件或build.gradle中添加支持AES加密的库，如BCrypt或Bouncy Castle Security Library。

<!-- Maven -->
<dependency>
    <groupId>org.bouncycastle</groupId>
    <artifactId>bcprov-jdk15on</artifactId>
    <version>1.68</version>
</dependency>

<!-- Gradle -->
implementation 'org.bouncycastle:bcpkix-jdk15on:1.68'

2. **配置环境变量**:
确保在运行环境中已经设置好Java SecureRandom所需的系统属性，例如`java.security.egd`。

3. **创建加解密工具**:
创建一个工具类，比如`PasswordEncryptor.java`，用于封装AES加密和解密操作。

import org.bouncycastle.jce.provider.BouncyCastleProvider;
import javax.crypto.Cipher;
import java.security.Key;
import java.security.Security;

public class PasswordEncryptor {

    static {
        Security.addProvider(new BouncyCastleProvider());
    }

    private static final String ALGORITHM = "AES";
    private static final String KEY = "your_secret_key"; // 设置你的密钥

    public static String encrypt(String password) throws Exception {
        Key key = generateKey();
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        cipher.init(Cipher.ENCRYPT_MODE, key);
        byte[] encryptedBytes = cipher.doFinal(password.getBytes());
        return Base64.getEncoder().encodeToString(encryptedBytes);
    }

    public static String decrypt(String encryptedPassword) throws Exception {
        Key key = generateKey();
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, key);
        byte[] decryptedBytes = cipher.doFinal(Base64.getDecoder().decode(encryptedPassword));
        return new String(decryptedBytes);
    }

    private static Key generateKey() throws Exception {
        KeyGenerator keyGen = KeyGenerator.getInstance(ALGORITHM);
        keyGen.init(256); // AES-256
        SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
        secureRandom.setSeed(KEY.getBytes()); // 使用你的密钥生成随机数
        return keyGen.generateKey();
    }
}

4. **在DAO或Service中应用加密**:
当需要存储密码时，调用`encrypt`方法；查询时，先解密再进行比较。

// DAO或Service保存密码
User user = new User();
String encryptedPassword = PasswordEncryptor.encrypt(user.getPassword());
user.setPassword(encryptedPassword);

// 查询时解密并比较
String storedPassword = ...; // 从数据库获取的加密密码
try {
    if (PasswordEncryptor.decrypt(storedPassword).equals(user.getPassword())) {
        // 用户名和密码匹配
    }
} catch (Exception e) {
    throw new RuntimeException("Failed to decrypt password", e);
}