如何在Java中实现智能加密

在Java中实现智能加密，你可以使用对称加密算法（如AES）和非对称加密算法（如RSA）的组合

1. 导入所需的库：

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import java.nio.charset.StandardCharsets;
import java.util.Base64;

2. 生成AES密钥：

public static SecretKey generateAesKey() throws Exception {
    KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");
    keyGenerator.init(256);
    return keyGenerator.generateKey();
}

3. 生成随机初始化向量（IV）：

public static IvParameterSpec generateIv() {
    byte[] iv = new byte[16];
    return new IvParameterSpec(iv);
}

4. 加密方法：

public static String encrypt(String plainText, SecretKey aesKey, IvParameterSpec iv) throws Exception {
    Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
    cipher.init(Cipher.ENCRYPT_MODE, aesKey, iv);
    byte[] encryptedBytes = cipher.doFinal(plainText.getBytes(StandardCharsets.UTF_8));
    return Base64.getEncoder().encodeToString(encryptedBytes);
}

5. 解密方法：

public static String decrypt(String encryptedText, SecretKey aesKey, IvParameterSpec iv) throws Exception {
    Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
    cipher.init(Cipher.DECRYPT_MODE, aesKey, iv);
    byte[] decodedBytes = Base64.getDecoder().decode(encryptedText);
    byte[] decryptedBytes = cipher.doFinal(decodedBytes);
    return new String(decryptedBytes, StandardCharsets.UTF_8);
}

6. 使用RSA加密AES密钥：

public static String encryptRsaKey(SecretKey aesKey) throws Exception {
    Cipher cipher = Cipher.getInstance("RSA");
    cipher.init(Cipher.ENCRYPT_MODE, generateRsaKey());
    byte[] encryptedBytes = cipher.doFinal(aesKey.getEncoded());
    return Base64.getEncoder().encodeToString(encryptedBytes);
}

7. 使用RSA解密AES密钥：

public static SecretKey decryptRsaKey(String encryptedAesKey, SecretKey rsaKey) throws Exception {
    Cipher cipher = Cipher.getInstance("RSA");
    cipher.init(Cipher.DECRYPT_MODE, rsaKey);
    byte[] decodedBytes = Base64.getDecoder().decode(encryptedAesKey);
    byte[] decryptedBytes = cipher.doFinal(decodedBytes);
    return new SecretKeySpec(decryptedBytes, "AES");
}

8. 生成RSA密钥对：

public static SecretKey generateRsaKey() throws Exception {
    KeyGenerator keyGenerator = KeyGenerator.getInstance("RSA");
    keyGenerator.init(2048);
    return keyGenerator.generateKey();
}

现在你可以使用这些方法来实现智能加密和解密。首先，生成一个RSA密钥对，然后使用RSA公钥加密AES密钥，接着使用AES密钥加密明文。最后，使用AES密钥解密加密后的数据。这样就实现了智能加密。