Java - RSA 不限制长度加解密算法，你就只知道个分段法？
问题描述
java javax.crypto.IllegalBlockSizeException: Data must not be longer than XXX bytes
今天发现用网上千篇一律的 RSA 加解密算法，待加密数据一旦比较大，就会报以上错误。查了网上一些解决方案——分段法，看起来实在有点繁琐，就想到了 Hutool 大法，还是一个字“香”~
解决方案
import cn.hutool.crypto.SecureUtil;
import cn.hutool.crypto.asymmetric.KeyType;
import cn.hutool.crypto.asymmetric.RSA;
/**
* @author Lux Sun
* @date 2023/9/19
*/
public class Demo {
public static void main(String[] args) {
// 公钥Key
String publicKey = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA0CcRgrBS89Bt7QcdrzCL+oli/xRusm4XJzL3u/tZWQ6n78fLnHA64rWQVoJRb0qCz/YMfaEO+cYjZxUO/JxwXfAQedZ7cpklCcA12FBoC02zDQhtnaTgyKEB55bOg+zPfbafWAOafvoqFlSxOsVzXCPvh/jA9T+hToIKHmub35ICAT07yRMD3CMIZdfRs3Kx7Qs2uaj1mHAM4QMS7HwPI/29OKuvgINRF0Z8nwLpooX/7JN9iE+kiZuQLy00CvqJdbLln9iF4MwT7ChUNbnxIHD8Qn30CAFFSCq0rGuWxt1zbhLfy+7REiBO9YOdLKsdA5okoYCHCXKmXkjDudflmQIDAQAB";
// 私钥Key
String privateKey = "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";
// 明文内容
String bigData = "123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789";
// 生产 RSA
RSA rsa = SecureUtil.rsa(privateKey, publicKey);
// 公钥加密原始数据
String encryptData = rsa.encryptBase64(bigData.getBytes(), KeyType.PublicKey);
// 私钥解密加密数据
String decryptData = rsa.decryptStr(encryptData, KeyType.PrivateKey);
// 日志
System.out.println("公钥加密原始数据: " + encryptData);
System.out.println("私钥解密加密数据: " + decryptData);
}
}公钥加密原始数据: 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
私钥解密加密数据: 123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789注意事项
- RSA公钥加密的结果每次都不一样是因为RSA加密算法中使用了随机数生成器来生成随机数，这些随机数会影响加密结果。
- 此外，RSA加密算法中还使用了填充算法，填充算法也会影响加密结果。因此，即使使用相同的明文和公钥进行加密，每次得到的密文都会不同。