RSA的使用（bouncycastle）

浅浅的花香味﹌ 2023-02-18 15:20 39阅读 0赞

*  **依赖**

<dependency>
      <groupId>org.bouncycastle</groupId>
      <artifactId>bcprov-jdk15on</artifactId>
      <version>1.65.01</version>
    </dependency>

*  **代码**

import lombok.extern.slf4j.Slf4j;
    import org.bouncycastle.crypto.engines.RSAEngine;
    import org.bouncycastle.crypto.util.PrivateKeyFactory;
    import org.bouncycastle.crypto.util.PublicKeyFactory;
    import org.bouncycastle.jcajce.provider.asymmetric.rsa.KeyPairGeneratorSpi;
    import org.bouncycastle.util.encoders.Base64;
    
    import java.security.KeyPair;
    import java.security.PrivateKey;
    import java.security.PublicKey;
    import java.security.SecureRandom;
    import java.util.Optional;
    
    @Slf4j
    public class RSAUtils {
        private RSAUtils() {
        }
    
        public static void generate() {
            KeyPairGeneratorSpi keyPairGeneratorSpi = new KeyPairGeneratorSpi();
            keyPairGeneratorSpi.initialize(512, new SecureRandom());//512 8的倍数
            KeyPair pair = keyPairGeneratorSpi.generateKeyPair();
            PrivateKey privateKey = pair.getPrivate();
            PublicKey publicKey = pair.getPublic();
            byte[] privateKeyEncoded = privateKey.getEncoded();
            byte[] publicKeyEncoded = publicKey.getEncoded();
            String privateKeyString = Base64.toBase64String(privateKeyEncoded);
            String publicKeyString = Base64.toBase64String(publicKeyEncoded);
            System.out.println("公钥:\n" + publicKeyString);
            System.out.println("私钥:\n" + privateKeyString);
        }
    
        public static Optional<String> encrypt(String publicKey, String content) {
            try {
                RSAEngine engine = new RSAEngine();
                engine.init(true, PublicKeyFactory.createKey(Base64.decode(publicKey)));
                byte[] contentByte = content.getBytes(StandardCharsets.UTF_8);
                byte[] bytes = engine.processBlock(contentByte, 0, contentByte.length);
                return Optional.of(Base64.toBase64String(bytes));
            } catch (Exception e) {
                log.error("加密异常!{}", e.getMessage());
            }
            return Optional.empty();
        }
    
        public static Optional<String> decrypt(String privateKey, String content) {
            try {
                RSAEngine engine = new RSAEngine();
                engine.init(false, PrivateKeyFactory.createKey(Base64.decode(privateKey)));
                byte[] contentByte = Base64.decode(content);
                byte[] bytes = engine.processBlock(contentByte, 0, contentByte.length);
                return Optional.of(new String(bytes, StandardCharsets.UTF_8));
            } catch (Exception e) {
                log.error("解密异常!{}", e.getMessage());
            }
            return Optional.empty();
        }
    
    
        public static void main(String[] args) {
            generate();
            String publicKey = "MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBALgRVslYl/4s+F+zMtr6NmrwG8416kf3JB6l2YKiXff8wvz/aIN9rmenEReaMJQepZC76rNYx886IK7cVPoRCcMCAwEAAQ==";
            String privateKey = "MIIBUwIBADANBgkqhkiG9w0BAQEFAASCAT0wggE5AgEAAkEAuBFWyViX/iz4X7My2vo2avAbzjXqR/ckHqXZgqJd9/zC/P9og32uZ6cRF5owlB6lkLvqs1jHzzogrtxU+hEJwwIDAQABAkAULsKHXVF9K00ooSuIWzswSpeh6sN/lJe/TIwnCMqo8DyMuiYw5BGwO2RRVuC5crOf1gVMEDwyNjDmIw4Ga6zRAiEA3MCTDoOw/XKHqiMY2lH/8nEwf/6uDNyT3bst0CxmgU8CIQDVdUFtMxcOJC4hmmcvoR28OVmAbxKaXu9lNhaJmIZLTQIgVgVsyKEknP6+Qtw+WQTPGehln9rcdAKYVDUWWyKSJx0CIDRjzAQWNwFkheH/eHXrMFYjKUFpgYJb7JvFs7BfvA49AiBM6X37qVqKq+dPFfH+0nk83s+YRhtHUDxHhzMqcEp7NQ==";
            System.out.println("加密:");
            encrypt(publicKey, "hello word").ifPresent(content -> {
                System.out.println(content);
                System.out.println("解密:");
                decrypt(privateKey, content).ifPresent(System.out::println);
            }); 
            //非lambda表达式 
            Optional<String> helloWord = encrypt(publicKey, "hello word");
            if (helloWord.isPresent()) {
                String content = helloWord.get();
                System.out.println(content);
                System.out.println("解密:");
                decrypt(privateKey, content).ifPresent(System.out::println);
            }
        }
    }