如何从AsymmetricCipherKeyPair获取PublicKey,而不是publickeycipher参数？

Question

我使用Bouncy Castle软件包在平台上生成密钥对.

SecureRandom random = new SecureRandom();

ECKeyPairGenerator pGen = new ECKeyPairGenerator();

ECKeyGenerationParameters genParam = new ECKeyGenerationParameters(params,random);

pGen.init(genParam);

AsymmetricCipherKeyPair pair = pGen.generateKeyPair();

这里pair是类型AsymmetricCipherKeyPair.而且,我需要使用这一对在服务器上生成X509V1Certificate.但是,X509Certificate setPublicKey(PublicKey pubkey)只接受类型的对象PublicKey.所以我需要PublicKey从AsymmetricCipherKeyPair服务器检索一个.但是,我得到了ECPublicKeyParameters,这在setPublicKey方法中是不被接受的.

所以,我在这里的要求是得到PublicKey一个AsymmetricCipherKeyPair.

Answer 1

最简单的方法是使用 BouncyCastle 作为 JavaCryptoProvider ：

1. 生成密钥对

   KeyPairGenerator kpg = KeyPairGenerator.getInstance("EC", "BC");
   ECGenParameterSpec ecsp = new ECGenParameterSpec(keyAlg);
   kpg.initialize(ecsp);
   KeyPair kp = kpg.generateKeyPair();
   

2. 制作 X509v1 证书

   X509V1CertificateGenerator certGen = new X509V1CertificateGenerator();
   X500Principal dnName = new X500Principal("CN=C3");
   Calendar c = Calendar.getInstance();
   c.add(Calendar.YEAR, 10);
   certGen.setSerialNumber(keyId);
   certGen.setIssuerDN(dnName);
   certGen.setNotBefore(new Date());
   certGen.setNotAfter(c.getTime());
   certGen.setSubjectDN(dnName);                      
   certGen.setPublicKey(keyPair.getPublic());
   certGen.setSignatureAlgorithm("SHA256withECDSA");
   certGen.generate(keyPair.getPrivate(), "BC");