java - X509 RSA bouncy caSTLe 在 Java 中签署和验证纯文本

Question

我目前正在使用 BouncyCaSTLe 编写一个 Java 程序，该程序生成一个带有 RSA key 对的 X509 SSL 证书。

我已经能够成功创建 SSL 证书，但我还希望能够对任意纯文本进行签名，并使用该签名通过针对纯文本验证签名来验证 key 的所有权。

方法应该是这样的:

protected String SignData(String privateKey, String text)
{
    //return a signature
}

和

protected boolean verifySignature(String text, String signature, String pubKey)
{
    //return either true or false depending on whether the signature is valid or not
}

我已经使用以下方法成功生成了自签名 SSL 证书:

protected X509Certificate generateCert()
{
    try
    {
        Security.addProvider(new BouncyCastleProvider());
        // generate a key pair
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA", "BC");
        keyPairGenerator.initialize(4096, new SecureRandom());
        KeyPair keyPair = keyPairGenerator.generateKeyPair();
        // build a certificate generator
        X509V3CertificateGenerator certGen = new X509V3CertificateGenerator();
        X500Principal dnName = new X500Principal("cn=example");
        // add some options
        certGen.setSerialNumber(BigInteger.valueOf(System.currentTimeMillis()));
        certGen.setSubjectDN(new X509Name("dc=name"));
        certGen.setIssuerDN(dnName); // use the same
        // yesterday
        certGen.setNotBefore(new Date(System.currentTimeMillis() - 24 * 60 * 60 * 1000));
        // in 2 years
        certGen.setNotAfter(new Date(System.currentTimeMillis() + 2 * 365 * 24 * 60 * 60 * 1000));
        certGen.setPublicKey(keyPair.getPublic());
        certGen.setSignatureAlgorithm("SHA256WithRSAEncryption");
        certGen.addExtension(X509Extensions.ExtendedKeyUsage, true, new ExtendedKeyUsage(KeyPurposeId.id_kp_timeStamping));

        // finally, sign the certificate with the private key of the same KeyPair
        X509Certificate cert = certGen.generate(keyPair.getPrivate(), "BC");

        return cert;
    }
    catch (Exception e)
    {
        e.printStackTrace();
        return null;
    }
}

Answer 1

找到解决方案:

签名:

        Signature rsaSign = Signature.getInstance("SHA256withRSA", "BC");
        rsaSign.initSign(pair.getPrivate());
        rsaSign.update(plaintext.getBytes("UTF-8"));
        byte[] signature = rsaSign.sign();
        return signature;

验证:

        rsaVerify = Signature.getInstance("SHA256withRSA", "BC");
        rsaVerify.initVerify(pubKey);
        rsaVerify.update(plaintext.getBytes("UTF-8"));
        return rsaVerify.verify(signature);