java - java中的RSA签名和验证

Question

我正在尝试用 java 对消息进行签名，但它似乎不起作用。验证步骤给了我错误。

谁能告诉我我的错误在哪里。我不明白我做错了什么。谢谢

String messageString = "text";
try {
        KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA", "BC");
        keyGen.initialize(512, new SecureRandom());
        KeyPair keyPair = keyGen.generateKeyPair();
        PublicKey RSAPublicKey = keyPair.getPublic();
        PrivateKey RSAPrivateKey = keyPair.getPrivate();

        System.out.println("public key = " + RSAPublicKey);
        System.out.println("private key = " + RSAPrivateKey);

        Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
        Signature signature = Signature.getInstance("SHA1withRSA", "BC");
        signature.initSign(RSAPrivateKey, new SecureRandom());
        byte[] message = messageString.getBytes();
        signature.update(message);
        byte[] sigBytes = signature.sign();

        Signature signature1 = Signature.getInstance("SHA1withRSA", "BC");
        signature1.initVerify(RSAPublicKey);
        signature1.update(sigBytes);

        boolean result = signature1.verify(sigBytes);
        System.out.println("result = "+result);
    } catch (NoSuchAlgorithmException | NoSuchProviderException | SignatureException | InvalidKeyException ex) {

    }    }

Answer 1

您的签名在变量 sigBytes 中，您的消息在变量 message 中。要验证消息，请先执行 signature1.update(message)，然后执行 signature1.verify(sigBytes)。

以下代码示例验证签名:

Signature signature1 = Signature.getInstance("SHA1withRSA", "BC");
signature1.initVerify(RSAPublicKey);
signature1.update(message);
boolean result = signature1.verify(sigBytes);

:)