如何在C＃中使用SHA256签名来签名和验证ECDSA

Question

我有一个包含EC私钥的文件：

-----BEGIN EC PRIVATE KEY-----
<data>
-----END EC PRIVATE KEY-----

我有一个具有与私钥相对应的公钥的证书：

pem格式：

-----BEGIN CERTIFICATE-----
<data>
-----END CERTIFICATE-----

以txt格式：

Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            80:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:15
        Signature Algorithm: ecdsa-with-SHA256
        Issuer: CN = MyIssuer
        Validity
            Not Before: Jan 27 19:33:43 2020 GMT
            Not After : Jun 10 19:33:43 2021 GMT
        Subject: CN = MyIssuer MyCert
        Subject Public Key Info:
            Public Key Algorithm: id-ecPublicKey
                Public-Key: (256 bit)
                pub:
                    04:6a:9c:40:7b:71:06:3a:7f:3a:1e:4c:5c:60:9e:
                    d0:c4:a0:c0:c7:39:ec:6d:f1:5b:27:5a:5f:3b:f8:
                    77:29:7e:38:8e:e6:77:cf:d2:9c:77:c2:43:f4:92:
                    73:a8:10:d2:e9:f2:bb:d7:4d:97:76:07:d0:1f:16:
                    7b:01:d3:35:26
                ASN1 OID: prime256v1
                NIST CURVE: P-256
        X509v3 extensions:
            X509v3 Basic Constraints: critical
                CA:FALSE
            X509v3 Authority Key Identifier: 
                keyid:E0:1C:E6:36:88:8B:3D:77:A6:9D:80:8B:7B:9B:1D:1E:FF:24:74:B3

            X509v3 Extended Key Usage: 
                TLS Web Server Authentication, TLS Web Client Authentication
            X509v3 Subject Key Identifier: 
                49:57:2F:01:37:1B:E2:B6:9C:1A:C7:A9:03:9A:D1:61:7E:9B:4A:84
            X509v3 Key Usage: critical
                Digital Signature, Non Repudiation, Key Encipherment, Data Encipherment
    Signature Algorithm: ecdsa-with-SHA256
         30:44:02:20:2c:1a:5c:ee:4a:58:59:f1:5a:4a:93:ed:e0:24:
         70:9d:15:11:5e:11:df:30:5a:0f:54:a0:9f:95:c4:eb:f9:6d:
         02:20:17:fe:e4:8c:ef:ef:34:56:fb:5d:79:40:f8:fc:f4:2f:
         97:90:4b:ac:cb:b6:64:c0:58:3e:2d:fe:7b:4f:ea:19
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

我正在尝试完成两件事：

1. 使用ecdsa-with-SHA256签名算法使用私钥对字节数组进行签名
2. 使用证书中的公钥验证签名是否正确

我曾尝试使用Bouncy Castle库。到目前为止，这就是我所拥有的。我的主张失败了。

    [TestMethod]
    public void TestSignAndVerify()
    {

        var data = new byte[] {6, 5, 4, 3, 2};

        var keyPair = GetKeyPair();

        var signature = SignData(data, keyPair.Private);

        var valid = VerifySignature(signature, keyPair.Public);
        Assert.IsTrue(valid);

    }

    // get key pair from two local files
    private AsymmetricCipherKeyPair GetKeyPair()
    {

        AsymmetricKeyParameter privateKey, publicKey;

        var privateKeyString = File.ReadAllText("C:\\privatekey.pem");
        using (var textReader = new StringReader(privateKeyString))
        {
            // Only a private key
            var pseudoKeyPair = (AsymmetricCipherKeyPair)new PemReader(textReader).ReadObject();
            privateKey = pseudoKeyPair.Private;
        }

        var certificateString = File.ReadAllText("C:\\publicCert.pem");
        using (var textReader = new StringReader(certificateString))
        {
            // Only a private key
            Org.BouncyCastle.X509.X509Certificate bcCertificate = (X509Certificate)new PemReader(textReader).ReadObject();
            publicKey = bcCertificate.GetPublicKey();
        }

        return new AsymmetricCipherKeyPair(publicKey, privateKey);

    }

    public byte[] SignData(byte[] data, AsymmetricKeyParameter privateKey)
    {
        var signer = SignerUtilities.GetSigner("SHA-256withECDSA");

        signer.Init(true, privateKey);

        signer.BlockUpdate(data, 0, data.Length);

        return signer.GenerateSignature();
    }

    public bool VerifySignature(byte[] signature, AsymmetricKeyParameter publicKey)
    {

        var verifier = SignerUtilities.GetSigner("SHA-256withECDSA");

        verifier.Init(false, publicKey);

        verifier.BlockUpdate(signature, 0, signature.Length);

        return verifier.VerifySignature(signature);

    }

Answer 1

Mr Polk is correct，您需要对数据使用verifier.blockUpdate，然后在VerifySignature中使用签名字节。