Question

我有一个Windows证书颁发机构，我用它通过.net / c＃发出客户端身份验证证书。通过COM调用证书颁发机构的API，我已经能够成功地以编程方式颁发证书。我在设置客户端时发出新证书。

在运行时，这些客户端将证书附加到我的服务器的请求。如何以编程方式验证X509Certificate2是否由我的证书颁发机构的根证书签名（并拒绝由任何其他来源签名的证书）？

Answer 1

我已经做了很多很多。这里有一些你可以使用的简单代码。

if (!isChainValid)块中的部分是一个非常错误的消息。如果您不想要，则不必使用它，但如果无法构建链，则应该抛出错误。链元素是检查根的必要条件。

X509Certificate2 authority = GetAuthorityCertificate();
X509Certificate2 certificateToValidate = GetCertificateToValidate();

X509Chain chain = new X509Chain();
chain.ChainPolicy.RevocationMode = X509RevocationMode.NoCheck;
chain.ChainPolicy.RevocationFlag = X509RevocationFlag.ExcludeRoot;
chain.ChainPolicy.VerificationFlags = X509VerificationFlags.AllowUnknownCertificateAuthority;
chain.ChainPolicy.VerificationTime = DateTime.Now;
chain.ChainPolicy.UrlRetrievalTimeout = new TimeSpan(0, 0, 0);

// This part is very important. You're adding your known root here.
// It doesn't have to be in the computer store at all. Neither certificates do.
chain.ChainPolicy.ExtraStore.Add(authority);

bool isChainValid = chain.Build(certificateToValidate);

if (!isChainValid)
{
    string[] errors = chain.ChainStatus
        .Select(x => String.Format("{0} ({1})", x.StatusInformation.Trim(), x.Status))
        .ToArray();
    string certificateErrorsString = "Unknown errors.";

    if (errors != null && errors.Length > 0)
    {
        certificateErrorsString = String.Join(", ", errors);
    }

    throw new Exception("Trust chain did not complete to the known authority anchor. Errors: " + certificateErrorsString);
}

// This piece makes sure it actually matches your known root
var valid = chain.ChainElements
    .Cast<X509ChainElement>()
    .Any(x => x.Certificate.Thumbprint == authority.Thumbprint);

if (!valid)
{
    throw new Exception("Trust chain did not complete to the known authority anchor. Thumbprints did not match.");
}

Answer 2

如果您说您拥有 root （自签名）证书，那么您唯一的选择就是在服务器上保留此根证书（当然没有私钥）并执行针对根证书的证书验证过程。这是Web客户端验证服务器证书链的镜像情况。

Answer 3

您还可以使用Verify()的内置方法X509Certificate2。

X509Certificate2 certificateToValidate = GetCertificateToValidate();
bool valid = certificateToValidate.Verify()

https://msdn.microsoft.com/en-us/library/system.security.cryptography.x509certificates.x509certificate2.verify.aspx

如何验证证书是否由特定证书颁发机构创建？

3 个答案: