C# 调用 crl.dll 的代码有哪些

调用 crl.dll 的代码主要是与数字证书相关的操作，以下是一些常见的调用 crl.dll 的 C# 代码：

1. 验证数字证书是否有效：

using System.Security.Cryptography.X509Certificates;

public bool VerifyCertificate(X509Certificate2 cert)
{
    X509Chain chain = new X509Chain();
    chain.ChainPolicy.RevocationMode = X509RevocationMode.Online;
    chain.ChainPolicy.RevocationFlag = X509RevocationFlag.EntireChain;
    chain.ChainPolicy.UrlRetrievalTimeout = new TimeSpan(0, 1, 0);
    chain.Build(cert);

    foreach (X509ChainElement element in chain.ChainElements)
    {
        foreach (X509ChainStatus status in element.ChainElementStatus)
        {
            if (status.Status != X509ChainStatusFlags.NoError && status.Status != X509ChainStatusFlags.UntrustedRoot)
            {
                return false;
            }
        }
    }

    return true;
}

2. 获取数字证书的 CRL（证书撤销列表）：

using System.Security.Cryptography.X509Certificates;

public X509Crl GetCrl(X509Certificate2 cert)
{
    X509ExtensionCollection extensions = cert.Extensions;
    foreach (X509Extension extension in extensions)
    {
        if (extension.Oid.Value.Equals("2.5.29.31"))
        {
            byte[] crlBytes = extension.RawData;
            X509Crl crl = new X509Crl(crlBytes);
            return crl;
        }
    }

    return null;
}

3. 撤销数字证书：

using System.Security.Cryptography.X509Certificates;

public void RevokeCertificate(X509Certificate2 cert, X509Crl crl, string reason, DateTime revokeDate)
{
    X509CrlEntry entry = new X509CrlEntry(cert.SerialNumber, revokeDate, CrlReason.PrivilegeWithdrawn);
    crl.Revoke(entry);
}

需要注意的是，为了调用 crl.dll，需要在代码中添加以下引用：

using System.Security.Cryptography.X509Certificates;
using System.Security.Cryptography.X509Certificates.Extensions;
using System.Security.Cryptography.X509Certificates.Crl;