c# – 如何使用CertEnroll生成扩展验证自签名证书？

由于 Windows Azure中存在错误,因此必须将Windows 8应用程序中与Azure REST API一起使用的所有自签名客户端证书指定为扩展验证证书.

为了提供更好的用户体验,我尝试在远程服务器上生成此自签名证书.我正在使用Certificate Enrolment API,一个作为Windows的一部分分发的COM库,如this answer到问题How to create a self-signed certificate using C#?中所述

代码基本相同,只是稍微修改一下供我自己使用：

public static X509Certificate2 CreateSelfSignedCertificate(
    string cname,string friendlyName,string password)
{
    // create DN for subject and issuer
    var dn = new CX500distinguishedname();
    dn.Encode("CN=" + cname,X500NameFlags.XCN_CERT_NAME_STR_NONE);

    // create a new private key for the certificate
    CX509PrivateKey privateKey = new CX509PrivateKey();
    privateKey.ProviderName = "Microsoft Base Cryptographic Provider v1.0";
    privateKey.MachineContext = true;
    privateKey.Length = 2048;
    privateKey.KeySpec = X509KeySpec.XCN_AT_SIGNATURE; // use is not limited
    privateKey.ExportPolicy 
        = X509PrivateKeyExportFlags.XCN_NCRYPT_ALLOW_PLAINTEXT_EXPORT_FLAG;
    privateKey.Create();

    // Use the stronger SHA512 hashing algorithm
    var hashobj = new CObjectId();
    hashobj.InitializefromAlgorithmName(
        ObjectIdGroupId.XCN_CRYPT_HASH_ALG_OID_GROUP_ID,ObjectIdPublicKeyFlags.XCN_CRYPT_OID_INFO_PUBKEY_ANY,AlgorithmFlags.AlgorithmFlagsNone,"SHA512");

    // Create the self signing request
    var cert = new CX509CertificateRequestCertificate();
    cert.InitializefromPrivateKey(
        X509CertificateEnrollmentContext.ContextMachine,privateKey,string.Empty);

    cert.Subject = dn;
    cert.Issuer = dn; // the issuer and the subject are the same
    cert.NotBefore = DateTime.Now;
    cert.NotAfter = DateTime.Now.AddYears(50); 
    cert.HashAlgorithm = hashobj;

    var clientAuthenticationOid = new CObjectId();
    clientAuthenticationOid.InitializefromValue("1.3.6.1.5.5.7.3.2");

    // Set up cert to be used for Client Authentication.
    var oids = new CObjectIds();
    oids.Add(clientAuthenticationOid);

    var eku = new CX509ExtensionEnhancedKeyUsage();
    eku.InitializeEncode(oids);

    cert.X509Extensions.Add((CX509Extension)eku);

    // Add the certificate policy.
    var policy = new CCertificatePolicy();
    policy.Initialize(clientAuthenticationOid);

    // THIS IS WRONG - NEEDS A DIFFERENT QUALIFIER
    var qualifier = new CPolicyQualifier();
    qualifier.InitializeEncode(
        "c0",PolicyQualifierType.PolicyQualifierTypeUserNotice);

    policy.PolicyQualifiers.Add(qualifier);

    var policies = new CCertificatePolicies();
    policies.Add(policy);

    var ecp = new CX509ExtensionCertificatePolicies();
    ecp.InitializeEncode(policies);

    cert.X509Extensions.Add((CX509Extension)ecp);

    cert.Encode();

    // Do the final enrolment process
    var enroll = new CX509Enrollment();
    enroll.Initializefromrequest(cert); // load the certificate
    enroll.CertificateFriendlyName = friendlyName;
    string csr = enroll.CreateRequest(); // Output the request in base64

    // and install it back as the response
    enroll.installresponse(
        installresponseRestrictionFlags.AllowUntrustedCertificate,csr,EncodingType.XCN_CRYPT_STRING_BASE64,""); // no password

    // output a base64 encoded PKCS#12 for import to .NET
    var base64encoded = enroll.CreatePFX(
        password,PFXExportOptions.PFXExportChainWithRoot);

    // instantiate the target class with the PKCS#12 data
    return new X509Certificate2(
        System.Convert.FromBase64String(base64encoded),password,X509KeyStorageFlags.Exportable);
}

我发现ICertificatePolicy界面似乎代表了正确的结构类型,但我无法推断出正确使用的IPolicyQualifier.在我的代码中,限定符是

为清楚起见,您可以在此处配置Windows 8证书管理器中的信息：

在证书上生成此属性：

我的代码目前生成此属性：

关闭,但还没有.

是否有另一种方法将数据加载到IPolicyQualifier中,以便它可能使用InitialiseDecode方法产生预期的结果？

解决方法

如果要将客户端身份验证OID设置为“1.3.6.1.5.5.7.2”,那么我认为您的代码确实可以正常工作.如何验证代码没有设置此值？

我编写了以下代码来使用您的代码保存生成的证书：

X509Certificate2 xx = CreateSelfSignedCertificate("Avkash CNAME","Test User Friendly Name","xx");
byte[] bCertExported = xx.Export(X509ContentType.Pkcs12,"xx");
File.WriteallBytes("c:\\InstallBox\\test.pfx",bCertExported);

我在本地安装证书并检查它是否为客户端身份验证OID后,它显示如下：