如何以编程方式为WCF服务创建自签名证书？

Question

我有一个自托管的WCF服务器作为本地系统帐户下的Windows服务运行.我正在尝试以编程方式在c#中创建自签名证书,以便使用消息级别安全性与net.tcp端点一起使用.

我使用以下代码,它非常基于如何使用C#创建自签名证书中的接受答案？试图解决我的问题的一些小变化.

public static X509Certificate2 CreateSelfSignedCertificate(string subjectName, TimeSpan expirationLength)
{
    // create DN for subject and issuer
    var dn = new CX500DistinguishedName();
    dn.Encode("CN=" + subjectName, X500NameFlags.XCN_CERT_NAME_STR_NONE);

    CX509PrivateKey privateKey = new CX509PrivateKey();
    privateKey.ProviderName = "Microsoft Strong Cryptographic Provider";
    privateKey.Length = 1024;
    privateKey.KeySpec = X509KeySpec.XCN_AT_KEYEXCHANGE;
    privateKey.KeyUsage = X509PrivateKeyUsageFlags.XCN_NCRYPT_ALLOW_DECRYPT_FLAG | X509PrivateKeyUsageFlags.XCN_NCRYPT_ALLOW_KEY_AGREEMENT_FLAG;
    privateKey.MachineContext = true;
    privateKey.ExportPolicy = X509PrivateKeyExportFlags.XCN_NCRYPT_ALLOW_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, "SHA1");

    // Create the self signing request
    var cert = new CX509CertificateRequestCertificate();
    cert.InitializeFromPrivateKey(X509CertificateEnrollmentContext.ContextMachine, privateKey, "");
    cert.Subject = dn;
    cert.Issuer = dn; // the issuer and the subject are the same
    cert.NotBefore = DateTime.Now.Date;
    // this cert expires immediately. Change to whatever makes sense for you
    cert.NotAfter = cert.NotBefore + expirationLength;
    //cert.X509Extensions.Add((CX509Extension)eku); // add the EKU
    cert.HashAlgorithm = hashobj; // Specify the hashing algorithm
    cert.Encode(); // encode the certificate

    // Do the final enrollment process
    var enroll = new CX509Enrollment();
    enroll.InitializeFromRequest(cert); // load the certificate
    enroll.CertificateFriendlyName = subjectName; // Optional: add a friendly name
    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 so we can import it back to the .Net security classes
    var base64encoded = enroll.CreatePFX("", // no password, this is for internal consumption
        PFXExportOptions.PFXExportChainWithRoot);

    // instantiate the target class with the PKCS#12 data (and the empty password)
    return new System.Security.Cryptography.X509Certificates.X509Certificate2(
        System.Convert.FromBase64String(base64encoded), "",
        // mark the private key as exportable (this is usually what you want to do)
        // mark private key to go into the Machine store instead of the current users store
        X509KeyStorageFlags.Exportable | X509KeyStorageFlags.MachineKeySet
    );
}

我用这段代码存储它:

X509Store store = new X509Store(storeName, StoreLocation.LocalMachine);
store.Open(OpenFlags.ReadWrite);
store.Add(newCert);
store.Close();

这将创建证书并将其放入LocalMachine证书库中.问题是,当我尝试启动WCF服务时,我得到以下异常:

证书'CN = myCertificate'可能没有能够进行密钥交换的私钥,或者该进程可能没有私钥的访问权限.详情请见内部异常.内部异常:Keyset不存在

我的证书的FindPrivateKey示例(http://msdn.microsoft.com/en-us/library/aa717039%28v=vs.100%29.aspx)的输出是:

Private key directory:
C:\ProgramData\Microsoft\Crypto\RSA\MachineKeys
Private key file name:
f0d47c7826b8ef5148b6d412f1c40024_4a8a026f-58e4-40f7-b779-3ae9b6aae1a7

我可以在资源管理器中看到这个1.43KB的文件.如果我查看属性|安全性,我看到SYSTEM和管理员都具有完全控制权.

在研究此错误时,我看到许多关于私钥丢失或权限不正确的答案.我看不出是什么问题.

真奇怪的是,如果我使用mmc Certificate插件,请转到证书并选择All Tasks | Manage Private Keys ...我看到相同的安全设置.查看后,即使我只是调出对话框并点击取消按钮,证书现在可以在WCF中正常工作.我可以简单地重启服务,一切都运行完美.

如果我使用MakeCert创建证书,它从一开始就可以正常工作.我不知道它的作用有何不同.

另一条可能不相关的信息是,证书不仅被放入我告诉它放入的我的商店,而且还被放入"中级证书颁发机构"商店.我不知道为什么或是否重要.

那么......任何想法我做错了什么？

更新:嗯,这不仅仅是一个WCF问题.当我尝试使用HttpSetServiceConfiguration使用证书绑定到具有http.sys的端点时,我基本上遇到了同样的问题.该方法返回1312 - "指定的登录会话不存在.它可能已经被终止".这实际上不是真正的错误.我在安全事件日志中看到一个审计失败,它说:

Cryptographic Parameters:
    Provider Name:  Microsoft Software Key Storage Provider
    Algorithm Name: Not Available.
    Key Name:   {A23712D0-9A7B-4377-89DB-B1B39E3DA8B5}
    Key Type:   Machine key.

Cryptographic Operation:
    Operation:  Open Key.
    Return Code:    0x80090011

0x80090011未找到Object.所以这似乎是同样的问题.再次,在我打开证书的"管理私钥"对话框之后,这也完美地起作用.

我仍然在寻找问题的原因.

更新#2:我能够使用下面接受的答案来解决这个问题.有趣的是,此代码现在似乎将证书放在机器商店中而不调用X509Store代码.我仍然会调用代码,因为我不确定它并没有伤害任何东西.这是我用来创建证书的最终代码.

    static public X509Certificate2 CreateSelfSignedCertificate(string subjectName, TimeSpan expirationLength)
    {
        // create DN for subject and issuer
        var dn = new CX500DistinguishedName();
        dn.Encode("CN=" + subjectName, X500NameFlags.XCN_CERT_NAME_STR_NONE);

        CX509PrivateKey privateKey = new CX509PrivateKey();
        privateKey.ProviderName = "Microsoft Strong Cryptographic Provider";
        privateKey.Length = 2048;
        privateKey.KeySpec = X509KeySpec.XCN_AT_KEYEXCHANGE;
        privateKey.KeyUsage = X509PrivateKeyUsageFlags.XCN_NCRYPT_ALLOW_DECRYPT_FLAG | X509PrivateKeyUsageFlags.XCN_NCRYPT_ALLOW_KEY_AGREEMENT_FLAG;
        privateKey.MachineContext = true;
        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, "");
        cert.Subject = dn;
        cert.Issuer = dn; // the issuer and the subject are the same
        cert.NotBefore = DateTime.Now.Date;
        // this cert expires immediately. Change to whatever makes sense for you
        cert.NotAfter = cert.NotBefore + expirationLength;
        cert.HashAlgorithm = hashobj; // Specify the hashing algorithm
        cert.Encode(); // encode the certificate

        // Do the final enrollment process
        var enroll = new CX509Enrollment();
        enroll.InitializeFromRequest(cert); // load the certificate
        enroll.CertificateFriendlyName = subjectName; // Optional: add a friendly name
        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 so we can import it back to the .Net security classes
        var base64encoded = enroll.CreatePFX("", // no password, this is for internal consumption
            PFXExportOptions.PFXExportChainWithRoot);

        // instantiate the target class with the PKCS#12 data (and the empty password)
        return new System.Security.Cryptography.X509Certificates.X509Certificate2(
            System.Convert.FromBase64String(base64encoded), "",
            // mark the private key as exportable (this is usually what you want to do)
            // mark private key to go into the Machine store instead of the current users store
            X509KeyStorageFlags.Exportable | X509KeyStorageFlags.MachineKeySet | X509KeyStorageFlags.PersistKeySet
        );
    }

Answer 1

我无法做到这一点,但我找到了另一种解决方案.(2014年12月更新:我现在使用接受的答案让它工作.)

我能够使用PluralSight.Crypto库来实现我的需求.我不得不稍微修改源代码以获取存储在LocalMachine存储中的私钥.我所做的更改是CryptContext.cs文件.我更改了CreateSelfSignedCertificate方法.以下是一段代码,包括我所做的更改.本质上,如果CryptContext对象在其Flags中包含此值,我将CryptKeyProviderInformation结构的Flags成员设置为0x20(CRYPT_MACHINE_KEYSET).

        byte[] asnName = properties.Name.RawData;
        GCHandle asnNameHandle = GCHandle.Alloc(asnName, GCHandleType.Pinned);

        int flags = 0;                    // New code
        if ((this.Flags & 0x20) == 0x20)  // New code
            flags = 0x20;                 // New code

        var kpi = new Win32Native.CryptKeyProviderInformation
        {
            ContainerName = this.ContainerName,
            KeySpec = (int)KeyType.Exchange,
            ProviderType = 1, // default RSA Full provider
            Flags = flags                 // New code
        };

然后我在我自己的代码中使用这个函数,如下所示:

        using (Pluralsight.Crypto.CryptContext ctx = new Pluralsight.Crypto.CryptContext()) {

            ctx.Flags = 0x8 | 0x20;
            ctx.Open();

            X509Certificate2 cert = ctx.CreateSelfSignedCertificate(
                new Pluralsight.Crypto.SelfSignedCertProperties
                {
                    IsPrivateKeyExportable = true,
                    KeyBitLength = 4096,
                    Name = new X500DistinguishedName("CN=" + subjectName),
                    ValidFrom = DateTime.Today,
                    ValidTo = DateTime.Today + expirationLength,
                });

            return cert;
        }

请注意,我将CryptContext对象的Flags设置为0x8 | 0x20(CRYPT_NEWKEYSET | CRYPT_MACHINE_KEYSET).

我希望我能弄明白我原来的解决方案有什么问题.但我需要一些工作,在我的测试中,这个解决方案可以满足我的需求.我希望它能帮助其他人.

Answer 2

我在PowerShell中使用等效代码时遇到了同样的问题.看来有时私钥就消失了.我使用了Process Monitor,您可以看到要删除的密钥文件.

我解决这个问题的方法是添加X509KeyStorageFlags.PersistKeySet到X509Certificate2构造函数中.