尝试创建非自签名证书时出现异常

时间:2016-11-07 15:02:41

标签: c# ssl x509certificate2 certenroll

我想从每个设备的自签名证书切换到一对证书,其中一个先前生成,放置在受信任的根证书颁发机构存储中,对所有设备都相同,并作为第二个证书的根CA工作,每个设备生成,并放置在个人存储中。

我不想使用makecert,因为创建签名证书会显示UI,我想避免使用它。此外,由于某些许可证相关的东西(虽然我有工作解决方案),OpenSSL无法使用。所以,现在我正在使用基于CertEnroll lib的小型C#工具。

这就是我为第一个根CA证书创建pfx的方法。

makecert -n "CN=Root CA" -cy authority -r -a sha256 -len 2048 -sv root.pvk root.cer
pvk2pfx -pvk root.pvk -spc root.cer -pfx root.pfx -pi 123 -po 123

要使用C#代码创建证书,我引用了问题How to create self-signed certificate programmatically for WCF service?C# Generate a non self signed client CX509Certificate Request without a CA using the certenroll.dll

到目前为止,我有以下代码。证书生成方法:

/// <summary>
/// Generates self-signed certificate with specified subject, which will expire after specified timespan.
/// </summary>
public X509Certificate2 CreateCertificate(string subjectName, TimeSpan expirationLength, X509Certificate2 issuer = null)
{
    // create DN for subject and issuer
    var dn = new CX500DistinguishedName();
    dn.Encode("CN=" + subjectName);

    var issuerName = new CX500DistinguishedName();
    if(issuer != null)
    {
        issuerName.Encode(issuer.Subject);
    }

    var privateKey = new CX509PrivateKey
    {
        ProviderName = "Microsoft Strong Cryptographic Provider",
        Length = 2048,
        KeySpec = X509KeySpec.XCN_AT_KEYEXCHANGE,
        KeyUsage = X509PrivateKeyUsageFlags.XCN_NCRYPT_ALLOW_DECRYPT_FLAG |
                       X509PrivateKeyUsageFlags.XCN_NCRYPT_ALLOW_KEY_AGREEMENT_FLAG,
        MachineContext = true,
        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");

    var cert = new CX509CertificateRequestCertificate();
    cert.InitializeFromPrivateKey(X509CertificateEnrollmentContext.ContextMachine, privateKey, "");
    cert.Subject = dn;
    if (issuer != null)
        cert.Issuer = issuerName;
    else
        cert.Issuer = dn;
    cert.NotBefore = DateTime.Now.Date;
    cert.NotAfter = cert.NotBefore + expirationLength;
    cert.HashAlgorithm = hashobj; // Specify the hashing algorithm

    if(issuer != null)
    {
        var signerCertificate = new CSignerCertificate();
        signerCertificate.Initialize(true, X509PrivateKeyVerify.VerifyAllowUI, EncodingType.XCN_CRYPT_STRING_HEX, issuer.GetRawCertDataString());
        cert.SignerCertificate = signerCertificate; 
    }
    cert.Encode();

    // Do the final enrollment process
    var enroll = new CX509Enrollment();
    enroll.InitializeFromRequest(cert); // load the certificate
    enroll.CertificateFriendlyName = subjectName; // Optional: add a friendly name

    var 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 X509Certificate2(Convert.FromBase64String(base64encoded), "",
        X509KeyStorageFlags.Exportable | X509KeyStorageFlags.MachineKeySet | X509KeyStorageFlags.PersistKeySet);
}

查找现有证书并根据它创建新证书的简单应用程序:

static void Main(string[] args)
{
    var certificateGenerator = new CertificateGenerator();

    X509Certificate2 rootCA;

    using (var store = new X509Store(StoreName.Root, StoreLocation.LocalMachine))
    {
        store.Open(OpenFlags.ReadWrite);

        rootCA = store.Certificates.OfType<X509Certificate2>()
            .FirstOrDefault(c => c.Subject.StartsWith("CN=Root CA", StringComparison.Ordinal));

        store.Close();
    }

    if (rootCA == null)
        throw new Exception("Can't find root CA certificate");

    var testCert = certificateGenerator.CreateCertificate("Test", new TimeSpan(3650, 0, 0, 0), rootCA);
    using (var store = new X509Store(StoreName.My, StoreLocation.LocalMachine))
    {
        store.Open(OpenFlags.ReadWrite);
        store.Add(testCert);
        store.Close();
    }
}

问题是,如果我尝试引用不在受信任的根证书颁发机构中的证书,但在个人中(即使我在证书上有密码),它也很有用。但是,如果我尝试根据受信任的根证书颁发机构的CA证书创建证书,我会在signerCertificate.Initialize上收到例外,说

Cannot find object or property. 0x80092004 (-2146885628 CRYPT_E_NOT_FOUND)

那么,我错过了什么?

1 个答案:

答案 0 :(得分:4)

ISignerCertificate::Initialize要求通过请求或我的商店绑定私钥:

https://msdn.microsoft.com/en-us/library/windows/desktop/aa376832(v=vs.85).aspx

  

如果需要私钥,则只有个人和请求商店   搜索。

     

如果不需要私钥,则为根CA和中间CA.   商店也被搜查。

Windows希望您只将CA的公共部分放入CA(中间)或Root / ThirdPartyRoot存储中,如果您是发行者,则还要安装它(使用私有)现在关键)进入CurrentUser \ My或LocalMachine \ My。