Question

我需要从字节数组导出和导入带有私钥的生成证书，除非我使用.NET framework 4.0和4.5，否则我没有任何问题。我正在使用BouncyCastle库生成自签名证书，然后将它们转换为.NET格式（X509Certificate2对象）。不幸的是，升级到最新的框架我无法导出私钥。这是代码：

using System;
using System.Diagnostics;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Generators;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Crypto.Prng;
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.X509;

namespace X509CertificateExport
{
    class Program
    {
        static void Main(string[] args)
        {
            var certificate = Generate();
            var exported = certificate.Export(X509ContentType.Pfx);
            var imported = new X509Certificate2(exported, (string)null, X509KeyStorageFlags.Exportable | X509KeyStorageFlags.PersistKeySet);

            Console.WriteLine("Certificate has private key: " + imported.HasPrivateKey);
            Console.ReadKey();
        }

        public static X509Certificate2 Generate()
        {
            var keyPairGenerator = new RsaKeyPairGenerator();
            var secureRandom = new SecureRandom(new CryptoApiRandomGenerator());
            keyPairGenerator.Init(new KeyGenerationParameters(secureRandom, 1024));
            var keyPair = keyPairGenerator.GenerateKeyPair();
            var publicKey = keyPair.Public;
            var privateKey = (RsaPrivateCrtKeyParameters)keyPair.Private;

            var generator = new X509V3CertificateGenerator();
            generator.SetSerialNumber(BigInteger.ProbablePrime(120, new Random()));
            generator.SetSubjectDN(new X509Name("CN=Test"));
            generator.SetIssuerDN(new X509Name("CN=Test"));
            generator.SetNotAfter(DateTime.Now + new TimeSpan(10, 10, 10, 10));
            generator.SetNotBefore(DateTime.Now.Subtract(new TimeSpan(7, 0, 0, 0)));
            generator.SetSignatureAlgorithm("MD5WithRSA");
            generator.SetPublicKey(publicKey);

            var newCert = generator.Generate(privateKey);
            var dotNetPrivateKey = ToDotNetKey(privateKey);
            var dotNetCert = new X509Certificate2(DotNetUtilities.ToX509Certificate(newCert));
            dotNetCert.PrivateKey = dotNetPrivateKey;

            return dotNetCert;
        }

        public static AsymmetricAlgorithm ToDotNetKey(RsaPrivateCrtKeyParameters privateKey)
        {
            var rsaProvider = new RSACryptoServiceProvider();
            var parameters = new RSAParameters
            {
                Modulus = privateKey.Modulus.ToByteArrayUnsigned(),
                P = privateKey.P.ToByteArrayUnsigned(),
                Q = privateKey.Q.ToByteArrayUnsigned(),
                DP = privateKey.DP.ToByteArrayUnsigned(),
                DQ = privateKey.DQ.ToByteArrayUnsigned(),
                InverseQ = privateKey.QInv.ToByteArrayUnsigned(),
                D = privateKey.Exponent.ToByteArrayUnsigned(),
                Exponent = privateKey.PublicExponent.ToByteArrayUnsigned()
            };

            rsaProvider.ImportParameters(parameters);
            return rsaProvider;
        }
    }
}

仔细查看生成的证书后，我注意到对于.NET Framework 3.5，PrivateKey.CspKeyContainerInfo.Exportable标志是正确的，但对于以后的版本，它会抛出：

'Exportable' threw an exception of type
'System.Security.Cryptography.CryptographicException' / Key does not exist

我看到的唯一区别是PrivateKey.CspKeyContainerInfo.m_parameters.Flags： .NET 3.5 - 'NoFlags'; .NET 4.5 - 'CreateEphemeralKey'。文档指出'CreateEphemeralKey'创建临时密钥，该密钥在关联的RSA对象关闭时释放。它是用4.0框架引入的，之前不存在。我试图通过明确地创建CspParameters来摆脱这个标志：

public static AsymmetricAlgorithm ToDotNetKey(RsaPrivateCrtKeyParameters privateKey)
{
    var cspParams = new CspParameters
    {
        Flags = CspProviderFlags.UseMachineKeyStore
    };

    var rsaProvider = new RSACryptoServiceProvider(cspParams);
    // ...

但没有运气。无论如何都添加了'CreateEphemeralKey'，所以我得到的结果是UseMachineKeyStore | CreateEphemeralKey标志，我不知道如何删除它。有没有办法可以忽略这个标志并通常用私钥导出证书？

Answer 1

我没有注意到在.NET 4.0和.NET 4.5中创建密钥后CspKeyContainerInfo.CspParameters.KeyContainerName为空，但它是在.NET 3.5中自动生成的。我为容器设置了一个唯一的名称，现在我可以导出私钥了。

public static AsymmetricAlgorithm ToDotNetKey(RsaPrivateCrtKeyParameters privateKey)
{
    var cspParams = new CspParameters
    {
          KeyContainerName = Guid.NewGuid().ToString(),
          KeyNumber = (int)KeyNumber.Exchange,
          Flags = CspProviderFlags.UseMachineKeyStore
    };

    var rsaProvider = new RSACryptoServiceProvider(cspParams);
    // ...

无法使用私钥将生成的证书导出到.NET 4.0 / 4.5中的字节数组

1 个答案: