BouncyCastle RSAPrivateKey to .NET RSAPrivateKey

Answer 1

I am also facing the same problem if you get the answer please do share it with me. and if i get any clues will defiantly tell you the problem is quite similar but the context (purpose) we are using certificates is different.

Answer 2

I found it!

Or atleast part of it :)

As for the PrivateKey.ExportToParameters(true) Still doens't work but this has something todo with the fact that the key was 2048 bit. Because when I changed it to 1024bit it did work. So if anyone ever finds out why keep me posted.

So here we go again.

//BouncyCastle's Key objects
RsaPrivateCrtKeyParameters rpckp = ((RsaPrivateCrtKeyParameters)ackp.Private);

//.NET RSA Key objects
System.Security.Cryptography.RSACryptoServiceProvider rcsp = new System.Security.Cryptography.RSACryptoServiceProvider();
System.Security.Cryptography.RSAParameters parms = new System.Security.Cryptography.RSAParameters();

//So the thing changed is offcourse the ToByteArrayUnsigned() instead of
//ToByteArray()
parms.Modulus   = rpckp.Modulus.ToByteArrayUnsigned();
parms.P         = rpckp.P.ToByteArrayUnsigned();
parms.Q         = rpckp.Q.ToByteArrayUnsigned();
parms.DP        = rpckp.DP.ToByteArrayUnsigned();
parms.DQ        = rpckp.DQ.ToByteArrayUnsigned();
parms.InverseQ  = rpckp.QInv.ToByteArrayUnsigned();
parms.D         = rpckp.Exponent.ToByteArrayUnsigned();
parms.Exponent  = rpckp.PublicExponent.ToByteArrayUnsigned();

//So now this now appears to work.
rcsp.ImportParameters(parms);

So now I can add the complete Certificate to my store :)

Answer 3

FYI, I've added this functionality to the Org.BouncyCastle.Security.DotNetUtilities class; it will be in release 1.6, due soon.

Answer 4

I think I found the solution to this problem. It has nothing to do with the key per, but rather with the X509Certificate2 object which must be created with the X509KeyStorageFlags.Exportable flag.

In this case your X509Certificate2 was created by this method: System.Security.Cryptography.X509Certificates.X509Certificate2 netcert = DotNetUtilities.ToX509Certificate(cert);

So make sure you pass the exportable flag in the constructor of the X509Certificate2 in that method. I my situation I needed to sign some data with a private key located in a PFX file so I had to write this:

X509KeyStorageFlags flags = X509KeyStorageFlags.Exportable;
X509Certificate2 cert = new X509Certificate2("my.pfx", "somepass", flags);

Now I can do
RSACryptoServiceProvider rsa = (RSACryptoServiceProvider)cert.PrivateKey;
RSAParameters rsaParam = rsa.ExportParameters(true);

HTH,

Stefan