Implmenet EC with X9ECParameters CKA_EC_PARAMS

[harrison314]

Implement support for explicit EC parameters for:

• Generate key pair
• Import key
• Sign

Example code for import:

X500DistinguishedName subject = new X500DistinguishedName("CN=Test");
using ECDsa ecdsa = ECDsa.Create(ECCurve.NamedCurves.nistP256);
 CertificateRequest request = new CertificateRequest(subject, ecdsa, HashAlgorithmName.SHA256);
using X509Certificate2 certificate = request.CreateSelfSigned(DateTime.Now, DateTime.Now.AddDays(2));
byte[] p12Data = certificate.Export(X509ContentType.Pkcs12, "Password");

using MemoryStream ms = new MemoryStream(p12Data);

Org.BouncyCastle.Pkcs.Pkcs12Store st = new Org.BouncyCastle.Pkcs.Pkcs12Store(ms, "Password".ToCharArray());
string? alias = st.Aliases.Cast<string>().FirstOrDefault(p => st.IsKeyEntry(p));
Org.BouncyCastle.Pkcs.X509CertificateEntry keyEntryX = st.GetCertificate(alias);
Org.BouncyCastle.Pkcs.AsymmetricKeyEntry keyEntry = st.GetKey(alias);
ECPrivateKeyParameters ecPrivateKey = (ECPrivateKeyParameters)keyEntry.Key;

using ISession session = slot.OpenSession(SessionType.ReadWrite);

X9ECParameters x9Parameters = new X9ECParameters(ecPrivateKey.Parameters.Curve,
    ecPrivateKey.Parameters.G,
    ecPrivateKey.Parameters.N,
    ecPrivateKey.Parameters.H,
    ecPrivateKey.Parameters.GetSeed());
    
List<IObjectAttribute> privateKeyAttributes = new List<IObjectAttribute>()
{
    session.Factories.ObjectAttributeFactory.Create(CKA.CKA_CLASS, CKO.CKO_PRIVATE_KEY),
    session.Factories.ObjectAttributeFactory.Create(CKA.CKA_TOKEN, true),
    session.Factories.ObjectAttributeFactory.Create(CKA.CKA_PRIVATE, true),
    session.Factories.ObjectAttributeFactory.Create(CKA.CKA_MODIFIABLE, true),
    session.Factories.ObjectAttributeFactory.Create(CKA.CKA_SIGN, true),
    session.Factories.ObjectAttributeFactory.Create(CKA.CKA_SIGN_RECOVER, false),
    session.Factories.ObjectAttributeFactory.Create(CKA.CKA_DECRYPT, true),
    session.Factories.ObjectAttributeFactory.Create(CKA.CKA_UNWRAP, true),
    session.Factories.ObjectAttributeFactory.Create(CKA.CKA_ID, Encoding.ASCII.GetBytes("test key")),
    session.Factories.ObjectAttributeFactory.Create(CKA.CKA_LABEL, "test key"),
    session.Factories.ObjectAttributeFactory.Create(CKA.CKA_KEY_TYPE, CKK.CKK_ECDSA),
    session.Factories.ObjectAttributeFactory.Create(CKA.CKA_EC_PARAMS, x9Parameters.ToAsn1Object().GetEncoded()),
    session.Factories.ObjectAttributeFactory.Create(CKA.CKA_VALUE, ecPrivateKey.D.ToByteArrayUnsigned())
};
_ = session.CreateObject(privateKeyAttributes);