public override void GenerateKey(ECCurve curve)
{
curve.Validate();
_core.DisposeKey();
if (curve.IsNamed)
{
if (string.IsNullOrEmpty(curve.Oid.FriendlyName))
{
throw new PlatformNotSupportedException(string.Format(SR.Cryptography_InvalidCurveOid, curve.Oid.Value));
}
// Map curve name to algorithm to support pre-Win10 curves
CngAlgorithm alg = CngKey.EcdhCurveNameToAlgorithm(curve.Oid.FriendlyName);
if (CngKey.IsECNamedCurve(alg.Algorithm))
{
CngKey key = _core.GetOrGenerateKey(curve);
ForceSetKeySize(key.KeySize);
}
else
{
int keySize = 0;
// Get the proper KeySize from algorithm name
if (alg == CngAlgorithm.ECDiffieHellmanP256)
{
keySize = 256;
}
else if (alg == CngAlgorithm.ECDiffieHellmanP384)
{
keySize = 384;
}
else if (alg == CngAlgorithm.ECDiffieHellmanP521)
{
keySize = 521;
}
else
{
Debug.Fail(string.Format("Unknown algorithm {0}", alg.ToString()));
throw new ArgumentException(SR.Cryptography_InvalidKeySize);
}
CngKey key = _core.GetOrGenerateKey(keySize, alg);
ForceSetKeySize(keySize);
}
}
else if (curve.IsExplicit)
{
CngKey key = _core.GetOrGenerateKey(curve);
ForceSetKeySize(key.KeySize);
}
else
{
throw new PlatformNotSupportedException(string.Format(SR.Cryptography_CurveNotSupported, curve.CurveType.ToString()));
}
}
internal static CngKey Create(ECCurve curve, Func <string, CngAlgorithm> algorithmResolver)
{
System.Diagnostics.Debug.Assert(algorithmResolver != null);
curve.Validate();
CngKeyCreationParameters creationParameters = new CngKeyCreationParameters
{
ExportPolicy = CngExportPolicies.AllowPlaintextExport,
};
CngAlgorithm alg;
if (curve.IsNamed)
{
if (string.IsNullOrEmpty(curve.Oid.FriendlyName))
{
throw new PlatformNotSupportedException(string.Format(SR.Cryptography_InvalidCurveOid, curve.Oid.Value));
}
// Map curve name to algorithm to support pre-Win10 curves
alg = algorithmResolver(curve.Oid.FriendlyName);
if (CngKey.IsECNamedCurve(alg.Algorithm))
{
creationParameters.Parameters.Add(GetPropertyFromNamedCurve(curve));
}
else
{
if (alg == CngAlgorithm.ECDsaP256 || alg == CngAlgorithm.ECDiffieHellmanP256 ||
alg == CngAlgorithm.ECDsaP384 || alg == CngAlgorithm.ECDiffieHellmanP384 ||
alg == CngAlgorithm.ECDsaP521 || alg == CngAlgorithm.ECDiffieHellmanP521)
{
// No parameters required, the algorithm ID has everything built-in.
}
else
{
Debug.Fail(string.Format("Unknown algorithm {0}", alg.ToString()));
throw new ArgumentException(SR.Cryptography_InvalidKeySize);
}
}
}
else if (curve.IsPrime)
{
byte[] parametersBlob = ECCng.GetPrimeCurveParameterBlob(ref curve);
CngProperty prop = new CngProperty(
KeyPropertyName.ECCParameters,
parametersBlob,
CngPropertyOptions.None);
creationParameters.Parameters.Add(prop);
alg = algorithmResolver(null);
}
else
{
throw new PlatformNotSupportedException(string.Format(SR.Cryptography_CurveNotSupported, curve.CurveType.ToString()));
}
try
{
return(Create(alg, null, creationParameters));
}
catch (CryptographicException e)
{
Interop.NCrypt.ErrorCode errorCode = (Interop.NCrypt.ErrorCode)e.HResult;
if (errorCode == Interop.NCrypt.ErrorCode.NTE_INVALID_PARAMETER ||
errorCode == Interop.NCrypt.ErrorCode.NTE_NOT_SUPPORTED)
{
string target = curve.IsNamed ? curve.Oid.FriendlyName : curve.CurveType.ToString();
throw new PlatformNotSupportedException(string.Format(SR.Cryptography_CurveNotSupported, target), e);
}
throw;
}
}
private CngKey GetKey(
#if !NETNATIVE
ECCurve?curve = null
#endif
)
{
CngKey key = null;
CngAlgorithm algorithm = null;
int keySize = 0;
#if !NETNATIVE
if (curve != null)
{
if (curve.Value.IsNamed)
{
// Map curve name to algorithm to support pre-Win10 curves
CngAlgorithm alg = CngKey.EcdsaCurveNameToAlgorithm(curve.Value.Oid.FriendlyName);
if (CngKey.IsECNamedCurve(alg.Algorithm))
{
key = _core.GetOrGenerateKey(curve.Value);
}
else
{
// Get the proper KeySize from algorithm name
if (alg == CngAlgorithm.ECDsaP256)
{
keySize = 256;
}
else if (alg == CngAlgorithm.ECDsaP384)
{
keySize = 384;
}
else if (alg == CngAlgorithm.ECDsaP521)
{
keySize = 521;
}
else
{
Debug.Fail(string.Format("Unknown algorithm {0}", alg.ToString()));
throw new ArgumentException(SR.Cryptography_InvalidKeySize);
}
key = _core.GetOrGenerateKey(keySize, alg);
}
ForceSetKeySize(key.KeySize);
}
else if (curve.Value.IsExplicit)
{
key = _core.GetOrGenerateKey(curve.Value);
ForceSetKeySize(key.KeySize);
}
else
{
throw new PlatformNotSupportedException(string.Format(SR.Cryptography_CurveNotSupported, curve.Value.CurveType.ToString()));
}
}
else if (_core.IsKeyGeneratedNamedCurve())
{
key = _core.GetOrGenerateKey(null);
}
else
#endif
{
// Map the current key size to a CNG algorithm name
keySize = KeySize;
switch (keySize)
{
case 256: algorithm = CngAlgorithm.ECDsaP256; break;
case 384: algorithm = CngAlgorithm.ECDsaP384; break;
case 521: algorithm = CngAlgorithm.ECDsaP521; break;
default:
Debug.Fail("Should not have invalid key size");
throw new ArgumentException(SR.Cryptography_InvalidKeySize);
}
key = _core.GetOrGenerateKey(keySize, algorithm);
}
return(key);
}