internal SafeNCryptKeyHandle GetDuplicatedKeyHandle(int callerKeySizeProperty)
{
ThrowIfDisposed();
if (ECCng.IsECNamedCurve(_lastAlgorithm))
{
// Curve was previously created, so use that
return(new DuplicateSafeNCryptKeyHandle(_keyHandle !));
}
else
{
if (_lastKeySize != callerKeySizeProperty)
{
// Map the current key size to a CNG algorithm name
string algorithm;
bool isEcdsa = _algorithmGroup == BCryptNative.AlgorithmName.ECDsa;
switch (callerKeySizeProperty)
{
case 256:
algorithm = isEcdsa
? BCryptNative.AlgorithmName.ECDsaP256
: BCryptNative.AlgorithmName.ECDHP256;
break;
case 384:
algorithm = isEcdsa
? BCryptNative.AlgorithmName.ECDsaP384
: BCryptNative.AlgorithmName.ECDHP384;
break;
case 521:
algorithm = isEcdsa
? BCryptNative.AlgorithmName.ECDsaP521
: BCryptNative.AlgorithmName.ECDHP521;
break;
default:
Debug.Fail("Should not have invalid key size");
throw new ArgumentException(SR.Cryptography_InvalidKeySize);
}
if (_keyHandle != null)
{
DisposeKey();
}
_keyHandle = CngKeyLite.GenerateNewExportableKey(algorithm, callerKeySizeProperty);
_lastKeySize = callerKeySizeProperty;
_lastAlgorithm = algorithm;
KeySize = callerKeySizeProperty;
}
return(new DuplicateSafeNCryptKeyHandle(_keyHandle !));
}
}
internal string GetCurveName(int callerKeySizeProperty)
{
// Ensure key\handle is created
using (SafeNCryptKeyHandle keyHandle = GetDuplicatedKeyHandle(callerKeySizeProperty))
{
string algorithm = _lastAlgorithm;
if (ECCng.IsECNamedCurve(algorithm))
{
return(CngKeyLite.GetCurveName(keyHandle));
}
// Use hard-coded values (for use with pre-Win10 APIs)
return(ECCng.SpecialNistAlgorithmToCurveName(algorithm));
}
}
internal void GenerateKey(ECCurve curve)
{
curve.Validate();
ThrowIfDisposed();
if (_keyHandle != null)
{
DisposeKey();
}
string algorithm;
int keySize = 0;
if (curve.IsNamed)
{
if (string.IsNullOrEmpty(curve.Oid.FriendlyName))
{
throw new PlatformNotSupportedException(
SR.Format(SR.Cryptography_InvalidCurveOid, curve.Oid.Value));
}
// Map curve name to algorithm to support pre-Win10 curves
if (_algorithmGroup == BCryptNative.AlgorithmName.ECDsa)
{
algorithm = ECCng.EcdsaCurveNameToAlgorithm(curve.Oid.FriendlyName);
}
else
{
Debug.Assert(_algorithmGroup == BCryptNative.AlgorithmName.ECDH);
algorithm = ECCng.EcdhCurveNameToAlgorithm(curve.Oid.FriendlyName);
}
if (ECCng.IsECNamedCurve(algorithm))
{
try
{
_keyHandle = CngKeyLite.GenerateNewExportableKey(algorithm, curve.Oid.FriendlyName);
keySize = CngKeyLite.GetKeyLength(_keyHandle);
}
catch (CryptographicException e)
{
// Map to PlatformNotSupportedException if appropriate
Interop.NCrypt.ErrorCode errorCode = (Interop.NCrypt.ErrorCode)e.HResult;
if (curve.IsNamed && errorCode == Interop.NCrypt.ErrorCode.NTE_INVALID_PARAMETER ||
errorCode == Interop.NCrypt.ErrorCode.NTE_NOT_SUPPORTED)
{
throw new PlatformNotSupportedException(
SR.Format(SR.Cryptography_CurveNotSupported, curve.Oid.FriendlyName), e);
}
throw;
}
}
else
{
// Get the proper KeySize from algorithm name
switch (algorithm)
{
case BCryptNative.AlgorithmName.ECDsaP256:
case BCryptNative.AlgorithmName.ECDHP256:
keySize = 256;
break;
case BCryptNative.AlgorithmName.ECDsaP384:
case BCryptNative.AlgorithmName.ECDHP384:
keySize = 384;
break;
case BCryptNative.AlgorithmName.ECDsaP521:
case BCryptNative.AlgorithmName.ECDHP521:
keySize = 521;
break;
default:
Debug.Fail($"Unknown algorithm {algorithm}");
throw new ArgumentException(SR.Cryptography_InvalidKeySize);
}
_keyHandle = CngKeyLite.GenerateNewExportableKey(algorithm, keySize);
}
}
else if (curve.IsExplicit)
{
algorithm = _algorithmGroup;
_keyHandle = CngKeyLite.GenerateNewExportableKey(algorithm, ref curve);
keySize = CngKeyLite.GetKeyLength(_keyHandle);
}
else
{
throw new PlatformNotSupportedException(
SR.Format(SR.Cryptography_CurveNotSupported, curve.CurveType.ToString()));
}
_lastAlgorithm = algorithm;
_lastKeySize = keySize;
KeySize = keySize;
}
