public CngKey GetOrGenerateKey(int keySize, CngAlgorithm algorithm)
{
ThrowIfDisposed();
// If our key size was changed, we need to generate a new key.
if (_lazyKey != null)
{
if (_lazyKey.KeySize != keySize)
{
DisposeKey();
}
}
// If we don't have a key yet, we need to generate one now.
if (_lazyKey == null)
{
CngKeyCreationParameters creationParameters = new CngKeyCreationParameters()
{
ExportPolicy = CngExportPolicies.AllowPlaintextExport,
};
CngProperty keySizeProperty = new CngProperty(KeyPropertyName.Length, BitConverter.GetBytes(keySize), CngPropertyOptions.None);
creationParameters.Parameters.Add(keySizeProperty);
_lazyKey = CngKey.Create(algorithm, null, creationParameters);
}
return(_lazyKey);
}
public CngKey GetOrGenerateKey(int keySize, CngAlgorithm algorithm)
{
ThrowIfDisposed();
// If our key size was changed, we need to generate a new key.
if (_lazyKey != null)
{
if (_lazyKey.KeySize != keySize)
{
DisposeKey();
}
}
// If we don't have a key yet, we need to generate one now.
if (_lazyKey == null)
{
CngKeyCreationParameters creationParameters = new CngKeyCreationParameters()
{
ExportPolicy = CngExportPolicies.AllowPlaintextExport,
};
Span <byte> keySizeBuffer = stackalloc byte[sizeof(int)];
bool success = BitConverter.TryWriteBytes(keySizeBuffer, keySize);
Debug.Assert(success);
CngProperty keySizeProperty = new CngProperty(KeyPropertyName.Length, keySizeBuffer, CngPropertyOptions.None);
creationParameters.Parameters.Add(keySizeProperty);
_lazyKey = CngKey.Create(algorithm, null, creationParameters);
}
return(_lazyKey);
}
public CngKey GetOrGenerateKey(ECCurve?curve)
{
ThrowIfDisposed();
if (_lazyKey != null)
{
return(_lazyKey);
}
// We don't have a key yet so generate
Debug.Assert(curve.HasValue);
CngKeyCreationParameters creationParameters = new CngKeyCreationParameters()
{
ExportPolicy = CngExportPolicies.AllowPlaintextExport,
};
if (curve.Value.IsNamed)
{
creationParameters.Parameters.Add(CngKey.GetPropertyFromNamedCurve(curve.Value));
}
else if (curve.Value.IsPrime)
{
ECCurve eccurve = curve.Value;
byte[] parametersBlob = ECCng.GetPrimeCurveParameterBlob(ref eccurve);
CngProperty prop = new CngProperty(
Interop.BCrypt.BCryptPropertyStrings.BCRYPT_ECC_PARAMETERS,
parametersBlob,
CngPropertyOptions.None);
creationParameters.Parameters.Add(prop);
}
else
{
throw new PlatformNotSupportedException(SR.Format(SR.Cryptography_CurveNotSupported, curve.Value.CurveType.ToString()));
}
try
{
_lazyKey = CngKey.Create(DefaultKeyType ?? CngAlgorithm.ECDsa, null, creationParameters);
}
catch (CryptographicException e)
{
// Map to PlatformNotSupportedException if appropriate
ErrorCode errorCode = (ErrorCode)e.HResult;
if (curve.Value.IsNamed &&
errorCode == ErrorCode.NTE_INVALID_PARAMETER || errorCode == ErrorCode.NTE_NOT_SUPPORTED)
{
throw new PlatformNotSupportedException(SR.Format(SR.Cryptography_CurveNotSupported, curve.Value.Oid.FriendlyName), e);
}
throw;
}
return(_lazyKey);
}
public override void GenerateKey(ECCurve curve)
{
curve.Validate();
if (m_key != null)
{
m_key.Dispose();
m_key = null;
}
CngKey newKey = CngKey.Create(curve, name => CngKey.EcdsaCurveNameToAlgorithm(name));
m_key = newKey;
KeySizeValue = newKey.KeySize;
}
