/// <summary>
/// ImportParameters will replace the existing key that ECDsaCng is working with by creating a
/// new CngKey. If the parameters contains only Q, then only a public key will be imported.
/// If the parameters also contains D, then a full key pair will be imported.
/// The parameters Curve value specifies the type of the curve to import.
/// </summary>
/// <exception cref="CryptographicException">
/// if <paramref name="parameters" /> does not contain valid values.
/// </exception>
/// <exception cref="NotSupportedException">
/// if <paramref name="parameters" /> references a curve that cannot be imported.
/// </exception>
/// <exception cref="PlatformNotSupportedException">
/// if <paramref name="parameters" /> references a curve that is not supported by this platform.
/// </exception>
public override void ImportParameters(ECParameters parameters)
{
parameters.Validate();
bool includePrivateParameters = (parameters.D != null);
ECCurve curve = parameters.Curve;
if (curve.IsPrime)
{
Key = ECCng.ImportPrimeCurveParameters(parameters, includePrivateParameters);
}
else if (curve.IsNamed)
{
// FriendlyName is required; an attempt was already made to default it in ECCurve
if (string.IsNullOrEmpty(curve.Oid.FriendlyName))
{
throw new PlatformNotSupportedException(string.Format(SR.Cryptography_InvalidCurveOid, curve.Oid.Value.ToString()));
}
Key = ECCng.ImportNamedCurveParameters(parameters, includePrivateParameters);
}
else
{
throw new PlatformNotSupportedException(string.Format(SR.Cryptography_CurveNotSupported, curve.CurveType.ToString()));
}
}
internal static ECDiffieHellmanCngPublicKey FromKey(CngKey key)
{
CngKeyBlobFormat format;
string curveName;
byte[] blob = ECCng.ExportKeyBlob(key, false, out format, out curveName);
return(new ECDiffieHellmanCngPublicKey(blob, curveName, format));
}
/// <summary>
/// Exports the key and explicit curve parameters used by the ECC object into an <see cref="ECParameters"/> object.
/// </summary>
/// <exception cref="CryptographicException">
/// if there was an issue obtaining the curve values.
/// </exception>
/// <exception cref="PlatformNotSupportedException">
/// if explicit export is not supported by this platform. Windows 10 or higher is required.
/// </exception>
/// <returns>The key and explicit curve parameters used by the ECC object.</returns>
public override ECParameters ExportExplicitParameters(bool includePrivateParameters)
{
byte[] blob = ExportFullKeyBlob(includePrivateParameters);
ECParameters ecparams = new ECParameters();
ECCng.ExportPrimeCurveParameters(ref ecparams, blob, includePrivateParameters);
return(ecparams);
}
/// <summary>
/// Exports the key and explicit curve parameters used by the ECC object into an <see cref="ECParameters"/> object.
/// </summary>
/// <exception cref="CryptographicException">
/// if there was an issue obtaining the curve values.
/// </exception>
/// <exception cref="PlatformNotSupportedException">
/// if explicit export is not supported by this platform. Windows 10 or higher is required.
/// </exception>
/// <returns>The key and explicit curve parameters used by the ECC object.</returns>
public override ECParameters ExportExplicitParameters()
{
using (CngKey key = Import())
{
ECParameters ecparams = new ECParameters();
byte[] blob = ECCng.ExportFullKeyBlob(key, includePrivateParameters: false);
ECCng.ExportPrimeCurveParameters(ref ecparams, blob, includePrivateParameters: false);
return(ecparams);
}
}
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);
}
/// <summary>
/// Exports the key used by the ECC object into an <see cref="ECParameters"/> object.
/// If the curve has a name, the Curve property will contain named curve parameters otherwise it will contain explicit parameters.
/// </summary>
/// <exception cref="CryptographicException">
/// if there was an issue obtaining the curve values.
/// </exception>
/// <returns>The key and named curve parameters used by the ECC object.</returns>
public override ECParameters ExportParameters(bool includePrivateParameters)
{
ECParameters ecparams;
if (string.IsNullOrEmpty(Key.GetCurveName()))
{
ecparams = ECCng.ExportPrimeCurveParameters(Key, includePrivateParameters);
}
else
{
ecparams = ECCng.ExportNamedCurveParameters(Key, includePrivateParameters);
}
return(ecparams);
}
public override ECParameters ExportExplicitParameters(bool includePrivateParameters)
{
byte[] blob = ExportFullKeyBlob(includePrivateParameters);
try
{
ECParameters ecparams = new ECParameters();
ECCng.ExportPrimeCurveParameters(ref ecparams, blob, includePrivateParameters);
return(ecparams);
}
finally
{
Array.Clear(blob, 0, blob.Length);
}
}
/// <summary>
/// Exports the key used by the ECC object into an <see cref="ECParameters"/> object.
/// If the curve has a name, the Curve property will contain named curve parameters otherwise it will contain explicit parameters.
/// </summary>
/// <exception cref="CryptographicException">
/// if there was an issue obtaining the curve values.
/// </exception>
/// <returns>The key and named curve parameters used by the ECC object.</returns>
public override ECParameters ExportParameters(bool includePrivateParameters)
{
ECParameters ecparams = new ECParameters();
string curveName = GetCurveName();
if (string.IsNullOrEmpty(curveName))
{
byte[] fullKeyBlob = ExportFullKeyBlob(includePrivateParameters);
ECCng.ExportPrimeCurveParameters(ref ecparams, fullKeyBlob, includePrivateParameters);
}
else
{
byte[] keyBlob = ExportKeyBlob(includePrivateParameters);
ECCng.ExportNamedCurveParameters(ref ecparams, keyBlob, includePrivateParameters);
ecparams.Curve = ECCurve.CreateFromFriendlyName(curveName);
}
return(ecparams);
}
/// <summary>
/// Exports the key used by the ECC object into an <see cref="ECParameters"/> object.
/// If the key was created as a named curve, the Curve property will contain named curve parameters
/// otherwise it will contain explicit parameters.
/// </summary>
/// <exception cref="CryptographicException">
/// if there was an issue obtaining the curve values.
/// </exception>
/// <returns>The key and named curve parameters used by the ECC object.</returns>
public override ECParameters ExportParameters()
{
using (CngKey key = Import())
{
ECParameters ecparams = new ECParameters();
string curveName = key.GetCurveName(out _);
if (string.IsNullOrEmpty(curveName))
{
byte[] fullKeyBlob = ECCng.ExportFullKeyBlob(key, includePrivateParameters: false);
ECCng.ExportPrimeCurveParameters(ref ecparams, fullKeyBlob, includePrivateParameters: false);
}
else
{
byte[] keyBlob = ECCng.ExportKeyBlob(key, includePrivateParameters: false);
ECCng.ExportNamedCurveParameters(ref ecparams, keyBlob, includePrivateParameters: false);
ecparams.Curve = ECCurve.CreateFromFriendlyName(curveName);
}
return(ecparams);
}
}
/// <summary>
/// Exports the key and explicit curve parameters used by the ECC object into an <see cref="ECParameters"/> object.
/// </summary>
/// <exception cref="CryptographicException">
/// if there was an issue obtaining the curve values.
/// </exception>
/// <exception cref="PlatformNotSupportedException">
/// if explicit export is not supported by this platform. Windows 10 or higher is required.
/// </exception>
/// <returns>The key and explicit curve parameters used by the ECC object.</returns>
public override ECParameters ExportExplicitParameters(bool includePrivateParameters)
{
return(ECCng.ExportPrimeCurveParameters(Key, includePrivateParameters));
}
