private static CngKey ImportKeyBlob(
byte[] blob,
string curveName,
CngKeyBlobFormat format,
ECCurve.ECCurveType curveType)
{
try
{
CngKey newKey = CngKey.Import(blob, curveName, format);
newKey.ExportPolicy |= CngExportPolicies.AllowPlaintextExport;
return(newKey);
}
catch (CryptographicException e)
{
if (curveType != ECCurve.ECCurveType.Named &&
e.HResult == (int)ErrorCode.NTE_NOT_SUPPORTED)
{
throw new PlatformNotSupportedException(
SR.GetString(SR.Cryptography_CurveNotSupported, curveType),
e);
}
throw;
}
}
/// <summary>
/// Helper method to map between BCrypt.ECC_CURVE_TYPE_ENUM and ECCurve.ECCurveType
/// </summary>
private static Interop.BCrypt.ECC_CURVE_TYPE_ENUM ConvertToCurveTypeEnum(ECCurve.ECCurveType value)
{
// Currently values 1-3 are interchangeable
Debug.Assert(value == ECCurve.ECCurveType.Characteristic2 ||
value == ECCurve.ECCurveType.PrimeShortWeierstrass ||
value == ECCurve.ECCurveType.PrimeTwistedEdwards);
return((Interop.BCrypt.ECC_CURVE_TYPE_ENUM)value);
}
/// <summary>
/// Helper method to map between BCrypt.ECC_CURVE_TYPE_ENUM and ECCurve.ECCurveType
/// </summary>
internal static ECCurve.ECCurveType ConvertToCurveTypeEnum(Interop.BCrypt.ECC_CURVE_TYPE_ENUM value)
{
// Currently values 1-3 are interchangeable
ECCurve.ECCurveType curveType = (ECCurve.ECCurveType)value;
Debug.Assert(curveType == ECCurve.ECCurveType.Characteristic2 ||
curveType == ECCurve.ECCurveType.PrimeShortWeierstrass ||
curveType == ECCurve.ECCurveType.PrimeTwistedEdwards);
return(curveType);
}
internal static partial SafeEcKeyHandle EcKeyCreateByExplicitParameters(
ECCurve.ECCurveType curveType,
byte[]?qx, int qxLength,
byte[]?qy, int qyLength,
byte[]?d, int dLength,
byte[] p, int pLength,
byte[] a, int aLength,
byte[] b, int bLength,
byte[] gx, int gxLength,
byte[] gy, int gyLength,
byte[] order, int nLength,
byte[]?cofactor, int cofactorLength,
byte[]?seed, int seedLength);
private static partial int CryptoNative_GetECCurveParameters(
SafeEcKeyHandle key,
[MarshalAs(UnmanagedType.Bool)] bool includePrivate,
out ECCurve.ECCurveType curveType,
out SafeBignumHandle qx, out int x_cb,
out SafeBignumHandle qy, out int y_cb,
out IntPtr d_bn_not_owned, out int d_cb,
out SafeBignumHandle p, out int P_cb,
out SafeBignumHandle a, out int A_cb,
out SafeBignumHandle b, out int B_cb,
out SafeBignumHandle gx, out int Gx_cb,
out SafeBignumHandle gy, out int Gy_cb,
out SafeBignumHandle order, out int order_cb,
out SafeBignumHandle cofactor, out int cofactor_cb,
out SafeBignumHandle seed, out int seed_cb);
private static extern int AndroidCryptoNative_GetECCurveParameters(
SafeEcKeyHandle key,
bool includePrivate,
out ECCurve.ECCurveType curveType,
out SafeBignumHandle qx, out int x_cb,
out SafeBignumHandle qy, out int y_cb,
out IntPtr d_bn_not_owned, out int d_cb,
out SafeBignumHandle p, out int P_cb,
out SafeBignumHandle a, out int A_cb,
out SafeBignumHandle b, out int B_cb,
out SafeBignumHandle gx, out int Gx_cb,
out SafeBignumHandle gy, out int Gy_cb,
out SafeBignumHandle order, out int order_cb,
out SafeBignumHandle cofactor, out int cofactor_cb,
out SafeBignumHandle seed, out int seed_cb);
public bool IsCurveTypeEqual(ECCurve.ECCurveType actual)
{
if (CurveType == actual)
{
return(true);
}
// Montgomery and Weierstrass are interchangable depending on the platform
if (CurveType == ECCurve.ECCurveType.PrimeMontgomery && actual == ECCurve.ECCurveType.PrimeShortWeierstrass ||
CurveType == ECCurve.ECCurveType.PrimeShortWeierstrass && actual == ECCurve.ECCurveType.PrimeMontgomery)
{
return(true);
}
return(false);
}
