private static string GetPropertyAsString(SafeBCryptKeyHandle cryptHandle, string propertyName)
{
Debug.Assert(!cryptHandle.IsInvalid);
byte[] value = GetProperty(cryptHandle, propertyName);
if (value == null || value.Length == 0)
{
return(null);
}
unsafe
{
fixed(byte *pValue = &value[0])
{
string valueAsString = Marshal.PtrToStringUni((IntPtr)pValue);
return(valueAsString);
}
}
}
private static ECDsa DecodeECDsaPublicKey(CertificatePal certificatePal)
{
ECDsa ecdsa;
using (SafeBCryptKeyHandle bCryptKeyHandle = ImportPublicKeyInfo(certificatePal.CertContext))
{
CngKeyBlobFormat blobFormat;
byte[] keyBlob;
string curveName = GetCurveName(bCryptKeyHandle);
if (curveName == null)
{
if (HasExplicitParameters(bCryptKeyHandle))
{
blobFormat = CngKeyBlobFormat.EccFullPublicBlob;
}
else
{
blobFormat = CngKeyBlobFormat.EccPublicBlob;
}
keyBlob = ExportKeyBlob(bCryptKeyHandle, blobFormat);
using (CngKey cngKey = CngKey.Import(keyBlob, blobFormat))
{
ecdsa = new ECDsaCng(cngKey);
}
}
else
{
blobFormat = CngKeyBlobFormat.EccPublicBlob;
keyBlob = ExportKeyBlob(bCryptKeyHandle, blobFormat);
ECParameters ecparams = new ECParameters();
ExportNamedCurveParameters(ref ecparams, keyBlob, false);
ecparams.Curve = ECCurve.CreateFromFriendlyName(curveName);
ecdsa = new ECDsaCng();
ecdsa.ImportParameters(ecparams);
}
}
return(ecdsa);
}
private static byte[] ExportKeyBlob(SafeBCryptKeyHandle bCryptKeyHandle, CngKeyBlobFormat blobFormat)
{
string blobFormatString = blobFormat.Format;
int numBytesNeeded = 0;
NTSTATUS ntStatus = Interop.BCrypt.BCryptExportKey(bCryptKeyHandle, IntPtr.Zero, blobFormatString, null, 0, out numBytesNeeded, 0);
if (ntStatus != NTSTATUS.STATUS_SUCCESS)
{
throw new CryptographicException(Interop.Kernel32.GetMessage((int)ntStatus));
}
byte[] keyBlob = new byte[numBytesNeeded];
ntStatus = Interop.BCrypt.BCryptExportKey(bCryptKeyHandle, IntPtr.Zero, blobFormatString, keyBlob, keyBlob.Length, out numBytesNeeded, 0);
if (ntStatus != NTSTATUS.STATUS_SUCCESS)
{
throw new CryptographicException(Interop.Kernel32.GetMessage((int)ntStatus));
}
Array.Resize(ref keyBlob, numBytesNeeded);
return(keyBlob);
}
private static byte[] GetProperty(SafeBCryptKeyHandle cryptHandle, string propertyName)
{
throw new CryptographicException("Not implemented");;
// Debug.Assert(!cryptHandle.IsInvalid);
// unsafe
// {
// int numBytesNeeded;
// NTSTATUS errorCode = Interop.BCrypt.BCryptGetProperty(cryptHandle, propertyName, null, 0, out numBytesNeeded, 0);
// if (errorCode != NTSTATUS.STATUS_SUCCESS)
// return null;
// byte[] propertyValue = new byte[numBytesNeeded];
// fixed (byte* pPropertyValue = propertyValue)
// {
// errorCode = Interop.BCrypt.BCryptGetProperty(cryptHandle, propertyName, pPropertyValue, propertyValue.Length, out numBytesNeeded, 0);
// }
// if (errorCode != NTSTATUS.STATUS_SUCCESS)
// return null;
// Array.Resize(ref propertyValue, numBytesNeeded);
// return propertyValue;
// }
}
private static string GetCurveName(SafeBCryptKeyHandle bcryptHandle)
{
return(GetPropertyAsString(bcryptHandle, BCRYPT_ECC_CURVE_NAME_PROPERTY));
}
private static bool HasExplicitParameters(SafeBCryptKeyHandle bcryptHandle)
{
byte[] explicitParams = GetProperty(bcryptHandle, BCRYPT_ECC_PARAMETERS_PROPERTY);
return(explicitParams != null && explicitParams.Length > 0);
}
private static byte[] ExportKeyBlob(SafeBCryptKeyHandle bCryptKeyHandle, CngKeyBlobFormat blobFormat)
{
#if NETNATIVE
// BCryptExportKey() not in the UWP api list.
throw new PlatformNotSupportedException();
#else
string blobFormatString = blobFormat.Format;
int numBytesNeeded = 0;
NTSTATUS ntStatus = Interop.BCrypt.BCryptExportKey(bCryptKeyHandle, IntPtr.Zero, blobFormatString, null, 0, out numBytesNeeded, 0);
if (ntStatus != NTSTATUS.STATUS_SUCCESS)
throw new CryptographicException(Interop.mincore.GetMessage((int)ntStatus));
byte[] keyBlob = new byte[numBytesNeeded];
ntStatus = Interop.BCrypt.BCryptExportKey(bCryptKeyHandle, IntPtr.Zero, blobFormatString, keyBlob, keyBlob.Length, out numBytesNeeded, 0);
if (ntStatus != NTSTATUS.STATUS_SUCCESS)
throw new CryptographicException(Interop.mincore.GetMessage((int)ntStatus));
Array.Resize(ref keyBlob, numBytesNeeded);
return keyBlob;
#endif //NETNATIVE
}
private static byte[] GetProperty(SafeBCryptKeyHandle cryptHandle, string propertyName)
{
Debug.Assert(!cryptHandle.IsInvalid);
unsafe
{
int numBytesNeeded;
NTSTATUS errorCode = Interop.BCrypt.BCryptGetProperty(cryptHandle, propertyName, null, 0, out numBytesNeeded, 0);
if (errorCode != NTSTATUS.STATUS_SUCCESS)
return null;
byte[] propertyValue = new byte[numBytesNeeded];
fixed (byte* pPropertyValue = propertyValue)
{
errorCode = Interop.BCrypt.BCryptGetProperty(cryptHandle, propertyName, pPropertyValue, propertyValue.Length, out numBytesNeeded, 0);
}
if (errorCode != NTSTATUS.STATUS_SUCCESS)
return null;
Array.Resize(ref propertyValue, numBytesNeeded);
return propertyValue;
}
}
private static string GetPropertyAsString(SafeBCryptKeyHandle cryptHandle, string propertyName)
{
Debug.Assert(!cryptHandle.IsInvalid);
byte[] value = GetProperty(cryptHandle, propertyName);
if (value == null || value.Length == 0)
return null;
unsafe
{
fixed (byte* pValue = value)
{
string valueAsString = Marshal.PtrToStringUni((IntPtr)pValue);
return valueAsString;
}
}
}
private static string GetCurveName(SafeBCryptKeyHandle bcryptHandle)
{
return GetPropertyAsString(bcryptHandle, BCRYPT_ECC_CURVE_NAME_PROPERTY);
}
private static bool HasExplicitParameters(SafeBCryptKeyHandle bcryptHandle)
{
byte[] explicitParams = GetProperty(bcryptHandle, BCRYPT_ECC_PARAMETERS_PROPERTY);
return (explicitParams != null && explicitParams.Length > 0);
}
