protected override bool ReleaseHandle()
{
if (!_callerFree)
{
return(true);
}
if (IsNCryptKey)
{
return(NCrypt.NCryptFreeObject(handle) == SECURITY_STATUS.ERROR_SUCCESS);
}
else
{
return(AdvApi32.CryptReleaseContext(handle, 0u));
}
}
/// <summary>
/// Computes the hash value of the specified byte array using the specified hash algorithm, and signs the resulting hash value.
/// </summary>
/// <param name="certificate">An <see cref="X509Certificate2"/> object of the signer certificate.</param>
/// <param name="message">Message to be signed.</param>
/// <param name="hashAlgorithm">The name of the hash algorithm to use in the signature. For example, 'SHA256'</param>
/// <returns>The signature for the specified data.</returns>
public static Byte[] SignMessage(X509Certificate2 certificate, Byte[] message, Oid hashAlgorithm)
{
SafeNCryptKeyHandle phCryptProv = new SafeNCryptKeyHandle();
UInt32 pdwKeySpec = 0;
Boolean pfCallerFreeProv = false;
if (!Crypt32.CryptAcquireCertificatePrivateKey(certificate.Handle, Wincrypt.CRYPT_ACQUIRE_ALLOW_NCRYPT_KEY_FLAG, IntPtr.Zero, out phCryptProv, out pdwKeySpec, out pfCallerFreeProv))
{
throw new CryptographicException(Marshal.GetLastWin32Error());
}
// true -> CNG, false -> legacy
if (pdwKeySpec == UInt32.MaxValue)
{
Byte[] hashBytes = calculateHash(message, hashAlgorithm.FriendlyName, false);
try {
Int32 hresult = NCrypt.NCryptSignHash(phCryptProv, IntPtr.Zero, hashBytes, hashBytes.Length, null, 0, out Int32 pcbResult, 0);
if (hresult != 0)
{
throw new CryptographicException(hresult);
}
Byte[] pbSignature = new Byte[pcbResult];
hresult = NCrypt.NCryptSignHash(phCryptProv, IntPtr.Zero, hashBytes, hashBytes.Length, pbSignature, pbSignature.Length, out pcbResult, 0);
if (hresult != 0)
{
throw new CryptographicException(hresult);
}
return(pbSignature);
} finally {
if (pfCallerFreeProv)
{
NCrypt.NCryptFreeObject(phCryptProv.DangerousGetHandle());
}
}
}
if (pfCallerFreeProv)
{
AdvAPI.CryptReleaseContext(phCryptProv.DangerousGetHandle(), 0);
}
calculateHash(message, hashAlgorithm.FriendlyName, false);
RSACryptoServiceProvider key = (RSACryptoServiceProvider)certificate.PrivateKey;
return(key.SignData(message, hashAlgorithm.Value));
}
protected override bool ReleaseHandle()
{
return(NCrypt.NCryptFreeObject(handle) == SECURITY_STATUS.ERROR_SUCCESS);
}
