private static SafeCryptMsgHandle OpenToDecode(byte[] encodedMessage, ContentInfo contentInfo, bool detached)
{
SafeCryptMsgHandle safeCryptMsgHandle = CAPI.CAPISafe.CryptMsgOpenToDecode(65537U, detached ? 4U : 0U, 0U, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero);
if (safeCryptMsgHandle == null || safeCryptMsgHandle.IsInvalid)
{
throw new CryptographicException(Marshal.GetLastWin32Error());
}
if (!CAPI.CAPISafe.CryptMsgUpdate(safeCryptMsgHandle, encodedMessage, (uint)encodedMessage.Length, true))
{
throw new CryptographicException(Marshal.GetLastWin32Error());
}
if (2 != (int)PkcsUtils.GetMessageType(safeCryptMsgHandle))
{
throw new CryptographicException(-2146889724);
}
if (detached)
{
byte[] content = contentInfo.Content;
if (content != null && content.Length > 0 && !CAPI.CAPISafe.CryptMsgUpdate(safeCryptMsgHandle, content, (uint)content.Length, true))
{
throw new CryptographicException(Marshal.GetLastWin32Error());
}
}
return(safeCryptMsgHandle);
}
public static Oid GetContentType(byte[] encodedMessage)
{
if (encodedMessage == null)
{
throw new ArgumentNullException("encodedMessage");
}
SafeCryptMsgHandle safeCryptMsgHandle = CAPI.CAPISafe.CryptMsgOpenToDecode(65537U, 0U, 0U, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero);
if (safeCryptMsgHandle == null || safeCryptMsgHandle.IsInvalid)
{
throw new CryptographicException(Marshal.GetLastWin32Error());
}
if (!CAPI.CAPISafe.CryptMsgUpdate(safeCryptMsgHandle, encodedMessage, (uint)encodedMessage.Length, true))
{
throw new CryptographicException(Marshal.GetLastWin32Error());
}
Oid oid;
switch (PkcsUtils.GetMessageType(safeCryptMsgHandle))
{
case 1U:
oid = new Oid("1.2.840.113549.1.7.1");
break;
case 2U:
oid = new Oid("1.2.840.113549.1.7.2");
break;
case 3U:
oid = new Oid("1.2.840.113549.1.7.3");
break;
case 4U:
oid = new Oid("1.2.840.113549.1.7.4");
break;
case 5U:
oid = new Oid("1.2.840.113549.1.7.5");
break;
case 6U:
oid = new Oid("1.2.840.113549.1.7.6");
break;
default:
throw new CryptographicException(-2146889724);
}
safeCryptMsgHandle.Dispose();
return(oid);
}