IOCTL_SMARTCARD_SET_PROTOCOL IOCTL (winsmcrd.h)

Article
07/19/2022

The IOCTL_SMARTCARD_SET_PROTOCOL request sets the protocol that the driver will use to communicate with the smart card after the card is detected (inserted).

Major code

IRP_MJ_DEVICE_CONTROL

Input buffer

Irp->AssociatedIrp.SystemBuffer Contains a mask of protocols that are acceptable for the following transmissions. The mask can be a bitwise OR of the following values:
- SCARD_PROTOCOL_RAW
- SCARD_PROTOCOL_T0
- SCARD_PROTOCOL_T1
- SCARD_PROTOCOL_DEFAULT
- SCARD_PROTOCOL_OPTIMAL
The last two values are additional bit definitions that indicate that the driver must either explicitly perform protocol type selection (PTS) with the best possible communication parameters (SCARD_PROTOCOL_OPTIMAL) or use the implicit protocol of the card with standard parameters (SCARD_PROTOCOL_DEFAULT). If the card supports only one protocol with one set of communication parameters, the bits are ignored.
Parameters.DeviceIoControl.InputBufferLength Must be set to sizeof(ULONG). The driver decides which protocol out of the mask to use with the inserted card.

Output buffer

Irp->AssociatedIrp.SystemBuffer The driver stores the selected protocol here (for example, SCARD_PROTOCOL_T1). Only one bit out of the mask can be set.

Output buffer length

Parameters.DeviceIoControl.OutputBufferLength Must be sizeof(ULONG).

Status block

Irp->IoStatus.Information must be set to sizeof(ULONG).

Irp->IoStatus.Status is set to one of the following values.

Value	Meaning
STATUS_SUCCESS	A protocol was successfully selected.
STATUS_NO_MEDIA	No smart card is detected in the reader.
STATUS_IO_TIMEOUT	The operation timed out.
STATUS_NOT_SUPPORTED	The smart card does not support any of the requested protocols.
STATUS_INVALID_DEVICE_REQUEST	The mask contains no known protocol.

For more information, see NTSTATUS Values.

Requirements

Requirement	Value
Header	winsmcrd.h