ISCardISO7816::ManageChannel

The ManageChannel method constructs an APDU command that opens and closes logical channels.

The open function opens a new logical channel other than the basic one. Options are provided for the card to assign a logical channel number, or for the logical channel number to be supplied to the card.

The close function explicitly closes a logical channel other than the basic one. After the successful closing, the logical channel shall be available for re-use.

HRESULT ManageChannel(
  BYTE byChannelState,
  BYTE byChannel, 
  LPSCARDCMD *ppCmd
);

Parameters

byChannelState [in, defaultvalue(ISO_CLOSE_LOGICAL_CHANNEL)]
Bit b8 of P1 is used to indicate the open function or the close function; if b8 is 0 then MANAGE CHANNEL shall open a logical channel and if b8 is 1 then MANAGE CHANNEL shall close a logical channel:

P1 = '00' to open

P1 = '80' to close

Other values are RFU

byChannel [in, defaultvalue(ISO_LOGICAL_CHANNEL_0)]
For the open function (P1 = '00'), the bits b1 and b2 of P2 are used to code the logical channel number in the same manner as in the class byte, the other bits of P2 are RFU.

When b1 and b2 of P2 are NULL, then the card will assign a logical channel number that will be returned in bits b1 and b2 of the data field.

When b1 and/or b2 of P2 are not NULL, they code a logical channel number other than the basic one; then the card will open the externally assigned logical channel number.

ppCmd [in, out]
On input, a pointer to an ISCardCmd interface object or NULL.

On return, it is filled with the APDU command constructed by this operation. If ppCmd was set to NULL, a smart card ISCardCmd object is internally created and returned via the ppCmd pointer.

Return Values

The possible return values are the following:

Value Meaning
S_OK Operation completed successfully.
E_INVALIDARG Invalid parameter.
E_POINTER A bad pointer was passed in.
E_OUTOFMEMORY Out of memory.

Remarks

When the open function is successfully performed from the basic logical channel, the MF shall be implicitly selected as the current DF and the security status of the new logical channel should be the same as the basic logical channel after ATR. The security status of the new logical channel should be separate from that of any other logical channel.

When the open function is successfully performed from a logical channel, which is not the basic one, the current DF of the logical channel that issued the command will be selected as the current DF. In addition, the security status for the new logical channel should be the same as the security status of the logical channel from which the open function was performed.

After a successful close function, the security status related to this logical channel is lost.

For a list of all the methods provided by the ISCardISO7816 interface, see ISCardISO7816.

In addition to the COM error codes listed above, this interface may return a smart card error code if a smart card function was called to complete the request. For information on smart card error codes, see Error Codes.

QuickInfo

  Windows NT: Use version 4.0 SP3 and later.
  Windows: Use Windows 95 OSR2.1.
  Windows CE: Unsupported.
  Header: Declared in scardsrv.h.
  Import Library: scardsrv.tlb.

See Also

ISCardISO7816