SCard Go Reference Documentation

SCard

Current Version: 10.0.0

A wrapper around the Resource Manager API of the PC/SC architecture for smart cards. On Windows it is a wrapper around the WinSCard functions implemented in the winscard.dll. On other systems (such as Linux) it is a wrapper around the same API implemented in pcsc-lite.so.

This class is introduced in Chilkat v9.5.0.87.

Object Creation

scard := chilkat.NewSCard()
...
scard.DisposeSCard()

Properties

ActiveProtocol
func (scard *SCard) ActiveProtocol() string
Introduced in version 9.50.87

The name of the active protocol if connected smart card reader, or an empty string if not connected. Possible values are "T0", "T1", "raw", "undefined", or "" if not connected to a reader.

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CardAtr
func (scard *SCard) CardAtr() string
Introduced in version 9.50.87

This is the Current ATR of a card in the connected reader.

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ConnectedReader
func (scard *SCard) ConnectedReader() string
Introduced in version 9.50.87

The name of the currently connected smart card reader, or an empty string if not connected.

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Context
func (scard *SCard) Context() string
Introduced in version 9.50.87

Contains the string "user" or "system" if this object has established a context (by calling EstablishContext). Contains the empty string if no context is established.

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DebugLogFilePath
func (scard *SCard) DebugLogFilePath() string
func (scard *SCard) SetDebugLogFilePath(s string)

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

More Information and Examples
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LastErrorHtml
func (scard *SCard) LastErrorHtml() string

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorText
func (scard *SCard) LastErrorText() string

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorXml
func (scard *SCard) LastErrorXml() string

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastMethodSuccess
func (scard *SCard) LastMethodSuccess() bool
func (scard *SCard) SetLastMethodSuccess(b bool)

Indicate whether the last method call succeeded or failed. A value of true indicates success, a value of false indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = true and failure = false.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to true. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

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PcscLibPath
func (scard *SCard) PcscLibPath() string
func (scard *SCard) SetPcscLibPath(s string)
Introduced in version 9.50.87

For Linux systems only. Specifies the full path of the libpcsclite.so shared lib. This property should only be used if the libpcsclite.so is in a non-standard location or if Chilkat cannot automatically located it.

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ReaderStatus
func (scard *SCard) ReaderStatus() string
Introduced in version 9.50.87

The current status of the connected reader. Possible values are:

  • "absent" - There is no card in the reader.
  • "present" - There is a card in the reader, but it has not been moved into position for use.
  • "swallowed" - There is a card in the reader in position for use. The card is not powered.
  • "powered" - Power is being provided to the card, but the reader driver is unaware of the mode of the card.
  • "negotiable" - The card has been reset and is awaiting PTS negotiation.
  • "specific" - The card has been reset and specific communication protocols have been established.

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ScardError
func (scard *SCard) ScardError() string
Introduced in version 9.50.87

The last error returned by an underlying PC/SC function. Can be one of the following:

  • "SCARD_W_REMOVED_CARD" - The smart card has been removed, so that further communication is not possible.
  • "SCARD_W_RESET_CARD" - The smart card has been reset, so any shared state information is invalid.
  • ...

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VerboseLogging
func (scard *SCard) VerboseLogging() bool
func (scard *SCard) SetVerboseLogging(b bool)

If set to true, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is false. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
func (scard *SCard) Version() string

Version of the component/library, such as "9.5.0.94"

More Information and Examples
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Methods

BeginTransaction
func (scard *SCard) BeginTransaction() bool
Introduced in version 9.50.87

Establishes a temporary exclusive access mode for doing a series of commands in a transaction.

Returns true for success, false for failure.

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CheckStatus
func (scard *SCard) CheckStatus() bool
Introduced in version 9.50.87

Check the current status of the currently connected reader. Calling this method updates the ReaderStatus, ActiveProtocol, and CardAtr properties. If this method returns false, none of the properties are updated.

Returns true for success, false for failure.

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Connect
func (scard *SCard) Connect(reader string, shareMode string, preferredProtocol string) bool
Introduced in version 9.50.87

Establish a connection to a reader. The reader is the name of a reader returned from ListReaders. The shareMode can be "shared", "exclusive", or "direct". The preferredProtocol can be "0" (valid only if the shareMode = "direct"), "T0", "T1", "raw", or "no_preference". (No preference is effectively T0 or T1.)

If successful, the state of this object instance is that it's connected to the reader.

Returns true for success, false for failure.

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Disconnect
func (scard *SCard) Disconnect(disposition string) bool
Introduced in version 9.50.87

Terminates a connection with a reader. The disposition can be one of the following values:

  • "leave": Do nothing.
  • "reset": Reset the card (warm reset).
  • "unpower": Power down the card (cold reset).
  • "eject": Eject the card.

Returns true for success, false for failure.

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EndTransaction
func (scard *SCard) EndTransaction(disposition string) bool
Introduced in version 9.50.87

Ends a previously begun transaction. The disposition is the action to be taken on the reader, and can be "leave" which is to do nothing, "reset", "unpower", or "eject".

Returns true for success, false for failure.

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EstablishContext
func (scard *SCard) EstablishContext(scope string) bool
Introduced in version 9.5.0.87

Creates an Application Context to the PC/SC Resource Manager. This must be the first WinSCard function called in a PC/SC application. The scope can be "user" or "system". After calling, this object will have context and all other methods will use the established context. The "Context" property will hold the value "user" or "system" if context was established, or will be empty if no context was established.

Returns true for success, false for failure.

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FindSmartcards
func (scard *SCard) FindSmartcards(json *JsonObject) bool
Introduced in version 9.50.87

Returns JSON containing information about the smartcards currently inserted into readers.

Returns true for success, false for failure.

More Information and Examples
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GetAttrib
func (scard *SCard) GetAttrib(attr string, bd *BinData) bool
Introduced in version 9.50.87

Get an attribute from the IFD Handler (reader driver).

The attr can be one of the following:

  • "ASYNC_PROTOCOL_TYPES"
  • "ATR_STRING"
  • "CHANNEL_ID"
  • "CHARACTERISTICS"
  • "CURRENT_BWT"
  • "CURRENT_CLK"
  • "CURRENT_CWT"
  • "CURRENT_D"
  • "CURRENT_EBC_ENCODING"
  • "CURRENT_F"
  • "CURRENT_IFSC"
  • "CURRENT_IFSD"
  • "CURRENT_IO_STATE"
  • "CURRENT_N"
  • "CURRENT_PROTOCOL_TYPE"
  • "CURRENT_W"
  • "DEFAULT_CLK"
  • "DEFAULT_DATA_RATE"
  • "DEVICE_FRIENDLY_NAME"
  • "DEVICE_IN_USE"
  • "DEVICE_SYSTEM_NAME"
  • "DEVICE_UNIT"
  • "ESC_AUTHREQUEST"
  • "ESC_CANCEL"
  • "ESC_RESET"
  • "EXTENDED_BWT"
  • "ICC_INTERFACE_STATUS"
  • "ICC_PRESENCE"
  • "ICC_TYPE_PER_ATR"
  • "MAX_CLK"
  • "MAX_DATA_RATE"
  • "MAX_IFSD"
  • "MAXINPUT"
  • "POWER_MGMT_SUPPORT"
  • "SUPRESS_T1_IFS_REQUEST"
  • "SYNC_PROTOCOL_TYPES"
  • "USER_AUTH_INPUT_DEVICE"
  • "USER_TO_CARD_AUTH_DEVICE"
  • "VENDOR_IFD_SERIAL_NO"
  • "VENDOR_IFD_TYPE"
  • "VENDOR_IFD_VERSION"
  • "VENDOR_NAME"

The attribute data is returned in bd.

Returns true for success, false for failure.

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GetAttribStr
func (scard *SCard) GetAttribStr(attr string) *string
Introduced in version 9.50.87

Get a string typed attribute from the IFD Handler (reader driver).

The attr can be one of the following, but should be limited to the particular attributes that return string values.

  • "ASYNC_PROTOCOL_TYPES"
  • "ATR_STRING"
  • "CHANNEL_ID"
  • "CHARACTERISTICS"
  • "CURRENT_BWT"
  • "CURRENT_CLK"
  • "CURRENT_CWT"
  • "CURRENT_D"
  • "CURRENT_EBC_ENCODING"
  • "CURRENT_F"
  • "CURRENT_IFSC"
  • "CURRENT_IFSD"
  • "CURRENT_IO_STATE"
  • "CURRENT_N"
  • "CURRENT_PROTOCOL_TYPE"
  • "CURRENT_W"
  • "DEFAULT_CLK"
  • "DEFAULT_DATA_RATE"
  • "DEVICE_FRIENDLY_NAME"
  • "DEVICE_IN_USE"
  • "DEVICE_SYSTEM_NAME"
  • "DEVICE_UNIT"
  • "ESC_AUTHREQUEST"
  • "ESC_CANCEL"
  • "ESC_RESET"
  • "EXTENDED_BWT"
  • "ICC_INTERFACE_STATUS"
  • "ICC_PRESENCE"
  • "ICC_TYPE_PER_ATR"
  • "MAX_CLK"
  • "MAX_DATA_RATE"
  • "MAX_IFSD"
  • "MAXINPUT"
  • "POWER_MGMT_SUPPORT"
  • "SUPRESS_T1_IFS_REQUEST"
  • "SYNC_PROTOCOL_TYPES"
  • "USER_AUTH_INPUT_DEVICE"
  • "USER_TO_CARD_AUTH_DEVICE"
  • "VENDOR_IFD_SERIAL_NO"
  • "VENDOR_IFD_TYPE"
  • "VENDOR_IFD_VERSION"
  • "VENDOR_NAME"

Returns nil on failure

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GetAttribUint
func (scard *SCard) GetAttribUint(attr string) uint
Introduced in version 9.50.87

Get an unsigned integer typed attribute from the IFD Handler (reader driver).

The attr can be one of the following, but should be limited to the particular attributes that return unsigned integer values.

  • "ASYNC_PROTOCOL_TYPES"
  • "ATR_STRING"
  • "CHANNEL_ID"
  • "CHARACTERISTICS"
  • "CURRENT_BWT"
  • "CURRENT_CLK"
  • "CURRENT_CWT"
  • "CURRENT_D"
  • "CURRENT_EBC_ENCODING"
  • "CURRENT_F"
  • "CURRENT_IFSC"
  • "CURRENT_IFSD"
  • "CURRENT_IO_STATE"
  • "CURRENT_N"
  • "CURRENT_PROTOCOL_TYPE"
  • "CURRENT_W"
  • "DEFAULT_CLK"
  • "DEFAULT_DATA_RATE"
  • "DEVICE_FRIENDLY_NAME"
  • "DEVICE_IN_USE"
  • "DEVICE_SYSTEM_NAME"
  • "DEVICE_UNIT"
  • "ESC_AUTHREQUEST"
  • "ESC_CANCEL"
  • "ESC_RESET"
  • "EXTENDED_BWT"
  • "ICC_INTERFACE_STATUS"
  • "ICC_PRESENCE"
  • "ICC_TYPE_PER_ATR"
  • "MAX_CLK"
  • "MAX_DATA_RATE"
  • "MAX_IFSD"
  • "MAXINPUT"
  • "POWER_MGMT_SUPPORT"
  • "SUPRESS_T1_IFS_REQUEST"
  • "SYNC_PROTOCOL_TYPES"
  • "USER_AUTH_INPUT_DEVICE"
  • "USER_TO_CARD_AUTH_DEVICE"
  • "VENDOR_IFD_SERIAL_NO"
  • "VENDOR_IFD_TYPE"
  • "VENDOR_IFD_VERSION"
  • "VENDOR_NAME"

Returns 0xFFFFFFFF on failure.

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GetStatusChange
func (scard *SCard) GetStatusChange(maxWaitMs int, stReaderNames *StringTable, json *JsonObject) bool
Introduced in version 9.50.87

Blocks execution until the current availability of the cards in a specific set of readers changes.

This function receives a list of reader names in stReaderNames. It then blocks waiting for a change in state to occur for a maximum blocking time of maxWaitMs (in milliseconds) or forever if 0 is used.

Information about the current reader states and which reader(s) changed is returned in json. See the example below for more information.

To wait for a reader event (reader added or removed) you may use the special reader name "\\?PnP?\Notification".

To cancel the ongoing call, call Cancel().

The stReaderNames contains the reader names to check. The json is empty on input, and if the call returns success contains information about the state (after the event change) of each reader.

Returns true for success, false for failure.

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GetStatusChangeAsync (1)
func (scard *SCard) GetStatusChangeAsync(maxWaitMs int, stReaderNames *StringTable, json *JsonObject, task chan *Task)
Introduced in version 9.50.87

Creates an asynchronous task to call the GetStatusChange method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns nil on failure

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GetStatusChangeCancel
func (scard *SCard) GetStatusChangeCancel() bool
Introduced in version 9.50.87

Cancels an ongoing GetStatusChange method call. This would be called from a separate thread in your application if GetStatusChange was called synchronously.

Returns true for success, false for failure.

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ListReaderGroups
func (scard *SCard) ListReaderGroups(readerGroups *StringTable) bool
Introduced in version 9.50.87

Returns a list of currently available reader groups on the system. The reader groups are returned in readerGroups.

Returns true for success, false for failure.

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ListReaders
func (scard *SCard) ListReaders(st *StringTable) bool
Introduced in version 9.50.87

Returns a list of currently available readers on the system.

Returns true for success, false for failure.

More Information and Examples
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Reconnect
func (scard *SCard) Reconnect(shareMode string, preferredProtocol string, action string) bool
Introduced in version 9.50.87

Reestablishes a connection to a reader that was previously connected to using Connect().

In a multi application environment it is possible for an application to reset the card in shared mode. When this occurs any other application trying to access certain commands will be returned the value SCARD_W_RESET_CARD. When this occurs Reconnect() must be called in order to acknowledge that the card was reset and allow it to change its state accordingly.

The shareMode can be "shared", "exclusive", or "direct". The preferredProtocol can be "0" (valid only if the shareMode = "direct"), "T0", "T1", "raw", or "no_preference". (No preference is effectively T0 or T1.) The action is the desired action taken on the card/reader. It can be "leave", "reset", "unpower", or "eject".

If successful, the state of this object instance is that it's connected to the reader.

Returns true for success, false for failure.

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ReleaseContext
func (scard *SCard) ReleaseContext() bool
Introduced in version 9.50.87

Destroys a communication context to the PC/SC Resource Manager. This must be the last function called in a PC/SC application.

Returns true for success, false for failure.

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SendControl
func (scard *SCard) SendControl(controlCode uint, bdSend *BinData, bdRecv *BinData) bool
Introduced in version 9.50.87

Sends a command directly to the IFD Handler (reader driver) to be processed by the reader.

This is useful for creating client side reader drivers for functions like PIN pads, biometrics, or other extensions to the normal smart card reader that are not normally handled by PC/SC.

The command data is sent in bdSend. The response is written to bdRecv.

Returns true for success, false for failure.

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SendControlHex
func (scard *SCard) SendControlHex(controlCode uint, sendData string, bdRecv *BinData) bool
Introduced in version 9.50.87

Sends a command directly to the IFD Handler (reader driver) to be processed by the reader.

This is useful for creating client side reader drivers for functions like PIN pads, biometrics, or other extensions to the normal smart card reader that are not normally handled by PC/SC.

The command data is provided as a hex string in sendData. The response is written to bdRecv.

Returns true for success, false for failure.

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Transmit
func (scard *SCard) Transmit(protocol string, bdSend *BinData, bdRecv *BinData, maxRecvLen int) bool
Introduced in version 9.50.87

Sends an APDU to the smart card contained in the currently connected reader. The protocol can be "T0", "T1", or "raw". The APDU to be sent is contained in bdSend. The response from the card is contained in bdRecv. The maxRecvLen is the maximum response size (in bytes) willing to be accepted.

Returns true for success, false for failure.

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TransmitHex
func (scard *SCard) TransmitHex(protocol string, apduHex string, bdRecv *BinData, maxRecvLen int) bool
Introduced in version 9.50.87

Sends an APDU to the smart card contained in the currently connected reader. The protocol can be "T0", "T1", or "raw". The APDU (in hexadecimal) to be sent is passed in apduHex. The response from the card is contained in bdRecv. The maxRecvLen is the maximum response size (in bytes) willing to be accepted.

Returns true for success, false for failure.

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