SCard Rust Reference Documentation
SCard
Current Version: 11.6.1
Chilkat.SCard
Enumerate available PC/SC smart card readers and identify the reader the
application should use.
Connect to a reader/card, check card presence and status, and manage the
active PC/SC connection.
Send APDU commands directly to the card and receive the raw response
bytes and status words.
Issue lower-level reader control commands when supported by the reader
driver and PC/SC environment.
Monitor reader or card status changes so applications can detect card
insertion, removal, or state changes.
Use PC/SC transactions for coordinated card access and inspect detailed
error information when reader or card operations fail.
For an extended overview, see
SCard Class Overview.
Communicate directly with smart card readers and cards through PC/SC.
Chilkat.SCard is the low-level PC/SC smart card interface for
applications that need direct reader and card communication. It supports
reader discovery, reader connection, card status checking, APDU transmission,
reader-control commands, status-change monitoring, transactions, and
diagnostic access to underlying PC/SC errors. Use this class when the
application needs APDU-level control rather than a higher-level certificate,
minidriver, or PKCS#11 abstraction.
Reader discovery
Connect to cards
Transmit APDUs
Reader-control commands
Status monitoring
Transactions and diagnostics
Chilkat.SCard for direct PC/SC
reader and APDU-level work; use Chilkat.ScMinidriver for
card-minidriver certificate and key-container operations, and
Chilkat.Pkcs11 for PKCS#11 token or HSM sessions.
Object Creation
// Cargo.toml:
// [dependencies]
// chilkat = "11.6"
use chilkat::SCard;
// Once per process, before any other Chilkat call:
chilkat::unlock_bundle("Anything for 30-day trial")?; // shorthand for Global::new().unlock_bundle(..)
let s_card = SCard::new();
// ... the native object is freed when `s_card` goes out of scope.Creates the underlying native Chilkat object (SCard also implements Default). Every method takes &self, so the object never needs to be declared mut. A SCard is Send but not Sync: it may be moved to another thread, but a reference to it cannot be shared between threads at the same time.
The native object is freed when the SCard is dropped — when it goes out of scope, or explicitly with drop(s_card). There is no Dispose method to call.
Errors
Methods that can fail return chilkat::Result<T>, which is Result<T, chilkat::Error>: a method whose only outcome is success or failure returns Result<()>, a method producing a string or an object returns Result<String> or Result<SCard>. The error carries the object's LastErrorText at the time of the failure (Error::last_error_text), the class and method names, and implements std::error::Error, so ? works in any function returning chilkat::Result or a Box<dyn Error>. Properties never fail, and methods that answer a question (has_..., is_..., ...) return a plain bool.
match s_card.some_method(...) {
Ok(value) => println!("{value:?}"),
Err(e) => eprintln!("{}", e.last_error_text()),
}Properties
ActiveProtocol
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.
CardAtr
This is the Current ATR of a card in the connected reader.
topConnectedReader
The name of the currently connected smart card reader, or an empty string if not connected.
topContext
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.
DebugLogFilePath
pub fn debug_log_file_path(&self) -> String
pub fn set_debug_log_file_path(&self, value: &str)
If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.
Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.
Possible causes of hangs include:
- A timeout property set to 0, indicating an infinite timeout.
- A hang occurring within an event callback in the application code.
- An internal bug in the Chilkat code causing the hang.
LastErrorHtml
Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
topLastErrorText
Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
LastErrorXml
Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
topLastMethodSuccess
pub fn last_method_success(&self) -> bool
pub fn set_last_method_success(&self, value: bool)
Indicates the success or failure of the most recent method call: true means success, false means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.
PcscLibPath
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.
topReaderStatus
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.
ScardError
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.
...
VerboseLogging
pub fn verbose_logging(&self) -> bool
pub fn set_verbose_logging(&self, value: 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.
Version
Methods
BeginTransaction
Establishes a temporary exclusive access mode for doing a series of commands in a transaction.
Returns Ok(()) for success, Err(chilkat::Error) for failure.
CheckStatus
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 Ok(()) for success, Err(chilkat::Error) for failure.
Connect
Establish a connection to a reader. The reader is the name of a reader returned from ListReaders. The share_mode can be shared, exclusive, or direct. The preferred_protocol 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 Ok(()) for success, Err(chilkat::Error) for failure.
Disconnect
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 Ok(()) for success, Err(chilkat::Error) for failure.
EndTransaction
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 Ok(()) for success, Err(chilkat::Error) for failure.
EstablishContext
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 Ok(()) for success, Err(chilkat::Error) for failure.
FindSmartcards
Returns JSON containing information about the smartcards currently inserted into readers.
Returns Ok(()) for success, Err(chilkat::Error) for failure.
GetAttrib
Get an attribute from the IFD Handler (reader driver).
The attr can be one of the following:
ASYNC_PROTOCOL_TYPESATR_STRINGCHANNEL_IDCHARACTERISTICSCURRENT_BWTCURRENT_CLKCURRENT_CWTCURRENT_DCURRENT_EBC_ENCODINGCURRENT_FCURRENT_IFSCCURRENT_IFSDCURRENT_IO_STATECURRENT_NCURRENT_PROTOCOL_TYPECURRENT_WDEFAULT_CLKDEFAULT_DATA_RATEDEVICE_FRIENDLY_NAMEDEVICE_IN_USEDEVICE_SYSTEM_NAMEDEVICE_UNITESC_AUTHREQUESTESC_CANCELESC_RESETEXTENDED_BWTICC_INTERFACE_STATUSICC_PRESENCEICC_TYPE_PER_ATRMAX_CLKMAX_DATA_RATEMAX_IFSDMAXINPUTPOWER_MGMT_SUPPORTSUPRESS_T1_IFS_REQUESTSYNC_PROTOCOL_TYPESUSER_AUTH_INPUT_DEVICEUSER_TO_CARD_AUTH_DEVICEVENDOR_IFD_SERIAL_NOVENDOR_IFD_TYPEVENDOR_IFD_VERSIONVENDOR_NAME
The attribute data is returned in bd.
Returns Ok(()) for success, Err(chilkat::Error) for failure.
GetAttribStr
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_TYPESATR_STRINGCHANNEL_IDCHARACTERISTICSCURRENT_BWTCURRENT_CLKCURRENT_CWTCURRENT_DCURRENT_EBC_ENCODINGCURRENT_FCURRENT_IFSCCURRENT_IFSDCURRENT_IO_STATECURRENT_NCURRENT_PROTOCOL_TYPECURRENT_WDEFAULT_CLKDEFAULT_DATA_RATEDEVICE_FRIENDLY_NAMEDEVICE_IN_USEDEVICE_SYSTEM_NAMEDEVICE_UNITESC_AUTHREQUESTESC_CANCELESC_RESETEXTENDED_BWTICC_INTERFACE_STATUSICC_PRESENCEICC_TYPE_PER_ATRMAX_CLKMAX_DATA_RATEMAX_IFSDMAXINPUTPOWER_MGMT_SUPPORTSUPRESS_T1_IFS_REQUESTSYNC_PROTOCOL_TYPESUSER_AUTH_INPUT_DEVICEUSER_TO_CARD_AUTH_DEVICEVENDOR_IFD_SERIAL_NOVENDOR_IFD_TYPEVENDOR_IFD_VERSIONVENDOR_NAME
Returns Err(chilkat::Error) on failure.
GetAttribUint
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_TYPESATR_STRINGCHANNEL_IDCHARACTERISTICSCURRENT_BWTCURRENT_CLKCURRENT_CWTCURRENT_DCURRENT_EBC_ENCODINGCURRENT_FCURRENT_IFSCCURRENT_IFSDCURRENT_IO_STATECURRENT_NCURRENT_PROTOCOL_TYPECURRENT_WDEFAULT_CLKDEFAULT_DATA_RATEDEVICE_FRIENDLY_NAMEDEVICE_IN_USEDEVICE_SYSTEM_NAMEDEVICE_UNITESC_AUTHREQUESTESC_CANCELESC_RESETEXTENDED_BWTICC_INTERFACE_STATUSICC_PRESENCEICC_TYPE_PER_ATRMAX_CLKMAX_DATA_RATEMAX_IFSDMAXINPUTPOWER_MGMT_SUPPORTSUPRESS_T1_IFS_REQUESTSYNC_PROTOCOL_TYPESUSER_AUTH_INPUT_DEVICEUSER_TO_CARD_AUTH_DEVICEVENDOR_IFD_SERIAL_NOVENDOR_IFD_TYPEVENDOR_IFD_VERSIONVENDOR_NAME
Returns 0xFFFFFFFF on failure.
topGetStatusChange
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 st_reader_names. It then blocks waiting for a change in state to occur for a maximum blocking time of max_wait_ms (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 st_reader_names 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 Ok(()) for success, Err(chilkat::Error) for failure.
GetStatusChangeCancel
Cancels an ongoing GetStatusChange method call. This would be called from a separate thread in your application if GetStatusChange was called synchronously.
Returns Ok(()) for success, Err(chilkat::Error) for failure.
ListReaderGroups
Returns a list of currently available reader groups on the system. The reader groups are returned in reader_groups.
Returns Ok(()) for success, Err(chilkat::Error) for failure.
ListReaders
Returns a list of currently available readers on the system.
Returns Ok(()) for success, Err(chilkat::Error) for failure.
Reconnect
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 share_mode can be shared, exclusive, or direct. The preferred_protocol 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 Ok(()) for success, Err(chilkat::Error) for failure.
ReleaseContext
Destroys a communication context to the PC/SC Resource Manager. This must be the last function called in a PC/SC application.
Returns Ok(()) for success, Err(chilkat::Error) for failure.
SendControl
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 bd_send. The response is written to bd_recv.
Returns Ok(()) for success, Err(chilkat::Error) for failure.
SendControlHex
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 send_data. The response is written to bd_recv.
Returns Ok(()) for success, Err(chilkat::Error) for failure.
Transmit
Sends an APDU to the smart card contained in the currently connected reader. The protocol_name can be T0, T1, or raw. The APDU to be sent is contained in bd_send. The response from the card is contained in bd_recv. The max_recv_len is the maximum response size (in bytes) willing to be accepted.
Returns Ok(()) for success, Err(chilkat::Error) for failure.
TransmitHex
Sends an APDU to the smart card contained in the currently connected reader. The protocol_name can be T0, T1, or raw. The APDU (in hexadecimal) to be sent is passed in apdu_hex. The response from the card is contained in bd_recv. The max_recv_len is the maximum response size (in bytes) willing to be accepted.
Returns Ok(()) for success, Err(chilkat::Error) for failure.
Events
All Chilkat methods are synchronous: the call returns when the work is done. During a call, SCard raises three events so your application can show progress and offer a way out. Implement the chilkat::EventHandler trait (every method has a do-nothing default, so implement only the events you need) and install it with set_event_handler:
use chilkat::{SCard, EventHandler};
struct Progress;
impl EventHandler for Progress {
fn percent_done(&mut self, pct: i32) -> bool {
println!("{pct}%");
false // return true to abort the method in progress
}
fn progress_info(&mut self, name: &str, value: &str) {
println!("{name}: {value}");
}
}
let s_card = SCard::new();
s_card.set_event_handler(Progress);
s_card.set_heartbeat_ms(250); // raise abort_check 4 times per second during Chilkat callsFor a one-off handler the closure methods avoid writing a type; they may be combined, and each replaces the previously set closure for that one event (installing a closure removes a trait handler set earlier, and vice versa):
s_card.on_percent_done(|pct| { println!("{pct}%"); false });
s_card.on_progress_info(|name, value| println!("{name}: {value}"));Installs handler as the receiver of this object's events, replacing any handler or closures set earlier. The object owns the handler, which must be Send + 'static.
Removes the handler and any closures; events are no longer delivered.
AbortCheck fires at regular intervals controlled by the HeartbeatMs property (0, the default, disables it); PercentDone fires when an operation's completion percentage is known; ProgressInfo delivers named progress values. Returning true from abort_check or percent_done aborts the running method, which then returns Err.
Events fire on the thread that called the method, before that method returns. A panic inside a handler aborts the running method and is re-raised to the caller once the native library has returned, so it never unwinds through C frames. To abort a long operation from another thread, share an Arc<AtomicBool> with an abort_check handler, or set the object's AbortCurrent property to true.
AbortCheck
fn abort_check(&mut self) -> bool
Enables a method call to be aborted by triggering the AbortCheck event at intervals defined by the HeartbeatMs property. If HeartbeatMs is set to its default value of 0, no events will occur. For instance, set HeartbeatMs to 200 to trigger 5 AbortCheck events per second.
Example (closure form; the EventHandler trait method is equivalent):
s_card.set_heartbeat_ms(250); // call abort_check 4 times per second
let stop = std::sync::Arc::new(std::sync::atomic::AtomicBool::new(false));
let flag = stop.clone();
s_card.on_abort_check(move || flag.load(std::sync::atomic::Ordering::Relaxed));
// ... another thread may now abort the method in progress with stop.store(true, Ordering::Relaxed)PercentDone
fn percent_done(&mut self, pct: i32) -> bool
This provides the percentage completion for any method involving network communications or time-consuming processing, assuming the progress can be measured as a percentage. This event is triggered only when it's possible and logical to express the operation's progress as a percentage. The pct_done argument will range from 1 to 100. For methods that finish quickly, the number of PercentDone callbacks may vary, but the final callback will have pct_done equal to 100. For longer operations, callbacks will not exceed one per percentage point (e.g., 1, 2, 3, ..., 98, 99, 100).
The PercentDone callback also acts as an AbortCheck event. For fast methods where PercentDone fires, an AbortCheck event may not trigger since the PercentDone callback already provides an opportunity to abort. For longer operations, where time between PercentDone callbacks is extended, AbortCheck callbacks enable more responsive operation termination.
To abort the operation, set the abort output argument to true. This will cause the method to terminate and return a failure status or corresponding failure value.
Example (closure form; the EventHandler trait method is equivalent):
s_card.on_percent_done(|pct| {
// pct ranges from 1 to 100.
println!("Percent done: {pct}");
false // return true to abort the method in progress
});ProgressInfo
fn progress_info(&mut self, name: &str, value: &str)
This event callback provides tag name/value pairs that detail what occurs during a method call. To discover existing tag names, create code to handle the event, emit the pairs, and review them. Most tag names are self-explanatory.
Note: Some Chilkat methods don't fire any ProgressInfo events.
Example (closure form; the EventHandler trait method is equivalent):
s_card.on_progress_info(|name, value| println!("{name}: {value}"));