node-pcsclite

Bindings over pcsclite to access Smart Cards. It works in Linux, macOS and Windows.

📌 Looking for library to work easy with NFC tags?
Then take a look at nfc-pcsc which offers an easy to use high level API for detecting / reading and writing NFC tags and cards.

Content

• Installation
• Example
• Behavior on different OS
• API
  • Class: PCSCLite
    • Event: error
    • Event: reader
    • pcsclite.close()
    • pcsclite.readers
  • Class: CardReader
    • Event: error
    • Event: end
    • Event: status
    • reader.connect([options], callback)
    • reader.disconnect(disposition, callback)
    • reader.transmit(input, res_len, protocol, callback)
    • reader.control(input, control_code, res_len, callback)
    • reader.close()
• FAQ
  • Can I use this library in my Electron app?
  • Are prebuilt binaries provided?
  • Disabling drivers to make pcsclite working on Linux
  • Which Node.js versions are supported?
  • Can I use this library in my React Native app?
• Frequent errors
  • Error: Cannot find module '../build/Release/pcsclite.node'
• License

Installation

Requirements: at least Node.js 8 or newer (see this FAQ for more info)

1. Node Native Modules build tools

   Because this library uses Node Native Modules (C++ Addons), which are automatically built (using node-gyp) when installing via npm or yarn, you need to have installed C/C++ compiler toolchain and some other tools depending on your OS.

   Please refer to the node-gyp > Installation for the list of required tools depending on your OS and steps how to install them.

2. PC/SC API in your OS

   On macOS and Windows you don't have to install anything, pcsclite API is provided by the OS.

   On Linux/UNIX you'd probably need to install pcsclite library and daemon**.

   For example, in Debian/Ubuntu:

   apt-get install libpcsclite1 libpcsclite-dev

   To run any code you will also need to have installed the pcsc daemon:

   apt-get install pcscd

3. Once you have all needed libraries, you can install node-pcsclite using npm:

   npm install @pokusew/pcsclite --save

   or using Yarn:

   yarn add @pokusew/pcsclite

Example

👉 If you'd prefer an easy to use high level API for detecting / reading and writing NFC tags and cards, take a look at nfc-pcsc.

const pcsclite = require('@pokusew/pcsclite');

const pcsc = pcsclite();

pcsc.on('reader', (reader) => {

    console.log('New reader detected', reader.name);

    reader.on('error', err => {
        console.log('Error(', reader.name, '):', err.message);
    });

    reader.on('status', (status) => {

        console.log('Status(', reader.name, '):', status);

        // check what has changed
        const changes = reader.state ^ status.state;

        if (!changes) {
            return;
        }

        if ((changes & reader.SCARD_STATE_EMPTY) && (status.state & reader.SCARD_STATE_EMPTY)) {

            console.log("card removed");

            reader.disconnect(reader.SCARD_LEAVE_CARD, err => {

                if (err) {
                    console.log(err);
                    return;
                }

                console.log('Disconnected');

            });

        }
        else if ((changes & reader.SCARD_STATE_PRESENT) && (status.state & reader.SCARD_STATE_PRESENT)) {

            console.log("card inserted");

            reader.connect({ share_mode: reader.SCARD_SHARE_SHARED }, (err, protocol) => {

                if (err) {
                    console.log(err);
                    return;
                }

                console.log('Protocol(', reader.name, '):', protocol);

                reader.transmit(Buffer.from([0x00, 0xB0, 0x00, 0x00, 0x20]), 40, protocol, (err, data) => {

                    if (err) {
                        console.log(err);
                        return;
                    }

                    console.log('Data received', data);
                    reader.close();
                    pcsc.close();

                });

            });

        }

    });

    reader.on('end', () => {
        console.log('Reader', reader.name, 'removed');
    });

});

pcsc.on('error', err => {
    console.log('PCSC error', err.message);
});

Behavior on different OS

TODO document

API

Class: PCSCLite

The PCSCLite object is an EventEmitter that notifies the existence of Card Readers.

Event: error

• err Error Object. The error.

Event: reader

• reader CardReader. A CardReader object associated to the card reader detected

Emitted whenever a new card reader is detected.

pcsclite.close()

It frees the resources associated with this PCSCLite instance. At a low level it calls SCardCancel so it stops watching for new readers.

pcsclite.readers

An object containing all detected readers by name. Updated as readers are attached and removed.

Class: CardReader

The CardReader object is an EventEmitter that allows to manipulate a card reader.

Event: error

• err Error Object. The error.

Event: end

Emitted when the card reader has been removed.

Event: status

• status Object.
  • state The current status of the card reader as returned by SCardGetStatusChange
  • atr ATR of the card inserted (if any)

Emitted whenever the status of the reader changes.

reader.connect([options], callback)

• options Object Optional
  • share_mode Number Shared mode. Defaults to SCARD_SHARE_EXCLUSIVE
  • protocol Number Preferred protocol. Defaults to SCARD_PROTOCOL_T0 | SCARD_PROTOCOL_T1
• callback Function called when connection operation ends
  • error Error
  • protocol Number Established protocol to this connection.

Wrapper around SCardConnect. Establishes a connection to the reader.

reader.disconnect(disposition, callback)

• disposition Number. Reader function to execute. Defaults to SCARD_UNPOWER_CARD
• callback Function called when disconnection operation ends
  • error Error

Wrapper around SCardDisconnect. Terminates a connection to the reader.

reader.transmit(input, res_len, protocol, callback)

• input Buffer input data to be transmitted
• res_len Number. Max. expected length of the response
• protocol Number. Protocol to be used in the transmission
• callback Function called when transmit operation ends
  • error Error
  • output Buffer

Wrapper around SCardTransmit. Sends an APDU to the smart card contained in the reader connected to.

reader.control(input, control_code, res_len, callback)

• input Buffer input data to be transmitted
• control_code Number. Control code for the operation
• res_len Number. Max. expected length of the response
• callback Function called when control operation ends
  • error Error
  • output Buffer

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

reader.close()

It frees the resources associated with this CardReader instance. At a low level it calls SCardCancel so it stops watching for the reader status changes.

FAQ

Can I use this library in my Electron app?

Yes, you can! It works well.

But please read carefully Using Native Node Modules guide in Electron documentation to fully understand the problematic.

Note, that because of Node Native Modules, you must build your app on target platform (you must run Windows build on Windows machine, etc.).
You can use CI/CD server to build your app for certain platforms.
For Windows, I recommend you to use AppVeyor.
For macOS and Linux build, there are plenty of services to choose from, for example CircleCI, Travis CI CodeShip.

Are prebuilt binaries provided?

No, because it brings more problems than it solves. The C++ code (Node Native Modules, C++ Addons) is built automatically during installation (using node-gyp).

That means that cross-compilation is not possible by default. If you want to use this library in your Electron or NW.js, see Can I use this library in my Electron app?.

Disabling drivers to make pcsclite working on Linux

In case there is another driver blocking the usb bus, you won't be able to access the NFC reader until you disable it. First, plug in your reader and check, which driver is being used:

$ lsusb -t
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/12p, 480M
    |__ Port 3: Dev 6, If 0, Class=Chip/SmartCard, Driver=pn533, 12M
        ...

In my case, there is a pn533 driver loaded by default. Now find the dependency tree of that driver:

$ lsmod | grep pn533
Module                  Size  Used by
pn533_usb              20480  0
pn533                  45056  1 pn533_usb
nfc                   131072  1 pn533

We see, that there are drivers nfc, pn533 and pn533_usb we need to disable. Create file in /etc/modprobe.d/ with the following content:

$ cat /etc/modprobe.d/nfc-blacklist.conf
blacklist pn533_usb
blacklist pn533
blacklist nfc

After reboot, there will be no driver blocking the usb bus anymore, so we can finally enable and start the pscs deamon:

# systemctl enable pcscd
# systemctl start pcscd

Which Node.js versions are supported?

@pokusew/pcsclite officially supports the following Node.js versions: 8.x, 9.x, 10.x, 11.x, 12.x, 13.x, 14.x, 16.x, 18.x, 20.x.

Can I use this library in my React Native app?

Short answer: NO

Explanation: Mobile support is virtually impossible because @pokusew/pcsclite uses Node Native Modules to access system PC/SC API. So the Node.js runtime and PC/SC API are required for @pokusew/pcsclite to run. That makes it possible to use it on the most of OS (Windows, macOS, Linux) directly in Node.js or in Electron.js and NW.js desktop apps. On the other hand, these requirements are not normally met on mobile devices. On top of that, React Native does not contain any Node.js runtime.

Frequent errors

Error: Cannot find module '../build/Release/pcsclite.node'

@pokusew/pcsclite uses Node Native Modules (Node.js C++ Addon) to access PC/SC API (pcsclite). The Node.js native C++ addon is built during installation via node-gyp (see package.json > scripts > install). When you see the error Cannot find module '../build/Release/pcsclite.node', something probably went wrong during the installation.

Follow the steps below to resolve your problem:

1. If there are any errors in the output of the npm install resp. yarn install,
   • ensure you meet all the requirements described in the Installation section of this README. Then try reinstalling @pokusew/pcsclite (npm uninstall / yarn remove and then npm install / yarn add).
   • If the problem persists, open a new issue and be sure to include the output of the npm install resp. yarn install and the details about your platform, OS, Node.js version and npm/yarn version.
2. If there are no errors during the installation,
   • then try reinstalling @pokusew/pcsclite (npm uninstall / yarn remove and then npm install / yarn add).
   • If it does not help, then examine the contents of the folder node_modules/@pokusew/pcsclite in your project (in case you installed @pokusew/pcsclite as a dependency). There should be a build folder with a Release folder inside. In the Release folder, there should be a pcsclite.node file. It is possible that this file is somewhere else. Whether you find the file somewhere or not, please open a new issue and describe the problem and be sure to include the details about your platform, OS, Node.js version and npm/yarn version.

License

ISC