1. Introduction

This manual serves as a guide to successfully carry out the Bit4id Kit installation process for the use of cryptographic cards and the procedure for accessing and using the management application. The Bit4id Kit consists of the following components:

  • Bit4id Middleware: libraries that allow any application of the Operating System to operate with cryptographic cards.

  • Bit4id PKI Manager: application for managing the card, which allows you to perform operations such as changing PIN or PUK, unlocking PIN, obtaining information about the card, importing or exporting certificates...

This manual will guide you in a simple way in the process of installing and using the Kit Bit4id.

1.1 To whom is this document addressed?

End users, who will use chip cards in Linux environments.

2. Before you start

Make sure you have:

  • one standard, PC/SC compatible card reader that is properly connected, installed and configured. Follow the instructions provided by the reader manufacturer to verify correct installation and operation.

  • The latest version of Kit Bit4id . Link to download the latest version.

  • To be able to carry out the installation, it is essential to have Administrator permissions .If you do not have it, the installation will be denied.

  • If using the GNOME desktop environment, it is essential to enable wayland. Below you will find a guide on how to do it .

3. Installation

If necessary, you will have to download and install the drivers for your computer to recognize the reader you have purchased. To do this, go to the official page of the reader manufacturer.

Follow the instructions provided by the reader manufacturer to verify correct installation and operation.

If you purchase a bit4id reader, if your version of Linux has the PCSC drivers installed by default, it will not be necessary to download any drivers.

3.1. PKI Manager Installation Assistant

  1. Go to the folder where you downloaded the zip file DEB.zip

Carpeta d'instal·lació

  1. Unzip the folder. Inside the folder you will see 2 installers.
  • If your operating system is Ubuntu/Debian you will need to run: Bit4id_Middleware.deb
  • If your operating system is Fedora/Centos you will need to run: Bit4id_Middleware.rpm
  1. Follow the installer steps. In this case we will do it with an Ubuntu 22.04.1

Executar instal·lador

Instal·lador de l'aplicació

Procés d'instal·lació

Aplicació instal·lada

  1. Once the PKI Manager installation is complete, restart the computer.

    Logo aplicació Bit4id PKI Manager

  2. Image without any device connected:

    Imatge sense cap dispusitiu conectat

Once the reboot is complete, open the app.

Logo aplicació Bit4id PKI Manager

Interfície principal PKI Manager

  1. With the application open, connect the reader to a USB port and then insert the card. You can also do this process by plugging the token into a USB port.

PKI Manager amb targeta connectada

4. Problems during installation

You may have older versions of the Card Management application (Bit4id PKI Manager) installed on your computer, so you will be prompted to remove older versions before running the install. lader Remove these versions and run the installer again.

How to uninstall an older version of PKI Manager?

  1. go to Software Center (Install Software)
  2. Find and select the Installed tab
  3. Select whatever you want to delete
  4. Prem uninstall
  5. If not, open the command console (Control + Alt + T)
  6. write Ubuntu/Debian(sudo apt-get --purge remove libbit4xpki), Fedora/Centos(sudo yum remove libbit4xpki)
  7. Enter your password and press Enter

5. Settings in Firefox

In order to be able to use the certificates contained in the smart card in the Mozilla Firefox browser, it is necessary to incorporate some Bit4id Universal Middleware libraries manually.

The automated incorporation of security devices in Firefox was disabled from version 3.5 as a security measure.

  1. We open Mozilla Firefox, we go to  Options → (  preferences)

Opciones Firefox

  1. In the section of  Privacy and Security, look for the certificates section and click on Security Devices

Privacitat Firefox

  1. Device Manager will open. Click on Upload

Carregar mòdul criptogràfic en Firefox

  1. When this window opens, you need to search for the PKCS#11 device driver. Click Browse to search for it on your computer.

Finestra mòdul PKCS#11

In the previous window, the following data must be entered:

  • Module Name: Bit4id Universal Middleware

  • Module archive: /usr/lib/bit4id/libbit4xpki.so

Finestra mòdul PKCS#11

6. Functionalities

The Bit4id PKI Manager application has multiple functionalities available from the main screen.

IMPORTANT: Bit4id PKI Manager comes by default with the user version. To be able to have all its functionalities, you must switch to the administrator version using the command: Ctrl+A

Finestra principal PKI Manager

6.1. Functionality tables

Basic functionalities:

Captura de les funcionalitats bàsiques

Table of basic functionalities

function Description
Unlock PIN Function to unlock the card PIN.
Change PIN Function to change the PIN of the card.
Change the PUK Function to change the PUK of the card.
Login/Logout Function to log in/out of the card.
Device information Tab where we will find the description of the connected device and the card.
Certificates Tab where we will find the user and CA certificates loaded on the card.

To access the extra features, click on:


Extra features:

Captura de les funcionalitats extres

Table of extra features

function Description
Login/Logout Sign in/out of card content.
Refresh Refresh the token/card content to see new certificates.
Change the device name Define the name under which the device appears.
Change PIN Function to change the PIN of the card.
Unlock PIN Function to unlock the PIN of the card using its PUK.
Change the PUK Function to change the PUK of the card.
Import certificate Function to import a certificate to your card.
Erase the device Function to delete ALL certificates and keys from the card token.
  • Log on

    To access any functionality offered by the software, you must enter the card's PIN

    Iniciar sessión

  • Change PIN
    To change the PIN, enter the card PIN and the new PIN. The new PIN must be between 4 and 8 alphanumeric digits.

Canviar PIN

  • Unlock PIN

To unlock the PIN, enter the PUK of the card and the new PIN. The new PIN must be between 4 and 8 alphanumeric digits.

Desbloquejar PIN

  • Change PUK

Enter the card's old PUK and the new PUK. The new PUK must be between 4 and 8 alphanumeric digits.

Canviar PUK

  • import

This option allows the import of certificates on the card. The accepted formats for importing .p12 or .pfx card certificates since these formats include the certificate's private key, which is essential to carry out cryptographic operations.

To start the import, first select the certificate from its location, as shown in the following image:

Seleccionar certificat

Once the certificate is selected, press "Open":

The system will ask you for the password of the PFX or P12 file (certificate and its private key) that you want to import, which contains its certificate and key pair. Insert it and complete the import options according to your convenience, where:

Contrasenya del certificat

– Import certificates with no associated key peer: allows you to import the entire certification hierarchy included in the PFX or P12 file. It is recommended NOT to MARK this option.

– Define CKA_ANEU from PKCS#11: identifier that certain applications use when displaying the certificate. It is recommended to enter a useful identifier value, for example pedro_signature, pedro_access, pedro_encryption, etc.

And the certificate import will be completed:

Importació OK

In the event that you wish to check that the certificate has been correctly saved, remember that you can review all the certificates stored on the card through the "View" option of Bit4id PKI Manager.

  • Certificate details

Once the card's PIN is entered, you can see the certificates included. In the pop-up window displayed by the application, you can see information about the previously selected certificate.

Info certificat

  • information

Provides detailed card information: model, serial number, manufacturer and label. It is possible that support ( soporte@bit4id.com ) will ask you for this information to know the type of card you are using.

Info targeta

7. Frequently asked questions

Can I mix numbers and letters for the card PIN number?
Yes, no problem, as long as the new PIN is between 4 and 8 digits.

Is there a maximum number of PIN entries in case I have any doubts and do not remember my PIN number? When can the card be blocked?
If you enter the PIN code incorrectly more than 3 times, it is blocked. Follow the 'Unlock PIN' steps above to unlock it.

Is there a maximum number of PUK entries to try to unlock the PIN? What happens if the card is blocked?
If you enter the PUK code incorrectly more than 3 times, it is blocked. For security reasons, the card is completely blocked.

8. Glossary

Certification Authority: is the trusted entity, responsible for issuing and revoking the electronic certificates used in the electronic signature. The Certification Authority, by itself or through the intervention of a Registration Authority, verifies the identity of the applicant for a certificate before it is issued or, in the case of certificates issued with the condition of being revoked, removes the revocation of certificates when verifying this identity.

Expiration of the digital certificate: the digital certificate has a period of validity that is stated in the certificate itself. It is generally 2 years, although by law a validity of up to 5 years is allowed. Once the certificate has expired, you will not be able to use the services offered by the Administration that require an electronic signature, and any electronic signature made after that time will not be valid.

Digital certificate: document in computer support issued and signed by the Certification Authority, which guarantees the identity of its owner.

Recognized certificate: certificate issued by a Certification Service Provider that meets the requirements established in the Law regarding the verification of the identity and other circumstances of the applicants and the reliability and guarantees of the certification services they provide, in accordance with the provisions Chapter II of Title II of Law 59/2003, of December 19, on Electronic Signatures.

Electronic signature: set of data, in electronic form, attached to other electronic data or functionally associated with them, used as a means to formally identify the author or authors of the document that collects it. There are 3 types of electronic signature: simple, advanced and recognized electronic signature.

Simple electronic signature: set of data, in electronic form, attached to other data.

Advanced electronic signature: electronic signature that allows the signer to be identified and any subsequent changes to the signed data to be detected, that is uniquely linked to the signer and the data it refers to, and that has been created by means that the signer can keep under its sole control.

Recognized electronic signature: an advanced electronic signature based on a recognized certificate and generated using a secure signature creation device is considered a recognized electronic signature. The recognized electronic signature will have the same value with respect to the data entered in electronic form as the handwritten signature in relation to those entered on paper.

Hash function: is an operation that is performed on a set of data of any size, so that the result obtained is another set of data of a fixed size, regardless of the original size, and that has the property of being uniquely associated with the data initials, that is, it is impossible to find two different messages that generate the same result when applying the Hash Function.

Hash or Fingerprint: fixed-size result obtained after applying a hash function to a message and satisfying the property of being uniquely associated with the initial data.

Integrity: integrity is the quality possessed by a document or archive that has not been altered and that also allows you to verify that no manipulation has occurred in the original document.

Certificate Revocation Lists or Revoked Certificate Lists: list showing exclusively the relationships of revoked or suspended certificates (not the expired ones).

I do not repudiate: the sender who electronically signs a document cannot deny that he sent the original message, since this is imputable to the sender by means of the private key that only he knows and that he is obliged to keep. Non-repudiation also allows you to check who participated in a transaction.

Non-repudiation or non-repudiation is a security service that is closely related to authentication and that allows you to prove the participation of the parties in a communication. The essential difference with authentication is that the former occurs between the parties establishing the communication and the non-repudiation service occurs against a third party

Certification Service Provider or PSC: natural or legal person that issues electronic certificates or provides other services in relation to the electronic signature. See Certification Authority.

PIN: sequence of characters that allow access to certificates. Personal Identification Number, sometimes called NIP.

PUK: sequence of characters that allow the PIN to be changed or unlocked. Personal Unlocking Key.

Renewal renewal consists of applying for a new certificate using a certificate that is valid but is about to expire. In this way, before the expiry of a certificate, the renewal can be requested and this implies that a new valid certificate is issued.

Revocation: definitive cancellation of a digital certificate at the request of the subscriber, or at the Certification Authority's own initiative in case of doubt about the security of the keys. Revocation is an irreversible state. The revocation of a certificate can be requested after a situation of suspension or at the will of the persons authorized to request it. Likewise, in the case of a suspended certificate, if the maximum suspension period has passed, if the certificate has not been enabled, it becomes definitively revoked. When the certification body revokes or suspends a certificate, it must make it appear in the Certificate Revocation Lists (CRL), to make this fact public. These lists are public and must always be available.

Smart card: any card with integrated circuits that allow the execution of certain programmed logic.