yubikey

Fixing KeePassXC Snap Not Detecting YubiKey

 in Bash / GNU/Linux  tagged bash / GNU/Linux / KeePassXC / ubuntu / yubikey by

If you’re using KeePassXC installed from Snap and notice it’s not recognizing your YubiKey, you’re not alone. Snap packages have strict sandboxing and confinement rules that often block access to hardware devices like USB, including YubiKeys. This can cause issues when using features like Challenge-Response authentication with your YubiKey in KeePassXC.

This blog post’ll cover multiple ways to solve this problem, including switching to a different installation method or adjusting the Snap confinement settings.

Why Doesn’t KeePassXC (Snap) See the YubiKey?

Snap packages are sandboxed, which is great for security but can be problematic for applications that need direct access to hardware like USB devices. This restriction prevents KeePassXC from communicating with your YubiKey, as it requires access to your USB ports and smart card services.

Let’s explore different solutions to fix this issue.

Solution 1: Install KeePassXC from the Official PPA (Recommended)

Installing KeePassXC using the official PPA (Personal Package Archive) is the best way to avoid the Snap sandbox restrictions. This version doesn’t have the same hardware access limitations as the Snap version and is more likely to work seamlessly with your YubiKey.

Steps to Install KeePassXC via PPA:

  1. Remove the Snap Version
    First, you’ll want to remove the Snap version of KeePassXC if it’s currently installed:
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sudo snap remove keepassxc;
  1. Add the Official KeePassXC PPA
    Next, add the official KeePassXC PPA to your system and update your package list:
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sudo add-apt-repository ppa:phoerious/keepassxc;
sudo apt-get update;
  1. Install KeePassXC from the PPA
    Now, install KeePassXC from the PPA:
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sudo apt-get install keepassxc;

This method bypasses the limitations of Snap and ensures full hardware access to devices like the YubiKey. After installation, KeePassXC should immediately detect your YubiKey.

Solution 2: Adjust Snap Confinement to Allow Hardware Access

If you prefer to stick with the Snap version of KeePassXC, you can adjust its permissions to allow access to the necessary system interfaces.

To enable USB and PC/SC (smart card) support for KeePassXC Snap, run the following commands:

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sudo snap connect keepassxc:raw-usb;

This command allows the Snap package to access the USB device and observe hardware resources.

After running the commands, restart KeePassXC:

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snap restart keepassxc;

This should grant KeePassXC Snap access to the YubiKey via USB and PC/SC protocols.

Solution 3: Use Classic Confinement for Snap (Less Secure)

Snap packages have strict confinement modes by default, but you can loosen these restrictions by installing KeePassXC in classic confinement mode. This allows the application to access your system as if it were a regular app installed outside of Snap, without the sandbox limitations.

Steps to Install KeePassXC with Classic Confinement:

  1. Remove the Existing Snap Version
    If you already have the standard Snap version of KeePassXC installed, remove it:
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sudo snap remove keepassxc;
  1. Install KeePassXC with Classic Confinement
    Now, reinstall KeePassXC with the --classic flag:
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sudo snap install keepassxc --classic;

By using --classic, you’re bypassing the tight confinement, which means KeePassXC will be able to access hardware devices like the YubiKey without the sandbox restrictions.

Note: This approach compromises some of the security benefits provided by Snap’s confinement model, so only use this method if you need it for specific reasons.

Solution 4: Use Flatpak as an Alternative to Snap

If you’re facing persistent issues with the Snap version of KeePassXC and don’t want to use the PPA, you can try installing KeePassXC via Flatpak. Flatpak offers a more flexible and modern sandboxing approach, and it often has better hardware access capabilities compared to Snap.

Steps to Install KeePassXC via Flatpak:

  1. Install Flatpak (if not already installed)
    First, install Flatpak on your system if you don’t have it yet:
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sudo apt-get install flatpak;
  1. Add the Flathub Repository
    Add the Flathub repository to your Flatpak sources:
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flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo;
  1. Install KeePassXC from Flathub
    Now install KeePassXC from the Flathub repository:
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flatpak install flathub org.keepassxc.KeePassXC;

Flatpak applications typically have more flexible access to hardware, so your YubiKey should work without issues after switching to this version of KeePassXC.

Solution 5: Ensure pcscd Is Running

YubiKeys often rely on the PC/SC daemon (pcscd) for smart card operations. If the daemon is not running, KeePassXC won’t be able to detect the YubiKey even if all permissions are set correctly.

To install and start pcscd:

  1. Install pcscd:
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sudo apt-get install pcscd;
  1. Start and enable the pcscd service:
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sudo systemctl start pcscd;
sudo systemctl enable pcscd;

Ensure that pcscd is running and that your system recognizes the YubiKey through PC/SC.

Conclusion

The most reliable solution for getting KeePassXC to work with your YubiKey on Linux is to install KeePassXC from the official PPA. This eliminates the Snap confinement issues that often prevent hardware from being detected. Alternatively, adjusting Snap’s permissions or switching to Flatpak are also viable solutions.

Here’s a quick recap of the options:

  • PPA Installation (Recommended): Full access to hardware without Snap’s restrictions.
  • Snap Adjustments: Grant KeePassXC Snap permissions to access USB and PC/SC devices.
  • Classic Confinement: Loosen Snap restrictions (less secure).
  • Flatpak Installation: Another sandboxed app system, but with better hardware access.
  • Ensure pcscd is Running: Required for YubiKey smart card functionality.

With these solutions, you should be able to get KeePassXC and your YubiKey working together on your system.

Happy securing your passwords with YubiKey and KeePassXC!

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Configuring YubiKey for Challenge-Response with YubiKey Manager (ykman)

 in Bash / GNU/Linux  tagged bash / GNU/Linux / ubuntu / ykman / yubi / yubico / yubikey by

YubiKeys are popular hardware security keys for multi-factor authentication, passwordless login, and cryptographic operations. YubiKey Manager (ykman) is a versatile command-line tool that helps manage YubiKeys and configure various features, such as OTP (One-Time Passwords), FIDO2, OpenPGP, and more.

In this blog, we’ll walk through installing ykman, configuring the system to support smart card (CCID) functionality, and setting up YubiKey’s OTP Challenge-Response mechanism on Slot 2 with a custom secret key.

Prerequisites

Before you proceed, ensure you have:

  • A YubiKey (any model that supports OTP)
  • A Linux-based system (although similar commands apply for macOS and Windows)
  • Administrative privileges (i.e., sudo access)

Step 1: Install YubiKey Manager (ykman)

The easiest way to install ykman is through the Snap package system. Open your terminal and run the following command:

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sudo snap install ykman

Snap packages offer the advantage of being automatically updated, and the installation process is streamlined across different Linux distributions.

Step 2: Install PC/SC Daemon (for Smart Card Functionality)

YubiKey’s advanced features such as PIV (Personal Identity Verification), OpenPGP, and OATH require the PC/SC daemon (pcscd). This daemon handles smart card communication and is crucial if you plan to use your YubiKey as a smart card device.

To install pcscd, run the following command:

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sudo apt-get install pcscd

Once installed, ensure that the service is running:

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sudo systemctl start pcscd
sudo systemctl enable pcscd

This ensures that the PC/SC daemon starts on boot and is ready to handle YubiKey interactions that require smart card protocols.

Step 3: Configure YubiKey OTP Slot 2 for Challenge-Response

YubiKeys supports OTP in two different slots. By default, Slot 1 is often used for standard Yubico OTP, while Slot 2 can be configured for custom purposes, such as Challenge-Response.

In this example, we will configure Slot 2 with a custom secret key for Challenge-Response using HMAC-SHA1. This key can be used in scenarios such as system authentication, password managers, or other cryptographic operations.

Generate or Define a Secret Key

For Challenge-Response to work, you need a 20-byte secret key in hexadecimal format. You can either generate this key yourself or use a tool like OpenSSL:

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openssl rand -hex 20

Ensure you securely store this secret key, as it will be used for Challenge-Response authentication.

Configure Slot 2 with the Secret Key

To configure the secret key for Challenge-Response in Slot 2, use the following ykman command. Replace the example key with your own 20-byte key:

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ykman otp chalresp 2 00112233445566778899aabbccddeeff00112233
  • otp chalresp tells YubiKey Manager that we are configuring OTP Challenge-Response.
  • 2 indicates Slot 2.
  • The hexadecimal string 00112233445566778899aabbccddeeff00112233 is your secret key.

Once this command runs successfully, your YubiKey is ready for Challenge-Response authentication in Slot 2.

Step 4: Verify the Configuration

To ensure that the configuration was successful, you can check the YubiKey’s slot status with the following command:

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ykman otp info

This command will display information about both Slot 1 and Slot 2, allowing you to verify that Slot 2 has been configured for Challenge-Response using HMAC-SHA1.

Conclusion

You have now successfully installed ykman, configured your system for smart card support with pcscd, and set up Slot 2 on your YubiKey for OTP Challenge-Response using a custom secret key. This setup is valuable for integrating YubiKey into secure systems, password managers, and custom cryptographic workflows.

By leveraging ykman, you unlock a wide range of features in your YubiKey, making it a powerful tool for authentication and security.

For further reading on YubiKey and its capabilities, you can explore the official Yubico documentation.

Common Issues

  1. PC/SC Not Available: If you encounter the warning PC/SC not available. Smart card (CCID) protocols will not function., ensure that the pcscd service is installed and running. You can restart it using:
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sudo systemctl restart pcscd
  1. Permission Denied: If you experience permission issues when running ykman, ensure that your user has access to USB devices, or try running the command with sudo.

With this setup, your YubiKey is now ready to provide robust security for your systems and applications!

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Enhancing KeePassXC with YubiKey on Ubuntu: Enabling the Raw-USB Interface

 in GNU/Linux  tagged bash / GNU/Linux / raw-usb / snap / ubuntu / usb / yubikey by

In digital security, combining hardware-based authentication devices like YubiKey with robust password management solutions such as KeePassXC represents a gold standard. YubiKey provides a physical, secure element for two-factor authentication, significantly enhancing security over traditional password-only systems. KeePassXC, a free and open-source password manager, allows users to manage their passwords securely. However, when running KeePassXC as a Snap package on Ubuntu, users may encounter an unexpected hurdle due to Snap’s inherent security and isolation features. This post aims to guide you through enabling your YubiKey hardware to work seamlessly with KeePassXC installed via Snap by manually allowing the raw-usb to interface.

Understanding the Challenge

Snap, a package management and deployment system developed by Canonical, allows for the consistent, secure distribution and installation of applications across different Linux distributions. Snap packages are containerized to ensure isolation from the rest of the system, enhancing security by restricting the application’s access to the host system’s resources and hardware interfaces.

While these isolation features benefit security, they can also impose limitations. Specifically, for KeePassXC users wishing to utilize a YubiKey for added security, Snap’s default restrictions prevent the application from accessing the USB hardware directly. This is where the raw-usb interface comes into play.

The raw-usb Interface

The raw-usb interface in Snap allows a snap-packaged application to communicate with USB hardware directly, bypassing the usual restrictions. By enabling this interface for KeePassXC, the application can interact with your YubiKey, utilizing it for secure two-factor authentication.

Step-by-Step Guide to Enabling the raw-usb Interface

  1. Open Your Terminal: First, access your terminal. You can do this by pressing Ctrl + Alt + T on your keyboard or searching for “Terminal” in your applications menu.
  2. Execute the Command: In the terminal, type the following command:
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sudo snap connect "keepassxc:raw-usb" "core:raw-usb"

This command instructs your system to enable the raw-usb interface specifically for KeePassXC. Here’s a breakdown of the command:

  • sudo: This prefix grants administrative (superuser) permissions for the operation, which is necessary for modifying system-wide settings.
  • snap connect: This is the command to link a Snap package to a specific interface.
  • "keepassxc:raw-usb": Specifies the KeePassXC snap package and the raw-usb interface within it.
  • "core:raw-usb": Refers to the raw-usb interface the core Snap provides, which grants access to USB devices.
  1. Enter Your Password: After entering the command, you’ll be prompted to enter your password. This is the password you use to log in to your Ubuntu account. Since you’re executing a command with sudo, your password is required to confirm that you have the necessary permissions to make system-level changes.
  2. Confirmation: If successful, you won’t see a detailed message; the lack of error messages typically indicates that the operation was successful. You’ve now enabled KeePassXC to access USB devices directly.

Testing the Configuration

After enabling the raw-usb interface, launch KeePassXC and attempt to use your YubiKey as part of your two-factor authentication setup. If everything is configured correctly, KeePassXC should recognize your YubiKey without any issues.

Conclusion

The security of your digital life is paramount in an era where online threats are increasingly sophisticated. By integrating YubiKey with KeePassXC on Ubuntu, you significantly enhance your digital security posture. The process of enabling the raw-usb interface for KeePassXC, while a bit technical, is a small step with significant benefits for your security setup. It exemplifies the balance between security and usability, allowing you to leverage cutting-edge security hardware without compromising on the convenience and ease of use offered by modern Linux distributions and applications.