#ctap #fido #webauthn #passkeys

app fido-key-manager

Management CLI for FIDO/CTAP 2.x authenticators

1 unstable release

0.5.0 Apr 28, 2024

#981 in Authentication

MPL-2.0 license

23K SLoC


fido-key-manager is a command line tool for managing and configuring FIDO/CTAP 2-compatible authenticators (security keys), based on the kanidm webauthn-authenticator-rs library.

Important: FIDO 1-only (U2F) tokens are not supported by this tool.

Building and running

First, you'll need to install OpenSSL's headers and libraries.

On Linux and macOS:

# Build fido-key-manager
cargo build --bin fido-key-manager

# Run fido-key-manager
./target/debug/fido-key-manager --help

On Windows (PowerShell):

# Build fido-key-manager
cargo build --bin fido-key-manager

# Either:
# A) run Windows Terminal as Administrator, or,
Start-Process "shell:AppsFolder\$((Get-StartApps Terminal | Select-Object -First 1).AppId)" -Verb RunAs
# B) run PowerShell as Administrator.
Start-Process -FilePath "powershell" -Verb RunAs

# Run fido-key-manager from the Administrator terminal:
.\target\debug\fido-key-manager.exe --help

By default, Cargo will build fido-key-manager with the nfc and usb features. Additional features are described in Cargo.toml and in the remainder of this document.


Most fido-key-manager commands (except info and factory-reset) will operate on the first compatible authenticator which:

  • is in a connected NFC reader's field
  • you press the button on an already-connected device
  • is connected while fido-key-manager is running

This should fairly reliably mitigate accidental or unintentional selection, but it's a good idea to have only one authenticator connected to your computer when running fido-key-manager.

More information about the commands listed below can be seen by running fido-key-manager --help or fido-key-manager [command] --help. Unless otherwise specified below, all commands require an authenticator which supports at least CTAP 2.0.

Command Description Requirements
info get information about connected authenticators
selection request user presence on a connected authenticator
set-pin sets a PIN on an authenticator which doesn't already have a PIN set
change-pin changes a PIN on an authenticator which has a PIN set
factory-reset resets an authenticator to factory defaults, deleting all key material
enable-enterprise-attestation enables the Enterprise Attestation feature CTAP 2.1
set-pin-policy set a Minimum PIN Length policy, or force a PIN change before next use CTAP 2.1
toggle-always-uv toggles the Always Require User Verification feature CTAP 2.1
bio-info shows information about an authenticator's fingerprint sensor CTAP 2.1-PRE, fingerprint sensor
list-fingerprints lists enrolled fingerprints CTAP 2.1-PRE, fingerprint sensor
enroll-fingerprint enroll a new fingerprint CTAP 2.1-PRE, fingerprint sensor
rename-fingerprint renames an enrolled fingerprint CTAP 2.1-PRE, fingerprint sensor
remove-fingerprint removes an enrolled fingerprint CTAP 2.1-PRE, fingerprint sensor
get-credential-metadata gets discoverable credential storage metadata CTAP 2.1-PRE, credential management
list-credentials lists discoverable credentials CTAP 2.1-PRE, credential management
delete-credential deletes a discoverable credential CTAP 2.1-PRE, credential management
update-credential-user updates user information for a discoverable credential CTAP 2.1, credential management

Vendor-specific commands

Warning: for safety, ensure that you only have security key(s) from that vendor connected to your computer when using any vendor-specific command, even benign ones.

In the CTAP 2 protocol, vendor-specific command IDs can (and do!) have different meanings on different vendors – one vendor may use a certain ID as a safe operation (such as "get info"), but another vendor might use the same ID to start firmware updates, change the key's operating mode or perform some potentially-destructive operation.

For operations that require multiple commands be sent to a security key, this tool will attempt to stop early if a key reports that it does not support one of the commands, or returns an unexpected value.

SoloKey 2 / Trussed

Tip: this functionality is only available when fido-key-manager is built with --features solokey.

SoloKey 2 / Trussed commands are currently only supported over USB HID. NFC support may be added in future, but we have encountered many problems communicating with SoloKey and Trussed devices at all over NFC, which has made things difficult.

Command Description
solo-key-info get all connected SoloKeys' unique ID, firmware version and secure boot status
solo-key-random get some random bytes from a SoloKey


Tip: this functionality is only available when fido-key-manager is built with --features yubikey.

This only supports YubiKey 5 series and Security Key by Yubico devices via USB HID with the CTAP 2.0 interface (FIDO2) enabled. NFC support may be added in future.

YubiKey 4 and earlier support is not planned - they do not support CTAP 2.0, they use a different config format and protocol, and some firmware versions report bogus data.

Command Description
yubikey-get-config gets a connected YubiKey's device info, firmware version and interface configuration

Platform-specific notes

Bluetooth is currently disabled by default, as it's not particularly reliable on anything but macOS, and can easily accidentally select nearby devices. It can be enabled with --features bluetooth.


  • Bluetooth support isn't particularly reliable, and may require pairing in advance of using this tool.

  • NFC support requires PC/SC Lite, and a PC/SC initiator (driver) for your NFC transceiver (reader).

    If you're using a transceiver with an NXP PN53x-series chipset (eg: ACS ACR122, Sony PaSoRi), you will need to block the pn533 and pn533_usb kernel modules (which are incompatible all other NFC software) from loading:

    echo "blacklist pn533" | sudo tee -a /etc/modprobe.d/nfc.conf
    echo "blacklist pn533_usb" | sudo tee -a /etc/modprobe.d/nfc.conf
    sudo modprobe -r pn533
    sudo modprobe -r pn533_usb

    One of those modprobe -r commands will fail, depending on your kernel version.

    Finally, unplug and replug the transceiver.

    If issues return after you've rebooted your computer, you may also need to rebuild your initrd to pick up the blacklist entries above, and then reboot again.

  • USB support requires libudev and appropriate permissions.

    systemd (udev) v252 and later automatically tag USB HID FIDO tokens and set permissions based on the 0xf1d0 usage page, which should work with any FIDO-compliant authenticator.

    Systems with older versions of systemd will need a "U2F rules" package (eg: libu2f-udev). But these match FIDO authenticators using a list of known USB manufacturer and product IDs, which can be a problem for new or esoteric authenticators.


  • Bluetooth support works fairly reliably, but automatic pairing could allow a nearby malicious device could open your computer up to long-term tracking over Bluetooth.

    It is not possible to pair a Bluetooth authenticator using System Settings, and instead programs need to pair it for you (which webauthn-authenticator-rs will do for you). However, it will try to pair any nearby authenticator, and some authenticators will stay online for several minutes after use.

  • NFC should "just work", provided you've installed a PC/SC initiator (driver) for your transciever (if it is not supported by libccid).

    macOS tends to "butt in" on exclusive connections by selecting the PIV applet, which can cause issues for some keys' firmware, especially if they support PIV.

  • USB should "just work".


Important: This tool has only been tested with the current builds of Windows 10 and 11 on 64-bit platforms (arm64 and x86_64). This tool (intentionally) does not support older versions of Windows, and is untested on 32-bit systems (it's 2023, come on).

Windows 10 build 1903 and later (as well as Windows 11) block direct communication with FIDO authenticators (or otherwise hide the USB devices), so this tool must be run as Administrator.

This tool has been configured with a manifest to run as Administrator, which has some caveats:

  • cargo run will not be able to run this program
  • if elevation was necessary, it won't show the output of the tool in your current console window

Always run this tool from within a terminal running as Administrator.

You can disable the elevation manifest at build time with:

$Env:RUSTFLAGS="--cfg disable_windows_manifest"
cargo build --bin fido-key-manager

But the program may not be usable anymore.

As long as you're running fido-key-manager as Administrator:

  • Bluetooth support requires pairing in advance in Settings, and is not particularly reliable.

  • NFC support should "just work", provided your transceiver supports the PC/SC API.

  • USB support should "just work".


~808K SLoC