README.adoc

April 15, 2026 · View on GitHub

== libfido2

image:https://github.com/yubico/libfido2/workflows/linux/badge.svg["Linux Build Status (github actions)", link="https://github.com/Yubico/libfido2/actions"] image:https://github.com/yubico/libfido2/workflows/macos/badge.svg["macOS Build Status (github actions)", link="https://github.com/Yubico/libfido2/actions"] image:https://github.com/yubico/libfido2/workflows/windows/badge.svg["Windows Build Status (github actions)", link="https://github.com/Yubico/libfido2/actions"] image:https://github.com/yubico/libfido2/workflows/fuzzer/badge.svg["Fuzz Status (github actions)", link="https://github.com/Yubico/libfido2/actions"] image:https://oss-fuzz-build-logs.storage.googleapis.com/badges/libfido2.svg["Fuzz Status (oss-fuzz)", link="https://bugs.chromium.org/p/oss-fuzz/issues/list?sort=-opened&can=1&q=proj:libfido2"]

libfido2 provides library functionality and command-line tools to communicate with a FIDO device over USB or NFC, and to verify attestation and assertion signatures.

libfido2 supports the FIDO U2F (CTAP 1) and FIDO2 (CTAP 2) protocols.

For usage, see the examples/ directory.

=== License

libfido2 is licensed under the BSD 2-clause license. See the LICENSE file for the full license text.

=== Supported Platforms

libfido2 is known to work on Linux, macOS, Windows, OpenBSD, and FreeBSD.

=== Documentation

Documentation is available in troff and HTML formats. An https://developers.yubico.com/libfido2/Manuals/[online mirror of libfido2's documentation] is also available.

=== Bindings

=== Releases

The current release of libfido2 is 1.17.0. Signed release tarballs are available at Yubico's https://developers.yubico.com/libfido2/Releases[release page].

=== Dependencies

libfido2 depends on https://github.com/pjk/libcbor[libcbor], https://www.openssl.org[OpenSSL] 3.0 or newer, and https://zlib.net[zlib]. On Linux, libudev (part of https://www.freedesktop.org/wiki/Software/systemd[systemd]) is also required.

=== Installation

==== Fedora 34 and later

$ sudo dnf install libfido2 libfido2-devel fido2-tools

==== Ubuntu 20.04 (Focal) and later

$ sudo apt install libfido2-1 libfido2-dev libfido2-doc fido2-tools

Alternatively, newer versions of libfido2 are available in Yubico's PPA. Follow the instructions for Ubuntu 18.04 (Bionic) below.

==== Ubuntu 18.04 (Bionic)

$sudo apt install software-properties-common$ sudo apt-add-repository ppa:yubico/stable $sudo apt update$ sudo apt install libfido2-1 libfido2-dev libfido2-doc fido2-tools

On Linux, you may need to add a udev rule to be able to access the FIDO device. For example, the udev rule may contain the following:

#udev rule for allowing HID access to Yubico devices for FIDO support.

KERNEL=="hidraw*", SUBSYSTEM=="hidraw",
MODE="0664", GROUP="plugdev", ATTRS{idVendor}=="1050"

==== macOS

$ brew install libfido2

==== Windows

Please consult Yubico's https://developers.yubico.com/libfido2/Releases[release page] for ARM, ARM64, Win32, and Win64 artefacts.

Safe usage of our libraries assumes that the artefacts are unpacked in a trusted, non-writable directory with DLLs alongside the executable. Please refer to Microsoft's official documentation for general guidance on DLL deployment and safe packaging techniques. Note that our dynamically linked artefacts are built with /MD and may require the corresponding Visual C++ runtime to be present.

=== Building from source

On UNIX-like systems:

$cmake -B build$ make -C build $ sudo make -C build install

Depending on the platform, https://www.freedesktop.org/wiki/Software/pkg-config/[pkg-config] may need to be installed, or the PKG_CONFIG_PATH environment variable set. For complete, OS-specific build instructions, please refer to the .actions/ (Linux, macOS, BSD) and windows/ directories.

=== Build-time Customisation

libfido2 supports a number of CMake options. Some of the options require additional dependencies. Options that are disabled by default are not officially supported.

The USE_HIDAPI option requires https://github.com/libusb/hidapi[hidapi]. The USE_PCSC option requires https://github.com/LudovicRousseau/PCSC[pcsc-lite] on Linux.

=== Development

Please use https://github.com/Yubico/libfido2/discussions[GitHub Discussions] to ask questions and suggest features, and https://github.com/Yubico/libfido2/pulls[GitHub pull-requests] for code contributions.

=== Reporting bugs

Please use https://github.com/Yubico/libfido2/issues[GitHub Issues] to report bugs. To report security issues, please contact security@yubico.com. A PGP public key can be found at https://www.yubico.com/support/security-advisories/issue-rating-system/.

KERNEL=="hidraw*", SUBSYSTEM=="hidraw", MODE="0664", GROUP="plugdev", ATTRS{idVendor}=="1050"

KERNEL=="hidraw*", SUBSYSTEM=="hidraw",
MODE="0664", GROUP="plugdev", ATTRS{idVendor}=="1050"