Keychain helps you to manage ssh and GPG keys in a convenient and secure manner. It acts as a frontend to ssh-agent and ssh-add, but allows you to easily have one long running ssh-agent process per system, rather than the norm of one ssh-agent per login session.

This dramatically reduces the number of times you need to enter your passphrase. With keychain, you only need to enter a passphrase once every time your local machine is rebooted. Keychain also makes it easy for remote cron jobs to securely "hook in" to a long running ssh-agent process, allowing your scripts to take advantage of key-based logins.

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

Supports the FIDO U2F (CTAP 1) and FIDO 2.0 (CTAP 2) protocols.

Libu2f-host provide a C library and command-line tool that implements
the host-side of the U2F protocol. There are APIs to talk to a U2F
device and perform the U2F Register and U2F Authenticate operations.

This is a C library that implements the server-side of the U2F protocol. More precisely, it provides an API for generating the JSON blobs required by U2F devices to perform the U2F Registration and U2F Authentication operations, and functionality for verifying the cryptographic operations.

To integrate decryption and parsing of YubiKey One-Time Passcodes (OTP) into your own server environment, you can use our free software libraries written in C and Java. To be useful, these packages need to be combined with a database and server component. Note that most applications typically talk to a verification server using our client libraries.

The PAM U2F module provides an easy way to integrate the Yubikey (or other U2F-compliant authenticators) into your existing user authentication infrastructure. PAM is used by GNU/Linux, Solaris and Mac OS X for user authentication.

This module allows you to use the Yubikey device to authenticate to the PAM system

This project implements online validation of Yubikey OTPs. It is written in C and provides a shared library for use by other software.

Yubico's YubiKey can be re-programmed. This project's purpose is to provide a reference implementation for configuration of YubiKey's.

This is a command line tool to interact with the PIV applet on a YubiKey NEO. Among other functions it supports, generating keys on device, importing keys and certificates and creating certificate requests.

The YubiKey NEO supports the Privilege and Identification Card (PIV) interface specified in NIST SP 800-73 document "Cryptographic Algorithms and Key Sizes for PIV". This enables you to perform RSA or ECC sign/decrypt operations using a private key stored on the smartcard, through common interfaces like PKCS#11.

Python 3 library and command line tool for configuring a YubiKey.

YubiKey Manager (ykman) is a command line tool for configuring a YubiKey over
all transports. It is capable of reading out device information as well as
configuring several aspects of a YubiKey, including enabling or disabling
connection transports an programming various types of credentials.

The YubiKey Personalization Tool is a Qt based Cross-Platform utility
designed to facilitate re-configuration of YubiKeys on Windows, Linux
and MAC platforms. The tool provides a same simple step-by-step
approach to make configuration of YubiKeys easy to follow and
understand, while still being powerful enough to exploit all
functionality both of the YubiKey 1 and YubiKey 2 generation of
keys. The tool provides the same functionality and user interface on
Windows, Linux and MAC platforms.

The Cross-Platform YubiKey Personalization Tool provides the following
main functions:

* Programming the YubiKey in "Yubico OTP" mode
* Programming the YubiKey in "OATH-HOTP" mode
* Programming the YubiKey in "Static Password" mode
* Programming the YubiKey in "Challenge-Response" mode
* Programming the NDEF feature of the YubiKey NEO
* Testing the challenge-response functionality of a YubiKey
* Deleting the configuration of a YubiKey
* Checking type and firmware version of the YubiKey

The Yubico Authenticator is a graphical desktop tool for generating Open AuTHentication (OATH) event-based HOTP and time-based TOTP one-time password codes, with the help of a Yubikey NEO that protects the shared secrets.