This guide covers using both PIV smartcard and FIDO2 features of your Yubikey, SoloKey(v2), and Windows Hello for SSH authentication in a secure and portable manner. FIDO2 support works with YubiKey, SoloKey(v2), and Windows Hello(biometric:face, biometric:fingerprint, secure-element/pin) with OpenSSH as a relatively new feature which requires updated client and server versions. PIV support has been around with PKCS#11 for many years in the OpenSSH codebase, and is considered a more stable and ubiquitous solution when an applicable PKCS#11 library is available for your platform.
Example below assumes that you have a piv key already generated in a yubikey slot the way you want. If you need to generate a new one, read the excellent documentation here: https://developers.yubico.com/PIV/Guides/SSH_with_PIV_and_PKCS11.html and https://support.yubico.com/hc/en-us/articles/360021606180-Using-YubiKey-PIV-with-Windows-native-SSH-client
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