The current external library in libextinc/ is horribly dated and most importantly unmaintained by Yubico.. Yubico did release a 2.6 version recently, but it's still not namespaced, not composer-installable and issues/PR's for that are open for many years..
The best replacement seems to be https://github.com/enygma/yubikey
History: https://github.com/simplesamlphp/simplesamlphp/issues/36 https://code.google.com/archive/p/simplesamlphp/issues/479
The current external library in
libextinc/
is horribly dated and most importantly unmaintained by Yubico.. Yubico did release a 2.6 version recently, but it's still not namespaced, not composer-installable and issues/PR's for that are open for many years.. The best replacement seems to be https://github.com/enygma/yubikey