Changes 

A list of all changes can be found on GitHub https://github.com/derhansen/sf_yubikey/

Version 1.0.0 

YubiKey OTP validation is only handled through the bundled class YubikeyAuth. The usage of PEAR classes has been removed.

Version 4.0.0 

The YubiKey validation is performed using the class YubikeyService which uses psr/http-client and psr/http-factory for requests. The disableSslVerification setting has been removed, since this can be configured global in TYPO3 HTTP client settings.

The extension setting yubikeyApiUrl has been renamed to yubikeyApiUrls. Users must adapt this setting manually if configured.