Deprecation: #95395 - GeneralUtility::isAllowedHostHeaderValue() and TRUSTED_HOSTS_PATTERN constants 

Description 

The PHP method \TYPO3\CMS\Core\Utility\GeneralUtility::isAllowedHostHeaderValue() and the PHP constants \TYPO3\CMS\Core\Utility\GeneralUtility::ENV_TRUSTED_HOSTS_PATTERN_ALLOW_ALL and \TYPO3\CMS\Core\Utility\GeneralUtility::ENV_TRUSTED_HOSTS_PATTERN_SERVER_NAME have been deprecated.

Impact 

A deprecation will be logged in TYPO3 v11 if \TYPO3\CMS\Core\Utility\GeneralUtility::isAllowedHostHeaderValue() is used. It is unlikely for extensions to have used this as the host header is checked for every frontend and backend request anyway.

Usage of the constants will cause a PHP error "Undefined class constant" in TYPO3 v12, the method \TYPO3\CMS\Core\Utility\GeneralUtility::isAllowedHostHeaderValue() will be dropped without replacement.

Affected Installations 

Installations using the constants instead of static strings or that call the method explicitly – which is unlikely.

Migration 

Use '.*' instead of \TYPO3\CMS\Core\Utility\GeneralUtility::ENV_TRUSTED_HOSTS_PATTERN_ALLOW_ALL and 'SERVER_NAME' instead of \TYPO3\CMS\Core\Utility\GeneralUtility::ENV_TRUSTED_HOSTS_PATTERN_SERVER_NAME .

Don't use \TYPO3\CMS\Core\Utility\GeneralUtility::isAllowedHostHeaderValue() .