What are the recommended steps for securely regenerating session IDs and preserving essential session data in PHP applications?

Session fixation attacks can occur when an attacker sets a fixed session ID for a user, allowing them to hijack the session. To prevent this, it's recommended to regenerate session IDs after a user logs in or changes privilege levels. To securely regenerate session IDs while preserving essential session data, you can store the data in a temporary variable, regenerate the session ID, and then restore the essential data back into the new session. 

// Store essential session data in a variable
$essentialData = $_SESSION['essential_data'];

// Regenerate session ID
session_regenerate_id(true);

// Restore essential data back into the new session
$_SESSION['essential_data'] = $essentialData;

Keywords

session IDs session regeneration session data preservation PHP security session hijacking

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