Description:
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I would like to propose a solution that will allow to test whether $_SERVER (or similar ) predefined variables have been changed since PHP initialized them.

string predefinedVarHash(string predefinedVar)

PHP at runtime, after variables have been initialized/loaded, would store the serialized hash of the predefined variable that could be later retrieved by the above function.











Reproduce code:
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e.g.

<?php

$md5Hash = predefinedVarHash("SERVER");

if ($md5Hash !== md5(serialize($_SERVER)))
   die('$_SERVER changed');
else
   echo '$_SERVER has not been changed';
?>

Expected result:
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This would allow us to validate the information stored in the variable, while still allowing us to legitimately change the value of $_SERVER or other predefind variables.