This module provides one function, equals (not exported by default).

You should pass this function two strings of the same length. It will
return true if they are string-wise identical and false otherwise, just
like eq. However, comparing any two differing strings will take a fixed
amount of time, unlike eq.

NOTE: If the lengths of the strings are different, equals will return
false right away.

Homepage:
https://metacpan.org/release/String-Compare-ConstantTime
