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-- This file is part of 'Finite Field Arithmetic', aka 'FFA'.               --
--                                                                          --
-- (C) 2018 Stanislav Datskovskiy ( www.loper-os.org )                      --
-- http://wot.deedbot.org/17215D118B7239507FAFED98B98228A001ABFFC7.html     --
--                                                                          --
-- You do not have, nor can you ever acquire the right to use, copy or      --
-- distribute this software ; Should you use this software for any purpose, --
-- or copy and distribute it to anyone or in any manner, you are breaking   --
-- the laws of whatever soi-disant jurisdiction, and you promise to         --
-- continue doing so for the indefinite future. In any case, please         --
-- always : read and understand any software ; verify any PGP signatures    --
-- that you use - for any purpose.                                          --
--                                                                          --
-- See also http://trilema.com/2015/a-new-software-licensing-paradigm .     --
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with FZ_Type; use FZ_Type;


package FZ_ModEx is
   
   pragma Pure;
   
   -- (Conventional) Modular Multiply: Product := X*Y mod Modulus
   procedure FZ_Mod_Mul(X        : in  FZ;
                        Y        : in  FZ;
                        Modulus  : in  FZ;
                        Product  : out FZ)
     with Pre => X'Length = Y'Length and
     Modulus'Length = X'Length and
     Product'Length = Modulus'Length;
   
   -- (Conventional) Modular Squaring: Product := X*X mod Modulus
   procedure FZ_Mod_Sqr(X        : in  FZ;
                        Modulus  : in  FZ;
                        Product  : out FZ)
     with Pre => Modulus'Length = X'Length and
     Product'Length = Modulus'Length;
   
   -- (Barrettronic) Modular Exponent: Result := Base^Exponent mod Modulus
   procedure FZ_Mod_Exp(Base     : in  FZ;
                        Exponent : in  FZ;
                        Modulus  : in  FZ;
                        Result   : out FZ) with
     Pre => Base'Length = Exponent'Length and
     Base'Length = Result'Length and
     Base'Length = Modulus'Length;
   
end FZ_ModEx;