Re: MD5 Function in Ada

[jerry@jvdsys.nextjk.stuyts.nl (Jerry van Dijk)]

Jon, long time since C_ECHO :-)

In article <Pine.LNX.3.91.970604091908.3334A-100000@weck.bro jguthrie@brokersys.com writes:

>That's okay.  I actually expected someone to suggest linking in a C source
>file.  As a matter of fact, I have two different MD5 implementations in C
>source (and I could type in the one in APPLIED CRYPTOGRAPHY if I wanted a
>third.) I just don't want to have to figure out how to call C code from
>Ada in order to implement this.

Actually, using GNAT, this doesn't take much figuring out:

   /* interface to 'int do_something(int input) */
   function Do_Something (Input : in Integer) return Integer;
   pragma Import (C, Do_Something, "do_something);

as in GNAT there's a direct correspondence between the Ada and C type's.

If you do not want to rely on this, standard Ada95 with support for
Annex B (Interface to other languages), has the package Interfaces.C
defining them portably (and also have Interfaces.C.Strings and
Interfaces.C.Pointers).

--

-- Jerry van Dijk       | Leiden, Holland
-- Consultant           | Team Ada
-- Ordina Finance       | jdijk@acm.org