From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=unavailable autolearn_force=no version=3.4.4 X-Received: by 10.66.157.41 with SMTP id wj9mr14050431pab.26.1408965693421; Mon, 25 Aug 2014 04:21:33 -0700 (PDT) X-Received: by 10.140.96.228 with SMTP id k91mr16872qge.23.1408965693365; Mon, 25 Aug 2014 04:21:33 -0700 (PDT) Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!news.eternal-september.org!news.eternal-september.org!feeder.eternal-september.org!news.glorb.com!r2no6848565igi.0!news-out.google.com!j6ni8038qas.0!nntp.google.com!m5no2702183qaj.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Mon, 25 Aug 2014 04:21:33 -0700 (PDT) Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=5.81.69.184; posting-account=j15vhwoAAABH_eywb4s2_dWxAM2kkx7W NNTP-Posting-Host: 5.81.69.184 User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: <9c5de333-276c-4e3a-be5a-4e5a98cdaa1d@googlegroups.com> Subject: Integer Overflow Question. From: austin.obyrne769@btinternet.com Injection-Date: Mon, 25 Aug 2014 11:21:33 +0000 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Xref: news.eternal-september.org comp.lang.ada:21896 Date: 2014-08-25T04:21:33-07:00 List-Id: I have written two Ada driven ciphers that are complete and have been tweak= ed for the last time. I have used an early Ada compiler - a Gnat311.p - of about 1995 vintage <= =3D Ada-95. In order that the ciphers can run in 32-bit computers which are still going= to be around for some time despite the availability of the 64-bit operatin= g system in Windows 8.1 which I also use, I have had to put a bound on the = maximum integer size output of computations at 2^31 which of course is the = maximum positive integer that 32-bit computers can handle. Running the same software that was written for 32-bit computers in the 64-= bit environment of 8.1 and raising the bar on integer size I thought I shou= ld be able to do this ok but no - the cipher will still crash if the intege= r size is greater than 2^31 when I thought I could go up to 2^63. As it happens this is not a problem crypto wise because the cipher is indep= endent of the integer size but I am intrigued that this overflow should sti= ll happen. I am coming to the conclusion that the max integer size than can be used wi= thout integer overflow occurring in any computer is a function of the Ada c= ompiler being used and not the computer operating system??? Could anybody throw some light on this conjecture? Thanking you in anticipation of your usual help, adacrypt