Groups > comp.os.linux.misc > #81952

Re: For those arguing over languages...

From	"Carlos E. R." <robin_listas@es.invalid>
Newsgroups	comp.os.linux.misc
Subject	Re: For those arguing over languages...
Date	2026-02-11 23:24 +0100
Message-ID	<mv4dtrFbh74U1@mid.individual.net> (permalink)
References	<10mesjc$3gnr9$1@dont-email.me> <azKdnRQU0p54ZRb0nZ2dnZfqnPWdnZ2d@giganews.com> <10mij0u$rimo$1@dont-email.me>

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On 2026-02-11 19:50, Rich wrote:
> c186282 <c186282@nnada.net> wrote:
>> On 2/10/26 04:09, The Natural Philosopher wrote:
>>> ...more fuel on the fire...
>>>
>>> https://www.theregister.com/2026/02/09/compilers_undermine_encryption/
>>>
>>> GCC erases code whose delays obfuscates encryption delays because it
>>> doesn't do anything...
>>>
>>
>>    Very interesting ! How 'optimization' sometimes ISN'T.
> 
> Nope.  As Richard Kettlewell has pointed out, what the encryption code
> writers want is "constant time execution, regardless of inputs" which
> is not a promised output from gcc, no matter the optimization level
> chosen.
> 
> The compiler is "properly optimizing" given the meaning of
> "optimization" it uses ("make code run as fast as possible" or "make
> code as small as possible" -- with -Os).  But the compiler was not
> designed to create "constant time execution" code.  The writers were
> expecting a promise the compiler never promised.

In the example posted:

   The user types in a password, which gets checked against
   a database, character by character. Once the first character
   doesn't match, an error message is returned.

...the fault is not of the compiler, but of the programmer. He has to 
examine all characters even if he knows there is no point.


-- 
Cheers,
        Carlos E.R.

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For those arguing over languages... The Natural Philosopher <tnp@invalid.invalid> - 2026-02-10 09:09 +0000
  Re: For those arguing over languages... Richard Kettlewell <invalid@invalid.invalid> - 2026-02-10 13:11 +0000
  Re: For those arguing over languages... Farley Flud <ff@linux.rocks> - 2026-02-10 14:08 +0000
    Re: For those arguing over languages... Marc Haber <mh+usenetspam1118@zugschl.us> - 2026-02-10 15:16 +0100
      Re: For those arguing over languages... Richard Kettlewell <invalid@invalid.invalid> - 2026-02-10 16:19 +0000
        Re: For those arguing over languages... Richard Kettlewell <invalid@invalid.invalid> - 2026-02-10 18:20 +0000
      Re: For those arguing over languages... Chris Ahlstrom <OFeem1987@teleworm.us> - 2026-02-10 11:22 -0500
      Re: For those arguing over languages... John  <john@panix.com> - 2026-02-17 16:23 +0000
        Re: For those arguing over languages... Rich <rich@example.invalid> - 2026-02-19 19:26 +0000
          Re: For those arguing over languages... Richard Kettlewell <invalid@invalid.invalid> - 2026-02-22 09:28 +0000
    Re: For those arguing over languages... John Ames <commodorejohn@gmail.com> - 2026-02-10 08:24 -0800
      Re: For those arguing over languages... Richard Kettlewell <invalid@invalid.invalid> - 2026-02-10 18:16 +0000
  Re: For those arguing over languages... c186282 <c186282@nnada.net> - 2026-02-10 22:34 -0500
    Re: For those arguing over languages... Rich <rich@example.invalid> - 2026-02-11 18:50 +0000
      Re: For those arguing over languages... The Natural Philosopher <tnp@invalid.invalid> - 2026-02-11 19:28 +0000
        Re: For those arguing over languages... Rich <rich@example.invalid> - 2026-02-11 21:27 +0000
          Re: For those arguing over languages... Richard Kettlewell <invalid@invalid.invalid> - 2026-02-12 09:48 +0000
            Re: For those arguing over languages... c186282 <c186282@nnada.net> - 2026-02-12 20:48 -0500
      Re: For those arguing over languages... Chris Ahlstrom <OFeem1987@teleworm.us> - 2026-02-11 16:24 -0500
        Re: For those arguing over languages... Rich <rich@example.invalid> - 2026-02-11 22:45 +0000
          Re: For those arguing over languages... The Natural Philosopher <tnp@invalid.invalid> - 2026-02-12 12:42 +0000
      Re: For those arguing over languages... "Carlos E. R." <robin_listas@es.invalid> - 2026-02-11 23:24 +0100
        Re: For those arguing over languages... Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-02-11 22:48 +0000
        Re: For those arguing over languages... Rich <rich@example.invalid> - 2026-02-11 22:49 +0000
        Re: For those arguing over languages... Richard Kettlewell <invalid@invalid.invalid> - 2026-02-12 09:55 +0000
          Re: For those arguing over languages... "Carlos E. R." <robin_listas@es.invalid> - 2026-02-12 11:49 +0100
          Re: For those arguing over languages... c186282 <c186282@nnada.net> - 2026-02-12 20:54 -0500
            Re: For those arguing over languages... Rich <rich@example.invalid> - 2026-02-13 03:20 +0000
              Re: For those arguing over languages... c186282 <c186282@nnada.net> - 2026-02-12 23:44 -0500
        Re: For those arguing over languages... The Natural Philosopher <tnp@invalid.invalid> - 2026-02-12 12:38 +0000
          Re: For those arguing over languages... "Carlos E. R." <robin_listas@es.invalid> - 2026-02-12 15:14 +0100
            Re: For those arguing over languages... Rich <rich@example.invalid> - 2026-02-12 17:23 +0000
              Re: For those arguing over languages... "Carlos E. R." <robin_listas@es.invalid> - 2026-02-12 19:52 +0100
                Re: For those arguing over languages... The Natural Philosopher <tnp@invalid.invalid> - 2026-02-13 10:11 +0000
                Re: For those arguing over languages... Richard Kettlewell <invalid@invalid.invalid> - 2026-02-13 10:20 +0000
            Re: For those arguing over languages... The Natural Philosopher <tnp@invalid.invalid> - 2026-02-13 10:10 +0000
              Re: For those arguing over languages... c186282 <c186282@nnada.net> - 2026-02-13 19:57 -0500
          Re: For those arguing over languages... c186282 <c186282@nnada.net> - 2026-02-12 20:56 -0500

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