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Re: new long doubles option: gcc libquadmath

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From:
Jarkko Hietaniemi
Date:
September 21, 2014 12:39
Subject:
Re: new long doubles option: gcc libquadmath
Message ID:
541EC6F3.5080901@iki.fi
On Saturday-201409-20, 0:05, demerphq wrote:
>     I know you're being facetious, and crypto uses integer math so we're

Moi?  Facetious?  I don't even know that word.

>     not talking about leaking private key material, but as a general
>     principle, transporting garbage should be avoided.  It was bad when
>     Microsoft Word bumped a document file's logical EOF to match its
>     physical EOF (thus carrying around a partial block of who-knows-what
>     prior data, which very well could have included your credit card
>     number), and it's bad now. Any unused bits in the in-memory format
>     should be zeroed before transmission or storage.
>
>
> I agree. Sereal will zero the extra bytes. (Cant remember this second if
> that is going to be the next release, or the current one.)

As does Perl's pack/unpack code for long double.
... checking ...
Wait, I can see explicit zeroing only in the pack() case (search for
"unused bits" in pp_pack.c.  Will investigate whether the unpack()
does it somehow more sneakily.







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