Re: TEA found the problem

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Article #5041

#5041

From: Skybuck Flying
Date: Tue, 27 Aug 2002 02:04

54 lines
2909 bytes

I found the problem:


 y = y + ((z << 4) ^ (z >> 5)) + z ^ (_sum + k[ _sum & 3 ]);


It's with this piece:

z ^ _sum + k[ _sum & 3 ];

Visual c interprets it as:

z ^ (_sum + k[ _sum & 3 ]);

Go figure...


<disastry@saiknes.lv.NO.SPaM.NET> wrote in message
news:3D69F6F6.E43591E6@saiknes.lv.NO.SPaM.NET...
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: RIPEMD160
>
> skybuck wrote:
> > The problems are probably with these lines of code:
> >
> > c version:
> >
> > y += (z<<4)+a ^ z+sum ^ (z>>5)+b;
> > z += (y<<4)+c ^ y+sum ^ (y>>5)+d;
> >
> > pascal version:
> >
> > y := y + (z shl 4) + a xor z + _sum xor (z shr 5) + b;
> > z := z + (y shl 4) + c xor y + _sum xor (y shr 5) + d;
>
> 1) try:
>   y := y + ((z shl 4) + a xor z + _sum xor (z shr 5) + b);
> or even
>   y := y + (((z shl 4) + a) xor (z + _sum) xor ((z shr 5) + b));
>
> 2) better use XTEA (aka (TEAN)
>
> __
> Disastry  http://disastry.dhs.org/
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From: "Skybuck Flying" <skybuck2000@hotmail.com>
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Subject: Re: TEA found the problem
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