Re: avr-crypto-lib

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wt., 1 cze 2021 o 08:37 BERTRAND Jo=C3=ABl <[email protected]>
napisa=C5=82(a):

> RSA doesn't run as expected. With expopent=3D3 and length=3D512, program
> doesn't crash but after four hours (@ 16 MHz on simavr), gdb shows that
> program stays in RSA subroutines and doesn't return to main routine.
> Something is probably broken somewhere.
>

try to replace in the example above:
  /* add your fix here */
with:
  bigint_adjust(&data);
  bigint_adjust(&public->exponent);
  bigint_adjust(&public->modulus);

The computation takes 4 seconds on my laptop.
Note that the "I" value changes (from I=3D0.. to):
   BIGINT: 0x40f5..
   L=3D14..
   I=3D6..

I've tried to find a "HOWTO use avr-crypto-lib" documentation,
but I couldn't find any, which is a little worrying (maybe I didn't try
hard enough).
If there is no documentation reading the source code and test code is an
option.



>
> I have found a uECC library but I don't understand how use this library
> to encrypt data (I think I have understand how I can sign data).
>
> Best regards,
>
> JB
>

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<div dir=3D"ltr"><div dir=3D"ltr"><br></div><br><div class=3D"gmail_quote">=
<div dir=3D"ltr" class=3D"gmail_attr">wt., 1 cze 2021 o 08:37=C2=A0BERTRAND=
 Jo=C3=ABl &lt;<a href=3D"mailto:[email protected]">joel.bertrand@s=
ystella.fr</a>&gt; napisa=C5=82(a):<br></div><blockquote class=3D"gmail_quo=
te" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204=
);padding-left:1ex">RSA doesn&#39;t run as expected. With expopent=3D3 and =
length=3D512, program<br>
doesn&#39;t crash but after four hours (@ 16 MHz on simavr), gdb shows that=
<br>
program stays in RSA subroutines and doesn&#39;t return to main routine.<br=
>
Something is probably broken somewhere.<br></blockquote><div><br></div><div=
>try to replace in the example above:<br>=C2=A0 /* add your fix here */<br>=
</div><div>with:<br>=C2=A0 bigint_adjust(&amp;data);<br>=C2=A0 bigint_adjus=
t(&amp;public-&gt;exponent);<br>=C2=A0 bigint_adjust(&amp;public-&gt;modulu=
s);<br></div><div><br>The computation takes 4 seconds on my laptop.<br>Note=
 that the &quot;I&quot;=C2=A0value changes (from I=3D0.. to):<br>=C2=A0 =C2=
=A0BIGINT: 0x40f5..<br>=C2=A0 =C2=A0L=3D14..<br>=C2=A0 =C2=A0I=3D6..<br><br=
>I&#39;ve tried to find a &quot;HOWTO use avr-crypto-lib&quot; documentatio=
n,<br>but I couldn&#39;t find any,=C2=A0which is a little worrying (maybe I=
 didn&#39;t try hard enough).<br>If there is no documentation reading the s=
ource code and test code is an option.<br><br></div><div>=C2=A0<br></div><b=
lockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-le=
ft:1px solid rgb(204,204,204);padding-left:1ex">
<br>
I have found a uECC library but I don&#39;t understand how use this library=
<br>
to encrypt data (I think I have understand how I can sign data).<br>
<br>
Best regards,<br>
<br>
JB<br>
</blockquote></div></div>

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