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Author SHA1 Message Date
Steffen Jaeckel
f5b5bc09fb Revert "Bugfix: clear the exceeding destination digits." 
This reverts commit 50f587c36f.
 2014-06-12 10:50:19 +02:00
Steffen Jaeckel
7d003805ad Revert "Regenerate sqr comba files with bugfix" 
This reverts commit ab4374299c.
 2014-06-12 10:50:03 +02:00
Steffen Jaeckel
bfa4582842 Merge pull request #2 from rasky/bugfix_sqr_destdigits 
Bugfix sqr destdigits, c.f. 50f587c36f for further explanation
 2011-09-21 03:31:20 -07:00
Giovanni Bajo
ab4374299c Regenerate sqr comba files with bugfix 2011-09-20 11:37:23 +02:00
Giovanni Bajo
782c6e52de Realign generators with existing files in repo. 2011-09-20 11:36:41 +02:00
Giovanni Bajo
8f059cd52f Add makefile for sqr generators 2011-09-20 11:35:51 +02:00
Giovanni Bajo
50f587c36f Bugfix: clear the exceeding destination digits. 
Currently, the fp_sqr_comba_* functions do not fully clear the destination
number, but only overwrites the digits they care about. Eg: if
you call a comba4, it will overwrite the first 8 digits and leave
the others unchanged.

On the other hand, fp_mul_comba_* functions do *not* check incoming
unused digits (relying on the guarantee that they must be zero),
so they will happily compute the wrong result if those digits
are not empty. Testcase for a 32-bit system:

   char buf[64];
   fp_int num, num2, d;

   memset(buf, 0xFF, sizeof(buf);
   fp_read_unsigned_bin(&num, buf);
   fp_set(&d, 1);

   fp_sqr_comba_3(&d, &num);
   // now num is { 0x1, 0x0, 0x0, 0x0, 0x0, 0x0,
   //              0xFFFFFFFF, 0xFFFFFFFF ... }
   // only first 6 digits have been written, but even
   // if num.used is correctly set to 6, this can trigger
   // bugs.

   // Create a number larger than 6 digits
   fp_2expt(&num2, 8*32+4);

   fp_mul_comba_8(&num, &num2, &num2);
   // wrong result has been computed, because the first 8
   // digits of num have been read and multiplied
   // even if num->used == 6, relying on the fact that
   // they should be zero.
 2011-09-20 11:02:53 +02:00
Steffen Jaeckel
da5fa59f2c fixed bug in testcase reported by martins.mozeiko@gmail.com 2011-03-27 19:57:48 +02:00
Steffen Jaeckel
1e90accef6 added testcase of problem reported by martins.mozeiko@gmail.com 2011-03-27 19:34:36 +02:00
Steffen Jaeckel
eb5075e7fc added typecast in fp_read_radix() to suppress compiler warning 2011-03-27 19:33:53 +02:00
Steffen Jaeckel
f340961df9 added gitignore 2011-03-27 19:33:13 +02:00
Steffen Jaeckel
a1ac91d15e after multiple objections of libtom users [1], we decided to change licensing 
to a dual licensing model.

[1] https://groups.google.com/group/libtom/browse_thread/thread/d7b67bc6410250b3
 2011-01-19 10:28:48 +01:00
Steffen Jaeckel
6efcb2e5e0 Re-licensed all code under WTFPL, c.f. http://sam.zoy.org/wtfpl/ 2010-10-26 16:02:37 +02:00
Patrick Oppenlander
cfb7c1e52e fix register constraints in fp_montgomery_reduce 2010-07-22 10:29:12 +02:00
Tom St Denis
da88c2d42f added tomsfastmath-0.12 2010-07-22 10:06:30 +02:00
Tom St Denis
ea10e969b2 added tomsfastmath-0.10 2010-07-22 10:06:29 +02:00
Tom St Denis
4b439169aa added tomsfastmath-0.09 2010-07-22 10:06:28 +02:00
Tom St Denis
f99cdec6b0 added tomsfastmath-0.08 2010-07-22 10:06:27 +02:00
Tom St Denis
9ce1fe4656 added tomsfastmath-0.07 2010-07-22 10:06:26 +02:00
Tom St Denis
091b337fe8 added tomsfastmath-0.06 2010-07-22 10:06:25 +02:00
Tom St Denis
a6c4c5a261 added tomsfastmath-0.05 2010-07-22 10:06:25 +02:00
Tom St Denis
f91cf2d1cf added tomsfastmath-0.04 2010-07-22 10:06:24 +02:00
Tom St Denis
ca551d4c5e added tomsfastmath-0.03 2010-07-22 10:06:23 +02:00
Tom St Denis
6bb413fd72 added tomsfastmath-0.02 2010-07-22 10:06:22 +02:00
Tom St Denis
5e92ed2a59 added tomsfastmath-0.01 2010-07-22 10:06:21 +02:00