30 lines
882 B
C
30 lines
882 B
C
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/* LibTomMath, multiple-precision integer library -- Tom St Denis
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*
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* LibTomMath is library that provides for multiple-precision
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* integer arithmetic as well as number theoretic functionality.
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*
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* The library is designed directly after the MPI library by
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* Michael Fromberger but has been written from scratch with
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* additional optimizations in place.
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*
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* The library is free for all purposes without any express
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* guarantee it works.
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*
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* Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org
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*/
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#include <tommath.h>
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/* pre-calculate the value required for Barrett reduction
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* For a given modulus "b" it calulates the value required in "a"
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*/
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int
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mp_reduce_setup (mp_int * a, mp_int * b)
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{
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int res;
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if ((res = mp_2expt (a, b->used * 2 * DIGIT_BIT)) != MP_OKAY) {
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return res;
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}
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return mp_div (a, b, a, NULL);
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}
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