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8608a8e64c
to branch 'au.asn.ucc.matt.dropbear' (head fff0894a0399405a9410ea1c6d118f342cf2aa64) --HG-- extra : convert_revision : fdf4a7a3b97ae5046139915de7e40399cceb2c01
40 lines
1001 B
C
40 lines
1001 B
C
#include <tommath.h>
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#ifdef BN_MP_INVMOD_C
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/* LibTomMath, multiple-precision integer library -- Tom St Denis
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*
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* LibTomMath is a library that provides multiple-precision
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* integer arithmetic as well as number theoretic functionality.
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*
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* The library was 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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/* hac 14.61, pp608 */
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int mp_invmod (mp_int * a, mp_int * b, mp_int * c)
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{
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/* b cannot be negative */
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if (b->sign == MP_NEG || mp_iszero(b) == 1) {
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return MP_VAL;
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}
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#ifdef BN_FAST_MP_INVMOD_C
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/* if the modulus is odd we can use a faster routine instead */
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if (mp_isodd (b) == 1) {
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return fast_mp_invmod (a, b, c);
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}
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#endif
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#ifdef BN_MP_INVMOD_SLOW_C
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return mp_invmod_slow(a, b, c);
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#endif
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return MP_VAL;
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}
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#endif
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