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authorLadislav Zezula <ladislav.zezula@avg.com>2013-01-11 14:55:08 +0100
committerLadislav Zezula <ladislav.zezula@avg.com>2013-01-11 14:55:08 +0100
commit3a926f0228c68d7d91cf3946624d7859976440ec (patch)
treec4e7d36dc8157576929988cdfcf5bfd8262cd09c /src/libtommath/bn_mp_invmod.c
parentdf4b0c085478389c9a21a09521d46735a0109c8a (diff)
Initial creation
Diffstat (limited to 'src/libtommath/bn_mp_invmod.c')
-rw-r--r--src/libtommath/bn_mp_invmod.c43
1 files changed, 43 insertions, 0 deletions
diff --git a/src/libtommath/bn_mp_invmod.c b/src/libtommath/bn_mp_invmod.c
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+++ b/src/libtommath/bn_mp_invmod.c
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+#include "tommath.h"
+#ifdef BN_MP_INVMOD_C
+/* LibTomMath, multiple-precision integer library -- Tom St Denis
+ *
+ * LibTomMath is a library that provides multiple-precision
+ * integer arithmetic as well as number theoretic functionality.
+ *
+ * The library was designed directly after the MPI library by
+ * Michael Fromberger but has been written from scratch with
+ * additional optimizations in place.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ *
+ * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
+ */
+
+/* hac 14.61, pp608 */
+int mp_invmod (mp_int * a, mp_int * b, mp_int * c)
+{
+ /* b cannot be negative */
+ if (b->sign == MP_NEG || mp_iszero(b) == 1) {
+ return MP_VAL;
+ }
+
+#ifdef BN_FAST_MP_INVMOD_C
+ /* if the modulus is odd we can use a faster routine instead */
+ if (mp_isodd (b) == 1) {
+ return fast_mp_invmod (a, b, c);
+ }
+#endif
+
+#ifdef BN_MP_INVMOD_SLOW_C
+ return mp_invmod_slow(a, b, c);
+#endif
+
+ return MP_VAL;
+}
+#endif
+
+/* $Source: /cvs/libtom/libtommath/bn_mp_invmod.c,v $ */
+/* $Revision: 1.4 $ */
+/* $Date: 2006/12/28 01:25:13 $ */