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authorMatt Johnston <matt@ucc.asn.au>2006-03-08 13:23:49 +0000
committerMatt Johnston <matt@ucc.asn.au>2006-03-08 13:23:49 +0000
commit8608a8e64c1aeda096867f43f89e29e1aee207ae (patch)
tree453ebf8873dd287a2def6a674d42afcc6637cde2 /libtommath/bn_mp_mod.c
parent2481693cf23dba90c693762a528d2923cde9c9cc (diff)
parent882a9ced901348b3a48023443bfd23e0ef9d9b67 (diff)
propagate from branch 'au.asn.ucc.matt.ltm.dropbear' (head 6c790cad5a7fa866ad062cb3a0c279f7ba788583)
to branch 'au.asn.ucc.matt.dropbear' (head fff0894a0399405a9410ea1c6d118f342cf2aa64) --HG-- extra : convert_revision : fdf4a7a3b97ae5046139915de7e40399cceb2c01
Diffstat (limited to 'libtommath/bn_mp_mod.c')
-rw-r--r--libtommath/bn_mp_mod.c44
1 files changed, 44 insertions, 0 deletions
diff --git a/libtommath/bn_mp_mod.c b/libtommath/bn_mp_mod.c
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+++ b/libtommath/bn_mp_mod.c
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+#include <tommath.h>
+#ifdef BN_MP_MOD_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@iahu.ca, http://math.libtomcrypt.org
+ */
+
+/* c = a mod b, 0 <= c < b */
+int
+mp_mod (mp_int * a, mp_int * b, mp_int * c)
+{
+ mp_int t;
+ int res;
+
+ if ((res = mp_init (&t)) != MP_OKAY) {
+ return res;
+ }
+
+ if ((res = mp_div (a, b, NULL, &t)) != MP_OKAY) {
+ mp_clear (&t);
+ return res;
+ }
+
+ if (t.sign != b->sign) {
+ res = mp_add (b, &t, c);
+ } else {
+ res = MP_OKAY;
+ mp_exch (&t, c);
+ }
+
+ mp_clear (&t);
+ return res;
+}
+#endif