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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_neg.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_neg.c')
-rw-r--r--libtommath/bn_mp_neg.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/libtommath/bn_mp_neg.c b/libtommath/bn_mp_neg.c
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+++ b/libtommath/bn_mp_neg.c
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+#include <tommath.h>
+#ifdef BN_MP_NEG_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
+ */
+
+/* b = -a */
+int mp_neg (mp_int * a, mp_int * b)
+{
+ int res;
+ if (a != b) {
+ if ((res = mp_copy (a, b)) != MP_OKAY) {
+ return res;
+ }
+ }
+
+ if (mp_iszero(b) != MP_YES) {
+ b->sign = (a->sign == MP_ZPOS) ? MP_NEG : MP_ZPOS;
+ } else {
+ b->sign = MP_ZPOS;
+ }
+
+ return MP_OKAY;
+}
+#endif