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authorMatt Johnston <matt@ucc.asn.au>2006-03-21 16:20:59 +0000
committerMatt Johnston <matt@ucc.asn.au>2006-03-21 16:20:59 +0000
commitf7caf6f5c640cb1756c01184898f176438a3a0c2 (patch)
tree4d32de11b18d5f6296207961b5f25d0949af80c0 /libtommath/bn_mp_reduce_is_2k_l.c
parente444f0cfe67c71d3f38854f27cefae9aea6c4cd9 (diff)
parent3f49fc5f2ca0ec4adb5cac081f502cbb86702efa (diff)
propagate from branch 'au.asn.ucc.matt.dropbear' (head 0501e6f661b5415eb76f3b312d183c3adfbfb712)
to branch 'au.asn.ucc.matt.dropbear.cli-agent' (head 01038174ec27245b51bd43a66c01ad930880f67b) --HG-- branch : agent-client extra : convert_revision : 12b2f59db65e7339d340e95ac67d6d9ddb193c2b
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diff --git a/libtommath/bn_mp_reduce_is_2k_l.c b/libtommath/bn_mp_reduce_is_2k_l.c
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+#include <tommath.h>
+#ifdef BN_MP_REDUCE_IS_2K_L_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
+ */
+
+/* determines if reduce_2k_l can be used */
+int mp_reduce_is_2k_l(mp_int *a)
+{
+ int ix, iy;
+
+ if (a->used == 0) {
+ return MP_NO;
+ } else if (a->used == 1) {
+ return MP_YES;
+ } else if (a->used > 1) {
+ /* if more than half of the digits are -1 we're sold */
+ for (iy = ix = 0; ix < a->used; ix++) {
+ if (a->dp[ix] == MP_MASK) {
+ ++iy;
+ }
+ }
+ return (iy >= (a->used/2)) ? MP_YES : MP_NO;
+
+ }
+ return MP_NO;
+}
+
+#endif