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authorMatt Johnston <matt@ucc.asn.au>2007-01-11 03:14:55 +0000
committerMatt Johnston <matt@ucc.asn.au>2007-01-11 03:14:55 +0000
commit68efaf4fb3d1cca475eee7ff15d6abb71a48cf88 (patch)
tree6dacbff2e9f5c60a1568382db55c72dd6d2ce925 /libtommath/bn_mp_rand.c
parent0e9e709195eb6421f80d4c62fe66e43ae3ac2422 (diff)
parent4ebcb4da9b179c9bc735698414524ccda5932568 (diff)
downloaddropbear-68efaf4fb3d1cca475eee7ff15d6abb71a48cf88.tar.gz
propagate from branch 'au.asn.ucc.matt.ltm.dropbear' (head 2af95f00ebd5bb7a28b3817db1218442c935388e)
to branch 'au.asn.ucc.matt.dropbear' (head ecd779509ef23a8cdf64888904fc9b31d78aa933)
Diffstat (limited to 'libtommath/bn_mp_rand.c')
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diff --git a/libtommath/bn_mp_rand.c b/libtommath/bn_mp_rand.c
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+#include <tommath.h>
+#ifdef BN_MP_RAND_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://math.libtomcrypt.com
+ */
+
+/* makes a pseudo-random int of a given size */
+int
+mp_rand (mp_int * a, int digits)
+{
+ int res;
+ mp_digit d;
+
+ mp_zero (a);
+ if (digits <= 0) {
+ return MP_OKAY;
+ }
+
+ /* first place a random non-zero digit */
+ do {
+ d = ((mp_digit) abs (rand ())) & MP_MASK;
+ } while (d == 0);
+
+ if ((res = mp_add_d (a, d, a)) != MP_OKAY) {
+ return res;
+ }
+
+ while (--digits > 0) {
+ if ((res = mp_lshd (a, 1)) != MP_OKAY) {
+ return res;
+ }
+
+ if ((res = mp_add_d (a, ((mp_digit) abs (rand ())), a)) != MP_OKAY) {
+ return res;
+ }
+ }
+
+ return MP_OKAY;
+}
+#endif
+
+/* $Source: /cvs/libtom/libtommath/bn_mp_rand.c,v $ */
+/* $Revision: 1.3 $ */
+/* $Date: 2006/03/31 14:18:44 $ */