diff libtommath/bn_mp_prime_rabin_miller_trials.c @ 389:5ff8218bcee9

propagate from branch 'au.asn.ucc.matt.ltm.dropbear' (head 2af95f00ebd5bb7a28b3817db1218442c935388e) to branch 'au.asn.ucc.matt.dropbear' (head ecd779509ef23a8cdf64888904fc9b31d78aa933)
author Matt Johnston <matt@ucc.asn.au>
date Thu, 11 Jan 2007 03:14:55 +0000
parents eed26cff980b
children 60fc6476e044
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libtommath/bn_mp_prime_rabin_miller_trials.c	Thu Jan 11 03:14:55 2007 +0000
@@ -0,0 +1,52 @@
+#include <tommath.h>
+#ifdef BN_MP_PRIME_RABIN_MILLER_TRIALS_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, [email protected], http://math.libtomcrypt.com
+ */
+
+
+static const struct {
+   int k, t;
+} sizes[] = {
+{   128,    28 },
+{   256,    16 },
+{   384,    10 },
+{   512,     7 },
+{   640,     6 },
+{   768,     5 },
+{   896,     4 },
+{  1024,     4 }
+};
+
+/* returns # of RM trials required for a given bit size */
+int mp_prime_rabin_miller_trials(int size)
+{
+   int x;
+
+   for (x = 0; x < (int)(sizeof(sizes)/(sizeof(sizes[0]))); x++) {
+       if (sizes[x].k == size) {
+          return sizes[x].t;
+       } else if (sizes[x].k > size) {
+          return (x == 0) ? sizes[0].t : sizes[x - 1].t;
+       }
+   }
+   return sizes[x-1].t + 1;
+}
+
+
+#endif
+
+/* $Source: /cvs/libtom/libtommath/bn_mp_prime_rabin_miller_trials.c,v $ */
+/* $Revision: 1.3 $ */
+/* $Date: 2006/03/31 14:18:44 $ */