diff libtommath/bn_mp_cmp_mag.c @ 293:9d110777f345 contrib-blacklist

propagate from branch 'au.asn.ucc.matt.dropbear' (head 7ad1775ed65e75dbece27fe6b65bf1a234db386a) to branch 'au.asn.ucc.matt.dropbear.contrib.blacklist' (head 1d86a4f0a401cc68c2670d821a2f6366c37af143)
author Matt Johnston <matt@ucc.asn.au>
date Fri, 10 Mar 2006 06:31:29 +0000
parents eed26cff980b
children 5ff8218bcee9
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libtommath/bn_mp_cmp_mag.c	Fri Mar 10 06:31:29 2006 +0000
@@ -0,0 +1,51 @@
+#include <tommath.h>
+#ifdef BN_MP_CMP_MAG_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.org
+ */
+
+/* compare maginitude of two ints (unsigned) */
+int mp_cmp_mag (mp_int * a, mp_int * b)
+{
+  int     n;
+  mp_digit *tmpa, *tmpb;
+
+  /* compare based on # of non-zero digits */
+  if (a->used > b->used) {
+    return MP_GT;
+  }
+  
+  if (a->used < b->used) {
+    return MP_LT;
+  }
+
+  /* alias for a */
+  tmpa = a->dp + (a->used - 1);
+
+  /* alias for b */
+  tmpb = b->dp + (a->used - 1);
+
+  /* compare based on digits  */
+  for (n = 0; n < a->used; ++n, --tmpa, --tmpb) {
+    if (*tmpa > *tmpb) {
+      return MP_GT;
+    }
+
+    if (*tmpa < *tmpb) {
+      return MP_LT;
+    }
+  }
+  return MP_EQ;
+}
+#endif