ltm-0.41

lib/hcrypto/libtommath/bn_mp_rand.c

@@ -0,0 +1,55 @@
+#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://libtom.org
+ */
+
+/* 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: 1.4 $ */
+/* $Date: 2006/12/28 01:25:13 $ */