From ab6e3fce040f9ad27cbce44e9038a24f15b601c8 Mon Sep 17 00:00:00 2001
From: Matthieu Patou <mat@matws.net>
Date: Sun, 15 Aug 2010 18:31:28 +0400
Subject: s4:heimdal: import lorikeet-heimdal-201009250123 (commit
 42cabfb5b683dbcb97d583c397b897507689e382)

I based this on Matthieu's import of lorikeet-heimdal, and then
updated it to this commit.

Andrew Bartlett
---
 .../lib/hcrypto/libtommath/bn_mp_reduce_2k_l.c     | 62 ++++++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 source4/heimdal/lib/hcrypto/libtommath/bn_mp_reduce_2k_l.c

(limited to 'source4/heimdal/lib/hcrypto/libtommath/bn_mp_reduce_2k_l.c')

diff --git a/source4/heimdal/lib/hcrypto/libtommath/bn_mp_reduce_2k_l.c b/source4/heimdal/lib/hcrypto/libtommath/bn_mp_reduce_2k_l.c
new file mode 100644
index 0000000000..f06103d6a6
--- /dev/null
+++ b/source4/heimdal/lib/hcrypto/libtommath/bn_mp_reduce_2k_l.c
@@ -0,0 +1,62 @@
+#include <tommath.h>
+#ifdef BN_MP_REDUCE_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@gmail.com, http://libtom.org
+ */
+
+/* reduces a modulo n where n is of the form 2**p - d 
+   This differs from reduce_2k since "d" can be larger
+   than a single digit.
+*/
+int mp_reduce_2k_l(mp_int *a, mp_int *n, mp_int *d)
+{
+   mp_int q;
+   int    p, res;
+   
+   if ((res = mp_init(&q)) != MP_OKAY) {
+      return res;
+   }
+   
+   p = mp_count_bits(n);    
+top:
+   /* q = a/2**p, a = a mod 2**p */
+   if ((res = mp_div_2d(a, p, &q, a)) != MP_OKAY) {
+      goto ERR;
+   }
+   
+   /* q = q * d */
+   if ((res = mp_mul(&q, d, &q)) != MP_OKAY) { 
+      goto ERR;
+   }
+   
+   /* a = a + q */
+   if ((res = s_mp_add(a, &q, a)) != MP_OKAY) {
+      goto ERR;
+   }
+   
+   if (mp_cmp_mag(a, n) != MP_LT) {
+      s_mp_sub(a, n, a);
+      goto top;
+   }
+   
+ERR:
+   mp_clear(&q);
+   return res;
+}
+
+#endif
+
+/* $Source: /cvs/libtom/libtommath/bn_mp_reduce_2k_l.c,v $ */
+/* $Revision: 1.4 $ */
+/* $Date: 2006/12/28 01:25:13 $ */
-- 
cgit