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authorMatthieu Patou <mat@matws.net>2010-08-15 18:31:28 +0400
committerAndrew Bartlett <abartlet@samba.org>2010-10-03 01:15:04 +0000
commitab6e3fce040f9ad27cbce44e9038a24f15b601c8 (patch)
treeab99a431c9610927b5d0d26335d2712b509fd6dc /source4/heimdal/lib/hcrypto/libtommath/bn_mp_expt_d.c
parent197a1514d62494cc8b862d169c841a26e04b8925 (diff)
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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
Diffstat (limited to 'source4/heimdal/lib/hcrypto/libtommath/bn_mp_expt_d.c')
-rw-r--r--source4/heimdal/lib/hcrypto/libtommath/bn_mp_expt_d.c57
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diff --git a/source4/heimdal/lib/hcrypto/libtommath/bn_mp_expt_d.c b/source4/heimdal/lib/hcrypto/libtommath/bn_mp_expt_d.c
new file mode 100644
index 0000000000..4bdc2d13a6
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+++ b/source4/heimdal/lib/hcrypto/libtommath/bn_mp_expt_d.c
@@ -0,0 +1,57 @@
+#include <tommath.h>
+#ifdef BN_MP_EXPT_D_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
+ */
+
+/* calculate c = a**b using a square-multiply algorithm */
+int mp_expt_d (mp_int * a, mp_digit b, mp_int * c)
+{
+ int res, x;
+ mp_int g;
+
+ if ((res = mp_init_copy (&g, a)) != MP_OKAY) {
+ return res;
+ }
+
+ /* set initial result */
+ mp_set (c, 1);
+
+ for (x = 0; x < (int) DIGIT_BIT; x++) {
+ /* square */
+ if ((res = mp_sqr (c, c)) != MP_OKAY) {
+ mp_clear (&g);
+ return res;
+ }
+
+ /* if the bit is set multiply */
+ if ((b & (mp_digit) (((mp_digit)1) << (DIGIT_BIT - 1))) != 0) {
+ if ((res = mp_mul (c, &g, c)) != MP_OKAY) {
+ mp_clear (&g);
+ return res;
+ }
+ }
+
+ /* shift to next bit */
+ b <<= 1;
+ }
+
+ mp_clear (&g);
+ return MP_OKAY;
+}
+#endif
+
+/* $Source: /cvs/libtom/libtommath/bn_mp_expt_d.c,v $ */
+/* $Revision: 1.4 $ */
+/* $Date: 2006/12/28 01:25:13 $ */