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
---
 .../heimdal/lib/hcrypto/libtommath/bn_mp_sqrt.c    | 81 ++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 source4/heimdal/lib/hcrypto/libtommath/bn_mp_sqrt.c

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

diff --git a/source4/heimdal/lib/hcrypto/libtommath/bn_mp_sqrt.c b/source4/heimdal/lib/hcrypto/libtommath/bn_mp_sqrt.c
new file mode 100644
index 0000000000..8fd057ceed
--- /dev/null
+++ b/source4/heimdal/lib/hcrypto/libtommath/bn_mp_sqrt.c
@@ -0,0 +1,81 @@
+#include <tommath.h>
+#ifdef BN_MP_SQRT_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
+ */
+
+/* this function is less generic than mp_n_root, simpler and faster */
+int mp_sqrt(mp_int *arg, mp_int *ret) 
+{
+  int res;
+  mp_int t1,t2;
+
+  /* must be positive */
+  if (arg->sign == MP_NEG) {
+    return MP_VAL;
+  }
+
+  /* easy out */
+  if (mp_iszero(arg) == MP_YES) {
+    mp_zero(ret);
+    return MP_OKAY;
+  }
+
+  if ((res = mp_init_copy(&t1, arg)) != MP_OKAY) {
+    return res;
+  }
+
+  if ((res = mp_init(&t2)) != MP_OKAY) {
+    goto E2;
+  }
+
+  /* First approx. (not very bad for large arg) */
+  mp_rshd (&t1,t1.used/2);
+
+  /* t1 > 0  */ 
+  if ((res = mp_div(arg,&t1,&t2,NULL)) != MP_OKAY) {
+    goto E1;
+  }
+  if ((res = mp_add(&t1,&t2,&t1)) != MP_OKAY) {
+    goto E1;
+  }
+  if ((res = mp_div_2(&t1,&t1)) != MP_OKAY) {
+    goto E1;
+  }
+  /* And now t1 > sqrt(arg) */
+  do { 
+    if ((res = mp_div(arg,&t1,&t2,NULL)) != MP_OKAY) {
+      goto E1;
+    }
+    if ((res = mp_add(&t1,&t2,&t1)) != MP_OKAY) {
+      goto E1;
+    }
+    if ((res = mp_div_2(&t1,&t1)) != MP_OKAY) {
+      goto E1;
+    }
+    /* t1 >= sqrt(arg) >= t2 at this point */
+  } while (mp_cmp_mag(&t1,&t2) == MP_GT);
+
+  mp_exch(&t1,ret);
+
+E1: mp_clear(&t2);
+E2: mp_clear(&t1);
+  return res;
+}
+
+#endif
+
+/* $Source: /cvs/libtom/libtommath/bn_mp_sqrt.c,v $ */
+/* $Revision: 1.4 $ */
+/* $Date: 2006/12/28 01:25:13 $ */
-- 
cgit