jdk/src/share/native/sun/security/ec/mpmontg.c
changeset 3492 e549cea58864
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/native/sun/security/ec/mpmontg.c	Tue Aug 11 16:52:26 2009 +0100
@@ -0,0 +1,199 @@
+/* *********************************************************************
+ *
+ * Sun elects to have this file available under and governed by the
+ * Mozilla Public License Version 1.1 ("MPL") (see
+ * http://www.mozilla.org/MPL/ for full license text). For the avoidance
+ * of doubt and subject to the following, Sun also elects to allow
+ * licensees to use this file under the MPL, the GNU General Public
+ * License version 2 only or the Lesser General Public License version
+ * 2.1 only. Any references to the "GNU General Public License version 2
+ * or later" or "GPL" in the following shall be construed to mean the
+ * GNU General Public License version 2 only. Any references to the "GNU
+ * Lesser General Public License version 2.1 or later" or "LGPL" in the
+ * following shall be construed to mean the GNU Lesser General Public
+ * License version 2.1 only. However, the following notice accompanied
+ * the original version of this file:
+ *
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is the Netscape security libraries.
+ *
+ * The Initial Developer of the Original Code is
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 2000
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Sheueling Chang Shantz <sheueling.chang@sun.com>,
+ *   Stephen Fung <stephen.fung@sun.com>, and
+ *   Douglas Stebila <douglas@stebila.ca> of Sun Laboratories.
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ *********************************************************************** */
+/*
+ * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma ident   "%Z%%M% %I%     %E% SMI"
+
+/* $Id: mpmontg.c,v 1.20 2006/08/29 02:41:38 nelson%bolyard.com Exp $ */
+
+/* This file implements moduluar exponentiation using Montgomery's
+ * method for modular reduction.  This file implements the method
+ * described as "Improvement 1" in the paper "A Cryptogrpahic Library for
+ * the Motorola DSP56000" by Stephen R. Dusse' and Burton S. Kaliski Jr.
+ * published in "Advances in Cryptology: Proceedings of EUROCRYPT '90"
+ * "Lecture Notes in Computer Science" volume 473, 1991, pg 230-244,
+ * published by Springer Verlag.
+ */
+
+#define MP_USING_CACHE_SAFE_MOD_EXP 1
+#ifndef _KERNEL
+#include <string.h>
+#include <stddef.h> /* ptrdiff_t */
+#endif
+#include "mpi-priv.h"
+#include "mplogic.h"
+#include "mpprime.h"
+#ifdef MP_USING_MONT_MULF
+#include "montmulf.h"
+#endif
+
+/* if MP_CHAR_STORE_SLOW is defined, we  */
+/* need to know endianness of this platform. */
+#ifdef MP_CHAR_STORE_SLOW
+#if !defined(MP_IS_BIG_ENDIAN) && !defined(MP_IS_LITTLE_ENDIAN)
+#error "You must define MP_IS_BIG_ENDIAN or MP_IS_LITTLE_ENDIAN\n" \
+       "  if you define MP_CHAR_STORE_SLOW."
+#endif
+#endif
+
+#ifndef STATIC
+#define STATIC
+#endif
+
+#define MAX_ODD_INTS    32   /* 2 ** (WINDOW_BITS - 1) */
+
+#ifndef _KERNEL
+#if defined(_WIN32_WCE)
+#define ABORT  res = MP_UNDEF; goto CLEANUP
+#else
+#define ABORT abort()
+#endif
+#else
+#define ABORT  res = MP_UNDEF; goto CLEANUP
+#endif /* _KERNEL */
+
+/* computes T = REDC(T), 2^b == R */
+mp_err s_mp_redc(mp_int *T, mp_mont_modulus *mmm)
+{
+  mp_err res;
+  mp_size i;
+
+  i = MP_USED(T) + MP_USED(&mmm->N) + 2;
+  MP_CHECKOK( s_mp_pad(T, i) );
+  for (i = 0; i < MP_USED(&mmm->N); ++i ) {
+    mp_digit m_i = MP_DIGIT(T, i) * mmm->n0prime;
+    /* T += N * m_i * (MP_RADIX ** i); */
+    MP_CHECKOK( s_mp_mul_d_add_offset(&mmm->N, m_i, T, i) );
+  }
+  s_mp_clamp(T);
+
+  /* T /= R */
+  s_mp_div_2d(T, mmm->b);
+
+  if ((res = s_mp_cmp(T, &mmm->N)) >= 0) {
+    /* T = T - N */
+    MP_CHECKOK( s_mp_sub(T, &mmm->N) );
+#ifdef DEBUG
+    if ((res = mp_cmp(T, &mmm->N)) >= 0) {
+      res = MP_UNDEF;
+      goto CLEANUP;
+    }
+#endif
+  }
+  res = MP_OKAY;
+CLEANUP:
+  return res;
+}
+
+#if !defined(MP_ASSEMBLY_MUL_MONT) && !defined(MP_MONT_USE_MP_MUL)
+mp_err s_mp_mul_mont(const mp_int *a, const mp_int *b, mp_int *c,
+                   mp_mont_modulus *mmm)
+{
+  mp_digit *pb;
+  mp_digit m_i;
+  mp_err   res;
+  mp_size  ib;
+  mp_size  useda, usedb;
+
+  ARGCHK(a != NULL && b != NULL && c != NULL, MP_BADARG);
+
+  if (MP_USED(a) < MP_USED(b)) {
+    const mp_int *xch = b;      /* switch a and b, to do fewer outer loops */
+    b = a;
+    a = xch;
+  }
+
+  MP_USED(c) = 1; MP_DIGIT(c, 0) = 0;
+  ib = MP_USED(a) + MP_MAX(MP_USED(b), MP_USED(&mmm->N)) + 2;
+  if((res = s_mp_pad(c, ib)) != MP_OKAY)
+    goto CLEANUP;
+
+  useda = MP_USED(a);
+  pb = MP_DIGITS(b);
+  s_mpv_mul_d(MP_DIGITS(a), useda, *pb++, MP_DIGITS(c));
+  s_mp_setz(MP_DIGITS(c) + useda + 1, ib - (useda + 1));
+  m_i = MP_DIGIT(c, 0) * mmm->n0prime;
+  s_mp_mul_d_add_offset(&mmm->N, m_i, c, 0);
+
+  /* Outer loop:  Digits of b */
+  usedb = MP_USED(b);
+  for (ib = 1; ib < usedb; ib++) {
+    mp_digit b_i    = *pb++;
+
+    /* Inner product:  Digits of a */
+    if (b_i)
+      s_mpv_mul_d_add_prop(MP_DIGITS(a), useda, b_i, MP_DIGITS(c) + ib);
+    m_i = MP_DIGIT(c, ib) * mmm->n0prime;
+    s_mp_mul_d_add_offset(&mmm->N, m_i, c, ib);
+  }
+  if (usedb < MP_USED(&mmm->N)) {
+    for (usedb = MP_USED(&mmm->N); ib < usedb; ++ib ) {
+      m_i = MP_DIGIT(c, ib) * mmm->n0prime;
+      s_mp_mul_d_add_offset(&mmm->N, m_i, c, ib);
+    }
+  }
+  s_mp_clamp(c);
+  s_mp_div_2d(c, mmm->b);
+  if (s_mp_cmp(c, &mmm->N) >= 0) {
+    MP_CHECKOK( s_mp_sub(c, &mmm->N) );
+  }
+  res = MP_OKAY;
+
+CLEANUP:
+  return res;
+}
+#endif