jdk/src/share/native/sun/security/ec/ecp_jm.c
changeset 3492 e549cea58864
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/native/sun/security/ec/ecp_jm.c	Tue Aug 11 16:52:26 2009 +0100
@@ -0,0 +1,353 @@
+/* *********************************************************************
+ *
+ * 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 elliptic curve math library for prime field curves.
+ *
+ * The Initial Developer of the Original Code is
+ * Sun Microsystems, Inc.
+ * Portions created by the Initial Developer are Copyright (C) 2003
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Stephen Fung <fungstep@hotmail.com>, Sun Microsystems 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"
+
+#include "ecp.h"
+#include "ecl-priv.h"
+#include "mplogic.h"
+#ifndef _KERNEL
+#include <stdlib.h>
+#endif
+
+#define MAX_SCRATCH 6
+
+/* Computes R = 2P.  Elliptic curve points P and R can be identical.  Uses
+ * Modified Jacobian coordinates.
+ *
+ * Assumes input is already field-encoded using field_enc, and returns
+ * output that is still field-encoded.
+ *
+ */
+mp_err
+ec_GFp_pt_dbl_jm(const mp_int *px, const mp_int *py, const mp_int *pz,
+                                 const mp_int *paz4, mp_int *rx, mp_int *ry, mp_int *rz,
+                                 mp_int *raz4, mp_int scratch[], const ECGroup *group)
+{
+        mp_err res = MP_OKAY;
+        mp_int *t0, *t1, *M, *S;
+
+        t0 = &scratch[0];
+        t1 = &scratch[1];
+        M = &scratch[2];
+        S = &scratch[3];
+
+#if MAX_SCRATCH < 4
+#error "Scratch array defined too small "
+#endif
+
+        /* Check for point at infinity */
+        if (ec_GFp_pt_is_inf_jac(px, py, pz) == MP_YES) {
+                /* Set r = pt at infinity by setting rz = 0 */
+
+                MP_CHECKOK(ec_GFp_pt_set_inf_jac(rx, ry, rz));
+                goto CLEANUP;
+        }
+
+        /* M = 3 (px^2) + a*(pz^4) */
+        MP_CHECKOK(group->meth->field_sqr(px, t0, group->meth));
+        MP_CHECKOK(group->meth->field_add(t0, t0, M, group->meth));
+        MP_CHECKOK(group->meth->field_add(t0, M, t0, group->meth));
+        MP_CHECKOK(group->meth->field_add(t0, paz4, M, group->meth));
+
+        /* rz = 2 * py * pz */
+        MP_CHECKOK(group->meth->field_mul(py, pz, S, group->meth));
+        MP_CHECKOK(group->meth->field_add(S, S, rz, group->meth));
+
+        /* t0 = 2y^2 , t1 = 8y^4 */
+        MP_CHECKOK(group->meth->field_sqr(py, t0, group->meth));
+        MP_CHECKOK(group->meth->field_add(t0, t0, t0, group->meth));
+        MP_CHECKOK(group->meth->field_sqr(t0, t1, group->meth));
+        MP_CHECKOK(group->meth->field_add(t1, t1, t1, group->meth));
+
+        /* S = 4 * px * py^2 = 2 * px * t0 */
+        MP_CHECKOK(group->meth->field_mul(px, t0, S, group->meth));
+        MP_CHECKOK(group->meth->field_add(S, S, S, group->meth));
+
+
+        /* rx = M^2 - 2S */
+        MP_CHECKOK(group->meth->field_sqr(M, rx, group->meth));
+        MP_CHECKOK(group->meth->field_sub(rx, S, rx, group->meth));
+        MP_CHECKOK(group->meth->field_sub(rx, S, rx, group->meth));
+
+        /* ry = M * (S - rx) - t1 */
+        MP_CHECKOK(group->meth->field_sub(S, rx, S, group->meth));
+        MP_CHECKOK(group->meth->field_mul(S, M, ry, group->meth));
+        MP_CHECKOK(group->meth->field_sub(ry, t1, ry, group->meth));
+
+        /* ra*z^4 = 2*t1*(apz4) */
+        MP_CHECKOK(group->meth->field_mul(paz4, t1, raz4, group->meth));
+        MP_CHECKOK(group->meth->field_add(raz4, raz4, raz4, group->meth));
+
+
+  CLEANUP:
+        return res;
+}
+
+/* Computes R = P + Q where R is (rx, ry, rz), P is (px, py, pz) and Q is
+ * (qx, qy, 1).  Elliptic curve points P, Q, and R can all be identical.
+ * Uses mixed Modified_Jacobian-affine coordinates. Assumes input is
+ * already field-encoded using field_enc, and returns output that is still
+ * field-encoded. */
+mp_err
+ec_GFp_pt_add_jm_aff(const mp_int *px, const mp_int *py, const mp_int *pz,
+                                         const mp_int *paz4, const mp_int *qx,
+                                         const mp_int *qy, mp_int *rx, mp_int *ry, mp_int *rz,
+                                         mp_int *raz4, mp_int scratch[], const ECGroup *group)
+{
+        mp_err res = MP_OKAY;
+        mp_int *A, *B, *C, *D, *C2, *C3;
+
+        A = &scratch[0];
+        B = &scratch[1];
+        C = &scratch[2];
+        D = &scratch[3];
+        C2 = &scratch[4];
+        C3 = &scratch[5];
+
+#if MAX_SCRATCH < 6
+#error "Scratch array defined too small "
+#endif
+
+        /* If either P or Q is the point at infinity, then return the other
+         * point */
+        if (ec_GFp_pt_is_inf_jac(px, py, pz) == MP_YES) {
+                MP_CHECKOK(ec_GFp_pt_aff2jac(qx, qy, rx, ry, rz, group));
+                MP_CHECKOK(group->meth->field_sqr(rz, raz4, group->meth));
+                MP_CHECKOK(group->meth->field_sqr(raz4, raz4, group->meth));
+                MP_CHECKOK(group->meth->
+                                   field_mul(raz4, &group->curvea, raz4, group->meth));
+                goto CLEANUP;
+        }
+        if (ec_GFp_pt_is_inf_aff(qx, qy) == MP_YES) {
+                MP_CHECKOK(mp_copy(px, rx));
+                MP_CHECKOK(mp_copy(py, ry));
+                MP_CHECKOK(mp_copy(pz, rz));
+                MP_CHECKOK(mp_copy(paz4, raz4));
+                goto CLEANUP;
+        }
+
+        /* A = qx * pz^2, B = qy * pz^3 */
+        MP_CHECKOK(group->meth->field_sqr(pz, A, group->meth));
+        MP_CHECKOK(group->meth->field_mul(A, pz, B, group->meth));
+        MP_CHECKOK(group->meth->field_mul(A, qx, A, group->meth));
+        MP_CHECKOK(group->meth->field_mul(B, qy, B, group->meth));
+
+        /* C = A - px, D = B - py */
+        MP_CHECKOK(group->meth->field_sub(A, px, C, group->meth));
+        MP_CHECKOK(group->meth->field_sub(B, py, D, group->meth));
+
+        /* C2 = C^2, C3 = C^3 */
+        MP_CHECKOK(group->meth->field_sqr(C, C2, group->meth));
+        MP_CHECKOK(group->meth->field_mul(C, C2, C3, group->meth));
+
+        /* rz = pz * C */
+        MP_CHECKOK(group->meth->field_mul(pz, C, rz, group->meth));
+
+        /* C = px * C^2 */
+        MP_CHECKOK(group->meth->field_mul(px, C2, C, group->meth));
+        /* A = D^2 */
+        MP_CHECKOK(group->meth->field_sqr(D, A, group->meth));
+
+        /* rx = D^2 - (C^3 + 2 * (px * C^2)) */
+        MP_CHECKOK(group->meth->field_add(C, C, rx, group->meth));
+        MP_CHECKOK(group->meth->field_add(C3, rx, rx, group->meth));
+        MP_CHECKOK(group->meth->field_sub(A, rx, rx, group->meth));
+
+        /* C3 = py * C^3 */
+        MP_CHECKOK(group->meth->field_mul(py, C3, C3, group->meth));
+
+        /* ry = D * (px * C^2 - rx) - py * C^3 */
+        MP_CHECKOK(group->meth->field_sub(C, rx, ry, group->meth));
+        MP_CHECKOK(group->meth->field_mul(D, ry, ry, group->meth));
+        MP_CHECKOK(group->meth->field_sub(ry, C3, ry, group->meth));
+
+        /* raz4 = a * rz^4 */
+        MP_CHECKOK(group->meth->field_sqr(rz, raz4, group->meth));
+        MP_CHECKOK(group->meth->field_sqr(raz4, raz4, group->meth));
+        MP_CHECKOK(group->meth->
+                           field_mul(raz4, &group->curvea, raz4, group->meth));
+CLEANUP:
+        return res;
+}
+
+/* Computes R = nP where R is (rx, ry) and P is the base point. Elliptic
+ * curve points P and R can be identical. Uses mixed Modified-Jacobian
+ * co-ordinates for doubling and Chudnovsky Jacobian coordinates for
+ * additions. Assumes input is already field-encoded using field_enc, and
+ * returns output that is still field-encoded. Uses 5-bit window NAF
+ * method (algorithm 11) for scalar-point multiplication from Brown,
+ * Hankerson, Lopez, Menezes. Software Implementation of the NIST Elliptic
+ * Curves Over Prime Fields. */
+mp_err
+ec_GFp_pt_mul_jm_wNAF(const mp_int *n, const mp_int *px, const mp_int *py,
+                                          mp_int *rx, mp_int *ry, const ECGroup *group)
+{
+        mp_err res = MP_OKAY;
+        mp_int precomp[16][2], rz, tpx, tpy;
+        mp_int raz4;
+        mp_int scratch[MAX_SCRATCH];
+        signed char *naf = NULL;
+        int i, orderBitSize;
+
+        MP_DIGITS(&rz) = 0;
+        MP_DIGITS(&raz4) = 0;
+        MP_DIGITS(&tpx) = 0;
+        MP_DIGITS(&tpy) = 0;
+        for (i = 0; i < 16; i++) {
+                MP_DIGITS(&precomp[i][0]) = 0;
+                MP_DIGITS(&precomp[i][1]) = 0;
+        }
+        for (i = 0; i < MAX_SCRATCH; i++) {
+                MP_DIGITS(&scratch[i]) = 0;
+        }
+
+        ARGCHK(group != NULL, MP_BADARG);
+        ARGCHK((n != NULL) && (px != NULL) && (py != NULL), MP_BADARG);
+
+        /* initialize precomputation table */
+        MP_CHECKOK(mp_init(&tpx, FLAG(n)));
+        MP_CHECKOK(mp_init(&tpy, FLAG(n)));;
+        MP_CHECKOK(mp_init(&rz, FLAG(n)));
+        MP_CHECKOK(mp_init(&raz4, FLAG(n)));
+
+        for (i = 0; i < 16; i++) {
+                MP_CHECKOK(mp_init(&precomp[i][0], FLAG(n)));
+                MP_CHECKOK(mp_init(&precomp[i][1], FLAG(n)));
+        }
+        for (i = 0; i < MAX_SCRATCH; i++) {
+                MP_CHECKOK(mp_init(&scratch[i], FLAG(n)));
+        }
+
+        /* Set out[8] = P */
+        MP_CHECKOK(mp_copy(px, &precomp[8][0]));
+        MP_CHECKOK(mp_copy(py, &precomp[8][1]));
+
+        /* Set (tpx, tpy) = 2P */
+        MP_CHECKOK(group->
+                           point_dbl(&precomp[8][0], &precomp[8][1], &tpx, &tpy,
+                                                 group));
+
+        /* Set 3P, 5P, ..., 15P */
+        for (i = 8; i < 15; i++) {
+                MP_CHECKOK(group->
+                                   point_add(&precomp[i][0], &precomp[i][1], &tpx, &tpy,
+                                                         &precomp[i + 1][0], &precomp[i + 1][1],
+                                                         group));
+        }
+
+        /* Set -15P, -13P, ..., -P */
+        for (i = 0; i < 8; i++) {
+                MP_CHECKOK(mp_copy(&precomp[15 - i][0], &precomp[i][0]));
+                MP_CHECKOK(group->meth->
+                                   field_neg(&precomp[15 - i][1], &precomp[i][1],
+                                                         group->meth));
+        }
+
+        /* R = inf */
+        MP_CHECKOK(ec_GFp_pt_set_inf_jac(rx, ry, &rz));
+
+        orderBitSize = mpl_significant_bits(&group->order);
+
+        /* Allocate memory for NAF */
+#ifdef _KERNEL
+        naf = (signed char *) kmem_alloc((orderBitSize + 1), FLAG(n));
+#else
+        naf = (signed char *) malloc(sizeof(signed char) * (orderBitSize + 1));
+        if (naf == NULL) {
+                res = MP_MEM;
+                goto CLEANUP;
+        }
+#endif
+
+        /* Compute 5NAF */
+        ec_compute_wNAF(naf, orderBitSize, n, 5);
+
+        /* wNAF method */
+        for (i = orderBitSize; i >= 0; i--) {
+                /* R = 2R */
+                ec_GFp_pt_dbl_jm(rx, ry, &rz, &raz4, rx, ry, &rz,
+                                             &raz4, scratch, group);
+                if (naf[i] != 0) {
+                        ec_GFp_pt_add_jm_aff(rx, ry, &rz, &raz4,
+                                                                 &precomp[(naf[i] + 15) / 2][0],
+                                                                 &precomp[(naf[i] + 15) / 2][1], rx, ry,
+                                                                 &rz, &raz4, scratch, group);
+                }
+        }
+
+        /* convert result S to affine coordinates */
+        MP_CHECKOK(ec_GFp_pt_jac2aff(rx, ry, &rz, rx, ry, group));
+
+  CLEANUP:
+        for (i = 0; i < MAX_SCRATCH; i++) {
+                mp_clear(&scratch[i]);
+        }
+        for (i = 0; i < 16; i++) {
+                mp_clear(&precomp[i][0]);
+                mp_clear(&precomp[i][1]);
+        }
+        mp_clear(&tpx);
+        mp_clear(&tpy);
+        mp_clear(&rz);
+        mp_clear(&raz4);
+#ifdef _KERNEL
+        kmem_free(naf, (orderBitSize + 1));
+#else
+        free(naf);
+#endif
+        return res;
+}