--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nss/lib/freebl/ecl/ecp_mont.c	Mon Jul 28 10:47:06 2014 +0200
@@ -0,0 +1,155 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* Uses Montgomery reduction for field arithmetic.  See mpi/mpmontg.c for
+ * code implementation. */
+
+#include "mpi.h"
+#include "mplogic.h"
+#include "mpi-priv.h"
+#include "ecl-priv.h"
+#include "ecp.h"
+#include <stdlib.h>
+#include <stdio.h>
+
+/* Construct a generic GFMethod for arithmetic over prime fields with
+ * irreducible irr. */
+GFMethod *
+GFMethod_consGFp_mont(const mp_int *irr)
+{
+	mp_err res = MP_OKAY;
+	GFMethod *meth = NULL;
+	mp_mont_modulus *mmm;
+
+	meth = GFMethod_consGFp(irr);
+	if (meth == NULL)
+		return NULL;
+
+	mmm = (mp_mont_modulus *) malloc(sizeof(mp_mont_modulus));
+	if (mmm == NULL) {
+		res = MP_MEM;
+		goto CLEANUP;
+	}
+
+	meth->field_mul = &ec_GFp_mul_mont;
+	meth->field_sqr = &ec_GFp_sqr_mont;
+	meth->field_div = &ec_GFp_div_mont;
+	meth->field_enc = &ec_GFp_enc_mont;
+	meth->field_dec = &ec_GFp_dec_mont;
+	meth->extra1 = mmm;
+	meth->extra2 = NULL;
+	meth->extra_free = &ec_GFp_extra_free_mont;
+
+	mmm->N = meth->irr;
+	mmm->n0prime = 0 - s_mp_invmod_radix(MP_DIGIT(&meth->irr, 0));
+
+  CLEANUP:
+	if (res != MP_OKAY) {
+		GFMethod_free(meth);
+		return NULL;
+	}
+	return meth;
+}
+
+/* Wrapper functions for generic prime field arithmetic. */
+
+/* Field multiplication using Montgomery reduction. */
+mp_err
+ec_GFp_mul_mont(const mp_int *a, const mp_int *b, mp_int *r,
+				const GFMethod *meth)
+{
+	mp_err res = MP_OKAY;
+
+#ifdef MP_MONT_USE_MP_MUL
+	/* if MP_MONT_USE_MP_MUL is defined, then the function s_mp_mul_mont
+	 * is not implemented and we have to use mp_mul and s_mp_redc directly 
+	 */
+	MP_CHECKOK(mp_mul(a, b, r));
+	MP_CHECKOK(s_mp_redc(r, (mp_mont_modulus *) meth->extra1));
+#else
+	mp_int s;
+
+	MP_DIGITS(&s) = 0;
+	/* s_mp_mul_mont doesn't allow source and destination to be the same */
+	if ((a == r) || (b == r)) {
+		MP_CHECKOK(mp_init(&s));
+		MP_CHECKOK(s_mp_mul_mont
+				   (a, b, &s, (mp_mont_modulus *) meth->extra1));
+		MP_CHECKOK(mp_copy(&s, r));
+		mp_clear(&s);
+	} else {
+		return s_mp_mul_mont(a, b, r, (mp_mont_modulus *) meth->extra1);
+	}
+#endif
+  CLEANUP:
+	return res;
+}
+
+/* Field squaring using Montgomery reduction. */
+mp_err
+ec_GFp_sqr_mont(const mp_int *a, mp_int *r, const GFMethod *meth)
+{
+	return ec_GFp_mul_mont(a, a, r, meth);
+}
+
+/* Field division using Montgomery reduction. */
+mp_err
+ec_GFp_div_mont(const mp_int *a, const mp_int *b, mp_int *r,
+				const GFMethod *meth)
+{
+	mp_err res = MP_OKAY;
+
+	/* if A=aZ represents a encoded in montgomery coordinates with Z and # 
+	 * and \ respectively represent multiplication and division in
+	 * montgomery coordinates, then A\B = (a/b)Z = (A/B)Z and Binv =
+	 * (1/b)Z = (1/B)(Z^2) where B # Binv = Z */
+	MP_CHECKOK(ec_GFp_div(a, b, r, meth));
+	MP_CHECKOK(ec_GFp_enc_mont(r, r, meth));
+	if (a == NULL) {
+		MP_CHECKOK(ec_GFp_enc_mont(r, r, meth));
+	}
+  CLEANUP:
+	return res;
+}
+
+/* Encode a field element in Montgomery form. See s_mp_to_mont in
+ * mpi/mpmontg.c */
+mp_err
+ec_GFp_enc_mont(const mp_int *a, mp_int *r, const GFMethod *meth)
+{
+	mp_mont_modulus *mmm;
+	mp_err res = MP_OKAY;
+
+	mmm = (mp_mont_modulus *) meth->extra1;
+	MP_CHECKOK(mp_copy(a, r));
+	MP_CHECKOK(s_mp_lshd(r, MP_USED(&mmm->N)));
+	MP_CHECKOK(mp_mod(r, &mmm->N, r));
+  CLEANUP:
+	return res;
+}
+
+/* Decode a field element from Montgomery form. */
+mp_err
+ec_GFp_dec_mont(const mp_int *a, mp_int *r, const GFMethod *meth)
+{
+	mp_err res = MP_OKAY;
+
+	if (a != r) {
+		MP_CHECKOK(mp_copy(a, r));
+	}
+	MP_CHECKOK(s_mp_redc(r, (mp_mont_modulus *) meth->extra1));
+  CLEANUP:
+	return res;
+}
+
+/* Free the memory allocated to the extra fields of Montgomery GFMethod
+ * object. */
+void
+ec_GFp_extra_free_mont(GFMethod *meth)
+{
+	if (meth->extra1 != NULL) {
+		free(meth->extra1);
+		meth->extra1 = NULL;
+	}
+}