1 files changed, 386 insertions, 0 deletions
diff --git a/openssl/crypto/ec/ec2_mult.c b/openssl/crypto/ec/ec2_mult.c
new file mode 100644
index 00000000..e12b9b28
--- /dev/null
+++ b/openssl/crypto/ec/ec2_mult.c
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+/* crypto/ec/ec2_mult.c */
+/* ====================================================================
+ * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
+ *
+ * The Elliptic Curve Public-Key Crypto Library (ECC Code) included
+ * herein is developed by SUN MICROSYSTEMS, INC., and is contributed
+ * to the OpenSSL project.
+ *
+ * The ECC Code is licensed pursuant to the OpenSSL open source
+ * license provided below.
+ *
+ * The software is originally written by Sheueling Chang Shantz and
+ * Douglas Stebila of Sun Microsystems Laboratories.
+ *
+ */
+/* ====================================================================
+ * Copyright (c) 1998-2003 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer. 
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com).  This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
+
+#include <openssl/err.h>
+
+#include "ec_lcl.h"
+
+
+/* Compute the x-coordinate x/z for the point 2*(x/z) in Montgomery projective 
+ * coordinates.
+ * Uses algorithm Mdouble in appendix of 
+ *     Lopez, J. and Dahab, R.  "Fast multiplication on elliptic curves over 
+ *     GF(2^m) without precomputation" (CHES '99, LNCS 1717).
+ * modified to not require precomputation of c=b^{2^{m-1}}.
+ */
+static int gf2m_Mdouble(const EC_GROUP *group, BIGNUM *x, BIGNUM *z, BN_CTX *ctx)
+	{
+	BIGNUM *t1;
+	int ret = 0;
+	
+	/* Since Mdouble is static we can guarantee that ctx != NULL. */
+	BN_CTX_start(ctx);
+	t1 = BN_CTX_get(ctx);
+	if (t1 == NULL) goto err;
+
+	if (!group->meth->field_sqr(group, x, x, ctx)) goto err;
+	if (!group->meth->field_sqr(group, t1, z, ctx)) goto err;
+	if (!group->meth->field_mul(group, z, x, t1, ctx)) goto err;
+	if (!group->meth->field_sqr(group, x, x, ctx)) goto err;
+	if (!group->meth->field_sqr(group, t1, t1, ctx)) goto err;
+	if (!group->meth->field_mul(group, t1, &group->b, t1, ctx)) goto err;
+	if (!BN_GF2m_add(x, x, t1)) goto err;
+
+	ret = 1;
+
+ err:
+	BN_CTX_end(ctx);
+	return ret;
+	}
+
+/* Compute the x-coordinate x1/z1 for the point (x1/z1)+(x2/x2) in Montgomery 
+ * projective coordinates.
+ * Uses algorithm Madd in appendix of 
+ *     Lopez, J. and Dahab, R.  "Fast multiplication on elliptic curves over 
+ *     GF(2^m) without precomputation" (CHES '99, LNCS 1717).
+ */
+static int gf2m_Madd(const EC_GROUP *group, const BIGNUM *x, BIGNUM *x1, BIGNUM *z1, 
+	const BIGNUM *x2, const BIGNUM *z2, BN_CTX *ctx)
+	{
+	BIGNUM *t1, *t2;
+	int ret = 0;
+	
+	/* Since Madd is static we can guarantee that ctx != NULL. */
+	BN_CTX_start(ctx);
+	t1 = BN_CTX_get(ctx);
+	t2 = BN_CTX_get(ctx);
+	if (t2 == NULL) goto err;
+
+	if (!BN_copy(t1, x)) goto err;
+	if (!group->meth->field_mul(group, x1, x1, z2, ctx)) goto err;
+	if (!group->meth->field_mul(group, z1, z1, x2, ctx)) goto err;
+	if (!group->meth->field_mul(group, t2, x1, z1, ctx)) goto err;
+	if (!BN_GF2m_add(z1, z1, x1)) goto err;
+	if (!group->meth->field_sqr(group, z1, z1, ctx)) goto err;
+	if (!group->meth->field_mul(group, x1, z1, t1, ctx)) goto err;
+	if (!BN_GF2m_add(x1, x1, t2)) goto err;
+
+	ret = 1;
+
+ err:
+	BN_CTX_end(ctx);
+	return ret;
+	}
+
+/* Compute the x, y affine coordinates from the point (x1, z1) (x2, z2) 
+ * using Montgomery point multiplication algorithm Mxy() in appendix of 
+ *     Lopez, J. and Dahab, R.  "Fast multiplication on elliptic curves over 
+ *     GF(2^m) without precomputation" (CHES '99, LNCS 1717).
+ * Returns:
+ *     0 on error
+ *     1 if return value should be the point at infinity
+ *     2 otherwise
+ */
+static int gf2m_Mxy(const EC_GROUP *group, const BIGNUM *x, const BIGNUM *y, BIGNUM *x1, 
+	BIGNUM *z1, BIGNUM *x2, BIGNUM *z2, BN_CTX *ctx)
+	{
+	BIGNUM *t3, *t4, *t5;
+	int ret = 0;
+	
+	if (BN_is_zero(z1))
+		{
+		BN_zero(x2);
+		BN_zero(z2);
+		return 1;
+		}
+	
+	if (BN_is_zero(z2))
+		{
+		if (!BN_copy(x2, x)) return 0;
+		if (!BN_GF2m_add(z2, x, y)) return 0;
+		return 2;
+		}
+		
+	/* Since Mxy is static we can guarantee that ctx != NULL. */
+	BN_CTX_start(ctx);
+	t3 = BN_CTX_get(ctx);
+	t4 = BN_CTX_get(ctx);
+	t5 = BN_CTX_get(ctx);
+	if (t5 == NULL) goto err;
+
+	if (!BN_one(t5)) goto err;
+
+	if (!group->meth->field_mul(group, t3, z1, z2, ctx)) goto err;
+
+	if (!group->meth->field_mul(group, z1, z1, x, ctx)) goto err;
+	if (!BN_GF2m_add(z1, z1, x1)) goto err;
+	if (!group->meth->field_mul(group, z2, z2, x, ctx)) goto err;
+	if (!group->meth->field_mul(group, x1, z2, x1, ctx)) goto err;
+	if (!BN_GF2m_add(z2, z2, x2)) goto err;
+
+	if (!group->meth->field_mul(group, z2, z2, z1, ctx)) goto err;
+	if (!group->meth->field_sqr(group, t4, x, ctx)) goto err;
+	if (!BN_GF2m_add(t4, t4, y)) goto err;
+	if (!group->meth->field_mul(group, t4, t4, t3, ctx)) goto err;
+	if (!BN_GF2m_add(t4, t4, z2)) goto err;
+
+	if (!group->meth->field_mul(group, t3, t3, x, ctx)) goto err;
+	if (!group->meth->field_div(group, t3, t5, t3, ctx)) goto err;
+	if (!group->meth->field_mul(group, t4, t3, t4, ctx)) goto err;
+	if (!group->meth->field_mul(group, x2, x1, t3, ctx)) goto err;
+	if (!BN_GF2m_add(z2, x2, x)) goto err;
+
+	if (!group->meth->field_mul(group, z2, z2, t4, ctx)) goto err;
+	if (!BN_GF2m_add(z2, z2, y)) goto err;
+
+	ret = 2;
+
+ err:
+	BN_CTX_end(ctx);
+	return ret;
+	}
+
+/* Computes scalar*point and stores the result in r.
+ * point can not equal r.
+ * Uses algorithm 2P of
+ *     Lopez, J. and Dahab, R.  "Fast multiplication on elliptic curves over 
+ *     GF(2^m) without precomputation" (CHES '99, LNCS 1717).
+ */
+static int ec_GF2m_montgomery_point_multiply(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
+	const EC_POINT *point, BN_CTX *ctx)
+	{
+	BIGNUM *x1, *x2, *z1, *z2;
+	int ret = 0, i;
+	BN_ULONG mask,word;
+
+	if (r == point)
+		{
+		ECerr(EC_F_EC_GF2M_MONTGOMERY_POINT_MULTIPLY, EC_R_INVALID_ARGUMENT);
+		return 0;
+		}
+	
+	/* if result should be point at infinity */
+	if ((scalar == NULL) || BN_is_zero(scalar) || (point == NULL) || 
+		EC_POINT_is_at_infinity(group, point))
+		{
+		return EC_POINT_set_to_infinity(group, r);
+		}
+
+	/* only support affine coordinates */
+	if (!point->Z_is_one) return 0;
+
+	/* Since point_multiply is static we can guarantee that ctx != NULL. */
+	BN_CTX_start(ctx);
+	x1 = BN_CTX_get(ctx);
+	z1 = BN_CTX_get(ctx);
+	if (z1 == NULL) goto err;
+
+	x2 = &r->X;
+	z2 = &r->Y;
+
+	if (!BN_GF2m_mod_arr(x1, &point->X, group->poly)) goto err; /* x1 = x */
+	if (!BN_one(z1)) goto err; /* z1 = 1 */
+	if (!group->meth->field_sqr(group, z2, x1, ctx)) goto err; /* z2 = x1^2 = x^2 */
+	if (!group->meth->field_sqr(group, x2, z2, ctx)) goto err;
+	if (!BN_GF2m_add(x2, x2, &group->b)) goto err; /* x2 = x^4 + b */
+
+	/* find top most bit and go one past it */
+	i = scalar->top - 1;
+	mask = BN_TBIT;
+	word = scalar->d[i];
+	while (!(word & mask)) mask >>= 1;
+	mask >>= 1;
+	/* if top most bit was at word break, go to next word */
+	if (!mask) 
+		{
+		i--;
+		mask = BN_TBIT;
+		}
+
+	for (; i >= 0; i--)
+		{
+		word = scalar->d[i];
+		while (mask)
+			{
+			if (word & mask)
+				{
+				if (!gf2m_Madd(group, &point->X, x1, z1, x2, z2, ctx)) goto err;
+				if (!gf2m_Mdouble(group, x2, z2, ctx)) goto err;
+				}
+			else
+				{
+				if (!gf2m_Madd(group, &point->X, x2, z2, x1, z1, ctx)) goto err;
+				if (!gf2m_Mdouble(group, x1, z1, ctx)) goto err;
+				}
+			mask >>= 1;
+			}
+		mask = BN_TBIT;
+		}
+
+	/* convert out of "projective" coordinates */
+	i = gf2m_Mxy(group, &point->X, &point->Y, x1, z1, x2, z2, ctx);
+	if (i == 0) goto err;
+	else if (i == 1) 
+		{
+		if (!EC_POINT_set_to_infinity(group, r)) goto err;
+		}
+	else
+		{
+		if (!BN_one(&r->Z)) goto err;
+		r->Z_is_one = 1;
+		}
+
+	/* GF(2^m) field elements should always have BIGNUM::neg = 0 */
+	BN_set_negative(&r->X, 0);
+	BN_set_negative(&r->Y, 0);
+
+	ret = 1;
+
+ err:
+	BN_CTX_end(ctx);
+	return ret;
+	}
+
+
+/* Computes the sum
+ *     scalar*group->generator + scalars[0]*points[0] + ... + scalars[num-1]*points[num-1]
+ * gracefully ignoring NULL scalar values.
+ */
+int ec_GF2m_simple_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
+	size_t num, const EC_POINT *points[], const BIGNUM *scalars[], BN_CTX *ctx)
+	{
+	BN_CTX *new_ctx = NULL;
+	int ret = 0;
+	size_t i;
+	EC_POINT *p=NULL;
+	EC_POINT *acc = NULL;
+
+	if (ctx == NULL)
+		{
+		ctx = new_ctx = BN_CTX_new();
+		if (ctx == NULL)
+			return 0;
+		}
+
+	/* This implementation is more efficient than the wNAF implementation for 2
+	 * or fewer points.  Use the ec_wNAF_mul implementation for 3 or more points,
+	 * or if we can perform a fast multiplication based on precomputation.
+	 */
+	if ((scalar && (num > 1)) || (num > 2) || (num == 0 && EC_GROUP_have_precompute_mult(group)))
+		{
+		ret = ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx);
+		goto err;
+		}
+
+	if ((p = EC_POINT_new(group)) == NULL) goto err;
+	if ((acc = EC_POINT_new(group)) == NULL) goto err;
+
+	if (!EC_POINT_set_to_infinity(group, acc)) goto err;
+
+	if (scalar)
+		{
+		if (!ec_GF2m_montgomery_point_multiply(group, p, scalar, group->generator, ctx)) goto err;
+		if (BN_is_negative(scalar))
+			if (!group->meth->invert(group, p, ctx)) goto err;
+		if (!group->meth->add(group, acc, acc, p, ctx)) goto err;
+		}
+
+	for (i = 0; i < num; i++)
+		{
+		if (!ec_GF2m_montgomery_point_multiply(group, p, scalars[i], points[i], ctx)) goto err;
+		if (BN_is_negative(scalars[i]))
+			if (!group->meth->invert(group, p, ctx)) goto err;
+		if (!group->meth->add(group, acc, acc, p, ctx)) goto err;
+		}
+
+	if (!EC_POINT_copy(r, acc)) goto err;
+
+	ret = 1;
+
+  err:
+	if (p) EC_POINT_free(p);
+	if (acc) EC_POINT_free(acc);
+	if (new_ctx != NULL)
+		BN_CTX_free(new_ctx);
+	return ret;
+	}
+
+
+/* Precomputation for point multiplication: fall back to wNAF methods
+ * because ec_GF2m_simple_mul() uses ec_wNAF_mul() if appropriate */
+
+int ec_GF2m_precompute_mult(EC_GROUP *group, BN_CTX *ctx)
+	{
+	return ec_wNAF_precompute_mult(group, ctx);
+ 	}
+
+int ec_GF2m_have_precompute_mult(const EC_GROUP *group)
+	{
+	return ec_wNAF_have_precompute_mult(group);
+ 	}