C++ BN_GF2m_add函数代码示例

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本文整理汇总了C++中BN_GF2m_add函数的典型用法代码示例。如果您正苦于以下问题：C++ BN_GF2m_add函数的具体用法？C++ BN_GF2m_add怎么用？C++ BN_GF2m_add使用的例子？那么恭喜您, 这里精选的函数代码示例或许可以为您提供帮助。

在下文中一共展示了BN_GF2m_add函数的8个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于我们的系统推荐出更棒的C++代码示例。

示例1: gf2m_Madd

/* 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;
	}

开发者ID:Chenhx，项目名称:moai-dev，代码行数:33，代码来源:ec2_mult.c

示例2: ec_GF2m_simple_is_on_curve

/*-
 * Determines whether the given EC_POINT is an actual point on the curve defined
 * in the EC_GROUP.  A point is valid if it satisfies the Weierstrass equation:
 *      y^2 + x*y = x^3 + a*x^2 + b.
 */
int ec_GF2m_simple_is_on_curve(const EC_GROUP *group, const EC_POINT *point,
                               BN_CTX *ctx)
{
    int ret = -1;
    BN_CTX *new_ctx = NULL;
    BIGNUM *lh, *y2;
    int (*field_mul) (const EC_GROUP *, BIGNUM *, const BIGNUM *,
                      const BIGNUM *, BN_CTX *);
    int (*field_sqr) (const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);

    if (EC_POINT_is_at_infinity(group, point))
        return 1;

    field_mul = group->meth->field_mul;
    field_sqr = group->meth->field_sqr;

    /* only support affine coordinates */
    if (!point->Z_is_one)
        return -1;

    if (ctx == NULL) {
        ctx = new_ctx = BN_CTX_new();
        if (ctx == NULL)
            return -1;
    }

    BN_CTX_start(ctx);
    y2 = BN_CTX_get(ctx);
    lh = BN_CTX_get(ctx);
    if (lh == NULL)
        goto err;

    /*-
     * We have a curve defined by a Weierstrass equation
     *      y^2 + x*y = x^3 + a*x^2 + b.
     *  <=> x^3 + a*x^2 + x*y + b + y^2 = 0
     *  <=> ((x + a) * x + y ) * x + b + y^2 = 0
     */
    if (!BN_GF2m_add(lh, &point->X, &group->a))
        goto err;
    if (!field_mul(group, lh, lh, &point->X, ctx))
        goto err;
    if (!BN_GF2m_add(lh, lh, &point->Y))
        goto err;
    if (!field_mul(group, lh, lh, &point->X, ctx))
        goto err;
    if (!BN_GF2m_add(lh, lh, &group->b))
        goto err;
    if (!field_sqr(group, y2, &point->Y, ctx))
        goto err;
    if (!BN_GF2m_add(lh, lh, y2))
        goto err;
    ret = BN_is_zero(lh);
 err:
    if (ctx)
        BN_CTX_end(ctx);
    if (new_ctx)
        BN_CTX_free(new_ctx);
    return ret;
}

开发者ID:commshare，项目名称:testST，代码行数:65，代码来源:ec2_smpl.c

示例3: gf2m_Mdouble

/*-
 * 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;
}

开发者ID:03050903，项目名称:godot，代码行数:41，代码来源:ec2_mult.c

示例4: ec_GF2m_simple_invert

int ec_GF2m_simple_invert(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
	{
	if (EC_POINT_is_at_infinity(group, point) || BN_is_zero(&point->Y))
		/* point is its own inverse */
		return 1;
	
	if (!EC_POINT_make_affine(group, point, ctx)) return 0;
	return BN_GF2m_add(&point->Y, &point->X, &point->Y);
	}

开发者ID:vmlemon，项目名称:OpenBSD-lib-patches，代码行数:9，代码来源:ec2_smpl.c

示例5: gf2m_Mxy

/* 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;
	}

开发者ID:Chenhx，项目名称:moai-dev，代码行数:67，代码来源:ec2_mult.c

示例6: ec_GF2m_montgomery_point_multiply

/* Computes scalar*point and stores the result in r.
 * point can not equal r.
 * Uses a modified algorithm 2P of
 *     Lopez, J. and Dahab, R.  "Fast multiplication on elliptic curves over 
 *     GF(2^m) without precomputation" (CHES '99, LNCS 1717).
 *
 * To protect against side-channel attack the function uses constant time swap,
 * avoiding conditional branches.
 */
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;

	bn_wexpand(x1, group->field.top);
	bn_wexpand(z1, group->field.top);
	bn_wexpand(x2, group->field.top);
	bn_wexpand(z2, group->field.top);

	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)
			{
			BN_consttime_swap(word & mask, x1, x2, group->field.top);
			BN_consttime_swap(word & mask, z1, z2, group->field.top);
			if (!gf2m_Madd(group, &point->X, x2, z2, x1, z1, ctx)) goto err;
			if (!gf2m_Mdouble(group, x1, z1, ctx)) goto err;
			BN_consttime_swap(word & mask, x1, x2, group->field.top);
			BN_consttime_swap(word & mask, z1, z2, group->field.top);
			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;

//.........这里部分代码省略.........

开发者ID:Chenhx，项目名称:moai-dev，代码行数:101，代码来源:ec2_mult.c

示例7: ec_GF2m_simple_add

/*
 * Computes a + b and stores the result in r.  r could be a or b, a could be
 * b. Uses algorithm A.10.2 of IEEE P1363.
 */
int ec_GF2m_simple_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
                       const EC_POINT *b, BN_CTX *ctx)
{
    BN_CTX *new_ctx = NULL;
    BIGNUM *x0, *y0, *x1, *y1, *x2, *y2, *s, *t;
    int ret = 0;

    if (EC_POINT_is_at_infinity(group, a)) {
        if (!EC_POINT_copy(r, b))
            return 0;
        return 1;
    }

    if (EC_POINT_is_at_infinity(group, b)) {
        if (!EC_POINT_copy(r, a))
            return 0;
        return 1;
    }

    if (ctx == NULL) {
        ctx = new_ctx = BN_CTX_new();
        if (ctx == NULL)
            return 0;
    }

    BN_CTX_start(ctx);
    x0 = BN_CTX_get(ctx);
    y0 = BN_CTX_get(ctx);
    x1 = BN_CTX_get(ctx);
    y1 = BN_CTX_get(ctx);
    x2 = BN_CTX_get(ctx);
    y2 = BN_CTX_get(ctx);
    s = BN_CTX_get(ctx);
    t = BN_CTX_get(ctx);
    if (t == NULL)
        goto err;

    if (a->Z_is_one) {
        if (!BN_copy(x0, &a->X))
            goto err;
        if (!BN_copy(y0, &a->Y))
            goto err;
    } else {
        if (!EC_POINT_get_affine_coordinates_GF2m(group, a, x0, y0, ctx))
            goto err;
    }
    if (b->Z_is_one) {
        if (!BN_copy(x1, &b->X))
            goto err;
        if (!BN_copy(y1, &b->Y))
            goto err;
    } else {
        if (!EC_POINT_get_affine_coordinates_GF2m(group, b, x1, y1, ctx))
            goto err;
    }

    if (BN_GF2m_cmp(x0, x1)) {
        if (!BN_GF2m_add(t, x0, x1))
            goto err;
        if (!BN_GF2m_add(s, y0, y1))
            goto err;
        if (!group->meth->field_div(group, s, s, t, ctx))
            goto err;
        if (!group->meth->field_sqr(group, x2, s, ctx))
            goto err;
        if (!BN_GF2m_add(x2, x2, &group->a))
            goto err;
        if (!BN_GF2m_add(x2, x2, s))
            goto err;
        if (!BN_GF2m_add(x2, x2, t))
            goto err;
    } else {
        if (BN_GF2m_cmp(y0, y1) || BN_is_zero(x1)) {
            if (!EC_POINT_set_to_infinity(group, r))
                goto err;
            ret = 1;
            goto err;
        }
        if (!group->meth->field_div(group, s, y1, x1, ctx))
            goto err;
        if (!BN_GF2m_add(s, s, x1))
            goto err;

        if (!group->meth->field_sqr(group, x2, s, ctx))
            goto err;
        if (!BN_GF2m_add(x2, x2, s))
            goto err;
        if (!BN_GF2m_add(x2, x2, &group->a))
            goto err;
    }

    if (!BN_GF2m_add(y2, x1, x2))
        goto err;
    if (!group->meth->field_mul(group, y2, y2, s, ctx))
        goto err;
    if (!BN_GF2m_add(y2, y2, x2))
//.........这里部分代码省略.........

开发者ID:commshare，项目名称:testST，代码行数:101，代码来源:ec2_smpl.c

示例8: ec_GF2m_simple_set_compressed_coordinates

/*-
 * Calculates and sets the affine coordinates of an EC_POINT from the given
 * compressed coordinates.  Uses algorithm 2.3.4 of SEC 1.
 * Note that the simple implementation only uses affine coordinates.
 *
 * The method is from the following publication:
 *
 *     Harper, Menezes, Vanstone:
 *     "Public-Key Cryptosystems with Very Small Key Lengths",
 *     EUROCRYPT '92, Springer-Verlag LNCS 658,
 *     published February 1993
 *
 * US Patents 6,141,420 and 6,618,483 (Vanstone, Mullin, Agnew) describe
 * the same method, but claim no priority date earlier than July 29, 1994
 * (and additionally fail to cite the EUROCRYPT '92 publication as prior art).
 */
int ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *group,
                                              EC_POINT *point,
                                              const BIGNUM *x_, int y_bit,
                                              BN_CTX *ctx)
{
    BN_CTX *new_ctx = NULL;
    BIGNUM *tmp, *x, *y, *z;
    int ret = 0, z0;

    /* clear error queue */
    ERR_clear_error();

    if (ctx == NULL) {
        ctx = new_ctx = BN_CTX_new();
        if (ctx == NULL)
            return 0;
    }

    y_bit = (y_bit != 0) ? 1 : 0;

    BN_CTX_start(ctx);
    tmp = BN_CTX_get(ctx);
    x = BN_CTX_get(ctx);
    y = BN_CTX_get(ctx);
    z = BN_CTX_get(ctx);
    if (z == NULL)
        goto err;

    if (!BN_GF2m_mod_arr(x, x_, group->poly))
        goto err;
    if (BN_is_zero(x)) {
        if (!BN_GF2m_mod_sqrt_arr(y, &group->b, group->poly, ctx))
            goto err;
    } else {
        if (!group->meth->field_sqr(group, tmp, x, ctx))
            goto err;
        if (!group->meth->field_div(group, tmp, &group->b, tmp, ctx))
            goto err;
        if (!BN_GF2m_add(tmp, &group->a, tmp))
            goto err;
        if (!BN_GF2m_add(tmp, x, tmp))
            goto err;
        if (!BN_GF2m_mod_solve_quad_arr(z, tmp, group->poly, ctx)) {
            unsigned long err = ERR_peek_last_error();

            if (ERR_GET_LIB(err) == ERR_LIB_BN
                && ERR_GET_REASON(err) == BN_R_NO_SOLUTION) {
                ERR_clear_error();
                ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES,
                      EC_R_INVALID_COMPRESSED_POINT);
            } else
                ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES,
                      ERR_R_BN_LIB);
            goto err;
        }
        z0 = (BN_is_odd(z)) ? 1 : 0;
        if (!group->meth->field_mul(group, y, x, z, ctx))
            goto err;
        if (z0 != y_bit) {
            if (!BN_GF2m_add(y, y, x))
                goto err;
        }
    }

    if (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ctx))
        goto err;

    ret = 1;

 err:
    BN_CTX_end(ctx);
    if (new_ctx != NULL)
        BN_CTX_free(new_ctx);
    return ret;
}

开发者ID:commshare，项目名称:testST，代码行数:91，代码来源:ec2_smpl.c

注：本文中的BN_GF2m_add函数示例整理自Github/MSDocs等源码及文档管理平台，相关代码片段筛选自各路编程大神贡献的开源项目，源码版权归原作者所有，传播和使用请参考对应项目的License；未经允许，请勿转载。