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C++ BN_CTX_start函數代碼示例

本文整理匯總了C++中BN_CTX_start函數的典型用法代碼示例。如果您正苦於以下問題:C++ BN_CTX_start函數的具體用法?C++ BN_CTX_start怎麽用?C++ BN_CTX_start使用的例子?那麽, 這裏精選的函數代碼示例或許可以為您提供幫助。


在下文中一共展示了BN_CTX_start函數的15個代碼示例,這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚,您的評價將有助於係統推薦出更棒的C++代碼示例。

示例1: EC_KEY_set_public_key_affine_coordinates

int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x,
                                             BIGNUM *y)
{
    BN_CTX *ctx = NULL;
    BIGNUM *tx, *ty;
    EC_POINT *point = NULL;
    int ok = 0;
#ifndef OPENSSL_NO_EC2M
    int tmp_nid, is_char_two = 0;
#endif

    if (key == NULL || key->group == NULL || x == NULL || y == NULL) {
        ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
              ERR_R_PASSED_NULL_PARAMETER);
        return 0;
    }
    ctx = BN_CTX_new();
    if (ctx == NULL)
        return 0;

    BN_CTX_start(ctx);
    point = EC_POINT_new(key->group);

    if (point == NULL)
        goto err;

    tx = BN_CTX_get(ctx);
    ty = BN_CTX_get(ctx);
    if (ty == NULL)
        goto err;

#ifndef OPENSSL_NO_EC2M
    tmp_nid = EC_METHOD_get_field_type(EC_GROUP_method_of(key->group));

    if (tmp_nid == NID_X9_62_characteristic_two_field)
        is_char_two = 1;

    if (is_char_two) {
        if (!EC_POINT_set_affine_coordinates_GF2m(key->group, point,
                                                  x, y, ctx))
            goto err;
        if (!EC_POINT_get_affine_coordinates_GF2m(key->group, point,
                                                  tx, ty, ctx))
            goto err;
    } else
#endif
    {
        if (!EC_POINT_set_affine_coordinates_GFp(key->group, point,
                                                 x, y, ctx))
            goto err;
        if (!EC_POINT_get_affine_coordinates_GFp(key->group, point,
                                                 tx, ty, ctx))
            goto err;
    }
    /*
     * Check if retrieved coordinates match originals and are less than field
     * order: if not values are out of range.
     */
    if (BN_cmp(x, tx) || BN_cmp(y, ty)
        || (BN_cmp(x, key->group->field) >= 0)
        || (BN_cmp(y, key->group->field) >= 0)) {
        ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
              EC_R_COORDINATES_OUT_OF_RANGE);
        goto err;
    }

    if (!EC_KEY_set_public_key(key, point))
        goto err;

    if (EC_KEY_check_key(key) == 0)
        goto err;

    ok = 1;

 err:
    BN_CTX_end(ctx);
    BN_CTX_free(ctx);
    EC_POINT_free(point);
    return ok;

}
開發者ID:2007750219,項目名稱:openssl,代碼行數:81,代碼來源:ec_key.c

示例2: ec_GF2m_montgomery_point_multiply

/* 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;
	}
開發者ID:Sorcha,項目名稱:NETMF-LPC,代碼行數:100,代碼來源:ec2_mult.cpp

示例3: ec_GFp_simple_add

int ec_GFp_simple_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
                      const EC_POINT *b, BN_CTX *ctx)
{
    int (*field_mul) (const EC_GROUP *, BIGNUM *, const BIGNUM *,
                      const BIGNUM *, BN_CTX *);
    int (*field_sqr) (const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
    const BIGNUM *p;
    BN_CTX *new_ctx = NULL;
    BIGNUM *n0, *n1, *n2, *n3, *n4, *n5, *n6;
    int ret = 0;

    if (a == b)
        return EC_POINT_dbl(group, r, a, ctx);
    if (EC_POINT_is_at_infinity(group, a))
        return EC_POINT_copy(r, b);
    if (EC_POINT_is_at_infinity(group, b))
        return EC_POINT_copy(r, a);

    field_mul = group->meth->field_mul;
    field_sqr = group->meth->field_sqr;
    p = &group->field;

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

    BN_CTX_start(ctx);
    n0 = BN_CTX_get(ctx);
    n1 = BN_CTX_get(ctx);
    n2 = BN_CTX_get(ctx);
    n3 = BN_CTX_get(ctx);
    n4 = BN_CTX_get(ctx);
    n5 = BN_CTX_get(ctx);
    n6 = BN_CTX_get(ctx);
    if (n6 == NULL)
        goto end;

    /*
     * Note that in this function we must not read components of 'a' or 'b'
     * once we have written the corresponding components of 'r'. ('r' might
     * be one of 'a' or 'b'.)
     */

    /* n1, n2 */
    if (b->Z_is_one) {
        if (!BN_copy(n1, &a->X))
            goto end;
        if (!BN_copy(n2, &a->Y))
            goto end;
        /* n1 = X_a */
        /* n2 = Y_a */
    } else {
        if (!field_sqr(group, n0, &b->Z, ctx))
            goto end;
        if (!field_mul(group, n1, &a->X, n0, ctx))
            goto end;
        /* n1 = X_a * Z_b^2 */

        if (!field_mul(group, n0, n0, &b->Z, ctx))
            goto end;
        if (!field_mul(group, n2, &a->Y, n0, ctx))
            goto end;
        /* n2 = Y_a * Z_b^3 */
    }

    /* n3, n4 */
    if (a->Z_is_one) {
        if (!BN_copy(n3, &b->X))
            goto end;
        if (!BN_copy(n4, &b->Y))
            goto end;
        /* n3 = X_b */
        /* n4 = Y_b */
    } else {
        if (!field_sqr(group, n0, &a->Z, ctx))
            goto end;
        if (!field_mul(group, n3, &b->X, n0, ctx))
            goto end;
        /* n3 = X_b * Z_a^2 */

        if (!field_mul(group, n0, n0, &a->Z, ctx))
            goto end;
        if (!field_mul(group, n4, &b->Y, n0, ctx))
            goto end;
        /* n4 = Y_b * Z_a^3 */
    }

    /* n5, n6 */
    if (!BN_mod_sub_quick(n5, n1, n3, p))
        goto end;
    if (!BN_mod_sub_quick(n6, n2, n4, p))
        goto end;
    /* n5 = n1 - n3 */
    /* n6 = n2 - n4 */

    if (BN_is_zero(n5)) {
        if (BN_is_zero(n6)) {
            /* a is the same point as b */
//.........這裏部分代碼省略.........
開發者ID:GrayKing,項目名稱:Leakfix-on-OpenSSL,代碼行數:101,代碼來源:ecp_smpl.c

示例4: ECDSA_SIG_recover_key_GFp

// Perform ECDSA key recovery (see SEC1 4.1.6) for curves over (mod p)-fields
// recid selects which key is recovered
// if check is non-zero, additional checks are performed
int ECDSA_SIG_recover_key_GFp(EC_KEY *eckey, ECDSA_SIG *ecsig, const unsigned char *msg, int msglen, int recid, int check)
{
    if (!eckey) return 0;

    int ret = 0;
    BN_CTX *ctx = NULL;

    BIGNUM *x = NULL;
    BIGNUM *e = NULL;
    BIGNUM *order = NULL;
    BIGNUM *sor = NULL;
    BIGNUM *eor = NULL;
    BIGNUM *field = NULL;
    EC_POINT *R = NULL;
    EC_POINT *O = NULL;
    EC_POINT *Q = NULL;
    BIGNUM *rr = NULL;
    BIGNUM *zero = NULL;
    int n = 0;
    int i = recid / 2;

    const EC_GROUP *group = EC_KEY_get0_group(eckey);
    if ((ctx = BN_CTX_new()) == NULL) { ret = -1; goto err; }
    BN_CTX_start(ctx);
    order = BN_CTX_get(ctx);
    if (!EC_GROUP_get_order(group, order, ctx)) { ret = -2; goto err; }
    x = BN_CTX_get(ctx);
    if (!BN_copy(x, order)) { ret=-1; goto err; }
    if (!BN_mul_word(x, i)) { ret=-1; goto err; }
    if (!BN_add(x, x, ecsig->r)) { ret=-1; goto err; }
    field = BN_CTX_get(ctx);
    if (!EC_GROUP_get_curve_GFp(group, field, NULL, NULL, ctx)) { ret=-2; goto err; }
    if (BN_cmp(x, field) >= 0) { ret=0; goto err; }
    if ((R = EC_POINT_new(group)) == NULL) { ret = -2; goto err; }
    if (!EC_POINT_set_compressed_coordinates_GFp(group, R, x, recid % 2, ctx)) { ret=0; goto err; }
    if (check)
    {
        if ((O = EC_POINT_new(group)) == NULL) { ret = -2; goto err; }
        if (!EC_POINT_mul(group, O, NULL, R, order, ctx)) { ret=-2; goto err; }
        if (!EC_POINT_is_at_infinity(group, O)) { ret = 0; goto err; }
    }
    if ((Q = EC_POINT_new(group)) == NULL) { ret = -2; goto err; }
    n = EC_GROUP_get_degree(group);
    e = BN_CTX_get(ctx);
    if (!BN_bin2bn(msg, msglen, e)) { ret=-1; goto err; }
    if (8*msglen > n) BN_rshift(e, e, 8-(n & 7));
    zero = BN_CTX_get(ctx);
    if (!BN_zero(zero)) { ret=-1; goto err; }
    if (!BN_mod_sub(e, zero, e, order, ctx)) { ret=-1; goto err; }
    rr = BN_CTX_get(ctx);
    if (!BN_mod_inverse(rr, ecsig->r, order, ctx)) { ret=-1; goto err; }
    sor = BN_CTX_get(ctx);
    if (!BN_mod_mul(sor, ecsig->s, rr, order, ctx)) { ret=-1; goto err; }
    eor = BN_CTX_get(ctx);
    if (!BN_mod_mul(eor, e, rr, order, ctx)) { ret=-1; goto err; }
    if (!EC_POINT_mul(group, Q, eor, R, sor, ctx)) { ret=-2; goto err; }
    if (!EC_KEY_set_public_key(eckey, Q)) { ret=-2; goto err; }

    ret = 1;

err:
    if (ctx) {
        BN_CTX_end(ctx);
        BN_CTX_free(ctx);
    }
    if (R != NULL) EC_POINT_free(R);
    if (O != NULL) EC_POINT_free(O);
    if (Q != NULL) EC_POINT_free(Q);
    return ret;
}
開發者ID:JohnLZeller,項目名稱:Gridcoin-Research,代碼行數:73,代碼來源:key.cpp

示例5: ec_GFp_simple_point_get_affine_coordinates

int ec_GFp_simple_point_get_affine_coordinates(const EC_GROUP *group,
                                               const EC_POINT *point,
                                               BIGNUM *x, BIGNUM *y,
                                               BN_CTX *ctx)
{
    BN_CTX *new_ctx = NULL;
    BIGNUM *Z, *Z_1, *Z_2, *Z_3;
    const BIGNUM *Z_;
    int ret = 0;

    if (EC_POINT_is_at_infinity(group, point)) {
        ECerr(EC_F_EC_GFP_SIMPLE_POINT_GET_AFFINE_COORDINATES,
              EC_R_POINT_AT_INFINITY);
        return 0;
    }

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

    BN_CTX_start(ctx);
    Z = BN_CTX_get(ctx);
    Z_1 = BN_CTX_get(ctx);
    Z_2 = BN_CTX_get(ctx);
    Z_3 = BN_CTX_get(ctx);
    if (Z_3 == NULL)
        goto err;

    /* transform  (X, Y, Z)  into  (x, y) := (X/Z^2, Y/Z^3) */

    if (group->meth->field_decode) {
        if (!group->meth->field_decode(group, Z, &point->Z, ctx))
            goto err;
        Z_ = Z;
    } else {
        Z_ = &point->Z;
    }

    if (BN_is_one(Z_)) {
        if (group->meth->field_decode) {
            if (x != NULL) {
                if (!group->meth->field_decode(group, x, &point->X, ctx))
                    goto err;
            }
            if (y != NULL) {
                if (!group->meth->field_decode(group, y, &point->Y, ctx))
                    goto err;
            }
        } else {
            if (x != NULL) {
                if (!BN_copy(x, &point->X))
                    goto err;
            }
            if (y != NULL) {
                if (!BN_copy(y, &point->Y))
                    goto err;
            }
        }
    } else {
        if (!BN_mod_inverse(Z_1, Z_, &group->field, ctx)) {
            ECerr(EC_F_EC_GFP_SIMPLE_POINT_GET_AFFINE_COORDINATES,
                  ERR_R_BN_LIB);
            goto err;
        }

        if (group->meth->field_encode == 0) {
            /* field_sqr works on standard representation */
            if (!group->meth->field_sqr(group, Z_2, Z_1, ctx))
                goto err;
        } else {
            if (!BN_mod_sqr(Z_2, Z_1, &group->field, ctx))
                goto err;
        }

        if (x != NULL) {
            /*
             * in the Montgomery case, field_mul will cancel out Montgomery
             * factor in X:
             */
            if (!group->meth->field_mul(group, x, &point->X, Z_2, ctx))
                goto err;
        }

        if (y != NULL) {
            if (group->meth->field_encode == 0) {
                /*
                 * field_mul works on standard representation
                 */
                if (!group->meth->field_mul(group, Z_3, Z_2, Z_1, ctx))
                    goto err;
            } else {
                if (!BN_mod_mul(Z_3, Z_2, Z_1, &group->field, ctx))
                    goto err;
            }

            /*
             * in the Montgomery case, field_mul will cancel out Montgomery
             * factor in Y:
//.........這裏部分代碼省略.........
開發者ID:derekmarcotte,項目名稱:freebsd,代碼行數:101,代碼來源:ecp_smpl.c

示例6: 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) > 0) {
		if (!EC_POINT_copy(r, b))
			return 0;
		return 1;
	}
	if (EC_POINT_is_at_infinity(group, b) > 0) {
		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);
	if ((x0 = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((y0 = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((x1 = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((y1 = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((x2 = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((y2 = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((s = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((t = BN_CTX_get(ctx)) == 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))
//.........這裏部分代碼省略.........
開發者ID:Heratom,項目名稱:Firefly-project,代碼行數:101,代碼來源:ec2_smpl.c

示例7: ec_GFp_simple_point2oct

size_t ec_GFp_simple_point2oct(const EC_GROUP *group, const EC_POINT *point, point_conversion_form_t form,
	unsigned char *buf, size_t len, BN_CTX *ctx)
	{
	size_t ret;
	BN_CTX *new_ctx = NULL;
	int used_ctx = 0;
	BIGNUM *x, *y;
	size_t field_len, i, skip;

	if ((form != POINT_CONVERSION_COMPRESSED)
		&& (form != POINT_CONVERSION_UNCOMPRESSED)
		&& (form != POINT_CONVERSION_HYBRID))
		{
		ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_INVALID_FORM);
		goto err;
		}

	if (EC_POINT_is_at_infinity(group, point))
		{
		/* encodes to a single 0 octet */
		if (buf != NULL)
			{
			if (len < 1)
				{
				ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
				return 0;
				}
			buf[0] = 0;
			}
		return 1;
		}


	/* ret := required output buffer length */
	field_len = BN_num_bytes(&group->field);
	ret = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;

	/* if 'buf' is NULL, just return required length */
	if (buf != NULL)
		{
		if (len < ret)
			{
			ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
			goto err;
			}

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

		BN_CTX_start(ctx);
		used_ctx = 1;
		x = BN_CTX_get(ctx);
		y = BN_CTX_get(ctx);
		if (y == NULL) goto err;

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

		if ((form == POINT_CONVERSION_COMPRESSED || form == POINT_CONVERSION_HYBRID) && BN_is_odd(y))
			buf[0] = form + 1;
		else
			buf[0] = form;
	
		i = 1;
		
		skip = field_len - BN_num_bytes(x);
		if (skip > field_len)
			{
			ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
			goto err;
			}
		while (skip > 0)
			{
			buf[i++] = 0;
			skip--;
			}
		skip = BN_bn2bin(x, buf + i);
		i += skip;
		if (i != 1 + field_len)
			{
			ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
			goto err;
			}

		if (form == POINT_CONVERSION_UNCOMPRESSED || form == POINT_CONVERSION_HYBRID)
			{
			skip = field_len - BN_num_bytes(y);
			if (skip > field_len)
				{
				ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
				goto err;
				}
			while (skip > 0)
				{
				buf[i++] = 0;
				skip--;
				}
//.........這裏部分代碼省略.........
開發者ID:imgits,項目名稱:rkanalyzer,代碼行數:101,代碼來源:ecp_smpl.c

示例8: ec_GFp_simple_oct2point

int ec_GFp_simple_oct2point(const EC_GROUP *group, EC_POINT *point,
	const unsigned char *buf, size_t len, BN_CTX *ctx)
	{
	point_conversion_form_t form;
	int y_bit;
	BN_CTX *new_ctx = NULL;
	BIGNUM *x, *y;
	size_t field_len, enc_len;
	int ret = 0;

	if (len == 0)
		{
		ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_BUFFER_TOO_SMALL);
		return 0;
		}
	form = buf[0];
	y_bit = form & 1;
	form = form & ~1U;
	if ((form != 0)	&& (form != POINT_CONVERSION_COMPRESSED)
		&& (form != POINT_CONVERSION_UNCOMPRESSED)
		&& (form != POINT_CONVERSION_HYBRID))
		{
		ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
		return 0;
		}
	if ((form == 0 || form == POINT_CONVERSION_UNCOMPRESSED) && y_bit)
		{
		ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
		return 0;
		}

	if (form == 0)
		{
		if (len != 1)
			{
			ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
			return 0;
			}

		return EC_POINT_set_to_infinity(group, point);
		}
	
	field_len = BN_num_bytes(&group->field);
	enc_len = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;

	if (len != enc_len)
		{
		ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
		return 0;
		}

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

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

	if (!BN_bin2bn(buf + 1, (int)field_len, x)) goto err;
	if (BN_ucmp(x, &group->field) >= 0)
		{
		ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
		goto err;
		}

	if (form == POINT_CONVERSION_COMPRESSED)
		{
		if (!EC_POINT_set_compressed_coordinates_GFp(group, point, x, y_bit, ctx)) goto err;
		}
	else
		{
		if (!BN_bin2bn(buf + 1 + field_len, (int)field_len, y)) goto err;
		if (BN_ucmp(y, &group->field) >= 0)
			{
			ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
			goto err;
			}
		if (form == POINT_CONVERSION_HYBRID)
			{
			if (y_bit != BN_is_odd(y))
				{
				ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
				goto err;
				}
			}

		if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
		}
	
	if (!EC_POINT_is_on_curve(group, point, ctx)) /* test required by X9.62 */
		{
		ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_POINT_IS_NOT_ON_CURVE);
		goto err;
		}

//.........這裏部分代碼省略.........
開發者ID:imgits,項目名稱:rkanalyzer,代碼行數:101,代碼來源:ecp_smpl.c

示例9: ec_GFp_simple_points_make_affine

int ec_GFp_simple_points_make_affine(const EC_GROUP *group, size_t num, EC_POINT *points[], BN_CTX *ctx)
	{
	BN_CTX *new_ctx = NULL;
	BIGNUM *tmp0, *tmp1;
	size_t pow2 = 0;
	BIGNUM **heap = NULL;
	size_t i;
	int ret = 0;

	if (num == 0)
		return 1;

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

	BN_CTX_start(ctx);
	tmp0 = BN_CTX_get(ctx);
	tmp1 = BN_CTX_get(ctx);
	if (tmp0  == NULL || tmp1 == NULL) goto err;

	/* Before converting the individual points, compute inverses of all Z values.
	 * Modular inversion is rather slow, but luckily we can do with a single
	 * explicit inversion, plus about 3 multiplications per input value.
	 */

	pow2 = 1;
	while (num > pow2)
		pow2 <<= 1;
	/* Now pow2 is the smallest power of 2 satifsying pow2 >= num.
	 * We need twice that. */
	pow2 <<= 1;

	heap = OPENSSL_malloc(pow2 * sizeof heap[0]);
	if (heap == NULL) goto err;
	
	/* The array is used as a binary tree, exactly as in heapsort:
	 *
	 *                               heap[1]
	 *                 heap[2]                     heap[3]
	 *          heap[4]       heap[5]       heap[6]       heap[7]
	 *   heap[8]heap[9] heap[10]heap[11] heap[12]heap[13] heap[14] heap[15]
	 *
	 * We put the Z's in the last line;
	 * then we set each other node to the product of its two child-nodes (where
	 * empty or 0 entries are treated as ones);
	 * then we invert heap[1];
	 * then we invert each other node by replacing it by the product of its
	 * parent (after inversion) and its sibling (before inversion).
	 */
	heap[0] = NULL;
	for (i = pow2/2 - 1; i > 0; i--)
		heap[i] = NULL;
	for (i = 0; i < num; i++)
		heap[pow2/2 + i] = &points[i]->Z;
	for (i = pow2/2 + num; i < pow2; i++)
		heap[i] = NULL;
	
	/* set each node to the product of its children */
	for (i = pow2/2 - 1; i > 0; i--)
		{
		heap[i] = BN_new();
		if (heap[i] == NULL) goto err;
		
		if (heap[2*i] != NULL)
			{
			if ((heap[2*i + 1] == NULL) || BN_is_zero(heap[2*i + 1]))
				{
				if (!BN_copy(heap[i], heap[2*i])) goto err;
				}
			else
				{
				if (BN_is_zero(heap[2*i]))
					{
					if (!BN_copy(heap[i], heap[2*i + 1])) goto err;
					}
				else
					{
					if (!group->meth->field_mul(group, heap[i],
						heap[2*i], heap[2*i + 1], ctx)) goto err;
					}
				}
			}
		}

	/* invert heap[1] */
	if (!BN_is_zero(heap[1]))
		{
		if (!BN_mod_inverse(heap[1], heap[1], &group->field, ctx))
			{
			ECerr(EC_F_EC_GFP_SIMPLE_POINTS_MAKE_AFFINE, ERR_R_BN_LIB);
			goto err;
			}
		}
	if (group->meth->field_encode != 0)
		{
		/* in the Montgomery case, we just turned  R*H  (representing H)
//.........這裏部分代碼省略.........
開發者ID:imgits,項目名稱:rkanalyzer,代碼行數:101,代碼來源:ecp_smpl.c

示例10: ec_GFp_simple_set_compressed_coordinates

int ec_GFp_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 *tmp1, *tmp2, *x, *y;
	int ret = 0;

	/* 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);

	BN_CTX_start(ctx);
	tmp1 = BN_CTX_get(ctx);
	tmp2 = BN_CTX_get(ctx);
	x = BN_CTX_get(ctx);
	y = BN_CTX_get(ctx);
	if (y == NULL) goto err;

	/* Recover y.  We have a Weierstrass equation
	 *     y^2 = x^3 + a*x + b,
	 * so  y  is one of the square roots of  x^3 + a*x + b.
	 */

	/* tmp1 := x^3 */
	if (!BN_nnmod(x, x_, &group->field,ctx)) goto err;
	if (group->meth->field_decode == 0)
		{
		/* field_{sqr,mul} work on standard representation */
		if (!group->meth->field_sqr(group, tmp2, x_, ctx)) goto err;
		if (!group->meth->field_mul(group, tmp1, tmp2, x_, ctx)) goto err;
		}
	else
		{
		if (!BN_mod_sqr(tmp2, x_, &group->field, ctx)) goto err;
		if (!BN_mod_mul(tmp1, tmp2, x_, &group->field, ctx)) goto err;
		}
	
	/* tmp1 := tmp1 + a*x */
	if (group->a_is_minus3)
		{
		if (!BN_mod_lshift1_quick(tmp2, x, &group->field)) goto err;
		if (!BN_mod_add_quick(tmp2, tmp2, x, &group->field)) goto err;
		if (!BN_mod_sub_quick(tmp1, tmp1, tmp2, &group->field)) goto err;
		}
	else
		{
		if (group->meth->field_decode)
			{
			if (!group->meth->field_decode(group, tmp2, &group->a, ctx)) goto err;
			if (!BN_mod_mul(tmp2, tmp2, x, &group->field, ctx)) goto err;
			}
		else
			{
			/* field_mul works on standard representation */
			if (!group->meth->field_mul(group, tmp2, &group->a, x, ctx)) goto err;
			}
		
		if (!BN_mod_add_quick(tmp1, tmp1, tmp2, &group->field)) goto err;
		}
	
	/* tmp1 := tmp1 + b */
	if (group->meth->field_decode)
		{
		if (!group->meth->field_decode(group, tmp2, &group->b, ctx)) goto err;
		if (!BN_mod_add_quick(tmp1, tmp1, tmp2, &group->field)) goto err;
		}
	else
		{
		if (!BN_mod_add_quick(tmp1, tmp1, &group->b, &group->field)) goto err;
		}
	
	if (!BN_mod_sqrt(y, tmp1, &group->field, ctx))
		{
		unsigned long err = ERR_peek_last_error();
		
		if (ERR_GET_LIB(err) == ERR_LIB_BN && ERR_GET_REASON(err) == BN_R_NOT_A_SQUARE)
			{
			ERR_clear_error();
			ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, EC_R_INVALID_COMPRESSED_POINT);
			}
		else
			ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, ERR_R_BN_LIB);
		goto err;
		}

	if (y_bit != BN_is_odd(y))
		{
		if (BN_is_zero(y))
			{
			int kron;

			kron = BN_kronecker(x, &group->field, ctx);
//.........這裏部分代碼省略.........
開發者ID:imgits,項目名稱:rkanalyzer,代碼行數:101,代碼來源:ecp_smpl.c

示例11: fill_GOST2001_params

/*
 * Fills EC_KEY structure hidden in the app_data field of DSA structure
 * with parameter information, extracted from parameter array in
 * params.c file.
 *
 * Also fils DSA->q field with copy of EC_GROUP order field to make
 * DSA_size function work
 */
int fill_GOST2001_params(EC_KEY *eckey, int nid)
{
    R3410_2001_params *params = R3410_2001_paramset;
    EC_GROUP *grp = NULL;
    BIGNUM *p = NULL, *q = NULL, *a = NULL, *b = NULL, *x = NULL, *y = NULL;
    EC_POINT *P = NULL;
    BN_CTX *ctx = BN_CTX_new();
    int ok = 0;

    if (!ctx) {
        GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_MALLOC_FAILURE);
        goto err;
    }

    BN_CTX_start(ctx);
    p = BN_CTX_get(ctx);
    a = BN_CTX_get(ctx);
    b = BN_CTX_get(ctx);
    x = BN_CTX_get(ctx);
    y = BN_CTX_get(ctx);
    q = BN_CTX_get(ctx);
    if (!p || !a || !b || !x || !y || !q) {
        GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    while (params->nid != NID_undef && params->nid != nid)
        params++;
    if (params->nid == NID_undef) {
        GOSTerr(GOST_F_FILL_GOST2001_PARAMS,
                GOST_R_UNSUPPORTED_PARAMETER_SET);
        goto err;
    }
    if (!BN_hex2bn(&p, params->p)
        || !BN_hex2bn(&a, params->a)
        || !BN_hex2bn(&b, params->b)) {
        GOSTerr(GOST_F_FILL_GOST2001_PARAMS,
                ERR_R_INTERNAL_ERROR);
        goto err;
    }

    grp = EC_GROUP_new_curve_GFp(p, a, b, ctx);
    if (!grp)  {
        GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_MALLOC_FAILURE);
        goto err;
    }

    P = EC_POINT_new(grp);
    if (!P)  {
        GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_MALLOC_FAILURE);
        goto err;
    }

    if (!BN_hex2bn(&x, params->x)
        || !BN_hex2bn(&y, params->y)
        || !EC_POINT_set_affine_coordinates_GFp(grp, P, x, y, ctx)
        || !BN_hex2bn(&q, params->q))  {
        GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_INTERNAL_ERROR);
        goto err;
    }
#ifdef DEBUG_KEYS
    fprintf(stderr, "Set params index %d oid %s\nq=",
            (params - R3410_2001_paramset), OBJ_nid2sn(params->nid));
    BN_print_fp(stderr, q);
    fprintf(stderr, "\n");
#endif

    if (!EC_GROUP_set_generator(grp, P, q, NULL)) {
        GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_INTERNAL_ERROR);
        goto err;
    }
    EC_GROUP_set_curve_name(grp, params->nid);
    if (!EC_KEY_set_group(eckey, grp)) {
        GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_INTERNAL_ERROR);
        goto err;
    }
    ok = 1;
 err:
    EC_POINT_free(P);
    EC_GROUP_free(grp);
    if (ctx)
        BN_CTX_end(ctx);
    BN_CTX_free(ctx);
    return ok;
}
開發者ID:375670450,項目名稱:openssl,代碼行數:92,代碼來源:gost2001.c

示例12: gost2001_do_verify

/*
 * Verifies gost 2001 signature
 *
 */
int gost2001_do_verify(const unsigned char *dgst, int dgst_len,
                       DSA_SIG *sig, EC_KEY *ec)
{
    BN_CTX *ctx = BN_CTX_new();
    const EC_GROUP *group = EC_KEY_get0_group(ec);
    BIGNUM *order;
    BIGNUM *md = NULL, *e = NULL, *R = NULL, *v = NULL, *z1 = NULL, *z2 =
        NULL;
    BIGNUM *X = NULL, *tmp = NULL;
    EC_POINT *C = NULL;
    const EC_POINT *pub_key = NULL;
    int ok = 0;

    if (!ctx || !group) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_INTERNAL_ERROR);
        goto err;
    }

    BN_CTX_start(ctx);
    order = BN_CTX_get(ctx);
    e = BN_CTX_get(ctx);
    z1 = BN_CTX_get(ctx);
    z2 = BN_CTX_get(ctx);
    tmp = BN_CTX_get(ctx);
    X = BN_CTX_get(ctx);
    R = BN_CTX_get(ctx);
    v = BN_CTX_get(ctx);
    if (!order || !e || !z1 || !z2 || !tmp || !X || !R || !v) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_MALLOC_FAILURE);
        goto err;
    }

    pub_key = EC_KEY_get0_public_key(ec);
    if (!pub_key || !EC_GROUP_get_order(group, order, ctx)) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_INTERNAL_ERROR);
        goto err;
    }

    if (BN_is_zero(sig->s) || BN_is_zero(sig->r) ||
        (BN_cmp(sig->s, order) >= 1) || (BN_cmp(sig->r, order) >= 1)) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY,
                GOST_R_SIGNATURE_PARTS_GREATER_THAN_Q);
        goto err;

    }
    md = hashsum2bn(dgst);

    if (!md || !BN_mod(e, md, order, ctx)) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_INTERNAL_ERROR);
        goto err;
    }
#ifdef DEBUG_SIGN
    fprintf(stderr, "digest as bignum: ");
    BN_print_fp(stderr, md);
    fprintf(stderr, "\ndigest mod q: ");
    BN_print_fp(stderr, e);
#endif
    if (BN_is_zero(e) && !BN_one(e)) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_INTERNAL_ERROR);
        goto err;
    }
    v = BN_mod_inverse(v, e, order, ctx);
    if (!v
        || !BN_mod_mul(z1, sig->s, v, order, ctx)
        || !BN_sub(tmp, order, sig->r)
        || !BN_mod_mul(z2, tmp, v, order, ctx)) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_INTERNAL_ERROR);
        goto err;
    }
#ifdef DEBUG_SIGN
    fprintf(stderr, "\nInverted digest value: ");
    BN_print_fp(stderr, v);
    fprintf(stderr, "\nz1: ");
    BN_print_fp(stderr, z1);
    fprintf(stderr, "\nz2: ");
    BN_print_fp(stderr, z2);
#endif
    C = EC_POINT_new(group);
    if (!C) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    if (!EC_POINT_mul(group, C, z1, pub_key, z2, ctx)) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_EC_LIB);
        goto err;
    }
    if (!EC_POINT_get_affine_coordinates_GFp(group, C, X, NULL, ctx)) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_EC_LIB);
        goto err;
    }
    if (!BN_mod(R, X, order, ctx)) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_INTERNAL_ERROR);
        goto err;
    }
#ifdef DEBUG_SIGN
    fprintf(stderr, "\nX=");
//.........這裏部分代碼省略.........
開發者ID:375670450,項目名稱:openssl,代碼行數:101,代碼來源:gost2001.c

示例13: hashsum2bn

/*
 * Computes gost2001 signature as DSA_SIG structure
 *
 *
 */
DSA_SIG *gost2001_do_sign(const unsigned char *dgst, int dlen, EC_KEY *eckey)
{
    DSA_SIG *newsig = NULL, *ret = NULL;
    BIGNUM *md = hashsum2bn(dgst);
    BIGNUM *order = NULL;
    const EC_GROUP *group;
    const BIGNUM *priv_key;
    BIGNUM *r = NULL, *s = NULL, *X = NULL, *tmp = NULL, *tmp2 = NULL, *k =
        NULL, *e = NULL;
    EC_POINT *C = NULL;
    BN_CTX *ctx = BN_CTX_new();
    if (!ctx || !md) {
        GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    BN_CTX_start(ctx);
    OPENSSL_assert(dlen == 32);
    newsig = DSA_SIG_new();
    if (!newsig) {
        GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    group = EC_KEY_get0_group(eckey);
    if (!group) {
        GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_INTERNAL_ERROR);
        goto err;
    }
    order = BN_CTX_get(ctx);
    if (!order || !EC_GROUP_get_order(group, order, ctx)) {
        GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_INTERNAL_ERROR);
        goto err;
    }
    priv_key = EC_KEY_get0_private_key(eckey);
    if (!priv_key) {
        GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_INTERNAL_ERROR);
        goto err;
    }
    e = BN_CTX_get(ctx);
    if (!e || !BN_mod(e, md, order, ctx)) {
        GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_INTERNAL_ERROR);
        goto err;
    }
#ifdef DEBUG_SIGN
    fprintf(stderr, "digest as bignum=");
    BN_print_fp(stderr, md);
    fprintf(stderr, "\ndigest mod q=");
    BN_print_fp(stderr, e);
    fprintf(stderr, "\n");
#endif
    if (BN_is_zero(e)) {
        BN_one(e);
    }
    k = BN_CTX_get(ctx);
    C = EC_POINT_new(group);
    if (!k || !C) {
        GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    do {
        do {
            if (!BN_rand_range(k, order)) {
                GOSTerr(GOST_F_GOST2001_DO_SIGN,
                        GOST_R_RANDOM_NUMBER_GENERATOR_FAILED);
                goto err;
            }
            if (!EC_POINT_mul(group, C, k, NULL, NULL, ctx)) {
                GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_EC_LIB);
                goto err;
            }
            if (!X)
                X = BN_CTX_get(ctx);
            if (!r)
                r = BN_CTX_get(ctx);
            if (!X || !r) {
                GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_MALLOC_FAILURE);
                goto err;
            }
            if (!EC_POINT_get_affine_coordinates_GFp(group, C, X, NULL, ctx)) {
                GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_EC_LIB);
                goto err;
            }

            if (!BN_nnmod(r, X, order, ctx)) {
                GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_INTERNAL_ERROR);
                goto err;
            }
        }
        while (BN_is_zero(r));
        /* s =  (r*priv_key+k*e) mod order */
        if (!tmp)
            tmp = BN_CTX_get(ctx);
        if (!tmp2)
            tmp2 = BN_CTX_get(ctx);
        if (!s)
            s = BN_CTX_get(ctx);
//.........這裏部分代碼省略.........
開發者ID:375670450,項目名稱:openssl,代碼行數:101,代碼來源:gost2001.c

示例14: ec_GFp_simple_points_make_affine

int ec_GFp_simple_points_make_affine(const EC_GROUP *group, size_t num,
                                     EC_POINT *points[], BN_CTX *ctx)
{
    BN_CTX *new_ctx = NULL;
    BIGNUM *tmp, *tmp_Z;
    BIGNUM **prod_Z = NULL;
    size_t i;
    int ret = 0;

    if (num == 0)
        return 1;

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

    BN_CTX_start(ctx);
    tmp = BN_CTX_get(ctx);
    tmp_Z = BN_CTX_get(ctx);
    if (tmp == NULL || tmp_Z == NULL)
        goto err;

    prod_Z = OPENSSL_malloc(num * sizeof(prod_Z[0]));
    if (prod_Z == NULL)
        goto err;
    for (i = 0; i < num; i++) {
        prod_Z[i] = BN_new();
        if (prod_Z[i] == NULL)
            goto err;
    }

    /*
     * Set each prod_Z[i] to the product of points[0]->Z .. points[i]->Z,
     * skipping any zero-valued inputs (pretend that they're 1).
     */

    if (!BN_is_zero(&points[0]->Z)) {
        if (!BN_copy(prod_Z[0], &points[0]->Z))
            goto err;
    } else {
        if (group->meth->field_set_to_one != 0) {
            if (!group->meth->field_set_to_one(group, prod_Z[0], ctx))
                goto err;
        } else {
            if (!BN_one(prod_Z[0]))
                goto err;
        }
    }

    for (i = 1; i < num; i++) {
        if (!BN_is_zero(&points[i]->Z)) {
            if (!group->meth->field_mul(group, prod_Z[i], prod_Z[i - 1],
                                        &points[i]->Z, ctx))
                goto err;
        } else {
            if (!BN_copy(prod_Z[i], prod_Z[i - 1]))
                goto err;
        }
    }

    /*
     * Now use a single explicit inversion to replace every non-zero
     * points[i]->Z by its inverse.
     */

    if (!BN_mod_inverse(tmp, prod_Z[num - 1], &group->field, ctx)) {
        ECerr(EC_F_EC_GFP_SIMPLE_POINTS_MAKE_AFFINE, ERR_R_BN_LIB);
        goto err;
    }
    if (group->meth->field_encode != 0) {
        /*
         * In the Montgomery case, we just turned R*H (representing H) into
         * 1/(R*H), but we need R*(1/H) (representing 1/H); i.e. we need to
         * multiply by the Montgomery factor twice.
         */
        if (!group->meth->field_encode(group, tmp, tmp, ctx))
            goto err;
        if (!group->meth->field_encode(group, tmp, tmp, ctx))
            goto err;
    }

    for (i = num - 1; i > 0; --i) {
        /*
         * Loop invariant: tmp is the product of the inverses of points[0]->Z
         * .. points[i]->Z (zero-valued inputs skipped).
         */
        if (!BN_is_zero(&points[i]->Z)) {
            /*
             * Set tmp_Z to the inverse of points[i]->Z (as product of Z
             * inverses 0 .. i, Z values 0 .. i - 1).
             */
            if (!group->
                meth->field_mul(group, tmp_Z, prod_Z[i - 1], tmp, ctx))
                goto err;
            /*
             * Update tmp to satisfy the loop invariant for i - 1.
             */
            if (!group->meth->field_mul(group, tmp, tmp, &points[i]->Z, ctx))
//.........這裏部分代碼省略.........
開發者ID:derekmarcotte,項目名稱:freebsd,代碼行數:101,代碼來源:ecp_smpl.c

示例15: ec_GFp_simple_group_check_discriminant

int ec_GFp_simple_group_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
{
    int ret = 0;
    BIGNUM *a, *b, *order, *tmp_1, *tmp_2;
    const BIGNUM *p = &group->field;
    BN_CTX *new_ctx = NULL;

    if (ctx == NULL) {
        ctx = new_ctx = BN_CTX_new();
        if (ctx == NULL) {
            ECerr(EC_F_EC_GFP_SIMPLE_GROUP_CHECK_DISCRIMINANT,
                  ERR_R_MALLOC_FAILURE);
            goto err;
        }
    }
    BN_CTX_start(ctx);
    a = BN_CTX_get(ctx);
    b = BN_CTX_get(ctx);
    tmp_1 = BN_CTX_get(ctx);
    tmp_2 = BN_CTX_get(ctx);
    order = BN_CTX_get(ctx);
    if (order == NULL)
        goto err;

    if (group->meth->field_decode) {
        if (!group->meth->field_decode(group, a, &group->a, ctx))
            goto err;
        if (!group->meth->field_decode(group, b, &group->b, ctx))
            goto err;
    } else {
        if (!BN_copy(a, &group->a))
            goto err;
        if (!BN_copy(b, &group->b))
            goto err;
    }

    /*-
     * check the discriminant:
     * y^2 = x^3 + a*x + b is an elliptic curve <=> 4*a^3 + 27*b^2 != 0 (mod p)
     * 0 =< a, b < p
     */
    if (BN_is_zero(a)) {
        if (BN_is_zero(b))
            goto err;
    } else if (!BN_is_zero(b)) {
        if (!BN_mod_sqr(tmp_1, a, p, ctx))
            goto err;
        if (!BN_mod_mul(tmp_2, tmp_1, a, p, ctx))
            goto err;
        if (!BN_lshift(tmp_1, tmp_2, 2))
            goto err;
        /* tmp_1 = 4*a^3 */

        if (!BN_mod_sqr(tmp_2, b, p, ctx))
            goto err;
        if (!BN_mul_word(tmp_2, 27))
            goto err;
        /* tmp_2 = 27*b^2 */

        if (!BN_mod_add(a, tmp_1, tmp_2, p, ctx))
            goto err;
        if (BN_is_zero(a))
            goto err;
    }
    ret = 1;

 err:
    if (ctx != NULL)
        BN_CTX_end(ctx);
    if (new_ctx != NULL)
        BN_CTX_free(new_ctx);
    return ret;
}
開發者ID:derekmarcotte,項目名稱:freebsd,代碼行數:73,代碼來源:ecp_smpl.c


注:本文中的BN_CTX_start函數示例由純淨天空整理自Github/MSDocs等開源代碼及文檔管理平台,相關代碼片段篩選自各路編程大神貢獻的開源項目,源碼版權歸原作者所有,傳播和使用請參考對應項目的License;未經允許,請勿轉載。