=head1 NAME
-EC_GROUP_copy, EC_GROUP_dup, EC_GROUP_method_of, EC_GROUP_set_generator, EC_GROUP_get0_generator, EC_GROUP_get_order, EC_GROUP_get_cofactor, EC_GROUP_set_curve_name, EC_GROUP_get_curve_name, EC_GROUP_set_asn1_flag, EC_GROUP_get_asn1_flag, EC_GROUP_set_point_conversion_form, EC_GROUP_get_point_conversion_form, EC_GROUP_get0_seed, EC_GROUP_get_seed_len, EC_GROUP_set_seed, EC_GROUP_get_degree, EC_GROUP_check, EC_GROUP_check_discriminant, EC_GROUP_cmp, EC_GROUP_get_basis_type, EC_GROUP_get_trinomial_basis, EC_GROUP_get_pentanomial_basis - Functions for manipulating B<EC_GROUP> objects.
+EC_GROUP_get0_order, EC_GROUP_order_bits, EC_GROUP_get0_cofactor,
+EC_GROUP_copy, EC_GROUP_dup, EC_GROUP_method_of, EC_GROUP_set_generator,
+EC_GROUP_get0_generator, EC_GROUP_get_order, EC_GROUP_get_cofactor,
+EC_GROUP_set_curve_name, EC_GROUP_get_curve_name, EC_GROUP_set_asn1_flag,
+EC_GROUP_get_asn1_flag, EC_GROUP_set_point_conversion_form,
+EC_GROUP_get_point_conversion_form, EC_GROUP_get0_seed,
+EC_GROUP_get_seed_len, EC_GROUP_set_seed, EC_GROUP_get_degree,
+EC_GROUP_check, EC_GROUP_check_discriminant, EC_GROUP_cmp,
+EC_GROUP_get_basis_type, EC_GROUP_get_trinomial_basis,
+EC_GROUP_get_pentanomial_basis
+- Functions for manipulating EC_GROUP objects
=head1 SYNOPSIS
#include <openssl/ec.h>
- #include <openssl/bn.h>
int EC_GROUP_copy(EC_GROUP *dst, const EC_GROUP *src);
EC_GROUP *EC_GROUP_dup(const EC_GROUP *src);
const EC_POINT *EC_GROUP_get0_generator(const EC_GROUP *group);
int EC_GROUP_get_order(const EC_GROUP *group, BIGNUM *order, BN_CTX *ctx);
+ const BIGNUM *EC_GROUP_get0_order(const EC_GROUP *group);
+ int EC_GROUP_order_bits(const EC_GROUP *group);
int EC_GROUP_get_cofactor(const EC_GROUP *group, BIGNUM *cofactor, BN_CTX *ctx);
+ const BIGNUM *EC_GROUP_get0_cofactor(const EC_GROUP *group);
void EC_GROUP_set_curve_name(EC_GROUP *group, int nid);
int EC_GROUP_get_curve_name(const EC_GROUP *group);
int EC_GROUP_get_basis_type(const EC_GROUP *);
int EC_GROUP_get_trinomial_basis(const EC_GROUP *, unsigned int *k);
- int EC_GROUP_get_pentanomial_basis(const EC_GROUP *, unsigned int *k1,
- unsigned int *k2, unsigned int *k3);
+ int EC_GROUP_get_pentanomial_basis(const EC_GROUP *, unsigned int *k1,
+ unsigned int *k2, unsigned int *k3);
=head1 DESCRIPTION
EC_GROUP_method_of obtains the EC_METHOD of B<group>.
-EC_GROUP_set_generator sets curve paramaters that must be agreed by all participants using the curve. These
-paramaters include the B<generator>, the B<order> and the B<cofactor>. The B<generator> is a well defined point on the
+EC_GROUP_set_generator sets curve parameters that must be agreed by all participants using the curve. These
+parameters include the B<generator>, the B<order> and the B<cofactor>. The B<generator> is a well defined point on the
curve chosen for cryptographic operations. Integers used for point multiplications will be between 0 and
-n-1 where n is the B<order>. The B<order> multipied by the B<cofactor> gives the number of points on the curve.
+n-1 where n is the B<order>. The B<order> multiplied by the B<cofactor> gives the number of points on the curve.
EC_GROUP_get0_generator returns the generator for the identified B<group>.
with the respective order and cofactors for the B<group>.
The functions EC_GROUP_set_curve_name and EC_GROUP_get_curve_name, set and get the NID for the curve respectively
-(see L<EC_GROUP_new(3)|EC_GROUP_new(3)>). If a curve does not have a NID associated with it, then EC_GROUP_get_curve_name
+(see L<EC_GROUP_new(3)>). If a curve does not have a NID associated with it, then EC_GROUP_get_curve_name
will return 0.
The asn1_flag value is used to determine whether the curve encoding uses
applications would have to explicitly set the named curve form) in OpenSSL
1.1.0 and later the named curve form is the default.
-The point_coversion_form for a curve controls how EC_POINT data is encoded as ASN1 as defined in X9.62 (ECDSA).
-point_conversion_form_t is an enum defined as follows:
+The point_conversion_form for a curve controls how EC_POINT data is encoded as ASN1 as defined in X9.62 (ECDSA).
+point_conversion_form_t is an enum defined as follows:
typedef enum {
- /** the point is encoded as z||x, where the octet z specifies
- * which solution of the quadratic equation y is */
- POINT_CONVERSION_COMPRESSED = 2,
- /** the point is encoded as z||x||y, where z is the octet 0x02 */
- POINT_CONVERSION_UNCOMPRESSED = 4,
- /** the point is encoded as z||x||y, where the octet z specifies
+ /** the point is encoded as z||x, where the octet z specifies
+ * which solution of the quadratic equation y is */
+ POINT_CONVERSION_COMPRESSED = 2,
+ /** the point is encoded as z||x||y, where z is the octet 0x04 */
+ POINT_CONVERSION_UNCOMPRESSED = 4,
+ /** the point is encoded as z||x||y, where the octet z specifies
* which solution of the quadratic equation y is */
- POINT_CONVERSION_HYBRID = 6
+ POINT_CONVERSION_HYBRID = 6
} point_conversion_form_t;
-
For POINT_CONVERSION_UNCOMPRESSED the point is encoded as an octet signifying the UNCOMPRESSED form has been used followed by
the octets for x, followed by the octets for y.
For any given x co-ordinate for a point on a curve it is possible to derive two possible y values. For
POINT_CONVERSION_COMPRESSED the point is encoded as an octet signifying that the COMPRESSED form has been used AND which of
-the two possible solutions for y has been used, followed by the octets for x.
+the two possible solutions for y has been used, followed by the octets for x.
For POINT_CONVERSION_HYBRID the point is encoded as an octet signifying the HYBRID form has been used AND which of the two
possible solutions for y has been used, followed by the octets for x, followed by the octets for y.
f(x) = x^m + x^k3 + x^k2 + x^k1 + 1 with m > k3 > k2 > k1 >= 1
The function EC_GROUP_get_basis_type returns a NID identifying whether a trinomial or pentanomial is in use for the field. The
-function EC_GROUP_get_trinomial_basis must only be called where f(x) is of the trinomial form, and returns the value of B<k>. Similary
+function EC_GROUP_get_trinomial_basis must only be called where f(x) is of the trinomial form, and returns the value of B<k>. Similarly
the function EC_GROUP_get_pentanomial_basis must only be called where f(x) is of the pentanomial form, and returns the values of B<k1>,
B<k2> and B<k3> respectively.
and EC_GROUP_get_degree return the order, cofactor, curve name (NID), ASN1 flag, point_conversion_form and degree for the
specified curve respectively. If there is no curve name associated with a curve then EC_GROUP_get_curve_name will return 0.
+EC_GROUP_get0_order() returns an internal pointer to the group order.
+EC_GROUP_get_order_bits() returns the number of bits in the group order.
+EC_GROUP_get0_cofactor() returns an internal pointer to the group cofactor.
+
EC_GROUP_get0_seed returns a pointer to the seed that was used to generate the parameter b, or NULL if the seed is not
specified. EC_GROUP_get_seed_len returns the length of the seed or 0 if the seed is not specified.
EC_GROUP_set_seed returns the length of the seed that has been set. If the supplied seed is NULL, or the supplied seed length is
-0, the the return value will be 1. On error 0 is returned.
+0, the return value will be 1. On error 0 is returned.
EC_GROUP_cmp returns 0 if the curves are equal, 1 if they are not equal, or -1 on error.
=head1 SEE ALSO
-L<crypto(3)|crypto(3)>, L<ec(3)|ec(3)>, L<EC_GROUP_new(3)|EC_GROUP_new(3)>,
-L<EC_POINT_new(3)|EC_POINT_new(3)>, L<EC_POINT_add(3)|EC_POINT_add(3)>, L<EC_KEY_new(3)|EC_KEY_new(3)>,
-L<EC_GFp_simple_method(3)|EC_GFp_simple_method(3)>, L<d2i_ECPKParameters(3)|d2i_ECPKParameters(3)>
+L<crypto(3)>, L<ec(3)>, L<EC_GROUP_new(3)>,
+L<EC_POINT_new(3)>, L<EC_POINT_add(3)>, L<EC_KEY_new(3)>,
+L<EC_GFp_simple_method(3)>, L<d2i_ECPKParameters(3)>
+
+=head1 COPYRIGHT
+
+Copyright 2013-2016 The OpenSSL Project Authors. All Rights Reserved.
+
+Licensed under the OpenSSL license (the "License"). You may not use
+this file except in compliance with the License. You can obtain a copy
+in the file LICENSE in the source distribution or at
+L<https://www.openssl.org/source/license.html>.
=cut