Imported OpenSSL 1.1.1a
This commit is contained in:
144
doc/man3/EC_GROUP_new.pod
Normal file
144
doc/man3/EC_GROUP_new.pod
Normal file
@@ -0,0 +1,144 @@
|
||||
=pod
|
||||
|
||||
=head1 NAME
|
||||
|
||||
EC_GROUP_get_ecparameters,
|
||||
EC_GROUP_get_ecpkparameters,
|
||||
EC_GROUP_new,
|
||||
EC_GROUP_new_from_ecparameters,
|
||||
EC_GROUP_new_from_ecpkparameters,
|
||||
EC_GROUP_free,
|
||||
EC_GROUP_clear_free,
|
||||
EC_GROUP_new_curve_GFp,
|
||||
EC_GROUP_new_curve_GF2m,
|
||||
EC_GROUP_new_by_curve_name,
|
||||
EC_GROUP_set_curve,
|
||||
EC_GROUP_get_curve,
|
||||
EC_GROUP_set_curve_GFp,
|
||||
EC_GROUP_get_curve_GFp,
|
||||
EC_GROUP_set_curve_GF2m,
|
||||
EC_GROUP_get_curve_GF2m,
|
||||
EC_get_builtin_curves - Functions for creating and destroying EC_GROUP
|
||||
objects
|
||||
|
||||
=head1 SYNOPSIS
|
||||
|
||||
#include <openssl/ec.h>
|
||||
|
||||
EC_GROUP *EC_GROUP_new(const EC_METHOD *meth);
|
||||
EC_GROUP *EC_GROUP_new_from_ecparameters(const ECPARAMETERS *params)
|
||||
EC_GROUP *EC_GROUP_new_from_ecpkparameters(const ECPKPARAMETERS *params)
|
||||
void EC_GROUP_free(EC_GROUP *group);
|
||||
void EC_GROUP_clear_free(EC_GROUP *group);
|
||||
|
||||
EC_GROUP *EC_GROUP_new_curve_GFp(const BIGNUM *p, const BIGNUM *a,
|
||||
const BIGNUM *b, BN_CTX *ctx);
|
||||
EC_GROUP *EC_GROUP_new_curve_GF2m(const BIGNUM *p, const BIGNUM *a,
|
||||
const BIGNUM *b, BN_CTX *ctx);
|
||||
EC_GROUP *EC_GROUP_new_by_curve_name(int nid);
|
||||
|
||||
int EC_GROUP_set_curve(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
|
||||
const BIGNUM *b, BN_CTX *ctx);
|
||||
int EC_GROUP_get_curve(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b,
|
||||
BN_CTX *ctx);
|
||||
int EC_GROUP_set_curve_GFp(EC_GROUP *group, const BIGNUM *p,
|
||||
const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx);
|
||||
int EC_GROUP_get_curve_GFp(const EC_GROUP *group, BIGNUM *p,
|
||||
BIGNUM *a, BIGNUM *b, BN_CTX *ctx);
|
||||
int EC_GROUP_set_curve_GF2m(EC_GROUP *group, const BIGNUM *p,
|
||||
const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx);
|
||||
int EC_GROUP_get_curve_GF2m(const EC_GROUP *group, BIGNUM *p,
|
||||
BIGNUM *a, BIGNUM *b, BN_CTX *ctx);
|
||||
|
||||
ECPARAMETERS *EC_GROUP_get_ecparameters(const EC_GROUP *group, ECPARAMETERS *params)
|
||||
ECPKPARAMETERS *EC_GROUP_get_ecpkparameters(const EC_GROUP *group, ECPKPARAMETERS *params)
|
||||
|
||||
size_t EC_get_builtin_curves(EC_builtin_curve *r, size_t nitems);
|
||||
|
||||
=head1 DESCRIPTION
|
||||
|
||||
Within the library there are two forms of elliptic curve that are of interest. The first form is those defined over the
|
||||
prime field Fp. The elements of Fp are the integers 0 to p-1, where p is a prime number. This gives us a revised
|
||||
elliptic curve equation as follows:
|
||||
|
||||
y^2 mod p = x^3 +ax + b mod p
|
||||
|
||||
The second form is those defined over a binary field F2^m where the elements of the field are integers of length at
|
||||
most m bits. For this form the elliptic curve equation is modified to:
|
||||
|
||||
y^2 + xy = x^3 + ax^2 + b (where b != 0)
|
||||
|
||||
Operations in a binary field are performed relative to an B<irreducible polynomial>. All such curves with OpenSSL
|
||||
use a trinomial or a pentanomial for this parameter.
|
||||
|
||||
A new curve can be constructed by calling EC_GROUP_new, using the implementation provided by B<meth> (see
|
||||
L<EC_GFp_simple_method(3)>). It is then necessary to call EC_GROUP_set_curve() to set the curve parameters.
|
||||
EC_GROUP_new_from_ecparameters() will create a group from the
|
||||
specified B<params> and
|
||||
EC_GROUP_new_from_ecpkparameters() will create a group from the specific PK B<params>.
|
||||
|
||||
EC_GROUP_set_curve() sets the curve parameters B<p>, B<a> and B<b>. For a curve over Fp B<b>
|
||||
is the prime for the field. For a curve over F2^m B<p> represents the irreducible polynomial - each bit
|
||||
represents a term in the polynomial. Therefore there will either be three or five bits set dependent on whether
|
||||
the polynomial is a trinomial or a pentanomial.
|
||||
|
||||
EC_group_get_curve() obtains the previously set curve parameters.
|
||||
|
||||
EC_GROUP_set_curve_GFp() and EC_GROUP_set_curve_GF2m() are synonyms for EC_GROUP_set_curve(). They are defined for
|
||||
backwards compatibility only and should not be used.
|
||||
|
||||
EC_GROUP_get_curve_GFp() and EC_GROUP_get_curve_GF2m() are synonyms for EC_GROUP_get_curve(). They are defined for
|
||||
backwards compatibility only and should not be used.
|
||||
|
||||
The functions EC_GROUP_new_curve_GFp and EC_GROUP_new_curve_GF2m are shortcuts for calling EC_GROUP_new and then the
|
||||
EC_GROUP_set_curve function. An appropriate default implementation method will be used.
|
||||
|
||||
Whilst the library can be used to create any curve using the functions described above, there are also a number of
|
||||
predefined curves that are available. In order to obtain a list of all of the predefined curves, call the function
|
||||
EC_get_builtin_curves. The parameter B<r> should be an array of EC_builtin_curve structures of size B<nitems>. The function
|
||||
will populate the B<r> array with information about the builtin curves. If B<nitems> is less than the total number of
|
||||
curves available, then the first B<nitems> curves will be returned. Otherwise the total number of curves will be
|
||||
provided. The return value is the total number of curves available (whether that number has been populated in B<r> or
|
||||
not). Passing a NULL B<r>, or setting B<nitems> to 0 will do nothing other than return the total number of curves available.
|
||||
The EC_builtin_curve structure is defined as follows:
|
||||
|
||||
typedef struct {
|
||||
int nid;
|
||||
const char *comment;
|
||||
} EC_builtin_curve;
|
||||
|
||||
Each EC_builtin_curve item has a unique integer id (B<nid>), and a human readable comment string describing the curve.
|
||||
|
||||
In order to construct a builtin curve use the function EC_GROUP_new_by_curve_name and provide the B<nid> of the curve to
|
||||
be constructed.
|
||||
|
||||
EC_GROUP_free frees the memory associated with the EC_GROUP.
|
||||
If B<group> is NULL nothing is done.
|
||||
|
||||
EC_GROUP_clear_free destroys any sensitive data held within the EC_GROUP and then frees its memory.
|
||||
If B<group> is NULL nothing is done.
|
||||
|
||||
=head1 RETURN VALUES
|
||||
|
||||
All EC_GROUP_new* functions return a pointer to the newly constructed group, or NULL on error.
|
||||
|
||||
EC_get_builtin_curves returns the number of builtin curves that are available.
|
||||
|
||||
EC_GROUP_set_curve_GFp, EC_GROUP_get_curve_GFp, EC_GROUP_set_curve_GF2m, EC_GROUP_get_curve_GF2m return 1 on success or 0 on error.
|
||||
|
||||
=head1 SEE ALSO
|
||||
|
||||
L<crypto(7)>, L<EC_GROUP_copy(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 2013-2018 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
|
||||
Reference in New Issue
Block a user