mirror of https://github.com/openssl/openssl.git
160 lines
4.9 KiB
Plaintext
160 lines
4.9 KiB
Plaintext
=pod
|
|
|
|
=head1 NAME
|
|
|
|
OSSL_METHOD_CONSTRUCT_METHOD, ossl_method_construct
|
|
- generic method constructor
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include "internal/core.h"
|
|
|
|
struct ossl_method_construct_method_st {
|
|
/* Create store */
|
|
void *(*alloc_tmp_store)(OPENSSL_CTX *ctx);
|
|
/* Remove a store */
|
|
void (*dealloc_tmp_store)(void *store);
|
|
/* Get an already existing method from a store */
|
|
void *(*get)(OPENSSL_CTX *libctx, void *store, void *data);
|
|
/* Store a method in a store */
|
|
int (*put)(OPENSSL_CTX *libctx, void *store, void *method,
|
|
const OSSL_PROVIDER *prov, int operation_id, const char *name,
|
|
const char *propdef, void *data);
|
|
/* Construct a new method */
|
|
void *(*construct)(const char *name, const OSSL_DISPATCH *fns,
|
|
OSSL_PROVIDER *prov, void *data);
|
|
/* Destruct a method */
|
|
void (*destruct)(void *method);
|
|
};
|
|
typedef struct ossl_method_construct_method OSSL_METHOD_CONSTRUCT_METHOD;
|
|
|
|
void *ossl_method_construct(OPENSSL_CTX *ctx, int operation_id,
|
|
int force_cache,
|
|
OSSL_METHOD_CONSTRUCT_METHOD *mcm, void *mcm_data);
|
|
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
All libcrypto sub-systems that want to create their own methods based
|
|
on provider dispatch tables need to do so in exactly the same way.
|
|
ossl_method_construct() does this while leaving it to the sub-systems
|
|
to define more precisely how the methods are created, stored, etc.
|
|
|
|
It's important to keep in mind that a method is identified by three things:
|
|
|
|
=over 4
|
|
|
|
=item The operation identity
|
|
|
|
=item The name of the algorithm
|
|
|
|
=item The properties associated with the algorithm implementation
|
|
|
|
=back
|
|
|
|
=head2 Functions
|
|
|
|
ossl_method_construct() creates a method by asking all available
|
|
providers for a dispatch table given an I<operation_id>, and then
|
|
calling the appropriate functions given by the sub-system specific
|
|
method creator through I<mcm> and the data in I<mcm_data> (which is
|
|
passed by ossl_method_construct()).
|
|
|
|
This function assumes that the sub-system method creator implements
|
|
reference counting and acts accordingly (i.e. it will call the
|
|
sub-system destruct() method to decrement the reference count when
|
|
appropriate).
|
|
|
|
=head2 Structures
|
|
|
|
A central part of constructing a sub-system specific method is to give
|
|
ossl_method_construct a set of functions, all in the
|
|
B<OSSL_METHOD_CONSTRUCT_METHOD> structure, which holds the following
|
|
function pointers:
|
|
|
|
=over 4
|
|
|
|
=item alloc_tmp_store()
|
|
|
|
Create a temporary method store in the scope of the library context I<ctx>.
|
|
This store is used to temporarily store methods for easier lookup, for
|
|
when the provider doesn't want its dispatch table stored in a longer
|
|
term cache.
|
|
|
|
=item dealloc_tmp_store()
|
|
|
|
Remove a temporary store.
|
|
|
|
=item get()
|
|
|
|
Look up an already existing method from a store by name.
|
|
|
|
The store may be given with I<store>.
|
|
NULL is a valid value and means that a sub-system default store
|
|
must be used.
|
|
This default store should be stored in the library context I<libctx>.
|
|
|
|
The method to be looked up should be identified with data found in I<data>
|
|
(which is the I<mcm_data> that was passed to ossl_construct_method()).
|
|
In other words, the ossl_method_construct() caller is entirely responsible
|
|
for ensuring the necesssary data is made available.
|
|
|
|
This function is expected to increment the method's reference count.
|
|
|
|
=item put()
|
|
|
|
Places the I<method> created by the construct() function (see below)
|
|
in a store.
|
|
|
|
The store may be given with I<store>.
|
|
NULL is a valid value and means that a sub-system default store
|
|
must be used.
|
|
This default store should be stored in the library context I<libctx>.
|
|
|
|
The method should be associated with the given I<operation_id>,
|
|
I<name> and property definition I<propdef> as well as any
|
|
identification data given through I<data> (which is the I<mcm_data>
|
|
that was passed to ossl_construct_method()).
|
|
|
|
This function is expected to increment the I<method>'s reference count.
|
|
|
|
=item construct()
|
|
|
|
Constructs a sub-system method for the given I<name> and the given
|
|
dispatch table I<fns>.
|
|
|
|
The associated provider object I<prov> is passed as well, to make
|
|
it possible for the sub-system constructor to keep a reference, which
|
|
is recommended.
|
|
If such a reference is kept, the I<provider object> reference counter
|
|
must be incremented, using ossl_provider_up_ref().
|
|
|
|
This function is expected to set the method's reference count to 1.
|
|
|
|
=item destruct()
|
|
|
|
Decrement the I<method>'s reference count, and destruct it when
|
|
the reference count reaches zero.
|
|
|
|
=back
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
ossl_method_construct() returns a constructed method on success, or
|
|
NULL on error.
|
|
|
|
=head1 HISTORY
|
|
|
|
This functionality was added to OpenSSL 3.0.
|
|
|
|
=head1 COPYRIGHT
|
|
|
|
Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
|
|
|
|
Licensed under the Apache License 2.0 (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
|