5 OSSL_METHOD_CONSTRUCT_METHOD, ossl_method_construct
6 - generic method constructor
10 #include "internal/core.h"
12 struct ossl_method_construct_method_st {
14 void *(*alloc_tmp_store)(void);
16 void (*dealloc_tmp_store)(void *store);
17 /* Get an already existing method from a store */
18 void *(*get)(OPENSSL_CTX *libctx, void *store, const char *propquery,
20 /* Store a method in a store */
21 int (*put)(OPENSSL_CTX *libctx, void *store, const char *propdef,
22 void *method, void *data);
23 /* Construct a new method */
24 void *(*construct)(const OSSL_DISPATCH *fns, OSSL_PROVIDER *prov,
26 /* Destruct a method */
27 void (*destruct)(void *method);
29 typedef struct ossl_method_construct_method OSSL_METHOD_CONSTRUCT_METHOD;
31 void *ossl_method_construct(OPENSSL_CTX *ctx, int operation_id,
32 const char *name, const char *properties,
34 OSSL_METHOD_CONSTRUCT_METHOD *mcm, void *mcm_data);
38 All libcrypto sub-systems that want to create their own methods based
39 on provider dispatch tables need to do so in exactly the same way.
40 ossl_method_construct() does this while leaving it to the sub-systems
41 to define more precisely how the methods are created, stored, etc.
45 ossl_method_construct() creates a method by asking all available
46 providers for a dispatch table given an C<operation_id>, an algorithm
47 C<name> and a set of C<properties>, and then calling appropriate
48 functions given by the sub-system specific method creator through
49 C<mcm> and the data in C<mcm_data> (which is passed by
50 ossl_method_construct()).
52 This function assumes that the sub-system method creator implements
53 reference counting and acts accordingly (i.e. it will call the
54 sub-system destruct() method to decrement the reference count when
59 A central part of constructing a sub-system specific method is to give
60 ossl_method_construct a set of functions, all in the
61 C<OSSL_METHOD_CONSTRUCT_METHOD> structure, which holds the following
66 =item alloc_tmp_store()
68 Create a temporary method store.
69 This store is used to temporarily store methods for easier lookup, for
70 when the provider doesn't want its dispatch table stored in a longer
73 =item dealloc_tmp_store()
75 Remove a temporary store.
79 Look up an already existing method from a store.
81 The store may be given with C<store>.
82 B<NULL> is a valid value and means that a sub-system default store
84 This default store should be stored in the library context C<libctx>.
86 The method to be looked up should be identified with data from C<data>
87 (which is the C<mcm_data> that was passed to ossl_construct_method())
88 and the provided property query C<propquery>.
90 This function is expected to increment the method's reference count.
94 Places the C<method> created by the construct() function (see below)
97 The store may be given with C<store>.
98 B<NULL> is a valid value and means that a sub-system default store
100 This default store should be stored in the library context C<libctx>.
102 The method should be associated with the given property definition
103 C<propdef> and any identification data given through C<data> (which is
104 the C<mcm_data> that was passed to ossl_construct_method()).
106 This function is expected to increment the C<method>'s reference count.
110 Constructs a sub-system method given a dispatch table C<fns>.
112 The associated I<provider object> C<prov> is passed as well, to make
113 it possible for the sub-system constructor to keep a reference, which
115 If such a reference is kept, the I<provider object> reference counter
116 must be incremented, using ossl_provider_upref().
118 This function is expected to set the method's reference count to 1.
122 Decrement the C<method>'s reference count, and destruct it when
123 the reference count reaches zero.
129 ossl_method_construct() returns a constructed method on success, or
134 This functionality was added to OpenSSL 3.0.0.
138 Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
140 Licensed under the Apache License 2.0 (the "License"). You may not use this
141 file except in compliance with the License. You can obtain a copy in the file
142 LICENSE in the source distribution or at
143 L<https://www.openssl.org/source/license.html>.