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1 | =pod |
2 | ||
3 | =head1 NAME | |
4 | ||
5 | ossl_provider_find, ossl_provider_new, ossl_provider_upref, | |
6 | ossl_provider_free, ossl_provider_add_module_location, | |
7 | ossl_provider_activate, ossl_provider_name, ossl_provider_dso, | |
8 | ossl_provider_module_name, ossl_provider_module_path, | |
9 | ossl_provider_teardown, ossl_provider_get_param_types, | |
10 | ossl_provider_get_params - internal provider routines | |
11 | ||
12 | =head1 SYNOPSIS | |
13 | ||
14 | #include "internal/provider.h" | |
15 | ||
16 | OSSL_PROVIDER *ossl_provider_find(OPENSSL_CTX *libctx, const char *name); | |
17 | OSSL_PROVIDER *ossl_provider_new(OPENSSL_CTX *libctx, const char *name, | |
18 | ossl_provider_init_fn *init_function); | |
19 | int ossl_provider_upref(OSSL_PROVIDER *prov); | |
20 | void ossl_provider_free(OSSL_PROVIDER *prov); | |
21 | ||
22 | /* Setters */ | |
23 | int ossl_provider_add_module_location(OSSL_PROVIDER *prov, const char *loc); | |
24 | ||
25 | /* Load and initialize the Provider */ | |
26 | int ossl_provider_activate(OSSL_PROVIDER *prov); | |
27 | ||
28 | /* Getters for other library functions */ | |
29 | const char *ossl_provider_name(OSSL_PROVIDER *prov); | |
30 | const DSO *ossl_provider_dso(OSSL_PROVIDER *prov); | |
31 | const char *ossl_provider_module_name(OSSL_PROVIDER *prov); | |
32 | const char *ossl_provider_module_path(OSSL_PROVIDER *prov); | |
33 | ||
34 | /* Thin wrappers around calls to the provider */ | |
35 | void ossl_provider_teardown(const OSSL_PROVIDER *prov); | |
36 | const OSSL_ITEM *ossl_provider_get_param_types(const OSSL_PROVIDER *prov); | |
37 | int ossl_provider_get_params(const OSSL_PROVIDER *prov, | |
38 | const OSSL_PARAM params[]); | |
39 | ||
40 | =head1 DESCRIPTION | |
41 | ||
42 | C<OSSL_PROVIDER> is a type that holds all the necessary information | |
43 | to handle a provider, regardless of if it's built in to the | |
44 | application or the OpenSSL libraries, or if it's a loadable provider | |
45 | module. | |
46 | Instances of this type are commonly refered to as I<provider object>s. | |
47 | ||
48 | A I<provider object> is always stored in a set of I<provider object>s | |
49 | in the library context. | |
50 | ||
51 | I<provider object>s are reference counted. | |
52 | ||
53 | I<provider object>s are initially inactive, i.e. they are only | |
54 | recorded in the store, but are not used. | |
55 | They are activated with the first call to ossl_provider_activate(), | |
56 | and are inactivated when ossl_provider_free() has been called as many | |
57 | times as ossl_provider_activate() has. | |
58 | ||
59 | =head2 Functions | |
60 | ||
61 | ossl_provider_find() finds an existing I<provider object> in the | |
62 | I<provider object> store by C<name>. | |
63 | The I<provider object> it finds gets it's reference count | |
64 | incremented. | |
65 | ||
66 | ossl_provider_new() creates a new I<provider object> and stores it in | |
67 | the I<provider object> store, unless there already is one there with | |
68 | the same name. | |
69 | The reference counter of a newly created I<provider object> will | |
70 | always be 2; one for being added to the store, and one for the | |
71 | returned reference. | |
72 | To indicate a built-in provider, the C<init_function> argument must | |
73 | point at the provider initialization function for that provider. | |
74 | ||
75 | ossl_provider_free() decrements a I<provider object>'s reference | |
76 | counter; if it drops to one, the I<provider object> will be | |
77 | inactivated (it's teardown function is called) but kept in the store; | |
78 | if it drops down to zero, the associated module will be unloaded if | |
79 | one was loaded, and the I<provider object> will be freed. | |
80 | ||
81 | ossl_provider_add_module_location() adds a location to look for a | |
82 | provider module. | |
83 | ||
84 | ossl_provider_activate() "activates" the provider for the given | |
85 | I<provider object>. | |
86 | What "activates" means depends on what type of I<provider object> it | |
87 | is: | |
88 | ||
89 | =over 4 | |
90 | ||
91 | =item * | |
92 | ||
93 | If an initialization function was given with ossl_provider_new(), that | |
94 | function will get called. | |
95 | ||
96 | =item * | |
97 | ||
98 | If no intialization function was given with ossl_provider_new(), a | |
99 | loadable module with the C<name> that was given to ossl_provider_new() | |
100 | will be located and loaded, then the symbol C<OSSL_provider_init> will | |
101 | be located in that module, and called. | |
102 | ||
103 | =back | |
104 | ||
105 | ossl_provider_name() returns the name that was given with | |
106 | ossl_provider_new(). | |
107 | ||
108 | ossl_provider_dso() returns a reference to the module, for providers | |
109 | that come in the form of loadable modules. | |
110 | ||
111 | ossl_provider_module_name() returns the file name of the module, for | |
112 | providers that come in the form of loadable modules. | |
113 | ||
114 | ossl_provider_module_path() returns the full path of the module file, | |
115 | for providers that come in the form of loadable modules. | |
116 | ||
117 | ossl_provider_teardown() calls the provider's C<teardown> function, if | |
118 | the provider has one. | |
119 | ||
120 | ossl_provider_get_param_types() calls the provider's C<get_param_types> | |
121 | function, if the provider has one. | |
122 | It should return an array of C<OSSL_ITEM> to describe all the | |
123 | parameters that the provider has for the I<provider object>. | |
124 | ||
125 | ossl_provider_get_params() calls the provider's parameter request | |
126 | responder. | |
127 | It should treat the given C<OSSL_PARAM> array as described in | |
128 | L<OSSL_PARAM(3)>. | |
129 | ||
130 | =head1 NOTES | |
131 | ||
132 | Locating a provider module happens as follows: | |
133 | ||
134 | =over 4 | |
135 | ||
136 | =item 1. | |
137 | ||
138 | Look in each directory given by ossl_provider_add_module_location(). | |
139 | ||
140 | =item 2. | |
141 | ||
142 | Look in the directory given by the environment variable | |
143 | B<OPENSSL_MODULES>. | |
144 | ||
145 | =item 3. | |
146 | ||
147 | Look in the directory given by the OpenSSL built in macro | |
148 | B<MODULESDIR>. | |
149 | ||
150 | =back | |
151 | ||
152 | =head1 RETURN VALUES | |
153 | ||
154 | ossl_provider_find() and ossl_provider_new() return a pointer to a | |
155 | I<provider object> (C<OSSL_PROVIDER>) on success, or B<NULL> on error. | |
156 | ||
157 | ossl_provider_upref() returns the value of the reference counter after | |
158 | it has been incremented. | |
159 | ||
160 | ossl_provider_free() doesn't return any value. | |
161 | ||
162 | ossl_provider_add_module_location() and ossl_provider_activate() | |
163 | return 1 on success, or 0 on error. | |
164 | ||
165 | ossl_provider_name(), ossl_provider_dso(), | |
166 | ossl_provider_module_name(), and ossl_provider_module_path() return a | |
167 | pointer to their respective data if it's available, otherwise B<NULL> | |
168 | is returned. | |
169 | ||
170 | ossl_provider_teardown() doesnt't return any value. | |
171 | ||
172 | ossl_provider_get_param_types() returns a pointer to an C<OSSL_ITEM> | |
173 | array if this function is available in the provider, otherwise | |
174 | B<NULL>. | |
175 | ||
176 | ossl_provider_get_params() returns 1 on success, or 0 on error. | |
177 | If this function isn't available in the provider, 0 is returned. | |
178 | ||
179 | =head1 SEE ALSO | |
180 | ||
181 | L<OSSL_PROVIDER(3)>, L<provider(7)> | |
182 | ||
183 | =head1 HISTORY | |
184 | ||
185 | The functions described here were all added in OpenSSL 3.0. | |
186 | ||
187 | =head1 COPYRIGHT | |
188 | ||
189 | Copyright 2019 The OpenSSL Project Authors. All Rights Reserved. | |
190 | ||
191 | Licensed under the Apache License 2.0 (the "License"). You may not use | |
192 | this file except in compliance with the License. You can obtain a copy | |
193 | in the file LICENSE in the source distribution or at | |
194 | L<https://www.openssl.org/source/license.html>. | |
195 | ||
196 | =cut |