[thirdparty/openssl.git] / doc / internal / man3 / ossl_provider_new.pod

=pod

=head1 NAME

ossl_provider_find, ossl_provider_new, ossl_provider_up_ref,
ossl_provider_free,
ossl_provider_set_fallback, ossl_provider_set_module_path,
ossl_provider_add_parameter,
ossl_provider_activate, ossl_provider_available,
ossl_provider_ctx,
ossl_provider_forall_loaded,
ossl_provider_name, ossl_provider_dso,
ossl_provider_module_name, ossl_provider_module_path,
ossl_provider_library_context,
ossl_provider_teardown, ossl_provider_gettable_params,
ossl_provider_get_params, ossl_provider_query_operation
- internal provider routines

=head1 SYNOPSIS

 #include "internal/provider.h"

 OSSL_PROVIDER *ossl_provider_find(OPENSSL_CTX *libctx, const char *name,
                                   int noconfig);
 OSSL_PROVIDER *ossl_provider_new(OPENSSL_CTX *libctx, const char *name,
                                  ossl_provider_init_fn *init_function
                                  int noconfig);
 int ossl_provider_up_ref(OSSL_PROVIDER *prov);
 void ossl_provider_free(OSSL_PROVIDER *prov);

 /* Setters */
 int ossl_provider_set_fallback(OSSL_PROVIDER *prov);
 int ossl_provider_set_module_path(OSSL_PROVIDER *prov, const char *path);
 int ossl_provider_add_parameter(OSSL_PROVIDER *prov, const char *name,
                                 const char *value);

 /* Load and initialize the Provider */
 int ossl_provider_activate(OSSL_PROVIDER *prov);
 /* Check if provider is available */
 int ossl_provider_available(OSSL_PROVIDER *prov);

 /* Return pointer to the provider's context */
 void *ossl_provider_ctx(const OSSL_PROVIDER *prov);

 /* Iterate over all loaded providers */
 int ossl_provider_forall_loaded(OPENSSL_CTX *,
                                 int (*cb)(OSSL_PROVIDER *provider,
                                           void *cbdata),
                                 void *cbdata);

 /* Getters for other library functions */
 const char *ossl_provider_name(OSSL_PROVIDER *prov);
 const DSO *ossl_provider_dso(OSSL_PROVIDER *prov);
 const char *ossl_provider_module_name(OSSL_PROVIDER *prov);
 const char *ossl_provider_module_path(OSSL_PROVIDER *prov);
 OPENSSL_CTX *ossl_provider_library_context(const OSSL_PROVIDER *prov);

 /* Thin wrappers around calls to the provider */
 void ossl_provider_teardown(const OSSL_PROVIDER *prov);
 const OSSL_PARAM *ossl_provider_gettable_params(const OSSL_PROVIDER *prov);
 int ossl_provider_get_params(const OSSL_PROVIDER *prov, OSSL_PARAM params[]);
 const OSSL_ALGORITHM *ossl_provider_query_operation(const OSSL_PROVIDER *prov,
                                                     int operation_id,
                                                     int *no_cache);

=head1 DESCRIPTION

I<OSSL_PROVIDER> is a type that holds all the necessary information
to handle a provider, regardless of if it's built in to the
application or the OpenSSL libraries, or if it's a loadable provider
module.
Instances of this type are commonly referred to as "provider objects".

A provider object is always stored in a set of provider objects
in the library context.

Provider objects are reference counted.

Provider objects are initially inactive, i.e. they are only recorded
in the store, but are not used.
They are activated with the first call to ossl_provider_activate(),
and are inactivated when ossl_provider_free() has been called as many
times as ossl_provider_activate() has.

=head2 Functions

ossl_provider_find() finds an existing provider object in the provider
object store by I<name>.
The config file will be automatically loaded unless I<noconfig> is set.
Typically I<noconfig> should be 0.
We set I<noconfig> to 1 only when calling these functions while processing a
config file in order to avoid recursively attempting to load the file.
The provider object it finds has its reference count incremented.

ossl_provider_new() creates a new provider object named I<name> and
stores it in the provider object store, unless there already is one
there with the same name.
If there already is one with the same name, it's returned with its
reference count incremented.
The config file will be automatically loaded unless I<noconfig> is set.
Typically I<noconfig> should be 0.
We set I<noconfig> to 1 only when calling these functions while processing a
config file in order to avoid recursively attempting to load the file.
The reference count of a newly created provider object will always
be 2; one for being added to the store, and one for the returned
reference.
If I<init_function> is NULL, the provider is assumed to be a
dynamically loadable module, with the symbol B<OSSL_provider_init> as
its initialisation function.
If I<init_function> isn't NULL, the provider is assumed to be built
in, with I<init_function> being the pointer to its initialisation
function.
For further description of the initialisation function, see the
description of ossl_provider_activate() below.

ossl_provider_up_ref() increments the provider object I<prov>'s
reference count.

ossl_provider_free() decrements the provider object I<prov>'s
reference count; if it drops below 2, the provider object is assumed
to have fallen out of use and will be deactivated (its I<teardown>
function is called); if it drops down to zero, I<prov> is assumed to
have been taken out of the store, and the associated module will be
unloaded if one was loaded, and I<prov> itself will be freed.

ossl_provider_set_fallback() marks an available provider I<prov> as
fallback.
Note that after this call, the provider object pointer that was
used can simply be dropped, but not freed.

ossl_provider_set_module_path() sets the module path to load the
provider module given the provider object I<prov>.
This will be used in preference to automatically trying to figure out
the path from the provider name and the default module directory (more
on this in L</NOTES>).

ossl_provider_library_context() returns the library context the given
provider I<prov> is registered in.

ossl_provider_add_parameter() adds a global parameter for the provider
to retrieve as it sees fit.
The parameters are a combination of I<name> and I<value>, and the
provider will use the name to find the value it wants.
Only text parameters can be given, and it's up to the provider to
interpret them.

ossl_provider_activate() "activates" the provider for the given
provider object I<prov>.
What "activates" means depends on what type of provider object it
is:

=over 4

=item *

If an initialization function was given with ossl_provider_new(), that
function will get called.

=item *

If no initialization function was given with ossl_provider_new(), a
loadable module with the I<name> that was given to ossl_provider_new()
will be located and loaded, then the symbol B<OSSL_provider_init> will
be located in that module, and called.

=back

ossl_provider_available() activates all fallbacks if no provider is
activated yet, then checks if given provider object I<prov> is
activated.

ossl_provider_ctx() returns a context created by the provider.
Outside of the provider, it's completely opaque, but it needs to be
passed back to some of the provider functions.

ossl_provider_forall_loaded() iterates over all the currently
"activated" providers, and calls I<cb> for each of them.
If no providers have been "activated" yet, it tries to activate all
available fallback providers and tries another iteration.

ossl_provider_name() returns the name that was given with
ossl_provider_new().

ossl_provider_dso() returns a reference to the module, for providers
that come in the form of loadable modules.

ossl_provider_module_name() returns the file name of the module, for
providers that come in the form of loadable modules.

ossl_provider_module_path() returns the full path of the module file,
for providers that come in the form of loadable modules.

ossl_provider_teardown() calls the provider's I<teardown> function, if
the provider has one.

ossl_provider_gettable_params() calls the provider's I<gettable_params>
function, if the provider has one.
It should return an array of I<OSSL_PARAM> to describe all the
parameters that the provider has for the provider object.

ossl_provider_get_params() calls the provider's parameter request
responder.
It should treat the given I<OSSL_PARAM> array as described in
L<OSSL_PARAM(3)>.

ossl_provider_query_operation() calls the provider's
I<query_operation> function, if the provider has one.
It should return an array of I<OSSL_ALGORITHM> for the given
I<operation_id>.

=head1 NOTES

Locating a provider module happens as follows:

=over 4

=item 1.

If a path was given with ossl_provider_set_module_path(), use that as
module path.
Otherwise, use the provider object's name as module path, with
platform specific standard extensions added.

=item 2.

If the environment variable B<OPENSSL_MODULES> is defined, assume its
value is a directory specification and merge it with the module path.
Otherwise, merge the value of the OpenSSL built in macro B<MODULESDIR>
with the module path.

=back

When this process is done, the result is used when trying to load the
provider module.

The command C<openssl version -m> can be used to find out the value
of the built in macro B<MODULESDIR>.

=head1 RETURN VALUES

ossl_provider_find() and ossl_provider_new() return a pointer to a
provider object (I<OSSL_PROVIDER>) on success, or NULL on error.

ossl_provider_up_ref() returns the value of the reference count after
it has been incremented.

ossl_provider_free() doesn't return any value.

ossl_provider_set_module_path(), ossl_provider_set_fallback() and
ossl_provider_activate() return 1 on success, or 0 on error.

ossl_provider_available() return 1 if the provider is available,
otherwise 0.

ossl_provider_name(), ossl_provider_dso(),
ossl_provider_module_name(), and ossl_provider_module_path() return a
pointer to their respective data if it's available, otherwise NULL
is returned.

ossl_provider_library_context() return a pointer to the library context.
This may be NULL, and is perfectly valid, as it denotes the default
global library context.

ossl_provider_teardown() doesnt't return any value.

ossl_provider_gettable_params() returns a pointer to a constant
I<OSSL_PARAM> array if this function is available in the provider,
otherwise NULL.

ossl_provider_get_params() returns 1 on success, or 0 on error.
If this function isn't available in the provider, 0 is returned.

=head1 SEE ALSO

L<OSSL_PROVIDER(3)>, L<provider(7)>, L<openssl(1)>

=head1 HISTORY

The functions described here were all added in 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
Commit	Line	Data
c4532834 RL	1	=pod
	2
	3	=head1 NAME
	4
7c95390e	5	ossl_provider_find, ossl_provider_new, ossl_provider_up_ref,
3bbec1af RL	6	ossl_provider_free,
	7	ossl_provider_set_fallback, ossl_provider_set_module_path,
	8	ossl_provider_add_parameter,
36f5ec55	9	ossl_provider_activate, ossl_provider_available,
3bbec1af RL	10	ossl_provider_ctx,
3bbec1af RL	11	ossl_provider_forall_loaded,
85e2417c	12	ossl_provider_name, ossl_provider_dso,
c4532834	13	ossl_provider_module_name, ossl_provider_module_path,
e74bd290	14	ossl_provider_library_context,
dca97d00	15	ossl_provider_teardown, ossl_provider_gettable_params,
099bd339 RL	16	ossl_provider_get_params, ossl_provider_query_operation
099bd339 RL	17	- internal provider routines
c4532834 RL	18
	19	=head1 SYNOPSIS
	20
	21	#include "internal/provider.h"
	22
29dc6e00 MC	23	OSSL_PROVIDER ossl_provider_find(OPENSSL_CTX libctx, const char *name,
29dc6e00 MC	24	int noconfig);
c4532834	25	OSSL_PROVIDER ossl_provider_new(OPENSSL_CTX libctx, const char *name,
29dc6e00 MC	26	ossl_provider_init_fn *init_function
29dc6e00 MC	27	int noconfig);
7c95390e	28	int ossl_provider_up_ref(OSSL_PROVIDER *prov);
c4532834 RL	29	void ossl_provider_free(OSSL_PROVIDER *prov);
	30
	31	/* Setters */
e55008a9	32	int ossl_provider_set_fallback(OSSL_PROVIDER *prov);
3bbec1af RL	33	int ossl_provider_set_module_path(OSSL_PROVIDER prov, const char path);
	34	int ossl_provider_add_parameter(OSSL_PROVIDER prov, const char name,
	35	const char *value);
c4532834 RL	36
	37	/* Load and initialize the Provider */
	38	int ossl_provider_activate(OSSL_PROVIDER *prov);
36f5ec55 RL	39	/* Check if provider is available */
36f5ec55 RL	40	int ossl_provider_available(OSSL_PROVIDER *prov);
c4532834	41
a39eb840 RL	42	/* Return pointer to the provider's context */
	43	void ossl_provider_ctx(const OSSL_PROVIDER prov);
	44
85e2417c RL	45	/* Iterate over all loaded providers */
	46	int ossl_provider_forall_loaded(OPENSSL_CTX *,
	47	int (cb)(OSSL_PROVIDER provider,
	48	void *cbdata),
	49	void *cbdata);
	50
c4532834 RL	51	/* Getters for other library functions */
	52	const char ossl_provider_name(OSSL_PROVIDER prov);
	53	const DSO ossl_provider_dso(OSSL_PROVIDER prov);
	54	const char ossl_provider_module_name(OSSL_PROVIDER prov);
	55	const char ossl_provider_module_path(OSSL_PROVIDER prov);
e74bd290	56	OPENSSL_CTX ossl_provider_library_context(const OSSL_PROVIDER prov);
c4532834 RL	57
	58	/* Thin wrappers around calls to the provider */
	59	void ossl_provider_teardown(const OSSL_PROVIDER *prov);
dca97d00	60	const OSSL_PARAM ossl_provider_gettable_params(const OSSL_PROVIDER prov);
4e7991b4	61	int ossl_provider_get_params(const OSSL_PROVIDER *prov, OSSL_PARAM params[]);
099bd339 RL	62	const OSSL_ALGORITHM ossl_provider_query_operation(const OSSL_PROVIDER prov,
	63	int operation_id,
	64	int *no_cache);
c4532834 RL	65
	66	=head1 DESCRIPTION
	67
3bbec1af	68	I<OSSL_PROVIDER> is a type that holds all the necessary information
c4532834 RL	69	to handle a provider, regardless of if it's built in to the
	70	application or the OpenSSL libraries, or if it's a loadable provider
	71	module.
3bbec1af	72	Instances of this type are commonly referred to as "provider objects".
c4532834	73
3bbec1af	74	A provider object is always stored in a set of provider objects
c4532834 RL	75	in the library context.
c4532834 RL	76
3bbec1af	77	Provider objects are reference counted.
c4532834	78
3bbec1af RL	79	Provider objects are initially inactive, i.e. they are only recorded
3bbec1af RL	80	in the store, but are not used.
c4532834 RL	81	They are activated with the first call to ossl_provider_activate(),
	82	and are inactivated when ossl_provider_free() has been called as many
	83	times as ossl_provider_activate() has.
	84
	85	=head2 Functions
	86
3bbec1af	87	ossl_provider_find() finds an existing provider object in the provider
29dc6e00 MC	88	object store by I<name>.
	89	The config file will be automatically loaded unless I<noconfig> is set.
	90	Typically I<noconfig> should be 0.
	91	We set I<noconfig> to 1 only when calling these functions while processing a
	92	config file in order to avoid recursively attempting to load the file.
3bbec1af RL	93	The provider object it finds has its reference count incremented.
	94
	95	ossl_provider_new() creates a new provider object named I<name> and
	96	stores it in the provider object store, unless there already is one
	97	there with the same name.
	98	If there already is one with the same name, it's returned with its
	99	reference count incremented.
29dc6e00 MC	100	The config file will be automatically loaded unless I<noconfig> is set.
	101	Typically I<noconfig> should be 0.
	102	We set I<noconfig> to 1 only when calling these functions while processing a
	103	config file in order to avoid recursively attempting to load the file.
3bbec1af RL	104	The reference count of a newly created provider object will always
	105	be 2; one for being added to the store, and one for the returned
	106	reference.
	107	If I<init_function> is NULL, the provider is assumed to be a
	108	dynamically loadable module, with the symbol B<OSSL_provider_init> as
	109	its initialisation function.
	110	If I<init_function> isn't NULL, the provider is assumed to be built
	111	in, with I<init_function> being the pointer to its initialisation
	112	function.
	113	For further description of the initialisation function, see the
	114	description of ossl_provider_activate() below.
	115
7c95390e	116	ossl_provider_up_ref() increments the provider object I<prov>'s
3bbec1af RL	117	reference count.
	118
	119	ossl_provider_free() decrements the provider object I<prov>'s
	120	reference count; if it drops below 2, the provider object is assumed
	121	to have fallen out of use and will be deactivated (its I<teardown>
	122	function is called); if it drops down to zero, I<prov> is assumed to
	123	have been taken out of the store, and the associated module will be
	124	unloaded if one was loaded, and I<prov> itself will be freed.
	125
	126	ossl_provider_set_fallback() marks an available provider I<prov> as
	127	fallback.
	128	Note that after this call, the provider object pointer that was
e55008a9 RL	129	used can simply be dropped, but not freed.
e55008a9 RL	130
3bbec1af RL	131	ossl_provider_set_module_path() sets the module path to load the
	132	provider module given the provider object I<prov>.
	133	This will be used in preference to automatically trying to figure out
	134	the path from the provider name and the default module directory (more
	135	on this in L</NOTES>).
	136
e74bd290 RL	137	ossl_provider_library_context() returns the library context the given
	138	provider I<prov> is registered in.
	139
3bbec1af RL	140	ossl_provider_add_parameter() adds a global parameter for the provider
	141	to retrieve as it sees fit.
	142	The parameters are a combination of I<name> and I<value>, and the
	143	provider will use the name to find the value it wants.
	144	Only text parameters can be given, and it's up to the provider to
	145	interpret them.
	146
c4532834	147	ossl_provider_activate() "activates" the provider for the given
3bbec1af RL	148	provider object I<prov>.
3bbec1af RL	149	What "activates" means depends on what type of provider object it
c4532834 RL	150	is:
	151
	152	=over 4
	153
	154	=item *
	155
	156	If an initialization function was given with ossl_provider_new(), that
	157	function will get called.
	158
	159	=item *
	160
c2969ff6	161	If no initialization function was given with ossl_provider_new(), a
3bbec1af RL	162	loadable module with the I<name> that was given to ossl_provider_new()
3bbec1af RL	163	will be located and loaded, then the symbol B<OSSL_provider_init> will
c4532834 RL	164	be located in that module, and called.
	165
	166	=back
	167
36f5ec55 RL	168	ossl_provider_available() activates all fallbacks if no provider is
	169	activated yet, then checks if given provider object I<prov> is
	170	activated.
	171
a39eb840 RL	172	ossl_provider_ctx() returns a context created by the provider.
	173	Outside of the provider, it's completely opaque, but it needs to be
	174	passed back to some of the provider functions.
	175
85e2417c	176	ossl_provider_forall_loaded() iterates over all the currently
3bbec1af	177	"activated" providers, and calls I<cb> for each of them.
e55008a9 RL	178	If no providers have been "activated" yet, it tries to activate all
e55008a9 RL	179	available fallback providers and tries another iteration.
85e2417c	180
c4532834 RL	181	ossl_provider_name() returns the name that was given with
	182	ossl_provider_new().
	183
	184	ossl_provider_dso() returns a reference to the module, for providers
	185	that come in the form of loadable modules.
	186
	187	ossl_provider_module_name() returns the file name of the module, for
	188	providers that come in the form of loadable modules.
	189
	190	ossl_provider_module_path() returns the full path of the module file,
	191	for providers that come in the form of loadable modules.
	192
3bbec1af	193	ossl_provider_teardown() calls the provider's I<teardown> function, if
c4532834 RL	194	the provider has one.
c4532834 RL	195
dca97d00	196	ossl_provider_gettable_params() calls the provider's I<gettable_params>
c4532834	197	function, if the provider has one.
26175013	198	It should return an array of I<OSSL_PARAM> to describe all the
3bbec1af	199	parameters that the provider has for the provider object.
c4532834 RL	200
	201	ossl_provider_get_params() calls the provider's parameter request
	202	responder.
3bbec1af	203	It should treat the given I<OSSL_PARAM> array as described in
c4532834 RL	204	L<OSSL_PARAM(3)>.
c4532834 RL	205
099bd339	206	ossl_provider_query_operation() calls the provider's
3bbec1af RL	207	I<query_operation> function, if the provider has one.
	208	It should return an array of I<OSSL_ALGORITHM> for the given
	209	I<operation_id>.
099bd339	210
c4532834 RL	211	=head1 NOTES
	212
	213	Locating a provider module happens as follows:
	214
	215	=over 4
	216
	217	=item 1.
	218
3bbec1af RL	219	If a path was given with ossl_provider_set_module_path(), use that as
	220	module path.
	221	Otherwise, use the provider object's name as module path, with
	222	platform specific standard extensions added.
c4532834 RL	223
	224	=item 2.
	225
3bbec1af RL	226	If the environment variable B<OPENSSL_MODULES> is defined, assume its
	227	value is a directory specification and merge it with the module path.
	228	Otherwise, merge the value of the OpenSSL built in macro B<MODULESDIR>
	229	with the module path.
c4532834	230
3bbec1af	231	=back
c4532834	232
3bbec1af RL	233	When this process is done, the result is used when trying to load the
3bbec1af RL	234	provider module.
c4532834	235
3bbec1af RL	236	The command C<openssl version -m> can be used to find out the value
3bbec1af RL	237	of the built in macro B<MODULESDIR>.
c4532834 RL	238
	239	=head1 RETURN VALUES
	240
	241	ossl_provider_find() and ossl_provider_new() return a pointer to a
3bbec1af	242	provider object (I<OSSL_PROVIDER>) on success, or NULL on error.
c4532834	243
7c95390e	244	ossl_provider_up_ref() returns the value of the reference count after
c4532834 RL	245	it has been incremented.
	246
	247	ossl_provider_free() doesn't return any value.
	248
3bbec1af	249	ossl_provider_set_module_path(), ossl_provider_set_fallback() and
e55008a9	250	ossl_provider_activate() return 1 on success, or 0 on error.
c4532834	251
36f5ec55 RL	252	ossl_provider_available() return 1 if the provider is available,
	253	otherwise 0.
	254
c4532834 RL	255	ossl_provider_name(), ossl_provider_dso(),
c4532834 RL	256	ossl_provider_module_name(), and ossl_provider_module_path() return a
3bbec1af	257	pointer to their respective data if it's available, otherwise NULL
c4532834 RL	258	is returned.
c4532834 RL	259
e74bd290 RL	260	ossl_provider_library_context() return a pointer to the library context.
	261	This may be NULL, and is perfectly valid, as it denotes the default
	262	global library context.
	263
c4532834 RL	264	ossl_provider_teardown() doesnt't return any value.
c4532834 RL	265
dca97d00	266	ossl_provider_gettable_params() returns a pointer to a constant
26175013 RL	267	I<OSSL_PARAM> array if this function is available in the provider,
26175013 RL	268	otherwise NULL.
c4532834 RL	269
	270	ossl_provider_get_params() returns 1 on success, or 0 on error.
	271	If this function isn't available in the provider, 0 is returned.
	272
	273	=head1 SEE ALSO
	274
3bbec1af	275	L<OSSL_PROVIDER(3)>, L<provider(7)>, L<openssl(1)>
c4532834 RL	276
	277	=head1 HISTORY
	278
	279	The functions described here were all added in OpenSSL 3.0.
	280
	281	=head1 COPYRIGHT
	282
	283	Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
	284
	285	Licensed under the Apache License 2.0 (the "License"). You may not use
	286	this file except in compliance with the License. You can obtain a copy
	287	in the file LICENSE in the source distribution or at
	288	L<https://www.openssl.org/source/license.html>.
	289
	290	=cut