[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_teardown, ossl_provider_get_param_types,
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);

 /* Thin wrappers around calls to the provider */
 void ossl_provider_teardown(const OSSL_PROVIDER *prov);
 const OSSL_PARAM *ossl_provider_get_param_types(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_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_get_param_types() calls the provider's I<get_param_types>
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_teardown() doesnt't return any value.

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