Add documentation

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8287)
This commit is contained in:
Richard Levitte 2019-02-21 21:20:53 +01:00
parent 021a655277
commit c453283421
3 changed files with 309 additions and 0 deletions

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=pod
=head1 NAME
ossl_provider_find, ossl_provider_new, ossl_provider_upref,
ossl_provider_free, ossl_provider_add_module_location,
ossl_provider_activate, 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 - internal provider routines
=head1 SYNOPSIS
#include "internal/provider.h"
OSSL_PROVIDER *ossl_provider_find(OPENSSL_CTX *libctx, const char *name);
OSSL_PROVIDER *ossl_provider_new(OPENSSL_CTX *libctx, const char *name,
ossl_provider_init_fn *init_function);
int ossl_provider_upref(OSSL_PROVIDER *prov);
void ossl_provider_free(OSSL_PROVIDER *prov);
/* Setters */
int ossl_provider_add_module_location(OSSL_PROVIDER *prov, const char *loc);
/* Load and initialize the Provider */
int ossl_provider_activate(OSSL_PROVIDER *prov);
/* 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_ITEM *ossl_provider_get_param_types(const OSSL_PROVIDER *prov);
int ossl_provider_get_params(const OSSL_PROVIDER *prov,
const OSSL_PARAM params[]);
=head1 DESCRIPTION
C<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 refered to as I<provider object>s.
A I<provider object> is always stored in a set of I<provider object>s
in the library context.
I<provider object>s are reference counted.
I<provider object>s 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 I<provider object> in the
I<provider object> store by C<name>.
The I<provider object> it finds gets it's reference count
incremented.
ossl_provider_new() creates a new I<provider object> and stores it in
the I<provider object> store, unless there already is one there with
the same name.
The reference counter of a newly created I<provider object> will
always be 2; one for being added to the store, and one for the
returned reference.
To indicate a built-in provider, the C<init_function> argument must
point at the provider initialization function for that provider.
ossl_provider_free() decrements a I<provider object>'s reference
counter; if it drops to one, the I<provider object> will be
inactivated (it's teardown function is called) but kept in the store;
if it drops down to zero, the associated module will be unloaded if
one was loaded, and the I<provider object> will be freed.
ossl_provider_add_module_location() adds a location to look for a
provider module.
ossl_provider_activate() "activates" the provider for the given
I<provider object>.
What "activates" means depends on what type of I<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 intialization function was given with ossl_provider_new(), a
loadable module with the C<name> that was given to ossl_provider_new()
will be located and loaded, then the symbol C<OSSL_provider_init> will
be located in that module, and called.
=back
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 C<teardown> function, if
the provider has one.
ossl_provider_get_param_types() calls the provider's C<get_param_types>
function, if the provider has one.
It should return an array of C<OSSL_ITEM> to describe all the
parameters that the provider has for the I<provider object>.
ossl_provider_get_params() calls the provider's parameter request
responder.
It should treat the given C<OSSL_PARAM> array as described in
L<OSSL_PARAM(3)>.
=head1 NOTES
Locating a provider module happens as follows:
=over 4
=item 1.
Look in each directory given by ossl_provider_add_module_location().
=item 2.
Look in the directory given by the environment variable
B<OPENSSL_MODULES>.
=item 3.
Look in the directory given by the OpenSSL built in macro
B<MODULESDIR>.
=back
=head1 RETURN VALUES
ossl_provider_find() and ossl_provider_new() return a pointer to a
I<provider object> (C<OSSL_PROVIDER>) on success, or B<NULL> on error.
ossl_provider_upref() returns the value of the reference counter after
it has been incremented.
ossl_provider_free() doesn't return any value.
ossl_provider_add_module_location() and ossl_provider_activate()
return 1 on success, or 0 on error.
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 B<NULL>
is returned.
ossl_provider_teardown() doesnt't return any value.
ossl_provider_get_param_types() returns a pointer to an C<OSSL_ITEM>
array if this function is available in the provider, otherwise
B<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)>
=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

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=pod
=head1 NAME
OSSL_PROVIDER, OSSL_PROVIDER_load, OSSL_PROVIDER_unload,
OSSL_PROVIDER_get_param_types, OSSL_PROVIDER_get_params,
OSSL_PROVIDER_add_builtin - provider routines
=head1 SYNOPSIS
#include <openssl/provider.h>
typedef struct ossl_provider_st OSSL_PROVIDER;
OSSL_PROVIDER *OSSL_PROVIDER_load(OPENSSL_CTX *, const char *name);
int OSSL_PROVIDER_unload(OSSL_PROVIDER *prov);
const OSSL_ITEM *OSSL_PROVIDER_get_param_types(OSSL_PROVIDER *prov);
int OSSL_PROVIDER_get_params(OSSL_PROVIDER *prov, const OSSL_PARAM params[]);
int OSSL_PROVIDER_add_builtin(OPENSSL_CTX *, const char *name,
ossl_provider_init_fn *init_fn);
=head1 DESCRIPTION
B<OSSL_PROVIDER> is a type that holds internal information about
implementation providers (see L<provider(7)> for information on what a
provider is).
A provider can be built in to the application or the OpenSSL
libraries, or can be a loadable module.
The functions described here handle both forms.
=head2 Functions
OSSL_PROVIDER_add_builtin() is used to add a built in provider to
B<OSSL_PROVIDER> store in the given library context, by associating a
provider name with a provider initialization function.
This name can then be used with OSSL_PROVIDER_load().
OSSL_PROVIDER_load() loads and initializes a provider.
This may simply initialize a provider that was previously added with
OSSL_PROVIDER_add_builtin() and run its given initialization function,
or load a provider module with the given name and run its provider
entry point, C<OSSL_provider_init>.
OSSL_PROVIDER_unload() unloads the given provider.
For a provider added with OSSL_PROVIDER_add_builtin(), this simply
runs its teardown function.
OSSL_PROVIDER_get_param_types() is used to get a provider parameter
descriptor set as an B<OSSL_ITEM> array.
Each element is a tuple of an B<OSSL_PARAM> parameter type and a name
in form of a C string.
See L<openssl-core.h(7)> for more information on B<OSSL_ITEM> and
parameter types.
OSSL_PROVIDER_get_params() is used to get provider parameter values.
The caller must prepare the B<OSSL_PARAM> array before calling this
function, and the variables acting as buffers for this parameter array
should be filled with data when it returns successfully.
=head1 RETURN VALUES
OSSL_PROVIDER_add() returns 1 on success, or 0 on error.
OSSL_PROVIDER_load() returns a pointer to a provider object on
success, or B<NULL> on error.
OSSL_PROVIDER_unload() returns 1 on success, or 0 on error.
OSSL_PROVIDER_get_param_types() returns a pointer to a constant array
of B<OSSL_ITEM>, or NULL if none is provided.
OSSL_PROVIDER_get_params() returns 1 on success, or 0 on error.
=head1 EXAMPLES
This demonstrates how to load the provider module "foo" and ask for
its build number.
OSSL_PROVIDER *prov = NULL;
const char *build = NULL;
size_t built_l = 0;
const OSSL_PARAM request[] = {
{ "build", OSSL_PARAM_UTF8_STRING_PTR, &build, 0, &build_l },
{ NULL, 0, NULL, 0, NULL }
};
if ((prov = OSSL_PROVIDER_load(NULL, "foo")) != NULL
&& OSSL_PROVIDER_get_params(prov, request))
printf("Provider 'foo' build %s\n", build);
else
ERR_print_errors_fp(stderr);
=head1 SEE ALSO
L<openssl-core.h(7)>, L<provider(7)>
=head1 HISTORY
The type and functions described here were 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

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@ -33,6 +33,7 @@ OPENSSL_Applink external
OPENSSL_CTX datatype
NAMING_AUTHORITY datatype
OSSL_PARAM datatype
OSSL_PROVIDER datatype
OSSL_STORE_CTX datatype
OSSL_STORE_INFO datatype
OSSL_STORE_LOADER datatype