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OSSL_PROVIDER(3) OpenSSL OSSL_PROVIDER(3)
NAME
OSSL_PROVIDER_set_default_search_path, OSSL_PROVIDER,
OSSL_PROVIDER_load, OSSL_PROVIDER_try_load, OSSL_PROVIDER_unload,
OSSL_PROVIDER_available, OSSL_PROVIDER_do_all,
OSSL_PROVIDER_gettable_params, OSSL_PROVIDER_get_params,
OSSL_PROVIDER_query_operation, OSSL_PROVIDER_unquery_operation,
OSSL_PROVIDER_get0_provider_ctx, OSSL_PROVIDER_get0_dispatch,
OSSL_PROVIDER_add_builtin, OSSL_PROVIDER_get0_name,
OSSL_PROVIDER_get_capabilities, OSSL_PROVIDER_self_test - provider
routines
LIBRARY
libcrypto, -lcrypto
SYNOPSIS
#include <openssl/provider.h>
typedef struct ossl_provider_st OSSL_PROVIDER;
int OSSL_PROVIDER_set_default_search_path(OSSL_LIB_CTX *libctx,
const char *path);
OSSL_PROVIDER *OSSL_PROVIDER_load(OSSL_LIB_CTX *libctx, const char *name);
OSSL_PROVIDER *OSSL_PROVIDER_try_load(OSSL_LIB_CTX *libctx, const char *name,
int retain_fallbacks);
int OSSL_PROVIDER_unload(OSSL_PROVIDER *prov);
int OSSL_PROVIDER_available(OSSL_LIB_CTX *libctx, const char *name);
int OSSL_PROVIDER_do_all(OSSL_LIB_CTX *ctx,
int (*cb)(OSSL_PROVIDER *provider, void *cbdata),
void *cbdata);
const OSSL_PARAM *OSSL_PROVIDER_gettable_params(OSSL_PROVIDER *prov);
int OSSL_PROVIDER_get_params(OSSL_PROVIDER *prov, OSSL_PARAM params[]);
const OSSL_ALGORITHM *OSSL_PROVIDER_query_operation(const OSSL_PROVIDER *prov,
int operation_id,
int *no_cache);
void OSSL_PROVIDER_unquery_operation(const OSSL_PROVIDER *prov,
int operation_id,
const OSSL_ALGORITHM *algs);
void *OSSL_PROVIDER_get0_provider_ctx(const OSSL_PROVIDER *prov);
const OSSL_DISPATCH *OSSL_PROVIDER_get0_dispatch(const OSSL_PROVIDER *prov);
int OSSL_PROVIDER_add_builtin(OSSL_LIB_CTX *libctx, const char *name,
ossl_provider_init_fn *init_fn);
const char *OSSL_PROVIDER_get0_name(const OSSL_PROVIDER *prov);
int OSSL_PROVIDER_get_capabilities(const OSSL_PROVIDER *prov,
const char *capability,
OSSL_CALLBACK *cb,
void *arg);
int OSSL_PROVIDER_self_test(const OSSL_PROVIDER *prov);
DESCRIPTION
OSSL_PROVIDER is a type that holds internal information about
implementation providers (see 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.
Some of these functions operate within a library context, please see
OSSL_LIB_CTX(3) for further details.
Functions
OSSL_PROVIDER_set_default_search_path() specifies the default search
path that is to be used for looking for providers in the specified
libctx. If left unspecified, an environment variable and a fall back
default value will be used instead.
OSSL_PROVIDER_add_builtin() is used to add a built in provider to
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, "OSSL_provider_init". The name can be a path to a provider
module, in that case the provider name as returned by
OSSL_PROVIDER_get0_name() will be the path. Interpretation of relative
paths is platform dependent and they are relative to the configured
"MODULESDIR" directory or the path set in the environment variable
OPENSSL_MODULES if set.
OSSL_PROVIDER_try_load() functions like OSSL_PROVIDER_load(), except
that it does not disable the fallback providers if the provider cannot
be loaded and initialized or if retain_fallbacks is nonzero. If the
provider loads successfully and retain_fallbacks is zero, the fallback
providers are disabled.
OSSL_PROVIDER_unload() unloads the given provider. For a provider
added with OSSL_PROVIDER_add_builtin(), this simply runs its teardown
function.
OSSL_PROVIDER_available() checks if a named provider is available for
use.
OSSL_PROVIDER_do_all() iterates over all loaded providers, calling cb
for each one, with the current provider in provider and the cbdata that
comes from the caller. If no other provider has been loaded before
calling this function, the default provider is still available as
fallback. See OSSL_PROVIDER-default(7) for more information on this
fallback behaviour.
OSSL_PROVIDER_gettable_params() is used to get a provider parameter
descriptor set as a constant OSSL_PARAM(3) array.
OSSL_PROVIDER_get_params() is used to get provider parameter values.
The caller must prepare the OSSL_PARAM(3) array before calling this
function, and the variables acting as buffers for this parameter array
should be filled with data when it returns successfully.
OSSL_PROVIDER_self_test() is used to run a provider's self tests on
demand. If the self tests fail then the provider will fail to provide
any further services and algorithms. OSSL_SELF_TEST_set_callback(3) may
be called beforehand in order to display diagnostics for the running
self tests.
OSSL_PROVIDER_query_operation() calls the provider's query_operation
function (see provider(7)), if the provider has one. It returns an
array of OSSL_ALGORITHM for the given operation_id terminated by an all
NULL OSSL_ALGORITHM entry. This is considered a low-level function that
most applications should not need to call.
OSSL_PROVIDER_unquery_operation() calls the provider's
unquery_operation function (see provider(7)), if the provider has one.
This is considered a low-level function that most applications should
not need to call.
OSSL_PROVIDER_get0_provider_ctx() returns the provider context for the
given provider. The provider context is an opaque handle set by the
provider itself and is passed back to the provider by libcrypto in
various function calls.
OSSL_PROVIDER_get0_dispatch() returns the provider's dispatch table as
it was returned in the out parameter from the provider's init function.
See provider-base(7).
If it is permissible to cache references to this array then *no_store
is set to 0 or 1 otherwise. If the array is not cacheable then it is
assumed to have a short lifetime.
OSSL_PROVIDER_get0_name() returns the name of the given provider.
OSSL_PROVIDER_get_capabilities() provides information about the
capabilities supported by the provider specified in prov with the
capability name capability. For each capability of that name supported
by the provider it will call the callback cb and supply a set of
OSSL_PARAM(3)s describing the capability. It will also pass back the
argument arg. For more details about capabilities and what they can be
used for please see "CAPABILTIIES" in provider-base(7).
RETURN VALUES
OSSL_PROVIDER_set_default_search_path(), OSSL_PROVIDER_add(),
OSSL_PROVIDER_unload(), OSSL_PROVIDER_get_params() and
OSSL_PROVIDER_get_capabilities() return 1 on success, or 0 on error.
OSSL_PROVIDER_load() and OSSL_PROVIDER_try_load() return a pointer to a
provider object on success, or NULL on error.
OSSL_PROVIDER_do_all() returns 1 if the callback cb returns 1 for every
provider it is called with, or 0 if any provider callback invocation
returns 0; callback processing stops at the first callback invocation
on a provider that returns 0.
OSSL_PROVIDER_available() returns 1 if the named provider is available,
otherwise 0.
OSSL_PROVIDER_gettable_params() returns a pointer to an array of
constant OSSL_PARAM(3), or NULL if none is provided.
OSSL_PROVIDER_get_params() and returns 1 on success, or 0 on error.
OSSL_PROVIDER_query_operation() returns an array of OSSL_ALGORITHM or
NULL on error.
OSSL_PROVIDER_self_test() returns 1 if the self tests pass, or 0 on
error.
EXAMPLES
This demonstrates how to load the provider module "foo" and ask for its
build information.
#include <openssl/params.h>
#include <openssl/provider.h>
#include <openssl/err.h>
OSSL_PROVIDER *prov = NULL;
const char *build = NULL;
OSSL_PARAM request[] = {
{ "buildinfo", OSSL_PARAM_UTF8_PTR, &build, 0, 0 },
{ NULL, 0, NULL, 0, 0 }
};
if ((prov = OSSL_PROVIDER_load(NULL, "foo")) != NULL
&& OSSL_PROVIDER_get_params(prov, request))
printf("Provider 'foo' buildinfo: %s\n", build);
else
ERR_print_errors_fp(stderr);
SEE ALSO
openssl-core.h(7), OSSL_LIB_CTX(3), provider(7)
HISTORY
The type and functions described here were added in OpenSSL 3.0.
COPYRIGHT
Copyright 2019-2023 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
<https://www.openssl.org/source/license.html>.
3.0.12 2023-10-25 OSSL_PROVIDER(3)