OSSL_STORE_OPEN(3ossl) OpenSSL OSSL_STORE_OPEN(3ossl)
NAME
OSSL_STORE_CTX, OSSL_STORE_post_process_info_fn, OSSL_STORE_open,
OSSL_STORE_open_ex, OSSL_STORE_ctrl, OSSL_STORE_load, OSSL_STORE_eof,
OSSL_STORE_delete, OSSL_STORE_error, OSSL_STORE_close - Types and
functions to read objects from a URI
SYNOPSIS
#include <openssl/store.h>
typedef struct ossl_store_ctx_st OSSL_STORE_CTX;
typedef OSSL_STORE_INFO *(*OSSL_STORE_post_process_info_fn)(OSSL_STORE_INFO *,
void *);
OSSL_STORE_CTX *OSSL_STORE_open(const char *uri, const UI_METHOD *ui_method,
void *ui_data,
OSSL_STORE_post_process_info_fn post_process,
void *post_process_data);
OSSL_STORE_CTX *
OSSL_STORE_open_ex(const char *uri, OSSL_LIB_CTX *libctx, const char *propq,
const UI_METHOD *ui_method, void *ui_data,
const OSSL_PARAM params[],
OSSL_STORE_post_process_info_fn post_process,
void *post_process_data);
OSSL_STORE_INFO *OSSL_STORE_load(OSSL_STORE_CTX *ctx);
int OSSL_STORE_eof(OSSL_STORE_CTX *ctx);
int OSSL_STORE_delete(const char *uri, OSSL_LIB_CTX *libctx, const char *propq,
const UI_METHOD *ui_method, void *ui_data,
const OSSL_PARAM params[]);
int OSSL_STORE_error(OSSL_STORE_CTX *ctx);
int OSSL_STORE_close(OSSL_STORE_CTX *ctx);
The following function has been deprecated since OpenSSL 3.0, and can
be hidden entirely by defining OPENSSL_API_COMPAT with a suitable
version value, see openssl_user_macros(7):
int OSSL_STORE_ctrl(OSSL_STORE_CTX *ctx, int cmd, ... /* args */);
DESCRIPTION
These functions help the application to fetch supported objects (see
"SUPPORTED OBJECTS" in OSSL_STORE_INFO(3) for information on which
those are) from a given URI. The general method to do so is to "open"
the URI using OSSL_STORE_open(3), read each available and supported
object using OSSL_STORE_load() as long as OSSL_STORE_eof() hasn't been
reached, and finish it off with OSSL_STORE_close().
The retrieved information is stored in a OSSL_STORE_INFO, which is
further described in OSSL_STORE_INFO(3).
Types
OSSL_STORE_CTX is a context variable that holds all the internal
information for OSSL_STORE_open(3), OSSL_STORE_open_ex(),
OSSL_STORE_load(), OSSL_STORE_eof() and OSSL_STORE_close() to work
together.
Functions
OSSL_STORE_open_ex() takes a uri or path uri, password UI method
ui_method with associated data ui_data, and post processing callback
post_process with associated data post_process_data, a library context
libctx with an associated property query propq, and opens a channel to
the data located at the URI and returns a OSSL_STORE_CTX with all
necessary internal information. The given ui_method and ui_data will
be reused by all functions that use OSSL_STORE_CTX when interaction is
needed, for instance to provide a password. The auxiliary
OSSL_PARAM(3) parameters in params can be set to further modify the
store operation. The given post_process and post_process_data will be
reused by OSSL_STORE_load() to manipulate or drop the value to be
returned. The post_process function drops values by returning NULL,
which will cause OSSL_STORE_load() to start its process over with
loading the next object, until post_process returns something other
than NULL, or the end of data is reached as indicated by
OSSL_STORE_eof().
OSSL_STORE_open(3) is similar to OSSL_STORE_open_ex() but uses NULL for
the params, the library context libctx and property query propq.
OSSL_STORE_ctrl() takes a OSSL_STORE_CTX, and command number cmd and
more arguments not specified here. The available loader specific
command numbers and arguments they each take depends on the loader
that's used and is documented together with that loader.
There are also global controls available:
OSSL_STORE_C_USE_SECMEM
Controls if the loader should attempt to use secure memory for any
allocated OSSL_STORE_INFO and its contents. This control expects
one argument, a pointer to an int that is expected to have the
value 1 (yes) or 0 (no). Any other value is an error.
OSSL_STORE_load() takes a OSSL_STORE_CTX and tries to load the next
available object and return it wrapped with OSSL_STORE_INFO.
OSSL_STORE_delete() deletes the object identified by uri.
OSSL_STORE_eof() takes a OSSL_STORE_CTX and checks if we've reached the
end of data.
OSSL_STORE_error() takes a OSSL_STORE_CTX and checks if an error
occurred in the last OSSL_STORE_load() call. Note that it may still be
meaningful to try and load more objects, unless OSSL_STORE_eof() shows
that the end of data has been reached.
OSSL_STORE_close() takes a OSSL_STORE_CTX, closes the channel that was
opened by OSSL_STORE_open(3) and frees all other information that was
stored in the OSSL_STORE_CTX, as well as the OSSL_STORE_CTX itself. If
ctx is NULL it does nothing.
NOTES
A string without a scheme prefix (that is, a non-URI string) is
implicitly interpreted as using the file: scheme.
There are some tools that can be used together with OSSL_STORE_open(3)
to determine if any failure is caused by an unparsable URI, or if it's
a different error (such as memory allocation failures); if the URI was
parsable but the scheme unregistered, the top error will have the
reason "OSSL_STORE_R_UNREGISTERED_SCHEME".
These functions make no direct assumption regarding the pass phrase
received from the password callback. The loaders may make assumptions,
however. For example, the file: scheme loader inherits the assumptions
made by OpenSSL functionality that handles the different file types;
this is mostly relevant for PKCS#12 objects. See
passphrase-encoding(7) for further information.
RETURN VALUES
OSSL_STORE_open(3) returns a pointer to a OSSL_STORE_CTX on success, or
NULL on failure.
OSSL_STORE_load() returns a pointer to a OSSL_STORE_INFO on success, or
NULL on error or when end of data is reached. Use OSSL_STORE_error()
and OSSL_STORE_eof() to determine the meaning of a returned NULL.
OSSL_STORE_eof() returns 1 if the end of data has been reached or an
error occurred, 0 otherwise.
OSSL_STORE_error() returns 1 if an error occurred in an
OSSL_STORE_load() call, otherwise 0.
OSSL_STORE_delete(), OSSL_STORE_ctrl() and OSSL_STORE_close() return 1
on success, or 0 on failure.
SEE ALSO
ossl_store(7), OSSL_STORE_INFO(3), OSSL_STORE_register_loader(3),
passphrase-encoding(7)
HISTORY
OSSL_STORE_delete() was added in OpenSSL 3.2.
OSSL_STORE_open_ex() was added in OpenSSL 3.0.
OSSL_STORE_open(3),
OSSL_STORE_ctrl(), OSSL_STORE_load(), OSSL_STORE_eof() and
OSSL_STORE_close() were added in OpenSSL 1.1.1.
Handling of NULL ctx argument for OSSL_STORE_close() was introduced in
OpenSSL 1.1.1h.
OSSL_STORE_ctrl() and OSSL_STORE_vctrl() were deprecated in OpenSSL
3.0.
COPYRIGHT
Copyright 2016-2023 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>.
3.3.2 2024-09-04 OSSL_STORE_OPEN(3ossl)
openssl 3.3.2 - Generated Tue Sep 17 16:16:10 CDT 2024