5 OSSL_STORE_CTX, OSSL_STORE_post_process_info_fn, OSSL_STORE_open,
6 OSSL_STORE_ctrl, OSSL_STORE_load, OSSL_STORE_eof, OSSL_STORE_error,
7 OSSL_STORE_close - Types and functions to read objects from a URI
11 #include <openssl/store.h>
13 typedef struct ossl_store_ctx_st OSSL_STORE_CTX;
15 typedef OSSL_STORE_INFO *(*OSSL_STORE_post_process_info_fn)(OSSL_STORE_INFO *,
18 OSSL_STORE_CTX *OSSL_STORE_open(const char *uri, const UI_METHOD *ui_method,
20 OSSL_STORE_post_process_info_fn post_process,
21 void *post_process_data);
22 int OSSL_STORE_ctrl(OSSL_STORE_CTX *ctx, int cmd, ... /* args */);
23 OSSL_STORE_INFO *OSSL_STORE_load(OSSL_STORE_CTX *ctx);
24 int OSSL_STORE_eof(OSSL_STORE_CTX *ctx);
25 int OSSL_STORE_error(OSSL_STORE_CTX *ctx);
26 int OSSL_STORE_close(OSSL_STORE_CTX *ctx);
30 These functions help the application to fetch supported objects (see
31 L<OSSL_STORE_INFO(3)/SUPPORTED OBJECTS> for information on which those are)
32 from a given URI (see L</SUPPORTED SCHEMES> for more information on
33 the supported URI schemes).
34 The general method to do so is to "open" the URI using OSSL_STORE_open(),
35 read each available and supported object using OSSL_STORE_load() as long as
36 OSSL_STORE_eof() hasn't been reached, and finish it off with OSSL_STORE_close().
38 The retrieved information is stored in a B<OSSL_STORE_INFO>, which is further
39 described in L<OSSL_STORE_INFO(3)>.
43 B<OSSL_STORE_CTX> is a context variable that holds all the internal
44 information for OSSL_STORE_open(), OSSL_STORE_load(), OSSL_STORE_eof() and
45 OSSL_STORE_close() to work together.
49 OSSL_STORE_open() takes a uri or path B<uri>, password UI method
50 B<ui_method> with associated data B<ui_data>, and post processing
51 callback B<post_process> with associated data B<post_process_data>,
52 opens a channel to the data located at that URI and returns a
53 B<OSSL_STORE_CTX> with all necessary internal information.
54 The given B<ui_method> and B<ui_data_data> will be reused by all
55 functions that use B<OSSL_STORE_CTX> when interaction is needed.
56 The given B<post_process> and B<post_process_data> will be reused by
57 OSSL_STORE_load() to manipulate or drop the value to be returned.
58 The B<post_process> function drops values by returning B<NULL>, which
59 will cause OSSL_STORE_load() to start its process over with loading
60 the next object, until B<post_process> returns something other than
61 B<NULL>, or the end of data is reached as indicated by OSSL_STORE_eof().
63 OSSL_STORE_ctrl() takes a B<OSSL_STORE_CTX>, and command number B<cmd> and
64 more arguments not specified here.
65 The available loader specific command numbers and arguments they each
66 take depends on the loader that's used and is documented together with
69 There are also global controls available:
73 =item B<OSSL_STORE_C_USE_SECMEM>
75 Controls if the loader should attempt to use secure memory for any
76 allocated B<OSSL_STORE_INFO> and its contents.
77 This control expects one argument, a pointer to an B<int> that is expected to
78 have the value 1 (yes) or 0 (no).
79 Any other value is an error.
83 OSSL_STORE_load() takes a B<OSSL_STORE_CTX>, tries to load the next available
84 object and return it wrapped with B<OSSL_STORE_INFO>.
86 OSSL_STORE_eof() takes a B<OSSL_STORE_CTX> and checks if we've reached the end
89 OSSL_STORE_error() takes a B<OSSL_STORE_CTX> and checks if an error occurred in
90 the last OSSL_STORE_load() call.
91 Note that it may still be meaningful to try and load more objects, unless
92 OSSL_STORE_eof() shows that the end of data has been reached.
94 OSSL_STORE_close() takes a B<OSSL_STORE_CTX>, closes the channel that was opened
95 by OSSL_STORE_open() and frees all other information that was stored in the
96 B<OSSL_STORE_CTX>, as well as the B<OSSL_STORE_CTX> itself.
98 =head1 SUPPORTED SCHEMES
100 The basic supported scheme is B<file:>.
101 Any other scheme can be added dynamically, using
102 OSSL_STORE_register_loader().
106 A string without a scheme prefix (that is, a non-URI string) is
107 implicitly interpreted as using the F<file:> scheme.
109 There are some tools that can be used together with
110 OSSL_STORE_open() to determine if any failure is caused by an unparsable
111 URI, or if it's a different error (such as memory allocation
112 failures); if the URI was parsable but the scheme unregistered, the
113 top error will have the reason C<OSSL_STORE_R_UNREGISTERED_SCHEME>.
115 These functions make no direct assumption regarding the pass phrase received
116 from the password callback.
117 The loaders may make assumptions, however.
118 For example, the B<file:> scheme loader inherits the assumptions made by
119 OpenSSL functionality that handles the different file types; this is mostly
120 relevant for PKCS#12 objects.
121 See L<passphrase-encoding(7)> for further information.
125 OSSL_STORE_open() returns a pointer to a B<OSSL_STORE_CTX> on success, or
128 OSSL_STORE_load() returns a pointer to a B<OSSL_STORE_INFO> on success, or
129 B<NULL> on error or when end of data is reached.
130 Use OSSL_STORE_error() and OSSL_STORE_eof() to determine the meaning of a
133 OSSL_STORE_eof() returns 1 if the end of data has been reached, otherwise
136 OSSL_STORE_error() returns 1 if an error occurred in an OSSL_STORE_load() call,
139 OSSL_STORE_ctrl() and OSSL_STORE_close() returns 1 on success, or 0 on failure.
143 L<ossl_store(7)>, L<OSSL_STORE_INFO(3)>, L<OSSL_STORE_register_loader(3)>,
144 L<passphrase-encoding(7)>
148 OSSL_STORE_CTX(), OSSL_STORE_post_process_info_fn(), OSSL_STORE_open(),
149 OSSL_STORE_ctrl(), OSSL_STORE_load(), OSSL_STORE_eof() and OSSL_STORE_close()
150 were added to OpenSSL 1.1.1.
154 Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
156 Licensed under the OpenSSL license (the "License"). You may not use
157 this file except in compliance with the License. You can obtain a copy
158 in the file LICENSE in the source distribution or at
159 L<https://www.openssl.org/source/license.html>.