5 OSSL_STORE_CTX, OSSL_STORE_post_process_info_fn,
6 OSSL_STORE_open, OSSL_STORE_open_with_libctx,
7 OSSL_STORE_ctrl, OSSL_STORE_load, OSSL_STORE_eof,
8 OSSL_STORE_error, OSSL_STORE_close
9 - Types and functions to read objects from a URI
13 #include <openssl/store.h>
15 typedef struct ossl_store_ctx_st OSSL_STORE_CTX;
17 typedef OSSL_STORE_INFO *(*OSSL_STORE_post_process_info_fn)(OSSL_STORE_INFO *,
20 OSSL_STORE_CTX *OSSL_STORE_open(const char *uri, const UI_METHOD *ui_method,
22 OSSL_STORE_post_process_info_fn post_process,
23 void *post_process_data);
24 OSSL_STORE_CTX *OSSL_STORE_open_with_libctx
25 (const char *uri, OPENSSL_CTX *libctx, const char *propq,
26 const UI_METHOD *ui_method, void *ui_data,
27 OSSL_STORE_post_process_info_fn post_process, void *post_process_data);
29 int OSSL_STORE_ctrl(OSSL_STORE_CTX *ctx, int cmd, ... /* args */);
30 OSSL_STORE_INFO *OSSL_STORE_load(OSSL_STORE_CTX *ctx);
31 int OSSL_STORE_eof(OSSL_STORE_CTX *ctx);
32 int OSSL_STORE_error(OSSL_STORE_CTX *ctx);
33 int OSSL_STORE_close(OSSL_STORE_CTX *ctx);
37 These functions help the application to fetch supported objects (see
38 L<OSSL_STORE_INFO(3)/SUPPORTED OBJECTS> for information on which those are)
39 from a given URI (see L</SUPPORTED SCHEMES> for more information on
40 the supported URI schemes).
41 The general method to do so is to "open" the URI using OSSL_STORE_open(),
42 read each available and supported object using OSSL_STORE_load() as long as
43 OSSL_STORE_eof() hasn't been reached, and finish it off with OSSL_STORE_close().
45 The retrieved information is stored in a B<OSSL_STORE_INFO>, which is further
46 described in L<OSSL_STORE_INFO(3)>.
50 B<OSSL_STORE_CTX> is a context variable that holds all the internal
51 information for OSSL_STORE_open(), OSSL_STORE_open_with_libctx(),
52 OSSL_STORE_load(), OSSL_STORE_eof() and OSSL_STORE_close() to work
57 OSSL_STORE_open_with_libctx() takes a uri or path I<uri>, password UI method
58 I<ui_method> with associated data I<ui_data>, and post processing
59 callback I<post_process> with associated data I<post_process_data>,
60 a library context I<libctx> with an associated property query <propq>,
61 and opens a channel to the data located at the URI and returns a
62 B<OSSL_STORE_CTX> with all necessary internal information.
63 The given I<ui_method> and I<ui_data> will be reused by all
64 functions that use B<OSSL_STORE_CTX> when interaction is needed,
65 for instance to provide a password.
66 The given I<post_process> and I<post_process_data> will be reused by
67 OSSL_STORE_load() to manipulate or drop the value to be returned.
68 The I<post_process> function drops values by returning NULL, which
69 will cause OSSL_STORE_load() to start its process over with loading
70 the next object, until I<post_process> returns something other than
71 NULL, or the end of data is reached as indicated by OSSL_STORE_eof().
73 OSSL_STORE_open() is similar to OSSL_STORE_open_with_libctx() but uses NULL for
74 the library context I<libctx> and property query <propq>.
76 OSSL_STORE_ctrl() takes a B<OSSL_STORE_CTX>, and command number I<cmd> and
77 more arguments not specified here.
78 The available loader specific command numbers and arguments they each
79 take depends on the loader that's used and is documented together with
82 There are also global controls available:
86 =item B<OSSL_STORE_C_USE_SECMEM>
88 Controls if the loader should attempt to use secure memory for any
89 allocated B<OSSL_STORE_INFO> and its contents.
90 This control expects one argument, a pointer to an B<int> that is expected to
91 have the value 1 (yes) or 0 (no).
92 Any other value is an error.
96 OSSL_STORE_load() takes a B<OSSL_STORE_CTX> and tries to load the next
97 available object and return it wrapped with B<OSSL_STORE_INFO>.
99 OSSL_STORE_eof() takes a B<OSSL_STORE_CTX> and checks if we've reached the end
102 OSSL_STORE_error() takes a B<OSSL_STORE_CTX> and checks if an error occurred in
103 the last OSSL_STORE_load() call.
104 Note that it may still be meaningful to try and load more objects, unless
105 OSSL_STORE_eof() shows that the end of data has been reached.
107 OSSL_STORE_close() takes a B<OSSL_STORE_CTX>, closes the channel that was opened
108 by OSSL_STORE_open() and frees all other information that was stored in the
109 B<OSSL_STORE_CTX>, as well as the B<OSSL_STORE_CTX> itself.
110 If I<ctx> is NULL it does nothing.
112 =head1 SUPPORTED SCHEMES
114 The basic supported scheme is B<file:>.
115 Any other scheme can be added dynamically, using
116 OSSL_STORE_register_loader().
120 A string without a scheme prefix (that is, a non-URI string) is
121 implicitly interpreted as using the F<file:> scheme.
123 There are some tools that can be used together with
124 OSSL_STORE_open() to determine if any failure is caused by an unparsable
125 URI, or if it's a different error (such as memory allocation
126 failures); if the URI was parsable but the scheme unregistered, the
127 top error will have the reason C<OSSL_STORE_R_UNREGISTERED_SCHEME>.
129 These functions make no direct assumption regarding the pass phrase received
130 from the password callback.
131 The loaders may make assumptions, however.
132 For example, the B<file:> scheme loader inherits the assumptions made by
133 OpenSSL functionality that handles the different file types; this is mostly
134 relevant for PKCS#12 objects.
135 See L<passphrase-encoding(7)> for further information.
139 OSSL_STORE_open() returns a pointer to a B<OSSL_STORE_CTX> on success, or
142 OSSL_STORE_load() returns a pointer to a B<OSSL_STORE_INFO> on success, or NULL
143 on error or when end of data is reached.
144 Use OSSL_STORE_error() and OSSL_STORE_eof() to determine the meaning of a
147 OSSL_STORE_eof() returns 1 if the end of data has been reached, otherwise
150 OSSL_STORE_error() returns 1 if an error occurred in an OSSL_STORE_load() call,
153 OSSL_STORE_ctrl() and OSSL_STORE_close() returns 1 on success, or 0 on failure.
157 L<ossl_store(7)>, L<OSSL_STORE_INFO(3)>, L<OSSL_STORE_register_loader(3)>,
158 L<passphrase-encoding(7)>
162 OSSL_STORE_open_with_libctx() was added in OpenSSL 3.0.
164 B<OSSL_STORE_CTX>, OSSL_STORE_post_process_info_fn(), OSSL_STORE_open(),
165 OSSL_STORE_ctrl(), OSSL_STORE_load(), OSSL_STORE_eof() and OSSL_STORE_close()
166 were added in OpenSSL 1.1.1.
168 Handling of NULL I<ctx> argument for OSSL_STORE_close()
169 was introduced in OpenSSL 1.1.1h.
173 Copyright 2016-2020 The OpenSSL Project Authors. All Rights Reserved.
175 Licensed under the Apache License 2.0 (the "License"). You may not use
176 this file except in compliance with the License. You can obtain a copy
177 in the file LICENSE in the source distribution or at
178 L<https://www.openssl.org/source/license.html>.