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