1OSSL_STORE_OPEN(3) OpenSSL OSSL_STORE_OPEN(3)
2
6 OSSL_STORE_CTX, OSSL_STORE_post_process_info_fn, OSSL_STORE_open,
7 OSSL_STORE_ctrl, OSSL_STORE_load, OSSL_STORE_eof, OSSL_STORE_error,
8 OSSL_STORE_close - Types and functions to read objects from a URI
9
11 #include <openssl/store.h>
12 typedef struct ossl_store_ctx_st OSSL_STORE_CTX;
14 typedef OSSL_STORE_INFO *(*OSSL_STORE_post_process_info_fn)(OSSL_STORE_INFO *,
16 void *);
17 OSSL_STORE_CTX *OSSL_STORE_open(const char *uri, const UI_METHOD *ui_method,
19 void *ui_data,
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);
27
29 These functions help the application to fetch supported objects (see
30 "SUPPORTED OBJECTS" in OSSL_STORE_INFO(3) for information on which
31 those are) from a given URI (see "SUPPORTED SCHEMES" for more
32 information on the supported URI schemes). The general method to do so
33 is to "open" the URI using OSSL_STORE_open(), read each available and
34 supported object using OSSL_STORE_load() as long as OSSL_STORE_eof()
35 hasn't been reached, and finish it off with OSSL_STORE_close().
36 The retrieved information is stored in a OSSL_STORE_INFO, which is
38 further described in OSSL_STORE_INFO(3).
39 Types
41 OSSL_STORE_CTX is a context variable that holds all the internal
42 information for OSSL_STORE_open(), OSSL_STORE_load(), OSSL_STORE_eof()
43 and OSSL_STORE_close() to work together.
44 Functions
46 OSSL_STORE_open() takes a uri or path uri, password UI method ui_method
47 with associated data ui_data, and post processing callback post_process
48 with associated data post_process_data, opens a channel to the data
49 located at that URI and returns a OSSL_STORE_CTX with all necessary
50 internal information. The given ui_method and ui_data will be reused
51 by all functions that use OSSL_STORE_CTX when interaction is needed,
52 for instance to provide a password. The given post_process and
53 post_process_data will be reused by OSSL_STORE_load() to manipulate or
54 drop the value to be returned. The post_process function drops values
55 by returning NULL, which will cause OSSL_STORE_load() to start its
56 process over with loading the next object, until post_process returns
57 something other than NULL, or the end of data is reached as indicated
58 by OSSL_STORE_eof().
59 OSSL_STORE_ctrl() takes a OSSL_STORE_CTX, and command number cmd and
61 more arguments not specified here. The available loader specific
62 command numbers and arguments they each take depends on the loader
63 that's used and is documented together with that loader.
64 There are also global controls available:
66 OSSL_STORE_C_USE_SECMEM
68 Controls if the loader should attempt to use secure memory for any
69 allocated OSSL_STORE_INFO and its contents. This control expects
70 one argument, a pointer to an int that is expected to have the
71 value 1 (yes) or 0 (no). Any other value is an error.
72 OSSL_STORE_load() takes a OSSL_STORE_CTX, tries to load the next
74 available object and return it wrapped with OSSL_STORE_INFO.
75 OSSL_STORE_eof() takes a OSSL_STORE_CTX and checks if we've reached the
77 end of data.
78 OSSL_STORE_error() takes a OSSL_STORE_CTX and checks if an error
80 occurred in the last OSSL_STORE_load() call. Note that it may still be
81 meaningful to try and load more objects, unless OSSL_STORE_eof() shows
82 that the end of data has been reached.
83 OSSL_STORE_close() takes a OSSL_STORE_CTX, closes the channel that was
85 opened by OSSL_STORE_open() and frees all other information that was
86 stored in the OSSL_STORE_CTX, as well as the OSSL_STORE_CTX itself. If
87 ctx is NULL it does nothing.
88
90 The basic supported scheme is file:. Any other scheme can be added
91 dynamically, using OSSL_STORE_register_loader().
92
94 A string without a scheme prefix (that is, a non-URI string) is
95 implicitly interpreted as using the file: scheme.
96 There are some tools that can be used together with OSSL_STORE_open()
98 to determine if any failure is caused by an unparsable URI, or if it's
99 a different error (such as memory allocation failures); if the URI was
100 parsable but the scheme unregistered, the top error will have the
101 reason "OSSL_STORE_R_UNREGISTERED_SCHEME".
102 These functions make no direct assumption regarding the pass phrase
104 received from the password callback. The loaders may make assumptions,
105 however. For example, the file: scheme loader inherits the assumptions
106 made by OpenSSL functionality that handles the different file types;
107 this is mostly relevant for PKCS#12 objects. See
108 passphrase-encoding(7) for further information.
109
111 OSSL_STORE_open() returns a pointer to a OSSL_STORE_CTX on success, or
112 NULL on failure.
113 OSSL_STORE_load() returns a pointer to a OSSL_STORE_INFO on success, or
115 NULL on error or when end of data is reached. Use OSSL_STORE_error()
116 and OSSL_STORE_eof() to determine the meaning of a returned NULL.
117 OSSL_STORE_eof() returns 1 if the end of data has been reached,
119 otherwise 0.
120 OSSL_STORE_error() returns 1 if an error occurred in an
122 OSSL_STORE_load() call, otherwise 0.
123 OSSL_STORE_ctrl() and OSSL_STORE_close() returns 1 on success, or 0 on
125 failure.
126
128 ossl_store(7), OSSL_STORE_INFO(3), OSSL_STORE_register_loader(3),
129 passphrase-encoding(7)
130
132 OSSL_STORE_CTX(), OSSL_STORE_post_process_info_fn(), OSSL_STORE_open(),
133 OSSL_STORE_ctrl(), OSSL_STORE_load(), OSSL_STORE_eof() and
134 OSSL_STORE_close() were added in OpenSSL 1.1.1.
135 Handling of NULL ctx argument for OSSL_STORE_close() was introduced in
137 OpenSSL 1.1.1h.
138
140 Copyright 2016-2020 The OpenSSL Project Authors. All Rights Reserved.
141 Licensed under the OpenSSL license (the "License"). You may not use
143 this file except in compliance with the License. You can obtain a copy
144 in the file LICENSE in the source distribution or at
145 <https://www.openssl.org/source/license.html>.
1461.1.1i 2021-07-22 OSSL_STORE_OPEN(3)