6 - The basic OpenSSL library E<lt>-E<gt> provider functions
10 #include <openssl/core_numbers.h>
13 * None of these are actual functions, but are displayed like this for
14 * the function signatures for functions that are offered as function
15 * pointers in OSSL_DISPATCH arrays.
18 /* Functions offered by libcrypto to the providers */
19 const OSSL_ITEM *core_get_param_types(const OSSL_PROVIDER *prov);
20 int core_get_params(const OSSL_PROVIDER *prov, OSSL_PARAM params[]);
21 int core_thread_start(const OSSL_PROVIDER *prov,
22 OSSL_thread_stop_handler_fn handfn);
23 OPENSSL_CTX *core_get_library_context(const OSSL_PROVIDER *prov);
24 void core_new_error(const OSSL_PROVIDER *prov);
25 void core_set_error_debug(const OSSL_PROVIDER *prov,
26 const char *file, int line, const char *func);
27 void core_vset_error(const OSSL_PROVIDER *prov,
28 uint32_t reason, const char *fmt, va_list args);
31 * Some OpenSSL functionality is directly offered to providers via
34 void *CRYPTO_malloc(size_t num, const char *file, int line);
35 void *CRYPTO_zalloc(size_t num, const char *file, int line);
36 void *CRYPTO_memdup(const void *str, size_t siz,
37 const char *file, int line);
38 char *CRYPTO_strdup(const char *str, const char *file, int line);
39 char *CRYPTO_strndup(const char *str, size_t s,
40 const char *file, int line);
41 void CRYPTO_free(void *ptr, const char *file, int line);
42 void CRYPTO_clear_free(void *ptr, size_t num,
43 const char *file, int line);
44 void *CRYPTO_realloc(void *addr, size_t num,
45 const char *file, int line);
46 void *CRYPTO_clear_realloc(void *addr, size_t old_num, size_t num,
47 const char *file, int line);
48 void *CRYPTO_secure_malloc(size_t num, const char *file, int line);
49 void *CRYPTO_secure_zalloc(size_t num, const char *file, int line);
50 void CRYPTO_secure_free(void *ptr, const char *file, int line);
51 void CRYPTO_secure_clear_free(void *ptr, size_t num,
52 const char *file, int line);
53 int CRYPTO_secure_allocated(const void *ptr);
54 void OPENSSL_cleanse(void *ptr, size_t len);
55 unsigned char *OPENSSL_hexstr2buf(const char *str, long *len);
57 /* Functions offered by the provider to libcrypto */
58 void provider_teardown(void *provctx);
59 const OSSL_ITEM *provider_get_param_types(void *provctx);
60 int provider_get_params(void *provctx, OSSL_PARAM params[]);
61 const OSSL_ALGORITHM *provider_query_operation(void *provctx,
64 const OSSL_ITEM *provider_get_reason_strings(void *provctx);
68 All "functions" mentioned here are passed as function pointers between
69 F<libcrypto> and the provider in B<OSSL_DISPATCH> arrays, in the call
70 of the provider initialization function. See L<provider(7)/Provider>
71 for a description of the initialization function.
73 All these "functions" have a corresponding function type definition
74 named B<OSSL_{name}_fn>, and a helper function to retrieve the
75 function pointer from a B<OSSL_DISPATCH> element named
77 For example, the "function" core_get_param_types() has these:
80 (OSSL_core_get_param_types_fn)(const OSSL_PROVIDER *prov);
81 static ossl_inline OSSL_NAME_core_get_param_types_fn
82 OSSL_get_core_get_param_types(const OSSL_DISPATCH *opf);
84 B<OSSL_DISPATCH> arrays are indexed by numbers that are provided as
85 macros in L<openssl-core_numbers.h(7)>, as follows:
87 For I<in> (the B<OSSL_DISPATCH> array passed from F<libcrypto> to the
90 core_get_param_types OSSL_FUNC_CORE_GET_PARAM_TYPES
91 core_get_params OSSL_FUNC_CORE_GET_PARAMS
92 core_thread_start OSSL_FUNC_CORE_THREAD_START
93 core_get_library_context OSSL_FUNC_CORE_GET_LIBRARY_CONTEXT
94 core_new_error OSSL_FUNC_CORE_NEW_ERROR
95 core_set_error_debug OSSL_FUNC_CORE_SET_ERROR_DEBUG
96 core_set_error OSSL_FUNC_CORE_SET_ERROR
97 CRYPTO_malloc OSSL_FUNC_CRYPTO_MALLOC
98 CRYPTO_zalloc OSSL_FUNC_CRYPTO_ZALLOC
99 CRYPTO_memdup OSSL_FUNC_CRYPTO_MEMDUP
100 CRYPTO_strdup OSSL_FUNC_CRYPTO_STRDUP
101 CRYPTO_strndup OSSL_FUNC_CRYPTO_STRNDUP
102 CRYPTO_free OSSL_FUNC_CRYPTO_FREE
103 CRYPTO_clear_free OSSL_FUNC_CRYPTO_CLEAR_FREE
104 CRYPTO_realloc OSSL_FUNC_CRYPTO_REALLOC
105 CRYPTO_clear_realloc OSSL_FUNC_CRYPTO_CLEAR_REALLOC
106 CRYPTO_secure_malloc OSSL_FUNC_CRYPTO_SECURE_MALLOC
107 CRYPTO_secure_zalloc OSSL_FUNC_CRYPTO_SECURE_ZALLOC
108 CRYPTO_secure_free OSSL_FUNC_CRYPTO_SECURE_FREE
109 CRYPTO_secure_clear_free OSSL_FUNC_CRYPTO_SECURE_CLEAR_FREE
110 CRYPTO_secure_allocated OSSL_FUNC_CRYPTO_SECURE_ALLOCATED
111 OPENSSL_cleanse OSSL_FUNC_OPENSSL_CLEANSE
112 OPENSSL_hexstr2buf OSSL_FUNC_OPENSSL_HEXSTR2BUF
114 For I<*out> (the B<OSSL_DISPATCH> array passed from the provider to
117 provider_teardown OSSL_FUNC_PROVIDER_TEARDOWN
118 provider_get_param_types OSSL_FUNC_PROVIDER_GET_PARAM_TYPES
119 provider_get_params OSSL_FUNC_PROVIDER_GET_PARAMS
120 provider_query_operation OSSL_FUNC_PROVIDER_QUERY_OPERATION
121 provider_get_reason_strings OSSL_FUNC_PROVIDER_GET_REASON_STRINGS
123 =head2 Core functions
125 core_get_param_types() returns a constant array of descriptor
126 B<OSSL_PARAM>, for parameters that core_get_params() can handle.
128 core_get_params() retrieves I<prov> parameters from the core.
129 See L</Core parameters> below for a description of currently known
132 =for comment core_thread_start() TBA
134 core_get_library_context() retrieves the library context in which the
135 B<OSSL_PROVIDER> object I<prov> is stored.
136 This may sometimes be useful if the provider wishes to store a
137 reference to its context in the same library context.
139 core_new_error(), core_set_error_debug() and core_set_error() are
140 building blocks for reporting an error back to the core, with
141 reference to the provider object I<prov>.
145 =item core_new_error()
147 allocates a new thread specific error record.
149 This corresponds to the OpenSSL function L<ERR_new(3)>.
151 =item core_set_error_debug()
153 sets debugging information in the current thread specific error
155 The debugging information includes the name of the file I<file>, the
156 line I<line> and the function name I<func> where the error occured.
158 This corresponds to the OpenSSL function L<ERR_set_debug(3)>.
160 =item core_set_error()
162 sets the I<reason> for the error, along with any addition data.
163 The I<reason> is a number defined by the provider and used to index
164 the reason strings table that's returned by
165 provider_get_reason_strings().
166 The additional data is given as a format string I<fmt> and a set of
167 arguments I<args>, which are treated in the same manner as with
169 I<file> and I<line> may also be passed to indicate exactly where the
170 error occured or was reported.
172 This corresponds to the OpenSSL function L<ERR_vset_error(3)>.
176 CRYPTO_malloc(), CRYPTO_zalloc(), CRYPTO_memdup(), CRYPTO_strdup(),
177 CRYPTO_strndup(), CRYPTO_free(), CRYPTO_clear_free(),
178 CRYPTO_realloc(), CRYPTO_clear_realloc(), CRYPTO_secure_malloc(),
179 CRYPTO_secure_zalloc(), CRYPTO_secure_free(),
180 CRYPTO_secure_clear_free(), CRYPTO_secure_allocated(),
181 OPENSSL_cleanse(), and OPENSSL_hexstr2buf() correspond exactly to the
182 public functions with the same name.
183 As a matter of fact, the pointers in the B<OSSL_DISPATCH> array are
184 direct pointers to those public functions.
186 =head2 Provider functions
188 provider_teardown() is called when a provider is shut down and removed
189 from the core's provider store.
190 It must free the passed I<provctx>.
192 provider_get_param_types() should return a constant array of
193 descriptor B<OSSL_PARAM>, for parameters that provider_get_params()
196 provider_get_params() should process the B<OSSL_PARAM> array
197 I<params>, setting the values of the parameters it understands.
199 provider_query_operation() should return a constant B<OSSL_ALGORITHM>
200 that corresponds to the given I<operation_id>.
201 It should indicate if the core may store a reference to this array by
202 setting I<*no_store> to 0 (core may store a reference) or 1 (core may
203 not store a reference).
205 provider_get_reason_strings() should return a constant B<OSSL_ITEM>
206 array that provides reason strings for reason codes the provider may
207 use when reporting errors using core_put_error().
209 None of these functions are mandatory, but a provider is fairly
210 useless without at least provider_query_operation(), and
211 provider_get_param_types() is fairly useless if not accompanied by
212 provider_get_params().
214 =head2 Core parameters
216 core_get_params() understands the following known parameters:
220 =item "openssl-version"
222 This is a B<OSSL_PARAM_UTF8_PTR> type of parameter, pointing at the
223 OpenSSL libraries' full version string, i.e. the string expanded from
224 the macro B<OPENSSL_VERSION_STR>.
226 =item "provider-name"
228 This is a B<OSSL_PARAM_UTF8_PTR> type of parameter, pointing at the
229 OpenSSL libraries' idea of what the calling provider is called.
233 Additionally, provider specific configuration parameters from the
234 config file are available, in dotted name form.
235 The dotted name form is a concatenation of section names and final
236 config command name separated by periods.
238 For example, let's say we have the following config example:
240 openssl_conf = openssl_init
243 providers = providers_sect
257 The provider will have these additional parameters available:
263 pointing at the string "1"
267 pointing at the string "2"
271 pointing at the string "str"
275 pointing at the string "foo,bar"
279 For more information on handling parameters, see L<OSSL_PARAM(3)> as
280 L<OSSL_PARAM_int(3)>.
284 This is an example of a simple provider made available as a
285 dynamically loadable module.
286 It implements the fictitious algorithm C<FOO> for the fictitious
290 #include <openssl/core.h>
291 #include <openssl/core_numbers.h>
293 /* Errors used in this provider */
296 static const OSSL_ITEM reasons[] = {
297 { E_MALLOC, "memory allocation failure" }.
298 { 0, NULL } /* Termination */
302 * To ensure we get the function signature right, forward declare
303 * them using function types provided by openssl/core_numbers.h
305 OSSL_OP_bar_newctx_fn foo_newctx;
306 OSSL_OP_bar_freectx_fn foo_freectx;
307 OSSL_OP_bar_init_fn foo_init;
308 OSSL_OP_bar_update_fn foo_update;
309 OSSL_OP_bar_final_fn foo_final;
311 OSSL_provider_query_operation_fn p_query;
312 OSSL_provider_get_reason_strings_fn p_reasons;
313 OSSL_provider_teardown_fn p_teardown;
315 OSSL_provider_init_fn OSSL_provider_init;
317 OSSL_core_put_error *c_put_error = NULL;
319 /* Provider context */
324 /* operation context for the algorithm FOO */
326 struct prov_ctx_st *provctx;
330 static void *foo_newctx(void *provctx)
332 struct foo_ctx_st *fooctx = malloc(sizeof(*fooctx));
335 fooctx->provctx = provctx;
337 c_put_error(provctx->prov, E_MALLOC, __FILE__, __LINE__);
341 static void foo_freectx(void *fooctx)
346 static int foo_init(void *vfooctx)
348 struct foo_ctx_st *fooctx = vfooctx;
353 static int foo_update(void *vfooctx, unsigned char *in, size_t inl)
355 struct foo_ctx_st *fooctx = vfooctx;
357 /* did you expect something serious? */
360 for (; inl-- > 0; in++)
365 static int foo_final(void *vfooctx)
367 struct foo_ctx_st *fooctx = vfooctx;
372 static const OSSL_DISPATCH foo_fns[] = {
373 { OSSL_FUNC_BAR_NEWCTX, (void (*)(void))foo_newctx },
374 { OSSL_FUNC_BAR_FREECTX, (void (*)(void))foo_freectx },
375 { OSSL_FUNC_BAR_INIT, (void (*)(void))foo_init },
376 { OSSL_FUNC_BAR_UPDATE, (void (*)(void))foo_update },
377 { OSSL_FUNC_BAR_FINAL, (void (*)(void))foo_final },
381 static const OSSL_ALGORITHM bars[] = {
382 { "FOO", "provider=chumbawamba", foo_fns },
386 static const OSSL_ALGORITHM *p_query(void *provctx, int operation_id,
389 switch (operation_id) {
396 static const OSSL_ITEM *p_reasons(void *provctx)
401 static void p_teardown(void *provctx)
406 static const OSSL_DISPATCH prov_fns[] = {
407 { OSSL_FUNC_PROVIDER_TEARDOWN, (void (*)(void))p_teardown },
408 { OSSL_FUNC_PROVIDER_QUERY_OPERATION, (void (*)(void))p_query },
409 { OSSL_FUNC_PROVIDER_GET_REASON_STRINGS, (void (*)(void))p_reasons },
413 int OSSL_provider_init(const OSSL_PROVIDER *provider,
414 const OSSL_DISPATCH *in,
415 const OSSL_DISPATCH **out,
418 struct prov_ctx_st *pctx = NULL;
420 for (; in->function_id != 0; in++)
421 switch (in->function_id) {
422 case OSSL_FUNC_CORE_PUT_ERROR:
423 c_put_error = OSSL_get_core_put_error(in);
429 if ((pctx = malloc(sizeof(*pctx))) == NULL) {
431 * ALEA IACTA EST, if the core retrieves the reason table
432 * regardless, that string will be displayed, otherwise not.
434 c_put_error(provider, E_MALLOC, __FILE__, __LINE__);
440 This relies on a few things existing in F<openssl/core_numbers.h>:
442 #define OSSL_OP_BAR 4711
444 #define OSSL_FUNC_BAR_NEWCTX 1
445 typedef void *(OSSL_OP_bar_newctx_fn)(void *provctx);
446 static ossl_inline OSSL_get_bar_newctx(const OSSL_DISPATCH *opf)
447 { return (OSSL_OP_bar_newctx_fn *)opf->function; }
449 #define OSSL_FUNC_BAR_FREECTX 2
450 typedef void (OSSL_OP_bar_freectx_fn)(void *ctx);
451 static ossl_inline OSSL_get_bar_newctx(const OSSL_DISPATCH *opf)
452 { return (OSSL_OP_bar_freectx_fn *)opf->function; }
454 #define OSSL_FUNC_BAR_INIT 3
455 typedef void *(OSSL_OP_bar_init_fn)(void *ctx);
456 static ossl_inline OSSL_get_bar_init(const OSSL_DISPATCH *opf)
457 { return (OSSL_OP_bar_init_fn *)opf->function; }
459 #define OSSL_FUNC_BAR_UPDATE 4
460 typedef void *(OSSL_OP_bar_update_fn)(void *ctx,
461 unsigned char *in, size_t inl);
462 static ossl_inline OSSL_get_bar_update(const OSSL_DISPATCH *opf)
463 { return (OSSL_OP_bar_update_fn *)opf->function; }
465 #define OSSL_FUNC_BAR_FINAL 5
466 typedef void *(OSSL_OP_bar_final_fn)(void *ctx);
467 static ossl_inline OSSL_get_bar_final(const OSSL_DISPATCH *opf)
468 { return (OSSL_OP_bar_final_fn *)opf->function; }
476 The concept of providers and everything surrounding them was
477 introduced in OpenSSL 3.0.
481 Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
483 Licensed under the Apache License 2.0 (the "License"). You may not use
484 this file except in compliance with the License. You can obtain a copy
485 in the file LICENSE in the source distribution or at
486 L<https://www.openssl.org/source/license.html>.