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_gettable_params(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_gettable_params(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_gettable_params() has these:
80 (OSSL_core_gettable_params_fn)(const OSSL_PROVIDER *prov);
81 static ossl_inline OSSL_NAME_core_gettable_params_fn
82 OSSL_get_core_gettable_params(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_gettable_params OSSL_FUNC_CORE_GETTABLE_PARAMS
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 CRYPTO_mem_ctrl OSSL_FUNC_CRYPTO_MEM_CTRL
112 BIO_new_file OSSL_FUNC_BIO_NEW_FILE
113 BIO_new_mem_buf OSSL_FUNC_BIO_NEW_MEMBUF
114 BIO_read_ex OSSL_FUNC_BIO_READ_EX
115 BIO_free OSSL_FUNC_BIO_FREE
116 OPENSSL_cleanse OSSL_FUNC_OPENSSL_CLEANSE
117 OPENSSL_hexstr2buf OSSL_FUNC_OPENSSL_HEXSTR2BUF
119 For I<*out> (the B<OSSL_DISPATCH> array passed from the provider to
122 provider_teardown OSSL_FUNC_PROVIDER_TEARDOWN
123 provider_gettable_params OSSL_FUNC_PROVIDER_GETTABLE_PARAMS
124 provider_get_params OSSL_FUNC_PROVIDER_GET_PARAMS
125 provider_query_operation OSSL_FUNC_PROVIDER_QUERY_OPERATION
126 provider_get_reason_strings OSSL_FUNC_PROVIDER_GET_REASON_STRINGS
128 =head2 Core functions
130 core_gettable_params() returns a constant array of descriptor
131 B<OSSL_PARAM>, for parameters that core_get_params() can handle.
133 core_get_params() retrieves I<prov> parameters from the core.
134 See L</Core parameters> below for a description of currently known
137 =for comment core_thread_start() TBA
139 core_get_library_context() retrieves the library context in which the
140 B<OSSL_PROVIDER> object I<prov> is stored.
141 This may sometimes be useful if the provider wishes to store a
142 reference to its context in the same library context.
144 core_new_error(), core_set_error_debug() and core_set_error() are
145 building blocks for reporting an error back to the core, with
146 reference to the provider object I<prov>.
150 =item core_new_error()
152 allocates a new thread specific error record.
154 This corresponds to the OpenSSL function L<ERR_new(3)>.
156 =item core_set_error_debug()
158 sets debugging information in the current thread specific error
160 The debugging information includes the name of the file I<file>, the
161 line I<line> and the function name I<func> where the error occured.
163 This corresponds to the OpenSSL function L<ERR_set_debug(3)>.
165 =item core_set_error()
167 sets the I<reason> for the error, along with any addition data.
168 The I<reason> is a number defined by the provider and used to index
169 the reason strings table that's returned by
170 provider_get_reason_strings().
171 The additional data is given as a format string I<fmt> and a set of
172 arguments I<args>, which are treated in the same manner as with
174 I<file> and I<line> may also be passed to indicate exactly where the
175 error occured or was reported.
177 This corresponds to the OpenSSL function L<ERR_vset_error(3)>.
181 CRYPTO_malloc(), CRYPTO_zalloc(), CRYPTO_memdup(), CRYPTO_strdup(),
182 CRYPTO_strndup(), CRYPTO_free(), CRYPTO_clear_free(),
183 CRYPTO_realloc(), CRYPTO_clear_realloc(), CRYPTO_secure_malloc(),
184 CRYPTO_secure_zalloc(), CRYPTO_secure_free(),
185 CRYPTO_secure_clear_free(), CRYPTO_secure_allocated(), CRYPTO_mem_ctrl(),
186 BIO_new_file(), BIO_new_mem_buf(), BIO_read_ex(), BIO_free(),
187 OPENSSL_cleanse(), and OPENSSL_hexstr2buf() correspond exactly to the
188 public functions with the same name.
189 As a matter of fact, the pointers in the B<OSSL_DISPATCH> array are
190 direct pointers to those public functions.
192 =head2 Provider functions
194 provider_teardown() is called when a provider is shut down and removed
195 from the core's provider store.
196 It must free the passed I<provctx>.
198 provider_gettable_params() should return a constant array of
199 descriptor B<OSSL_PARAM>, for parameters that provider_get_params()
202 provider_get_params() should process the B<OSSL_PARAM> array
203 I<params>, setting the values of the parameters it understands.
205 provider_query_operation() should return a constant B<OSSL_ALGORITHM>
206 that corresponds to the given I<operation_id>.
207 It should indicate if the core may store a reference to this array by
208 setting I<*no_store> to 0 (core may store a reference) or 1 (core may
209 not store a reference).
211 provider_get_reason_strings() should return a constant B<OSSL_ITEM>
212 array that provides reason strings for reason codes the provider may
213 use when reporting errors using core_put_error().
215 None of these functions are mandatory, but a provider is fairly
216 useless without at least provider_query_operation(), and
217 provider_gettable_params() is fairly useless if not accompanied by
218 provider_get_params().
220 =head2 Core parameters
222 core_get_params() understands the following known parameters:
226 =item "openssl-version"
228 This is a B<OSSL_PARAM_UTF8_PTR> type of parameter, pointing at the
229 OpenSSL libraries' full version string, i.e. the string expanded from
230 the macro B<OPENSSL_VERSION_STR>.
232 =item "provider-name"
234 This is a B<OSSL_PARAM_UTF8_PTR> type of parameter, pointing at the
235 OpenSSL libraries' idea of what the calling provider is called.
239 Additionally, provider specific configuration parameters from the
240 config file are available, in dotted name form.
241 The dotted name form is a concatenation of section names and final
242 config command name separated by periods.
244 For example, let's say we have the following config example:
246 openssl_conf = openssl_init
249 providers = providers_sect
263 The provider will have these additional parameters available:
269 pointing at the string "1"
273 pointing at the string "2"
277 pointing at the string "str"
281 pointing at the string "foo,bar"
285 For more information on handling parameters, see L<OSSL_PARAM(3)> as
286 L<OSSL_PARAM_int(3)>.
290 This is an example of a simple provider made available as a
291 dynamically loadable module.
292 It implements the fictitious algorithm C<FOO> for the fictitious
296 #include <openssl/core.h>
297 #include <openssl/core_numbers.h>
299 /* Errors used in this provider */
302 static const OSSL_ITEM reasons[] = {
303 { E_MALLOC, "memory allocation failure" }.
304 { 0, NULL } /* Termination */
308 * To ensure we get the function signature right, forward declare
309 * them using function types provided by openssl/core_numbers.h
311 OSSL_OP_bar_newctx_fn foo_newctx;
312 OSSL_OP_bar_freectx_fn foo_freectx;
313 OSSL_OP_bar_init_fn foo_init;
314 OSSL_OP_bar_update_fn foo_update;
315 OSSL_OP_bar_final_fn foo_final;
317 OSSL_provider_query_operation_fn p_query;
318 OSSL_provider_get_reason_strings_fn p_reasons;
319 OSSL_provider_teardown_fn p_teardown;
321 OSSL_provider_init_fn OSSL_provider_init;
323 OSSL_core_put_error *c_put_error = NULL;
325 /* Provider context */
330 /* operation context for the algorithm FOO */
332 struct prov_ctx_st *provctx;
336 static void *foo_newctx(void *provctx)
338 struct foo_ctx_st *fooctx = malloc(sizeof(*fooctx));
341 fooctx->provctx = provctx;
343 c_put_error(provctx->prov, E_MALLOC, __FILE__, __LINE__);
347 static void foo_freectx(void *fooctx)
352 static int foo_init(void *vfooctx)
354 struct foo_ctx_st *fooctx = vfooctx;
359 static int foo_update(void *vfooctx, unsigned char *in, size_t inl)
361 struct foo_ctx_st *fooctx = vfooctx;
363 /* did you expect something serious? */
366 for (; inl-- > 0; in++)
371 static int foo_final(void *vfooctx)
373 struct foo_ctx_st *fooctx = vfooctx;
378 static const OSSL_DISPATCH foo_fns[] = {
379 { OSSL_FUNC_BAR_NEWCTX, (void (*)(void))foo_newctx },
380 { OSSL_FUNC_BAR_FREECTX, (void (*)(void))foo_freectx },
381 { OSSL_FUNC_BAR_INIT, (void (*)(void))foo_init },
382 { OSSL_FUNC_BAR_UPDATE, (void (*)(void))foo_update },
383 { OSSL_FUNC_BAR_FINAL, (void (*)(void))foo_final },
387 static const OSSL_ALGORITHM bars[] = {
388 { "FOO", "provider=chumbawamba", foo_fns },
392 static const OSSL_ALGORITHM *p_query(void *provctx, int operation_id,
395 switch (operation_id) {
402 static const OSSL_ITEM *p_reasons(void *provctx)
407 static void p_teardown(void *provctx)
412 static const OSSL_DISPATCH prov_fns[] = {
413 { OSSL_FUNC_PROVIDER_TEARDOWN, (void (*)(void))p_teardown },
414 { OSSL_FUNC_PROVIDER_QUERY_OPERATION, (void (*)(void))p_query },
415 { OSSL_FUNC_PROVIDER_GET_REASON_STRINGS, (void (*)(void))p_reasons },
419 int OSSL_provider_init(const OSSL_PROVIDER *provider,
420 const OSSL_DISPATCH *in,
421 const OSSL_DISPATCH **out,
424 struct prov_ctx_st *pctx = NULL;
426 for (; in->function_id != 0; in++)
427 switch (in->function_id) {
428 case OSSL_FUNC_CORE_PUT_ERROR:
429 c_put_error = OSSL_get_core_put_error(in);
435 if ((pctx = malloc(sizeof(*pctx))) == NULL) {
437 * ALEA IACTA EST, if the core retrieves the reason table
438 * regardless, that string will be displayed, otherwise not.
440 c_put_error(provider, E_MALLOC, __FILE__, __LINE__);
446 This relies on a few things existing in F<openssl/core_numbers.h>:
448 #define OSSL_OP_BAR 4711
450 #define OSSL_FUNC_BAR_NEWCTX 1
451 typedef void *(OSSL_OP_bar_newctx_fn)(void *provctx);
452 static ossl_inline OSSL_get_bar_newctx(const OSSL_DISPATCH *opf)
453 { return (OSSL_OP_bar_newctx_fn *)opf->function; }
455 #define OSSL_FUNC_BAR_FREECTX 2
456 typedef void (OSSL_OP_bar_freectx_fn)(void *ctx);
457 static ossl_inline OSSL_get_bar_newctx(const OSSL_DISPATCH *opf)
458 { return (OSSL_OP_bar_freectx_fn *)opf->function; }
460 #define OSSL_FUNC_BAR_INIT 3
461 typedef void *(OSSL_OP_bar_init_fn)(void *ctx);
462 static ossl_inline OSSL_get_bar_init(const OSSL_DISPATCH *opf)
463 { return (OSSL_OP_bar_init_fn *)opf->function; }
465 #define OSSL_FUNC_BAR_UPDATE 4
466 typedef void *(OSSL_OP_bar_update_fn)(void *ctx,
467 unsigned char *in, size_t inl);
468 static ossl_inline OSSL_get_bar_update(const OSSL_DISPATCH *opf)
469 { return (OSSL_OP_bar_update_fn *)opf->function; }
471 #define OSSL_FUNC_BAR_FINAL 5
472 typedef void *(OSSL_OP_bar_final_fn)(void *ctx);
473 static ossl_inline OSSL_get_bar_final(const OSSL_DISPATCH *opf)
474 { return (OSSL_OP_bar_final_fn *)opf->function; }
482 The concept of providers and everything surrounding them was
483 introduced in OpenSSL 3.0.
487 Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
489 Licensed under the Apache License 2.0 (the "License"). You may not use
490 this file except in compliance with the License. You can obtain a copy
491 in the file LICENSE in the source distribution or at
492 L<https://www.openssl.org/source/license.html>.