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 BIO_new_file OSSL_FUNC_BIO_NEW_FILE
112 BIO_new_mem_buf OSSL_FUNC_BIO_NEW_MEMBUF
113 BIO_read OSSL_FUNC_BIO_READ
114 BIO_free OSSL_FUNC_BIO_FREE
115 OPENSSL_cleanse OSSL_FUNC_OPENSSL_CLEANSE
116 OPENSSL_hexstr2buf OSSL_FUNC_OPENSSL_HEXSTR2BUF
118 For I<*out> (the B<OSSL_DISPATCH> array passed from the provider to
121 provider_teardown OSSL_FUNC_PROVIDER_TEARDOWN
122 provider_gettable_params OSSL_FUNC_PROVIDER_GETTABLE_PARAMS
123 provider_get_params OSSL_FUNC_PROVIDER_GET_PARAMS
124 provider_query_operation OSSL_FUNC_PROVIDER_QUERY_OPERATION
125 provider_get_reason_strings OSSL_FUNC_PROVIDER_GET_REASON_STRINGS
127 =head2 Core functions
129 core_gettable_params() returns a constant array of descriptor
130 B<OSSL_PARAM>, for parameters that core_get_params() can handle.
132 core_get_params() retrieves I<prov> parameters from the core.
133 See L</Core parameters> below for a description of currently known
136 =for comment core_thread_start() TBA
138 core_get_library_context() retrieves the library context in which the
139 B<OSSL_PROVIDER> object I<prov> is stored.
140 This may sometimes be useful if the provider wishes to store a
141 reference to its context in the same library context.
143 core_new_error(), core_set_error_debug() and core_set_error() are
144 building blocks for reporting an error back to the core, with
145 reference to the provider object I<prov>.
149 =item core_new_error()
151 allocates a new thread specific error record.
153 This corresponds to the OpenSSL function L<ERR_new(3)>.
155 =item core_set_error_debug()
157 sets debugging information in the current thread specific error
159 The debugging information includes the name of the file I<file>, the
160 line I<line> and the function name I<func> where the error occured.
162 This corresponds to the OpenSSL function L<ERR_set_debug(3)>.
164 =item core_set_error()
166 sets the I<reason> for the error, along with any addition data.
167 The I<reason> is a number defined by the provider and used to index
168 the reason strings table that's returned by
169 provider_get_reason_strings().
170 The additional data is given as a format string I<fmt> and a set of
171 arguments I<args>, which are treated in the same manner as with
173 I<file> and I<line> may also be passed to indicate exactly where the
174 error occured or was reported.
176 This corresponds to the OpenSSL function L<ERR_vset_error(3)>.
180 CRYPTO_malloc(), CRYPTO_zalloc(), CRYPTO_memdup(), CRYPTO_strdup(),
181 CRYPTO_strndup(), CRYPTO_free(), CRYPTO_clear_free(),
182 CRYPTO_realloc(), CRYPTO_clear_realloc(), CRYPTO_secure_malloc(),
183 CRYPTO_secure_zalloc(), CRYPTO_secure_free(),
184 CRYPTO_secure_clear_free(), CRYPTO_secure_allocated(),
185 BIO_new_file(), BIO_new_mem_buf(), BIO_read(), BIO_free(),
186 OPENSSL_cleanse(), and OPENSSL_hexstr2buf() correspond exactly to the
187 public functions with the same name.
188 As a matter of fact, the pointers in the B<OSSL_DISPATCH> array are
189 direct pointers to those public functions.
191 =head2 Provider functions
193 provider_teardown() is called when a provider is shut down and removed
194 from the core's provider store.
195 It must free the passed I<provctx>.
197 provider_gettable_params() should return a constant array of
198 descriptor B<OSSL_PARAM>, for parameters that provider_get_params()
201 provider_get_params() should process the B<OSSL_PARAM> array
202 I<params>, setting the values of the parameters it understands.
204 provider_query_operation() should return a constant B<OSSL_ALGORITHM>
205 that corresponds to the given I<operation_id>.
206 It should indicate if the core may store a reference to this array by
207 setting I<*no_store> to 0 (core may store a reference) or 1 (core may
208 not store a reference).
210 provider_get_reason_strings() should return a constant B<OSSL_ITEM>
211 array that provides reason strings for reason codes the provider may
212 use when reporting errors using core_put_error().
214 None of these functions are mandatory, but a provider is fairly
215 useless without at least provider_query_operation(), and
216 provider_gettable_params() is fairly useless if not accompanied by
217 provider_get_params().
219 =head2 Core parameters
221 core_get_params() understands the following known parameters:
225 =item "openssl-version"
227 This is a B<OSSL_PARAM_UTF8_PTR> type of parameter, pointing at the
228 OpenSSL libraries' full version string, i.e. the string expanded from
229 the macro B<OPENSSL_VERSION_STR>.
231 =item "provider-name"
233 This is a B<OSSL_PARAM_UTF8_PTR> type of parameter, pointing at the
234 OpenSSL libraries' idea of what the calling provider is called.
238 Additionally, provider specific configuration parameters from the
239 config file are available, in dotted name form.
240 The dotted name form is a concatenation of section names and final
241 config command name separated by periods.
243 For example, let's say we have the following config example:
245 openssl_conf = openssl_init
248 providers = providers_sect
262 The provider will have these additional parameters available:
268 pointing at the string "1"
272 pointing at the string "2"
276 pointing at the string "str"
280 pointing at the string "foo,bar"
284 For more information on handling parameters, see L<OSSL_PARAM(3)> as
285 L<OSSL_PARAM_int(3)>.
289 This is an example of a simple provider made available as a
290 dynamically loadable module.
291 It implements the fictitious algorithm C<FOO> for the fictitious
295 #include <openssl/core.h>
296 #include <openssl/core_numbers.h>
298 /* Errors used in this provider */
301 static const OSSL_ITEM reasons[] = {
302 { E_MALLOC, "memory allocation failure" }.
303 { 0, NULL } /* Termination */
307 * To ensure we get the function signature right, forward declare
308 * them using function types provided by openssl/core_numbers.h
310 OSSL_OP_bar_newctx_fn foo_newctx;
311 OSSL_OP_bar_freectx_fn foo_freectx;
312 OSSL_OP_bar_init_fn foo_init;
313 OSSL_OP_bar_update_fn foo_update;
314 OSSL_OP_bar_final_fn foo_final;
316 OSSL_provider_query_operation_fn p_query;
317 OSSL_provider_get_reason_strings_fn p_reasons;
318 OSSL_provider_teardown_fn p_teardown;
320 OSSL_provider_init_fn OSSL_provider_init;
322 OSSL_core_put_error *c_put_error = NULL;
324 /* Provider context */
329 /* operation context for the algorithm FOO */
331 struct prov_ctx_st *provctx;
335 static void *foo_newctx(void *provctx)
337 struct foo_ctx_st *fooctx = malloc(sizeof(*fooctx));
340 fooctx->provctx = provctx;
342 c_put_error(provctx->prov, E_MALLOC, __FILE__, __LINE__);
346 static void foo_freectx(void *fooctx)
351 static int foo_init(void *vfooctx)
353 struct foo_ctx_st *fooctx = vfooctx;
358 static int foo_update(void *vfooctx, unsigned char *in, size_t inl)
360 struct foo_ctx_st *fooctx = vfooctx;
362 /* did you expect something serious? */
365 for (; inl-- > 0; in++)
370 static int foo_final(void *vfooctx)
372 struct foo_ctx_st *fooctx = vfooctx;
377 static const OSSL_DISPATCH foo_fns[] = {
378 { OSSL_FUNC_BAR_NEWCTX, (void (*)(void))foo_newctx },
379 { OSSL_FUNC_BAR_FREECTX, (void (*)(void))foo_freectx },
380 { OSSL_FUNC_BAR_INIT, (void (*)(void))foo_init },
381 { OSSL_FUNC_BAR_UPDATE, (void (*)(void))foo_update },
382 { OSSL_FUNC_BAR_FINAL, (void (*)(void))foo_final },
386 static const OSSL_ALGORITHM bars[] = {
387 { "FOO", "provider=chumbawamba", foo_fns },
391 static const OSSL_ALGORITHM *p_query(void *provctx, int operation_id,
394 switch (operation_id) {
401 static const OSSL_ITEM *p_reasons(void *provctx)
406 static void p_teardown(void *provctx)
411 static const OSSL_DISPATCH prov_fns[] = {
412 { OSSL_FUNC_PROVIDER_TEARDOWN, (void (*)(void))p_teardown },
413 { OSSL_FUNC_PROVIDER_QUERY_OPERATION, (void (*)(void))p_query },
414 { OSSL_FUNC_PROVIDER_GET_REASON_STRINGS, (void (*)(void))p_reasons },
418 int OSSL_provider_init(const OSSL_PROVIDER *provider,
419 const OSSL_DISPATCH *in,
420 const OSSL_DISPATCH **out,
423 struct prov_ctx_st *pctx = NULL;
425 for (; in->function_id != 0; in++)
426 switch (in->function_id) {
427 case OSSL_FUNC_CORE_PUT_ERROR:
428 c_put_error = OSSL_get_core_put_error(in);
434 if ((pctx = malloc(sizeof(*pctx))) == NULL) {
436 * ALEA IACTA EST, if the core retrieves the reason table
437 * regardless, that string will be displayed, otherwise not.
439 c_put_error(provider, E_MALLOC, __FILE__, __LINE__);
445 This relies on a few things existing in F<openssl/core_numbers.h>:
447 #define OSSL_OP_BAR 4711
449 #define OSSL_FUNC_BAR_NEWCTX 1
450 typedef void *(OSSL_OP_bar_newctx_fn)(void *provctx);
451 static ossl_inline OSSL_get_bar_newctx(const OSSL_DISPATCH *opf)
452 { return (OSSL_OP_bar_newctx_fn *)opf->function; }
454 #define OSSL_FUNC_BAR_FREECTX 2
455 typedef void (OSSL_OP_bar_freectx_fn)(void *ctx);
456 static ossl_inline OSSL_get_bar_newctx(const OSSL_DISPATCH *opf)
457 { return (OSSL_OP_bar_freectx_fn *)opf->function; }
459 #define OSSL_FUNC_BAR_INIT 3
460 typedef void *(OSSL_OP_bar_init_fn)(void *ctx);
461 static ossl_inline OSSL_get_bar_init(const OSSL_DISPATCH *opf)
462 { return (OSSL_OP_bar_init_fn *)opf->function; }
464 #define OSSL_FUNC_BAR_UPDATE 4
465 typedef void *(OSSL_OP_bar_update_fn)(void *ctx,
466 unsigned char *in, size_t inl);
467 static ossl_inline OSSL_get_bar_update(const OSSL_DISPATCH *opf)
468 { return (OSSL_OP_bar_update_fn *)opf->function; }
470 #define OSSL_FUNC_BAR_FINAL 5
471 typedef void *(OSSL_OP_bar_final_fn)(void *ctx);
472 static ossl_inline OSSL_get_bar_final(const OSSL_DISPATCH *opf)
473 { return (OSSL_OP_bar_final_fn *)opf->function; }
481 The concept of providers and everything surrounding them was
482 introduced in OpenSSL 3.0.
486 Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
488 Licensed under the Apache License 2.0 (the "License"). You may not use
489 this file except in compliance with the License. You can obtain a copy
490 in the file LICENSE in the source distribution or at
491 L<https://www.openssl.org/source/license.html>.