1PROVIDER-BASE(7ossl) OpenSSL PROVIDER-BASE(7ossl)
2
6 provider-base - The basic OpenSSL library <-> provider functions
7
9 #include <openssl/core_dispatch.h>
10 /*
12 * None of these are actual functions, but are displayed like this for
13 * the function signatures for functions that are offered as function
14 * pointers in OSSL_DISPATCH arrays.
15 */
16 /* Functions offered by libcrypto to the providers */
18 const OSSL_ITEM *core_gettable_params(const OSSL_CORE_HANDLE *handle);
19 int core_get_params(const OSSL_CORE_HANDLE *handle, OSSL_PARAM params[]);
20 typedef void (*OSSL_thread_stop_handler_fn)(void *arg);
22 int core_thread_start(const OSSL_CORE_HANDLE *handle,
23 OSSL_thread_stop_handler_fn handfn,
24 void *arg);
25 OPENSSL_CORE_CTX *core_get_libctx(const OSSL_CORE_HANDLE *handle);
27 void core_new_error(const OSSL_CORE_HANDLE *handle);
28 void core_set_error_debug(const OSSL_CORE_HANDLE *handle,
29 const char *file, int line, const char *func);
30 void core_vset_error(const OSSL_CORE_HANDLE *handle,
31 uint32_t reason, const char *fmt, va_list args);
32 int core_obj_add_sigid(const OSSL_CORE_HANDLE *prov, const char *sign_name,
34 const char *digest_name, const char *pkey_name);
35 int core_obj_create(const OSSL_CORE_HANDLE *handle, const char *oid,
36 const char *sn, const char *ln);
37 /*
39 * Some OpenSSL functionality is directly offered to providers via
40 * dispatch
41 */
42 void *CRYPTO_malloc(size_t num, const char *file, int line);
43 void *CRYPTO_zalloc(size_t num, const char *file, int line);
44 void CRYPTO_free(void *ptr, const char *file, int line);
45 void CRYPTO_clear_free(void *ptr, size_t num,
46 const char *file, int line);
47 void *CRYPTO_realloc(void *addr, size_t num,
48 const char *file, int line);
49 void *CRYPTO_clear_realloc(void *addr, size_t old_num, size_t num,
50 const char *file, int line);
51 void *CRYPTO_secure_malloc(size_t num, const char *file, int line);
52 void *CRYPTO_secure_zalloc(size_t num, const char *file, int line);
53 void CRYPTO_secure_free(void *ptr, const char *file, int line);
54 void CRYPTO_secure_clear_free(void *ptr, size_t num,
55 const char *file, int line);
56 int CRYPTO_secure_allocated(const void *ptr);
57 void OPENSSL_cleanse(void *ptr, size_t len);
58 unsigned char *OPENSSL_hexstr2buf(const char *str, long *buflen);
60 OSSL_CORE_BIO *BIO_new_file(const char *filename, const char *mode);
62 OSSL_CORE_BIO *BIO_new_membuf(const void *buf, int len);
63 int BIO_read_ex(OSSL_CORE_BIO *bio, void *data, size_t data_len,
64 size_t *bytes_read);
65 int BIO_write_ex(OSSL_CORE_BIO *bio, const void *data, size_t data_len,
66 size_t *written);
67 int BIO_up_ref(OSSL_CORE_BIO *bio);
68 int BIO_free(OSSL_CORE_BIO *bio);
69 int BIO_vprintf(OSSL_CORE_BIO *bio, const char *format, va_list args);
70 int BIO_vsnprintf(char *buf, size_t n, const char *fmt, va_list args);
71 void OSSL_SELF_TEST_set_callback(OSSL_LIB_CTX *libctx, OSSL_CALLBACK *cb,
73 void *cbarg);
74 size_t get_entropy(const OSSL_CORE_HANDLE *handle,
76 unsigned char **pout, int entropy,
77 size_t min_len, size_t max_len);
78 void cleanup_entropy(const OSSL_CORE_HANDLE *handle,
79 unsigned char *buf, size_t len);
80 size_t get_nonce(const OSSL_CORE_HANDLE *handle,
81 unsigned char **pout, size_t min_len, size_t max_len,
82 const void *salt, size_t salt_len);
83 void cleanup_nonce(const OSSL_CORE_HANDLE *handle,
84 unsigned char *buf, size_t len);
85 /* Functions for querying the providers in the application library context */
87 int provider_register_child_cb(const OSSL_CORE_HANDLE *handle,
88 int (*create_cb)(const OSSL_CORE_HANDLE *provider,
89 void *cbdata),
90 int (*remove_cb)(const OSSL_CORE_HANDLE *provider,
91 void *cbdata),
92 int (*global_props_cb)(const char *props, void *cbdata),
93 void *cbdata);
94 void provider_deregister_child_cb(const OSSL_CORE_HANDLE *handle);
95 const char *provider_name(const OSSL_CORE_HANDLE *prov);
96 void *provider_get0_provider_ctx(const OSSL_CORE_HANDLE *prov);
97 const OSSL_DISPATCH *provider_get0_dispatch(const OSSL_CORE_HANDLE *prov);
98 int provider_up_ref(const OSSL_CORE_HANDLE *prov, int activate);
99 int provider_free(const OSSL_CORE_HANDLE *prov, int deactivate);
100 /* Functions offered by the provider to libcrypto */
102 void provider_teardown(void *provctx);
103 const OSSL_ITEM *provider_gettable_params(void *provctx);
104 int provider_get_params(void *provctx, OSSL_PARAM params[]);
105 const OSSL_ALGORITHM *provider_query_operation(void *provctx,
106 int operation_id,
107 const int *no_store);
108 void provider_unquery_operation(void *provctx, int operation_id,
109 const OSSL_ALGORITHM *algs);
110 const OSSL_ITEM *provider_get_reason_strings(void *provctx);
111 int provider_get_capabilities(void *provctx, const char *capability,
112 OSSL_CALLBACK *cb, void *arg);
113 int provider_self_test(void *provctx);
114
116 All "functions" mentioned here are passed as function pointers between
117 libcrypto and the provider in OSSL_DISPATCH arrays, in the call of the
118 provider initialization function. See "Provider" in provider(7) for a
119 description of the initialization function. They are known as
120 "upcalls".
121 All these "functions" have a corresponding function type definition
123 named OSSL_FUNC_{name}_fn, and a helper function to retrieve the
124 function pointer from a OSSL_DISPATCH element named OSSL_FUNC_{name}.
125 For example, the "function" core_gettable_params() has these:
126 typedef OSSL_PARAM *
128 (OSSL_FUNC_core_gettable_params_fn)(const OSSL_CORE_HANDLE *handle);
129 static ossl_inline OSSL_NAME_core_gettable_params_fn
130 OSSL_FUNC_core_gettable_params(const OSSL_DISPATCH *opf);
131 OSSL_DISPATCH arrays are indexed by numbers that are provided as macros
133 in openssl-core_dispatch.h(7), as follows:
134 For in (the OSSL_DISPATCH array passed from libcrypto to the provider):
136 core_gettable_params OSSL_FUNC_CORE_GETTABLE_PARAMS
138 core_get_params OSSL_FUNC_CORE_GET_PARAMS
139 core_thread_start OSSL_FUNC_CORE_THREAD_START
140 core_get_libctx OSSL_FUNC_CORE_GET_LIBCTX
141 core_new_error OSSL_FUNC_CORE_NEW_ERROR
142 core_set_error_debug OSSL_FUNC_CORE_SET_ERROR_DEBUG
143 core_vset_error OSSL_FUNC_CORE_VSET_ERROR
144 core_obj_add_sigid OSSL_FUNC_CORE_OBJ_ADD_SIGID
145 core_obj_create OSSL_FUNC_CORE_OBJ_CREATE
146 CRYPTO_malloc OSSL_FUNC_CRYPTO_MALLOC
147 CRYPTO_zalloc OSSL_FUNC_CRYPTO_ZALLOC
148 CRYPTO_free OSSL_FUNC_CRYPTO_FREE
149 CRYPTO_clear_free OSSL_FUNC_CRYPTO_CLEAR_FREE
150 CRYPTO_realloc OSSL_FUNC_CRYPTO_REALLOC
151 CRYPTO_clear_realloc OSSL_FUNC_CRYPTO_CLEAR_REALLOC
152 CRYPTO_secure_malloc OSSL_FUNC_CRYPTO_SECURE_MALLOC
153 CRYPTO_secure_zalloc OSSL_FUNC_CRYPTO_SECURE_ZALLOC
154 CRYPTO_secure_free OSSL_FUNC_CRYPTO_SECURE_FREE
155 CRYPTO_secure_clear_free OSSL_FUNC_CRYPTO_SECURE_CLEAR_FREE
156 CRYPTO_secure_allocated OSSL_FUNC_CRYPTO_SECURE_ALLOCATED
157 BIO_new_file OSSL_FUNC_BIO_NEW_FILE
158 BIO_new_mem_buf OSSL_FUNC_BIO_NEW_MEMBUF
159 BIO_read_ex OSSL_FUNC_BIO_READ_EX
160 BIO_write_ex OSSL_FUNC_BIO_WRITE_EX
161 BIO_up_ref OSSL_FUNC_BIO_UP_REF
162 BIO_free OSSL_FUNC_BIO_FREE
163 BIO_vprintf OSSL_FUNC_BIO_VPRINTF
164 BIO_vsnprintf OSSL_FUNC_BIO_VSNPRINTF
165 BIO_puts OSSL_FUNC_BIO_PUTS
166 BIO_gets OSSL_FUNC_BIO_GETS
167 BIO_ctrl OSSL_FUNC_BIO_CTRL
168 OPENSSL_cleanse OSSL_FUNC_OPENSSL_CLEANSE
169 OSSL_SELF_TEST_set_callback OSSL_FUNC_SELF_TEST_CB
170 ossl_rand_get_entropy OSSL_FUNC_GET_ENTROPY
171 ossl_rand_cleanup_entropy OSSL_FUNC_CLEANUP_ENTROPY
172 ossl_rand_get_nonce OSSL_FUNC_GET_NONCE
173 ossl_rand_cleanup_nonce OSSL_FUNC_CLEANUP_NONCE
174 provider_register_child_cb OSSL_FUNC_PROVIDER_REGISTER_CHILD_CB
175 provider_deregister_child_cb OSSL_FUNC_PROVIDER_DEREGISTER_CHILD_CB
176 provider_name OSSL_FUNC_PROVIDER_NAME
177 provider_get0_provider_ctx OSSL_FUNC_PROVIDER_GET0_PROVIDER_CTX
178 provider_get0_dispatch OSSL_FUNC_PROVIDER_GET0_DISPATCH
179 provider_up_ref OSSL_FUNC_PROVIDER_UP_REF
180 provider_free OSSL_FUNC_PROVIDER_FREE
181 For *out (the OSSL_DISPATCH array passed from the provider to
183 libcrypto):
184 provider_teardown OSSL_FUNC_PROVIDER_TEARDOWN
186 provider_gettable_params OSSL_FUNC_PROVIDER_GETTABLE_PARAMS
187 provider_get_params OSSL_FUNC_PROVIDER_GET_PARAMS
188 provider_query_operation OSSL_FUNC_PROVIDER_QUERY_OPERATION
189 provider_unquery_operation OSSL_FUNC_PROVIDER_UNQUERY_OPERATION
190 provider_get_reason_strings OSSL_FUNC_PROVIDER_GET_REASON_STRINGS
191 provider_get_capabilities OSSL_FUNC_PROVIDER_GET_CAPABILITIES
192 provider_self_test OSSL_FUNC_PROVIDER_SELF_TEST
193 Core functions
195 core_gettable_params() returns a constant array of descriptor
196 OSSL_PARAM, for parameters that core_get_params() can handle.
197 core_get_params() retrieves parameters from the core for the given
199 handle. See "Core parameters" below for a description of currently
200 known parameters.
201 The core_thread_start() function informs the core that the provider has
203 stated an interest in the current thread. The core will inform the
204 provider when the thread eventually stops. It must be passed the handle
205 for this provider, as well as a callback handfn which will be called
206 when the thread stops. The callback will subsequently be called, with
207 the supplied argument arg, from the thread that is stopping and gets
208 passed the provider context as an argument. This may be useful to
209 perform thread specific clean up such as freeing thread local
210 variables.
211 core_get_libctx() retrieves the core context in which the library
213 object for the current provider is stored, accessible through the
214 handle. This function is useful only for built-in providers such as
215 the default provider. Never cast this to OSSL_LIB_CTX in a provider
216 that is not built-in as the OSSL_LIB_CTX of the library loading the
217 provider might be a completely different structure than the
218 OSSL_LIB_CTX of the library the provider is linked to. Use
219 OSSL_LIB_CTX_new_child(3) instead to obtain a proper library context
220 that is linked to the application library context.
221 core_new_error(), core_set_error_debug() and core_vset_error() are
223 building blocks for reporting an error back to the core, with reference
224 to the handle.
225 core_new_error()
227 allocates a new thread specific error record.
228 This corresponds to the OpenSSL function ERR_new(3).
230 core_set_error_debug()
232 sets debugging information in the current thread specific error
233 record. The debugging information includes the name of the file
234 file, the line line and the function name func where the error
235 occurred.
236 This corresponds to the OpenSSL function ERR_set_debug(3).
238 core_vset_error()
240 sets the reason for the error, along with any addition data. The
241 reason is a number defined by the provider and used to index the
242 reason strings table that's returned by
243 provider_get_reason_strings(). The additional data is given as a
244 format string fmt and a set of arguments args, which are treated in
245 the same manner as with BIO_vsnprintf(). file and line may also be
246 passed to indicate exactly where the error occurred or was
247 reported.
248 This corresponds to the OpenSSL function ERR_vset_error(3).
250 The core_obj_create() function registers a new OID and associated short
252 name sn and long name ln for the given handle. It is similar to the
253 OpenSSL function OBJ_create(3) except that it returns 1 on success or 0
254 on failure. It will treat as success the case where the OID already
255 exists (even if the short name sn or long name ln provided as arguments
256 differ from those associated with the existing OID, in which case the
257 new names are not associated). This function is not thread safe.
258 The core_obj_add_sigid() function registers a new composite signature
260 algorithm (sign_name) consisting of an underlying signature algorithm
261 (pkey_name) and digest algorithm (digest_name) for the given handle. It
262 assumes that the OIDs for the composite signature algorithm as well as
263 for the underlying signature and digest algorithms are either already
264 known to OpenSSL or have been registered via a call to
265 core_obj_create(). It corresponds to the OpenSSL function
266 OBJ_add_sigid(3), except that the objects are identified by name rather
267 than a numeric NID. Any name (OID, short name or long name) can be used
268 to identify the object. It will treat as success the case where the
269 composite signature algorithm already exists (even if registered
270 against a different underlying signature or digest algorithm). For
271 digest_name, NULL or an empty string is permissible for signature
272 algorithms that do not need a digest to operate correctly. The function
273 returns 1 on success or 0 on failure. This function is not thread
274 safe.
275 CRYPTO_malloc(), CRYPTO_zalloc(), CRYPTO_free(), CRYPTO_clear_free(),
277 CRYPTO_realloc(), CRYPTO_clear_realloc(), CRYPTO_secure_malloc(),
278 CRYPTO_secure_zalloc(), CRYPTO_secure_free(),
279 CRYPTO_secure_clear_free(), CRYPTO_secure_allocated(), BIO_new_file(),
280 BIO_new_mem_buf(), BIO_read_ex(), BIO_write_ex(), BIO_up_ref(),
281 BIO_free(), BIO_vprintf(), BIO_vsnprintf(), BIO_gets(), BIO_puts(),
282 BIO_ctrl(), OPENSSL_cleanse() and OPENSSL_hexstr2buf() correspond
283 exactly to the public functions with the same name. As a matter of
284 fact, the pointers in the OSSL_DISPATCH array are typically direct
285 pointers to those public functions. Note that the BIO functions take an
286 OSSL_CORE_BIO type rather than the standard BIO type. This is to ensure
287 that a provider does not mix BIOs from the core with BIOs used on the
288 provider side (the two are not compatible).
289 OSSL_SELF_TEST_set_callback() is used to set an optional callback that
290 can be passed into a provider. This may be ignored by a provider.
291 get_entropy() retrieves seeding material from the operating system.
293 The seeding material will have at least entropy bytes of randomness and
294 the output will have at least min_len and at most max_len bytes. The
295 buffer address is stored in *pout and the buffer length is returned to
296 the caller. On error, zero is returned.
297 cleanup_entropy() is used to clean up and free the buffer returned by
299 get_entropy(). The entropy pointer returned by get_entropy() is passed
300 in buf and its length in len.
301 get_nonce() retrieves a nonce using the passed salt parameter of length
303 salt_len and operating system specific information. The salt should
304 contain uniquely identifying information and this is included, in an
305 unspecified manner, as part of the output. The output is stored in a
306 buffer which contrains at least min_len and at most max_len bytes. The
307 buffer address is stored in *pout and the buffer length returned to the
308 caller. On error, zero is returned.
309 cleanup_nonce() is used to clean up and free the buffer returned by
311 get_nonce(). The nonce pointer returned by get_nonce() is passed in
312 buf and its length in len.
313 provider_register_child_cb() registers callbacks for being informed
315 about the loading and unloading of providers in the application's
316 library context. handle is this provider's handle and cbdata is this
317 provider's data that will be passed back to the callbacks. It returns 1
318 on success or 0 otherwise. These callbacks may be called while holding
319 locks in libcrypto. In order to avoid deadlocks the callback
320 implementation must not be long running and must not call other OpenSSL
321 API functions or upcalls.
322 create_cb is a callback that will be called when a new provider is
324 loaded into the application's library context. It is also called for
325 any providers that are already loaded at the point that this callback
326 is registered. The callback is passed the handle being used for the new
327 provider being loadded and this provider's data in cbdata. It should
328 return 1 on success or 0 on failure.
329 remove_cb is a callback that will be called when a new provider is
331 unloaded from the application's library context. It is passed the
332 handle being used for the provider being unloaded and this provider's
333 data in cbdata. It should return 1 on success or 0 on failure.
334 global_props_cb is a callback that will be called when the global
336 properties from the parent library context are changed. It should
337 return 1 on success or 0 on failure.
338 provider_deregister_child_cb() unregisters callbacks previously
340 registered via provider_register_child_cb(). If
341 provider_register_child_cb() has been called then
342 provider_deregister_child_cb() should be called at or before the point
343 that this provider's teardown function is called.
344 provider_name() returns a string giving the name of the provider
346 identified by handle.
347 provider_get0_provider_ctx() returns the provider context that is
349 associated with the provider identified by prov.
350 provider_get0_dispatch() gets the dispatch table registered by the
352 provider identified by prov when it initialised.
353 provider_up_ref() increments the reference count on the provider prov.
355 If activate is nonzero then the provider is also loaded if it is not
356 already loaded. It returns 1 on success or 0 on failure.
357 provider_free() decrements the reference count on the provider prov. If
359 deactivate is nonzero then the provider is also unloaded if it is not
360 already loaded. It returns 1 on success or 0 on failure.
361 Provider functions
363 provider_teardown() is called when a provider is shut down and removed
364 from the core's provider store. It must free the passed provctx.
365 provider_gettable_params() should return a constant array of descriptor
367 OSSL_PARAM, for parameters that provider_get_params() can handle.
368 provider_get_params() should process the OSSL_PARAM array params,
370 setting the values of the parameters it understands.
371 provider_query_operation() should return a constant OSSL_ALGORITHM that
373 corresponds to the given operation_id. It should indicate if the core
374 may store a reference to this array by setting *no_store to 0 (core may
375 store a reference) or 1 (core may not store a reference).
376 provider_unquery_operation() informs the provider that the result of a
378 provider_query_operation() is no longer directly required and that the
379 function pointers have been copied. The operation_id should match that
380 passed to provider_query_operation() and algs should be its return
381 value.
382 provider_get_reason_strings() should return a constant OSSL_ITEM array
384 that provides reason strings for reason codes the provider may use when
385 reporting errors using core_put_error().
386 The provider_get_capabilities() function should call the callback cb
388 passing it a set of OSSL_PARAMs and the caller supplied argument arg.
389 The OSSL_PARAMs should provide details about the capability with the
390 name given in the capability argument relevant for the provider context
391 provctx. If a provider supports multiple capabilities with the given
392 name then it may call the callback multiple times (one for each
393 capability). Capabilities can be useful for describing the services
394 that a provider can offer. For further details see the "CAPABILITIES"
395 section below. It should return 1 on success or 0 on error.
396 The provider_self_test() function should perform known answer tests on
398 a subset of the algorithms that it uses, and may also verify the
399 integrity of the provider module. It should return 1 on success or 0 on
400 error. It will return 1 if this function is not used.
401 None of these functions are mandatory, but a provider is fairly useless
403 without at least provider_query_operation(), and
404 provider_gettable_params() is fairly useless if not accompanied by
405 provider_get_params().
406 Provider parameters
408 provider_get_params() can return the following provider parameters to
409 the core:
410 "name" (OSSL_PROV_PARAM_NAME) <UTF8 ptr>
412 This points to a string that should give a unique name for the
413 provider.
414 "version" (OSSL_PROV_PARAM_VERSION) <UTF8 ptr>
416 This points to a string that is a version number associated with
417 this provider. OpenSSL in-built providers use OPENSSL_VERSION_STR,
418 but this may be different for any third party provider. This string
419 is for informational purposes only.
420 "buildinfo" (OSSL_PROV_PARAM_BUILDINFO) <UTF8 ptr>
422 This points to a string that is a build information associated with
423 this provider. OpenSSL in-built providers use
424 OPENSSL_FULL_VERSION_STR, but this may be different for any third
425 party provider.
426 "status" (OSSL_PROV_PARAM_STATUS) <unsigned integer>
428 This returns 0 if the provider has entered an error state,
429 otherwise it returns 1.
430 provider_gettable_params() should return the above parameters.
432 Core parameters
434 core_get_params() can retrieve the following core parameters for each
435 provider:
436 "openssl-version" (OSSL_PROV_PARAM_CORE_VERSION) <UTF8 string ptr>
438 This points to the OpenSSL libraries' full version string, i.e. the
439 string expanded from the macro OPENSSL_VERSION_STR.
440 "provider-name" (OSSL_PROV_PARAM_CORE_PROV_NAME) <UTF8 string ptr>
442 This points to the OpenSSL libraries' idea of what the calling
443 provider is named.
444 "module-filename" (OSSL_PROV_PARAM_CORE_MODULE_FILENAME) <UTF8 string
446 ptr>
447 This points to a string containing the full filename of the
448 providers module file.
449 Additionally, provider specific configuration parameters from the
451 config file are available, in dotted name form. The dotted name form
452 is a concatenation of section names and final config command name
453 separated by periods.
454 For example, let's say we have the following config example:
456 config_diagnostics = 1
458 openssl_conf = openssl_init
459 [openssl_init]
461 providers = providers_sect
462 [providers_sect]
464 foo = foo_sect
465 [foo_sect]
467 activate = 1
468 data1 = 2
469 data2 = str
470 more = foo_more
471 [foo_more]
473 data3 = foo,bar
474 The provider will have these additional parameters available:
476 "activate"
478 pointing at the string "1"
479 "data1"
481 pointing at the string "2"
482 "data2"
484 pointing at the string "str"
485 "more.data3"
487 pointing at the string "foo,bar"
488 For more information on handling parameters, see OSSL_PARAM(3) as
490 OSSL_PARAM_int(3).
491
493 Capabilities describe some of the services that a provider can offer.
494 Applications can query the capabilities to discover those services.
495 "TLS-GROUP" Capability
497 The "TLS-GROUP" capability can be queried by libssl to discover the
499 list of TLS groups that a provider can support. Each group supported
500 can be used for key exchange (KEX) or key encapsulation method (KEM)
501 during a TLS handshake. TLS clients can advertise the list of TLS
502 groups they support in the supported_groups extension, and TLS servers
503 can select a group from the offered list that they also support. In
504 this way a provider can add to the list of groups that libssl already
505 supports with additional ones.
506 Each TLS group that a provider supports should be described via the
508 callback passed in through the provider_get_capabilities function. Each
509 group should have the following details supplied (all are mandatory,
510 except OSSL_CAPABILITY_TLS_GROUP_IS_KEM):
511 "tls-group-name" (OSSL_CAPABILITY_TLS_GROUP_NAME) <UTF8 string>
513 The name of the group as given in the IANA TLS Supported Groups
514 registry
515 <https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-8>.
516 "tls-group-name-internal" (OSSL_CAPABILITY_TLS_GROUP_NAME_INTERNAL)
518 <UTF8 string>
519 The name of the group as known by the provider. This could be the
520 same as the "tls-group-name", but does not have to be.
521 "tls-group-id" (OSSL_CAPABILITY_TLS_GROUP_ID) <unsigned integer>
523 The TLS group id value as given in the IANA TLS Supported Groups
524 registry.
525 "tls-group-alg" (OSSL_CAPABILITY_TLS_GROUP_ALG) <UTF8 string>
527 The name of a Key Management algorithm that the provider offers and
528 that should be used with this group. Keys created should be able to
529 support key exchange or key encapsulation method (KEM), as implied
530 by the optional OSSL_CAPABILITY_TLS_GROUP_IS_KEM flag. The
531 algorithm must support key and parameter generation as well as the
532 key/parameter generation parameter, OSSL_PKEY_PARAM_GROUP_NAME. The
533 group name given via "tls-group-name-internal" above will be passed
534 via OSSL_PKEY_PARAM_GROUP_NAME when libssl wishes to generate
535 keys/parameters.
536 "tls-group-sec-bits" (OSSL_CAPABILITY_TLS_GROUP_SECURITY_BITS)
538 <unsigned integer>
539 The number of bits of security offered by keys in this group. The
540 number of bits should be comparable with the ones given in table 2
541 and 3 of the NIST SP800-57 document.
542 "tls-group-is-kem" (OSSL_CAPABILITY_TLS_GROUP_IS_KEM) <unsigned
544 integer>
545 Boolean flag to describe if the group should be used in key
546 exchange (KEX) mode (0, default) or in key encapsulation method
547 (KEM) mode (1).
548 This parameter is optional: if not specified, KEX mode is assumed
550 as the default mode for the group.
551 In KEX mode, in a typical Diffie-Hellman fashion, both sides
553 execute keygen then derive against the peer public key. To operate
554 in KEX mode, the group implementation must support the provider
555 functions as described in provider-keyexch(7).
556 In KEM mode, the client executes keygen and sends its public key,
558 the server executes encapsulate using the client's public key and
559 sends back the resulting ciphertext, finally the client executes
560 decapsulate to retrieve the same shared secret generated by the
561 server's encapsulate. To operate in KEM mode, the group
562 implementation must support the provider functions as described in
563 provider-kem(7).
564 Both in KEX and KEM mode, the resulting shared secret is then used
566 according to the protocol specification.
567 "tls-min-tls" (OSSL_CAPABILITY_TLS_GROUP_MIN_TLS) <integer>
569 "tls-max-tls" (OSSL_CAPABILITY_TLS_GROUP_MAX_TLS) <integer>
570 "tls-min-dtls" (OSSL_CAPABILITY_TLS_GROUP_MIN_DTLS) <integer>
571 "tls-max-dtls" (OSSL_CAPABILITY_TLS_GROUP_MAX_DTLS) <integer>
572 These parameters can be used to describe the minimum and maximum
573 TLS and DTLS versions supported by the group. The values equate to
574 the on-the-wire encoding of the various TLS versions. For example
575 TLSv1.3 is 0x0304 (772 decimal), and TLSv1.2 is 0x0303 (771
576 decimal). A 0 indicates that there is no defined minimum or
577 maximum. A -1 indicates that the group should not be used in that
578 protocol.
579
581 This is an example of a simple provider made available as a dynamically
582 loadable module. It implements the fictitious algorithm "FOO" for the
583 fictitious operation "BAR".
584 #include <malloc.h>
586 #include <openssl/core.h>
587 #include <openssl/core_dispatch.h>
588 /* Errors used in this provider */
590 #define E_MALLOC 1
591 static const OSSL_ITEM reasons[] = {
593 { E_MALLOC, "memory allocation failure" }.
594 { 0, NULL } /* Termination */
595 };
596 /*
598 * To ensure we get the function signature right, forward declare
599 * them using function types provided by openssl/core_dispatch.h
600 */
601 OSSL_FUNC_bar_newctx_fn foo_newctx;
602 OSSL_FUNC_bar_freectx_fn foo_freectx;
603 OSSL_FUNC_bar_init_fn foo_init;
604 OSSL_FUNC_bar_update_fn foo_update;
605 OSSL_FUNC_bar_final_fn foo_final;
606 OSSL_FUNC_provider_query_operation_fn p_query;
608 OSSL_FUNC_provider_get_reason_strings_fn p_reasons;
609 OSSL_FUNC_provider_teardown_fn p_teardown;
610 OSSL_provider_init_fn OSSL_provider_init;
612 OSSL_FUNC_core_put_error *c_put_error = NULL;
614 /* Provider context */
616 struct prov_ctx_st {
617 OSSL_CORE_HANDLE *handle;
618 }
619 /* operation context for the algorithm FOO */
621 struct foo_ctx_st {
622 struct prov_ctx_st *provctx;
623 int b;
624 };
625 static void *foo_newctx(void *provctx)
627 {
628 struct foo_ctx_st *fooctx = malloc(sizeof(*fooctx));
629 if (fooctx != NULL)
631 fooctx->provctx = provctx;
632 else
633 c_put_error(provctx->handle, E_MALLOC, __FILE__, __LINE__);
634 return fooctx;
635 }
636 static void foo_freectx(void *fooctx)
638 {
639 free(fooctx);
640 }
641 static int foo_init(void *vfooctx)
643 {
644 struct foo_ctx_st *fooctx = vfooctx;
645 fooctx->b = 0x33;
647 }
648 static int foo_update(void *vfooctx, unsigned char *in, size_t inl)
650 {
651 struct foo_ctx_st *fooctx = vfooctx;
652 /* did you expect something serious? */
654 if (inl == 0)
655 return 1;
656 for (; inl-- > 0; in++)
657 *in ^= fooctx->b;
658 return 1;
659 }
660 static int foo_final(void *vfooctx)
662 {
663 struct foo_ctx_st *fooctx = vfooctx;
664 fooctx->b = 0x66;
666 }
667 static const OSSL_DISPATCH foo_fns[] = {
669 { OSSL_FUNC_BAR_NEWCTX, (void (*)(void))foo_newctx },
670 { OSSL_FUNC_BAR_FREECTX, (void (*)(void))foo_freectx },
671 { OSSL_FUNC_BAR_INIT, (void (*)(void))foo_init },
672 { OSSL_FUNC_BAR_UPDATE, (void (*)(void))foo_update },
673 { OSSL_FUNC_BAR_FINAL, (void (*)(void))foo_final },
674 { 0, NULL }
675 };
676 static const OSSL_ALGORITHM bars[] = {
678 { "FOO", "provider=chumbawamba", foo_fns },
679 { NULL, NULL, NULL }
680 };
681 static const OSSL_ALGORITHM *p_query(void *provctx, int operation_id,
683 int *no_store)
684 {
685 switch (operation_id) {
686 case OSSL_OP_BAR:
687 return bars;
688 }
689 return NULL;
690 }
691 static const OSSL_ITEM *p_reasons(void *provctx)
693 {
694 return reasons;
695 }
696 static void p_teardown(void *provctx)
698 {
699 free(provctx);
700 }
701 static const OSSL_DISPATCH prov_fns[] = {
703 { OSSL_FUNC_PROVIDER_TEARDOWN, (void (*)(void))p_teardown },
704 { OSSL_FUNC_PROVIDER_QUERY_OPERATION, (void (*)(void))p_query },
705 { OSSL_FUNC_PROVIDER_GET_REASON_STRINGS, (void (*)(void))p_reasons },
706 { 0, NULL }
707 };
708 int OSSL_provider_init(const OSSL_CORE_HANDLE *handle,
710 const OSSL_DISPATCH *in,
711 const OSSL_DISPATCH **out,
712 void **provctx)
713 {
714 struct prov_ctx_st *pctx = NULL;
715 for (; in->function_id != 0; in++)
717 switch (in->function_id) {
718 case OSSL_FUNC_CORE_PUT_ERROR:
719 c_put_error = OSSL_FUNC_core_put_error(in);
720 break;
721 }
722 *out = prov_fns;
724 if ((pctx = malloc(sizeof(*pctx))) == NULL) {
726 /*
727 * ALEA IACTA EST, if the core retrieves the reason table
728 * regardless, that string will be displayed, otherwise not.
729 */
730 c_put_error(handle, E_MALLOC, __FILE__, __LINE__);
731 return 0;
732 }
733 pctx->handle = handle;
734 return 1;
735 }
736 This relies on a few things existing in openssl/core_dispatch.h:
738 #define OSSL_OP_BAR 4711
740 #define OSSL_FUNC_BAR_NEWCTX 1
742 typedef void *(OSSL_FUNC_bar_newctx_fn)(void *provctx);
743 static ossl_inline OSSL_FUNC_bar_newctx(const OSSL_DISPATCH *opf)
744 { return (OSSL_FUNC_bar_newctx_fn *)opf->function; }
745 #define OSSL_FUNC_BAR_FREECTX 2
747 typedef void (OSSL_FUNC_bar_freectx_fn)(void *ctx);
748 static ossl_inline OSSL_FUNC_bar_newctx(const OSSL_DISPATCH *opf)
749 { return (OSSL_FUNC_bar_freectx_fn *)opf->function; }
750 #define OSSL_FUNC_BAR_INIT 3
752 typedef void *(OSSL_FUNC_bar_init_fn)(void *ctx);
753 static ossl_inline OSSL_FUNC_bar_init(const OSSL_DISPATCH *opf)
754 { return (OSSL_FUNC_bar_init_fn *)opf->function; }
755 #define OSSL_FUNC_BAR_UPDATE 4
757 typedef void *(OSSL_FUNC_bar_update_fn)(void *ctx,
758 unsigned char *in, size_t inl);
759 static ossl_inline OSSL_FUNC_bar_update(const OSSL_DISPATCH *opf)
760 { return (OSSL_FUNC_bar_update_fn *)opf->function; }
761 #define OSSL_FUNC_BAR_FINAL 5
763 typedef void *(OSSL_FUNC_bar_final_fn)(void *ctx);
764 static ossl_inline OSSL_FUNC_bar_final(const OSSL_DISPATCH *opf)
765 { return (OSSL_FUNC_bar_final_fn *)opf->function; }
766
768 provider(7)
769
771 The concept of providers and everything surrounding them was introduced
772 in OpenSSL 3.0.
773
775 Copyright 2019-2022 The OpenSSL Project Authors. All Rights Reserved.
776 Licensed under the Apache License 2.0 (the "License"). You may not use
778 this file except in compliance with the License. You can obtain a copy
779 in the file LICENSE in the source distribution or at
780 <https://www.openssl.org/source/license.html>.
7813.0.5 2022-11-01 PROVIDER-BASE(7ossl)