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(3) arrays, in the call of
118 the provider initialization function. See "Provider" in provider(7)
119 for a 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(3) element named
125 OSSL_FUNC_{name}. For example, the "function" core_gettable_params()
126 has these:
127 typedef OSSL_PARAM *
129 (OSSL_FUNC_core_gettable_params_fn)(const OSSL_CORE_HANDLE *handle);
130 static ossl_inline OSSL_NAME_core_gettable_params_fn
131 OSSL_FUNC_core_gettable_params(const OSSL_DISPATCH *opf);
132 OSSL_DISPATCH(3) arrays are indexed by numbers that are provided as
134 macros in openssl-core_dispatch.h(7), as follows:
135 For in (the OSSL_DISPATCH(3) array passed from libcrypto to the
137 provider):
138 core_gettable_params OSSL_FUNC_CORE_GETTABLE_PARAMS
140 core_get_params OSSL_FUNC_CORE_GET_PARAMS
141 core_thread_start OSSL_FUNC_CORE_THREAD_START
142 core_get_libctx OSSL_FUNC_CORE_GET_LIBCTX
143 core_new_error OSSL_FUNC_CORE_NEW_ERROR
144 core_set_error_debug OSSL_FUNC_CORE_SET_ERROR_DEBUG
145 core_vset_error OSSL_FUNC_CORE_VSET_ERROR
146 core_obj_add_sigid OSSL_FUNC_CORE_OBJ_ADD_SIGID
147 core_obj_create OSSL_FUNC_CORE_OBJ_CREATE
148 CRYPTO_malloc OSSL_FUNC_CRYPTO_MALLOC
149 CRYPTO_zalloc OSSL_FUNC_CRYPTO_ZALLOC
150 CRYPTO_free OSSL_FUNC_CRYPTO_FREE
151 CRYPTO_clear_free OSSL_FUNC_CRYPTO_CLEAR_FREE
152 CRYPTO_realloc OSSL_FUNC_CRYPTO_REALLOC
153 CRYPTO_clear_realloc OSSL_FUNC_CRYPTO_CLEAR_REALLOC
154 CRYPTO_secure_malloc OSSL_FUNC_CRYPTO_SECURE_MALLOC
155 CRYPTO_secure_zalloc OSSL_FUNC_CRYPTO_SECURE_ZALLOC
156 CRYPTO_secure_free OSSL_FUNC_CRYPTO_SECURE_FREE
157 CRYPTO_secure_clear_free OSSL_FUNC_CRYPTO_SECURE_CLEAR_FREE
158 CRYPTO_secure_allocated OSSL_FUNC_CRYPTO_SECURE_ALLOCATED
159 BIO_new_file OSSL_FUNC_BIO_NEW_FILE
160 BIO_new_mem_buf OSSL_FUNC_BIO_NEW_MEMBUF
161 BIO_read_ex OSSL_FUNC_BIO_READ_EX
162 BIO_write_ex OSSL_FUNC_BIO_WRITE_EX
163 BIO_up_ref OSSL_FUNC_BIO_UP_REF
164 BIO_free OSSL_FUNC_BIO_FREE
165 BIO_vprintf OSSL_FUNC_BIO_VPRINTF
166 BIO_vsnprintf OSSL_FUNC_BIO_VSNPRINTF
167 BIO_puts OSSL_FUNC_BIO_PUTS
168 BIO_gets OSSL_FUNC_BIO_GETS
169 BIO_ctrl OSSL_FUNC_BIO_CTRL
170 OPENSSL_cleanse OSSL_FUNC_OPENSSL_CLEANSE
171 OSSL_SELF_TEST_set_callback OSSL_FUNC_SELF_TEST_CB
172 ossl_rand_get_entropy OSSL_FUNC_GET_ENTROPY
173 ossl_rand_cleanup_entropy OSSL_FUNC_CLEANUP_ENTROPY
174 ossl_rand_get_nonce OSSL_FUNC_GET_NONCE
175 ossl_rand_cleanup_nonce OSSL_FUNC_CLEANUP_NONCE
176 provider_register_child_cb OSSL_FUNC_PROVIDER_REGISTER_CHILD_CB
177 provider_deregister_child_cb OSSL_FUNC_PROVIDER_DEREGISTER_CHILD_CB
178 provider_name OSSL_FUNC_PROVIDER_NAME
179 provider_get0_provider_ctx OSSL_FUNC_PROVIDER_GET0_PROVIDER_CTX
180 provider_get0_dispatch OSSL_FUNC_PROVIDER_GET0_DISPATCH
181 provider_up_ref OSSL_FUNC_PROVIDER_UP_REF
182 provider_free OSSL_FUNC_PROVIDER_FREE
183 For *out (the OSSL_DISPATCH(3) array passed from the provider to
185 libcrypto):
186 provider_teardown OSSL_FUNC_PROVIDER_TEARDOWN
188 provider_gettable_params OSSL_FUNC_PROVIDER_GETTABLE_PARAMS
189 provider_get_params OSSL_FUNC_PROVIDER_GET_PARAMS
190 provider_query_operation OSSL_FUNC_PROVIDER_QUERY_OPERATION
191 provider_unquery_operation OSSL_FUNC_PROVIDER_UNQUERY_OPERATION
192 provider_get_reason_strings OSSL_FUNC_PROVIDER_GET_REASON_STRINGS
193 provider_get_capabilities OSSL_FUNC_PROVIDER_GET_CAPABILITIES
194 provider_self_test OSSL_FUNC_PROVIDER_SELF_TEST
195 Core functions
197 core_gettable_params() returns a constant array of descriptor
198 OSSL_PARAM(3), for parameters that core_get_params() can handle.
199 core_get_params() retrieves parameters from the core for the given
201 handle. See "Core parameters" below for a description of currently
202 known parameters.
203 The core_thread_start() function informs the core that the provider has
205 stated an interest in the current thread. The core will inform the
206 provider when the thread eventually stops. It must be passed the handle
207 for this provider, as well as a callback handfn which will be called
208 when the thread stops. The callback will subsequently be called, with
209 the supplied argument arg, from the thread that is stopping and gets
210 passed the provider context as an argument. This may be useful to
211 perform thread specific clean up such as freeing thread local
212 variables.
213 core_get_libctx() retrieves the core context in which the library
215 object for the current provider is stored, accessible through the
216 handle. This function is useful only for built-in providers such as
217 the default provider. Never cast this to OSSL_LIB_CTX in a provider
218 that is not built-in as the OSSL_LIB_CTX of the library loading the
219 provider might be a completely different structure than the
220 OSSL_LIB_CTX of the library the provider is linked to. Use
221 OSSL_LIB_CTX_new_child(3) instead to obtain a proper library context
222 that is linked to the application library context.
223 core_new_error(), core_set_error_debug() and core_vset_error() are
225 building blocks for reporting an error back to the core, with reference
226 to the handle.
227 core_new_error()
229 allocates a new thread specific error record.
230 This corresponds to the OpenSSL function ERR_new(3).
232 core_set_error_debug()
234 sets debugging information in the current thread specific error
235 record. The debugging information includes the name of the file
236 file, the line line and the function name func where the error
237 occurred.
238 This corresponds to the OpenSSL function ERR_set_debug(3).
240 core_vset_error()
242 sets the reason for the error, along with any addition data. The
243 reason is a number defined by the provider and used to index the
244 reason strings table that's returned by
245 provider_get_reason_strings(). The additional data is given as a
246 format string fmt and a set of arguments args, which are treated in
247 the same manner as with BIO_vsnprintf(). file and line may also be
248 passed to indicate exactly where the error occurred or was
249 reported.
250 This corresponds to the OpenSSL function ERR_vset_error(3).
252 The core_obj_create() function registers a new OID and associated short
254 name sn and long name ln for the given handle. It is similar to the
255 OpenSSL function OBJ_create(3) except that it returns 1 on success or 0
256 on failure. It will treat as success the case where the OID already
257 exists (even if the short name sn or long name ln provided as arguments
258 differ from those associated with the existing OID, in which case the
259 new names are not associated). This function is not thread safe.
260 The core_obj_add_sigid() function registers a new composite signature
262 algorithm (sign_name) consisting of an underlying signature algorithm
263 (pkey_name) and digest algorithm (digest_name) for the given handle. It
264 assumes that the OIDs for the composite signature algorithm as well as
265 for the underlying signature and digest algorithms are either already
266 known to OpenSSL or have been registered via a call to
267 core_obj_create(). It corresponds to the OpenSSL function
268 OBJ_add_sigid(3), except that the objects are identified by name rather
269 than a numeric NID. Any name (OID, short name or long name) can be used
270 to identify the object. It will treat as success the case where the
271 composite signature algorithm already exists (even if registered
272 against a different underlying signature or digest algorithm). For
273 digest_name, NULL or an empty string is permissible for signature
274 algorithms that do not need a digest to operate correctly. The function
275 returns 1 on success or 0 on failure. This function is not thread
276 safe.
277 CRYPTO_malloc(), CRYPTO_zalloc(), CRYPTO_free(), CRYPTO_clear_free(),
279 CRYPTO_realloc(), CRYPTO_clear_realloc(), CRYPTO_secure_malloc(),
280 CRYPTO_secure_zalloc(), CRYPTO_secure_free(),
281 CRYPTO_secure_clear_free(), CRYPTO_secure_allocated(), BIO_new_file(),
282 BIO_new_mem_buf(), BIO_read_ex(), BIO_write_ex(), BIO_up_ref(),
283 BIO_free(), BIO_vprintf(), BIO_vsnprintf(), BIO_gets(), BIO_puts(),
284 BIO_ctrl(), OPENSSL_cleanse() and OPENSSL_hexstr2buf() correspond
285 exactly to the public functions with the same name. As a matter of
286 fact, the pointers in the OSSL_DISPATCH(3) array are typically direct
287 pointers to those public functions. Note that the BIO functions take an
288 OSSL_CORE_BIO type rather than the standard BIO type. This is to ensure
289 that a provider does not mix BIOs from the core with BIOs used on the
290 provider side (the two are not compatible).
291 OSSL_SELF_TEST_set_callback() is used to set an optional callback that
292 can be passed into a provider. This may be ignored by a provider.
293 get_entropy() retrieves seeding material from the operating system.
295 The seeding material will have at least entropy bytes of randomness and
296 the output will have at least min_len and at most max_len bytes. The
297 buffer address is stored in *pout and the buffer length is returned to
298 the caller. On error, zero is returned.
299 cleanup_entropy() is used to clean up and free the buffer returned by
301 get_entropy(). The entropy pointer returned by get_entropy() is passed
302 in buf and its length in len.
303 get_nonce() retrieves a nonce using the passed salt parameter of length
305 salt_len and operating system specific information. The salt should
306 contain uniquely identifying information and this is included, in an
307 unspecified manner, as part of the output. The output is stored in a
308 buffer which contains at least min_len and at most max_len bytes. The
309 buffer address is stored in *pout and the buffer length returned to the
310 caller. On error, zero is returned.
311 cleanup_nonce() is used to clean up and free the buffer returned by
313 get_nonce(). The nonce pointer returned by get_nonce() is passed in
314 buf and its length in len.
315 provider_register_child_cb() registers callbacks for being informed
317 about the loading and unloading of providers in the application's
318 library context. handle is this provider's handle and cbdata is this
319 provider's data that will be passed back to the callbacks. It returns 1
320 on success or 0 otherwise. These callbacks may be called while holding
321 locks in libcrypto. In order to avoid deadlocks the callback
322 implementation must not be long running and must not call other OpenSSL
323 API functions or upcalls.
324 create_cb is a callback that will be called when a new provider is
326 loaded into the application's library context. It is also called for
327 any providers that are already loaded at the point that this callback
328 is registered. The callback is passed the handle being used for the new
329 provider being loadded and this provider's data in cbdata. It should
330 return 1 on success or 0 on failure.
331 remove_cb is a callback that will be called when a new provider is
333 unloaded from the application's library context. It is passed the
334 handle being used for the provider being unloaded and this provider's
335 data in cbdata. It should return 1 on success or 0 on failure.
336 global_props_cb is a callback that will be called when the global
338 properties from the parent library context are changed. It should
339 return 1 on success or 0 on failure.
340 provider_deregister_child_cb() unregisters callbacks previously
342 registered via provider_register_child_cb(). If
343 provider_register_child_cb() has been called then
344 provider_deregister_child_cb() should be called at or before the point
345 that this provider's teardown function is called.
346 provider_name() returns a string giving the name of the provider
348 identified by handle.
349 provider_get0_provider_ctx() returns the provider context that is
351 associated with the provider identified by prov.
352 provider_get0_dispatch() gets the dispatch table registered by the
354 provider identified by prov when it initialised.
355 provider_up_ref() increments the reference count on the provider prov.
357 If activate is nonzero then the provider is also loaded if it is not
358 already loaded. It returns 1 on success or 0 on failure.
359 provider_free() decrements the reference count on the provider prov. If
361 deactivate is nonzero then the provider is also unloaded if it is not
362 already loaded. It returns 1 on success or 0 on failure.
363 Provider functions
365 provider_teardown() is called when a provider is shut down and removed
366 from the core's provider store. It must free the passed provctx.
367 provider_gettable_params() should return a constant array of descriptor
369 OSSL_PARAM(3), for parameters that provider_get_params() can handle.
370 provider_get_params() should process the OSSL_PARAM(3) array params,
372 setting the values of the parameters it understands.
373 provider_query_operation() should return a constant OSSL_ALGORITHM(3)
375 that corresponds to the given operation_id. It should indicate if the
376 core may store a reference to this array by setting *no_store to 0
377 (core may store a reference) or 1 (core may not store a reference).
378 provider_unquery_operation() informs the provider that the result of a
380 provider_query_operation() is no longer directly required and that the
381 function pointers have been copied. The operation_id should match that
382 passed to provider_query_operation() and algs should be its return
383 value.
384 provider_get_reason_strings() should return a constant OSSL_ITEM(3)
386 array that provides reason strings for reason codes the provider may
387 use when reporting errors using core_put_error().
388 The provider_get_capabilities() function should call the callback cb
390 passing it a set of OSSL_PARAM(3)s and the caller supplied argument
391 arg. The OSSL_PARAM(3)s should provide details about the capability
392 with the name given in the capability argument relevant for the
393 provider context provctx. If a provider supports multiple capabilities
394 with the given name then it may call the callback multiple times (one
395 for each capability). Capabilities can be useful for describing the
396 services that a provider can offer. For further details see the
397 "CAPABILITIES" section below. It should return 1 on success or 0 on
398 error.
399 The provider_self_test() function should perform known answer tests on
401 a subset of the algorithms that it uses, and may also verify the
402 integrity of the provider module. It should return 1 on success or 0 on
403 error. It will return 1 if this function is not used.
404 None of these functions are mandatory, but a provider is fairly useless
406 without at least provider_query_operation(), and
407 provider_gettable_params() is fairly useless if not accompanied by
408 provider_get_params().
409 Provider parameters
411 provider_get_params() can return the following provider parameters to
412 the core:
413 "name" (OSSL_PROV_PARAM_NAME) <UTF8 ptr>
415 This points to a string that should give a unique name for the
416 provider.
417 "version" (OSSL_PROV_PARAM_VERSION) <UTF8 ptr>
419 This points to a string that is a version number associated with
420 this provider. OpenSSL in-built providers use OPENSSL_VERSION_STR,
421 but this may be different for any third party provider. This string
422 is for informational purposes only.
423 "buildinfo" (OSSL_PROV_PARAM_BUILDINFO) <UTF8 ptr>
425 This points to a string that is a build information associated with
426 this provider. OpenSSL in-built providers use
427 OPENSSL_FULL_VERSION_STR, but this may be different for any third
428 party provider.
429 "status" (OSSL_PROV_PARAM_STATUS) <unsigned integer>
431 This returns 0 if the provider has entered an error state,
432 otherwise it returns 1.
433 provider_gettable_params() should return the above parameters.
435 Core parameters
437 core_get_params() can retrieve the following core parameters for each
438 provider:
439 "openssl-version" (OSSL_PROV_PARAM_CORE_VERSION) <UTF8 string ptr>
441 This points to the OpenSSL libraries' full version string, i.e. the
442 string expanded from the macro OPENSSL_VERSION_STR.
443 "provider-name" (OSSL_PROV_PARAM_CORE_PROV_NAME) <UTF8 string ptr>
445 This points to the OpenSSL libraries' idea of what the calling
446 provider is named.
447 "module-filename" (OSSL_PROV_PARAM_CORE_MODULE_FILENAME) <UTF8 string
449 ptr>
450 This points to a string containing the full filename of the
451 providers module file.
452 Additionally, provider specific configuration parameters from the
454 config file are available, in dotted name form. The dotted name form
455 is a concatenation of section names and final config command name
456 separated by periods.
457 For example, let's say we have the following config example:
459 config_diagnostics = 1
461 openssl_conf = openssl_init
462 [openssl_init]
464 providers = providers_sect
465 [providers_sect]
467 foo = foo_sect
468 [foo_sect]
470 activate = 1
471 data1 = 2
472 data2 = str
473 more = foo_more
474 [foo_more]
476 data3 = foo,bar
477 The provider will have these additional parameters available:
479 "activate"
481 pointing at the string "1"
482 "data1"
484 pointing at the string "2"
485 "data2"
487 pointing at the string "str"
488 "more.data3"
490 pointing at the string "foo,bar"
491 For more information on handling parameters, see OSSL_PARAM(3) as
493 OSSL_PARAM_int(3).
494
496 Capabilities describe some of the services that a provider can offer.
497 Applications can query the capabilities to discover those services.
498 "TLS-GROUP" Capability
500 The "TLS-GROUP" capability can be queried by libssl to discover the
502 list of TLS groups that a provider can support. Each group supported
503 can be used for key exchange (KEX) or key encapsulation method (KEM)
504 during a TLS handshake. TLS clients can advertise the list of TLS
505 groups they support in the supported_groups extension, and TLS servers
506 can select a group from the offered list that they also support. In
507 this way a provider can add to the list of groups that libssl already
508 supports with additional ones.
509 Each TLS group that a provider supports should be described via the
511 callback passed in through the provider_get_capabilities function. Each
512 group should have the following details supplied (all are mandatory,
513 except OSSL_CAPABILITY_TLS_GROUP_IS_KEM):
514 "tls-group-name" (OSSL_CAPABILITY_TLS_GROUP_NAME) <UTF8 string>
516 The name of the group as given in the IANA TLS Supported Groups
517 registry
518 <https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-8>.
519 "tls-group-name-internal" (OSSL_CAPABILITY_TLS_GROUP_NAME_INTERNAL)
521 <UTF8 string>
522 The name of the group as known by the provider. This could be the
523 same as the "tls-group-name", but does not have to be.
524 "tls-group-id" (OSSL_CAPABILITY_TLS_GROUP_ID) <unsigned integer>
526 The TLS group id value as given in the IANA TLS Supported Groups
527 registry.
528 "tls-group-alg" (OSSL_CAPABILITY_TLS_GROUP_ALG) <UTF8 string>
530 The name of a Key Management algorithm that the provider offers and
531 that should be used with this group. Keys created should be able to
532 support key exchange or key encapsulation method (KEM), as implied
533 by the optional OSSL_CAPABILITY_TLS_GROUP_IS_KEM flag. The
534 algorithm must support key and parameter generation as well as the
535 key/parameter generation parameter, OSSL_PKEY_PARAM_GROUP_NAME. The
536 group name given via "tls-group-name-internal" above will be passed
537 via OSSL_PKEY_PARAM_GROUP_NAME when libssl wishes to generate
538 keys/parameters.
539 "tls-group-sec-bits" (OSSL_CAPABILITY_TLS_GROUP_SECURITY_BITS)
541 <unsigned integer>
542 The number of bits of security offered by keys in this group. The
543 number of bits should be comparable with the ones given in table 2
544 and 3 of the NIST SP800-57 document.
545 "tls-group-is-kem" (OSSL_CAPABILITY_TLS_GROUP_IS_KEM) <unsigned
547 integer>
548 Boolean flag to describe if the group should be used in key
549 exchange (KEX) mode (0, default) or in key encapsulation method
550 (KEM) mode (1).
551 This parameter is optional: if not specified, KEX mode is assumed
553 as the default mode for the group.
554 In KEX mode, in a typical Diffie-Hellman fashion, both sides
556 execute keygen then derive against the peer public key. To operate
557 in KEX mode, the group implementation must support the provider
558 functions as described in provider-keyexch(7).
559 In KEM mode, the client executes keygen and sends its public key,
561 the server executes encapsulate using the client's public key and
562 sends back the resulting ciphertext, finally the client executes
563 decapsulate to retrieve the same shared secret generated by the
564 server's encapsulate. To operate in KEM mode, the group
565 implementation must support the provider functions as described in
566 provider-kem(7).
567 Both in KEX and KEM mode, the resulting shared secret is then used
569 according to the protocol specification.
570 "tls-min-tls" (OSSL_CAPABILITY_TLS_GROUP_MIN_TLS) <integer>
572 "tls-max-tls" (OSSL_CAPABILITY_TLS_GROUP_MAX_TLS) <integer>
573 "tls-min-dtls" (OSSL_CAPABILITY_TLS_GROUP_MIN_DTLS) <integer>
574 "tls-max-dtls" (OSSL_CAPABILITY_TLS_GROUP_MAX_DTLS) <integer>
575 These parameters can be used to describe the minimum and maximum
576 TLS and DTLS versions supported by the group. The values equate to
577 the on-the-wire encoding of the various TLS versions. For example
578 TLSv1.3 is 0x0304 (772 decimal), and TLSv1.2 is 0x0303 (771
579 decimal). A 0 indicates that there is no defined minimum or
580 maximum. A -1 indicates that the group should not be used in that
581 protocol.
582
584 This is an example of a simple provider made available as a dynamically
585 loadable module. It implements the fictitious algorithm "FOO" for the
586 fictitious operation "BAR".
587 #include <malloc.h>
589 #include <openssl/core.h>
590 #include <openssl/core_dispatch.h>
591 /* Errors used in this provider */
593 #define E_MALLOC 1
594 static const OSSL_ITEM reasons[] = {
596 { E_MALLOC, "memory allocation failure" }.
597 { 0, NULL } /* Termination */
598 };
599 /*
601 * To ensure we get the function signature right, forward declare
602 * them using function types provided by openssl/core_dispatch.h
603 */
604 OSSL_FUNC_bar_newctx_fn foo_newctx;
605 OSSL_FUNC_bar_freectx_fn foo_freectx;
606 OSSL_FUNC_bar_init_fn foo_init;
607 OSSL_FUNC_bar_update_fn foo_update;
608 OSSL_FUNC_bar_final_fn foo_final;
609 OSSL_FUNC_provider_query_operation_fn p_query;
611 OSSL_FUNC_provider_get_reason_strings_fn p_reasons;
612 OSSL_FUNC_provider_teardown_fn p_teardown;
613 OSSL_provider_init_fn OSSL_provider_init;
615 OSSL_FUNC_core_put_error *c_put_error = NULL;
617 /* Provider context */
619 struct prov_ctx_st {
620 OSSL_CORE_HANDLE *handle;
621 }
622 /* operation context for the algorithm FOO */
624 struct foo_ctx_st {
625 struct prov_ctx_st *provctx;
626 int b;
627 };
628 static void *foo_newctx(void *provctx)
630 {
631 struct foo_ctx_st *fooctx = malloc(sizeof(*fooctx));
632 if (fooctx != NULL)
634 fooctx->provctx = provctx;
635 else
636 c_put_error(provctx->handle, E_MALLOC, __FILE__, __LINE__);
637 return fooctx;
638 }
639 static void foo_freectx(void *fooctx)
641 {
642 free(fooctx);
643 }
644 static int foo_init(void *vfooctx)
646 {
647 struct foo_ctx_st *fooctx = vfooctx;
648 fooctx->b = 0x33;
650 }
651 static int foo_update(void *vfooctx, unsigned char *in, size_t inl)
653 {
654 struct foo_ctx_st *fooctx = vfooctx;
655 /* did you expect something serious? */
657 if (inl == 0)
658 return 1;
659 for (; inl-- > 0; in++)
660 *in ^= fooctx->b;
661 return 1;
662 }
663 static int foo_final(void *vfooctx)
665 {
666 struct foo_ctx_st *fooctx = vfooctx;
667 fooctx->b = 0x66;
669 }
670 static const OSSL_DISPATCH foo_fns[] = {
672 { OSSL_FUNC_BAR_NEWCTX, (void (*)(void))foo_newctx },
673 { OSSL_FUNC_BAR_FREECTX, (void (*)(void))foo_freectx },
674 { OSSL_FUNC_BAR_INIT, (void (*)(void))foo_init },
675 { OSSL_FUNC_BAR_UPDATE, (void (*)(void))foo_update },
676 { OSSL_FUNC_BAR_FINAL, (void (*)(void))foo_final },
677 { 0, NULL }
678 };
679 static const OSSL_ALGORITHM bars[] = {
681 { "FOO", "provider=chumbawamba", foo_fns },
682 { NULL, NULL, NULL }
683 };
684 static const OSSL_ALGORITHM *p_query(void *provctx, int operation_id,
686 int *no_store)
687 {
688 switch (operation_id) {
689 case OSSL_OP_BAR:
690 return bars;
691 }
692 return NULL;
693 }
694 static const OSSL_ITEM *p_reasons(void *provctx)
696 {
697 return reasons;
698 }
699 static void p_teardown(void *provctx)
701 {
702 free(provctx);
703 }
704 static const OSSL_DISPATCH prov_fns[] = {
706 { OSSL_FUNC_PROVIDER_TEARDOWN, (void (*)(void))p_teardown },
707 { OSSL_FUNC_PROVIDER_QUERY_OPERATION, (void (*)(void))p_query },
708 { OSSL_FUNC_PROVIDER_GET_REASON_STRINGS, (void (*)(void))p_reasons },
709 { 0, NULL }
710 };
711 int OSSL_provider_init(const OSSL_CORE_HANDLE *handle,
713 const OSSL_DISPATCH *in,
714 const OSSL_DISPATCH **out,
715 void **provctx)
716 {
717 struct prov_ctx_st *pctx = NULL;
718 for (; in->function_id != 0; in++)
720 switch (in->function_id) {
721 case OSSL_FUNC_CORE_PUT_ERROR:
722 c_put_error = OSSL_FUNC_core_put_error(in);
723 break;
724 }
725 *out = prov_fns;
727 if ((pctx = malloc(sizeof(*pctx))) == NULL) {
729 /*
730 * ALEA IACTA EST, if the core retrieves the reason table
731 * regardless, that string will be displayed, otherwise not.
732 */
733 c_put_error(handle, E_MALLOC, __FILE__, __LINE__);
734 return 0;
735 }
736 pctx->handle = handle;
737 return 1;
738 }
739 This relies on a few things existing in openssl/core_dispatch.h:
741 #define OSSL_OP_BAR 4711
743 #define OSSL_FUNC_BAR_NEWCTX 1
745 typedef void *(OSSL_FUNC_bar_newctx_fn)(void *provctx);
746 static ossl_inline OSSL_FUNC_bar_newctx(const OSSL_DISPATCH *opf)
747 { return (OSSL_FUNC_bar_newctx_fn *)opf->function; }
748 #define OSSL_FUNC_BAR_FREECTX 2
750 typedef void (OSSL_FUNC_bar_freectx_fn)(void *ctx);
751 static ossl_inline OSSL_FUNC_bar_freectx(const OSSL_DISPATCH *opf)
752 { return (OSSL_FUNC_bar_freectx_fn *)opf->function; }
753 #define OSSL_FUNC_BAR_INIT 3
755 typedef void *(OSSL_FUNC_bar_init_fn)(void *ctx);
756 static ossl_inline OSSL_FUNC_bar_init(const OSSL_DISPATCH *opf)
757 { return (OSSL_FUNC_bar_init_fn *)opf->function; }
758 #define OSSL_FUNC_BAR_UPDATE 4
760 typedef void *(OSSL_FUNC_bar_update_fn)(void *ctx,
761 unsigned char *in, size_t inl);
762 static ossl_inline OSSL_FUNC_bar_update(const OSSL_DISPATCH *opf)
763 { return (OSSL_FUNC_bar_update_fn *)opf->function; }
764 #define OSSL_FUNC_BAR_FINAL 5
766 typedef void *(OSSL_FUNC_bar_final_fn)(void *ctx);
767 static ossl_inline OSSL_FUNC_bar_final(const OSSL_DISPATCH *opf)
768 { return (OSSL_FUNC_bar_final_fn *)opf->function; }
769
771 provider(7)
772
774 The concept of providers and everything surrounding them was introduced
775 in OpenSSL 3.0.
776
778 Copyright 2019-2023 The OpenSSL Project Authors. All Rights Reserved.
779 Licensed under the Apache License 2.0 (the "License"). You may not use
781 this file except in compliance with the License. You can obtain a copy
782 in the file LICENSE in the source distribution or at
783 <https://www.openssl.org/source/license.html>.
7843.0.9 2023-07-27 PROVIDER-BASE(7ossl)