xref: /freebsd/crypto/openssl/include/openssl/engine.h (revision b077aed33b7b6aefca7b17ddb250cf521f938613)
1 /*
2  * Copyright 2000-2022 The OpenSSL Project Authors. All Rights Reserved.
3  * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
4  *
5  * Licensed under the Apache License 2.0 (the "License").  You may not use
6  * this file except in compliance with the License.  You can obtain a copy
7  * in the file LICENSE in the source distribution or at
8  * https://www.openssl.org/source/license.html
9  */
10 
11 #ifndef OPENSSL_ENGINE_H
12 # define OPENSSL_ENGINE_H
13 # pragma once
14 
15 # include <openssl/macros.h>
16 # ifndef OPENSSL_NO_DEPRECATED_3_0
17 #  define HEADER_ENGINE_H
18 # endif
19 
20 # include <openssl/opensslconf.h>
21 
22 # ifndef OPENSSL_NO_ENGINE
23 #  ifndef OPENSSL_NO_DEPRECATED_1_1_0
24 #   include <openssl/bn.h>
25 #   include <openssl/rsa.h>
26 #   include <openssl/dsa.h>
27 #   include <openssl/dh.h>
28 #   include <openssl/ec.h>
29 #   include <openssl/rand.h>
30 #   include <openssl/ui.h>
31 #   include <openssl/err.h>
32 #  endif
33 #  include <openssl/types.h>
34 #  include <openssl/symhacks.h>
35 #  include <openssl/x509.h>
36 #  include <openssl/engineerr.h>
37 #  ifdef  __cplusplus
38 extern "C" {
39 #  endif
40 
41 /*
42  * These flags are used to control combinations of algorithm (methods) by
43  * bitwise "OR"ing.
44  */
45 #  define ENGINE_METHOD_RSA               (unsigned int)0x0001
46 #  define ENGINE_METHOD_DSA               (unsigned int)0x0002
47 #  define ENGINE_METHOD_DH                (unsigned int)0x0004
48 #  define ENGINE_METHOD_RAND              (unsigned int)0x0008
49 #  define ENGINE_METHOD_CIPHERS           (unsigned int)0x0040
50 #  define ENGINE_METHOD_DIGESTS           (unsigned int)0x0080
51 #  define ENGINE_METHOD_PKEY_METHS        (unsigned int)0x0200
52 #  define ENGINE_METHOD_PKEY_ASN1_METHS   (unsigned int)0x0400
53 #  define ENGINE_METHOD_EC                (unsigned int)0x0800
54 /* Obvious all-or-nothing cases. */
55 #  define ENGINE_METHOD_ALL               (unsigned int)0xFFFF
56 #  define ENGINE_METHOD_NONE              (unsigned int)0x0000
57 
58 /*
59  * This(ese) flag(s) controls behaviour of the ENGINE_TABLE mechanism used
60  * internally to control registration of ENGINE implementations, and can be
61  * set by ENGINE_set_table_flags(). The "NOINIT" flag prevents attempts to
62  * initialise registered ENGINEs if they are not already initialised.
63  */
64 #  define ENGINE_TABLE_FLAG_NOINIT        (unsigned int)0x0001
65 
66 /* ENGINE flags that can be set by ENGINE_set_flags(). */
67 /* Not used */
68 /* #define ENGINE_FLAGS_MALLOCED        0x0001 */
69 
70 /*
71  * This flag is for ENGINEs that wish to handle the various 'CMD'-related
72  * control commands on their own. Without this flag, ENGINE_ctrl() handles
73  * these control commands on behalf of the ENGINE using their "cmd_defns"
74  * data.
75  */
76 #  define ENGINE_FLAGS_MANUAL_CMD_CTRL    (int)0x0002
77 
78 /*
79  * This flag is for ENGINEs who return new duplicate structures when found
80  * via "ENGINE_by_id()". When an ENGINE must store state (eg. if
81  * ENGINE_ctrl() commands are called in sequence as part of some stateful
82  * process like key-generation setup and execution), it can set this flag -
83  * then each attempt to obtain the ENGINE will result in it being copied into
84  * a new structure. Normally, ENGINEs don't declare this flag so
85  * ENGINE_by_id() just increments the existing ENGINE's structural reference
86  * count.
87  */
88 #  define ENGINE_FLAGS_BY_ID_COPY         (int)0x0004
89 
90 /*
91  * This flag if for an ENGINE that does not want its methods registered as
92  * part of ENGINE_register_all_complete() for example if the methods are not
93  * usable as default methods.
94  */
95 
96 #  define ENGINE_FLAGS_NO_REGISTER_ALL    (int)0x0008
97 
98 /*
99  * ENGINEs can support their own command types, and these flags are used in
100  * ENGINE_CTRL_GET_CMD_FLAGS to indicate to the caller what kind of input
101  * each command expects. Currently only numeric and string input is
102  * supported. If a control command supports none of the _NUMERIC, _STRING, or
103  * _NO_INPUT options, then it is regarded as an "internal" control command -
104  * and not for use in config setting situations. As such, they're not
105  * available to the ENGINE_ctrl_cmd_string() function, only raw ENGINE_ctrl()
106  * access. Changes to this list of 'command types' should be reflected
107  * carefully in ENGINE_cmd_is_executable() and ENGINE_ctrl_cmd_string().
108  */
109 
110 /* accepts a 'long' input value (3rd parameter to ENGINE_ctrl) */
111 #  define ENGINE_CMD_FLAG_NUMERIC         (unsigned int)0x0001
112 /*
113  * accepts string input (cast from 'void*' to 'const char *', 4th parameter
114  * to ENGINE_ctrl)
115  */
116 #  define ENGINE_CMD_FLAG_STRING          (unsigned int)0x0002
117 /*
118  * Indicates that the control command takes *no* input. Ie. the control
119  * command is unparameterised.
120  */
121 #  define ENGINE_CMD_FLAG_NO_INPUT        (unsigned int)0x0004
122 /*
123  * Indicates that the control command is internal. This control command won't
124  * be shown in any output, and is only usable through the ENGINE_ctrl_cmd()
125  * function.
126  */
127 #  define ENGINE_CMD_FLAG_INTERNAL        (unsigned int)0x0008
128 
129 /*
130  * NB: These 3 control commands are deprecated and should not be used.
131  * ENGINEs relying on these commands should compile conditional support for
132  * compatibility (eg. if these symbols are defined) but should also migrate
133  * the same functionality to their own ENGINE-specific control functions that
134  * can be "discovered" by calling applications. The fact these control
135  * commands wouldn't be "executable" (ie. usable by text-based config)
136  * doesn't change the fact that application code can find and use them
137  * without requiring per-ENGINE hacking.
138  */
139 
140 /*
141  * These flags are used to tell the ctrl function what should be done. All
142  * command numbers are shared between all engines, even if some don't make
143  * sense to some engines.  In such a case, they do nothing but return the
144  * error ENGINE_R_CTRL_COMMAND_NOT_IMPLEMENTED.
145  */
146 #  define ENGINE_CTRL_SET_LOGSTREAM               1
147 #  define ENGINE_CTRL_SET_PASSWORD_CALLBACK       2
148 #  define ENGINE_CTRL_HUP                         3/* Close and reinitialise
149                                                    * any handles/connections
150                                                    * etc. */
151 #  define ENGINE_CTRL_SET_USER_INTERFACE          4/* Alternative to callback */
152 #  define ENGINE_CTRL_SET_CALLBACK_DATA           5/* User-specific data, used
153                                                    * when calling the password
154                                                    * callback and the user
155                                                    * interface */
156 #  define ENGINE_CTRL_LOAD_CONFIGURATION          6/* Load a configuration,
157                                                    * given a string that
158                                                    * represents a file name
159                                                    * or so */
160 #  define ENGINE_CTRL_LOAD_SECTION                7/* Load data from a given
161                                                    * section in the already
162                                                    * loaded configuration */
163 
164 /*
165  * These control commands allow an application to deal with an arbitrary
166  * engine in a dynamic way. Warn: Negative return values indicate errors FOR
167  * THESE COMMANDS because zero is used to indicate 'end-of-list'. Other
168  * commands, including ENGINE-specific command types, return zero for an
169  * error. An ENGINE can choose to implement these ctrl functions, and can
170  * internally manage things however it chooses - it does so by setting the
171  * ENGINE_FLAGS_MANUAL_CMD_CTRL flag (using ENGINE_set_flags()). Otherwise
172  * the ENGINE_ctrl() code handles this on the ENGINE's behalf using the
173  * cmd_defns data (set using ENGINE_set_cmd_defns()). This means an ENGINE's
174  * ctrl() handler need only implement its own commands - the above "meta"
175  * commands will be taken care of.
176  */
177 
178 /*
179  * Returns non-zero if the supplied ENGINE has a ctrl() handler. If "not",
180  * then all the remaining control commands will return failure, so it is
181  * worth checking this first if the caller is trying to "discover" the
182  * engine's capabilities and doesn't want errors generated unnecessarily.
183  */
184 #  define ENGINE_CTRL_HAS_CTRL_FUNCTION           10
185 /*
186  * Returns a positive command number for the first command supported by the
187  * engine. Returns zero if no ctrl commands are supported.
188  */
189 #  define ENGINE_CTRL_GET_FIRST_CMD_TYPE          11
190 /*
191  * The 'long' argument specifies a command implemented by the engine, and the
192  * return value is the next command supported, or zero if there are no more.
193  */
194 #  define ENGINE_CTRL_GET_NEXT_CMD_TYPE           12
195 /*
196  * The 'void*' argument is a command name (cast from 'const char *'), and the
197  * return value is the command that corresponds to it.
198  */
199 #  define ENGINE_CTRL_GET_CMD_FROM_NAME           13
200 /*
201  * The next two allow a command to be converted into its corresponding string
202  * form. In each case, the 'long' argument supplies the command. In the
203  * NAME_LEN case, the return value is the length of the command name (not
204  * counting a trailing EOL). In the NAME case, the 'void*' argument must be a
205  * string buffer large enough, and it will be populated with the name of the
206  * command (WITH a trailing EOL).
207  */
208 #  define ENGINE_CTRL_GET_NAME_LEN_FROM_CMD       14
209 #  define ENGINE_CTRL_GET_NAME_FROM_CMD           15
210 /* The next two are similar but give a "short description" of a command. */
211 #  define ENGINE_CTRL_GET_DESC_LEN_FROM_CMD       16
212 #  define ENGINE_CTRL_GET_DESC_FROM_CMD           17
213 /*
214  * With this command, the return value is the OR'd combination of
215  * ENGINE_CMD_FLAG_*** values that indicate what kind of input a given
216  * engine-specific ctrl command expects.
217  */
218 #  define ENGINE_CTRL_GET_CMD_FLAGS               18
219 
220 /*
221  * ENGINE implementations should start the numbering of their own control
222  * commands from this value. (ie. ENGINE_CMD_BASE, ENGINE_CMD_BASE + 1, etc).
223  */
224 #  define ENGINE_CMD_BASE                         200
225 
226 /*
227  * NB: These 2 nCipher "chil" control commands are deprecated, and their
228  * functionality is now available through ENGINE-specific control commands
229  * (exposed through the above-mentioned 'CMD'-handling). Code using these 2
230  * commands should be migrated to the more general command handling before
231  * these are removed.
232  */
233 
234 /* Flags specific to the nCipher "chil" engine */
235 #  define ENGINE_CTRL_CHIL_SET_FORKCHECK          100
236          /*
237           * Depending on the value of the (long)i argument, this sets or
238           * unsets the SimpleForkCheck flag in the CHIL API to enable or
239           * disable checking and workarounds for applications that fork().
240           */
241 #  define ENGINE_CTRL_CHIL_NO_LOCKING             101
242          /*
243           * This prevents the initialisation function from providing mutex
244           * callbacks to the nCipher library.
245           */
246 
247 /*
248  * If an ENGINE supports its own specific control commands and wishes the
249  * framework to handle the above 'ENGINE_CMD_***'-manipulation commands on
250  * its behalf, it should supply a null-terminated array of ENGINE_CMD_DEFN
251  * entries to ENGINE_set_cmd_defns(). It should also implement a ctrl()
252  * handler that supports the stated commands (ie. the "cmd_num" entries as
253  * described by the array). NB: The array must be ordered in increasing order
254  * of cmd_num. "null-terminated" means that the last ENGINE_CMD_DEFN element
255  * has cmd_num set to zero and/or cmd_name set to NULL.
256  */
257 typedef struct ENGINE_CMD_DEFN_st {
258     unsigned int cmd_num;       /* The command number */
259     const char *cmd_name;       /* The command name itself */
260     const char *cmd_desc;       /* A short description of the command */
261     unsigned int cmd_flags;     /* The input the command expects */
262 } ENGINE_CMD_DEFN;
263 
264 /* Generic function pointer */
265 typedef int (*ENGINE_GEN_FUNC_PTR) (void);
266 /* Generic function pointer taking no arguments */
267 typedef int (*ENGINE_GEN_INT_FUNC_PTR) (ENGINE *);
268 /* Specific control function pointer */
269 typedef int (*ENGINE_CTRL_FUNC_PTR) (ENGINE *, int, long, void *,
270                                      void (*f) (void));
271 /* Generic load_key function pointer */
272 typedef EVP_PKEY *(*ENGINE_LOAD_KEY_PTR)(ENGINE *, const char *,
273                                          UI_METHOD *ui_method,
274                                          void *callback_data);
275 typedef int (*ENGINE_SSL_CLIENT_CERT_PTR) (ENGINE *, SSL *ssl,
276                                            STACK_OF(X509_NAME) *ca_dn,
277                                            X509 **pcert, EVP_PKEY **pkey,
278                                            STACK_OF(X509) **pother,
279                                            UI_METHOD *ui_method,
280                                            void *callback_data);
281 /*-
282  * These callback types are for an ENGINE's handler for cipher and digest logic.
283  * These handlers have these prototypes;
284  *   int foo(ENGINE *e, const EVP_CIPHER **cipher, const int **nids, int nid);
285  *   int foo(ENGINE *e, const EVP_MD **digest, const int **nids, int nid);
286  * Looking at how to implement these handlers in the case of cipher support, if
287  * the framework wants the EVP_CIPHER for 'nid', it will call;
288  *   foo(e, &p_evp_cipher, NULL, nid);    (return zero for failure)
289  * If the framework wants a list of supported 'nid's, it will call;
290  *   foo(e, NULL, &p_nids, 0); (returns number of 'nids' or -1 for error)
291  */
292 /*
293  * Returns to a pointer to the array of supported cipher 'nid's. If the
294  * second parameter is non-NULL it is set to the size of the returned array.
295  */
296 typedef int (*ENGINE_CIPHERS_PTR) (ENGINE *, const EVP_CIPHER **,
297                                    const int **, int);
298 typedef int (*ENGINE_DIGESTS_PTR) (ENGINE *, const EVP_MD **, const int **,
299                                    int);
300 typedef int (*ENGINE_PKEY_METHS_PTR) (ENGINE *, EVP_PKEY_METHOD **,
301                                       const int **, int);
302 typedef int (*ENGINE_PKEY_ASN1_METHS_PTR) (ENGINE *, EVP_PKEY_ASN1_METHOD **,
303                                            const int **, int);
304 /*
305  * STRUCTURE functions ... all of these functions deal with pointers to
306  * ENGINE structures where the pointers have a "structural reference". This
307  * means that their reference is to allowed access to the structure but it
308  * does not imply that the structure is functional. To simply increment or
309  * decrement the structural reference count, use ENGINE_by_id and
310  * ENGINE_free. NB: This is not required when iterating using ENGINE_get_next
311  * as it will automatically decrement the structural reference count of the
312  * "current" ENGINE and increment the structural reference count of the
313  * ENGINE it returns (unless it is NULL).
314  */
315 
316 /* Get the first/last "ENGINE" type available. */
317 #  ifndef OPENSSL_NO_DEPRECATED_3_0
318 OSSL_DEPRECATEDIN_3_0 ENGINE *ENGINE_get_first(void);
319 OSSL_DEPRECATEDIN_3_0 ENGINE *ENGINE_get_last(void);
320 #  endif
321 /* Iterate to the next/previous "ENGINE" type (NULL = end of the list). */
322 #  ifndef OPENSSL_NO_DEPRECATED_3_0
323 OSSL_DEPRECATEDIN_3_0 ENGINE *ENGINE_get_next(ENGINE *e);
324 OSSL_DEPRECATEDIN_3_0 ENGINE *ENGINE_get_prev(ENGINE *e);
325 #  endif
326 /* Add another "ENGINE" type into the array. */
327 #  ifndef OPENSSL_NO_DEPRECATED_3_0
328 OSSL_DEPRECATEDIN_3_0 int ENGINE_add(ENGINE *e);
329 #  endif
330 /* Remove an existing "ENGINE" type from the array. */
331 #  ifndef OPENSSL_NO_DEPRECATED_3_0
332 OSSL_DEPRECATEDIN_3_0 int ENGINE_remove(ENGINE *e);
333 #  endif
334 /* Retrieve an engine from the list by its unique "id" value. */
335 #  ifndef OPENSSL_NO_DEPRECATED_3_0
336 OSSL_DEPRECATEDIN_3_0 ENGINE *ENGINE_by_id(const char *id);
337 #  endif
338 
339 #  ifndef OPENSSL_NO_DEPRECATED_1_1_0
340 #   define ENGINE_load_openssl() \
341         OPENSSL_init_crypto(OPENSSL_INIT_ENGINE_OPENSSL, NULL)
342 #   define ENGINE_load_dynamic() \
343         OPENSSL_init_crypto(OPENSSL_INIT_ENGINE_DYNAMIC, NULL)
344 #   ifndef OPENSSL_NO_STATIC_ENGINE
345 #    define ENGINE_load_padlock() \
346         OPENSSL_init_crypto(OPENSSL_INIT_ENGINE_PADLOCK, NULL)
347 #    define ENGINE_load_capi() \
348         OPENSSL_init_crypto(OPENSSL_INIT_ENGINE_CAPI, NULL)
349 #    define ENGINE_load_afalg() \
350         OPENSSL_init_crypto(OPENSSL_INIT_ENGINE_AFALG, NULL)
351 #   endif
352 #   define ENGINE_load_cryptodev() \
353         OPENSSL_init_crypto(OPENSSL_INIT_ENGINE_CRYPTODEV, NULL)
354 #   define ENGINE_load_rdrand() \
355         OPENSSL_init_crypto(OPENSSL_INIT_ENGINE_RDRAND, NULL)
356 #  endif
357 #  ifndef OPENSSL_NO_DEPRECATED_3_0
358 OSSL_DEPRECATEDIN_3_0 void ENGINE_load_builtin_engines(void);
359 #  endif
360 
361 /*
362  * Get and set global flags (ENGINE_TABLE_FLAG_***) for the implementation
363  * "registry" handling.
364  */
365 #  ifndef OPENSSL_NO_DEPRECATED_3_0
366 OSSL_DEPRECATEDIN_3_0 unsigned int ENGINE_get_table_flags(void);
367 OSSL_DEPRECATEDIN_3_0 void ENGINE_set_table_flags(unsigned int flags);
368 #  endif
369 
370 /*- Manage registration of ENGINEs per "table". For each type, there are 3
371  * functions;
372  *   ENGINE_register_***(e) - registers the implementation from 'e' (if it has one)
373  *   ENGINE_unregister_***(e) - unregister the implementation from 'e'
374  *   ENGINE_register_all_***() - call ENGINE_register_***() for each 'e' in the list
375  * Cleanup is automatically registered from each table when required.
376  */
377 #  ifndef OPENSSL_NO_DEPRECATED_3_0
378 OSSL_DEPRECATEDIN_3_0 int ENGINE_register_RSA(ENGINE *e);
379 OSSL_DEPRECATEDIN_3_0 void ENGINE_unregister_RSA(ENGINE *e);
380 OSSL_DEPRECATEDIN_3_0 void ENGINE_register_all_RSA(void);
381 OSSL_DEPRECATEDIN_3_0 int ENGINE_register_DSA(ENGINE *e);
382 OSSL_DEPRECATEDIN_3_0 void ENGINE_unregister_DSA(ENGINE *e);
383 OSSL_DEPRECATEDIN_3_0 void ENGINE_register_all_DSA(void);
384 OSSL_DEPRECATEDIN_3_0 int ENGINE_register_EC(ENGINE *e);
385 OSSL_DEPRECATEDIN_3_0 void ENGINE_unregister_EC(ENGINE *e);
386 OSSL_DEPRECATEDIN_3_0 void ENGINE_register_all_EC(void);
387 OSSL_DEPRECATEDIN_3_0 int ENGINE_register_DH(ENGINE *e);
388 OSSL_DEPRECATEDIN_3_0 void ENGINE_unregister_DH(ENGINE *e);
389 OSSL_DEPRECATEDIN_3_0 void ENGINE_register_all_DH(void);
390 OSSL_DEPRECATEDIN_3_0 int ENGINE_register_RAND(ENGINE *e);
391 OSSL_DEPRECATEDIN_3_0 void ENGINE_unregister_RAND(ENGINE *e);
392 OSSL_DEPRECATEDIN_3_0 void ENGINE_register_all_RAND(void);
393 OSSL_DEPRECATEDIN_3_0 int ENGINE_register_ciphers(ENGINE *e);
394 OSSL_DEPRECATEDIN_3_0 void ENGINE_unregister_ciphers(ENGINE *e);
395 OSSL_DEPRECATEDIN_3_0 void ENGINE_register_all_ciphers(void);
396 OSSL_DEPRECATEDIN_3_0 int ENGINE_register_digests(ENGINE *e);
397 OSSL_DEPRECATEDIN_3_0 void ENGINE_unregister_digests(ENGINE *e);
398 OSSL_DEPRECATEDIN_3_0 void ENGINE_register_all_digests(void);
399 OSSL_DEPRECATEDIN_3_0 int ENGINE_register_pkey_meths(ENGINE *e);
400 OSSL_DEPRECATEDIN_3_0 void ENGINE_unregister_pkey_meths(ENGINE *e);
401 OSSL_DEPRECATEDIN_3_0 void ENGINE_register_all_pkey_meths(void);
402 OSSL_DEPRECATEDIN_3_0 int ENGINE_register_pkey_asn1_meths(ENGINE *e);
403 OSSL_DEPRECATEDIN_3_0 void ENGINE_unregister_pkey_asn1_meths(ENGINE *e);
404 OSSL_DEPRECATEDIN_3_0 void ENGINE_register_all_pkey_asn1_meths(void);
405 #  endif
406 
407 /*
408  * These functions register all support from the above categories. Note, use
409  * of these functions can result in static linkage of code your application
410  * may not need. If you only need a subset of functionality, consider using
411  * more selective initialisation.
412  */
413 #  ifndef OPENSSL_NO_DEPRECATED_3_0
414 OSSL_DEPRECATEDIN_3_0 int ENGINE_register_complete(ENGINE *e);
415 OSSL_DEPRECATEDIN_3_0 int ENGINE_register_all_complete(void);
416 #  endif
417 
418 /*
419  * Send parameterised control commands to the engine. The possibilities to
420  * send down an integer, a pointer to data or a function pointer are
421  * provided. Any of the parameters may or may not be NULL, depending on the
422  * command number. In actuality, this function only requires a structural
423  * (rather than functional) reference to an engine, but many control commands
424  * may require the engine be functional. The caller should be aware of trying
425  * commands that require an operational ENGINE, and only use functional
426  * references in such situations.
427  */
428 #  ifndef OPENSSL_NO_DEPRECATED_3_0
429 OSSL_DEPRECATEDIN_3_0 int ENGINE_ctrl(ENGINE *e, int cmd, long i, void *p,
430                                       void (*f) (void));
431 #  endif
432 
433 /*
434  * This function tests if an ENGINE-specific command is usable as a
435  * "setting". Eg. in an application's config file that gets processed through
436  * ENGINE_ctrl_cmd_string(). If this returns zero, it is not available to
437  * ENGINE_ctrl_cmd_string(), only ENGINE_ctrl().
438  */
439 #  ifndef OPENSSL_NO_DEPRECATED_3_0
440 OSSL_DEPRECATEDIN_3_0 int ENGINE_cmd_is_executable(ENGINE *e, int cmd);
441 #  endif
442 
443 /*
444  * This function works like ENGINE_ctrl() with the exception of taking a
445  * command name instead of a command number, and can handle optional
446  * commands. See the comment on ENGINE_ctrl_cmd_string() for an explanation
447  * on how to use the cmd_name and cmd_optional.
448  */
449 #  ifndef OPENSSL_NO_DEPRECATED_3_0
450 OSSL_DEPRECATEDIN_3_0 int ENGINE_ctrl_cmd(ENGINE *e, const char *cmd_name,
451                                           long i, void *p, void (*f) (void),
452                                           int cmd_optional);
453 #  endif
454 
455 /*
456  * This function passes a command-name and argument to an ENGINE. The
457  * cmd_name is converted to a command number and the control command is
458  * called using 'arg' as an argument (unless the ENGINE doesn't support such
459  * a command, in which case no control command is called). The command is
460  * checked for input flags, and if necessary the argument will be converted
461  * to a numeric value. If cmd_optional is non-zero, then if the ENGINE
462  * doesn't support the given cmd_name the return value will be success
463  * anyway. This function is intended for applications to use so that users
464  * (or config files) can supply engine-specific config data to the ENGINE at
465  * run-time to control behaviour of specific engines. As such, it shouldn't
466  * be used for calling ENGINE_ctrl() functions that return data, deal with
467  * binary data, or that are otherwise supposed to be used directly through
468  * ENGINE_ctrl() in application code. Any "return" data from an ENGINE_ctrl()
469  * operation in this function will be lost - the return value is interpreted
470  * as failure if the return value is zero, success otherwise, and this
471  * function returns a boolean value as a result. In other words, vendors of
472  * 'ENGINE'-enabled devices should write ENGINE implementations with
473  * parameterisations that work in this scheme, so that compliant ENGINE-based
474  * applications can work consistently with the same configuration for the
475  * same ENGINE-enabled devices, across applications.
476  */
477 #  ifndef OPENSSL_NO_DEPRECATED_3_0
478 OSSL_DEPRECATEDIN_3_0
479 int ENGINE_ctrl_cmd_string(ENGINE *e, const char *cmd_name, const char *arg,
480                            int cmd_optional);
481 #  endif
482 
483 /*
484  * These functions are useful for manufacturing new ENGINE structures. They
485  * don't address reference counting at all - one uses them to populate an
486  * ENGINE structure with personalised implementations of things prior to
487  * using it directly or adding it to the builtin ENGINE list in OpenSSL.
488  * These are also here so that the ENGINE structure doesn't have to be
489  * exposed and break binary compatibility!
490  */
491 #  ifndef OPENSSL_NO_DEPRECATED_3_0
492 OSSL_DEPRECATEDIN_3_0 ENGINE *ENGINE_new(void);
493 OSSL_DEPRECATEDIN_3_0 int ENGINE_free(ENGINE *e);
494 OSSL_DEPRECATEDIN_3_0 int ENGINE_up_ref(ENGINE *e);
495 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_id(ENGINE *e, const char *id);
496 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_name(ENGINE *e, const char *name);
497 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_RSA(ENGINE *e, const RSA_METHOD *rsa_meth);
498 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_DSA(ENGINE *e, const DSA_METHOD *dsa_meth);
499 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_EC(ENGINE *e, const EC_KEY_METHOD *ecdsa_meth);
500 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_DH(ENGINE *e, const DH_METHOD *dh_meth);
501 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_RAND(ENGINE *e, const RAND_METHOD *rand_meth);
502 OSSL_DEPRECATEDIN_3_0
503 int ENGINE_set_destroy_function(ENGINE *e,ENGINE_GEN_INT_FUNC_PTR destroy_f);
504 OSSL_DEPRECATEDIN_3_0
505 int ENGINE_set_init_function(ENGINE *e, ENGINE_GEN_INT_FUNC_PTR init_f);
506 OSSL_DEPRECATEDIN_3_0
507 int ENGINE_set_finish_function(ENGINE *e, ENGINE_GEN_INT_FUNC_PTR finish_f);
508 OSSL_DEPRECATEDIN_3_0
509 int ENGINE_set_ctrl_function(ENGINE *e, ENGINE_CTRL_FUNC_PTR ctrl_f);
510 OSSL_DEPRECATEDIN_3_0
511 int ENGINE_set_load_privkey_function(ENGINE *e, ENGINE_LOAD_KEY_PTR loadpriv_f);
512 OSSL_DEPRECATEDIN_3_0
513 int ENGINE_set_load_pubkey_function(ENGINE *e, ENGINE_LOAD_KEY_PTR loadpub_f);
514 OSSL_DEPRECATEDIN_3_0
515 int ENGINE_set_load_ssl_client_cert_function(ENGINE *e,
516                                              ENGINE_SSL_CLIENT_CERT_PTR loadssl_f);
517 OSSL_DEPRECATEDIN_3_0
518 int ENGINE_set_ciphers(ENGINE *e, ENGINE_CIPHERS_PTR f);
519 OSSL_DEPRECATEDIN_3_0
520 int ENGINE_set_digests(ENGINE *e, ENGINE_DIGESTS_PTR f);
521 OSSL_DEPRECATEDIN_3_0
522 int ENGINE_set_pkey_meths(ENGINE *e, ENGINE_PKEY_METHS_PTR f);
523 OSSL_DEPRECATEDIN_3_0
524 int ENGINE_set_pkey_asn1_meths(ENGINE *e, ENGINE_PKEY_ASN1_METHS_PTR f);
525 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_flags(ENGINE *e, int flags);
526 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_cmd_defns(ENGINE *e,
527                                                const ENGINE_CMD_DEFN *defns);
528 #  endif
529 /* These functions allow control over any per-structure ENGINE data. */
530 #  define ENGINE_get_ex_new_index(l, p, newf, dupf, freef) \
531     CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_ENGINE, l, p, newf, dupf, freef)
532 # ifndef OPENSSL_NO_DEPRECATED_3_0
533 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_ex_data(ENGINE *e, int idx, void *arg);
534 OSSL_DEPRECATEDIN_3_0 void *ENGINE_get_ex_data(const ENGINE *e, int idx);
535 # endif
536 
537 #  ifndef OPENSSL_NO_DEPRECATED_1_1_0
538 /*
539  * This function previously cleaned up anything that needs it. Auto-deinit will
540  * now take care of it so it is no longer required to call this function.
541  */
542 #   define ENGINE_cleanup() while(0) continue
543 #  endif
544 
545 /*
546  * These return values from within the ENGINE structure. These can be useful
547  * with functional references as well as structural references - it depends
548  * which you obtained. Using the result for functional purposes if you only
549  * obtained a structural reference may be problematic!
550  */
551 #  ifndef OPENSSL_NO_DEPRECATED_3_0
552 OSSL_DEPRECATEDIN_3_0 const char *ENGINE_get_id(const ENGINE *e);
553 OSSL_DEPRECATEDIN_3_0 const char *ENGINE_get_name(const ENGINE *e);
554 OSSL_DEPRECATEDIN_3_0 const RSA_METHOD *ENGINE_get_RSA(const ENGINE *e);
555 OSSL_DEPRECATEDIN_3_0 const DSA_METHOD *ENGINE_get_DSA(const ENGINE *e);
556 OSSL_DEPRECATEDIN_3_0 const EC_KEY_METHOD *ENGINE_get_EC(const ENGINE *e);
557 OSSL_DEPRECATEDIN_3_0 const DH_METHOD *ENGINE_get_DH(const ENGINE *e);
558 OSSL_DEPRECATEDIN_3_0 const RAND_METHOD *ENGINE_get_RAND(const ENGINE *e);
559 OSSL_DEPRECATEDIN_3_0
560 ENGINE_GEN_INT_FUNC_PTR ENGINE_get_destroy_function(const ENGINE *e);
561 OSSL_DEPRECATEDIN_3_0
562 ENGINE_GEN_INT_FUNC_PTR ENGINE_get_init_function(const ENGINE *e);
563 OSSL_DEPRECATEDIN_3_0
564 ENGINE_GEN_INT_FUNC_PTR ENGINE_get_finish_function(const ENGINE *e);
565 OSSL_DEPRECATEDIN_3_0
566 ENGINE_CTRL_FUNC_PTR ENGINE_get_ctrl_function(const ENGINE *e);
567 OSSL_DEPRECATEDIN_3_0
568 ENGINE_LOAD_KEY_PTR ENGINE_get_load_privkey_function(const ENGINE *e);
569 OSSL_DEPRECATEDIN_3_0
570 ENGINE_LOAD_KEY_PTR ENGINE_get_load_pubkey_function(const ENGINE *e);
571 OSSL_DEPRECATEDIN_3_0
572 ENGINE_SSL_CLIENT_CERT_PTR ENGINE_get_ssl_client_cert_function(const ENGINE *e);
573 OSSL_DEPRECATEDIN_3_0
574 ENGINE_CIPHERS_PTR ENGINE_get_ciphers(const ENGINE *e);
575 OSSL_DEPRECATEDIN_3_0
576 ENGINE_DIGESTS_PTR ENGINE_get_digests(const ENGINE *e);
577 OSSL_DEPRECATEDIN_3_0
578 ENGINE_PKEY_METHS_PTR ENGINE_get_pkey_meths(const ENGINE *e);
579 OSSL_DEPRECATEDIN_3_0
580 ENGINE_PKEY_ASN1_METHS_PTR ENGINE_get_pkey_asn1_meths(const ENGINE *e);
581 OSSL_DEPRECATEDIN_3_0
582 const EVP_CIPHER *ENGINE_get_cipher(ENGINE *e, int nid);
583 OSSL_DEPRECATEDIN_3_0
584 const EVP_MD *ENGINE_get_digest(ENGINE *e, int nid);
585 OSSL_DEPRECATEDIN_3_0
586 const EVP_PKEY_METHOD *ENGINE_get_pkey_meth(ENGINE *e, int nid);
587 OSSL_DEPRECATEDIN_3_0
588 const EVP_PKEY_ASN1_METHOD *ENGINE_get_pkey_asn1_meth(ENGINE *e, int nid);
589 OSSL_DEPRECATEDIN_3_0
590 const EVP_PKEY_ASN1_METHOD *ENGINE_get_pkey_asn1_meth_str(ENGINE *e,
591                                                           const char *str,
592                                                           int len);
593 OSSL_DEPRECATEDIN_3_0
594 const EVP_PKEY_ASN1_METHOD *ENGINE_pkey_asn1_find_str(ENGINE **pe,
595                                                       const char *str, int len);
596 OSSL_DEPRECATEDIN_3_0
597 const ENGINE_CMD_DEFN *ENGINE_get_cmd_defns(const ENGINE *e);
598 OSSL_DEPRECATEDIN_3_0 int ENGINE_get_flags(const ENGINE *e);
599 #  endif
600 
601 /*
602  * FUNCTIONAL functions. These functions deal with ENGINE structures that
603  * have (or will) be initialised for use. Broadly speaking, the structural
604  * functions are useful for iterating the list of available engine types,
605  * creating new engine types, and other "list" operations. These functions
606  * actually deal with ENGINEs that are to be used. As such these functions
607  * can fail (if applicable) when particular engines are unavailable - eg. if
608  * a hardware accelerator is not attached or not functioning correctly. Each
609  * ENGINE has 2 reference counts; structural and functional. Every time a
610  * functional reference is obtained or released, a corresponding structural
611  * reference is automatically obtained or released too.
612  */
613 
614 /*
615  * Initialise a engine type for use (or up its reference count if it's
616  * already in use). This will fail if the engine is not currently operational
617  * and cannot initialise.
618  */
619 #  ifndef OPENSSL_NO_DEPRECATED_3_0
620 OSSL_DEPRECATEDIN_3_0 int ENGINE_init(ENGINE *e);
621 #  endif
622 /*
623  * Free a functional reference to a engine type. This does not require a
624  * corresponding call to ENGINE_free as it also releases a structural
625  * reference.
626  */
627 #  ifndef OPENSSL_NO_DEPRECATED_3_0
628 OSSL_DEPRECATEDIN_3_0 int ENGINE_finish(ENGINE *e);
629 #  endif
630 
631 /*
632  * The following functions handle keys that are stored in some secondary
633  * location, handled by the engine.  The storage may be on a card or
634  * whatever.
635  */
636 #  ifndef OPENSSL_NO_DEPRECATED_3_0
637 OSSL_DEPRECATEDIN_3_0
638 EVP_PKEY *ENGINE_load_private_key(ENGINE *e, const char *key_id,
639                                   UI_METHOD *ui_method, void *callback_data);
640 OSSL_DEPRECATEDIN_3_0
641 EVP_PKEY *ENGINE_load_public_key(ENGINE *e, const char *key_id,
642                                  UI_METHOD *ui_method, void *callback_data);
643 OSSL_DEPRECATEDIN_3_0
644 int ENGINE_load_ssl_client_cert(ENGINE *e, SSL *s, STACK_OF(X509_NAME) *ca_dn,
645                                 X509 **pcert, EVP_PKEY **ppkey,
646                                 STACK_OF(X509) **pother,
647                                 UI_METHOD *ui_method, void *callback_data);
648 #  endif
649 
650 /*
651  * This returns a pointer for the current ENGINE structure that is (by
652  * default) performing any RSA operations. The value returned is an
653  * incremented reference, so it should be free'd (ENGINE_finish) before it is
654  * discarded.
655  */
656 #  ifndef OPENSSL_NO_DEPRECATED_3_0
657 OSSL_DEPRECATEDIN_3_0 ENGINE *ENGINE_get_default_RSA(void);
658 #  endif
659 /* Same for the other "methods" */
660 #  ifndef OPENSSL_NO_DEPRECATED_3_0
661 OSSL_DEPRECATEDIN_3_0 ENGINE *ENGINE_get_default_DSA(void);
662 OSSL_DEPRECATEDIN_3_0 ENGINE *ENGINE_get_default_EC(void);
663 OSSL_DEPRECATEDIN_3_0 ENGINE *ENGINE_get_default_DH(void);
664 OSSL_DEPRECATEDIN_3_0 ENGINE *ENGINE_get_default_RAND(void);
665 #  endif
666 /*
667  * These functions can be used to get a functional reference to perform
668  * ciphering or digesting corresponding to "nid".
669  */
670 #  ifndef OPENSSL_NO_DEPRECATED_3_0
671 OSSL_DEPRECATEDIN_3_0 ENGINE *ENGINE_get_cipher_engine(int nid);
672 OSSL_DEPRECATEDIN_3_0 ENGINE *ENGINE_get_digest_engine(int nid);
673 OSSL_DEPRECATEDIN_3_0 ENGINE *ENGINE_get_pkey_meth_engine(int nid);
674 OSSL_DEPRECATEDIN_3_0 ENGINE *ENGINE_get_pkey_asn1_meth_engine(int nid);
675 #  endif
676 
677 /*
678  * This sets a new default ENGINE structure for performing RSA operations. If
679  * the result is non-zero (success) then the ENGINE structure will have had
680  * its reference count up'd so the caller should still free their own
681  * reference 'e'.
682  */
683 #  ifndef OPENSSL_NO_DEPRECATED_3_0
684 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_default_RSA(ENGINE *e);
685 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_default_string(ENGINE *e,
686                                                     const char *def_list);
687 #  endif
688 /* Same for the other "methods" */
689 #  ifndef OPENSSL_NO_DEPRECATED_3_0
690 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_default_DSA(ENGINE *e);
691 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_default_EC(ENGINE *e);
692 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_default_DH(ENGINE *e);
693 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_default_RAND(ENGINE *e);
694 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_default_ciphers(ENGINE *e);
695 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_default_digests(ENGINE *e);
696 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_default_pkey_meths(ENGINE *e);
697 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_default_pkey_asn1_meths(ENGINE *e);
698 #  endif
699 
700 /*
701  * The combination "set" - the flags are bitwise "OR"d from the
702  * ENGINE_METHOD_*** defines above. As with the "ENGINE_register_complete()"
703  * function, this function can result in unnecessary static linkage. If your
704  * application requires only specific functionality, consider using more
705  * selective functions.
706  */
707 #  ifndef OPENSSL_NO_DEPRECATED_3_0
708 OSSL_DEPRECATEDIN_3_0 int ENGINE_set_default(ENGINE *e, unsigned int flags);
709 OSSL_DEPRECATEDIN_3_0 void ENGINE_add_conf_module(void);
710 #  endif
711 
712 /* Deprecated functions ... */
713 /* int ENGINE_clear_defaults(void); */
714 
715 /**************************/
716 /* DYNAMIC ENGINE SUPPORT */
717 /**************************/
718 
719 /* Binary/behaviour compatibility levels */
720 #  define OSSL_DYNAMIC_VERSION            (unsigned long)0x00030000
721 /*
722  * Binary versions older than this are too old for us (whether we're a loader
723  * or a loadee)
724  */
725 #  define OSSL_DYNAMIC_OLDEST             (unsigned long)0x00030000
726 
727 /*
728  * When compiling an ENGINE entirely as an external shared library, loadable
729  * by the "dynamic" ENGINE, these types are needed. The 'dynamic_fns'
730  * structure type provides the calling application's (or library's) error
731  * functionality and memory management function pointers to the loaded
732  * library. These should be used/set in the loaded library code so that the
733  * loading application's 'state' will be used/changed in all operations. The
734  * 'static_state' pointer allows the loaded library to know if it shares the
735  * same static data as the calling application (or library), and thus whether
736  * these callbacks need to be set or not.
737  */
738 typedef void *(*dyn_MEM_malloc_fn) (size_t, const char *, int);
739 typedef void *(*dyn_MEM_realloc_fn) (void *, size_t, const char *, int);
740 typedef void (*dyn_MEM_free_fn) (void *, const char *, int);
741 typedef struct st_dynamic_MEM_fns {
742     dyn_MEM_malloc_fn malloc_fn;
743     dyn_MEM_realloc_fn realloc_fn;
744     dyn_MEM_free_fn free_fn;
745 } dynamic_MEM_fns;
746 /*
747  * FIXME: Perhaps the memory and locking code (crypto.h) should declare and
748  * use these types so we (and any other dependent code) can simplify a bit??
749  */
750 /* The top-level structure */
751 typedef struct st_dynamic_fns {
752     void *static_state;
753     dynamic_MEM_fns mem_fns;
754 } dynamic_fns;
755 
756 /*
757  * The version checking function should be of this prototype. NB: The
758  * ossl_version value passed in is the OSSL_DYNAMIC_VERSION of the loading
759  * code. If this function returns zero, it indicates a (potential) version
760  * incompatibility and the loaded library doesn't believe it can proceed.
761  * Otherwise, the returned value is the (latest) version supported by the
762  * loading library. The loader may still decide that the loaded code's
763  * version is unsatisfactory and could veto the load. The function is
764  * expected to be implemented with the symbol name "v_check", and a default
765  * implementation can be fully instantiated with
766  * IMPLEMENT_DYNAMIC_CHECK_FN().
767  */
768 typedef unsigned long (*dynamic_v_check_fn) (unsigned long ossl_version);
769 #  define IMPLEMENT_DYNAMIC_CHECK_FN() \
770         OPENSSL_EXPORT unsigned long v_check(unsigned long v); \
771         OPENSSL_EXPORT unsigned long v_check(unsigned long v) { \
772                 if (v >= OSSL_DYNAMIC_OLDEST) return OSSL_DYNAMIC_VERSION; \
773                 return 0; }
774 
775 /*
776  * This function is passed the ENGINE structure to initialise with its own
777  * function and command settings. It should not adjust the structural or
778  * functional reference counts. If this function returns zero, (a) the load
779  * will be aborted, (b) the previous ENGINE state will be memcpy'd back onto
780  * the structure, and (c) the shared library will be unloaded. So
781  * implementations should do their own internal cleanup in failure
782  * circumstances otherwise they could leak. The 'id' parameter, if non-NULL,
783  * represents the ENGINE id that the loader is looking for. If this is NULL,
784  * the shared library can choose to return failure or to initialise a
785  * 'default' ENGINE. If non-NULL, the shared library must initialise only an
786  * ENGINE matching the passed 'id'. The function is expected to be
787  * implemented with the symbol name "bind_engine". A standard implementation
788  * can be instantiated with IMPLEMENT_DYNAMIC_BIND_FN(fn) where the parameter
789  * 'fn' is a callback function that populates the ENGINE structure and
790  * returns an int value (zero for failure). 'fn' should have prototype;
791  * [static] int fn(ENGINE *e, const char *id);
792  */
793 typedef int (*dynamic_bind_engine) (ENGINE *e, const char *id,
794                                     const dynamic_fns *fns);
795 #  define IMPLEMENT_DYNAMIC_BIND_FN(fn) \
796         OPENSSL_EXPORT \
797         int bind_engine(ENGINE *e, const char *id, const dynamic_fns *fns); \
798         OPENSSL_EXPORT \
799         int bind_engine(ENGINE *e, const char *id, const dynamic_fns *fns) { \
800             if (ENGINE_get_static_state() == fns->static_state) goto skip_cbs; \
801             CRYPTO_set_mem_functions(fns->mem_fns.malloc_fn, \
802                                      fns->mem_fns.realloc_fn, \
803                                      fns->mem_fns.free_fn); \
804             OPENSSL_init_crypto(OPENSSL_INIT_NO_ATEXIT, NULL); \
805         skip_cbs: \
806             if (!fn(e, id)) return 0; \
807             return 1; }
808 
809 /*
810  * If the loading application (or library) and the loaded ENGINE library
811  * share the same static data (eg. they're both dynamically linked to the
812  * same libcrypto.so) we need a way to avoid trying to set system callbacks -
813  * this would fail, and for the same reason that it's unnecessary to try. If
814  * the loaded ENGINE has (or gets from through the loader) its own copy of
815  * the libcrypto static data, we will need to set the callbacks. The easiest
816  * way to detect this is to have a function that returns a pointer to some
817  * static data and let the loading application and loaded ENGINE compare
818  * their respective values.
819  */
820 void *ENGINE_get_static_state(void);
821 
822 #  if defined(__OpenBSD__) || defined(__FreeBSD__) || defined(__DragonFly__)
823 #   ifndef OPENSSL_NO_DEPRECATED_1_1_0
824 OSSL_DEPRECATEDIN_1_1_0 void ENGINE_setup_bsd_cryptodev(void);
825 #   endif
826 #  endif
827 
828 
829 #  ifdef  __cplusplus
830 }
831 #  endif
832 # endif /* OPENSSL_NO_ENGINE */
833 #endif  /* OPENSSL_ENGINE_H */
834