Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
/*
 * Copyright 2000-2022 The OpenSSL Project Authors. All Rights Reserved.
 * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
 *
 * Licensed under the OpenSSL license (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

#ifndef HEADER_ENGINE_H
# define HEADER_ENGINE_H

# include <openssl/opensslconf.h>

# ifndef OPENSSL_NO_ENGINE
# if OPENSSL_API_COMPAT < 0x10100000L
#  include <openssl/bn.h>
#  include <openssl/rsa.h>
#  include <openssl/dsa.h>
#  include <openssl/dh.h>
#  include <openssl/ec.h>
#  include <openssl/rand.h>
#  include <openssl/ui.h>
#  include <openssl/err.h>
# endif
# include <openssl/ossl_typ.h>
# include <openssl/symhacks.h>
# include <openssl/x509.h>
# include <openssl/engineerr.h>
# ifdef  __cplusplus
extern "C" {
# endif

/*
 * These flags are used to control combinations of algorithm (methods) by
 * bitwise "OR"ing.
 */
# define ENGINE_METHOD_RSA               (unsigned int)0x0001
# define ENGINE_METHOD_DSA               (unsigned int)0x0002
# define ENGINE_METHOD_DH                (unsigned int)0x0004
# define ENGINE_METHOD_RAND              (unsigned int)0x0008
# define ENGINE_METHOD_CIPHERS           (unsigned int)0x0040
# define ENGINE_METHOD_DIGESTS           (unsigned int)0x0080
# define ENGINE_METHOD_PKEY_METHS        (unsigned int)0x0200
# define ENGINE_METHOD_PKEY_ASN1_METHS   (unsigned int)0x0400
# define ENGINE_METHOD_EC                (unsigned int)0x0800
/* Obvious all-or-nothing cases. */
# define ENGINE_METHOD_ALL               (unsigned int)0xFFFF
# define ENGINE_METHOD_NONE              (unsigned int)0x0000

/*
 * This(ese) flag(s) controls behaviour of the ENGINE_TABLE mechanism used
 * internally to control registration of ENGINE implementations, and can be
 * set by ENGINE_set_table_flags(). The "NOINIT" flag prevents attempts to
 * initialise registered ENGINEs if they are not already initialised.
 */
# define ENGINE_TABLE_FLAG_NOINIT        (unsigned int)0x0001

/* ENGINE flags that can be set by ENGINE_set_flags(). */
/* Not used */
/* #define ENGINE_FLAGS_MALLOCED        0x0001 */

/*
 * This flag is for ENGINEs that wish to handle the various 'CMD'-related
 * control commands on their own. Without this flag, ENGINE_ctrl() handles
 * these control commands on behalf of the ENGINE using their "cmd_defns"
 * data.
 */
# define ENGINE_FLAGS_MANUAL_CMD_CTRL    (int)0x0002

/*
 * This flag is for ENGINEs who return new duplicate structures when found
 * via "ENGINE_by_id()". When an ENGINE must store state (eg. if
 * ENGINE_ctrl() commands are called in sequence as part of some stateful
 * process like key-generation setup and execution), it can set this flag -
 * then each attempt to obtain the ENGINE will result in it being copied into
 * a new structure. Normally, ENGINEs don't declare this flag so
 * ENGINE_by_id() just increments the existing ENGINE's structural reference
 * count.
 */
# define ENGINE_FLAGS_BY_ID_COPY         (int)0x0004

/*
 * This flag if for an ENGINE that does not want its methods registered as
 * part of ENGINE_register_all_complete() for example if the methods are not
 * usable as default methods.
 */

# define ENGINE_FLAGS_NO_REGISTER_ALL    (int)0x0008

/*
 * ENGINEs can support their own command types, and these flags are used in
 * ENGINE_CTRL_GET_CMD_FLAGS to indicate to the caller what kind of input
 * each command expects. Currently only numeric and string input is
 * supported. If a control command supports none of the _NUMERIC, _STRING, or
 * _NO_INPUT options, then it is regarded as an "internal" control command -
 * and not for use in config setting situations. As such, they're not
 * available to the ENGINE_ctrl_cmd_string() function, only raw ENGINE_ctrl()
 * access. Changes to this list of 'command types' should be reflected
 * carefully in ENGINE_cmd_is_executable() and ENGINE_ctrl_cmd_string().
 */

/* accepts a 'long' input value (3rd parameter to ENGINE_ctrl) */
# define ENGINE_CMD_FLAG_NUMERIC         (unsigned int)0x0001
/*
 * accepts string input (cast from 'void*' to 'const char *', 4th parameter
 * to ENGINE_ctrl)
 */
# define ENGINE_CMD_FLAG_STRING          (unsigned int)0x0002
/*
 * Indicates that the control command takes *no* input. Ie. the control
 * command is unparameterised.
 */
# define ENGINE_CMD_FLAG_NO_INPUT        (unsigned int)0x0004
/*
 * Indicates that the control command is internal. This control command won't
 * be shown in any output, and is only usable through the ENGINE_ctrl_cmd()
 * function.
 */
# define ENGINE_CMD_FLAG_INTERNAL        (unsigned int)0x0008

/*
 * NB: These 3 control commands are deprecated and should not be used.
 * ENGINEs relying on these commands should compile conditional support for
 * compatibility (eg. if these symbols are defined) but should also migrate
 * the same functionality to their own ENGINE-specific control functions that
 * can be "discovered" by calling applications. The fact these control
 * commands wouldn't be "executable" (ie. usable by text-based config)
 * doesn't change the fact that application code can find and use them
 * without requiring per-ENGINE hacking.
 */

/*
 * These flags are used to tell the ctrl function what should be done. All
 * command numbers are shared between all engines, even if some don't make
 * sense to some engines.  In such a case, they do nothing but return the
 * error ENGINE_R_CTRL_COMMAND_NOT_IMPLEMENTED.
 */
# define ENGINE_CTRL_SET_LOGSTREAM               1
# define ENGINE_CTRL_SET_PASSWORD_CALLBACK       2
# define ENGINE_CTRL_HUP                         3/* Close and reinitialise
                                                   * any handles/connections
                                                   * etc. */
# define ENGINE_CTRL_SET_USER_INTERFACE          4/* Alternative to callback */
# define ENGINE_CTRL_SET_CALLBACK_DATA           5/* User-specific data, used
                                                   * when calling the password
                                                   * callback and the user
                                                   * interface */
# define ENGINE_CTRL_LOAD_CONFIGURATION          6/* Load a configuration,
                                                   * given a string that
                                                   * represents a file name
                                                   * or so */
# define ENGINE_CTRL_LOAD_SECTION                7/* Load data from a given
                                                   * section in the already
                                                   * loaded configuration */

/*
 * These control commands allow an application to deal with an arbitrary
 * engine in a dynamic way. Warn: Negative return values indicate errors FOR
 * THESE COMMANDS because zero is used to indicate 'end-of-list'. Other
 * commands, including ENGINE-specific command types, return zero for an
 * error. An ENGINE can choose to implement these ctrl functions, and can
 * internally manage things however it chooses - it does so by setting the
 * ENGINE_FLAGS_MANUAL_CMD_CTRL flag (using ENGINE_set_flags()). Otherwise
 * the ENGINE_ctrl() code handles this on the ENGINE's behalf using the
 * cmd_defns data (set using ENGINE_set_cmd_defns()). This means an ENGINE's
 * ctrl() handler need only implement its own commands - the above "meta"
 * commands will be taken care of.
 */

/*
 * Returns non-zero if the supplied ENGINE has a ctrl() handler. If "not",
 * then all the remaining control commands will return failure, so it is
 * worth checking this first if the caller is trying to "discover" the
 * engine's capabilities and doesn't want errors generated unnecessarily.
 */
# define ENGINE_CTRL_HAS_CTRL_FUNCTION           10
/*
 * Returns a positive command number for the first command supported by the
 * engine. Returns zero if no ctrl commands are supported.
 */
# define ENGINE_CTRL_GET_FIRST_CMD_TYPE          11
/*
 * The 'long' argument specifies a command implemented by the engine, and the
 * return value is the next command supported, or zero if there are no more.
 */
# define ENGINE_CTRL_GET_NEXT_CMD_TYPE           12
/*
 * The 'void*' argument is a command name (cast from 'const char *'), and the
 * return value is the command that corresponds to it.
 */
# define ENGINE_CTRL_GET_CMD_FROM_NAME           13
/*
 * The next two allow a command to be converted into its corresponding string
 * form. In each case, the 'long' argument supplies the command. In the
 * NAME_LEN case, the return value is the length of the command name (not
 * counting a trailing EOL). In the NAME case, the 'void*' argument must be a
 * string buffer large enough, and it will be populated with the name of the
 * command (WITH a trailing EOL).
 */
# define ENGINE_CTRL_GET_NAME_LEN_FROM_CMD       14
# define ENGINE_CTRL_GET_NAME_FROM_CMD           15
/* The next two are similar but give a "short description" of a command. */
# define ENGINE_CTRL_GET_DESC_LEN_FROM_CMD       16
# define ENGINE_CTRL_GET_DESC_FROM_CMD           17
/*
 * With this command, the return value is the OR'd combination of
 * ENGINE_CMD_FLAG_*** values that indicate what kind of input a given
 * engine-specific ctrl command expects.
 */
# define ENGINE_CTRL_GET_CMD_FLAGS               18

/*
 * ENGINE implementations should start the numbering of their own control
 * commands from this value. (ie. ENGINE_CMD_BASE, ENGINE_CMD_BASE + 1, etc).
 */
# define ENGINE_CMD_BASE                         200

/*
 * NB: These 2 nCipher "chil" control commands are deprecated, and their
 * functionality is now available through ENGINE-specific control commands
 * (exposed through the above-mentioned 'CMD'-handling). Code using these 2
 * commands should be migrated to the more general command handling before
 * these are removed.
 */

/* Flags specific to the nCipher "chil" engine */
# define ENGINE_CTRL_CHIL_SET_FORKCHECK          100
        /*
         * Depending on the value of the (long)i argument, this sets or
         * unsets the SimpleForkCheck flag in the CHIL API to enable or
         * disable checking and workarounds for applications that fork().
         */
# define ENGINE_CTRL_CHIL_NO_LOCKING             101
        /*
         * This prevents the initialisation function from providing mutex
         * callbacks to the nCipher library.
         */

/*
 * If an ENGINE supports its own specific control commands and wishes the
 * framework to handle the above 'ENGINE_CMD_***'-manipulation commands on
 * its behalf, it should supply a null-terminated array of ENGINE_CMD_DEFN
 * entries to ENGINE_set_cmd_defns(). It should also implement a ctrl()
 * handler that supports the stated commands (ie. the "cmd_num" entries as
 * described by the array). NB: The array must be ordered in increasing order
 * of cmd_num. "null-terminated" means that the last ENGINE_CMD_DEFN element
 * has cmd_num set to zero and/or cmd_name set to NULL.
 */
typedef struct ENGINE_CMD_DEFN_st {
    unsigned int cmd_num;       /* The command number */
    const char *cmd_name;       /* The command name itself */
    const char *cmd_desc;       /* A short description of the command */
    unsigned int cmd_flags;     /* The input the command expects */
} ENGINE_CMD_DEFN;

/* Generic function pointer */
typedef int (*ENGINE_GEN_FUNC_PTR) (void);
/* Generic function pointer taking no arguments */
typedef int (*ENGINE_GEN_INT_FUNC_PTR) (ENGINE *);
/* Specific control function pointer */
typedef int (*ENGINE_CTRL_FUNC_PTR) (ENGINE *, int, long, void *,
                                     void (*f) (void));
/* Generic load_key function pointer */
typedef EVP_PKEY *(*ENGINE_LOAD_KEY_PTR)(ENGINE *, const char *,
                                         UI_METHOD *ui_method,
                                         void *callback_data);
typedef int (*ENGINE_SSL_CLIENT_CERT_PTR) (ENGINE *, SSL *ssl,
                                           STACK_OF(X509_NAME) *ca_dn,
                                           X509 **pcert, EVP_PKEY **pkey,
                                           STACK_OF(X509) **pother,
                                           UI_METHOD *ui_method,
                                           void *callback_data);
/*-
 * These callback types are for an ENGINE's handler for cipher and digest logic.
 * These handlers have these prototypes;
 *   int foo(ENGINE *e, const EVP_CIPHER **cipher, const int **nids, int nid);
 *   int foo(ENGINE *e, const EVP_MD **digest, const int **nids, int nid);
 * Looking at how to implement these handlers in the case of cipher support, if
 * the framework wants the EVP_CIPHER for 'nid', it will call;
 *   foo(e, &p_evp_cipher, NULL, nid);    (return zero for failure)
 * If the framework wants a list of supported 'nid's, it will call;
 *   foo(e, NULL, &p_nids, 0); (returns number of 'nids' or -1 for error)
 */
/*
 * Returns to a pointer to the array of supported cipher 'nid's. If the
 * second parameter is non-NULL it is set to the size of the returned array.
 */
typedef int (*ENGINE_CIPHERS_PTR) (ENGINE *, const EVP_CIPHER **,
                                   const int **, int);
typedef int (*ENGINE_DIGESTS_PTR) (ENGINE *, const EVP_MD **, const int **,
                                   int);
typedef int (*ENGINE_PKEY_METHS_PTR) (ENGINE *, EVP_PKEY_METHOD **,
                                      const int **, int);
typedef int (*ENGINE_PKEY_ASN1_METHS_PTR) (ENGINE *, EVP_PKEY_ASN1_METHOD **,
                                           const int **, int);
/*
 * STRUCTURE functions ... all of these functions deal with pointers to
 * ENGINE structures where the pointers have a "structural reference". This
 * means that their reference is to allowed access to the structure but it
 * does not imply that the structure is functional. To simply increment or
 * decrement the structural reference count, use ENGINE_by_id and
 * ENGINE_free. NB: This is not required when iterating using ENGINE_get_next
 * as it will automatically decrement the structural reference count of the
 * "current" ENGINE and increment the structural reference count of the
 * ENGINE it returns (unless it is NULL).
 */

/* Get the first/last "ENGINE" type available. */
ENGINE *ENGINE_get_first(void);
ENGINE *ENGINE_get_last(void);
/* Iterate to the next/previous "ENGINE" type (NULL = end of the list). */
ENGINE *ENGINE_get_next(ENGINE *e);
ENGINE *ENGINE_get_prev(ENGINE *e);
/* Add another "ENGINE" type into the array. */
int ENGINE_add(ENGINE *e);
/* Remove an existing "ENGINE" type from the array. */
int ENGINE_remove(ENGINE *e);
/* Retrieve an engine from the list by its unique "id" value. */
ENGINE *ENGINE_by_id(const char *id);

#if OPENSSL_API_COMPAT < 0x10100000L
# define ENGINE_load_openssl() \
    OPENSSL_init_crypto(OPENSSL_INIT_ENGINE_OPENSSL, NULL)
# define ENGINE_load_dynamic() \
    OPENSSL_init_crypto(OPENSSL_INIT_ENGINE_DYNAMIC, NULL)
# ifndef OPENSSL_NO_STATIC_ENGINE
#  define ENGINE_load_padlock() \
    OPENSSL_init_crypto(OPENSSL_INIT_ENGINE_PADLOCK, NULL)
#  define ENGINE_load_capi() \
    OPENSSL_init_crypto(OPENSSL_INIT_ENGINE_CAPI, NULL)
#  define ENGINE_load_afalg() \
    OPENSSL_init_crypto(OPENSSL_INIT_ENGINE_AFALG, NULL)
# endif
# define ENGINE_load_cryptodev() \
    OPENSSL_init_crypto(OPENSSL_INIT_ENGINE_CRYPTODEV, NULL)
# define ENGINE_load_rdrand() \
    OPENSSL_init_crypto(OPENSSL_INIT_ENGINE_RDRAND, NULL)
#endif
void ENGINE_load_builtin_engines(void);

/*
 * Get and set global flags (ENGINE_TABLE_FLAG_***) for the implementation
 * "registry" handling.
 */
unsigned int ENGINE_get_table_flags(void);
void ENGINE_set_table_flags(unsigned int flags);

/*- Manage registration of ENGINEs per "table". For each type, there are 3
 * functions;
 *   ENGINE_register_***(e) - registers the implementation from 'e' (if it has one)
 *   ENGINE_unregister_***(e) - unregister the implementation from 'e'
 *   ENGINE_register_all_***() - call ENGINE_register_***() for each 'e' in the list
 * Cleanup is automatically registered from each table when required.
 */

int ENGINE_register_RSA(ENGINE *e);
void ENGINE_unregister_RSA(ENGINE *e);
void ENGINE_register_all_RSA(void);

int ENGINE_register_DSA(ENGINE *e);
void ENGINE_unregister_DSA(ENGINE *e);
void ENGINE_register_all_DSA(void);

int ENGINE_register_EC(ENGINE *e);
void ENGINE_unregister_EC(ENGINE *e);
void ENGINE_register_all_EC(void);

int ENGINE_register_DH(ENGINE *e);
void ENGINE_unregister_DH(ENGINE *e);
void ENGINE_register_all_DH(void);

int ENGINE_register_RAND(ENGINE *e);
void ENGINE_unregister_RAND(ENGINE *e);
void ENGINE_register_all_RAND(void);

int ENGINE_register_ciphers(ENGINE *e);
void ENGINE_unregister_ciphers(ENGINE *e);
void ENGINE_register_all_ciphers(void);

int ENGINE_register_digests(ENGINE *e);
void ENGINE_unregister_digests(ENGINE *e);
void ENGINE_register_all_digests(void);

int ENGINE_register_pkey_meths(ENGINE *e);
void ENGINE_unregister_pkey_meths(ENGINE *e);
void ENGINE_register_all_pkey_meths(void);

int ENGINE_register_pkey_asn1_meths(ENGINE *e);
void ENGINE_unregister_pkey_asn1_meths(ENGINE *e);
void ENGINE_register_all_pkey_asn1_meths(void);

/*
 * These functions register all support from the above categories. Note, use
 * of these functions can result in static linkage of code your application
 * may not need. If you only need a subset of functionality, consider using
 * more selective initialisation.
 */
int ENGINE_register_complete(ENGINE *e);
int ENGINE_register_all_complete(void);

/*
 * Send parameterised control commands to the engine. The possibilities to
 * send down an integer, a pointer to data or a function pointer are
 * provided. Any of the parameters may or may not be NULL, depending on the
 * command number. In actuality, this function only requires a structural
 * (rather than functional) reference to an engine, but many control commands
 * may require the engine be functional. The caller should be aware of trying
 * commands that require an operational ENGINE, and only use functional
 * references in such situations.
 */
int ENGINE_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void));

/*
 * This function tests if an ENGINE-specific command is usable as a
 * "setting". Eg. in an application's config file that gets processed through
 * ENGINE_ctrl_cmd_string(). If this returns zero, it is not available to
 * ENGINE_ctrl_cmd_string(), only ENGINE_ctrl().
 */
int ENGINE_cmd_is_executable(ENGINE *e, int cmd);

/*
 * This function works like ENGINE_ctrl() with the exception of taking a
 * command name instead of a command number, and can handle optional
 * commands. See the comment on ENGINE_ctrl_cmd_string() for an explanation
 * on how to use the cmd_name and cmd_optional.
 */
int ENGINE_ctrl_cmd(ENGINE *e, const char *cmd_name,
                    long i, void *p, void (*f) (void), int cmd_optional);

/*
 * This function passes a command-name and argument to an ENGINE. The
 * cmd_name is converted to a command number and the control command is
 * called using 'arg' as an argument (unless the ENGINE doesn't support such
 * a command, in which case no control command is called). The command is
 * checked for input flags, and if necessary the argument will be converted
 * to a numeric value. If cmd_optional is non-zero, then if the ENGINE
 * doesn't support the given cmd_name the return value will be success
 * anyway. This function is intended for applications to use so that users
 * (or config files) can supply engine-specific config data to the ENGINE at
 * run-time to control behaviour of specific engines. As such, it shouldn't
 * be used for calling ENGINE_ctrl() functions that return data, deal with
 * binary data, or that are otherwise supposed to be used directly through
 * ENGINE_ctrl() in application code. Any "return" data from an ENGINE_ctrl()
 * operation in this function will be lost - the return value is interpreted
 * as failure if the return value is zero, success otherwise, and this
 * function returns a boolean value as a result. In other words, vendors of
 * 'ENGINE'-enabled devices should write ENGINE implementations with
 * parameterisations that work in this scheme, so that compliant ENGINE-based
 * applications can work consistently with the same configuration for the
 * same ENGINE-enabled devices, across applications.
 */
int ENGINE_ctrl_cmd_string(ENGINE *e, const char *cmd_name, const char *arg,
                           int cmd_optional);

/*
 * These functions are useful for manufacturing new ENGINE structures. They
 * don't address reference counting at all - one uses them to populate an
 * ENGINE structure with personalised implementations of things prior to
 * using it directly or adding it to the builtin ENGINE list in OpenSSL.
 * These are also here so that the ENGINE structure doesn't have to be
 * exposed and break binary compatibility!
 */
ENGINE *ENGINE_new(void);
int ENGINE_free(ENGINE *e);
int ENGINE_up_ref(ENGINE *e);
int ENGINE_set_id(ENGINE *e, const char *id);
int ENGINE_set_name(ENGINE *e, const char *name);
int ENGINE_set_RSA(ENGINE *e, const RSA_METHOD *rsa_meth);
int ENGINE_set_DSA(ENGINE *e, const DSA_METHOD *dsa_meth);
int ENGINE_set_EC(ENGINE *e, const EC_KEY_METHOD *ecdsa_meth);
int ENGINE_set_DH(ENGINE *e, const DH_METHOD *dh_meth);
int ENGINE_set_RAND(ENGINE *e, const RAND_METHOD *rand_meth);
int ENGINE_set_destroy_function(ENGINE *e, ENGINE_GEN_INT_FUNC_PTR destroy_f);
int ENGINE_set_init_function(ENGINE *e, ENGINE_GEN_INT_FUNC_PTR init_f);
int ENGINE_set_finish_function(ENGINE *e, ENGINE_GEN_INT_FUNC_PTR finish_f);
int ENGINE_set_ctrl_function(ENGINE *e, ENGINE_CTRL_FUNC_PTR ctrl_f);
int ENGINE_set_load_privkey_function(ENGINE *e,
                                     ENGINE_LOAD_KEY_PTR loadpriv_f);
int ENGINE_set_load_pubkey_function(ENGINE *e, ENGINE_LOAD_KEY_PTR loadpub_f);
int ENGINE_set_load_ssl_client_cert_function(ENGINE *e,
                                             ENGINE_SSL_CLIENT_CERT_PTR
                                             loadssl_f);
int ENGINE_set_ciphers(ENGINE *e, ENGINE_CIPHERS_PTR f);
int ENGINE_set_digests(ENGINE *e, ENGINE_DIGESTS_PTR f);
int ENGINE_set_pkey_meths(ENGINE *e, ENGINE_PKEY_METHS_PTR f);
int ENGINE_set_pkey_asn1_meths(ENGINE *e, ENGINE_PKEY_ASN1_METHS_PTR f);
int ENGINE_set_flags(ENGINE *e, int flags);
int ENGINE_set_cmd_defns(ENGINE *e, const ENGINE_CMD_DEFN *defns);
/* These functions allow control over any per-structure ENGINE data. */
#define ENGINE_get_ex_new_index(l, p, newf, dupf, freef) \
    CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_ENGINE, l, p, newf, dupf, freef)
int ENGINE_set_ex_data(ENGINE *e, int idx, void *arg);
void *ENGINE_get_ex_data(const ENGINE *e, int idx);

#if OPENSSL_API_COMPAT < 0x10100000L
/*
 * This function previously cleaned up anything that needs it. Auto-deinit will
 * now take care of it so it is no longer required to call this function.
 */
# define ENGINE_cleanup() while(0) continue
#endif

/*
 * These return values from within the ENGINE structure. These can be useful
 * with functional references as well as structural references - it depends
 * which you obtained. Using the result for functional purposes if you only
 * obtained a structural reference may be problematic!
 */
const char *ENGINE_get_id(const ENGINE *e);
const char *ENGINE_get_name(const ENGINE *e);
const RSA_METHOD *ENGINE_get_RSA(const ENGINE *e);
const DSA_METHOD *ENGINE_get_DSA(const ENGINE *e);
const EC_KEY_METHOD *ENGINE_get_EC(const ENGINE *e);
const DH_METHOD *ENGINE_get_DH(const ENGINE *e);
const RAND_METHOD *ENGINE_get_RAND(const ENGINE *e);
ENGINE_GEN_INT_FUNC_PTR ENGINE_get_destroy_function(const ENGINE *e);
ENGINE_GEN_INT_FUNC_PTR ENGINE_get_init_function(const ENGINE *e);
ENGINE_GEN_INT_FUNC_PTR ENGINE_get_finish_function(const ENGINE *e);
ENGINE_CTRL_FUNC_PTR ENGINE_get_ctrl_function(const ENGINE *e);
ENGINE_LOAD_KEY_PTR ENGINE_get_load_privkey_function(const ENGINE *e);
ENGINE_LOAD_KEY_PTR ENGINE_get_load_pubkey_function(const ENGINE *e);
ENGINE_SSL_CLIENT_CERT_PTR ENGINE_get_ssl_client_cert_function(const ENGINE
                                                               *e);
ENGINE_CIPHERS_PTR ENGINE_get_ciphers(const ENGINE *e);
ENGINE_DIGESTS_PTR ENGINE_get_digests(const ENGINE *e);
ENGINE_PKEY_METHS_PTR ENGINE_get_pkey_meths(const ENGINE *e);
ENGINE_PKEY_ASN1_METHS_PTR ENGINE_get_pkey_asn1_meths(const ENGINE *e);
const EVP_CIPHER *ENGINE_get_cipher(ENGINE *e, int nid);
const EVP_MD *ENGINE_get_digest(ENGINE *e, int nid);
const EVP_PKEY_METHOD *ENGINE_get_pkey_meth(ENGINE *e, int nid);
const EVP_PKEY_ASN1_METHOD *ENGINE_get_pkey_asn1_meth(ENGINE *e, int nid);
const EVP_PKEY_ASN1_METHOD *ENGINE_get_pkey_asn1_meth_str(ENGINE *e,
                                                          const char *str,
                                                          int len);
const EVP_PKEY_ASN1_METHOD *ENGINE_pkey_asn1_find_str(ENGINE **pe,
                                                      const char *str,
                                                      int len);
const ENGINE_CMD_DEFN *ENGINE_get_cmd_defns(const ENGINE *e);
int ENGINE_get_flags(const ENGINE *e);

/*
 * FUNCTIONAL functions. These functions deal with ENGINE structures that
 * have (or will) be initialised for use. Broadly speaking, the structural
 * functions are useful for iterating the list of available engine types,
 * creating new engine types, and other "list" operations. These functions
 * actually deal with ENGINEs that are to be used. As such these functions
 * can fail (if applicable) when particular engines are unavailable - eg. if
 * a hardware accelerator is not attached or not functioning correctly. Each
 * ENGINE has 2 reference counts; structural and functional. Every time a
 * functional reference is obtained or released, a corresponding structural
 * reference is automatically obtained or released too.
 */

/*
 * Initialise a engine type for use (or up its reference count if it's
 * already in use). This will fail if the engine is not currently operational
 * and cannot initialise.
 */
int ENGINE_init(ENGINE *e);
/*
 * Free a functional reference to a engine type. This does not require a
 * corresponding call to ENGINE_free as it also releases a structural
 * reference.
 */
int ENGINE_finish(ENGINE *e);

/*
 * The following functions handle keys that are stored in some secondary
 * location, handled by the engine.  The storage may be on a card or
 * whatever.
 */
EVP_PKEY *ENGINE_load_private_key(ENGINE *e, const char *key_id,
                                  UI_METHOD *ui_method, void *callback_data);
EVP_PKEY *ENGINE_load_public_key(ENGINE *e, const char *key_id,
                                 UI_METHOD *ui_method, void *callback_data);
int ENGINE_load_ssl_client_cert(ENGINE *e, SSL *s,
                                STACK_OF(X509_NAME) *ca_dn, X509 **pcert,
                                EVP_PKEY **ppkey, STACK_OF(X509) **pother,
                                UI_METHOD *ui_method, void *callback_data);

/*
 * This returns a pointer for the current ENGINE structure that is (by
 * default) performing any RSA operations. The value returned is an
 * incremented reference, so it should be free'd (ENGINE_finish) before it is
 * discarded.
 */
ENGINE *ENGINE_get_default_RSA(void);
/* Same for the other "methods" */
ENGINE *ENGINE_get_default_DSA(void);
ENGINE *ENGINE_get_default_EC(void);
ENGINE *ENGINE_get_default_DH(void);
ENGINE *ENGINE_get_default_RAND(void);
/*
 * These functions can be used to get a functional reference to perform
 * ciphering or digesting corresponding to "nid".
 */
ENGINE *ENGINE_get_cipher_engine(int nid);
ENGINE *ENGINE_get_digest_engine(int nid);
ENGINE *ENGINE_get_pkey_meth_engine(int nid);
ENGINE *ENGINE_get_pkey_asn1_meth_engine(int nid);

/*
 * This sets a new default ENGINE structure for performing RSA operations. If
 * the result is non-zero (success) then the ENGINE structure will have had
 * its reference count up'd so the caller should still free their own
 * reference 'e'.
 */
int ENGINE_set_default_RSA(ENGINE *e);
int ENGINE_set_default_string(ENGINE *e, const char *def_list);
/* Same for the other "methods" */
int ENGINE_set_default_DSA(ENGINE *e);
int ENGINE_set_default_EC(ENGINE *e);
int ENGINE_set_default_DH(ENGINE *e);
int ENGINE_set_default_RAND(ENGINE *e);
int ENGINE_set_default_ciphers(ENGINE *e);
int ENGINE_set_default_digests(ENGINE *e);
int ENGINE_set_default_pkey_meths(ENGINE *e);
int ENGINE_set_default_pkey_asn1_meths(ENGINE *e);

/*
 * The combination "set" - the flags are bitwise "OR"d from the
 * ENGINE_METHOD_*** defines above. As with the "ENGINE_register_complete()"
 * function, this function can result in unnecessary static linkage. If your
 * application requires only specific functionality, consider using more
 * selective functions.
 */
int ENGINE_set_default(ENGINE *e, unsigned int flags);

void ENGINE_add_conf_module(void);

/* Deprecated functions ... */
/* int ENGINE_clear_defaults(void); */

/**************************/
/* DYNAMIC ENGINE SUPPORT */
/**************************/

/* Binary/behaviour compatibility levels */
# define OSSL_DYNAMIC_VERSION            (unsigned long)0x00030000
/*
 * Binary versions older than this are too old for us (whether we're a loader
 * or a loadee)
 */
# define OSSL_DYNAMIC_OLDEST             (unsigned long)0x00030000

/*
 * When compiling an ENGINE entirely as an external shared library, loadable
 * by the "dynamic" ENGINE, these types are needed. The 'dynamic_fns'
 * structure type provides the calling application's (or library's) error
 * functionality and memory management function pointers to the loaded
 * library. These should be used/set in the loaded library code so that the
 * loading application's 'state' will be used/changed in all operations. The
 * 'static_state' pointer allows the loaded library to know if it shares the
 * same static data as the calling application (or library), and thus whether
 * these callbacks need to be set or not.
 */
typedef void *(*dyn_MEM_malloc_fn) (size_t, const char *, int);
typedef void *(*dyn_MEM_realloc_fn) (void *, size_t, const char *, int);
typedef void (*dyn_MEM_free_fn) (void *, const char *, int);
typedef struct st_dynamic_MEM_fns {
    dyn_MEM_malloc_fn malloc_fn;
    dyn_MEM_realloc_fn realloc_fn;
    dyn_MEM_free_fn free_fn;
} dynamic_MEM_fns;
/*
 * FIXME: Perhaps the memory and locking code (crypto.h) should declare and
 * use these types so we (and any other dependent code) can simplify a bit??
 */
/* The top-level structure */
typedef struct st_dynamic_fns {
    void *static_state;
    dynamic_MEM_fns mem_fns;
} dynamic_fns;

/*
 * The version checking function should be of this prototype. NB: The
 * ossl_version value passed in is the OSSL_DYNAMIC_VERSION of the loading
 * code. If this function returns zero, it indicates a (potential) version
 * incompatibility and the loaded library doesn't believe it can proceed.
 * Otherwise, the returned value is the (latest) version supported by the
 * loading library. The loader may still decide that the loaded code's
 * version is unsatisfactory and could veto the load. The function is
 * expected to be implemented with the symbol name "v_check", and a default
 * implementation can be fully instantiated with
 * IMPLEMENT_DYNAMIC_CHECK_FN().
 */
typedef unsigned long (*dynamic_v_check_fn) (unsigned long ossl_version);
# define IMPLEMENT_DYNAMIC_CHECK_FN() \
        OPENSSL_EXPORT unsigned long v_check(unsigned long v); \
        OPENSSL_EXPORT unsigned long v_check(unsigned long v) { \
                if (v >= OSSL_DYNAMIC_OLDEST) return OSSL_DYNAMIC_VERSION; \
                return 0; }

/*
 * This function is passed the ENGINE structure to initialise with its own
 * function and command settings. It should not adjust the structural or
 * functional reference counts. If this function returns zero, (a) the load
 * will be aborted, (b) the previous ENGINE state will be memcpy'd back onto
 * the structure, and (c) the shared library will be unloaded. So
 * implementations should do their own internal cleanup in failure
 * circumstances otherwise they could leak. The 'id' parameter, if non-NULL,
 * represents the ENGINE id that the loader is looking for. If this is NULL,
 * the shared library can choose to return failure or to initialise a
 * 'default' ENGINE. If non-NULL, the shared library must initialise only an
 * ENGINE matching the passed 'id'. The function is expected to be
 * implemented with the symbol name "bind_engine". A standard implementation
 * can be instantiated with IMPLEMENT_DYNAMIC_BIND_FN(fn) where the parameter
 * 'fn' is a callback function that populates the ENGINE structure and
 * returns an int value (zero for failure). 'fn' should have prototype;
 * [static] int fn(ENGINE *e, const char *id);
 */
typedef int (*dynamic_bind_engine) (ENGINE *e, const char *id,
                                    const dynamic_fns *fns);
# define IMPLEMENT_DYNAMIC_BIND_FN(fn) \
        OPENSSL_EXPORT \
        int bind_engine(ENGINE *e, const char *id, const dynamic_fns *fns); \
        OPENSSL_EXPORT \
        int bind_engine(ENGINE *e, const char *id, const dynamic_fns *fns) { \
            if (ENGINE_get_static_state() == fns->static_state) goto skip_cbs; \
            CRYPTO_set_mem_functions(fns->mem_fns.malloc_fn, \
                                     fns->mem_fns.realloc_fn, \
                                     fns->mem_fns.free_fn); \
            OPENSSL_init_crypto(OPENSSL_INIT_NO_ATEXIT, NULL); \
        skip_cbs: \
            if (!fn(e, id)) return 0; \
            return 1; }

/*
 * If the loading application (or library) and the loaded ENGINE library
 * share the same static data (eg. they're both dynamically linked to the
 * same libcrypto.so) we need a way to avoid trying to set system callbacks -
 * this would fail, and for the same reason that it's unnecessary to try. If
 * the loaded ENGINE has (or gets from through the loader) its own copy of
 * the libcrypto static data, we will need to set the callbacks. The easiest
 * way to detect this is to have a function that returns a pointer to some
 * static data and let the loading application and loaded ENGINE compare
 * their respective values.
 */
void *ENGINE_get_static_state(void);

# if defined(__OpenBSD__) || defined(__FreeBSD__) || defined(__DragonFly__)
DEPRECATEDIN_1_1_0(void ENGINE_setup_bsd_cryptodev(void))
# endif


#  ifdef  __cplusplus
}
#  endif
# endif
#endif