1/* Copyright (c) 2014, Google Inc.
2 *
3 * Permission to use, copy, modify, and/or distribute this software for any
4 * purpose with or without fee is hereby granted, provided that the above
5 * copyright notice and this permission notice appear in all copies.
6 *
7 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
10 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
14
15#ifndef OPENSSL_HEADER_ENGINE_H
16#define OPENSSL_HEADER_ENGINE_H
17
18#include <openssl/base.h>
19
20#if defined(__cplusplus)
21extern "C" {
22#endif
23
24
25// Engines are collections of methods. Methods are tables of function pointers,
26// defined for certain algorithms, that allow operations on those algorithms to
27// be overridden via a callback. This can be used, for example, to implement an
28// RSA* that forwards operations to a hardware module.
29//
30// Methods are reference counted but |ENGINE|s are not. When creating a method,
31// you should zero the whole structure and fill in the function pointers that
32// you wish before setting it on an |ENGINE|. Any functions pointers that
33// are NULL indicate that the default behaviour should be used.
34
35
36// Allocation and destruction.
37
38// ENGINE_new returns an empty ENGINE that uses the default method for all
39// algorithms.
40OPENSSL_EXPORT ENGINE *ENGINE_new(void);
41
42// ENGINE_free decrements the reference counts for all methods linked from
43// |engine| and frees |engine| itself. It returns one.
44OPENSSL_EXPORT int ENGINE_free(ENGINE *engine);
45
46
47// Method accessors.
48//
49// Method accessors take a method pointer and the size of the structure. The
50// size allows for ABI compatibility in the case that the method structure is
51// extended with extra elements at the end. Methods are always copied by the
52// set functions.
53//
54// Set functions return one on success and zero on allocation failure.
55
56OPENSSL_EXPORT int ENGINE_set_RSA_method(ENGINE *engine,
57 const RSA_METHOD *method,
58 size_t method_size);
59OPENSSL_EXPORT RSA_METHOD *ENGINE_get_RSA_method(const ENGINE *engine);
60
61OPENSSL_EXPORT int ENGINE_set_ECDSA_method(ENGINE *engine,
62 const ECDSA_METHOD *method,
63 size_t method_size);
64OPENSSL_EXPORT ECDSA_METHOD *ENGINE_get_ECDSA_method(const ENGINE *engine);
65
66
67// Generic method functions.
68//
69// These functions take a void* type but actually operate on all method
70// structures.
71
72// METHOD_ref increments the reference count of |method|. This is a no-op for
73// now because all methods are currently static.
74void METHOD_ref(void *method);
75
76// METHOD_unref decrements the reference count of |method| and frees it if the
77// reference count drops to zero. This is a no-op for now because all methods
78// are currently static.
79void METHOD_unref(void *method);
80
81
82// Private functions.
83
84// openssl_method_common_st contains the common part of all method structures.
85// This must be the first member of all method structures.
86struct openssl_method_common_st {
87 int references; // dummy – not used.
88 char is_static;
89};
90
91
92#if defined(__cplusplus)
93} // extern C
94
95extern "C++" {
96
97BSSL_NAMESPACE_BEGIN
98
99BORINGSSL_MAKE_DELETER(ENGINE, ENGINE_free)
100
101BSSL_NAMESPACE_END
102
103} // extern C++
104
105#endif
106
107#define ENGINE_R_OPERATION_NOT_SUPPORTED 100
108
109#endif // OPENSSL_HEADER_ENGINE_H
110