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) 21 extern "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. */ 40 OPENSSL_EXPORT ENGINE *ENGINE_new(void); 41 42 /* ENGINE_free decrements the reference counts for all methods linked from 43 * |engine| and frees |engine| itself. */ 44 OPENSSL_EXPORT void 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 56 OPENSSL_EXPORT int ENGINE_set_DH_method(ENGINE *engine, const DH_METHOD *method, 57 size_t method_size); 58 OPENSSL_EXPORT DH_METHOD *ENGINE_get_DH_method(const ENGINE *engine); 59 60 OPENSSL_EXPORT int ENGINE_set_DSA_method(ENGINE *engine, 61 const DSA_METHOD *method, 62 size_t method_size); 63 OPENSSL_EXPORT DSA_METHOD *ENGINE_get_DSA_method(const ENGINE *engine); 64 65 OPENSSL_EXPORT int ENGINE_set_RSA_method(ENGINE *engine, 66 const RSA_METHOD *method, 67 size_t method_size); 68 OPENSSL_EXPORT RSA_METHOD *ENGINE_get_RSA_method(const ENGINE *engine); 69 70 OPENSSL_EXPORT int ENGINE_set_ECDSA_method(ENGINE *engine, 71 const ECDSA_METHOD *method, 72 size_t method_size); 73 OPENSSL_EXPORT ECDSA_METHOD *ENGINE_get_ECDSA_method(const ENGINE *engine); 74 75 76 /* Generic method functions. 77 * 78 * These functions take a void* type but actually operate on all method 79 * structures. */ 80 81 /* METHOD_ref increments the reference count of |method|. This is a no-op for 82 * now because all methods are currently static. */ 83 void METHOD_ref(void *method); 84 85 /* METHOD_unref decrements the reference count of |method| and frees it if the 86 * reference count drops to zero. This is a no-op for now because all methods 87 * are currently static. */ 88 void METHOD_unref(void *method); 89 90 91 /* Private functions. */ 92 93 /* openssl_method_common_st contains the common part of all method structures. 94 * This must be the first member of all method structures. */ 95 struct openssl_method_common_st { 96 int references; /* dummy – not used. */ 97 char is_static; 98 }; 99 100 101 #if defined(__cplusplus) 102 } /* extern C */ 103 #endif 104 105 #define ENGINE_R_OPERATION_NOT_SUPPORTED 100 106 107 #endif /* OPENSSL_HEADER_ENGINE_H */ 108