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. It returns one. 44 OPENSSL_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 56 OPENSSL_EXPORT int ENGINE_set_RSA_method(ENGINE *engine, 57 const RSA_METHOD *method, 58 size_t method_size); 59 OPENSSL_EXPORT RSA_METHOD *ENGINE_get_RSA_method(const ENGINE *engine); 60 61 OPENSSL_EXPORT int ENGINE_set_ECDSA_method(ENGINE *engine, 62 const ECDSA_METHOD *method, 63 size_t method_size); 64 OPENSSL_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. 74 void 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. 79 void 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. 86 struct 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 95 extern "C++" { 96 97 BSSL_NAMESPACE_BEGIN 98 99 BORINGSSL_MAKE_DELETER(ENGINE, ENGINE_free) 100 101 BSSL_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