include/openssl/core.h

   1 /*
   2  * Copyright 2019-2021 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #ifndef OPENSSL_CORE_H
  11 # define OPENSSL_CORE_H
  12 # pragma once
  13
  14 # include <stddef.h>
  15 # include <openssl/types.h>
  16
  17 # ifdef __cplusplus
  18 extern "C" {
  19 # endif
  20
  21 /*-
  22  * Base types
  23  * ----------
  24  *
  25  * These are the types that the OpenSSL core and providers have in common
  26  * to communicate data between them.
  27  */
  28
  29 /* Opaque handles to be used with core upcall functions from providers */
  30 typedef struct ossl_core_handle_st OSSL_CORE_HANDLE;
  31 typedef struct openssl_core_ctx_st OPENSSL_CORE_CTX;
  32 typedef struct ossl_core_bio_st OSSL_CORE_BIO;
  33
  34 /*
  35  * Dispatch table element.  function_id numbers and the functions are defined
  36  * in core_dispatch.h, see macros with 'OSSL_CORE_MAKE_FUNC' in their names.
  37  *
  38  * An array of these is always terminated by function_id == 0
  39  */
  40 struct ossl_dispatch_st {
  41     int function_id;
  42     void (*function)(void);
  43 };
  44
  45 # define OSSL_DISPATCH_END \
  46     { 0, NULL }
  47
  48 /*
  49  * Other items, essentially an int<->pointer map element.
  50  *
  51  * We make this type distinct from OSSL_DISPATCH to ensure that dispatch
  52  * tables remain tables with function pointers only.
  53  *
  54  * This is used whenever we need to pass things like a table of error reason
  55  * codes <-> reason string maps, ...
  56  *
  57  * Usage determines which field works as key if any, rather than field order.
  58  *
  59  * An array of these is always terminated by id == 0 && ptr == NULL
  60  */
  61 struct ossl_item_st {
  62     unsigned int id;
  63     void *ptr;
  64 };
  65
  66 /*
  67  * Type to tie together algorithm names, property definition string and
  68  * the algorithm implementation in the form of a dispatch table.
  69  *
  70  * An array of these is always terminated by algorithm_names == NULL
  71  */
  72 struct ossl_algorithm_st {
  73     const char *algorithm_names;     /* key */
  74     const char *property_definition; /* key */
  75     const OSSL_DISPATCH *implementation;
  76     const char *algorithm_description;
  77 };
  78
  79 /*
  80  * Type to pass object data in a uniform way, without exposing the object
  81  * structure.
  82  *
  83  * An array of these is always terminated by key == NULL
  84  */
  85 struct ossl_param_st {
  86     const char *key;             /* the name of the parameter */
  87     unsigned int data_type;      /* declare what kind of content is in buffer */
  88     void *data;                  /* value being passed in or out */
  89     size_t data_size;            /* data size */
  90     size_t return_size;          /* returned content size */
  91 };
  92
  93 /* Currently supported OSSL_PARAM data types */
  94 /*
  95  * OSSL_PARAM_INTEGER and OSSL_PARAM_UNSIGNED_INTEGER
  96  * are arbitrary length and therefore require an arbitrarily sized buffer,
  97  * since they may be used to pass numbers larger than what is natively
  98  * available.
  99  *
 100  * The number must be buffered in native form, i.e. MSB first on B_ENDIAN
 101  * systems and LSB first on L_ENDIAN systems.  This means that arbitrary
 102  * native integers can be stored in the buffer, just make sure that the
 103  * buffer size is correct and the buffer itself is properly aligned (for
 104  * example by having the buffer field point at a C integer).
 105  */
 106 # define OSSL_PARAM_INTEGER              1
 107 # define OSSL_PARAM_UNSIGNED_INTEGER     2
 108 /*-
 109  * OSSL_PARAM_REAL
 110  * is a C binary floating point values in native form and alignment.
 111  */
 112 # define OSSL_PARAM_REAL                 3
 113 /*-
 114  * OSSL_PARAM_UTF8_STRING
 115  * is a printable string.  It is expected to be printed as it is.
 116  */
 117 # define OSSL_PARAM_UTF8_STRING          4
 118 /*-
 119  * OSSL_PARAM_OCTET_STRING
 120  * is a string of bytes with no further specification.  It is expected to be
 121  * printed as a hexdump.
 122  */
 123 # define OSSL_PARAM_OCTET_STRING         5
 124 /*-
 125  * OSSL_PARAM_UTF8_PTR
 126  * is a pointer to a printable string.  It is expected to be printed as it is.
 127  *
 128  * The difference between this and OSSL_PARAM_UTF8_STRING is that only pointers
 129  * are manipulated for this type.
 130  *
 131  * This is more relevant for parameter requests, where the responding
 132  * function doesn't need to copy the data to the provided buffer, but
 133  * sets the provided buffer to point at the actual data instead.
 134  *
 135  * WARNING!  Using these is FRAGILE, as it assumes that the actual
 136  * data and its location are constant.
 137  *
 138  * EXTRA WARNING!  If you are not completely sure you most likely want
 139  * to use the OSSL_PARAM_UTF8_STRING type.
 140  */
 141 # define OSSL_PARAM_UTF8_PTR             6
 142 /*-
 143  * OSSL_PARAM_OCTET_PTR
 144  * is a pointer to a string of bytes with no further specification.  It is
 145  * expected to be printed as a hexdump.
 146  *
 147  * The difference between this and OSSL_PARAM_OCTET_STRING is that only pointers
 148  * are manipulated for this type.
 149  *
 150  * This is more relevant for parameter requests, where the responding
 151  * function doesn't need to copy the data to the provided buffer, but
 152  * sets the provided buffer to point at the actual data instead.
 153  *
 154  * WARNING!  Using these is FRAGILE, as it assumes that the actual
 155  * data and its location are constant.
 156  *
 157  * EXTRA WARNING!  If you are not completely sure you most likely want
 158  * to use the OSSL_PARAM_OCTET_STRING type.
 159  */
 160 # define OSSL_PARAM_OCTET_PTR            7
 161
 162 /*
 163  * Typedef for the thread stop handling callback. Used both internally and by
 164  * providers.
 165  *
 166  * Providers may register for notifications about threads stopping by
 167  * registering a callback to hear about such events. Providers register the
 168  * callback using the OSSL_FUNC_CORE_THREAD_START function in the |in| dispatch
 169  * table passed to OSSL_provider_init(). The arg passed back to a provider will
 170  * be the provider side context object.
 171  */
 172 typedef void (*OSSL_thread_stop_handler_fn)(void *arg);
 173
 174
 175 /*-
 176  * Provider entry point
 177  * --------------------
 178  *
 179  * This function is expected to be present in any dynamically loadable
 180  * provider module.  By definition, if this function doesn't exist in a
 181  * module, that module is not an OpenSSL provider module.
 182  */
 183 /*-
 184  * |handle|     pointer to opaque type OSSL_CORE_HANDLE.  This can be used
 185  *              together with some functions passed via |in| to query data.
 186  * |in|         is the array of functions that the Core passes to the provider.
 187  * |out|        will be the array of base functions that the provider passes
 188  *              back to the Core.
 189  * |provctx|    a provider side context object, optionally created if the
 190  *              provider needs it.  This value is passed to other provider
 191  *              functions, notably other context constructors.
 192  */
 193 typedef int (OSSL_provider_init_fn)(const OSSL_CORE_HANDLE *handle,
 194                                     const OSSL_DISPATCH *in,
 195                                     const OSSL_DISPATCH **out,
 196                                     void **provctx);
 197 # ifdef __VMS
 198 #  pragma names save
 199 #  pragma names uppercase,truncated
 200 # endif
 201 OPENSSL_EXPORT OSSL_provider_init_fn OSSL_provider_init;
 202 # ifdef __VMS
 203 #  pragma names restore
 204 # endif
 205
 206 /*
 207  * Generic callback function signature.
 208  *
 209  * The expectation is that any provider function that wants to offer
 210  * a callback / hook can do so by taking an argument with this type,
 211  * as well as a pointer to caller-specific data.  When calling the
 212  * callback, the provider function can populate an OSSL_PARAM array
 213  * with data of its choice and pass that in the callback call, along
 214  * with the caller data argument.
 215  *
 216  * libcrypto may use the OSSL_PARAM array to create arguments for an
 217  * application callback it knows about.
 218  */
 219 typedef int (OSSL_CALLBACK)(const OSSL_PARAM params[], void *arg);
 220 typedef int (OSSL_INOUT_CALLBACK)(const OSSL_PARAM in_params[],
 221                                   OSSL_PARAM out_params[], void *arg);
 222 /*
 223  * Passphrase callback function signature
 224  *
 225  * This is similar to the generic callback function above, but adds a
 226  * result parameter.
 227  */
 228 typedef int (OSSL_PASSPHRASE_CALLBACK)(char *pass, size_t pass_size,
 229                                        size_t *pass_len,
 230                                        const OSSL_PARAM params[], void *arg);
 231
 232 # ifdef __cplusplus
 233 }
 234 # endif
 235
 236 #endif