xref: /freebsd/contrib/bearssl/inc/bearssl.h (revision 9c474dc51b0b09ff81339caee6772e454dd470e4)
10957b409SSimon J. Gerraty /*
20957b409SSimon J. Gerraty  * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
30957b409SSimon J. Gerraty  *
40957b409SSimon J. Gerraty  * Permission is hereby granted, free of charge, to any person obtaining
50957b409SSimon J. Gerraty  * a copy of this software and associated documentation files (the
60957b409SSimon J. Gerraty  * "Software"), to deal in the Software without restriction, including
70957b409SSimon J. Gerraty  * without limitation the rights to use, copy, modify, merge, publish,
80957b409SSimon J. Gerraty  * distribute, sublicense, and/or sell copies of the Software, and to
90957b409SSimon J. Gerraty  * permit persons to whom the Software is furnished to do so, subject to
100957b409SSimon J. Gerraty  * the following conditions:
110957b409SSimon J. Gerraty  *
120957b409SSimon J. Gerraty  * The above copyright notice and this permission notice shall be
130957b409SSimon J. Gerraty  * included in all copies or substantial portions of the Software.
140957b409SSimon J. Gerraty  *
150957b409SSimon J. Gerraty  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
160957b409SSimon J. Gerraty  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
170957b409SSimon J. Gerraty  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
180957b409SSimon J. Gerraty  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
190957b409SSimon J. Gerraty  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
200957b409SSimon J. Gerraty  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
210957b409SSimon J. Gerraty  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
220957b409SSimon J. Gerraty  * SOFTWARE.
230957b409SSimon J. Gerraty  */
240957b409SSimon J. Gerraty 
250957b409SSimon J. Gerraty #ifndef BR_BEARSSL_H__
260957b409SSimon J. Gerraty #define BR_BEARSSL_H__
270957b409SSimon J. Gerraty 
280957b409SSimon J. Gerraty #include <stddef.h>
290957b409SSimon J. Gerraty #include <stdint.h>
300957b409SSimon J. Gerraty 
310957b409SSimon J. Gerraty /** \mainpage BearSSL API
320957b409SSimon J. Gerraty  *
330957b409SSimon J. Gerraty  * # API Layout
340957b409SSimon J. Gerraty  *
350957b409SSimon J. Gerraty  * The functions and structures defined by the BearSSL API are located
360957b409SSimon J. Gerraty  * in various header files:
370957b409SSimon J. Gerraty  *
380957b409SSimon J. Gerraty  * | Header file     | Elements                                          |
390957b409SSimon J. Gerraty  * | :-------------- | :------------------------------------------------ |
400957b409SSimon J. Gerraty  * | bearssl_hash.h  | Hash functions                                    |
410957b409SSimon J. Gerraty  * | bearssl_hmac.h  | HMAC                                              |
420957b409SSimon J. Gerraty  * | bearssl_kdf.h   | Key Derivation Functions                          |
430957b409SSimon J. Gerraty  * | bearssl_rand.h  | Pseudorandom byte generators                      |
440957b409SSimon J. Gerraty  * | bearssl_prf.h   | PRF implementations (for SSL/TLS)                 |
450957b409SSimon J. Gerraty  * | bearssl_block.h | Symmetric encryption                              |
460957b409SSimon J. Gerraty  * | bearssl_aead.h  | AEAD algorithms (combined encryption + MAC)       |
470957b409SSimon J. Gerraty  * | bearssl_rsa.h   | RSA encryption and signatures                     |
480957b409SSimon J. Gerraty  * | bearssl_ec.h    | Elliptic curves support (including ECDSA)         |
490957b409SSimon J. Gerraty  * | bearssl_ssl.h   | SSL/TLS engine interface                          |
500957b409SSimon J. Gerraty  * | bearssl_x509.h  | X.509 certificate decoding and validation         |
510957b409SSimon J. Gerraty  * | bearssl_pem.h   | Base64/PEM decoding support functions             |
520957b409SSimon J. Gerraty  *
530957b409SSimon J. Gerraty  * Applications using BearSSL are supposed to simply include `bearssl.h`
540957b409SSimon J. Gerraty  * as follows:
550957b409SSimon J. Gerraty  *
560957b409SSimon J. Gerraty  *     #include <bearssl.h>
570957b409SSimon J. Gerraty  *
580957b409SSimon J. Gerraty  * The `bearssl.h` file itself includes all the other header files. It is
590957b409SSimon J. Gerraty  * possible to include specific header files, but it has no practical
600957b409SSimon J. Gerraty  * advantage for the application. The API is separated into separate
610957b409SSimon J. Gerraty  * header files only for documentation convenience.
620957b409SSimon J. Gerraty  *
630957b409SSimon J. Gerraty  *
640957b409SSimon J. Gerraty  * # Conventions
650957b409SSimon J. Gerraty  *
660957b409SSimon J. Gerraty  * ## MUST and SHALL
670957b409SSimon J. Gerraty  *
680957b409SSimon J. Gerraty  * In all descriptions, the usual "MUST", "SHALL", "MAY",... terminology
690957b409SSimon J. Gerraty  * is used. Failure to meet requirements expressed with a "MUST" or
700957b409SSimon J. Gerraty  * "SHALL" implies undefined behaviour, which means that segmentation
710957b409SSimon J. Gerraty  * faults, buffer overflows, and other similar adverse events, may occur.
720957b409SSimon J. Gerraty  *
730957b409SSimon J. Gerraty  * In general, BearSSL is not very forgiving of programming errors, and
740957b409SSimon J. Gerraty  * does not include much failsafes or error reporting when the problem
750957b409SSimon J. Gerraty  * does not arise from external transient conditions, and can be fixed
760957b409SSimon J. Gerraty  * only in the application code. This is done so in order to make the
770957b409SSimon J. Gerraty  * total code footprint lighter.
780957b409SSimon J. Gerraty  *
790957b409SSimon J. Gerraty  *
800957b409SSimon J. Gerraty  * ## `NULL` values
810957b409SSimon J. Gerraty  *
820957b409SSimon J. Gerraty  * Function parameters with a pointer type shall not be `NULL` unless
830957b409SSimon J. Gerraty  * explicitly authorised by the documentation. As an exception, when
840957b409SSimon J. Gerraty  * the pointer aims at a sequence of bytes and is accompanied with
850957b409SSimon J. Gerraty  * a length parameter, and the length is zero (meaning that there is
860957b409SSimon J. Gerraty  * no byte at all to retrieve), then the pointer may be `NULL` even if
870957b409SSimon J. Gerraty  * not explicitly allowed.
880957b409SSimon J. Gerraty  *
890957b409SSimon J. Gerraty  *
900957b409SSimon J. Gerraty  * ## Memory Allocation
910957b409SSimon J. Gerraty  *
920957b409SSimon J. Gerraty  * BearSSL does not perform dynamic memory allocation. This implies that
930957b409SSimon J. Gerraty  * for any functionality that requires a non-transient state, the caller
940957b409SSimon J. Gerraty  * is responsible for allocating the relevant context structure. Such
950957b409SSimon J. Gerraty  * allocation can be done in any appropriate area, including static data
960957b409SSimon J. Gerraty  * segments, the heap, and the stack, provided that proper alignment is
970957b409SSimon J. Gerraty  * respected. The header files define these context structures
980957b409SSimon J. Gerraty  * (including size and contents), so the C compiler should handle
990957b409SSimon J. Gerraty  * alignment automatically.
1000957b409SSimon J. Gerraty  *
1010957b409SSimon J. Gerraty  * Since there is no dynamic resource allocation, there is also nothing to
1020957b409SSimon J. Gerraty  * release. When the calling code is done with a BearSSL feature, it
1030957b409SSimon J. Gerraty  * may simple release the context structures it allocated itself, with
1040957b409SSimon J. Gerraty  * no "close function" to call. If the context structures were allocated
1050957b409SSimon J. Gerraty  * on the stack (as local variables), then even that release operation is
1060957b409SSimon J. Gerraty  * implicit.
1070957b409SSimon J. Gerraty  *
1080957b409SSimon J. Gerraty  *
1090957b409SSimon J. Gerraty  * ## Structure Contents
1100957b409SSimon J. Gerraty  *
1110957b409SSimon J. Gerraty  * Except when explicitly indicated, structure contents are opaque: they
1120957b409SSimon J. Gerraty  * are included in the header files so that calling code may know the
1130957b409SSimon J. Gerraty  * structure sizes and alignment requirements, but callers SHALL NOT
1140957b409SSimon J. Gerraty  * access individual fields directly. For fields that are supposed to
1150957b409SSimon J. Gerraty  * be read from or written to, the API defines accessor functions (the
1160957b409SSimon J. Gerraty  * simplest of these accessor functions are defined as `static inline`
1170957b409SSimon J. Gerraty  * functions, and the C compiler will optimise them away).
1180957b409SSimon J. Gerraty  *
1190957b409SSimon J. Gerraty  *
1200957b409SSimon J. Gerraty  * # API Usage
1210957b409SSimon J. Gerraty  *
1220957b409SSimon J. Gerraty  * BearSSL usage for running a SSL/TLS client or server is described
1230957b409SSimon J. Gerraty  * on the [BearSSL Web site](https://www.bearssl.org/api1.html). The
1240957b409SSimon J. Gerraty  * BearSSL source archive also comes with sample code.
1250957b409SSimon J. Gerraty  */
1260957b409SSimon J. Gerraty 
1270957b409SSimon J. Gerraty #include "bearssl_hash.h"
1280957b409SSimon J. Gerraty #include "bearssl_hmac.h"
1290957b409SSimon J. Gerraty #include "bearssl_kdf.h"
1300957b409SSimon J. Gerraty #include "bearssl_rand.h"
1310957b409SSimon J. Gerraty #include "bearssl_prf.h"
1320957b409SSimon J. Gerraty #include "bearssl_block.h"
1330957b409SSimon J. Gerraty #include "bearssl_aead.h"
1340957b409SSimon J. Gerraty #include "bearssl_rsa.h"
1350957b409SSimon J. Gerraty #include "bearssl_ec.h"
1360957b409SSimon J. Gerraty #include "bearssl_ssl.h"
1370957b409SSimon J. Gerraty #include "bearssl_x509.h"
1380957b409SSimon J. Gerraty #include "bearssl_pem.h"
1390957b409SSimon J. Gerraty 
140*9c474dc5SSimon J. Gerraty #ifdef __cplusplus
141*9c474dc5SSimon J. Gerraty extern "C" {
142*9c474dc5SSimon J. Gerraty #endif
143*9c474dc5SSimon J. Gerraty 
1440957b409SSimon J. Gerraty /** \brief Type for a configuration option.
1450957b409SSimon J. Gerraty  *
1460957b409SSimon J. Gerraty  * A "configuration option" is a value that is selected when the BearSSL
1470957b409SSimon J. Gerraty  * library itself is compiled. Most options are boolean; their value is
1480957b409SSimon J. Gerraty  * then either 1 (option is enabled) or 0 (option is disabled). Some
1490957b409SSimon J. Gerraty  * values have other integer values. Option names correspond to macro
1500957b409SSimon J. Gerraty  * names. Some of the options can be explicitly set in the internal
1510957b409SSimon J. Gerraty  * `"config.h"` file.
1520957b409SSimon J. Gerraty  */
1530957b409SSimon J. Gerraty typedef struct {
1540957b409SSimon J. Gerraty 	/** \brief Configurable option name. */
1550957b409SSimon J. Gerraty 	const char *name;
1560957b409SSimon J. Gerraty 	/** \brief Configurable option value. */
1570957b409SSimon J. Gerraty 	long value;
1580957b409SSimon J. Gerraty } br_config_option;
1590957b409SSimon J. Gerraty 
1600957b409SSimon J. Gerraty /** \brief Get configuration report.
1610957b409SSimon J. Gerraty  *
1620957b409SSimon J. Gerraty  * This function returns compiled configuration options, each as a
1630957b409SSimon J. Gerraty  * 'long' value. Names match internal macro names, in particular those
1640957b409SSimon J. Gerraty  * that can be set in the `"config.h"` inner file. For boolean options,
1650957b409SSimon J. Gerraty  * the numerical value is 1 if enabled, 0 if disabled. For maximum
1660957b409SSimon J. Gerraty  * key sizes, values are expressed in bits.
1670957b409SSimon J. Gerraty  *
1680957b409SSimon J. Gerraty  * The returned array is terminated by an entry whose `name` is `NULL`.
1690957b409SSimon J. Gerraty  *
1700957b409SSimon J. Gerraty  * \return  the configuration report.
1710957b409SSimon J. Gerraty  */
1720957b409SSimon J. Gerraty const br_config_option *br_get_config(void);
1730957b409SSimon J. Gerraty 
174*9c474dc5SSimon J. Gerraty /* ======================================================================= */
175*9c474dc5SSimon J. Gerraty 
176*9c474dc5SSimon J. Gerraty /** \brief Version feature: support for time callback. */
177*9c474dc5SSimon J. Gerraty #define BR_FEATURE_X509_TIME_CALLBACK   1
178*9c474dc5SSimon J. Gerraty 
179*9c474dc5SSimon J. Gerraty #ifdef __cplusplus
180*9c474dc5SSimon J. Gerraty }
181*9c474dc5SSimon J. Gerraty #endif
182*9c474dc5SSimon J. Gerraty 
1830957b409SSimon J. Gerraty #endif
184