X-Git-Url: https://bearssl.org/gitweb//home/git/?p=BearSSL;a=blobdiff_plain;f=inc%2Fbearssl.h;h=34367894f04a7c8cbe9baeb9a1b7ed0f1a9e005d;hp=c11080e8b9807d499e4ee357db25518b9edca40f;hb=127fb4a31d24e58fa8e04a154c6e87a2cb28245b;hpb=3210f38e0491b39aec1ef419cb4114e9483089fb;ds=sidebyside diff --git a/inc/bearssl.h b/inc/bearssl.h index c11080e..3436789 100644 --- a/inc/bearssl.h +++ b/inc/bearssl.h @@ -28,11 +28,106 @@ #include #include +/** \mainpage BearSSL API + * + * # API Layout + * + * The functions and structures defined by the BearSSL API are located + * in various header files: + * + * | Header file | Elements | + * | :-------------- | :------------------------------------------------ | + * | bearssl_hash.h | Hash functions | + * | bearssl_hmac.h | HMAC | + * | bearssl_rand.h | Pseudorandom byte generators | + * | bearssl_prf.h | PRF implementations (for SSL/TLS) | + * | bearssl_block.h | Symmetric encryption | + * | bearssl_rsa.h | RSA encryption and signatures | + * | bearssl_ec.h | Elliptic curves support (including ECDSA) | + * | bearssl_ssl.h | SSL/TLS engine interface | + * | bearssl_x509.h | X.509 certificate decoding and validation | + * | bearssl_pem.h | Base64/PEM decoding support functions | + * + * Applications using BearSSL are supposed to simply include `bearssl.h` + * as follows: + * + * #include + * + * The `bearssl.h` file itself includes all the other header files. It is + * possible to include specific header files, but it has no practical + * advantage for the application. The API is separated into separate + * header files only for documentation convenience. + * + * + * # Conventions + * + * ## MUST and SHALL + * + * In all descriptions, the usual "MUST", "SHALL", "MAY",... terminology + * is used. Failure to meet requirements expressed with a "MUST" or + * "SHALL" implies undefined behaviour, which means that segmentation + * faults, buffer overflows, and other similar adverse events, may occur. + * + * In general, BearSSL is not very forgiving of programming errors, and + * does not include much failsafes or error reporting when the problem + * does not arise from external transient conditions, and can be fixed + * only in the application code. This is done so in order to make the + * total code footprint lighter. + * + * + * ## `NULL` values + * + * Function parameters with a pointer type shall not be `NULL` unless + * explicitly authorised by the documentation. As an exception, when + * the pointer aims at a sequence of bytes and is accompanied with + * a length parameter, and the length is zero (meaning that there is + * no byte at all to retrieve), then the pointer may be `NULL` even if + * not explicitly allowed. + * + * + * ## Memory Allocation + * + * BearSSL does not perform dynamic memory allocation. This implies that + * for any functionality that requires a non-transient state, the caller + * is responsible for allocating the relevant context structure. Such + * allocation can be done in any appropriate area, including static data + * segments, the heap, and the stack, provided that proper alignment is + * respected. The header files define these context structures + * (including size and contents), so the C compiler should handle + * alignment automatically. + * + * Since there is no dynamic resource allocation, there is also nothing to + * release. When the calling code is done with a BearSSL feature, it + * may simple release the context structures it allocated itself, with + * no "close function" to call. If the context structures were allocated + * on the stack (as local variables), then even that release operation is + * implicit. + * + * + * ## Structure Contents + * + * Except when explicitly indicated, structure contents are opaque: they + * are included in the header files so that calling code may know the + * structure sizes and alignment requirements, but callers SHALL NOT + * access individual fields directly. For fields that are supposed to + * be read from or written to, the API defines accessor functions (the + * simplest of these accessor functions are defined as `static inline` + * functions, and the C compiler will optimise them away). + * + * + * # API Usage + * + * BearSSL usage for running a SSL/TLS client or server is described + * on the [BearSSL Web site](https://www.bearssl.org/api1.html). The + * BearSSL source archive also comes with sample code. + */ + #include "bearssl_hash.h" #include "bearssl_hmac.h" #include "bearssl_rand.h" #include "bearssl_prf.h" #include "bearssl_block.h" +#include "bearssl_aead.h" #include "bearssl_rsa.h" #include "bearssl_ec.h" #include "bearssl_ssl.h"