mirror of https://github.com/openssl/openssl.git
117 lines
3.6 KiB
Plaintext
117 lines
3.6 KiB
Plaintext
=pod
|
|
|
|
=head1 NAME
|
|
|
|
ssl - OpenSSL SSL/TLS library
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
See the individual manual pages for details.
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
The OpenSSL B<ssl> library implements several versions of the
|
|
Secure Sockets Layer, Transport Layer Security, and Datagram Transport Layer
|
|
Security protocols.
|
|
This page gives a brief overview of the extensive API and data types
|
|
provided by the library.
|
|
|
|
An B<SSL_CTX> object is created as a framework to establish
|
|
TLS/SSL enabled connections (see L<SSL_CTX_new(3)>).
|
|
Various options regarding certificates, algorithms etc. can be set
|
|
in this object.
|
|
|
|
When a network connection has been created, it can be assigned to an
|
|
B<SSL> object. After the B<SSL> object has been created using
|
|
L<SSL_new(3)>, L<SSL_set_fd(3)> or
|
|
L<SSL_set_bio(3)> can be used to associate the network
|
|
connection with the object.
|
|
|
|
When the TLS/SSL handshake is performed using
|
|
L<SSL_accept(3)> or L<SSL_connect(3)>
|
|
respectively.
|
|
L<SSL_read_ex(3)>, L<SSL_read(3)>, L<SSL_write_ex(3)> and L<SSL_write(3)> are
|
|
used to read and write data on the TLS/SSL connection.
|
|
L<SSL_shutdown(3)> can be used to shut down the
|
|
TLS/SSL connection.
|
|
|
|
=head1 DATA STRUCTURES
|
|
|
|
Here are some of the main data structures in the library.
|
|
|
|
=over 4
|
|
|
|
=item B<SSL_METHOD> (SSL Method)
|
|
|
|
This is a dispatch structure describing the internal B<ssl> library
|
|
methods/functions which implement the various protocol versions (SSLv3
|
|
TLSv1, ...). It's needed to create an B<SSL_CTX>.
|
|
|
|
=item B<SSL_CIPHER> (SSL Cipher)
|
|
|
|
This structure holds the algorithm information for a particular cipher which
|
|
are a core part of the SSL/TLS protocol. The available ciphers are configured
|
|
on a B<SSL_CTX> basis and the actual ones used are then part of the
|
|
B<SSL_SESSION>.
|
|
|
|
=item B<SSL_CTX> (SSL Context)
|
|
|
|
This is the global context structure which is created by a server or client
|
|
once per program life-time and which holds mainly default values for the
|
|
B<SSL> structures which are later created for the connections.
|
|
|
|
=item B<SSL_SESSION> (SSL Session)
|
|
|
|
This is a structure containing the current TLS/SSL session details for a
|
|
connection: B<SSL_CIPHER>s, client and server certificates, keys, etc.
|
|
|
|
=item B<SSL> (SSL Connection)
|
|
|
|
This is the main SSL/TLS structure which is created by a server or client per
|
|
established connection. This actually is the core structure in the SSL API.
|
|
At run-time the application usually deals with this structure which has
|
|
links to mostly all other structures.
|
|
|
|
=back
|
|
|
|
=head1 HEADER FILES
|
|
|
|
Currently the OpenSSL B<ssl> library provides the following C header files
|
|
containing the prototypes for the data structures and functions:
|
|
|
|
=over 4
|
|
|
|
=item F<< <openssl/ssl.h> >>
|
|
|
|
This is the common header file for the SSL/TLS API. Include it into your
|
|
program to make the API of the B<ssl> library available. It internally
|
|
includes both more private SSL headers and headers from the B<crypto> library.
|
|
Whenever you need hard-core details on the internals of the SSL API, look
|
|
inside this header file.
|
|
This file also includes the others listed below.
|
|
|
|
=item F<< <openssl/ssl2.h> >>
|
|
|
|
Unused. Present for backwards compatibility only.
|
|
|
|
=item F<< <openssl/ssl3.h> >>
|
|
|
|
This is the sub header file dealing with the SSLv3 protocol only.
|
|
|
|
=item F<< <openssl/tls1.h> >>
|
|
|
|
This is the sub header file dealing with the TLSv1 protocol only.
|
|
|
|
=back
|
|
|
|
=head1 COPYRIGHT
|
|
|
|
Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
|
|
|
|
Licensed under the Apache License 2.0 (the "License"). You may not use
|
|
this file except in compliance with the License. You can obtain a copy
|
|
in the file LICENSE in the source distribution or at
|
|
L<https://www.openssl.org/source/license.html>.
|
|
|
|
=cut
|