More structuring and sorting of the SSL API documentation.

Transport Layer Security (TLS v1) protocols. It provides a rich API which is

documented here.

=head1 HEADERS

=head1 HEADER FILES

Currently the OpenSSL B<ssl> library provides the following C header files

containing the prototypes for the data structures and and functions:

That's 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.

=item B<ssl2.h>

That's the sub header file dealing with the SSLv2 protocol only.

I<Usually you don't have to include it explicitly because

it's already included by ssl.h>.

=item B<ssl3.h>

That's the sub header file dealing with the SSLv3 protocol only.

I<Usually you don't have to include it explicitly because

it's already included by ssl.h>.

=item B<ssl23.h>

That's the sub header file dealing with the combined use of the SSLv2 and

SSLv3 protocols.

I<Usually you don't have to include it explicitly because

it's already included by ssl.h>.

=item B<tls1.h>

That's the sub header file dealing with the TLSv1 protocol only.

I<Usually you don't have to include it explicitly because

it's already included by ssl.h>.

=back

=head1 STRUCTURES

=head1 DATA STRUCTURES

Currently the OpenSSL B<ssl> library functions deal with the following data

Currently the OpenSSL B<ssl> library functions deals with the following data

structures:

=over 4

=item B<SSL_CTX> (SSL Context)

=item B<SSL_METHOD> (SSL Method)

=item B<SSL> (SSL Connection)

That's a dispatch structure describing the internal B<ssl> library

methods/functions which implement the various protocol versions (SSLv1, SSLv2

and TLSv1). It's needed to create an B<SSL_CTX>.

=item B<SSL_CIPHER> (SSL Cipher)

That's the SSL/TLS structure which is created by

a server or client per established connection. 

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 actually used ones are then part of the

B<SSL_SESSION>.

=item B<SSL_METHOD> (SSL Method)

=item B<SSL_CTX> (SSL Context)

=item B<SSL_CIPHER> (SSL Cipher)

That's 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 SSL session details for a

connection: B<SSL_CIPHER>s, client and server certificates, keys, etc.

=item B<SSL> (SSL Connection)

That's 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.

Under run-time the application usually deals with this structure which has

links to mostly all other structures.

=back

=head1 FUNCTIONS

=head1 API FUNCTIONS

Currently the OpenSSL B<ssl> library exports 214 API functions.

They are documented in the following:

=head2 DEALING WITH PROTOCOL METHODS

Here we document the various API functions which deal with the SSL/TLS

protocol methods defined in B<SSL_METHOD> structures.

=over 4

=item SSL_METHOD *B<SSLv2_client_method>(void);

Constructor for the SSLv2 SSL_METHOD structure for a dedicated client.

=item SSL_METHOD *B<SSLv2_server_method>(void);

Constructor for the SSLv2 SSL_METHOD structure for a dedicated server.

=item SSL_METHOD *B<SSLv2_method>(void);

Constructor for the SSLv2 SSL_METHOD structure for combined client and server.

=item SSL_METHOD *B<SSLv3_client_method>(void);

Constructor for the SSLv3 SSL_METHOD structure for a dedicated client.

=item SSL_METHOD *B<SSLv3_server_method>(void);

Constructor for the SSLv3 SSL_METHOD structure for a dedicated server.

=item SSL_METHOD *B<SSLv3_method>(void);

Constructor for the SSLv3 SSL_METHOD structure for combined client and server.

=item SSL_METHOD *B<TLSv1_client_method>(void);

Constructor for the TLSv1 SSL_METHOD structure for a dedicated client.

=item SSL_METHOD *B<TLSv1_server_method>(void);

Constructor for the TLSv1 SSL_METHOD structure for a dedicated server.

=item SSL_METHOD *B<TLSv1_method>(void);

Constructor for the TLSv1 SSL_METHOD structure for combined client and server.

=back

=head2 DEALING WITH CIPHERS

Here we document the various API functions which deal with the SSL/TLS

ciphers defined in B<SSL_CIPHER> structures.

=over 4

=item char *B<SSL_CIPHER_description>(SSL_CIPHER *cipher, char *buf, int len);

=item int B<SSL_CIPHER_get_bits>(SSL_CIPHER *c, int *alg_bits);

Write a string to I<buf> (with a maximum size of I<len>) containing a human

readable description of I<cipher>. Returns I<buf>.

=item int B<SSL_CIPHER_get_bits>(SSL_CIPHER *cipher, int *alg_bits);

Determine the number of bits in I<cipher>. Because of export crippled ciphers

there are two bits: The bits the algorithm supports in general (stored to

I<alg_bits>) and the bits which are actually used (the return value).

=item char *B<SSL_CIPHER_get_name>(SSL_CIPHER *cipher);

Return the internal name of I<cipher> as a string. These are the various

strings defined by the I<SSL2_TXT_xxx>, I<SSL3_TXT_xxx> and I<TLS1_TXT_xxx>

definitions in the header files.

=item char *B<SSL_CIPHER_get_version>(SSL_CIPHER *cipher);

=item char *B<SSL_CIPHER_get_name>(SSL_CIPHER *c);

Returns a string like "C<TLSv1/SSLv3>" or "C<SSLv2>" which indicates the

SSL/TLS protocol version to which I<cipher> belongs (i.e. where it was defined

in the specification the first time).

=item char *B<SSL_CIPHER_get_version>(SSL_CIPHER *c);

=back

=head2 DEALING WITH PROTOCOL CONTEXTS

Here we document the various API functions which deal with the SSL/TLS

protocol context defined in the B<SSL_CTX> structure.

=over 4

=item int B<SSL_CTX_add_client_CA>(SSL_CTX *ctx, X509 *x);

=item int B<SSL_CTX_use_certificate_file>(SSL_CTX *ctx, char *file, int type);

=back

=head2 DEALING WITH SESSIONS

Here we document the various API functions which deal with the SSL/TLS

sessions defined in the B<SSL_SESSION> structures.

=over 4

=item int B<SSL_SESSION_cmp>(SSL_SESSION *a, SSL_SESSION *b);

=item void B<SSL_SESSION_free>(SSL_SESSION *ss);

=item long B<SSL_SESSION_set_timeout>(SSL_SESSION *s, long t);

=back

=head2 DEALING WITH CONNECTIONS

Here we document the various API functions which deal with the SSL/TLS

connection defined in the B<SSL> structure.

=over 4

=item int B<SSL_accept>(SSL *ssl);

=item int B<SSL_add_client_CA>(SSL *ssl, X509 *x);

=item int B<SSL_write>(SSL *ssl, char *buf, int num);

=item SSL_METHOD *B<SSLv2_client_method>(void);

=item SSL_METHOD *B<SSLv2_method>(void);

=item SSL_METHOD *B<SSLv2_server_method>(void);

=item SSL_METHOD *B<SSLv3_client_method>(void);

=item SSL_METHOD *B<SSLv3_method>(void);

=item SSL_METHOD *B<SSLv3_server_method>(void);

=item SSL_METHOD *B<TLSv1_client_method>(void);

=item SSL_METHOD *B<TLSv1_method>(void);

=item SSL_METHOD *B<TLSv1_server_method>(void);

=back

=head1 SEE ALSO