c8919dde09
Newer pod2man considers =item [1-9] part of a numbered list, while =item 0 starts an unnumbered list. Add a zero effect formatting mark to override this. doc/apps/smime.pod around line 315: Expected text after =item, not a number ... PR#3146
70 lines
2.3 KiB
Text
70 lines
2.3 KiB
Text
=pod
|
|
|
|
=head1 NAME
|
|
|
|
SSL_COMP_add_compression_method - handle SSL/TLS integrated compression methods
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/ssl.h>
|
|
|
|
int SSL_COMP_add_compression_method(int id, COMP_METHOD *cm);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
SSL_COMP_add_compression_method() adds the compression method B<cm> with
|
|
the identifier B<id> to the list of available compression methods. This
|
|
list is globally maintained for all SSL operations within this application.
|
|
It cannot be set for specific SSL_CTX or SSL objects.
|
|
|
|
=head1 NOTES
|
|
|
|
The TLS standard (or SSLv3) allows the integration of compression methods
|
|
into the communication. The TLS RFC does however not specify compression
|
|
methods or their corresponding identifiers, so there is currently no compatible
|
|
way to integrate compression with unknown peers. It is therefore currently not
|
|
recommended to integrate compression into applications. Applications for
|
|
non-public use may agree on certain compression methods. Using different
|
|
compression methods with the same identifier will lead to connection failure.
|
|
|
|
An OpenSSL client speaking a protocol that allows compression (SSLv3, TLSv1)
|
|
will unconditionally send the list of all compression methods enabled with
|
|
SSL_COMP_add_compression_method() to the server during the handshake.
|
|
Unlike the mechanisms to set a cipher list, there is no method available to
|
|
restrict the list of compression method on a per connection basis.
|
|
|
|
An OpenSSL server will match the identifiers listed by a client against
|
|
its own compression methods and will unconditionally activate compression
|
|
when a matching identifier is found. There is no way to restrict the list
|
|
of compression methods supported on a per connection basis.
|
|
|
|
The OpenSSL library has the compression methods B<COMP_rle()> and (when
|
|
especially enabled during compilation) B<COMP_zlib()> available.
|
|
|
|
=head1 WARNINGS
|
|
|
|
Once the identities of the compression methods for the TLS protocol have
|
|
been standardized, the compression API will most likely be changed. Using
|
|
it in the current state is not recommended.
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
SSL_COMP_add_compression_method() may return the following values:
|
|
|
|
=over 4
|
|
|
|
=item Z<>0
|
|
|
|
The operation succeeded.
|
|
|
|
=item Z<>1
|
|
|
|
The operation failed. Check the error queue to find out the reason.
|
|
|
|
=back
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<ssl(3)|ssl(3)>
|
|
|
|
=cut
|