SSLCOMPaddcompressionmethod(3) OpenSSL SSLCOMPaddcompressionmethod(3)

NAME
       SSLCOMPaddcompressionmethod - handle SSL/TLS integrated compression
       methods

SYNOPSIS
        #include 

        int SSLCOMPaddcompressionmethod(int id, COMPMETHOD *cm);

DESCRIPTION
       SSLCOMPaddcompressionmethod() adds the compression method ccmm with
       the identifier iidd 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 SSLCTX or SSL objects.

NNOOTTEESS
       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 SSLCOMPaddcompressionmethod() 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 CCOOMMPPrrllee(()) and (when
       especially enabled during compilation) CCOOMMPPzzlliibb(()) available.

WWAARRNNIINNGGSS
       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.

RETURN VALUES
       SSLCOMPaddcompressionmethod() may return the following values:

       0   The operation succeeded.

       1   The operation failed. Check the error queue to find out the reason.

SEE ALSO
       ssl(3)



0.9.7l                            2003-11-29SSLCOMPaddcompressionmethod(3)