SSLCTXsetsessionidcontext(3) OpenSSL SSLCTXsetsessionidcontext(3)

NAME
       SSLCTXsetsessionidcontext, SSLsetsessionidcontext - set
       context within which session can be reused (server side only)

SYNOPSIS
        #include 

        int SSLCTXsetsessionidcontext(SSLCTX *ctx, const unsigned char *sidctx,
                                           unsigned int sidctxlen);
        int SSLsetsessionidcontext(SSL *ssl, const unsigned char *sidctx,
                                       unsigned int sidctxlen);

DESCRIPTION
       SSLCTXsetsessionidcontext() sets the context ssiiddccttxx of length
       ssiiddccttxxlleenn within which a session can be reused for the ccttxx object.

       SSLsetsessionidcontext() sets the context ssiiddccttxx of length
       ssiiddccttxxlleenn within which a session can be reused for the ssssll object.

NNOOTTEESS
       Sessions are generated within a certain context. When
       exporting/importing sessions with ii22ddSSSSLLSSEESSSSIIOONN/dd22iiSSSSLLSSEESSSSIIOONN it
       would be possible, to re-import a session generated from another
       context (e.g. another application), which might lead to malfunctions.
       Therefore each application must set its own session id context ssiiddccttxx
       which is used to distinguish the contexts and is stored in exported
       sessions. The ssiiddccttxx can be any kind of binary data with a given
       length, it is therefore possible to use e.g. the name of the
       application and/or the hostname and/or service name ...

       The session id context becomes part of the session. The session id
       context is set by the SSL/TLS server. The
       SSLCTXsetsessionidcontext() and SSLsetsessionidcontext()
       functions are therefore only useful on the server side.

       OpenSSL clients will check the session id context returned by the
       server when reusing a session.

       The maximum length of the ssiiddccttxx is limited to
       SSSSLLMMAAXXSSSSLLSSEESSSSIIOONNIIDDLLEENNGGTTHH.

WWAARRNNIINNGGSS
       If the session id context is not set on an SSL/TLS server and client
       certificates are used, stored sessions will not be reused but a fatal
       error will be flagged and the handshake will fail.

       If a server returns a different session id context to an OpenSSL client
       when reusing a session, an error will be flagged and the handshake will
       fail. OpenSSL servers will always return the correct session id
       context, as an OpenSSL server checks the session id context itself
       before reusing a session as described above.

RETURN VALUES
       SSLCTXsetsessionidcontext() and SSLsetsessionidcontext()
       return the following values:

       0   The length ssiiddccttxxlleenn of the session id context ssiiddccttxx exceeded
           the maximum allowed length of SSSSLLMMAAXXSSSSLLSSEESSSSIIOONNIIDDLLEENNGGTTHH. The
           error is logged to the error stack.

       1   The operation succeeded.

SEE ALSO
       ssl(3)



0.9.7l                            2004-06-14 SSLCTXsetsessionidcontext(3)