SSL_CTX_SET_SESSION_ID_CONTEXOpenSSL_CTX_SET_SESSION_ID_CONTEXT(3)

NAME    [Toc]    [Back]

       SSL_CTX_set_session_id_context, SSL_set_session_id_context
       - set context within which session can be reused (server
       side only)

SYNOPSIS    [Toc]    [Back]

        #include <openssl/ssl.h>

        int  SSL_CTX_set_session_id_context(SSL_CTX  *ctx,  const
unsigned char *sid_ctx,
                                           unsigned           int
sid_ctx_len);
        int  SSL_set_session_id_context(SSL  *ssl, const unsigned
char *sid_ctx,
                                       unsigned int sid_ctx_len);

DESCRIPTION    [Toc]    [Back]

       SSL_CTX_set_session_id_context() sets the context sid_ctx
       of length sid_ctx_len within which a session can be reused
       for the ctx object.

       SSL_set_session_id_context() sets the context sid_ctx of
       length sid_ctx_len within which a session can be reused
       for the ssl object.

NOTES    [Toc]    [Back]

       Sessions are generated within a certain context. When
       exporting/importing sessions with i2d_SSL_SES-
       SION/d2i_SSL_SESSION 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
       sid_ctx which is used to distinguish the contexts and is
       stored in exported sessions. The sid_ctx 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
       SSL_CTX_set_session_id_context() and SSL_set_ses-
       sion_id_context() 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 sid_ctx is limited to
       SSL_MAX_SSL_SESSION_ID_LENGTH.

WARNINGS    [Toc]    [Back]

       If the session id context is not set on an SSL/TLS server,
       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
SSL_CTX_SET_SESSION_ID_CONTEXOpenSSL_CTX_SET_SESSION_ID_CONTEXT(3)


       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    [Toc]    [Back]

       SSL_CTX_set_session_id_context() and SSL_set_ses-
       sion_id_context() return the following values:

       0   The length sid_ctx_len of the session id context
           sid_ctx exceeded the maximum allowed length of
           SSL_MAX_SSL_SESSION_ID_LENGTH. The error is logged to
           the error stack.

       1   The operation succeeded.

SEE ALSO    [Toc]    [Back]

       ssl(3)


OpenBSD 3.6                 2001-06-21                          2