SSL_get_session(3)

NAME

       SSL_get_session - retrieve TLS/SSL session data

SYNOPSIS

        #include <openssl/ssl.h>

        SSL_SESSION *SSL_get_session(const SSL *ssl);
        SSL_SESSION *SSL_get0_session(const SSL *ssl);
        SSL_SESSION *SSL_get1_session(SSL *ssl);

DESCRIPTION

       SSL_get_session() returns a pointer to the SSL_SESSION actually used in
       ssl. The reference count of the SSL_SESSION is not incremented, so that
       the pointer can become invalid by other operations.

       SSL_get0_session() is the same as SSL_get_session().

       SSL_get1_session() is the same as SSL_get_session(), but the reference
       count of the SSL_SESSION is incremented by one.

NOTES

       The ssl session contains all information required to re-establish the
       connection without a new handshake.

       A session will be automatically removed from the session cache and
       marked as non-resumable if the connection is not closed down cleanly,
       e.g. if a fatal error occurs on the connection or SSL_shutdown(3) is
       not called prior to SSL_free(3).

       SSL_get0_session() returns a pointer to the actual session. As the ref-
       erence counter is not incremented, the pointer is only valid while the
       connection is in use. If SSL_clear(3) or SSL_free(3) is called, the
       session may be removed completely (if considered bad), and the pointer
       obtained will become invalid. Even if the session is valid, it can be
       removed at any time due to timeout during SSL_CTX_flush_sessions(3).

       If the data is to be kept, SSL_get1_session() will increment the refer-
       ence count, so that the session will not be implicitly removed by other
       operations but stays in memory. In order to remove the session SSL_SES-
       SION_free(3) must be explicitly called once to decrement the reference
       count again.

       SSL_SESSION objects keep internal link information about the session
       cache list, when being inserted into one SSL_CTX object's session
       cache.  One SSL_SESSION object, regardless of its reference count, must
       therefore only be used with one SSL_CTX object (and the SSL objects
       created from this SSL_CTX object).

RETURN VALUES

       The following return values can occur:

       NULL
           There is no session available in ssl.

       Pointer to an SSL
           The return value points to the data of an SSL session.

SEE ALSO

       ssl(3), SSL_free(3), SSL_clear(3), SSL_SESSION_free(3)

1.0.2t                            2019-09-10                SSL_get_session(3)