1=pod 2 3=head1 NAME 4 5SSL_get_session - retrieve TLS/SSL session data 6 7=head1 SYNOPSIS 8 9 #include <openssl/ssl.h> 10 11 SSL_SESSION *SSL_get_session(const SSL *ssl); 12 SSL_SESSION *SSL_get0_session(const SSL *ssl); 13 SSL_SESSION *SSL_get1_session(SSL *ssl); 14 15=head1 DESCRIPTION 16 17SSL_get_session() returns a pointer to the B<SSL_SESSION> actually used in 18B<ssl>. The reference count of the B<SSL_SESSION> is not incremented, so 19that the pointer can become invalid by other operations. 20 21SSL_get0_session() is the same as SSL_get_session(). 22 23SSL_get1_session() is the same as SSL_get_session(), but the reference 24count of the B<SSL_SESSION> is incremented by one. 25 26=head1 NOTES 27 28The ssl session contains all information required to re-establish the 29connection without a new handshake. 30 31SSL_get0_session() returns a pointer to the actual session. As the 32reference counter is not incremented, the pointer is only valid while 33the connection is in use. If L<SSL_clear(3)|SSL_clear(3)> or 34L<SSL_free(3)|SSL_free(3)> is called, the session may be removed completely 35(if considered bad), and the pointer obtained will become invalid. Even 36if the session is valid, it can be removed at any time due to timeout 37during L<SSL_CTX_flush_sessions(3)|SSL_CTX_flush_sessions(3)>. 38 39If the data is to be kept, SSL_get1_session() will increment the reference 40count, so that the session will not be implicitly removed by other operations 41but stays in memory. In order to remove the session 42L<SSL_SESSION_free(3)|SSL_SESSION_free(3)> must be explicitly called once 43to decrement the reference count again. 44 45SSL_SESSION objects keep internal link information about the session cache 46list, when being inserted into one SSL_CTX object's session cache. 47One SSL_SESSION object, regardless of its reference count, must therefore 48only be used with one SSL_CTX object (and the SSL objects created 49from this SSL_CTX object). 50 51=head1 RETURN VALUES 52 53The following return values can occur: 54 55=over 4 56 57=item NULL 58 59There is no session available in B<ssl>. 60 61=item Pointer to an SSL 62 63The return value points to the data of an SSL session. 64 65=back 66 67=head1 SEE ALSO 68 69L<ssl(3)|ssl(3)>, L<SSL_free(3)|SSL_free(3)>, 70L<SSL_clear(3)|SSL_clear(3)>, 71L<SSL_SESSION_free(3)|SSL_SESSION_free(3)> 72 73=cut 74