SSL_get_session(3ssl)
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.
SSL_get0_session() returns a pointer to the actual session. As the
reference 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
reference count, so that the session will not be implicitly removed by
other operations but stays in memory. In order to remove the session
SSL_SESSION_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.