SSL_CTX_sessions() returns a pointer to the lhash databases containing the
internal session cache for ctx.
NOTES
The sessions in the internal session cache are kept in an
lhash(3) type database. It is possible to directly
access this database e.g. for searching. In parallel, the sessions
form a linked list which is maintained separately from the
lhash(3) operations, so that the database must not be
modified directly but by using the
SSL_CTX_add_session(3) family of functions.