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SSL_CTX_sess_set_get_cb(3)
NAME
  SSL_CTX_sess_set_get_cb, SSL_CTX_sess_set_new_cb,
  SSL_CTX_sess_set_remove_cb, SSL_CTX_sess_get_new_cb,
  SSL_CTX_sess_get_remove_cb, SSL_CTX_sess_get_get_cb - Provide callback
  functions for server side external session caching

SYNOPSIS
  #include <openssl/ssl.h>

  void SSL_CTX_sess_set_new_cb(
	  SSL_CTX *ctx,
	  int (*new_session_cb) (SSL *, SSL_SESSION *) );

  void SSL_CTX_sess_set_remove_cb(
	  SSL_CTX *ctx,
	  void (*remove_session_cb) (SSL_CTX *ctx, SSL_SESSION *) );

  void SSL_CTX_sess_set_get_cb(
	  SSL_CTX *ctx,
	  SSL_SESSION (*get_session_cb) (SSL *, unsigned char *, int, int *)
  );

  int*SSL_CTX_sess_get_new_cb (SSL_CTX *ctx))(
	  struct ssl_st *ssl,
	  SSL_SESSION *sess );

  void (*SSL_CTX_sess_get_remove_cb(SSL_CTX *ctx))(
	  struct ssl_ctx_st *ctx,
	  SSL_SESSION *sess );

  SSL_SESSION *(*SSL_CTX_sess_get_get_cb(SSL_CTX *ctx))(
	  struct ssl_st *ssl,
	  unsigned char *data ,
	  int len ,
	  int *copy );

  int (*new_session_cb)(
	  struct ssl_st *ssl,
	  SSL_SESSION *sess );

  void(*remove_session_cb)(
	  struct ssl_ctx_st *ctx,
	  SSL_SESSION *sess );

  SSL_SESSION *(*get_session_cb)(
	  struct ssl_st *ssl,
	  unsigned char *data,
	  int len,
	  int *copy );

DESCRIPTION
  The SSL_CTX_sess_set_get_cb() function sets the callback function which is
  called whenever an SSL/TLS client proposes to resume a session but the
  session could not be found in the internal session cache (see
  SSL_CTX_set_session_cache_mode(3)). (SSL/TLS server only.)

  The SSL_CTX_sess_set_new_cb() function sets the callback function, which is
  automatically called whenever a new session is negotiated.

  The SSL_CTX_sess_set_remove_cb() function sets the callback function, which
  is automatically called whenever a session is removed by the SSL engine,
  because it is considered faulty or the session has become obsolete because
  of exceeding the timeout value.

  The SSL_CTX_sess_get_new_cb(), SSL_CTX_sess_get_remove_cb(), and
  SSL_CTX_sess_get_get_cb() functions retrieve the function pointers of the
  provided callback functions. If a callback function has not been set, the
  NULL pointer is returned.

NOTES
  In order to allow external session caching, synchronization with the
  internal session cache is realized via callback functions. Inside these
  callback functions, session can be saved to disk or put into a database
  using the d2i_SSL_SESSION(3) interface.

  The new_session_cb() function is called whenever a new session has been
  negotiated and session caching is enabled (see
  SSL_CTX_set_session_cache_mode(3)). The new_session_cb() function is passed
  the ssl connection and the ssl session sess.	If the callback returns 0,
  the session will be removed immediately.

  The remove_session_cb() function is called whenever the SSL engine removes
  a session from the internal cache. This happens if the session is removed
  because it is expired or when a connection was not shutdown cleanly. The
  remove_session_cb() function is passed the ctx and the ssl session sess. It
  does not provide any feedback.

  The get_session_cb() function is only called on SSL/TLS servers with the
  session id proposed by the client. The get_session_cb() function is always
  called, also when session caching is disabled.  The get_session_cb()
  function is passed the ssl connection, the session id of length length at
  the memory location data. With the parameter copy the callback can require
  the SSL engine to increment the reference count of the SSL_SESSION object.
  Normally the reference count is not incremented, and therefore the session
  must not be	 explicitly freed with SSL_SESSION_free().

SEE ALSO
  Functions: ssl(3), d2i_SSL_SESSION(3), SSL_CTX_set_session_cache_mode(3),
  SSL_CTX_flush_sessions(3), SSL_SESSION_free(3)

Index for Section 3

Alphabetical listing for S

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