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Diffstat (limited to 'deps/openssl/openssl/doc/man3/SSL_CTX_sess_set_get_cb.pod')
| -rw-r--r-- | deps/openssl/openssl/doc/man3/SSL_CTX_sess_set_get_cb.pod | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/deps/openssl/openssl/doc/man3/SSL_CTX_sess_set_get_cb.pod b/deps/openssl/openssl/doc/man3/SSL_CTX_sess_set_get_cb.pod new file mode 100644 index 0000000000..774c4b120f --- /dev/null +++ b/deps/openssl/openssl/doc/man3/SSL_CTX_sess_set_get_cb.pod @@ -0,0 +1,114 @@ +=pod + +=head1 NAME + +SSL_CTX_sess_set_new_cb, SSL_CTX_sess_set_remove_cb, SSL_CTX_sess_set_get_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 + +=head1 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 *, + const 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, + const unsigned char *data, + int len, int *copy); + +=head1 DESCRIPTION + +SSL_CTX_sess_set_new_cb() sets the callback function, which is automatically +called whenever a new session was negotiated. + +SSL_CTX_sess_set_remove_cb() 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. + +SSL_CTX_sess_set_get_cb() sets the callback function which is called, +whenever a SSL/TLS client proposed to resume a session but the session +could not be found in the internal session cache (see +L<SSL_CTX_set_session_cache_mode(3)>). +(SSL/TLS server only.) + +SSL_CTX_sess_get_new_cb(), SSL_CTX_sess_get_remove_cb(), and +SSL_CTX_sess_get_get_cb() retrieve the function pointers set by the +corresponding set callback functions. If a callback function has not been +set, the NULL pointer is returned. + +=head1 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 +L<d2i_SSL_SESSION(3)> interface. + +The new_session_cb() is called, whenever a new session has been negotiated +and session caching is enabled (see +L<SSL_CTX_set_session_cache_mode(3)>). +The new_session_cb() is passed the B<ssl> connection and the ssl session +B<sess>. If the callback returns B<0>, the session will be immediately +removed again. Note that in TLSv1.3, sessions are established after the main +handshake has completed. The server decides when to send the client the session +information and this may occur some time after the end of the handshake (or not +at all). This means that applications should expect the new_session_cb() +function to be invoked during the handshake (for <= TLSv1.2) or after the +handshake (for TLSv1.3). It is also possible in TLSv1.3 for multiple sessions to +be established with a single connection. In these case the new_session_cb() +function will be invoked multiple times. + +In TLSv1.3 it is recommended that each SSL_SESSION object is only used for +resumption once. One way of enforcing that is for applications to call +L<SSL_CTX_remove_session(3)> after a session has been used. + +The remove_session_cb() is called, whenever the SSL engine removes a session +from the internal cache. This happens when the session is removed because +it is expired or when a connection was not shutdown cleanly. It also happens +for all sessions in the internal session cache when +L<SSL_CTX_free(3)> is called. The remove_session_cb() is passed +the B<ctx> and the ssl session B<sess>. It does not provide any feedback. + +The get_session_cb() is only called on SSL/TLS servers with the session id +proposed by the client. The get_session_cb() is always called, also when +session caching was disabled. The get_session_cb() is passed the +B<ssl> connection, the session id of length B<length> at the memory location +B<data>. With the parameter B<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 +L<SSL_SESSION_free(3)>. + +=head1 RETURN VALUES + +SSL_CTX_sess_get_new_cb(), SSL_CTX_sess_get_remove_cb() and SSL_CTX_sess_get_get_cb() +return different callback function pointers respectively. + +=head1 SEE ALSO + +L<ssl(7)>, L<d2i_SSL_SESSION(3)>, +L<SSL_CTX_set_session_cache_mode(3)>, +L<SSL_CTX_flush_sessions(3)>, +L<SSL_SESSION_free(3)>, +L<SSL_CTX_free(3)> + +=head1 COPYRIGHT + +Copyright 2001-2018 The OpenSSL Project Authors. All Rights Reserved. + +Licensed under the OpenSSL license (the "License"). You may not use +this file except in compliance with the License. You can obtain a copy +in the file LICENSE in the source distribution or at +L<https://www.openssl.org/source/license.html>. + +=cut |