SSL_shutdown.pod revision 79998
1=pod 2 3=head1 NAME 4 5SSL_shutdown - shut down a TLS/SSL connection 6 7=head1 SYNOPSIS 8 9 #include <openssl/ssl.h> 10 11 int SSL_shutdown(SSL *ssl); 12 13=head1 DESCRIPTION 14 15SSL_shutdown() shuts down an active TLS/SSL connection. It sends the 16"close notify" shutdown alert to the peer. 17 18=head1 NOTES 19 20SSL_shutdown() tries to send the "close notify" shutdown alert to the peer. 21Whether the operation succeeds or not, the SSL_SENT_SHUTDOWN flag is set and 22a currently open session is considered closed and good and will be kept in the 23session cache for further reuse. 24 25The behaviour of SSL_shutdown() depends on the underlying BIO. 26 27If the underlying BIO is B<blocking>, SSL_shutdown() will only return once the 28handshake has been finished or an error occurred. 29 30If the underlying BIO is B<non-blocking>, SSL_shutdown() will also return 31when the underlying BIO could not satisfy the needs of SSL_shutdown() 32to continue the handshake. In this case a call to SSL_get_error() with the 33return value of SSL_shutdown() will yield B<SSL_ERROR_WANT_READ> or 34B<SSL_ERROR_WANT_WRITE>. The calling process then must repeat the call after 35taking appropriate action to satisfy the needs of SSL_shutdown(). 36The action depends on the underlying BIO. When using a non-blocking socket, 37nothing is to be done, but select() can be used to check for the required 38condition. When using a buffering BIO, like a BIO pair, data must be written 39into or retrieved out of the BIO before being able to continue. 40 41=head1 RETURN VALUES 42 43The following return values can occur: 44 45=over 4 46 47=item 1 48 49The shutdown was successfully completed. 50 51=item 0 52 53The shutdown was not successful. Call SSL_get_error() with the return 54value B<ret> to find out the reason. 55 56=item -1 57 58The shutdown was not successful because a fatal error occurred either 59at the protocol level or a connection failure occurred. It can also occur of 60action is need to continue the operation for non-blocking BIOs. 61Call SSL_get_error() with the return value B<ret> to find out the reason. 62 63=back 64 65=head1 SEE ALSO 66 67L<SSL_get_error(3)|SSL_get_error(3)>, L<SSL_connect(3)|SSL_connect(3)>, 68L<SSL_accept(3)|SSL_accept(3)>, L<SSL_set_shutdown(3)|SSL_set_shutdown(3)>, 69L<SSL_clear(3)|SSL_clear(3)>, L<SSL_free(3)|SSL_free(3)>, 70L<ssl(3)|ssl(3)>, L<bio(3)|bio(3)> 71 72=cut 73