NAME
SSL_set_shutdown, SSL_get_shutdown - manipulate shutdown state of an SSL connection
SYNOPSIS
#include <openssl/ssl.h> void SSL_set_shutdown(SSL *ssl, int mode); int SSL_get_shutdown(const SSL *ssl);
DESCRIPTION
SSL_set_shutdown() sets the shutdown state of ssl to mode.
SSL_get_shutdown() returns the shutdown mode of ssl.
NOTES
The shutdown state of an ssl connection is a bit-mask of:
- 0
-
No shutdown setting, yet.
- SSL_SENT_SHUTDOWN
-
A close_notify shutdown alert was sent to the peer, the connection is being considered closed and the session is closed and correct.
- SSL_RECEIVED_SHUTDOWN
-
A shutdown alert was received form the peer, either a normal close_notify or a fatal error.
SSL_SENT_SHUTDOWN and SSL_RECEIVED_SHUTDOWN can be set at the same time.
The shutdown state of the connection is used to determine the state of the ssl session. If the session is still open, when SSL_clear(3) or SSL_free(3) is called, it is considered bad and removed according to RFC2246. The actual condition for a correctly closed session is SSL_SENT_SHUTDOWN (according to the TLS RFC, it is acceptable to only send the close_notify alert but to not wait for the peer's answer, when the underlying connection is closed). SSL_set_shutdown() can be used to set this state without sending a close alert to the peer (see SSL_shutdown(3)).
If a close_notify was received, SSL_RECEIVED_SHUTDOWN will be set, for setting SSL_SENT_SHUTDOWN the application must however still call SSL_shutdown(3) or SSL_set_shutdown() itself.
SSL_set_shutdown() is not supported for QUIC SSL objects.
RETURN VALUES
SSL_set_shutdown() does not return diagnostic information.
SSL_get_shutdown() returns the current shutdown state as set or based on the actual connection state.
SSL_get_shutdown() returns 0 if called on a QUIC stream SSL object. If it is called on a QUIC connection SSL object, it returns a value with SSL_SENT_SHUTDOWN set if CONNECTION_CLOSE has been sent to the peer and it returns a value with SSL_RECEIVED_SHUTDOWN set if CONNECTION_CLOSE has been received from the peer or the QUIC connection is fully terminated for other reasons.
SEE ALSO
ssl(7), SSL_shutdown(3), SSL_CTX_set_quiet_shutdown(3), SSL_clear(3), SSL_free(3)
COPYRIGHT
Copyright 2001-2023 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (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 https://www.openssl.org/source/license.html.
