SSL_SET_SHUTDOWN(3) | Library Functions Manual | SSL_SET_SHUTDOWN(3)

# NAME

`SSL_set_shutdown`, `SSL_get_shutdown` — manipulate shutdown state of an SSL connection

# SYNOPSIS

library “libssl” libcrypto
`#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.

The shutdown state of an ssl connection is a bitmask 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 from 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 RFC 2246. 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, but to set `SSL_SENT_SHUTDOWN` the application must still call SSL_shutdown(3) or `SSL_set_shutdown`() itself.

# RETURN VALUES

`SSL_get_shutdown`() returns the current setting.

# SEE ALSO

ssl(3), SSL_clear(3), SSL_CTX_set_quiet_shutdown(3), SSL_free(3), SSL_shutdown(3)

# HISTORY

`SSL_set_shutdown`() and `SSL_get_shutdown`() first appeared in SSLeay 0.8.0 and have been available since OpenBSD 2.4.

June 8, 2025 | Debian