SSL_CLEAR(3) BSD Library Functions Manual SSL_CLEAR(3)NAMESSL_clear — reset SSL object to allow another connection
SYNOPSIS
#include <openssl/ssl.h>
int
SSL_clear(SSL *ssl);
DESCRIPTION
Reset ssl to allow another connection. All settings (method, ciphers,
BIOs) are kept.
NOTESSSL_clear() is used to prepare an SSL object for a new connection. While
all settings are kept, a side effect is the handling of the current SSL
session. If a session is still open, it is considered bad and will be
removed from the session cache, as required by RFC2246. A session is
considered open if SSL_shutdown(3) was not called for the connection or
at least SSL_set_shutdown(3) was used to set the SSL_SENT_SHUTDOWN state.
If a session was closed cleanly, the session object will be kept and all
settings corresponding. This explicitly means that for example the spe‐
cial method used during the session will be kept for the next handshake.
So if the session was a TLSv1 session, a SSL client object will use a
TLSv1 client method for the next handshake and a SSL server object will
use a TLSv1 server method, even if SSLv23_*_method()s were chosen on
startup. This might lead to connection failures (see SSL_new(3)) for a
description of the method's properties.
WARNINGSSSL_clear() resets the SSL object to allow for another connection. The
reset operation however keeps several settings of the last sessions (some
of these settings were made automatically during the last handshake). It
only makes sense for a new connection with the exact same peer that
shares these settings, and may fail if that peer changes its settings
between connections. Use the sequence SSL_get_session(3); SSL_new(3);
SSL_set_session(3); SSL_free(3) instead to avoid such failures (or simply
SSL_free(3); SSL_new(3) if session reuse is not desired).
RETURN VALUES
The following return values can occur:
0 The SSL_clear() operation could not be performed. Check the
error stack to find out the reason.
1 The SSL_clear() operation was successful.
SEE ALSOssl(3), SSL_CTX_set_client_cert_cb(3), SSL_CTX_set_options(3),
SSL_free(3), SSL_new(3), SSL_set_shutdown(3), SSL_shutdown(3)BSD April 29, 2024 BSD
