SSL_dup, SSL_new, SSL_up_ref - create an SSL structure for a connection
#include <openssl/ssl.h>
SSL *SSL_dup(SSL *s);
SSL *SSL_new(SSL_CTX *ctx);
int SSL_up_ref(SSL *s);
SSL_new() creates a new
SSL structure which is needed to hold the
data for a TLS/SSL connection. The new structure inherits the settings of the
underlying context
ctx: connection method, options, verification
settings, timeout settings. An
SSL structure is reference counted.
Creating an
SSL structure for the first time increments the reference
count. Freeing it (using SSL_free) decrements it. When the reference count
drops to zero, any memory or resources allocated to the
SSL structure
are freed.
SSL_up_ref() increments the reference count for an existing
SSL
structure.
The function
SSL_dup() creates and returns a new
SSL structure
from the same
SSL_CTX that was used to create
s. It additionally
duplicates a subset of the settings in
s into the new
SSL
object.
For
SSL_dup() to work, the connection MUST be in its initial state and
MUST NOT have yet started the SSL handshake. For connections that are not in
their initial state
SSL_dup() just increments an internal reference
count and returns the
same handle. It may be possible to use
SSL_clear(3) to recycle an SSL handle that is not in its initial state
for reuse, but this is best avoided. Instead, save and restore the session, if
desired, and construct a fresh handle for each connection.
The subset of settings in
s that are duplicated are:
- any session data if configured (including the
session_id_context)
- any tmp_dh settings set via SSL_set_tmp_dh(3),
SSL_set_tmp_dh_callback(3), or SSL_set_dh_auto(3)
- any configured certificates, private keys or certificate
chains
- any configured signature algorithms, or client signature
algorithms
- any DANE settings
- any Options set via SSL_set_options(3)
- any Mode set via SSL_set_mode(3)
- any minimum or maximum protocol settings set via
SSL_set_min_proto_version(3) or SSL_set_max_proto_version(3)
(Note: Only from OpenSSL 1.1.1h and above)
- any verify mode, callback or depth set via
SSL_set_verify(3) or SSL_set_verify_depth(3) or any configured
X509 verification parameters
- any msg callback or info callback set via
SSL_set_msg_callback(3) or SSL_set_info_callback(3)
- any default password callback set via
SSL_set_default_passwd_cb(3)
- any session id generation callback set via
SSL_set_generate_session_id(3)
- any configured Cipher List
- initial accept (server) or connect (client) state
- the max cert list value set via
SSL_set_max_cert_list(3)
- the read_ahead value set via
SSL_set_read_ahead(3)
- application specific data set via
SSL_set_ex_data(3)
- any CA list or client CA list set via
SSL_set0_CA_list(3), SSL_set0_client_CA_list() or similar
functions
- any security level settings or callbacks
- any configured serverinfo data
- any configured PSK identity hint
- any configured custom extensions
- any client certificate types configured via
SSL_set1_client_certificate_types
The following return values can occur:
- NULL
- The creation of a new SSL structure failed. Check the error
stack to find out the reason.
- Pointer to an SSL structure
- The return value points to an allocated SSL structure.
SSL_up_ref() returns 1 for success and 0 for failure.
SSL_free(3),
SSL_clear(3),
SSL_CTX_set_options(3),
SSL_get_SSL_CTX(3),
ssl(7)
Copyright 2000-2023 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>.