= nng_tls_config_alloc(3tls)
//
// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
// Copyright 2018 Capitar IT Group BV <info@capitar.com>
//
// This document is supplied under the terms of the MIT License, a
// copy of which should be located in the distribution where this
// file was obtained (LICENSE.txt).  A copy of the license may also be
// found online at https://opensource.org/licenses/MIT.
//

== NAME

nng_tls_config_alloc - allocate TLS configuration object

== SYNOPSIS

[source, c]
----
#include <nng/nng.h>
#include <nng/supplemental/tls/tls.h>

typedef enum nng_tls_mode {
    NNG_TLS_MODE_CLIENT,
    NNG_TLS_MODE_SERVER
} nng_tls_mode;

int nng_tls_config_alloc(nng_tls_config **cfgp, nng_tls_mode mode);
----

== DESCRIPTION

The `nng_tls_config_alloc()` function creates a newly initialized
https://tools.ietf.org/html/rfc5246[Transport Layer Security])
configuration object, and stores a pointer to it in the value pointed
to by _cfgp_.

This object is initialized for use when acting as either a
client (`NNG_TLS_MODE_CLIENT`) or as a server (`NNG_TLS_MODE_SERVER`),
depending on the value of _mode_.

A TLS object can be further modified by functions that set the security
keys used, peer certificates, protocol policies, and so forth.

A single TLS configuration object can be used with multiple TLS streams
or services.
The underlying system uses reference counting to ensure
that object is not inadvertently freed while in use.

Also note that a TLS configuration object becomes "read-only" after it
is first used with a service.
After this points, attempts to apply
further changes to the configuration will result in `NNG_EBUSY`.


== RETURN VALUES

This function returns 0 on success, and non-zero otherwise.

== ERRORS

[horizontal]
`NNG_ENOMEM`:: Insufficient memory is available.
`NNG_EINVAL`:: An invalid _mode_ was specified.

== SEE ALSO

[.text-left]
<<nng_strerror.3#,nng_strerror(3)>>,
<<nng_tls_config_auth_mode.3tls#,nng_tls_config_auth_mode(3tls)>>,
<<nng_tls_config_ca_chain.3tls#,nng_tls_config_ca_chain(3tls)>>,
<<nng_tls_config_own_cert.3tls#,nng_tls_config_own_cert(3tls)>>,
<<nng_tls_config_free.3tls#,nng_tls_config_free(3tls)>>,
<<nng_tls_config_server_name.3tls#,nng_tls_config_server_name(3tls)>>,
<<nng.7#,nng(7)>>
