---
name: "libressl-tls_client"
section: "3"
platform: "linux"
package: "libressl"
version: "4.4.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/libressl-tls_client"
---

# libressl-tls\_client(3)

configure a TLS connection

## NAME

**tls\_client**, **tls\_server**, **tls\_configure**, **tls\_reset**, **tls\_free** – configure a TLS connection

## SYNOPSIS

library “libtls” libssl libcrypto

**#include \<tls.h\>**

*struct* *tls* *\**\

**tls\_client**(*void*);

*struct* *tls* *\**\

**tls\_server**(*void*);

*int*\

**tls\_configure**(*struct tls \*ctx*, *struct tls\_config \*config*);

*void*\

**tls\_free**(*struct tls \*ctx*);

*void*\

**tls\_reset**(*struct tls \*ctx*);

## DESCRIPTION

A TLS connection is represented as a *struct* *tls* object called a “context”. A new context is created by either the **tls\_client**() or **tls\_server**() functions. **tls\_client**() is used in TLS client programs, **tls\_server**() in TLS server programs.

The context can then be configured with the function **tls\_configure**(). The same *tls\_config* object can be used to configure multiple contexts.

After configuration, [tls\_connect(3)](/tls_connect/3.md) can be called on objects created with **tls\_client**(), and [tls\_accept\_socket(3)](/tls_accept_socket/3.md) on objects created with **tls\_server**().

After use, a TLS context should be closed with [tls\_close(3)](/tls_close/3.md), and then freed by calling **tls\_free**(). If **tls\_free**() is called with an argument of NULL, no action occurs.

A TLS context can be reset by calling **tls\_reset**(), allowing for it to be reused. This is essentially equivalent to calling **tls\_free**(), followed by a call to the same function that was used to originally allocate the TLS context.

## RETURN VALUES

**tls\_client**() and **tls\_server**() return NULL on error or an out of memory condition.

**tls\_configure**() returns 0 on success or -1 on error.

## SEE ALSO

[tls\_accept\_socket(3)](/tls_accept_socket/3.md), [tls\_config\_new(3)](/tls_config_new/3.md), [tls\_connect(3)](/tls_connect/3.md), [tls\_init(3)](/tls_init/3.md)

## HISTORY

These functions appeared in OpenBSD 5.6 and got their final names in OpenBSD 5.7.

## AUTHORS

Joel Sing ⟨*jsing@openbsd.org*⟩