TLS_CONNECT(3)             Library Functions Manual             TLS_CONNECT(3)

NAME
     tls_connect, tls_connect_fds, tls_connect_servername, tls_connect_socket,
     tls_connect_cbs - instruct a TLS client to establish a connection

SYNOPSIS
     #include <tls.h>

     int
     tls_connect(struct tls *ctx, const char *host, const char *port);

     int
     tls_connect_fds(struct tls *ctx, int fd_read, int fd_write,
         const char *servername);

     int
     tls_connect_servername(struct tls *ctx, const char *host,
         const char *port, const char *servername);

     int
     tls_connect_socket(struct tls *ctx, int s, const char *servername);

     int
     tls_connect_cbs(struct tls *ctx,
         ssize_t (*tls_read_cb)(struct tls *ctx,
         void *buf, size_t buflen, void *cb_arg),
         ssize_t
         (*tls_write_cb)(struct tls *ctx, const void *buf, size_t
         buflen, void *cb_arg), void *cb_arg, const char *servername);

DESCRIPTION
     After creating a TLS client context with tls_client(3) and configuring it
     with tls_configure(3), a client connection is initiated by calling
     tls_connect().  This function will create a new socket, connect to the
     specified host and port, and then establish a secure connection.  The
     port may be numeric or a service name.  If it is NULL, then a host of the
     format "hostname:port" is permitted.  The name to use for verification is
     inferred from the host value.

     The tls_connect_servername() function has the same behaviour, however the
     name to use for verification is explicitly provided, for the case where
     the TLS server name differs from the DNS name.

     An already existing socket can be upgraded to a secure connection by
     calling tls_connect_socket().

     Alternatively, a secure connection can be established over a pair of
     existing file descriptors by calling tls_connect_fds().

     Calling tls_connect_cbs() allows read and write callback functions to
     handle data transfers.  The specified cb_arg parameter is passed back to
     the functions, and can contain a pointer to any caller-specified data.

RETURN VALUES
     These functions return 0 on success or -1 on error.

SEE ALSO
     tls_accept_socket(3), tls_client(3), tls_close(3),
     tls_config_ocsp_require_stapling(3), tls_configure(3), tls_handshake(3),
     tls_init(3)

HISTORY
     tls_connect() and tls_connect_socket() appeared in OpenBSD 5.6 and got
     their final names in OpenBSD 5.7.

     tls_connect_fds() and tls_connect_servername() appeared in OpenBSD 5.7
     and tls_connect_cbs() in OpenBSD 6.1.

AUTHORS
     Joel Sing <jsing@openbsd.org>
     Reyk Floeter <reyk@openbsd.org>

     tls_connect_cbs() was written by Tobias Pape <tobias@netshed.de>.

Linux 6.8.7-arch1-1              July 9, 2018              Linux 6.8.7-arch1-1