.TH sslclient 1
.SH NAME
sslclient \- setup a TLS client connection
.SH SYNOPSIS
.B sslclient 
[
.I opts
]
.I host 
.I port 
.I prog 
.SH DESCRIPTION
.I opts 
is a series of getopt-style options,
.I host 
is a host name for the client to connect to, and
.I prog 
is one or more arguments specifying a program to run 
for each successful connection. 

.B sslclient 
attempts to connect to a TCP server at 
.I host
.IR port . 
The server's address is given by
.I host
and
.IR port .
.I host
may be
.IR 0 ,
which is identical to
.IR 127.0.0.1 ,
or
.IR ::1
referring to the IPv6 loopback address,
a compactified IPv6 address,
a dotted-decimal IPv4 address,
or a host name.
If a host name is given,
.B sslclient
facilitates a DNS lookup and tries each address in turn.

If the connection succeeds, 
.B sslclient 
runs 
.IR prog , 
with file descriptors 6 and 7 reading from and 
writing to a child process ssl. 
The ssl process attempts an SSL connect via the network. 
If it succeeds, it translates data between 
.I prog 
and the network, performing any necessary SSL encoding and decoding. 

Before running 
.I prog, 
.B sslclient 
sets certain environment variables. 
.SH OPTIONS
.B General Options: 
.TP
.B \-q
Quiet. Do not print error messages. 
.TP
.B \-Q
(Default.) Print error messages. 
.TP
.B \-v 
Verbose. Print error messages and status messages.
.P
.B Connection options: 
.TP
.B \-4
Use IPv4 sockets for connections and DNS queries. 
.TP
.B \-6
Force IPv6 mode for connections and set up in UCSPI environment variables. 
.TP
.B \-T \fIx+y
Give up on the connection attempt or SSL connection attempt after 
.I x+y 
seconds. The default value is: 2+58. When a 
.I host 
has several IP addresses,
.B sslclient 
tries to connect to the first IP address, waits 
.I x 
seconds, tries to connect to the second IP address, waits 
- Ix 
seconds, etc.; then it retries each address that timed out, waiting 
.I y 
seconds per address. You may omit 
.I +y 
to skip the second try. 
.TP
.B \-i \fIlocalip
Use 
.I localip 
as the IP address for the local side of the connection; quit if 
.I localip 
is not available. Normally 
.B sslclient 
lets the operating system choose an address. 
.TP
.B \-p \fIlocalport
Use 
.I localport
as the TCP port for the local side of the connection; quit if 
.I localport 
is not available. Normally 
.B sslclient 
lets the operating system choose a port. 
.TP
.B \-d
Delay sending data for a fraction of a second whenever 
the remote host is responding slowly. 
This is currently the default, but it may not be in the future; 
if you want it, set it explicitly. 
.TP 
.B \-D
Never delay sending data; enable TCP_NODELAY. 
.TP
.B \-I \fIifname
Use
.I ifname
as the local network interface.  This is only defined for IPv6 sockets
and needed if you use link-local IPv6 addresses.
.TP
.B \-M
(Default.) No Server Name Indications are present.
.TP
.B \-m
Employ Server Name Indication (SNI) for 
the given
.I hostname
in the Client Helo.

\fINote\fR: You can use \fIDNSCACHEIP\fR to set the DNS resolver IP dynamically.

.P
.B X509 certificate handling:
.TP
.B \-3
Read a null-terminated 
.I key password 
from file descriptor 3. 
.TP
.B \-a \fIcafile
Override the compiled-in CA file name. 
The CA file contains the list of CAs used to verify the server certificate. 
.TP
.B \-A \fIcadir
Override the compiled-in CA directory name. 
The CA directory contains certificates files used 
to verify the client certificate. This list augments the list from 
.I \-a \fIcafile. 
.TP
.B \-c \fIcertfile
Use the client certificate in 
.IR certfile . 
.TP
.B \-k \fIkeyfile
Use the client certificate key in 
.IR keyfile . 
.TP
.B \-V \fIverifydepth
Verify the server certificate chain to depth 
.IR verifydepth . 
The default value is 1. 
.TP
.B \-z \fIciphers 
Use the cipher list specified in 
.IR ciphers . 
.TP
.B \-x
(Default.) Verify the server certificate. 
.TP
.B \-X 
Do not verify the server certificate.
.TP
.B \-n 
(Default.) Verify that the server host name matches 
the FQDN provided in the certificate.
.TP
.B \-N
Do not verify that the server host name matches 
the FQDN provided in the certificate.
.P
.B Data-gathering options: 
.TP
.B \-h
(Default.) Look up the remote host name in DNS 
to set the environment variable $SSLREMOTEHOST. 
.TP
.B \-H
Do not look up the remote host name in DNS; 
remove the environment variable $SSLREMOTEHOST. 
.TP
.B \-l \fIlocalname
Do not look up the local host name in DNS; use 
.I localname 
for the environment variable $SSLLOCALHOST. 
A common choice for
.I localname 
is
.I 0
or
.IR :: . 
.TP
.B \-r 
Attempt to obtain $SSLREMOTEINFO from the remote host. 
.TP
.B \-R 
(Default.) Do not attempt to obtain $SSLREMOTEINFO from the remote host. 
.TP
.B \-t \fIn
Give up on the $SSLREMOTEINFO connection attempt after 
.I n 
seconds. The default value is: 26. 
.TP
.B \-w \fIn
Give up on a connection or program after waiting 
.I n 
seconds for read or write. The default value is: 3600. 
.TP
.B \-s 
Store client and server certificate information in the environment, a la mod_ssl.
.TP 
.B \-S
(Default.) Do not store client and server certificate information in the environment. 
.TP
.B \-e 
Set protocol environment a la 
.BR tcpserver . 
Set $PROTO, $TCPLOCALIP, $TCPLOCALPORT, $TCPLOCALHOST, $TCPREMOTEIP, 
$TCPREMOTEPORT, $TCPREMOTEHOST, and $TCPREMOTEINFO 
from the corresponding $SSL variables. 
.TP
.B \-E 
(Default.) Do not set any 
.B tcpserver 
environment variables.
.SH SEE ALSO
sslserver(1),
sslhandle(1),
sslconnect(1),
sslcat(1),
https@(1),
ucspi-tls(2),
tcpclient(1),
tcpserver(1),
tcp-environ(5).
.SH REFERENCE
http://httpd.apache.org/docs/2.4/mod/mod_ssl.html