=pod
{- OpenSSL::safe::output_do_not_edit_headers(); -}

=head1 NAME

openssl-s_time - SSL/TLS performance timing program

=head1 SYNOPSIS

B<openssl> B<s_time>
[B<-help>]
[B<-connect> I<host>:I<port>]
[B<-www> I<page>]
[B<-cert> I<filename>]
[B<-key> I<filename>]
[B<-reuse>]
[B<-new>]
[B<-verify> I<depth>]
[B<-time> I<seconds>]
[B<-ssl3>]
[B<-tls1>]
[B<-tls1_1>]
[B<-tls1_2>]
[B<-tls1_3>]
[B<-bugs>]
[B<-cipher> I<cipherlist>]
[B<-ciphersuites> I<val>]
{- $OpenSSL::safe::opt_name_synopsis -}
[B<-cafile> I<file>]
{- $OpenSSL::safe::opt_trust_synopsis -}
{- $OpenSSL::safe::opt_provider_synopsis -}

=head1 DESCRIPTION

This command implements a generic SSL/TLS client which
connects to a remote host using SSL/TLS. It can request a page from the server
and includes the time to transfer the payload data in its timing measurements.
It measures the number of connections within a given timeframe, the amount of
data transferred (if any), and calculates the average time spent for one
connection.

=head1 OPTIONS

=over 4

=item B<-help>

Print out a usage message.

=item B<-connect> I<host>:I<port>

This specifies the host and optional port to connect to.
If the host string is an IPv6 address, it must be enclosed in C<[> and C<]>.

=item B<-www> I<page>

This specifies the page to GET from the server. A value of '/' gets the
F<index.html> page. If this parameter is not specified, then this command
will only perform the handshake to establish SSL connections but not transfer
any payload data.

=item B<-cert> I<certname>

The certificate to use, if one is requested by the server. The default is
not to use a certificate. The file is in PEM format.

=item B<-key> I<keyfile>

The private key to use. If not specified then the certificate file will
be used. The file is in PEM format.

=item B<-verify> I<depth>

The verify depth to use. This specifies the maximum length of the
server certificate chain and turns on server certificate verification.
Currently the verify operation continues after errors so all the problems
with a certificate chain can be seen. As a side effect the connection
will never fail due to a server certificate verify failure.

=item B<-new>

Performs the timing test using a new session ID for each connection.
If neither B<-new> nor B<-reuse> are specified, they are both on by default
and executed in sequence.

=item B<-reuse>

Performs the timing test using the same session ID; this can be used as a test
that session caching is working. If neither B<-new> nor B<-reuse> are
specified, they are both on by default and executed in sequence.

=item B<-bugs>

There are several known bugs in SSL and TLS implementations. Adding this
option enables various workarounds.

=item B<-cipher> I<cipherlist>

This allows the TLSv1.2 and below cipher list sent by the client to be modified.
This list will be combined with any TLSv1.3 ciphersuites that have been
configured. Although the server determines which cipher suite is used it should
take the first supported cipher in the list sent by the client. See
L<openssl-ciphers(1)> for more information.

=item B<-ciphersuites> I<val>

This allows the TLSv1.3 ciphersuites sent by the client to be modified. This
list will be combined with any TLSv1.2 and below ciphersuites that have been
configured. Although the server determines which cipher suite is used it should
take the first supported cipher in the list sent by the client. See
L<openssl-ciphers(1)> for more information. The format for this list is a
simple colon (":") separated list of TLSv1.3 ciphersuite names.

=item B<-time> I<length>

Specifies how long (in seconds) this command should establish connections
and optionally transfer payload data from a server. Server and client
performance and the link speed determine how many connections it
can establish.

{- $OpenSSL::safe::opt_name_item -}

{- $OpenSSL::safe::opt_trust_item -}

{- $OpenSSL::safe::opt_provider_item -}

=item B<-cafile> I<file>

This is an obsolete synonym for B<-CAfile>.

=item B<-ssl3>, B<-tls1>, B<-tls1_1>, B<-tls1_2>, B<-tls1_3>

See L<openssl(1)/TLS Version Options>.

=back

=head1 NOTES

This command can be used to measure the performance of an SSL connection.
To connect to an SSL HTTP server and get the default page the command

 openssl s_time -connect servername:443 -www / -CApath yourdir -CAfile yourfile.pem -cipher commoncipher [-ssl3]

would typically be used (https uses port 443). I<commoncipher> is a cipher to
which both client and server can agree, see the L<openssl-ciphers(1)> command
for details.

If the handshake fails then there are several possible causes, if it is
nothing obvious like no client certificate then the B<-bugs> and
B<-ssl3> options can be tried
in case it is a buggy server. In particular you should play with these
options B<before> submitting a bug report to an OpenSSL mailing list.

A frequent problem when attempting to get client certificates working
is that a web client complains it has no certificates or gives an empty
list to choose from. This is normally because the server is not sending
the clients certificate authority in its "acceptable CA list" when it
requests a certificate. By using L<openssl-s_client(1)> the CA list can be
viewed and checked. However, some servers only request client authentication
after a specific URL is requested. To obtain the list in this case it
is necessary to use the B<-prexit> option of L<openssl-s_client(1)> and
send an HTTP request for an appropriate page.

If a certificate is specified on the command line using the B<-cert>
option it will not be used unless the server specifically requests
a client certificate. Therefore, merely including a client certificate
on the command line is no guarantee that the certificate works.

=head1 BUGS

Because this program does not have all the options of the
L<openssl-s_client(1)> program to turn protocols on and off, you may not
be able to measure the performance of all protocols with all servers.

The B<-verify> option should really exit if the server verification
fails.

=head1 HISTORY

The B<-cafile> option was deprecated in OpenSSL 3.0.

=head1 SEE ALSO

L<openssl(1)>,
L<openssl-s_client(1)>,
L<openssl-s_server(1)>,
L<openssl-ciphers(1)>,
L<ossl_store-file(7)>

=head1 COPYRIGHT

Copyright 2004-2024 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
L<https://www.openssl.org/source/license.html>.

=cut
