NAME

       openssl-s_time, s_time - SSL/TLS performance timing program

SYNOPSIS

       openssl s_time [-help] [-connect host:port] [-www page] [-cert filename] [-key filename]
       [-CApath directory] [-cafile filename] [-no-CAfile] [-no-CApath] [-reuse] [-new] [-verify
       depth] [-nameopt option] [-time seconds] [-ssl3] [-bugs] [-cipher cipherlist]
       [-ciphersuites val]

DESCRIPTION

       The s_time 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.

OPTIONS

       -help
           Print out a usage message.

       -connect host:port
           This specifies the host and optional port to connect to.

       -www page
           This specifies the page to GET from the server. A value of '/' gets the index.htm[l]
           page. If this parameter is not specified, then s_time will only perform the handshake
           to establish SSL connections but not transfer any payload data.

       -cert 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.

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

       -verify 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.

       -nameopt option
           Option which determines how the subject or issuer names are displayed. The option
           argument can be a single option or multiple options separated by commas.
           Alternatively the -nameopt switch may be used more than once to set multiple options.
           See the x509(1) manual page for details.

       -CApath directory
           The directory to use for server certificate verification. This directory must be in
           "hash format", see verify for more information. These are also used when building the
           client certificate chain.

       -CAfile file
           A file containing trusted certificates to use during server authentication and to use
           when attempting to build the client certificate chain.

       -no-CAfile
           Do not load the trusted CA certificates from the default file location

       -no-CApath
           Do not load the trusted CA certificates from the default directory location

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

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

       -ssl3
           This option disables the use of SSL version 3. By default the initial handshake uses a
           method which should be compatible with all servers and permit them to use SSL v3 or
           TLS as appropriate.

           The timing program is not as rich in options to turn protocols on and off as the
           s_client(1) program and may not connect to all servers.  Unfortunately there are a lot
           of ancient and broken servers in use which cannot handle this technique and will fail
           to connect. Some servers only work if TLS is turned off with the -ssl3 option.

           Note that this option may not be available, depending on how OpenSSL was built.

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

       -cipher 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 ciphers(1) for more information.

       -ciphersuites 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 ciphers(1) for more information.
           The format for this list is a simple colon (":") separated list of TLSv1.3 ciphersuite
           names.

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

NOTES

       s_time 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). 'commoncipher' is a cipher to which both
       client and server can agree, see the 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 -bugs and -ssl3 options can be tried in case it is a
       buggy server. In particular you should play with these options 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 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 -prexit option of
       s_client(1) and send an HTTP request for an appropriate page.

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

BUGS

       Because this program does not have all the options of the 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 -verify option should really exit if the server verification fails.

SEE ALSO

       s_client(1), s_server(1), ciphers(1)

COPYRIGHT

       Copyright 2004-2019 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the OpenSSL license (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 <https://www.openssl.org/source/license.html>.