NAME

       openssl-s_time - SSL/TLS performance timing program

SYNOPSIS

       openssl s_time [-help] [-connect host:port] [-www page] [-cert filename] [-key filename] [-reuse] [-new]
       [-verify depth] [-time seconds] [-ssl3] [-tls1] [-tls1_1] [-tls1_2] [-tls1_3] [-bugs] [-cipher
       cipherlist] [-ciphersuites val] [-nameopt option] [-cafile file] [-CAfile file] [-no-CAfile] [-CApath
       dir] [-no-CApath] [-CAstore uri] [-no-CAstore] [-provider name] [-provider-path path] [-provparam
       [name:]key=value] [-propquery propq]

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.

OPTIONS

       -help
           Print out a usage message.

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

       -www page
           This specifies the page to GET from the server. A value of '/' gets  the  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.

       -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.

       -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.

       -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 openssl-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  openssl-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) 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.

       -nameopt option
           This specifies how the subject or issuer names are displayed.  See openssl-namedisplay-options(1) for
           details.

       -CAfile file, -no-CAfile, -CApath dir, -no-CApath, -CAstore uri, -no-CAstore
           See "Trusted Certificate Options" in openssl-verification-options(1) for details.

       -provider name
       -provider-path path
       -provparam [name:]key=value
       -propquery propq
           See "Provider Options" in openssl(1), provider(7), and property(7).

       -cafile file
           This is an obsolete synonym for -CAfile.

       -ssl3, -tls1, -tls1_1, -tls1_2, -tls1_3
           See "TLS Version Options" in openssl(1).

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). commoncipher is a cipher to which both client and server
       can agree, see the 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 -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 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 -prexit option of openssl-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. Therefore, 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 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 -verify option should really exit if the server verification fails.

HISTORY

       The -cafile option was deprecated in OpenSSL 3.0.

SEE ALSO

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

COPYRIGHT

       Copyright 2004-2021 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
       <https://www.openssl.org/source/license.html>.

3.5.3                                              2025-09-16                               OPENSSL-S_TIME(1SSL)