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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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. Therefore, merely including a client certificate
on the command line is no guarantee that the certificate works.
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.
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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.