6 s_time - SSL/TLS performance timing program
12 [B<-connect host:port>]
16 [B<-CApath directory>]
27 [B<-cipher cipherlist>]
28 [B<-ciphersuites val>]
32 The B<s_time> command implements a generic SSL/TLS client which connects to a
33 remote host using SSL/TLS. It can request a page from the server and includes
34 the time to transfer the payload data in its timing measurements. It measures
35 the number of connections within a given timeframe, the amount of data
36 transferred (if any), and calculates the average time spent for one connection.
44 Print out a usage message.
46 =item B<-connect host:port>
48 This specifies the host and optional port to connect to.
52 This specifies the page to GET from the server. A value of '/' gets the
53 index.htm[l] page. If this parameter is not specified, then B<s_time> will only
54 perform the handshake to establish SSL connections but not transfer any
57 =item B<-cert certname>
59 The certificate to use, if one is requested by the server. The default is
60 not to use a certificate. The file is in PEM format.
64 The private key to use. If not specified then the certificate file will
65 be used. The file is in PEM format.
67 =item B<-verify depth>
69 The verify depth to use. This specifies the maximum length of the
70 server certificate chain and turns on server certificate verification.
71 Currently the verify operation continues after errors so all the problems
72 with a certificate chain can be seen. As a side effect the connection
73 will never fail due to a server certificate verify failure.
75 =item B<-nameopt option>
77 Option which determines how the subject or issuer names are displayed. The
78 B<option> argument can be a single option or multiple options separated by
79 commas. Alternatively the B<-nameopt> switch may be used more than once to
80 set multiple options. See the L<x509(1)> manual page for details.
82 =item B<-CApath directory>
84 The directory to use for server certificate verification. This directory
85 must be in "hash format", see B<verify> for more information. These are
86 also used when building the client certificate chain.
90 A file containing trusted certificates to use during server authentication
91 and to use when attempting to build the client certificate chain.
95 Do not load the trusted CA certificates from the default file location
99 Do not load the trusted CA certificates from the default directory location
103 Performs the timing test using a new session ID for each connection.
104 If neither B<-new> nor B<-reuse> are specified, they are both on by default
105 and executed in sequence.
109 Performs the timing test using the same session ID; this can be used as a test
110 that session caching is working. If neither B<-new> nor B<-reuse> are
111 specified, they are both on by default and executed in sequence.
115 These options disable the use of certain SSL or TLS protocols. By default
116 the initial handshake uses a method which should be compatible with all
117 servers and permit them to use SSL v3 or TLS as appropriate.
118 The timing program is not as rich in options to turn protocols on and off as
119 the L<s_client(1)> program and may not connect to all servers.
121 Unfortunately there are a lot of ancient and broken servers in use which
122 cannot handle this technique and will fail to connect. Some servers only
123 work if TLS is turned off with the B<-ssl3> option.
127 There are several known bug in SSL and TLS implementations. Adding this
128 option enables various workarounds.
130 =item B<-cipher cipherlist>
132 This allows the TLSv1.2 and below cipher list sent by the client to be modified.
133 This list will be combined with any TLSv1.3 ciphersuites that have been
134 configured. Although the server determines which cipher suite is used it should
135 take the first supported cipher in the list sent by the client. See the
136 L<ciphers(1)> command for more information.
138 =item B<-ciphersuites val>
140 This allows the TLSv1.3 ciphersuites sent by the client to be modified. This
141 list will be combined with any TLSv1.2 and below ciphersuites that have been
142 configured. Although the server determines which cipher suite is used it should
143 take the first supported cipher in the list sent by the client. See the
144 B<ciphers> command for more information. The format for this list is a simple
145 colon (":") separated list of TLSv1.3 ciphersuite names.
147 =item B<-time length>
149 Specifies how long (in seconds) B<s_time> should establish connections and
150 optionally transfer payload data from a server. Server and client performance
151 and the link speed determine how many connections B<s_time> can establish.
157 B<s_time> can be used to measure the performance of an SSL connection.
158 To connect to an SSL HTTP server and get the default page the command
160 openssl s_time -connect servername:443 -www / -CApath yourdir -CAfile yourfile.pem -cipher commoncipher [-ssl3]
162 would typically be used (https uses port 443). 'commoncipher' is a cipher to
163 which both client and server can agree, see the L<ciphers(1)> command
166 If the handshake fails then there are several possible causes, if it is
167 nothing obvious like no client certificate then the B<-bugs> and
168 B<-ssl3> options can be tried
169 in case it is a buggy server. In particular you should play with these
170 options B<before> submitting a bug report to an OpenSSL mailing list.
172 A frequent problem when attempting to get client certificates working
173 is that a web client complains it has no certificates or gives an empty
174 list to choose from. This is normally because the server is not sending
175 the clients certificate authority in its "acceptable CA list" when it
176 requests a certificate. By using L<s_client(1)> the CA list can be
177 viewed and checked. However some servers only request client authentication
178 after a specific URL is requested. To obtain the list in this case it
179 is necessary to use the B<-prexit> option of L<s_client(1)> and
180 send an HTTP request for an appropriate page.
182 If a certificate is specified on the command line using the B<-cert>
183 option it will not be used unless the server specifically requests
184 a client certificate. Therefor merely including a client certificate
185 on the command line is no guarantee that the certificate works.
189 Because this program does not have all the options of the
190 L<s_client(1)> program to turn protocols on and off, you may not be
191 able to measure the performance of all protocols with all servers.
193 The B<-verify> option should really exit if the server verification
198 L<s_client(1)>, L<s_server(1)>, L<ciphers(1)>
202 Copyright 2004-2018 The OpenSSL Project Authors. All Rights Reserved.
204 Licensed under the OpenSSL license (the "License"). You may not use
205 this file except in compliance with the License. You can obtain a copy
206 in the file LICENSE in the source distribution or at
207 L<https://www.openssl.org/source/license.html>.