=pod=head1 NAMEs_time - SSL/TLS performance timing program=head1 SYNOPSISB<openssl> B<s_time>[B<-connect host:port>][B<-www page>][B<-cert filename>][B<-key filename>][B<-CApath directory>][B<-CAfile filename>][B<-reuse>][B<-new>][B<-verify depth>][B<-nbio>][B<-time seconds>][B<-ssl2>][B<-ssl3>][B<-bugs>][B<-cipher cipherlist>]=head1 DESCRIPTIONThe B<s_client> command implements a generic SSL/TLS client which connects to aremote host using SSL/TLS. It can request a page from the server and includesthe time to transfer the payload data in its timing measurements. It measuresthe number of connections within a given timeframe, the amount of datatransferred (if any), and calculates the average time spent for one connection.=head1 OPTIONS=over 4=item B<-connect host:port>This specifies the host and optional port to connect to.=item B<-www page>This specifies the page to GET from the server. A value of '/' gets theindex.htm[l] page. If this parameter is not specified, then B<s_time> will onlyperform the handshake to establish SSL connections but not transfer anypayload data.=item B<-cert certname>The certificate to use, if one is requested by the server. The default isnot to use a certificate. The file is in PEM format.=item B<-key keyfile>The private key to use. If not specified then the certificate file willbe used. The file is in PEM format.=item B<-verify depth>The verify depth to use. This specifies the maximum length of theserver certificate chain and turns on server certificate verification.Currently the verify operation continues after errors so all the problemswith a certificate chain can be seen. As a side effect the connectionwill never fail due to a server certificate verify failure.=item B<-CApath directory>The directory to use for server certificate verification. This directorymust be in "hash format", see B<verify> for more information. These arealso used when building the client certificate chain.=item B<-CAfile file>A file containing trusted certificates to use during server authenticationand to use when attempting to build the client certificate chain.=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 defaultand executed in sequence.=item B<-reuse>performs the timing test using the same session ID; this can be used as a testthat session caching is working. If neither B<-new> nor B<-reuse> arespecified, they are both on by default and executed in sequence.=item B<-nbio>turns on non-blocking I/O.=item B<-ssl2>, B<-ssl3>these options disable the use of certain SSL or TLS protocols. By defaultthe initial handshake uses a method which should be compatible with allservers and permit them to use SSL v3, SSL v2 or TLS as appropriate.The timing program is not as rich in options to turn protocols on and off asthe L<s_client(1)|s_client(1)> program and may not connect to all servers.Unfortunately there are a lot of ancient and broken servers in use whichcannot handle this technique and will fail to connect. Some servers onlywork if TLS is turned off with the B<-ssl3> option; otherswill only support SSL v2 and may need the B<-ssl2> option.=item B<-bugs>there are several known bug in SSL and TLS implementations. Adding thisoption enables various workarounds.=item B<-cipher cipherlist>this allows the cipher list sent by the client to be modified. Althoughthe server determines which cipher suite is used it should take the firstsupported cipher in the list sent by the client.See the L<ciphers(1)|ciphers(1)> command for more information.=item B<-time length>specifies how long (in seconds) B<s_time> should establish connections andoptionally transfer payload data from a server. Server and client performanceand the link speed determine how many connections B<s_time> can establish.=back=head1 NOTESB<s_client> 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 towhich both client and server can agree, see the L<ciphers(1)|ciphers(1)> commandfor details.If the handshake fails then there are several possible causes, if it isnothing obvious like no client certificate then the B<-bugs>, B<-ssl2>,B<-ssl3> options can be triedin case it is a buggy server. In particular you should play with theseoptions B<before> submitting a bug report to an OpenSSL mailing list.A frequent problem when attempting to get client certificates workingis that a web client complains it has no certificates or gives an emptylist to choose from. This is normally because the server is not sendingthe clients certificate authority in its "acceptable CA list" when itrequests a certificate. By using L<s_client(1)|s_client(1)> the CA list can beviewed and checked. However some servers only request client authenticationafter a specific URL is requested. To obtain the list in this case itis necessary to use the B<-prexit> option of L<s_client(1)|s_client(1)> andsend 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 requestsa client certificate. Therefor merely including a client certificateon the command line is no guarantee that the certificate works.=head1 BUGSBecause this program does not have all the options of theL<s_client(1)|s_client(1)> program to turn protocols on and off, you may not beable to measure the performance of all protocols with all servers.The B<-verify> option should really exit if the server verificationfails.=head1 SEE ALSOL<s_client(1)|s_client(1)>, L<s_server(1)|s_server(1)>, L<ciphers(1)|ciphers(1)>=cut