MAN page from Trustix openssl-0.9.7m-1tr.i586.rpm


Section: OpenSSL (1)
Updated: 2004-01-08


s_time - SSL/TLS performance timing program 


openssl s_time[-connect host:port][-www page][-cert filename][-key filename][-CApath directory][-CAfile filename][-reuse][-new][-verify depth][-nbio][-time seconds][-ssl2][-ssl3][-bugs][-cipher cipherlist] 


The 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. 


-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 theindex.htm[l] page. If this parameter is not specified, then s_time will onlyperform the handshake to establish SSL connections but not transfer anypayload data.
-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.
-key keyfile
The private key to use. If not specified then the certificate file willbe used. The file is in PEM format.
-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.
-CApath directory
The directory to use for server certificate verification. This directorymust be in ``hash format'', see verify for more information. These arealso used when building the client certificate chain.
-CAfile file
A file containing trusted certificates to use during server authenticationand to use when attempting to build 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 defaultand executed in sequence.
performs the timing test using the same session ID; this can be used as a testthat session caching is working. If neither -new nor -reuse arespecified, they are both on by default and executed in sequence.
turns on non-blocking I/O.
-ssl2, -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 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 -ssl3 option; otherswill only support SSL v2 and may need the -ssl2 option.

there are several known bug in SSL and TLS implementations. Adding thisoption enables various workarounds.
-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 ciphers(1) command for more information.
-time length
specifies how long (in seconds) s_time should establish connections andoptionally transfer payload data from a server. Server and client performanceand the link speed determine how many connections s_time can establish.


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 ciphers(1) commandfor details.

If the handshake fails then there are several possible causes, if it isnothing obvious like no client certificate then the -bugs, -ssl2,-ssl3 options can be triedin case it is a buggy server. In particular you should play with theseoptions 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 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 -prexit option of s_client(1) andsend an HTTP request for an appropriate page.

If a certificate is specified on the command line using the -certoption 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. 


Because this program does not have all the options of thes_client(1) program to turn protocols on and off, you may not beable to measure the performance of all protocols with all servers.

The -verify option should really exit if the server verificationfails. 


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




This document was created byman2html,using the manual pages.