1S_TIME(1) OpenSSL S_TIME(1)
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6 s_time - SSL/TLS performance timing program
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9 openssl s_time [-connect host:port] [-www page] [-cert filename] [-key
10 filename] [-CApath directory] [-CAfile filename] [-reuse] [-new] [-ver‐
11 ify depth] [-nbio] [-time seconds] [-ssl2] [-ssl3] [-bugs] [-cipher
12 cipherlist]
13
15 The s_client command implements a generic SSL/TLS client which connects
16 to a remote host using SSL/TLS. It can request a page from the server
17 and includes the time to transfer the payload data in its timing mea‐
18 surements. It measures the number of connections within a given time‐
19 frame, the amount of data transferred (if any), and calculates the
20 average time spent for one connection.
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23 -connect host:port
24 This specifies the host and optional port to connect to.
25 -www page
27 This specifies the page to GET from the server. A value of '/' gets
28 the index.htm[l] page. If this parameter is not specified, then
29 s_time will only perform the handshake to establish SSL connections
30 but not transfer any payload data.
31 -cert certname
33 The certificate to use, if one is requested by the server. The
34 default is not to use a certificate. The file is in PEM format.
35 -key keyfile
37 The private key to use. If not specified then the certificate file
38 will be used. The file is in PEM format.
39 -verify depth
41 The verify depth to use. This specifies the maximum length of the
42 server certificate chain and turns on server certificate verifica‐
43 tion. Currently the verify operation continues after errors so all
44 the problems with a certificate chain can be seen. As a side effect
45 the connection will never fail due to a server certificate verify
46 failure.
47 -CApath directory
49 The directory to use for server certificate verification. This
50 directory must be in "hash format", see verify for more informa‐
51 tion. These are also used when building the client certificate
52 chain.
53 -CAfile file
55 A file containing trusted certificates to use during server authen‐
56 tication and to use when attempting to build the client certificate
57 chain.
58 -new
60 performs the timing test using a new session ID for each connec‐
61 tion. If neither -new nor -reuse are specified, they are both on
62 by default and executed in sequence.
63 -reuse
65 performs the timing test using the same session ID; this can be
66 used as a test that session caching is working. If neither -new nor
67 -reuse are specified, they are both on by default and executed in
68 sequence.
69 -nbio
71 turns on non-blocking I/O.
72 -ssl2, -ssl3
74 these options disable the use of certain SSL or TLS protocols. By
75 default the initial handshake uses a method which should be compat‐
76 ible with all servers and permit them to use SSL v3, SSL v2 or TLS
77 as appropriate. The timing program is not as rich in options to
78 turn protocols on and off as the s_client(1) program and may not
79 connect to all servers.
80 Unfortunately there are a lot of ancient and broken servers in use
82 which cannot handle this technique and will fail to connect. Some
83 servers only work if TLS is turned off with the -ssl3 option; oth‐
84 ers will only support SSL v2 and may need the -ssl2 option.
85 -bugs
87 there are several known bug in SSL and TLS implementations. Adding
88 this option enables various workarounds.
89 -cipher cipherlist
91 this allows the cipher list sent by the client to be modified.
92 Although the server determines which cipher suite is used it should
93 take the first supported cipher in the list sent by the client.
94 See the ciphers(1) command for more information.
95 -time length
97 specifies how long (in seconds) s_time should establish connections
98 and optionally transfer payload data from a server. Server and
99 client performance and the link speed determine how many connec‐
100 tions s_time can establish.
101
103 s_client can be used to measure the performance of an SSL connection.
104 To connect to an SSL HTTP server and get the default page the command
105 openssl s_time -connect servername:443 -www / -CApath yourdir -CAfile yourfile.pem -cipher commoncipher [-ssl3]
107 would typically be used (https uses port 443). 'commoncipher' is a
109 cipher to which both client and server can agree, see the ciphers(1)
110 command for details.
111 If the handshake fails then there are several possible causes, if it is
113 nothing obvious like no client certificate then the -bugs, -ssl2, -ssl3
114 options can be tried in case it is a buggy server. In particular you
115 should play with these options before submitting a bug report to an
116 OpenSSL mailing list.
117 A frequent problem when attempting to get client certificates working
119 is that a web client complains it has no certificates or gives an empty
120 list to choose from. This is normally because the server is not sending
121 the clients certificate authority in its "acceptable CA list" when it
122 requests a certificate. By using s_client(1) the CA list can be viewed
123 and checked. However some servers only request client authentication
124 after a specific URL is requested. To obtain the list in this case it
125 is necessary to use the -prexit option of s_client(1) and send an HTTP
126 request for an appropriate page.
127 If a certificate is specified on the command line using the -cert
129 option it will not be used unless the server specifically requests a
130 client certificate. Therefor merely including a client certificate on
131 the command line is no guarantee that the certificate works.
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134 Because this program does not have all the options of the s_client(1)
135 program to turn protocols on and off, you may not be able to measure
136 the performance of all protocols with all servers.
137 The -verify option should really exit if the server verification fails.
139
141 s_client(1), s_server(1), ciphers(1)
1420.9.8b 2004-01-08 S_TIME(1)