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] [-trusted_first]
11 [-reuse] [-new] [-verify depth] [-nbio] [-time seconds] [-ssl2] [-ssl3]
12 [-bugs] [-cipher cipherlist]
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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
18 measurements. It measures the number of connections within a given
19 timeframe, 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
43 verification. Currently the verify operation continues after
44 errors so all the problems with a certificate chain can be seen. As
45 a side effect the connection will never fail due to a server
46 certificate verify 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
51 information. These are also used when building the client
52 certificate chain.
53 -CAfile file
55 A file containing trusted certificates to use during server
56 authentication and to use when attempting to build the client
57 certificate chain.
58 -trusted_first
60 Use certificates in CA file or CA directory over the certificates
61 provided by the server when building the trust chain to verify
62 server certificate. This is mainly useful in environments with
63 Bridge CA or Cross-Certified CAs.
64 -new
66 performs the timing test using a new session ID for each
67 connection. If neither -new nor -reuse are specified, they are
68 both on by default and executed in sequence.
69 -reuse
71 performs the timing test using the same session ID; this can be
72 used as a test that session caching is working. If neither -new nor
73 -reuse are specified, they are both on by default and executed in
74 sequence.
75 -nbio
77 turns on non-blocking I/O.
78 -ssl2, -ssl3
80 these options disable the use of certain SSL or TLS protocols. By
81 default the initial handshake uses a method which should be
82 compatible with all servers and permit them to use SSL v3, SSL v2
83 or TLS as appropriate. The timing program is not as rich in
84 options to turn protocols on and off as the s_client(1) program and
85 may not connect to all servers.
86 Unfortunately there are a lot of ancient and broken servers in use
88 which cannot handle this technique and will fail to connect. Some
89 servers only work if TLS is turned off with the -ssl3 option;
90 others will only support SSL v2 and may need the -ssl2 option.
91 -bugs
93 there are several known bug in SSL and TLS implementations. Adding
94 this option enables various workarounds.
95 -cipher cipherlist
97 this allows the cipher list sent by the client to be modified.
98 Although the server determines which cipher suite is used it should
99 take the first supported cipher in the list sent by the client.
100 See the ciphers(1) command for more information.
101 -time length
103 specifies how long (in seconds) s_time should establish connections
104 and optionally transfer payload data from a server. Server and
105 client performance and the link speed determine how many
106 connections s_time can establish.
107
109 s_client can be used to measure the performance of an SSL connection.
110 To connect to an SSL HTTP server and get the default page the command
111 openssl s_time -connect servername:443 -www / -CApath yourdir -CAfile yourfile.pem -cipher commoncipher [-ssl3]
113 would typically be used (https uses port 443). 'commoncipher' is a
115 cipher to which both client and server can agree, see the ciphers(1)
116 command for details.
117 If the handshake fails then there are several possible causes, if it is
119 nothing obvious like no client certificate then the -bugs, -ssl2, -ssl3
120 options can be tried in case it is a buggy server. In particular you
121 should play with these options before submitting a bug report to an
122 OpenSSL mailing list.
123 A frequent problem when attempting to get client certificates working
125 is that a web client complains it has no certificates or gives an empty
126 list to choose from. This is normally because the server is not sending
127 the clients certificate authority in its "acceptable CA list" when it
128 requests a certificate. By using s_client(1) the CA list can be viewed
129 and checked. However some servers only request client authentication
130 after a specific URL is requested. To obtain the list in this case it
131 is necessary to use the -prexit option of s_client(1) and send an HTTP
132 request for an appropriate page.
133 If a certificate is specified on the command line using the -cert
135 option it will not be used unless the server specifically requests a
136 client certificate. Therefor merely including a client certificate on
137 the command line is no guarantee that the certificate works.
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140 Because this program does not have all the options of the s_client(1)
141 program to turn protocols on and off, you may not be able to measure
142 the performance of all protocols with all servers.
143 The -verify option should really exit if the server verification fails.
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147 s_client(1), s_server(1), ciphers(1)
1481.0.1e 2017-03-22 S_TIME(1)