B<openssl> B<s_client>
[B<-connect host:port>]
+[B<-proxy host:port>]
[B<-servername name>]
[B<-verify depth>]
[B<-verify_return_error>]
[B<-pass arg>]
[B<-CApath directory>]
[B<-CAfile filename>]
-[B<-trusted_first>]
[B<-attime timestamp>]
[B<-check_ss_sig>]
[B<-crl_check>]
[B<-suiteB_128_only>]
[B<-suiteB_192>]
[B<-trusted_first>]
+[B<-no_alt_chains>]
[B<-use_deltas>]
[B<-verify_depth num>]
[B<-verify_email email>]
[B<-ign_eof>]
[B<-no_ign_eof>]
[B<-quiet>]
-[B<-ssl2>]
[B<-ssl3>]
[B<-tls1>]
-[B<-no_ssl2>]
[B<-no_ssl3>]
[B<-no_tls1>]
+[B<-no_tls1_1>]
+[B<-no_tls1_2>]
+[B<-fallback_scsv>]
[B<-bugs>]
[B<-cipher cipherlist>]
[B<-serverpref>]
[B<-sess_in filename>]
[B<-rand file(s)>]
[B<-serverinfo types>]
-[B<-auth>]
-[B<-auth_require_reneg>]
+[B<-status>]
+[B<-nextprotoneg protocols>]
=head1 DESCRIPTION
This specifies the host and optional port to connect to. If not specified
then an attempt is made to connect to the local host on port 4433.
+=item B<-proxy host:port>
+
+When used with the B<-connect> flag, the program uses the host and port
+specified with this flag and issues an HTTP CONNECT command to connect
+to the desired server.
+
=item B<-servername name>
Set the TLS SNI (Server Name Indication) extension in the ClientHello message.
B<explicit_policy>, B<-extended_crl>, B<-ignore_critical>, B<-inhibit_any>,
B<-inhibit_map>, B<-issuer_checks>, B<-partial_chain>, B<-policy>,
B<-policy_check>, B<-policy_print>, B<-purpose>, B<-suiteB_128>,
-B<-suiteB_128_only>, B<-suiteB_192>, B<-trusted_first>, B<-use_deltas>,
-B<-verify_depth>, B<-verify_email>, B<-verify_hostname>, B<-verify_ip>,
-B<-verify_name>, B<-x509_strict>
+B<-suiteB_128_only>, B<-suiteB_192>, B<-trusted_first>, B<-no_alt_chains>,
+B<-use_deltas>, B<-verify_depth>, B<-verify_email>, B<-verify_hostname>,
+B<-verify_ip>, B<-verify_name>, B<-x509_strict>
-Set various certificate chain valiadition options. See the
+Set various certificate chain validation options. See the
L<B<verify>|verify(1)> manual page for details.
=item B<-reconnect>
given as a hexadecimal number without leading 0x, for example -psk
1a2b3c4d.
-=item B<-ssl2>, B<-ssl3>, B<-tls1>, B<-no_ssl2>, B<-no_ssl3>, B<-no_tls1>
+=item B<-ssl3>, B<-tls1>, B<-no_ssl3>, B<-no_tls1>, B<-no_tls1_1>, B<-no_tls1_2>
these options disable the use of certain SSL or TLS protocols. By default
the initial handshake uses a method which should be compatible with all
-servers and permit them to use SSL v3, SSL v2 or TLS as appropriate.
+servers and permit them to use SSL v3 or TLS as appropriate.
-Unfortunately there are a lot of ancient and broken servers in use which
+Unfortunately there are still ancient and broken servers in use which
cannot handle this technique and will fail to connect. Some servers only
-work if TLS is turned off with the B<-no_tls> option others will only
-support SSL v2 and may need the B<-ssl2> option.
+work if TLS is turned off.
+
+=item B<-fallback_scsv>
+
+Send TLS_FALLBACK_SCSV in the ClientHello.
=item B<-bugs>
supported cipher in the list sent by the client. See the B<ciphers>
command for more information.
-=item B<-serverpref>
-
-use the server's cipher preferences; only used for SSLV2.
-
=item B<-starttls protocol>
send the protocol-specific message(s) to switch to TLS for communication.
B<protocol> is a keyword for the intended protocol. Currently, the only
-supported keywords are "smtp", "pop3", "imap", "ftp" and "xmpp".
+supported keywords are "smtp", "pop3", "imap", "ftp", "xmpp",
+and "xmpp-server".
=item B<-xmpphost hostname>
-This option, when used with "-starttls xmpp", specifies the host for the
-"to" attribute of the stream element.
+This option, when used with "-starttls xmpp" or "-starttls xmpp-server",
+specifies the host for the "to" attribute of the stream element.
If this option is not specified, then the host specified with "-connect"
will be used.
The server's response (if any) will be encoded and displayed as a PEM
file.
-=item B<-auth>
+=item B<-status>
-send RFC 5878 client and server authorization extensions in the Client Hello as well as
-supplemental data if the server also sent the authorization extensions in the Server Hello.
+sends a certificate status request to the server (OCSP stapling). The server
+response (if any) is printed out.
-=item B<-auth_require_reneg>
+=item B<-nextprotoneg protocols>
-only send RFC 5878 client and server authorization extensions during renegotiation.
+enable Next Protocol Negotiation TLS extension and provide a list of
+comma-separated protocol names that the client should advertise
+support for. The list should contain most wanted protocols first.
+Protocol names are printable ASCII strings, for example "http/1.1" or
+"spdy/3".
+Empty list of protocols is treated specially and will cause the client to
+advertise support for the TLS extension but disconnect just after
+receiving ServerHello with a list of server supported protocols.
=back
then an HTTP command can be given such as "GET /" to retrieve a web page.
If the handshake fails then there are several possible causes, if it is
-nothing obvious like no client certificate then the B<-bugs>, B<-ssl2>,
-B<-ssl3>, B<-tls1>, B<-no_ssl2>, B<-no_ssl3>, B<-no_tls1> options can be tried
+nothing obvious like no client certificate then the B<-bugs>,
+B<-ssl3>, B<-tls1>, B<-no_ssl3>, B<-no_tls1> options can be tried
in case it is a buggy server. In particular you should play with these
options B<before> submitting a bug report to an OpenSSL mailing list.
If there are problems verifying a server certificate then the
B<-showcerts> option can be used to show the whole chain.
-Since the SSLv23 client hello cannot include compression methods or extensions
-these will only be supported if its use is disabled, for example by using the
-B<-no_sslv2> option.
-
The B<s_client> utility is a test tool and is designed to continue the
handshake after any certificate verification errors. As a result it will
accept any certificate chain (trusted or not) sent by the peer. None test
L<sess_id(1)|sess_id(1)>, L<s_server(1)|s_server(1)>, L<ciphers(1)|ciphers(1)>
+=head1 HISTORY
+
+The -no_alt_chains options was first added to OpenSSL 1.1.0.
+
=cut
projects / openssl.git / blobdiff