=head1 SYNOPSIS
B<openssl> B<s_client>
-[B<-connect> host:port>]
+[B<-connect host:port>]
+[B<-servername name>]
[B<-verify depth>]
+[B<-verify_return_error>]
[B<-cert filename>]
+[B<-certform DER|PEM>]
[B<-key filename>]
+[B<-keyform DER|PEM>]
+[B<-pass arg>]
[B<-CApath directory>]
[B<-CAfile filename>]
+[B<-trusted_first>]
+[B<-attime timestamp>]
+[B<-check_ss_sig>]
+[B<-crl_check>]
+[B<-crl_check_all>]
+[B<-explicit_policy>]
+[B<-extended_crl>]
+[B<-ignore_critical>]
+[B<-inhibit_any>]
+[B<-inhibit_map>]
+[B<-issuer_checks>]
+[B<-partial_chain>]
+[B<-policy arg>]
+[B<-policy_check>]
+[B<-policy_print>]
+[B<-purpose purpose>]
+[B<-suiteB_128>]
+[B<-suiteB_128_only>]
+[B<-suiteB_192>]
+[B<-trusted_first>]
+[B<-use_deltas>]
+[B<-verify_depth num>]
+[B<-verify_email email>]
+[B<-verify_hostname hostname>]
+[B<-verify_ip ip>]
+[B<-verify_name name>]
+[B<-x509_strict>]
[B<-reconnect>]
[B<-pause>]
[B<-showcerts>]
[B<-debug>]
+[B<-msg>]
[B<-nbio_test>]
[B<-state>]
[B<-nbio>]
[B<-crlf>]
[B<-ign_eof>]
+[B<-no_ign_eof>]
[B<-quiet>]
[B<-ssl2>]
[B<-ssl3>]
[B<-no_tls1>]
[B<-bugs>]
[B<-cipher cipherlist>]
+[B<-serverpref>]
+[B<-starttls protocol>]
+[B<-xmpphost hostname>]
[B<-engine id>]
+[B<-tlsextdebug>]
+[B<-no_ticket>]
+[B<-sess_out filename>]
+[B<-sess_in filename>]
+[B<-rand file(s)>]
+[B<-serverinfo types>]
+[B<-status>]
=head1 DESCRIPTION
=head1 OPTIONS
+In addition to the options below the B<s_client> utility also supports the
+common and client only options documented in the
+in the L<SSL_CONF_cmd(3)|SSL_CONF_cmd(3)/SUPPORTED COMMAND LINE COMMANDS>
+manual page.
+
=over 4
=item B<-connect host:port>
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<-servername name>
+
+Set the TLS SNI (Server Name Indication) extension in the ClientHello message.
+
=item B<-cert certname>
The certificate to use, if one is requested by the server. The default is
not to use a certificate.
+=item B<-certform format>
+
+The certificate format to use: DER or PEM. PEM is the default.
+
=item B<-key keyfile>
The private key to use. If not specified then the certificate file will
be used.
+=item B<-keyform format>
+
+The private format to use: DER or PEM. PEM is the default.
+
+=item B<-pass arg>
+
+the private key password source. For more information about the format of B<arg>
+see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
+
=item B<-verify depth>
The verify depth to use. This specifies the maximum length of the
with a certificate chain can be seen. As a side effect the connection
will never fail due to a server certificate verify failure.
+=item B<-verify_return_error>
+
+Return verification errors instead of continuing. This will typically
+abort the handshake with a fatal error.
+
=item B<-CApath directory>
The directory to use for server certificate verification. This directory
A file containing trusted certificates to use during server authentication
and to use when attempting to build the client certificate chain.
+=item B<-attime>, B<-check_ss_sig>, B<-crl_check>, B<-crl_check_all>,
+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>
+
+Set various certificate chain valiadition options. See the
+L<B<verify>|verify(1)> manual page for details.
+
=item B<-reconnect>
reconnects to the same server 5 times using the same session ID, this can
print extensive debugging information including a hex dump of all traffic.
+=item B<-msg>
+
+show all protocol messages with hex dump.
+
+=item B<-trace>
+
+show verbose trace output of protocol messages. OpenSSL needs to be compiled
+with B<enable-ssl-trace> for this option to work.
+
+=item B<-msgfile>
+
+file to send output of B<-msg> or B<-trace> to, default standard output.
+
=item B<-nbio_test>
tests non-blocking I/O
=item B<-quiet>
-inhibit printing of session and certificate information. This implicitely
+inhibit printing of session and certificate information. This implicitly
turns on B<-ign_eof> as well.
+=item B<-no_ign_eof>
+
+shut down the connection when end of file is reached in the input.
+Can be used to override the implicit B<-ign_eof> after B<-quiet>.
+
+=item B<-psk_identity identity>
+
+Use the PSK identity B<identity> when using a PSK cipher suite.
+
+=item B<-psk key>
+
+Use the PSK key B<key> when using a PSK cipher suite. The key is
+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>
these options disable the use of certain SSL or TLS protocols. By default
there are several known bug in SSL and TLS implementations. Adding this
option enables various workarounds.
+=item B<-brief>
+
+only provide a brief summary of connection parameters instead of the
+normal verbose output.
+
=item B<-cipher cipherlist>
this allows the cipher list sent by the client to be modified. Although
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".
+
+=item B<-xmpphost hostname>
+
+This option, when used with "-starttls xmpp", 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.
+
+=item B<-tlsextdebug>
+
+print out a hex dump of any TLS extensions received from the server.
+
+=item B<-no_ticket>
+
+disable RFC4507bis session ticket support.
+
+=item B<-sess_out filename>
+
+output SSL session to B<filename>
+
+=item B<-sess_in sess.pem>
+
+load SSL session from B<filename>. The client will attempt to resume a
+connection from this session.
+
=item B<-engine id>
-specifying an engine (by it's unique B<id> string) will cause B<s_client>
+specifying an engine (by its unique B<id> string) will cause B<s_client>
to attempt to obtain a functional reference to the specified engine,
thus initialising it if needed. The engine will then be set as the default
for all available algorithms.
+=item B<-rand file(s)>
+
+a file or files containing random data used to seed the random number
+generator, or an EGD socket (see L<RAND_egd(3)|RAND_egd(3)>).
+Multiple files can be specified separated by a OS-dependent character.
+The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
+all others.
+
+=item B<-serverinfo types>
+
+a list of comma-separated TLS Extension Types (numbers between 0 and
+65535). Each type will be sent as an empty ClientHello TLS Extension.
+The server's response (if any) will be encoded and displayed as a PEM
+file.
+
+=item B<-status>
+
+sends a certificate status request to the server (OCSP stapling). The server
+response (if any) is printed out.
+
=back
=head1 CONNECTED COMMANDS
If a connection is established with an SSL server then any data received
from the server is displayed and any key presses will be sent to the
server. When used interactively (which means neither B<-quiet> nor B<-ign_eof>
-have been given), the session will be renegociated if the line begins with an
+have been given), the session will be renegotiated if the line begins with an
B<R>, and if the line begins with a B<Q> or if end of file is reached, the
connection will be closed down.
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> can be tried
+B<-ssl3>, B<-tls1>, B<-no_ssl2>, 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.
requests a certificate. By using B<s_client> the CA list can be viewed
and checked. However some servers only request client authentication
after a specific URL is requested. To obtain the list in this case it
-is necessary to use the B<-prexit> command and send an HTTP request
+is necessary to use the B<-prexit> option and send an HTTP request
for an appropriate page.
If a certificate is specified on the command line using the B<-cert>
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
+applications should B<not> do this as it makes them vulnerable to a MITM
+attack. This behaviour can be changed by with the B<-verify_return_error>
+option: any verify errors are then returned aborting the handshake.
+
=head1 BUGS
Because this program has a lot of options and also because some of
hard to read and not a model of how things should be done. A typical
SSL client program would be much simpler.
-The B<-verify> option should really exit if the server verification
-fails.
-
The B<-prexit> option is a bit of a hack. We should really report
information whenever a session is renegotiated.
projects / openssl.git / blobdiff