mirror of https://github.com/openssl/openssl
945 lines
29 KiB
Plaintext
945 lines
29 KiB
Plaintext
=pod
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{- OpenSSL::safe::output_do_not_edit_headers(); -}
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=head1 NAME
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openssl-s_client - SSL/TLS client program
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=head1 SYNOPSIS
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B<openssl> B<s_client>
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[B<-help>]
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[B<-ssl_config> I<section>]
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[B<-connect> I<host:port>]
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[B<-host> I<hostname>]
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[B<-port> I<port>]
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[B<-bind> I<host:port>]
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[B<-proxy> I<host:port>]
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[B<-proxy_user> I<userid>]
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[B<-proxy_pass> I<arg>]
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[B<-unix> I<path>]
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[B<-4>]
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[B<-6>]
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[B<-servername> I<name>]
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[B<-noservername>]
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[B<-verify> I<depth>]
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[B<-verify_return_error>]
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[B<-verify_quiet>]
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[B<-verifyCAfile> I<filename>]
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[B<-verifyCApath> I<dir>]
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[B<-verifyCAstore> I<uri>]
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[B<-cert> I<filename>]
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[B<-certform> B<DER>|B<PEM>|B<P12>]
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[B<-cert_chain> I<filename>]
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[B<-build_chain>]
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[B<-CRL> I<filename>]
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[B<-CRLform> B<DER>|B<PEM>]
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[B<-crl_download>]
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[B<-key> I<filename>|I<uri>]
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[B<-keyform> B<DER>|B<PEM>|B<P12>|B<ENGINE>]
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[B<-pass> I<arg>]
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[B<-chainCAfile> I<filename>]
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[B<-chainCApath> I<directory>]
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[B<-chainCAstore> I<uri>]
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[B<-requestCAfile> I<filename>]
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[B<-dane_tlsa_domain> I<domain>]
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[B<-dane_tlsa_rrdata> I<rrdata>]
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[B<-dane_ee_no_namechecks>]
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[B<-reconnect>]
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[B<-showcerts>]
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[B<-prexit>]
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[B<-no-interactive>]
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[B<-debug>]
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[B<-trace>]
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[B<-nocommands>]
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[B<-security_debug>]
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[B<-security_debug_verbose>]
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[B<-msg>]
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[B<-timeout>]
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[B<-mtu> I<size>]
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[B<-no_etm>]
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[B<-no_ems>]
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[B<-keymatexport> I<label>]
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[B<-keymatexportlen> I<len>]
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[B<-msgfile> I<filename>]
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[B<-nbio_test>]
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[B<-state>]
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[B<-nbio>]
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[B<-crlf>]
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[B<-ign_eof>]
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[B<-no_ign_eof>]
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[B<-psk_identity> I<identity>]
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[B<-psk> I<key>]
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[B<-psk_session> I<file>]
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[B<-quiet>]
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[B<-sctp>]
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[B<-sctp_label_bug>]
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[B<-fallback_scsv>]
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[B<-async>]
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[B<-maxfraglen> I<len>]
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[B<-max_send_frag>]
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[B<-split_send_frag>]
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[B<-max_pipelines>]
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[B<-read_buf>]
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[B<-ignore_unexpected_eof>]
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[B<-bugs>]
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[B<-comp>]
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[B<-no_comp>]
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[B<-brief>]
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[B<-legacy_server_connect>]
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[B<-no_legacy_server_connect>]
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[B<-allow_no_dhe_kex>]
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[B<-sigalgs> I<sigalglist>]
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[B<-curves> I<curvelist>]
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[B<-cipher> I<cipherlist>]
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[B<-ciphersuites> I<val>]
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[B<-serverpref>]
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[B<-starttls> I<protocol>]
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[B<-name> I<hostname>]
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[B<-xmpphost> I<hostname>]
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[B<-name> I<hostname>]
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[B<-tlsextdebug>]
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[B<-no_ticket>]
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[B<-sess_out> I<filename>]
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[B<-serverinfo> I<types>]
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[B<-sess_in> I<filename>]
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[B<-serverinfo> I<types>]
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[B<-status>]
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[B<-alpn> I<protocols>]
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[B<-nextprotoneg> I<protocols>]
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[B<-ct>]
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[B<-noct>]
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[B<-ctlogfile>]
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[B<-keylogfile> I<file>]
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[B<-early_data> I<file>]
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[B<-enable_pha>]
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[B<-use_srtp> I<value>]
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[B<-srpuser> I<value>]
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[B<-srppass> I<value>]
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[B<-srp_lateuser>]
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[B<-srp_moregroups>]
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[B<-srp_strength> I<number>]
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[B<-ktls>]
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[B<-tfo>]
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{- $OpenSSL::safe::opt_name_synopsis -}
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{- $OpenSSL::safe::opt_version_synopsis -}
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{- $OpenSSL::safe::opt_x_synopsis -}
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{- $OpenSSL::safe::opt_trust_synopsis -}
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{- $OpenSSL::safe::opt_s_synopsis -}
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{- $OpenSSL::safe::opt_r_synopsis -}
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{- $OpenSSL::safe::opt_provider_synopsis -}
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{- $OpenSSL::safe::opt_engine_synopsis -}[B<-ssl_client_engine> I<id>]
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{- $OpenSSL::safe::opt_v_synopsis -}
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[I<host>:I<port>]
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=head1 DESCRIPTION
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This command implements a generic SSL/TLS client which
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connects to a remote host using SSL/TLS. It is a I<very> useful diagnostic
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tool for SSL servers.
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=head1 OPTIONS
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In addition to the options below, this command also supports the
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common and client only options documented
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in the "Supported Command Line Commands" section of the L<SSL_CONF_cmd(3)>
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manual page.
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=over 4
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=item B<-help>
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Print out a usage message.
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=item B<-ssl_config> I<section>
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Use the specified section of the configuration file to configure the B<SSL_CTX> object.
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=item B<-connect> I<host>:I<port>
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This specifies the host and optional port to connect to. It is possible to
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select the host and port using the optional target positional argument instead.
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If neither this nor the target positional argument are specified then an attempt
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is made to connect to the local host on port 4433.
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=item B<-host> I<hostname>
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Host to connect to; use B<-connect> instead.
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=item B<-port> I<port>
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Connect to the specified port; use B<-connect> instead.
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=item B<-bind> I<host:port>
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This specifies the host address and or port to bind as the source for the
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connection. For Unix-domain sockets the port is ignored and the host is
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used as the source socket address.
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=item B<-proxy> I<host:port>
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When used with the B<-connect> flag, the program uses the host and port
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specified with this flag and issues an HTTP CONNECT command to connect
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to the desired server.
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=item B<-proxy_user> I<userid>
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When used with the B<-proxy> flag, the program will attempt to authenticate
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with the specified proxy using basic (base64) authentication.
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NB: Basic authentication is insecure; the credentials are sent to the proxy
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in easily reversible base64 encoding before any TLS/SSL session is established.
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Therefore, these credentials are easily recovered by anyone able to sniff/trace
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the network. Use with caution.
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=item B<-proxy_pass> I<arg>
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The proxy password source, used with the B<-proxy_user> flag.
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For more information about the format of B<arg>
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see L<openssl-passphrase-options(1)>.
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=item B<-unix> I<path>
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Connect over the specified Unix-domain socket.
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=item B<-4>
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Use IPv4 only.
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=item B<-6>
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Use IPv6 only.
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=item B<-servername> I<name>
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Set the TLS SNI (Server Name Indication) extension in the ClientHello message to
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the given value.
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If B<-servername> is not provided, the TLS SNI extension will be populated with
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the name given to B<-connect> if it follows a DNS name format. If B<-connect> is
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not provided either, the SNI is set to "localhost".
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This is the default since OpenSSL 1.1.1.
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Even though SNI should normally be a DNS name and not an IP address, if
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B<-servername> is provided then that name will be sent, regardless of whether
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it is a DNS name or not.
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This option cannot be used in conjunction with B<-noservername>.
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=item B<-noservername>
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Suppresses sending of the SNI (Server Name Indication) extension in the
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ClientHello message. Cannot be used in conjunction with the B<-servername> or
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B<-dane_tlsa_domain> options.
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=item B<-cert> I<filename>
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The client certificate to use, if one is requested by the server.
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The default is not to use a certificate.
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The chain for the client certificate may be specified using B<-cert_chain>.
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=item B<-certform> B<DER>|B<PEM>|B<P12>
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The client certificate file format to use; unspecified by default.
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See L<openssl-format-options(1)> for details.
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=item B<-cert_chain>
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A file or URI of untrusted certificates to use when attempting to build the
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certificate chain related to the certificate specified via the B<-cert> option.
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The input can be in PEM, DER, or PKCS#12 format.
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=item B<-build_chain>
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Specify whether the application should build the client certificate chain to be
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provided to the server.
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=item B<-CRL> I<filename>
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CRL file to use to check the server's certificate.
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=item B<-CRLform> B<DER>|B<PEM>
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The CRL file format; unspecified by default.
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See L<openssl-format-options(1)> for details.
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=item B<-crl_download>
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Download CRL from distribution points in the certificate.
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=item B<-key> I<filename>|I<uri>
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The client private key to use.
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If not specified then the certificate file will be used to read also the key.
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=item B<-keyform> B<DER>|B<PEM>|B<P12>|B<ENGINE>
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The key format; unspecified by default.
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See L<openssl-format-options(1)> for details.
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=item B<-pass> I<arg>
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the private key and certificate file password source.
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For more information about the format of I<arg>
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see L<openssl-passphrase-options(1)>.
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=item B<-verify> I<depth>
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The verify depth to use. This specifies the maximum length of the
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server certificate chain and turns on server certificate verification.
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Currently the verify operation continues after errors so all the problems
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with a certificate chain can be seen. As a side effect the connection
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will never fail due to a server certificate verify failure.
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=item B<-verify_return_error>
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Return verification errors instead of continuing. This will typically
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abort the handshake with a fatal error.
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=item B<-verify_quiet>
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Limit verify output to only errors.
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=item B<-verifyCAfile> I<filename>
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A file in PEM format containing trusted certificates to use
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for verifying the server's certificate.
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=item B<-verifyCApath> I<dir>
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A directory containing trusted certificates to use
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for verifying the server's certificate.
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This directory must be in "hash format",
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see L<openssl-verify(1)> for more information.
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=item B<-verifyCAstore> I<uri>
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The URI of a store containing trusted certificates to use
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for verifying the server's certificate.
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=item B<-chainCAfile> I<file>
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A file in PEM format containing trusted certificates to use
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when attempting to build the client certificate chain.
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=item B<-chainCApath> I<directory>
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A directory containing trusted certificates to use
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for building the client certificate chain provided to the server.
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This directory must be in "hash format",
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see L<openssl-verify(1)> for more information.
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=item B<-chainCAstore> I<uri>
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The URI of a store containing trusted certificates to use
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when attempting to build the client certificate chain.
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The URI may indicate a single certificate, as well as a collection of them.
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With URIs in the C<file:> scheme, this acts as B<-chainCAfile> or
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B<-chainCApath>, depending on if the URI indicates a directory or a
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single file.
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See L<ossl_store-file(7)> for more information on the C<file:> scheme.
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=item B<-requestCAfile> I<file>
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A file containing a list of certificates whose subject names will be sent
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to the server in the B<certificate_authorities> extension. Only supported
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for TLS 1.3
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=item B<-dane_tlsa_domain> I<domain>
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Enable RFC6698/RFC7671 DANE TLSA authentication and specify the
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TLSA base domain which becomes the default SNI hint and the primary
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reference identifier for hostname checks. This must be used in
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combination with at least one instance of the B<-dane_tlsa_rrdata>
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option below.
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When DANE authentication succeeds, the diagnostic output will include
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the lowest (closest to 0) depth at which a TLSA record authenticated
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a chain certificate. When that TLSA record is a "2 1 0" trust
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anchor public key that signed (rather than matched) the top-most
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certificate of the chain, the result is reported as "TA public key
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verified". Otherwise, either the TLSA record "matched TA certificate"
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at a positive depth or else "matched EE certificate" at depth 0.
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=item B<-dane_tlsa_rrdata> I<rrdata>
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Use one or more times to specify the RRDATA fields of the DANE TLSA
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RRset associated with the target service. The I<rrdata> value is
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specified in "presentation form", that is four whitespace separated
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fields that specify the usage, selector, matching type and associated
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data, with the last of these encoded in hexadecimal. Optional
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whitespace is ignored in the associated data field. For example:
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$ openssl s_client -brief -starttls smtp \
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-connect smtp.example.com:25 \
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-dane_tlsa_domain smtp.example.com \
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-dane_tlsa_rrdata "2 1 1
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B111DD8A1C2091A89BD4FD60C57F0716CCE50FEEFF8137CDBEE0326E 02CF362B" \
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-dane_tlsa_rrdata "2 1 1
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60B87575447DCBA2A36B7D11AC09FB24A9DB406FEE12D2CC90180517 616E8A18"
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...
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Verification: OK
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Verified peername: smtp.example.com
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DANE TLSA 2 1 1 ...ee12d2cc90180517616e8a18 matched TA certificate at depth 1
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...
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=item B<-dane_ee_no_namechecks>
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This disables server name checks when authenticating via DANE-EE(3) TLSA
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records.
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For some applications, primarily web browsers, it is not safe to disable name
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checks due to "unknown key share" attacks, in which a malicious server can
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convince a client that a connection to a victim server is instead a secure
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connection to the malicious server.
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The malicious server may then be able to violate cross-origin scripting
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restrictions.
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Thus, despite the text of RFC7671, name checks are by default enabled for
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DANE-EE(3) TLSA records, and can be disabled in applications where it is safe
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to do so.
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In particular, SMTP and XMPP clients should set this option as SRV and MX
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records already make it possible for a remote domain to redirect client
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connections to any server of its choice, and in any case SMTP and XMPP clients
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do not execute scripts downloaded from remote servers.
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=item B<-reconnect>
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Reconnects to the same server 5 times using the same session ID, this can
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be used as a test that session caching is working.
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=item B<-showcerts>
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Displays the server certificate list as sent by the server: it only consists of
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certificates the server has sent (in the order the server has sent them). It is
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B<not> a verified chain.
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=item B<-prexit>
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Print session information when the program exits. This will always attempt
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to print out information even if the connection fails. Normally information
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will only be printed out once if the connection succeeds. This option is useful
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because the cipher in use may be renegotiated or the connection may fail
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because a client certificate is required or is requested only after an
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attempt is made to access a certain URL. Note: the output produced by this
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option is not always accurate because a connection might never have been
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established.
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=item B<-no-interactive>
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This flag can be used to run the client in a non-interactive mode.
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=item B<-state>
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Prints out the SSL session states.
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=item B<-debug>
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Print extensive debugging information including a hex dump of all traffic.
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=item B<-nocommands>
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Do not use interactive command letters.
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=item B<-security_debug>
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Enable security debug messages.
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=item B<-security_debug_verbose>
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Output more security debug output.
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=item B<-msg>
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Show protocol messages.
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=item B<-timeout>
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Enable send/receive timeout on DTLS connections.
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=item B<-mtu> I<size>
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Set MTU of the link layer to the specified size.
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=item B<-no_etm>
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Disable Encrypt-then-MAC negotiation.
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=item B<-no_ems>
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Disable Extended master secret negotiation.
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=item B<-keymatexport> I<label>
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Export keying material using the specified label.
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=item B<-keymatexportlen> I<len>
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Export the specified number of bytes of keying material; default is 20.
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Show all protocol messages with hex dump.
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=item B<-trace>
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Show verbose trace output of protocol messages.
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=item B<-msgfile> I<filename>
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File to send output of B<-msg> or B<-trace> to, default standard output.
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=item B<-nbio_test>
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Tests nonblocking I/O
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=item B<-nbio>
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Turns on nonblocking I/O
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=item B<-crlf>
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This option translated a line feed from the terminal into CR+LF as required
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by some servers.
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=item B<-ign_eof>
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Inhibit shutting down the connection when end of file is reached in the
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input.
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=item B<-quiet>
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Inhibit printing of session and certificate information. This implicitly
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turns on B<-ign_eof> as well.
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=item B<-no_ign_eof>
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Shut down the connection when end of file is reached in the input.
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Can be used to override the implicit B<-ign_eof> after B<-quiet>.
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=item B<-psk_identity> I<identity>
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Use the PSK identity I<identity> when using a PSK cipher suite.
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The default value is "Client_identity" (without the quotes).
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=item B<-psk> I<key>
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|
|
Use the PSK key I<key> when using a PSK cipher suite. The key is
|
|
given as a hexadecimal number without leading 0x, for example -psk
|
|
1a2b3c4d.
|
|
This option must be provided in order to use a PSK cipher.
|
|
|
|
=item B<-psk_session> I<file>
|
|
|
|
Use the pem encoded SSL_SESSION data stored in I<file> as the basis of a PSK.
|
|
Note that this will only work if TLSv1.3 is negotiated.
|
|
|
|
=item B<-sctp>
|
|
|
|
Use SCTP for the transport protocol instead of UDP in DTLS. Must be used in
|
|
conjunction with B<-dtls>, B<-dtls1> or B<-dtls1_2>. This option is only
|
|
available where OpenSSL has support for SCTP enabled.
|
|
|
|
=item B<-sctp_label_bug>
|
|
|
|
Use the incorrect behaviour of older OpenSSL implementations when computing
|
|
endpoint-pair shared secrets for DTLS/SCTP. This allows communication with
|
|
older broken implementations but breaks interoperability with correct
|
|
implementations. Must be used in conjunction with B<-sctp>. This option is only
|
|
available where OpenSSL has support for SCTP enabled.
|
|
|
|
=item B<-fallback_scsv>
|
|
|
|
Send TLS_FALLBACK_SCSV in the ClientHello.
|
|
|
|
=item B<-async>
|
|
|
|
Switch on asynchronous mode. Cryptographic operations will be performed
|
|
asynchronously. This will only have an effect if an asynchronous capable engine
|
|
is also used via the B<-engine> option. For test purposes the dummy async engine
|
|
(dasync) can be used (if available).
|
|
|
|
=item B<-maxfraglen> I<len>
|
|
|
|
Enable Maximum Fragment Length Negotiation; allowed values are
|
|
C<512>, C<1024>, C<2048>, and C<4096>.
|
|
|
|
=item B<-max_send_frag> I<int>
|
|
|
|
The maximum size of data fragment to send.
|
|
See L<SSL_CTX_set_max_send_fragment(3)> for further information.
|
|
|
|
=item B<-split_send_frag> I<int>
|
|
|
|
The size used to split data for encrypt pipelines. If more data is written in
|
|
one go than this value then it will be split into multiple pipelines, up to the
|
|
maximum number of pipelines defined by max_pipelines. This only has an effect if
|
|
a suitable cipher suite has been negotiated, an engine that supports pipelining
|
|
has been loaded, and max_pipelines is greater than 1. See
|
|
L<SSL_CTX_set_split_send_fragment(3)> for further information.
|
|
|
|
=item B<-max_pipelines> I<int>
|
|
|
|
The maximum number of encrypt/decrypt pipelines to be used. This will only have
|
|
an effect if an engine has been loaded that supports pipelining (e.g. the dasync
|
|
engine) and a suitable cipher suite has been negotiated. The default value is 1.
|
|
See L<SSL_CTX_set_max_pipelines(3)> for further information.
|
|
|
|
=item B<-read_buf> I<int>
|
|
|
|
The default read buffer size to be used for connections. This will only have an
|
|
effect if the buffer size is larger than the size that would otherwise be used
|
|
and pipelining is in use (see L<SSL_CTX_set_default_read_buffer_len(3)> for
|
|
further information).
|
|
|
|
=item B<-ignore_unexpected_eof>
|
|
|
|
Some TLS implementations do not send the mandatory close_notify alert on
|
|
shutdown. If the application tries to wait for the close_notify alert but the
|
|
peer closes the connection without sending it, an error is generated. When this
|
|
option is enabled the peer does not need to send the close_notify alert and a
|
|
closed connection will be treated as if the close_notify alert was received.
|
|
For more information on shutting down a connection, see L<SSL_shutdown(3)>.
|
|
|
|
=item B<-bugs>
|
|
|
|
There are several known bugs in SSL and TLS implementations. Adding this
|
|
option enables various workarounds.
|
|
|
|
=item B<-comp>
|
|
|
|
Enables support for SSL/TLS compression.
|
|
This option was introduced in OpenSSL 1.1.0.
|
|
TLS compression is not recommended and is off by default as of
|
|
OpenSSL 1.1.0.
|
|
|
|
=item B<-no_comp>
|
|
|
|
Disables support for SSL/TLS compression.
|
|
TLS compression is not recommended and is off by default as of
|
|
OpenSSL 1.1.0.
|
|
|
|
=item B<-brief>
|
|
|
|
Only provide a brief summary of connection parameters instead of the
|
|
normal verbose output.
|
|
|
|
=item B<-sigalgs> I<sigalglist>
|
|
|
|
Specifies the list of signature algorithms that are sent by the client.
|
|
The server selects one entry in the list based on its preferences.
|
|
For example strings, see L<SSL_CTX_set1_sigalgs(3)>
|
|
|
|
=item B<-curves> I<curvelist>
|
|
|
|
Specifies the list of supported curves to be sent by the client. The curve is
|
|
ultimately selected by the server. For a list of all curves, use:
|
|
|
|
$ openssl ecparam -list_curves
|
|
|
|
=item B<-cipher> I<cipherlist>
|
|
|
|
This allows the TLSv1.2 and below cipher list sent by the client to be modified.
|
|
This list will be combined with any TLSv1.3 ciphersuites that have been
|
|
configured. Although the server determines which ciphersuite is used it should
|
|
take the first supported cipher in the list sent by the client. See
|
|
L<openssl-ciphers(1)> for more information.
|
|
|
|
=item B<-ciphersuites> I<val>
|
|
|
|
This allows the TLSv1.3 ciphersuites sent by the client to be modified. This
|
|
list will be combined with any TLSv1.2 and below ciphersuites that have been
|
|
configured. Although the server determines which cipher suite is used it should
|
|
take the first supported cipher in the list sent by the client. See
|
|
L<openssl-ciphers(1)> for more information. The format for this list is a simple
|
|
colon (":") separated list of TLSv1.3 ciphersuite names.
|
|
|
|
=item B<-starttls> I<protocol>
|
|
|
|
Send the protocol-specific message(s) to switch to TLS for communication.
|
|
I<protocol> is a keyword for the intended protocol. Currently, the only
|
|
supported keywords are "smtp", "pop3", "imap", "ftp", "xmpp", "xmpp-server",
|
|
"irc", "postgres", "mysql", "lmtp", "nntp", "sieve" and "ldap".
|
|
|
|
=item B<-xmpphost> I<hostname>
|
|
|
|
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.
|
|
|
|
This option is an alias of the B<-name> option for "xmpp" and "xmpp-server".
|
|
|
|
=item B<-name> I<hostname>
|
|
|
|
This option is used to specify hostname information for various protocols
|
|
used with B<-starttls> option. Currently only "xmpp", "xmpp-server",
|
|
"smtp" and "lmtp" can utilize this B<-name> option.
|
|
|
|
If this option is used with "-starttls xmpp" or "-starttls xmpp-server",
|
|
if 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.
|
|
|
|
If this option is used with "-starttls lmtp" or "-starttls smtp", it specifies
|
|
the name to use in the "LMTP LHLO" or "SMTP EHLO" message, respectively. If
|
|
this option is not specified, then "mail.example.com" 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> I<filename>
|
|
|
|
Output SSL session to I<filename>.
|
|
|
|
=item B<-sess_in> I<filename>
|
|
|
|
Load SSL session from I<filename>. The client will attempt to resume a
|
|
connection from this session.
|
|
|
|
=item B<-serverinfo> I<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.
|
|
|
|
=item B<-alpn> I<protocols>, B<-nextprotoneg> I<protocols>
|
|
|
|
These flags enable the Enable the Application-Layer Protocol Negotiation
|
|
or Next Protocol Negotiation (NPN) extension, respectively. ALPN is the
|
|
IETF standard and replaces NPN.
|
|
The I<protocols> list is a comma-separated list of protocol names that
|
|
the client should advertise support for. The list should contain the most
|
|
desirable protocols first. Protocol names are printable ASCII strings,
|
|
for example "http/1.1" or "spdy/3".
|
|
An 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.
|
|
The flag B<-nextprotoneg> cannot be specified if B<-tls1_3> is used.
|
|
|
|
=item B<-ct>, B<-noct>
|
|
|
|
Use one of these two options to control whether Certificate Transparency (CT)
|
|
is enabled (B<-ct>) or disabled (B<-noct>).
|
|
If CT is enabled, signed certificate timestamps (SCTs) will be requested from
|
|
the server and reported at handshake completion.
|
|
|
|
Enabling CT also enables OCSP stapling, as this is one possible delivery method
|
|
for SCTs.
|
|
|
|
=item B<-ctlogfile>
|
|
|
|
A file containing a list of known Certificate Transparency logs. See
|
|
L<SSL_CTX_set_ctlog_list_file(3)> for the expected file format.
|
|
|
|
=item B<-keylogfile> I<file>
|
|
|
|
Appends TLS secrets to the specified keylog file such that external programs
|
|
(like Wireshark) can decrypt TLS connections.
|
|
|
|
=item B<-early_data> I<file>
|
|
|
|
Reads the contents of the specified file and attempts to send it as early data
|
|
to the server. This will only work with resumed sessions that support early
|
|
data and when the server accepts the early data.
|
|
|
|
=item B<-enable_pha>
|
|
|
|
For TLSv1.3 only, send the Post-Handshake Authentication extension. This will
|
|
happen whether or not a certificate has been provided via B<-cert>.
|
|
|
|
=item B<-use_srtp> I<value>
|
|
|
|
Offer SRTP key management, where B<value> is a colon-separated profile list.
|
|
|
|
=item B<-srpuser> I<value>
|
|
|
|
Set the SRP username to the specified value. This option is deprecated.
|
|
|
|
=item B<-srppass> I<value>
|
|
|
|
Set the SRP password to the specified value. This option is deprecated.
|
|
|
|
=item B<-srp_lateuser>
|
|
|
|
SRP username for the second ClientHello message. This option is deprecated.
|
|
|
|
=item B<-srp_moregroups> This option is deprecated.
|
|
|
|
Tolerate other than the known B<g> and B<N> values.
|
|
|
|
=item B<-srp_strength> I<number>
|
|
|
|
Set the minimal acceptable length, in bits, for B<N>. This option is
|
|
deprecated.
|
|
|
|
=item B<-ktls>
|
|
|
|
Enable Kernel TLS for sending and receiving.
|
|
This option was introduced in OpenSSL 3.2.0.
|
|
Kernel TLS is off by default as of OpenSSL 3.2.0.
|
|
|
|
=item B<-tfo>
|
|
|
|
Enable creation of connections via TCP fast open (RFC7413).
|
|
|
|
{- $OpenSSL::safe::opt_version_item -}
|
|
|
|
{- $OpenSSL::safe::opt_name_item -}
|
|
|
|
{- $OpenSSL::safe::opt_x_item -}
|
|
|
|
{- $OpenSSL::safe::opt_trust_item -}
|
|
|
|
{- $OpenSSL::safe::opt_s_item -}
|
|
|
|
{- $OpenSSL::safe::opt_r_item -}
|
|
|
|
{- $OpenSSL::safe::opt_provider_item -}
|
|
|
|
{- $OpenSSL::safe::opt_engine_item -}
|
|
|
|
{- output_off() if $disabled{"deprecated-3.0"}; "" -}
|
|
=item B<-ssl_client_engine> I<id>
|
|
|
|
Specify engine to be used for client certificate operations.
|
|
{- output_on() if $disabled{"deprecated-3.0"}; "" -}
|
|
|
|
{- $OpenSSL::safe::opt_v_item -}
|
|
|
|
Verification errors are displayed, for debugging, but the command will
|
|
proceed unless the B<-verify_return_error> option is used.
|
|
|
|
=item I<host>:I<port>
|
|
|
|
Rather than providing B<-connect>, the target hostname and optional port may
|
|
be provided as a single positional argument after all options. If neither this
|
|
nor B<-connect> are provided, falls back to attempting to connect to
|
|
I<localhost> on port I<4433>.
|
|
|
|
=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. If end of file is reached then the connection will be closed down. When
|
|
used interactively (which means neither B<-quiet> nor B<-ign_eof> have been
|
|
given), then certain commands are also recognized which perform special
|
|
operations. These commands are a letter which must appear at the start of a
|
|
line. They are listed below.
|
|
|
|
=over 4
|
|
|
|
=item B<Q>
|
|
|
|
End the current SSL connection and exit.
|
|
|
|
=item B<R>
|
|
|
|
Renegotiate the SSL session (TLSv1.2 and below only).
|
|
|
|
=item B<k>
|
|
|
|
Send a key update message to the server (TLSv1.3 only)
|
|
|
|
=item B<K>
|
|
|
|
Send a key update message to the server and request one back (TLSv1.3 only)
|
|
|
|
=back
|
|
|
|
=head1 NOTES
|
|
|
|
This command can be used to debug SSL servers. To connect to an SSL HTTP
|
|
server the command:
|
|
|
|
openssl s_client -connect servername:443
|
|
|
|
would typically be used (https uses port 443). If the connection succeeds
|
|
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<-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.
|
|
|
|
A frequent problem when attempting to get client certificates working
|
|
is that a web client complains it has no certificates or gives an empty
|
|
list to choose from. This is normally because the server is not sending
|
|
the clients certificate authority in its "acceptable CA list" when it
|
|
requests a certificate. By using this command, 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> option and send an HTTP request
|
|
for an appropriate page.
|
|
|
|
If a certificate is specified on the command line using the B<-cert>
|
|
option it will not be used unless the server specifically requests
|
|
a client certificate. Therefore, merely including a client certificate
|
|
on the command line is no guarantee that the certificate works.
|
|
|
|
If there are problems verifying a server certificate then the
|
|
B<-showcerts> option can be used to show all the certificates sent by the
|
|
server.
|
|
|
|
This command 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. Non-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.
|
|
|
|
The B<-bind> option may be useful if the server or a firewall requires
|
|
connections to come from some particular address and or port.
|
|
|
|
=head1 BUGS
|
|
|
|
Because this program has a lot of options and also because some of the
|
|
techniques used are rather old, the C source for this command is rather
|
|
hard to read and not a model of how things should be done.
|
|
A typical SSL client program would be much simpler.
|
|
|
|
The B<-prexit> option is a bit of a hack. We should really report
|
|
information whenever a session is renegotiated.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<openssl(1)>,
|
|
L<openssl-sess_id(1)>,
|
|
L<openssl-s_server(1)>,
|
|
L<openssl-ciphers(1)>,
|
|
L<SSL_CONF_cmd(3)>,
|
|
L<SSL_CTX_set_max_send_fragment(3)>,
|
|
L<SSL_CTX_set_split_send_fragment(3)>,
|
|
L<SSL_CTX_set_max_pipelines(3)>,
|
|
L<ossl_store-file(7)>
|
|
|
|
=head1 HISTORY
|
|
|
|
The B<-no_alt_chains> option was added in OpenSSL 1.1.0.
|
|
The B<-name> option was added in OpenSSL 1.1.1.
|
|
|
|
The B<-certform> option has become obsolete in OpenSSL 3.0.0 and has no effect.
|
|
|
|
The B<-engine> option was deprecated in OpenSSL 3.0.
|
|
|
|
The -tfo option was added in OpenSSL 3.2.
|
|
|
|
=head1 COPYRIGHT
|
|
|
|
Copyright 2000-2022 The OpenSSL Project Authors. All Rights Reserved.
|
|
|
|
Licensed under the Apache License 2.0 (the "License"). You may not use
|
|
this file except in compliance with the License. You can obtain a copy
|
|
in the file LICENSE in the source distribution or at
|
|
L<https://www.openssl.org/source/license.html>.
|
|
|
|
=cut
|