forked from cory/tildefriends
Cory McWilliams
09ddfffa6b
git-svn-id: https://www.unprompted.com/svn/projects/tildefriends/trunk@4088 ed5197a5-7fde-0310-b194-c3ffbd925b24
864 lines
36 KiB
Groff
864 lines
36 KiB
Groff
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.\" ========================================================================
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.\"
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.IX Title "S_CLIENT 1"
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.TH S_CLIENT 1 "2020-04-21" "1.1.1g" "OpenSSL"
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.\" For nroff, turn off justification. Always turn off hyphenation; it makes
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.\" way too many mistakes in technical documents.
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.if n .ad l
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.nh
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.SH "NAME"
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openssl\-s_client, s_client \- SSL/TLS client program
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.SH "SYNOPSIS"
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.IX Header "SYNOPSIS"
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\&\fBopenssl\fR \fBs_client\fR
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[\fB\-help\fR]
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[\fB\-connect host:port\fR]
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[\fB\-bind host:port\fR]
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[\fB\-proxy host:port\fR]
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[\fB\-unix path\fR]
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[\fB\-4\fR]
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[\fB\-6\fR]
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[\fB\-servername name\fR]
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[\fB\-noservername\fR]
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[\fB\-verify depth\fR]
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[\fB\-verify_return_error\fR]
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[\fB\-cert filename\fR]
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[\fB\-certform DER|PEM\fR]
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[\fB\-key filename\fR]
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[\fB\-keyform DER|PEM\fR]
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[\fB\-cert_chain filename\fR]
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[\fB\-build_chain\fR]
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[\fB\-xkey\fR]
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[\fB\-xcert\fR]
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[\fB\-xchain\fR]
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[\fB\-xchain_build\fR]
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[\fB\-xcertform PEM|DER\fR]
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[\fB\-xkeyform PEM|DER\fR]
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[\fB\-pass arg\fR]
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[\fB\-CApath directory\fR]
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[\fB\-CAfile filename\fR]
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[\fB\-chainCApath directory\fR]
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[\fB\-chainCAfile filename\fR]
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[\fB\-no\-CAfile\fR]
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[\fB\-no\-CApath\fR]
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[\fB\-requestCAfile filename\fR]
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[\fB\-dane_tlsa_domain domain\fR]
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[\fB\-dane_tlsa_rrdata rrdata\fR]
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[\fB\-dane_ee_no_namechecks\fR]
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[\fB\-attime timestamp\fR]
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[\fB\-check_ss_sig\fR]
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[\fB\-crl_check\fR]
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[\fB\-crl_check_all\fR]
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[\fB\-explicit_policy\fR]
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[\fB\-extended_crl\fR]
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[\fB\-ignore_critical\fR]
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[\fB\-inhibit_any\fR]
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[\fB\-inhibit_map\fR]
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[\fB\-no_check_time\fR]
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[\fB\-partial_chain\fR]
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[\fB\-policy arg\fR]
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[\fB\-policy_check\fR]
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[\fB\-policy_print\fR]
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[\fB\-purpose purpose\fR]
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[\fB\-suiteB_128\fR]
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[\fB\-suiteB_128_only\fR]
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[\fB\-suiteB_192\fR]
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[\fB\-trusted_first\fR]
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[\fB\-no_alt_chains\fR]
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[\fB\-use_deltas\fR]
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[\fB\-auth_level num\fR]
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[\fB\-nameopt option\fR]
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[\fB\-verify_depth num\fR]
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[\fB\-verify_email email\fR]
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[\fB\-verify_hostname hostname\fR]
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[\fB\-verify_ip ip\fR]
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[\fB\-verify_name name\fR]
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[\fB\-build_chain\fR]
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[\fB\-x509_strict\fR]
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[\fB\-reconnect\fR]
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[\fB\-showcerts\fR]
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[\fB\-debug\fR]
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[\fB\-msg\fR]
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[\fB\-nbio_test\fR]
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[\fB\-state\fR]
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[\fB\-nbio\fR]
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[\fB\-crlf\fR]
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[\fB\-ign_eof\fR]
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[\fB\-no_ign_eof\fR]
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[\fB\-psk_identity identity\fR]
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[\fB\-psk key\fR]
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[\fB\-psk_session file\fR]
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[\fB\-quiet\fR]
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[\fB\-ssl3\fR]
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[\fB\-tls1\fR]
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[\fB\-tls1_1\fR]
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[\fB\-tls1_2\fR]
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[\fB\-tls1_3\fR]
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[\fB\-no_ssl3\fR]
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[\fB\-no_tls1\fR]
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[\fB\-no_tls1_1\fR]
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[\fB\-no_tls1_2\fR]
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[\fB\-no_tls1_3\fR]
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[\fB\-dtls\fR]
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[\fB\-dtls1\fR]
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[\fB\-dtls1_2\fR]
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[\fB\-sctp\fR]
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[\fB\-sctp_label_bug\fR]
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[\fB\-fallback_scsv\fR]
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[\fB\-async\fR]
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[\fB\-max_send_frag\fR]
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[\fB\-split_send_frag\fR]
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[\fB\-max_pipelines\fR]
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[\fB\-read_buf\fR]
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[\fB\-bugs\fR]
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[\fB\-comp\fR]
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[\fB\-no_comp\fR]
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[\fB\-allow_no_dhe_kex\fR]
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[\fB\-sigalgs sigalglist\fR]
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[\fB\-curves curvelist\fR]
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[\fB\-cipher cipherlist\fR]
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[\fB\-ciphersuites val\fR]
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[\fB\-serverpref\fR]
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[\fB\-starttls protocol\fR]
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[\fB\-xmpphost hostname\fR]
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[\fB\-name hostname\fR]
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[\fB\-engine id\fR]
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[\fB\-tlsextdebug\fR]
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[\fB\-no_ticket\fR]
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[\fB\-sess_out filename\fR]
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[\fB\-sess_in filename\fR]
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[\fB\-rand file...\fR]
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[\fB\-writerand file\fR]
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[\fB\-serverinfo types\fR]
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[\fB\-status\fR]
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[\fB\-alpn protocols\fR]
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[\fB\-nextprotoneg protocols\fR]
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[\fB\-ct\fR]
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[\fB\-noct\fR]
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[\fB\-ctlogfile\fR]
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[\fB\-keylogfile file\fR]
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[\fB\-early_data file\fR]
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[\fB\-enable_pha\fR]
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[\fBtarget\fR]
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.SH "DESCRIPTION"
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.IX Header "DESCRIPTION"
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The \fBs_client\fR command implements a generic \s-1SSL/TLS\s0 client which connects
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to a remote host using \s-1SSL/TLS.\s0 It is a \fIvery\fR useful diagnostic tool for
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\&\s-1SSL\s0 servers.
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.SH "OPTIONS"
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.IX Header "OPTIONS"
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In addition to the options below the \fBs_client\fR utility also supports the
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common and client only options documented
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in the \*(L"Supported Command Line Commands\*(R" section of the \fBSSL_CONF_cmd\fR\|(3)
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manual page.
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.IP "\fB\-help\fR" 4
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.IX Item "-help"
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Print out a usage message.
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.IP "\fB\-connect host:port\fR" 4
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.IX Item "-connect host: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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.IP "\fB\-bind host:port\fR]" 4
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.IX Item "-bind 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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.IP "\fB\-proxy host:port\fR" 4
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.IX Item "-proxy host:port"
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When used with the \fB\-connect\fR flag, the program uses the host and port
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specified with this flag and issues an \s-1HTTP CONNECT\s0 command to connect
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to the desired server.
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.IP "\fB\-unix path\fR" 4
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.IX Item "-unix path"
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Connect over the specified Unix-domain socket.
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.IP "\fB\-4\fR" 4
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.IX Item "-4"
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Use IPv4 only.
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.IP "\fB\-6\fR" 4
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.IX Item "-6"
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Use IPv6 only.
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.IP "\fB\-servername name\fR" 4
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.IX Item "-servername name"
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Set the \s-1TLS SNI\s0 (Server Name Indication) extension in the ClientHello message to
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the given value.
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If \fB\-servername\fR is not provided, the \s-1TLS SNI\s0 extension will be populated with
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the name given to \fB\-connect\fR if it follows a \s-1DNS\s0 name format. If \fB\-connect\fR is
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not provided either, the \s-1SNI\s0 is set to \*(L"localhost\*(R".
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This is the default since OpenSSL 1.1.1.
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.Sp
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Even though \s-1SNI\s0 should normally be a \s-1DNS\s0 name and not an \s-1IP\s0 address, if
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\&\fB\-servername\fR is provided then that name will be sent, regardless of whether
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it is a \s-1DNS\s0 name or not.
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.Sp
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This option cannot be used in conjunction with \fB\-noservername\fR.
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.IP "\fB\-noservername\fR" 4
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.IX Item "-noservername"
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Suppresses sending of the \s-1SNI\s0 (Server Name Indication) extension in the
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ClientHello message. Cannot be used in conjunction with the \fB\-servername\fR or
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<\-dane_tlsa_domain> options.
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.IP "\fB\-cert certname\fR" 4
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.IX Item "-cert certname"
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The certificate to use, if one is requested by the server. The default is
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not to use a certificate.
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.IP "\fB\-certform format\fR" 4
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.IX Item "-certform format"
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The certificate format to use: \s-1DER\s0 or \s-1PEM. PEM\s0 is the default.
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.IP "\fB\-key keyfile\fR" 4
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.IX Item "-key keyfile"
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The private key to use. If not specified then the certificate file will
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be used.
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.IP "\fB\-keyform format\fR" 4
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.IX Item "-keyform format"
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The private format to use: \s-1DER\s0 or \s-1PEM. PEM\s0 is the default.
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.IP "\fB\-cert_chain\fR" 4
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.IX Item "-cert_chain"
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A file containing trusted certificates to use when attempting to build the
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client/server certificate chain related to the certificate specified via the
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\&\fB\-cert\fR option.
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.IP "\fB\-build_chain\fR" 4
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.IX Item "-build_chain"
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Specify whether the application should build the certificate chain to be
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provided to the server.
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.IP "\fB\-xkey infile\fR, \fB\-xcert infile\fR, \fB\-xchain\fR" 4
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.IX Item "-xkey infile, -xcert infile, -xchain"
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Specify an extra certificate, private key and certificate chain. These behave
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in the same manner as the \fB\-cert\fR, \fB\-key\fR and \fB\-cert_chain\fR options. When
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specified, the callback returning the first valid chain will be in use by the
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client.
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.IP "\fB\-xchain_build\fR" 4
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.IX Item "-xchain_build"
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Specify whether the application should build the certificate chain to be
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provided to the server for the extra certificates provided via \fB\-xkey infile\fR,
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\&\fB\-xcert infile\fR, \fB\-xchain\fR options.
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.IP "\fB\-xcertform PEM|DER\fR, \fB\-xkeyform PEM|DER\fR" 4
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.IX Item "-xcertform PEM|DER, -xkeyform PEM|DER"
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Extra certificate and private key format respectively.
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.IP "\fB\-pass arg\fR" 4
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.IX Item "-pass arg"
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the private key password source. For more information about the format of \fBarg\fR
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see the \fB\s-1PASS PHRASE ARGUMENTS\s0\fR section in \fBopenssl\fR\|(1).
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.IP "\fB\-verify depth\fR" 4
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.IX Item "-verify 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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.IP "\fB\-verify_return_error\fR" 4
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.IX Item "-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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.IP "\fB\-nameopt option\fR" 4
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.IX Item "-nameopt option"
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Option which determines how the subject or issuer names are displayed. The
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\&\fBoption\fR argument can be a single option or multiple options separated by
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commas. Alternatively the \fB\-nameopt\fR switch may be used more than once to
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set multiple options. See the \fBx509\fR\|(1) manual page for details.
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.IP "\fB\-CApath directory\fR" 4
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.IX Item "-CApath directory"
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The directory to use for server certificate verification. This directory
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must be in \*(L"hash format\*(R", see \fBverify\fR\|(1) for more information. These are
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also used when building the client certificate chain.
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.IP "\fB\-CAfile file\fR" 4
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.IX Item "-CAfile file"
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A file containing trusted certificates to use during server authentication
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and to use when attempting to build the client certificate chain.
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.IP "\fB\-chainCApath directory\fR" 4
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.IX Item "-chainCApath directory"
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The directory to use for building the chain provided to the server. This
|
|
directory must be in \*(L"hash format\*(R", see \fBverify\fR\|(1) for more information.
|
|
.IP "\fB\-chainCAfile file\fR" 4
|
|
.IX Item "-chainCAfile file"
|
|
A file containing trusted certificates to use when attempting to build the
|
|
client certificate chain.
|
|
.IP "\fB\-no\-CAfile\fR" 4
|
|
.IX Item "-no-CAfile"
|
|
Do not load the trusted \s-1CA\s0 certificates from the default file location
|
|
.IP "\fB\-no\-CApath\fR" 4
|
|
.IX Item "-no-CApath"
|
|
Do not load the trusted \s-1CA\s0 certificates from the default directory location
|
|
.IP "\fB\-requestCAfile file\fR" 4
|
|
.IX Item "-requestCAfile file"
|
|
A file containing a list of certificates whose subject names will be sent
|
|
to the server in the \fBcertificate_authorities\fR extension. Only supported
|
|
for \s-1TLS 1.3\s0
|
|
.IP "\fB\-dane_tlsa_domain domain\fR" 4
|
|
.IX Item "-dane_tlsa_domain domain"
|
|
Enable \s-1RFC6698/RFC7671 DANE TLSA\s0 authentication and specify the
|
|
\&\s-1TLSA\s0 base domain which becomes the default \s-1SNI\s0 hint and the primary
|
|
reference identifier for hostname checks. This must be used in
|
|
combination with at least one instance of the \fB\-dane_tlsa_rrdata\fR
|
|
option below.
|
|
.Sp
|
|
When \s-1DANE\s0 authentication succeeds, the diagnostic output will include
|
|
the lowest (closest to 0) depth at which a \s-1TLSA\s0 record authenticated
|
|
a chain certificate. When that \s-1TLSA\s0 record is a \*(L"2 1 0\*(R" trust
|
|
anchor public key that signed (rather than matched) the top-most
|
|
certificate of the chain, the result is reported as \*(L"\s-1TA\s0 public key
|
|
verified\*(R". Otherwise, either the \s-1TLSA\s0 record \*(L"matched \s-1TA\s0 certificate\*(R"
|
|
at a positive depth or else \*(L"matched \s-1EE\s0 certificate\*(R" at depth 0.
|
|
.IP "\fB\-dane_tlsa_rrdata rrdata\fR" 4
|
|
.IX Item "-dane_tlsa_rrdata rrdata"
|
|
Use one or more times to specify the \s-1RRDATA\s0 fields of the \s-1DANE TLSA\s0
|
|
RRset associated with the target service. The \fBrrdata\fR value is
|
|
specified in \*(L"presentation form\*(R", that is four whitespace separated
|
|
fields that specify the usage, selector, matching type and associated
|
|
data, with the last of these encoded in hexadecimal. Optional
|
|
whitespace is ignored in the associated data field. For example:
|
|
.Sp
|
|
.Vb 12
|
|
\& $ openssl s_client \-brief \-starttls smtp \e
|
|
\& \-connect smtp.example.com:25 \e
|
|
\& \-dane_tlsa_domain smtp.example.com \e
|
|
\& \-dane_tlsa_rrdata "2 1 1
|
|
\& B111DD8A1C2091A89BD4FD60C57F0716CCE50FEEFF8137CDBEE0326E 02CF362B" \e
|
|
\& \-dane_tlsa_rrdata "2 1 1
|
|
\& 60B87575447DCBA2A36B7D11AC09FB24A9DB406FEE12D2CC90180517 616E8A18"
|
|
\& ...
|
|
\& Verification: OK
|
|
\& Verified peername: smtp.example.com
|
|
\& DANE TLSA 2 1 1 ...ee12d2cc90180517616e8a18 matched TA certificate at depth 1
|
|
\& ...
|
|
.Ve
|
|
.IP "\fB\-dane_ee_no_namechecks\fR" 4
|
|
.IX Item "-dane_ee_no_namechecks"
|
|
This disables server name checks when authenticating via \s-1\fBDANE\-EE\s0\fR\|(3) \s-1TLSA\s0
|
|
records.
|
|
For some applications, primarily web browsers, it is not safe to disable name
|
|
checks due to \*(L"unknown key share\*(R" attacks, in which a malicious server can
|
|
convince a client that a connection to a victim server is instead a secure
|
|
connection to the malicious server.
|
|
The malicious server may then be able to violate cross-origin scripting
|
|
restrictions.
|
|
Thus, despite the text of \s-1RFC7671,\s0 name checks are by default enabled for
|
|
\&\s-1\fBDANE\-EE\s0\fR\|(3) \s-1TLSA\s0 records, and can be disabled in applications where it is safe
|
|
to do so.
|
|
In particular, \s-1SMTP\s0 and \s-1XMPP\s0 clients should set this option as \s-1SRV\s0 and \s-1MX\s0
|
|
records already make it possible for a remote domain to redirect client
|
|
connections to any server of its choice, and in any case \s-1SMTP\s0 and \s-1XMPP\s0 clients
|
|
do not execute scripts downloaded from remote servers.
|
|
.IP "\fB\-attime\fR, \fB\-check_ss_sig\fR, \fB\-crl_check\fR, \fB\-crl_check_all\fR, \fB\-explicit_policy\fR, \fB\-extended_crl\fR, \fB\-ignore_critical\fR, \fB\-inhibit_any\fR, \fB\-inhibit_map\fR, \fB\-no_alt_chains\fR, \fB\-no_check_time\fR, \fB\-partial_chain\fR, \fB\-policy\fR, \fB\-policy_check\fR, \fB\-policy_print\fR, \fB\-purpose\fR, \fB\-suiteB_128\fR, \fB\-suiteB_128_only\fR, \fB\-suiteB_192\fR, \fB\-trusted_first\fR, \fB\-use_deltas\fR, \fB\-auth_level\fR, \fB\-verify_depth\fR, \fB\-verify_email\fR, \fB\-verify_hostname\fR, \fB\-verify_ip\fR, \fB\-verify_name\fR, \fB\-x509_strict\fR" 4
|
|
.IX Item "-attime, -check_ss_sig, -crl_check, -crl_check_all, -explicit_policy, -extended_crl, -ignore_critical, -inhibit_any, -inhibit_map, -no_alt_chains, -no_check_time, -partial_chain, -policy, -policy_check, -policy_print, -purpose, -suiteB_128, -suiteB_128_only, -suiteB_192, -trusted_first, -use_deltas, -auth_level, -verify_depth, -verify_email, -verify_hostname, -verify_ip, -verify_name, -x509_strict"
|
|
Set various certificate chain validation options. See the
|
|
\&\fBverify\fR\|(1) manual page for details.
|
|
.IP "\fB\-reconnect\fR" 4
|
|
.IX Item "-reconnect"
|
|
Reconnects to the same server 5 times using the same session \s-1ID,\s0 this can
|
|
be used as a test that session caching is working.
|
|
.IP "\fB\-showcerts\fR" 4
|
|
.IX Item "-showcerts"
|
|
Displays the server certificate list as sent by the server: it only consists of
|
|
certificates the server has sent (in the order the server has sent them). It is
|
|
\&\fBnot\fR a verified chain.
|
|
.IP "\fB\-prexit\fR" 4
|
|
.IX Item "-prexit"
|
|
Print session information when the program exits. This will always attempt
|
|
to print out information even if the connection fails. Normally information
|
|
will only be printed out once if the connection succeeds. This option is useful
|
|
because the cipher in use may be renegotiated or the connection may fail
|
|
because a client certificate is required or is requested only after an
|
|
attempt is made to access a certain \s-1URL.\s0 Note: the output produced by this
|
|
option is not always accurate because a connection might never have been
|
|
established.
|
|
.IP "\fB\-state\fR" 4
|
|
.IX Item "-state"
|
|
Prints out the \s-1SSL\s0 session states.
|
|
.IP "\fB\-debug\fR" 4
|
|
.IX Item "-debug"
|
|
Print extensive debugging information including a hex dump of all traffic.
|
|
.IP "\fB\-msg\fR" 4
|
|
.IX Item "-msg"
|
|
Show all protocol messages with hex dump.
|
|
.IP "\fB\-trace\fR" 4
|
|
.IX Item "-trace"
|
|
Show verbose trace output of protocol messages. OpenSSL needs to be compiled
|
|
with \fBenable-ssl-trace\fR for this option to work.
|
|
.IP "\fB\-msgfile\fR" 4
|
|
.IX Item "-msgfile"
|
|
File to send output of \fB\-msg\fR or \fB\-trace\fR to, default standard output.
|
|
.IP "\fB\-nbio_test\fR" 4
|
|
.IX Item "-nbio_test"
|
|
Tests non-blocking I/O
|
|
.IP "\fB\-nbio\fR" 4
|
|
.IX Item "-nbio"
|
|
Turns on non-blocking I/O
|
|
.IP "\fB\-crlf\fR" 4
|
|
.IX Item "-crlf"
|
|
This option translated a line feed from the terminal into \s-1CR+LF\s0 as required
|
|
by some servers.
|
|
.IP "\fB\-ign_eof\fR" 4
|
|
.IX Item "-ign_eof"
|
|
Inhibit shutting down the connection when end of file is reached in the
|
|
input.
|
|
.IP "\fB\-quiet\fR" 4
|
|
.IX Item "-quiet"
|
|
Inhibit printing of session and certificate information. This implicitly
|
|
turns on \fB\-ign_eof\fR as well.
|
|
.IP "\fB\-no_ign_eof\fR" 4
|
|
.IX Item "-no_ign_eof"
|
|
Shut down the connection when end of file is reached in the input.
|
|
Can be used to override the implicit \fB\-ign_eof\fR after \fB\-quiet\fR.
|
|
.IP "\fB\-psk_identity identity\fR" 4
|
|
.IX Item "-psk_identity identity"
|
|
Use the \s-1PSK\s0 identity \fBidentity\fR when using a \s-1PSK\s0 cipher suite.
|
|
The default value is \*(L"Client_identity\*(R" (without the quotes).
|
|
.IP "\fB\-psk key\fR" 4
|
|
.IX Item "-psk key"
|
|
Use the \s-1PSK\s0 key \fBkey\fR when using a \s-1PSK\s0 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 \s-1PSK\s0 cipher.
|
|
.IP "\fB\-psk_session file\fR" 4
|
|
.IX Item "-psk_session file"
|
|
Use the pem encoded \s-1SSL_SESSION\s0 data stored in \fBfile\fR as the basis of a \s-1PSK.\s0
|
|
Note that this will only work if TLSv1.3 is negotiated.
|
|
.IP "\fB\-ssl3\fR, \fB\-tls1\fR, \fB\-tls1_1\fR, \fB\-tls1_2\fR, \fB\-tls1_3\fR, \fB\-no_ssl3\fR, \fB\-no_tls1\fR, \fB\-no_tls1_1\fR, \fB\-no_tls1_2\fR, \fB\-no_tls1_3\fR" 4
|
|
.IX Item "-ssl3, -tls1, -tls1_1, -tls1_2, -tls1_3, -no_ssl3, -no_tls1, -no_tls1_1, -no_tls1_2, -no_tls1_3"
|
|
These options require or disable the use of the specified \s-1SSL\s0 or \s-1TLS\s0 protocols.
|
|
By default \fBs_client\fR will negotiate the highest mutually supported protocol
|
|
version.
|
|
When a specific \s-1TLS\s0 version is required, only that version will be offered to
|
|
and accepted from the server.
|
|
Note that not all protocols and flags may be available, depending on how
|
|
OpenSSL was built.
|
|
.IP "\fB\-dtls\fR, \fB\-dtls1\fR, \fB\-dtls1_2\fR" 4
|
|
.IX Item "-dtls, -dtls1, -dtls1_2"
|
|
These options make \fBs_client\fR use \s-1DTLS\s0 protocols instead of \s-1TLS.\s0
|
|
With \fB\-dtls\fR, \fBs_client\fR will negotiate any supported \s-1DTLS\s0 protocol version,
|
|
whilst \fB\-dtls1\fR and \fB\-dtls1_2\fR will only support \s-1DTLS1.0\s0 and \s-1DTLS1.2\s0
|
|
respectively.
|
|
.IP "\fB\-sctp\fR" 4
|
|
.IX Item "-sctp"
|
|
Use \s-1SCTP\s0 for the transport protocol instead of \s-1UDP\s0 in \s-1DTLS.\s0 Must be used in
|
|
conjunction with \fB\-dtls\fR, \fB\-dtls1\fR or \fB\-dtls1_2\fR. This option is only
|
|
available where OpenSSL has support for \s-1SCTP\s0 enabled.
|
|
.IP "\fB\-sctp_label_bug\fR" 4
|
|
.IX Item "-sctp_label_bug"
|
|
Use the incorrect behaviour of older OpenSSL implementations when computing
|
|
endpoint-pair shared secrets for \s-1DTLS/SCTP.\s0 This allows communication with
|
|
older broken implementations but breaks interoperability with correct
|
|
implementations. Must be used in conjunction with \fB\-sctp\fR. This option is only
|
|
available where OpenSSL has support for \s-1SCTP\s0 enabled.
|
|
.IP "\fB\-fallback_scsv\fR" 4
|
|
.IX Item "-fallback_scsv"
|
|
Send \s-1TLS_FALLBACK_SCSV\s0 in the ClientHello.
|
|
.IP "\fB\-async\fR" 4
|
|
.IX Item "-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 \fB\-engine\fR option. For test purposes the dummy async engine
|
|
(dasync) can be used (if available).
|
|
.IP "\fB\-max_send_frag int\fR" 4
|
|
.IX Item "-max_send_frag int"
|
|
The maximum size of data fragment to send.
|
|
See \fBSSL_CTX_set_max_send_fragment\fR\|(3) for further information.
|
|
.IP "\fB\-split_send_frag int\fR" 4
|
|
.IX Item "-split_send_frag 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
|
|
\&\fBSSL_CTX_set_split_send_fragment\fR\|(3) for further information.
|
|
.IP "\fB\-max_pipelines int\fR" 4
|
|
.IX Item "-max_pipelines 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 \fBSSL_CTX_set_max_pipelines\fR\|(3) for further information.
|
|
.IP "\fB\-read_buf int\fR" 4
|
|
.IX Item "-read_buf 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 \fBSSL_CTX_set_default_read_buffer_len\fR\|(3) for
|
|
further information).
|
|
.IP "\fB\-bugs\fR" 4
|
|
.IX Item "-bugs"
|
|
There are several known bugs in \s-1SSL\s0 and \s-1TLS\s0 implementations. Adding this
|
|
option enables various workarounds.
|
|
.IP "\fB\-comp\fR" 4
|
|
.IX Item "-comp"
|
|
Enables support for \s-1SSL/TLS\s0 compression.
|
|
This option was introduced in OpenSSL 1.1.0.
|
|
\&\s-1TLS\s0 compression is not recommended and is off by default as of
|
|
OpenSSL 1.1.0.
|
|
.IP "\fB\-no_comp\fR" 4
|
|
.IX Item "-no_comp"
|
|
Disables support for \s-1SSL/TLS\s0 compression.
|
|
\&\s-1TLS\s0 compression is not recommended and is off by default as of
|
|
OpenSSL 1.1.0.
|
|
.IP "\fB\-brief\fR" 4
|
|
.IX Item "-brief"
|
|
Only provide a brief summary of connection parameters instead of the
|
|
normal verbose output.
|
|
.IP "\fB\-sigalgs sigalglist\fR" 4
|
|
.IX Item "-sigalgs 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 \fBSSL_CTX_set1_sigalgs\fR\|(3)
|
|
.IP "\fB\-curves curvelist\fR" 4
|
|
.IX Item "-curves 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:
|
|
.Sp
|
|
.Vb 1
|
|
\& $ openssl ecparam \-list_curves
|
|
.Ve
|
|
.IP "\fB\-cipher cipherlist\fR" 4
|
|
.IX Item "-cipher 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 the
|
|
\&\fBciphers\fR command for more information.
|
|
.IP "\fB\-ciphersuites val\fR" 4
|
|
.IX Item "-ciphersuites 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 the
|
|
\&\fBciphers\fR command for more information. The format for this list is a simple
|
|
colon (\*(L":\*(R") separated list of TLSv1.3 ciphersuite names.
|
|
.IP "\fB\-starttls protocol\fR" 4
|
|
.IX Item "-starttls protocol"
|
|
Send the protocol-specific message(s) to switch to \s-1TLS\s0 for communication.
|
|
\&\fBprotocol\fR is a keyword for the intended protocol. Currently, the only
|
|
supported keywords are \*(L"smtp\*(R", \*(L"pop3\*(R", \*(L"imap\*(R", \*(L"ftp\*(R", \*(L"xmpp\*(R", \*(L"xmpp-server\*(R",
|
|
\&\*(L"irc\*(R", \*(L"postgres\*(R", \*(L"mysql\*(R", \*(L"lmtp\*(R", \*(L"nntp\*(R", \*(L"sieve\*(R" and \*(L"ldap\*(R".
|
|
.IP "\fB\-xmpphost hostname\fR" 4
|
|
.IX Item "-xmpphost hostname"
|
|
This option, when used with \*(L"\-starttls xmpp\*(R" or \*(L"\-starttls xmpp-server\*(R",
|
|
specifies the host for the \*(L"to\*(R" attribute of the stream element.
|
|
If this option is not specified, then the host specified with \*(L"\-connect\*(R"
|
|
will be used.
|
|
.Sp
|
|
This option is an alias of the \fB\-name\fR option for \*(L"xmpp\*(R" and \*(L"xmpp-server\*(R".
|
|
.IP "\fB\-name hostname\fR" 4
|
|
.IX Item "-name hostname"
|
|
This option is used to specify hostname information for various protocols
|
|
used with \fB\-starttls\fR option. Currently only \*(L"xmpp\*(R", \*(L"xmpp-server\*(R",
|
|
\&\*(L"smtp\*(R" and \*(L"lmtp\*(R" can utilize this \fB\-name\fR option.
|
|
.Sp
|
|
If this option is used with \*(L"\-starttls xmpp\*(R" or \*(L"\-starttls xmpp-server\*(R",
|
|
if specifies the host for the \*(L"to\*(R" attribute of the stream element. If this
|
|
option is not specified, then the host specified with \*(L"\-connect\*(R" will be used.
|
|
.Sp
|
|
If this option is used with \*(L"\-starttls lmtp\*(R" or \*(L"\-starttls smtp\*(R", it specifies
|
|
the name to use in the \*(L"\s-1LMTP LHLO\*(R"\s0 or \*(L"\s-1SMTP EHLO\*(R"\s0 message, respectively. If
|
|
this option is not specified, then \*(L"mail.example.com\*(R" will be used.
|
|
.IP "\fB\-tlsextdebug\fR" 4
|
|
.IX Item "-tlsextdebug"
|
|
Print out a hex dump of any \s-1TLS\s0 extensions received from the server.
|
|
.IP "\fB\-no_ticket\fR" 4
|
|
.IX Item "-no_ticket"
|
|
Disable RFC4507bis session ticket support.
|
|
.IP "\fB\-sess_out filename\fR" 4
|
|
.IX Item "-sess_out filename"
|
|
Output \s-1SSL\s0 session to \fBfilename\fR.
|
|
.IP "\fB\-sess_in sess.pem\fR" 4
|
|
.IX Item "-sess_in sess.pem"
|
|
Load \s-1SSL\s0 session from \fBfilename\fR. The client will attempt to resume a
|
|
connection from this session.
|
|
.IP "\fB\-engine id\fR" 4
|
|
.IX Item "-engine id"
|
|
Specifying an engine (by its unique \fBid\fR string) will cause \fBs_client\fR
|
|
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.
|
|
.IP "\fB\-rand file...\fR" 4
|
|
.IX Item "-rand file..."
|
|
A file or files containing random data used to seed the random number
|
|
generator.
|
|
Multiple files can be specified separated by an OS-dependent character.
|
|
The separator is \fB;\fR for MS-Windows, \fB,\fR for OpenVMS, and \fB:\fR for
|
|
all others.
|
|
.IP "[\fB\-writerand file\fR]" 4
|
|
.IX Item "[-writerand file]"
|
|
Writes random data to the specified \fIfile\fR upon exit.
|
|
This can be used with a subsequent \fB\-rand\fR flag.
|
|
.IP "\fB\-serverinfo types\fR" 4
|
|
.IX Item "-serverinfo types"
|
|
A list of comma-separated \s-1TLS\s0 Extension Types (numbers between 0 and
|
|
65535). Each type will be sent as an empty ClientHello \s-1TLS\s0 Extension.
|
|
The server's response (if any) will be encoded and displayed as a \s-1PEM\s0
|
|
file.
|
|
.IP "\fB\-status\fR" 4
|
|
.IX Item "-status"
|
|
Sends a certificate status request to the server (\s-1OCSP\s0 stapling). The server
|
|
response (if any) is printed out.
|
|
.IP "\fB\-alpn protocols\fR, \fB\-nextprotoneg protocols\fR" 4
|
|
.IX Item "-alpn protocols, -nextprotoneg protocols"
|
|
These flags enable the Enable the Application-Layer Protocol Negotiation
|
|
or Next Protocol Negotiation (\s-1NPN\s0) extension, respectively. \s-1ALPN\s0 is the
|
|
\&\s-1IETF\s0 standard and replaces \s-1NPN.\s0
|
|
The \fBprotocols\fR 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 \s-1ASCII\s0 strings,
|
|
for example \*(L"http/1.1\*(R" or \*(L"spdy/3\*(R".
|
|
An empty list of protocols is treated specially and will cause the
|
|
client to advertise support for the \s-1TLS\s0 extension but disconnect just
|
|
after receiving ServerHello with a list of server supported protocols.
|
|
The flag \fB\-nextprotoneg\fR cannot be specified if \fB\-tls1_3\fR is used.
|
|
.IP "\fB\-ct\fR, \fB\-noct\fR" 4
|
|
.IX Item "-ct, -noct"
|
|
Use one of these two options to control whether Certificate Transparency (\s-1CT\s0)
|
|
is enabled (\fB\-ct\fR) or disabled (\fB\-noct\fR).
|
|
If \s-1CT\s0 is enabled, signed certificate timestamps (SCTs) will be requested from
|
|
the server and reported at handshake completion.
|
|
.Sp
|
|
Enabling \s-1CT\s0 also enables \s-1OCSP\s0 stapling, as this is one possible delivery method
|
|
for SCTs.
|
|
.IP "\fB\-ctlogfile\fR" 4
|
|
.IX Item "-ctlogfile"
|
|
A file containing a list of known Certificate Transparency logs. See
|
|
\&\fBSSL_CTX_set_ctlog_list_file\fR\|(3) for the expected file format.
|
|
.IP "\fB\-keylogfile file\fR" 4
|
|
.IX Item "-keylogfile file"
|
|
Appends \s-1TLS\s0 secrets to the specified keylog file such that external programs
|
|
(like Wireshark) can decrypt \s-1TLS\s0 connections.
|
|
.IP "\fB\-early_data file\fR" 4
|
|
.IX Item "-early_data 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.
|
|
.IP "\fB\-enable_pha\fR" 4
|
|
.IX Item "-enable_pha"
|
|
For TLSv1.3 only, send the Post-Handshake Authentication extension. This will
|
|
happen whether or not a certificate has been provided via \fB\-cert\fR.
|
|
.IP "\fB[target]\fR" 4
|
|
.IX Item "[target]"
|
|
Rather than providing \fB\-connect\fR, the target hostname and optional port may
|
|
be provided as a single positional argument after all options. If neither this
|
|
nor \fB\-connect\fR are provided, falls back to attempting to connect to localhost
|
|
on port 4433.
|
|
.SH "CONNECTED COMMANDS"
|
|
.IX Header "CONNECTED COMMANDS"
|
|
If a connection is established with an \s-1SSL\s0 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 \fB\-quiet\fR nor \fB\-ign_eof\fR 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.
|
|
.IP "\fBQ\fR" 4
|
|
.IX Item "Q"
|
|
End the current \s-1SSL\s0 connection and exit.
|
|
.IP "\fBR\fR" 4
|
|
.IX Item "R"
|
|
Renegotiate the \s-1SSL\s0 session (TLSv1.2 and below only).
|
|
.IP "\fBB\fR" 4
|
|
.IX Item "B"
|
|
Send a heartbeat message to the server (\s-1DTLS\s0 only)
|
|
.IP "\fBk\fR" 4
|
|
.IX Item "k"
|
|
Send a key update message to the server (TLSv1.3 only)
|
|
.IP "\fBK\fR" 4
|
|
.IX Item "K"
|
|
Send a key update message to the server and request one back (TLSv1.3 only)
|
|
.SH "NOTES"
|
|
.IX Header "NOTES"
|
|
\&\fBs_client\fR can be used to debug \s-1SSL\s0 servers. To connect to an \s-1SSL HTTP\s0
|
|
server the command:
|
|
.PP
|
|
.Vb 1
|
|
\& openssl s_client \-connect servername:443
|
|
.Ve
|
|
.PP
|
|
would typically be used (https uses port 443). If the connection succeeds
|
|
then an \s-1HTTP\s0 command can be given such as \*(L"\s-1GET /\*(R"\s0 to retrieve a web page.
|
|
.PP
|
|
If the handshake fails then there are several possible causes, if it is
|
|
nothing obvious like no client certificate then the \fB\-bugs\fR,
|
|
\&\fB\-ssl3\fR, \fB\-tls1\fR, \fB\-no_ssl3\fR, \fB\-no_tls1\fR options can be tried
|
|
in case it is a buggy server. In particular you should play with these
|
|
options \fBbefore\fR submitting a bug report to an OpenSSL mailing list.
|
|
.PP
|
|
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 \*(L"acceptable \s-1CA\s0 list\*(R" when it
|
|
requests a certificate. By using \fBs_client\fR the \s-1CA\s0 list can be viewed
|
|
and checked. However some servers only request client authentication
|
|
after a specific \s-1URL\s0 is requested. To obtain the list in this case it
|
|
is necessary to use the \fB\-prexit\fR option and send an \s-1HTTP\s0 request
|
|
for an appropriate page.
|
|
.PP
|
|
If a certificate is specified on the command line using the \fB\-cert\fR
|
|
option it will not be used unless the server specifically requests
|
|
a client certificate. Therefor merely including a client certificate
|
|
on the command line is no guarantee that the certificate works.
|
|
.PP
|
|
If there are problems verifying a server certificate then the
|
|
\&\fB\-showcerts\fR option can be used to show all the certificates sent by the
|
|
server.
|
|
.PP
|
|
The \fBs_client\fR 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 \fBnot\fR do this as it makes them vulnerable to a \s-1MITM\s0
|
|
attack. This behaviour can be changed by with the \fB\-verify_return_error\fR
|
|
option: any verify errors are then returned aborting the handshake.
|
|
.PP
|
|
The \fB\-bind\fR option may be useful if the server or a firewall requires
|
|
connections to come from some particular address and or port.
|
|
.SH "BUGS"
|
|
.IX Header "BUGS"
|
|
Because this program has a lot of options and also because some of the
|
|
techniques used are rather old, the C source of \fBs_client\fR is rather hard to
|
|
read and not a model of how things should be done.
|
|
A typical \s-1SSL\s0 client program would be much simpler.
|
|
.PP
|
|
The \fB\-prexit\fR option is a bit of a hack. We should really report
|
|
information whenever a session is renegotiated.
|
|
.SH "SEE ALSO"
|
|
.IX Header "SEE ALSO"
|
|
\&\fBSSL_CONF_cmd\fR\|(3), \fBsess_id\fR\|(1), \fBs_server\fR\|(1), \fBciphers\fR\|(1),
|
|
\&\fBSSL_CTX_set_max_send_fragment\fR\|(3), \fBSSL_CTX_set_split_send_fragment\fR\|(3),
|
|
\&\fBSSL_CTX_set_max_pipelines\fR\|(3)
|
|
.SH "HISTORY"
|
|
.IX Header "HISTORY"
|
|
The \fB\-no_alt_chains\fR option was added in OpenSSL 1.1.0.
|
|
The \fB\-name\fR option was added in OpenSSL 1.1.1.
|
|
.SH "COPYRIGHT"
|
|
.IX Header "COPYRIGHT"
|
|
Copyright 2000\-2020 The OpenSSL Project Authors. All Rights Reserved.
|
|
.PP
|
|
Licensed under the OpenSSL license (the \*(L"License\*(R"). You may not use
|
|
this file except in compliance with the License. You can obtain a copy
|
|
in the file \s-1LICENSE\s0 in the source distribution or at
|
|
<https://www.openssl.org/source/license.html>.
|