9d772829c9
Document that -psk is required to use PSK cipher [skip ci] Reviewed-by: Ben Kaduk <kaduk@mit.edu> (Merged from https://github.com/openssl/openssl/pull/3607)
671 lines
20 KiB
Text
671 lines
20 KiB
Text
=pod
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=head1 NAME
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s_server - SSL/TLS server program
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=head1 SYNOPSIS
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B<openssl> B<s_server>
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[B<-help>]
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[B<-port port>]
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[B<-accept val>]
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[B<-naccept count>]
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[B<-unix val>]
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[B<-unlink>]
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[B<-4>]
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[B<-6>]
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[B<-context id>]
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[B<-verify depth>]
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[B<-Verify depth>]
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[B<-crl_check>]
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[B<-crl_check_all>]
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[B<-cert filename>]
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[B<-certform DER|PEM>]
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[B<-key keyfile>]
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[B<-keyform DER|PEM>]
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[B<-pass arg>]
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[B<-dcert filename>]
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[B<-dcertform DER|PEM>]
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[B<-dkey keyfile>]
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[B<-dkeyform DER|PEM>]
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[B<-dpass arg>]
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[B<-dhparam filename>]
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[B<-nbio>]
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[B<-nbio_test>]
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[B<-crlf>]
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[B<-debug>]
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[B<-msg>]
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[B<-state>]
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[B<-CApath directory>]
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[B<-CAfile filename>]
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[B<-no-CAfile>]
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[B<-no-CApath>]
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[B<-attime timestamp>]
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[B<-check_ss_sig>]
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[B<-explicit_policy>]
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[B<-extended_crl>]
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[B<-ignore_critical>]
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[B<-inhibit_any>]
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[B<-inhibit_map>]
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[B<-no_check_time>]
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[B<-partial_chain>]
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[B<-policy arg>]
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[B<-policy_check>]
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[B<-policy_print>]
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[B<-purpose purpose>]
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[B<-suiteB_128>]
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[B<-suiteB_128_only>]
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[B<-suiteB_192>]
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[B<-trusted_first>]
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[B<-no_alt_chains>]
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[B<-use_deltas>]
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[B<-auth_level num>]
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[B<-nameopt option>]
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[B<-verify_depth num>]
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[B<-verify_return_error>]
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[B<-verify_email email>]
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[B<-verify_hostname hostname>]
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[B<-verify_ip ip>]
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[B<-verify_name name>]
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[B<-x509_strict>]
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[B<-nocert>]
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[B<-client_sigalgs sigalglist>]
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[B<-named_curve curve>]
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[B<-cipher cipherlist>]
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[B<-serverpref>]
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[B<-quiet>]
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[B<-ssl3>]
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[B<-tls1>]
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[B<-tls1_1>]
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[B<-tls1_2>]
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[B<-tls1_3>]
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[B<-dtls>]
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[B<-dtls1>]
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[B<-dtls1_2>]
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[B<-sctp>]
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[B<-listen>]
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[B<-async>]
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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<-no_ssl3>]
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[B<-no_tls1>]
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[B<-no_tls1_1>]
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[B<-no_tls1_2>]
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[B<-no_tls1_3>]
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[B<-no_dhe>]
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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<-www>]
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[B<-WWW>]
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[B<-HTTP>]
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[B<-engine id>]
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[B<-tlsextdebug>]
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[B<-no_ticket>]
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[B<-id_prefix arg>]
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[B<-rand file(s)>]
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[B<-serverinfo file>]
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[B<-no_resumption_on_reneg>]
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[B<-status>]
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[B<-status_verbose>]
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[B<-status_timeout nsec>]
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[B<-status_url url>]
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[B<-status_file file>]
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[B<-alpn protocols>]
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[B<-nextprotoneg protocols>]
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[B<-max_early_data>]
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[B<-early_data>]
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=head1 DESCRIPTION
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The B<s_server> command implements a generic SSL/TLS server which listens
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for connections on a given port using SSL/TLS.
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=head1 OPTIONS
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In addition to the options below the B<s_server> utility also supports the
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common and server only options documented in the
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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<-port port>
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The TCP port to listen on for connections. If not specified 4433 is used.
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=item B<-accept val>
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The optional TCP host and port to listen on for connections. If not specified, *:4433 is used.
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=item B<-naccept count>
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The server will exit after receiving B<number> connections, default unlimited.
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=item B<-unix val>
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Unix domain socket to accept on.
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=item B<-unlink>
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For -unix, unlink existing socket first.
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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<-context id>
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Sets the SSL context id. It can be given any string value. If this option
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is not present a default value will be used.
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=item B<-cert certname>
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The certificate to use, most servers cipher suites require the use of a
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certificate and some require a certificate with a certain public key type:
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for example the DSS cipher suites require a certificate containing a DSS
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(DSA) key. If not specified then the filename "server.pem" will be used.
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=item B<-certform format>
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The certificate format to use: DER or PEM. PEM is the default.
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=item B<-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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=item B<-keyform format>
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The private format to use: DER or PEM. PEM is the default.
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=item B<-pass arg>
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The private key password source. For more information about the format of B<arg>
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see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
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=item B<-dcert filename>, B<-dkey keyname>
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Specify an additional certificate and private key, these behave in the
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same manner as the B<-cert> and B<-key> options except there is no default
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if they are not specified (no additional certificate and key is used). As
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noted above some cipher suites require a certificate containing a key of
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a certain type. Some cipher suites need a certificate carrying an RSA key
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and some a DSS (DSA) key. By using RSA and DSS certificates and keys
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a server can support clients which only support RSA or DSS cipher suites
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by using an appropriate certificate.
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=item B<-dcertform format>, B<-dkeyform format>, B<-dpass arg>
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Additional certificate and private key format and passphrase respectively.
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=item B<-nocert>
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If this option is set then no certificate is used. This restricts the
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cipher suites available to the anonymous ones (currently just anonymous
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DH).
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=item B<-dhparam filename>
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The DH parameter file to use. The ephemeral DH cipher suites generate keys
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using a set of DH parameters. If not specified then an attempt is made to
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load the parameters from the server certificate file.
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If this fails then a static set of parameters hard coded into the B<s_server>
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program will be used.
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=item B<-no_dhe>
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If this option is set then no DH parameters will be loaded effectively
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disabling the ephemeral DH cipher suites.
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=item B<-crl_check>, B<-crl_check_all>
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Check the peer certificate has not been revoked by its CA.
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The CRL(s) are appended to the certificate file. With the B<-crl_check_all>
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option all CRLs of all CAs in the chain are checked.
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=item B<-CApath directory>
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The directory to use for client certificate verification. This directory
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must be in "hash format", see B<verify> for more information. These are
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also used when building the server certificate chain.
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=item B<-CAfile file>
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A file containing trusted certificates to use during client authentication
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and to use when attempting to build the server certificate chain. The list
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is also used in the list of acceptable client CAs passed to the client when
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a certificate is requested.
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=item B<-no-CAfile>
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Do not load the trusted CA certificates from the default file location.
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=item B<-no-CApath>
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Do not load the trusted CA certificates from the default directory location.
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=item B<-verify depth>, B<-Verify depth>
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The verify depth to use. This specifies the maximum length of the
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client certificate chain and makes the server request a certificate from
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the client. With the B<-verify> option a certificate is requested but the
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client does not have to send one, with the B<-Verify> option the client
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must supply a certificate or an error occurs.
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If the cipher suite cannot request a client certificate (for example an
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anonymous cipher suite or PSK) this option has no effect.
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=item B<-nameopt option>
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Option which determines how the subject or issuer names are displayed. The
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B<option> argument can be a single option or multiple options separated by
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commas. Alternatively the B<-nameopt> switch may be used more than once to
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set multiple options. See the L<x509(1)> manual page for details.
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=item B<-attime>, B<-check_ss_sig>, B<-crl_check>, B<-crl_check_all>,
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B<-explicit_policy>, B<-extended_crl>, B<-ignore_critical>, B<-inhibit_any>,
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B<-inhibit_map>, B<-no_alt_chains>, B<-no_check_time>, B<-partial_chain>, B<-policy>,
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B<-policy_check>, B<-policy_print>, B<-purpose>, B<-suiteB_128>,
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B<-suiteB_128_only>, B<-suiteB_192>, B<-trusted_first>, B<-use_deltas>,
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B<-auth_level>, B<-verify_depth>, B<-verify_email>, B<-verify_hostname>,
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B<-verify_ip>, B<-verify_name>, B<-x509_strict>
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Set different peer certificate verification options.
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See the L<verify(1)> manual page for details.
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=item B<-verify_return_error>
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Verification errors normally just print a message but allow the
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connection to continue, for debugging purposes.
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If this option is used, then verification errors close the connection.
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=item B<-state>
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Prints 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<-msg>
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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. OpenSSL needs to be compiled
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with B<enable-ssl-trace> for this option to work.
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=item B<-msgfile>
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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 non blocking I/O.
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=item B<-nbio>
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Turns on non blocking 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.
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=item B<-quiet>
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Inhibit printing of session and certificate information.
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=item B<-psk_hint hint>
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Use the PSK identity hint B<hint> when using a PSK cipher suite.
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=item B<-psk_identity identity>
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Expect the client to send PSK identity B<identity> when using a PSK
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cipher suite, and warn if they do not. By default, the expected PSK
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identity is the string "Client_identity".
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=item B<-psk key>
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Use the PSK key B<key> when using a PSK cipher suite. The key is
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given as a hexadecimal number without leading 0x, for example -psk
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1a2b3c4d.
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This option must be provided in order to use a PSK cipher.
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=item B<-ssl2>, B<-ssl3>, B<-tls1>, B<-tls1_1>, B<-tls1_2>, B<-tls1_3>, B<-no_ssl2>, B<-no_ssl3>, B<-no_tls1>, B<-no_tls1_1>, B<-no_tls1_2>, B<-no_tls1_3>
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These options require or disable the use of the specified SSL or TLS protocols.
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By default B<s_server> will negotiate the highest mutually supported protocol
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version.
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When a specific TLS version is required, only that version will be accepted
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from the client.
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=item B<-dtls>, B<-dtls1>, B<-dtls1_2>
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These options make B<s_server> use DTLS protocols instead of TLS.
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With B<-dtls>, B<s_server> will negotiate any supported DTLS protocol version,
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whilst B<-dtls1> and B<-dtls1_2> will only support DTLSv1.0 and DTLSv1.2
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respectively.
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=item B<-listen>
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This option can only be used in conjunction with one of the DTLS options above.
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With this option B<s_server> will listen on a UDP port for incoming connections.
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Any ClientHellos that arrive will be checked to see if they have a cookie in
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them or not.
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Any without a cookie will be responded to with a HelloVerifyRequest.
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If a ClientHello with a cookie is received then B<s_server> will connect to
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that peer and complete the handshake.
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=item B<-sctp>
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Use SCTP for the transport protocol instead of UDP in DTLS. Must be used in
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conjunction with B<-dtls>, B<-dtls1> or B<-dtls1_2>. This option is only
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available where OpenSSL has support for SCTP enabled.
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=item B<-async>
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Switch on asynchronous mode. Cryptographic operations will be performed
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asynchronously. This will only have an effect if an asynchronous capable engine
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is also used via the B<-engine> option. For test purposes the dummy async engine
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(dasync) can be used (if available).
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=item B<-max_send_frag int>
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The maximum size of data fragment to send.
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See L<SSL_CTX_set_max_send_fragment(3)> for further information.
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=item B<-split_send_frag int>
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The size used to split data for encrypt pipelines. If more data is written in
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one go than this value then it will be split into multiple pipelines, up to the
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maximum number of pipelines defined by max_pipelines. This only has an effect if
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a suitable cipher suite has been negotiated, an engine that supports pipelining
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has been loaded, and max_pipelines is greater than 1. See
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L<SSL_CTX_set_split_send_fragment(3)> for further information.
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=item B<-max_pipelines int>
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The maximum number of encrypt/decrypt pipelines to be used. This will only have
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an effect if an engine has been loaded that supports pipelining (e.g. the dasync
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engine) and a suitable cipher suite has been negotiated. The default value is 1.
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See L<SSL_CTX_set_max_pipelines(3)> for further information.
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=item B<-read_buf int>
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The default read buffer size to be used for connections. This will only have an
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effect if the buffer size is larger than the size that would otherwise be used
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and pipelining is in use (see L<SSL_CTX_set_default_read_buffer_len(3)> for
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further information).
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=item B<-bugs>
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There are several known bug in SSL and TLS implementations. Adding this
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option enables various workarounds.
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=item B<-comp>
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Enable negotiation of TLS compression.
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This option was introduced in OpenSSL 1.1.0.
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TLS compression is not recommended and is off by default as of
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OpenSSL 1.1.0.
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=item B<-no_comp>
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Disable negotiation of TLS compression.
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TLS compression is not recommended and is off by default as of
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OpenSSL 1.1.0.
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=item B<-brief>
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Provide a brief summary of connection parameters instead of the normal verbose
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output.
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=item B<-client_sigalgs sigalglist>
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Signature algorithms to support for client certificate authentication
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(colon-separated list).
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=item B<-named_curve curve>
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Specifies the elliptic curve to use. NOTE: this is single curve, not a list.
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For a list of all possible curves, use:
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$ openssl ecparam -list_curves
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=item B<-cipher cipherlist>
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This allows the cipher list used by the server to be modified. When
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the client sends a list of supported ciphers the first client cipher
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also included in the server list is used. Because the client specifies
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the preference order, the order of the server cipherlist irrelevant. See
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the B<ciphers> command for more information.
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=item B<-serverpref>
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Use the server's cipher preferences, rather than the client's preferences.
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=item B<-tlsextdebug>
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Print a hex dump of any TLS extensions received from the server.
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=item B<-no_ticket>
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Disable RFC4507bis session ticket support.
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=item B<-www>
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Sends a status message back to the client when it connects. This includes
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information about the ciphers used and various session parameters.
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The output is in HTML format so this option will normally be used with a
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web browser.
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=item B<-WWW>
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Emulates a simple web server. Pages will be resolved relative to the
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current directory, for example if the URL https://myhost/page.html is
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requested the file ./page.html will be loaded.
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=item B<-HTTP>
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Emulates a simple web server. Pages will be resolved relative to the
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current directory, for example if the URL https://myhost/page.html is
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requested the file ./page.html will be loaded. The files loaded are
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assumed to contain a complete and correct HTTP response (lines that
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are part of the HTTP response line and headers must end with CRLF).
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=item B<-rev>
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Simple test server which just reverses the text received from the client
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and sends it back to the server. Also sets B<-brief>.
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=item B<-engine id>
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Specifying an engine (by its unique B<id> string) will cause B<s_server>
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to attempt to obtain a functional reference to the specified engine,
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thus initialising it if needed. The engine will then be set as the default
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for all available algorithms.
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=item B<-id_prefix arg>
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Generate SSL/TLS session IDs prefixed by B<arg>. This is mostly useful
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for testing any SSL/TLS code (eg. proxies) that wish to deal with multiple
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servers, when each of which might be generating a unique range of session
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IDs (eg. with a certain prefix).
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=item B<-rand file(s)>
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A file or files containing random data used to seed the random number
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generator, or an EGD socket (see L<RAND_egd(3)>).
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Multiple files can be specified separated by an OS-dependent character.
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The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
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all others.
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=item B<-serverinfo file>
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A file containing one or more blocks of PEM data. Each PEM block
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must encode a TLS ServerHello extension (2 bytes type, 2 bytes length,
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followed by "length" bytes of extension data). If the client sends
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an empty TLS ClientHello extension matching the type, the corresponding
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ServerHello extension will be returned.
|
|
|
|
=item B<-no_resumption_on_reneg>
|
|
|
|
Set the B<SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION> option.
|
|
|
|
=item B<-status>
|
|
|
|
Enables certificate status request support (aka OCSP stapling).
|
|
|
|
=item B<-status_verbose>
|
|
|
|
Enables certificate status request support (aka OCSP stapling) and gives
|
|
a verbose printout of the OCSP response.
|
|
|
|
=item B<-status_timeout nsec>
|
|
|
|
Sets the timeout for OCSP response to B<nsec> seconds.
|
|
|
|
=item B<-status_url url>
|
|
|
|
Sets a fallback responder URL to use if no responder URL is present in the
|
|
server certificate. Without this option an error is returned if the server
|
|
certificate does not contain a responder address.
|
|
|
|
=item B<-status_file file>
|
|
|
|
Overrides any OCSP responder URLs from the certificate and always provides the
|
|
OCSP Response stored in the file. The file must be in DER format.
|
|
|
|
=item B<-alpn protocols>, B<-nextprotoneg 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 B<protocols> list is a comma-separated list of supported protocol
|
|
names. The list should contain the most desirable protocols first.
|
|
Protocol names are printable ASCII strings, for example "http/1.1" or
|
|
"spdy/3".
|
|
|
|
=item B<-keylogfile path>
|
|
|
|
Appends TLS secrets to the specified keylog file such that external programs
|
|
(like Wireshark) can decrypt TLS connections.
|
|
|
|
=item B<-max_early_data arg>
|
|
|
|
Change the default maximum early data bytes that are specified for new sessions
|
|
and any incoming early data (when used in conjunction with the B<-early_data>
|
|
flag). The default value is approximately 16k. The argument must be an integer
|
|
greater than or equal to 0.
|
|
|
|
=item B<-early_data>
|
|
|
|
Accept early data where possible.
|
|
|
|
=back
|
|
|
|
=head1 CONNECTED COMMANDS
|
|
|
|
If a connection request is established with an SSL client and neither the
|
|
B<-www> nor the B<-WWW> option has been used then normally any data received
|
|
from the client is displayed and any key presses will be sent to the client.
|
|
|
|
Certain single letter commands are also recognized which perform special
|
|
operations: these are listed below.
|
|
|
|
=over 4
|
|
|
|
=item B<q>
|
|
|
|
End the current SSL connection but still accept new connections.
|
|
|
|
=item B<Q>
|
|
|
|
End the current SSL connection and exit.
|
|
|
|
=item B<r>
|
|
|
|
Renegotiate the SSL session.
|
|
|
|
=item B<R>
|
|
|
|
Renegotiate the SSL session and request a client certificate.
|
|
|
|
=item B<P>
|
|
|
|
Send some plain text down the underlying TCP connection: this should
|
|
cause the client to disconnect due to a protocol violation.
|
|
|
|
=item B<S>
|
|
|
|
Print out some session cache status information.
|
|
|
|
=back
|
|
|
|
=head1 NOTES
|
|
|
|
B<s_server> can be used to debug SSL clients. To accept connections from
|
|
a web browser the command:
|
|
|
|
openssl s_server -accept 443 -www
|
|
|
|
can be used for example.
|
|
|
|
Most web browsers (in particular Netscape and MSIE) only support RSA cipher
|
|
suites, so they cannot connect to servers which don't use a certificate
|
|
carrying an RSA key or a version of OpenSSL with RSA disabled.
|
|
|
|
Although specifying an empty list of CAs when requesting a client certificate
|
|
is strictly speaking a protocol violation, some SSL clients interpret this to
|
|
mean any CA is acceptable. This is useful for debugging purposes.
|
|
|
|
The session parameters can printed out using the B<sess_id> program.
|
|
|
|
=head1 BUGS
|
|
|
|
Because this program has a lot of options and also because some of the
|
|
techniques used are rather old, the C source of B<s_server> is rather hard to
|
|
read and not a model of how things should be done.
|
|
A typical SSL server program would be much simpler.
|
|
|
|
The output of common ciphers is wrong: it just gives the list of ciphers that
|
|
OpenSSL recognizes and the client supports.
|
|
|
|
There should be a way for the B<s_server> program to print out details of any
|
|
unknown cipher suites a client says it supports.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<SSL_CONF_cmd(3)>, L<sess_id(1)>, L<s_client(1)>, L<ciphers(1)>
|
|
L<SSL_CTX_set_max_send_fragment(3)>, L<SSL_CTX_set_split_send_fragment(3)>
|
|
L<SSL_CTX_set_max_pipelines(3)>
|
|
|
|
=head1 HISTORY
|
|
|
|
The -no_alt_chains options was first added to OpenSSL 1.1.0.
|
|
|
|
=head1 COPYRIGHT
|
|
|
|
Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
|
|
|
|
Licensed under the OpenSSL license (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
|