=head1 NAME
+openssl-s_server,
s_server - SSL/TLS server program
=head1 SYNOPSIS
B<openssl> B<s_server>
[B<-help>]
-[B<-port port>]
+[B<-port +int>]
[B<-accept val>]
-[B<-naccept count>]
[B<-unix val>]
-[B<-unlink>]
[B<-4>]
[B<-6>]
-[B<-context id>]
-[B<-verify depth>]
-[B<-Verify depth>]
-[B<-crl_check>]
-[B<-crl_check_all>]
-[B<-cert filename>]
-[B<-certform DER|PEM>]
-[B<-key keyfile>]
-[B<-keyform DER|PEM>]
-[B<-pass arg>]
-[B<-dcert filename>]
-[B<-dcertform DER|PEM>]
-[B<-dkey keyfile>]
-[B<-dkeyform DER|PEM>]
-[B<-dpass arg>]
-[B<-dhparam filename>]
-[B<-nbio>]
+[B<-unlink>]
+[B<-context val>]
+[B<-verify int>]
+[B<-Verify int>]
+[B<-cert infile>]
+[B<-nameopt val>]
+[B<-naccept +int>]
+[B<-serverinfo val>]
+[B<-certform PEM|DER>]
+[B<-key infile>]
+[B<-keyform format>]
+[B<-pass val>]
+[B<-dcert infile>]
+[B<-dcertform PEM|DER>]
+[B<-dkey infile>]
+[B<-dkeyform PEM|DER>]
+[B<-dpass val>]
[B<-nbio_test>]
[B<-crlf>]
[B<-debug>]
[B<-msg>]
+[B<-msgfile outfile>]
[B<-state>]
-[B<-CApath directory>]
-[B<-CAfile filename>]
+[B<-CAfile infile>]
+[B<-CApath dir>]
[B<-no-CAfile>]
[B<-no-CApath>]
-[B<-attime timestamp>]
-[B<-check_ss_sig>]
-[B<-explicit_policy>]
-[B<-extended_crl>]
+[B<-nocert>]
+[B<-quiet>]
+[B<-no_resume_ephemeral>]
+[B<-www>]
+[B<-WWW>]
+[B<-servername>]
+[B<-servername_fatal>]
+[B<-cert2 infile>]
+[B<-key2 infile>]
+[B<-tlsextdebug>]
+[B<-HTTP>]
+[B<-id_prefix val>]
+[B<-rand file...>]
+[B<-writerand file>]
+[B<-keymatexport val>]
+[B<-keymatexportlen +int>]
+[B<-CRL infile>]
+[B<-crl_download>]
+[B<-cert_chain infile>]
+[B<-dcert_chain infile>]
+[B<-chainCApath dir>]
+[B<-verifyCApath dir>]
+[B<-no_cache>]
+[B<-ext_cache>]
+[B<-CRLform PEM|DER>]
+[B<-verify_return_error>]
+[B<-verify_quiet>]
+[B<-build_chain>]
+[B<-chainCAfile infile>]
+[B<-verifyCAfile infile>]
+[B<-ign_eof>]
+[B<-no_ign_eof>]
+[B<-status>]
+[B<-status_verbose>]
+[B<-status_timeout int>]
+[B<-status_url val>]
+[B<-status_file infile>]
+[B<-trace>]
+[B<-security_debug>]
+[B<-security_debug_verbose>]
+[B<-brief>]
+[B<-rev>]
+[B<-async>]
+[B<-ssl_config val>]
+[B<-max_send_frag +int>]
+[B<-split_send_frag +int>]
+[B<-max_pipelines +int>]
+[B<-read_buf +int>]
+[B<-no_ssl3>]
+[B<-no_tls1>]
+[B<-no_tls1_1>]
+[B<-no_tls1_2>]
+[B<-no_tls1_3>]
+[B<-bugs>]
+[B<-no_comp>]
+[B<-comp>]
+[B<-no_ticket>]
+[B<-num_tickets>]
+[B<-serverpref>]
+[B<-legacy_renegotiation>]
+[B<-no_renegotiation>]
+[B<-legacy_server_connect>]
+[B<-no_resumption_on_reneg>]
+[B<-no_legacy_server_connect>]
+[B<-allow_no_dhe_kex>]
+[B<-prioritize_chacha>]
+[B<-strict>]
+[B<-sigalgs val>]
+[B<-client_sigalgs val>]
+[B<-groups val>]
+[B<-curves val>]
+[B<-named_curve val>]
+[B<-cipher val>]
+[B<-ciphersuites val>]
+[B<-dhparam infile>]
+[B<-record_padding val>]
+[B<-debug_broken_protocol>]
+[B<-policy val>]
+[B<-purpose val>]
+[B<-verify_name val>]
+[B<-verify_depth int>]
+[B<-auth_level int>]
+[B<-attime intmax>]
+[B<-verify_hostname val>]
+[B<-verify_email val>]
+[B<-verify_ip>]
[B<-ignore_critical>]
+[B<-issuer_checks>]
+[B<-crl_check>]
+[B<-crl_check_all>]
+[B<-policy_check>]
+[B<-explicit_policy>]
[B<-inhibit_any>]
[B<-inhibit_map>]
-[B<-no_check_time>]
-[B<-partial_chain>]
-[B<-policy arg>]
-[B<-policy_check>]
+[B<-x509_strict>]
+[B<-extended_crl>]
+[B<-use_deltas>]
[B<-policy_print>]
-[B<-purpose purpose>]
-[B<-suiteB_128>]
+[B<-check_ss_sig>]
+[B<-trusted_first>]
[B<-suiteB_128_only>]
+[B<-suiteB_128>]
[B<-suiteB_192>]
-[B<-trusted_first>]
+[B<-partial_chain>]
[B<-no_alt_chains>]
-[B<-use_deltas>]
-[B<-auth_level num>]
-[B<-nameopt option>]
-[B<-verify_depth num>]
-[B<-verify_return_error>]
-[B<-verify_email email>]
-[B<-verify_hostname hostname>]
-[B<-verify_ip ip>]
-[B<-verify_name name>]
-[B<-x509_strict>]
-[B<-nocert>]
-[B<-cipher cipherlist>]
-[B<-serverpref>]
-[B<-quiet>]
+[B<-no_check_time>]
+[B<-allow_proxy_certs>]
+[B<-xkey>]
+[B<-xcert>]
+[B<-xchain>]
+[B<-xchain_build>]
+[B<-xcertform PEM|DER>]
+[B<-xkeyform PEM|DER>]
+[B<-nbio>]
+[B<-psk_identity val>]
+[B<-psk_hint val>]
+[B<-psk val>]
+[B<-psk_session file>]
+[B<-srpvfile infile>]
+[B<-srpuserseed val>]
[B<-ssl3>]
[B<-tls1>]
[B<-tls1_1>]
[B<-tls1_2>]
[B<-tls1_3>]
[B<-dtls>]
+[B<-timeout>]
+[B<-mtu +int>]
+[B<-listen>]
[B<-dtls1>]
[B<-dtls1_2>]
-[B<-listen>]
-[B<-async>]
-[B<-split_send_frag>]
-[B<-max_pipelines>]
-[B<-read_buf>]
-[B<-no_ssl3>]
-[B<-no_tls1>]
-[B<-no_tls1_1>]
-[B<-no_tls1_2>]
-[B<-no_tls1_3>]
+[B<-sctp>]
+[B<-sctp_label_bug>]
[B<-no_dhe>]
-[B<-bugs>]
-[B<-comp>]
-[B<-no_comp>]
-[B<-brief>]
-[B<-www>]
-[B<-WWW>]
-[B<-HTTP>]
-[B<-engine id>]
-[B<-tlsextdebug>]
-[B<-no_ticket>]
-[B<-id_prefix arg>]
-[B<-rand file(s)>]
-[B<-serverinfo file>]
-[B<-no_resumption_on_reneg>]
-[B<-status>]
-[B<-status_verbose>]
-[B<-status_timeout nsec>]
-[B<-status_url url>]
-[B<-status_file file>]
-[B<-alpn protocols>]
-[B<-nextprotoneg protocols>]
+[B<-nextprotoneg val>]
+[B<-use_srtp val>]
+[B<-alpn val>]
+[B<-engine val>]
+[B<-keylogfile outfile>]
+[B<-max_early_data int>]
+[B<-early_data>]
+[B<-anti_replay>]
+[B<-no_anti_replay>]
+[B<-http_server_binmode>]
=head1 DESCRIPTION
=head1 OPTIONS
In addition to the options below the B<s_server> utility also supports the
-common and server only options documented in the
+common and server only options documented
in the "Supported Command Line Commands" section of the L<SSL_CONF_cmd(3)>
manual page.
Print out a usage message.
-=item B<-port port>
+=item B<-port +int>
The TCP port to listen on for connections. If not specified 4433 is used.
The optional TCP host and port to listen on for connections. If not specified, *:4433 is used.
-=item B<-naccept count>
-
-The server will exit after receiving B<number> connections, default unlimited.
-
=item B<-unix val>
Unix domain socket to accept on.
-=item B<-unlink>
-
-For -unix, unlink existing socket first.
-
=item B<-4>
Use IPv4 only.
Use IPv6 only.
-=item B<-context id>
+=item B<-unlink>
+
+For -unix, unlink any existing socket first.
+
+=item B<-context val>
Sets the SSL context id. It can be given any string value. If this option
is not present a default value will be used.
-=item B<-cert certname>
+=item B<-verify int>, B<-Verify int>
+
+The verify depth to use. This specifies the maximum length of the
+client certificate chain and makes the server request a certificate from
+the client. With the B<-verify> option a certificate is requested but the
+client does not have to send one, with the B<-Verify> option the client
+must supply a certificate or an error occurs.
+
+If the cipher suite cannot request a client certificate (for example an
+anonymous cipher suite or PSK) this option has no effect.
+
+=item B<-cert infile>
The certificate to use, most servers cipher suites require the use of a
certificate and some require a certificate with a certain public key type:
for example the DSS cipher suites require a certificate containing a DSS
(DSA) key. If not specified then the filename "server.pem" will be used.
-=item B<-certform format>
+=item B<-cert_chain>
+
+A file containing trusted certificates to use when attempting to build the
+client/server certificate chain related to the certificate specified via the
+B<-cert> option.
+
+=item B<-build_chain>
+
+Specify whether the application should build the certificate chain to be
+provided to the client.
+
+=item B<-nameopt val>
+
+Option which determines how the subject or issuer names are displayed. The
+B<val> argument can be a single option or multiple options separated by
+commas. Alternatively the B<-nameopt> switch may be used more than once to
+set multiple options. See the L<x509(1)> manual page for details.
+
+=item B<-naccept +int>
+
+The server will exit after receiving the specified number of connections,
+default unlimited.
+
+=item B<-serverinfo val>
+
+A file containing one or more blocks of PEM data. Each PEM block
+must encode a TLS ServerHello extension (2 bytes type, 2 bytes length,
+followed by "length" bytes of extension data). If the client sends
+an empty TLS ClientHello extension matching the type, the corresponding
+ServerHello extension will be returned.
+
+=item B<-certform PEM|DER>
The certificate format to use: DER or PEM. PEM is the default.
-=item B<-key keyfile>
+=item B<-key infile>
The private key to use. If not specified then the certificate file will
be used.
The private format to use: DER or PEM. PEM is the default.
-=item B<-pass arg>
+=item B<-pass val>
-The private key password source. For more information about the format of B<arg>
+The private key password source. For more information about the format of B<val>
see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
-=item B<-dcert filename>, B<-dkey keyname>
+=item B<-dcert infile>, B<-dkey infile>
Specify an additional certificate and private key, these behave in the
same manner as the B<-cert> and B<-key> options except there is no default
a server can support clients which only support RSA or DSS cipher suites
by using an appropriate certificate.
-=item B<-dcertform format>, B<-dkeyform format>, B<-dpass arg>
+=item B<-dcert_chain>
+
+A file containing trusted certificates to use when attempting to build the
+server certificate chain when a certificate specified via the B<-dcert> option
+is in use.
+
+=item B<-dcertform PEM|DER>, B<-dkeyform PEM|DER>, B<-dpass val>
Additional certificate and private key format and passphrase respectively.
-=item B<-nocert>
+=item B<-xkey infile>, B<-xcert infile>, B<-xchain>
-If this option is set then no certificate is used. This restricts the
-cipher suites available to the anonymous ones (currently just anonymous
-DH).
+Specify an extra certificate, private key and certificate chain. These behave
+in the same manner as the B<-cert>, B<-key> and B<-cert_chain> options. When
+specified, the callback returning the first valid chain will be in use by
+the server.
-=item B<-dhparam filename>
+=item B<-xchain_build>
-The DH parameter file to use. The ephemeral DH cipher suites generate keys
-using a set of DH parameters. If not specified then an attempt is made to
-load the parameters from the server certificate file.
-If this fails then a static set of parameters hard coded into the B<s_server>
-program will be used.
+Specify whether the application should build the certificate chain to be
+provided to the client for the extra certificates provided via B<-xkey infile>,
+B<-xcert infile>, B<-xchain> options.
-=item B<-no_dhe>
+=item B<-xcertform PEM|DER>, B<-xkeyform PEM|DER>
-If this option is set then no DH parameters will be loaded effectively
-disabling the ephemeral DH cipher suites.
+Extra certificate and private key format respectively.
-=item B<-crl_check>, B<-crl_check_all>
+=item B<-nbio_test>
-Check the peer certificate has not been revoked by its CA.
-The CRL(s) are appended to the certificate file. With the B<-crl_check_all>
-option all CRLs of all CAs in the chain are checked.
+Tests non blocking I/O.
-=item B<-CApath directory>
+=item B<-crlf>
-The directory to use for client certificate verification. This directory
-must be in "hash format", see B<verify> for more information. These are
-also used when building the server certificate chain.
+This option translated a line feed from the terminal into CR+LF.
-=item B<-CAfile file>
+=item B<-debug>
+
+Print extensive debugging information including a hex dump of all traffic.
+
+=item B<-msg>
+
+Show all protocol messages with hex dump.
+
+=item B<-msgfile outfile>
+
+File to send output of B<-msg> or B<-trace> to, default standard output.
+
+=item B<-state>
+
+Prints the SSL session states.
+
+=item B<-CAfile infile>
A file containing trusted certificates to use during client authentication
and to use when attempting to build the server certificate chain. The list
is also used in the list of acceptable client CAs passed to the client when
a certificate is requested.
+=item B<-CApath dir>
+
+The directory to use for client certificate verification. This directory
+must be in "hash format", see L<verify(1)> for more information. These are
+also used when building the server certificate chain.
+
+=item B<-chainCApath dir>
+
+The directory to use for building the chain provided to the client. This
+directory must be in "hash format", see L<verify(1)> for more information.
+
+=item B<-chainCAfile file>
+
+A file containing trusted certificates to use when attempting to build the
+server certificate chain.
+
=item B<-no-CAfile>
-Do not load the trusted CA certificates from the default file location
+Do not load the trusted CA certificates from the default file location.
=item B<-no-CApath>
-Do not load the trusted CA certificates from the default directory location
+Do not load the trusted CA certificates from the default directory location.
-=item B<-verify depth>, B<-Verify depth>
-
-The verify depth to use. This specifies the maximum length of the
-client certificate chain and makes the server request a certificate from
-the client. With the B<-verify> option a certificate is requested but the
-client does not have to send one, with the B<-Verify> option the client
-must supply a certificate or an error occurs.
+=item B<-nocert>
-If the ciphersuite cannot request a client certificate (for example an
-anonymous ciphersuite or PSK) this option has no effect.
+If this option is set then no certificate is used. This restricts the
+cipher suites available to the anonymous ones (currently just anonymous
+DH).
-=item B<-nameopt option>
+=item B<-quiet>
-option which determines how the subject or issuer names are displayed. The
-B<option> argument can be a single option or multiple options separated by
-commas. Alternatively the B<-nameopt> switch may be used more than once to
-set multiple options. See the L<x509(1)> manual page for details.
+Inhibit printing of session and certificate information.
-=item B<-attime>, B<-check_ss_sig>, B<-crl_check>, B<-crl_check_all>,
-B<-explicit_policy>, B<-extended_crl>, B<-ignore_critical>, B<-inhibit_any>,
-B<-inhibit_map>, B<-no_alt_chains>, B<-no_check_time>, B<-partial_chain>, B<-policy>,
-B<-policy_check>, B<-policy_print>, B<-purpose>, B<-suiteB_128>,
-B<-suiteB_128_only>, B<-suiteB_192>, B<-trusted_first>, B<-use_deltas>,
-B<-auth_level>, B<-verify_depth>, B<-verify_email>, B<-verify_hostname>,
-B<-verify_ip>, B<-verify_name>, B<-x509_strict>
+=item B<-www>
-Set different peer certificate verification options.
-See the L<verify(1)> manual page for details.
+Sends a status message back to the client when it connects. This includes
+information about the ciphers used and various session parameters.
+The output is in HTML format so this option will normally be used with a
+web browser. Cannot be used in conjunction with B<-early_data>.
-=item B<-verify_return_error>
+=item B<-WWW>
-Verification errors normally just print a message but allow the
-connection to continue, for debugging purposes.
-If this option is used, then verification errors close the connection.
+Emulates a simple web server. Pages will be resolved relative to the
+current directory, for example if the URL https://myhost/page.html is
+requested the file ./page.html will be loaded. Cannot be used in conjunction
+with B<-early_data>.
-=item B<-state>
+=item B<-tlsextdebug>
-Prints the SSL session states.
+Print a hex dump of any TLS extensions received from the server.
-=item B<-debug>
+=item B<-HTTP>
-Print extensive debugging information including a hex dump of all traffic.
+Emulates a simple web server. Pages will be resolved relative to the
+current directory, for example if the URL https://myhost/page.html is
+requested the file ./page.html will be loaded. The files loaded are
+assumed to contain a complete and correct HTTP response (lines that
+are part of the HTTP response line and headers must end with CRLF). Cannot be
+used in conjunction with B<-early_data>.
-=item B<-msg>
+=item B<-id_prefix val>
-Show all protocol messages with hex dump.
+Generate SSL/TLS session IDs prefixed by B<val>. This is mostly useful
+for testing any SSL/TLS code (eg. proxies) that wish to deal with multiple
+servers, when each of which might be generating a unique range of session
+IDs (eg. with a certain prefix).
-=item B<-trace>
+=item B<-rand file...>
-Show verbose trace output of protocol messages. OpenSSL needs to be compiled
-with B<enable-ssl-trace> for this option to work.
+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 B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
+all others.
-=item B<-msgfile>
+=item [B<-writerand file>]
-File to send output of B<-msg> or B<-trace> to, default standard output.
+Writes random data to the specified I<file> upon exit.
+This can be used with a subsequent B<-rand> flag.
-=item B<-nbio_test>
+=item B<-verify_return_error>
-Tests non blocking I/O
+Verification errors normally just print a message but allow the
+connection to continue, for debugging purposes.
+If this option is used, then verification errors close the connection.
-=item B<-nbio>
+=item B<-status>
-Turns on non blocking I/O
+Enables certificate status request support (aka OCSP stapling).
-=item B<-crlf>
+=item B<-status_verbose>
-This option translated a line feed from the terminal into CR+LF.
+Enables certificate status request support (aka OCSP stapling) and gives
+a verbose printout of the OCSP response.
-=item B<-quiet>
+=item B<-status_timeout int>
-Inhibit printing of session and certificate information.
+Sets the timeout for OCSP response to B<int> seconds.
-=item B<-psk_hint hint>
+=item B<-status_url val>
-Use the PSK identity hint B<hint> when using a PSK cipher suite.
+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<-psk key>
+=item B<-status_file infile>
-Use the PSK key B<key> when using a PSK cipher suite. The key is
-given as a hexadecimal number without leading 0x, for example -psk
-1a2b3c4d.
+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<-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>
+=item B<-trace>
-These options require or disable the use of the specified SSL or TLS protocols.
-By default B<s_server> will negotiate the highest mutually supported protocol
-version.
-When a specific TLS version is required, only that version will be accepted
-from the client.
+Show verbose trace output of protocol messages. OpenSSL needs to be compiled
+with B<enable-ssl-trace> for this option to work.
-=item B<-dtls>, B<-dtls1>, B<-dtls1_2>
+=item B<-brief>
-These options make B<s_server> use DTLS protocols instead of TLS.
-With B<-dtls>, B<s_server> will negotiate any supported DTLS protocol version,
-whilst B<-dtls1> and B<-dtls1_2> will only support DTLSv1.0 and DTLSv1.2
-respectively.
+Provide a brief summary of connection parameters instead of the normal verbose
+output.
-=item B<-listen>
+=item B<-rev>
-This option can only be used in conjunction with one of the DTLS options above.
-With this option B<s_server> will listen on a UDP port for incoming connections.
-Any ClientHellos that arrive will be checked to see if they have a cookie in
-them or not.
-Any without a cookie will be responded to with a HelloVerifyRequest.
-If a ClientHello with a cookie is received then B<s_server> will connect to
-that peer and complete the handshake.
+Simple test server which just reverses the text received from the client
+and sends it back to the server. Also sets B<-brief>. Cannot be used in
+conjunction with B<-early_data>.
=item B<-async>
is also used via the B<-engine> option. For test purposes the dummy async engine
(dasync) can be used (if available).
-=item B<-split_send_frag int>
+=item B<-max_send_frag +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 +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 ciphersuite has been negotiated, an engine that supports pipelining
+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 int>
+=item B<-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 ciphersuite has been negotiated. The default value is 1.
+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 int>
+=item B<-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 L<SSL_CTX_set_default_read_buffer_len(3)> for
further information).
+=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>
+
+These options require or disable the use of the specified SSL or TLS protocols.
+By default B<s_server> will negotiate the highest mutually supported protocol
+version.
+When a specific TLS version is required, only that version will be accepted
+from the client.
+Note that not all protocols and flags may be available, depending on how
+OpenSSL was built.
+
=item B<-bugs>
-There are several known bug in SSL and TLS implementations. Adding this
+There are several known bugs in SSL and TLS implementations. Adding this
option enables various workarounds.
-=item B<-comp>
+=item B<-no_comp>
-Enable negotiation of TLS compression.
-This option was introduced in OpenSSL 1.1.0.
+Disable negotiation of TLS compression.
TLS compression is not recommended and is off by default as of
OpenSSL 1.1.0.
-=item B<-no_comp>
+=item B<-comp>
-Disable negotiation of TLS compression.
+Enable negotiation of 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<-brief>
+=item B<-no_ticket>
-Provide a brief summary of connection parameters instead of the normal verbose
-output.
+Disable RFC4507bis session ticket support. This option has no effect if TLSv1.3
+is negotiated. See B<-num_tickets>.
-=item B<-cipher cipherlist>
+=item B<-num_tickets>
-This allows the cipher list used by the server to be modified. When
-the client sends a list of supported ciphers the first client cipher
-also included in the server list is used. Because the client specifies
-the preference order, the order of the server cipherlist irrelevant. See
-the B<ciphers> command for more information.
+Control the number of tickets that will be sent to the client after a full
+handshake in TLSv1.3. The default number of tickets is 2. This option does not
+affect the number of tickets sent after a resumption handshake.
=item B<-serverpref>
Use the server's cipher preferences, rather than the client's preferences.
-=item B<-tlsextdebug>
+=item B<-prioritize_chacha>
-Print a hex dump of any TLS extensions received from the server.
+Prioritize ChaCha ciphers when preferred by clients. Requires B<-serverpref>.
-=item B<-no_ticket>
+=item B<-no_resumption_on_reneg>
-Disable RFC4507bis session ticket support.
+Set the B<SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION> option.
-=item B<-www>
+=item B<-client_sigalgs val>
-Sends a status message back to the client when it connects. This includes
-information about the ciphers used and various session parameters.
-The output is in HTML format so this option will normally be used with a
-web browser.
+Signature algorithms to support for client certificate authentication
+(colon-separated list).
-=item B<-WWW>
+=item B<-named_curve val>
-Emulates a simple web server. Pages will be resolved relative to the
-current directory, for example if the URL https://myhost/page.html is
-requested the file ./page.html will be loaded.
+Specifies the elliptic curve to use. NOTE: this is single curve, not a list.
+For a list of all possible curves, use:
-=item B<-HTTP>
+ $ openssl ecparam -list_curves
-Emulates a simple web server. Pages will be resolved relative to the
-current directory, for example if the URL https://myhost/page.html is
-requested the file ./page.html will be loaded. The files loaded are
-assumed to contain a complete and correct HTTP response (lines that
-are part of the HTTP response line and headers must end with CRLF).
+=item B<-cipher val>
-=item B<-rev>
+This allows the list of TLSv1.2 and below ciphersuites used by the server to be
+modified. This list is combined with any TLSv1.3 ciphersuites that have been
+configured. When the client sends a list of supported ciphers the first client
+cipher also included in the server list is used. Because the client specifies
+the preference order, the order of the server cipherlist is irrelevant. See
+the B<ciphers> command for more information.
-Simple test server which just reverses the text received from the client
-and sends it back to the server. Also sets B<-brief>.
+=item B<-ciphersuites val>
-=item B<-engine id>
+This allows the list of TLSv1.3 ciphersuites used by the server to be modified.
+This list is combined with any TLSv1.2 and below ciphersuites that have been
+configured. When the client sends a list of supported ciphers the first client
+cipher also included in the server list is used. Because the client specifies
+the preference order, the order of the server cipherlist is irrelevant. See
+the B<ciphers> command for more information. The format for this list is a
+simple colon (":") separated list of TLSv1.3 ciphersuite names.
-Specifying an engine (by its unique B<id> string) will cause B<s_server>
-to attempt to obtain a functional reference to the specified engine,
-thus initialising it if needed. The engine will then be set as the default
-for all available algorithms.
+=item B<-dhparam infile>
-=item B<-id_prefix arg>
+The DH parameter file to use. The ephemeral DH cipher suites generate keys
+using a set of DH parameters. If not specified then an attempt is made to
+load the parameters from the server certificate file.
+If this fails then a static set of parameters hard coded into the B<s_server>
+program will be used.
-Generate SSL/TLS session IDs prefixed by B<arg>. This is mostly useful
-for testing any SSL/TLS code (eg. proxies) that wish to deal with multiple
-servers, when each of which might be generating a unique range of session
-IDs (eg. with a certain prefix).
+=item B<-attime>, B<-check_ss_sig>, B<-crl_check>, B<-crl_check_all>,
+B<-explicit_policy>, B<-extended_crl>, B<-ignore_critical>, B<-inhibit_any>,
+B<-inhibit_map>, B<-no_alt_chains>, B<-no_check_time>, B<-partial_chain>, B<-policy>,
+B<-policy_check>, B<-policy_print>, B<-purpose>, B<-suiteB_128>,
+B<-suiteB_128_only>, B<-suiteB_192>, B<-trusted_first>, B<-use_deltas>,
+B<-auth_level>, B<-verify_depth>, B<-verify_email>, B<-verify_hostname>,
+B<-verify_ip>, B<-verify_name>, B<-x509_strict>
-=item B<-rand file(s)>
+Set different peer certificate verification options.
+See the L<verify(1)> manual page for details.
-A file or files containing random data used to seed the random number
-generator, or an EGD socket (see L<RAND_egd(3)>).
-Multiple files can be specified separated by an OS-dependent character.
-The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
-all others.
+=item B<-crl_check>, B<-crl_check_all>
-=item B<-serverinfo file>
+Check the peer certificate has not been revoked by its CA.
+The CRL(s) are appended to the certificate file. With the B<-crl_check_all>
+option all CRLs of all CAs in the chain are checked.
-A file containing one or more blocks of PEM data. Each PEM block
-must encode a TLS ServerHello extension (2 bytes type, 2 bytes length,
-followed by "length" bytes of extension data). If the client sends
-an empty TLS ClientHello extension matching the type, the corresponding
-ServerHello extension will be returned.
+=item B<-nbio>
-=item B<-no_resumption_on_reneg>
+Turns on non blocking I/O.
-Set the B<SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION> option.
+=item B<-psk_identity val>
-=item B<-status>
+Expect the client to send PSK identity B<val> when using a PSK
+cipher suite, and warn if they do not. By default, the expected PSK
+identity is the string "Client_identity".
-Enables certificate status request support (aka OCSP stapling).
+=item B<-psk_hint val>
-=item B<-status_verbose>
+Use the PSK identity hint B<val> when using a PSK cipher suite.
-Enables certificate status request support (aka OCSP stapling) and gives
-a verbose printout of the OCSP response.
+=item B<-psk val>
-=item B<-status_timeout nsec>
+Use the PSK key B<val> 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.
-Sets the timeout for OCSP response to B<nsec> seconds.
+=item B<-psk_session file>
-=item B<-status_url url>
+Use the pem encoded SSL_SESSION data stored in B<file> as the basis of a PSK.
+Note that this will only work if TLSv1.3 is negotiated.
-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<-listen>
-=item B<-status_file file>
+This option can only be used in conjunction with one of the DTLS options above.
+With this option B<s_server> will listen on a UDP port for incoming connections.
+Any ClientHellos that arrive will be checked to see if they have a cookie in
+them or not.
+Any without a cookie will be responded to with a HelloVerifyRequest.
+If a ClientHello with a cookie is received then B<s_server> will connect to
+that peer and complete the handshake.
-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<-dtls>, B<-dtls1>, B<-dtls1_2>
+
+These options make B<s_server> use DTLS protocols instead of TLS.
+With B<-dtls>, B<s_server> will negotiate any supported DTLS protocol version,
+whilst B<-dtls1> and B<-dtls1_2> will only support DTLSv1.0 and DTLSv1.2
+respectively.
+
+=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<-no_dhe>
+
+If this option is set then no DH parameters will be loaded effectively
+disabling the ephemeral DH cipher suites.
-=item B<-alpn protocols>, B<-nextprotoneg protocols>
+=item B<-alpn val>, B<-nextprotoneg val>
-these flags enable the
-Enable the Application-Layer Protocol Negotiation or Next Protocol
-Negotiation 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 most wanted protocols first.
+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<val> 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".
+The flag B<-nextprotoneg> cannot be specified if B<-tls1_3> is used.
+
+=item B<-engine val>
+
+Specifying an engine (by its unique id string in B<val>) will cause B<s_server>
+to attempt to obtain a functional reference to the specified engine,
+thus initialising it if needed. The engine will then be set as the default
+for all available algorithms.
+
+=item B<-keylogfile outfile>
+
+Appends TLS secrets to the specified keylog file such that external programs
+(like Wireshark) can decrypt TLS connections.
+
+=item B<-max_early_data int>
+
+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. Cannot be used in conjunction with B<-www>,
+B<-WWW>, B<-HTTP> or B<-rev>.
+
+=item B<-anti_replay>, B<-no_anti_replay>
+
+Switches replay protection on or off, respectively. Replay protection is on by
+default unless overridden by a configuration file. When it is on, OpenSSL will
+automatically detect if a session ticket has been used more than once, TLSv1.3
+has been negotiated, and early data is enabled on the server. A full handshake
+is forced if a session ticket is used a second or subsequent time. Any early
+data that was sent will be rejected.
+
+=item B<-http_server_binmode>
+
+When acting as web-server (using option B<-WWW> or B<-HTTP>) open files requested
+by the client in binary mode.
=back
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.
+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 but still accept new connections.
+End the current SSL connection but still accept new connections.
=item B<Q>
-end the current SSL connection and exit.
+End the current SSL connection and exit.
=item B<r>
-renegotiate the SSL session.
+Renegotiate the SSL session (TLSv1.2 and below only).
=item B<R>
-renegotiate the SSL session and request a client certificate.
+Renegotiate the SSL session and request a client certificate (TLSv1.2 and below
+only).
=item B<P>
-send some plain text down the underlying TCP connection: this should
+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.
+Print out some session cache status information.
-=item B<-keylogfile path>
+=item B<k>
-Appends TLS secrets to the specified keylog file such that external programs
-(like Wireshark) can decrypt TLS connections.
+Send a key update message to the client (TLSv1.3 only)
+
+=item B<K>
+
+Send a key update message to the client and request one back (TLSv1.3 only)
+
+=item B<c>
+
+Send a certificate request to the client (TLSv1.3 only)
=back
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.
=head1 SEE ALSO
-L<SSL_CONF_cmd(3)>,
-L<sess_id(1)>, L<s_client(1)>, L<ciphers(1)>
+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.
+The -no_alt_chains option was added in OpenSSL 1.1.0.
+
+The
+-allow-no-dhe-kex and -prioritize_chacha options were added in OpenSSL 1.1.1.
=head1 COPYRIGHT
-Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
-Licensed under the OpenSSL license (the "License"). You may not use
+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>.
projects / openssl.git / blobdiff