4 {- join("\n", @autowarntext) -}
10 openssl-s_client - SSL/TLS client program
14 B<openssl> B<s_client>
16 [B<-connect> I<host:port>]
17 [B<-bind> I<host:port>]
18 [B<-proxy> I<host:port>]
19 [B<-proxy_user> I<userid>]
20 [B<-proxy_pass> I<arg>]
24 [B<-servername> I<name>]
27 [B<-verify_return_error>]
28 [B<-cert> I<filename>]
29 [B<-certform> B<DER>|B<PEM>]
30 [B<-CRLform> B<DER>|B<PEM>]
32 [B<-keyform> B<DER>|B<PEM>]
33 [B<-cert_chain> I<filename>]
36 [B<-chainCApath> I<directory>]
37 [B<-chainCAfile> I<filename>]
38 [B<-requestCAfile> I<filename>]
39 [B<-dane_tlsa_domain> I<domain>]
40 [B<-dane_tlsa_rrdata> I<rrdata>]
41 [B<-dane_ee_no_namechecks>]
42 [B<-attime> I<timestamp>]
56 [B<-purpose> I<purpose>]
63 [B<-auth_level> I<num>]
64 [B<-nameopt> I<option>]
65 [B<-verify_depth> I<num>]
66 [B<-verify_email> I<email>]
67 [B<-verify_hostname> I<hostname>]
69 [B<-verify_name> I<name>]
82 [B<-psk_identity> I<identity>]
84 [B<-psk_session> I<file>]
104 [B<-split_send_frag>]
110 [B<-allow_no_dhe_kex>]
111 [B<-sigalgs> I<sigalglist>]
112 [B<-curves> I<curvelist>]
113 [B<-cipher> I<cipherlist>]
114 [B<-ciphersuites> I<val>]
116 [B<-starttls> I<protocol>]
117 [B<-xmpphost> I<hostname>]
118 [B<-name> I<hostname>]
122 [B<-sess_out> I<filename>]
123 [B<-sess_in> I<filename>]
124 [B<-serverinfo> I<types>]
126 [B<-alpn> I<protocols>]
127 [B<-nextprotoneg> I<protocols>]
131 [B<-keylogfile> I<file>]
132 [B<-early_data> I<file>]
134 {- $OpenSSL::safe::opt_x_synopsis -}
135 {- $OpenSSL::safe::opt_trust_synopsis -}
136 {- $OpenSSL::safe::opt_r_synopsis -}
139 =for openssl ifdef engine ssl_client_engine ct noct ctlogfile
141 =for openssl ifdef ssl3 unix 4 6 use_srtp status trace wdebug nextprotoneg
143 =for openssl ifdef ssl3 tls1 tls1_1 tls1_2 tls1_3 dtls mtu dtls1 dtls1_2
145 =for openssl ifdef sctp_label_bug sctp
147 =for openssl ifdef srpuser srppass srp_lateuser srp_moregroups srp_strength
151 This command implements a generic SSL/TLS client which
152 connects to a remote host using SSL/TLS. It is a I<very> useful diagnostic
153 tool for SSL servers.
157 In addition to the options below, this command also supports the
158 common and client only options documented
159 in the "Supported Command Line Commands" section of the L<SSL_CONF_cmd(3)>
166 Print out a usage message.
168 =item B<-connect> I<host>:I<port>
170 This specifies the host and optional port to connect to. It is possible to
171 select the host and port using the optional target positional argument instead.
172 If neither this nor the target positional argument are specified then an attempt
173 is made to connect to the local host on port 4433.
175 =item B<-bind> I<host:port>
177 This specifies the host address and or port to bind as the source for the
178 connection. For Unix-domain sockets the port is ignored and the host is
179 used as the source socket address.
181 =item B<-proxy> I<host:port>
183 When used with the B<-connect> flag, the program uses the host and port
184 specified with this flag and issues an HTTP CONNECT command to connect
185 to the desired server.
187 =item B<-proxy_user> I<userid>
189 When used with the B<-proxy> flag, the program will attempt to authenticate
190 with the specified proxy using basic (base64) authentication.
191 NB: Basic authentication is insecure; the credentials are sent to the proxy
192 in easily reversible base64 encoding before any TLS/SSL session is established.
193 Therefore these credentials are easily recovered by anyone able to sniff/trace
194 the network. Use with caution.
196 =item B<-proxy_pass> I<arg>
198 The proxy password source, used with the B<-proxy_user> flag.
199 For more information about the format of B<arg>
200 see L<openssl(1)/Pass Phrase Options>.
202 =item B<-unix> I<path>
204 Connect over the specified Unix-domain socket.
214 =item B<-servername> I<name>
216 Set the TLS SNI (Server Name Indication) extension in the ClientHello message to
218 If B<-servername> is not provided, the TLS SNI extension will be populated with
219 the name given to B<-connect> if it follows a DNS name format. If B<-connect> is
220 not provided either, the SNI is set to "localhost".
221 This is the default since OpenSSL 1.1.1.
223 Even though SNI should normally be a DNS name and not an IP address, if
224 B<-servername> is provided then that name will be sent, regardless of whether
225 it is a DNS name or not.
227 This option cannot be used in conjunction with B<-noservername>.
229 =item B<-noservername>
231 Suppresses sending of the SNI (Server Name Indication) extension in the
232 ClientHello message. Cannot be used in conjunction with the B<-servername> or
233 <-dane_tlsa_domain> options.
235 =item B<-cert> I<certname>
237 The certificate to use, if one is requested by the server. The default is
238 not to use a certificate.
240 =item B<-certform> I<format>
242 The certificate format to use: DER or PEM. PEM is the default.
244 =item B<-CRLform> B<DER>|B<PEM>
246 The CRL format; the default is B<PEM>.
247 See L<openssl(1)/Format Options> for details.
249 =item B<-key> I<keyfile>
251 The private key to use. If not specified then the certificate file will
254 =item B<-keyform> I<format>
256 The key format; the default is B<PEM>.
257 See L<openssl(1)/Format Options> for details.
261 A file containing trusted certificates to use when attempting to build the
262 client/server certificate chain related to the certificate specified via the
265 =item B<-build_chain>
267 Specify whether the application should build the certificate chain to be
268 provided to the server.
270 =item B<-pass> I<arg>
272 the private key password source. For more information about the format of I<arg>
273 see L<openssl(1)/Pass phrase options>.
275 =item B<-verify> I<depth>
277 The verify depth to use. This specifies the maximum length of the
278 server certificate chain and turns on server certificate verification.
279 Currently the verify operation continues after errors so all the problems
280 with a certificate chain can be seen. As a side effect the connection
281 will never fail due to a server certificate verify failure.
283 =item B<-verify_return_error>
285 Return verification errors instead of continuing. This will typically
286 abort the handshake with a fatal error.
288 =item B<-nameopt> I<option>
290 Option which determines how the subject or issuer names are displayed. The
291 I<option> argument can be a single option or multiple options separated by
292 commas. Alternatively the B<-nameopt> switch may be used more than once to
293 set multiple options. See the L<openssl-x509(1)> manual page for details.
295 =item B<-chainCApath> I<directory>
297 The directory to use for building the chain provided to the server. This
298 directory must be in "hash format", see L<openssl-verify(1)> for more
301 =item B<-chainCAfile> I<file>
303 A file containing trusted certificates to use when attempting to build the
304 client certificate chain.
306 =item B<-requestCAfile> I<file>
308 A file containing a list of certificates whose subject names will be sent
309 to the server in the B<certificate_authorities> extension. Only supported
312 =item B<-dane_tlsa_domain> I<domain>
314 Enable RFC6698/RFC7671 DANE TLSA authentication and specify the
315 TLSA base domain which becomes the default SNI hint and the primary
316 reference identifier for hostname checks. This must be used in
317 combination with at least one instance of the B<-dane_tlsa_rrdata>
320 When DANE authentication succeeds, the diagnostic output will include
321 the lowest (closest to 0) depth at which a TLSA record authenticated
322 a chain certificate. When that TLSA record is a "2 1 0" trust
323 anchor public key that signed (rather than matched) the top-most
324 certificate of the chain, the result is reported as "TA public key
325 verified". Otherwise, either the TLSA record "matched TA certificate"
326 at a positive depth or else "matched EE certificate" at depth 0.
328 =item B<-dane_tlsa_rrdata> I<rrdata>
330 Use one or more times to specify the RRDATA fields of the DANE TLSA
331 RRset associated with the target service. The I<rrdata> value is
332 specied in "presentation form", that is four whitespace separated
333 fields that specify the usage, selector, matching type and associated
334 data, with the last of these encoded in hexadecimal. Optional
335 whitespace is ignored in the associated data field. For example:
337 $ openssl s_client -brief -starttls smtp \
338 -connect smtp.example.com:25 \
339 -dane_tlsa_domain smtp.example.com \
340 -dane_tlsa_rrdata "2 1 1
341 B111DD8A1C2091A89BD4FD60C57F0716CCE50FEEFF8137CDBEE0326E 02CF362B" \
342 -dane_tlsa_rrdata "2 1 1
343 60B87575447DCBA2A36B7D11AC09FB24A9DB406FEE12D2CC90180517 616E8A18"
346 Verified peername: smtp.example.com
347 DANE TLSA 2 1 1 ...ee12d2cc90180517616e8a18 matched TA certificate at depth 1
350 =item B<-dane_ee_no_namechecks>
352 This disables server name checks when authenticating via DANE-EE(3) TLSA
354 For some applications, primarily web browsers, it is not safe to disable name
355 checks due to "unknown key share" attacks, in which a malicious server can
356 convince a client that a connection to a victim server is instead a secure
357 connection to the malicious server.
358 The malicious server may then be able to violate cross-origin scripting
360 Thus, despite the text of RFC7671, name checks are by default enabled for
361 DANE-EE(3) TLSA records, and can be disabled in applications where it is safe
363 In particular, SMTP and XMPP clients should set this option as SRV and MX
364 records already make it possible for a remote domain to redirect client
365 connections to any server of its choice, and in any case SMTP and XMPP clients
366 do not execute scripts downloaded from remote servers.
368 =item B<-attime>, B<-check_ss_sig>, B<-crl_check>, B<-crl_check_all>,
369 B<-explicit_policy>, B<-extended_crl>, B<-ignore_critical>, B<-inhibit_any>,
370 B<-inhibit_map>, B<-no_alt_chains>, B<-no_check_time>, B<-partial_chain>, B<-policy>,
371 B<-policy_check>, B<-policy_print>, B<-purpose>, B<-suiteB_128>,
372 B<-suiteB_128_only>, B<-suiteB_192>, B<-trusted_first>, B<-use_deltas>,
373 B<-auth_level>, B<-verify_depth>, B<-verify_email>, B<-verify_hostname>,
374 B<-verify_ip>, B<-verify_name>, B<-x509_strict>
376 Set various certificate chain validation options. See the
377 L<openssl-verify(1)> manual page for details.
381 Reconnects to the same server 5 times using the same session ID, this can
382 be used as a test that session caching is working.
386 Displays the server certificate list as sent by the server: it only consists of
387 certificates the server has sent (in the order the server has sent them). It is
388 B<not> a verified chain.
392 Print session information when the program exits. This will always attempt
393 to print out information even if the connection fails. Normally information
394 will only be printed out once if the connection succeeds. This option is useful
395 because the cipher in use may be renegotiated or the connection may fail
396 because a client certificate is required or is requested only after an
397 attempt is made to access a certain URL. Note: the output produced by this
398 option is not always accurate because a connection might never have been
403 Prints out the SSL session states.
407 Print extensive debugging information including a hex dump of all traffic.
411 Show all protocol messages with hex dump.
415 Show verbose trace output of protocol messages. OpenSSL needs to be compiled
416 with B<enable-ssl-trace> for this option to work.
420 File to send output of B<-msg> or B<-trace> to, default standard output.
424 Tests non-blocking I/O
428 Turns on non-blocking I/O
432 This option translated a line feed from the terminal into CR+LF as required
437 Inhibit shutting down the connection when end of file is reached in the
442 Inhibit printing of session and certificate information. This implicitly
443 turns on B<-ign_eof> as well.
447 Shut down the connection when end of file is reached in the input.
448 Can be used to override the implicit B<-ign_eof> after B<-quiet>.
450 =item B<-psk_identity> I<identity>
452 Use the PSK identity I<identity> when using a PSK cipher suite.
453 The default value is "Client_identity" (without the quotes).
457 Use the PSK key I<key> when using a PSK cipher suite. The key is
458 given as a hexadecimal number without leading 0x, for example -psk
460 This option must be provided in order to use a PSK cipher.
462 =item B<-psk_session> I<file>
464 Use the pem encoded SSL_SESSION data stored in I<file> as the basis of a PSK.
465 Note that this will only work if TLSv1.3 is negotiated.
467 =item B<-ssl3>, B<-tls1>, B<-tls1_1>, B<-tls1_2>, B<-tls1_3>, B<-no_ssl3>, B<-no_tls1>, B<-no_tls1_1>, B<-no_tls1_2>, B<-no_tls1_3>
469 These options require or disable the use of the specified SSL or TLS protocols.
470 By default, this command will negotiate the highest mutually supported protocol
472 When a specific TLS version is required, only that version will be offered to
473 and accepted from the server.
474 Note that not all protocols and flags may be available, depending on how
477 =item B<-dtls>, B<-dtls1>, B<-dtls1_2>
479 These options make this command use DTLS protocols instead of TLS.
480 With B<-dtls>, it will negotiate any supported DTLS protocol version,
481 whilst B<-dtls1> and B<-dtls1_2> will only support DTLS1.0 and DTLS1.2
486 Use SCTP for the transport protocol instead of UDP in DTLS. Must be used in
487 conjunction with B<-dtls>, B<-dtls1> or B<-dtls1_2>. This option is only
488 available where OpenSSL has support for SCTP enabled.
490 =item B<-sctp_label_bug>
492 Use the incorrect behaviour of older OpenSSL implementations when computing
493 endpoint-pair shared secrets for DTLS/SCTP. This allows communication with
494 older broken implementations but breaks interoperability with correct
495 implementations. Must be used in conjunction with B<-sctp>. This option is only
496 available where OpenSSL has support for SCTP enabled.
498 =item B<-fallback_scsv>
500 Send TLS_FALLBACK_SCSV in the ClientHello.
504 Switch on asynchronous mode. Cryptographic operations will be performed
505 asynchronously. This will only have an effect if an asynchronous capable engine
506 is also used via the B<-engine> option. For test purposes the dummy async engine
507 (dasync) can be used (if available).
509 =item B<-max_send_frag> I<int>
511 The maximum size of data fragment to send.
512 See L<SSL_CTX_set_max_send_fragment(3)> for further information.
514 =item B<-split_send_frag> I<int>
516 The size used to split data for encrypt pipelines. If more data is written in
517 one go than this value then it will be split into multiple pipelines, up to the
518 maximum number of pipelines defined by max_pipelines. This only has an effect if
519 a suitable cipher suite has been negotiated, an engine that supports pipelining
520 has been loaded, and max_pipelines is greater than 1. See
521 L<SSL_CTX_set_split_send_fragment(3)> for further information.
523 =item B<-max_pipelines> I<int>
525 The maximum number of encrypt/decrypt pipelines to be used. This will only have
526 an effect if an engine has been loaded that supports pipelining (e.g. the dasync
527 engine) and a suitable cipher suite has been negotiated. The default value is 1.
528 See L<SSL_CTX_set_max_pipelines(3)> for further information.
530 =item B<-read_buf> I<int>
532 The default read buffer size to be used for connections. This will only have an
533 effect if the buffer size is larger than the size that would otherwise be used
534 and pipelining is in use (see L<SSL_CTX_set_default_read_buffer_len(3)> for
535 further information).
539 There are several known bugs in SSL and TLS implementations. Adding this
540 option enables various workarounds.
544 Enables support for SSL/TLS compression.
545 This option was introduced in OpenSSL 1.1.0.
546 TLS compression is not recommended and is off by default as of
551 Disables support for SSL/TLS compression.
552 TLS compression is not recommended and is off by default as of
557 Only provide a brief summary of connection parameters instead of the
558 normal verbose output.
560 =item B<-sigalgs> I<sigalglist>
562 Specifies the list of signature algorithms that are sent by the client.
563 The server selects one entry in the list based on its preferences.
564 For example strings, see L<SSL_CTX_set1_sigalgs(3)>
566 =item B<-curves> I<curvelist>
568 Specifies the list of supported curves to be sent by the client. The curve is
569 ultimately selected by the server. For a list of all curves, use:
571 $ openssl ecparam -list_curves
573 =item B<-cipher> I<cipherlist>
575 This allows the TLSv1.2 and below cipher list sent by the client to be modified.
576 This list will be combined with any TLSv1.3 ciphersuites that have been
577 configured. Although the server determines which ciphersuite is used it should
578 take the first supported cipher in the list sent by the client. See
579 L<openssl-ciphers(1)> for more information.
581 =item B<-ciphersuites> I<val>
583 This allows the TLSv1.3 ciphersuites sent by the client to be modified. This
584 list will be combined with any TLSv1.2 and below ciphersuites that have been
585 configured. Although the server determines which cipher suite is used it should
586 take the first supported cipher in the list sent by the client. See
587 L<openssl-ciphers(1)> for more information. The format for this list is a simple
588 colon (":") separated list of TLSv1.3 ciphersuite names.
590 =item B<-starttls> I<protocol>
592 Send the protocol-specific message(s) to switch to TLS for communication.
593 I<protocol> is a keyword for the intended protocol. Currently, the only
594 supported keywords are "smtp", "pop3", "imap", "ftp", "xmpp", "xmpp-server",
595 "irc", "postgres", "mysql", "lmtp", "nntp", "sieve" and "ldap".
597 =item B<-xmpphost> I<hostname>
599 This option, when used with "-starttls xmpp" or "-starttls xmpp-server",
600 specifies the host for the "to" attribute of the stream element.
601 If this option is not specified, then the host specified with "-connect"
604 This option is an alias of the B<-name> option for "xmpp" and "xmpp-server".
606 =item B<-name> I<hostname>
608 This option is used to specify hostname information for various protocols
609 used with B<-starttls> option. Currently only "xmpp", "xmpp-server",
610 "smtp" and "lmtp" can utilize this B<-name> option.
612 If this option is used with "-starttls xmpp" or "-starttls xmpp-server",
613 if specifies the host for the "to" attribute of the stream element. If this
614 option is not specified, then the host specified with "-connect" will be used.
616 If this option is used with "-starttls lmtp" or "-starttls smtp", it specifies
617 the name to use in the "LMTP LHLO" or "SMTP EHLO" message, respectively. If
618 this option is not specified, then "mail.example.com" will be used.
620 =item B<-tlsextdebug>
622 Print out a hex dump of any TLS extensions received from the server.
626 Disable RFC4507bis session ticket support.
628 =item B<-sess_out> I<filename>
630 Output SSL session to I<filename>.
632 =item B<-sess_in> I<filename>
634 Load SSL session from I<filename>. The client will attempt to resume a
635 connection from this session.
637 =item B<-engine> I<id>
639 Specifying an engine (by its unique I<id> string) will cause this command
640 to attempt to obtain a functional reference to the specified engine,
641 thus initialising it if needed. The engine will then be set as the default
642 for all available algorithms.
644 =item B<-serverinfo> I<types>
646 A list of comma-separated TLS Extension Types (numbers between 0 and
647 65535). Each type will be sent as an empty ClientHello TLS Extension.
648 The server's response (if any) will be encoded and displayed as a PEM
653 Sends a certificate status request to the server (OCSP stapling). The server
654 response (if any) is printed out.
656 =item B<-alpn> I<protocols>, B<-nextprotoneg> I<protocols>
658 These flags enable the Enable the Application-Layer Protocol Negotiation
659 or Next Protocol Negotiation (NPN) extension, respectively. ALPN is the
660 IETF standard and replaces NPN.
661 The I<protocols> list is a comma-separated list of protocol names that
662 the client should advertise support for. The list should contain the most
663 desirable protocols first. Protocol names are printable ASCII strings,
664 for example "http/1.1" or "spdy/3".
665 An empty list of protocols is treated specially and will cause the
666 client to advertise support for the TLS extension but disconnect just
667 after receiving ServerHello with a list of server supported protocols.
668 The flag B<-nextprotoneg> cannot be specified if B<-tls1_3> is used.
670 =item B<-ct>, B<-noct>
672 Use one of these two options to control whether Certificate Transparency (CT)
673 is enabled (B<-ct>) or disabled (B<-noct>).
674 If CT is enabled, signed certificate timestamps (SCTs) will be requested from
675 the server and reported at handshake completion.
677 Enabling CT also enables OCSP stapling, as this is one possible delivery method
682 A file containing a list of known Certificate Transparency logs. See
683 L<SSL_CTX_set_ctlog_list_file(3)> for the expected file format.
685 =item B<-keylogfile> I<file>
687 Appends TLS secrets to the specified keylog file such that external programs
688 (like Wireshark) can decrypt TLS connections.
690 =item B<-early_data> I<file>
692 Reads the contents of the specified file and attempts to send it as early data
693 to the server. This will only work with resumed sessions that support early
694 data and when the server accepts the early data.
698 For TLSv1.3 only, send the Post-Handshake Authentication extension. This will
699 happen whether or not a certificate has been provided via B<-cert>.
701 =item I<host>:I<port>
703 Rather than providing B<-connect>, the target hostname and optional port may
704 be provided as a single positional argument after all options. If neither this
705 nor B<-connect> are provided, falls back to attempting to connect to
706 I<localhost> on port I<4433>.
708 {- $OpenSSL::safe::opt_x_item -}
710 {- $OpenSSL::safe::opt_trust_item -}
712 {- $OpenSSL::safe::opt_r_item -}
716 =head1 CONNECTED COMMANDS
718 If a connection is established with an SSL server then any data received
719 from the server is displayed and any key presses will be sent to the
720 server. If end of file is reached then the connection will be closed down. When
721 used interactively (which means neither B<-quiet> nor B<-ign_eof> have been
722 given), then certain commands are also recognized which perform special
723 operations. These commands are a letter which must appear at the start of a
724 line. They are listed below.
730 End the current SSL connection and exit.
734 Renegotiate the SSL session (TLSv1.2 and below only).
738 Send a key update message to the server (TLSv1.3 only)
742 Send a key update message to the server and request one back (TLSv1.3 only)
748 This command can be used to debug SSL servers. To connect to an SSL HTTP
751 openssl s_client -connect servername:443
753 would typically be used (https uses port 443). If the connection succeeds
754 then an HTTP command can be given such as "GET /" to retrieve a web page.
756 If the handshake fails then there are several possible causes, if it is
757 nothing obvious like no client certificate then the B<-bugs>,
758 B<-ssl3>, B<-tls1>, B<-no_ssl3>, B<-no_tls1> options can be tried
759 in case it is a buggy server. In particular you should play with these
760 options B<before> submitting a bug report to an OpenSSL mailing list.
762 A frequent problem when attempting to get client certificates working
763 is that a web client complains it has no certificates or gives an empty
764 list to choose from. This is normally because the server is not sending
765 the clients certificate authority in its "acceptable CA list" when it
766 requests a certificate. By using this command, the CA list can be viewed
767 and checked. However some servers only request client authentication
768 after a specific URL is requested. To obtain the list in this case it
769 is necessary to use the B<-prexit> option and send an HTTP request
770 for an appropriate page.
772 If a certificate is specified on the command line using the B<-cert>
773 option it will not be used unless the server specifically requests
774 a client certificate. Therefor merely including a client certificate
775 on the command line is no guarantee that the certificate works.
777 If there are problems verifying a server certificate then the
778 B<-showcerts> option can be used to show all the certificates sent by the
781 This command is a test tool and is designed to continue the
782 handshake after any certificate verification errors. As a result it will
783 accept any certificate chain (trusted or not) sent by the peer. None test
784 applications should B<not> do this as it makes them vulnerable to a MITM
785 attack. This behaviour can be changed by with the B<-verify_return_error>
786 option: any verify errors are then returned aborting the handshake.
788 The B<-bind> option may be useful if the server or a firewall requires
789 connections to come from some particular address and or port.
793 Because this program has a lot of options and also because some of the
794 techniques used are rather old, the C source for this command is rather
795 hard to read and not a model of how things should be done.
796 A typical SSL client program would be much simpler.
798 The B<-prexit> option is a bit of a hack. We should really report
799 information whenever a session is renegotiated.
804 L<openssl-sess_id(1)>,
805 L<openssl-s_server(1)>,
806 L<openssl-ciphers(1)>,
808 L<SSL_CTX_set_max_send_fragment(3)>,
809 L<SSL_CTX_set_split_send_fragment(3)>,
810 L<SSL_CTX_set_max_pipelines(3)>
814 The B<-no_alt_chains> option was added in OpenSSL 1.1.0.
815 The B<-name> option was added in OpenSSL 1.1.1.
819 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
821 Licensed under the Apache License 2.0 (the "License"). You may not use
822 this file except in compliance with the License. You can obtain a copy
823 in the file LICENSE in the source distribution or at
824 L<https://www.openssl.org/source/license.html>.