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Update documentation of SSL METHODs and ciphers 

Reviewed-by: Kurt Roeckx <kurt@openssl.org>
This commit is contained in:
Viktor Dukhovni 2016-02-21 16:37:14 -05:00
parent 1cb7757ee7
commit 8c73aeb61e
6 changed files with 291 additions and 221 deletions
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163
doc/apps/ciphers.pod
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@ -32,7 +32,7 @@ the appropriate cipherlist.
=item B<-help> =item B<-help>
Print out a usage message. Print a usage message.
=item B<-s> =item B<-s>
@ -53,21 +53,25 @@ L<SSL_CIPHER_description(3)>.
Like B<-v>, but include the official cipher suite values in hex. Like B<-v>, but include the official cipher suite values in hex.
=item B<-tls1_2>
In combination with the B<-s> option, list the ciphers which would be used if
TLSv1.2 were negotiated.
=item B<-ssl3> =item B<-ssl3>
List the ciphers which would be used if SSL v3 was negotiated. In combination with the B<-s> option, list the ciphers which would be used if
SSLv3 were negotiated.
=item B<-tls1> =item B<-tls1>
List the ciphers which would be used if TLS v1.0 was negotiated. In combination with the B<-s> option, list the ciphers which would be used if
TLSv1 were negotiated.
=item B<-tls1_1> =item B<-tls1_1>
List the ciphers which would be used if TLS v1.1 was negotiated. In combination with the B<-s> option, list the ciphers which would be used if
TLSv1.1 were negotiated.
=item B<-tls1_2>
List the ciphers which would be used if TLS v1.2 was negotiated.
=item B<-stdname> =item B<-stdname>
@ -132,25 +136,27 @@ The following is a list of all permitted cipher strings and their meanings.
=item B<DEFAULT> =item B<DEFAULT>
the default cipher list. This is determined at compile time and The default cipher list.
is B<ALL:!COMPLEMENTOFDEFAULT:!eNULL>. This must be the first cipher This is determined at compile time and is normally
string specified. B<ALL:!COMPLEMENTOFDEFAULT:!eNULL>.
When used, this must be the first cipherstring specified.
=item B<COMPLEMENTOFDEFAULT> =item B<COMPLEMENTOFDEFAULT>
the ciphers included in B<ALL>, but not enabled by default. Currently The ciphers included in B<ALL>, but not enabled by default. Currently
this includes all RC4, DES, RC2 and anonymous ciphers. Note that this rule does this includes all RC4, DES, RC2 and anonymous ciphers. Note that this rule does
not cover B<eNULL>, which is not included by B<ALL> (use B<COMPLEMENTOFALL> if not cover B<eNULL>, which is not included by B<ALL> (use B<COMPLEMENTOFALL> if
necessary). necessary).
=item B<ALL> =item B<ALL>
all cipher suites except the B<eNULL> ciphers which must be explicitly enabled; All cipher suites except the B<eNULL> ciphers (which must be explicitly enabled
as of OpenSSL, the B<ALL> cipher suites are reasonably ordered by default if needed).
As of OpenSSL 1.0.0, the B<ALL> cipher suites are sensibly ordered by default.
=item B<COMPLEMENTOFALL> =item B<COMPLEMENTOFALL>
the cipher suites not enabled by B<ALL>, currently being B<eNULL>. The cipher suites not enabled by B<ALL>, currently B<eNULL>.
=item B<HIGH> =item B<HIGH>
@ -170,83 +176,86 @@ ciphersuites have been removed as of OpenSSL 1.1.0.
=item B<eNULL>, B<NULL> =item B<eNULL>, B<NULL>
the "NULL" ciphers that is those offering no encryption. Because these offer no The "NULL" ciphers that is those offering no encryption. Because these offer no
encryption at all and are a security risk they are disabled unless explicitly encryption at all and are a security risk they are not enabled via either the
included. B<DEFAULT> or B<ALL> cipher strings.
Be careful when building cipherlists out of lower-level primitives such as
B<kRSA> or B<aECDSA> as these do overlap with the B<eNULL> ciphers. When in
doubt, include B<!eNULL> in your cipherlist.
=item B<aNULL> =item B<aNULL>
the cipher suites offering no authentication. This is currently the anonymous The cipher suites offering no authentication. This is currently the anonymous
DH algorithms and anonymous ECDH algorithms. These cipher suites are vulnerable DH algorithms and anonymous ECDH algorithms. These cipher suites are vulnerable
to a "man in the middle" attack and so their use is normally discouraged. to "man in the middle" attacks and so their use is discouraged.
These are excluded from the B<DEFAULT> ciphers, but included in the B<ALL>
ciphers.
Be careful when building cipherlists out of lower-level primitives such as
B<kDHE> or B<AES> as these do overlap with the B<aNULL> ciphers.
When in doubt, include B<!aNULL> in your cipherlist.
=item B<kRSA>, B<aRSA>, B<RSA> =item B<kRSA>, B<aRSA>, B<RSA>
cipher suites using RSA key exchange, authentication or either respectively. Cipher suites using RSA key exchange, authentication or either respectively.
=item B<kDHr>, B<kDHd>, B<kDH> =item B<kDHr>, B<kDHd>, B<kDH>
cipher suites using DH key agreement and DH certificates signed by CAs with RSA Cipher suites using static DH key agreement and DH certificates signed by CAs
and DSS keys or either respectively. with RSA and DSS keys or either respectively.
All these cipher suites have been removed in OpenSSL 1.1.0.
=item B<kDHE>, B<kEDH> =item B<kDHE>, B<kEDH>, B<DH>
cipher suites using ephemeral DH key agreement, including anonymous cipher Cipher suites using ephemeral DH key agreement, including anonymous cipher
suites. suites.
=item B<DHE>, B<EDH> =item B<DHE>, B<EDH>
cipher suites using authenticated ephemeral DH key agreement. Cipher suites using authenticated ephemeral DH key agreement.
=item B<ADH> =item B<ADH>
anonymous DH cipher suites, note that this does not include anonymous Elliptic Anonymous DH cipher suites, note that this does not include anonymous Elliptic
Curve DH (ECDH) cipher suites. Curve DH (ECDH) cipher suites.
=item B<DH> =item B<kEECDH>, B<kECDHE>, B<ECDH>
cipher suites using DH, including anonymous DH, ephemeral DH and fixed DH. Cipher suites using ephemeral ECDH key agreement, including anonymous
=item B<kEECDH>, B<kECDHE>
cipher suites using ephemeral ECDH key agreement, including anonymous
cipher suites. cipher suites.
=item B<ECDHE>, B<EECDH> =item B<ECDHE>, B<EECDH>
cipher suites using authenticated ephemeral ECDH key agreement. Cipher suites using authenticated ephemeral ECDH key agreement.
=item B<AECDH> =item B<AECDH>
anonymous Elliptic Curve Diffie Hellman cipher suites. Anonymous Elliptic Curve Diffie Hellman cipher suites.
=item B<ECDH>
cipher suites using ECDH key exchange, including anonymous and ephemeral.
=item B<aDSS>, B<DSS> =item B<aDSS>, B<DSS>
cipher suites using DSS authentication, i.e. the certificates carry DSS keys. Cipher suites using DSS authentication, i.e. the certificates carry DSS keys.
=item B<aDH> =item B<aDH>
cipher suites effectively using DH authentication, i.e. the certificates carry Cipher suites effectively using DH authentication, i.e. the certificates carry
DH keys. DH keys.
All these cipher suites have been removed in OpenSSL 1.1.0.
=item B<aECDSA>, B<ECDSA> =item B<aECDSA>, B<ECDSA>
cipher suites using ECDSA authentication, i.e. the certificates carry ECDSA Cipher suites using ECDSA authentication, i.e. the certificates carry ECDSA
keys. keys.
=item B<TLSv1.2>, B<TLSv1.0>, B<SSLv3> =item B<TLSv1.2>, B<TLSv1.0>, B<SSLv3>
Lists ciphersuites which are only supported in at least TLS v1.2, TLS v1.0 Lists ciphersuites which are only supported in at least TLS v1.2, TLS v1.0 or
or SSL v3.0 respectively. Note: there are no ciphersuites specific to TLS v1.1. SSL v3.0 respectively.
Since this is only the minimum version if, for example, TLS v1.0 is supported Note: there are no ciphersuites specific to TLS v1.1.
then both TLS v1.0 and SSL v3.0 ciphersuites are included. Since this is only the minimum version, if, for example, TLSv1.0 is negotiated
then both TLSv1.0 and SSLv3.0 ciphersuites are available.
Note: these cipher strings B<do not> change the negotiated version of SSL or Note: these cipher strings B<do not> change the negotiated version of SSL or
TLS only the list of cipher suites. TLS, they only affect the list of available cipher suites.
=item B<AES128>, B<AES256>, B<AES> =item B<AES128>, B<AES256>, B<AES>
@ -279,81 +288,85 @@ cipher suites using triple DES.
=item B<DES> =item B<DES>
cipher suites using DES (not triple DES). Cipher suites using DES (not triple DES).
All these cipher suites have been removed in OpenSSL 1.1.0.
=item B<RC4> =item B<RC4>
cipher suites using RC4. Cipher suites using RC4.
=item B<RC2> =item B<RC2>
cipher suites using RC2. Cipher suites using RC2.
=item B<IDEA> =item B<IDEA>
cipher suites using IDEA. Cipher suites using IDEA.
=item B<SEED> =item B<SEED>
cipher suites using SEED. Cipher suites using SEED.
=item B<MD5> =item B<MD5>
cipher suites using MD5. Cipher suites using MD5.
=item B<SHA1>, B<SHA> =item B<SHA1>, B<SHA>
cipher suites using SHA1. Cipher suites using SHA1.
=item B<SHA256>, B<SHA384> =item B<SHA256>, B<SHA384>
ciphersuites using SHA256 or SHA384. Ciphersuites using SHA256 or SHA384.
=item B<aGOST> =item B<aGOST>
cipher suites using GOST R 34.10 (either 2001 or 94) for authentication Cipher suites using GOST R 34.10 (either 2001 or 94) for authentication
(needs an engine supporting GOST algorithms). (needs an engine supporting GOST algorithms).
=item B<aGOST01> =item B<aGOST01>
cipher suites using GOST R 34.10-2001 authentication. Cipher suites using GOST R 34.10-2001 authentication.
=item B<kGOST> =item B<kGOST>
cipher suites, using VKO 34.10 key exchange, specified in the RFC 4357. Cipher suites, using VKO 34.10 key exchange, specified in the RFC 4357.
=item B<GOST94> =item B<GOST94>
cipher suites, using HMAC based on GOST R 34.11-94. Cipher suites, using HMAC based on GOST R 34.11-94.
=item B<GOST89MAC> =item B<GOST89MAC>
cipher suites using GOST 28147-89 MAC B<instead of> HMAC. Cipher suites using GOST 28147-89 MAC B<instead of> HMAC.
=item B<PSK> =item B<PSK>
all cipher suites using pre-shared keys (PSK). All cipher suites using pre-shared keys (PSK).
=item B<kPSK>, B<kECDHEPSK>, B<kDHEPSK>, B<kRSAPSK> =item B<kPSK>, B<kECDHEPSK>, B<kDHEPSK>, B<kRSAPSK>
cipher suites using PSK key exchange, ECDHE_PSK, DHE_PSK or RSA_PSK. Cipher suites using PSK key exchange, ECDHE_PSK, DHE_PSK or RSA_PSK.
=item B<aPSK> =item B<aPSK>
cipher suites using PSK authentication (currently all PSK modes apart from Cipher suites using PSK authentication (currently all PSK modes apart from
RSA_PSK). RSA_PSK).
=item B<SUITEB128>, B<SUITEB128ONLY>, B<SUITEB192> =item B<SUITEB128>, B<SUITEB128ONLY>, B<SUITEB192>
enables suite B mode operation using 128 (permitting 192 bit mode by peer) Enables suite B mode of operation using 128 (permitting 192 bit mode by peer)
128 bit (not permitting 192 bit by peer) or 192 bit level of security 128 bit (not permitting 192 bit by peer) or 192 bit level of security
respectively. If used these cipherstrings should appear first in the cipher respectively.
list and anything after them is ignored. Setting Suite B mode has additional If used these cipherstrings should appear first in the cipher
consequences required to comply with RFC6460. In particular the supported list and anything after them is ignored.
signature algorithms is reduced to support only ECDSA and SHA256 or SHA384, Setting Suite B mode has additional consequences required to comply with
only the elliptic curves P-256 and P-384 can be used and only the two suite B RFC6460.
compliant ciphersuites (ECDHE-ECDSA-AES128-GCM-SHA256 and In particular the supported signature algorithms is reduced to support only
ECDHE-ECDSA-AES256-GCM-SHA384) are permissible. ECDSA and SHA256 or SHA384, only the elliptic curves P-256 and P-384 can be
used and only the two suite B compliant ciphersuites
(ECDHE-ECDSA-AES128-GCM-SHA256 and ECDHE-ECDSA-AES256-GCM-SHA384) are
permissible.
=back =back
@ -473,13 +486,13 @@ Note: these ciphers can also be used in SSL v3.
TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA ECDHE-RSA-DES-CBC3-SHA TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA ECDHE-RSA-DES-CBC3-SHA
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA ECDHE-RSA-AES128-SHA TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA ECDHE-RSA-AES128-SHA
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA ECDHE-RSA-AES256-SHA TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA ECDHE-RSA-AES256-SHA
TLS_ECDHE_ECDSA_WITH_NULL_SHA ECDHE-ECDSA-NULL-SHA TLS_ECDHE_ECDSA_WITH_NULL_SHA ECDHE-ECDSA-NULL-SHA
TLS_ECDHE_ECDSA_WITH_RC4_128_SHA ECDHE-ECDSA-RC4-SHA TLS_ECDHE_ECDSA_WITH_RC4_128_SHA ECDHE-ECDSA-RC4-SHA
TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA ECDHE-ECDSA-DES-CBC3-SHA TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA ECDHE-ECDSA-DES-CBC3-SHA
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA ECDHE-ECDSA-AES128-SHA TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA ECDHE-ECDSA-AES128-SHA
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA ECDHE-ECDSA-AES256-SHA TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA ECDHE-ECDSA-AES256-SHA
TLS_ECDH_anon_WITH_NULL_SHA AECDH-NULL-SHA TLS_ECDH_anon_WITH_NULL_SHA AECDH-NULL-SHA
TLS_ECDH_anon_WITH_RC4_128_SHA AECDH-RC4-SHA TLS_ECDH_anon_WITH_RC4_128_SHA AECDH-RC4-SHA
TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA AECDH-DES-CBC3-SHA TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA AECDH-DES-CBC3-SHA

32
doc/apps/s_client.pod
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@ -64,10 +64,15 @@ B<openssl> B<s_client>
[B<-quiet>] [B<-quiet>]
[B<-ssl3>] [B<-ssl3>]
[B<-tls1>] [B<-tls1>]
[B<-tls1_1>]
[B<-tls1_2>]
[B<-no_ssl3>] [B<-no_ssl3>]
[B<-no_tls1>] [B<-no_tls1>]
[B<-no_tls1_1>] [B<-no_tls1_1>]
[B<-no_tls1_2>] [B<-no_tls1_2>]
[B<-dtls>]
[B<-dtls1>]
[B<-dtls1_2>]
[B<-fallback_scsv>] [B<-fallback_scsv>]
[B<-async>] [B<-async>]
[B<-bugs>] [B<-bugs>]
@ -305,15 +310,20 @@ 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 given as a hexadecimal number without leading 0x, for example -psk
1a2b3c4d. 1a2b3c4d.
=item B<-ssl3>, B<-tls1>, B<-no_ssl3>, B<-no_tls1>, B<-no_tls1_1>, B<-no_tls1_2> =item B<-ssl3>, B<-tls1>, B<-tls1_1>, B<-tls1_2>, B<-no_ssl3>, B<-no_tls1>, B<-no_tls1_1>, B<-no_tls1_2>
these options disable the use of certain SSL or TLS protocols. By default These options require or disable the use of the specified SSL or TLS protocols.
the initial handshake uses a method which should be compatible with all By default B<s_client> will negotiate the highest mutually supported protocol
servers and permit them to use SSL v3 or TLS as appropriate. version.
When a specific TLS version is required, only that version will be offered to
and accepted from the server.
Unfortunately there are still ancient and broken servers in use which =item B<-dtls>, B<-dtls1>, B<-dtls1_2>
cannot handle this technique and will fail to connect. Some servers only
work if TLS is turned off. These options make B<s_client> use DTLS protocols instead of TLS.
With B<-dtls>, B<s_client> will negotiate any supported DTLS protcol version,
whilst B<-dtls1> and B<-dtls1_2> will only support DTLS1.0 and DTLS1.2
respectively.
=item B<-fallback_scsv> =item B<-fallback_scsv>
@ -479,10 +489,10 @@ option: any verify errors are then returned aborting the handshake.
=head1 BUGS =head1 BUGS
Because this program has a lot of options and also because some of Because this program has a lot of options and also because some of the
the techniques used are rather old, the C source of s_client is rather techniques used are rather old, the C source of B<s_client> is rather hard to
hard to read and not a model of how things should be done. A typical read and not a model of how things should be done.
SSL client program would be much simpler. A typical SSL client program would be much simpler.
The B<-prexit> option is a bit of a hack. We should really report The B<-prexit> option is a bit of a hack. We should really report
information whenever a session is renegotiated. information whenever a session is renegotiated.

127
doc/apps/s_server.pod
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@ -75,6 +75,8 @@ B<openssl> B<s_server>
[B<-async>] [B<-async>]
[B<-no_ssl3>] [B<-no_ssl3>]
[B<-no_tls1>] [B<-no_tls1>]
[B<-no_tls1_1>]
[B<-no_tls1_2>]
[B<-no_dhe>] [B<-no_dhe>]
[B<-bugs>] [B<-bugs>]
[B<-comp>] [B<-comp>]
@ -116,15 +118,15 @@ Print out a usage message.
=item B<-accept port> =item B<-accept port>
the TCP port to listen on for connections. If not specified 4433 is used. The TCP port to listen on for connections. If not specified 4433 is used.
=item B<-naccept count> =item B<-naccept count>
The server will exit after receiving B<number> connections, default unlimited. The server will exit after receiving B<number> connections, default unlimited.
=item B<-context id> =item B<-context id>
sets the SSL context id. It can be given any string value. If this option Sets the SSL context id. It can be given any string value. If this option
is not present a default value will be used. is not present a default value will be used.
=item B<-cert certname> =item B<-cert certname>
@ -149,12 +151,12 @@ The private format to use: DER or PEM. PEM is the default.
=item B<-pass arg> =item B<-pass arg>
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<arg>
see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>. see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
=item B<-dcert filename>, B<-dkey keyname> =item B<-dcert filename>, B<-dkey keyname>
specify an additional certificate and private key, these behave in the 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 same manner as the B<-cert> and B<-key> options except there is no default
if they are not specified (no additional certificate and key is used). As if they are not specified (no additional certificate and key is used). As
noted above some cipher suites require a certificate containing a key of noted above some cipher suites require a certificate containing a key of
@ -165,24 +167,25 @@ by using an appropriate certificate.
=item B<-dcertform format>, B<-dkeyform format>, B<-dpass arg> =item B<-dcertform format>, B<-dkeyform format>, B<-dpass arg>
additional certificate and private key format and passphrase respectively. Additional certificate and private key format and passphrase respectively.
=item B<-nocert> =item B<-nocert>
if this option is set then no certificate is used. This restricts the If this option is set then no certificate is used. This restricts the
cipher suites available to the anonymous ones (currently just anonymous cipher suites available to the anonymous ones (currently just anonymous
DH). DH).
=item B<-dhparam filename> =item B<-dhparam filename>
the DH parameter file to use. The ephemeral DH cipher suites generate keys 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 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 load the parameters from the server certificate file.
a static set of parameters hard coded into the s_server program will be used. If this fails then a static set of parameters hard coded into the B<s_server>
program will be used.
=item B<-no_dhe> =item B<-no_dhe>
if this option is set then no DH parameters will be loaded effectively If this option is set then no DH parameters will be loaded effectively
disabling the ephemeral DH cipher suites. disabling the ephemeral DH cipher suites.
=item B<-crl_check>, B<-crl_check_all> =item B<-crl_check>, B<-crl_check_all>
@ -242,40 +245,40 @@ If this option is used, then verification errors close the connection.
=item B<-state> =item B<-state>
prints out the SSL session states. Prints the SSL session states.
=item B<-debug> =item B<-debug>
print extensive debugging information including a hex dump of all traffic. Print extensive debugging information including a hex dump of all traffic.
=item B<-msg> =item B<-msg>
show all protocol messages with hex dump. Show all protocol messages with hex dump.
=item B<-trace> =item B<-trace>
show verbose trace output of protocol messages. OpenSSL needs to be compiled Show verbose trace output of protocol messages. OpenSSL needs to be compiled
with B<enable-ssl-trace> for this option to work. with B<enable-ssl-trace> for this option to work.
=item B<-msgfile> =item B<-msgfile>
file to send output of B<-msg> or B<-trace> to, default standard output. File to send output of B<-msg> or B<-trace> to, default standard output.
=item B<-nbio_test> =item B<-nbio_test>
tests non blocking I/O Tests non blocking I/O
=item B<-nbio> =item B<-nbio>
turns on non blocking I/O Turns on non blocking I/O
=item B<-crlf> =item B<-crlf>
this option translated a line feed from the terminal into CR+LF. This option translated a line feed from the terminal into CR+LF.
=item B<-quiet> =item B<-quiet>
inhibit printing of session and certificate information. Inhibit printing of session and certificate information.
=item B<-psk_hint hint> =item B<-psk_hint hint>
@ -287,37 +290,41 @@ 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 given as a hexadecimal number without leading 0x, for example -psk
1a2b3c4d. 1a2b3c4d.
=item B<-ssl3>, B<-tls1>, B<-no_ssl3>, B<-no_tls1> =item B<-ssl2>, B<-ssl3>, B<-tls1>, B<-tls1_1>, B<-tls1_2>, B<-no_ssl2>, B<-no_ssl3>, B<-no_tls1>, B<-no_tls1_1>, B<-no_tls1_2>
these options disable the use of certain SSL or TLS protocols. By default These options require or disable the use of the specified SSL or TLS protocols.
the initial handshake uses a method which should be compatible with all By default B<s_server> will negotiate the highest mutually supported protocol
servers and permit them to use SSL v3 or TLS as appropriate. version.
When a specific TLS version is required, only that version will be accepted
from the client.
=item B<-dtls>, B<-dtls1>, B<-dtls1_2> =item B<-dtls>, B<-dtls1>, B<-dtls1_2>
these options make s_server use DTLS protocols instead of TLS. With B<-dtls> These options make B<s_server> use DTLS protocols instead of TLS.
s_server will negotiate any supported DTLS protcol version, whilst B<-dtls1> and With B<-dtls>, B<s_server> will negotiate any supported DTLS protcol version,
B<-dtls1_2> will only support DTLS1.0 and DTLS1.2 respectively. whilst B<-dtls1> and B<-dtls1_2> will only support DTLSv1.0 and DTLSv1.2
respectively.
=item B<-listen> =item B<-listen>
this option can only be used in conjunction with one of the DTLS options above. This option can only be used in conjunction with one of the DTLS options above.
With this option s_server will listen on a UDP port for incoming connections. 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 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 them or not.
HelloVerifyRequest. If a ClientHello with a cookie is received then s_server Any without a cookie will be responded to with a HelloVerifyRequest.
will connect to that peer and complete the handshake. If a ClientHello with a cookie is received then B<s_server> will connect to
that peer and complete the handshake.
=item B<-async> =item B<-async>
switch on asynchronous mode. Cryptographic operations will be performed Switch on asynchronous mode. Cryptographic operations will be performed
asynchronously. This will only have an effect if an asynchronous capable engine asynchronously. This will only have an effect if an asynchronous capable engine
is also used via the B<-engine> option. For test purposes the dummy async engine is also used via the B<-engine> option. For test purposes the dummy async engine
(dasync) can be used (if available). (dasync) can be used (if available).
=item B<-bugs> =item B<-bugs>
there are several known bug in SSL and TLS implementations. Adding this There are several known bug in SSL and TLS implementations. Adding this
option enables various workarounds. option enables various workarounds.
=item B<-comp> =item B<-comp>
@ -335,12 +342,12 @@ OpenSSL 1.1.0.
=item B<-brief> =item B<-brief>
only provide a brief summary of connection parameters instead of the Provide a brief summary of connection parameters instead of the normal verbose
normal verbose output. output.
=item B<-cipher cipherlist> =item B<-cipher cipherlist>
this allows the cipher list used by the server to be modified. When 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 the client sends a list of supported ciphers the first client cipher
also included in the server list is used. Because the client specifies also included in the server list is used. Because the client specifies
the preference order, the order of the server cipherlist irrelevant. See the preference order, the order of the server cipherlist irrelevant. See
@ -348,32 +355,32 @@ the B<ciphers> command for more information.
=item B<-serverpref> =item B<-serverpref>
use the server's cipher preferences, rather than the client's preferences. Use the server's cipher preferences, rather than the client's preferences.
=item B<-tlsextdebug> =item B<-tlsextdebug>
print out a hex dump of any TLS extensions received from the server. Print a hex dump of any TLS extensions received from the server.
=item B<-no_ticket> =item B<-no_ticket>
disable RFC4507bis session ticket support. Disable RFC4507bis session ticket support.
=item B<-www> =item B<-www>
sends a status message back to the client when it connects. This includes Sends a status message back to the client when it connects. This includes
lots of information about the ciphers used and various session parameters. information about the ciphers used and various session parameters.
The output is in HTML format so this option will normally be used with a The output is in HTML format so this option will normally be used with a
web browser. web browser.
=item B<-WWW> =item B<-WWW>
emulates a simple web server. Pages will be resolved relative to the Emulates a simple web server. Pages will be resolved relative to the
current directory, for example if the URL https://myhost/page.html is current directory, for example if the URL https://myhost/page.html is
requested the file ./page.html will be loaded. requested the file ./page.html will be loaded.
=item B<-HTTP> =item B<-HTTP>
emulates a simple web server. Pages will be resolved relative to the Emulates a simple web server. Pages will be resolved relative to the
current directory, for example if the URL https://myhost/page.html is current directory, for example if the URL https://myhost/page.html is
requested the file ./page.html will be loaded. The files loaded are requested the file ./page.html will be loaded. The files loaded are
assumed to contain a complete and correct HTTP response (lines that assumed to contain a complete and correct HTTP response (lines that
@ -381,26 +388,26 @@ are part of the HTTP response line and headers must end with CRLF).
=item B<-rev> =item B<-rev>
simple test server which just reverses the text received from the client Simple test server which just reverses the text received from the client
and sends it back to the server. Also sets B<-brief>. and sends it back to the server. Also sets B<-brief>.
=item B<-engine id> =item B<-engine id>
specifying an engine (by its unique B<id> string) will cause B<s_server> 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, 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 thus initialising it if needed. The engine will then be set as the default
for all available algorithms. for all available algorithms.
=item B<-id_prefix arg> =item B<-id_prefix arg>
generate SSL/TLS session IDs prefixed by B<arg>. This is mostly useful 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 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 servers, when each of which might be generating a unique range of session
IDs (eg. with a certain prefix). IDs (eg. with a certain prefix).
=item B<-rand file(s)> =item B<-rand file(s)>
a file or files containing random data used to seed the random number A file or files containing random data used to seed the random number
generator, or an EGD socket (see L<RAND_egd(3)>). generator, or an EGD socket (see L<RAND_egd(3)>).
Multiple files can be specified separated by a OS-dependent character. Multiple files can be specified separated by a OS-dependent character.
The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
@ -408,7 +415,7 @@ all others.
=item B<-serverinfo file> =item B<-serverinfo file>
a file containing one or more blocks of PEM data. Each PEM block 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, must encode a TLS ServerHello extension (2 bytes type, 2 bytes length,
followed by "length" bytes of extension data). If the client sends followed by "length" bytes of extension data). If the client sends
an empty TLS ClientHello extension matching the type, the corresponding an empty TLS ClientHello extension matching the type, the corresponding
@ -416,30 +423,30 @@ ServerHello extension will be returned.
=item B<-no_resumption_on_reneg> =item B<-no_resumption_on_reneg>
set SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION flag. Set the B<SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION> option.
=item B<-status> =item B<-status>
enables certificate status request support (aka OCSP stapling). Enables certificate status request support (aka OCSP stapling).
=item B<-status_verbose> =item B<-status_verbose>
enables certificate status request support (aka OCSP stapling) and gives Enables certificate status request support (aka OCSP stapling) and gives
a verbose printout of the OCSP response. a verbose printout of the OCSP response.
=item B<-status_timeout nsec> =item B<-status_timeout nsec>
sets the timeout for OCSP response to B<nsec> seconds. Sets the timeout for OCSP response to B<nsec> seconds.
=item B<-status_url url> =item B<-status_url url>
sets a fallback responder URL to use if no responder URL is present in the 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 server certificate. Without this option an error is returned if the server
certificate does not contain a responder address. certificate does not contain a responder address.
=item B<-nextprotoneg protocols> =item B<-nextprotoneg protocols>
enable Next Protocol Negotiation TLS extension and provide a Enable Next Protocol Negotiation TLS extension and provide a
comma-separated list of supported protocol names. comma-separated list of supported protocol names.
The list should contain most wanted protocols first. The list should contain most wanted protocols first.
Protocol names are printable ASCII strings, for example "http/1.1" or Protocol names are printable ASCII strings, for example "http/1.1" or
@ -451,7 +458,7 @@ Protocol names are printable ASCII strings, for example "http/1.1" or
If a connection request is established with an SSL client and neither the 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 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. 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 Certain single letter commands are also recognized which perform special
operations: these are listed below. operations: these are listed below.
@ -506,10 +513,10 @@ The session parameters can printed out using the B<sess_id> program.
=head1 BUGS =head1 BUGS
Because this program has a lot of options and also because some of Because this program has a lot of options and also because some of the
the techniques used are rather old, the C source of s_server is rather techniques used are rather old, the C source of B<s_server> is rather hard to
hard to read and not a model of how things should be done. A typical read and not a model of how things should be done.
SSL server program would be much simpler. A typical SSL server program would be much simpler.
The output of common ciphers is wrong: it just gives the list of ciphers that The output of common ciphers is wrong: it just gives the list of ciphers that
OpenSSL recognizes and the client supports. OpenSSL recognizes and the client supports.

6
doc/ssl/SSL_CONF_cmd.pod
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@ -122,9 +122,9 @@ than the deprecated alternative commands below.
=item B<-no_ssl3>, B<-no_tls1>, B<-no_tls1_1>, B<-no_tls1_2> =item B<-no_ssl3>, B<-no_tls1>, B<-no_tls1_1>, B<-no_tls1_2>
Disables protocol support for SSLv3, TLS 1.0, TLS 1.1 or TLS 1.2 Disables protocol support for SSLv3, TLSv1.0, TLSv1.1 or TLSv1.2 by setting the
by setting the corresponding options B<SSL_OP_NO_SSL3>, B<SSL_OP_NO_TLS1>, corresponding options B<SSL_OP_NO_SSL3>, B<SSL_OP_NO_TLS1>, B<SSL_OP_NO_TLS1_1>
B<SSL_OP_NO_TLS1_1> and B<SSL_OP_NO_TLS1_2> respectively. and B<SSL_OP_NO_TLS1_2> respectively.
These options are deprecated, instead use B<-min_protocol> and B<-max_protocol>. These options are deprecated, instead use B<-min_protocol> and B<-max_protocol>.
=item B<-bugs> =item B<-bugs>

124
doc/ssl/SSL_CTX_new.pod
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@ -76,85 +76,88 @@ B<method> can be of the following types:
=over 4 =over 4
=item SSLv3_method(), SSLv3_server_method(), SSLv3_client_method()
An SSL connection established with these methods will only understand
the SSLv3 protocol.
A client will send out a SSLv3 client hello messages and will
indicate that it supports SSLv3.
A server will only understand SSLv3 client hello message and only
support the SSLv3 protocol.
=item TLSv1_method(), TLSv1_server_method(), TLSv1_client_method()
A TLS connection established with these methods will only understand
the TLS 1.0 protocol.
=item TLSv1_1_method(), TLSv1_1_server_method(), TLSv1_1_client_method()
A TLS connection established with these methods will only understand
the TLS 1.1 protocol.
=item TLSv1_2_method(), TLSv1_2_server_method(), TLSv1_2_client_method()
A TLS connection established with these methods will only understand
the TLS 1.2 protocol.
=item TLS_method(), TLS_server_method(), TLS_client_method() =item TLS_method(), TLS_server_method(), TLS_client_method()
A TLS/SSL connection established with these methods may understand These are the general-purpose I<version-flexible> SSL/TLS methods.
the SSLv3, TLSv1, TLSv1.1 and TLSv1.2 protocols. The actual protocol version used will be negotiated to the highest version
mutually supported by the client and the server.
If extensions are required (for example server name) The supported protocols are SSLv3, TLSv1, TLSv1.1 and TLSv1.2.
a client will send out TLSv1 client hello messages including extensions and Most applications should use these method, and avoid the version specific
will indicate that it also understands TLSv1.1, TLSv1.2 and permits a methods described below.
fallback to SSLv3. A server will support SSLv3, TLSv1, TLSv1.1 and TLSv1.2
protocols. This is the best choice when compatibility is a concern.
=item SSLv23_method(), SSLv23_server_method(), SSLv23_client_method() =item SSLv23_method(), SSLv23_server_method(), SSLv23_client_method()
Use of these functions is deprecated. They have been replaced with TLS_method(), Use of these functions is deprecated. They have been replaced with the above
TLS_server_method() and TLS_client_method() respectively. New code should use TLS_method(), TLS_server_method() and TLS_client_method() respectively. New
those functions instead. code should use those functions instead.
=item TLSv1_2_method(), TLSv1_2_server_method(), TLSv1_2_client_method()
A TLS/SSL connection established with these methods will only understand the
TLSv1.2 protocol.
=item TLSv1_1_method(), TLSv1_1_server_method(), TLSv1_1_client_method()
A TLS/SSL connection established with these methods will only understand the
TLSv1.1 protocol.
=item TLSv1_method(), TLSv1_server_method(), TLSv1_client_method()
A TLS/SSL connection established with these methods will only understand the
TLSv1 protocol.
=item SSLv3_method(), SSLv3_server_method(), SSLv3_client_method()
A TLS/SSL connection established with these methods will only understand the
SSLv3 protocol.
The SSLv3 protocol is deprecated and should not be used.
=item DTLS_method(), DTLS_server_method(), DTLS_client_method() =item DTLS_method(), DTLS_server_method(), DTLS_client_method()
A DTLS connection established with those methods understands all These are the version-flexible DTLS methods.
supported DTLS protocols.
Currently supported protocols are DTLS 1.0 and DTLS 1.2. Currently supported protocols are DTLS 1.0 and DTLS 1.2.
=item DTLSv1_method(), DTLSv1_server_method(), DTLSv1_client_method()
A DTLS connection established with these methods will only understand
the DTLS 1.0 protocol.
=item DTLSv1_2_method(), DTLSv1_2_server_method(), DTLSv1_2_client_method() =item DTLSv1_2_method(), DTLSv1_2_server_method(), DTLSv1_2_client_method()
A DTLS connection established with these methods will only understand These are the version-specific methods for DTLSv1.2.
the DTLS 1.2 protocol.
=item DTLSv1_method(), DTLSv1_server_method(), DTLSv1_client_method()
These are the version-specific methods for DTLSv1.
=back =back
SSL_CTX_new() initializes the list of ciphers, the session cache setting, the
callbacks, the keys and certificates and the options to their default values.
TLS_method(), TLS_server_method(), TLS_client_method(), DTLS_method(), TLS_method(), TLS_server_method(), TLS_client_method(), DTLS_method(),
DTLS_server_method() and DTLS_client_method() are the version DTLS_server_method() and DTLS_client_method() are the I<version-flexible>
flexible methods. methods.
All other methods only support one specific protocol version. All other methods only support one specific protocol version.
Use these methods instead of the other version specific methods. Use the I<version-flexible> methods instead of the version specific methods.
If you want to limit the supported protocols for the version flexible If you want to limit the supported protocols for the version flexible
methods you can use SSL_CTX_set_min_proto_version(), methods you can use L<SSL_CTX_set_min_proto_version(3)>,
SSL_set_min_proto_version(), SSL_CTX_set_max_proto_version() and L<SSL_set_min_proto_version(3)>, L<SSL_CTX_set_max_proto_version(3)> and
SSL_set_max_proto_version() functions. LSSL_set_max_proto_version(3)> functions.
They can also be limited by setting an option like B<SSL_OP_NO_SSLv3>
via the L<SSL_CTX_set_options(3)> or L<SSL_set_options(3)> functions,
but that's not recommended.
Using these functions it is possible to choose e.g. TLS_server_method() Using these functions it is possible to choose e.g. TLS_server_method()
and be able to negotiate with all possible clients, but to only and be able to negotiate with all possible clients, but to only
allow newer protocols like TLS 1.0, TLS 1.1 or TLS 1.2. allow newer protocols like TLS 1.0, TLS 1.1 or TLS 1.2.
SSL_CTX_new() initializes the list of ciphers, the session cache The list of protocols available can also be limited using the
setting, the callbacks, the keys and certificates and the options B<SSL_OP_NO_SSLv3>, B<SSL_OP_NO_TLSv1>, B<SSL_OP_NO_TLSv1_1> and
to its default values. B<SSL_OP_NO_TLSv1_2> options of the L<SSL_CTX_set_options(3)> or
L<SSL_set_options(3)> functions, but this approach is not recommended.
Clients should avoid creating "holes" in the set of protocols they support.
When disabling a protocol, make sure that you also disable either all previous
or all subsequent protocol versions.
In clients, when a protocol version is disabled without disabling I<all>
previous protocol versions, the effect is to also disable all subsequent
protocol versions.
The SSLv3 protocol is deprecated and should generally not be used.
Applications should typically use L<SSL_CTX_set_min_proto_version(3)> to set
the minimum protocol to at least B<TLS1_VERSION>.
=head1 RETURN VALUES =head1 RETURN VALUES
@ -164,8 +167,8 @@ The following return values can occur:
=item NULL =item NULL
The creation of a new SSL_CTX object failed. Check the error stack to The creation of a new SSL_CTX object failed. Check the error stack to find out
find out the reason. the reason.
=item Pointer to an SSL_CTX object =item Pointer to an SSL_CTX object
@ -185,8 +188,7 @@ and TLS_client_method() functions were introduced in OpenSSL 1.1.0.
=head1 SEE ALSO =head1 SEE ALSO
L<SSL_CTX_free(3)>, L<SSL_accept(3)>, L<SSL_CTX_set_options(3)>, L<SSL_CTX_free(3)>, L<SSL_accept(3)>,
L<SSL_CTX_set_min_proto_version(3)>, L<SSL_CTX_set_min_proto_version(3)>, L<ssl(3)>, L<SSL_set_connect_state(3)>
L<ssl(3)>, L<SSL_set_connect_state(3)>
=cut =cut

60
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@ -118,29 +118,67 @@ protocol methods defined in B<SSL_METHOD> structures.
=over 4 =over 4
=item const SSL_METHOD *B<SSLv3_client_method>(void); =item const SSL_METHOD *B<TLS_method>(void);
Constructor for the SSLv3 SSL_METHOD structure for a dedicated client. Constructor for the I<version-flexible> SSL_METHOD structure for clients,
servers or both.
See L<SSL_CTX_new(3)> for details.
=item const SSL_METHOD *B<SSLv3_server_method>(void); =item const SSL_METHOD *B<TLS_client_method>(void);
Constructor for the SSLv3 SSL_METHOD structure for a dedicated server. Constructor for the I<version-flexible> SSL_METHOD structure for clients.
=item const SSL_METHOD *B<SSLv3_method>(void); =item const SSL_METHOD *B<TLS_server_method>(void);
Constructor for the SSLv3 SSL_METHOD structure for combined client and server. Constructor for the I<version-flexible> SSL_METHOD structure for servers.
=item const SSL_METHOD *B<TLSv1_client_method>(void); =item const SSL_METHOD *B<TLSv1_2_method>(void);
Constructor for the TLSv1 SSL_METHOD structure for a dedicated client. Constructor for the TLSv1.2 SSL_METHOD structure for clients, servers or both.
=item const SSL_METHOD *B<TLSv1_server_method>(void); =item const SSL_METHOD *B<TLSv1_2_client_method>(void);
Constructor for the TLSv1 SSL_METHOD structure for a dedicated server. Constructor for the TLSv1.2 SSL_METHOD structure for clients.
=item const SSL_METHOD *B<TLSv1_2_server_method>(void);
Constructor for the TLSv1.2 SSL_METHOD structure for servers.
=item const SSL_METHOD *B<TLSv1_1_method>(void);
Constructor for the TLSv1.1 SSL_METHOD structure for clients, servers or both.
=item const SSL_METHOD *B<TLSv1_1_client_method>(void);
Constructor for the TLSv1.1 SSL_METHOD structure for clients.
=item const SSL_METHOD *B<TLSv1_1_server_method>(void);
Constructor for the TLSv1.1 SSL_METHOD structure for servers.
=item const SSL_METHOD *B<TLSv1_method>(void); =item const SSL_METHOD *B<TLSv1_method>(void);
Constructor for the TLSv1 SSL_METHOD structure for combined client and server. Constructor for the TLSv1 SSL_METHOD structure for clients, servers or both.
=item const SSL_METHOD *B<TLSv1_client_method>(void);
Constructor for the TLSv1 SSL_METHOD structure for clients.
=item const SSL_METHOD *B<TLSv1_server_method>(void);
Constructor for the TLSv1 SSL_METHOD structure for servers.
=item const SSL_METHOD *B<SSLv3_method>(void);
Constructor for the SSLv3 SSL_METHOD structure for clients, servers or both.
=item const SSL_METHOD *B<SSLv3_client_method>(void);
Constructor for the SSLv3 SSL_METHOD structure for clients.
=item const SSL_METHOD *B<SSLv3_server_method>(void);
Constructor for the SSLv3 SSL_METHOD structure for servers.
=back =back