The function SSL_CONF_cmd() performs configuration operation B<cmd> with
optional parameter B<value> on B<ctx>. Its purpose is to simplify application
configuration of B<SSL_CTX> or B<SSL> structures by providing a common
-framework for configuration files or command line options.
+framework for command line options or configuration files.
+
+=head1 SUPPORTED COMMAND LINE COMMANDS
+
+Currently supported B<cmd> names for command lines (i.e. when the
+flag B<SSL_CONF_CMDLINE> is set) are listed below. Note: all B<cmd> names
+and are case sensitive. Unless otherwise stated commands can be used by
+both clients and servers and the B<value> parameter is not used. The default
+prefix for command line commands is B<-> and that is reflected below.
+
+=over 4
+
+=item B<-sigalgs>
+
+This sets the supported signature algorithms for TLS v1.2. For clients this
+value is used directly for the supported signature algorithms extension. For
+servers it is used to determine which signature algorithms to support.
+
+The B<value> argument should be a colon separated list of signature algorithms
+in order of decreasing preference of the form B<algorithm+hash>. B<algorithm>
+is one of B<RSA>, B<DSA> or B<ECDSA> and B<hash> is a supported algorithm
+OID short name such as B<SHA1>, B<SHA224>, B<SHA256>, B<SHA384> of B<SHA512>.
+Note: algorithm and hash names are case sensitive.
+
+If this option is not set then all signature algorithms supported by the
+OpenSSL library are permissible.
+
+=item B<-client_sigalgs>
+
+This sets the supported signature algorithms associated with client
+authentication for TLS v1.2. For servers the value is used in the supported
+signature algorithms field of a certificate request. For clients it is
+used to determine which signature algorithm to with the client certificate.
+If a server does not request a certificate this option has no effect.
+
+The syntax of B<value> is identical to B<-sigalgs>. If not set then
+the value set for B<-sigalgs> will be used instead.
+
+=item B<-curves>
+
+This sets the supported elliptic curves. For servers the curves are
+sent using the supported curves extension for TLS v1.2. For clients it is used
+to determine which curve to use. This setting affects curves used for both
+signatures and key exchange, if applicable.
+
+The B<value> argument is a colon separated list of curves. The curve can be
+either the B<NIST> name (e.g. B<P-256>) or an OpenSSL OID name (e.g
+B<prime256v1>). Curve names are case sensitive.
+
+=item B<-named_curve>
+
+This sets the temporary curve used for ephemeral ECDH modes. Only used by
+servers
+
+The B<value> argument is a curve name or the special value B<auto> which
+picks an appropriate curve based on client and server preferences. The curve
+can be either the B<NIST> name (e.g. B<P-256>) or an OpenSSL OID name
+(e.g B<prime256v1>). Curve names are case sensitive.
+
+=item B<-cipher>
+
+Sets the cipher suite list to B<value>. Note: syntax checking of B<value> is
+currently not performed unless a B<SSL> or B<SSL_CTX> structure is
+associated with B<cctx>.
+
+=item B<-no_ssl2>, B<-no_ssl3>, B<-no_tls1>, B<-no_tls1_1>, B<-no_tls1_2>
+
+Disables protocol support for SSLv2, SSLv3, TLS 1.0, TLS 1.1 or TLS 1.2
+by setting the corresponding options B<SSL_OP_NO_SSL2>, B<SSL_OP_NO_SSL3>,
+B<SSL_OP_NO_TLS1>, B<SSL_OP_NO_TLS1_1> and B<SSL_OP_NO_TLS1_2> respectively.
+
+=item B<-bugs>
+
+Various bug workarounds are set, same as setting B<SSL_OP_ALL>.
+
+=item B<-no_comp>
+
+Disables support for SSL/TLS compression, same as setting B<SSL_OP_NO_COMPRESS>.
+
+=item B<-no_ticket>
+
+Disables support for session tickets, same as setting B<SSL_OP_NO_TICKET>.
+
+=item B<-serverpref>
+
+Use server and not client preference order when determining which cipher suite,
+signature algorithm or elliptic curve to use for an incoming connection.
+Equivalent to B<SSL_OP_CIPHER_SERVER_PREFERENCE>. Only used by servers.
+
+=item B<-legacyrenegotiation>
+
+permits the use of unsafe legacy renegotiation. Equivalent to setting
+B<SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION>.
+
+=item B<-legacy_server_connect>, B<-no_legacy_server_connect>
+
+permits or prohibits the use of unsafe legacy renegotiation for OpenSSL
+clients only. Equivalent to setting or clearing B<SSL_OP_LEGACY_SERVER_CONNECT>.
+Set by default.
+
+=item B<-strict>
+
+enables strict mode protocol handling. Equivalent to setting
+B<SSL_CERT_FLAG_TLS_STRICT>.
+
+=item B<-debug_broken_protocol>
+
+disables various checks and permits several kinds of broken protocol behaviour
+for testing purposes: it should B<NEVER> be used in anything other than a test
+environment. Only supported if OpenSSL is configured with
+B<-DOPENSSL_SSL_DEBUG_BROKEN_PROTOCOL>.
+
+=back
=head1 SUPPORTED CONFIGURATION FILE COMMANDS
=item B<ECDHParameters>
-This sets the temporary curve used for ephemeral ECDH modes.
+This sets the temporary curve used for ephemeral ECDH modes. Only used by
+servers
The B<value> argument is a curve name or the special value B<Automatic> which
picks an appropriate curve based on client and server preferences. The curve
=back
-=head1 SUPPORTED COMMAND LINE COMMANDS
-
-Currently supported B<cmd> names for command lines (i.e. when the
-flag B<SSL_CONF_CMDLINE> is set) are listed below. Note: all B<cmd> names
-and are case sensitive. Unless otherwise stated the B<value> parameter is
-not used. The default prefix for command line commands is B<-> and that is
-reflected below.
-
-=over 4
-
-=item B<-sigalgs>
-
-Sets the supported signature algorithms to B<value>. Equivalent to the
-B<SignatureAlgorithms> file command.
-
-=item B<-client_sigalgs>
-
-Sets the supported client signature algorithms to B<value>. Equivalent to the
-B<ClientSignatureAlgorithms> file command.
-
-=item B<-curves>
-
-Sets supported elliptic curves to B<value>. Equivalent to B<Curves> file
-command.
-
-=item B<-named_curve>
-
-Sets supported ECDH parameters to B<value>. For automatic curve selection
-B<value> should be set to B<auto>, otherwise the command is identical to
-the B<ECDHParameters> file command.
-
-=item B<-cipher>
-
-Sets the cipher suite list to B<value>. Note: syntax checking of B<value> is
-currently not performed unless a B<SSL> or B<SSL_CTX> structure is
-associated with B<cctx>.
-
-=item B<-no_ssl2>, B<-no_ssl3>, B<-no_tls1>, B<-no_tls1_1>, B<-no_tls1_2>
-
-Disables protocol support for SSLv2, SSLv3, TLS 1.0, TLS 1.1 or TLS 1.2
-by setting the corresponding options B<SSL_OP_NO_SSL2>, B<SSL_OP_NO_SSL3>,
-B<SSL_OP_NO_TLS1>, B<SSL_OP_NO_TLS1_1> and B<SSL_OP_NO_TLS1_2> respectively.
-
-=item B<-bugs>
-
-Various bug workarounds are set, same as setting B<SSL_OP_ALL>.
-
-=item B<-no_comp>
-
-Disables support for SSL/TLS compression, same as setting B<SSL_OP_NO_COMPRESS>.
-
-=item B<-no_ticket>
-
-Disables support for session tickets, same as setting B<SSL_OP_NO_TICKET>.
-
-=item B<-serverpref>
-
-Use server and not client preference order when determining which cipher suite,
-signature algorithm or elliptic curve to use for an incoming connection.
-Equivalent to B<SSL_OP_CIPHER_SERVER_PREFERENCE>. Only used by servers.
-
-=item B<-legacyrenegotiation>
-
-permits the use of unsafe legacy renegotiation. Equivalent to setting
-B<SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION>.
-
-=item B<-legacy_server_connect>, B<-no_legacy_server_connect>
-
-permits or prohibits the use of unsafe legacy renegotiation for OpenSSL
-clients only. Equivalent to setting or clearing B<SSL_OP_LEGACY_SERVER_CONNECT>.
-Set by default.
-
-=item B<-strict>
-
-enables strict mode protocol handling. Equivalent to setting
-B<SSL_CERT_FLAG_TLS_STRICT>.
-
-=item B<-debug_broken_protocol>
-
-disables various checks and permits several kinds of broken protocol behaviour
-for testing purposes: it should B<NEVER> be used in anything other than a test
-environment. Only supported if OpenSSL is configured with
-B<-DOPENSSL_SSL_DEBUG_BROKEN_PROTOCOL>.
-
-=back
-
=head1 NOTES
The order of operations is significant. This can be used to set either defaults