1 files changed, 438 insertions, 0 deletions
diff --git a/doc/ssl/SSL_CONF_cmd.pod b/doc/ssl/SSL_CONF_cmd.pod
new file mode 100644
index 000000000000..2bf1a60e9013
--- /dev/null
+++ b/doc/ssl/SSL_CONF_cmd.pod
@@ -0,0 +1,438 @@
+=pod
+
+=head1 NAME
+
+SSL_CONF_cmd - send configuration command
+
+=head1 SYNOPSIS
+
+ #include <openssl/ssl.h>
+
+ int SSL_CONF_cmd(SSL_CONF_CTX *cctx, const char *cmd, const char *value);
+ int SSL_CONF_cmd_value_type(SSL_CONF_CTX *cctx, const char *cmd);
+ int SSL_CONF_finish(SSL_CONF_CTX *cctx);
+
+=head1 DESCRIPTION
+
+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 command line options or configuration files.
+
+SSL_CONF_cmd_value_type() returns the type of value that B<cmd> refers to.
+
+The function SSL_CONF_finish() must be called after all configuration
+operations have been completed. It is used to finalise any operations
+or to process defaults.
+
+=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
+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 clients the curves are
+sent using the supported curves extension. For servers 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<-cert>
+
+Attempts to use the file B<value> as the certificate for the appropriate
+context. It currently uses SSL_CTX_use_certificate_chain_file() if an B<SSL_CTX>
+structure is set or SSL_use_certificate_file() with filetype PEM if an B<SSL>
+structure is set. This option is only supported if certificate operations
+are permitted.
+
+=item B<-key>
+
+Attempts to use the file B<value> as the private key for the appropriate
+context. This option is only supported if certificate operations
+are permitted. Note: if no B<-key> option is set then a private key is
+not loaded: it does not currently use the B<-cert> file.
+
+=item B<-dhparam>
+
+Attempts to use the file B<value> as the set of temporary DH parameters for
+the appropriate context. This option is only supported if certificate
+operations are permitted.
+
+=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<-no_resumption_on_reneg>
+
+set SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION flag. 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
+
+Currently supported B<cmd> names for configuration files (i.e. when the
+flag B<SSL_CONF_FLAG_FILE> is set) are listed below. All configuration file
+B<cmd> names and are case insensitive so B<signaturealgorithms> is recognised
+as well as B<SignatureAlgorithms>. Unless otherwise stated the B<value> names
+are also case insensitive.
+
+Note: the command prefix (if set) alters the recognised B<cmd> values.
+
+=over 4
+
+=item B<CipherString>
+
+Sets the cipher suite list to B<value>. Note: syntax checking of B<value> is
+currently not performed unless an B<SSL> or B<SSL_CTX> structure is 
+associated with B<cctx>.
+
+=item B<Certificate>
+
+Attempts to use the file B<value> as the certificate for the appropriate
+context. It currently uses SSL_CTX_use_certificate_chain_file() if an B<SSL_CTX>
+structure is set or SSL_use_certificate_file() with filetype PEM if an B<SSL>
+structure is set. This option is only supported if certificate operations
+are permitted.
+
+=item B<PrivateKey>
+
+Attempts to use the file B<value> as the private key for the appropriate
+context. This option is only supported if certificate operations
+are permitted. Note: if no B<-key> option is set then a private key is
+not loaded: it does not currently use the B<Certificate> file.
+
+=item B<ServerInfoFile>
+
+Attempts to use the file B<value> in the "serverinfo" extension using the
+function SSL_CTX_use_serverinfo_file.
+
+=item B<DHParameters>
+
+Attempts to use the file B<value> as the set of temporary DH parameters for
+the appropriate context. This option is only supported if certificate
+operations are permitted.
+
+=item B<SignatureAlgorithms>
+
+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<ClientSignatureAlgorithms>
+
+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.
+
+The syntax of B<value> is identical to B<SignatureAlgorithms>. If not set then
+the value set for B<SignatureAlgorithms> will be used instead.
+
+=item B<Curves>
+
+This sets the supported elliptic curves. For clients the curves are
+sent using the supported curves extension. For servers 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<ECDHParameters>
+
+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
+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<Protocol>
+
+The supported versions of the SSL or TLS protocol.
+
+The B<value> argument is a comma separated list of supported protocols to
+enable or disable. If an protocol is preceded by B<-> that version is disabled.
+All versions are enabled by default, though applications may choose to
+explicitly disable some. Currently supported protocol values are B<SSLv2>,
+B<SSLv3>, B<TLSv1>, B<TLSv1.1> and B<TLSv1.2>. The special value B<ALL> refers
+to all supported versions.
+
+=item B<Options>
+
+The B<value> argument is a comma separated list of various flags to set.
+If a flag string is preceded B<-> it is disabled. See the
+B<SSL_CTX_set_options> function for more details of individual options.
+
+Each option is listed below. Where an operation is enabled by default
+the B<-flag> syntax is needed to disable it.
+
+B<SessionTicket>: session ticket support, enabled by default. Inverse of
+B<SSL_OP_NO_TICKET>: that is B<-SessionTicket> is the same as setting
+B<SSL_OP_NO_TICKET>.
+
+B<Compression>: SSL/TLS compression support, enabled by default. Inverse
+of B<SSL_OP_NO_COMPRESSION>.
+
+B<EmptyFragments>: use empty fragments as a countermeasure against a
+SSL 3.0/TLS 1.0 protocol vulnerability affecting CBC ciphers. It
+is set by default. Inverse of B<SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS>.
+
+B<Bugs>: enable various bug workarounds. Same as B<SSL_OP_ALL>.
+
+B<DHSingle>: enable single use DH keys, set by default. Inverse of
+B<SSL_OP_DH_SINGLE>. Only used by servers.
+
+B<ECDHSingle> enable single use ECDH keys, set by default. Inverse of
+B<SSL_OP_ECDH_SINGLE>. Only used by servers.
+
+B<ServerPreference> 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.
+
+B<NoResumptionOnRenegotiation> set
+B<SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION> flag. Only used by servers.
+
+B<UnsafeLegacyRenegotiation> permits the use of unsafe legacy renegotiation.
+Equivalent to B<SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION>.
+
+B<UnsafeLegacyServerConnect> permits the use of unsafe legacy renegotiation
+for OpenSSL clients only. Equivalent to B<SSL_OP_LEGACY_SERVER_CONNECT>.
+Set by default.
+
+=back
+
+=head1 SUPPORTED COMMAND TYPES
+
+The function SSL_CONF_cmd_value_type() currently returns one of the following
+types:
+
+=over 4
+
+=item B<SSL_CONF_TYPE_UNKNOWN>
+
+The B<cmd> string is unrecognised, this return value can be use to flag
+syntax errors.
+
+=item B<SSL_CONF_TYPE_STRING>
+
+The value is a string without any specific structure.
+
+=item B<SSL_CONF_TYPE_FILE>
+
+The value is a file name.
+
+=item B<SSL_CONF_TYPE_DIR>
+
+The value is a directory name.
+
+=back
+
+=head1 NOTES
+
+The order of operations is significant. This can be used to set either defaults
+or values which cannot be overridden. For example if an application calls:
+
+ SSL_CONF_cmd(ctx, "Protocol", "-SSLv2");
+ SSL_CONF_cmd(ctx, userparam, uservalue);
+
+it will disable SSLv2 support by default but the user can override it. If 
+however the call sequence is:
+
+ SSL_CONF_cmd(ctx, userparam, uservalue);
+ SSL_CONF_cmd(ctx, "Protocol", "-SSLv2");
+
+SSLv2 is B<always> disabled and attempt to override this by the user are
+ignored.
+
+By checking the return code of SSL_CTX_cmd() it is possible to query if a
+given B<cmd> is recognised, this is useful is SSL_CTX_cmd() values are
+mixed with additional application specific operations.
+
+For example an application might call SSL_CTX_cmd() and if it returns
+-2 (unrecognised command) continue with processing of application specific
+commands.
+
+Applications can also use SSL_CTX_cmd() to process command lines though the
+utility function SSL_CTX_cmd_argv() is normally used instead. One way
+to do this is to set the prefix to an appropriate value using
+SSL_CONF_CTX_set1_prefix(), pass the current argument to B<cmd> and the
+following argument to B<value> (which may be NULL).
+
+In this case if the return value is positive then it is used to skip that
+number of arguments as they have been processed by SSL_CTX_cmd(). If -2 is
+returned then B<cmd> is not recognised and application specific arguments
+can be checked instead. If -3 is returned a required argument is missing
+and an error is indicated. If 0 is returned some other error occurred and
+this can be reported back to the user.
+
+The function SSL_CONF_cmd_value_type() can be used by applications to 
+check for the existence of a command or to perform additional syntax
+checking or translation of the command value. For example if the return
+value is B<SSL_CONF_TYPE_FILE> an application could translate a relative
+pathname to an absolute pathname.
+
+=head1 EXAMPLES
+
+Set supported signature algorithms:
+
+ SSL_CONF_cmd(ctx, "SignatureAlgorithms", "ECDSA+SHA256:RSA+SHA256:DSA+SHA256");
+
+Enable all protocols except SSLv3 and SSLv2:
+
+ SSL_CONF_cmd(ctx, "Protocol", "ALL,-SSLv3,-SSLv2");
+
+Only enable TLSv1.2:
+
+ SSL_CONF_cmd(ctx, "Protocol", "-ALL,TLSv1.2");
+
+Disable TLS session tickets:
+
+ SSL_CONF_cmd(ctx, "Options", "-SessionTicket");
+
+Set supported curves to P-256, P-384:
+
+ SSL_CONF_cmd(ctx, "Curves", "P-256:P-384");
+
+Set automatic support for any elliptic curve for key exchange:
+
+ SSL_CONF_cmd(ctx, "ECDHParameters", "Automatic");
+
+=head1 RETURN VALUES
+
+SSL_CONF_cmd() returns 1 if the value of B<cmd> is recognised and B<value> is
+B<NOT> used and 2 if both B<cmd> and B<value> are used. In other words it
+returns the number of arguments processed. This is useful when processing
+command lines.
+
+A return value of -2 means B<cmd> is not recognised.
+
+A return value of -3 means B<cmd> is recognised and the command requires a
+value but B<value> is NULL.
+
+A return code of 0 indicates that both B<cmd> and B<value> are valid but an
+error occurred attempting to perform the operation: for example due to an
+error in the syntax of B<value> in this case the error queue may provide
+additional information.
+
+SSL_CONF_finish() returns 1 for success and 0 for failure.
+
+=head1 SEE ALSO
+
+L<SSL_CONF_CTX_new(3)|SSL_CONF_CTX_new(3)>,
+L<SSL_CONF_CTX_set_flags(3)|SSL_CONF_CTX_set_flags(3)>,
+L<SSL_CONF_CTX_set1_prefix(3)|SSL_CONF_CTX_set1_prefix(3)>,
+L<SSL_CONF_CTX_set_ssl_ctx(3)|SSL_CONF_CTX_set_ssl_ctx(3)>,
+L<SSL_CONF_cmd_argv(3)|SSL_CONF_cmd_argv(3)>
+
+=head1 HISTORY
+
+SSL_CONF_cmd() was first added to OpenSSL 1.0.2
+
+=cut