add SSL_CONF functions and documentation (backport from HEAD)

6 files changed, 584 insertions, 0 deletions

diff --git a/doc/ssl/SSL_CONF_CTX_new.pod b/doc/ssl/SSL_CONF_CTX_new.pod
new file mode 100644
index 0000000000..1ae4ac627e
--- /dev/null
+++ b/doc/ssl/SSL_CONF_CTX_new.pod
@@ -0,0 +1,40 @@
+=pod
+
+=head1 NAME
+
+SSL_CONF_CTX_new, SSL_CONF_CTX_free - SSL configuration allocation functions
+
+=head1 SYNOPSIS
+
+ #include <openssl/ssl.h>
+
+ SSL_CONF_CTX *SSL_CONF_CTX_new(void);
+ void SSL_CONF_CTX_free(SSL_CONF_CTX *cctx);
+
+=head1 DESCRIPTION
+
+The function SSL_CONF_CTX_new() allocates and initialises an B<SSL_CONF_CTX>
+structure for use with the SSL_CONF functions.
+
+The function SSL_CONF_CTX_free() frees up the context B<cctx>.
+
+=head1 RETURN VALUES
+
+SSL_CONF_CTX_new() returns either the newly allocated B<SSL_CONF_CTX> structure
+or B<NULL> if an error occurs.
+
+SSL_CONF_CTX_free() does not return a value.
+
+=head1 SEE ALSO
+
+L<SSL_CONF_CTX_set_flags(3)|SSL_CONF_CTX_set_flags(3)>,
+L<SSL_CONF_CTX_set_ssl_ctx(3)|SSL_CONF_CTX_set_ssl_ctx(3)>,
+L<SSL_CONF_CTX_set1_prefix(3)|SSL_CONF_CTX_set1_prefix(3)>,
+L<SSL_CONF_cmd(3)|SSL_CONF_cmd(3)>,
+L<SSL_CONF_cmd_argv(3)|SSL_CONF_cmd_argv(3)>
+
+=head1 HISTORY
+
+These functions were first added to OpenSSL 1.1.0
+
+=cut
diff --git a/doc/ssl/SSL_CONF_CTX_set1_prefix.pod b/doc/ssl/SSL_CONF_CTX_set1_prefix.pod
new file mode 100644
index 0000000000..3b165db89b
--- /dev/null
+++ b/doc/ssl/SSL_CONF_CTX_set1_prefix.pod
@@ -0,0 +1,49 @@
+=pod
+
+=head1 NAME
+
+SSL_CONF_CTX_set1_prefix - Set configuration context command prefix
+
+=head1 SYNOPSIS
+
+ #include <openssl/ssl.h>
+
+ unsigned int SSL_CONF_CTX_set1_prefix(SSL_CONF_CTX *cctx, const char *prefix);
+
+=head1 DESCRIPTION
+
+The function SSL_CONF_CTX_set1_prefix() sets the command prefix of B<cctx>
+to B<prefix>. If B<prefix> is B<NULL> it is restored to the default value.
+
+=head1 NOTES
+
+Command prefixes alter the commands recognised by subsequent SSL_CTX_cmd()
+calls. For example for files, if the prefix "SSL" is set then command names
+such as "SSLProtocol", "SSLOptions" etc. are recognised instead of "Protocol"
+and "Options". Similarly for command lines if the prefix is "--ssl-" then 
+"--ssl-no_tls1_2" is recognised instead of "-no_tls1_2".
+
+If the B<SSL_CONF_FLAG_CMDLINE> flag is set then prefix checks are case
+sensitive and "-" is the default. In the unlikely even an application
+explicitly wants to set no prefix it must be explicitly set to "".
+
+If the B<SSL_CONF_FLAG_FILE> flag is set then prefix checks are case
+insensitive and no prefix is the default.
+
+=head1 RETURN VALUES
+
+SSL_CONF_CTX_set1_prefix() 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_set_ssl_ctx(3)|SSL_CONF_CTX_set_ssl_ctx(3)>,
+L<SSL_CONF_cmd(3)|SSL_CONF_cmd(3)>,
+L<SSL_CONF_cmd_argv(3)|SSL_CONF_cmd_argv(3)>
+
+=head1 HISTORY
+
+These functions were first added to OpenSSL 1.1.0
+
+=cut
diff --git a/doc/ssl/SSL_CONF_CTX_set_flags.pod b/doc/ssl/SSL_CONF_CTX_set_flags.pod
new file mode 100644
index 0000000000..90d97e74f0
--- /dev/null
+++ b/doc/ssl/SSL_CONF_CTX_set_flags.pod
@@ -0,0 +1,64 @@
+=pod
+
+=head1 NAME
+
+SSL_CONF_CTX_set_flags, SSL_CONF_CTX_clear_flags - Set of clear SSL configuration context flags
+
+=head1 SYNOPSIS
+
+ #include <openssl/ssl.h>
+
+ unsigned int SSL_CONF_CTX_set_flags(SSL_CONF_CTX *cctx, unsigned int flags);
+ unsigned int SSL_CONF_CTX_clear_flags(SSL_CONF_CTX *cctx, unsigned int flags);
+
+=head1 DESCRIPTION
+
+The function SSL_CONF_CTX_set_flags() sets B<flags> in the context B<cctx>.
+
+The function SSL_CONF_CTX_clear_flags() clears B<flags> in the context B<cctx>.
+
+=head1 NOTES
+
+The flags set affect how subsequent calls to SSL_CONF_cmd() or
+SSL_CONF_argv() behave.
+
+Currently the following B<flags> values are recognised:
+
+=over 4
+
+=item SSL_CONF_FLAG_CMDLINE, SSL_CONF_FLAG_FILE
+
+recognise options intended for command line or configuration file use. At
+least one of these flags must be set.
+
+=item SSL_CONF_FLAG_CLIENT, SSL_CONF_FLAG_SERVER
+
+recognise options intended for use in SSL/TLS clients or servers. One or
+both of these flags must be set.
+
+=item SSL_CONF_FLAG_SHOW_ERRORS
+
+indicate errors relating to unrecognised options or missing arguments in
+the error queue. If this option isn't set such errors are only reflected
+in the return values of SSL_CONF_set_cmd() or SSL_CONF_set_argv()
+
+=back
+
+=head1 RETURN VALUES
+
+SSL_CONF_CTX_set_flags() and SSL_CONF_CTX_clear_flags() returns the new flags
+value after setting or clearing flags.
+
+=head1 SEE ALSO
+
+L<SSL_CONF_CTX_new(3)|SSL_CONF_CTX_new(3)>,
+L<SSL_CONF_CTX_set_ssl_ctx(3)|SSL_CONF_CTX_set_ssl_ctx(3)>,
+L<SSL_CONF_CTX_set1_prefix(3)|SSL_CONF_CTX_set1_prefix(3)>,
+L<SSL_CONF_cmd(3)|SSL_CONF_cmd(3)>,
+L<SSL_CONF_cmd_argv(3)|SSL_CONF_cmd_argv(3)>
+
+=head1 HISTORY
+
+These functions were first added to OpenSSL 1.1.0
+
+=cut
diff --git a/doc/ssl/SSL_CONF_CTX_set_ssl_ctx.pod b/doc/ssl/SSL_CONF_CTX_set_ssl_ctx.pod
new file mode 100644
index 0000000000..cfb7cb2599
--- /dev/null
+++ b/doc/ssl/SSL_CONF_CTX_set_ssl_ctx.pod
@@ -0,0 +1,47 @@
+=pod
+
+=head1 NAME
+
+SSL_CONF_CTX_set_ssl_ctx, SSL_CONF_CTX_set_ssl - set context to configure
+
+=head1 SYNOPSIS
+
+ #include <openssl/ssl.h>
+
+ void SSL_CONF_CTX_set_ssl_ctx(SSL_CONF_CTX *cctx, SSL_CTX *ctx);
+ void SSL_CONF_CTX_set_ssl(SSL_CONF_CTX *cctx, SSL *ssl);
+
+=head1 DESCRIPTION
+
+SSL_CONF_CTX_set_ssl_ctx() sets the context associated with B<cctx> to the
+B<SSL_CTX> structure B<ctx>. Any previos B<SSL> or B<SSL_CTX> associated with
+B<cctx> is cleared. Subsequent calls to SSL_CONF_cmd() will be sent to
+B<ctx>.
+
+SSL_CONF_CTX_set_ssl() sets the context associated with B<cctx> to the
+B<SSL> structure B<ssl>. Any previos B<SSL> or B<SSL_CTX> associated with
+B<cctx> is cleared. Subsequent calls to SSL_CONF_cmd() will be sent to
+B<ssl>.
+
+=head1 NOTES
+
+The context need not be set or it can be set to B<NULL> in which case only
+syntax checking of commands is performed, where possible.
+
+=head1 RETURN VALUES
+
+SSL_CONF_CTX_set_ssl_ctx() and SSL_CTX_set_ssl() do not return a value.
+
+=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_cmd(3)|SSL_CONF_cmd(3)>,
+L<SSL_CONF_cmd_argv(3)|SSL_CONF_cmd_argv(3)>
+
+=head1 HISTORY
+
+These functions were first added to OpenSSL 1.1.0
+
+=cut
diff --git a/doc/ssl/SSL_CONF_cmd.pod b/doc/ssl/SSL_CONF_cmd.pod
new file mode 100644
index 0000000000..0fbf0d75df
--- /dev/null
+++ b/doc/ssl/SSL_CONF_cmd.pod
@@ -0,0 +1,342 @@
+=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);
+
+=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.
+
+=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 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<-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
+
+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<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<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 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.
+
+=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() return 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.
+
+=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 1.1.0
+
+=cut
diff --git a/doc/ssl/SSL_CONF_cmd_argv.pod b/doc/ssl/SSL_CONF_cmd_argv.pod
new file mode 100644
index 0000000000..8d495ba5cb
--- /dev/null
+++ b/doc/ssl/SSL_CONF_cmd_argv.pod
@@ -0,0 +1,42 @@
+=pod
+
+=head1 NAME
+
+SSL_CONF_cmd_argv - SSL configuration command line processing.
+
+=head1 SYNOPSIS
+
+ #include <openssl/ssl.h>
+
+ int SSL_CONF_cmd_argv(SSL_CONF_CTX *cctx, int *pargc, char ***pargv);
+
+=head1 DESCRIPTION
+
+The function SSL_CONF_cmd_argv() processes at most two command line
+arguments from B<pargv> and B<pargc>. The values of B<pargv> and B<pargc>
+are updated to reflect the number of command options procesed. The B<pargc>
+argument can be set to B<NULL> is it is not used.
+
+=head1 RETURN VALUES
+
+SSL_CONF_cmd_argv() returns the number of command arguments processed: 0, 1, 2
+2 or a negative error code.
+
+If -2 is returned then an argument for a command is missing.
+
+If -1 is returned the command is recognised but couldn't be processed due
+to an error: for example a syntax error in the argument.
+
+=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(3)|SSL_CONF_cmd(3)>
+
+=head1 HISTORY
+
+These functions were first added to OpenSSL 1.1.0
+
+=cut