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CONFIG(5)			    OpenSSL			     CONFIG(5)

       config -	OpenSSL	CONF library configuration files

       The OpenSSL CONF	library	can be used to read configuration files.  It
       is used for the OpenSSL master configuration file openssl.cnf and in a
       few other places	like SPKAC files and certificate extension files for
       the x509	utility. OpenSSL applications can also use the CONF library
       for their own purposes.

       A configuration file is divided into a number of	sections. Each section
       starts with a line [ section_name ] and ends when a new section is
       started or end of file is reached. A section name can consist of
       alphanumeric characters and underscores.

       The first section of a configuration file is special and	is referred to
       as the default section. This section is usually unnamed and spans from
       the start of file until the first named section.	When a name is being
       looked up it is first looked up in a named section (if any) and then
       the default section.

       The environment is mapped onto a	section	called ENV.

       Comments	can be included	by preceding them with the # character

       Other files can be included using the .include directive	followed by a
       path. If	the path points	to a directory all files with names ending
       with .cnf or .conf are included from the	directory.  Recursive
       inclusion of directories	from files in such directory is	not supported.
       That means the files in the included directory can also contain
       .include	directives but only inclusion of regular files is supported
       there. The inclusion of directories is not supported on systems without
       POSIX IO	support.

       It is strongly recommended to use absolute paths	with the .include
       directive. Relative paths are evaluated based on	the application
       current working directory so unless the configuration file containing
       the .include directive is application specific the inclusion will not
       work as expected.

       There can be optional = character and whitespace	characters between
       .include	directive and the path which can be useful in cases the
       configuration file needs	to be loaded by	old OpenSSL versions which do
       not support the .include	syntax.	They would bail	out with error if the
       = character is not present but with it they just	ignore the include.

       Each section in a configuration file consists of	a number of name and
       value pairs of the form name=value

       The name	string can contain any alphanumeric characters as well as a
       few punctuation symbols such as . , ; and _.

       The value string	consists of the	string following the = character until
       end of line with	any leading and	trailing white space removed.

       The value string	undergoes variable expansion. This can be done by
       including the form $var or ${var}: this will substitute the value of
       the named variable in the current section. It is	also possible to
       substitute a value from another section using the syntax	$section::name
       or ${section::name}. By using the form $ENV::name environment variables
       can be substituted. It is also possible to assign values	to environment
       variables by using the name ENV::name, this will	work if	the program
       looks up	environment variables using the	CONF library instead of
       calling getenv()	directly. The value string must	not exceed 64k in
       length after variable expansion.	Otherwise an error will	occur.

       It is possible to escape	certain	characters by using any	kind of	quote
       or the \	character. By making the last character	of a line a \ a	value
       string can be spread across multiple lines. In addition the sequences
       \n, \r, \b and \t are recognized.

       All expansion and escape	rules as described above that apply to value
       also apply to the path of the .include directive.

       Applications can	automatically configure	certain	aspects	of OpenSSL
       using the master	OpenSSL	configuration file, or optionally an
       alternative configuration file. The openssl utility includes this
       functionality: any sub command uses the master OpenSSL configuration
       file unless an option is	used in	the sub	command	to use an alternative
       configuration file.

       To enable library configuration the default section needs to contain an
       appropriate line	which points to	the main configuration section.	The
       default name is openssl_conf which is used by the openssl utility.
       Other applications may use an alternative name such as
       myapplication_conf.  All	library	configuration lines appear in the
       default section at the start of the configuration file.

       The configuration section should	consist	of a set of name value pairs
       which contain specific module configuration information.	The name
       represents the name of the configuration	module.	The meaning of the
       value is	module specific: it may, for example, represent	a further
       configuration section containing	configuration module specific
       information. E.g.:

	# This must be in the default section
	openssl_conf = openssl_init


	oid_section = new_oids
	engines	= engine_section


	... new	oids here ...


	... engine stuff here ...

       The features of each configuration module are described below.

   ASN1	Object Configuration Module
       This module has the name	oid_section. The value of this variable	points
       to a section containing name value pairs	of OIDs: the name is the OID
       short and long name, the	value is the numerical form of the OID.
       Although	some of	the openssl utility sub	commands already have their
       own ASN1	OBJECT section functionality not all do. By using the ASN1
       OBJECT configuration module all the openssl utility sub commands	can
       see the new objects as well as any compliant applications. For example:


	some_new_oid =
	some_other_oid =

       It is also possible to set the value to the long	name followed by a
       comma and the numerical OID form. For example:

	shortName = some object	long name,

   Engine Configuration	Module
       This ENGINE configuration module	has the	name engines. The value	of
       this variable points to a section containing further ENGINE
       configuration information.

       The section pointed to by engines is a table of engine names (though
       see engine_id below) and	further	sections containing configuration
       information specific to each ENGINE.

       Each ENGINE specific section is used to set default algorithms, load
       dynamic,	perform	initialization and send	ctrls. The actual operation
       performed depends on the	command	name which is the name of the name
       value pair. The currently supported commands are	listed below.

       For example:


	# Configure ENGINE named "foo"
	foo = foo_section
	# Configure ENGINE named "bar"
	bar = bar_section

	... foo	ENGINE specific	commands ...

	... "bar" ENGINE specific commands ...

       The command engine_id is	used to	give the ENGINE	name. If used this
       command must be first. For example:

	# This would normally handle an	ENGINE named "foo"
	foo = foo_section

	# Override default name	and use	"myfoo"	instead.
	engine_id = myfoo

       The command dynamic_path	loads and adds an ENGINE from the given	path.
       It is equivalent	to sending the ctrls SO_PATH with the path argument
       followed	by LIST_ADD with value 2 and LOAD to the dynamic ENGINE. If
       this is not the required	behaviour then alternative ctrls can be	sent
       directly	to the dynamic ENGINE using ctrl commands.

       The command init	determines whether to initialize the ENGINE. If	the
       value is	0 the ENGINE will not be initialized, if 1 and attempt it made
       to initialized the ENGINE immediately. If the init command is not
       present then an attempt will be made to initialize the ENGINE after all
       commands	in its section have been processed.

       The command default_algorithms sets the default algorithms an ENGINE
       will supply using the functions ENGINE_set_default_string().

       If the name matches none	of the above command names it is assumed to be
       a ctrl command which is sent to the ENGINE. The value of	the command is
       the argument to the ctrl	command. If the	value is the string EMPTY then
       no value	is sent	to the command.

       For example:


	# Configure ENGINE named "foo"
	foo = foo_section

	# Load engine from DSO
	dynamic_path = /some/path/
	# A foo	specific ctrl.
	some_ctrl = some_value
	# Another ctrl that doesn't take a value.
	other_ctrl = EMPTY
	# Supply all default algorithms
	default_algorithms = ALL

   EVP Configuration Module
       This modules has	the name alg_section which points to a section
       containing algorithm commands.

       Currently the only algorithm command supported is fips_mode whose value
       can only	be the boolean string off. If fips_mode	is set to on, an error
       occurs as this library version is not FIPS capable.

   SSL Configuration Module
       This module has the name	ssl_conf which points to a section containing
       SSL configurations.

       Each line in the	SSL configuration section contains the name of the
       configuration and the section containing	it.

       Each configuration section consists of command value pairs for
       SSL_CONF.  Each pair will be passed to a	SSL_CTX	or SSL structure if it
       calls SSL_CTX_config() or SSL_config() with the appropriate
       configuration name.

       Note: any characters before an initial dot in the configuration section
       are ignored so the same command can be used multiple times.

       For example:

	ssl_conf = ssl_sect


	server = server_section


	RSA.Certificate	= server-rsa.pem
	ECDSA.Certificate = server-ecdsa.pem
	Ciphers	= ALL:!RC4

       The system default configuration	with name system_default if present
       will be applied during any creation of the SSL_CTX structure.

       Example of a configuration with the system default:

	ssl_conf = ssl_sect

	system_default = system_default_sect

	MinProtocol = TLSv1.2
	MinProtocol = DTLSv1.2

       If a configuration file attempts	to expand a variable that doesn't
       exist then an error is flagged and the file will	not load. This can
       happen if an attempt is made to expand an environment variable that
       doesn't exist. For example in a previous	version	of OpenSSL the default
       OpenSSL master configuration file used the value	of HOME	which may not
       be defined on non Unix systems and would	cause an error.

       This can	be worked around by including a	default	section	to provide a
       default value: then if the environment lookup fails the default value
       will be used instead. For this to work properly the default value must
       be defined earlier in the configuration file than the expansion.	See
       the EXAMPLES section for	an example of how to do	this.

       If the same variable exists in the same section then all	but the	last
       value will be silently ignored. In certain circumstances	such as	with
       DNs the same field may occur multiple times. This is usually worked
       around by ignoring any characters before	an initial . e.g.

	1.OU="My first OU"
	2.OU="My Second	OU"

       Here is a sample	configuration file using some of the features
       mentioned above.

	# This is the default section.


	[ section_one ]

	# We are now in	section	one.

	# Quotes permit	leading	and trailing whitespace
	any = "	any variable name "

	other =	A string that can \
	cover several lines \
	by including \\	characters

	message	= Hello	World\n

	[ section_two ]

	greeting = $section_one::message

       This next example shows how to expand environment variables safely.

       Suppose you want	a variable called tmpfile to refer to a	temporary
       filename. The directory it is placed in can determined by the TEMP or
       TMP environment variables but they may not be set to any	value at all.
       If you just include the environment variable names and the variable
       doesn't exist then this will cause an error when	an attempt is made to
       load the	configuration file. By making use of the default section both
       values can be looked up with TEMP taking	priority and /tmp used if
       neither is defined:

	# The above value is used if TMP isn't in the environment
	# The above value is used if TEMP isn't	in the environment

       Simple OpenSSL library configuration example to enter FIPS mode:

	# Default appname: should match	"appname" parameter (if	any)
	# supplied to CONF_modules_load_file et	al.
	openssl_conf = openssl_conf_section

	# Configuration	module list
	alg_section = evp_sect

	# Set to "yes" to enter	FIPS mode if supported
	fips_mode = yes

       Note: in	the above example you will get an error	in non FIPS capable
       versions	of OpenSSL.

       Simple OpenSSL library configuration to make TLS	1.2 and	DTLS 1.2 the
       system-default minimum TLS and DTLS versions, respectively:

	# Toplevel section for openssl (including libssl)
	openssl_conf = default_conf_section

	# We only specify configuration	for the	"ssl module"
	ssl_conf = ssl_section

	system_default = system_default_section

	MinProtocol = TLSv1.2
	MinProtocol = DTLSv1.2

       The minimum TLS protocol	is applied to SSL_CTX objects that are TLS-
       based, and the minimum DTLS protocol to those are DTLS-based.  The same
       applies also to maximum versions	set with MaxProtocol.

       More complex OpenSSL library configuration. Add OID and don't enter
       FIPS mode:

	# Default appname: should match	"appname" parameter (if	any)
	# supplied to CONF_modules_load_file et	al.
	openssl_conf = openssl_conf_section

	# Configuration	module list
	alg_section = evp_sect
	oid_section = new_oids

	# This will have no effect as FIPS mode	is off by default.
	# Set to "yes" to enter	FIPS mode, if supported
	fips_mode = no

	# New OID, just	short name
	newoid1	=
	# New OID shortname and	long name
	newoid2	= New OID 2 long name,

       The above examples can be used with any application supporting library
       configuration if	"openssl_conf" is modified to match the	appropriate

       For example if the second sample	file above is saved to "example.cnf"
       then the	command	line:

	OPENSSL_CONF=example.cnf openssl asn1parse -genstr OID:

       will output:

	   0:d=0  hl=2 l=   4 prim: OBJECT	      :newoid1

       showing that the	OID "newoid1" has been added as	"".

	   The path to the config file.	 Ignored in set-user-ID	and set-group-
	   ID programs.

	   The path to the engines directory.  Ignored in set-user-ID and set-
	   group-ID programs.

       Currently there is no way to include characters using the octal \nnn
       form. Strings are all null terminated so	nulls cannot form part of the

       The escaping isn't quite	right: if you want to use sequences like \n
       you can't use any quote escaping	on the same line.

       Files are loaded	in a single pass. This means that a variable expansion
       will only work if the variables referenced are defined earlier in the

       x509(1),	req(1),	ca(1)

       Copyright 2000-2020 The OpenSSL Project Authors.	All Rights Reserved.

       Licensed	under the OpenSSL license (the "License").  You	may not	use
       this file except	in compliance with the License.	 You can obtain	a copy
       in the file LICENSE in the source distribution or at

1.1.1n				  2022-03-15			     CONFIG(5)


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