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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 is usually unnamed and is 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

       The environment is mapped onto a	section	called ENV.

       Comments	can be included	by preceding them with the # character

       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.

       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.

       In OpenSSL 0.9.7	and later 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

       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.

	openssl_conf = openssl_init


	oid_section = new_oids
	engines	= engine_section


	... new	oids here ...


	... engine stuff here ...

       Currently there are two configuration modules. One for ASN1 objects
       another for ENGINE configuration.

       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 =

       In OpenSSL 0.9.8	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,

       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

       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 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

       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 an variable
       expansion will only work	if the variables referenced are	defined
       earlier in the file.

       openssl_x509(1),	openssl_req(1),	openssl_ca(1)

1.0.1i				  2014-04-08			     CONFIG(5)


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