1.\" $OpenBSD: openssl.cnf.5,v 1.5 2019/01/02 07:42:21 jmc Exp $ 2.\" full merge up to: OpenSSL man5/config b53338cb Feb 28 12:30:28 2017 +0100 3.\" selective merge up to: OpenSSL a8c5ed81 Jul 18 13:57:25 2017 -0400 4.\" 5.\" This file was written by Dr. Stephen Henson <steve@openssl.org>. 6.\" Copyright (c) 1999, 2000, 2004, 2013, 2015, 2016, 2017 The OpenSSL Project. 7.\" All rights reserved. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 16.\" 2. Redistributions in binary form must reproduce the above copyright 17.\" notice, this list of conditions and the following disclaimer in 18.\" the documentation and/or other materials provided with the 19.\" distribution. 20.\" 21.\" 3. All advertising materials mentioning features or use of this 22.\" software must display the following acknowledgment: 23.\" "This product includes software developed by the OpenSSL Project 24.\" for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 25.\" 26.\" 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 27.\" endorse or promote products derived from this software without 28.\" prior written permission. For written permission, please contact 29.\" openssl-core@openssl.org. 30.\" 31.\" 5. Products derived from this software may not be called "OpenSSL" 32.\" nor may "OpenSSL" appear in their names without prior written 33.\" permission of the OpenSSL Project. 34.\" 35.\" 6. Redistributions of any form whatsoever must retain the following 36.\" acknowledgment: 37.\" "This product includes software developed by the OpenSSL Project 38.\" for use in the OpenSSL Toolkit (http://www.openssl.org/)" 39.\" 40.\" THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 41.\" EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 43.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 44.\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 45.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 46.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 47.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 49.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 50.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 51.\" OF THE POSSIBILITY OF SUCH DAMAGE. 52.\" 53.Dd $Mdocdate: January 2 2019 $ 54.Dt OPENSSL.CNF 5 55.Os 56.Sh NAME 57.Nm openssl.cnf 58.Nd OpenSSL configuration files 59.Sh DESCRIPTION 60The OpenSSL CONF library can be used to read configuration files; see 61.Xr CONF_modules_load_file 3 . 62It is used for the OpenSSL master configuration file 63.Pa /etc/ssl/openssl.cnf 64and in a few other places like 65.Sy SPKAC 66files and certificate extension files for the 67.Xr openssl 1 68.Cm x509 69utility. 70OpenSSL applications can also use the CONF library for their own 71purposes. 72.Pp 73A configuration file is divided into a number of sections. 74Each section starts with a line 75.Bq Ar section_name 76and ends when a new section is started or the end of the file is reached. 77A section name can consist of alphanumeric characters and underscores. 78.Pp 79The first section of a configuration file is special and is referred to 80as the 81.Dq default section . 82It is usually unnamed and extends from the start of file to the 83first named section. 84When a name is being looked up, it is first looked up in a named 85section (if any) and then in the default section. 86.Pp 87The environment is mapped onto a section called 88.Ic ENV . 89.Pp 90Comments can be included by preceding them with the 91.Ql # 92character. 93.Pp 94Each section in a configuration file consists of a number of name and 95value pairs of the form 96.Ar name Ns = Ns Ar value . 97.Pp 98The 99.Ar name 100string can contain any alphanumeric characters as well as a few 101punctuation symbols such as 102.Ql \&. 103.Ql \&, 104.Ql \&; 105and 106.Ql _ . 107.Pp 108The 109.Ar value 110string consists of the string following the 111.Ql = 112character until the end of the line with any leading and trailing 113whitespace removed. 114.Pp 115The value string undergoes variable expansion. 116This can be done by including substrings of the form 117.Pf $ Ar name 118or 119.Pf $ Brq Ar name : 120this will substitute the value of the named variable in the current 121section. 122It is also possible to substitute a value from another section using the 123syntax 124.Pf $ Ar section Ns :: Ns Ar name 125or 126.Pf $ Brq Ar section Ns :: Ns Ar name . 127By using the form 128.Pf $ Ic ENV Ns :: Ns Ar name , 129environment variables can be substituted. 130It is also possible to assign values to environment variables by using 131the name 132.Ic ENV Ns :: Ns Ar name . 133This will work if the program looks up environment variables using 134the CONF library instead of calling 135.Xr getenv 3 136directly. 137.Pp 138It is possible to escape certain characters by using any kind of quote 139or the 140.Ql \e 141character. 142By making the last character of a line a 143.Ql \e , 144a 145.Ar value 146string can be spread across multiple lines. 147In addition the sequences 148.Ql \en , 149.Ql \er , 150.Ql \eb , 151and 152.Ql \et 153are recognized. 154.Sh OPENSSL LIBRARY CONFIGURATION 155Applications can automatically configure certain aspects of OpenSSL 156using the master OpenSSL configuration file, or optionally an 157alternative configuration file. 158The 159.Xr openssl 1 160utility includes this functionality: any sub command uses the master 161OpenSSL configuration file unless an option is used in the sub command 162to use an alternative configuration file. 163.Pp 164To enable library configuration, the default section needs to contain 165an appropriate line which points to the main configuration section. 166The default name is 167.Ic openssl_conf , 168which is used by the 169.Xr openssl 1 170utility. 171Other applications may use an alternative name such as 172.Sy myapplication_conf . 173All library configuration lines appear in the default section 174at the start of the configuration file. 175.Pp 176The configuration section should consist of a set of name value pairs 177which contain specific module configuration information. 178The 179.Ar name 180represents the name of the configuration module. 181The meaning of the 182.Ar value 183is module specific: it may, for example, represent a further 184configuration section containing configuration module specific 185information. 186For example: 187.Bd -literal -offset indent 188# The following line must be in the default section. 189openssl_conf = openssl_init 190 191[openssl_init] 192oid_section = new_oids 193engines = engine_section 194 195[new_oids] 196\&... new oids here ... 197 198[engine_section] 199\&... engine stuff here ... 200.Ed 201.Pp 202The features of each configuration module are described below. 203.Ss ASN1 Object Configuration Module 204This module has the name 205.Ic oid_section . 206The value of this variable points to a section containing name value 207pairs of OIDs: the name is the OID short and long name, and the value is the 208numerical form of the OID. 209Although some of the 210.Xr openssl 1 211utility subcommands already have their own ASN1 OBJECT section 212functionality, not all do. 213By using the ASN1 OBJECT configuration module, all the 214.Xr openssl 1 215utility subcommands can see the new objects as well as any compliant 216applications. 217For example: 218.Bd -literal -offset indent 219[new_oids] 220some_new_oid = 1.2.3.4 221some_other_oid = 1.2.3.5 222.Ed 223.Pp 224It is also possible to set the value to the long name followed by a 225comma and the numerical OID form. 226For example: 227.Pp 228.Dl shortName = some object long name, 1.2.3.4 229.Ss Engine Configuration Module 230This ENGINE configuration module has the name 231.Ic engines . 232The value of this variable points to a section containing further ENGINE 233configuration information. 234.Pp 235The section pointed to by 236.Ic engines 237is a table of engine names (though see 238.Ic engine_id 239below) and further sections containing configuration information 240specific to each ENGINE. 241.Pp 242Each ENGINE specific section is used to set default algorithms, load 243dynamic ENGINEs, perform initialization and send ctrls. 244The actual operation performed depends on the command 245name which is the name of the name value pair. 246The currently supported commands are listed below. 247.Pp 248For example: 249.Bd -literal -offset indent 250[engine_section] 251# Configure ENGINE named "foo" 252foo = foo_section 253# Configure ENGINE named "bar" 254bar = bar_section 255 256[foo_section] 257\&... foo ENGINE specific commands ... 258 259[bar_section] 260\&... "bar" ENGINE specific commands ... 261.Ed 262.Pp 263The command 264.Ic engine_id 265is used to give the ENGINE name. 266If used this command must be first. 267For example: 268.Bd -literal -offset indent 269[engine_section] 270# This would normally handle an ENGINE named "foo" 271foo = foo_section 272 273[foo_section] 274# Override default name and use "myfoo" instead. 275engine_id = myfoo 276.Ed 277.Pp 278The command 279.Ic dynamic_path 280loads and adds an ENGINE from the given path. 281It is equivalent to sending the ctrls 282.Sy SO_PATH 283with the path argument followed by 284.Sy LIST_ADD 285with value 2 and 286.Sy LOAD 287to the dynamic ENGINE. 288If this is not the required behaviour then alternative ctrls can be sent 289directly to the dynamic ENGINE using ctrl commands. 290.Pp 291The command 292.Ic init 293determines whether to initialize the ENGINE. 294If the value is 0, the ENGINE will not be initialized. 295If it is 1, an attempt is made to initialized the ENGINE immediately. 296If the 297.Ic init 298command is not present, then an attempt will be made to initialize 299the ENGINE after all commands in its section have been processed. 300.Pp 301The command 302.Ic default_algorithms 303sets the default algorithms an ENGINE will supply using the functions 304.Xr ENGINE_set_default_string 3 . 305.Pp 306If the name matches none of the above command names it is assumed 307to be a ctrl command which is sent to the ENGINE. 308The value of the command is the argument to the ctrl command. 309If the value is the string 310.Cm EMPTY , 311then no value is sent to the command. 312.Pp 313For example: 314.Bd -literal -offset indent 315[engine_section] 316# Configure ENGINE named "foo" 317foo = foo_section 318 319[foo_section] 320# Load engine from DSO 321dynamic_path = /some/path/fooengine.so 322# A foo specific ctrl. 323some_ctrl = some_value 324# Another ctrl that doesn't take a value. 325other_ctrl = EMPTY 326# Supply all default algorithms 327default_algorithms = ALL 328.Ed 329.Sh FILES 330.Bl -tag -width /etc/ssl/openssl.cnf -compact 331.It Pa /etc/ssl/openssl.cnf 332standard configuration file 333.El 334.Sh EXAMPLES 335Here is a sample configuration file using some of the features 336mentioned above: 337.Bd -literal -offset indent 338# This is the default section. 339HOME=/temp 340RANDFILE= ${ENV::HOME}/.rnd 341configdir=$ENV::HOME/config 342 343[ section_one ] 344# We are now in section one. 345 346# Quotes permit leading and trailing whitespace 347any = " any variable name " 348 349other = A string that can \e 350cover several lines \e 351by including \e\e characters 352 353message = Hello World\en 354 355[ section_two ] 356greeting = $section_one::message 357.Ed 358.Pp 359This next example shows how to expand environment variables safely. 360.Pp 361Suppose you want a variable called 362.Sy tmpfile 363to refer to a temporary filename. 364The directory it is placed in can determined by the 365.Ev TEMP 366or 367.Ev TMP 368environment variables but they may not be set to any value at all. 369If you just include the environment variable names and the variable 370doesn't exist then this will cause an error when an attempt is made to 371load the configuration file. 372By making use of the default section both values can be looked up with 373.Ev TEMP 374taking priority and 375.Pa /tmp 376used if neither is defined: 377.Bd -literal -offset indent 378TMP=/tmp 379# The above value is used if TMP isn't in the environment 380TEMP=$ENV::TMP 381# The above value is used if TEMP isn't in the environment 382tmpfile=${ENV::TEMP}/tmp.filename 383.Ed 384.Pp 385More complex OpenSSL library configuration. 386Add OID: 387.Bd -literal -offset indent 388# Default appname: should match "appname" parameter (if any) 389# supplied to CONF_modules_load_file et al. 390openssl_conf = openssl_conf_section 391 392[openssl_conf_section] 393# Configuration module list 394alg_section = evp_sect 395oid_section = new_oids 396 397[new_oids] 398# New OID, just short name 399newoid1 = 1.2.3.4.1 400# New OID shortname and long name 401newoid2 = New OID 2 long name, 1.2.3.4.2 402.Ed 403.Pp 404The above examples can be used with any application supporting library 405configuration if "openssl_conf" is modified to match the appropriate 406"appname". 407.Pp 408For example if the second sample file above is saved to "example.cnf" 409then the command line: 410.Pp 411.Dl OPENSSL_CONF=example.cnf openssl asn1parse -genstr OID:1.2.3.4.1 412.Pp 413will output: 414.Dl 0:d=0 hl=2 l= 4 prim: OBJECT :newoid1 415.Pp 416showing that the OID "newoid1" has been added as "1.2.3.4.1". 417.Sh SEE ALSO 418.Xr openssl 1 , 419.Xr CONF_modules_load_file 3 , 420.Xr x509v3.cnf 5 421.Sh CAVEATS 422If a configuration file attempts to expand a variable that doesn't 423exist, then an error is flagged and the file will not load. 424This can also happen if an attempt is made to expand an environment 425variable that doesn't exist. 426For example, in a previous version of OpenSSL the default OpenSSL 427master configuration file used the value of 428.Ev HOME 429which may not be defined on non Unix systems and would cause an error. 430.Pp 431This can be worked around by including a default section to provide 432a default value: then if the environment lookup fails, the default 433value will be used instead. 434For this to work properly, the default value must be defined earlier 435in the configuration file than the expansion. 436See the 437.Sx EXAMPLES 438section for an example of how to do this. 439.Pp 440If the same variable is defined more than once in the same section, 441then all but the last value will be silently ignored. 442In certain circumstances such as with DNs, the same field may occur 443multiple times. 444This is usually worked around by ignoring any characters before an 445initial 446.Ql \&. , 447for example: 448.Bd -literal -offset indent 4491.OU="My first OU" 4502.OU="My Second OU" 451.Ed 452.Sh BUGS 453Currently there is no way to include characters using the octal 454.Pf \e Ar nnn 455form. 456Strings are all NUL terminated, so NUL bytes cannot form part of 457the value. 458.Pp 459The escaping isn't quite right: if you want to use sequences like 460.Ql \en , 461you can't use any quote escaping on the same line. 462.Pp 463Files are loaded in a single pass. 464This means that a variable expansion will only work if the variables 465referenced are defined earlier in the file. 466