6 req - PKCS#10 certificate request and certificate generating utility
32 [B<-keygen_engine id>]
41 [B<-extensions section>]
55 The B<req> command primarily creates and processes certificate requests
56 in PKCS#10 format. It can additionally create self signed certificates
57 for use as root CAs for example.
65 Print out a usage message.
67 =item B<-inform DER|PEM>
69 This specifies the input format. The B<DER> option uses an ASN1 DER encoded
70 form compatible with the PKCS#10. The B<PEM> form is the default format: it
71 consists of the B<DER> format base64 encoded with additional header and
74 =item B<-outform DER|PEM>
76 This specifies the output format, the options have the same meaning and default
77 as the B<-inform> option.
81 This specifies the input filename to read a request from or standard input
82 if this option is not specified. A request is only read if the creation
83 options (B<-new> and B<-newkey>) are not specified.
87 The input file password source. For more information about the format of B<arg>
88 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
90 =item B<-out filename>
92 This specifies the output filename to write to or standard output by
97 The output file password source. For more information about the format of B<arg>
98 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
102 Prints out the certificate request in text form.
106 Prints out the request subject (or certificate subject if B<-x509> is
111 Outputs the public key.
115 This option prevents output of the encoded version of the request.
119 This option prints out the value of the modulus of the public key
120 contained in the request.
124 Verifies the signature on the request.
128 This option generates a new certificate request. It will prompt
129 the user for the relevant field values. The actual fields
130 prompted for and their maximum and minimum sizes are specified
131 in the configuration file and any requested extensions.
133 If the B<-key> option is not used it will generate a new RSA private
134 key using information specified in the configuration file.
136 =item B<-rand file...>
138 A file or files containing random data used to seed the random number
140 Multiple files can be specified separated by an OS-dependent character.
141 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
144 =item [B<-writerand file>]
146 Writes random data to the specified I<file> upon exit.
147 This can be used with a subsequent B<-rand> flag.
151 This option creates a new certificate request and a new private
152 key. The argument takes one of several forms. B<rsa:nbits>, where
153 B<nbits> is the number of bits, generates an RSA key B<nbits>
154 in size. If B<nbits> is omitted, i.e. B<-newkey rsa> specified,
155 the default key size, specified in the configuration file is used.
157 All other algorithms support the B<-newkey alg:file> form, where file may be
158 an algorithm parameter file, created by the B<genpkey -genparam> command
159 or and X.509 certificate for a key with appropriate algorithm.
161 B<param:file> generates a key using the parameter file or certificate B<file>,
162 the algorithm is determined by the parameters. B<algname:file> use algorithm
163 B<algname> and parameter file B<file>: the two algorithms must match or an
164 error occurs. B<algname> just uses algorithm B<algname>, and parameters,
165 if necessary should be specified via B<-pkeyopt> parameter.
167 B<dsa:filename> generates a DSA key using the parameters
168 in the file B<filename>. B<ec:filename> generates EC key (usable both with
169 ECDSA or ECDH algorithms), B<gost2001:filename> generates GOST R
170 34.10-2001 key (requires B<ccgost> engine configured in the configuration
171 file). If just B<gost2001> is specified a parameter set should be
172 specified by B<-pkeyopt paramset:X>
175 =item B<-pkeyopt opt:value>
177 Set the public key algorithm option B<opt> to B<value>. The precise set of
178 options supported depends on the public key algorithm used and its
179 implementation. See B<KEY GENERATION OPTIONS> in the B<genpkey> manual page
182 =item B<-key filename>
184 This specifies the file to read the private key from. It also
185 accepts PKCS#8 format private keys for PEM format files.
187 =item B<-keyform PEM|DER>
189 The format of the private key file specified in the B<-key>
190 argument. PEM is the default.
192 =item B<-keyout filename>
194 This gives the filename to write the newly created private key to.
195 If this option is not specified then the filename present in the
196 configuration file is used.
200 If this option is specified then if a private key is created it
201 will not be encrypted.
205 This specifies the message digest to sign the request.
206 Any digest supported by the OpenSSL B<dgst> command can be used.
207 This overrides the digest algorithm specified in
208 the configuration file.
210 Some public key algorithms may override this choice. For instance, DSA
211 signatures always use SHA1, GOST R 34.10 signatures always use
212 GOST R 34.11-94 (B<-md_gost94>).
214 =item B<-config filename>
216 This allows an alternative configuration file to be specified.
217 Optional; for a description of the default value,
218 see L<openssl(1)/COMMAND SUMMARY>.
222 Sets subject name for new request or supersedes the subject name
223 when processing a request.
224 The arg must be formatted as I</type0=value0/type1=value1/type2=...>,
225 characters may be escaped by \ (backslash), no spaces are skipped.
227 =item B<-multivalue-rdn>
229 This option causes the -subj argument to be interpreted with full
230 support for multivalued RDNs. Example:
232 I</DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe>
234 If -multi-rdn is not used then the UID value is I<123456+CN=John Doe>.
238 This option outputs a self signed certificate instead of a certificate
239 request. This is typically used to generate a test certificate or
240 a self signed root CA. The extensions added to the certificate
241 (if any) are specified in the configuration file. Unless specified
242 using the B<set_serial> option, a large random number will be used for
245 If existing request is specified with the B<-in> option, it is converted
246 to the self signed certificate otherwise new request is created.
250 When the B<-x509> option is being used this specifies the number of
251 days to certify the certificate for, otherwise it is ignored. B<n> should
252 be a positive integer. The default is 30 days.
254 =item B<-set_serial n>
256 Serial number to use when outputting a self signed certificate. This
257 may be specified as a decimal value or a hex value if preceded by B<0x>.
261 Add a specific extension to the certificate (if the B<-x509> option is
262 present) or certificate request. The argument must have the form of
263 a key=value pair as it would appear in a config file.
265 This option can be given multiple times.
267 =item B<-extensions section>
269 =item B<-reqexts section>
271 These options specify alternative sections to include certificate
272 extensions (if the B<-x509> option is present) or certificate
273 request extensions. This allows several different sections to
274 be used in the same configuration file to specify requests for
275 a variety of purposes.
279 A poison extension will be added to the certificate, making it a
280 "pre-certificate" (see RFC6962). This can be submitted to Certificate
281 Transparency logs in order to obtain signed certificate timestamps (SCTs).
282 These SCTs can then be embedded into the pre-certificate as an extension, before
283 removing the poison and signing the certificate.
285 This implies the B<-new> flag.
289 This option causes field values to be interpreted as UTF8 strings, by
290 default they are interpreted as ASCII. This means that the field
291 values, whether prompted from a terminal or obtained from a
292 configuration file, must be valid UTF8 strings.
294 =item B<-nameopt option>
296 Option which determines how the subject or issuer names are displayed. The
297 B<option> argument can be a single option or multiple options separated by
298 commas. Alternatively the B<-nameopt> switch may be used more than once to
299 set multiple options. See the L<x509(1)> manual page for details.
303 Customise the output format used with B<-text>. The B<option> argument can be
304 a single option or multiple options separated by commas.
306 See discussion of the B<-certopt> parameter in the L<x509(1)>
311 Adds the word B<NEW> to the PEM file header and footer lines on the outputted
312 request. Some software (Netscape certificate server) and some CAs need this.
316 Non-interactive mode.
320 Print extra details about the operations being performed.
324 Specifying an engine (by its unique B<id> string) will cause B<req>
325 to attempt to obtain a functional reference to the specified engine,
326 thus initialising it if needed. The engine will then be set as the default
327 for all available algorithms.
329 =item B<-keygen_engine id>
331 Specifies an engine (by its unique B<id> string) which would be used
332 for key generation operations.
336 =head1 CONFIGURATION FILE FORMAT
338 The configuration options are specified in the B<req> section of
339 the configuration file. As with all configuration files if no
340 value is specified in the specific section (i.e. B<req>) then
341 the initial unnamed or B<default> section is searched too.
343 The options available are described in detail below.
347 =item B<input_password output_password>
349 The passwords for the input private key file (if present) and
350 the output private key file (if one will be created). The
351 command line options B<passin> and B<passout> override the
352 configuration file values.
354 =item B<default_bits>
356 Specifies the default key size in bits.
358 This option is used in conjunction with the B<-new> option to generate
359 a new key. It can be overridden by specifying an explicit key size in
360 the B<-newkey> option. The smallest accepted key size is 512 bits. If
361 no key size is specified then 2048 bits is used.
363 =item B<default_keyfile>
365 This is the default filename to write a private key to. If not
366 specified the key is written to standard output. This can be
367 overridden by the B<-keyout> option.
371 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
372 Each line of the file should consist of the numerical form of the
373 object identifier followed by white space then the short name followed
374 by white space and finally the long name.
378 This specifies a section in the configuration file containing extra
379 object identifiers. Each line should consist of the short name of the
380 object identifier followed by B<=> and the numerical form. The short
381 and long names are the same when this option is used.
385 At startup the specified file is loaded into the random number generator,
386 and at exit 256 bytes will be written to it.
387 It is used for private key generation.
391 If this is set to B<no> then if a private key is generated it is
392 B<not> encrypted. This is equivalent to the B<-nodes> command line
393 option. For compatibility B<encrypt_rsa_key> is an equivalent option.
397 This option specifies the digest algorithm to use.
398 Any digest supported by the OpenSSL B<dgst> command can be used.
399 If not present then MD5 is used.
400 This option can be overridden on the command line.
404 This option masks out the use of certain string types in certain
405 fields. Most users will not need to change this option.
407 It can be set to several values B<default> which is also the default
408 option uses PrintableStrings, T61Strings and BMPStrings if the
409 B<pkix> value is used then only PrintableStrings and BMPStrings will
410 be used. This follows the PKIX recommendation in RFC2459. If the
411 B<utf8only> option is used then only UTF8Strings will be used: this
412 is the PKIX recommendation in RFC2459 after 2003. Finally the B<nombstr>
413 option just uses PrintableStrings and T61Strings: certain software has
414 problems with BMPStrings and UTF8Strings: in particular Netscape.
416 =item B<req_extensions>
418 This specifies the configuration file section containing a list of
419 extensions to add to the certificate request. It can be overridden
420 by the B<-reqexts> command line switch. See the
421 L<x509v3_config(5)> manual page for details of the
422 extension section format.
424 =item B<x509_extensions>
426 This specifies the configuration file section containing a list of
427 extensions to add to certificate generated when the B<-x509> switch
428 is used. It can be overridden by the B<-extensions> command line switch.
432 If set to the value B<no> this disables prompting of certificate fields
433 and just takes values from the config file directly. It also changes the
434 expected format of the B<distinguished_name> and B<attributes> sections.
438 If set to the value B<yes> then field values to be interpreted as UTF8
439 strings, by default they are interpreted as ASCII. This means that
440 the field values, whether prompted from a terminal or obtained from a
441 configuration file, must be valid UTF8 strings.
445 This specifies the section containing any request attributes: its format
446 is the same as B<distinguished_name>. Typically these may contain the
447 challengePassword or unstructuredName types. They are currently ignored
448 by OpenSSL's request signing utilities but some CAs might want them.
450 =item B<distinguished_name>
452 This specifies the section containing the distinguished name fields to
453 prompt for when generating a certificate or certificate request. The format
454 is described in the next section.
458 =head1 DISTINGUISHED NAME AND ATTRIBUTE SECTION FORMAT
460 There are two separate formats for the distinguished name and attribute
461 sections. If the B<prompt> option is set to B<no> then these sections
462 just consist of field names and values: for example,
466 emailAddress=someone@somewhere.org
468 This allows external programs (e.g. GUI based) to generate a template file
469 with all the field names and values and just pass it to B<req>. An example
470 of this kind of configuration file is contained in the B<EXAMPLES> section.
472 Alternatively if the B<prompt> option is absent or not set to B<no> then the
473 file contains field prompting information. It consists of lines of the form:
476 fieldName_default="default field value"
480 "fieldName" is the field name being used, for example commonName (or CN).
481 The "prompt" string is used to ask the user to enter the relevant
482 details. If the user enters nothing then the default value is used if no
483 default value is present then the field is omitted. A field can
484 still be omitted if a default value is present if the user just
485 enters the '.' character.
487 The number of characters entered must be between the fieldName_min and
488 fieldName_max limits: there may be additional restrictions based
489 on the field being used (for example countryName can only ever be
490 two characters long and must fit in a PrintableString).
492 Some fields (such as organizationName) can be used more than once
493 in a DN. This presents a problem because configuration files will
494 not recognize the same name occurring twice. To avoid this problem
495 if the fieldName contains some characters followed by a full stop
496 they will be ignored. So for example a second organizationName can
497 be input by calling it "1.organizationName".
499 The actual permitted field names are any object identifier short or
500 long names. These are compiled into OpenSSL and include the usual
501 values such as commonName, countryName, localityName, organizationName,
502 organizationalUnitName, stateOrProvinceName. Additionally emailAddress
503 is include as well as name, surname, givenName initials and dnQualifier.
505 Additional object identifiers can be defined with the B<oid_file> or
506 B<oid_section> options in the configuration file. Any additional fields
507 will be treated as though they were a DirectoryString.
512 Examine and verify certificate request:
514 openssl req -in req.pem -text -verify -noout
516 Create a private key and then generate a certificate request from it:
518 openssl genrsa -out key.pem 2048
519 openssl req -new -key key.pem -out req.pem
521 The same but just using req:
523 openssl req -newkey rsa:2048 -keyout key.pem -out req.pem
525 Generate a self signed root certificate:
527 openssl req -x509 -newkey rsa:2048 -keyout key.pem -out req.pem
529 Example of a file pointed to by the B<oid_file> option:
531 1.2.3.4 shortName A longer Name
532 1.2.3.6 otherName Other longer Name
534 Example of a section pointed to by B<oid_section> making use of variable
538 testoid2=${testoid1}.6
540 Sample configuration file prompting for field values:
544 default_keyfile = privkey.pem
545 distinguished_name = req_distinguished_name
546 attributes = req_attributes
547 req_extensions = v3_ca
549 dirstring_type = nobmp
551 [ req_distinguished_name ]
552 countryName = Country Name (2 letter code)
553 countryName_default = AU
557 localityName = Locality Name (eg, city)
559 organizationalUnitName = Organizational Unit Name (eg, section)
561 commonName = Common Name (eg, YOUR name)
564 emailAddress = Email Address
565 emailAddress_max = 40
568 challengePassword = A challenge password
569 challengePassword_min = 4
570 challengePassword_max = 20
574 subjectKeyIdentifier=hash
575 authorityKeyIdentifier=keyid:always,issuer:always
576 basicConstraints = critical, CA:true
578 Sample configuration containing all field values:
581 RANDFILE = $ENV::HOME/.rnd
585 default_keyfile = keyfile.pem
586 distinguished_name = req_distinguished_name
587 attributes = req_attributes
589 output_password = mypass
591 [ req_distinguished_name ]
593 ST = Test State or Province
595 O = Organization Name
596 OU = Organizational Unit Name
598 emailAddress = test@email.address
601 challengePassword = A challenge password
603 Example of giving the most common attributes (subject and extensions)
606 openssl req -new -subj "/C=GB/CN=foo" \
607 -addext "subjectAltName = DNS:foo.co.uk" \
608 -addext "certificatePolicies = 1.2.3.4" \
609 -newkey rsa:2048 -keyout key.pem -out req.pem
614 The header and footer lines in the B<PEM> format are normally:
616 -----BEGIN CERTIFICATE REQUEST-----
617 -----END CERTIFICATE REQUEST-----
619 some software (some versions of Netscape certificate server) instead needs:
621 -----BEGIN NEW CERTIFICATE REQUEST-----
622 -----END NEW CERTIFICATE REQUEST-----
624 which is produced with the B<-newhdr> option but is otherwise compatible.
625 Either form is accepted transparently on input.
627 The certificate requests generated by B<Xenroll> with MSIE have extensions
628 added. It includes the B<keyUsage> extension which determines the type of
629 key (signature only or general purpose) and any additional OIDs entered
630 by the script in an extendedKeyUsage extension.
634 The following messages are frequently asked about:
636 Using configuration from /some/path/openssl.cnf
637 Unable to load config info
639 This is followed some time later by...
641 unable to find 'distinguished_name' in config
642 problems making Certificate Request
644 The first error message is the clue: it can't find the configuration
645 file! Certain operations (like examining a certificate request) don't
646 need a configuration file so its use isn't enforced. Generation of
647 certificates or requests however does need a configuration file. This
648 could be regarded as a bug.
650 Another puzzling message is this:
655 this is displayed when no attributes are present and the request includes
656 the correct empty B<SET OF> structure (the DER encoding of which is 0xa0
657 0x00). If you just see:
661 then the B<SET OF> is missing and the encoding is technically invalid (but
662 it is tolerated). See the description of the command line option B<-asn1-kludge>
663 for more information.
667 OpenSSL's handling of T61Strings (aka TeletexStrings) is broken: it effectively
668 treats them as ISO-8859-1 (Latin 1), Netscape and MSIE have similar behaviour.
669 This can cause problems if you need characters that aren't available in
670 PrintableStrings and you don't want to or can't use BMPStrings.
672 As a consequence of the T61String handling the only correct way to represent
673 accented characters in OpenSSL is to use a BMPString: unfortunately Netscape
674 currently chokes on these. If you have to use accented characters with Netscape
675 and MSIE then you currently need to use the invalid T61String form.
677 The current prompting is not very friendly. It doesn't allow you to confirm what
678 you've just entered. Other things like extensions in certificate requests are
679 statically defined in the configuration file. Some of these: like an email
680 address in subjectAltName should be input by the user.
684 L<x509(1)>, L<ca(1)>, L<genrsa(1)>,
685 L<gendsa(1)>, L<config(5)>,
690 Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
692 Licensed under the OpenSSL license (the "License"). You may not use
693 this file except in compliance with the License. You can obtain a copy
694 in the file LICENSE in the source distribution or at
695 L<https://www.openssl.org/source/license.html>.