6 req - PKCS#10 certificate request and certificate generating utility
32 [B<-keygen_engine id>]
41 [B<-extensions section>]
56 The B<req> command primarily creates and processes certificate requests
57 in PKCS#10 format. It can additionally create self signed certificates
58 for use as root CAs for example.
66 Print out a usage message.
68 =item B<-inform DER|PEM>
70 This specifies the input format. The B<DER> option uses an ASN1 DER encoded
71 form compatible with the PKCS#10. The B<PEM> form is the default format: it
72 consists of the B<DER> format base64 encoded with additional header and
75 =item B<-outform DER|PEM>
77 This specifies the output format, the options have the same meaning and default
78 as the B<-inform> option.
82 This specifies the input filename to read a request from or standard input
83 if this option is not specified. A request is only read if the creation
84 options (B<-new> and B<-newkey>) are not specified.
88 Pass options to the signature algorithm during sign or verify operations.
89 Names and values of these options are algorithm-specific.
93 The input file password source. For more information about the format of B<arg>
94 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
96 =item B<-out filename>
98 This specifies the output filename to write to or standard output by
101 =item B<-passout arg>
103 The output file password source. For more information about the format of B<arg>
104 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
108 Prints out the certificate request in text form.
112 Prints out the request subject (or certificate subject if B<-x509> is
117 Outputs the public key.
121 This option prevents output of the encoded version of the request.
125 This option prints out the value of the modulus of the public key
126 contained in the request.
130 Verifies the signature on the request.
134 This option generates a new certificate request. It will prompt
135 the user for the relevant field values. The actual fields
136 prompted for and their maximum and minimum sizes are specified
137 in the configuration file and any requested extensions.
139 If the B<-key> option is not used it will generate a new RSA private
140 key using information specified in the configuration file.
142 =item B<-rand file...>
144 A file or files containing random data used to seed the random number
146 Multiple files can be specified separated by an OS-dependent character.
147 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
150 =item [B<-writerand file>]
152 Writes random data to the specified I<file> upon exit.
153 This can be used with a subsequent B<-rand> flag.
157 This option creates a new certificate request and a new private
158 key. The argument takes one of several forms. B<rsa:nbits>, where
159 B<nbits> is the number of bits, generates an RSA key B<nbits>
160 in size. If B<nbits> is omitted, i.e. B<-newkey rsa> specified,
161 the default key size, specified in the configuration file is used.
163 All other algorithms support the B<-newkey alg:file> form, where file may be
164 an algorithm parameter file, created by the B<genpkey -genparam> command
165 or and X.509 certificate for a key with appropriate algorithm.
167 B<param:file> generates a key using the parameter file or certificate B<file>,
168 the algorithm is determined by the parameters. B<algname:file> use algorithm
169 B<algname> and parameter file B<file>: the two algorithms must match or an
170 error occurs. B<algname> just uses algorithm B<algname>, and parameters,
171 if necessary should be specified via B<-pkeyopt> parameter.
173 B<dsa:filename> generates a DSA key using the parameters
174 in the file B<filename>. B<ec:filename> generates EC key (usable both with
175 ECDSA or ECDH algorithms), B<gost2001:filename> generates GOST R
176 34.10-2001 key (requires B<ccgost> engine configured in the configuration
177 file). If just B<gost2001> is specified a parameter set should be
178 specified by B<-pkeyopt paramset:X>
181 =item B<-pkeyopt opt:value>
183 Set the public key algorithm option B<opt> to B<value>. The precise set of
184 options supported depends on the public key algorithm used and its
185 implementation. See B<KEY GENERATION OPTIONS> in the B<genpkey> manual page
188 =item B<-key filename>
190 This specifies the file to read the private key from. It also
191 accepts PKCS#8 format private keys for PEM format files.
193 =item B<-keyform PEM|DER>
195 The format of the private key file specified in the B<-key>
196 argument. PEM is the default.
198 =item B<-keyout filename>
200 This gives the filename to write the newly created private key to.
201 If this option is not specified then the filename present in the
202 configuration file is used.
206 If this option is specified then if a private key is created it
207 will not be encrypted.
211 This specifies the message digest to sign the request.
212 Any digest supported by the OpenSSL B<dgst> command can be used.
213 This overrides the digest algorithm specified in
214 the configuration file.
216 Some public key algorithms may override this choice. For instance, DSA
217 signatures always use SHA1, GOST R 34.10 signatures always use
218 GOST R 34.11-94 (B<-md_gost94>), Ed25519 and Ed448 never use any digest.
220 =item B<-config filename>
222 This allows an alternative configuration file to be specified.
223 Optional; for a description of the default value,
224 see L<openssl(1)/COMMAND SUMMARY>.
228 Sets subject name for new request or supersedes the subject name
229 when processing a request.
230 The arg must be formatted as I</type0=value0/type1=value1/type2=...>.
231 Keyword characters may be escaped by \ (backslash), and whitespace is retained.
232 Empty values are permitted, but the corresponding type will not be included
235 =item B<-multivalue-rdn>
237 This option causes the -subj argument to be interpreted with full
238 support for multivalued RDNs. Example:
240 I</DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe>
242 If -multi-rdn is not used then the UID value is I<123456+CN=John Doe>.
246 This option outputs a self signed certificate instead of a certificate
247 request. This is typically used to generate a test certificate or
248 a self signed root CA. The extensions added to the certificate
249 (if any) are specified in the configuration file. Unless specified
250 using the B<set_serial> option, a large random number will be used for
253 If existing request is specified with the B<-in> option, it is converted
254 to the self signed certificate otherwise new request is created.
258 When the B<-x509> option is being used this specifies the number of
259 days to certify the certificate for, otherwise it is ignored. B<n> should
260 be a positive integer. The default is 30 days.
262 =item B<-set_serial n>
264 Serial number to use when outputting a self signed certificate. This
265 may be specified as a decimal value or a hex value if preceded by B<0x>.
269 Add a specific extension to the certificate (if the B<-x509> option is
270 present) or certificate request. The argument must have the form of
271 a key=value pair as it would appear in a config file.
273 This option can be given multiple times.
275 =item B<-extensions section>
277 =item B<-reqexts section>
279 These options specify alternative sections to include certificate
280 extensions (if the B<-x509> option is present) or certificate
281 request extensions. This allows several different sections to
282 be used in the same configuration file to specify requests for
283 a variety of purposes.
287 A poison extension will be added to the certificate, making it a
288 "pre-certificate" (see RFC6962). This can be submitted to Certificate
289 Transparency logs in order to obtain signed certificate timestamps (SCTs).
290 These SCTs can then be embedded into the pre-certificate as an extension, before
291 removing the poison and signing the certificate.
293 This implies the B<-new> flag.
297 This option causes field values to be interpreted as UTF8 strings, by
298 default they are interpreted as ASCII. This means that the field
299 values, whether prompted from a terminal or obtained from a
300 configuration file, must be valid UTF8 strings.
302 =item B<-nameopt option>
304 Option which determines how the subject or issuer names are displayed. The
305 B<option> argument can be a single option or multiple options separated by
306 commas. Alternatively the B<-nameopt> switch may be used more than once to
307 set multiple options. See the L<x509(1)> manual page for details.
311 Customise the output format used with B<-text>. The B<option> argument can be
312 a single option or multiple options separated by commas.
314 See discussion of the B<-certopt> parameter in the L<x509(1)>
319 Adds the word B<NEW> to the PEM file header and footer lines on the outputted
320 request. Some software (Netscape certificate server) and some CAs need this.
324 Non-interactive mode.
328 Print extra details about the operations being performed.
332 Specifying an engine (by its unique B<id> string) will cause B<req>
333 to attempt to obtain a functional reference to the specified engine,
334 thus initialising it if needed. The engine will then be set as the default
335 for all available algorithms.
337 =item B<-keygen_engine id>
339 Specifies an engine (by its unique B<id> string) which would be used
340 for key generation operations.
344 =head1 CONFIGURATION FILE FORMAT
346 The configuration options are specified in the B<req> section of
347 the configuration file. As with all configuration files if no
348 value is specified in the specific section (i.e. B<req>) then
349 the initial unnamed or B<default> section is searched too.
351 The options available are described in detail below.
355 =item B<input_password output_password>
357 The passwords for the input private key file (if present) and
358 the output private key file (if one will be created). The
359 command line options B<passin> and B<passout> override the
360 configuration file values.
362 =item B<default_bits>
364 Specifies the default key size in bits.
366 This option is used in conjunction with the B<-new> option to generate
367 a new key. It can be overridden by specifying an explicit key size in
368 the B<-newkey> option. The smallest accepted key size is 512 bits. If
369 no key size is specified then 2048 bits is used.
371 =item B<default_keyfile>
373 This is the default filename to write a private key to. If not
374 specified the key is written to standard output. This can be
375 overridden by the B<-keyout> option.
379 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
380 Each line of the file should consist of the numerical form of the
381 object identifier followed by white space then the short name followed
382 by white space and finally the long name.
386 This specifies a section in the configuration file containing extra
387 object identifiers. Each line should consist of the short name of the
388 object identifier followed by B<=> and the numerical form. The short
389 and long names are the same when this option is used.
393 At startup the specified file is loaded into the random number generator,
394 and at exit 256 bytes will be written to it.
395 It is used for private key generation.
399 If this is set to B<no> then if a private key is generated it is
400 B<not> encrypted. This is equivalent to the B<-nodes> command line
401 option. For compatibility B<encrypt_rsa_key> is an equivalent option.
405 This option specifies the digest algorithm to use. Any digest supported by the
406 OpenSSL B<dgst> command can be used. This option can be overridden on the
407 command line. Certain signing algorithms (i.e. Ed25519 and Ed448) will ignore
408 any digest that has been set.
412 This option masks out the use of certain string types in certain
413 fields. Most users will not need to change this option.
415 It can be set to several values B<default> which is also the default
416 option uses PrintableStrings, T61Strings and BMPStrings if the
417 B<pkix> value is used then only PrintableStrings and BMPStrings will
418 be used. This follows the PKIX recommendation in RFC2459. If the
419 B<utf8only> option is used then only UTF8Strings will be used: this
420 is the PKIX recommendation in RFC2459 after 2003. Finally the B<nombstr>
421 option just uses PrintableStrings and T61Strings: certain software has
422 problems with BMPStrings and UTF8Strings: in particular Netscape.
424 =item B<req_extensions>
426 This specifies the configuration file section containing a list of
427 extensions to add to the certificate request. It can be overridden
428 by the B<-reqexts> command line switch. See the
429 L<x509v3_config(5)> manual page for details of the
430 extension section format.
432 =item B<x509_extensions>
434 This specifies the configuration file section containing a list of
435 extensions to add to certificate generated when the B<-x509> switch
436 is used. It can be overridden by the B<-extensions> command line switch.
440 If set to the value B<no> this disables prompting of certificate fields
441 and just takes values from the config file directly. It also changes the
442 expected format of the B<distinguished_name> and B<attributes> sections.
446 If set to the value B<yes> then field values to be interpreted as UTF8
447 strings, by default they are interpreted as ASCII. This means that
448 the field values, whether prompted from a terminal or obtained from a
449 configuration file, must be valid UTF8 strings.
453 This specifies the section containing any request attributes: its format
454 is the same as B<distinguished_name>. Typically these may contain the
455 challengePassword or unstructuredName types. They are currently ignored
456 by OpenSSL's request signing utilities but some CAs might want them.
458 =item B<distinguished_name>
460 This specifies the section containing the distinguished name fields to
461 prompt for when generating a certificate or certificate request. The format
462 is described in the next section.
466 =head1 DISTINGUISHED NAME AND ATTRIBUTE SECTION FORMAT
468 There are two separate formats for the distinguished name and attribute
469 sections. If the B<prompt> option is set to B<no> then these sections
470 just consist of field names and values: for example,
474 emailAddress=someone@somewhere.org
476 This allows external programs (e.g. GUI based) to generate a template file
477 with all the field names and values and just pass it to B<req>. An example
478 of this kind of configuration file is contained in the B<EXAMPLES> section.
480 Alternatively if the B<prompt> option is absent or not set to B<no> then the
481 file contains field prompting information. It consists of lines of the form:
484 fieldName_default="default field value"
488 "fieldName" is the field name being used, for example commonName (or CN).
489 The "prompt" string is used to ask the user to enter the relevant
490 details. If the user enters nothing then the default value is used if no
491 default value is present then the field is omitted. A field can
492 still be omitted if a default value is present if the user just
493 enters the '.' character.
495 The number of characters entered must be between the fieldName_min and
496 fieldName_max limits: there may be additional restrictions based
497 on the field being used (for example countryName can only ever be
498 two characters long and must fit in a PrintableString).
500 Some fields (such as organizationName) can be used more than once
501 in a DN. This presents a problem because configuration files will
502 not recognize the same name occurring twice. To avoid this problem
503 if the fieldName contains some characters followed by a full stop
504 they will be ignored. So for example a second organizationName can
505 be input by calling it "1.organizationName".
507 The actual permitted field names are any object identifier short or
508 long names. These are compiled into OpenSSL and include the usual
509 values such as commonName, countryName, localityName, organizationName,
510 organizationalUnitName, stateOrProvinceName. Additionally emailAddress
511 is included as well as name, surname, givenName, initials, and dnQualifier.
513 Additional object identifiers can be defined with the B<oid_file> or
514 B<oid_section> options in the configuration file. Any additional fields
515 will be treated as though they were a DirectoryString.
520 Examine and verify certificate request:
522 openssl req -in req.pem -text -verify -noout
524 Create a private key and then generate a certificate request from it:
526 openssl genrsa -out key.pem 2048
527 openssl req -new -key key.pem -out req.pem
529 The same but just using req:
531 openssl req -newkey rsa:2048 -keyout key.pem -out req.pem
533 Generate a self signed root certificate:
535 openssl req -x509 -newkey rsa:2048 -keyout key.pem -out req.pem
537 Example of a file pointed to by the B<oid_file> option:
539 1.2.3.4 shortName A longer Name
540 1.2.3.6 otherName Other longer Name
542 Example of a section pointed to by B<oid_section> making use of variable
546 testoid2=${testoid1}.6
548 Sample configuration file prompting for field values:
552 default_keyfile = privkey.pem
553 distinguished_name = req_distinguished_name
554 attributes = req_attributes
555 req_extensions = v3_ca
557 dirstring_type = nobmp
559 [ req_distinguished_name ]
560 countryName = Country Name (2 letter code)
561 countryName_default = AU
565 localityName = Locality Name (eg, city)
567 organizationalUnitName = Organizational Unit Name (eg, section)
569 commonName = Common Name (eg, YOUR name)
572 emailAddress = Email Address
573 emailAddress_max = 40
576 challengePassword = A challenge password
577 challengePassword_min = 4
578 challengePassword_max = 20
582 subjectKeyIdentifier=hash
583 authorityKeyIdentifier=keyid:always,issuer:always
584 basicConstraints = critical, CA:true
586 Sample configuration containing all field values:
589 RANDFILE = $ENV::HOME/.rnd
593 default_keyfile = keyfile.pem
594 distinguished_name = req_distinguished_name
595 attributes = req_attributes
597 output_password = mypass
599 [ req_distinguished_name ]
601 ST = Test State or Province
603 O = Organization Name
604 OU = Organizational Unit Name
606 emailAddress = test@email.address
609 challengePassword = A challenge password
611 Example of giving the most common attributes (subject and extensions)
614 openssl req -new -subj "/C=GB/CN=foo" \
615 -addext "subjectAltName = DNS:foo.co.uk" \
616 -addext "certificatePolicies = 1.2.3.4" \
617 -newkey rsa:2048 -keyout key.pem -out req.pem
622 The header and footer lines in the B<PEM> format are normally:
624 -----BEGIN CERTIFICATE REQUEST-----
625 -----END CERTIFICATE REQUEST-----
627 some software (some versions of Netscape certificate server) instead needs:
629 -----BEGIN NEW CERTIFICATE REQUEST-----
630 -----END NEW CERTIFICATE REQUEST-----
632 which is produced with the B<-newhdr> option but is otherwise compatible.
633 Either form is accepted transparently on input.
635 The certificate requests generated by B<Xenroll> with MSIE have extensions
636 added. It includes the B<keyUsage> extension which determines the type of
637 key (signature only or general purpose) and any additional OIDs entered
638 by the script in an extendedKeyUsage extension.
642 The following messages are frequently asked about:
644 Using configuration from /some/path/openssl.cnf
645 Unable to load config info
647 This is followed some time later by...
649 unable to find 'distinguished_name' in config
650 problems making Certificate Request
652 The first error message is the clue: it can't find the configuration
653 file! Certain operations (like examining a certificate request) don't
654 need a configuration file so its use isn't enforced. Generation of
655 certificates or requests however does need a configuration file. This
656 could be regarded as a bug.
658 Another puzzling message is this:
663 this is displayed when no attributes are present and the request includes
664 the correct empty B<SET OF> structure (the DER encoding of which is 0xa0
665 0x00). If you just see:
669 then the B<SET OF> is missing and the encoding is technically invalid (but
670 it is tolerated). See the description of the command line option B<-asn1-kludge>
671 for more information.
675 OpenSSL's handling of T61Strings (aka TeletexStrings) is broken: it effectively
676 treats them as ISO-8859-1 (Latin 1), Netscape and MSIE have similar behaviour.
677 This can cause problems if you need characters that aren't available in
678 PrintableStrings and you don't want to or can't use BMPStrings.
680 As a consequence of the T61String handling the only correct way to represent
681 accented characters in OpenSSL is to use a BMPString: unfortunately Netscape
682 currently chokes on these. If you have to use accented characters with Netscape
683 and MSIE then you currently need to use the invalid T61String form.
685 The current prompting is not very friendly. It doesn't allow you to confirm what
686 you've just entered. Other things like extensions in certificate requests are
687 statically defined in the configuration file. Some of these: like an email
688 address in subjectAltName should be input by the user.
692 L<x509(1)>, L<ca(1)>, L<genrsa(1)>,
693 L<gendsa(1)>, L<config(5)>,
698 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
700 Licensed under the OpenSSL license (the "License"). You may not use
701 this file except in compliance with the License. You can obtain a copy
702 in the file LICENSE in the source distribution or at
703 L<https://www.openssl.org/source/license.html>.