5 req - PKCS#10 certificate request and certificate generating utility
30 [B<-keygen_engine id>]
38 [B<-extensions section>]
52 The B<req> command primarily creates and processes certificate requests
53 in PKCS#10 format. It can additionally create self signed certificates
54 for use as root CAs for example.
62 Print out a usage message.
64 =item B<-inform DER|PEM>
66 This specifies the input format. The B<DER> option uses an ASN1 DER encoded
67 form compatible with the PKCS#10. The B<PEM> form is the default format: it
68 consists of the B<DER> format base64 encoded with additional header and
71 =item B<-outform DER|PEM>
73 This specifies the output format, the options have the same meaning as the
78 This specifies the input filename to read a request from or standard input
79 if this option is not specified. A request is only read if the creation
80 options (B<-new> and B<-newkey>) are not specified.
84 The input file password source. For more information about the format of B<arg>
85 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
87 =item B<-out filename>
89 This specifies the output filename to write to or standard output by
94 The output file password source. For more information about the format of B<arg>
95 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
99 Prints out the certificate request in text form.
103 Prints out the request subject (or certificate subject if B<-x509> is
108 Outputs the public key.
112 This option prevents output of the encoded version of the request.
116 This option prints out the value of the modulus of the public key
117 contained in the request.
121 Verifies the signature on the request.
125 This option generates a new certificate request. It will prompt
126 the user for the relevant field values. The actual fields
127 prompted for and their maximum and minimum sizes are specified
128 in the configuration file and any requested extensions.
130 If the B<-key> option is not used it will generate a new RSA private
131 key using information specified in the configuration file.
133 =item B<-rand file(s)>
135 A file or files containing random data used to seed the random number
136 generator, or an EGD socket (see L<RAND_egd(3)>).
137 Multiple files can be specified separated by an OS-dependent character.
138 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
143 This option creates a new certificate request and a new private
144 key. The argument takes one of several forms. B<rsa:nbits>, where
145 B<nbits> is the number of bits, generates an RSA key B<nbits>
146 in size. If B<nbits> is omitted, i.e. B<-newkey rsa> specified,
147 the default key size, specified in the configuration file is used.
149 All other algorithms support the B<-newkey alg:file> form, where file may be
150 an algorithm parameter file, created by the B<genpkey -genparam> command
151 or and X.509 certificate for a key with appropriate algorithm.
153 B<param:file> generates a key using the parameter file or certificate B<file>,
154 the algorithm is determined by the parameters. B<algname:file> use algorithm
155 B<algname> and parameter file B<file>: the two algorithms must match or an
156 error occurs. B<algname> just uses algorithm B<algname>, and parameters,
157 if necessary should be specified via B<-pkeyopt> parameter.
159 B<dsa:filename> generates a DSA key using the parameters
160 in the file B<filename>. B<ec:filename> generates EC key (usable both with
161 ECDSA or ECDH algorithms), B<gost2001:filename> generates GOST R
162 34.10-2001 key (requires B<ccgost> engine configured in the configuration
163 file). If just B<gost2001> is specified a parameter set should be
164 specified by B<-pkeyopt paramset:X>
167 =item B<-pkeyopt opt:value>
169 Set the public key algorithm option B<opt> to B<value>. The precise set of
170 options supported depends on the public key algorithm used and its
171 implementation. See B<KEY GENERATION OPTIONS> in the B<genpkey> manual page
174 =item B<-key filename>
176 This specifies the file to read the private key from. It also
177 accepts PKCS#8 format private keys for PEM format files.
179 =item B<-keyform PEM|DER>
181 The format of the private key file specified in the B<-key>
182 argument. PEM is the default.
184 =item B<-keyout filename>
186 This gives the filename to write the newly created private key to.
187 If this option is not specified then the filename present in the
188 configuration file is used.
192 If this option is specified then if a private key is created it
193 will not be encrypted.
197 This specifies the message digest to sign the request.
198 Any digest supported by the OpenSSL B<dgst> command can be used.
199 This overrides the digest algorithm specified in
200 the configuration file.
202 Some public key algorithms may override this choice. For instance, DSA
203 signatures always use SHA1, GOST R 34.10 signatures always use
204 GOST R 34.11-94 (B<-md_gost94>).
206 =item B<-config filename>
208 This allows an alternative configuration file to be specified.
209 Optional; for a description of the default value,
210 see L<openssl(1)/COMMAND SUMMARY>.
214 Sets subject name for new request or supersedes the subject name
215 when processing a request.
216 The arg must be formatted as I</type0=value0/type1=value1/type2=...>,
217 characters may be escaped by \ (backslash), no spaces are skipped.
219 =item B<-multivalue-rdn>
221 This option causes the -subj argument to be interpreted with full
222 support for multivalued RDNs. Example:
224 I</DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe>
226 If -multi-rdn is not used then the UID value is I<123456+CN=John Doe>.
230 This option outputs a self signed certificate instead of a certificate
231 request. This is typically used to generate a test certificate or
232 a self signed root CA. The extensions added to the certificate
233 (if any) are specified in the configuration file. Unless specified
234 using the B<set_serial> option, a large random number will be used for
237 If existing request is specified with the B<-in> option, it is converted
238 to the self signed certificate otherwise new request is created.
242 When the B<-x509> option is being used this specifies the number of
243 days to certify the certificate for. The default is 30 days.
245 =item B<-set_serial n>
247 Serial number to use when outputting a self signed certificate. This
248 may be specified as a decimal value or a hex value if preceded by B<0x>.
250 =item B<-extensions section>
252 =item B<-reqexts section>
254 These options specify alternative sections to include certificate
255 extensions (if the B<-x509> option is present) or certificate
256 request extensions. This allows several different sections to
257 be used in the same configuration file to specify requests for
258 a variety of purposes.
262 A poison extension will be added to the certificate, making it a
263 "pre-certificate" (see RFC6962). This can be submitted to Certificate
264 Transparency logs in order to obtain signed certificate timestamps (SCTs).
265 These SCTs can then be embedded into the pre-certificate as an extension, before
266 removing the poison and signing the certificate.
268 This implies the B<-new> flag.
272 This option causes field values to be interpreted as UTF8 strings, by
273 default they are interpreted as ASCII. This means that the field
274 values, whether prompted from a terminal or obtained from a
275 configuration file, must be valid UTF8 strings.
277 =item B<-nameopt option>
279 Option which determines how the subject or issuer names are displayed. The
280 B<option> argument can be a single option or multiple options separated by
281 commas. Alternatively the B<-nameopt> switch may be used more than once to
282 set multiple options. See the L<x509(1)> manual page for details.
286 Customise the output format used with B<-text>. The B<option> argument can be
287 a single option or multiple options separated by commas.
289 See discussion of the B<-certopt> parameter in the L<x509(1)>
294 Adds the word B<NEW> to the PEM file header and footer lines on the outputted
295 request. Some software (Netscape certificate server) and some CAs need this.
299 Non-interactive mode.
303 Print extra details about the operations being performed.
307 Specifying an engine (by its unique B<id> string) will cause B<req>
308 to attempt to obtain a functional reference to the specified engine,
309 thus initialising it if needed. The engine will then be set as the default
310 for all available algorithms.
312 =item B<-keygen_engine id>
314 Specifies an engine (by its unique B<id> string) which would be used
315 for key generation operations.
319 =head1 CONFIGURATION FILE FORMAT
321 The configuration options are specified in the B<req> section of
322 the configuration file. As with all configuration files if no
323 value is specified in the specific section (i.e. B<req>) then
324 the initial unnamed or B<default> section is searched too.
326 The options available are described in detail below.
330 =item B<input_password output_password>
332 The passwords for the input private key file (if present) and
333 the output private key file (if one will be created). The
334 command line options B<passin> and B<passout> override the
335 configuration file values.
337 =item B<default_bits>
339 Specifies the default key size in bits.
341 This option is used in conjunction with the B<-new> option to generate
342 a new key. It can be overridden by specifying an explicit key size in
343 the B<-newkey> option. The smallest accepted key size is 512 bits. If
344 no key size is specified then 2048 bits is used.
346 =item B<default_keyfile>
348 This is the default filename to write a private key to. If not
349 specified the key is written to standard output. This can be
350 overridden by the B<-keyout> option.
354 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
355 Each line of the file should consist of the numerical form of the
356 object identifier followed by white space then the short name followed
357 by white space and finally the long name.
361 This specifies a section in the configuration file containing extra
362 object identifiers. Each line should consist of the short name of the
363 object identifier followed by B<=> and the numerical form. The short
364 and long names are the same when this option is used.
368 This specifies a filename in which random number seed information is
369 placed and read from, or an EGD socket (see L<RAND_egd(3)>).
370 It is used for private key generation.
374 If this is set to B<no> then if a private key is generated it is
375 B<not> encrypted. This is equivalent to the B<-nodes> command line
376 option. For compatibility B<encrypt_rsa_key> is an equivalent option.
380 This option specifies the digest algorithm to use.
381 Any digest supported by the OpenSSL B<dgst> command can be used.
382 If not present then MD5 is used.
383 This option can be overridden on the command line.
387 This option masks out the use of certain string types in certain
388 fields. Most users will not need to change this option.
390 It can be set to several values B<default> which is also the default
391 option uses PrintableStrings, T61Strings and BMPStrings if the
392 B<pkix> value is used then only PrintableStrings and BMPStrings will
393 be used. This follows the PKIX recommendation in RFC2459. If the
394 B<utf8only> option is used then only UTF8Strings will be used: this
395 is the PKIX recommendation in RFC2459 after 2003. Finally the B<nombstr>
396 option just uses PrintableStrings and T61Strings: certain software has
397 problems with BMPStrings and UTF8Strings: in particular Netscape.
399 =item B<req_extensions>
401 This specifies the configuration file section containing a list of
402 extensions to add to the certificate request. It can be overridden
403 by the B<-reqexts> command line switch. See the
404 L<x509v3_config(5)> manual page for details of the
405 extension section format.
407 =item B<x509_extensions>
409 This specifies the configuration file section containing a list of
410 extensions to add to certificate generated when the B<-x509> switch
411 is used. It can be overridden by the B<-extensions> command line switch.
415 If set to the value B<no> this disables prompting of certificate fields
416 and just takes values from the config file directly. It also changes the
417 expected format of the B<distinguished_name> and B<attributes> sections.
421 If set to the value B<yes> then field values to be interpreted as UTF8
422 strings, by default they are interpreted as ASCII. This means that
423 the field values, whether prompted from a terminal or obtained from a
424 configuration file, must be valid UTF8 strings.
428 This specifies the section containing any request attributes: its format
429 is the same as B<distinguished_name>. Typically these may contain the
430 challengePassword or unstructuredName types. They are currently ignored
431 by OpenSSL's request signing utilities but some CAs might want them.
433 =item B<distinguished_name>
435 This specifies the section containing the distinguished name fields to
436 prompt for when generating a certificate or certificate request. The format
437 is described in the next section.
441 =head1 DISTINGUISHED NAME AND ATTRIBUTE SECTION FORMAT
443 There are two separate formats for the distinguished name and attribute
444 sections. If the B<prompt> option is set to B<no> then these sections
445 just consist of field names and values: for example,
449 emailAddress=someone@somewhere.org
451 This allows external programs (e.g. GUI based) to generate a template file
452 with all the field names and values and just pass it to B<req>. An example
453 of this kind of configuration file is contained in the B<EXAMPLES> section.
455 Alternatively if the B<prompt> option is absent or not set to B<no> then the
456 file contains field prompting information. It consists of lines of the form:
459 fieldName_default="default field value"
463 "fieldName" is the field name being used, for example commonName (or CN).
464 The "prompt" string is used to ask the user to enter the relevant
465 details. If the user enters nothing then the default value is used if no
466 default value is present then the field is omitted. A field can
467 still be omitted if a default value is present if the user just
468 enters the '.' character.
470 The number of characters entered must be between the fieldName_min and
471 fieldName_max limits: there may be additional restrictions based
472 on the field being used (for example countryName can only ever be
473 two characters long and must fit in a PrintableString).
475 Some fields (such as organizationName) can be used more than once
476 in a DN. This presents a problem because configuration files will
477 not recognize the same name occurring twice. To avoid this problem
478 if the fieldName contains some characters followed by a full stop
479 they will be ignored. So for example a second organizationName can
480 be input by calling it "1.organizationName".
482 The actual permitted field names are any object identifier short or
483 long names. These are compiled into OpenSSL and include the usual
484 values such as commonName, countryName, localityName, organizationName,
485 organizationalUnitName, stateOrProvinceName. Additionally emailAddress
486 is include as well as name, surname, givenName initials and dnQualifier.
488 Additional object identifiers can be defined with the B<oid_file> or
489 B<oid_section> options in the configuration file. Any additional fields
490 will be treated as though they were a DirectoryString.
495 Examine and verify certificate request:
497 openssl req -in req.pem -text -verify -noout
499 Create a private key and then generate a certificate request from it:
501 openssl genrsa -out key.pem 2048
502 openssl req -new -key key.pem -out req.pem
504 The same but just using req:
506 openssl req -newkey rsa:2048 -keyout key.pem -out req.pem
508 Generate a self signed root certificate:
510 openssl req -x509 -newkey rsa:2048 -keyout key.pem -out req.pem
512 Example of a file pointed to by the B<oid_file> option:
514 1.2.3.4 shortName A longer Name
515 1.2.3.6 otherName Other longer Name
517 Example of a section pointed to by B<oid_section> making use of variable
521 testoid2=${testoid1}.6
523 Sample configuration file prompting for field values:
527 default_keyfile = privkey.pem
528 distinguished_name = req_distinguished_name
529 attributes = req_attributes
530 req_extensions = v3_ca
532 dirstring_type = nobmp
534 [ req_distinguished_name ]
535 countryName = Country Name (2 letter code)
536 countryName_default = AU
540 localityName = Locality Name (eg, city)
542 organizationalUnitName = Organizational Unit Name (eg, section)
544 commonName = Common Name (eg, YOUR name)
547 emailAddress = Email Address
548 emailAddress_max = 40
551 challengePassword = A challenge password
552 challengePassword_min = 4
553 challengePassword_max = 20
557 subjectKeyIdentifier=hash
558 authorityKeyIdentifier=keyid:always,issuer:always
559 basicConstraints = critical, CA:true
561 Sample configuration containing all field values:
564 RANDFILE = $ENV::HOME/.rnd
568 default_keyfile = keyfile.pem
569 distinguished_name = req_distinguished_name
570 attributes = req_attributes
572 output_password = mypass
574 [ req_distinguished_name ]
576 ST = Test State or Province
578 O = Organization Name
579 OU = Organizational Unit Name
581 emailAddress = test@email.address
584 challengePassword = A challenge password
589 The header and footer lines in the B<PEM> format are normally:
591 -----BEGIN CERTIFICATE REQUEST-----
592 -----END CERTIFICATE REQUEST-----
594 some software (some versions of Netscape certificate server) instead needs:
596 -----BEGIN NEW CERTIFICATE REQUEST-----
597 -----END NEW CERTIFICATE REQUEST-----
599 which is produced with the B<-newhdr> option but is otherwise compatible.
600 Either form is accepted transparently on input.
602 The certificate requests generated by B<Xenroll> with MSIE have extensions
603 added. It includes the B<keyUsage> extension which determines the type of
604 key (signature only or general purpose) and any additional OIDs entered
605 by the script in an extendedKeyUsage extension.
609 The following messages are frequently asked about:
611 Using configuration from /some/path/openssl.cnf
612 Unable to load config info
614 This is followed some time later by...
616 unable to find 'distinguished_name' in config
617 problems making Certificate Request
619 The first error message is the clue: it can't find the configuration
620 file! Certain operations (like examining a certificate request) don't
621 need a configuration file so its use isn't enforced. Generation of
622 certificates or requests however does need a configuration file. This
623 could be regarded as a bug.
625 Another puzzling message is this:
630 this is displayed when no attributes are present and the request includes
631 the correct empty B<SET OF> structure (the DER encoding of which is 0xa0
632 0x00). If you just see:
636 then the B<SET OF> is missing and the encoding is technically invalid (but
637 it is tolerated). See the description of the command line option B<-asn1-kludge>
638 for more information.
642 OpenSSL's handling of T61Strings (aka TeletexStrings) is broken: it effectively
643 treats them as ISO-8859-1 (Latin 1), Netscape and MSIE have similar behaviour.
644 This can cause problems if you need characters that aren't available in
645 PrintableStrings and you don't want to or can't use BMPStrings.
647 As a consequence of the T61String handling the only correct way to represent
648 accented characters in OpenSSL is to use a BMPString: unfortunately Netscape
649 currently chokes on these. If you have to use accented characters with Netscape
650 and MSIE then you currently need to use the invalid T61String form.
652 The current prompting is not very friendly. It doesn't allow you to confirm what
653 you've just entered. Other things like extensions in certificate requests are
654 statically defined in the configuration file. Some of these: like an email
655 address in subjectAltName should be input by the user.
659 L<x509(1)>, L<ca(1)>, L<genrsa(1)>,
660 L<gendsa(1)>, L<config(5)>,
665 Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
667 Licensed under the OpenSSL license (the "License"). You may not use
668 this file except in compliance with the License. You can obtain a copy
669 in the file LICENSE in the source distribution or at
670 L<https://www.openssl.org/source/license.html>.