6 req - PKCS#10 certificate request and certificate generating utility
32 [B<-keygen_engine id>]
40 [B<-extensions section>]
54 The B<req> command primarily creates and processes certificate requests
55 in PKCS#10 format. It can additionally create self signed certificates
56 for use as root CAs for example.
64 Print out a usage message.
66 =item B<-inform DER|PEM>
68 This specifies the input format. The B<DER> option uses an ASN1 DER encoded
69 form compatible with the PKCS#10. The B<PEM> form is the default format: it
70 consists of the B<DER> format base64 encoded with additional header and
73 =item B<-outform DER|PEM>
75 This specifies the output format, the options have the same meaning and default
76 as the B<-inform> option.
80 This specifies the input filename to read a request from or standard input
81 if this option is not specified. A request is only read if the creation
82 options (B<-new> and B<-newkey>) are not specified.
86 The input file password source. For more information about the format of B<arg>
87 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
89 =item B<-out filename>
91 This specifies the output filename to write to or standard output by
96 The output file password source. For more information about the format of B<arg>
97 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
101 Prints out the certificate request in text form.
105 Prints out the request subject (or certificate subject if B<-x509> is
110 Outputs the public key.
114 This option prevents output of the encoded version of the request.
118 This option prints out the value of the modulus of the public key
119 contained in the request.
123 Verifies the signature on the request.
127 This option generates a new certificate request. It will prompt
128 the user for the relevant field values. The actual fields
129 prompted for and their maximum and minimum sizes are specified
130 in the configuration file and any requested extensions.
132 If the B<-key> option is not used it will generate a new RSA private
133 key using information specified in the configuration file.
135 =item B<-rand file...>
137 A file or files containing random data used to seed the random number
139 Multiple files can be specified separated by an OS-dependent character.
140 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
143 =item [B<-writerand file>]
145 Writes random data to the specified I<file> upon exit.
146 This can be used with a subsequent B<-rand> flag.
150 This option creates a new certificate request and a new private
151 key. The argument takes one of several forms. B<rsa:nbits>, where
152 B<nbits> is the number of bits, generates an RSA key B<nbits>
153 in size. If B<nbits> is omitted, i.e. B<-newkey rsa> specified,
154 the default key size, specified in the configuration file is used.
156 All other algorithms support the B<-newkey alg:file> form, where file may be
157 an algorithm parameter file, created by the B<genpkey -genparam> command
158 or and X.509 certificate for a key with appropriate algorithm.
160 B<param:file> generates a key using the parameter file or certificate B<file>,
161 the algorithm is determined by the parameters. B<algname:file> use algorithm
162 B<algname> and parameter file B<file>: the two algorithms must match or an
163 error occurs. B<algname> just uses algorithm B<algname>, and parameters,
164 if necessary should be specified via B<-pkeyopt> parameter.
166 B<dsa:filename> generates a DSA key using the parameters
167 in the file B<filename>. B<ec:filename> generates EC key (usable both with
168 ECDSA or ECDH algorithms), B<gost2001:filename> generates GOST R
169 34.10-2001 key (requires B<ccgost> engine configured in the configuration
170 file). If just B<gost2001> is specified a parameter set should be
171 specified by B<-pkeyopt paramset:X>
174 =item B<-pkeyopt opt:value>
176 Set the public key algorithm option B<opt> to B<value>. The precise set of
177 options supported depends on the public key algorithm used and its
178 implementation. See B<KEY GENERATION OPTIONS> in the B<genpkey> manual page
181 =item B<-key filename>
183 This specifies the file to read the private key from. It also
184 accepts PKCS#8 format private keys for PEM format files.
186 =item B<-keyform PEM|DER>
188 The format of the private key file specified in the B<-key>
189 argument. PEM is the default.
191 =item B<-keyout filename>
193 This gives the filename to write the newly created private key to.
194 If this option is not specified then the filename present in the
195 configuration file is used.
199 If this option is specified then if a private key is created it
200 will not be encrypted.
204 This specifies the message digest to sign the request.
205 Any digest supported by the OpenSSL B<dgst> command can be used.
206 This overrides the digest algorithm specified in
207 the configuration file.
209 Some public key algorithms may override this choice. For instance, DSA
210 signatures always use SHA1, GOST R 34.10 signatures always use
211 GOST R 34.11-94 (B<-md_gost94>).
213 =item B<-config filename>
215 This allows an alternative configuration file to be specified.
216 Optional; for a description of the default value,
217 see L<openssl(1)/COMMAND SUMMARY>.
221 Sets subject name for new request or supersedes the subject name
222 when processing a request.
223 The arg must be formatted as I</type0=value0/type1=value1/type2=...>,
224 characters may be escaped by \ (backslash), no spaces are skipped.
226 =item B<-multivalue-rdn>
228 This option causes the -subj argument to be interpreted with full
229 support for multivalued RDNs. Example:
231 I</DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe>
233 If -multi-rdn is not used then the UID value is I<123456+CN=John Doe>.
237 This option outputs a self signed certificate instead of a certificate
238 request. This is typically used to generate a test certificate or
239 a self signed root CA. The extensions added to the certificate
240 (if any) are specified in the configuration file. Unless specified
241 using the B<set_serial> option, a large random number will be used for
244 If existing request is specified with the B<-in> option, it is converted
245 to the self signed certificate otherwise new request is created.
249 When the B<-x509> option is being used this specifies the number of
250 days to certify the certificate for, otherwise it is ignored. B<n> should
251 be a positive integer. The default is 30 days.
253 =item B<-set_serial n>
255 Serial number to use when outputting a self signed certificate. This
256 may be specified as a decimal value or a hex value if preceded by B<0x>.
258 =item B<-extensions section>
260 =item B<-reqexts section>
262 These options specify alternative sections to include certificate
263 extensions (if the B<-x509> option is present) or certificate
264 request extensions. This allows several different sections to
265 be used in the same configuration file to specify requests for
266 a variety of purposes.
270 A poison extension will be added to the certificate, making it a
271 "pre-certificate" (see RFC6962). This can be submitted to Certificate
272 Transparency logs in order to obtain signed certificate timestamps (SCTs).
273 These SCTs can then be embedded into the pre-certificate as an extension, before
274 removing the poison and signing the certificate.
276 This implies the B<-new> flag.
280 This option causes field values to be interpreted as UTF8 strings, by
281 default they are interpreted as ASCII. This means that the field
282 values, whether prompted from a terminal or obtained from a
283 configuration file, must be valid UTF8 strings.
285 =item B<-nameopt option>
287 Option which determines how the subject or issuer names are displayed. The
288 B<option> argument can be a single option or multiple options separated by
289 commas. Alternatively the B<-nameopt> switch may be used more than once to
290 set multiple options. See the L<x509(1)> manual page for details.
294 Customise the output format used with B<-text>. The B<option> argument can be
295 a single option or multiple options separated by commas.
297 See discussion of the B<-certopt> parameter in the L<x509(1)>
302 Adds the word B<NEW> to the PEM file header and footer lines on the outputted
303 request. Some software (Netscape certificate server) and some CAs need this.
307 Non-interactive mode.
311 Print extra details about the operations being performed.
315 Specifying an engine (by its unique B<id> string) will cause B<req>
316 to attempt to obtain a functional reference to the specified engine,
317 thus initialising it if needed. The engine will then be set as the default
318 for all available algorithms.
320 =item B<-keygen_engine id>
322 Specifies an engine (by its unique B<id> string) which would be used
323 for key generation operations.
327 =head1 CONFIGURATION FILE FORMAT
329 The configuration options are specified in the B<req> section of
330 the configuration file. As with all configuration files if no
331 value is specified in the specific section (i.e. B<req>) then
332 the initial unnamed or B<default> section is searched too.
334 The options available are described in detail below.
338 =item B<input_password output_password>
340 The passwords for the input private key file (if present) and
341 the output private key file (if one will be created). The
342 command line options B<passin> and B<passout> override the
343 configuration file values.
345 =item B<default_bits>
347 Specifies the default key size in bits.
349 This option is used in conjunction with the B<-new> option to generate
350 a new key. It can be overridden by specifying an explicit key size in
351 the B<-newkey> option. The smallest accepted key size is 512 bits. If
352 no key size is specified then 2048 bits is used.
354 =item B<default_keyfile>
356 This is the default filename to write a private key to. If not
357 specified the key is written to standard output. This can be
358 overridden by the B<-keyout> option.
362 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
363 Each line of the file should consist of the numerical form of the
364 object identifier followed by white space then the short name followed
365 by white space and finally the long name.
369 This specifies a section in the configuration file containing extra
370 object identifiers. Each line should consist of the short name of the
371 object identifier followed by B<=> and the numerical form. The short
372 and long names are the same when this option is used.
376 At startup the specified file is loaded into the random number generator,
377 and at exit 256 bytes will be written to it.
378 It is used for private key generation.
382 If this is set to B<no> then if a private key is generated it is
383 B<not> encrypted. This is equivalent to the B<-nodes> command line
384 option. For compatibility B<encrypt_rsa_key> is an equivalent option.
388 This option specifies the digest algorithm to use.
389 Any digest supported by the OpenSSL B<dgst> command can be used.
390 If not present then MD5 is used.
391 This option can be overridden on the command line.
395 This option masks out the use of certain string types in certain
396 fields. Most users will not need to change this option.
398 It can be set to several values B<default> which is also the default
399 option uses PrintableStrings, T61Strings and BMPStrings if the
400 B<pkix> value is used then only PrintableStrings and BMPStrings will
401 be used. This follows the PKIX recommendation in RFC2459. If the
402 B<utf8only> option is used then only UTF8Strings will be used: this
403 is the PKIX recommendation in RFC2459 after 2003. Finally the B<nombstr>
404 option just uses PrintableStrings and T61Strings: certain software has
405 problems with BMPStrings and UTF8Strings: in particular Netscape.
407 =item B<req_extensions>
409 This specifies the configuration file section containing a list of
410 extensions to add to the certificate request. It can be overridden
411 by the B<-reqexts> command line switch. See the
412 L<x509v3_config(5)> manual page for details of the
413 extension section format.
415 =item B<x509_extensions>
417 This specifies the configuration file section containing a list of
418 extensions to add to certificate generated when the B<-x509> switch
419 is used. It can be overridden by the B<-extensions> command line switch.
423 If set to the value B<no> this disables prompting of certificate fields
424 and just takes values from the config file directly. It also changes the
425 expected format of the B<distinguished_name> and B<attributes> sections.
429 If set to the value B<yes> then field values to be interpreted as UTF8
430 strings, by default they are interpreted as ASCII. This means that
431 the field values, whether prompted from a terminal or obtained from a
432 configuration file, must be valid UTF8 strings.
436 This specifies the section containing any request attributes: its format
437 is the same as B<distinguished_name>. Typically these may contain the
438 challengePassword or unstructuredName types. They are currently ignored
439 by OpenSSL's request signing utilities but some CAs might want them.
441 =item B<distinguished_name>
443 This specifies the section containing the distinguished name fields to
444 prompt for when generating a certificate or certificate request. The format
445 is described in the next section.
449 =head1 DISTINGUISHED NAME AND ATTRIBUTE SECTION FORMAT
451 There are two separate formats for the distinguished name and attribute
452 sections. If the B<prompt> option is set to B<no> then these sections
453 just consist of field names and values: for example,
457 emailAddress=someone@somewhere.org
459 This allows external programs (e.g. GUI based) to generate a template file
460 with all the field names and values and just pass it to B<req>. An example
461 of this kind of configuration file is contained in the B<EXAMPLES> section.
463 Alternatively if the B<prompt> option is absent or not set to B<no> then the
464 file contains field prompting information. It consists of lines of the form:
467 fieldName_default="default field value"
471 "fieldName" is the field name being used, for example commonName (or CN).
472 The "prompt" string is used to ask the user to enter the relevant
473 details. If the user enters nothing then the default value is used if no
474 default value is present then the field is omitted. A field can
475 still be omitted if a default value is present if the user just
476 enters the '.' character.
478 The number of characters entered must be between the fieldName_min and
479 fieldName_max limits: there may be additional restrictions based
480 on the field being used (for example countryName can only ever be
481 two characters long and must fit in a PrintableString).
483 Some fields (such as organizationName) can be used more than once
484 in a DN. This presents a problem because configuration files will
485 not recognize the same name occurring twice. To avoid this problem
486 if the fieldName contains some characters followed by a full stop
487 they will be ignored. So for example a second organizationName can
488 be input by calling it "1.organizationName".
490 The actual permitted field names are any object identifier short or
491 long names. These are compiled into OpenSSL and include the usual
492 values such as commonName, countryName, localityName, organizationName,
493 organizationalUnitName, stateOrProvinceName. Additionally emailAddress
494 is include as well as name, surname, givenName initials and dnQualifier.
496 Additional object identifiers can be defined with the B<oid_file> or
497 B<oid_section> options in the configuration file. Any additional fields
498 will be treated as though they were a DirectoryString.
503 Examine and verify certificate request:
505 openssl req -in req.pem -text -verify -noout
507 Create a private key and then generate a certificate request from it:
509 openssl genrsa -out key.pem 2048
510 openssl req -new -key key.pem -out req.pem
512 The same but just using req:
514 openssl req -newkey rsa:2048 -keyout key.pem -out req.pem
516 Generate a self signed root certificate:
518 openssl req -x509 -newkey rsa:2048 -keyout key.pem -out req.pem
520 Example of a file pointed to by the B<oid_file> option:
522 1.2.3.4 shortName A longer Name
523 1.2.3.6 otherName Other longer Name
525 Example of a section pointed to by B<oid_section> making use of variable
529 testoid2=${testoid1}.6
531 Sample configuration file prompting for field values:
535 default_keyfile = privkey.pem
536 distinguished_name = req_distinguished_name
537 attributes = req_attributes
538 req_extensions = v3_ca
540 dirstring_type = nobmp
542 [ req_distinguished_name ]
543 countryName = Country Name (2 letter code)
544 countryName_default = AU
548 localityName = Locality Name (eg, city)
550 organizationalUnitName = Organizational Unit Name (eg, section)
552 commonName = Common Name (eg, YOUR name)
555 emailAddress = Email Address
556 emailAddress_max = 40
559 challengePassword = A challenge password
560 challengePassword_min = 4
561 challengePassword_max = 20
565 subjectKeyIdentifier=hash
566 authorityKeyIdentifier=keyid:always,issuer:always
567 basicConstraints = critical, CA:true
569 Sample configuration containing all field values:
572 RANDFILE = $ENV::HOME/.rnd
576 default_keyfile = keyfile.pem
577 distinguished_name = req_distinguished_name
578 attributes = req_attributes
580 output_password = mypass
582 [ req_distinguished_name ]
584 ST = Test State or Province
586 O = Organization Name
587 OU = Organizational Unit Name
589 emailAddress = test@email.address
592 challengePassword = A challenge password
597 The header and footer lines in the B<PEM> format are normally:
599 -----BEGIN CERTIFICATE REQUEST-----
600 -----END CERTIFICATE REQUEST-----
602 some software (some versions of Netscape certificate server) instead needs:
604 -----BEGIN NEW CERTIFICATE REQUEST-----
605 -----END NEW CERTIFICATE REQUEST-----
607 which is produced with the B<-newhdr> option but is otherwise compatible.
608 Either form is accepted transparently on input.
610 The certificate requests generated by B<Xenroll> with MSIE have extensions
611 added. It includes the B<keyUsage> extension which determines the type of
612 key (signature only or general purpose) and any additional OIDs entered
613 by the script in an extendedKeyUsage extension.
617 The following messages are frequently asked about:
619 Using configuration from /some/path/openssl.cnf
620 Unable to load config info
622 This is followed some time later by...
624 unable to find 'distinguished_name' in config
625 problems making Certificate Request
627 The first error message is the clue: it can't find the configuration
628 file! Certain operations (like examining a certificate request) don't
629 need a configuration file so its use isn't enforced. Generation of
630 certificates or requests however does need a configuration file. This
631 could be regarded as a bug.
633 Another puzzling message is this:
638 this is displayed when no attributes are present and the request includes
639 the correct empty B<SET OF> structure (the DER encoding of which is 0xa0
640 0x00). If you just see:
644 then the B<SET OF> is missing and the encoding is technically invalid (but
645 it is tolerated). See the description of the command line option B<-asn1-kludge>
646 for more information.
650 OpenSSL's handling of T61Strings (aka TeletexStrings) is broken: it effectively
651 treats them as ISO-8859-1 (Latin 1), Netscape and MSIE have similar behaviour.
652 This can cause problems if you need characters that aren't available in
653 PrintableStrings and you don't want to or can't use BMPStrings.
655 As a consequence of the T61String handling the only correct way to represent
656 accented characters in OpenSSL is to use a BMPString: unfortunately Netscape
657 currently chokes on these. If you have to use accented characters with Netscape
658 and MSIE then you currently need to use the invalid T61String form.
660 The current prompting is not very friendly. It doesn't allow you to confirm what
661 you've just entered. Other things like extensions in certificate requests are
662 statically defined in the configuration file. Some of these: like an email
663 address in subjectAltName should be input by the user.
667 L<x509(1)>, L<ca(1)>, L<genrsa(1)>,
668 L<gendsa(1)>, L<config(5)>,
673 Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
675 Licensed under the OpenSSL license (the "License"). You may not use
676 this file except in compliance with the License. You can obtain a copy
677 in the file LICENSE in the source distribution or at
678 L<https://www.openssl.org/source/license.html>.