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
239 When the B<-x509> option is being used this specifies the number of
240 days to certify the certificate for. The default is 30 days.
242 =item B<-set_serial n>
244 Serial number to use when outputting a self signed certificate. This
245 may be specified as a decimal value or a hex value if preceded by B<0x>.
247 =item B<-extensions section>
249 =item B<-reqexts section>
251 These options specify alternative sections to include certificate
252 extensions (if the B<-x509> option is present) or certificate
253 request extensions. This allows several different sections to
254 be used in the same configuration file to specify requests for
255 a variety of purposes.
259 A poison extension will be added to the certificate, making it a
260 "pre-certificate" (see RFC6962). This can be submitted to Certificate
261 Transparency logs in order to obtain signed certificate timestamps (SCTs).
262 These SCTs can then be embedded into the pre-certificate as an extension, before
263 removing the poison and signing the certificate.
265 This implies the B<-new> flag.
269 This option causes field values to be interpreted as UTF8 strings, by
270 default they are interpreted as ASCII. This means that the field
271 values, whether prompted from a terminal or obtained from a
272 configuration file, must be valid UTF8 strings.
274 =item B<-nameopt option>
276 Option which determines how the subject or issuer names are displayed. The
277 B<option> argument can be a single option or multiple options separated by
278 commas. Alternatively the B<-nameopt> switch may be used more than once to
279 set multiple options. See the L<x509(1)> manual page for details.
283 Customise the output format used with B<-text>. The B<option> argument can be
284 a single option or multiple options separated by commas.
286 See discussion of the B<-certopt> parameter in the L<x509(1)>
291 Adds the word B<NEW> to the PEM file header and footer lines on the outputted
292 request. Some software (Netscape certificate server) and some CAs need this.
296 Non-interactive mode.
300 Print extra details about the operations being performed.
304 Specifying an engine (by its unique B<id> string) will cause B<req>
305 to attempt to obtain a functional reference to the specified engine,
306 thus initialising it if needed. The engine will then be set as the default
307 for all available algorithms.
309 =item B<-keygen_engine id>
311 Specifies an engine (by its unique B<id> string) which would be used
312 for key generation operations.
316 =head1 CONFIGURATION FILE FORMAT
318 The configuration options are specified in the B<req> section of
319 the configuration file. As with all configuration files if no
320 value is specified in the specific section (i.e. B<req>) then
321 the initial unnamed or B<default> section is searched too.
323 The options available are described in detail below.
327 =item B<input_password output_password>
329 The passwords for the input private key file (if present) and
330 the output private key file (if one will be created). The
331 command line options B<passin> and B<passout> override the
332 configuration file values.
334 =item B<default_bits>
336 Specifies the default key size in bits.
338 This option is used in conjunction with the B<-new> option to generate
339 a new key. It can be overridden by specifying an explicit key size in
340 the B<-newkey> option. The smallest accepted key size is 512 bits. If
341 no key size is specified then 2048 bits is used.
343 =item B<default_keyfile>
345 This is the default filename to write a private key to. If not
346 specified the key is written to standard output. This can be
347 overridden by the B<-keyout> option.
351 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
352 Each line of the file should consist of the numerical form of the
353 object identifier followed by white space then the short name followed
354 by white space and finally the long name.
358 This specifies a section in the configuration file containing extra
359 object identifiers. Each line should consist of the short name of the
360 object identifier followed by B<=> and the numerical form. The short
361 and long names are the same when this option is used.
365 This specifies a filename in which random number seed information is
366 placed and read from, or an EGD socket (see L<RAND_egd(3)>).
367 It is used for private key generation.
371 If this is set to B<no> then if a private key is generated it is
372 B<not> encrypted. This is equivalent to the B<-nodes> command line
373 option. For compatibility B<encrypt_rsa_key> is an equivalent option.
377 This option specifies the digest algorithm to use.
378 Any digest supported by the OpenSSL B<dgst> command can be used.
379 If not present then MD5 is used.
380 This option can be overridden on the command line.
384 This option masks out the use of certain string types in certain
385 fields. Most users will not need to change this option.
387 It can be set to several values B<default> which is also the default
388 option uses PrintableStrings, T61Strings and BMPStrings if the
389 B<pkix> value is used then only PrintableStrings and BMPStrings will
390 be used. This follows the PKIX recommendation in RFC2459. If the
391 B<utf8only> option is used then only UTF8Strings will be used: this
392 is the PKIX recommendation in RFC2459 after 2003. Finally the B<nombstr>
393 option just uses PrintableStrings and T61Strings: certain software has
394 problems with BMPStrings and UTF8Strings: in particular Netscape.
396 =item B<req_extensions>
398 This specifies the configuration file section containing a list of
399 extensions to add to the certificate request. It can be overridden
400 by the B<-reqexts> command line switch. See the
401 L<x509v3_config(5)> manual page for details of the
402 extension section format.
404 =item B<x509_extensions>
406 This specifies the configuration file section containing a list of
407 extensions to add to certificate generated when the B<-x509> switch
408 is used. It can be overridden by the B<-extensions> command line switch.
412 If set to the value B<no> this disables prompting of certificate fields
413 and just takes values from the config file directly. It also changes the
414 expected format of the B<distinguished_name> and B<attributes> sections.
418 If set to the value B<yes> then field values to be interpreted as UTF8
419 strings, by default they are interpreted as ASCII. This means that
420 the field values, whether prompted from a terminal or obtained from a
421 configuration file, must be valid UTF8 strings.
425 This specifies the section containing any request attributes: its format
426 is the same as B<distinguished_name>. Typically these may contain the
427 challengePassword or unstructuredName types. They are currently ignored
428 by OpenSSL's request signing utilities but some CAs might want them.
430 =item B<distinguished_name>
432 This specifies the section containing the distinguished name fields to
433 prompt for when generating a certificate or certificate request. The format
434 is described in the next section.
438 =head1 DISTINGUISHED NAME AND ATTRIBUTE SECTION FORMAT
440 There are two separate formats for the distinguished name and attribute
441 sections. If the B<prompt> option is set to B<no> then these sections
442 just consist of field names and values: for example,
446 emailAddress=someone@somewhere.org
448 This allows external programs (e.g. GUI based) to generate a template file
449 with all the field names and values and just pass it to B<req>. An example
450 of this kind of configuration file is contained in the B<EXAMPLES> section.
452 Alternatively if the B<prompt> option is absent or not set to B<no> then the
453 file contains field prompting information. It consists of lines of the form:
456 fieldName_default="default field value"
460 "fieldName" is the field name being used, for example commonName (or CN).
461 The "prompt" string is used to ask the user to enter the relevant
462 details. If the user enters nothing then the default value is used if no
463 default value is present then the field is omitted. A field can
464 still be omitted if a default value is present if the user just
465 enters the '.' character.
467 The number of characters entered must be between the fieldName_min and
468 fieldName_max limits: there may be additional restrictions based
469 on the field being used (for example countryName can only ever be
470 two characters long and must fit in a PrintableString).
472 Some fields (such as organizationName) can be used more than once
473 in a DN. This presents a problem because configuration files will
474 not recognize the same name occurring twice. To avoid this problem
475 if the fieldName contains some characters followed by a full stop
476 they will be ignored. So for example a second organizationName can
477 be input by calling it "1.organizationName".
479 The actual permitted field names are any object identifier short or
480 long names. These are compiled into OpenSSL and include the usual
481 values such as commonName, countryName, localityName, organizationName,
482 organizationalUnitName, stateOrProvinceName. Additionally emailAddress
483 is include as well as name, surname, givenName initials and dnQualifier.
485 Additional object identifiers can be defined with the B<oid_file> or
486 B<oid_section> options in the configuration file. Any additional fields
487 will be treated as though they were a DirectoryString.
492 Examine and verify certificate request:
494 openssl req -in req.pem -text -verify -noout
496 Create a private key and then generate a certificate request from it:
498 openssl genrsa -out key.pem 2048
499 openssl req -new -key key.pem -out req.pem
501 The same but just using req:
503 openssl req -newkey rsa:2048 -keyout key.pem -out req.pem
505 Generate a self signed root certificate:
507 openssl req -x509 -newkey rsa:2048 -keyout key.pem -out req.pem
509 Example of a file pointed to by the B<oid_file> option:
511 1.2.3.4 shortName A longer Name
512 1.2.3.6 otherName Other longer Name
514 Example of a section pointed to by B<oid_section> making use of variable
518 testoid2=${testoid1}.6
520 Sample configuration file prompting for field values:
524 default_keyfile = privkey.pem
525 distinguished_name = req_distinguished_name
526 attributes = req_attributes
527 req_extensions = v3_ca
529 dirstring_type = nobmp
531 [ req_distinguished_name ]
532 countryName = Country Name (2 letter code)
533 countryName_default = AU
537 localityName = Locality Name (eg, city)
539 organizationalUnitName = Organizational Unit Name (eg, section)
541 commonName = Common Name (eg, YOUR name)
544 emailAddress = Email Address
545 emailAddress_max = 40
548 challengePassword = A challenge password
549 challengePassword_min = 4
550 challengePassword_max = 20
554 subjectKeyIdentifier=hash
555 authorityKeyIdentifier=keyid:always,issuer:always
556 basicConstraints = critical, CA:true
558 Sample configuration containing all field values:
561 RANDFILE = $ENV::HOME/.rnd
565 default_keyfile = keyfile.pem
566 distinguished_name = req_distinguished_name
567 attributes = req_attributes
569 output_password = mypass
571 [ req_distinguished_name ]
573 ST = Test State or Province
575 O = Organization Name
576 OU = Organizational Unit Name
578 emailAddress = test@email.address
581 challengePassword = A challenge password
586 The header and footer lines in the B<PEM> format are normally:
588 -----BEGIN CERTIFICATE REQUEST-----
589 -----END CERTIFICATE REQUEST-----
591 some software (some versions of Netscape certificate server) instead needs:
593 -----BEGIN NEW CERTIFICATE REQUEST-----
594 -----END NEW CERTIFICATE REQUEST-----
596 which is produced with the B<-newhdr> option but is otherwise compatible.
597 Either form is accepted transparently on input.
599 The certificate requests generated by B<Xenroll> with MSIE have extensions
600 added. It includes the B<keyUsage> extension which determines the type of
601 key (signature only or general purpose) and any additional OIDs entered
602 by the script in an extendedKeyUsage extension.
606 The following messages are frequently asked about:
608 Using configuration from /some/path/openssl.cnf
609 Unable to load config info
611 This is followed some time later by...
613 unable to find 'distinguished_name' in config
614 problems making Certificate Request
616 The first error message is the clue: it can't find the configuration
617 file! Certain operations (like examining a certificate request) don't
618 need a configuration file so its use isn't enforced. Generation of
619 certificates or requests however does need a configuration file. This
620 could be regarded as a bug.
622 Another puzzling message is this:
627 this is displayed when no attributes are present and the request includes
628 the correct empty B<SET OF> structure (the DER encoding of which is 0xa0
629 0x00). If you just see:
633 then the B<SET OF> is missing and the encoding is technically invalid (but
634 it is tolerated). See the description of the command line option B<-asn1-kludge>
635 for more information.
639 OpenSSL's handling of T61Strings (aka TeletexStrings) is broken: it effectively
640 treats them as ISO-8859-1 (Latin 1), Netscape and MSIE have similar behaviour.
641 This can cause problems if you need characters that aren't available in
642 PrintableStrings and you don't want to or can't use BMPStrings.
644 As a consequence of the T61String handling the only correct way to represent
645 accented characters in OpenSSL is to use a BMPString: unfortunately Netscape
646 currently chokes on these. If you have to use accented characters with Netscape
647 and MSIE then you currently need to use the invalid T61String form.
649 The current prompting is not very friendly. It doesn't allow you to confirm what
650 you've just entered. Other things like extensions in certificate requests are
651 statically defined in the configuration file. Some of these: like an email
652 address in subjectAltName should be input by the user.
656 L<x509(1)>, L<ca(1)>, L<genrsa(1)>,
657 L<gendsa(1)>, L<config(5)>,
662 Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
664 Licensed under the OpenSSL license (the "License"). You may not use
665 this file except in compliance with the License. You can obtain a copy
666 in the file LICENSE in the source distribution or at
667 L<https://www.openssl.org/source/license.html>.