5 req - PKCS#10 certificate request and certificate generating utility
31 [B<-keygen_engine id>]
39 [B<-extensions section>]
53 The B<req> command primarily creates and processes certificate requests
54 in PKCS#10 format. It can additionally create self signed certificates
55 for use as root CAs for example.
63 Print out a usage message.
65 =item B<-inform DER|PEM>
67 This specifies the input format. The B<DER> option uses an ASN1 DER encoded
68 form compatible with the PKCS#10. The B<PEM> form is the default format: it
69 consists of the B<DER> format base64 encoded with additional header and
72 =item B<-outform DER|PEM>
74 This specifies the output format, the options have the same meaning and default
75 as the B<-inform> option.
79 This specifies the input filename to read a request from or standard input
80 if this option is not specified. A request is only read if the creation
81 options (B<-new> and B<-newkey>) are not specified.
85 The input file password source. For more information about the format of B<arg>
86 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
88 =item B<-out filename>
90 This specifies the output filename to write to or standard output by
95 The output file password source. For more information about the format of B<arg>
96 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
100 Prints out the certificate request in text form.
104 Prints out the request subject (or certificate subject if B<-x509> is
109 Outputs the public key.
113 This option prevents output of the encoded version of the request.
117 This option prints out the value of the modulus of the public key
118 contained in the request.
122 Verifies the signature on the request.
126 This option generates a new certificate request. It will prompt
127 the user for the relevant field values. The actual fields
128 prompted for and their maximum and minimum sizes are specified
129 in the configuration file and any requested extensions.
131 If the B<-key> option is not used it will generate a new RSA private
132 key using information specified in the configuration file.
134 =item B<-rand file...>
136 A file or files containing random data used to seed the random number
138 Multiple files can be specified separated by an OS-dependent character.
139 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
142 =item [B<-writerand file>]
144 Writes random data to the specified I<file> upon exit.
145 This can be used with a subsequent B<-rand> flag.
149 This option creates a new certificate request and a new private
150 key. The argument takes one of several forms. B<rsa:nbits>, where
151 B<nbits> is the number of bits, generates an RSA key B<nbits>
152 in size. If B<nbits> is omitted, i.e. B<-newkey rsa> specified,
153 the default key size, specified in the configuration file is used.
155 All other algorithms support the B<-newkey alg:file> form, where file may be
156 an algorithm parameter file, created by the B<genpkey -genparam> command
157 or and X.509 certificate for a key with appropriate algorithm.
159 B<param:file> generates a key using the parameter file or certificate B<file>,
160 the algorithm is determined by the parameters. B<algname:file> use algorithm
161 B<algname> and parameter file B<file>: the two algorithms must match or an
162 error occurs. B<algname> just uses algorithm B<algname>, and parameters,
163 if necessary should be specified via B<-pkeyopt> parameter.
165 B<dsa:filename> generates a DSA key using the parameters
166 in the file B<filename>. B<ec:filename> generates EC key (usable both with
167 ECDSA or ECDH algorithms), B<gost2001:filename> generates GOST R
168 34.10-2001 key (requires B<ccgost> engine configured in the configuration
169 file). If just B<gost2001> is specified a parameter set should be
170 specified by B<-pkeyopt paramset:X>
173 =item B<-pkeyopt opt:value>
175 Set the public key algorithm option B<opt> to B<value>. The precise set of
176 options supported depends on the public key algorithm used and its
177 implementation. See B<KEY GENERATION OPTIONS> in the B<genpkey> manual page
180 =item B<-key filename>
182 This specifies the file to read the private key from. It also
183 accepts PKCS#8 format private keys for PEM format files.
185 =item B<-keyform PEM|DER>
187 The format of the private key file specified in the B<-key>
188 argument. PEM is the default.
190 =item B<-keyout filename>
192 This gives the filename to write the newly created private key to.
193 If this option is not specified then the filename present in the
194 configuration file is used.
198 If this option is specified then if a private key is created it
199 will not be encrypted.
203 This specifies the message digest to sign the request.
204 Any digest supported by the OpenSSL B<dgst> command can be used.
205 This overrides the digest algorithm specified in
206 the configuration file.
208 Some public key algorithms may override this choice. For instance, DSA
209 signatures always use SHA1, GOST R 34.10 signatures always use
210 GOST R 34.11-94 (B<-md_gost94>).
212 =item B<-config filename>
214 This allows an alternative configuration file to be specified.
215 Optional; for a description of the default value,
216 see L<openssl(1)/COMMAND SUMMARY>.
220 Sets subject name for new request or supersedes the subject name
221 when processing a request.
222 The arg must be formatted as I</type0=value0/type1=value1/type2=...>,
223 characters may be escaped by \ (backslash), no spaces are skipped.
225 =item B<-multivalue-rdn>
227 This option causes the -subj argument to be interpreted with full
228 support for multivalued RDNs. Example:
230 I</DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe>
232 If -multi-rdn is not used then the UID value is I<123456+CN=John Doe>.
236 This option outputs a self signed certificate instead of a certificate
237 request. This is typically used to generate a test certificate or
238 a self signed root CA. The extensions added to the certificate
239 (if any) are specified in the configuration file. Unless specified
240 using the B<set_serial> option, a large random number will be used for
243 If existing request is specified with the B<-in> option, it is converted
244 to the self signed certificate otherwise new request is created.
248 When the B<-x509> option is being used this specifies the number of
249 days to certify the certificate for. The default is 30 days.
251 =item B<-set_serial n>
253 Serial number to use when outputting a self signed certificate. This
254 may be specified as a decimal value or a hex value if preceded by B<0x>.
256 =item B<-extensions section>
258 =item B<-reqexts section>
260 These options specify alternative sections to include certificate
261 extensions (if the B<-x509> option is present) or certificate
262 request extensions. This allows several different sections to
263 be used in the same configuration file to specify requests for
264 a variety of purposes.
268 A poison extension will be added to the certificate, making it a
269 "pre-certificate" (see RFC6962). This can be submitted to Certificate
270 Transparency logs in order to obtain signed certificate timestamps (SCTs).
271 These SCTs can then be embedded into the pre-certificate as an extension, before
272 removing the poison and signing the certificate.
274 This implies the B<-new> flag.
278 This option causes field values to be interpreted as UTF8 strings, by
279 default they are interpreted as ASCII. This means that the field
280 values, whether prompted from a terminal or obtained from a
281 configuration file, must be valid UTF8 strings.
283 =item B<-nameopt option>
285 Option which determines how the subject or issuer names are displayed. The
286 B<option> argument can be a single option or multiple options separated by
287 commas. Alternatively the B<-nameopt> switch may be used more than once to
288 set multiple options. See the L<x509(1)> manual page for details.
292 Customise the output format used with B<-text>. The B<option> argument can be
293 a single option or multiple options separated by commas.
295 See discussion of the B<-certopt> parameter in the L<x509(1)>
300 Adds the word B<NEW> to the PEM file header and footer lines on the outputted
301 request. Some software (Netscape certificate server) and some CAs need this.
305 Non-interactive mode.
309 Print extra details about the operations being performed.
313 Specifying an engine (by its unique B<id> string) will cause B<req>
314 to attempt to obtain a functional reference to the specified engine,
315 thus initialising it if needed. The engine will then be set as the default
316 for all available algorithms.
318 =item B<-keygen_engine id>
320 Specifies an engine (by its unique B<id> string) which would be used
321 for key generation operations.
325 =head1 CONFIGURATION FILE FORMAT
327 The configuration options are specified in the B<req> section of
328 the configuration file. As with all configuration files if no
329 value is specified in the specific section (i.e. B<req>) then
330 the initial unnamed or B<default> section is searched too.
332 The options available are described in detail below.
336 =item B<input_password output_password>
338 The passwords for the input private key file (if present) and
339 the output private key file (if one will be created). The
340 command line options B<passin> and B<passout> override the
341 configuration file values.
343 =item B<default_bits>
345 Specifies the default key size in bits.
347 This option is used in conjunction with the B<-new> option to generate
348 a new key. It can be overridden by specifying an explicit key size in
349 the B<-newkey> option. The smallest accepted key size is 512 bits. If
350 no key size is specified then 2048 bits is used.
352 =item B<default_keyfile>
354 This is the default filename to write a private key to. If not
355 specified the key is written to standard output. This can be
356 overridden by the B<-keyout> option.
360 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
361 Each line of the file should consist of the numerical form of the
362 object identifier followed by white space then the short name followed
363 by white space and finally the long name.
367 This specifies a section in the configuration file containing extra
368 object identifiers. Each line should consist of the short name of the
369 object identifier followed by B<=> and the numerical form. The short
370 and long names are the same when this option is used.
374 At startup the specified file is loaded into the random number generator,
375 and at exit 256 bytes will be written to it.
376 It is used for private key generation.
380 If this is set to B<no> then if a private key is generated it is
381 B<not> encrypted. This is equivalent to the B<-nodes> command line
382 option. For compatibility B<encrypt_rsa_key> is an equivalent option.
386 This option specifies the digest algorithm to use.
387 Any digest supported by the OpenSSL B<dgst> command can be used.
388 If not present then MD5 is used.
389 This option can be overridden on the command line.
393 This option masks out the use of certain string types in certain
394 fields. Most users will not need to change this option.
396 It can be set to several values B<default> which is also the default
397 option uses PrintableStrings, T61Strings and BMPStrings if the
398 B<pkix> value is used then only PrintableStrings and BMPStrings will
399 be used. This follows the PKIX recommendation in RFC2459. If the
400 B<utf8only> option is used then only UTF8Strings will be used: this
401 is the PKIX recommendation in RFC2459 after 2003. Finally the B<nombstr>
402 option just uses PrintableStrings and T61Strings: certain software has
403 problems with BMPStrings and UTF8Strings: in particular Netscape.
405 =item B<req_extensions>
407 This specifies the configuration file section containing a list of
408 extensions to add to the certificate request. It can be overridden
409 by the B<-reqexts> command line switch. See the
410 L<x509v3_config(5)> manual page for details of the
411 extension section format.
413 =item B<x509_extensions>
415 This specifies the configuration file section containing a list of
416 extensions to add to certificate generated when the B<-x509> switch
417 is used. It can be overridden by the B<-extensions> command line switch.
421 If set to the value B<no> this disables prompting of certificate fields
422 and just takes values from the config file directly. It also changes the
423 expected format of the B<distinguished_name> and B<attributes> sections.
427 If set to the value B<yes> then field values to be interpreted as UTF8
428 strings, by default they are interpreted as ASCII. This means that
429 the field values, whether prompted from a terminal or obtained from a
430 configuration file, must be valid UTF8 strings.
434 This specifies the section containing any request attributes: its format
435 is the same as B<distinguished_name>. Typically these may contain the
436 challengePassword or unstructuredName types. They are currently ignored
437 by OpenSSL's request signing utilities but some CAs might want them.
439 =item B<distinguished_name>
441 This specifies the section containing the distinguished name fields to
442 prompt for when generating a certificate or certificate request. The format
443 is described in the next section.
447 =head1 DISTINGUISHED NAME AND ATTRIBUTE SECTION FORMAT
449 There are two separate formats for the distinguished name and attribute
450 sections. If the B<prompt> option is set to B<no> then these sections
451 just consist of field names and values: for example,
455 emailAddress=someone@somewhere.org
457 This allows external programs (e.g. GUI based) to generate a template file
458 with all the field names and values and just pass it to B<req>. An example
459 of this kind of configuration file is contained in the B<EXAMPLES> section.
461 Alternatively if the B<prompt> option is absent or not set to B<no> then the
462 file contains field prompting information. It consists of lines of the form:
465 fieldName_default="default field value"
469 "fieldName" is the field name being used, for example commonName (or CN).
470 The "prompt" string is used to ask the user to enter the relevant
471 details. If the user enters nothing then the default value is used if no
472 default value is present then the field is omitted. A field can
473 still be omitted if a default value is present if the user just
474 enters the '.' character.
476 The number of characters entered must be between the fieldName_min and
477 fieldName_max limits: there may be additional restrictions based
478 on the field being used (for example countryName can only ever be
479 two characters long and must fit in a PrintableString).
481 Some fields (such as organizationName) can be used more than once
482 in a DN. This presents a problem because configuration files will
483 not recognize the same name occurring twice. To avoid this problem
484 if the fieldName contains some characters followed by a full stop
485 they will be ignored. So for example a second organizationName can
486 be input by calling it "1.organizationName".
488 The actual permitted field names are any object identifier short or
489 long names. These are compiled into OpenSSL and include the usual
490 values such as commonName, countryName, localityName, organizationName,
491 organizationalUnitName, stateOrProvinceName. Additionally emailAddress
492 is include as well as name, surname, givenName initials and dnQualifier.
494 Additional object identifiers can be defined with the B<oid_file> or
495 B<oid_section> options in the configuration file. Any additional fields
496 will be treated as though they were a DirectoryString.
501 Examine and verify certificate request:
503 openssl req -in req.pem -text -verify -noout
505 Create a private key and then generate a certificate request from it:
507 openssl genrsa -out key.pem 2048
508 openssl req -new -key key.pem -out req.pem
510 The same but just using req:
512 openssl req -newkey rsa:2048 -keyout key.pem -out req.pem
514 Generate a self signed root certificate:
516 openssl req -x509 -newkey rsa:2048 -keyout key.pem -out req.pem
518 Example of a file pointed to by the B<oid_file> option:
520 1.2.3.4 shortName A longer Name
521 1.2.3.6 otherName Other longer Name
523 Example of a section pointed to by B<oid_section> making use of variable
527 testoid2=${testoid1}.6
529 Sample configuration file prompting for field values:
533 default_keyfile = privkey.pem
534 distinguished_name = req_distinguished_name
535 attributes = req_attributes
536 req_extensions = v3_ca
538 dirstring_type = nobmp
540 [ req_distinguished_name ]
541 countryName = Country Name (2 letter code)
542 countryName_default = AU
546 localityName = Locality Name (eg, city)
548 organizationalUnitName = Organizational Unit Name (eg, section)
550 commonName = Common Name (eg, YOUR name)
553 emailAddress = Email Address
554 emailAddress_max = 40
557 challengePassword = A challenge password
558 challengePassword_min = 4
559 challengePassword_max = 20
563 subjectKeyIdentifier=hash
564 authorityKeyIdentifier=keyid:always,issuer:always
565 basicConstraints = critical, CA:true
567 Sample configuration containing all field values:
570 RANDFILE = $ENV::HOME/.rnd
574 default_keyfile = keyfile.pem
575 distinguished_name = req_distinguished_name
576 attributes = req_attributes
578 output_password = mypass
580 [ req_distinguished_name ]
582 ST = Test State or Province
584 O = Organization Name
585 OU = Organizational Unit Name
587 emailAddress = test@email.address
590 challengePassword = A challenge password
595 The header and footer lines in the B<PEM> format are normally:
597 -----BEGIN CERTIFICATE REQUEST-----
598 -----END CERTIFICATE REQUEST-----
600 some software (some versions of Netscape certificate server) instead needs:
602 -----BEGIN NEW CERTIFICATE REQUEST-----
603 -----END NEW CERTIFICATE REQUEST-----
605 which is produced with the B<-newhdr> option but is otherwise compatible.
606 Either form is accepted transparently on input.
608 The certificate requests generated by B<Xenroll> with MSIE have extensions
609 added. It includes the B<keyUsage> extension which determines the type of
610 key (signature only or general purpose) and any additional OIDs entered
611 by the script in an extendedKeyUsage extension.
615 The following messages are frequently asked about:
617 Using configuration from /some/path/openssl.cnf
618 Unable to load config info
620 This is followed some time later by...
622 unable to find 'distinguished_name' in config
623 problems making Certificate Request
625 The first error message is the clue: it can't find the configuration
626 file! Certain operations (like examining a certificate request) don't
627 need a configuration file so its use isn't enforced. Generation of
628 certificates or requests however does need a configuration file. This
629 could be regarded as a bug.
631 Another puzzling message is this:
636 this is displayed when no attributes are present and the request includes
637 the correct empty B<SET OF> structure (the DER encoding of which is 0xa0
638 0x00). If you just see:
642 then the B<SET OF> is missing and the encoding is technically invalid (but
643 it is tolerated). See the description of the command line option B<-asn1-kludge>
644 for more information.
648 OpenSSL's handling of T61Strings (aka TeletexStrings) is broken: it effectively
649 treats them as ISO-8859-1 (Latin 1), Netscape and MSIE have similar behaviour.
650 This can cause problems if you need characters that aren't available in
651 PrintableStrings and you don't want to or can't use BMPStrings.
653 As a consequence of the T61String handling the only correct way to represent
654 accented characters in OpenSSL is to use a BMPString: unfortunately Netscape
655 currently chokes on these. If you have to use accented characters with Netscape
656 and MSIE then you currently need to use the invalid T61String form.
658 The current prompting is not very friendly. It doesn't allow you to confirm what
659 you've just entered. Other things like extensions in certificate requests are
660 statically defined in the configuration file. Some of these: like an email
661 address in subjectAltName should be input by the user.
665 L<x509(1)>, L<ca(1)>, L<genrsa(1)>,
666 L<gendsa(1)>, L<config(5)>,
671 Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
673 Licensed under the OpenSSL license (the "License"). You may not use
674 this file except in compliance with the License. You can obtain a copy
675 in the file LICENSE in the source distribution or at
676 L<https://www.openssl.org/source/license.html>.