5 openssl-req - PKCS#10 certificate request and certificate generating utility
31 [B<-keygen_engine id>]
40 [B<-extensions section>]
53 [B<-sm2-hex-id hex-string>]
57 The B<req> command primarily creates and processes certificate requests
58 in PKCS#10 format. It can additionally create self signed certificates
59 for use as root CAs for example.
67 Print out a usage message.
69 =item B<-inform DER|PEM>
71 This specifies the input format. The B<DER> option uses an ASN1 DER encoded
72 form compatible with the PKCS#10. The B<PEM> form is the default format: it
73 consists of the B<DER> format base64 encoded with additional header and
76 =item B<-outform DER|PEM>
78 This specifies the output format, the options have the same meaning and default
79 as the B<-inform> option.
83 This specifies the input filename to read a request from or standard input
84 if this option is not specified. A request is only read if the creation
85 options (B<-new> and B<-newkey>) are not specified.
89 Pass options to the signature algorithm during sign or verify operations.
90 Names and values of these options are algorithm-specific.
94 The input file password source. For more information about the format of B<arg>
95 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
97 =item B<-out filename>
99 This specifies the output filename to write to or standard output by
102 =item B<-passout arg>
104 The output file password source. For more information about the format of B<arg>
105 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
109 Prints out the certificate request in text form.
113 Prints out the request subject (or certificate subject if B<-x509> is
118 Outputs the public key.
122 This option prevents output of the encoded version of the request.
126 This option prints out the value of the modulus of the public key
127 contained in the request.
131 Verifies the signature on the request.
135 This option generates a new certificate request. It will prompt
136 the user for the relevant field values. The actual fields
137 prompted for and their maximum and minimum sizes are specified
138 in the configuration file and any requested extensions.
140 If the B<-key> option is not used it will generate a new RSA private
141 key using information specified in the configuration file.
143 =item B<-rand file...>
145 A file or files containing random data used to seed the random number
147 Multiple files can be specified separated by an OS-dependent character.
148 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
151 =item [B<-writerand file>]
153 Writes random data to the specified I<file> upon exit.
154 This can be used with a subsequent B<-rand> flag.
158 This option creates a new certificate request and a new private
159 key. The argument takes one of several forms. B<rsa:nbits>, where
160 B<nbits> is the number of bits, generates an RSA key B<nbits>
161 in size. If B<nbits> is omitted, i.e. B<-newkey rsa> specified,
162 the default key size, specified in the configuration file is used.
164 All other algorithms support the B<-newkey alg:file> form, where file may be
165 an algorithm parameter file, created by the B<genpkey -genparam> command
166 or and X.509 certificate for a key with appropriate algorithm.
168 B<param:file> generates a key using the parameter file or certificate B<file>,
169 the algorithm is determined by the parameters. B<algname:file> use algorithm
170 B<algname> and parameter file B<file>: the two algorithms must match or an
171 error occurs. B<algname> just uses algorithm B<algname>, and parameters,
172 if necessary should be specified via B<-pkeyopt> parameter.
174 B<dsa:filename> generates a DSA key using the parameters
175 in the file B<filename>. B<ec:filename> generates EC key (usable both with
176 ECDSA or ECDH algorithms), B<gost2001:filename> generates GOST R
177 34.10-2001 key (requires B<ccgost> engine configured in the configuration
178 file). If just B<gost2001> is specified a parameter set should be
179 specified by B<-pkeyopt paramset:X>
182 =item B<-pkeyopt opt:value>
184 Set the public key algorithm option B<opt> to B<value>. The precise set of
185 options supported depends on the public key algorithm used and its
186 implementation. See B<KEY GENERATION OPTIONS> in the B<genpkey> manual page
189 =item B<-key filename>
191 This specifies the file to read the private key from. It also
192 accepts PKCS#8 format private keys for PEM format files.
194 =item B<-keyform PEM|DER>
196 The format of the private key file specified in the B<-key>
197 argument. PEM is the default.
199 =item B<-keyout filename>
201 This gives the filename to write the newly created private key to.
202 If this option is not specified then the filename present in the
203 configuration file is used.
207 If this option is specified then if a private key is created it
208 will not be encrypted.
212 This specifies the message digest to sign the request.
213 Any digest supported by the OpenSSL B<dgst> command can be used.
214 This overrides the digest algorithm specified in
215 the configuration file.
217 Some public key algorithms may override this choice. For instance, DSA
218 signatures always use SHA1, GOST R 34.10 signatures always use
219 GOST R 34.11-94 (B<-md_gost94>), Ed25519 and Ed448 never use any digest.
221 =item B<-config filename>
223 This allows an alternative configuration file to be specified.
224 Optional; for a description of the default value,
225 see L<openssl(1)/COMMAND SUMMARY>.
229 Sets subject name for new request or supersedes the subject name
230 when processing a request.
231 The arg must be formatted as I</type0=value0/type1=value1/type2=...>.
232 Keyword characters may be escaped by \ (backslash), and whitespace is retained.
233 Empty values are permitted, but the corresponding type will not be included
236 =item B<-multivalue-rdn>
238 This option causes the -subj argument to be interpreted with full
239 support for multivalued RDNs. Example:
241 I</DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe>
243 If -multi-rdn is not used then the UID value is I<123456+CN=John Doe>.
247 This option outputs a self signed certificate instead of a certificate
248 request. This is typically used to generate a test certificate or
249 a self signed root CA. The extensions added to the certificate
250 (if any) are specified in the configuration file. Unless specified
251 using the B<set_serial> option, a large random number will be used for
254 If existing request is specified with the B<-in> option, it is converted
255 to the self signed certificate otherwise new request is created.
259 When the B<-x509> option is being used this specifies the number of
260 days to certify the certificate for, otherwise it is ignored. B<n> should
261 be a positive integer. The default is 30 days.
263 =item B<-set_serial n>
265 Serial number to use when outputting a self signed certificate. This
266 may be specified as a decimal value or a hex value if preceded by B<0x>.
270 Add a specific extension to the certificate (if the B<-x509> option is
271 present) or certificate request. The argument must have the form of
272 a key=value pair as it would appear in a config file.
274 This option can be given multiple times.
276 =item B<-extensions section>
278 =item B<-reqexts section>
280 These options specify alternative sections to include certificate
281 extensions (if the B<-x509> option is present) or certificate
282 request extensions. This allows several different sections to
283 be used in the same configuration file to specify requests for
284 a variety of purposes.
288 A poison extension will be added to the certificate, making it a
289 "pre-certificate" (see RFC6962). This can be submitted to Certificate
290 Transparency logs in order to obtain signed certificate timestamps (SCTs).
291 These SCTs can then be embedded into the pre-certificate as an extension, before
292 removing the poison and signing the certificate.
294 This implies the B<-new> flag.
298 This option causes field values to be interpreted as UTF8 strings, by
299 default they are interpreted as ASCII. This means that the field
300 values, whether prompted from a terminal or obtained from a
301 configuration file, must be valid UTF8 strings.
303 =item B<-nameopt option>
305 Option which determines how the subject or issuer names are displayed. The
306 B<option> argument can be a single option or multiple options separated by
307 commas. Alternatively the B<-nameopt> switch may be used more than once to
308 set multiple options. See the L<x509(1)> manual page for details.
312 Customise the output format used with B<-text>. The B<option> argument can be
313 a single option or multiple options separated by commas.
315 See discussion of the B<-certopt> parameter in the L<x509(1)>
320 Adds the word B<NEW> to the PEM file header and footer lines on the outputted
321 request. Some software (Netscape certificate server) and some CAs need this.
325 Non-interactive mode.
329 Print extra details about the operations being performed.
333 Specifying an engine (by its unique B<id> string) will cause B<req>
334 to attempt to obtain a functional reference to the specified engine,
335 thus initialising it if needed. The engine will then be set as the default
336 for all available algorithms.
338 =item B<-keygen_engine id>
340 Specifies an engine (by its unique B<id> string) which would be used
341 for key generation operations.
345 Specify the ID string to use when verifying an SM2 certificate. The ID string is
346 required by the SM2 signature algorithm for signing and verification.
350 Specify a binary ID string to use when signing or verifying using an SM2
351 certificate. The argument for this option is string of hexadecimal digits.
355 =head1 CONFIGURATION FILE FORMAT
357 The configuration options are specified in the B<req> section of
358 the configuration file. As with all configuration files if no
359 value is specified in the specific section (i.e. B<req>) then
360 the initial unnamed or B<default> section is searched too.
362 The options available are described in detail below.
366 =item B<input_password output_password>
368 The passwords for the input private key file (if present) and
369 the output private key file (if one will be created). The
370 command line options B<passin> and B<passout> override the
371 configuration file values.
373 =item B<default_bits>
375 Specifies the default key size in bits.
377 This option is used in conjunction with the B<-new> option to generate
378 a new key. It can be overridden by specifying an explicit key size in
379 the B<-newkey> option. The smallest accepted key size is 512 bits. If
380 no key size is specified then 2048 bits is used.
382 =item B<default_keyfile>
384 This is the default filename to write a private key to. If not
385 specified the key is written to standard output. This can be
386 overridden by the B<-keyout> option.
390 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
391 Each line of the file should consist of the numerical form of the
392 object identifier followed by white space then the short name followed
393 by white space and finally the long name.
397 This specifies a section in the configuration file containing extra
398 object identifiers. Each line should consist of the short name of the
399 object identifier followed by B<=> and the numerical form. The short
400 and long names are the same when this option is used.
404 At startup the specified file is loaded into the random number generator,
405 and at exit 256 bytes will be written to it.
406 It is used for private key generation.
410 If this is set to B<no> then if a private key is generated it is
411 B<not> encrypted. This is equivalent to the B<-nodes> command line
412 option. For compatibility B<encrypt_rsa_key> is an equivalent option.
416 This option specifies the digest algorithm to use. Any digest supported by the
417 OpenSSL B<dgst> command can be used. This option can be overridden on the
418 command line. Certain signing algorithms (i.e. Ed25519 and Ed448) will ignore
419 any digest that has been set.
423 This option masks out the use of certain string types in certain
424 fields. Most users will not need to change this option.
426 It can be set to several values B<default> which is also the default
427 option uses PrintableStrings, T61Strings and BMPStrings if the
428 B<pkix> value is used then only PrintableStrings and BMPStrings will
429 be used. This follows the PKIX recommendation in RFC2459. If the
430 B<utf8only> option is used then only UTF8Strings will be used: this
431 is the PKIX recommendation in RFC2459 after 2003. Finally the B<nombstr>
432 option just uses PrintableStrings and T61Strings: certain software has
433 problems with BMPStrings and UTF8Strings: in particular Netscape.
435 =item B<req_extensions>
437 This specifies the configuration file section containing a list of
438 extensions to add to the certificate request. It can be overridden
439 by the B<-reqexts> command line switch. See the
440 L<x509v3_config(5)> manual page for details of the
441 extension section format.
443 =item B<x509_extensions>
445 This specifies the configuration file section containing a list of
446 extensions to add to certificate generated when the B<-x509> switch
447 is used. It can be overridden by the B<-extensions> command line switch.
451 If set to the value B<no> this disables prompting of certificate fields
452 and just takes values from the config file directly. It also changes the
453 expected format of the B<distinguished_name> and B<attributes> sections.
457 If set to the value B<yes> then field values to be interpreted as UTF8
458 strings, by default they are interpreted as ASCII. This means that
459 the field values, whether prompted from a terminal or obtained from a
460 configuration file, must be valid UTF8 strings.
464 This specifies the section containing any request attributes: its format
465 is the same as B<distinguished_name>. Typically these may contain the
466 challengePassword or unstructuredName types. They are currently ignored
467 by OpenSSL's request signing utilities but some CAs might want them.
469 =item B<distinguished_name>
471 This specifies the section containing the distinguished name fields to
472 prompt for when generating a certificate or certificate request. The format
473 is described in the next section.
477 =head1 DISTINGUISHED NAME AND ATTRIBUTE SECTION FORMAT
479 There are two separate formats for the distinguished name and attribute
480 sections. If the B<prompt> option is set to B<no> then these sections
481 just consist of field names and values: for example,
485 emailAddress=someone@somewhere.org
487 This allows external programs (e.g. GUI based) to generate a template file
488 with all the field names and values and just pass it to B<req>. An example
489 of this kind of configuration file is contained in the B<EXAMPLES> section.
491 Alternatively if the B<prompt> option is absent or not set to B<no> then the
492 file contains field prompting information. It consists of lines of the form:
495 fieldName_default="default field value"
499 "fieldName" is the field name being used, for example commonName (or CN).
500 The "prompt" string is used to ask the user to enter the relevant
501 details. If the user enters nothing then the default value is used if no
502 default value is present then the field is omitted. A field can
503 still be omitted if a default value is present if the user just
504 enters the '.' character.
506 The number of characters entered must be between the fieldName_min and
507 fieldName_max limits: there may be additional restrictions based
508 on the field being used (for example countryName can only ever be
509 two characters long and must fit in a PrintableString).
511 Some fields (such as organizationName) can be used more than once
512 in a DN. This presents a problem because configuration files will
513 not recognize the same name occurring twice. To avoid this problem
514 if the fieldName contains some characters followed by a full stop
515 they will be ignored. So for example a second organizationName can
516 be input by calling it "1.organizationName".
518 The actual permitted field names are any object identifier short or
519 long names. These are compiled into OpenSSL and include the usual
520 values such as commonName, countryName, localityName, organizationName,
521 organizationalUnitName, stateOrProvinceName. Additionally emailAddress
522 is included as well as name, surname, givenName, initials, and dnQualifier.
524 Additional object identifiers can be defined with the B<oid_file> or
525 B<oid_section> options in the configuration file. Any additional fields
526 will be treated as though they were a DirectoryString.
531 Examine and verify certificate request:
533 openssl req -in req.pem -text -verify -noout
535 Create a private key and then generate a certificate request from it:
537 openssl genrsa -out key.pem 2048
538 openssl req -new -key key.pem -out req.pem
540 The same but just using req:
542 openssl req -newkey rsa:2048 -keyout key.pem -out req.pem
544 Generate a self signed root certificate:
546 openssl req -x509 -newkey rsa:2048 -keyout key.pem -out req.pem
548 Create an SM2 private key and then generate a certificate request from it:
550 openssl ecparam -genkey -name SM2 -out sm2.key
551 openssl req -new -key sm2.key -out sm2.csr -sm3 -sigopt "sm2_id:1234567812345678"
553 Examine and verify an SM2 certificate request:
555 openssl req -verify -in sm2.csr -sm3 -sm2-id 1234567812345678
557 Example of a file pointed to by the B<oid_file> option:
559 1.2.3.4 shortName A longer Name
560 1.2.3.6 otherName Other longer Name
562 Example of a section pointed to by B<oid_section> making use of variable
566 testoid2=${testoid1}.6
568 Sample configuration file prompting for field values:
572 default_keyfile = privkey.pem
573 distinguished_name = req_distinguished_name
574 attributes = req_attributes
575 req_extensions = v3_ca
577 dirstring_type = nobmp
579 [ req_distinguished_name ]
580 countryName = Country Name (2 letter code)
581 countryName_default = AU
585 localityName = Locality Name (eg, city)
587 organizationalUnitName = Organizational Unit Name (eg, section)
589 commonName = Common Name (eg, YOUR name)
592 emailAddress = Email Address
593 emailAddress_max = 40
596 challengePassword = A challenge password
597 challengePassword_min = 4
598 challengePassword_max = 20
602 subjectKeyIdentifier=hash
603 authorityKeyIdentifier=keyid:always,issuer:always
604 basicConstraints = critical, CA:true
606 Sample configuration containing all field values:
609 RANDFILE = $ENV::HOME/.rnd
613 default_keyfile = keyfile.pem
614 distinguished_name = req_distinguished_name
615 attributes = req_attributes
617 output_password = mypass
619 [ req_distinguished_name ]
621 ST = Test State or Province
623 O = Organization Name
624 OU = Organizational Unit Name
626 emailAddress = test@email.address
629 challengePassword = A challenge password
631 Example of giving the most common attributes (subject and extensions)
634 openssl req -new -subj "/C=GB/CN=foo" \
635 -addext "subjectAltName = DNS:foo.co.uk" \
636 -addext "certificatePolicies = 1.2.3.4" \
637 -newkey rsa:2048 -keyout key.pem -out req.pem
642 The header and footer lines in the B<PEM> format are normally:
644 -----BEGIN CERTIFICATE REQUEST-----
645 -----END CERTIFICATE REQUEST-----
647 some software (some versions of Netscape certificate server) instead needs:
649 -----BEGIN NEW CERTIFICATE REQUEST-----
650 -----END NEW CERTIFICATE REQUEST-----
652 which is produced with the B<-newhdr> option but is otherwise compatible.
653 Either form is accepted transparently on input.
655 The certificate requests generated by B<Xenroll> with MSIE have extensions
656 added. It includes the B<keyUsage> extension which determines the type of
657 key (signature only or general purpose) and any additional OIDs entered
658 by the script in an extendedKeyUsage extension.
662 The following messages are frequently asked about:
664 Using configuration from /some/path/openssl.cnf
665 Unable to load config info
667 This is followed some time later by...
669 unable to find 'distinguished_name' in config
670 problems making Certificate Request
672 The first error message is the clue: it can't find the configuration
673 file! Certain operations (like examining a certificate request) don't
674 need a configuration file so its use isn't enforced. Generation of
675 certificates or requests however does need a configuration file. This
676 could be regarded as a bug.
678 Another puzzling message is this:
683 this is displayed when no attributes are present and the request includes
684 the correct empty B<SET OF> structure (the DER encoding of which is 0xa0
685 0x00). If you just see:
689 then the B<SET OF> is missing and the encoding is technically invalid (but
690 it is tolerated). See the description of the command line option B<-asn1-kludge>
691 for more information.
695 OpenSSL's handling of T61Strings (aka TeletexStrings) is broken: it effectively
696 treats them as ISO-8859-1 (Latin 1), Netscape and MSIE have similar behaviour.
697 This can cause problems if you need characters that aren't available in
698 PrintableStrings and you don't want to or can't use BMPStrings.
700 As a consequence of the T61String handling the only correct way to represent
701 accented characters in OpenSSL is to use a BMPString: unfortunately Netscape
702 currently chokes on these. If you have to use accented characters with Netscape
703 and MSIE then you currently need to use the invalid T61String form.
705 The current prompting is not very friendly. It doesn't allow you to confirm what
706 you've just entered. Other things like extensions in certificate requests are
707 statically defined in the configuration file. Some of these: like an email
708 address in subjectAltName should be input by the user.
715 L<openssl-genrsa(1)>,
716 L<openssl-gendsa(1)>,
722 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
724 Licensed under the Apache License 2.0 (the "License"). You may not use
725 this file except in compliance with the License. You can obtain a copy
726 in the file LICENSE in the source distribution or at
727 L<https://www.openssl.org/source/license.html>.