5 openssl-req - PKCS#10 certificate request and certificate generating utility
11 [B<-inform> B<DER>|B<PEM>]
12 [B<-outform> B<DER>|B<PEM>]
24 [B<-writerand> I<file>]
28 [B<-keyform> B<DER>|B<PEM>]
29 [B<-keyout> I<filename>]
30 [B<-keygen_engine> I<id>]
32 [B<-config> I<filename>]
39 [B<-extensions> I<section>]
40 [B<-reqexts> I<section>]
47 [B<-sigopt> I<nm>:I<v>]
51 [B<-sm2-id> I<string>]
52 [B<-sm2-hex-id> I<hex-string>]
54 =for comment ifdef engine keygen_engine sm2-id sm2-hex-id
58 This command primarily creates and processes certificate requests
59 in PKCS#10 format. It can additionally create self signed certificates
60 for use as root CAs for example.
68 Print out a usage message.
70 =item B<-inform> B<DER>|B<PEM>
72 This specifies the input format. The B<DER> option uses an ASN1 DER encoded
73 form compatible with the PKCS#10. The B<PEM> form is the default format: it
74 consists of the B<DER> format base64 encoded with additional header and
77 =item B<-outform> B<DER>|B<PEM>
79 This specifies the output format, the options have the same meaning and default
80 as the B<-inform> option.
82 =item B<-in> I<filename>
84 This specifies the input filename to read a request from or standard input
85 if this option is not specified. A request is only read if the creation
86 options (B<-new> and B<-newkey>) are not specified.
88 =item B<-sigopt> I<nm>:I<v>
90 Pass options to the signature algorithm during sign or verify operations.
91 Names and values of these options are algorithm-specific.
93 =item B<-passin> I<arg>, B<-passout> I<arg>
95 The password source for the input and output file.
96 For more information about the format of B<arg>
97 see L<openssl(1)/Pass Phrase Options>.
99 =item B<-out> I<filename>
101 This specifies the output filename to write to or standard output by
106 Prints out the certificate request in text form.
110 Prints out the request subject (or certificate subject if B<-x509> is
115 Outputs the public key.
119 This option prevents output of the encoded version of the request.
123 This option prints out the value of the modulus of the public key
124 contained in the request.
128 Verifies the signature on the request.
132 This option generates a new certificate request. It will prompt
133 the user for the relevant field values. The actual fields
134 prompted for and their maximum and minimum sizes are specified
135 in the configuration file and any requested extensions.
137 If the B<-key> option is not used it will generate a new RSA private
138 key using information specified in the configuration file.
140 =item B<-rand> I<files>
142 The files containing random data used to seed the random number generator.
143 Multiple files can be specified separated by an OS-dependent character.
144 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
147 =item B<-writerand> I<file>
149 Writes random data to the specified I<file> upon exit.
150 This can be used with a subsequent B<-rand> flag.
152 =item B<-newkey> I<arg>
154 This option creates a new certificate request and a new private
155 key. The argument takes one of several forms.
157 B<rsa:>I<nbits>, where
158 I<nbits> is the number of bits, generates an RSA key I<nbits>
159 in size. If I<nbits> is omitted, i.e. B<-newkey> I<rsa> specified,
160 the default key size, specified in the configuration file is used.
162 All other algorithms support the B<-newkey> I<alg>:I<file> form, where file
163 may be an algorithm parameter file, created with C<openssl genpkey -genparam>
164 or an X.509 certificate for a key with appropriate algorithm.
166 B<param:>I<file> generates a key using the parameter file or certificate
167 I<file>, the algorithm is determined by the parameters. I<algname>:I<file>
168 use algorithm I<algname> and parameter file I<file>: the two algorithms must
169 match or an error occurs. I<algname> just uses algorithm I<algname>, and
170 parameters, if necessary should be specified via B<-pkeyopt> parameter.
172 B<dsa:>I<filename> generates a DSA key using the parameters
173 in the file I<filename>. B<ec:>I<filename> generates EC key (usable both with
174 ECDSA or ECDH algorithms), B<gost2001:>I<filename> generates GOST R
175 34.10-2001 key (requires B<gost> engine configured in the configuration
176 file). If just B<gost2001> is specified a parameter set should be
177 specified by B<-pkeyopt> I<paramset:X>
179 =item B<-pkeyopt> I<opt>:I<value>
181 Set the public key algorithm option I<opt> to I<value>. The precise set of
182 options supported depends on the public key algorithm used and its
184 See L<openssl-genpkey(1)/KEY GENERATION OPTIONS> for more details.
186 =item B<-key> I<filename>
188 This specifies the file to read the private key from. It also
189 accepts PKCS#8 format private keys for PEM format files.
191 =item B<-keyform> B<DER>|B<PEM>
193 The format of the private key file specified in the B<-key>
194 argument. PEM is the default.
196 =item B<-keyout> I<filename>
198 This gives the filename to write the newly created private key to.
199 If this option is not specified then the filename present in the
200 configuration file is used.
204 If this option is specified then if a private key is created it
205 will not be encrypted.
209 This specifies the message digest to sign the request.
210 Any digest supported by the OpenSSL B<dgst> command can be used.
211 This overrides the digest algorithm specified in
212 the configuration file.
214 Some public key algorithms may override this choice. For instance, DSA
215 signatures always use SHA1, GOST R 34.10 signatures always use
216 GOST R 34.11-94 (B<-md_gost94>), Ed25519 and Ed448 never use any digest.
218 =item B<-config> I<filename>
220 This allows an alternative configuration file to be specified.
221 Optional; for a description of the default value,
222 see L<openssl(1)/COMMAND SUMMARY>.
224 =item B<-subj> I<arg>
226 Sets subject name for new request or supersedes the subject name
227 when processing a request.
228 The arg must be formatted as C</type0=value0/type1=value1/type2=...>.
229 Keyword characters may be escaped by \ (backslash), and whitespace is retained.
230 Empty values are permitted, but the corresponding type will not be included
233 =item B<-multivalue-rdn>
235 This option causes the -subj argument to be interpreted with full
236 support for multivalued RDNs. Example:
238 C</DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe>
240 If -multi-rdn is not used then the UID value is C<123456+CN=John Doe>.
244 This option outputs a self signed certificate instead of a certificate
245 request. This is typically used to generate a test certificate or
246 a self signed root CA. The extensions added to the certificate
247 (if any) are specified in the configuration file. Unless specified
248 using the B<-set_serial> option, a large random number will be used for
251 If existing request is specified with the B<-in> option, it is converted
252 to the self signed certificate otherwise new request is created.
256 When the B<-x509> option is being used this specifies the number of
257 days to certify the certificate for, otherwise it is ignored. I<n> should
258 be a positive integer. The default is 30 days.
260 =item B<-set_serial> I<n>
262 Serial number to use when outputting a self signed certificate. This
263 may be specified as a decimal value or a hex value if preceded by C<0x>.
265 =item B<-addext> I<ext>
267 Add a specific extension to the certificate (if the B<-x509> option is
268 present) or certificate request. The argument must have the form of
269 a key=value pair as it would appear in a config file.
271 This option can be given multiple times.
273 =item B<-extensions> I<section>
275 =item B<-reqexts> I<section>
277 These options specify alternative sections to include certificate
278 extensions (if the B<-x509> option is present) or certificate
279 request extensions. This allows several different sections to
280 be used in the same configuration file to specify requests for
281 a variety of purposes.
285 A poison extension will be added to the certificate, making it a
286 "pre-certificate" (see RFC6962). This can be submitted to Certificate
287 Transparency logs in order to obtain signed certificate timestamps (SCTs).
288 These SCTs can then be embedded into the pre-certificate as an extension, before
289 removing the poison and signing the certificate.
291 This implies the B<-new> flag.
295 This option causes field values to be interpreted as UTF8 strings, by
296 default they are interpreted as ASCII. This means that the field
297 values, whether prompted from a terminal or obtained from a
298 configuration file, must be valid UTF8 strings.
300 =item B<-nameopt> I<option>
302 Option which determines how the subject or issuer names are displayed. The
303 I<option> argument can be a single option or multiple options separated by
304 commas. Alternatively the B<-nameopt> switch may be used more than once to
305 set multiple options. See the L<openssl-x509(1)> manual page for details.
307 =item B<-reqopt> I<option>
309 Customise the output format used with B<-text>. The I<option> argument can be
310 a single option or multiple options separated by commas.
312 See discussion of the B<-certopt> parameter in the L<openssl-x509(1)>
317 Adds the word B<NEW> to the PEM file header and footer lines on the outputted
318 request. Some software (Netscape certificate server) and some CAs need this.
322 Non-interactive mode.
326 Print extra details about the operations being performed.
328 =item B<-engine> I<id>
330 Specifying an engine (by its unique I<id> string) will cause this command
331 to attempt to obtain a functional reference to the specified engine,
332 thus initialising it if needed. The engine will then be set as the default
333 for all available algorithms.
335 =item B<-keygen_engine> I<id>
337 Specifies an engine (by its unique I<id> string) which would be used
338 for key generation operations.
342 Specify the ID string to use when verifying an SM2 certificate request. The ID
343 string is required by the SM2 signature algorithm for signing and verification.
347 Specify a binary ID string to use when verifying an SM2 certificate request. The
348 argument for this option is string of hexadecimal digits.
352 =head1 CONFIGURATION FILE FORMAT
354 The configuration options are specified in the B<req> section of
355 the configuration file. As with all configuration files if no
356 value is specified in the specific section (i.e. B<req>) then
357 the initial unnamed or B<default> section is searched too.
359 The options available are described in detail below.
363 =item B<input_password output_password>
365 The passwords for the input private key file (if present) and
366 the output private key file (if one will be created). The
367 command line options B<passin> and B<passout> override the
368 configuration file values.
370 =item B<default_bits>
372 Specifies the default key size in bits.
374 This option is used in conjunction with the B<-new> option to generate
375 a new key. It can be overridden by specifying an explicit key size in
376 the B<-newkey> option. The smallest accepted key size is 512 bits. If
377 no key size is specified then 2048 bits is used.
379 =item B<default_keyfile>
381 This is the default filename to write a private key to. If not
382 specified the key is written to standard output. This can be
383 overridden by the B<-keyout> option.
387 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
388 Each line of the file should consist of the numerical form of the
389 object identifier followed by white space then the short name followed
390 by white space and finally the long name.
394 This specifies a section in the configuration file containing extra
395 object identifiers. Each line should consist of the short name of the
396 object identifier followed by B<=> and the numerical form. The short
397 and long names are the same when this option is used.
401 At startup the specified file is loaded into the random number generator,
402 and at exit 256 bytes will be written to it.
403 It is used for private key generation.
407 If this is set to B<no> then if a private key is generated it is
408 B<not> encrypted. This is equivalent to the B<-nodes> command line
409 option. For compatibility B<encrypt_rsa_key> is an equivalent option.
413 This option specifies the digest algorithm to use. Any digest supported by the
414 OpenSSL B<dgst> command can be used. This option can be overridden on the
415 command line. Certain signing algorithms (i.e. Ed25519 and Ed448) will ignore
416 any digest that has been set.
420 This option masks out the use of certain string types in certain
421 fields. Most users will not need to change this option.
423 It can be set to several values B<default> which is also the default
424 option uses PrintableStrings, T61Strings and BMPStrings if the
425 B<pkix> value is used then only PrintableStrings and BMPStrings will
426 be used. This follows the PKIX recommendation in RFC2459. If the
427 B<utf8only> option is used then only UTF8Strings will be used: this
428 is the PKIX recommendation in RFC2459 after 2003. Finally the B<nombstr>
429 option just uses PrintableStrings and T61Strings: certain software has
430 problems with BMPStrings and UTF8Strings: in particular Netscape.
432 =item B<req_extensions>
434 This specifies the configuration file section containing a list of
435 extensions to add to the certificate request. It can be overridden
436 by the B<-reqexts> command line switch. See the
437 L<x509v3_config(5)> manual page for details of the
438 extension section format.
440 =item B<x509_extensions>
442 This specifies the configuration file section containing a list of
443 extensions to add to certificate generated when the B<-x509> switch
444 is used. It can be overridden by the B<-extensions> command line switch.
448 If set to the value B<no> this disables prompting of certificate fields
449 and just takes values from the config file directly. It also changes the
450 expected format of the B<distinguished_name> and B<attributes> sections.
454 If set to the value B<yes> then field values to be interpreted as UTF8
455 strings, by default they are interpreted as ASCII. This means that
456 the field values, whether prompted from a terminal or obtained from a
457 configuration file, must be valid UTF8 strings.
461 This specifies the section containing any request attributes: its format
462 is the same as B<distinguished_name>. Typically these may contain the
463 challengePassword or unstructuredName types. They are currently ignored
464 by OpenSSL's request signing utilities but some CAs might want them.
466 =item B<distinguished_name>
468 This specifies the section containing the distinguished name fields to
469 prompt for when generating a certificate or certificate request. The format
470 is described in the next section.
474 =head1 DISTINGUISHED NAME AND ATTRIBUTE SECTION FORMAT
476 There are two separate formats for the distinguished name and attribute
477 sections. If the B<prompt> option is set to B<no> then these sections
478 just consist of field names and values: for example,
482 emailAddress=someone@somewhere.org
484 This allows external programs (e.g. GUI based) to generate a template file with
485 all the field names and values and just pass it to this command. An example
486 of this kind of configuration file is contained in the B<EXAMPLES> section.
488 Alternatively if the B<prompt> option is absent or not set to B<no> then the
489 file contains field prompting information. It consists of lines of the form:
492 fieldName_default="default field value"
496 "fieldName" is the field name being used, for example commonName (or CN).
497 The "prompt" string is used to ask the user to enter the relevant
498 details. If the user enters nothing then the default value is used if no
499 default value is present then the field is omitted. A field can
500 still be omitted if a default value is present if the user just
501 enters the '.' character.
503 The number of characters entered must be between the fieldName_min and
504 fieldName_max limits: there may be additional restrictions based
505 on the field being used (for example countryName can only ever be
506 two characters long and must fit in a PrintableString).
508 Some fields (such as organizationName) can be used more than once
509 in a DN. This presents a problem because configuration files will
510 not recognize the same name occurring twice. To avoid this problem
511 if the fieldName contains some characters followed by a full stop
512 they will be ignored. So for example a second organizationName can
513 be input by calling it "1.organizationName".
515 The actual permitted field names are any object identifier short or
516 long names. These are compiled into OpenSSL and include the usual
517 values such as commonName, countryName, localityName, organizationName,
518 organizationalUnitName, stateOrProvinceName. Additionally emailAddress
519 is included as well as name, surname, givenName, initials, and dnQualifier.
521 Additional object identifiers can be defined with the B<oid_file> or
522 B<oid_section> options in the configuration file. Any additional fields
523 will be treated as though they were a DirectoryString.
528 Examine and verify certificate request:
530 openssl req -in req.pem -text -verify -noout
532 Create a private key and then generate a certificate request from it:
534 openssl genrsa -out key.pem 2048
535 openssl req -new -key key.pem -out req.pem
537 The same but just using req:
539 openssl req -newkey rsa:2048 -keyout key.pem -out req.pem
541 Generate a self signed root certificate:
543 openssl req -x509 -newkey rsa:2048 -keyout key.pem -out req.pem
545 Create an SM2 private key and then generate a certificate request from it:
547 openssl ecparam -genkey -name SM2 -out sm2.key
548 openssl req -new -key sm2.key -out sm2.csr -sm3 -sigopt "sm2_id:1234567812345678"
550 Examine and verify an SM2 certificate request:
552 openssl req -verify -in sm2.csr -sm3 -sm2-id 1234567812345678
554 Example of a file pointed to by the B<oid_file> option:
556 1.2.3.4 shortName A longer Name
557 1.2.3.6 otherName Other longer Name
559 Example of a section pointed to by B<oid_section> making use of variable
563 testoid2=${testoid1}.6
565 Sample configuration file prompting for field values:
569 default_keyfile = privkey.pem
570 distinguished_name = req_distinguished_name
571 attributes = req_attributes
572 req_extensions = v3_ca
574 dirstring_type = nobmp
576 [ req_distinguished_name ]
577 countryName = Country Name (2 letter code)
578 countryName_default = AU
582 localityName = Locality Name (eg, city)
584 organizationalUnitName = Organizational Unit Name (eg, section)
586 commonName = Common Name (eg, YOUR name)
589 emailAddress = Email Address
590 emailAddress_max = 40
593 challengePassword = A challenge password
594 challengePassword_min = 4
595 challengePassword_max = 20
599 subjectKeyIdentifier=hash
600 authorityKeyIdentifier=keyid:always,issuer:always
601 basicConstraints = critical, CA:true
603 Sample configuration containing all field values:
606 RANDFILE = $ENV::HOME/.rnd
610 default_keyfile = keyfile.pem
611 distinguished_name = req_distinguished_name
612 attributes = req_attributes
614 output_password = mypass
616 [ req_distinguished_name ]
618 ST = Test State or Province
620 O = Organization Name
621 OU = Organizational Unit Name
623 emailAddress = test@email.address
626 challengePassword = A challenge password
628 Example of giving the most common attributes (subject and extensions)
631 openssl req -new -subj "/C=GB/CN=foo" \
632 -addext "subjectAltName = DNS:foo.co.uk" \
633 -addext "certificatePolicies = 1.2.3.4" \
634 -newkey rsa:2048 -keyout key.pem -out req.pem
639 The header and footer lines in the B<PEM> format are normally:
641 -----BEGIN CERTIFICATE REQUEST-----
642 -----END CERTIFICATE REQUEST-----
644 some software (some versions of Netscape certificate server) instead needs:
646 -----BEGIN NEW CERTIFICATE REQUEST-----
647 -----END NEW CERTIFICATE REQUEST-----
649 which is produced with the B<-newhdr> option but is otherwise compatible.
650 Either form is accepted transparently on input.
652 The certificate requests generated by B<Xenroll> with MSIE have extensions
653 added. It includes the B<keyUsage> extension which determines the type of
654 key (signature only or general purpose) and any additional OIDs entered
655 by the script in an extendedKeyUsage extension.
659 The following messages are frequently asked about:
661 Using configuration from /some/path/openssl.cnf
662 Unable to load config info
664 This is followed some time later by:
666 unable to find 'distinguished_name' in config
667 problems making Certificate Request
669 The first error message is the clue: it can't find the configuration
670 file! Certain operations (like examining a certificate request) don't
671 need a configuration file so its use isn't enforced. Generation of
672 certificates or requests however does need a configuration file. This
673 could be regarded as a bug.
675 Another puzzling message is this:
680 this is displayed when no attributes are present and the request includes
681 the correct empty B<SET OF> structure (the DER encoding of which is 0xa0
682 0x00). If you just see:
686 then the B<SET OF> is missing and the encoding is technically invalid (but
687 it is tolerated). See the description of the command line option B<-asn1-kludge>
688 for more information.
692 OpenSSL's handling of T61Strings (aka TeletexStrings) is broken: it effectively
693 treats them as ISO-8859-1 (Latin 1), Netscape and MSIE have similar behaviour.
694 This can cause problems if you need characters that aren't available in
695 PrintableStrings and you don't want to or can't use BMPStrings.
697 As a consequence of the T61String handling the only correct way to represent
698 accented characters in OpenSSL is to use a BMPString: unfortunately Netscape
699 currently chokes on these. If you have to use accented characters with Netscape
700 and MSIE then you currently need to use the invalid T61String form.
702 The current prompting is not very friendly. It doesn't allow you to confirm what
703 you've just entered. Other things like extensions in certificate requests are
704 statically defined in the configuration file. Some of these: like an email
705 address in subjectAltName should be input by the user.
712 L<openssl-genrsa(1)>,
713 L<openssl-gendsa(1)>,
719 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
721 Licensed under the Apache License 2.0 (the "License"). You may not use
722 this file except in compliance with the License. You can obtain a copy
723 in the file LICENSE in the source distribution or at
724 L<https://www.openssl.org/source/license.html>.