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>]
25 [B<-newkey> I<rsa:bits>]
26 [B<-newkey> I<alg:file>]
29 [B<-keyform> B<DER>|B<PEM>]
30 [B<-keyout> I<filename>]
31 [B<-keygen_engine> I<id>]
33 [B<-config> I<filename>]
40 [B<-extensions> I<section>]
41 [B<-reqexts> I<section>]
48 [B<-sigopt> I<nm>:I<v>]
52 [B<-sm2-id> I<string>]
53 [B<-sm2-hex-id> I<hex-string>]
55 =for comment ifdef engine keygen_engine sm2-id sm2-hex-id
59 The B<req> command primarily creates and processes certificate requests
60 in PKCS#10 format. It can additionally create self signed certificates
61 for use as root CAs for example.
69 Print out a usage message.
71 =item B<-inform> B<DER>|B<PEM>
73 This specifies the input format. The B<DER> option uses an ASN1 DER encoded
74 form compatible with the PKCS#10. The B<PEM> form is the default format: it
75 consists of the B<DER> format base64 encoded with additional header and
78 =item B<-outform> B<DER>|B<PEM>
80 This specifies the output format, the options have the same meaning and default
81 as the B<-inform> option.
83 =item B<-in> I<filename>
85 This specifies the input filename to read a request from or standard input
86 if this option is not specified. A request is only read if the creation
87 options (B<-new> and B<-newkey>) are not specified.
89 =item B<-sigopt> I<nm>:I<v>
91 Pass options to the signature algorithm during sign or verify operations.
92 Names and values of these options are algorithm-specific.
94 =item B<-passin> I<arg>
96 The input file password source. 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
104 =item B<-passout> I<arg>
106 The output file password source. For more information about the format of B<arg>
107 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
111 Prints out the certificate request in text form.
115 Prints out the request subject (or certificate subject if B<-x509> is
120 Outputs the public key.
124 This option prevents output of the encoded version of the request.
128 This option prints out the value of the modulus of the public key
129 contained in the request.
133 Verifies the signature on the request.
137 This option generates a new certificate request. It will prompt
138 the user for the relevant field values. The actual fields
139 prompted for and their maximum and minimum sizes are specified
140 in the configuration file and any requested extensions.
142 If the B<-key> option is not used it will generate a new RSA private
143 key using information specified in the configuration file.
145 =item B<-rand> I<file...>
147 A file or files containing random data used to seed the random number
149 Multiple files can be specified separated by an OS-dependent character.
150 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
153 =item B<-writerand> I<file>
155 Writes random data to the specified I<file> upon exit.
156 This can be used with a subsequent B<-rand> flag.
158 =item B<-newkey> I<arg>
160 This option creates a new certificate request and a new private
161 key. The argument takes one of several forms. B<rsa:nbits>, where
162 B<nbits> is the number of bits, generates an RSA key B<nbits>
163 in size. If B<nbits> is omitted, i.e. B<-newkey> I<rsa> specified,
164 the default key size, specified in the configuration file is used.
166 All other algorithms support the B<-newkey> I<alg:file> form, where file may be
167 an algorithm parameter file, created by the B<genpkey -genparam> command
168 or and X.509 certificate for a key with appropriate algorithm.
170 B<param:file> generates a key using the parameter file or certificate B<file>,
171 the algorithm is determined by the parameters. B<algname:file> use algorithm
172 B<algname> and parameter file B<file>: the two algorithms must match or an
173 error occurs. B<algname> just uses algorithm B<algname>, and parameters,
174 if necessary should be specified via B<-pkeyopt> parameter.
176 B<dsa:filename> generates a DSA key using the parameters
177 in the file B<filename>. B<ec:filename> generates EC key (usable both with
178 ECDSA or ECDH algorithms), B<gost2001:filename> generates GOST R
179 34.10-2001 key (requires B<ccgost> engine configured in the configuration
180 file). If just B<gost2001> is specified a parameter set should be
181 specified by B<-pkeyopt> I<paramset:X>
184 =item B<-pkeyopt> I<opt:value>
186 Set the public key algorithm option B<opt> to B<value>. The precise set of
187 options supported depends on the public key algorithm used and its
188 implementation. See B<KEY GENERATION OPTIONS> in the B<genpkey> manual page
191 =item B<-key> I<filename>
193 This specifies the file to read the private key from. It also
194 accepts PKCS#8 format private keys for PEM format files.
196 =item B<-keyform> B<DER>|B<PEM>
198 The format of the private key file specified in the B<-key>
199 argument. PEM is the default.
201 =item B<-keyout> I<filename>
203 This gives the filename to write the newly created private key to.
204 If this option is not specified then the filename present in the
205 configuration file is used.
209 If this option is specified then if a private key is created it
210 will not be encrypted.
214 This specifies the message digest to sign the request.
215 Any digest supported by the OpenSSL B<dgst> command can be used.
216 This overrides the digest algorithm specified in
217 the configuration file.
219 Some public key algorithms may override this choice. For instance, DSA
220 signatures always use SHA1, GOST R 34.10 signatures always use
221 GOST R 34.11-94 (B<-md_gost94>), Ed25519 and Ed448 never use any digest.
223 =item B<-config> I<filename>
225 This allows an alternative configuration file to be specified.
226 Optional; for a description of the default value,
227 see L<openssl(1)/COMMAND SUMMARY>.
229 =item B<-subj> I<arg>
231 Sets subject name for new request or supersedes the subject name
232 when processing a request.
233 The arg must be formatted as I</type0=value0/type1=value1/type2=...>.
234 Keyword characters may be escaped by \ (backslash), and whitespace is retained.
235 Empty values are permitted, but the corresponding type will not be included
238 =item B<-multivalue-rdn>
240 This option causes the -subj argument to be interpreted with full
241 support for multivalued RDNs. Example:
243 I</DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe>
245 If -multi-rdn is not used then the UID value is I<123456+CN=John Doe>.
249 This option outputs a self signed certificate instead of a certificate
250 request. This is typically used to generate a test certificate or
251 a self signed root CA. The extensions added to the certificate
252 (if any) are specified in the configuration file. Unless specified
253 using the B<set_serial> option, a large random number will be used for
256 If existing request is specified with the B<-in> option, it is converted
257 to the self signed certificate otherwise new request is created.
261 When the B<-x509> option is being used this specifies the number of
262 days to certify the certificate for, otherwise it is ignored. B<n> should
263 be a positive integer. The default is 30 days.
265 =item B<-set_serial> I<n>
267 Serial number to use when outputting a self signed certificate. This
268 may be specified as a decimal value or a hex value if preceded by B<0x>.
270 =item B<-addext> I<ext>
272 Add a specific extension to the certificate (if the B<-x509> option is
273 present) or certificate request. The argument must have the form of
274 a key=value pair as it would appear in a config file.
276 This option can be given multiple times.
278 =item B<-extensions> I<section>
280 =item B<-reqexts> I<section>
282 These options specify alternative sections to include certificate
283 extensions (if the B<-x509> option is present) or certificate
284 request extensions. This allows several different sections to
285 be used in the same configuration file to specify requests for
286 a variety of purposes.
290 A poison extension will be added to the certificate, making it a
291 "pre-certificate" (see RFC6962). This can be submitted to Certificate
292 Transparency logs in order to obtain signed certificate timestamps (SCTs).
293 These SCTs can then be embedded into the pre-certificate as an extension, before
294 removing the poison and signing the certificate.
296 This implies the B<-new> flag.
300 This option causes field values to be interpreted as UTF8 strings, by
301 default they are interpreted as ASCII. This means that the field
302 values, whether prompted from a terminal or obtained from a
303 configuration file, must be valid UTF8 strings.
305 =item B<-nameopt> I<option>
307 Option which determines how the subject or issuer names are displayed. The
308 B<option> argument can be a single option or multiple options separated by
309 commas. Alternatively the B<-nameopt> switch may be used more than once to
310 set multiple options. See the L<x509(1)> manual page for details.
314 Customise the output format used with B<-text>. The B<option> argument can be
315 a single option or multiple options separated by commas.
317 See discussion of the B<-certopt> parameter in the L<x509(1)>
322 Adds the word B<NEW> to the PEM file header and footer lines on the outputted
323 request. Some software (Netscape certificate server) and some CAs need this.
327 Non-interactive mode.
331 Print extra details about the operations being performed.
333 =item B<-engine> I<id>
335 Specifying an engine (by its unique B<id> string) will cause B<req>
336 to attempt to obtain a functional reference to the specified engine,
337 thus initialising it if needed. The engine will then be set as the default
338 for all available algorithms.
340 =item B<-keygen_engine> I<id>
342 Specifies an engine (by its unique B<id> string) which would be used
343 for key generation operations.
347 Specify the ID string to use when verifying an SM2 certificate request. The ID
348 string is required by the SM2 signature algorithm for signing and verification.
352 Specify a binary ID string to use when verifying an SM2 certificate request. The
353 argument for this option is string of hexadecimal digits.
357 =head1 CONFIGURATION FILE FORMAT
359 The configuration options are specified in the B<req> section of
360 the configuration file. As with all configuration files if no
361 value is specified in the specific section (i.e. B<req>) then
362 the initial unnamed or B<default> section is searched too.
364 The options available are described in detail below.
368 =item B<input_password output_password>
370 The passwords for the input private key file (if present) and
371 the output private key file (if one will be created). The
372 command line options B<passin> and B<passout> override the
373 configuration file values.
375 =item B<default_bits>
377 Specifies the default key size in bits.
379 This option is used in conjunction with the B<-new> option to generate
380 a new key. It can be overridden by specifying an explicit key size in
381 the B<-newkey> option. The smallest accepted key size is 512 bits. If
382 no key size is specified then 2048 bits is used.
384 =item B<default_keyfile>
386 This is the default filename to write a private key to. If not
387 specified the key is written to standard output. This can be
388 overridden by the B<-keyout> option.
392 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
393 Each line of the file should consist of the numerical form of the
394 object identifier followed by white space then the short name followed
395 by white space and finally the long name.
399 This specifies a section in the configuration file containing extra
400 object identifiers. Each line should consist of the short name of the
401 object identifier followed by B<=> and the numerical form. The short
402 and long names are the same when this option is used.
406 At startup the specified file is loaded into the random number generator,
407 and at exit 256 bytes will be written to it.
408 It is used for private key generation.
412 If this is set to B<no> then if a private key is generated it is
413 B<not> encrypted. This is equivalent to the B<-nodes> command line
414 option. For compatibility B<encrypt_rsa_key> is an equivalent option.
418 This option specifies the digest algorithm to use. Any digest supported by the
419 OpenSSL B<dgst> command can be used. This option can be overridden on the
420 command line. Certain signing algorithms (i.e. Ed25519 and Ed448) will ignore
421 any digest that has been set.
425 This option masks out the use of certain string types in certain
426 fields. Most users will not need to change this option.
428 It can be set to several values B<default> which is also the default
429 option uses PrintableStrings, T61Strings and BMPStrings if the
430 B<pkix> value is used then only PrintableStrings and BMPStrings will
431 be used. This follows the PKIX recommendation in RFC2459. If the
432 B<utf8only> option is used then only UTF8Strings will be used: this
433 is the PKIX recommendation in RFC2459 after 2003. Finally the B<nombstr>
434 option just uses PrintableStrings and T61Strings: certain software has
435 problems with BMPStrings and UTF8Strings: in particular Netscape.
437 =item B<req_extensions>
439 This specifies the configuration file section containing a list of
440 extensions to add to the certificate request. It can be overridden
441 by the B<-reqexts> command line switch. See the
442 L<x509v3_config(5)> manual page for details of the
443 extension section format.
445 =item B<x509_extensions>
447 This specifies the configuration file section containing a list of
448 extensions to add to certificate generated when the B<-x509> switch
449 is used. It can be overridden by the B<-extensions> command line switch.
453 If set to the value B<no> this disables prompting of certificate fields
454 and just takes values from the config file directly. It also changes the
455 expected format of the B<distinguished_name> and B<attributes> sections.
459 If set to the value B<yes> then field values to be interpreted as UTF8
460 strings, by default they are interpreted as ASCII. This means that
461 the field values, whether prompted from a terminal or obtained from a
462 configuration file, must be valid UTF8 strings.
466 This specifies the section containing any request attributes: its format
467 is the same as B<distinguished_name>. Typically these may contain the
468 challengePassword or unstructuredName types. They are currently ignored
469 by OpenSSL's request signing utilities but some CAs might want them.
471 =item B<distinguished_name>
473 This specifies the section containing the distinguished name fields to
474 prompt for when generating a certificate or certificate request. The format
475 is described in the next section.
479 =head1 DISTINGUISHED NAME AND ATTRIBUTE SECTION FORMAT
481 There are two separate formats for the distinguished name and attribute
482 sections. If the B<prompt> option is set to B<no> then these sections
483 just consist of field names and values: for example,
487 emailAddress=someone@somewhere.org
489 This allows external programs (e.g. GUI based) to generate a template file
490 with all the field names and values and just pass it to B<req>. An example
491 of this kind of configuration file is contained in the B<EXAMPLES> section.
493 Alternatively if the B<prompt> option is absent or not set to B<no> then the
494 file contains field prompting information. It consists of lines of the form:
497 fieldName_default="default field value"
501 "fieldName" is the field name being used, for example commonName (or CN).
502 The "prompt" string is used to ask the user to enter the relevant
503 details. If the user enters nothing then the default value is used if no
504 default value is present then the field is omitted. A field can
505 still be omitted if a default value is present if the user just
506 enters the '.' character.
508 The number of characters entered must be between the fieldName_min and
509 fieldName_max limits: there may be additional restrictions based
510 on the field being used (for example countryName can only ever be
511 two characters long and must fit in a PrintableString).
513 Some fields (such as organizationName) can be used more than once
514 in a DN. This presents a problem because configuration files will
515 not recognize the same name occurring twice. To avoid this problem
516 if the fieldName contains some characters followed by a full stop
517 they will be ignored. So for example a second organizationName can
518 be input by calling it "1.organizationName".
520 The actual permitted field names are any object identifier short or
521 long names. These are compiled into OpenSSL and include the usual
522 values such as commonName, countryName, localityName, organizationName,
523 organizationalUnitName, stateOrProvinceName. Additionally emailAddress
524 is included as well as name, surname, givenName, initials, and dnQualifier.
526 Additional object identifiers can be defined with the B<oid_file> or
527 B<oid_section> options in the configuration file. Any additional fields
528 will be treated as though they were a DirectoryString.
533 Examine and verify certificate request:
535 openssl req -in req.pem -text -verify -noout
537 Create a private key and then generate a certificate request from it:
539 openssl genrsa -out key.pem 2048
540 openssl req -new -key key.pem -out req.pem
542 The same but just using req:
544 openssl req -newkey rsa:2048 -keyout key.pem -out req.pem
546 Generate a self signed root certificate:
548 openssl req -x509 -newkey rsa:2048 -keyout key.pem -out req.pem
550 Create an SM2 private key and then generate a certificate request from it:
552 openssl ecparam -genkey -name SM2 -out sm2.key
553 openssl req -new -key sm2.key -out sm2.csr -sm3 -sigopt "sm2_id:1234567812345678"
555 Examine and verify an SM2 certificate request:
557 openssl req -verify -in sm2.csr -sm3 -sm2-id 1234567812345678
559 Example of a file pointed to by the B<oid_file> option:
561 1.2.3.4 shortName A longer Name
562 1.2.3.6 otherName Other longer Name
564 Example of a section pointed to by B<oid_section> making use of variable
568 testoid2=${testoid1}.6
570 Sample configuration file prompting for field values:
574 default_keyfile = privkey.pem
575 distinguished_name = req_distinguished_name
576 attributes = req_attributes
577 req_extensions = v3_ca
579 dirstring_type = nobmp
581 [ req_distinguished_name ]
582 countryName = Country Name (2 letter code)
583 countryName_default = AU
587 localityName = Locality Name (eg, city)
589 organizationalUnitName = Organizational Unit Name (eg, section)
591 commonName = Common Name (eg, YOUR name)
594 emailAddress = Email Address
595 emailAddress_max = 40
598 challengePassword = A challenge password
599 challengePassword_min = 4
600 challengePassword_max = 20
604 subjectKeyIdentifier=hash
605 authorityKeyIdentifier=keyid:always,issuer:always
606 basicConstraints = critical, CA:true
608 Sample configuration containing all field values:
611 RANDFILE = $ENV::HOME/.rnd
615 default_keyfile = keyfile.pem
616 distinguished_name = req_distinguished_name
617 attributes = req_attributes
619 output_password = mypass
621 [ req_distinguished_name ]
623 ST = Test State or Province
625 O = Organization Name
626 OU = Organizational Unit Name
628 emailAddress = test@email.address
631 challengePassword = A challenge password
633 Example of giving the most common attributes (subject and extensions)
636 openssl req -new -subj "/C=GB/CN=foo" \
637 -addext "subjectAltName = DNS:foo.co.uk" \
638 -addext "certificatePolicies = 1.2.3.4" \
639 -newkey rsa:2048 -keyout key.pem -out req.pem
644 The header and footer lines in the B<PEM> format are normally:
646 -----BEGIN CERTIFICATE REQUEST-----
647 -----END CERTIFICATE REQUEST-----
649 some software (some versions of Netscape certificate server) instead needs:
651 -----BEGIN NEW CERTIFICATE REQUEST-----
652 -----END NEW CERTIFICATE REQUEST-----
654 which is produced with the B<-newhdr> option but is otherwise compatible.
655 Either form is accepted transparently on input.
657 The certificate requests generated by B<Xenroll> with MSIE have extensions
658 added. It includes the B<keyUsage> extension which determines the type of
659 key (signature only or general purpose) and any additional OIDs entered
660 by the script in an extendedKeyUsage extension.
664 The following messages are frequently asked about:
666 Using configuration from /some/path/openssl.cnf
667 Unable to load config info
669 This is followed some time later by...
671 unable to find 'distinguished_name' in config
672 problems making Certificate Request
674 The first error message is the clue: it can't find the configuration
675 file! Certain operations (like examining a certificate request) don't
676 need a configuration file so its use isn't enforced. Generation of
677 certificates or requests however does need a configuration file. This
678 could be regarded as a bug.
680 Another puzzling message is this:
685 this is displayed when no attributes are present and the request includes
686 the correct empty B<SET OF> structure (the DER encoding of which is 0xa0
687 0x00). If you just see:
691 then the B<SET OF> is missing and the encoding is technically invalid (but
692 it is tolerated). See the description of the command line option B<-asn1-kludge>
693 for more information.
697 OpenSSL's handling of T61Strings (aka TeletexStrings) is broken: it effectively
698 treats them as ISO-8859-1 (Latin 1), Netscape and MSIE have similar behaviour.
699 This can cause problems if you need characters that aren't available in
700 PrintableStrings and you don't want to or can't use BMPStrings.
702 As a consequence of the T61String handling the only correct way to represent
703 accented characters in OpenSSL is to use a BMPString: unfortunately Netscape
704 currently chokes on these. If you have to use accented characters with Netscape
705 and MSIE then you currently need to use the invalid T61String form.
707 The current prompting is not very friendly. It doesn't allow you to confirm what
708 you've just entered. Other things like extensions in certificate requests are
709 statically defined in the configuration file. Some of these: like an email
710 address in subjectAltName should be input by the user.
717 L<openssl-genrsa(1)>,
718 L<openssl-gendsa(1)>,
724 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
726 Licensed under the Apache License 2.0 (the "License"). You may not use
727 this file except in compliance with the License. You can obtain a copy
728 in the file LICENSE in the source distribution or at
729 L<https://www.openssl.org/source/license.html>.