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 openssl 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>, B<-outform> B<DER>|B<PEM>
72 The input and formats; the default is B<PEM>.
73 See L<openssl(1)/Format Options> for details.
75 The data is a PKCS#10 object.
77 =item B<-in> I<filename>
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.
83 =item B<-sigopt> I<nm>:I<v>
85 Pass options to the signature algorithm during sign or verify operations.
86 Names and values of these options are algorithm-specific.
88 =item B<-passin> I<arg>, B<-passout> I<arg>
90 The password source for the input and output file.
91 For more information about the format of B<arg>
92 see L<openssl(1)/Pass Phrase Options>.
94 =item B<-out> I<filename>
96 This specifies the output filename to write to or standard output by
101 Prints out the certificate request in text form.
105 Prints out the request subject (or certificate subject if B<-x509> is
110 Outputs the public key.
114 This option prevents output of the encoded version of the request.
118 This option prints out the value of the modulus of the public key
119 contained in the request.
123 Verifies the signature on the request.
127 This option generates a new certificate request. It will prompt
128 the user for the relevant field values. The actual fields
129 prompted for and their maximum and minimum sizes are specified
130 in the configuration file and any requested extensions.
132 If the B<-key> option is not used it will generate a new RSA private
133 key using information specified in the configuration file.
135 =item B<-rand> I<files>, B<-writerand> I<file>
137 See L<openssl(1)/Random State Options> for more information.
139 =item B<-newkey> I<arg>
141 This option creates a new certificate request and a new private
142 key. The argument takes one of several forms.
144 B<rsa:>I<nbits>, where
145 I<nbits> is the number of bits, generates an RSA key I<nbits>
146 in size. If I<nbits> is omitted, i.e. B<-newkey> I<rsa> specified,
147 the default key size, specified in the configuration file is used.
149 All other algorithms support the B<-newkey> I<alg>:I<file> form, where file
150 may be an algorithm parameter file, created with C<openssl genpkey -genparam>
151 or an X.509 certificate for a key with appropriate algorithm.
153 B<param:>I<file> generates a key using the parameter file or certificate
154 I<file>, the algorithm is determined by the parameters. I<algname>:I<file>
155 use algorithm I<algname> and parameter file I<file>: the two algorithms must
156 match or an error occurs. I<algname> just uses algorithm I<algname>, and
157 parameters, if necessary should be specified via B<-pkeyopt> parameter.
159 B<dsa:>I<filename> generates a DSA key using the parameters
160 in the file I<filename>. B<ec:>I<filename> generates EC key (usable both with
161 ECDSA or ECDH algorithms), B<gost2001:>I<filename> generates GOST R
162 34.10-2001 key (requires B<gost> engine configured in the configuration
163 file). If just B<gost2001> is specified a parameter set should be
164 specified by B<-pkeyopt> I<paramset:X>
166 =item B<-pkeyopt> I<opt>:I<value>
168 Set the public key algorithm option I<opt> to I<value>. The precise set of
169 options supported depends on the public key algorithm used and its
171 See L<openssl-genpkey(1)/KEY GENERATION OPTIONS> for more details.
173 =item B<-key> I<filename>
175 This specifies the file to read the private key from. It also
176 accepts PKCS#8 format private keys for PEM format files.
178 =item B<-keyform> B<DER>|B<PEM>
180 The format of the private key; the default is B<PEM>.
181 See L<openssl(1)/Format Options> for details.
183 =item B<-keyout> I<filename>
185 This gives the filename to write the newly created private key to.
186 If this option is not specified then the filename present in the
187 configuration file is used.
191 If this option is specified then if a private key is created it
192 will not be encrypted.
196 This specifies the message digest to sign the request.
197 Any digest supported by the OpenSSL B<dgst> command can be used.
198 This overrides the digest algorithm specified in
199 the configuration file.
201 Some public key algorithms may override this choice. For instance, DSA
202 signatures always use SHA1, GOST R 34.10 signatures always use
203 GOST R 34.11-94 (B<-md_gost94>), Ed25519 and Ed448 never use any digest.
205 =item B<-config> I<filename>
207 This allows an alternative configuration file to be specified.
208 Optional; for a description of the default value,
209 see L<openssl(1)/COMMAND SUMMARY>.
211 =item B<-subj> I<arg>
213 Sets subject name for new request or supersedes the subject name
214 when processing a request.
215 The arg must be formatted as C</type0=value0/type1=value1/type2=...>.
216 Keyword characters may be escaped by \ (backslash), and whitespace is retained.
217 Empty values are permitted, but the corresponding type will not be included
220 =item B<-multivalue-rdn>
222 This option causes the -subj argument to be interpreted with full
223 support for multivalued RDNs. Example:
225 C</DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe>
227 If -multi-rdn is not used then the UID value is C<123456+CN=John Doe>.
231 This option outputs a self signed certificate instead of a certificate
232 request. This is typically used to generate a test certificate or
233 a self signed root CA. The extensions added to the certificate
234 (if any) are specified in the configuration file. Unless specified
235 using the B<-set_serial> option, a large random number will be used for
238 If existing request is specified with the B<-in> option, it is converted
239 to the self signed certificate otherwise new request is created.
243 When the B<-x509> option is being used this specifies the number of
244 days to certify the certificate for, otherwise it is ignored. I<n> should
245 be a positive integer. The default is 30 days.
247 =item B<-set_serial> I<n>
249 Serial number to use when outputting a self signed certificate. This
250 may be specified as a decimal value or a hex value if preceded by C<0x>.
252 =item B<-addext> I<ext>
254 Add a specific extension to the certificate (if the B<-x509> option is
255 present) or certificate request. The argument must have the form of
256 a key=value pair as it would appear in a config file.
258 This option can be given multiple times.
260 =item B<-extensions> I<section>
262 =item B<-reqexts> I<section>
264 These options specify alternative sections to include certificate
265 extensions (if the B<-x509> option is present) or certificate
266 request extensions. This allows several different sections to
267 be used in the same configuration file to specify requests for
268 a variety of purposes.
272 A poison extension will be added to the certificate, making it a
273 "pre-certificate" (see RFC6962). This can be submitted to Certificate
274 Transparency logs in order to obtain signed certificate timestamps (SCTs).
275 These SCTs can then be embedded into the pre-certificate as an extension, before
276 removing the poison and signing the certificate.
278 This implies the B<-new> flag.
282 This option causes field values to be interpreted as UTF8 strings, by
283 default they are interpreted as ASCII. This means that the field
284 values, whether prompted from a terminal or obtained from a
285 configuration file, must be valid UTF8 strings.
287 =item B<-nameopt> I<option>
289 Option which determines how the subject or issuer names are displayed. The
290 I<option> argument can be a single option or multiple options separated by
291 commas. Alternatively the B<-nameopt> switch may be used more than once to
292 set multiple options. See the L<openssl-x509(1)> manual page for details.
294 =item B<-reqopt> I<option>
296 Customise the output format used with B<-text>. The I<option> argument can be
297 a single option or multiple options separated by commas.
299 See discussion of the B<-certopt> parameter in the L<openssl-x509(1)>
304 Adds the word B<NEW> to the PEM file header and footer lines on the outputted
305 request. Some software (Netscape certificate server) and some CAs need this.
309 Non-interactive mode.
313 Print extra details about the operations being performed.
315 =item B<-engine> I<id>
317 Specifying an engine (by its unique I<id> string) will cause this command
318 to attempt to obtain a functional reference to the specified engine,
319 thus initialising it if needed. The engine will then be set as the default
320 for all available algorithms.
322 =item B<-keygen_engine> I<id>
324 Specifies an engine (by its unique I<id> string) which would be used
325 for key generation operations.
329 Specify the ID string to use when verifying an SM2 certificate request. The ID
330 string is required by the SM2 signature algorithm for signing and verification.
334 Specify a binary ID string to use when verifying an SM2 certificate request. The
335 argument for this option is string of hexadecimal digits.
339 =head1 CONFIGURATION FILE FORMAT
341 The configuration options are specified in the B<req> section of
342 the configuration file. As with all configuration files if no
343 value is specified in the specific section (i.e. B<req>) then
344 the initial unnamed or B<default> section is searched too.
346 The options available are described in detail below.
350 =item B<input_password output_password>
352 The passwords for the input private key file (if present) and
353 the output private key file (if one will be created). The
354 command line options B<passin> and B<passout> override the
355 configuration file values.
357 =item B<default_bits>
359 Specifies the default key size in bits.
361 This option is used in conjunction with the B<-new> option to generate
362 a new key. It can be overridden by specifying an explicit key size in
363 the B<-newkey> option. The smallest accepted key size is 512 bits. If
364 no key size is specified then 2048 bits is used.
366 =item B<default_keyfile>
368 This is the default filename to write a private key to. If not
369 specified the key is written to standard output. This can be
370 overridden by the B<-keyout> option.
374 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
375 Each line of the file should consist of the numerical form of the
376 object identifier followed by white space then the short name followed
377 by white space and finally the long name.
381 This specifies a section in the configuration file containing extra
382 object identifiers. Each line should consist of the short name of the
383 object identifier followed by B<=> and the numerical form. The short
384 and long names are the same when this option is used.
388 At startup the specified file is loaded into the random number generator,
389 and at exit 256 bytes will be written to it.
390 It is used for private key generation.
394 If this is set to B<no> then if a private key is generated it is
395 B<not> encrypted. This is equivalent to the B<-nodes> command line
396 option. For compatibility B<encrypt_rsa_key> is an equivalent option.
400 This option specifies the digest algorithm to use. Any digest supported by the
401 OpenSSL B<dgst> command can be used. This option can be overridden on the
402 command line. Certain signing algorithms (i.e. Ed25519 and Ed448) will ignore
403 any digest that has been set.
407 This option masks out the use of certain string types in certain
408 fields. Most users will not need to change this option.
410 It can be set to several values B<default> which is also the default
411 option uses PrintableStrings, T61Strings and BMPStrings if the
412 B<pkix> value is used then only PrintableStrings and BMPStrings will
413 be used. This follows the PKIX recommendation in RFC2459. If the
414 B<utf8only> option is used then only UTF8Strings will be used: this
415 is the PKIX recommendation in RFC2459 after 2003. Finally the B<nombstr>
416 option just uses PrintableStrings and T61Strings: certain software has
417 problems with BMPStrings and UTF8Strings: in particular Netscape.
419 =item B<req_extensions>
421 This specifies the configuration file section containing a list of
422 extensions to add to the certificate request. It can be overridden
423 by the B<-reqexts> command line switch. See the
424 L<x509v3_config(5)> manual page for details of the
425 extension section format.
427 =item B<x509_extensions>
429 This specifies the configuration file section containing a list of
430 extensions to add to certificate generated when the B<-x509> switch
431 is used. It can be overridden by the B<-extensions> command line switch.
435 If set to the value B<no> this disables prompting of certificate fields
436 and just takes values from the config file directly. It also changes the
437 expected format of the B<distinguished_name> and B<attributes> sections.
441 If set to the value B<yes> then field values to be interpreted as UTF8
442 strings, by default they are interpreted as ASCII. This means that
443 the field values, whether prompted from a terminal or obtained from a
444 configuration file, must be valid UTF8 strings.
448 This specifies the section containing any request attributes: its format
449 is the same as B<distinguished_name>. Typically these may contain the
450 challengePassword or unstructuredName types. They are currently ignored
451 by OpenSSL's request signing utilities but some CAs might want them.
453 =item B<distinguished_name>
455 This specifies the section containing the distinguished name fields to
456 prompt for when generating a certificate or certificate request. The format
457 is described in the next section.
461 =head1 DISTINGUISHED NAME AND ATTRIBUTE SECTION FORMAT
463 There are two separate formats for the distinguished name and attribute
464 sections. If the B<prompt> option is set to B<no> then these sections
465 just consist of field names and values: for example,
469 emailAddress=someone@somewhere.org
471 This allows external programs (e.g. GUI based) to generate a template file with
472 all the field names and values and just pass it to this command. An example
473 of this kind of configuration file is contained in the B<EXAMPLES> section.
475 Alternatively if the B<prompt> option is absent or not set to B<no> then the
476 file contains field prompting information. It consists of lines of the form:
479 fieldName_default="default field value"
483 "fieldName" is the field name being used, for example commonName (or CN).
484 The "prompt" string is used to ask the user to enter the relevant
485 details. If the user enters nothing then the default value is used if no
486 default value is present then the field is omitted. A field can
487 still be omitted if a default value is present if the user just
488 enters the '.' character.
490 The number of characters entered must be between the fieldName_min and
491 fieldName_max limits: there may be additional restrictions based
492 on the field being used (for example countryName can only ever be
493 two characters long and must fit in a PrintableString).
495 Some fields (such as organizationName) can be used more than once
496 in a DN. This presents a problem because configuration files will
497 not recognize the same name occurring twice. To avoid this problem
498 if the fieldName contains some characters followed by a full stop
499 they will be ignored. So for example a second organizationName can
500 be input by calling it "1.organizationName".
502 The actual permitted field names are any object identifier short or
503 long names. These are compiled into OpenSSL and include the usual
504 values such as commonName, countryName, localityName, organizationName,
505 organizationalUnitName, stateOrProvinceName. Additionally emailAddress
506 is included as well as name, surname, givenName, initials, and dnQualifier.
508 Additional object identifiers can be defined with the B<oid_file> or
509 B<oid_section> options in the configuration file. Any additional fields
510 will be treated as though they were a DirectoryString.
515 Examine and verify certificate request:
517 openssl req -in req.pem -text -verify -noout
519 Create a private key and then generate a certificate request from it:
521 openssl genrsa -out key.pem 2048
522 openssl req -new -key key.pem -out req.pem
524 The same but just using req:
526 openssl req -newkey rsa:2048 -keyout key.pem -out req.pem
528 Generate a self signed root certificate:
530 openssl req -x509 -newkey rsa:2048 -keyout key.pem -out req.pem
532 Create an SM2 private key and then generate a certificate request from it:
534 openssl ecparam -genkey -name SM2 -out sm2.key
535 openssl req -new -key sm2.key -out sm2.csr -sm3 -sigopt "sm2_id:1234567812345678"
537 Examine and verify an SM2 certificate request:
539 openssl req -verify -in sm2.csr -sm3 -sm2-id 1234567812345678
541 Example of a file pointed to by the B<oid_file> option:
543 1.2.3.4 shortName A longer Name
544 1.2.3.6 otherName Other longer Name
546 Example of a section pointed to by B<oid_section> making use of variable
550 testoid2=${testoid1}.6
552 Sample configuration file prompting for field values:
556 default_keyfile = privkey.pem
557 distinguished_name = req_distinguished_name
558 attributes = req_attributes
559 req_extensions = v3_ca
561 dirstring_type = nobmp
563 [ req_distinguished_name ]
564 countryName = Country Name (2 letter code)
565 countryName_default = AU
569 localityName = Locality Name (eg, city)
571 organizationalUnitName = Organizational Unit Name (eg, section)
573 commonName = Common Name (eg, YOUR name)
576 emailAddress = Email Address
577 emailAddress_max = 40
580 challengePassword = A challenge password
581 challengePassword_min = 4
582 challengePassword_max = 20
586 subjectKeyIdentifier=hash
587 authorityKeyIdentifier=keyid:always,issuer:always
588 basicConstraints = critical, CA:true
590 Sample configuration containing all field values:
593 RANDFILE = $ENV::HOME/.rnd
597 default_keyfile = keyfile.pem
598 distinguished_name = req_distinguished_name
599 attributes = req_attributes
601 output_password = mypass
603 [ req_distinguished_name ]
605 ST = Test State or Province
607 O = Organization Name
608 OU = Organizational Unit Name
610 emailAddress = test@email.address
613 challengePassword = A challenge password
615 Example of giving the most common attributes (subject and extensions)
618 openssl req -new -subj "/C=GB/CN=foo" \
619 -addext "subjectAltName = DNS:foo.co.uk" \
620 -addext "certificatePolicies = 1.2.3.4" \
621 -newkey rsa:2048 -keyout key.pem -out req.pem
626 The certificate requests generated by B<Xenroll> with MSIE have extensions
627 added. It includes the B<keyUsage> extension which determines the type of
628 key (signature only or general purpose) and any additional OIDs entered
629 by the script in an B<extendedKeyUsage> extension.
633 The following messages are frequently asked about:
635 Using configuration from /some/path/openssl.cnf
636 Unable to load config info
638 This is followed some time later by:
640 unable to find 'distinguished_name' in config
641 problems making Certificate Request
643 The first error message is the clue: it can't find the configuration
644 file! Certain operations (like examining a certificate request) don't
645 need a configuration file so its use isn't enforced. Generation of
646 certificates or requests however does need a configuration file. This
647 could be regarded as a bug.
649 Another puzzling message is this:
654 this is displayed when no attributes are present and the request includes
655 the correct empty B<SET OF> structure (the DER encoding of which is 0xa0
656 0x00). If you just see:
660 then the B<SET OF> is missing and the encoding is technically invalid (but
661 it is tolerated). See the description of the command line option B<-asn1-kludge>
662 for more information.
666 OpenSSL's handling of T61Strings (aka TeletexStrings) is broken: it effectively
667 treats them as ISO-8859-1 (Latin 1), Netscape and MSIE have similar behaviour.
668 This can cause problems if you need characters that aren't available in
669 PrintableStrings and you don't want to or can't use BMPStrings.
671 As a consequence of the T61String handling the only correct way to represent
672 accented characters in OpenSSL is to use a BMPString: unfortunately Netscape
673 currently chokes on these. If you have to use accented characters with Netscape
674 and MSIE then you currently need to use the invalid T61String form.
676 The current prompting is not very friendly. It doesn't allow you to confirm what
677 you've just entered. Other things like extensions in certificate requests are
678 statically defined in the configuration file. Some of these: like an email
679 address in subjectAltName should be input by the user.
686 L<openssl-genrsa(1)>,
687 L<openssl-gendsa(1)>,
693 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
695 Licensed under the Apache License 2.0 (the "License"). You may not use
696 this file except in compliance with the License. You can obtain a copy
697 in the file LICENSE in the source distribution or at
698 L<https://www.openssl.org/source/license.html>.