1REQ(1) OpenSSL REQ(1)
2
6 openssl-req, req - PKCS#10 certificate request and certificate
7 generating utility
8
10 openssl req [-help] [-inform PEM|DER] [-outform PEM|DER] [-in filename]
11 [-passin arg] [-out filename] [-passout arg] [-text] [-pubkey] [-noout]
12 [-verify] [-modulus] [-new] [-rand file...] [-writerand file] [-newkey
13 rsa:bits] [-newkey alg:file] [-nodes] [-key filename] [-keyform
14 PEM|DER] [-keyout filename] [-keygen_engine id] [-digest] [-config
15 filename] [-multivalue-rdn] [-x509] [-days n] [-set_serial n] [-newhdr]
16 [-addext ext] [-extensions section] [-reqexts section] [-precert]
17 [-utf8] [-nameopt] [-reqopt] [-subject] [-subj arg] [-sigopt nm:v]
18 [-batch] [-verbose] [-engine id]
19
21 The req command primarily creates and processes certificate requests in
22 PKCS#10 format. It can additionally create self signed certificates for
23 use as root CAs for example.
24
26 -help
27 Print out a usage message.
28 -inform DER|PEM
30 This specifies the input format. The DER option uses an ASN1 DER
31 encoded form compatible with the PKCS#10. The PEM form is the
32 default format: it consists of the DER format base64 encoded with
33 additional header and footer lines.
34 -outform DER|PEM
36 This specifies the output format, the options have the same meaning
37 and default as the -inform option.
38 -in filename
40 This specifies the input filename to read a request from or
41 standard input if this option is not specified. A request is only
42 read if the creation options (-new and -newkey) are not specified.
43 -sigopt nm:v
45 Pass options to the signature algorithm during sign or verify
46 operations. Names and values of these options are algorithm-
47 specific.
48 -passin arg
50 The input file password source. For more information about the
51 format of arg see "Pass Phrase Options" in openssl(1).
52 -out filename
54 This specifies the output filename to write to or standard output
55 by default.
56 -passout arg
58 The output file password source. For more information about the
59 format of arg see "Pass Phrase Options" in openssl(1).
60 -text
62 Prints out the certificate request in text form.
63 -subject
65 Prints out the request subject (or certificate subject if -x509 is
66 specified)
67 -pubkey
69 Outputs the public key.
70 -noout
72 This option prevents output of the encoded version of the request.
73 -modulus
75 This option prints out the value of the modulus of the public key
76 contained in the request.
77 -verify
79 Verifies the signature on the request.
80 -new
82 This option generates a new certificate request. It will prompt the
83 user for the relevant field values. The actual fields prompted for
84 and their maximum and minimum sizes are specified in the
85 configuration file and any requested extensions.
86 If the -key option is not used it will generate a new RSA private
88 key using information specified in the configuration file.
89 -rand file...
91 A file or files containing random data used to seed the random
92 number generator. Multiple files can be specified separated by an
93 OS-dependent character. The separator is ; for MS-Windows, , for
94 OpenVMS, and : for all others.
95 [-writerand file]
97 Writes random data to the specified file upon exit. This can be
98 used with a subsequent -rand flag.
99 -newkey arg
101 This option creates a new certificate request and a new private
102 key. The argument takes one of several forms. rsa:nbits, where
103 nbits is the number of bits, generates an RSA key nbits in size. If
104 nbits is omitted, i.e. -newkey rsa specified, the default key size,
105 specified in the configuration file is used.
106 All other algorithms support the -newkey alg:file form, where file
108 may be an algorithm parameter file, created by the genpkey
109 -genparam command or and X.509 certificate for a key with
110 appropriate algorithm.
111 param:file generates a key using the parameter file or certificate
113 file, the algorithm is determined by the parameters. algname:file
114 use algorithm algname and parameter file file: the two algorithms
115 must match or an error occurs. algname just uses algorithm algname,
116 and parameters, if necessary should be specified via -pkeyopt
117 parameter.
118 dsa:filename generates a DSA key using the parameters in the file
120 filename. ec:filename generates EC key (usable both with ECDSA or
121 ECDH algorithms), gost2001:filename generates GOST R 34.10-2001 key
122 (requires ccgost engine configured in the configuration file). If
123 just gost2001 is specified a parameter set should be specified by
124 -pkeyopt paramset:X
125 -pkeyopt opt:value
127 Set the public key algorithm option opt to value. The precise set
128 of options supported depends on the public key algorithm used and
129 its implementation. See KEY GENERATION OPTIONS in the genpkey
130 manual page for more details.
131 -key filename
133 This specifies the file to read the private key from. It also
134 accepts PKCS#8 format private keys for PEM format files.
135 -keyform PEM|DER
137 The format of the private key file specified in the -key argument.
138 PEM is the default.
139 -keyout filename
141 This gives the filename to write the newly created private key to.
142 If this option is not specified then the filename present in the
143 configuration file is used.
144 -nodes
146 If this option is specified then if a private key is created it
147 will not be encrypted.
148 -digest
150 This specifies the message digest to sign the request. Any digest
151 supported by the OpenSSL dgst command can be used. This overrides
152 the digest algorithm specified in the configuration file.
153 Some public key algorithms may override this choice. For instance,
155 DSA signatures always use SHA1, GOST R 34.10 signatures always use
156 GOST R 34.11-94 (-md_gost94), Ed25519 and Ed448 never use any
157 digest.
158 -config filename
160 This allows an alternative configuration file to be specified.
161 Optional; for a description of the default value, see "COMMAND
162 SUMMARY" in openssl(1).
163 -subj arg
165 Sets subject name for new request or supersedes the subject name
166 when processing a request. The arg must be formatted as
167 /type0=value0/type1=value1/type2=.... Keyword characters may be
168 escaped by \ (backslash), and whitespace is retained. Empty values
169 are permitted, but the corresponding type will not be included in
170 the request.
171 -multivalue-rdn
173 This option causes the -subj argument to be interpreted with full
174 support for multivalued RDNs. Example:
175 /DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe
177 If -multi-rdn is not used then the UID value is 123456+CN=John Doe.
179 -x509
181 This option outputs a self signed certificate instead of a
182 certificate request. This is typically used to generate a test
183 certificate or a self signed root CA. The extensions added to the
184 certificate (if any) are specified in the configuration file.
185 Unless specified using the set_serial option, a large random number
186 will be used for the serial number.
187 If existing request is specified with the -in option, it is
189 converted to the self signed certificate otherwise new request is
190 created.
191 -days n
193 When the -x509 option is being used this specifies the number of
194 days to certify the certificate for, otherwise it is ignored. n
195 should be a positive integer. The default is 30 days.
196 -set_serial n
198 Serial number to use when outputting a self signed certificate.
199 This may be specified as a decimal value or a hex value if preceded
200 by 0x.
201 -addext ext
203 Add a specific extension to the certificate (if the -x509 option is
204 present) or certificate request. The argument must have the form
205 of a key=value pair as it would appear in a config file.
206 This option can be given multiple times.
208 -extensions section
210 -reqexts section
211 These options specify alternative sections to include certificate
212 extensions (if the -x509 option is present) or certificate request
213 extensions. This allows several different sections to be used in
214 the same configuration file to specify requests for a variety of
215 purposes.
216 -precert
218 A poison extension will be added to the certificate, making it a
219 "pre-certificate" (see RFC6962). This can be submitted to
220 Certificate Transparency logs in order to obtain signed certificate
221 timestamps (SCTs). These SCTs can then be embedded into the pre-
222 certificate as an extension, before removing the poison and signing
223 the certificate.
224 This implies the -new flag.
226 -utf8
228 This option causes field values to be interpreted as UTF8 strings,
229 by default they are interpreted as ASCII. This means that the field
230 values, whether prompted from a terminal or obtained from a
231 configuration file, must be valid UTF8 strings.
232 -nameopt option
234 Option which determines how the subject or issuer names are
235 displayed. The option argument can be a single option or multiple
236 options separated by commas. Alternatively the -nameopt switch may
237 be used more than once to set multiple options. See the x509(1)
238 manual page for details.
239 -reqopt
241 Customise the output format used with -text. The option argument
242 can be a single option or multiple options separated by commas.
243 See discussion of the -certopt parameter in the x509(1) command.
245 -newhdr
247 Adds the word NEW to the PEM file header and footer lines on the
248 outputted request. Some software (Netscape certificate server) and
249 some CAs need this.
250 -batch
252 Non-interactive mode.
253 -verbose
255 Print extra details about the operations being performed.
256 -engine id
258 Specifying an engine (by its unique id string) will cause req to
259 attempt to obtain a functional reference to the specified engine,
260 thus initialising it if needed. The engine will then be set as the
261 default for all available algorithms.
262 -keygen_engine id
264 Specifies an engine (by its unique id string) which would be used
265 for key generation operations.
266
268 The configuration options are specified in the req section of the
269 configuration file. As with all configuration files if no value is
270 specified in the specific section (i.e. req) then the initial unnamed
271 or default section is searched too.
272 The options available are described in detail below.
274 input_password output_password
276 The passwords for the input private key file (if present) and the
277 output private key file (if one will be created). The command line
278 options passin and passout override the configuration file values.
279 default_bits
281 Specifies the default key size in bits.
282 This option is used in conjunction with the -new option to generate
284 a new key. It can be overridden by specifying an explicit key size
285 in the -newkey option. The smallest accepted key size is 512 bits.
286 If no key size is specified then 2048 bits is used.
287 default_keyfile
289 This is the default filename to write a private key to. If not
290 specified the key is written to standard output. This can be
291 overridden by the -keyout option.
292 oid_file
294 This specifies a file containing additional OBJECT IDENTIFIERS.
295 Each line of the file should consist of the numerical form of the
296 object identifier followed by white space then the short name
297 followed by white space and finally the long name.
298 oid_section
300 This specifies a section in the configuration file containing extra
301 object identifiers. Each line should consist of the short name of
302 the object identifier followed by = and the numerical form. The
303 short and long names are the same when this option is used.
304 RANDFILE
306 At startup the specified file is loaded into the random number
307 generator, and at exit 256 bytes will be written to it. It is used
308 for private key generation.
309 encrypt_key
311 If this is set to no then if a private key is generated it is not
312 encrypted. This is equivalent to the -nodes command line option.
313 For compatibility encrypt_rsa_key is an equivalent option.
314 default_md
316 This option specifies the digest algorithm to use. Any digest
317 supported by the OpenSSL dgst command can be used. This option can
318 be overridden on the command line. Certain signing algorithms (i.e.
319 Ed25519 and Ed448) will ignore any digest that has been set.
320 string_mask
322 This option masks out the use of certain string types in certain
323 fields. Most users will not need to change this option.
324 It can be set to several values default which is also the default
326 option uses PrintableStrings, T61Strings and BMPStrings if the pkix
327 value is used then only PrintableStrings and BMPStrings will be
328 used. This follows the PKIX recommendation in RFC2459. If the
329 utf8only option is used then only UTF8Strings will be used: this is
330 the PKIX recommendation in RFC2459 after 2003. Finally the nombstr
331 option just uses PrintableStrings and T61Strings: certain software
332 has problems with BMPStrings and UTF8Strings: in particular
333 Netscape.
334 req_extensions
336 This specifies the configuration file section containing a list of
337 extensions to add to the certificate request. It can be overridden
338 by the -reqexts command line switch. See the x509v3_config(5)
339 manual page for details of the extension section format.
340 x509_extensions
342 This specifies the configuration file section containing a list of
343 extensions to add to certificate generated when the -x509 switch is
344 used. It can be overridden by the -extensions command line switch.
345 prompt
347 If set to the value no this disables prompting of certificate
348 fields and just takes values from the config file directly. It also
349 changes the expected format of the distinguished_name and
350 attributes sections.
351 utf8
353 If set to the value yes then field values to be interpreted as UTF8
354 strings, by default they are interpreted as ASCII. This means that
355 the field values, whether prompted from a terminal or obtained from
356 a configuration file, must be valid UTF8 strings.
357 attributes
359 This specifies the section containing any request attributes: its
360 format is the same as distinguished_name. Typically these may
361 contain the challengePassword or unstructuredName types. They are
362 currently ignored by OpenSSL's request signing utilities but some
363 CAs might want them.
364 distinguished_name
366 This specifies the section containing the distinguished name fields
367 to prompt for when generating a certificate or certificate request.
368 The format is described in the next section.
369
371 There are two separate formats for the distinguished name and attribute
372 sections. If the prompt option is set to no then these sections just
373 consist of field names and values: for example,
374 CN=My Name
376 OU=My Organization
377 emailAddress=someone@somewhere.org
378 This allows external programs (e.g. GUI based) to generate a template
380 file with all the field names and values and just pass it to req. An
381 example of this kind of configuration file is contained in the EXAMPLES
382 section.
383 Alternatively if the prompt option is absent or not set to no then the
385 file contains field prompting information. It consists of lines of the
386 form:
387 fieldName="prompt"
389 fieldName_default="default field value"
390 fieldName_min= 2
391 fieldName_max= 4
392 "fieldName" is the field name being used, for example commonName (or
394 CN). The "prompt" string is used to ask the user to enter the relevant
395 details. If the user enters nothing then the default value is used if
396 no default value is present then the field is omitted. A field can
397 still be omitted if a default value is present if the user just enters
398 the '.' character.
399 The number of characters entered must be between the fieldName_min and
401 fieldName_max limits: there may be additional restrictions based on the
402 field being used (for example countryName can only ever be two
403 characters long and must fit in a PrintableString).
404 Some fields (such as organizationName) can be used more than once in a
406 DN. This presents a problem because configuration files will not
407 recognize the same name occurring twice. To avoid this problem if the
408 fieldName contains some characters followed by a full stop they will be
409 ignored. So for example a second organizationName can be input by
410 calling it "1.organizationName".
411 The actual permitted field names are any object identifier short or
413 long names. These are compiled into OpenSSL and include the usual
414 values such as commonName, countryName, localityName, organizationName,
415 organizationalUnitName, stateOrProvinceName. Additionally emailAddress
416 is included as well as name, surname, givenName, initials, and
417 dnQualifier.
418 Additional object identifiers can be defined with the oid_file or
420 oid_section options in the configuration file. Any additional fields
421 will be treated as though they were a DirectoryString.
422
424 Examine and verify certificate request:
425 openssl req -in req.pem -text -verify -noout
427 Create a private key and then generate a certificate request from it:
429 openssl genrsa -out key.pem 2048
431 openssl req -new -key key.pem -out req.pem
432 The same but just using req:
434 openssl req -newkey rsa:2048 -keyout key.pem -out req.pem
436 Generate a self signed root certificate:
438 openssl req -x509 -newkey rsa:2048 -keyout key.pem -out req.pem
440 Example of a file pointed to by the oid_file option:
442 1.2.3.4 shortName A longer Name
444 1.2.3.6 otherName Other longer Name
445 Example of a section pointed to by oid_section making use of variable
447 expansion:
448 testoid1=1.2.3.5
450 testoid2=${testoid1}.6
451 Sample configuration file prompting for field values:
453 [ req ]
455 default_bits = 2048
456 default_keyfile = privkey.pem
457 distinguished_name = req_distinguished_name
458 attributes = req_attributes
459 req_extensions = v3_ca
460 dirstring_type = nobmp
462 [ req_distinguished_name ]
464 countryName = Country Name (2 letter code)
465 countryName_default = AU
466 countryName_min = 2
467 countryName_max = 2
468 localityName = Locality Name (eg, city)
470 organizationalUnitName = Organizational Unit Name (eg, section)
472 commonName = Common Name (eg, YOUR name)
474 commonName_max = 64
475 emailAddress = Email Address
477 emailAddress_max = 40
478 [ req_attributes ]
480 challengePassword = A challenge password
481 challengePassword_min = 4
482 challengePassword_max = 20
483 [ v3_ca ]
485 subjectKeyIdentifier=hash
487 authorityKeyIdentifier=keyid:always,issuer:always
488 basicConstraints = critical, CA:true
489 Sample configuration containing all field values:
491 RANDFILE = $ENV::HOME/.rnd
493 [ req ]
495 default_bits = 2048
496 default_keyfile = keyfile.pem
497 distinguished_name = req_distinguished_name
498 attributes = req_attributes
499 prompt = no
500 output_password = mypass
501 [ req_distinguished_name ]
503 C = GB
504 ST = Test State or Province
505 L = Test Locality
506 O = Organization Name
507 OU = Organizational Unit Name
508 CN = Common Name
509 emailAddress = test@email.address
510 [ req_attributes ]
512 challengePassword = A challenge password
513 Example of giving the most common attributes (subject and extensions)
515 on the command line:
516 openssl req -new -subj "/C=GB/CN=foo" \
518 -addext "subjectAltName = DNS:foo.co.uk" \
519 -addext "certificatePolicies = 1.2.3.4" \
520 -newkey rsa:2048 -keyout key.pem -out req.pem
521
523 The header and footer lines in the PEM format are normally:
524 -----BEGIN CERTIFICATE REQUEST-----
526 -----END CERTIFICATE REQUEST-----
527 some software (some versions of Netscape certificate server) instead
529 needs:
530 -----BEGIN NEW CERTIFICATE REQUEST-----
532 -----END NEW CERTIFICATE REQUEST-----
533 which is produced with the -newhdr option but is otherwise compatible.
535 Either form is accepted transparently on input.
536 The certificate requests generated by Xenroll with MSIE have extensions
538 added. It includes the keyUsage extension which determines the type of
539 key (signature only or general purpose) and any additional OIDs entered
540 by the script in an extendedKeyUsage extension.
541
543 The following messages are frequently asked about:
544 Using configuration from /some/path/openssl.cnf
546 Unable to load config info
547 This is followed some time later by...
549 unable to find 'distinguished_name' in config
551 problems making Certificate Request
552 The first error message is the clue: it can't find the configuration
554 file! Certain operations (like examining a certificate request) don't
555 need a configuration file so its use isn't enforced. Generation of
556 certificates or requests however does need a configuration file. This
557 could be regarded as a bug.
558 Another puzzling message is this:
560 Attributes:
562 a0:00
563 this is displayed when no attributes are present and the request
565 includes the correct empty SET OF structure (the DER encoding of which
566 is 0xa0 0x00). If you just see:
567 Attributes:
569 then the SET OF is missing and the encoding is technically invalid (but
571 it is tolerated). See the description of the command line option
572 -asn1-kludge for more information.
573
575 OpenSSL's handling of T61Strings (aka TeletexStrings) is broken: it
576 effectively treats them as ISO-8859-1 (Latin 1), Netscape and MSIE have
577 similar behaviour. This can cause problems if you need characters that
578 aren't available in PrintableStrings and you don't want to or can't use
579 BMPStrings.
580 As a consequence of the T61String handling the only correct way to
582 represent accented characters in OpenSSL is to use a BMPString:
583 unfortunately Netscape currently chokes on these. If you have to use
584 accented characters with Netscape and MSIE then you currently need to
585 use the invalid T61String form.
586 The current prompting is not very friendly. It doesn't allow you to
588 confirm what you've just entered. Other things like extensions in
589 certificate requests are statically defined in the configuration file.
590 Some of these: like an email address in subjectAltName should be input
591 by the user.
592
594 x509(1), ca(1), genrsa(1), gendsa(1), config(5), x509v3_config(5)
595
597 Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.
598 Licensed under the OpenSSL license (the "License"). You may not use
600 this file except in compliance with the License. You can obtain a copy
601 in the file LICENSE in the source distribution or at
602 <https://www.openssl.org/source/license.html>.
6031.1.1l 2021-09-15 REQ(1)