7 req - PKCS#10 certificate request and certificate generating utility.
31 [B<-keygen_engine id>]
41 [B<-extensions section>]
54 The B<req> command primarily creates and processes certificate requests
55 in PKCS#10 format. It can additionally create self signed certificates
56 for use as root CAs for example.
58 =head1 COMMAND OPTIONS
62 =item B<-inform DER|PEM>
64 This specifies the input format. The B<DER> option uses an ASN1 DER encoded
65 form compatible with the PKCS#10. The B<PEM> form is the default format: it
66 consists of the B<DER> format base64 encoded with additional header and
69 =item B<-outform DER|PEM>
71 This specifies the output format, the options have the same meaning as the
76 This specifies the input filename to read a request from or standard input
77 if this option is not specified. A request is only read if the creation
78 options (B<-new> and B<-newkey>) are not specified.
82 the input file password source. For more information about the format of B<arg>
83 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
85 =item B<-out filename>
87 This specifies the output filename to write to or standard output by
92 the output file password source. For more information about the format of B<arg>
93 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
97 prints out the certificate request in text form.
101 prints out the request subject (or certificate subject if B<-x509> is
106 outputs the public key.
110 this option prevents output of the encoded version of the request.
114 this option prints out the value of the modulus of the public key
115 contained in the request.
119 verifies the signature on the request.
123 this option generates a new certificate request. It will prompt
124 the user for the relevant field values. The actual fields
125 prompted for and their maximum and minimum sizes are specified
126 in the configuration file and any requested extensions.
128 If the B<-key> option is not used it will generate a new RSA private
129 key using information specified in the configuration file.
133 Replaces subject field of input request with specified data and outputs
134 modified request. The arg must be formatted as
135 I</type0=value0/type1=value1/type2=...>,
136 characters may be escaped by \ (backslash), no spaces are skipped.
138 =item B<-rand file(s)>
140 a file or files containing random data used to seed the random number
141 generator, or an EGD socket (see L<RAND_egd(3)|RAND_egd(3)>).
142 Multiple files can be specified separated by a OS-dependent character.
143 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
148 this option creates a new certificate request and a new private
149 key. The argument takes one of several forms. B<rsa:nbits>, where
150 B<nbits> is the number of bits, generates an RSA key B<nbits>
151 in size. If B<nbits> is omitted, i.e. B<-newkey rsa> specified,
152 the default key size, specified in the configuration file is used.
154 All other algorithms support the B<-newkey alg:file> form, where file may be
155 an algorithm parameter file, created by the B<genpkey -genparam> command
156 or and X.509 certificate for a key with approriate algorithm.
158 B<param:file> generates a key using the parameter file or certificate B<file>,
159 the algorithm is determined by the parameters. B<algname:file> use algorithm
160 B<algname> and parameter file B<file>: the two algorithms must match or an
161 error occurs. B<algname> just uses algorithm B<algname>, and parameters,
162 if neccessary should be specified via B<-pkeyopt> parameter.
164 B<dsa:filename> generates a DSA key using the parameters
165 in the file B<filename>. B<ec:filename> generates EC key (usable both with
166 ECDSA or ECDH algorithms), B<gost2001:filename> generates GOST R
167 34.10-2001 key (requires B<ccgost> engine configured in the configuration
168 file). If just B<gost2001> is specified a parameter set should be
169 specified by B<-pkeyopt paramset:X>
172 =item B<-pkeyopt opt:value>
174 set the public key algorithm option B<opt> to B<value>. The precise set of
175 options supported depends on the public key algorithm used and its
176 implementation. See B<KEY GENERATION OPTIONS> in the B<genpkey> manual page
179 =item B<-key filename>
181 This specifies the file to read the private key from. It also
182 accepts PKCS#8 format private keys for PEM format files.
184 =item B<-keyform PEM|DER>
186 the format of the private key file specified in the B<-key>
187 argument. PEM is the default.
189 =item B<-keyout filename>
191 this gives the filename to write the newly created private key to.
192 If this option is not specified then the filename present in the
193 configuration file is used.
197 if this option is specified then if a private key is created it
198 will not be encrypted.
202 this specifies the message digest to sign the request with (such as
203 B<-md5>, B<-sha1>). This overrides the digest algorithm specified in
204 the configuration file.
206 Some public key algorithms may override this choice. For instance, DSA
207 signatures always use SHA1, GOST R 34.10 signatures always use
208 GOST R 34.11-94 (B<-md_gost94>).
210 =item B<-config filename>
212 this allows an alternative configuration file to be specified,
213 this overrides the compile time filename or any specified in
214 the B<OPENSSL_CONF> environment variable.
218 sets subject name for new request or supersedes the subject name
219 when processing a request.
220 The arg must be formatted as I</type0=value0/type1=value1/type2=...>,
221 characters may be escaped by \ (backslash), no spaces are skipped.
223 =item B<-multivalue-rdn>
225 this option causes the -subj argument to be interpreted with full
226 support for multivalued RDNs. Example:
228 I</DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe>
230 If -multi-rdn is not used then the UID value is I<123456+CN=John Doe>.
234 this option outputs a self signed certificate instead of a certificate
235 request. This is typically used to generate a test certificate or
236 a self signed root CA. The extensions added to the certificate
237 (if any) are specified in the configuration file. Unless specified
238 using the B<set_serial> option, a large random number will be used for
241 If existing request is specified with the B<-in> option, it is converted
242 to the self signed certificate otherwise new request is created.
246 when the B<-x509> option is being used this specifies the number of
247 days to certify the certificate for. The default is 30 days.
249 =item B<-set_serial n>
251 serial number to use when outputting a self signed certificate. This
252 may be specified as a decimal value or a hex value if preceded by B<0x>.
253 It is possible to use negative serial numbers but this is not recommended.
255 =item B<-extensions section>
257 =item B<-reqexts section>
259 these options specify alternative sections to include certificate
260 extensions (if the B<-x509> option is present) or certificate
261 request extensions. This allows several different sections to
262 be used in the same configuration file to specify requests for
263 a variety of purposes.
267 this option causes field values to be interpreted as UTF8 strings, by
268 default they are interpreted as ASCII. This means that the field
269 values, whether prompted from a terminal or obtained from a
270 configuration file, must be valid UTF8 strings.
272 =item B<-nameopt option>
274 option which determines how the subject or issuer names are displayed. The
275 B<option> argument can be a single option or multiple options separated by
276 commas. Alternatively the B<-nameopt> switch may be used more than once to
277 set multiple options. See the L<x509(1)|x509(1)> manual page for details.
281 customise the output format used with B<-text>. The B<option> argument can be
282 a single option or multiple options separated by commas.
284 See discission of the B<-certopt> parameter in the L<B<x509>|x509(1)>
288 =item B<-asn1-kludge>
290 by default the B<req> command outputs certificate requests containing
291 no attributes in the correct PKCS#10 format. However certain CAs will only
292 accept requests containing no attributes in an invalid form: this
293 option produces this invalid format.
295 More precisely the B<Attributes> in a PKCS#10 certificate request
296 are defined as a B<SET OF Attribute>. They are B<not OPTIONAL> so
297 if no attributes are present then they should be encoded as an
298 empty B<SET OF>. The invalid form does not include the empty
299 B<SET OF> whereas the correct form does.
301 It should be noted that very few CAs still require the use of this option.
303 =item B<-no-asn1-kludge>
305 Reverses effect of B<-asn1-kludge>
309 Adds the word B<NEW> to the PEM file header and footer lines on the outputted
310 request. Some software (Netscape certificate server) and some CAs need this.
314 non-interactive mode.
318 print extra details about the operations being performed.
322 specifying an engine (by its unique B<id> string) will cause B<req>
323 to attempt to obtain a functional reference to the specified engine,
324 thus initialising it if needed. The engine will then be set as the default
325 for all available algorithms.
327 =item B<-keygen_engine id>
329 specifies an engine (by its unique B<id> string) which would be used
330 for key generation operations.
334 =head1 CONFIGURATION FILE FORMAT
336 The configuration options are specified in the B<req> section of
337 the configuration file. As with all configuration files if no
338 value is specified in the specific section (i.e. B<req>) then
339 the initial unnamed or B<default> section is searched too.
341 The options available are described in detail below.
345 =item B<input_password output_password>
347 The passwords for the input private key file (if present) and
348 the output private key file (if one will be created). The
349 command line options B<passin> and B<passout> override the
350 configuration file values.
352 =item B<default_bits>
354 Specifies the default key size in bits.
356 This option is used in conjunction with the B<-new> option to generate
357 a new key. It can be overridden by specifying an explicit key size in
358 the B<-newkey> option. The smallest accepted key size is 512 bits. If
359 no key size is specified then 2048 bits is used.
361 =item B<default_keyfile>
363 This is the default filename to write a private key to. If not
364 specified the key is written to standard output. This can be
365 overridden by the B<-keyout> option.
369 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
370 Each line of the file should consist of the numerical form of the
371 object identifier followed by white space then the short name followed
372 by white space and finally the long name.
376 This specifies a section in the configuration file containing extra
377 object identifiers. Each line should consist of the short name of the
378 object identifier followed by B<=> and the numerical form. The short
379 and long names are the same when this option is used.
383 This specifies a filename in which random number seed information is
384 placed and read from, or an EGD socket (see L<RAND_egd(3)|RAND_egd(3)>).
385 It is used for private key generation.
389 If this is set to B<no> then if a private key is generated it is
390 B<not> encrypted. This is equivalent to the B<-nodes> command line
391 option. For compatibility B<encrypt_rsa_key> is an equivalent option.
395 This option specifies the digest algorithm to use. Possible values
396 include B<md5 sha1 mdc2>. If not present then MD5 is used. This
397 option can be overridden on the command line.
401 This option masks out the use of certain string types in certain
402 fields. Most users will not need to change this option.
404 It can be set to several values B<default> which is also the default
405 option uses PrintableStrings, T61Strings and BMPStrings if the
406 B<pkix> value is used then only PrintableStrings and BMPStrings will
407 be used. This follows the PKIX recommendation in RFC2459. If the
408 B<utf8only> option is used then only UTF8Strings will be used: this
409 is the PKIX recommendation in RFC2459 after 2003. Finally the B<nombstr>
410 option just uses PrintableStrings and T61Strings: certain software has
411 problems with BMPStrings and UTF8Strings: in particular Netscape.
413 =item B<req_extensions>
415 this specifies the configuration file section containing a list of
416 extensions to add to the certificate request. It can be overridden
417 by the B<-reqexts> command line switch. See the
418 L<x509v3_config(5)|x509v3_config(5)> manual page for details of the
419 extension section format.
421 =item B<x509_extensions>
423 this specifies the configuration file section containing a list of
424 extensions to add to certificate generated when the B<-x509> switch
425 is used. It can be overridden by the B<-extensions> command line switch.
429 if set to the value B<no> this disables prompting of certificate fields
430 and just takes values from the config file directly. It also changes the
431 expected format of the B<distinguished_name> and B<attributes> sections.
435 if set to the value B<yes> then field values to be interpreted as UTF8
436 strings, by default they are interpreted as ASCII. This means that
437 the field values, whether prompted from a terminal or obtained from a
438 configuration file, must be valid UTF8 strings.
442 this specifies the section containing any request attributes: its format
443 is the same as B<distinguished_name>. Typically these may contain the
444 challengePassword or unstructuredName types. They are currently ignored
445 by OpenSSL's request signing utilities but some CAs might want them.
447 =item B<distinguished_name>
449 This specifies the section containing the distinguished name fields to
450 prompt for when generating a certificate or certificate request. The format
451 is described in the next section.
455 =head1 DISTINGUISHED NAME AND ATTRIBUTE SECTION FORMAT
457 There are two separate formats for the distinguished name and attribute
458 sections. If the B<prompt> option is set to B<no> then these sections
459 just consist of field names and values: for example,
463 emailAddress=someone@somewhere.org
465 This allows external programs (e.g. GUI based) to generate a template file
466 with all the field names and values and just pass it to B<req>. An example
467 of this kind of configuration file is contained in the B<EXAMPLES> section.
469 Alternatively if the B<prompt> option is absent or not set to B<no> then the
470 file contains field prompting information. It consists of lines of the form:
473 fieldName_default="default field value"
477 "fieldName" is the field name being used, for example commonName (or CN).
478 The "prompt" string is used to ask the user to enter the relevant
479 details. If the user enters nothing then the default value is used if no
480 default value is present then the field is omitted. A field can
481 still be omitted if a default value is present if the user just
482 enters the '.' character.
484 The number of characters entered must be between the fieldName_min and
485 fieldName_max limits: there may be additional restrictions based
486 on the field being used (for example countryName can only ever be
487 two characters long and must fit in a PrintableString).
489 Some fields (such as organizationName) can be used more than once
490 in a DN. This presents a problem because configuration files will
491 not recognize the same name occurring twice. To avoid this problem
492 if the fieldName contains some characters followed by a full stop
493 they will be ignored. So for example a second organizationName can
494 be input by calling it "1.organizationName".
496 The actual permitted field names are any object identifier short or
497 long names. These are compiled into OpenSSL and include the usual
498 values such as commonName, countryName, localityName, organizationName,
499 organizationalUnitName, stateOrProvinceName. Additionally emailAddress
500 is include as well as name, surname, givenName initials and dnQualifier.
502 Additional object identifiers can be defined with the B<oid_file> or
503 B<oid_section> options in the configuration file. Any additional fields
504 will be treated as though they were a DirectoryString.
509 Examine and verify certificate request:
511 openssl req -in req.pem -text -verify -noout
513 Create a private key and then generate a certificate request from it:
515 openssl genrsa -out key.pem 2048
516 openssl req -new -key key.pem -out req.pem
518 The same but just using req:
520 openssl req -newkey rsa:2048 -keyout key.pem -out req.pem
522 Generate a self signed root certificate:
524 openssl req -x509 -newkey rsa:2048 -keyout key.pem -out req.pem
526 Example of a file pointed to by the B<oid_file> option:
528 1.2.3.4 shortName A longer Name
529 1.2.3.6 otherName Other longer Name
531 Example of a section pointed to by B<oid_section> making use of variable
535 testoid2=${testoid1}.6
537 Sample configuration file prompting for field values:
541 default_keyfile = privkey.pem
542 distinguished_name = req_distinguished_name
543 attributes = req_attributes
544 x509_extensions = v3_ca
546 dirstring_type = nobmp
548 [ req_distinguished_name ]
549 countryName = Country Name (2 letter code)
550 countryName_default = AU
554 localityName = Locality Name (eg, city)
556 organizationalUnitName = Organizational Unit Name (eg, section)
558 commonName = Common Name (eg, YOUR name)
561 emailAddress = Email Address
562 emailAddress_max = 40
565 challengePassword = A challenge password
566 challengePassword_min = 4
567 challengePassword_max = 20
571 subjectKeyIdentifier=hash
572 authorityKeyIdentifier=keyid:always,issuer:always
573 basicConstraints = CA:true
575 Sample configuration containing all field values:
578 RANDFILE = $ENV::HOME/.rnd
582 default_keyfile = keyfile.pem
583 distinguished_name = req_distinguished_name
584 attributes = req_attributes
586 output_password = mypass
588 [ req_distinguished_name ]
590 ST = Test State or Province
592 O = Organization Name
593 OU = Organizational Unit Name
595 emailAddress = test@email.address
598 challengePassword = A challenge password
603 The header and footer lines in the B<PEM> format are normally:
605 -----BEGIN CERTIFICATE REQUEST-----
606 -----END CERTIFICATE REQUEST-----
608 some software (some versions of Netscape certificate server) instead needs:
610 -----BEGIN NEW CERTIFICATE REQUEST-----
611 -----END NEW CERTIFICATE REQUEST-----
613 which is produced with the B<-newhdr> option but is otherwise compatible.
614 Either form is accepted transparently on input.
616 The certificate requests generated by B<Xenroll> with MSIE have extensions
617 added. It includes the B<keyUsage> extension which determines the type of
618 key (signature only or general purpose) and any additional OIDs entered
619 by the script in an extendedKeyUsage extension.
623 The following messages are frequently asked about:
625 Using configuration from /some/path/openssl.cnf
626 Unable to load config info
628 This is followed some time later by...
630 unable to find 'distinguished_name' in config
631 problems making Certificate Request
633 The first error message is the clue: it can't find the configuration
634 file! Certain operations (like examining a certificate request) don't
635 need a configuration file so its use isn't enforced. Generation of
636 certificates or requests however does need a configuration file. This
637 could be regarded as a bug.
639 Another puzzling message is this:
644 this is displayed when no attributes are present and the request includes
645 the correct empty B<SET OF> structure (the DER encoding of which is 0xa0
646 0x00). If you just see:
650 then the B<SET OF> is missing and the encoding is technically invalid (but
651 it is tolerated). See the description of the command line option B<-asn1-kludge>
652 for more information.
654 =head1 ENVIRONMENT VARIABLES
656 The variable B<OPENSSL_CONF> if defined allows an alternative configuration
657 file location to be specified, it will be overridden by the B<-config> command
658 line switch if it is present. For compatibility reasons the B<SSLEAY_CONF>
659 environment variable serves the same purpose but its use is discouraged.
663 OpenSSL's handling of T61Strings (aka TeletexStrings) is broken: it effectively
664 treats them as ISO-8859-1 (Latin 1), Netscape and MSIE have similar behaviour.
665 This can cause problems if you need characters that aren't available in
666 PrintableStrings and you don't want to or can't use BMPStrings.
668 As a consequence of the T61String handling the only correct way to represent
669 accented characters in OpenSSL is to use a BMPString: unfortunately Netscape
670 currently chokes on these. If you have to use accented characters with Netscape
671 and MSIE then you currently need to use the invalid T61String form.
673 The current prompting is not very friendly. It doesn't allow you to confirm what
674 you've just entered. Other things like extensions in certificate requests are
675 statically defined in the configuration file. Some of these: like an email
676 address in subjectAltName should be input by the user.
680 L<x509(1)|x509(1)>, L<ca(1)|ca(1)>, L<genrsa(1)|genrsa(1)>,
681 L<gendsa(1)|gendsa(1)>, L<config(5)|config(5)>,
682 L<x509v3_config(5)|x509v3_config(5)>