6 req - PKCS#10 certificate and certificate generating utility.
28 [B<-[md5|sha1|md2|mdc2]>]
33 [B<-extensions section>]
38 The B<req> command primarily creates and processes certificate requests
39 in PKCS#10 format. It can additionally create self signed certificates
40 for use as root CAs for example.
42 =head1 COMMAND OPTIONS
46 =item B<-inform DER|PEM>
48 This specifies the input format. The B<DER> option uses an ASN1 DER encoded
49 form compatible with the PKCS#10. The B<PEM> form is the default format: it
50 consists of the B<DER> format base64 encoded with additional header and
53 =item B<-outform DER|PEM>
55 This specifies the output format, the options have the same meaning as the
60 This specifies the input filename to read a request from or standard input
61 if this option is not specified. A request is only read if the creation
62 options (B<-new> and B<-newkey>) are not specified.
66 the input file password source. For more information about the format of B<arg>
67 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
69 =item B<-out filename>
71 This specifies the output filename to write to or standard output by
76 the output file password source. For more information about the format of B<arg>
77 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
81 prints out the certificate request in text form.
85 this option prevents output of the encoded version of the request.
89 this option prints out the value of the modulus of the public key
90 contained in the request.
94 verifies the signature on the request.
98 this option generates a new certificate request. It will prompt
99 the user for the relevant field values. The actual fields
100 prompted for and their maximum and minimum sizes are specified
101 in the configuration file and any requested extensions.
103 If the B<-key> option is not used it will generate a new RSA private
104 key using information specified in the configuration file.
108 this option creates a new certificate request and a new private
109 key. The argument takes one of two forms. B<rsa:nbits>, where
110 B<nbits> is the number of bits, generates an RSA key B<nbits>
111 in size. B<dsa:filename> generates a DSA key using the parameters
112 in the file B<filename>.
114 =item B<-key filename>
116 This specifies the file to read the private key from. It also
117 accepts PKCS#8 format private keys for PEM format files.
119 =item B<-keyform PEM|DER>
121 the format of the private key file specified in the B<-key>
122 argument. PEM is the default.
124 =item B<-keyout filename>
126 this gives the filename to write the newly created private key to.
127 If this option is not specified then the filename present in the
128 configuration file is used.
132 if this option is specified then if a private key is created it
133 will not be encrypted.
135 =item B<-[md5|sha1|md2|mdc2]>
137 this specifies the message digest to sign the request with. This
138 overrides the digest algorithm specified in the configuration file.
139 This option is ignored for DSA requests: they always use SHA1.
141 =item B<-config filename>
143 this allows an alternative configuration file to be specified,
144 this overrides the compile time filename or any specified in
145 the B<OPENSSL_CONF> environment variable.
149 this option outputs a self signed certificate instead of a certificate
150 request. This is typically used to generate a test certificate or
151 a self signed root CA. The extensions added to the certificate
152 (if any) are specified in the configuration file.
156 when the B<-x509> option is being used this specifies the number of
157 days to certify the certificate for. The default is 30 days.
159 =item B<-extensions section>
160 =item B<-reqexts section>
162 these options specify alternative sections to include certificate
163 extensions (if the B<-x509> option is present) or certificate
164 request extensions. This allows several different sections to
165 be used in the same configuration file to specify requests for
166 a variety of purposes.
168 =item B<-asn1-kludge>
170 by default the B<req> command outputs certificate requests containing
171 no attributes in the correct PKCS#10 format. However certain CAs will only
172 accept requests containing no attributes in an invalid form: this
173 option produces this invalid format.
175 More precisely the B<Attributes> in a PKCS#10 certificate request
176 are defined as a B<SET OF Attribute>. They are B<not OPTIONAL> so
177 if no attributes are present then they should be encoded as an
178 empty B<SET OF>. The invalid form does not include the empty
179 B<SET OF> whereas the correct form does.
181 It should be noted that very few CAs still require the use of this option.
185 =head1 CONFIGURATION FILE FORMAT
187 The configuration options are specified in the B<req> section of
188 the configuration file. As with all configuration files if no
189 value is specified in the specific section (i.e. B<req>) then
190 the initial unnamed or B<default> section is searched too.
192 The options available are described in detail below.
196 =item B<input_password output_password>
198 The passwords for the input private key file (if present) and
199 the output private key file (if one will be created). The
200 command line options B<passin> and B<passout> override the
201 configuration file values.
203 =item B<default_bits>
205 This specifies the default key size in bits. If not specified then
206 512 is used. It is used if the B<-new> option is used. It can be
207 overridden by using the B<-newkey> option.
209 =item B<default_keyfile>
211 This is the default filename to write a private key to. If not
212 specified the key is written to standard output. This can be
213 overridden by the B<-keyout> option.
217 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
218 Each line of the file should consist of the numerical form of the
219 object identifier followed by white space then the short name followed
220 by white space and finally the long name.
224 This specifies a section in the configuration file containing extra
225 object identifiers. Each line should consist of the short name of the
226 object identifier followed by B<=> and the numerical form. The short
227 and long names are the same when this option is used.
231 This specifies a filename in which random number seed information is
232 placed and read from. It is used for private key generation.
236 If this is set to B<no> then if a private key is generated it is
237 B<not> encrypted. This is equivalent to the B<-nodes> command line
238 option. For compatibility B<encrypt_rsa_key> is an equivalent option.
242 This option specifies the digest algorithm to use. Possible values
243 include B<md5 sha1 mdc2>. If not present then MD5 is used. This
244 option can be overridden on the command line.
248 This option masks out the use of certain string types in certain
249 fields. Most users will not need to change this option.
251 It can be set to several values B<default> which is also the default
252 option uses PrintableStrings, T61Strings and BMPStrings if the
253 B<pkix> value is used then only PrintableStrings and BMPStrings will
254 be used. This follows the PKIX recommendation in RFC2459. If the
255 B<utf8only> option is used then only UTF8Strings will be used: this
256 is the PKIX recommendation in RFC2459 after 2003. Finally the B<nombstr>
257 option just uses PrintableStrings and T61Strings: certain software has
258 problems with BMPStrings and UTF8Strings: in particular Netscape.
260 =item B<req_extensions>
262 this specifies the configuration file section containing a list of
263 extensions to add to the certificate request. It can be overridden
264 by the B<-reqexts> command line switch.
266 =item B<x509_extensions>
268 this specifies the configuration file section containing a list of
269 extensions to add to certificate generated when the B<-x509> switch
270 is used. It can be overridden by the B<-extensions> command line switch.
274 if set to the value B<no> this disables prompting of certificate fields
275 and just takes values from the config file directly. It also changes the
276 expected format of the B<distinguished_name> and B<attributes> sections.
280 this specifies the section containing any request attributes: its format
281 is the same as B<distinguished_name>. Typically these may contain the
282 challengePassword or unstructuredName types. They are currently ignored
283 by OpenSSL's request signing utilities but some CAs might want them.
285 =item B<distinguished_name>
287 This specifies the section containing the distinguished name fields to
288 prompt for when generating a certificate or certificate request. The format
289 is described in the next section.
293 =head1 DISTINGUISHED NAME AND ATTRIBUTE SECTION FORMAT
295 There are two separate formats for the distinguished name and attribute
296 sections. If the B<prompt> option is set to B<no> then these sections
297 just consist of field names and values: for example,
301 emailAddress=someone@somewhere.org
303 This allows external programs (e.g. GUI based) to generate a template file
304 with all the field names and values and just pass it to B<req>. An example
305 of this kind of configuration files is contained in the B<EXAMPLES> section.
307 Alternatively if the B<prompt> option is absent or not set to B<no> the the
308 file contains field prompting information. It consists of lines of the form:
311 fieldName_default="default field value"
315 "fieldName" is the field name being used, for example commonName (or CN).
316 The "prompt" string is used to ask the user to enter the relevant
317 details. If the user enters nothing then the default value is used if no
318 default value is present then the field is omitted. A field can
319 still be omitted if a default value is present if the user just
320 enters the '.' character.
322 The number of characters entered must be between the fieldName_min and
323 fieldName_max limits: there may be additional restrictions based
324 on the field being used (for example countryName can only ever be
325 two characters long and must fit in a PrintableString).
327 Some fields (such as organizationName) can be used more than once
328 in a DN. This presents a problem because configuration files will
329 not recognize the same name occurring twice. To avoid this problem
330 if the fieldName contains an some characters followed by a full stop
331 they will be ignored. So for example a second organizationName can
332 be input by calling it "1.organizationName".
334 The actual permitted field names are any object identifier short or
335 long names. These are compiled into OpenSSL and include the usual
336 values such as commonName, countryName, localityName, organizationName,
337 organizationUnitName, stateOrPrivinceName. Additionally emailAddress
338 is include as well as name, surname, givenName initials and dnQualifier
341 Additional object identifiers can be defined with the B<oid_file> or
342 B<oid_section> options in the configuration file. Any additional fields
343 will be treated as though they were a DirectoryString.
348 Examine and verify certificate request:
350 openssl req -in req.pem -text -verify -noout
352 Create a private key and then generate a certificate request from it:
354 openssl genrsa -out key.pem 1024
355 openssl req -new -key key.pem -out req.pem
357 The same but just using req:
359 openssl req -newkey rsa:1024 -keyout key.pem -out req.pem
361 Generate a self signed root certificate:
363 openssl req -x509 -newkey rsa:1024 -keyout key.pem -out req.pem
365 Example of a file pointed to by the B<oid_file> option:
367 1.2.3.4 shortName A longer Name
368 1.2.3.6 otherName Other longer Name
370 Example of a section pointed to by B<oid_section> making use of variable
374 testoid2=${testoid1}.6
376 Sample configuration file prompting for field values:
380 default_keyfile = privkey.pem
381 distinguished_name = req_distinguished_name
382 attributes = req_attributes
383 x509_extensions = v3_ca
385 dirstring_type = nobmp
387 [ req_distinguished_name ]
388 countryName = Country Name (2 letter code)
389 countryName_default = AU
393 localityName = Locality Name (eg, city)
395 organizationalUnitName = Organizational Unit Name (eg, section)
397 commonName = Common Name (eg, YOUR name)
400 emailAddress = Email Address
401 emailAddress_max = 40
404 challengePassword = A challenge password
405 challengePassword_min = 4
406 challengePassword_max = 20
410 subjectKeyIdentifier=hash
411 authorityKeyIdentifier=keyid:always,issuer:always
412 basicConstraints = CA:true
414 Sample configuration containing all field values:
417 RANDFILE = $ENV::HOME/.rnd
421 default_keyfile = keyfile.pem
422 distinguished_name = req_distinguished_name
423 attributes = req_attributes
425 output_password = mypass
427 [ req_distinguished_name ]
429 ST = Test State or Province
431 O = Organization Name
432 OU = Organizational Unit Name
434 emailAddress = test@email.address
437 challengePassword = A challenge password
442 The header and footer lines in the B<PEM> format are respectively:
444 -----BEGIN CERTIFICATE REQUEST----
445 -----END CERTIFICATE REQUEST----
447 some software (some versions of Netscape certificate server) instead needs:
449 -----BEGIN NEW CERTIFICATE REQUEST----
450 -----END NEW CERTIFICATE REQUEST----
452 but is otherwise compatible. Either form is accepted on input.
454 The certificate requests generated by B<Xenroll> with MSIE have extensions
455 added. It includes the B<keyUsage> extension which determines the type of
456 key (signature only or general purpose) and any additional OIDs entered
457 by the script in an extendedKeyUsage extension.
461 The following messages are frequently asked about:
463 Using configuration from /some/path/openssl.cnf
464 Unable to load config info
466 This is followed some time later by...
468 unable to find 'distinguished_name' in config
469 problems making Certificate Request
471 The first error message is the clue: it can't find the configuration
472 file! Certain operations (like examining a certificate request) don't
473 need a configuration file so its use isn't enforced. Generation of
474 certificates or requests however does need a configuration file. This
475 could be regarded as a bug.
477 Another puzzling message is this:
482 this is displayed when no attributes are present and the request includes
483 the correct empty B<SET OF> structure (the DER encoding of which is 0xa0
484 0x00). If you just see:
488 then the B<SET OF> is missing and the encoding is technically invalid (but
489 it is tolerated). See the description of the command line option B<-asn1-kludge>
490 for more information.
492 =head1 ENVIRONMENT VARIABLES
494 The variable B<OPENSSL_CONF> if defined allows an alternative configuration
495 file location to be specified, it will be overridden by the B<-config> command
496 line switch if it is present. For compatibility reasons the B<SSLEAY_CONF>
497 environment variable serves the same purpose but its use is discouraged.
501 OpenSSL's handling of T61Strings (aka TeletexStrings) is broken: it effectively
502 treats them as ISO-8859-1 (Latin 1), Netscape and MSIE have similar behaviour.
503 This can cause problems if you need characters that aren't available in
504 PrintableStrings and you don't want to or can't use BMPStrings.
506 As a consequence of the T61String handling the only correct way to represent
507 accented characters in OpenSSL is to use a BMPString: unfortunately Netscape
508 currently chokes on these. If you have to use accented characters with Netscape
509 and MSIE then you currently need to use the invalid T61String form.
511 The current prompting is not very friendly. It doesn't allow you to confirm what
512 you've just entered. Other things like extensions in certificate requests are
513 statically defined in the configuration file. Some of these: like an email
514 address in subjectAltName should be input by the user.
518 L<x509(1)|x509(1)>, L<ca(1)|ca(1)>, L<genrsa(1)|genrsa(1)>,
519 L<gendsa(1)|gendsa(1)>, L<config(5)|config(5)>