6 req - PKCS#10 certificate and certificate generating utility.
17 [B<-passout password>]
30 [B<-[md5|sha1|md2|mdc2]>]
35 [B<-extensions section>]
40 The B<req> command primarily creates and processes certificate requests
41 in PKCS#10 format. It can additionally create self signed certificates
42 for use as root CAs for example.
44 =head1 COMMAND OPTIONS
48 =item B<-inform DER|PEM>
50 This specifies the input format. The B<DER> option uses an ASN1 DER encoded
51 form compatible with the PKCS#10. The B<PEM> form is the default format: it
52 consists of the B<DER> format base64 encoded with additional header and
55 =item B<-outform DER|PEM>
57 This specifies the output format, the options have the same meaning as the
62 This specifies the input filename to read a request from or standard input
63 if this option is not specified. A request is only read if the creation
64 options (B<-new> and B<-newkey>) are not specified.
66 =item B<-passin password>
68 the input file password. Since certain utilities like "ps" make the command line
69 visible this option should be used with caution.
71 =item B<-envpassin var>
73 read the input file password from the environment variable B<var>.
75 =item B<-out filename>
77 This specifies the output filename to write to or standard output by
80 =item B<-passout password>
82 the output file password. Since certain utilities like "ps" make the command line
83 visible this option should be used with caution.
85 =item B<-envpassout var>
87 read the output file password from the environment variable B<var>.
91 prints out the certificate request in text form.
95 this option prevents output of the encoded version of the request.
99 this option prints out the value of the modulus of the public key
100 contained in the request.
104 verifies the signature on the request.
108 this option generates a new certificate request. It will prompt
109 the user for the relevant field values. The actual fields
110 prompted for and their maximum and minimum sizes are specified
111 in the configuration file and any requested extensions.
113 If the B<-key> option is not used it will generate a new RSA private
114 key using information specified in the configuration file.
118 this option creates a new certificate request and a new private
119 key. The argument takes one of two forms. B<rsa:nbits>, where
120 B<nbits> is the number of bits, generates an RSA key B<nbits>
121 in size. B<dsa:filename> generates a DSA key using the parameters
122 in the file B<filename>.
124 =item B<-key filename>
126 This specifies the file to read the private key from. It also
127 accepts PKCS#8 format private keys for PEM format files.
129 =item B<-keyform PEM|DER>
131 the format of the private key file specified in the B<-key>
132 argument. PEM is the default.
134 =item B<-keyout filename>
136 this gives the filename to write the newly created private key to.
137 If this option is not specified then the filename present in the
138 configuration file is used.
142 if this option is specified then if a private key is created it
143 will not be encrypted.
145 =item B<-[md5|sha1|md2|mdc2]>
147 this specifies the message digest to sign the request with. This
148 overrides the digest algorithm specified in the configuration file.
149 This option is ignore for DSA requests: they always use SHA1.
151 =item B<-config filename>
153 this allows an alternative configuration file to be specified,
154 this overrides the compile time filename or any specified in
155 the B<OPENSSL_CONF> environment variable.
159 this option outputs a self signed certificate instead of a certificate
160 request. This is typically used to generate a test certificate or
161 a self signed root CA. The extensions added to the certificate
162 (if any) are specified in the configuration file.
166 when the B<-x509> option is being used this specifies the number of
167 days to certify the certificate for. The default is 30 days.
169 =item B<-extensions section>
170 =item B<-reqexts section>
172 these options specify alternative sections to include certificate
173 extensions (if the B<-x509> option is present) or certificate
174 request extensions. This allows several different sections to
175 be used in the same configuration file to specify requests for
176 a variety of purposes.
178 =item B<-asn1-kludge>
180 by default the B<req> command outputs certificate requests containing
181 no attributes in the correct PKCS#10 format. However certain CAs will only
182 accept requests containing no attributes in an invalid form: this
183 option produces this invalid format.
185 More precisely the B<Attributes> in a PKCS#10 certificate request
186 are defined as a B<SET OF Attribute>. They are B<not OPTIONAL> so
187 if no attributes are present then they should be encoded as an
188 empty B<SET OF>. The invalid form does not include the empty
189 B<SET OF> whereas the correct form does.
191 It should be noted that very few CAs still require the use of this option.
195 =head1 CONFIGURATION FILE FORMAT
197 The configuation options are specified in the B<req> section of
198 the configuration file. As with all configuration files if no
199 value is specified in the specific section (i.e. B<req>) then
200 the initial unnamed or B<default> section is searched too.
202 The options available are described in detail below.
206 =item B<default_bits>
208 This specifies the default key size in bits. If not specified then
209 512 is used. It is used if the B<-new> option is used. It can be
210 overriden by using the B<-newkey> option.
212 =item B<default_keyfile>
214 This is the default filename to write a private key to. If not
215 specified the key is written to standard output. This can be
216 overriden by the B<-keyout> option.
220 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
221 Each line of the file should consist of the numerical form of the
222 object identifier followed by white space then the short name followed
223 by white space and finally the long name.
227 This specifies a section in the configuration file containing extra
228 object identifiers. Each line should consist of the short name of the
229 object identifier followed by B<=> and the numerical form. The short
230 and long names are the same when this option is used.
234 This specifies a filename in which random number seed information is
235 placed and read from. It is used for private key generation.
237 =item B<encrypt_rsa_key|encrypt_key>
239 If this is set to B<no> then if a private key is generated it is
240 B<not> encrypted. This is equivalent to the B<-nodes> command line
245 This option specifies the digest algorithm to use. Possible values
246 include B<md5 sha1 mdc2>. If not present then MD5 is used. This
247 option can be overridden on the command line.
249 =item B<dirstring_type>
251 This option specifies which string types are permissible in a
252 B<DirectoryString>. Most users will not need to change this option.
254 It can be set to several values B<default> which is also the default
255 option uses PrintableStrings, T61Strings and BMPStrings if the
256 B<pkix> value is used then only PrintableStrings and BMPStrings will
257 be used. This follows the PKIX recommendation in RFC2459. If the
258 B<utf8only> option is used then only UTF8Strings will be used: this
259 is the PKIX recommendation in RFC2459 after 2003. Finally the B<nobmp>
260 option just uses PrintableStrings and T61Strings: certain software has
261 problems with BMPStrings.
263 =item B<req_extensions>
265 this specifies the configuration file section containing a list of
266 extensions to add to the certificate request. It can be overridden
267 by the B<-reqexts> command line switch.
269 =item B<x509_extensions>
271 this specifies the configuration file section containing a list of
272 extensions to add to certificate generated when the B<-x509> switch
273 is used. It can be overridden by the B<-extensions> command line switch.
277 this specifies the section containing any request attributes: its format
278 is the same as B<distinguished_name> described below. Typically these
279 may contain the challengePassword or unstructuredName types. They are
280 currently ignored by OpenSSLs request signing utilities but some CAs might want
283 =item B<distinguished_name>
285 This specifies the section containing the distiguished name fields to
286 prompt for when generating a certificate or certificate request. This
287 consists of lines of the form:
290 fieldName_default="default field value"
294 "fieldName" is the field name being used, for example commonName (or CN).
295 The "prompt" string is used to ask the user to enter the relvant
296 details. If the user enters nothing then the default value is used if no
297 default value is present then the field is omitted. A field can
298 still be omitted if a default value is present if the user just
299 enters the '.' character.
301 The number of characters entered must be between the fieldName_min and
302 fieldName_max limits: there may be additional restrictions based
303 on the field being used (for example countryName can only ever be
304 two characters long and must fit in a PrintableString).
306 Some fields (such as organizationName) can be used more than once
307 in a DN. This presents a problem because configuration files will
308 not recognise the same name occurring twice. To avoid this problem
309 if the fieldName contains an some characters followed by a full stop
310 they will be ignored. So for example a second organizationName can
311 be input by calling it "1.organizationName".
313 The actual permitted field names are any object identifier short or
314 long names. These are compiled into OpenSSL and include the usual
315 values such as commonName, countryName, localityName, organizationName,
316 organizationUnitName, stateOrPrivinceName. Additionally emailAddress
317 is include as well as name, surname, givenName initials and dnQualifier
320 Additional object identifiers can be defined with the B<oid_file> or
321 B<oid_section> options in the configuration file. Any additional fields
322 will be treated as though they were a DirectoryString.
328 Examine and verify certificate request:
330 openssl req -in req.pem -text -verify -noout
332 Create a private key and then generate a certificate request from it:
334 openssl genrsa -out key.pem 1024
335 openssl req -new -key key.pem -out req.pem
337 The same but just using req:
339 openssl req -newkey rsa:1024 -keyout key.pem -out req.pem
341 Generate a self signed root certificate:
343 openssl req -x509 -newkey rsa:1024 -keyout key.pem -out req.pem
345 Example of a file pointed to by the B<oid_file> option:
347 1.2.3.4 shortName A longer Name
348 1.2.3.6 otherName Other longer Name
350 Example of a section pointed to by B<oid_section> making use of variable
354 testoid2=${testoid1}.6
356 Sample configuration file:
360 default_keyfile = privkey.pem
361 distinguished_name = req_distinguished_name
362 attributes = req_attributes
363 x509_extensions = v3_ca
365 dirstring_type = nobmp
367 [ req_distinguished_name ]
368 countryName = Country Name (2 letter code)
369 countryName_default = AU
373 localityName = Locality Name (eg, city)
375 organizationalUnitName = Organizational Unit Name (eg, section)
377 commonName = Common Name (eg, YOUR name)
380 emailAddress = Email Address
381 emailAddress_max = 40
384 challengePassword = A challenge password
385 challengePassword_min = 4
386 challengePassword_max = 20
390 subjectKeyIdentifier=hash
391 authorityKeyIdentifier=keyid:always,issuer:always
392 basicConstraints = CA:true
396 The header and footer lines in the B<PEM> format are respectively:
398 -----BEGIN CERTIFICATE REQUEST----
399 -----END CERTIFICATE REQUEST----
401 some software (some versions of Netscape certificate server) instead needs:
403 -----BEGIN NEW CERTIFICATE REQUEST----
404 -----END NEW CERTIFICATE REQUEST----
406 but is otherwise compatible. Either form is accepted on input.
408 The certificate requests generated by B<Xenroll> with MSIE have extensions
409 added. It includes the B<keyUsage> extension which determines the type of
410 key (signature only or general purpose) and any additional OIDs entered
411 by the script in an extendedKeyUsage extension.
415 The following messages are frequently asked about:
417 Using configuration from /some/path/openssl.cnf
418 Unable to load config info
420 This is followed some time later by...
422 unable to find 'distinguished_name' in config
423 problems making Certificate Request
425 The first error message is the clue: it can't find the configuration
426 file! Certain operations (like examining a certificate request) don't
427 need a configuration file so its use isn't enforced. Generation of
428 certficates or requests however does need a configuration file. This
429 could be regarded as a bug.
431 Another puzzling message is this:
436 this is displayed when no attributes are present and the request includes
437 the correct empty B<SET OF> structure (the DER encoding of which is 0xa0
438 0x00). If you just see:
442 then the B<SET OF> is missing and the encoding is technically invalid (but
443 it is tolerated). See the description of the command line option B<-asn1-kludge>
444 for more information.
446 =head1 ENVIRONMENT VARIABLES
448 The variable B<OPENSSL_CONF> if defined allows an alternative configuration
449 file location to be specified, it will be overridden by the B<-config> command
450 line switch if it is present. For compatability reasons the B<SSLEAY_CONF>
451 environment variable serves the same purpose but its use is discouraged.
455 OpenSSLs handling of T61Strings (aka TeletexStrings) is broken: it effectively
456 treats them as ISO-8859-1 (latin 1), Netscape and MSIE have similar behaviour.
457 This can cause problems if you need characters that aren't available in
458 PrintableStrings and you don't want to or can't use BMPStrings.
460 As a consequence of the T61String handling the only correct way to represent
461 accented characters in OpenSSL is to use a BMPString: unfortunately Netscape
462 currently chokes on these. If you have to use accented characters with Netscape
463 and MSIE then you currently need to use the invalid T61String form.
465 The current prompting is not very friendly. It exits if you get the strings
466 wrong and doesn't allow you to confirm what you've just entered. Other things
467 like extensions in certificate requests are statically defined in the configuration
468 file. Some of these: like an email address in subjectAltName should be input
471 There should be a way to have a friendly front end (e.g. perl script or GUI)
472 handle all user input and then just feed a "template" file into B<req> which
473 then silently creates the request or certificate. This would also shift the
474 responsibility for handling such problems as internationalisation of characters
475 onto the front end: the template could then just expect valid UTF8 character
480 x509(1), ca(1), genrsa(1), gendsa(1), config(5)