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X509(1)				    OpenSSL			       X509(1)

       x509 - Certificate display and signing utility

       openssl x509 [-inform DER|PEM|NET] [-outform DER|PEM|NET] [-keyform
       DER|PEM]	[-CAform DER|PEM] [-CAkeyform DER|PEM] [-in filename] [-out
       filename] [-serial] [-hash] [-subject] [-issuer]	[-nameopt option]
       [-email]	[-startdate] [-enddate]	[-purpose] [-dates] [-modulus] [-fin-
       gerprint] [-alias] [-noout] [-trustout] [-clrtrust] [-clrreject]	[-ad-
       dtrust arg] [-addreject arg] [-setalias arg] [-days arg]	[-set_serial
       n] [-signkey filename] [-x509toreq] [-req] [-CA filename] [-CAkey file-
       name] [-CAcreateserial] [-CAserial filename] [-text] [-C]
       [-md2|-md5|-sha1|-mdc2] [-clrext] [-extfile filename] [-extensions sec-
       tion] [-engine id]

       The x509	command	is a multi purpose certificate utility.	It can be used
       to display certificate information, convert certificates	to various
       forms, sign certificate requests	like a "mini CA" or edit certificate
       trust settings.

       Since there are a large number of options they will split up into vari-
       ous sections.


       -inform DER|PEM|NET
	   This	specifies the input format normally the	command	will expect an
	   X509	certificate but	this can change	if other options such as -req
	   are present.	The DER	format is the DER encoding of the certificate
	   and PEM is the base64 encoding of the DER encoding with header and
	   footer lines	added. The NET option is an obscure Netscape server
	   format that is now obsolete.

       -outform	DER|PEM|NET
	   This	specifies the output format, the options have the same meaning
	   as the -inform option.

       -in filename
	   This	specifies the input filename to	read a certificate from	or
	   standard input if this option is not	specified.

       -out filename
	   This	specifies the output filename to write to or standard output
	   by default.

	   the digest to use. This affects any signing or display option that
	   uses	a message digest, such as the -fingerprint, -signkey and -CA
	   options. If not specified then MD5 is used. If the key being	used
	   to sign with	is a DSA key then this option has no effect: SHA1 is
	   always used with DSA	keys.

       -engine id
	   specifying an engine	(by it's unique	id string) will	cause req to
	   attempt to obtain a functional reference to the specified engine,
	   thus	initialising it	if needed. The engine will then	be set as the
	   default for all available algorithms.


       Note: the -alias	and -purpose options are also display options but are
       described in the	TRUST SETTINGS section.

	   prints out the certificate in text form. Full details are output
	   including the public	key, signature algorithms, issuer and subject
	   names, serial number	any extensions present and any trust settings.

       -certopt	option
	   customise the output	format used with -text.	The option argument
	   can be a single option or multiple options separated	by commas. The
	   -certopt switch may be also be used more than once to set multiple
	   options. See	the TEXT OPTIONS section for more information.

	   this	option prevents	output of the encoded version of the request.

	   this	option prints out the value of the modulus of the public key
	   contained in	the certificate.

	   outputs the certificate serial number.

	   outputs the "hash" of the certificate subject name. This is used in
	   OpenSSL to form an index to allow certificates in a directory to be
	   looked up by	subject	name.

	   outputs the subject name.

	   outputs the issuer name.

       -nameopt	option
	   option which	determines how the subject or issuer names are dis-
	   played. The option argument can be a	single option or multiple op-
	   tions separated by commas.  Alternatively the -nameopt switch may
	   be used more	than once to set multiple options. See the NAME	OP-
	   TIONS section for more information.

	   outputs the email address(es) if any.

	   prints out the start	date of	the certificate, that is the notBefore

	   prints out the expiry date of the certificate, that is the notAfter

	   prints out the start	and expiry dates of a certificate.

	   prints out the digest of the	DER encoded version of the whole cer-
	   tificate (see digest	options).

       -C  this	outputs	the certificate	in the form of a C source file.


       Please note these options are currently experimental and	may well

       A trusted certificate is	an ordinary certificate	which has several ad-
       ditional	pieces of information attached to it such as the permitted and
       prohibited uses of the certificate and an "alias".

       Normally	when a certificate is being verified at	least one certificate
       must be "trusted". By default a trusted certificate must	be stored lo-
       cally and must be a root	CA: any	certificate chain ending in this CA is
       then usable for any purpose.

       Trust settings currently	are only used with a root CA. They allow a
       finer control over the purposes the root	CA can be used for. For	exam-
       ple a CA	may be trusted for SSL client but not SSL server use.

       See the description of the verify utility for more information on the
       meaning of trust	settings.

       Future versions of OpenSSL will recognize trust settings	on any cer-
       tificate: not just root CAs.

	   this	causes x509 to output a	trusted	certificate. An	ordinary or
	   trusted certificate can be input but	by default an ordinary cer-
	   tificate is output and any trust settings are discarded. With the
	   -trustout option a trusted certificate is output. A trusted cer-
	   tificate is automatically output if any trust settings are modi-

       -setalias arg
	   sets	the alias of the certificate. This will	allow the certificate
	   to be referred to using a nickname for example "Steve's Certifi-

	   outputs the certificate alias, if any.

	   clears all the permitted or trusted uses of the certificate.

	   clears all the prohibited or	rejected uses of the certificate.

       -addtrust arg
	   adds	a trusted certificate use. Any object name can be used here
	   but currently only clientAuth (SSL client use), serverAuth (SSL
	   server use) and emailProtection (S/MIME email) are used.  Other
	   OpenSSL applications	may define additional uses.

       -addreject arg
	   adds	a prohibited use. It accepts the same values as	the -addtrust

	   this	option performs	tests on the certificate extensions and	out-
	   puts	the results. For a more	complete description see the CERTIFI-
	   CATE	EXTENSIONS section.


       The x509	utility	can be used to sign certificates and requests: it can
       thus behave like	a "mini	CA".

       -signkey	filename
	   this	option causes the input	file to	be self	signed using the sup-
	   plied private key.

	   If the input	file is	a certificate it sets the issuer name to the
	   subject name	(i.e.  makes it	self signed) changes the public	key to
	   the supplied	value and changes the start and	end dates. The start
	   date	is set to the current time and the end date is set to a	value
	   determined by the -days option. Any certificate extensions are re-
	   tained unless the -clrext option is supplied.

	   If the input	is a certificate request then a	self signed certifi-
	   cate	is created using the supplied private key using	the subject
	   name	in the request.

	   delete any extensions from a	certificate. This option is used when
	   a certificate is being created from another certificate (for	exam-
	   ple with the	-signkey or the	-CA options). Normally all extensions
	   are retained.

       -keyform	PEM|DER
	   specifies the format	(DER or	PEM) of	the private key	file used in
	   the -signkey	option.

       -days arg
	   specifies the number	of days	to make	a certificate valid for. The
	   default is 30 days.

	   converts a certificate into a certificate request. The -signkey op-
	   tion	is used	to pass	the required private key.

	   by default a	certificate is expected	on input. With this option a
	   certificate request is expected instead.

       -set_serial n
	   specifies the serial	number to use. This option can be used with
	   either the -signkey or -CA options. If used in conjunction with the
	   -CA option the serial number	file (as specified by the -CAserial or
	   -CAcreateserial options) is not used.

	   The serial number can be decimal or hex (if preceded	by 0x).	Nega-
	   tive	serial numbers can also	be specified but their use is not rec-

       -CA filename
	   specifies the CA certificate	to be used for signing.	When this op-
	   tion	is present x509	behaves	like a "mini CA". The input file is
	   signed by this CA using this	option:	that is	its issuer name	is set
	   to the subject name of the CA and it	is digitally signed using the
	   CAs private key.

	   This	option is normally combined with the -req option. Without the
	   -req	option the input is a certificate which	must be	self signed.

       -CAkey filename
	   sets	the CA private key to sign a certificate with. If this option
	   is not specified then it is assumed that the	CA private key is
	   present in the CA certificate file.

       -CAserial filename
	   sets	the CA serial number file to use.

	   When	the -CA	option is used to sign a certificate it	uses a serial
	   number specified in a file. This file consist of one	line contain-
	   ing an even number of hex digits with the serial number to use. Af-
	   ter each use	the serial number is incremented and written out to
	   the file again.

	   The default filename	consists of the	CA certificate file base name
	   with	".srl" appended. For example if	the CA certificate file	is
	   called "mycacert.pem" it expects to find a serial number file
	   called "".

	   with	this option the	CA serial number file is created if it does
	   not exist: it will contain the serial number	"02" and the certifi-
	   cate	being signed will have the 1 as	its serial number. Normally if
	   the -CA option is specified and the serial number file does not ex-
	   ist it is an	error.

       -extfile	filename
	   file	containing certificate extensions to use. If not specified
	   then	no extensions are added	to the certificate.

       -extensions section
	   the section to add certificate extensions from. If this option is
	   not specified then the extensions should either be contained	in the
	   unnamed (default) section or	the default section should contain a
	   variable called "extensions"	which contains the section to use.


       The nameopt command line	switch determines how the subject and issuer
       names are displayed. If no nameopt switch is present the	default	"one-
       line" format is used which is compatible	with previous versions of
       OpenSSL.	 Each option is	described in detail below, all options can be
       preceded	by a - to turn the option off. Only the	first four will	nor-
       mally be	used.

	   use the old format. This is equivalent to specifying	no name	op-
	   tions at all.

	   displays names compatible with RFC2253 equivalent to	esc_2253,
	   esc_ctrl, esc_msb, utf8, dump_nostr,	dump_unknown, dump_der,
	   sep_comma_plus, dn_rev and sname.

	   a oneline format which is more readable than	RFC2253. It is equiva-
	   lent	to specifying the  esc_2253, esc_ctrl, esc_msb,	utf8,
	   dump_nostr, dump_der, use_quote, sep_comma_plus_spc,	spc_eq and
	   sname options.

	   a multiline format. It is equivalent	esc_ctrl, esc_msb, sep_multi-
	   line, spc_eq, lname and align.

	   escape the "special"	characters required by RFC2253 in a field That
	   is ,+"<>;. Additionally # is	escaped	at the beginning of a string
	   and a space character at the	beginning or end of a string.

	   escape control characters. That is those with ASCII values less
	   than	0x20 (space) and the delete (0x7f) character. They are escaped
	   using the RFC2253 \XX notation (where XX are	two hex	digits repre-
	   senting the character value).

	   escape characters with the MSB set, that is with ASCII values
	   larger than 127.

	   escapes some	characters by surrounding the whole string with	"
	   characters, without the option all escaping is done with the	\

	   convert all strings to UTF8 format first. This is required by
	   RFC2253. If you are lucky enough to have a UTF8 compatible terminal
	   then	the use	of this	option (and not	setting	esc_msb) may result in
	   the correct display of multibyte (international) characters.	Is
	   this	option is not present then multibyte characters	larger than
	   0xff	will be	represented using the format \UXXXX for	16 bits	and
	   \WXXXXXXXX for 32 bits.  Also if this option	is off any UTF8Strings
	   will	be converted to	their character	form first.

	   this	option does not	attempt	to interpret multibyte characters in
	   any way. That is their content octets are merely dumped as though
	   one octet represents	each character.	This is	useful for diagnostic
	   purposes but	will result in rather odd looking output.

	   show	the type of the	ASN1 character string. The type	precedes the
	   field contents. For example "BMPSTRING: Hello World".

	   when	this option is set any fields that need	to be hexdumped	will
	   be dumped using the DER encoding of the field. Otherwise just the
	   content octets will be displayed. Both options use the RFC2253
	   #XXXX... format.

	   dump	non character string types (for	example	OCTET STRING) if this
	   option is not set then non character	string types will be displayed
	   as though each content octet	represents a single character.

	   dump	all fields. This option	when used with dump_der	allows the DER
	   encoding of the structure to	be unambiguously determined.

	   dump	any field whose	OID is not recognised by OpenSSL.

       sep_comma_plus, sep_comma_plus_space, sep_semi_plus_space, sep_multi-
	   these options determine the field separators. The first character
	   is between RDNs and the second between multiple AVAs	(multiple AVAs
	   are very rare and their use is discouraged).	The options ending in
	   "space" additionally	place a	space after the	separator to make it
	   more	readable. The sep_multiline uses a linefeed character for the
	   RDN separator and a spaced +	for the	AVA separator. It also indents
	   the fields by four characters.

	   reverse the fields of the DN. This is required by RFC2253. As a
	   side	effect this also reverses the order of multiple	AVAs but this
	   is permissible.

       nofname,	sname, lname, oid
	   these options alter how the field name is displayed.	nofname	does
	   not display the field at all. sname uses the	"short name" form (CN
	   for commonName for example).	lname uses the long form.  oid repre-
	   sents the OID in numerical form and is useful for diagnostic	pur-

	   align field values for a more readable output. Only usable with

	   places spaces round the = character which follows the field name.


       As well as customising the name output format, it is also possible to
       customise the actual fields printed using the certopt options when the
       text option is present. The default behaviour is	to print all fields.

	   use the old format. This is equivalent to specifying	no output op-
	   tions at all.

	   don't print header information: that	is the lines saying "Certifi-
	   cate" and "Data".

	   don't print out the version number.

	   don't print out the serial number.

	   don't print out the signature algorithm used.

	   don't print the validity, that is the notBefore and notAfter

	   don't print out the subject name.

	   don't print out the issuer name.

	   don't print out the public key.

	   don't give a	hexadecimal dump of the	certificate signature.

	   don't print out certificate trust information.

	   don't print out any X509V3 extensions.

	   retain default extension behaviour: attempt to print	out unsup-
	   ported certificate extensions.

	   print an error message for unsupported certificate extensions.

	   ASN1	parse unsupported extensions.

	   hex dump unsupported	extensions.

	   the value used by the ca utility, equivalent	to no_issuer, no_pub-
	   key,	no_header, no_version, no_sigdump and no_signame.

       Note: in	these examples the '\' means the example should	be all on one

       Display the contents of a certificate:

	openssl	x509 -in cert.pem -noout -text

       Display the certificate serial number:

	openssl	x509 -in cert.pem -noout -serial

       Display the certificate subject name:

	openssl	x509 -in cert.pem -noout -subject

       Display the certificate subject name in RFC2253 form:

	openssl	x509 -in cert.pem -noout -subject -nameopt RFC2253

       Display the certificate subject name in oneline form on a terminal sup-
       porting UTF8:

	openssl	x509 -in cert.pem -noout -subject -nameopt oneline,-escmsb

       Display the certificate MD5 fingerprint:

	openssl	x509 -in cert.pem -noout -fingerprint

       Display the certificate SHA1 fingerprint:

	openssl	x509 -sha1 -in cert.pem	-noout -fingerprint

       Convert a certificate from PEM to DER format:

	openssl	x509 -in cert.pem -inform PEM -out cert.der -outform DER

       Convert a certificate to	a certificate request:

	openssl	x509 -x509toreq	-in cert.pem -out req.pem -signkey key.pem

       Convert a certificate request into a self signed	certificate using ex-
       tensions	for a CA:

	openssl	x509 -req -in careq.pem	-extfile openssl.cnf -extensions v3_ca \
	       -signkey	key.pem	-out cacert.pem

       Sign a certificate request using	the CA certificate above and add user
       certificate extensions:

	openssl	x509 -req -in req.pem -extfile openssl.cnf -extensions v3_usr \
	       -CA cacert.pem -CAkey key.pem -CAcreateserial

       Set a certificate to be trusted for SSL client use and change set its
       alias to	"Steve's Class 1 CA"

	openssl	x509 -in cert.pem -addtrust clientAuth \
	       -setalias "Steve's Class	1 CA" -out trust.pem

       The PEM format uses the header and footer lines:


       it will also handle files containing:

	-----END X509 CERTIFICATE-----

       Trusted certificates have the lines


       The conversion to UTF8 format used with the name	options	assumes	that
       T61Strings use the ISO8859-1 character set. This	is wrong but Netscape
       and MSIE	do this	as do many certificates. So although this is incorrect
       it is more likely to display the	majority of certificates correctly.

       The -fingerprint	option takes the digest	of the DER encoded certifi-
       cate.  This is commonly called a	"fingerprint". Because of the nature
       of message digests the fingerprint of a certificate is unique to	that
       certificate and two certificates	with the same fingerprint can be con-
       sidered to be the same.

       The Netscape fingerprint	uses MD5 whereas MSIE uses SHA1.

       The -email option searches the subject name and the subject alternative
       name extension. Only unique email addresses will	be printed out:	it
       will not	print the same address more than once.

       The -purpose option checks the certificate extensions and determines
       what the	certificate can	be used	for. The actual	checks done are	rather
       complex and include various hacks and workarounds to handle broken cer-
       tificates and software.

       The same	code is	used when verifying untrusted certificates in chains
       so this section is useful if a chain is rejected	by the verify code.

       The basicConstraints extension CA flag is used to determine whether the
       certificate can be used as a CA.	If the CA flag is true then it is a
       CA, if the CA flag is false then	it is not a CA.	All CAs	should have
       the CA flag set to true.

       If the basicConstraints extension is absent then	the certificate	is
       considered to be	a "possible CA"	other extensions are checked according
       to the intended use of the certificate. A warning is given in this case
       because the certificate should really not be regarded as	a CA: however
       it is allowed to	be a CA	to work	around some broken software.

       If the certificate is a V1 certificate (and thus	has no extensions) and
       it is self signed it is also assumed to be a CA but a warning is	again
       given: this is to work around the problem of Verisign roots which are
       V1 self signed certificates.

       If the keyUsage extension is present then additional restraints are
       made on the uses	of the certificate. A CA certificate must have the
       keyCertSign bit set if the keyUsage extension is	present.

       The extended key	usage extension	places additional restrictions on the
       certificate uses. If this extension is present (whether critical	or
       not) the	key can	only be	used for the purposes specified.

       A complete description of each test is given below. The comments	about
       basicConstraints	and keyUsage and V1 certificates above apply to	all CA

       SSL Client
	   The extended	key usage extension must be absent or include the "web
	   client authentication" OID.	keyUsage must be absent	or it must
	   have	the digitalSignature bit set. Netscape certificate type	must
	   be absent or	it must	have the SSL client bit	set.

       SSL Client CA
	   The extended	key usage extension must be absent or include the "web
	   client authentication" OID. Netscape	certificate type must be ab-
	   sent	or it must have	the SSL	CA bit set: this is used as a work
	   around if the basicConstraints extension is absent.

       SSL Server
	   The extended	key usage extension must be absent or include the "web
	   server authentication" and/or one of	the SGC	OIDs.  keyUsage	must
	   be absent or	it must	have the digitalSignature, the keyEncipherment
	   set or both bits set.  Netscape certificate type must be absent or
	   have	the SSL	server bit set.

       SSL Server CA
	   The extended	key usage extension must be absent or include the "web
	   server authentication" and/or one of	the SGC	OIDs.  Netscape	cer-
	   tificate type must be absent	or the SSL CA bit must be set: this is
	   used	as a work around if the	basicConstraints extension is absent.

       Netscape	SSL Server
	   For Netscape	SSL clients to connect to an SSL server	it must	have
	   the keyEncipherment bit set if the keyUsage extension is present.
	   This	isn't always valid because some	cipher suites use the key for
	   digital signing.  Otherwise it is the same as a normal SSL server.

       Common S/MIME Client Tests
	   The extended	key usage extension must be absent or include the
	   "email protection" OID. Netscape certificate	type must be absent or
	   should have the S/MIME bit set. If the S/MIME bit is	not set	in
	   netscape certificate	type then the SSL client bit is	tolerated as
	   an alternative but a	warning	is shown: this is because some
	   Verisign certificates don't set the S/MIME bit.

       S/MIME Signing
	   In addition to the common S/MIME client tests the digitalSignature
	   bit must be set if the keyUsage extension is	present.

       S/MIME Encryption
	   In addition to the common S/MIME tests the keyEncipherment bit must
	   be set if the keyUsage extension is present.

       S/MIME CA
	   The extended	key usage extension must be absent or include the
	   "email protection" OID. Netscape certificate	type must be absent or
	   must	have the S/MIME	CA bit set: this is used as a work around if
	   the basicConstraints	extension is absent.

       CRL Signing
	   The keyUsage	extension must be absent or it must have the CRL sign-
	   ing bit set.

       CRL Signing CA
	   The normal CA tests apply. Except in	this case the basicConstraints
	   extension must be present.

       Extensions in certificates are not transferred to certificate requests
       and vice	versa.

       It is possible to produce invalid certificates or requests by specify-
       ing the wrong private key or using inconsistent options in some cases:
       these should be checked.

       There should be options to explicitly set such things as	start and end
       dates rather than an offset from	the current time.

       The code	to implement the verify	behaviour described in the TRUST SET-
       TINGS is	currently being	developed. It thus describes the intended be-
       haviour rather than the current behaviour. It is	hoped that it will
       represent reality in OpenSSL 0.9.5 and later.

       req(1), ca(1), genrsa(1), gendsa(1), verify(1)

0.9.7d				  2005-02-25			       X509(1)


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