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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] [-modu-
       lus] [-fingerprint] [-alias] [-noout] [-trustout] [-clrtrust] [-clrreject] [-addtrust arg]
       [-addreject arg] [-setalias arg] [-days arg] [-set_serial n] [-signkey filename]
       [-x509toreq] [-req] [-CA filename] [-CAkey filename] [-CAcreateserial] [-CAserial file-
       name] [-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 cer-
       tificate 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 various 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 for-
	   mat that is now obsolete.

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

       -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

	   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

	   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 displayed. The option
	   argument can be a single option or multiple options separated by commas.  Alterna-
	   tively the -nameopt switch may be used more than once to set multiple options. See the
	   NAME OPTIONS section for more information.

	   outputs the email address(es) if any.

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

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

	   prints out the start and expiry dates of a certificate.

	   prints out the digest of the DER encoded version of the whole certificate (see digest

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


       Please note these options are currently experimental and may well change.

       A trusted certificate is an ordinary certificate which has several additional 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 locally and must be a root CA: any cer-
       tificate 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 example 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

       Future versions of OpenSSL will recognize trust settings on any certificate: not just root

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

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

	   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 option.

	   this option performs tests on the certificate extensions and outputs the results. For
	   a more complete description see the CERTIFICATE 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 supplied 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 retained
	   unless the -clrext option is supplied.

	   If the input is a certificate request then a self signed certificate 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 example 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 option 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). Negative serial numbers
	   can also be specified but their use is not recommended.

       -CA filename
	   specifies the CA certificate to be used for signing. When this option 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 containing an even number of hex digits with the
	   serial number to use. After 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 "mycacert.srl".

	   with this option the CA serial number file is created if it does not exist: it will
	   contain the serial number "02" and the certificate being signed will have the 1 as its
	   serial number. Normally if the -CA option is specified and the serial number file does
	   not exist 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 sec-
	   tion to use.


       The nameopt command line switch determines how the subject and issuer names are displayed.
       If no nameopt switch is present the default "oneline" 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 normally be used.

	   use the old format. This is equivalent to specifying no name options 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 equivalent 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_multiline, spc_eq, lname
	   and align.

	   escape the "special" characters required by RFC2253 in a field That is ,+"<>;. Addi-
	   tionally # is escaped at the beginning of a string and a space character at the begin-
	   ning 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 representing 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 \ character.

	   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) char-
	   acters. 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 repre-
	   sents 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_multiline
	   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 dis-
	   couraged). The options ending in "space" additionally place a space after the separa-
	   tor 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

	   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 represents the OID in numerical form and is useful for diag-
	   nostic purpose.

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

	   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 be-
       haviour is to print all fields.

	   use the old format. This is equivalent to specifying no output options at all.

	   don't print header information: that is the lines saying "Certificate" 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 fields.

	   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 unsupported certificate

	   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_pubkey, no_header,
	   no_version, no_sigdump and no_signame.

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

       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 supporting 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 extensions 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 exten-

	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 certifi-
       cates. So although this is incorrect it is more likely to display the majority of certifi-
       cates correctly.

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

       SSL Client
	   The extended key usage extension must be absent or include the "web client authentica-
	   tion" OID.  keyUsage must be absent or it must have the digitalSignature bit set. Net-
	   scape 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 authentica-
	   tion" OID. Netscape certificate type must be absent 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 authentica-
	   tion" and/or one of the SGC OIDs.  keyUsage must be absent or it must have the digi-
	   talSignature, 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 authentica-
	   tion" and/or one of the SGC OIDs.  Netscape certificate type must be absent or the SSL
	   CA bit must be set: this is used as a work around if the basicConstraints extension is

       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 toler-
	   ated as an alternative but a warning is shown: this is because some Verisign certifi-
	   cates 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 signing bit set.

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

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

       It is possible to produce invalid certificates or requests by specifying 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 SETTINGS is currently
       being developed. It thus describes the intended behaviour rather than the current behav-
       iour. 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)

0.9.7a					    2003-01-30					  X509(1)
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