X509(1)                     OpenSSL                     X509(1)





NAME
       x509 - Certificate display and signing utility

SYNOPSIS
       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] [-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 filename]
       [-text] [-C] [-md2|-md5|-sha1|-mdc2] [-clrext] [-extfile
       filename] [-extensions section] [-engine id]

DESCRIPTION
       The x509 command is a multi purpose certificate utility.
       It can be used to display certificate information, con-
       vert certificates to various forms, sign certificate
       requests like a "mini CA" or edit certificate trust set-
       tings.

       Since there are a large number of options they will
       split up into various sections.

OPTIONS
       INPUT, OUTPUT AND GENERAL PURPOSE OPTIONS


       -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 certifi-
           cate 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.

       -md2|-md5|-sha1|-mdc2
           the digest to use. This affects any signing or dis-
           play option that uses a message digest, such as the
           -fingerprint, -signkey and -CA options. If not spec-
           ified 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.

       DISPLAY OPTIONS

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

       -text
           prints out the certificate in text form. Full
           details are output including the public key, signa-
           ture algorithms, issuer and subject names, serial
           number any extensions present and any trust set-
           tings.

       -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.

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

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

       -serial
           outputs the certificate serial number.

       -hash
           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 sub-
           ject name.

       -subject
           outputs the subject name.

       -issuer
           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 com-
           mas.  Alternatively the -nameopt switch may be used
           more than once to set multiple options. See the NAME
           OPTIONS section for more information.

       -email
           outputs the email address(es) if any.

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

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

       -dates
           prints out the start and expiry dates of a certifi-
           cate.

       -fingerprint
           prints out the digest of the DER encoded version of
           the whole certificate (see digest options).

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

       TRUST SETTINGS

       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 cer-
       tificate 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 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 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 settings.

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

       -trustout
           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".

       -alias
           outputs the certificate alias, if any.

       -clrtrust
           clears all the permitted or trusted uses of the cer-
           tificate.

       -clrreject
           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 email-
           Protection (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.

       -purpose
           this option performs tests on the certificate exten-
           sions and outputs the results. For a more complete
           description see the CERTIFICATE EXTENSIONS section.

       SIGNING OPTIONS

       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 cer-
           tificate 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.

       -clrext
           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 exten-
           sions 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.

       -x509toreq
           converts a certificate into a certificate request.
           The -signkey option is used to pass the required
           private key.

       -req
           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 speci-
           fied 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 cer-
           tificate 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 cer-
           tificate 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 "mycac-
           ert.srl".

       -CAcreateserial
           with this option the CA serial number file is cre-
           ated 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.

       NAME OPTIONS

       The nameopt command line switch determines how the sub-
       ject 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.

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

       RFC2253
           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.

       oneline
           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.

       multiline
           a multiline format. It is equivalent esc_ctrl,
           esc_msb, sep_multiline, spc_eq, lname and align.

       esc_2253
           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.

       esc_ctrl
           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).

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

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

       utf8
           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) charac-
           ters. 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.

       no_type
           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 pur-
           poses but will result in rather odd looking output.

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

       dump_der
           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_nostr
           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 con-
           tent octet represents a single character.

       dump_all
           dump all fields. This option when used with dump_der
           allows the DER encoding of the structure to be unam-
           biguously determined.

       dump_unknown
           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 discouraged). 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 characters.

       dn_rev
           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 diagnos-
           tic purpose.

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

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

       TEXT OPTIONS

       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.

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

       no_header
           don't print header information: that is the lines
           saying "Certificate" and "Data".

       no_version
           don't print out the version number.

       no_serial
           don't print out the serial number.

       no_signame
           don't print out the signature algorithm used.

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

       no_subject
           don't print out the subject name.

       no_issuer
           don't print out the issuer name.

       no_pubkey
           don't print out the public key.

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

       no_aux
           don't print out certificate trust information.

       no_extensions
           don't print out any X509V3 extensions.

       ext_default
           retain default extension behaviour: attempt to print
           out unsupported certificate extensions.

       ext_error
           print an error message for unsupported certificate
           extensions.

       ext_parse
           ASN1 parse unsupported extensions.

       ext_dump
           hex dump unsupported extensions.

       ca_default
           the value used by the ca utility, equivalent to
           no_issuer, no_pubkey, no_header, no_version, no_sig-
           dump and no_signame.

EXAMPLES
       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 cer-
       tificate 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 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

NOTES
       The PEM format uses the header and footer lines:

        -----BEGIN CERTIFICATE-----
        -----END CERTIFICATE-----

       it will also handle files containing:

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

       Trusted certificates have the lines

        -----BEGIN TRUSTED CERTIFICATE-----
        -----END TRUSTED CERTIFICATE-----

       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 cor-
       rectly.

       The -fingerprint option takes the digest of the DER
       encoded certificate.  This is commonly called a "finger-
       print". Because of the nature of message digests the
       fingerprint of a certificate is unique to that certifi-
       cate 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 sub-
       ject alternative name extension. Only unique email
       addresses will be printed out: it will not print the
       same address more than once.

CERTIFICATE EXTENSIONS
       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 vari-
       ous hacks and workarounds to handle broken certificates
       and software.

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

       The basicConstraints extension CA flag is used to deter-
       mine 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 cer-
       tificates above apply to all CA certificates.

       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 digi-
           talSignature 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 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 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 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 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 nor-
           mal SSL server.

       Common S/MIME Client Tests
           The extended key usage extension must be absent or
           include the "email protection" OID. Netscape cer-
           tificate 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 keyEnci-
           pherment 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 cer-
           tificate 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 present.

BUGS
       Extensions in certificates are not transferred to cer-
       tificate 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 cur-
       rent 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
       behaviour. It is hoped that it will represent reality in
       OpenSSL 0.9.5 and later.

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



0.9.7c                     2003-01-30                   X509(1)
