X509(1)                             OpenSSL                            X509(1)



NAME
       x509 - Certificate display and signing utility

LIBRARY
       libcrypto, -lcrypto

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_hash] [-issuer_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, 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.

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 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.

       -md2|-md5|-sha1|-mdc2
           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 SHA1 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, 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.

       -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.

       -subject_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 subject name.

       -issuer_hash
           outputs the "hash" of the certificate issuer name.

       -hash
           synonym for "-hash" for backward compatibility reasons.

       -subject
           outputs the subject name.

       -issuer
           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
           options separated by commas.  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 certificate.

       -fingerprint
           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.

       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 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 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.

       -trustout
           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-
           fied.

       -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-
           cate".

       -alias
           outputs the certificate alias, if any.

       -clrtrust
           clears all the permitted or trusted uses of the certificate.

       -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 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.

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

       -clrext
           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.

       -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). Nega-
           tive serial numbers can also be specified but their use is not rec-
           ommended.

       -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 contain-
           ing 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".

       -CAcreateserial
           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
           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 section to use. See
           the x509v3_config(5) manual page for details of the extension sec-
           tion format.

       NAME OPTIONS

       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.

       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 equiva-
           lent to specifying the  esc_2253, esc_ctrl, esc_msb, utf8,
           dump_nostr, dump_der, use_quote, sep_comma_plus_space, space_eq and
           sname options.

       multiline
           a multiline format. It is equivalent esc_ctrl, esc_msb, sep_multi-
           line, space_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 repre-
           senting 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) 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.

       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
           purposes 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 content 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 unambiguously 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_multi-
       line
           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.

       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 repre-
           sents the OID in numerical form and is useful for diagnostic pur-
           pose.

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

       space_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 "Certifi-
           cate" 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 unsup-
           ported 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_pub-
           key, no_header, no_version, no_sigdump 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 sup-
       porting UTF8:

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

       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 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 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.

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 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
       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 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
           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 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.

BUGS
       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.

SEE ALSO
       openssl_req(1), openssl_ca(1), openssl_genrsa(1), openssl_gendsa(1),
       openssl_verify(1), x509v3_config(5)

HISTORY
       Before OpenSSL 0.9.8, the default digest for RSA keys was MD5.



0.9.9-dev                         2008-05-09                           X509(1)
