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X509(1)                      OpenSSL                      X509(1)


NAME

     openssl-x509, 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_hash] [-issuer_hash] [-ocspid] [-subject]
     [-issuer] [-nameopt option] [-email] [-ocsp_uri]
     [-startdate] [-enddate] [-purpose] [-dates] [-checkend num]
     [-modulus] [-pubkey] [-fingerprint] [-alias] [-noout]
     [-trustout] [-clrtrust] [-clrreject] [-addtrust arg]
     [-addreject arg] [-setalias arg] [-days arg] [-set_serial n]
     [-signkey filename] [-passin arg] [-x509toreq] [-req] [-CA
     filename] [-CAkey filename] [-CAcreateserial] [-CAserial
     filename] [-force_pubkey key] [-text] [-certopt option] [-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 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 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.

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     -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 its unique id string) will
         cause x509 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.

     -pubkey
         outputs the the certificate's SubjectPublicKeyInfo block
         in PEM format.

     -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

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X509(1)                      OpenSSL                      X509(1)

         name.

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

     -ocspid
         outputs the OCSP hash values for the subject name and
         public key.

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

     -subject_hash_old
         outputs the "hash" of the certificate subject name using
         the older algorithm as used by OpenSSL versions before
         1.0.0.

     -issuer_hash_old
         outputs the "hash" of the certificate issuer name using
         the older algorithm as used by OpenSSL versions before
         1.0.0.

     -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 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.

     -ocsp_uri
         outputs the OCSP responder 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

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         prints out the start and expiry dates of a certificate.

     -checkend arg
         checks if the certificate expires within the next arg
         seconds and exits non-zero if yes it will expire or zero
         if not.

     -fingerprint
         Calculates and outputs the digest of the DER encoded
         version of the entire certificate (see digest options).
         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 considered
         to be the same.

     -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 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

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         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
         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 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 certificate
         extensions are retained unless the -clrext option is
         supplied.

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         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.

     -passin arg
         the key password source. For more information about the
         format of arg see the PASS PHRASE ARGUMENTS section in
         openssl(1).

     -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 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). 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.

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         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".

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

     -force_pubkey key
         when a certificate is created set its public key to key
         instead of the key in the certificate or certificate
         request. This option is useful for creating certificates
         where the algorithm can't normally sign requests, for
         example DH.

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         The format or key can be specified using the -keyform
         option.

     NAME OPTIONS

     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.

     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_space, space_eq and sname options.

     multiline
         a multiline format. It is equivalent esc_ctrl, esc_msb,
         sep_multiline, 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 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

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         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.

     ignore_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_multiline

     sep_comma_plus, sep_comma_plus_space, sep_semi_plus_space,
         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

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         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. If no field separator is specified then
         sep_comma_plus_space is used by default.

     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 diagnostic purpose.

     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
         "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.

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     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, and no_version.


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:

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      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,-esc_msb

     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-----

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     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 -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 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
     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

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     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 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 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.

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         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 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
     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
     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),
     x509v3_config(5)

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HISTORY

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

     The hash algorithm used in the -subject_hash and
     -issuer_hash options before OpenSSL 1.0.0 was based on the
     deprecated MD5 algorithm and the encoding of the
     distinguished name. In OpenSSL 1.0.0 and later it is based
     on a canonical version of the DN using SHA1. This means that
     any directories using the old form must have their links
     rebuilt using c_rehash or similar.

1.0.2t               Last change: 2019-09-10                   16

See also x509(1)

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