X509(1SSL)                          OpenSSL                         X509(1SSL)

       openssl-x509, x509 - Certificate display and signing utility

       openssl x509 [-help] [-inform DER|PEM] [-outform DER|PEM] [-keyform
       DER|PEM|ENGINE] [-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 arg] [-passin arg] [-x509toreq] [-req]
       [-CA filename] [-CAkey filename] [-CAcreateserial] [-CAserial filename]
       [-force_pubkey key] [-text] [-ext extensions] [-certopt option] [-C]
       [-digest] [-clrext] [-extfile filename] [-extensions section] [-sigopt
       nm:v] [-rand file...]  [-writerand file] [-engine id] [-preserve_dates]

       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.

   Input, Output, and General Purpose Options
           Print out a usage message.

       -inform DER|PEM
           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 default format is PEM.

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

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

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

           The digest to use.  This affects any signing or display option that
           uses a message digest, such as the -fingerprint, -signkey and -CA
           options.  Any digest supported by the OpenSSL dgst command can be
           used.  If not specified then SHA1 is used with -fingerprint or the
           default digest for the signing algorithm is used, typically SHA256.

       -rand file...
           A file or files containing random data used to seed the random
           number generator.  Multiple files can be specified separated by an
           OS-dependent character.  The separator is ; for MS-Windows, , for
           OpenVMS, and : for all others.

       [-writerand file]
           Writes random data to the specified file upon exit.  This can be
           used with a subsequent -rand flag.

       -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.

           When signing a certificate, preserve the "notBefore" and "notAfter"
           dates instead of adjusting them to current time and duration.
           Cannot be used with the -days option.

   Display Options
       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.

       -ext extensions
           Prints out the certificate extensions in text form. Extensions are
           specified with a comma separated string, e.g.,
           "subjectAltName,subjectKeyIdentifier".  See the x509v3_config(5)
           manual page for the extension names.

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

           This option prevents output of the encoded version of the

           Outputs the certificate's SubjectPublicKeyInfo block in PEM format.

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

           Outputs the certificate serial number.

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

           Outputs the "hash" of the certificate issuer name.

           Outputs the OCSP hash values for the subject name and public key.

           Synonym for "-subject_hash" for backward compatibility reasons.

           Outputs the "hash" of the certificate subject name using the older
           algorithm as used by OpenSSL before version 1.0.0.

           Outputs the "hash" of the certificate issuer name using the older
           algorithm as used by OpenSSL before version 1.0.0.

           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.  Alternatively 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.

           Outputs the OCSP responder address(es) if any.

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

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

           Prints out the start and expiry dates of a certificate.

       -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.

           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

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

   Trust Settings
       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.

           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

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

           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), emailProtection (S/MIME email) and anyExtendedKeyUsage
           are used.  As of OpenSSL 1.1.0, the last of these blocks all
           purposes when rejected or enables all purposes when trusted.  Other
           OpenSSL applications may define additional uses.

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

           This option performs tests on the certificate extensions and
           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 arg
           This option causes the input file to be self signed using the
           supplied private key or engine. The private key's format is
           specified with the -keyform option.

           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; this includes, for
           example, any existing key identifier extensions.

           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.

       -sigopt nm:v
           Pass options to the signature algorithm during sign or verify
           operations.  Names and values of these options are algorithm-

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

           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|ENGINE
           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. Cannot be used with the -preserve_dates option.

           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).

       -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 consists 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. If
           the -CA option is specified and the serial number file does not
           exist a random number is generated; this is the recommended

       -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.

           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.

           Use the old format.

           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_space, space_eq and
           sname options.  This is the default of no name options are given

           A multiline format. It is equivalent esc_ctrl, esc_msb,
           sep_multiline, space_eq, lname and align.

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

           Escape the "special" characters required by RFC2254 in a field.
           That is the NUL character as well as and ()*.

           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 \

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

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

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

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

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

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

           Dump any field whose OID is not recognised by OpenSSL.

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

           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

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

           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.

           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

           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 extensions.

           Print an error message for unsupported certificate extensions.

           ASN1 parse unsupported extensions.

           Hex dump unsupported extensions.

           The value used by the ca utility, equivalent to no_issuer,
           no_pubkey, no_header, and no_version.

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

       Display the contents of a certificate:

        openssl x509 -in cert.pem -noout -text

       Display the "Subject Alternative Name" extension of a certificate:

        openssl x509 -in cert.pem -noout -ext subjectAltName

       Display more extensions of a certificate:

        openssl x509 -in cert.pem -noout -ext subjectAltName,nsCertType

       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,-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

       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


       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.

       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 certificate must have the
       keyCertSign bit set if the keyUsage extension is present.

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

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

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

       SSL Client CA
           The extended key usage extension must be absent or include the "web
           client authentication" OID. Netscape certificate type must be
           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

       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 or the nonRepudiation 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.

       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.

       req(1), ca(1), genrsa(1), gendsa(1), verify(1), x509v3_config(5)

       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.

       Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the OpenSSL license (the "License").  You may not use
       this file except in compliance with the License.  You can obtain a copy
       in the file LICENSE in the source distribution or at

1.1.1f                            2023-10-10                        X509(1SSL)
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