certtool

certtool(1)                       User Commands                      certtool(1)



NAME
       certtool - GnuTLS certificate tool

SYNOPSIS
       certtool [-flags] [-flag [value]] [--option-name[[=| ]value]]

       All arguments must be options.


DESCRIPTION
       Tool to parse and generate X.509 certificates, requests and private keys.
       It can be used interactively or non interactively by specifying the
       template command line option.

       The tool accepts files or supported URIs via the --infile option. In case
       PIN is required for URI access you can provide it using the environment
       variables GNUTLS_PIN and GNUTLS_SO_PIN.


OPTIONS
       -d number, --debug=number
              Enable debugging.  This option takes an integer number as its
              argument.  The value of number is constrained to being:
                  in the range  0 through 9999

              Specifies the debug level.

       -V, --verbose
              More verbose output.  This option may appear an unlimited number
              of times.


       --infile=file
              Input file.


       --outfile=string
              Output file.


   Certificate related options
       -i, --certificate-info
              Print information on the given certificate.


       --pubkey-info
              Print information on a public key.

              The option combined with --load-request, --load-pubkey, --load-
              privkey and --load-certificate will extract the public key of the
              object in question.

       -s, --generate-self-signed
              Generate a self-signed certificate.


       -c, --generate-certificate
              Generate a signed certificate.


       --generate-proxy
              Generates a proxy certificate.


       -u, --update-certificate
              Update a signed certificate.


       --fingerprint
              Print the fingerprint of the given certificate.

              This is a simple hash of the DER encoding of the certificate. It
              can be combined with the --hash parameter. However, it is
              recommended for identification to use the key-id which depends
              only on the certificate's key.

       --key-id
              Print the key ID of the given certificate.

              This is a hash of the public key of the given certificate. It
              identifies the key uniquely, remains the same on a certificate
              renewal and depends only on signed fields of the certificate.

       --certificate-pubkey
              Print certificate's public key.

              This option is deprecated as a duplicate of --pubkey-info

              NOTE: THIS OPTION IS DEPRECATED

       --v1   Generate an X.509 version 1 certificate (with no extensions).


       --sign-params=string
              Sign a certificate with a specific signature algorithm.

              This option can be combined with --generate-certificate, to sign
              the certificate with a specific signature algorithm variant. The
              only option supported is 'RSA-PSS', and should be specified when
              the signer does not have a certificate which is marked for RSA-PSS
              use only.

   Certificate request related options
       --crq-info
              Print information on the given certificate request.


       -q, --generate-request
              Generate a PKCS #10 certificate request.  This option must not
              appear in combination with any of the following options: infile.

              Will generate a PKCS #10 certificate request. To specify a private
              key use --load-privkey.

       --no-crq-extensions
              Do not use extensions in certificate requests.


   PKCS#12 file related options
       --p12-info
              Print information on a PKCS #12 structure.

              This option will dump the contents and print the metadata of the
              provided PKCS #12 structure.

       --p12-name=string
              The PKCS #12 friendly name to use.

              The name to be used for the primary certificate and private key in
              a PKCS #12 file.

       --to-p12
              Generate a PKCS #12 structure.

              It requires a certificate, a private key and possibly a CA
              certificate to be specified.

   Private key related options
       -k, --key-info
              Print information on a private key.


       --p8-info
              Print information on a PKCS #8 structure.

              This option will print information about encrypted PKCS #8
              structures. That option does not require the decryption of the
              structure.

       --to-rsa
              Convert an RSA-PSS key to raw RSA format.

              It requires an RSA-PSS key as input and will output a raw RSA key.
              This command is necessary for compatibility with applications that
              cannot read RSA-PSS keys.

       -p, --generate-privkey
              Generate a private key.

              When generating RSA-PSS private keys, the --hash option will
              restrict the allowed hash for the key; in the same keys the
              --salt-size option is also acceptable.

       --key-type=string
              Specify the key type to use on key generation.

              This option can be combined with --generate-privkey, to specify
              the key type to be generated. Valid options are, 'rsa', 'rsa-pss',
              'dsa', 'ecdsa', 'ed25519, and 'ed448'.'.  When combined with
              certificate generation it can be used to specify an RSA-PSS
              certificate when an RSA key is given.

       --bits=number
              Specify the number of bits for key generation.  This option takes
              an integer number as its argument.


       --curve=string
              Specify the curve used for EC key generation.

              Supported values are secp192r1, secp224r1, secp256r1, secp384r1
              and secp521r1.

       --sec-param=security parameter
              Specify the security level [low, legacy, medium, high, ultra].

              This is alternative to the bits option.

       --to-p8
              Convert a given key to a PKCS #8 structure.

              This needs to be combined with --load-privkey.

       -8, --pkcs8
              Use PKCS #8 format for private keys.


       --provable
              Generate a private key or parameters from a seed using a provable
              method.

              This will use the FIPS PUB186-4 algorithms (i.e., Shawe-Taylor)
              for provable key generation.  When specified the private keys or
              parameters will be generated from a seed, and can be later
              validated with --verify-provable-privkey to be correctly generated
              from the seed. You may specify --seed or allow GnuTLS to generate
              one (recommended). This option can be combined with --generate-
              privkey or --generate-dh-params.

              That option applies to RSA and DSA keys. On the DSA keys the PQG
              parameters are generated using the seed, and on RSA the two
              primes.

       --verify-provable-privkey
              Verify a private key generated from a seed using a provable
              method.

              This will use the FIPS-186-4 algorithms for provable key
              generation. You may specify --seed or use the seed stored in the
              private key structure.

       --seed=string
              When generating a private key use the given hex-encoded seed.

              The seed acts as a security parameter for the private key, and
              thus a seed size which corresponds to the security level of the
              private key should be provided (e.g., 256-bits seed).

   CRL related options
       -l, --crl-info
              Print information on the given CRL structure.


       --generate-crl
              Generate a CRL.

              This option generates a Certificate Revocation List. When combined
              with --load-crl it would use the loaded CRL as base for the
              generated (i.e., all revoked certificates in the base will be
              copied to the new CRL).  To add new certificates to the CRL use
              --load-certificate.

       --verify-crl
              Verify a Certificate Revocation List using a trusted list.  This
              option must appear in combination with the following options:
              load-ca-certificate.

              The trusted certificate list must be loaded with --load-ca-
              certificate.

   Certificate verification related options
       -e, --verify-chain
              Verify a PEM encoded certificate chain.

              Verifies the validity of a certificate chain. That is, an ordered
              set of certificates where each one is the issuer of the previous,
              and the first is the end-certificate to be validated. In a proper
              chain the last certificate is a self signed one. It can be
              combined with --verify-purpose or --verify-hostname.

       --verify
              Verify a PEM encoded certificate (chain) against a trusted set.

              The trusted certificate list can be loaded with --load-ca-
              certificate. If no certificate list is provided, then the system's
              trusted certificate list is used. Note that during verification
              multiple paths may be explored. On a successful verification the
              successful path will be the last one. It can be combined with
              --verify-purpose or --verify-hostname.

       --verify-hostname=string
              Specify a hostname to be used for certificate chain verification.

              This is to be combined with one of the verify certificate options.

       --verify-email=string
              Specify a email to be used for certificate chain verification.
              This option must not appear in combination with any of the
              following options: verify-hostname.

              This is to be combined with one of the verify certificate options.

       --verify-purpose=string
              Specify a purpose OID to be used for certificate chain
              verification.

              This object identifier restricts the purpose of the certificates
              to be verified. Example purposes are 1.3.6.1.5.5.7.3.1 (TLS WWW),
              1.3.6.1.5.5.7.3.4 (EMAIL) etc. Note that a CA certificate without
              a purpose set (extended key usage) is valid for any purpose.

       --verify-allow-broken
              Allow broken algorithms, such as MD5 for verification.

              This can be combined with --p7-verify, --verify or --verify-chain.

       --verify-profile=string
              Specify a security level profile to be used for verification.

              This option can be used to specify a certificate verification
              profile. Certificate
                  verification profiles correspond to the security level. This
              should be one of
                  'none', 'very weak', 'low', 'legacy', 'medium', 'high',
              'ultra',
                  'future'. Note that by default no profile is applied, unless
              one is set
                  as minimum in the gnutls configuration file.

   PKCS#7 structure options
       --p7-generate
              Generate a PKCS #7 structure.

              This option generates a PKCS #7 certificate container structure.
              To add certificates in the structure use --load-certificate and
              --load-crl.

       --p7-sign
              Signs using a PKCS #7 structure.

              This option generates a PKCS #7 structure containing a signature
              for the provided data from infile. The data are stored within the
              structure. The signer certificate has to be specified using
              --load-certificate and --load-privkey. The input to --load-
              certificate can be a list of certificates. In case of a list, the
              first certificate is used for signing and the other certificates
              are included in the structure.

       --p7-detached-sign
              Signs using a detached PKCS #7 structure.

              This option generates a PKCS #7 structure containing a signature
              for the provided data from infile. The signer certificate has to
              be specified using --load-certificate and --load-privkey. The
              input to --load-certificate can be a list of certificates. In case
              of a list, the first certificate is used for signing and the other
              certificates are included in the structure.

       --p7-include-cert, --no-p7-include-cert
              The signer's certificate will be included in the cert list..  The
              no-p7-include-cert form will disable the option.  This option is
              enabled by default.

              This options works with --p7-sign or --p7-detached-sign and will
              include or exclude the signer's certificate into the generated
              signature.

       --p7-time, --no-p7-time
              Will include a timestamp in the PKCS #7 structure.  The no-p7-time
              form will disable the option.

              This option will include a timestamp in the generated signature

       --p7-show-data, --no-p7-show-data
              Will show the embedded data in the PKCS #7 structure.  The
              no-p7-show-data form will disable the option.

              This option can be combined with --p7-verify or --p7-info and will
              display the embedded signed data in the PKCS #7 structure.

       --p7-info
              Print information on a PKCS #7 structure.


       --p7-verify
              Verify the provided PKCS #7 structure.

              This option verifies the signed PKCS #7 structure. The certificate
              list to use for verification can be specified with --load-ca-
              certificate. When no certificate list is provided, then the
              system's certificate list is used. Alternatively a direct signer
              can be provided using --load-certificate. A key purpose can be
              enforced with the --verify-purpose option, and the --load-data
              option will utilize detached data.

       --smime-to-p7
              Convert S/MIME to PKCS #7 structure.


   Other options
       --generate-dh-params
              Generate PKCS #3 encoded Diffie-Hellman parameters.

              The will generate random parameters to be used with Diffie-Hellman
              key exchange. The output parameters will be in PKCS #3 format.
              Note that it is recommended to use the --get-dh-params option
              instead.

              NOTE: THIS OPTION IS DEPRECATED

       --get-dh-params
              List the included PKCS #3 encoded Diffie-Hellman parameters.

              Returns stored DH parameters in GnuTLS. Those parameters returned
              are defined in RFC7919, and can be considered standard parameters
              for a TLS key exchange. This option is provided for old
              applications which require DH parameters to be specified; modern
              GnuTLS applications should not require them.

       --dh-info
              Print information PKCS #3 encoded Diffie-Hellman parameters.


       --load-privkey=string
              Loads a private key file.

              This can be either a file or a PKCS #11 URL

       --load-pubkey=string
              Loads a public key file.

              This can be either a file or a PKCS #11 URL

       --load-request=string
              Loads a certificate request file.

              This option can be used with a file

       --load-certificate=string
              Loads a certificate file.

              This option can be used with a file

       --load-ca-privkey=string
              Loads the certificate authority's private key file.

              This can be either a file or a PKCS #11 URL

       --load-ca-certificate=string
              Loads the certificate authority's certificate file.

              This can be either a file or a PKCS #11 URL

       --load-crl=string
              Loads the provided CRL.

              This option can be used with a file

       --load-data=string
              Loads auxiliary data.

              This option can be used with a file

       --password=string
              Password to use.

              You can use this option to specify the password in the command
              line instead of reading it from the tty. Note, that the command
              line arguments are available for view in others in the system.
              Specifying password as '' is the same as specifying no password.

       --null-password
              Enforce a NULL password.

              This option enforces a NULL password. This is different than the
              empty or no password in schemas like PKCS #8.

       --empty-password
              Enforce an empty password.

              This option enforces an empty password. This is different than the
              NULL or no password in schemas like PKCS #8.

       --hex-numbers
              Print big number in an easier format to parse.


       --cprint
              In certain operations it prints the information in C-friendly
              format.

              In certain operations it prints the information in C-friendly
              format, suitable for including into C programs.

       --rsa  Generate RSA key.

              When combined with --generate-privkey generates an RSA private
              key.

              NOTE: THIS OPTION IS DEPRECATED

       --dsa  Generate DSA key.

              When combined with --generate-privkey generates a DSA private key.

              NOTE: THIS OPTION IS DEPRECATED

       --ecc  Generate ECC (ECDSA) key.

              When combined with --generate-privkey generates an elliptic curve
              private key to be used with ECDSA.

              NOTE: THIS OPTION IS DEPRECATED

       --ecdsa
              This is an alias for the --ecc option.

              NOTE: THIS OPTION IS DEPRECATED

       --hash=string
              Hash algorithm to use for signing.

              Available hash functions are SHA1, RMD160, SHA256, SHA384, SHA512,
              SHA3-224, SHA3-256, SHA3-384, SHA3-512.

       --salt-size=number
              Specify the RSA-PSS key default salt size.  This option takes an
              integer number as its argument.

              Typical keys shouldn't set or restrict this option.

       --inder, --no-inder
              Use DER format for input certificates, private keys, and DH
              parameters .  The no-inder form will disable the option.

              The input files will be assumed to be in DER or RAW format.
              Unlike options that in PEM input would allow multiple input data
              (e.g. multiple certificates), when reading in DER format a single
              data structure is read.

       --inraw
              This is an alias for the --inder option.

       --outder, --no-outder
              Use DER format for output certificates, private keys, and DH
              parameters.  The no-outder form will disable the option.

              The output will be in DER or RAW format.

       --outraw
              This is an alias for the --outder option.

       --disable-quick-random
              No effect.


              NOTE: THIS OPTION IS DEPRECATED

       --template=string
              Template file to use for non-interactive operation.


       --stdout-info
              Print information to stdout instead of stderr.


       --ask-pass
              Enable interaction for entering password when in batch mode..

              This option will enable interaction to enter password when in
              batch mode. That is useful when the template option has been
              specified.

       --pkcs-cipher=cipher
              Cipher to use for PKCS #8 and #12 operations.

              Cipher may be one of 3des, 3des-pkcs12, aes-128, aes-192, aes-256,
              rc2-40, arcfour.

       --provider=string
              Specify the PKCS #11 provider library.

              This will override the default options in /etc/gnutls/pkcs11.conf

       --text, --no-text
              Output textual information before PEM-encoded certificates,
              private keys, etc.  The no-text form will disable the option.
              This option is enabled by default.

              Output textual information before PEM-encoded data

       -h, --help
              Display usage information and exit.

       -!, --more-help
              Pass the extended usage information through a pager.

       -v [{v|c|n --version [{v|c|n}]}]
              Output version of program and exit.  The default mode is `v', a
              simple version.  The `c' mode will print copyright information and
              `n' will print the full copyright notice.

FILES
       Certtool's template file format
       A template file can be used to avoid the interactive questions of
       certtool. Initially create a file named 'cert.cfg' that contains the
       information about the certificate. The template can be used as below:

           $ certtool --generate-certificate --load-privkey key.pem     --template cert.cfg --outfile cert.pem    --load-ca-certificate ca-cert.pem --load-ca-privkey ca-key.pem

       An example certtool template file that can be used to generate a
       certificate request or a self signed certificate follows.

           # X.509 Certificate options
           #
           # DN options

           # The organization of the subject.
           organization = "Koko inc."

           # The organizational unit of the subject.
           unit = "sleeping dept."

           # The locality of the subject.
           # locality =

           # The state of the certificate owner.
           state = "Attiki"

           # The country of the subject. Two letter code.
           country = GR

           # The common name of the certificate owner.
           cn = "Cindy Lauper"

           # A user id of the certificate owner.
           #uid = "clauper"

           # Set domain components
           #dc = "name"
           #dc = "domain"

           # If the supported DN OIDs are not adequate you can set
           # any OID here.
           # For example set the X.520 Title and the X.520 Pseudonym
           # by using OID and string pairs.
           #dn_oid = "2.5.4.12 Dr."
           #dn_oid = "2.5.4.65 jackal"

           # This is deprecated and should not be used in new
           # certificates.
           # pkcs9_email = "none@none.org"

           # An alternative way to set the certificate's distinguished name directly
           # is with the "dn" option. The attribute names allowed are:
           # C (country), street, O (organization), OU (unit), title, CN (common name),
           # L (locality), ST (state), placeOfBirth, gender, countryOfCitizenship,
           # countryOfResidence, serialNumber, telephoneNumber, surName, initials,
           # generationQualifier, givenName, pseudonym, dnQualifier, postalCode, name,
           # businessCategory, DC, UID, jurisdictionOfIncorporationLocalityName,
           # jurisdictionOfIncorporationStateOrProvinceName,
           # jurisdictionOfIncorporationCountryName, XmppAddr, and numeric OIDs.

           #dn = "cn = Nikos,st = New Something,C=GR,surName=Mavrogiannopoulos,2.5.4.9=Arkadias"

           # The serial number of the certificate
           # The value is in decimal (i.e. 1963) or hex (i.e. 0x07ab).
           # Comment the field for a random serial number.
           serial = 007

           # In how many days, counting from today, this certificate will expire.
           # Use -1 if there is no expiration date.
           expiration_days = 700

           # Alternatively you may set concrete dates and time. The GNU date string
           # formats are accepted. See:
           # https://www.gnu.org/software/tar/manual/html_node/Date-input-formats.html

           #activation_date = "2004-02-29 16:21:42"
           #expiration_date = "2025-02-29 16:24:41"

           # X.509 v3 extensions

           # A dnsname in case of a WWW server.
           #dns_name = "www.none.org"
           #dns_name = "www.morethanone.org"

           # An othername defined by an OID and a hex encoded string
           #other_name = "1.3.6.1.5.2.2 302ca00d1b0b56414e5245494e2e4f5247a11b3019a006020400000002a10f300d1b047269636b1b0561646d696e"
           #other_name_utf8 = "1.2.4.5.6 A UTF8 string"
           #other_name_octet = "1.2.4.5.6 A string that will be encoded as ASN.1 octet string"

           # Allows writing an XmppAddr Identifier
           #xmpp_name = juliet@im.example.com

           # Names used in PKINIT
           #krb5_principal = user@REALM.COM
           #krb5_principal = HTTP/user@REALM.COM

           # A subject alternative name URI
           #uri = "https://www.example.com"

           # An IP address in case of a server.
           #ip_address = "192.168.1.1"

           # An email in case of a person
           email = "none@none.org"

           # TLS feature (rfc7633) extension. That can is used to indicate mandatory TLS
           # extension features to be provided by the server. In practice this is used
           # to require the Status Request (extid: 5) extension from the server. That is,
           # to require the server holding this certificate to provide a stapled OCSP response.
           # You can have multiple lines for multiple TLS features.

           # To ask for OCSP status request use:
           #tls_feature = 5

           # Challenge password used in certificate requests
           challenge_password = 123456

           # Password when encrypting a private key
           #password = secret

           # An URL that has CRLs (certificate revocation lists)
           # available. Needed in CA certificates.
           #crl_dist_points = "https://www.getcrl.crl/getcrl/"

           # Whether this is a CA certificate or not
           #ca

           # Subject Unique ID (in hex)
           #subject_unique_id = 00153224

           # Issuer Unique ID (in hex)
           #issuer_unique_id = 00153225

           #### Key usage

           # The following key usage flags are used by CAs and end certificates

           # Whether this certificate will be used to sign data (needed
           # in TLS DHE ciphersuites). This is the digitalSignature flag
           # in RFC5280 terminology.
           signing_key

           # Whether this certificate will be used to encrypt data (needed
           # in TLS RSA ciphersuites). Note that it is preferred to use different
           # keys for encryption and signing. This is the keyEncipherment flag
           # in RFC5280 terminology.
           encryption_key

           # Whether this key will be used to sign other certificates. The
           # keyCertSign flag in RFC5280 terminology.
           #cert_signing_key

           # Whether this key will be used to sign CRLs. The
           # cRLSign flag in RFC5280 terminology.
           #crl_signing_key

           # The keyAgreement flag of RFC5280. It's purpose is loosely
           # defined. Not use it unless required by a protocol.
           #key_agreement

           # The dataEncipherment flag of RFC5280. It's purpose is loosely
           # defined. Not use it unless required by a protocol.
           #data_encipherment

           # The nonRepudiation flag of RFC5280. It's purpose is loosely
           # defined. Not use it unless required by a protocol.
           #non_repudiation

           #### Extended key usage (key purposes)

           # The following extensions are used in an end certificate
           # to clarify its purpose. Some CAs also use it to indicate
           # the types of certificates they are purposed to sign.


           # Whether this certificate will be used for a TLS client;
           # this sets the id-kp-clientAuth (1.3.6.1.5.5.7.3.2) of
           # extended key usage.
           #tls_www_client

           # Whether this certificate will be used for a TLS server;
           # this sets the id-kp-serverAuth (1.3.6.1.5.5.7.3.1) of
           # extended key usage.
           #tls_www_server

           # Whether this key will be used to sign code. This sets the
           # id-kp-codeSigning (1.3.6.1.5.5.7.3.3) of extended key usage
           # extension.
           #code_signing_key

           # Whether this key will be used to sign OCSP data. This sets the
           # id-kp-OCSPSigning (1.3.6.1.5.5.7.3.9) of extended key usage extension.
           #ocsp_signing_key

           # Whether this key will be used for time stamping. This sets the
           # id-kp-timeStamping (1.3.6.1.5.5.7.3.8) of extended key usage extension.
           #time_stamping_key

           # Whether this key will be used for email protection. This sets the
           # id-kp-emailProtection (1.3.6.1.5.5.7.3.4) of extended key usage extension.
           #email_protection_key

           # Whether this key will be used for IPsec IKE operations (1.3.6.1.5.5.7.3.17).
           #ipsec_ike_key

           ## adding custom key purpose OIDs

           # for microsoft smart card logon
           # key_purpose_oid = 1.3.6.1.4.1.311.20.2.2

           # for email protection
           # key_purpose_oid = 1.3.6.1.5.5.7.3.4

           # for any purpose (must not be used in intermediate CA certificates)
           # key_purpose_oid = 2.5.29.37.0

           ### end of key purpose OIDs

           ### Adding arbitrary extensions
           # This requires to provide the extension OIDs, as well as the extension data in
           # hex format. The following two options are available since GnuTLS 3.5.3.
           #add_extension = "1.2.3.4 0x0AAB01ACFE"

           # As above but encode the data as an octet string
           #add_extension = "1.2.3.4 octet_string(0x0AAB01ACFE)"

           # For portability critical extensions shouldn't be set to certificates.
           #add_critical_extension = "5.6.7.8 0x1AAB01ACFE"

           # When generating a certificate from a certificate
           # request, then honor the extensions stored in the request
           # and store them in the real certificate.
           #honor_crq_extensions

           # Alternatively only specific extensions can be copied.
           #honor_crq_ext = 2.5.29.17
           #honor_crq_ext = 2.5.29.15

           # Path length contraint. Sets the maximum number of
           # certificates that can be used to certify this certificate.
           # (i.e. the certificate chain length)
           #path_len = -1
           #path_len = 2

           # OCSP URI
           # ocsp_uri = https://my.ocsp.server/ocsp

           # CA issuers URI
           # ca_issuers_uri = https://my.ca.issuer

           # Certificate policies
           #policy1 = 1.3.6.1.4.1.5484.1.10.99.1.0
           #policy1_txt = "This is a long policy to summarize"
           #policy1_url = https://www.example.com/a-policy-to-read

           #policy2 = 1.3.6.1.4.1.5484.1.10.99.1.1
           #policy2_txt = "This is a short policy"
           #policy2_url = https://www.example.com/another-policy-to-read

           # The number of additional certificates that may appear in a
           # path before the anyPolicy is no longer acceptable.
           #inhibit_anypolicy_skip_certs 1

           # Name constraints

           # DNS
           #nc_permit_dns = example.com
           #nc_exclude_dns = test.example.com

           # EMAIL
           #nc_permit_email = "nmav@ex.net"

           # Exclude subdomains of example.com
           #nc_exclude_email = .example.com

           # Exclude all e-mail addresses of example.com
           #nc_exclude_email = example.com

           # IP
           #nc_permit_ip = 192.168.0.0/16
           #nc_exclude_ip = 192.168.5.0/24
           #nc_permit_ip = fc0a:eef2:e7e7:a56e::/64


           # Options for proxy certificates
           #proxy_policy_language = 1.3.6.1.5.5.7.21.1


           # Options for generating a CRL

           # The number of days the next CRL update will be due.
           # next CRL update will be in 43 days
           #crl_next_update = 43

           # this is the 5th CRL by this CA
           # The value is in decimal (i.e. 1963) or hex (i.e. 0x07ab).
           # Comment the field for a time-based number.
           # Time-based CRL numbers generated in GnuTLS 3.6.3 and later
           # are significantly larger than those generated in previous
           # versions. Since CRL numbers need to be monotonic, you need
           # to specify the CRL number here manually if you intend to
           # downgrade to an earlier version than 3.6.3 after publishing
           # the CRL as it is not possible to specify CRL numbers greater
           # than 263-2 using hex notation in those versions.
           #crl_number = 5

           # Specify the update dates more precisely.
           #crl_this_update_date = "2004-02-29 16:21:42"
           #crl_next_update_date = "2025-02-29 16:24:41"

           # The date that the certificates will be made seen as
           # being revoked.
           #crl_revocation_date = "2025-02-29 16:24:41"



EXAMPLES
       Generating private keys
       To create an RSA private key, run:
           $ certtool --generate-privkey --outfile key.pem --rsa

       To create a DSA or elliptic curves (ECDSA) private key use the above
       command combined with 'dsa' or 'ecc' options.

       Generating certificate requests
       To create a certificate request (needed when the certificate is  issued
       by another party), run:
           certtool --generate-request --load-privkey key.pem    --outfile request.pem

       If the private key is stored in a smart card you can generate a request
       by specifying the private key object URL.
           $ ./certtool --generate-request --load-privkey "pkcs11:..."   --load-pubkey "pkcs11:..." --outfile request.pem


       Generating a self-signed certificate
       To create a self signed certificate, use the command:
           $ certtool --generate-privkey --outfile ca-key.pem
           $ certtool --generate-self-signed --load-privkey ca-key.pem    --outfile ca-cert.pem

       Note that a self-signed certificate usually belongs to a certificate
       authority, that signs other certificates.

       Generating a certificate
       To generate a certificate using the previous request, use the command:
           $ certtool --generate-certificate --load-request request.pem    --outfile cert.pem --load-ca-certificate ca-cert.pem    --load-ca-privkey ca-key.pem

       To generate a certificate using the private key only, use the command:
           $ certtool --generate-certificate --load-privkey key.pem    --outfile cert.pem --load-ca-certificate ca-cert.pem    --load-ca-privkey ca-key.pem

       Certificate information
       To view the certificate information, use:
           $ certtool --certificate-info --infile cert.pem

       Changing the certificate format
       To convert the certificate from PEM to DER format, use:
           $ certtool --certificate-info --infile cert.pem --outder --outfile cert.der

       PKCS #12 structure generation
       To generate a PKCS #12 structure using the previous key and certificate,
       use the command:
           $ certtool --load-certificate cert.pem --load-privkey key.pem    --to-p12 --outder --outfile key.p12

       Some tools (reportedly web browsers) have problems with that file because
       it does not contain the CA certificate for the certificate.  To work
       around that problem in the tool, you can use the --load-ca-certificate
       parameter as follows:

           $ certtool --load-ca-certificate ca.pem   --load-certificate cert.pem --load-privkey key.pem   --to-p12 --outder --outfile key.p12

       Obtaining Diffie-Hellman parameters
       To obtain the RFC7919 parameters for Diffie-Hellman key exchange, use the
       command:
           $ certtool --get-dh-params --outfile dh.pem --sec-param medium

       Verifying a certificate
       To verify a certificate in a file against the system's CA trust store use
       the following command:
           $ certtool --verify --infile cert.pem

       It is also possible to simulate hostname verification with the following
       options:
           $ certtool --verify --verify-hostname www.example.com --infile cert.pem


       Proxy certificate generation
       Proxy certificate can be used to delegate your credential to a temporary,
       typically short-lived, certificate.  To create one from the previously
       created certificate, first create a temporary key and then generate a
       proxy certificate for it, using the commands:

           $ certtool --generate-privkey > proxy-key.pem
           $ certtool --generate-proxy --load-ca-privkey key.pem   --load-privkey proxy-key.pem --load-certificate cert.pem   --outfile proxy-cert.pem

       Certificate revocation list generation
       To create an empty Certificate Revocation List (CRL) do:

           $ certtool --generate-crl --load-ca-privkey x509-ca-key.pem            --load-ca-certificate x509-ca.pem

       To create a CRL that contains some revoked certificates, place the
       certificates in a file and use --load-certificate as follows:

           $ certtool --generate-crl --load-ca-privkey x509-ca-key.pem   --load-ca-certificate x509-ca.pem --load-certificate revoked-certs.pem

       To verify a Certificate Revocation List (CRL) do:

           $ certtool --verify-crl --load-ca-certificate x509-ca.pem < crl.pem

EXIT STATUS
       One of the following exit values will be returned:

       0  (EXIT_SUCCESS)
              Successful program execution.

       1  (EXIT_FAILURE)
              The operation failed or the command syntax was not valid.

       70  (EX_SOFTWARE)
              libopts had an internal operational error.  Please report it to
              autogen-users@lists.sourceforge.net.  Thank you.

SEE ALSO
           p11tool (1), psktool (1), srptool (1)

AUTHORS
       Nikos Mavrogiannopoulos, Simon Josefsson and others; see
       /usr/share/doc/gnutls/AUTHORS for a complete list.

COPYRIGHT
       Copyright (C) 2000-2020 Free Software Foundation, and others all rights
       reserved.  This program is released under the terms of the GNU General
       Public License, version 3 or later.

BUGS
       Please send bug reports to: bugs@gnutls.org

NOTES
       This manual page was AutoGen-erated from the certtool option definitions.



3.6.12                             28 Mar 2020                       certtool(1)