Name

certtool — GnuTLS certificate tool

Synopsis

certtool [ −flag [value] ...] [ −−opt−name [[=|]value] ...]

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.

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.

−s, −−generate−self−signed

Generate a self-signed certificate.

−c, −−generate−certificate

Generate a signed certificate.

−−generate−proxy

Generates a proxy certificate.

−−generate−crl

Generate a CRL.

−u, −−update−certificate

Update a signed certificate.

−p, −−generate−privkey

Generate a private key.

−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.

−e, −−verify−chain

Verify a PEM encoded certificate chain..

The last certificate in the chain must be a self signed one.

−−verify

Verify a PEM encoded certificate chain 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.

−−verify−crl

Verify a CRL 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.

−−generate−dh−params

Generate PKCS #3 encoded Diffie-Hellman parameters..

−−get−dh−params

Get the included PKCS #3 encoded Diffie-Hellman parameters..

Returns stored DH parameters in GnuTLS. Those parameters are used in the SRP protocol. The parameters returned by fresh generation are more efficient since GnuTLS 3.0.9.

−−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=file

Loads a certificate request file.

−−load−certificate=string

Loads a certificate file.

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

−−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

−−password=string

Password to use.

−−hex−numbers

Print big number in an easier format to parse.

−−cprint

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

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

−−null−password

Enforce a NULL password.

This option enforces a NULL password. This may be different than the empty password in some schemas.

−i, −−certificate−info

Print information on the given certificate.

−−certificate−pubkey

Print certificate's public key.

−−pgp−certificate−info

Print information on the given OpenPGP certificate.

−−pgp−ring−info

Print information on the given OpenPGP keyring structure.

−l, −−crl−info

Print information on the given CRL structure.

−−crq−info

Print information on the given certificate request.

−−no−crq−extensions

Do not use extensions in certificate requests.

−−p12−info

Print information on a PKCS #12 structure.

−−p7−info

Print information on a PKCS #7 structure.

−−smime−to−p7

Convert S/MIME to PKCS #7 structure.

−k, −−key−info

Print information on a private key.

−−pgp−key−info

Print information on an OpenPGP private key.

−−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.

−−v1

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

−−to−p12

Generate a PKCS #12 structure. This option must appear in combination with the following options: load-certificate.

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

−−to−p8

Generate a PKCS #8 structure.

−8, -−pkcs8

Use PKCS #8 format for private keys.

−−rsa

Generate RSA key.

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

−−dsa

Generate DSA key.

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

−−ecc

Generate ECC (ECDSA) key.

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

−−ecc

This is an alias for the ecc option.

−−hash=string

Hash algorithm to use for signing..

Available hash functions are SHA1, RMD160, SHA256, SHA384, SHA512.

−−inder, −−no−inder

Use DER format for input certificates and private keys.. 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.

−−inder

This is an alias for the inder option.

−−outder, −−no−outder

Use DER format for output certificates and private keys. The no−outder form will disable the option.

The output will be in DER or RAW format.

−−outder

This is an alias for the outder option.

−−bits=number

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

−−sec−param=security parameter

Specify the security level [low, legacy, normal, high, ultra]..

This is alternative to the bits option.

−−disable−quick−random

No effect.

−−template=file

Template file to use for non-interactive operation.

−−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.

−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 cert.pem −−load−privkey key.pem     −−template cert.cfg    −−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=Nik,st=Attiki,C=GR,surName=Mavrogiannopoulos,2.5.4.9=Arkadias"

# The serial number of the certificate
serial = 007

# In how many days, counting from today, this certificate will expire.
expiration_days = 700

# X.509 v3 extensions

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

# A subject alternative name URI
#uri = "http://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"

# 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 = "http://www.getcrl.crl/getcrl/"

# Whether this is a CA certificate or not
#ca

# for microsoft smart card logon
# key_purpose_oid = 1.3.6.1.4.1.311.20.2.2

### Other predefined key purpose OIDs

# Whether this certificate will be used for a TLS client
#tls_www_client

# Whether this certificate will be used for a TLS server
#tls_www_server

# Whether this certificate will be used to sign data (needed
# in TLS DHE ciphersuites).
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.
encryption_key

# Whether this key will be used to sign other certificates.
#cert_signing_key

# Whether this key will be used to sign CRLs.
#crl_signing_key

# Whether this key will be used to sign code.
#code_signing_key

# Whether this key will be used to sign OCSP data.
#ocsp_signing_key

# Whether this key will be used for time stamping.
#time_stamping_key

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

### end of key purpose OIDs

# 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

# 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 = http://my.ocsp.server/ocsp

# CA issuers URI
# ca_issuers_uri = http://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 = http://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 = http://www.example.com/another−policy−to−read


# Options for proxy certificates
# proxy_policy_language = 1.3.6.1.5.5.7.21.1


# Options for generating a CRL

# next CRL update will be in 43 days (wow)
#crl_next_update = 43

# this is the 5th CRL by this CA
#crl_number = 5

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

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

Diffie−Hellman parameter generation

To generate parameters for Diffie−Hellman key exchange, use the command:

$ certtool −−generate−dh−params −−outfile dh.pem −−sec−param normal

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)

AUTHORS

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

BUGS

Please send bug reports to: bug-gnutls@gnu.org

NOTES

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

COPYRIGHT

Copyright (C) 2000-2012 Free Software Foundation all rights reserved. This program is released under the terms of the GNU General Public License, version 3 or later.