certtool(1) User Commands certtool(1)NAMEcerttool - GnuTLS certificate tool
SYNOPSIScerttool [-flag [value]]... [--opt-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.
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 pri‐
vate 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-cer‐
tificate.
--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-cer‐
tificate.
--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 gen‐
eration 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 com‐
bination with the following options: load-certificate.
It requires a certificate, a private key and possibly a CA cer‐
tificate 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 sin‐
gle 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 cert‐
tool. Initially create a file named 'cert.cfg' that contains the infor‐
mation 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 cer‐
tificate 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 certifi‐
cate, 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-cer‐
tificate 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 com‐
mand:
$ certtool--generate-dh-params --outfile dh.pem --sec-param normal
Proxy certificate generation
Proxy certificate can be used to delegate your credential to a tempo‐
rary, typically short-lived, certificate. To create one from the pre‐
viously created certificate, first create a temporary key and then gen‐
erate 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 cer‐
tificates 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.
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.
BUGS
Please send bug reports to: bug-gnutls@gnu.org
NOTES
This manual page was AutoGen-erated from the certtool option defini‐
tions.
3.2.4 31 Aug 2013 certtool(1)
