|
NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | EXIT STATUS | SEE ALSO | AUTHORS | COPYRIGHT | BUGS | NOTES | COLOPHON |
|
ocsptool(1) User Commands ocsptool(1)
ocsptool - GnuTLS OCSP tool
ocsptool [-flags] [-flag [value]] [--option-name[[=| ]value]]
All arguments must be options.
On verification
Responses are typically signed/issued by designated certificates or
certificate authorities and thus this tool requires on verification
the certificate of the issuer or the full certificate chain in order
to determine the appropriate signing authority. The specified
certificate of the issuer is assumed trusted.
-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.
--ask [=server name|url]
Ask an OCSP/HTTP server on a certificate validity.
Connects to the specified HTTP OCSP server and queries on the
validity of the loaded certificate. Its argument can be a URL
or a plain server name. It can be combined with --load-chain,
where it checks all certificates in the provided chain, or
with --load-cert and --load-issuer options. The latter checks
the provided certificate against its specified issuer
certificate.
-e, --verify-response
Verify response.
Verifies the provided OCSP response against the system trust
anchors (unless --load-trust is provided). It requires the
--load-signer or --load-chain options to obtain the signer of
the OCSP response.
-i, --request-info
Print information on a OCSP request.
Display detailed information on the provided OCSP request.
-j, --response-info
Print information on a OCSP response.
Display detailed information on the provided OCSP response.
-q, --generate-request
Generates an OCSP request.
--nonce, --no-nonce
Use (or not) a nonce to OCSP request. The no-nonce form will
disable the option.
--load-chain=file
Reads a set of certificates forming a chain from file.
--load-issuer=file
Reads issuer's certificate from file.
--load-cert=file
Reads the certificate to check from file.
--load-trust=file
Read OCSP trust anchors from file. This option must not
appear in combination with any of the following options: load-
signer.
When verifying an OCSP response read the trust anchors from
the provided file. When this is not provided, the system's
trust anchors will be used.
--load-signer=file
Reads the OCSP response signer from file. This option must
not appear in combination with any of the following options:
load-trust.
--inder, --no-inder
Use DER format for input certificates and private keys. The
no-inder form will disable the option.
-Q file, --load-request=file
Reads the DER encoded OCSP request from file.
-S file, --load-response=file
Reads the DER encoded OCSP response from file.
--ignore-errors
Ignore any verification errors.
--verify-allow-broken
Allow broken algorithms, such as MD5 for verification.
This can be combined with --verify-response.
-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.
Print information about an OCSP request
To parse an OCSP request and print information about the content, the
-i or --request-info parameter may be used as follows. The -Q
parameter specify the name of the file containing the OCSP request,
and it should contain the OCSP request in binary DER format.
$ ocsptool -i -Q ocsp-request.der
The input file may also be sent to standard input like this:
$ cat ocsp-request.der | ocsptool --request-info
Print information about an OCSP response
Similar to parsing OCSP requests, OCSP responses can be parsed using
the -j or --response-info as follows.
$ ocsptool -j -Q ocsp-response.der
$ cat ocsp-response.der | ocsptool --response-info
Generate an OCSP request
The -q or --generate-request parameters are used to generate an OCSP
request. By default the OCSP request is written to standard output
in binary DER format, but can be stored in a file using --outfile.
To generate an OCSP request the issuer of the certificate to check
needs to be specified with --load-issuer and the certificate to check
with --load-cert. By default PEM format is used for these files,
although --inder can be used to specify that the input files are in
DER format.
$ ocsptool -q --load-issuer issuer.pem --load-cert client.pem --outfile ocsp-request.der
When generating OCSP requests, the tool will add an OCSP extension
containing a nonce. This behaviour can be disabled by specifying
--no-nonce.
Verify signature in OCSP response
To verify the signature in an OCSP response the -e or
--verify-response parameter is used. The tool will read an OCSP
response in DER format from standard input, or from the file
specified by --load-response. The OCSP response is verified against
a set of trust anchors, which are specified using --load-trust. The
trust anchors are concatenated certificates in PEM format. The
certificate that signed the OCSP response needs to be in the set of
trust anchors, or the issuer of the signer certificate needs to be in
the set of trust anchors and the OCSP Extended Key Usage bit has to
be asserted in the signer certificate.
$ ocsptool -e --load-trust issuer.pem --load-response ocsp-response.der
The tool will print status of verification.
Verify signature in OCSP response against given certificate
It is possible to override the normal trust logic if you know that a
certain certificate is supposed to have signed the OCSP response, and
you want to use it to check the signature. This is achieved using
--load-signer instead of --load-trust. This will load one
certificate and it will be used to verify the signature in the OCSP
response. It will not check the Extended Key Usage bit.
$ ocsptool -e --load-signer ocsp-signer.pem --load-response ocsp-response.der
This approach is normally only relevant in two situations. The first
is when the OCSP response does not contain a copy of the signer
certificate, so the --load-trust code would fail. The second is if
you want to avoid the indirect mode where the OCSP response signer
certificate is signed by a trust anchor.
Real-world example
Here is an example of how to generate an OCSP request for a
certificate and to verify the response. For illustration we'll use
the blog.josefsson.org host, which (as of writing) uses a certificate
from CACert. First we'll use gnutls-cli to get a copy of the server
certificate chain. The server is not required to send this
information, but this particular one is configured to do so.
$ echo | gnutls-cli -p 443 blog.josefsson.org --save-cert chain.pem
The saved certificates normally contain a pointer to where the OCSP
responder is located, in the Authority Information Access Information
extension. For example, from certtool -i < chain.pem there is this
information:
Authority Information Access Information (not critical):
Access Method: 1.3.6.1.5.5.7.48.1 (id-ad-ocsp)
Access Location URI: http://ocsp.CAcert.org/
This means that ocsptool can discover the servers to contact over
HTTP. We can now request information on the chain certificates.
$ ocsptool --ask --load-chain chain.pem
The request is sent via HTTP to the OCSP server address found in the
certificates. It is possible to override the address of the OCSP
server as well as ask information on a particular certificate using
--load-cert and --load-issuer.
$ ocsptool --ask http://ocsp.CAcert.org/ --load-chain chain.pem
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.
certtool (1)
Nikos Mavrogiannopoulos, Simon Josefsson and others; see
/usr/share/doc/gnutls/AUTHORS for a complete list.
Copyright (C) 2000-2017 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.
Please send bug reports to: bugs@gnutls.org
This manual page was AutoGen-erated from the ocsptool option
definitions.
This page is part of the GnuTLS (GnuTLS Transport Layer Security
Library) project. Information about the project can be found at
⟨http://www.gnutls.org/⟩. If you have a bug report for this manual
page, send it to bugs@gnutls.org.. This page was obtained from the
tarball gnutls-3.6.1.tar.xz fetched from
⟨http://www.gnutls.org/download.html⟩ on 2018-02-02. If you discover
any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page, or
you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
to man-pages@man7.org
3.6.1 21 Oct 2017 ocsptool(1)
|
HTML rendering created 2018-02-02 by Michael Kerrisk, author of The Linux Programming Interface, maintainer of the Linux man-pages project. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH.
|
|