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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | EXIT STATUS | SEE ALSO | AUTHORS | COPYRIGHT | BUGS | COLOPHON |
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gnutls-serv(1) User Commands gnutls-serv(1)
gnutls-serv - GnuTLS server
gnutls-serv [-flags] [-flag [value]] [--option-name[[=| ]value]]
All arguments must be options.
Server program that listens to incoming TLS connections.
-d num, --debug=num Enable debugging. This option takes an
integer number as its argument. The value of num is constrained
to being:
in the range 0 through 9999
Specifies the debug level.
--sni-hostname=str Server's hostname for server name extension.
Server name of type host_name that the server will recognise as
its own. If the server receives client hello with different name,
it will send a warning-level unrecognized_name alert.
--sni-hostname-fatal Send fatal alert on sni-hostname mismatch.
--alpn=str Specify ALPN protocol to be enabled by the server.
This option may appear an unlimited number of times.
Specify the (textual) ALPN protocol for the server to use.
--alpn-fatal Send fatal alert on non-matching ALPN name.
--noticket Don't accept session tickets.
--earlydata Accept early data.
--maxearlydata=num The maximum early data size to accept. This
option takes an integer number as its argument. The value of num
is constrained to being:
in the range 1 through 2147483648
--nocookie Don't require cookie on DTLS sessions.
-g, --generate Generate Diffie-Hellman parameters.
-q, --quiet Suppress some messages.
--nodb Do not use a resumption database.
--http Act as an HTTP server.
--echo Act as an Echo server.
--crlf Do not replace CRLF by LF in Echo server mode.
-u, --udp Use DTLS (datagram TLS) over UDP.
--mtu=num Set MTU for datagram TLS. This option takes an integer
number as its argument. The value of num is constrained to
being:
in the range 0 through 17000
--srtp-profiles=str Offer SRTP profiles.
-a, --disable-client-cert Do not request a client certificate.
This option must not appear in combination with any of the
following options: require-client-cert.
-r, --require-client-cert Require a client certificate.
This option before 3.6.0 used to imply --verify-client-cert.
Since 3.6.0 it will no longer verify the certificate by default.
--verify-client-cert If a client certificate is sent then verify
it.
Do not require, but if a client certificate is sent then verify
it and close the connection if invalid.
--compress-cert=str Compress certificate. This option may appear
an unlimited number of times.
This option sets a supported compression method for certificate
compression.
-b, --heartbeat Activate heartbeat support.
Regularly ping client via heartbeat extension messages
--x509fmtder Use DER format for certificates to read from.
--priority=str Priorities string.
TLS algorithms and protocols to enable. You can use predefined
sets of ciphersuites such as PERFORMANCE, NORMAL, SECURE128,
SECURE256. The default is NORMAL.
Check the GnuTLS manual on section “Priority strings” for
more information on allowed keywords
--dhparams=file DH params file to use.
--x509cafile=str Certificate file or PKCS #11 URL to use.
--x509crlfile=file CRL file to use.
--pgpkeyfile=file PGP Key file to use.
NOTE: THIS OPTION IS DEPRECATED
--x509keyfile=str X.509 key file or PKCS #11 URL to use. This
option may appear an unlimited number of times.
Specify the private key file or URI to use; it must correspond to
the certificate specified in --x509certfile. Multiple keys and
certificates can be specified with this option and in that case
each occurrence of keyfile must be followed by the corresponding
x509certfile or vice-versa.
--x509certfile=str X.509 Certificate file or PKCS #11 URL to use.
This option may appear an unlimited number of times.
Specify the certificate file or URI to use; it must correspond to
the key specified in --x509keyfile. Multiple keys and
certificates can be specified with this option and in that case
each occurrence of keyfile must be followed by the corresponding
x509certfile or vice-versa.
--x509dsakeyfile This is an alias for the --x509keyfile option.
NOTE: THIS OPTION IS DEPRECATED
--x509dsacertfile This is an alias for the --x509certfile option.
NOTE: THIS OPTION IS DEPRECATED
--x509ecckeyfile This is an alias for the --x509keyfile option.
NOTE: THIS OPTION IS DEPRECATED
--x509ecccertfile This is an alias for the --x509certfile option.
NOTE: THIS OPTION IS DEPRECATED
--rawpkkeyfile=str Private key file (PKCS #8 or PKCS #12) or PKCS
#11 URL to use. This option may appear an unlimited number of
times.
Specify the private key file or URI to use; it must correspond to
the raw public-key specified in --rawpkfile. Multiple key pairs
can be specified with this option and in that case each
occurrence of keyfile must be followed by the corresponding
rawpkfile or vice-versa.
In order to instruct the application to negotiate raw public keys
one must enable the respective certificate types via the priority
strings (i.e. CTYPE-CLI-* and CTYPE-SRV-* flags).
Check the GnuTLS manual on section “Priority strings” for
more information on how to set certificate types.
--rawpkfile=str Raw public-key file to use. This option may
appear an unlimited number of times. This option must appear in
combination with the following options: rawpkkeyfile.
Specify the raw public-key file to use; it must correspond to the
private key specified in --rawpkkeyfile. Multiple key pairs can
be specified with this option and in that case each occurrence of
keyfile must be followed by the corresponding rawpkfile or
vice-versa.
In order to instruct the application to negotiate raw public keys
one must enable the respective certificate types via the priority
strings (i.e. CTYPE-CLI-* and CTYPE-SRV-* flags).
Check the GnuTLS manual on section “Priority strings” for
more information on how to set certificate types.
--srppasswd=file SRP password file to use.
--srppasswdconf=file SRP password configuration file to use.
--pskpasswd=file PSK password file to use.
--pskhint=str PSK identity hint to use.
--ocsp-response=str The OCSP response to send to client. This
option may appear an unlimited number of times.
If the client requested an OCSP response, return data from this
file to the client.
--ignore-ocsp-response-errors Ignore any errors when setting the
OCSP response.
That option instructs gnutls to not attempt to match the provided
OCSP responses with the certificates.
-p num, --port=num The port to connect to. This option takes an
integer number as its argument.
-l, --list Print a list of the supported algorithms and modes.
Print a list of the supported algorithms and modes. If a priority
string is given then only the enabled ciphersuites are shown.
--provider=file Specify the PKCS #11 provider library.
This will override the default options in /etc/gnutls/pkcs11.conf
--keymatexport=str Label used for exporting keying material.
--keymatexportsize=num Size of the exported keying material.
This option takes an integer number as its argument.
--recordsize=num The maximum record size to advertise. This
option takes an integer number as its argument. The value of num
is constrained to being:
in the range 0 through 16384
--httpdata=file The data used as HTTP response.
--timeout=num The timeout period for server. This option takes
an integer number as its argument.
--attime=timestamp Perform validation at the timestamp instead of
the system time.
timestamp is an instance in time encoded as Unix time or in a
human
readable timestring such as "29 Feb 2004", "2004-02-29". Full
documentation available at
<https://www.gnu.org/software/coreutils/manual/html_node/Date-input-formats.html>
or locally via info '(coreutils) date invocation'.
-v arg, --version=arg 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.
-h, --help Display usage information and exit.
-!, --more-help Pass the extended usage information through a
pager.
Running your own TLS server based on GnuTLS can be useful
when debugging clients and/or GnuTLS itself. This section
describes how to use gnutls-serv as a simple HTTPS server.
The most basic server can be started as:
gnutls-serv --http --priority "NORMAL:+ANON-ECDH:+ANON-DH"
It will only support anonymous ciphersuites, which many
TLS clients refuse to use.
The next step is to add support for X.509. First we
generate a CA:
$ certtool --generate-privkey > x509-ca-key.pem
$ echo 'cn = GnuTLS test CA' > ca.tmpl
$ echo 'ca' >> ca.tmpl
$ echo 'cert_signing_key' >> ca.tmpl
$ certtool --generate-self-signed --load-privkey x509-ca-key.pem --template ca.tmpl --outfile x509-ca.pem
Then generate a server certificate. Remember to change
the dns_name value to the name of your server host, or
skip that command to avoid the field.
$ certtool --generate-privkey > x509-server-key.pem
$ echo 'organization = GnuTLS test server' > server.tmpl
$ echo 'cn = test.gnutls.org' >> server.tmpl
$ echo 'tls_www_server' >> server.tmpl
$ echo 'encryption_key' >> server.tmpl
$ echo 'signing_key' >> server.tmpl
$ echo 'dns_name = test.gnutls.org' >> server.tmpl
$ certtool --generate-certificate --load-privkey x509-server-key.pem --load-ca-certificate x509-ca.pem --load-ca-privkey x509-ca-key.pem --template server.tmpl --outfile x509-server.pem
For use in the client, you may want to generate a client
certificate as well.
$ certtool --generate-privkey > x509-client-key.pem
$ echo 'cn = GnuTLS test client' > client.tmpl
$ echo 'tls_www_client' >> client.tmpl
$ echo 'encryption_key' >> client.tmpl
$ echo 'signing_key' >> client.tmpl
$ certtool --generate-certificate --load-privkey x509-client-key.pem --load-ca-certificate x509-ca.pem --load-ca-privkey x509-ca-key.pem --template client.tmpl --outfile x509-client.pem
To be able to import the client key/certificate into some
applications, you will need to convert them into a PKCS#12
structure. This also encrypts the security sensitive key
with a password.
$ certtool --to-p12 --load-ca-certificate x509-ca.pem --load-privkey x509-client-key.pem --load-certificate x509-client.pem --outder --outfile x509-client.p12
For icing, we'll create a proxy certificate for the client
too.
$ certtool --generate-privkey > x509-proxy-key.pem
$ echo 'cn = GnuTLS test client proxy' > proxy.tmpl
$ certtool --generate-proxy --load-privkey x509-proxy-key.pem --load-ca-certificate x509-client.pem --load-ca-privkey x509-client-key.pem --load-certificate x509-client.pem --template proxy.tmpl --outfile x509-proxy.pem
Then start the server again:
$ gnutls-serv --http --x509cafile x509-ca.pem --x509keyfile x509-server-key.pem --x509certfile x509-server.pem
Try connecting to the server using your web browser. Note
that the server listens to port 5556 by default.
While you are at it, to allow connections using ECDSA, you
can also create a ECDSA key and certificate for the
server. These credentials will be used in the final
example below.
$ certtool --generate-privkey --ecdsa > x509-server-key-ecc.pem
$ certtool --generate-certificate --load-privkey x509-server-key-ecc.pem --load-ca-certificate x509-ca.pem --load-ca-privkey x509-ca-key.pem --template server.tmpl --outfile x509-server-ecc.pem
The next step is to add support for SRP authentication.
This requires an SRP password file created with srptool.
To start the server with SRP support:
gnutls-serv --http --priority NORMAL:+SRP-RSA:+SRP --srppasswdconf srp-tpasswd.conf --srppasswd srp-passwd.txt
Let's also start a server with support for PSK. This would
require a password file created with psktool.
gnutls-serv --http --priority NORMAL:+ECDHE-PSK:+PSK --pskpasswd psk-passwd.txt
If you want a server with support for raw public-keys we
can also add these credentials. Note however that there is
no identity information linked to these keys as is the
case with regular x509 certificates. Authentication must
be done via different means. Also we need to explicitly
enable raw public-key certificates via the priority
strings.
gnutls-serv --http --priority NORMAL:+CTYPE-CLI-RAWPK:+CTYPE-SRV-RAWPK --rawpkfile srv.rawpk.pem --rawpkkeyfile srv.key.pem
Finally, we start the server with all the earlier
parameters and you get this command:
gnutls-serv --http --priority NORMAL:+PSK:+SRP:+CTYPE-CLI-RAWPK:+CTYPE-SRV-RAWPK --x509cafile x509-ca.pem --x509keyfile x509-server-key.pem --x509certfile x509-server.pem --x509keyfile x509-server-key-ecc.pem --x509certfile x509-server-ecc.pem --srppasswdconf srp-tpasswd.conf --srppasswd srp-passwd.txt --pskpasswd psk-passwd.txt --rawpkfile srv.rawpk.pem --rawpkkeyfile srv.key.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.
gnutls-cli-debug(1), gnutls-cli(1)
Copyright (C) 2020-2023 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 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-3.8.5.tar.xz fetched from
⟨http://www.gnutls.org/download.html⟩ on 2024-06-14. 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
3.8.5 04 Apr 2024 gnutls-serv(1)
Pages that refer to this page: gnutls-cli(1), gnutls-cli-debug(1), psktool(1), srptool(1)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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