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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.
-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) 2020-2021 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-3.8.0.tar.xz fetched from
⟨http://www.gnutls.org/download.html⟩ on 2023-06-23. 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
3.8.0 09 Feb 2023 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 2023-06-24 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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