Ubuntu Manpage: unbound-anchor - Unbound anchor utility.

Provided by: unbound-anchor_1.17.1-1_amd64

NAME

       unbound-anchor - Unbound anchor utility.

SYNOPSIS

       unbound-anchor [opts]

DESCRIPTION

Unbound-anchor performs setup or update of the root trust anchor for DNSSEC validation.
The program fetches the trust anchor with the method from RFC7958 when regular RFC5011
update fails to bring it up to date. It can be run (as root) from the commandline, or run
as part of startup scripts. Before you start the unbound(8) DNS server.

Suggested usage:

# in the init scripts.
# provide or update the root anchor (if necessary)
unbound-anchor -a "/usr/share/dns/root.key"
# Please note usage of this root anchor is at your own risk
# and under the terms of our LICENSE (see source).
#
# start validating resolver
# the unbound.conf contains:
# auto-trust-anchor-file: "/usr/share/dns/root.key"
unbound -c unbound.conf

This tool provides builtin default contents for the root anchor and root update
certificate files.

It tests if the root anchor file works, and if not, and an update is possible, attempts to
update the root anchor using the root update certificate. It performs a https fetch of
root-anchors.xml and checks the results (RFC7958), if all checks are successful, it
updates the root anchor file. Otherwise the root anchor file is unchanged. It performs
RFC5011 tracking if the DNSSEC information available via the DNS makes that possible.

It does not perform an update if the certificate is expired, if the network is down or
other errors occur.

The available options are:

-a file
The root anchor key file, that is read in and written out. Default is
/usr/share/dns/root.key. If the file does not exist, or is empty, a builtin root
key is written to it.

-c file
The root update certificate file, that is read in. Default is
/etc/unbound/icannbundle.pem. If the file does not exist, or is empty, a builtin
certificate is used.

-l List the builtin root key and builtin root update certificate on stdout.

-u name
The server name, it connects to https://name. Specify without https:// prefix.
The default is "data.iana.org". It connects to the port specified with -P. You
can pass an IPv4 address or IPv6 address (no brackets) if you want.

-S Do not use SNI for the HTTPS connection. Default is to use SNI.

-b address
The source address to bind to for domain resolution and contacting the server on
https. May be either an IPv4 address or IPv6 address (no brackets).

-x path
The pathname to the root-anchors.xml file on the server. (forms URL with -u). The
default is /root-anchors/root-anchors.xml.

-s path
The pathname to the root-anchors.p7s file on the server. (forms URL with -u). The
default is /root-anchors/root-anchors.p7s. This file has to be a PKCS7 signature
over the xml file, using the pem file (-c) as trust anchor.

-n name
The emailAddress for the Subject of the signer's certificate from the p7s signature
file. Only signatures from this name are allowed. default is dnssec@iana.org. If
you pass "" then the emailAddress is not checked.

-4 Use IPv4 for domain resolution and contacting the server on https. Default is to
use IPv4 and IPv6 where appropriate.

-6 Use IPv6 for domain resolution and contacting the server on https. Default is to
use IPv4 and IPv6 where appropriate.

-f resolv.conf
Use the given resolv.conf file. Not enabled by default, but you could try to pass
/etc/resolv.conf on some systems. It contains the IP addresses of the recursive
nameservers to use. However, since this tool could be used to bootstrap that very
recursive nameserver, it would not be useful (since that server is not up yet,
since we are bootstrapping it). It could be useful in a situation where you know
an upstream cache is deployed (and running) and in captive portal situations.

-r root.hints
Use the given root.hints file (same syntax as the BIND and Unbound root hints file)
to bootstrap domain resolution. By default a list of builtin root hints is used.
Unbound-anchor goes to the network itself for these roots, to resolve the server
(-u option) and to check the root DNSKEY records. It does so, because the tool
when used for bootstrapping the recursive resolver, cannot use that recursive
resolver itself because it is bootstrapping that server.

-R Allow fallback from -f resolv.conf file to direct root servers query. It allows
you to prefer local resolvers, but fallback automatically to direct root query if
they do not respond or do not support DNSSEC.

-v More verbose. Once prints informational messages, multiple times may enable large
debug amounts (such as full certificates or byte-dumps of downloaded files). By
default it prints almost nothing. It also prints nothing on errors by default; in
that case the original root anchor file is simply left undisturbed, so that a
recursive server can start right after it.

-C unbound.conf
Debug option to read unbound.conf into the resolver process used.

-P port
Set the port number to use for the https connection. The default is 443.

-F Debug option to force update of the root anchor through downloading the xml file
and verifying it with the certificate. By default it first tries to update by
contacting the DNS, which uses much less bandwidth, is much faster (200 msec not 2
sec), and is nicer to the deployed infrastructure. With this option, it still
attempts to do so (and may verbosely tell you), but then ignores the result and
goes on to use the xml fallback method.

-h Show the version and commandline option help.

EXIT CODE

       This  tool  exits  with value 1 if the root anchor was updated using the certificate or if
       the builtin root-anchor was used.  It exits with code 0 if no update was necessary, if the
       update was possible with RFC5011 tracking, or if an error occurred.

       You can check the exit value in this manner:
            unbound-anchor -a "root.key" || logger "Please check root.key"
       Or something more suitable for your operational environment.

TRUST

       The  root  keys  and update certificate included in this tool are provided for convenience
       and under the terms of our license (see the LICENSE file in  the  source  distribution  or
       https://github.com/NLnetLabs/unbound/blob/master/LICENSE)   and  might  be  stale  or  not
       suitable to your purpose.

       By running "unbound-anchor -l" the  keys and certificate that are configured in  the  code
       are printed for your convenience.

       The  build-in  configuration can be overridden by providing a root-cert file and a rootkey
       file.

FILES