README ¶
dnssec
Name
dnssec - enable on-the-fly DNSSEC signing of served data.
Description
With dnssec any reply that doesn't (or can't) do DNSSEC will get signed on the fly. Authenticated denial of existence is implemented with NSEC black lies. Using ECDSA as an algorithm is preferred as this leads to smaller signatures (compared to RSA). NSEC3 is not supported.
This plugin can only be used once per Server Block.
Syntax
dnssec [ZONES... ] {
key file KEY...
cache_capacity CAPACITY
}
The signing behavior depends on the keys specified. If multiple keys are specified of which there is at least one key with the SEP bit set and at least one key with the SEP bit unset, signing will happen in split ZSK/KSK mode. DNSKEY records will be signed with all keys that have the SEP bit set. All other records will be signed with all keys that do not have the SEP bit set.
In any other case, each specified key will be treated as a CSK (common signing key), forgoing the ZSK/KSK split. All signing operations are done online. Authenticated denial of existence is implemented with NSEC black lies. Using ECDSA as an algorithm is preferred as this leads to smaller signatures (compared to RSA). NSEC3 is not supported.
If multiple dnssec plugins are specified in the same zone, the last one specified will be used (See bugs).
-
ZONES zones that should be signed. If empty, the zones from the configuration block are used.
-
key file
indicates that KEY file(s) should be read from disk. When multiple keys are specified, RRsets will be signed with all keys. Generating a key can be done withdnssec-keygen
:dnssec-keygen -a ECDSAP256SHA256 <zonename>
. A key created for zone A can be safely used for zone B. The name of the key file can be specified in one of the following formats- basename of the generated key
Kexample.org+013+45330
- generated public key
Kexample.org+013+45330.key
- generated private key
Kexample.org+013+45330.private
- basename of the generated key
-
cache_capacity
indicates the capacity of the cache. The dnssec plugin uses a cache to store RRSIGs. The default for CAPACITY is 10000.
Metrics
If monitoring is enabled (via the prometheus directive) then the following metrics are exported:
coredns_dnssec_cache_size{server, type}
- total elements in the cache, type is "signature".coredns_dnssec_cache_hits_total{server}
- Counter of cache hits.coredns_dnssec_cache_misses_total{server}
- Counter of cache misses.
The label server
indicated the server handling the request, see the metrics plugin for details.
Examples
Sign responses for example.org
with the key "Kexample.org.+013+45330.key".
example.org {
dnssec {
key file Kexample.org.+013+45330
}
whoami
}
Sign responses for a kubernetes zone with the key "Kcluster.local+013+45129.key".
cluster.local {
kubernetes
dnssec {
key file Kcluster.local+013+45129
}
}
Documentation ¶
Overview ¶
Package dnssec implements a plugin that signs responses on-the-fly using NSEC black lies.
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type DNSKEY ¶
DNSKEY holds a DNSSEC public and private key used for on-the-fly signing.
func ParseKeyFile ¶
ParseKeyFile read a DNSSEC keyfile as generated by dnssec-keygen or other utilities. It adds ".key" for the public key and ".private" for the private key.
type Dnssec ¶
Dnssec signs the reply on-the-fly.
func New ¶
func New(zones []string, keys []*DNSKEY, splitkeys bool, next plugin.Handler, c *cache.Cache) Dnssec
New returns a new Dnssec.
func (Dnssec) Sign ¶
Sign signs the message in state. it takes care of negative or nodata responses. It uses NSEC black lies for authenticated denial of existence. For delegations it will insert DS records and sign those. Signatures will be cached for a short while. By default we sign for 8 days, starting 3 hours ago.
type ResponseWriter ¶
type ResponseWriter struct { dns.ResponseWriter // contains filtered or unexported fields }
ResponseWriter sign the response on the fly.