Files
coredns/plugin/dnssec/README.md
Miek Gieben 87c9f00c83 readme: more tests (#1184)
* readme: more tests

Add dnssec and file plugin to the test readme. This requires creating a
bunch of files with the right content. Doing so already unconvered an
unconditional type assertion in DNSSEC. This PR will include the fix for
that as well.

Also extended the snippets in the file plugin README, so that they are
whole Corefile - showing more value and checking all corefile snippets.

Create outliner right now is the kubernetes plugin, because even setting
the right env vars will result in:

open /var/run/secrets/kubernetes.io/serviceaccount/token: no such file or directory":

Which we can't create for a test.

* lint
2017-10-31 07:14:49 +00:00

2.6 KiB

dnssec

dnssec enables on-the-fly DNSSEC signing of served data.

Syntax

dnssec [ZONES... ] {
    key file KEY...
    cache_capacity CAPACITY
}

The specified key is used for all signing operations. The DNSSEC signing will treat this key 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 with dnssec-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 as 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
  • 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{type} - total elements in the cache, type is "signature".
  • coredns_dnssec_cache_capacity{type} - total capacity of the cache, type is "signature".
  • coredns_dnssec_cache_hits_total{} - Counter of cache hits.
  • coredns_dnssec_cache_misses_total{} - Counter of cache misses.

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
    }
}

Bugs

Multiple dnssec plugins inside one server stanza will silently overwrite earlier ones, here example.local will overwrite the one for cluster.org.

. {
    kubernetes cluster.local
    dnssec cluster.local {
      key file Kcluster.local+013+45129
    }
    dnssec example.org {
      key file Kexample.org.+013+45330
    }
}