@nictool/dns-resource-record

v1.2.2

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5 days ago

DNS Resource Records

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tnpi

DNS resource record validator validation import export BIND djbdns tinydns nictool

dns-resource-record

DNS resource record parser, validator, importer, and exporter.

SYNOPSIS

This module is used to:

validate well formedness and RFC compliance of DNS resource records
import RRs to and from the following formats:

This package intends to import and export RFC compliant DNS resource records. Please raise an issue if a valid resource record fails to pass or an invalid resource record passes.

This package is for working with individual Resource Records. For working with zones of RRs, use dns-zone.

USAGE

Load the index for access to all RR types:

import * as RR from '@nictool/dns-resource-record'

EXAMPLES

const exampleRRs = {
    A: {
        owner  : 'test.example.com.',
        type   : 'A',
        address: '192.0.2.127',
        ttl    : 3600,
    },
    AAAA: {
        owner  : 'test.example.com.',
        type   : 'AAAA',
        address: '2605:7900:20:a::4',
        ttl    : 3600,
    },
    SOA: {
        owner  : 'example.com.',
        type   : 'SOA',
        mname  : 'matt.example.com.',
        rname  : 'ns1.example.com.',
        serial : 1,
        refresh: 7200,
        retry  : 3600,
        expire : 1209600,
        minimum: 3600,
        ttl    : 3600,
    }
}
try {
    console.log(new RR.SOA(exampleRRs.SOA))
    SOA(11) [Map] {
        'owner' => 'example.com.',
        'ttl' => 3600,
        'class' => 'IN',
        'type' => 'SOA',
        'mname' => 'matt.example.com.',
        'rname' => 'ns1.example.com.',
        'serial' => 1,
        'refresh' => 7200,
        'retry' => 3600,
        'expire' => 1209600,
        'minimum' => 3600
    }
}
catch (e) {
    console.error(e.message) // invalid RRs throw
}

Validate records by passing a properly formatted JS object to the record-specific class. To validate an A record:

const validatedA = new RR.A(exampleRRs.A)

Manipulate the validated record using pattern named setters:

console.log(validatedA.toBind())
test.example.com.    3600    IN  A   192.0.2.127

validatedA.setAddress('192.0.2.128')
console.log(validatedA.toBind())
test.example.com.    3600    IN  A   192.0.2.128

The setters are named: set + Field, where field is the resource record field name to modify. Multi-word names are camel cased, so a field named Certificate Usage has a setter named setCertificateUsage. The RFCs aren't always consistent regarding RR field names so aliases are permissible for interoperability.

FUNCTIONS

Get the field names for each RR type with getFields():

> import * as RR from 'dns-resource-record'
> new RR.A(null).getFields()
[ 'owner', 'ttl', 'class', 'type', 'address' ]

> new RR.PTR(null).getFields()
[ 'owner', 'ttl', 'class', 'type', 'dname' ]

> new RR.SSHFP(null).getFields()
[ 'owner', 'ttl', 'class', 'type', 'algorithm', 'fptype', 'fingerprint' ]

Get a list of RFCs for references about each RR type:

> new RR.A(null).getRFCs()
[ 1035 ]

> new RR.SRV(null).getRFCs()
[ 2782 ]

> new RR.MX(null).getRFCs()
[ 1035, 2181, 7505 ]

toBind

Validate a record and export to BIND format.

console.log(new RR.A(exampleRRs.A).toBind())
test.example.com    3600    IN  A   192.0.2.127

console.log(new RR.AAAA(exampleRRs.AAAA).toBind())
test.example.com    3600    IN  AAAA    2605:7900:20:a::4

toTinydns

Validate a record and export to tinydns format:

console.log(new RR.A(exampleRRs.A).toTinydns())
+test.example.com:192.0.2.127:3600::

fromTinydns toBind

Convert a tinydns line to BIND:

console.log(new RR.CAA({
  tinyline: ':ns1.example.com:257:\\000\\005issue"http\\072\\057\\057letsencrypt.org":3600::\n'
}).toBind())
ns1.example.com 3600    IN  CAA 0   issue   "http://letsencrypt.org"

set

The DNS validation checks can be bypassed entirely by using 'set':

> validatedA.set('address', 'oops')
A(5) [Map] {
  'owner' => 'test.example.com',
  'ttl' => 3600,
  'class' => 'IN',
  'type' => 'A',
  'address' => 'oops'
}

Consider this a "running with scissors" mode.

Supported Records

This module intends to include support for all current (ie, not officially deprecated) DNS RRs and all RRs that are in active use on the internet.

PRs are welcome, especially PRs with tests.

TIPS

Domain owner names are:
- stored fully qualified, aka absolute.
- normalized to lower case, because:
  - DNS is case insensitive (see RFCs 4343, 1035, 1034)
  - this library enforces duplicate suppression
  - DNSSEC canonicalization (see RFC 4034)
  - wire format for most RRs require it
- Master Zone File expansions exist in dns-zone
to{Bind|MaraDNS} output can be influenced (suppress TTL, class, relative domain names) with an options object. See it in bin/dns-zone in the dns-zone package.

TODO

[x] Change all IPs to use RFC example/doc address space
[x] change all domains to use reserved doc names
[x] import tests from nictool/server/t/12_records.t
[x] add defaults for empty values like TTL
[x] DNSSEC RRs: DS, NSEC, NSEC3, NSEC3PARAM, RRSIG
[x] CERT RRs: CERT, KEY, SIG, OPENPGPKEY
[x] RFC 4034: if the type of RR is NS, MD, MF, CNAME, SOA, MB, MG, MR, PTR, HINFO, MINFO, MX, RP, AFSDB, RT, SIG, PX, NXT, NAPTR, KX, SRV, DNAME, A6, RRSIG, or NSEC, all uppercase letters in the DNS names contained within the RDATA are replaced by the lowercase letters;
[x] LOC record ingest/out isn't consistent with API
[ ] export a web page for each RR type

DEVELOP

There are no dependencies. That's no accident.
ES modules for use by node.js and browser
Platform independence is a goal
- [x] CI tests are on linux, windows, and macos

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