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'use strict'
const Buffer = require('buffer').Buffer
const types = require('./types')
const rcodes = require('./rcodes')
const opcodes = require('./opcodes')
const classes = require('./classes')
const optioncodes = require('./optioncodes')
const ip = require('@leichtgewicht/ip-codec')
const QUERY_FLAG = 0
const RESPONSE_FLAG = 1 << 15
const FLUSH_MASK = 1 << 15
const NOT_FLUSH_MASK = ~FLUSH_MASK
const QU_MASK = 1 << 15
const NOT_QU_MASK = ~QU_MASK
const name = exports.name = {}
name.encode = function (str, buf, offset) {
if (!buf) buf = Buffer.alloc(name.encodingLength(str))
if (!offset) offset = 0
const oldOffset = offset
// strip leading and trailing .
const n = str.replace(/^\.|\.$/gm, '')
if (n.length) {
const list = n.split('.')
for (let i = 0; i < list.length; i++) {
const len = buf.write(list[i], offset + 1)
buf[offset] = len
offset += len + 1
}
}
buf[offset++] = 0
name.encode.bytes = offset - oldOffset
return buf
}
name.encode.bytes = 0
name.decode = function (buf, offset) {
if (!offset) offset = 0
const list = []
let oldOffset = offset
let totalLength = 0
let consumedBytes = 0
let jumped = false
while (true) {
if (offset >= buf.length) {
throw new Error('Cannot decode name (buffer overflow)')
}
const len = buf[offset++]
consumedBytes += jumped ? 0 : 1
if (len === 0) {
break
} else if ((len & 0xc0) === 0) {
if (offset + len > buf.length) {
throw new Error('Cannot decode name (buffer overflow)')
}
totalLength += len + 1
if (totalLength > 254) {
throw new Error('Cannot decode name (name too long)')
}
list.push(buf.toString('utf-8', offset, offset + len))
offset += len
consumedBytes += jumped ? 0 : len
} else if ((len & 0xc0) === 0xc0) {
if (offset + 1 > buf.length) {
throw new Error('Cannot decode name (buffer overflow)')
}
const jumpOffset = buf.readUInt16BE(offset - 1) - 0xc000
if (jumpOffset >= oldOffset) {
// Allow only pointers to prior data. RFC 1035, section 4.1.4 states:
// "[...] an entire domain name or a list of labels at the end of a domain name
// is replaced with a pointer to a prior occurance (sic) of the same name."
throw new Error('Cannot decode name (bad pointer)')
}
offset = jumpOffset
oldOffset = jumpOffset
consumedBytes += jumped ? 0 : 1
jumped = true
} else {
throw new Error('Cannot decode name (bad label)')
}
}
name.decode.bytes = consumedBytes
return list.length === 0 ? '.' : list.join('.')
}
name.decode.bytes = 0
name.encodingLength = function (n) {
if (n === '.' || n === '..') return 1
return Buffer.byteLength(n.replace(/^\.|\.$/gm, '')) + 2
}
const string = {}
string.encode = function (s, buf, offset) {
if (!buf) buf = Buffer.alloc(string.encodingLength(s))
if (!offset) offset = 0
const len = buf.write(s, offset + 1)
buf[offset] = len
string.encode.bytes = len + 1
return buf
}
string.encode.bytes = 0
string.decode = function (buf, offset) {
if (!offset) offset = 0
const len = buf[offset]
const s = buf.toString('utf-8', offset + 1, offset + 1 + len)
string.decode.bytes = len + 1
return s
}
string.decode.bytes = 0
string.encodingLength = function (s) {
return Buffer.byteLength(s) + 1
}
const header = {}
header.encode = function (h, buf, offset) {
if (!buf) buf = header.encodingLength(h)
if (!offset) offset = 0
const flags = (h.flags || 0) & 32767
const type = h.type === 'response' ? RESPONSE_FLAG : QUERY_FLAG
buf.writeUInt16BE(h.id || 0, offset)
buf.writeUInt16BE(flags | type, offset + 2)
buf.writeUInt16BE(h.questions.length, offset + 4)
buf.writeUInt16BE(h.answers.length, offset + 6)
buf.writeUInt16BE(h.authorities.length, offset + 8)
buf.writeUInt16BE(h.additionals.length, offset + 10)
return buf
}
header.encode.bytes = 12
header.decode = function (buf, offset) {
if (!offset) offset = 0
if (buf.length < 12) throw new Error('Header must be 12 bytes')
const flags = buf.readUInt16BE(offset + 2)
return {
id: buf.readUInt16BE(offset),
type: flags & RESPONSE_FLAG ? 'response' : 'query',
flags: flags & 32767,
flag_qr: ((flags >> 15) & 0x1) === 1,
opcode: opcodes.toString((flags >> 11) & 0xf),
flag_aa: ((flags >> 10) & 0x1) === 1,
flag_tc: ((flags >> 9) & 0x1) === 1,
flag_rd: ((flags >> 8) & 0x1) === 1,
flag_ra: ((flags >> 7) & 0x1) === 1,
flag_z: ((flags >> 6) & 0x1) === 1,
flag_ad: ((flags >> 5) & 0x1) === 1,
flag_cd: ((flags >> 4) & 0x1) === 1,
rcode: rcodes.toString(flags & 0xf),
questions: new Array(buf.readUInt16BE(offset + 4)),
answers: new Array(buf.readUInt16BE(offset + 6)),
authorities: new Array(buf.readUInt16BE(offset + 8)),
additionals: new Array(buf.readUInt16BE(offset + 10))
}
}
header.decode.bytes = 12
header.encodingLength = function () {
return 12
}
const runknown = exports.unknown = {}
runknown.encode = function (data, buf, offset) {
if (!buf) buf = Buffer.alloc(runknown.encodingLength(data))
if (!offset) offset = 0
buf.writeUInt16BE(data.length, offset)
data.copy(buf, offset + 2)
runknown.encode.bytes = data.length + 2
return buf
}
runknown.encode.bytes = 0
runknown.decode = function (buf, offset) {
if (!offset) offset = 0
const len = buf.readUInt16BE(offset)
const data = buf.slice(offset + 2, offset + 2 + len)
runknown.decode.bytes = len + 2
return data
}
runknown.decode.bytes = 0
runknown.encodingLength = function (data) {
return data.length + 2
}
const rns = exports.ns = {}
rns.encode = function (data, buf, offset) {
if (!buf) buf = Buffer.alloc(rns.encodingLength(data))
if (!offset) offset = 0
name.encode(data, buf, offset + 2)
buf.writeUInt16BE(name.encode.bytes, offset)
rns.encode.bytes = name.encode.bytes + 2
return buf
}
rns.encode.bytes = 0
rns.decode = function (buf, offset) {
if (!offset) offset = 0
const len = buf.readUInt16BE(offset)
const dd = name.decode(buf, offset + 2)
rns.decode.bytes = len + 2
return dd
}
rns.decode.bytes = 0
rns.encodingLength = function (data) {
return name.encodingLength(data) + 2
}
const rsoa = exports.soa = {}
rsoa.encode = function (data, buf, offset) {
if (!buf) buf = Buffer.alloc(rsoa.encodingLength(data))
if (!offset) offset = 0
const oldOffset = offset
offset += 2
name.encode(data.mname, buf, offset)
offset += name.encode.bytes
name.encode(data.rname, buf, offset)
offset += name.encode.bytes
buf.writeUInt32BE(data.serial || 0, offset)
offset += 4
buf.writeUInt32BE(data.refresh || 0, offset)
offset += 4
buf.writeUInt32BE(data.retry || 0, offset)
offset += 4
buf.writeUInt32BE(data.expire || 0, offset)
offset += 4
buf.writeUInt32BE(data.minimum || 0, offset)
offset += 4
buf.writeUInt16BE(offset - oldOffset - 2, oldOffset)
rsoa.encode.bytes = offset - oldOffset
return buf
}
rsoa.encode.bytes = 0
rsoa.decode = function (buf, offset) {
if (!offset) offset = 0
const oldOffset = offset
const data = {}
offset += 2
data.mname = name.decode(buf, offset)
offset += name.decode.bytes
data.rname = name.decode(buf, offset)
offset += name.decode.bytes
data.serial = buf.readUInt32BE(offset)
offset += 4
data.refresh = buf.readUInt32BE(offset)
offset += 4
data.retry = buf.readUInt32BE(offset)
offset += 4
data.expire = buf.readUInt32BE(offset)
offset += 4
data.minimum = buf.readUInt32BE(offset)
offset += 4
rsoa.decode.bytes = offset - oldOffset
return data
}
rsoa.decode.bytes = 0
rsoa.encodingLength = function (data) {
return 22 + name.encodingLength(data.mname) + name.encodingLength(data.rname)
}
const rtxt = exports.txt = {}
rtxt.encode = function (data, buf, offset) {
if (!Array.isArray(data)) data = [data]
for (let i = 0; i < data.length; i++) {
if (typeof data[i] === 'string') {
data[i] = Buffer.from(data[i])
}
if (!Buffer.isBuffer(data[i])) {
throw new Error('Must be a Buffer')
}
}
if (!buf) buf = Buffer.alloc(rtxt.encodingLength(data))
if (!offset) offset = 0
const oldOffset = offset
offset += 2
data.forEach(function (d) {
buf[offset++] = d.length
d.copy(buf, offset, 0, d.length)
offset += d.length
})
buf.writeUInt16BE(offset - oldOffset - 2, oldOffset)
rtxt.encode.bytes = offset - oldOffset
return buf
}
rtxt.encode.bytes = 0
rtxt.decode = function (buf, offset) {
if (!offset) offset = 0
const oldOffset = offset
let remaining = buf.readUInt16BE(offset)
offset += 2
let data = []
while (remaining > 0) {
const len = buf[offset++]
--remaining
if (remaining < len) {
throw new Error('Buffer overflow')
}
data.push(buf.slice(offset, offset + len))
offset += len
remaining -= len
}
rtxt.decode.bytes = offset - oldOffset
return data
}
rtxt.decode.bytes = 0
rtxt.encodingLength = function (data) {
if (!Array.isArray(data)) data = [data]
let length = 2
data.forEach(function (buf) {
if (typeof buf === 'string') {
length += Buffer.byteLength(buf) + 1
} else {
length += buf.length + 1
}
})
return length
}
const rnull = exports.null = {}
rnull.encode = function (data, buf, offset) {
if (!buf) buf = Buffer.alloc(rnull.encodingLength(data))
if (!offset) offset = 0
if (typeof data === 'string') data = Buffer.from(data)
if (!data) data = Buffer.alloc(0)
const oldOffset = offset
offset += 2
const len = data.length
data.copy(buf, offset, 0, len)
offset += len
buf.writeUInt16BE(offset - oldOffset - 2, oldOffset)
rnull.encode.bytes = offset - oldOffset
return buf
}
rnull.encode.bytes = 0
rnull.decode = function (buf, offset) {
if (!offset) offset = 0
const oldOffset = offset
const len = buf.readUInt16BE(offset)
offset += 2
const data = buf.slice(offset, offset + len)
offset += len
rnull.decode.bytes = offset - oldOffset
return data
}
rnull.decode.bytes = 0
rnull.encodingLength = function (data) {
if (!data) return 2
return (Buffer.isBuffer(data) ? data.length : Buffer.byteLength(data)) + 2
}
const rhinfo = exports.hinfo = {}
rhinfo.encode = function (data, buf, offset) {
if (!buf) buf = Buffer.alloc(rhinfo.encodingLength(data))
if (!offset) offset = 0
const oldOffset = offset
offset += 2
string.encode(data.cpu, buf, offset)
offset += string.encode.bytes
string.encode(data.os, buf, offset)
offset += string.encode.bytes
buf.writeUInt16BE(offset - oldOffset - 2, oldOffset)
rhinfo.encode.bytes = offset - oldOffset
return buf
}
rhinfo.encode.bytes = 0
rhinfo.decode = function (buf, offset) {
if (!offset) offset = 0
const oldOffset = offset
const data = {}
offset += 2
data.cpu = string.decode(buf, offset)
offset += string.decode.bytes
data.os = string.decode(buf, offset)
offset += string.decode.bytes
rhinfo.decode.bytes = offset - oldOffset
return data
}
rhinfo.decode.bytes = 0
rhinfo.encodingLength = function (data) {
return string.encodingLength(data.cpu) + string.encodingLength(data.os) + 2
}
const rptr = exports.ptr = {}
const rcname = exports.cname = rptr
const rdname = exports.dname = rptr
rptr.encode = function (data, buf, offset) {
if (!buf) buf = Buffer.alloc(rptr.encodingLength(data))
if (!offset) offset = 0
name.encode(data, buf, offset + 2)
buf.writeUInt16BE(name.encode.bytes, offset)
rptr.encode.bytes = name.encode.bytes + 2
return buf
}
rptr.encode.bytes = 0
rptr.decode = function (buf, offset) {
if (!offset) offset = 0
const data = name.decode(buf, offset + 2)
rptr.decode.bytes = name.decode.bytes + 2
return data
}
rptr.decode.bytes = 0
rptr.encodingLength = function (data) {
return name.encodingLength(data) + 2
}
const rsrv = exports.srv = {}
rsrv.encode = function (data, buf, offset) {
if (!buf) buf = Buffer.alloc(rsrv.encodingLength(data))
if (!offset) offset = 0
buf.writeUInt16BE(data.priority || 0, offset + 2)
buf.writeUInt16BE(data.weight || 0, offset + 4)
buf.writeUInt16BE(data.port || 0, offset + 6)
name.encode(data.target, buf, offset + 8)
const len = name.encode.bytes + 6
buf.writeUInt16BE(len, offset)
rsrv.encode.bytes = len + 2
return buf
}
rsrv.encode.bytes = 0
rsrv.decode = function (buf, offset) {
if (!offset) offset = 0
const len = buf.readUInt16BE(offset)
const data = {}
data.priority = buf.readUInt16BE(offset + 2)
data.weight = buf.readUInt16BE(offset + 4)
data.port = buf.readUInt16BE(offset + 6)
data.target = name.decode(buf, offset + 8)
rsrv.decode.bytes = len + 2
return data
}
rsrv.decode.bytes = 0
rsrv.encodingLength = function (data) {
return 8 + name.encodingLength(data.target)
}
const rcaa = exports.caa = {}
rcaa.ISSUER_CRITICAL = 1 << 7
rcaa.encode = function (data, buf, offset) {
const len = rcaa.encodingLength(data)
if (!buf) buf = Buffer.alloc(rcaa.encodingLength(data))
if (!offset) offset = 0
if (data.issuerCritical) {
data.flags = rcaa.ISSUER_CRITICAL
}
buf.writeUInt16BE(len - 2, offset)
offset += 2
buf.writeUInt8(data.flags || 0, offset)
offset += 1
string.encode(data.tag, buf, offset)
offset += string.encode.bytes
buf.write(data.value, offset)
offset += Buffer.byteLength(data.value)
rcaa.encode.bytes = len
return buf
}
rcaa.encode.bytes = 0
rcaa.decode = function (buf, offset) {
if (!offset) offset = 0
const len = buf.readUInt16BE(offset)
offset += 2
const oldOffset = offset
const data = {}
data.flags = buf.readUInt8(offset)
offset += 1
data.tag = string.decode(buf, offset)
offset += string.decode.bytes
data.value = buf.toString('utf-8', offset, oldOffset + len)
data.issuerCritical = !!(data.flags & rcaa.ISSUER_CRITICAL)
rcaa.decode.bytes = len + 2
return data
}
rcaa.decode.bytes = 0
rcaa.encodingLength = function (data) {
return string.encodingLength(data.tag) + string.encodingLength(data.value) + 2
}
const rmx = exports.mx = {}
rmx.encode = function (data, buf, offset) {
if (!buf) buf = Buffer.alloc(rmx.encodingLength(data))
if (!offset) offset = 0
const oldOffset = offset
offset += 2
buf.writeUInt16BE(data.preference || 0, offset)
offset += 2
name.encode(data.exchange, buf, offset)
offset += name.encode.bytes
buf.writeUInt16BE(offset - oldOffset - 2, oldOffset)
rmx.encode.bytes = offset - oldOffset
return buf
}
rmx.encode.bytes = 0
rmx.decode = function (buf, offset) {
if (!offset) offset = 0
const oldOffset = offset
const data = {}
offset += 2
data.preference = buf.readUInt16BE(offset)
offset += 2
data.exchange = name.decode(buf, offset)
offset += name.decode.bytes
rmx.decode.bytes = offset - oldOffset
return data
}
rmx.encodingLength = function (data) {
return 4 + name.encodingLength(data.exchange)
}
const ra = exports.a = {}
ra.encode = function (host, buf, offset) {
if (!buf) buf = Buffer.alloc(ra.encodingLength(host))
if (!offset) offset = 0
buf.writeUInt16BE(4, offset)
offset += 2
ip.v4.encode(host, buf, offset)
ra.encode.bytes = 6
return buf
}
ra.encode.bytes = 0
ra.decode = function (buf, offset) {
if (!offset) offset = 0
offset += 2
const host = ip.v4.decode(buf, offset)
ra.decode.bytes = 6
return host
}
ra.decode.bytes = 0
ra.encodingLength = function () {
return 6
}
const raaaa = exports.aaaa = {}
raaaa.encode = function (host, buf, offset) {
if (!buf) buf = Buffer.alloc(raaaa.encodingLength(host))
if (!offset) offset = 0
buf.writeUInt16BE(16, offset)
offset += 2
ip.v6.encode(host, buf, offset)
raaaa.encode.bytes = 18
return buf
}
raaaa.encode.bytes = 0
raaaa.decode = function (buf, offset) {
if (!offset) offset = 0
offset += 2
const host = ip.v6.decode(buf, offset)
raaaa.decode.bytes = 18
return host
}
raaaa.decode.bytes = 0
raaaa.encodingLength = function () {
return 18
}
const roption = exports.option = {}
roption.encode = function (option, buf, offset) {
if (!buf) buf = Buffer.alloc(roption.encodingLength(option))
if (!offset) offset = 0
const oldOffset = offset
const code = optioncodes.toCode(option.code)
buf.writeUInt16BE(code, offset)
offset += 2
if (option.data) {
buf.writeUInt16BE(option.data.length, offset)
offset += 2
option.data.copy(buf, offset)
offset += option.data.length
} else {
switch (code) {
// case 3: NSID. No encode makes sense.
// case 5,6,7: Not implementable
case 8: // ECS
// note: do IP math before calling
const spl = option.sourcePrefixLength || 0
const fam = option.family || ip.familyOf(option.ip)
const ipBuf = ip.encode(option.ip, Buffer.alloc)
const ipLen = Math.ceil(spl / 8)
buf.writeUInt16BE(ipLen + 4, offset)
offset += 2
buf.writeUInt16BE(fam, offset)
offset += 2
buf.writeUInt8(spl, offset++)
buf.writeUInt8(option.scopePrefixLength || 0, offset++)
ipBuf.copy(buf, offset, 0, ipLen)
offset += ipLen
break
// case 9: EXPIRE (experimental)
// case 10: COOKIE. No encode makes sense.
case 11: // KEEP-ALIVE
if (option.timeout) {
buf.writeUInt16BE(2, offset)
offset += 2
buf.writeUInt16BE(option.timeout, offset)
offset += 2
} else {
buf.writeUInt16BE(0, offset)
offset += 2
}
break
case 12: // PADDING
const len = option.length || 0
buf.writeUInt16BE(len, offset)
offset += 2
buf.fill(0, offset, offset + len)
offset += len
break
// case 13: CHAIN. Experimental.
case 14: // KEY-TAG
const tagsLen = option.tags.length * 2
buf.writeUInt16BE(tagsLen, offset)
offset += 2
for (const tag of option.tags) {
buf.writeUInt16BE(tag, offset)
offset += 2
}
break
default:
throw new Error(`Unknown roption code: ${option.code}`)
}
}
roption.encode.bytes = offset - oldOffset
return buf
}
roption.encode.bytes = 0
roption.decode = function (buf, offset) {
if (!offset) offset = 0
const option = {}
option.code = buf.readUInt16BE(offset)
option.type = optioncodes.toString(option.code)
offset += 2
const len = buf.readUInt16BE(offset)
offset += 2
option.data = buf.slice(offset, offset + len)
switch (option.code) {
// case 3: NSID. No decode makes sense.
case 8: // ECS
option.family = buf.readUInt16BE(offset)
offset += 2
option.sourcePrefixLength = buf.readUInt8(offset++)
option.scopePrefixLength = buf.readUInt8(offset++)
const padded = Buffer.alloc((option.family === 1) ? 4 : 16)
buf.copy(padded, 0, offset, offset + len - 4)
option.ip = ip.decode(padded)
break
// case 12: Padding. No decode makes sense.
case 11: // KEEP-ALIVE
if (len > 0) {
option.timeout = buf.readUInt16BE(offset)
offset += 2
}
break
case 14:
option.tags = []
for (let i = 0; i < len; i += 2) {
option.tags.push(buf.readUInt16BE(offset))
offset += 2
}
// don't worry about default. caller will use data if desired
}
roption.decode.bytes = len + 4
return option
}
roption.decode.bytes = 0
roption.encodingLength = function (option) {
if (option.data) {
return option.data.length + 4
}
const code = optioncodes.toCode(option.code)
switch (code) {
case 8: // ECS
const spl = option.sourcePrefixLength || 0
return Math.ceil(spl / 8) + 8
case 11: // KEEP-ALIVE
return (typeof option.timeout === 'number') ? 6 : 4
case 12: // PADDING
return option.length + 4
case 14: // KEY-TAG
return 4 + (option.tags.length * 2)
}
throw new Error(`Unknown roption code: ${option.code}`)
}
const ropt = exports.opt = {}
ropt.encode = function (options, buf, offset) {
if (!buf) buf = Buffer.alloc(ropt.encodingLength(options))
if (!offset) offset = 0
const oldOffset = offset
const rdlen = encodingLengthList(options, roption)
buf.writeUInt16BE(rdlen, offset)
offset = encodeList(options, roption, buf, offset + 2)
ropt.encode.bytes = offset - oldOffset
return buf
}
ropt.encode.bytes = 0
ropt.decode = function (buf, offset) {
if (!offset) offset = 0
const oldOffset = offset
const options = []
let rdlen = buf.readUInt16BE(offset)
offset += 2
let o = 0
while (rdlen > 0) {
options[o++] = roption.decode(buf, offset)
offset += roption.decode.bytes
rdlen -= roption.decode.bytes
}
ropt.decode.bytes = offset - oldOffset
return options
}
ropt.decode.bytes = 0
ropt.encodingLength = function (options) {
return 2 + encodingLengthList(options || [], roption)
}
const rdnskey = exports.dnskey = {}
rdnskey.PROTOCOL_DNSSEC = 3
rdnskey.ZONE_KEY = 0x80
rdnskey.SECURE_ENTRYPOINT = 0x8000
rdnskey.encode = function (key, buf, offset) {
if (!buf) buf = Buffer.alloc(rdnskey.encodingLength(key))
if (!offset) offset = 0
const oldOffset = offset
const keydata = key.key
if (!Buffer.isBuffer(keydata)) {
throw new Error('Key must be a Buffer')
}
offset += 2 // Leave space for length
buf.writeUInt16BE(key.flags, offset)
offset += 2
buf.writeUInt8(rdnskey.PROTOCOL_DNSSEC, offset)
offset += 1
buf.writeUInt8(key.algorithm, offset)
offset += 1
keydata.copy(buf, offset, 0, keydata.length)
offset += keydata.length
rdnskey.encode.bytes = offset - oldOffset
buf.writeUInt16BE(rdnskey.encode.bytes - 2, oldOffset)
return buf
}
rdnskey.encode.bytes = 0
rdnskey.decode = function (buf, offset) {
if (!offset) offset = 0
const oldOffset = offset
var key = {}
var length = buf.readUInt16BE(offset)
offset += 2
key.flags = buf.readUInt16BE(offset)
offset += 2
if (buf.readUInt8(offset) !== rdnskey.PROTOCOL_DNSSEC) {
throw new Error('Protocol must be 3')
}
offset += 1
key.algorithm = buf.readUInt8(offset)
offset += 1
key.key = buf.slice(offset, oldOffset + length + 2)
offset += key.key.length
rdnskey.decode.bytes = offset - oldOffset
return key
}
rdnskey.decode.bytes = 0
rdnskey.encodingLength = function (key) {
return 6 + Buffer.byteLength(key.key)
}
const rrrsig = exports.rrsig = {}
rrrsig.encode = function (sig, buf, offset) {
if (!buf) buf = Buffer.alloc(rrrsig.encodingLength(sig))
if (!offset) offset = 0
const oldOffset = offset
const signature = sig.signature
if (!Buffer.isBuffer(signature)) {
throw new Error('Signature must be a Buffer')
}
offset += 2 // Leave space for length
buf.writeUInt16BE(types.toType(sig.typeCovered), offset)
offset += 2
buf.writeUInt8(sig.algorithm, offset)
offset += 1
buf.writeUInt8(sig.labels, offset)
offset += 1
buf.writeUInt32BE(sig.originalTTL, offset)
offset += 4
buf.writeUInt32BE(sig.expiration, offset)
offset += 4
buf.writeUInt32BE(sig.inception, offset)
offset += 4
buf.writeUInt16BE(sig.keyTag, offset)
offset += 2
name.encode(sig.signersName, buf, offset)
offset += name.encode.bytes
signature.copy(buf, offset, 0, signature.length)
offset += signature.length
rrrsig.encode.bytes = offset - oldOffset
buf.writeUInt16BE(rrrsig.encode.bytes - 2, oldOffset)
return buf
}
rrrsig.encode.bytes = 0
rrrsig.decode = function (buf, offset) {
if (!offset) offset = 0
const oldOffset = offset
var sig = {}
var length = buf.readUInt16BE(offset)
offset += 2
sig.typeCovered = types.toString(buf.readUInt16BE(offset))
offset += 2
sig.algorithm = buf.readUInt8(offset)
offset += 1
sig.labels = buf.readUInt8(offset)
offset += 1
sig.originalTTL = buf.readUInt32BE(offset)
offset += 4
sig.expiration = buf.readUInt32BE(offset)
offset += 4
sig.inception = buf.readUInt32BE(offset)
offset += 4
sig.keyTag = buf.readUInt16BE(offset)
offset += 2
sig.signersName = name.decode(buf, offset)
offset += name.decode.bytes
sig.signature = buf.slice(offset, oldOffset + length + 2)
offset += sig.signature.length
rrrsig.decode.bytes = offset - oldOffset
return sig
}
rrrsig.decode.bytes = 0
rrrsig.encodingLength = function (sig) {
return 20 +
name.encodingLength(sig.signersName) +
Buffer.byteLength(sig.signature)
}
const rrp = exports.rp = {}
rrp.encode = function (data, buf, offset) {
if (!buf) buf = Buffer.alloc(rrp.encodingLength(data))
if (!offset) offset = 0
const oldOffset = offset
offset += 2 // Leave space for length
name.encode(data.mbox || '.', buf, offset)
offset += name.encode.bytes
name.encode(data.txt || '.', buf, offset)
offset += name.encode.bytes
rrp.encode.bytes = offset - oldOffset
buf.writeUInt16BE(rrp.encode.bytes - 2, oldOffset)
return buf
}
rrp.encode.bytes = 0
rrp.decode = function (buf, offset) {
if (!offset) offset = 0
const oldOffset = offset
const data = {}
offset += 2
data.mbox = name.decode(buf, offset) || '.'
offset += name.decode.bytes
data.txt = name.decode(buf, offset) || '.'
offset += name.decode.bytes
rrp.decode.bytes = offset - oldOffset
return data
}
rrp.decode.bytes = 0
rrp.encodingLength = function (data) {
return 2 + name.encodingLength(data.mbox || '.') + name.encodingLength(data.txt || '.')
}
const typebitmap = {}
typebitmap.encode = function (typelist, buf, offset) {
if (!buf) buf = Buffer.alloc(typebitmap.encodingLength(typelist))
if (!offset) offset = 0
const oldOffset = offset
var typesByWindow = []
for (var i = 0; i < typelist.length; i++) {
var typeid = types.toType(typelist[i])
if (typesByWindow[typeid >> 8] === undefined) {
typesByWindow[typeid >> 8] = []
}
typesByWindow[typeid >> 8][(typeid >> 3) & 0x1F] |= 1 << (7 - (typeid & 0x7))
}
for (i = 0; i < typesByWindow.length; i++) {
if (typesByWindow[i] !== undefined) {
var windowBuf = Buffer.from(typesByWindow[i])
buf.writeUInt8(i, offset)
offset += 1
buf.writeUInt8(windowBuf.length, offset)
offset += 1
windowBuf.copy(buf, offset)
offset += windowBuf.length
}
}
typebitmap.encode.bytes = offset - oldOffset
return buf
}
typebitmap.encode.bytes = 0
typebitmap.decode = function (buf, offset, length) {
if (!offset) offset = 0
const oldOffset = offset
var typelist = []
while (offset - oldOffset < length) {
var window = buf.readUInt8(offset)
offset += 1
var windowLength = buf.readUInt8(offset)
offset += 1
for (var i = 0; i < windowLength; i++) {
var b = buf.readUInt8(offset + i)
for (var j = 0; j < 8; j++) {
if (b & (1 << (7 - j))) {
var typeid = types.toString((window << 8) | (i << 3) | j)
typelist.push(typeid)
}
}
}
offset += windowLength
}
typebitmap.decode.bytes = offset - oldOffset
return typelist
}
typebitmap.decode.bytes = 0
typebitmap.encodingLength = function (typelist) {
var extents = []
for (var i = 0; i < typelist.length; i++) {
var typeid = types.toType(typelist[i])
extents[typeid >> 8] = Math.max(extents[typeid >> 8] || 0, typeid & 0xFF)
}
var len = 0
for (i = 0; i < extents.length; i++) {
if (extents[i] !== undefined) {
len += 2 + Math.ceil((extents[i] + 1) / 8)
}
}
return len
}
const rnsec = exports.nsec = {}
rnsec.encode = function (record, buf, offset) {
if (!buf) buf = Buffer.alloc(rnsec.encodingLength(record))
if (!offset) offset = 0
const oldOffset = offset
offset += 2 // Leave space for length
name.encode(record.nextDomain, buf, offset)
offset += name.encode.bytes
typebitmap.encode(record.rrtypes, buf, offset)
offset += typebitmap.encode.bytes
rnsec.encode.bytes = offset - oldOffset
buf.writeUInt16BE(rnsec.encode.bytes - 2, oldOffset)
return buf
}
rnsec.encode.bytes = 0
rnsec.decode = function (buf, offset) {
if (!offset) offset = 0
const oldOffset = offset
var record = {}
var length = buf.readUInt16BE(offset)
offset += 2
record.nextDomain = name.decode(buf, offset)
offset += name.decode.bytes
record.rrtypes = typebitmap.decode(buf, offset, length - (offset - oldOffset))
offset += typebitmap.decode.bytes
rnsec.decode.bytes = offset - oldOffset
return record
}
rnsec.decode.bytes = 0
rnsec.encodingLength = function (record) {
return 2 +
name.encodingLength(record.nextDomain) +
typebitmap.encodingLength(record.rrtypes)
}
const rnsec3 = exports.nsec3 = {}
rnsec3.encode = function (record, buf, offset) {
if (!buf) buf = Buffer.alloc(rnsec3.encodingLength(record))
if (!offset) offset = 0
const oldOffset = offset
const salt = record.salt
if (!Buffer.isBuffer(salt)) {
throw new Error('salt must be a Buffer')
}
const nextDomain = record.nextDomain
if (!Buffer.isBuffer(nextDomain)) {
throw new Error('nextDomain must be a Buffer')
}
offset += 2 // Leave space for length
buf.writeUInt8(record.algorithm, offset)
offset += 1
buf.writeUInt8(record.flags, offset)
offset += 1
buf.writeUInt16BE(record.iterations, offset)
offset += 2
buf.writeUInt8(salt.length, offset)
offset += 1
salt.copy(buf, offset, 0, salt.length)
offset += salt.length
buf.writeUInt8(nextDomain.length, offset)
offset += 1
nextDomain.copy(buf, offset, 0, nextDomain.length)
offset += nextDomain.length
typebitmap.encode(record.rrtypes, buf, offset)
offset += typebitmap.encode.bytes
rnsec3.encode.bytes = offset - oldOffset
buf.writeUInt16BE(rnsec3.encode.bytes - 2, oldOffset)
return buf
}
rnsec3.encode.bytes = 0
rnsec3.decode = function (buf, offset) {
if (!offset) offset = 0
const oldOffset = offset
var record = {}
var length = buf.readUInt16BE(offset)
offset += 2
record.algorithm = buf.readUInt8(offset)
offset += 1
record.flags = buf.readUInt8(offset)
offset += 1
record.iterations = buf.readUInt16BE(offset)
offset += 2
const saltLength = buf.readUInt8(offset)
offset += 1
record.salt = buf.slice(offset, offset + saltLength)
offset += saltLength
const hashLength = buf.readUInt8(offset)
offset += 1
record.nextDomain = buf.slice(offset, offset + hashLength)
offset += hashLength
record.rrtypes = typebitmap.decode(buf, offset, length - (offset - oldOffset))
offset += typebitmap.decode.bytes
rnsec3.decode.bytes = offset - oldOffset
return record
}
rnsec3.decode.bytes = 0
rnsec3.encodingLength = function (record) {
return 8 +
record.salt.length +
record.nextDomain.length +
typebitmap.encodingLength(record.rrtypes)
}
const rds = exports.ds = {}
rds.encode = function (digest, buf, offset) {
if (!buf) buf = Buffer.alloc(rds.encodingLength(digest))
if (!offset) offset = 0
const oldOffset = offset
const digestdata = digest.digest
if (!Buffer.isBuffer(digestdata)) {
throw new Error('Digest must be a Buffer')
}
offset += 2 // Leave space for length
buf.writeUInt16BE(digest.keyTag, offset)
offset += 2
buf.writeUInt8(digest.algorithm, offset)
offset += 1
buf.writeUInt8(digest.digestType, offset)
offset += 1
digestdata.copy(buf, offset, 0, digestdata.length)
offset += digestdata.length
rds.encode.bytes = offset - oldOffset
buf.writeUInt16BE(rds.encode.bytes - 2, oldOffset)
return buf
}
rds.encode.bytes = 0
rds.decode = function (buf, offset) {
if (!offset) offset = 0
const oldOffset = offset
var digest = {}
var length = buf.readUInt16BE(offset)
offset += 2
digest.keyTag = buf.readUInt16BE(offset)
offset += 2
digest.algorithm = buf.readUInt8(offset)
offset += 1
digest.digestType = buf.readUInt8(offset)
offset += 1
digest.digest = buf.slice(offset, oldOffset + length + 2)
offset += digest.digest.length
rds.decode.bytes = offset - oldOffset
return digest
}
rds.decode.bytes = 0
rds.encodingLength = function (digest) {
return 6 + Buffer.byteLength(digest.digest)
}
const rsshfp = exports.sshfp = {}
rsshfp.getFingerprintLengthForHashType = function getFingerprintLengthForHashType (hashType) {
switch (hashType) {
case 1: return 20
case 2: return 32
}
}
rsshfp.encode = function encode (record, buf, offset) {
if (!buf) buf = Buffer.alloc(rsshfp.encodingLength(record))
if (!offset) offset = 0
const oldOffset = offset
offset += 2 // The function call starts with the offset pointer at the RDLENGTH field, not the RDATA one
buf[offset] = record.algorithm
offset += 1
buf[offset] = record.hash
offset += 1
const fingerprintBuf = Buffer.from(record.fingerprint.toUpperCase(), 'hex')
if (fingerprintBuf.length !== rsshfp.getFingerprintLengthForHashType(record.hash)) {
throw new Error('Invalid fingerprint length')
}
fingerprintBuf.copy(buf, offset)
offset += fingerprintBuf.byteLength
rsshfp.encode.bytes = offset - oldOffset
buf.writeUInt16BE(rsshfp.encode.bytes - 2, oldOffset)
return buf
}
rsshfp.encode.bytes = 0
rsshfp.decode = function decode (buf, offset) {
if (!offset) offset = 0
const oldOffset = offset
const record = {}
offset += 2 // Account for the RDLENGTH field
record.algorithm = buf[offset]
offset += 1
record.hash = buf[offset]
offset += 1
const fingerprintLength = rsshfp.getFingerprintLengthForHashType(record.hash)
record.fingerprint = buf.slice(offset, offset + fingerprintLength).toString('hex').toUpperCase()
offset += fingerprintLength
rsshfp.decode.bytes = offset - oldOffset
return record
}
rsshfp.decode.bytes = 0
rsshfp.encodingLength = function (record) {
return 4 + Buffer.from(record.fingerprint, 'hex').byteLength
}
const renc = exports.record = function (type) {
switch (type.toUpperCase()) {
case 'A': return ra
case 'PTR': return rptr
case 'CNAME': return rcname
case 'DNAME': return rdname
case 'TXT': return rtxt
case 'NULL': return rnull
case 'AAAA': return raaaa
case 'SRV': return rsrv
case 'HINFO': return rhinfo
case 'CAA': return rcaa
case 'NS': return rns
case 'SOA': return rsoa
case 'MX': return rmx
case 'OPT': return ropt
case 'DNSKEY': return rdnskey
case 'RRSIG': return rrrsig
case 'RP': return rrp
case 'NSEC': return rnsec
case 'NSEC3': return rnsec3
case 'SSHFP': return rsshfp
case 'DS': return rds
}
return runknown
}
const answer = exports.answer = {}
answer.encode = function (a, buf, offset) {
if (!buf) buf = Buffer.alloc(answer.encodingLength(a))
if (!offset) offset = 0
const oldOffset = offset
name.encode(a.name, buf, offset)
offset += name.encode.bytes
buf.writeUInt16BE(types.toType(a.type), offset)
if (a.type.toUpperCase() === 'OPT') {
if (a.name !== '.') {
throw new Error('OPT name must be root.')
}
buf.writeUInt16BE(a.udpPayloadSize || 4096, offset + 2)
buf.writeUInt8(a.extendedRcode || 0, offset + 4)
buf.writeUInt8(a.ednsVersion || 0, offset + 5)
buf.writeUInt16BE(a.flags || 0, offset + 6)
offset += 8
ropt.encode(a.options || [], buf, offset)
offset += ropt.encode.bytes
} else {
let klass = classes.toClass(a.class === undefined ? 'IN' : a.class)
if (a.flush) klass |= FLUSH_MASK // the 1st bit of the class is the flush bit
buf.writeUInt16BE(klass, offset + 2)
buf.writeUInt32BE(a.ttl || 0, offset + 4)
offset += 8
const enc = renc(a.type)
enc.encode(a.data, buf, offset)
offset += enc.encode.bytes
}
answer.encode.bytes = offset - oldOffset
return buf
}
answer.encode.bytes = 0
answer.decode = function (buf, offset) {
if (!offset) offset = 0
const a = {}
const oldOffset = offset
a.name = name.decode(buf, offset)
offset += name.decode.bytes
a.type = types.toString(buf.readUInt16BE(offset))
if (a.type === 'OPT') {
a.udpPayloadSize = buf.readUInt16BE(offset + 2)
a.extendedRcode = buf.readUInt8(offset + 4)
a.ednsVersion = buf.readUInt8(offset + 5)
a.flags = buf.readUInt16BE(offset + 6)
a.flag_do = ((a.flags >> 15) & 0x1) === 1
a.options = ropt.decode(buf, offset + 8)
offset += 8 + ropt.decode.bytes
} else {
const klass = buf.readUInt16BE(offset + 2)
a.ttl = buf.readUInt32BE(offset + 4)
a.class = classes.toString(klass & NOT_FLUSH_MASK)
a.flush = !!(klass & FLUSH_MASK)
const enc = renc(a.type)
a.data = enc.decode(buf, offset + 8)
offset += 8 + enc.decode.bytes
}
answer.decode.bytes = offset - oldOffset
return a
}
answer.decode.bytes = 0
answer.encodingLength = function (a) {
const data = (a.data !== null && a.data !== undefined) ? a.data : a.options
return name.encodingLength(a.name) + 8 + renc(a.type).encodingLength(data)
}
const question = exports.question = {}
question.encode = function (q, buf, offset) {
if (!buf) buf = Buffer.alloc(question.encodingLength(q))
if (!offset) offset = 0
const oldOffset = offset
name.encode(q.name, buf, offset)
offset += name.encode.bytes
buf.writeUInt16BE(types.toType(q.type), offset)
offset += 2
buf.writeUInt16BE(classes.toClass(q.class === undefined ? 'IN' : q.class), offset)
offset += 2
question.encode.bytes = offset - oldOffset
return q
}
question.encode.bytes = 0
question.decode = function (buf, offset) {
if (!offset) offset = 0
const oldOffset = offset
const q = {}
q.name = name.decode(buf, offset)
offset += name.decode.bytes
q.type = types.toString(buf.readUInt16BE(offset))
offset += 2
q.class = classes.toString(buf.readUInt16BE(offset))
offset += 2
const qu = !!(q.class & QU_MASK)
if (qu) q.class &= NOT_QU_MASK
question.decode.bytes = offset - oldOffset
return q
}
question.decode.bytes = 0
question.encodingLength = function (q) {
return name.encodingLength(q.name) + 4
}
exports.AUTHORITATIVE_ANSWER = 1 << 10
exports.TRUNCATED_RESPONSE = 1 << 9
exports.RECURSION_DESIRED = 1 << 8
exports.RECURSION_AVAILABLE = 1 << 7
exports.AUTHENTIC_DATA = 1 << 5
exports.CHECKING_DISABLED = 1 << 4
exports.DNSSEC_OK = 1 << 15
exports.encode = function (result, buf, offset) {
const allocing = !buf
if (allocing) buf = Buffer.alloc(exports.encodingLength(result))
if (!offset) offset = 0
const oldOffset = offset
if (!result.questions) result.questions = []
if (!result.answers) result.answers = []
if (!result.authorities) result.authorities = []
if (!result.additionals) result.additionals = []
header.encode(result, buf, offset)
offset += header.encode.bytes
offset = encodeList(result.questions, question, buf, offset)
offset = encodeList(result.answers, answer, buf, offset)
offset = encodeList(result.authorities, answer, buf, offset)
offset = encodeList(result.additionals, answer, buf, offset)
exports.encode.bytes = offset - oldOffset
// just a quick sanity check
if (allocing && exports.encode.bytes !== buf.length) {
return buf.slice(0, exports.encode.bytes)
}
return buf
}
exports.encode.bytes = 0
exports.decode = function (buf, offset) {
if (!offset) offset = 0
const oldOffset = offset
const result = header.decode(buf, offset)
offset += header.decode.bytes
offset = decodeList(result.questions, question, buf, offset)
offset = decodeList(result.answers, answer, buf, offset)
offset = decodeList(result.authorities, answer, buf, offset)
offset = decodeList(result.additionals, answer, buf, offset)
exports.decode.bytes = offset - oldOffset
return result
}
exports.decode.bytes = 0
exports.encodingLength = function (result) {
return header.encodingLength(result) +
encodingLengthList(result.questions || [], question) +
encodingLengthList(result.answers || [], answer) +
encodingLengthList(result.authorities || [], answer) +
encodingLengthList(result.additionals || [], answer)
}
exports.streamEncode = function (result) {
const buf = exports.encode(result)
const sbuf = Buffer.alloc(2)
sbuf.writeUInt16BE(buf.byteLength)
const combine = Buffer.concat([sbuf, buf])
exports.streamEncode.bytes = combine.byteLength
return combine
}
exports.streamEncode.bytes = 0
exports.streamDecode = function (sbuf) {
const len = sbuf.readUInt16BE(0)
if (sbuf.byteLength < len + 2) {
// not enough data
return null
}
const result = exports.decode(sbuf.slice(2))
exports.streamDecode.bytes = exports.decode.bytes
return result
}
exports.streamDecode.bytes = 0
function encodingLengthList (list, enc) {
let len = 0
for (let i = 0; i < list.length; i++) len += enc.encodingLength(list[i])
return len
}
function encodeList (list, enc, buf, offset) {
for (let i = 0; i < list.length; i++) {
enc.encode(list[i], buf, offset)
offset += enc.encode.bytes
}
return offset
}
function decodeList (list, enc, buf, offset) {
for (let i = 0; i < list.length; i++) {
list[i] = enc.decode(buf, offset)
offset += enc.decode.bytes
}
return offset
}