commonMain.fr.acinq.lightning.payment.Bolt11Invoice.kt Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of lightning-kmp-jvm Show documentation
Show all versions of lightning-kmp-jvm Show documentation
A Kotlin Multiplatform implementation of the Lightning Network
package fr.acinq.lightning.payment
import fr.acinq.bitcoin.*
import fr.acinq.bitcoin.Script.tail
import fr.acinq.bitcoin.io.ByteArrayInput
import fr.acinq.bitcoin.io.ByteArrayOutput
import fr.acinq.bitcoin.utils.Either
import fr.acinq.bitcoin.utils.Try
import fr.acinq.bitcoin.utils.runTrying
import fr.acinq.lightning.*
import fr.acinq.lightning.Lightning.randomBytes32
import fr.acinq.lightning.utils.*
import fr.acinq.lightning.wire.LightningCodecs
import kotlin.experimental.and
data class Bolt11Invoice(
val prefix: String,
override val amount: MilliSatoshi?,
val timestampSeconds: Long,
override val nodeId: PublicKey,
val tags: List,
val signature: ByteVector
) : PaymentRequest() {
val chain: Chain? get() = prefixes.entries.firstOrNull { it.value == prefix }?.key
override val paymentHash: ByteVector32 get() = tags.find { it is TaggedField.PaymentHash }!!.run { (this as TaggedField.PaymentHash).hash }
val paymentSecret: ByteVector32 get() = tags.find { it is TaggedField.PaymentSecret }!!.run { (this as TaggedField.PaymentSecret).secret }
val paymentMetadata: ByteVector? get() = tags.find { it is TaggedField.PaymentMetadata }?.run { (this as TaggedField.PaymentMetadata).data }
val description: String? get() = tags.find { it is TaggedField.Description }?.run { (this as TaggedField.Description).description }
val descriptionHash: ByteVector32? get() = tags.find { it is TaggedField.DescriptionHash }?.run { (this as TaggedField.DescriptionHash).hash }
val expirySeconds: Long? get() = tags.find { it is TaggedField.Expiry }?.run { (this as TaggedField.Expiry).expirySeconds }
val minFinalExpiryDelta: CltvExpiryDelta? get() = tags.find { it is TaggedField.MinFinalCltvExpiry }?.run { CltvExpiryDelta((this as TaggedField.MinFinalCltvExpiry).cltvExpiry.toInt()) }
val fallbackAddress: String? = tags.find { it is TaggedField.FallbackAddress }?.run { (this as TaggedField.FallbackAddress).toAddress(prefix) }
override val features: Features get() = tags.filterIsInstance().firstOrNull()?.run { Features(this.bits) } ?: Features.empty
val routingInfo: List = tags.filterIsInstance()
init {
val f = features.invoiceFeatures()
require(f.hasFeature(Feature.VariableLengthOnion)) { "${Feature.VariableLengthOnion.rfcName} must be supported" }
require(f.hasFeature(Feature.PaymentSecret)) { "${Feature.PaymentSecret.rfcName} must be supported" }
require(Features.validateFeatureGraph(f) == null)
require(amount == null || amount > 0.msat) { "amount is not valid" }
require(tags.filterIsInstance().size == 1) { "there must be exactly one payment hash tag" }
require(tags.filterIsInstance().size == 1) { "there must be exactly one payment secret tag" }
require(description != null || descriptionHash != null) { "there must be exactly one description tag or one description hash tag" }
}
override fun isExpired(currentTimestampSeconds: Long): Boolean = when (val expirySeconds = expirySeconds) {
null -> timestampSeconds + DEFAULT_EXPIRY_SECONDS <= currentTimestampSeconds
else -> timestampSeconds + expirySeconds <= currentTimestampSeconds
}
private fun hrp() = prefix + encodeAmount(amount)
private fun rawData(): List {
val data5 = ArrayList()
data5.addAll(encodeTimestamp(timestampSeconds))
tags
.filterNot { it is TaggedField.Features && it.bits.isEmpty() }
.forEach {
val encoded = it.encode()
val len = encoded.size
data5.add(it.tag)
data5.add((len / 32).toByte())
data5.add((len.rem(32)).toByte())
data5.addAll(encoded)
}
return data5
}
private fun signedPreimage(): ByteArray {
return hrp().encodeToByteArray() + toByteArray(rawData())
}
private fun signedHash(): ByteVector32 = Crypto.sha256(signedPreimage()).toByteVector32()
/**
* Sign a payment request.
*
* @param privateKey private key, which must match the payment request's node id
* @return a signature (64 bytes) plus a recovery id (1 byte)
*/
fun sign(privateKey: PrivateKey): Bolt11Invoice {
require(privateKey.publicKey() == nodeId) { "private key does not match node id" }
val msg = signedHash()
val sig = Crypto.sign(msg, privateKey)
val (pub1, _) = Crypto.recoverPublicKey(sig, msg.toByteArray())
val recid = if (nodeId == pub1) 0.toByte() else 1.toByte()
return this.copy(signature = sig.concat(recid))
}
override fun write(): String {
val signature5 = Bech32.eight2five(signature.toByteArray())
return Bech32.encode(hrp(), rawData().toTypedArray() + signature5, Bech32.Encoding.Bech32)
}
companion object {
const val DEFAULT_EXPIRY_SECONDS = 3600
val DEFAULT_MIN_FINAL_EXPIRY_DELTA = CltvExpiryDelta(18)
private val prefixes = mapOf(
Chain.Regtest to "lnbcrt",
Chain.Testnet3 to "lntb",
Chain.Testnet4 to "lntb",
Chain.Mainnet to "lnbc"
)
fun create(
chain: Chain,
amount: MilliSatoshi?,
paymentHash: ByteVector32,
privateKey: PrivateKey,
description: Either,
minFinalCltvExpiryDelta: CltvExpiryDelta,
features: Features,
paymentSecret: ByteVector32 = randomBytes32(),
paymentMetadata: ByteVector? = null,
expirySeconds: Long? = null,
extraHops: List> = listOf(),
timestampSeconds: Long = currentTimestampSeconds()
): Bolt11Invoice {
val prefix = prefixes[chain] ?: error("unknown chain hash")
val tags = mutableListOf(
TaggedField.PaymentHash(paymentHash),
TaggedField.MinFinalCltvExpiry(minFinalCltvExpiryDelta.toLong()),
TaggedField.PaymentSecret(paymentSecret),
// We remove unknown features which could make the invoice too big.
TaggedField.Features(features.invoiceFeatures().copy(unknown = setOf()).toByteArray().toByteVector())
)
description.left?.let { tags.add(TaggedField.Description(it)) }
description.right?.let { tags.add(TaggedField.DescriptionHash(it)) }
paymentMetadata?.let { tags.add(TaggedField.PaymentMetadata(it)) }
expirySeconds?.let { tags.add(TaggedField.Expiry(it)) }
if (extraHops.isNotEmpty()) {
extraHops.forEach { tags.add(TaggedField.RoutingInfo(it)) }
}
return Bolt11Invoice(
prefix = prefix,
amount = amount,
timestampSeconds = timestampSeconds,
nodeId = privateKey.publicKey(),
tags = tags,
signature = ByteVector.empty
).sign(privateKey)
}
private fun decodeTimestamp(input: List): Long = input.take(7).fold(0L) { a, b -> 32 * a + b }
fun encodeTimestamp(input: Long): List {
tailrec fun loop(value: Long, acc: List): List = if (acc.size == 7) acc.reversed() else loop(value / 32, acc + value.rem(32).toByte())
return loop(input, listOf())
}
fun read(input: String): Try = runTrying {
val (hrp, data) = Bech32.decode(input)
val prefix = prefixes.values.find { hrp.startsWith(it) } ?: throw IllegalArgumentException("unknown prefix $hrp")
val amount = decodeAmount(hrp.drop(prefix.length))
val timestamp = decodeTimestamp(data.toList())
// signature and recovery id, encoded on 65 bytes = 5 * 13 bytes = 5 * 13 * 8 bits = 8 * 13 "5-bits integers"
val sigandrecid = toByteArray(data.copyOfRange(data.size - 8 * 13, data.size).toList())
val sig = sigandrecid.dropLast(1).toByteArray().toByteVector64()
val recid = sigandrecid.last()
val data1 = toByteArray(data.copyOfRange(0, data.size - 8 * 13).toList())
val tohash = hrp.encodeToByteArray() + data1
val msg = Crypto.sha256(tohash)
val nodeId = Crypto.recoverPublicKey(sig, msg, recid.toInt())
val check = Crypto.verifySignature(msg, sig, nodeId)
require(check) { "invalid signature" }
val tags = ArrayList()
tailrec fun loop(input: List) {
if (input.isNotEmpty()) {
val tag = input[0]
val len = 32 * input[1] + input[2]
val value = input.drop(3).take(len)
when (tag) {
TaggedField.PaymentHash.tag -> tags.add(kotlin.runCatching { TaggedField.PaymentHash.decode(value) }.getOrDefault(TaggedField.InvalidTag(tag, value)))
TaggedField.PaymentSecret.tag -> tags.add(kotlin.runCatching { TaggedField.PaymentSecret.decode(value) }.getOrDefault(TaggedField.InvalidTag(tag, value)))
TaggedField.PaymentMetadata.tag -> tags.add(kotlin.runCatching { TaggedField.PaymentMetadata.decode(value) }.getOrDefault(TaggedField.InvalidTag(tag, value)))
TaggedField.Description.tag -> tags.add(kotlin.runCatching { TaggedField.Description.decode(value) }.getOrDefault(TaggedField.InvalidTag(tag, value)))
TaggedField.DescriptionHash.tag -> tags.add(kotlin.runCatching { TaggedField.DescriptionHash.decode(value) }.getOrDefault(TaggedField.InvalidTag(tag, value)))
TaggedField.Expiry.tag -> tags.add(kotlin.runCatching { TaggedField.Expiry.decode(value) }.getOrDefault(TaggedField.InvalidTag(tag, value)))
TaggedField.MinFinalCltvExpiry.tag -> tags.add(kotlin.runCatching { TaggedField.MinFinalCltvExpiry.decode(value) }.getOrDefault(TaggedField.InvalidTag(tag, value)))
TaggedField.FallbackAddress.tag -> tags.add(kotlin.runCatching { TaggedField.FallbackAddress.decode(value) }.getOrDefault(TaggedField.InvalidTag(tag, value)))
TaggedField.Features.tag -> tags.add(kotlin.runCatching { TaggedField.Features.decode(value) }.getOrDefault(TaggedField.InvalidTag(tag, value)))
TaggedField.RoutingInfo.tag -> tags.add(kotlin.runCatching { TaggedField.RoutingInfo.decode(value) }.getOrDefault(TaggedField.InvalidTag(tag, value)))
else -> tags.add(TaggedField.UnknownTag(tag, value))
}
loop(input.drop(3 + len))
}
}
loop(data.drop(7).dropLast(104))
val pr = Bolt11Invoice(prefix, amount, timestamp, nodeId, tags, sigandrecid.toByteVector())
require(pr.signedPreimage().contentEquals(tohash)) { "invoice isn't canonically encoded" }
pr
}
fun decodeAmount(input: String): MilliSatoshi? {
val amount = when {
input.isEmpty() -> null
input.last() == 'p' -> {
require(input.endsWith("0p")) { "invalid sub-millisatoshi precision" }
MilliSatoshi(input.dropLast(1).toLong() / 10L)
}
input.last() == 'n' -> MilliSatoshi(input.dropLast(1).toLong() * 100L)
input.last() == 'u' -> MilliSatoshi(input.dropLast(1).toLong() * 100000L)
input.last() == 'm' -> MilliSatoshi(input.dropLast(1).toLong() * 100000000L)
else -> MilliSatoshi(input.toLong() * 100000000000L)
}
return if (amount == MilliSatoshi(0)) null else amount
}
/**
* @return the unit allowing for the shortest representation possible
*/
fun unit(amount: MilliSatoshi): Char? {
val pico = amount.toLong() * 10
return when {
pico.rem(1_000) > 0 -> 'p'
pico.rem(1_000_000) > 0 -> 'n'
pico.rem(1_000_000_000) > 0 -> 'u'
pico.rem(1_000_000_000_000) > 0 -> 'm'
else -> null
}
}
fun encodeAmount(amount: MilliSatoshi?): String {
return when {
amount == null -> ""
unit(amount) == 'p' -> "${amount.toLong() * 10}p" // 1 pico-bitcoin == 10 milli-satoshis
unit(amount) == 'n' -> "${amount.toLong() / 100}n"
unit(amount) == 'u' -> "${amount.toLong() / 100_000}u"
unit(amount) == 'm' -> "${amount.toLong() / 100_000_000}m"
unit(amount) == null -> "${amount.toLong() / 100_000_000_000}"
else -> throw IllegalArgumentException("invalid amount $amount")
}
}
fun toBits(value: Int5): List = listOf(
(value and 16) != 0.toByte(),
(value and 8) != 0.toByte(),
(value and 4) != 0.toByte(),
(value and 2) != 0.toByte(),
(value and 1) != 0.toByte()
)
// converts a list of booleans (1 per bit) to a byte, right-padded if there are less than 8 bits
internal fun toByte(bits: List): Byte {
require(bits.size <= 8)
val raw = bits.fold(0) { a, b -> 2 * a + if (b) 1 else 0 }
val shift = 8 - bits.size
return (raw.shl(shift) and 0xff).toByte()
}
// converts a list of 5 bits values to a byte array
internal fun toByteArray(int5s: List): ByteArray {
val allbits = int5s.flatMap { toBits(it) }
return allbits.windowed(8, 8, partialWindows = true) { toByte(it) }.toByteArray()
}
}
sealed class TaggedField {
abstract val tag: Int5
abstract fun encode(): List
/** @param description a free-format string that will be included in the payment request */
data class Description(val description: String) : TaggedField() {
override val tag: Int5 = Description.tag
override fun encode(): List = Bech32.eight2five(description.encodeToByteArray()).toList()
companion object {
const val tag: Int5 = 13
fun decode(input: List): Description = Description(Bech32.five2eight(input.toTypedArray(), 0).decodeToString())
}
}
/** @param hash sha256 hash of an associated description */
data class DescriptionHash(val hash: ByteVector32) : TaggedField() {
override val tag: Int5 = DescriptionHash.tag
override fun encode(): List = Bech32.eight2five(hash.toByteArray()).toList()
companion object {
const val tag: Int5 = 23
fun decode(input: List): DescriptionHash {
require(input.size == 52)
return DescriptionHash(Bech32.five2eight(input.toTypedArray(), 0).toByteVector32())
}
}
}
/** @param hash payment hash */
data class PaymentHash(val hash: ByteVector32) : TaggedField() {
override val tag: Int5 = PaymentHash.tag
override fun encode(): List = Bech32.eight2five(hash.toByteArray()).toList()
companion object {
const val tag: Int5 = 1
fun decode(input: List): PaymentHash {
require(input.size == 52)
return PaymentHash(Bech32.five2eight(input.toTypedArray(), 0).toByteVector32())
}
}
}
/** @param secret payment secret */
data class PaymentSecret(val secret: ByteVector32) : TaggedField() {
override val tag: Int5 = PaymentSecret.tag
override fun encode(): List = Bech32.eight2five(secret.toByteArray()).toList()
companion object {
const val tag: Int5 = 16
fun decode(input: List): PaymentSecret {
require(input.size == 52)
return PaymentSecret(Bech32.five2eight(input.toTypedArray(), 0).toByteVector32())
}
}
}
data class PaymentMetadata(val data: ByteVector) : TaggedField() {
override val tag: Int5 = PaymentMetadata.tag
override fun encode(): List = Bech32.eight2five(data.toByteArray()).toList()
companion object {
const val tag: Int5 = 27
fun decode(input: List): PaymentMetadata = PaymentMetadata(Bech32.five2eight(input.toTypedArray(), 0).toByteVector())
}
}
/** @param expirySeconds payment expiry (in seconds) */
data class Expiry(val expirySeconds: Long) : TaggedField() {
override val tag: Int5 = Expiry.tag
override fun encode(): List {
tailrec fun loop(value: Long, acc: List): List = if (value == 0L) acc.reversed() else {
loop(value / 32, acc + (value.rem(32)).toByte())
}
return loop(expirySeconds, listOf())
}
companion object {
const val tag: Int5 = 6
fun decode(input: List): Expiry {
var expiry = 0L
input.forEach { expiry = expiry * 32 + it }
return Expiry(expiry)
}
}
}
/** @param cltvExpiry minimum final expiry delta */
data class MinFinalCltvExpiry(val cltvExpiry: Long) : TaggedField() {
override val tag: Int5 = MinFinalCltvExpiry.tag
override fun encode(): List {
tailrec fun loop(value: Long, acc: List): List = if (value == 0L) acc.reversed() else {
loop(value / 32, acc + (value.rem(32)).toByte())
}
return loop(cltvExpiry, listOf())
}
companion object {
const val tag: Int5 = 24
fun decode(input: List): MinFinalCltvExpiry {
var expiry = 0L
input.forEach { expiry = expiry * 32 + it }
return MinFinalCltvExpiry(expiry)
}
}
}
/** Fallback on-chain payment address to be used if LN payment cannot be processed */
data class FallbackAddress(val version: Byte, val data: ByteVector) : TaggedField() {
override val tag: Int5 = FallbackAddress.tag
override fun encode(): List = listOf(version) + Bech32.eight2five(data.toByteArray()).toList()
fun toAddress(prefix: String): String = when (version.toInt()) {
17 -> when (prefix) {
"lnbc" -> Base58Check.encode(Base58.Prefix.PubkeyAddress, data)
else -> Base58Check.encode(Base58.Prefix.PubkeyAddressTestnet, data)
}
18 -> when (prefix) {
"lnbc" -> Base58Check.encode(Base58.Prefix.ScriptAddress, data)
else -> Base58Check.encode(Base58.Prefix.ScriptAddressTestnet, data)
}
else -> when (prefix) {
"lnbc" -> Bech32.encodeWitnessAddress("bc", version, data.toByteArray())
"lntb" -> Bech32.encodeWitnessAddress("tb", version, data.toByteArray())
"lnbcrt" -> Bech32.encodeWitnessAddress("bcrt", version, data.toByteArray())
else -> throw IllegalArgumentException("unknown prefix $prefix")
}
}
companion object {
const val tag: Int5 = 9
fun decode(input: List): FallbackAddress = FallbackAddress(input.first().toByte(), Bech32.five2eight(input.tail().toTypedArray(), 0).toByteVector())
}
}
data class Features(val bits: ByteVector) : TaggedField() {
override val tag: Int5 = Features.tag
override fun encode(): List {
// We pad left to a multiple of 5
val padded = bits.toByteArray().toMutableList()
while (padded.size * 8 % 5 != 0) {
padded.add(0, 0)
}
// Then we remove leading 0 bytes
return Bech32.eight2five(padded.toByteArray()).dropWhile { it == 0.toByte() }
}
companion object {
const val tag: Int5 = 5
fun decode(input: List): Features {
// We pad left to a multiple of 8
val padded = input.toMutableList()
while (padded.size * 5 % 8 != 0) {
padded.add(0, 0)
}
// Then we remove leading 0 bytes
val features = Bech32.five2eight(padded.toTypedArray(), 0).dropWhile { it == 0.toByte() }
return Features(features.toByteArray().toByteVector())
}
}
}
/**
* Extra hop contained in RoutingInfoTag
*
* @param nodeId start of the channel
* @param shortChannelId channel id
* @param feeBase node fixed fee
* @param feeProportionalMillionths node proportional fee
* @param cltvExpiryDelta node cltv expiry delta
*/
data class ExtraHop(
val nodeId: PublicKey,
val shortChannelId: ShortChannelId,
val feeBase: MilliSatoshi,
val feeProportionalMillionths: Long,
val cltvExpiryDelta: CltvExpiryDelta
)
/** @param hints extra routing information for a private route */
data class RoutingInfo(val hints: List) : TaggedField() {
override val tag: Int5 = RoutingInfo.tag
override fun encode(): List {
val out = ByteArrayOutput()
hints.forEach {
LightningCodecs.writeBytes(it.nodeId.value, out)
LightningCodecs.writeU64(it.shortChannelId.toLong(), out)
LightningCodecs.writeU32(it.feeBase.toLong().toInt(), out)
LightningCodecs.writeU32(it.feeProportionalMillionths.toInt(), out)
LightningCodecs.writeU16(it.cltvExpiryDelta.toInt(), out)
}
return Bech32.eight2five(out.toByteArray()).toList()
}
companion object {
const val tag: Int5 = 3
fun decode(input: List): RoutingInfo {
val stream = ByteArrayInput(Bech32.five2eight(input.toTypedArray(), 0))
val hints = ArrayList()
while (stream.availableBytes >= 51) {
val hint = ExtraHop(
PublicKey(LightningCodecs.bytes(stream, 33)),
ShortChannelId(LightningCodecs.u64(stream)),
MilliSatoshi(LightningCodecs.u32(stream).toLong()),
LightningCodecs.u32(stream).toLong(),
CltvExpiryDelta(LightningCodecs.u16(stream))
)
hints.add(hint)
}
return RoutingInfo(hints)
}
}
}
/** Unknown tag (may or may not be valid) */
data class UnknownTag(override val tag: Int5, val value: List) : TaggedField() {
override fun encode(): List = value.toList()
}
/** Tag that we know is not valid (value is of the wrong length for example) */
data class InvalidTag(override val tag: Int5, val value: List) : TaggedField() {
override fun encode(): List = value.toList()
}
}
} © 2015 - 2024 Weber Informatics LLC | Privacy Policy