Fix BIP353 implementation details

- accept BIP353 address starting with ₿
- skip LNURL resolution for address starting with ₿
- accept `lno` offer parameter in BIP21 uris
- do not reject BIP21 uris without an address

on Android:
- display the ₿ prefix in BIP353 address
- copying the address now includes the ₿ prefix
- add a button to copy the BIP21 uri
- allow the user to pay the offer in bip21 uris

Fixes #588

phoenix-android/src/main/kotlin/fr/acinq/phoenix/android/components/Inputs.kt

@@ -64,6 +64,7 @@ fun TextInput(
     onTextChange: (String) -> Unit,
     textFieldColors: TextFieldColors = outlinedTextFieldColors(),
     showResetButton: Boolean = true,
+    keyboardType: KeyboardType = KeyboardType.Text
 ) {
     val charsCount by remember(text) { mutableStateOf(text.length) }
     val focusManager = LocalFocusManager.current
@@ -81,7 +82,7 @@ fun TextInput(
             singleLine = singleLine,
             keyboardOptions = KeyboardOptions.Default.copy(
                 imeAction = ImeAction.Done,
-                keyboardType = KeyboardType.Text
+                keyboardType = keyboardType
             ),
             label = null,
             placeholder = placeholder,

phoenix-android/src/main/kotlin/fr/acinq/phoenix/android/payments/ScanDataView.kt

@@ -52,6 +52,7 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.input.KeyboardType
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import androidx.compose.ui.viewinterop.AndroidViewBinding
@@ -157,8 +158,8 @@ fun ScanDataView(
                 SendOfferView(offer = model.offer, trampolineFees = trampolineFees, onBackClick = onBackClick, onPaymentSent = onProcessingFinished)
             }
             is Scan.Model.OnchainFlow -> {
-                val paymentRequest = model.uri.paymentRequest
-                if (paymentRequest == null) {
+                val lightningRequest = model.uri.paymentRequest?.write() ?: model.uri.offer?.encode()
+                if (lightningRequest == null) {
                     SendSpliceOutView(
                         requestedAmount = model.uri.amount,
                         address = model.uri.address,
@@ -171,11 +172,11 @@ fun ScanDataView(
                         ChoosePaymentModeDialog(
                             onPayOffchainClick = {
                                 showPaymentModeDialog = true
-                                postIntent(Scan.Intent.Parse(request = paymentRequest.write()))
+                                postIntent(Scan.Intent.Parse(request = lightningRequest))
                             },
                             onPayOnchainClick = {
                                 showPaymentModeDialog = true
-                                postIntent(Scan.Intent.Parse(request = model.uri.copy(paymentRequest = null).write()))
+                                postIntent(Scan.Intent.Parse(request = model.uri.copy(paymentRequest = null, offer = null).write()))
                             },
                             onDismiss = {
                                 showPaymentModeDialog = false
@@ -428,6 +429,8 @@ private fun ManualInputDialog(
                 minLines = 2,
                 maxLines = 3,
                 staticLabel = stringResource(id = R.string.scan_manual_input_label),
+                placeholder = { Text(text = stringResource(id = R.string.scan_manual_input_hint)) },
+                keyboardType = KeyboardType.Email,
             )
         }
     }

phoenix-android/src/main/kotlin/fr/acinq/phoenix/android/payments/receive/ReceiveOfferView.kt

@@ -134,7 +134,7 @@ fun Bip353AddressDisplay(address: String?) {
         address.isNullOrBlank() -> {}
         else -> {
             SelectionContainer {
-                Text(text = address, style = MaterialTheme.typography.body2)
+                Text(text = stringResource(id = R.string.utils_bip353_with_prefix, address), style = MaterialTheme.typography.body2)
             }
             Spacer(modifier = Modifier.height(16.dp))
         }
@@ -161,19 +161,24 @@ private fun CopyAddressDialog(
         containerColor = MaterialTheme.colors.surface,
         contentColor = MaterialTheme.colors.onSurface,
         scrimColor = MaterialTheme.colors.onBackground.copy(alpha = 0.2f),
-        //dragHandle = null
     ) {
         Column(Modifier.padding(bottom = 50.dp)) {
             Button(
-                text = "Copy Bolt12 code",
+                text = stringResource(id = R.string.receive_offer_copy_bip353),
+                icon = R.drawable.ic_copy,
+                onClick = { copyToClipboard(context, data = context.getString(R.string.utils_bip353_with_prefix, address)) },
+                modifier = Modifier.fillMaxWidth(),
+            )
+            Button(
+                text = stringResource(id = R.string.receive_offer_copy_bolt12),
                 icon = R.drawable.ic_copy,
                 onClick = { copyToClipboard(context, data = offer) },
                 modifier = Modifier.fillMaxWidth(),
             )
             Button(
-                text = "Copy address",
+                text = stringResource(id = R.string.receive_offer_copy_bip21),
                 icon = R.drawable.ic_copy,
-                onClick = { copyToClipboard(context, data = address) },
+                onClick = { copyToClipboard(context, data = "bitcoin:?lno=$offer") },
                 modifier = Modifier.fillMaxWidth(),
             )
         }

phoenix-android/src/main/kotlin/fr/acinq/phoenix/android/settings/ExperimentalView.kt

@@ -177,9 +177,14 @@ private fun ClaimAddressButton(
         is ClaimAddressState.Done -> {
             val context = LocalContext.current
             Setting(
-                title = state.address,
+                title = stringResource(id = R.string.utils_bip353_with_prefix, state.address),
                 leadingIcon = { PhoenixIcon(R.drawable.ic_arobase) },
-                trailingIcon = { Button(icon = R.drawable.ic_copy, onClick = { copyToClipboard(context, state.address) }) },
+                trailingIcon = {
+                    Button(
+                        icon = R.drawable.ic_copy,
+                        onClick = { copyToClipboard(context, context.getString(R.string.utils_bip353_with_prefix, state.address)) }
+                    )
+                },
                 subtitle = {
                     Text(text = stringResource(id = R.string.bip353_subtitle))
                     Spacer(modifier = Modifier.height(4.dp))

phoenix-android/src/main/kotlin/fr/acinq/phoenix/android/settings/walletinfo/SwapInRefundViewModel.kt

@@ -22,6 +22,7 @@ import androidx.compose.runtime.setValue
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.viewModelScope
+import fr.acinq.bitcoin.BitcoinError
 import fr.acinq.bitcoin.Satoshi
 import fr.acinq.bitcoin.Transaction
 import fr.acinq.bitcoin.utils.Either
@@ -83,18 +84,26 @@ class SwapInRefundViewModel(
                 is Either.Right -> {
                     val keyManager = walletManager.keyManager.filterNotNull().first()
                     val swapInWallet = peerManager.swapInWallet.filterNotNull().first()
-                    val res = swapInWallet.spendExpiredSwapIn(
-                        swapInKeys = keyManager.swapInOnChainWallet,
-                        scriptPubKey = parseAddress.value.script,
-                        feerate = FeeratePerKw(feerate)
-                    )
-                    state = if (res == null) {
-                        log.error("could not generate a swap-in refund transaction")
-                        SwapInRefundState.Done.Failed.CannotCreateTx
+                    val script = parseAddress.value.script
+                    if (script == null) {
+                        state = SwapInRefundState.Done.Failed.InvalidAddress(
+                            address = parseAddress.value.address,
+                            error = BitcoinUriError.InvalidScript(BitcoinError.InvalidScript)
+                        )
                     } else {
-                        val (tx, fee) = res
-                        log.info("estimated fee=$fee for swap-in refund")
-                        SwapInRefundState.ReviewFee(fees = fee, transaction = tx)
+                        val res = swapInWallet.spendExpiredSwapIn(
+                            swapInKeys = keyManager.swapInOnChainWallet,
+                            scriptPubKey = script,
+                            feerate = FeeratePerKw(feerate)
+                        )
+                        state = if (res == null) {
+                            log.error("could not generate a swap-in refund transaction")
+                            SwapInRefundState.Done.Failed.CannotCreateTx
+                        } else {
+                            val (tx, fee) = res
+                            log.info("estimated fee=$fee for swap-in refund")
+                            SwapInRefundState.ReviewFee(fees = fee, transaction = tx)
+                        }
                     }
                 }
             }

phoenix-android/src/main/res/values/important_strings.xml

@@ -157,6 +157,10 @@
     <string name="receive_offer_howto_details_5">Check that Android does not apply a battery saving mode to Phoenix. Otherwise, you won\'t be able to receive payments if the app is closed or in the background. Enabling TOR in Phoenix will also cause issues.</string>
     <string name="receive_offer_howto_details_faq_link">Learn more</string>
 
+    <string name="receive_offer_copy_bip353">Copy human-readable address</string>
+    <string name="receive_offer_copy_bolt12">Copy payment code</string>
+    <string name="receive_offer_copy_bip21">Copy full URI</string>
+
     <!-- receive: Tor warning -->
 
     <string name="receive_tor_warning_title">Tor is enabled</string>

phoenix-android/src/main/res/values/strings.xml

@@ -198,8 +198,9 @@
     <string name="scan_bip353_resolving">Resolving payment request over DNS…</string>
 
     <string name="scan_manual_input_title">Manual input</string>
-    <string name="scan_manual_input_instructions">Enter a Lightning invoice, LNURL or Lightning address you want to send money to.</string>
-    <string name="scan_manual_input_label">Invoice or LN address</string>
+    <string name="scan_manual_input_instructions">Enter a Lightning invoice, an offer, a LNURL or a Lightning address you want to send money to.</string>
+    <string name="scan_manual_input_label">Invoice, LN address…</string>
+    <string name="scan_manual_input_hint" translatable="false">₿satoshi@domain.com</string>
 
     <!-- utils: misc strings -->
 
@@ -214,6 +215,8 @@
     <string name="utils_loading_prefs">Loading preferences…</string>
     <string name="utils_copied">Copied to clipboard!</string>
 
+    <string name="utils_bip353_with_prefix" translatable="false">₿%1$s</string>
+
     <string name="accessibility_link">Open link in a browser</string>
     <string name="accessibility_explorer_link">Open transaction in an explorer</string>
     <string name="accessibility_address_explorer_link">Open address in an explorer</string>

phoenix-shared/src/commonMain/kotlin/fr.acinq.phoenix/controllers/payments/ScanController.kt

@@ -20,35 +20,45 @@ import fr.acinq.bitcoin.BitcoinError
 import fr.acinq.bitcoin.Chain
 import fr.acinq.bitcoin.utils.Either
 import fr.acinq.bitcoin.utils.Try
-import fr.acinq.lightning.*
+import fr.acinq.lightning.Lightning
+import fr.acinq.lightning.MilliSatoshi
+import fr.acinq.lightning.TrampolineFees
 import fr.acinq.lightning.db.LightningOutgoingPayment
 import fr.acinq.lightning.io.PayInvoice
 import fr.acinq.lightning.logging.LoggerFactory
 import fr.acinq.lightning.logging.debug
-import fr.acinq.lightning.utils.*
-import fr.acinq.phoenix.PhoenixBusiness
-import fr.acinq.phoenix.controllers.AppController
-import fr.acinq.phoenix.data.*
-import fr.acinq.phoenix.data.lnurl.*
-import fr.acinq.phoenix.db.payments.WalletPaymentMetadataRow
-import fr.acinq.phoenix.managers.*
-import fr.acinq.phoenix.utils.Parser
 import fr.acinq.lightning.logging.error
 import fr.acinq.lightning.logging.info
-import fr.acinq.lightning.logging.warning
 import fr.acinq.lightning.payment.Bolt11Invoice
+import fr.acinq.lightning.utils.UUID
+import fr.acinq.lightning.utils.currentTimestampSeconds
 import fr.acinq.lightning.wire.OfferTypes
-import io.ktor.client.HttpClient
-import io.ktor.client.plugins.contentnegotiation.ContentNegotiation
-import io.ktor.client.request.get
-import io.ktor.client.statement.bodyAsText
+import fr.acinq.phoenix.PhoenixBusiness
+import fr.acinq.phoenix.controllers.AppController
+import fr.acinq.phoenix.data.BitcoinUri
+import fr.acinq.phoenix.data.BitcoinUriError
+import fr.acinq.phoenix.data.LnurlPayMetadata
+import fr.acinq.phoenix.data.WalletPaymentId
+import fr.acinq.phoenix.data.WalletPaymentMetadata
+import fr.acinq.phoenix.data.lnurl.Lnurl
+import fr.acinq.phoenix.data.lnurl.LnurlAuth
+import fr.acinq.phoenix.data.lnurl.LnurlError
+import fr.acinq.phoenix.data.lnurl.LnurlPay
+import fr.acinq.phoenix.data.lnurl.LnurlWithdraw
+import fr.acinq.phoenix.db.payments.WalletPaymentMetadataRow
+import fr.acinq.phoenix.managers.DatabaseManager
+import fr.acinq.phoenix.managers.LnurlManager
+import fr.acinq.phoenix.managers.PeerManager
+import fr.acinq.phoenix.utils.DnsResolvers
+import fr.acinq.phoenix.utils.Parser
 import io.ktor.http.Url
-import io.ktor.serialization.kotlinx.json.json
-import io.ktor.utils.io.charsets.Charsets
-import kotlinx.coroutines.*
+import kotlinx.coroutines.Deferred
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.filterNotNull
 import kotlinx.coroutines.flow.first
-import kotlinx.serialization.json.Json
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 import kotlinx.serialization.json.JsonObject
 import kotlinx.serialization.json.booleanOrNull
 import kotlinx.serialization.json.intOrNull
@@ -528,17 +538,15 @@ class AppScanController(
         val username = components[0].lowercase()
         val domain = components[1]
 
-        return resolveBip353Offer(username, domain)?.let {
-            Either.Left(it)
-        } ?: Either.Right(Lnurl.Request(Url("https://$domain/.well-known/lnurlp/$username"), tag = Lnurl.Tag.Pay))
-    }
+        val signalBip353 = username.startsWith("₿")
+        val cleanUsername = username.dropWhile { it == '₿' }
 
-    val bip353HttpClient: HttpClient by lazy {
-        HttpClient {
-            install(ContentNegotiation) {
-                json(json = Json { ignoreUnknownKeys = true })
-                expectSuccess = true
-            }
+        val offer = resolveBip353Offer(cleanUsername, domain)
+        return if (signalBip353) {
+            offer?.let { Either.Left(it) } // skip lnurl resolution if it's a bip353 address
+        } else {
+            offer?.let { Either.Left(it) }
+                ?: Either.Right(Lnurl.Request(Url("https://$domain/.well-known/lnurlp/$username"), tag = Lnurl.Tag.Pay))
         }
     }
 
@@ -550,26 +558,22 @@ class AppScanController(
         model(Scan.Model.ResolvingBip353)
         val dnsPath = "$username.user._bitcoin-payment.$domain."
 
-        // list of resolvers: https://dnsprivacy.org/public_resolvers/
-        val url = Url("https://dns.google/resolve?name=$dnsPath&type=TXT")
-
         try {
-            val response = bip353HttpClient.get(url)
-            val json = Json.decodeFromString<JsonObject>(response.bodyAsText(Charsets.UTF_8))
-            logger.info { "dns resolved to ${json.toString().take(100)}" }
+            val json = DnsResolvers.getRandom().getTxtRecord(dnsPath)
+            logger.debug { "dns resolved to ${json.toString().take(100)}" }
 
             val status = json["Status"]?.jsonPrimitive?.intOrNull
             if (status == null || status > 0) throw RuntimeException("invalid status=$status")
 
             val ad = json["AD"]?.jsonPrimitive?.booleanOrNull
             if (ad != true) {
-                logger.info { "AD false, abort dns lookup to $url" }
+                logger.info { "AD false, abort dns lookup" }
                 return null
             }
 
             val records = json["Answer"]?.jsonArray
             if (records.isNullOrEmpty()) {
-                logger.debug { "no records for $url" }
+                logger.debug { "no records for $dnsPath" }
                 return null
             }
 
@@ -586,7 +590,7 @@ class AppScanController(
             return when (val offer = OfferTypes.Offer.decode(offerString)) {
                 is Try.Success -> { offer.result }
                 is Try.Failure -> {
-                    model(Scan.Model.BadRequest(request = url.toString(), reason = Scan.BadRequestReason.InvalidBip353(dnsPath)))
+                    model(Scan.Model.BadRequest(request = dnsPath, reason = Scan.BadRequestReason.InvalidBip353(dnsPath)))
                     null
                 }
             }

phoenix-shared/src/commonMain/kotlin/fr.acinq.phoenix/data/BitcoinAddress.kt

@@ -21,20 +21,22 @@ import fr.acinq.bitcoin.ByteVector
 import fr.acinq.bitcoin.Chain
 import fr.acinq.bitcoin.Satoshi
 import fr.acinq.lightning.payment.Bolt11Invoice
+import fr.acinq.lightning.wire.OfferTypes
 import io.ktor.http.*
 
 data class BitcoinUri(
     val chain: Chain,
     /** Actual Bitcoin address; may be different than the source, e.g. if the source is an URI like "bitcoin:xyz?param=123". */
     val address: String,
-    val script: ByteVector,
+    val script: ByteVector?,
     // Bip-21 parameters
     val label: String? = null,
     val message: String? = null,
     /** Amount requested in the URI. */
     val amount: Satoshi? = null,
-    /** A Bitcoin URI may contain a Lightning payment request as an alternative way to make the payment. */
+    /** A Bitcoin URI may contain a Bolt11 invoice or an offer as an alternative way to make the payment. */
     val paymentRequest: Bolt11Invoice? = null,
+    val offer: OfferTypes.Offer? = null,
     /** Other bip-21 parameters in the URI that we do not handle. */
     val ignoredParams: Parameters = Parameters.Empty,
 ) {