fix: check duplicated BIP21

Author: jvsena42

app/src/main/java/to/bitkit/utils/Bip21Utils.kt

@@ -4,6 +4,22 @@ import to.bitkit.models.SATS_IN_BTC
 
 object Bip21Utils {
 
+    private const val BIP21_PREFIX = "bitcoin:"
+
+    /**
+     * Checks if a BIP21 URI is duplicated (contains multiple bitcoin: prefixes).
+     * Workaround for https://github.com/synonymdev/bitkit-core/issues/63
+     * @return true if the input contains duplicated BIP21 URIs, false otherwise
+     */
+    fun isDuplicatedBip21(input: String): Boolean {
+        val lowercased = input.lowercase()
+        val firstIndex = lowercased.indexOf(BIP21_PREFIX)
+        if (firstIndex == -1) return false
+
+        val secondIndex = lowercased.indexOf(BIP21_PREFIX, firstIndex + BIP21_PREFIX.length)
+        return secondIndex != -1
+    }
+
     fun buildBip21Url(
         bitcoinAddress: String,
         amountSats: ULong? = null,

app/src/main/java/to/bitkit/viewmodels/AppViewModel.kt

@@ -108,6 +108,7 @@ import to.bitkit.ui.shared.toast.ToastEventBus
 import to.bitkit.ui.shared.toast.ToastQueueManager
 import to.bitkit.ui.sheets.SendRoute
 import to.bitkit.ui.theme.TRANSITION_SCREEN_MS
+import to.bitkit.utils.Bip21Utils
 import to.bitkit.utils.Logger
 import to.bitkit.utils.NetworkValidationHelper
 import to.bitkit.utils.jsonLogOf
@@ -702,6 +703,16 @@ class AppViewModel @Inject constructor(
     }
 
     private suspend fun validateAddressWithFeedback(input: String) = withContext(bgDispatcher) {
+        // TODO Workaround for https://github.com/synonymdev/bitkit-core/issues/63
+        if (Bip21Utils.isDuplicatedBip21(input)) {
+            showAddressValidationError(
+                titleRes = R.string.other__scan_err_decoding,
+                descriptionRes = R.string.other__scan__error__generic,
+                testTag = "DuplicatedBip21Toast",
+            )
+            return@withContext
+        }
+
         val scanResult = runCatching { decode(input) }
 
         if (scanResult.isFailure) {
@@ -983,6 +994,17 @@ class AppViewModel @Inject constructor(
         resetSendState()
         resetQuickPay()
 
+        // TODO Workaround for https://github.com/synonymdev/bitkit-core/issues/63
+        if (Bip21Utils.isDuplicatedBip21(result)) {
+            toast(
+                type = Toast.ToastType.ERROR,
+                title = context.getString(R.string.other__scan_err_decoding),
+                description = context.getString(R.string.other__scan__error__generic),
+                testTag = "DuplicatedBip21Toast",
+            )
+            return@withContext
+        }
+
         @Suppress("ForbiddenComment") // TODO: wrap `decode` from bindings in a `CoreService` method and call that one
         val scan = runCatching { decode(result) }
             .onFailure { Logger.error("Failed to decode scan data: '$result'", it, context = TAG) }

app/src/test/java/to/bitkit/utils/Bip21UrlBuilderTest.kt

@@ -5,6 +5,7 @@ import org.junit.Test
 import org.junit.runner.RunWith
 import org.junit.runners.JUnit4
 import to.bitkit.utils.Bip21Utils.buildBip21Url
+import to.bitkit.utils.Bip21Utils.isDuplicatedBip21
 
 @RunWith(JUnit4::class)
 class Bip21UrlBuilderTest {
@@ -171,4 +172,47 @@ class Bip21UrlBuilderTest {
         val expected = "bitcoin:$address?amount=0.0001&message=Bitkit&lightning=${invoice.encodeToUrl()}"
         Assert.assertEquals(expected, buildBip21Url(address, amount, lightningInvoice = invoice))
     }
+
+    // Tests for isDuplicatedBip21 - Workaround for bitkit-core#63
+
+    @Test
+    fun `isDuplicatedBip21 returns false for single valid BIP21 URI`() {
+        val input = "bitcoin:bc1qar0srrr7xfkvy5l643lydnw9re59gtzzwf5mdq?amount=0.001&message=Bitkit"
+        Assert.assertFalse(isDuplicatedBip21(input))
+    }
+
+    @Test
+    fun `isDuplicatedBip21 returns true when BIP21 URI is duplicated`() {
+        val first = "bitcoin:bcrt1qr289x0fhg62672e8urudfnxnsr8tcax64xk2vk?amount=0.0000002&message=Bitkit"
+        val second = "bitcoin:bcrt1qr289x0fhg62672e8urudfnxnsr8tcax64xk2vk?amount=0.0000003&message=Bitkit"
+        val input = first + second
+        Assert.assertTrue(isDuplicatedBip21(input))
+    }
+
+    @Test
+    fun `isDuplicatedBip21 handles case-insensitive bitcoin prefix`() {
+        val first = "BITCOIN:bc1qar0srrr7xfkvy5l643lydnw9re59gtzzwf5mdq?amount=0.001"
+        val second = "bitcoin:bc1qar0srrr7xfkvy5l643lydnw9re59gtzzwf5mdq?amount=0.002"
+        val input = first + second
+        Assert.assertTrue(isDuplicatedBip21(input))
+    }
+
+    @Test
+    fun `isDuplicatedBip21 returns false for non-bitcoin URIs`() {
+        val input = "lnbc500n1p3k9v3pp5kzmj..."
+        Assert.assertFalse(isDuplicatedBip21(input))
+    }
+
+    @Test
+    fun `isDuplicatedBip21 returns false for empty string`() {
+        Assert.assertFalse(isDuplicatedBip21(""))
+    }
+
+    @Test
+    fun `isDuplicatedBip21 handles mixed case duplicated URIs`() {
+        val first = "Bitcoin:bc1qaddr1?amount=0.001"
+        val second = "BITCOIN:bc1qaddr2?amount=0.002"
+        val input = first + second
+        Assert.assertTrue(isDuplicatedBip21(input))
+    }
 }