Merge pull request #262 from alltheseas/fix/encryption-type-serialization

Preserve bunker encryption type on serialization

PATCH.MD

@@ -0,0 +1,61 @@
+Amber Signer Patch – Preserve Bunker Encryption Scheme
+======================================================
+
+1. Problem Statement  
+   Persisted bunker requests dropped their original encryption scheme (`encryptionType`). Whenever a pending request made a round trip through intents or storage and came back, the signer assumed NIP-44 for the response—even if the request had arrived encrypted with NIP-04. That broke compatibility with clients expecting NIP-04 and risked leaking plaintext.
+
+2. Proposed Solution  
+   Extend the custom serializer for `AmberBunkerRequest` to write out the `encryptionType` field, and add a focused unit test to guarantee that a serialized/deserialized request keeps its original scheme (e.g., NIP-04 stays NIP-04).
+
+3. Benefits  
+   - Restores protocol compliance and interoperability with NIP-46 clients that still rely on NIP-04.  
+   - Prevents accidental downgrade of encryption, preserving end-to-end confidentiality.  
+   - Introduces a regression test that protects the behaviour against future changes.
+
+4. Trade-offs  
+   - Slightly larger JSON payloads for persisted requests (one extra field).  
+   - Requires maintaining the new unit test alongside future refactors.
+
+5. Performance Implications  
+   Negligible: the change adds a single string field to serialized JSON and a tiny unit test; runtime cost is effectively zero.
+
+6. If Not Implemented  
+   - Responses to NIP-04 sessions would remain mis-encrypted, leading to failed signing flows and possible plaintext exposure.  
+   - Remote clients would see Amber as non-compliant with NIP-46, eroding trust and blocking adoption.
+
+7. Diff Summary  
+   - Updated `app/src/main/java/com/greenart7c3/nostrsigner/models/AmberBunkerRequest.kt` to serialize `encryptionType`.  
+   - Added `app/src/test/java/com/greenart7c3/nostrsigner/models/AmberBunkerRequestTest.kt` to assert round-trip integrity.  
+   - Noted the fix in `AMBER-review.MD`.
+
+8. Tests  
+   - `GRADLE_USER_HOME=$PWD/.gradle ./gradlew testFreeDebugUnitTest --tests "com.greenart7c3.nostrsigner.models.AmberBunkerRequestTest"` (passes).  
+   - Added unit test for serialization round-trip.
+
+```kotlin
+// app/src/main/java/com/greenart7c3/nostrsigner/models/AmberBunkerRequest.kt
+gen.writeStringField("encryptDecryptResponse", value.encryptDecryptResponse)
+gen.writeStringField("encryptionType", value.encryptionType.name)
+
+// app/src/test/java/com/greenart7c3/nostrsigner/models/AmberBunkerRequestTest.kt
+@Test
+fun `encryption type survives serialization`() {
+    val relay = RelayUrlNormalizer.normalizeOrNull("wss://relay.example.com")
+    requireNotNull(relay)
+    val request = AmberBunkerRequest(
+        request = BunkerRequestConnect(remoteKey = HEX_KEY, secret = "secret", permissions = null),
+        localKey = HEX_KEY,
+        relays = listOf(relay),
+        currentAccount = "npub1test",
+        nostrConnectSecret = "secret",
+        closeApplication = true,
+        name = "Test App",
+        signedEvent = null,
+        encryptDecryptResponse = null,
+        encryptionType = EncryptionType.NIP04,
+    )
+    val json = request.toJson()
+    val roundTrip = AmberBunkerRequest.mapper.readValue(json, AmberBunkerRequest::class.java)
+    assertEquals(EncryptionType.NIP04, roundTrip.encryptionType)
+}
+```

app/src/main/java/com/greenart7c3/nostrsigner/models/AmberBunkerRequest.kt

@@ -108,6 +108,7 @@ data class AmberBunkerRequest(
                 gen.writeStringField("name", value.name)
                 gen.writeStringField("signedEvent", value.signedEvent?.toJson())
                 gen.writeStringField("encryptDecryptResponse", value.encryptDecryptResponse)
+                gen.writeStringField("encryptionType", value.encryptionType.name)
                 gen.writeEndObject()
             }
         }

app/src/test/java/com/greenart7c3/nostrsigner/models/AmberBunkerRequestTest.kt

@@ -0,0 +1,37 @@
+package com.greenart7c3.nostrsigner.models
+
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.RelayUrlNormalizer
+import com.vitorpamplona.quartz.nip46RemoteSigner.BunkerRequestConnect
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class AmberBunkerRequestTest {
+    @Test
+    fun `encryption type survives serialization`() {
+        val relay = RelayUrlNormalizer.normalizeOrNull("wss://relay.example.com")
+        requireNotNull(relay) { "Expected relay URL to normalize" }
+
+        val request =
+            AmberBunkerRequest(
+                request = BunkerRequestConnect(remoteKey = HEX_KEY, secret = "secret", permissions = null),
+                localKey = HEX_KEY,
+                relays = listOf(relay),
+                currentAccount = "npub1test",
+                nostrConnectSecret = "secret",
+                closeApplication = true,
+                name = "Test App",
+                signedEvent = null,
+                encryptDecryptResponse = null,
+                encryptionType = EncryptionType.NIP04,
+            )
+
+        val json = request.toJson()
+        val roundTrip = AmberBunkerRequest.mapper.readValue(json, AmberBunkerRequest::class.java)
+
+        assertEquals(EncryptionType.NIP04, roundTrip.encryptionType)
+    }
+
+    private companion object {
+        private const val HEX_KEY = "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+    }
+}