Cryptographic support for NIP24

app/build.gradle

@@ -194,6 +194,10 @@ dependencies {
     // GeoHash
     implementation 'com.github.drfonfon:android-kotlin-geohash:1.0'
 
+    // LibSodium for XChaCha encryption
+    implementation "com.goterl:lazysodium-android:5.1.0@aar"
+    implementation "net.java.dev.jna:jna:5.12.1@aar"
+
     // Video compression lib
     implementation 'com.github.AbedElazizShe:LightCompressor:1.3.1'
     // Image compression lib

app/src/androidTest/java/com/vitorpamplona/amethyst/CryptoUtilsTest.kt

@@ -0,0 +1,83 @@
+package com.vitorpamplona.amethyst
+
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.vitorpamplona.amethyst.model.toHexKey
+import com.vitorpamplona.amethyst.service.CryptoUtils
+import com.vitorpamplona.amethyst.service.KeyPair
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+class CryptoUtilsTest {
+    @Test()
+    fun testSharedSecret() {
+        val sender = KeyPair()
+        val receiver = KeyPair()
+
+        val sharedSecret1 = CryptoUtils.getSharedSecret(sender.privKey!!, receiver.pubKey)
+        val sharedSecret2 = CryptoUtils.getSharedSecret(receiver.privKey!!, sender.pubKey)
+
+        assertEquals(sharedSecret1.toHexKey(), sharedSecret2.toHexKey())
+
+        val secretKey1 = KeyPair(privKey = sharedSecret1)
+        val secretKey2 = KeyPair(privKey = sharedSecret2)
+
+        assertEquals(secretKey1.pubKey.toHexKey(), secretKey2.pubKey.toHexKey())
+        assertEquals(secretKey1.privKey?.toHexKey(), secretKey2.privKey?.toHexKey())
+    }
+
+    @Test
+    fun encryptDecryptNIP4Test() {
+        val msg = "Hi"
+
+        val privateKey = CryptoUtils.privkeyCreate()
+        val publicKey = CryptoUtils.pubkeyCreate(privateKey)
+
+        val encrypted = CryptoUtils.encrypt(msg, privateKey, publicKey)
+        val decrypted = CryptoUtils.decrypt(encrypted, privateKey, publicKey)
+
+        assertEquals(msg, decrypted)
+    }
+
+    @Test
+    fun encryptDecryptNIP24Test() {
+        val msg = "Hi"
+
+        val privateKey = CryptoUtils.privkeyCreate()
+        val publicKey = CryptoUtils.pubkeyCreate(privateKey)
+
+        val encrypted = CryptoUtils.encryptXChaCha(msg, privateKey, publicKey)
+        val decrypted = CryptoUtils.decryptXChaCha(encrypted, privateKey, publicKey)
+
+        assertEquals(msg, decrypted)
+    }
+
+    @Test
+    fun encryptSharedSecretDecryptNIP4Test() {
+        val msg = "Hi"
+
+        val privateKey = CryptoUtils.privkeyCreate()
+        val publicKey = CryptoUtils.pubkeyCreate(privateKey)
+        val sharedSecret = CryptoUtils.getSharedSecret(privateKey, publicKey)
+
+        val encrypted = CryptoUtils.encrypt(msg, sharedSecret)
+        val decrypted = CryptoUtils.decrypt(encrypted, sharedSecret)
+
+        assertEquals(msg, decrypted)
+    }
+
+    @Test
+    fun encryptSharedSecretDecryptNIP24Test() {
+        val msg = "Hi"
+
+        val privateKey = CryptoUtils.privkeyCreate()
+        val publicKey = CryptoUtils.pubkeyCreate(privateKey)
+        val sharedSecret = CryptoUtils.getSharedSecret(privateKey, publicKey)
+
+        val encrypted = CryptoUtils.encryptXChaCha(msg, sharedSecret)
+        val decrypted = CryptoUtils.decryptXChaCha(encrypted, sharedSecret)
+
+        assertEquals(msg, decrypted)
+    }
+}

app/src/androidTest/java/com/vitorpamplona/amethyst/GiftWrapEventTest.kt

@@ -0,0 +1,432 @@
+package com.vitorpamplona.amethyst
+
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.vitorpamplona.amethyst.model.hexToByteArray
+import com.vitorpamplona.amethyst.model.toHexKey
+import com.vitorpamplona.amethyst.service.CryptoUtils
+import com.vitorpamplona.amethyst.service.KeyPair
+import com.vitorpamplona.amethyst.service.model.ChatMessageEvent
+import com.vitorpamplona.amethyst.service.model.Event
+import com.vitorpamplona.amethyst.service.model.GiftWrapEvent
+import com.vitorpamplona.amethyst.service.model.NIP24Factory
+import com.vitorpamplona.amethyst.service.model.SealedGossipEvent
+import com.vitorpamplona.amethyst.service.relays.Client
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotEquals
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Assert.fail
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+class GiftWrapEventTest {
+    @Test()
+    fun testNip24Utils() {
+        val sender = KeyPair()
+        val receiver = KeyPair()
+        val message = "Hola, que tal?"
+
+        val events = NIP24Factory().createMsgNIP24(
+            message,
+            listOf(receiver.pubKey.toHexKey()),
+            sender.privKey!!
+        )
+
+        // Simulate Receiver
+        val eventsReceiverGets = events.filter { it.isTaggedUser(receiver.pubKey.toHexKey()) }
+        eventsReceiverGets.forEach {
+            val event = it.unwrap(receiver.privKey!!)
+            if (event is SealedGossipEvent) {
+                val innerData = event.unseal(receiver.privKey!!)
+                assertEquals(message, innerData?.content)
+            } else {
+                fail("Wrong Event")
+            }
+        }
+
+        // Simulate Sender
+        val eventsSenderGets = events.filter { it.isTaggedUser(sender.pubKey.toHexKey()) }
+        eventsSenderGets.forEach {
+            val event = it.unwrap(sender.privKey!!)
+            if (event is SealedGossipEvent) {
+                val innerData = event.unseal(sender.privKey!!)
+                assertEquals(message, innerData?.content)
+            } else {
+                fail("Wrong Event")
+            }
+        }
+    }
+
+    @Test()
+    fun testNip24UtilsForGroups() {
+        val sender = KeyPair()
+        println("AAAA - ${sender.privKey?.toHexKey()}")
+        val receiver1 = KeyPair()
+        val receiver2 = KeyPair()
+        val receiver3 = KeyPair()
+        val receiver4 = KeyPair()
+        val message = "Hola, que tal?"
+
+        val receivers = listOf(
+            receiver1,
+            receiver2,
+            receiver3,
+            receiver4
+        )
+
+        val events = NIP24Factory().createMsgNIP24(
+            message,
+            receivers.map { it.pubKey.toHexKey() },
+            sender.privKey!!
+        )
+
+        // Simulate Receiver
+        receivers.forEach { receiver ->
+            val eventsReceiverGets = events.filter { it.isTaggedUser(receiver.pubKey.toHexKey()) }
+            eventsReceiverGets.forEach {
+                val event = it.unwrap(receiver.privKey!!)
+                if (event is SealedGossipEvent) {
+                    val innerData = event.unseal(receiver.privKey!!)
+                    assertEquals(message, innerData?.content)
+                } else {
+                    fail("Wrong Event")
+                }
+            }
+        }
+
+        // Simulate Sender
+        val eventsSenderGets = events.filter { it.isTaggedUser(sender.pubKey.toHexKey()) }
+        eventsSenderGets.forEach {
+            val event = it.unwrap(sender.privKey!!)
+            if (event is SealedGossipEvent) {
+                val innerData = event.unseal(sender.privKey!!)
+                assertEquals(message, innerData?.content)
+            } else {
+                fail("Wrong Event")
+            }
+        }
+    }
+
+    @Test()
+    fun testInternalsSimpleMessage() {
+        val sender = KeyPair()
+        val receiver = KeyPair()
+
+        val senderMessage = ChatMessageEvent.create(
+            msg = "Hi There!",
+            to = listOf(receiver.pubKey.toHexKey()),
+            privateKey = sender.privKey!!
+        )
+
+        // MsgFor the Receiver
+
+        val encMsgFromSenderToReceiver = SealedGossipEvent.create(
+            event = senderMessage,
+            encryptTo = receiver.pubKey.toHexKey(),
+            privateKey = sender.privKey!!
+        )
+
+        // Should expose sender
+        assertEquals(encMsgFromSenderToReceiver.pubKey, sender.pubKey.toHexKey())
+        // Should not expose receiver
+        assertTrue(encMsgFromSenderToReceiver.tags.isEmpty())
+
+        val giftWrapEventToReceiver = GiftWrapEvent.create(
+            event = encMsgFromSenderToReceiver,
+            recipientPubKey = receiver.pubKey.toHexKey()
+        )
+
+        // Should not be signed by neither sender nor receiver
+        assertNotEquals(giftWrapEventToReceiver.pubKey, sender.pubKey.toHexKey())
+        assertNotEquals(giftWrapEventToReceiver.pubKey, receiver.pubKey.toHexKey())
+
+        // Should not include sender as recipient
+        assertNotEquals(giftWrapEventToReceiver.recipientPubKey(), sender.pubKey.toHexKey())
+
+        // Should be addressed to the receiver
+        assertEquals(giftWrapEventToReceiver.recipientPubKey(), receiver.pubKey.toHexKey())
+
+        // MsgFor the Sender
+
+        val encMsgFromSenderToSender = SealedGossipEvent.create(
+            event = senderMessage,
+            encryptTo = sender.pubKey.toHexKey(),
+            privateKey = sender.privKey!!
+        )
+
+        // Should expose sender
+        assertEquals(encMsgFromSenderToSender.pubKey, sender.pubKey.toHexKey())
+        // Should not expose receiver
+        assertTrue(encMsgFromSenderToSender.tags.isEmpty())
+
+        val giftWrapEventToSender = GiftWrapEvent.create(
+            event = encMsgFromSenderToSender,
+            recipientPubKey = sender.pubKey.toHexKey()
+        )
+
+        // Should not be signed by neither the sender, not the receiver
+        assertNotEquals(giftWrapEventToSender.pubKey, sender.pubKey.toHexKey())
+        assertNotEquals(giftWrapEventToSender.pubKey, receiver.pubKey.toHexKey())
+
+        // Should not be addressed to the receiver
+        assertNotEquals(giftWrapEventToSender.recipientPubKey(), receiver.pubKey.toHexKey())
+        // Should be addressed to the sender
+        assertEquals(giftWrapEventToSender.recipientPubKey(), sender.pubKey.toHexKey())
+
+        // Done
+
+        println(senderMessage.toJson())
+        println(encMsgFromSenderToReceiver.toJson())
+        println(giftWrapEventToReceiver.toJson())
+        println(giftWrapEventToSender.toJson())
+
+        // Receiver's side
+        // Unwrapping
+
+        val unwrappedMsgForSenderBySender = giftWrapEventToSender.unwrap(sender.privKey!!)
+        val unwrappedMsgForReceiverBySender = giftWrapEventToReceiver.unwrap(sender.privKey!!)
+
+        assertNotNull(unwrappedMsgForSenderBySender)
+        assertNull(unwrappedMsgForReceiverBySender)
+
+        val unwrappedMsgForSenderByReceiver = giftWrapEventToSender.unwrap(receiver.privKey!!)
+        val unwrappedMsgForReceiverByReceiver = giftWrapEventToReceiver.unwrap(receiver.privKey!!)
+
+        assertNull(unwrappedMsgForSenderByReceiver)
+        assertNotNull(unwrappedMsgForReceiverByReceiver)
+
+        assertEquals(SealedGossipEvent.kind, unwrappedMsgForSenderBySender?.kind)
+        assertEquals(SealedGossipEvent.kind, unwrappedMsgForReceiverByReceiver?.kind)
+
+        assertTrue(unwrappedMsgForSenderBySender is SealedGossipEvent)
+        assertTrue(unwrappedMsgForReceiverByReceiver is SealedGossipEvent)
+
+        if (unwrappedMsgForSenderBySender is SealedGossipEvent &&
+            unwrappedMsgForReceiverByReceiver is SealedGossipEvent
+        ) {
+            val unwrappedGossipToSenderByReceiver = unwrappedMsgForSenderBySender.unseal(receiver.privKey!!)
+            val unwrappedGossipToReceiverByReceiver = unwrappedMsgForReceiverByReceiver.unseal(receiver.privKey!!)
+
+            assertNull(unwrappedGossipToSenderByReceiver)
+            assertNotNull(unwrappedGossipToReceiverByReceiver)
+
+            val unwrappedGossipToSenderBySender = unwrappedMsgForSenderBySender.unseal(sender.privKey!!)
+            val unwrappedGossipToReceiverBySender = unwrappedMsgForReceiverByReceiver.unseal(sender.privKey!!)
+
+            assertNotNull(unwrappedGossipToSenderBySender)
+            assertNull(unwrappedGossipToReceiverBySender)
+
+            assertEquals("Hi There!", unwrappedGossipToReceiverByReceiver?.content)
+            assertEquals("Hi There!", unwrappedGossipToSenderBySender?.content)
+        }
+    }
+
+    @Test()
+    fun testInternalsGroupMessage() {
+        val sender = KeyPair()
+        val receiverA = KeyPair()
+        val receiverB = KeyPair()
+
+        val senderMessage = ChatMessageEvent.create(
+            msg = "Hi There!",
+            to = listOf(receiverA.pubKey.toHexKey(), receiverB.pubKey.toHexKey()),
+            privateKey = sender.privKey!!
+        )
+
+        val encMsgFromSenderToReceiverA = SealedGossipEvent.create(
+            event = senderMessage,
+            encryptTo = receiverA.pubKey.toHexKey(),
+            privateKey = sender.privKey!!
+        )
+
+        val encMsgFromSenderToReceiverB = SealedGossipEvent.create(
+            event = senderMessage,
+            encryptTo = receiverB.pubKey.toHexKey(),
+            privateKey = sender.privKey!!
+        )
+
+        val encMsgFromSenderToSender = SealedGossipEvent.create(
+            event = senderMessage,
+            encryptTo = sender.pubKey.toHexKey(),
+            privateKey = sender.privKey!!
+        )
+
+        // Should expose sender
+        assertEquals(encMsgFromSenderToReceiverA.pubKey, sender.pubKey.toHexKey())
+        // Should not expose receiver
+        assertTrue(encMsgFromSenderToReceiverA.tags.isEmpty())
+
+        // Should expose sender
+        assertEquals(encMsgFromSenderToReceiverB.pubKey, sender.pubKey.toHexKey())
+        // Should not expose receiver
+        assertTrue(encMsgFromSenderToReceiverB.tags.isEmpty())
+
+        // Should expose sender
+        assertEquals(encMsgFromSenderToSender.pubKey, sender.pubKey.toHexKey())
+        // Should not expose receiver
+        assertTrue(encMsgFromSenderToSender.tags.isEmpty())
+
+        val giftWrapEventForReceiverA = GiftWrapEvent.create(
+            event = encMsgFromSenderToReceiverA,
+            recipientPubKey = receiverA.pubKey.toHexKey()
+        )
+
+        val giftWrapEventForReceiverB = GiftWrapEvent.create(
+            event = encMsgFromSenderToReceiverB,
+            recipientPubKey = receiverB.pubKey.toHexKey()
+        )
+
+        // Should not be signed by neither sender nor receiver
+        assertNotEquals(giftWrapEventForReceiverA.pubKey, sender.pubKey.toHexKey())
+        assertNotEquals(giftWrapEventForReceiverA.pubKey, receiverA.pubKey.toHexKey())
+        assertNotEquals(giftWrapEventForReceiverA.pubKey, receiverB.pubKey.toHexKey())
+
+        // Should not include sender as recipient
+        assertNotEquals(giftWrapEventForReceiverA.recipientPubKey(), sender.pubKey.toHexKey())
+
+        // Should be addressed to the receiver
+        assertEquals(giftWrapEventForReceiverA.recipientPubKey(), receiverA.pubKey.toHexKey())
+
+        // Should not be signed by neither sender nor receiver
+        assertNotEquals(giftWrapEventForReceiverB.pubKey, sender.pubKey.toHexKey())
+        assertNotEquals(giftWrapEventForReceiverB.pubKey, receiverA.pubKey.toHexKey())
+        assertNotEquals(giftWrapEventForReceiverB.pubKey, receiverB.pubKey.toHexKey())
+
+        // Should not include sender as recipient
+        assertNotEquals(giftWrapEventForReceiverB.recipientPubKey(), sender.pubKey.toHexKey())
+
+        // Should be addressed to the receiver
+        assertEquals(giftWrapEventForReceiverB.recipientPubKey(), receiverB.pubKey.toHexKey())
+
+        val giftWrapEventToSender = GiftWrapEvent.create(
+            event = encMsgFromSenderToSender,
+            recipientPubKey = sender.pubKey.toHexKey()
+        )
+
+        // Should not be signed by neither the sender, not the receiver
+        assertNotEquals(giftWrapEventToSender.pubKey, sender.pubKey.toHexKey())
+        assertNotEquals(giftWrapEventToSender.pubKey, receiverA.pubKey.toHexKey())
+        assertNotEquals(giftWrapEventToSender.pubKey, receiverB.pubKey.toHexKey())
+
+        // Should not be addressed to the receiver
+        assertNotEquals(giftWrapEventToSender.recipientPubKey(), receiverA.pubKey.toHexKey())
+        assertNotEquals(giftWrapEventToSender.recipientPubKey(), receiverB.pubKey.toHexKey())
+        // Should be addressed to the sender
+        assertEquals(giftWrapEventToSender.recipientPubKey(), sender.pubKey.toHexKey())
+
+        println(senderMessage.toJson())
+        println(encMsgFromSenderToReceiverA.toJson())
+        println(encMsgFromSenderToReceiverB.toJson())
+        println(giftWrapEventForReceiverA.toJson())
+        println(giftWrapEventForReceiverB.toJson())
+        println(giftWrapEventToSender.toJson())
+
+        val unwrappedMsgForSenderBySender = giftWrapEventToSender.unwrap(sender.privKey!!)
+        val unwrappedMsgForReceiverBySenderA = giftWrapEventForReceiverA.unwrap(sender.privKey!!)
+        val unwrappedMsgForReceiverBySenderB = giftWrapEventForReceiverB.unwrap(sender.privKey!!)
+
+        assertNotNull(unwrappedMsgForSenderBySender)
+        assertNull(unwrappedMsgForReceiverBySenderA)
+        assertNull(unwrappedMsgForReceiverBySenderB)
+
+        val unwrappedMsgForSenderByReceiverA = giftWrapEventToSender.unwrap(receiverA.privKey!!)
+        val unwrappedMsgForReceiverAByReceiverA = giftWrapEventForReceiverA.unwrap(receiverA.privKey!!)
+        val unwrappedMsgForReceiverBByReceiverA = giftWrapEventForReceiverB.unwrap(receiverA.privKey!!)
+
+        assertNull(unwrappedMsgForSenderByReceiverA)
+        assertNotNull(unwrappedMsgForReceiverAByReceiverA)
+        assertNull(unwrappedMsgForReceiverBByReceiverA)
+
+        val unwrappedMsgForSenderByReceiverB = giftWrapEventToSender.unwrap(receiverB.privKey!!)
+        val unwrappedMsgForReceiverAByReceiverB = giftWrapEventForReceiverA.unwrap(receiverB.privKey!!)
+        val unwrappedMsgForReceiverBByReceiverB = giftWrapEventForReceiverB.unwrap(receiverB.privKey!!)
+
+        assertNull(unwrappedMsgForSenderByReceiverB)
+        assertNull(unwrappedMsgForReceiverAByReceiverB)
+        assertNotNull(unwrappedMsgForReceiverBByReceiverB)
+
+        assertEquals(SealedGossipEvent.kind, unwrappedMsgForSenderBySender?.kind)
+        assertEquals(SealedGossipEvent.kind, unwrappedMsgForReceiverAByReceiverA?.kind)
+        assertEquals(SealedGossipEvent.kind, unwrappedMsgForReceiverBByReceiverB?.kind)
+
+        assertTrue(unwrappedMsgForSenderBySender is SealedGossipEvent)
+        assertTrue(unwrappedMsgForReceiverAByReceiverA is SealedGossipEvent)
+        assertTrue(unwrappedMsgForReceiverBByReceiverB is SealedGossipEvent)
+
+        if (unwrappedMsgForSenderBySender is SealedGossipEvent &&
+            unwrappedMsgForReceiverAByReceiverA is SealedGossipEvent &&
+            unwrappedMsgForReceiverBByReceiverB is SealedGossipEvent
+        ) {
+            val unwrappedGossipToSenderByReceiverA = unwrappedMsgForSenderBySender.unseal(receiverA.privKey!!)
+            val unwrappedGossipToReceiverAByReceiverA = unwrappedMsgForReceiverAByReceiverA.unseal(receiverA.privKey!!)
+            val unwrappedGossipToReceiverBByReceiverA = unwrappedMsgForReceiverBByReceiverB.unseal(receiverA.privKey!!)
+
+            assertNull(unwrappedGossipToSenderByReceiverA)
+            assertNotNull(unwrappedGossipToReceiverAByReceiverA)
+            assertNull(unwrappedGossipToReceiverBByReceiverA)
+
+            val unwrappedGossipToSenderByReceiverB = unwrappedMsgForSenderBySender.unseal(receiverB.privKey!!)
+            val unwrappedGossipToReceiverAByReceiverB = unwrappedMsgForReceiverAByReceiverA.unseal(receiverB.privKey!!)
+            val unwrappedGossipToReceiverBByReceiverB = unwrappedMsgForReceiverBByReceiverB.unseal(receiverB.privKey!!)
+
+            assertNull(unwrappedGossipToSenderByReceiverB)
+            assertNull(unwrappedGossipToReceiverAByReceiverB)
+            assertNotNull(unwrappedGossipToReceiverBByReceiverB)
+
+            val unwrappedGossipToSenderBySender = unwrappedMsgForSenderBySender.unseal(sender.privKey!!)
+            val unwrappedGossipToReceiverABySender = unwrappedMsgForReceiverAByReceiverA.unseal(sender.privKey!!)
+            val unwrappedGossipToReceiverBBySender = unwrappedMsgForReceiverBByReceiverB.unseal(sender.privKey!!)
+
+            assertNotNull(unwrappedGossipToSenderBySender)
+            assertNull(unwrappedGossipToReceiverABySender)
+            assertNull(unwrappedGossipToReceiverBBySender)
+
+            assertEquals("Hi There!", unwrappedGossipToReceiverAByReceiverA?.content)
+            assertEquals("Hi There!", unwrappedGossipToReceiverBByReceiverB?.content)
+            assertEquals("Hi There!", unwrappedGossipToSenderBySender?.content)
+        }
+    }
+
+    @Test
+    fun testDecryptFromCoracle() {
+        val json = """
+{
+  "content": "{\"ciphertext\":\"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\",\"nonce\":\"Mv70S6jgrs4D1rlqV9b5DddiymGAcVVe\",\"v\":1}",
+  "created_at": 1690528373,
+  "id": "6b108e4236c3c338236ee589388ce0f91f921e1532ae52e75d1d2add6f8e691a",
+  "kind": 1059,
+  "pubkey": "627dc0248335e2bf9adac14be9494139ebbeb12c422d7df5b0e3cd72d04c209c",
+  "sig": "be11da487196db298e4ffb7a03e74176c37441c88b39c95b518fadce6fd02f23c58b2c435ca38c24d512713935ab719dae80bf952267630809e1f84be8e95174",
+  "tags": [
+    [
+      "p",
+      "e7764a227c12ac1ef2db79ae180392c90903b2cec1e37f5c1a4afed38117185e"
+    ]
+  ],
+  "seenOn": [
+    "wss://relay.damus.io/"
+  ]
+}
+        """.trimIndent()
+
+        val privateKey = "09e0051fdf5fdd9dd7a54713583006442cbdbf87bdcdab1a402f26e527d56771".hexToByteArray()
+        val wrap = Event.fromJson(json, Client.lenient) as GiftWrapEvent
+
+        wrap.checkSignature()
+
+        assertEquals(CryptoUtils.pubkeyCreate(privateKey).toHexKey(), wrap.recipientPubKey())
+
+        val event = wrap.unwrap(privateKey)
+        assertNotNull(event)
+
+        if (event is SealedGossipEvent) {
+            val innerData = event.unseal(privateKey)
+            assertEquals("Hi", innerData?.content)
+        } else {
+            println(event?.toJson())
+            fail()
+        }
+    }
+}

app/src/main/java/com/vitorpamplona/amethyst/model/LocalCache.kt

@@ -1110,6 +1110,40 @@ object LocalCache {
         refreshObservers(note)
     }
 
+    private fun consume(event: SealedGossipEvent, relay: Relay?) {
+        val note = getOrCreateNote(event.id)
+        val author = getOrCreateUser(event.pubKey)
+
+        if (relay != null) {
+            author.addRelayBeingUsed(relay, event.createdAt)
+            note.addRelay(relay)
+        }
+
+        // Already processed this event.
+        if (note.event != null) return
+
+        note.loadEvent(event, author, emptyList())
+
+        refreshObservers(note)
+    }
+
+    private fun consume(event: GiftWrapEvent, relay: Relay?) {
+        val note = getOrCreateNote(event.id)
+        val author = getOrCreateUser(event.pubKey)
+
+        if (relay != null) {
+            author.addRelayBeingUsed(relay, event.createdAt)
+            note.addRelay(relay)
+        }
+
+        // Already processed this event.
+        if (note.event != null) return
+
+        note.loadEvent(event, author, emptyList())
+
+        refreshObservers(note)
+    }
+
     fun consume(event: LnZapPaymentRequestEvent) {
         // Does nothing without a response callback.
     }
@@ -1337,10 +1371,12 @@ object LocalCache {
                 is DeletionEvent -> consume(event)
                 is EmojiPackEvent -> consume(event)
                 is EmojiPackSelectionEvent -> consume(event)
+                is SealedGossipEvent -> consume(event, relay)
 
                 is FileHeaderEvent -> consume(event, relay)
                 is FileStorageEvent -> consume(event, relay)
                 is FileStorageHeaderEvent -> consume(event, relay)
+                is GiftWrapEvent -> consume(event, relay)
                 is HighlightEvent -> consume(event, relay)
                 is LiveActivitiesEvent -> consume(event, relay)
                 is LiveActivitiesChatMessageEvent -> consume(event, relay)

app/src/main/java/com/vitorpamplona/amethyst/service/CryptoUtils.kt

@@ -1,5 +1,11 @@
 package com.vitorpamplona.amethyst.service
 
+import com.goterl.lazysodium.LazySodium
+import com.goterl.lazysodium.LazySodiumAndroid
+import com.goterl.lazysodium.Sodium
+import com.goterl.lazysodium.SodiumAndroid
+import com.goterl.lazysodium.utils.Base64MessageEncoder
+import com.goterl.lazysodium.utils.Key
 import fr.acinq.secp256k1.Hex
 import fr.acinq.secp256k1.Secp256k1
 import java.security.MessageDigest
@@ -58,6 +64,56 @@ object CryptoUtils {
         return String(cipher.doFinal(encryptedMsg))
     }
 
+    fun encryptXChaCha(msg: String, privateKey: ByteArray, pubKey: ByteArray): EncryptedInfo {
+        val sharedSecret = getSharedSecret(privateKey, pubKey)
+        return encryptXChaCha(msg, sharedSecret)
+    }
+
+    fun encryptXChaCha(msg: String, sharedSecret: ByteArray): EncryptedInfo {
+        val lazySodium = LazySodiumAndroid(SodiumAndroid(), Base64MessageEncoder())
+
+        val key = Key.fromBytes(sharedSecret)
+
+        val nonce: ByteArray = lazySodium.nonce(24)
+        val messageBytes: ByteArray = msg.toByteArray()
+
+        val cipher = lazySodium.cryptoStreamXChaCha20Xor(
+            messageBytes = messageBytes,
+            nonce = nonce,
+            key = key
+        )
+
+        val cipherBase64 = Base64.getEncoder().encodeToString(cipher)
+        val nonceBase64 = Base64.getEncoder().encodeToString(nonce)
+
+        return EncryptedInfo(
+            ciphertext = cipherBase64,
+            nonce = nonceBase64,
+            v = Nip44Version.XChaCha20.versionCode
+        )
+    }
+
+    fun decryptXChaCha(encryptedInfo: EncryptedInfo, privateKey: ByteArray, pubKey: ByteArray): String {
+        val sharedSecret = getSharedSecret(privateKey, pubKey)
+        return decryptXChaCha(encryptedInfo, sharedSecret)
+    }
+
+    fun decryptXChaCha(encryptedInfo: EncryptedInfo, sharedSecret: ByteArray): String {
+        val lazySodium = LazySodiumAndroid(SodiumAndroid(), Base64MessageEncoder())
+
+        val key = Key.fromBytes(sharedSecret)
+        val nonceBytes = Base64.getDecoder().decode(encryptedInfo.nonce)
+        val messageBytes = Base64.getDecoder().decode(encryptedInfo.ciphertext)
+
+        val cipher = lazySodium.cryptoStreamXChaCha20Xor(
+            messageBytes = messageBytes,
+            nonce = nonceBytes,
+            key = key
+        )
+
+        return cipher.decodeToString()
+    }
+
     fun verifySignature(
         signature: ByteArray,
         hash: ByteArray,
@@ -85,3 +141,83 @@ fun Int.toByteArray(): ByteArray {
     }
     return bytes
 }
+
+data class EncryptedInfo(val ciphertext: String, val nonce: String, val v: Int)
+
+enum class Nip44Version(val versionCode: Int) {
+    Reserved(0),
+    XChaCha20(1)
+}
+
+fun Sodium.crypto_stream_xchacha20_xor_ic(
+    cipher: ByteArray,
+    message: ByteArray,
+    messageLen: Long,
+    nonce: ByteArray,
+    ic: Long,
+    key: ByteArray
+): Int {
+    /**
+     *
+     *     unsigned char k2[crypto_core_hchacha20_OUTPUTBYTES];
+
+     crypto_core_hchacha20(k2, n, k, NULL);
+     return crypto_stream_chacha20_xor_ic(
+     c, m, mlen, n + crypto_core_hchacha20_INPUTBYTES, ic, k2);
+     */
+
+    val k2 = ByteArray(32)
+
+    val nonceChaCha = nonce.drop(16).toByteArray()
+    assert(nonceChaCha.size == 8)
+
+    crypto_core_hchacha20(k2, nonce, key, null)
+    return crypto_stream_chacha20_xor_ic(
+        cipher,
+        message,
+        messageLen,
+        nonceChaCha,
+        ic,
+        k2
+    )
+}
+
+fun Sodium.crypto_stream_xchacha20_xor(
+    cipher: ByteArray,
+    message: ByteArray,
+    messageLen: Long,
+    nonce: ByteArray,
+    key: ByteArray
+): Int {
+    return crypto_stream_xchacha20_xor_ic(cipher, message, messageLen, nonce, 0, key)
+}
+
+fun LazySodium.cryptoStreamXChaCha20Xor(
+    cipher: ByteArray,
+    message: ByteArray,
+    messageLen: Long,
+    nonce: ByteArray,
+    key: ByteArray
+): Boolean {
+    require(!(messageLen < 0 || messageLen > message.size)) { "messageLen out of bounds: $messageLen" }
+    return successful(
+        getSodium().crypto_stream_xchacha20_xor(
+            cipher,
+            message,
+            messageLen,
+            nonce,
+            key
+        )
+    )
+}
+
+private fun LazySodium.cryptoStreamXChaCha20Xor(
+    messageBytes: ByteArray,
+    nonce: ByteArray,
+    key: Key
+): ByteArray {
+    val mLen = messageBytes.size
+    val cipher = ByteArray(mLen)
+    cryptoStreamXChaCha20Xor(cipher, messageBytes, mLen.toLong(), nonce, key.asBytes)
+    return cipher
+}

app/src/main/java/com/vitorpamplona/amethyst/service/model/ChatMessageEvent.kt

@@ -0,0 +1,72 @@
+package com.vitorpamplona.amethyst.service.model
+
+import androidx.compose.runtime.Immutable
+import com.vitorpamplona.amethyst.model.HexKey
+import com.vitorpamplona.amethyst.model.TimeUtils
+import com.vitorpamplona.amethyst.model.toHexKey
+import com.vitorpamplona.amethyst.service.CryptoUtils
+
+@Immutable
+class ChatMessageEvent(
+    id: HexKey,
+    pubKey: HexKey,
+    createdAt: Long,
+    tags: List<List<String>>,
+    content: String,
+    sig: HexKey
+) : Event(id, pubKey, createdAt, kind, tags, content, sig) {
+    /**
+     * Recepients intended to receive this conversation
+     */
+    private fun recipientsPubKey() = tags.mapNotNull {
+        if (it.size > 1 && it[0] == "p") it[1] else null
+    }
+
+    fun replyTo() = tags.firstOrNull { it.size > 1 && it[0] == "e" }?.get(1)
+
+    companion object {
+        const val kind = 14
+
+        fun create(
+            msg: String,
+            to: List<String>? = null,
+            replyTos: List<String>? = null,
+            mentions: List<String>? = null,
+            zapReceiver: String? = null,
+            markAsSensitive: Boolean = false,
+            zapRaiserAmount: Long? = null,
+            geohash: String? = null,
+            privateKey: ByteArray,
+            createdAt: Long = TimeUtils.now()
+        ): ChatMessageEvent {
+            val content = msg
+            val tags = mutableListOf<List<String>>()
+            to?.forEach {
+                tags.add(listOf("p", it))
+            }
+            replyTos?.forEach {
+                tags.add(listOf("e", it))
+            }
+            mentions?.forEach {
+                tags.add(listOf("p", it, "", "mention"))
+            }
+            zapReceiver?.let {
+                tags.add(listOf("zap", it))
+            }
+            if (markAsSensitive) {
+                tags.add(listOf("content-warning", ""))
+            }
+            zapRaiserAmount?.let {
+                tags.add(listOf("zapraiser", "$it"))
+            }
+            geohash?.let {
+                tags.add(listOf("g", it))
+            }
+
+            val pubKey = CryptoUtils.pubkeyCreate(privateKey).toHexKey()
+            val id = generateId(pubKey, createdAt, ClassifiedsEvent.kind, tags, content)
+            val sig = CryptoUtils.sign(id, privateKey)
+            return ChatMessageEvent(id.toHexKey(), pubKey, createdAt, tags, content, sig.toHexKey())
+        }
+    }
+}

app/src/main/java/com/vitorpamplona/amethyst/service/model/EventFactory.kt

@@ -29,13 +29,19 @@ class EventFactory {
             CommunityPostApprovalEvent.kind -> CommunityPostApprovalEvent(id, pubKey, createdAt, tags, content, sig)
             ContactListEvent.kind -> ContactListEvent(id, pubKey, createdAt, tags, content, sig)
             DeletionEvent.kind -> DeletionEvent(id, pubKey, createdAt, tags, content, sig)
+
+            // Will never happen.
+            // DirectMessageEvent.kind -> DirectMessageEvent(createdAt, tags, content)
+
             EmojiPackEvent.kind -> EmojiPackEvent(id, pubKey, createdAt, tags, content, sig)
             EmojiPackSelectionEvent.kind -> EmojiPackSelectionEvent(id, pubKey, createdAt, tags, content, sig)
+            SealedGossipEvent.kind -> SealedGossipEvent(id, pubKey, createdAt, tags, content, sig)
 
             FileHeaderEvent.kind -> FileHeaderEvent(id, pubKey, createdAt, tags, content, sig)
             FileStorageEvent.kind -> FileStorageEvent(id, pubKey, createdAt, tags, content, sig)
             FileStorageHeaderEvent.kind -> FileStorageHeaderEvent(id, pubKey, createdAt, tags, content, sig)
             GenericRepostEvent.kind -> GenericRepostEvent(id, pubKey, createdAt, tags, content, sig)
+            GiftWrapEvent.kind -> GiftWrapEvent(id, pubKey, createdAt, tags, content, sig)
             HighlightEvent.kind -> HighlightEvent(id, pubKey, createdAt, tags, content, sig)
             LiveActivitiesEvent.kind -> LiveActivitiesEvent(id, pubKey, createdAt, tags, content, sig)
             LiveActivitiesChatMessageEvent.kind -> LiveActivitiesChatMessageEvent(id, pubKey, createdAt, tags, content, sig)

app/src/main/java/com/vitorpamplona/amethyst/service/model/GiftWrapEvent.kt

@@ -0,0 +1,87 @@
+package com.vitorpamplona.amethyst.service.model
+
+import android.util.Log
+import androidx.compose.runtime.Immutable
+import com.vitorpamplona.amethyst.model.HexKey
+import com.vitorpamplona.amethyst.model.TimeUtils
+import com.vitorpamplona.amethyst.model.hexToByteArray
+import com.vitorpamplona.amethyst.model.toHexKey
+import com.vitorpamplona.amethyst.service.CryptoUtils
+import com.vitorpamplona.amethyst.service.EncryptedInfo
+import com.vitorpamplona.amethyst.service.relays.Client
+
+@Immutable
+class GiftWrapEvent(
+    id: HexKey,
+    pubKey: HexKey,
+    createdAt: Long,
+    tags: List<List<String>>,
+    content: String,
+    sig: HexKey
+) : Event(id, pubKey, createdAt, kind, tags, content, sig) {
+    private var innerEvent: Event? = null
+
+    fun cachedInnerEvent(privKey: ByteArray): Event? {
+        if (innerEvent != null) return innerEvent
+
+        val myInnerEvent = unwrap(privKey = privKey)
+        innerEvent = myInnerEvent
+        return myInnerEvent
+    }
+
+    fun unwrap(privKey: ByteArray) = try {
+        plainContent(privKey)?.let { println("$it"); fromJson(it, Client.lenient) }
+    } catch (e: Exception) {
+        Log.e("UnwrapError", "Couldn't Decrypt the content", e)
+        null
+    }
+
+    private fun plainContent(privKey: ByteArray): String? {
+        if (content.isBlank()) return null
+
+        return try {
+            val sharedSecret = CryptoUtils.getSharedSecret(privKey, pubKey.hexToByteArray())
+
+            val toDecrypt = gson.fromJson<EncryptedInfo>(
+                content,
+                EncryptedInfo::class.java
+            )
+
+            println(toDecrypt.ciphertext)
+            println(toDecrypt.nonce)
+            println(toDecrypt.v)
+
+            return CryptoUtils.decryptXChaCha(toDecrypt, sharedSecret)
+        } catch (e: Exception) {
+            Log.w("GeneralList", "Error decrypting the message ${e.message}")
+            null
+        }
+    }
+
+    fun recipientPubKey() = tags.firstOrNull { it.size > 1 && it[0] == "p" }?.get(1)
+
+    companion object {
+        const val kind = 1059
+
+        fun create(
+            event: Event,
+            recipientPubKey: HexKey,
+            createdAt: Long = TimeUtils.now()
+        ): GiftWrapEvent {
+            val privateKey = CryptoUtils.privkeyCreate() // GiftWrap is always a random key
+            val sharedSecret = CryptoUtils.getSharedSecret(privateKey, recipientPubKey.hexToByteArray())
+
+            val content = gson.toJson(
+                CryptoUtils.encryptXChaCha(
+                    gson.toJson(event),
+                    sharedSecret
+                )
+            )
+            val pubKey = CryptoUtils.pubkeyCreate(privateKey).toHexKey()
+            val tags = listOf(listOf("p", recipientPubKey))
+            val id = generateId(pubKey, createdAt, kind, tags, content)
+            val sig = CryptoUtils.sign(id, privateKey)
+            return GiftWrapEvent(id.toHexKey(), pubKey, createdAt, tags, content, sig.toHexKey())
+        }
+    }
+}

app/src/main/java/com/vitorpamplona/amethyst/service/model/NIP24Factory.kt

@@ -0,0 +1,32 @@
+package com.vitorpamplona.amethyst.service.model
+
+import com.vitorpamplona.amethyst.model.HexKey
+import com.vitorpamplona.amethyst.model.toHexKey
+import com.vitorpamplona.amethyst.service.CryptoUtils
+
+class NIP24Factory {
+    fun createMsgNIP24(
+        msg: String,
+        to: List<HexKey>,
+        from: ByteArray
+    ): List<GiftWrapEvent> {
+        val senderPublicKey = CryptoUtils.pubkeyCreate(from).toHexKey()
+
+        val senderMessage = ChatMessageEvent.create(
+            msg = msg,
+            to = to,
+            privateKey = from
+        )
+
+        return to.plus(senderPublicKey).map {
+            GiftWrapEvent.create(
+                event = SealedGossipEvent.create(
+                    event = senderMessage,
+                    encryptTo = it,
+                    privateKey = from
+                ),
+                recipientPubKey = it
+            )
+        }
+    }
+}

app/src/main/java/com/vitorpamplona/amethyst/service/model/SealedGossipEvent.kt

@@ -0,0 +1,104 @@
+package com.vitorpamplona.amethyst.service.model
+
+import android.util.Log
+import androidx.compose.runtime.Immutable
+import com.vitorpamplona.amethyst.model.HexKey
+import com.vitorpamplona.amethyst.model.TimeUtils
+import com.vitorpamplona.amethyst.model.hexToByteArray
+import com.vitorpamplona.amethyst.model.toHexKey
+import com.vitorpamplona.amethyst.service.CryptoUtils
+import com.vitorpamplona.amethyst.service.EncryptedInfo
+
+@Immutable
+class SealedGossipEvent(
+    id: HexKey,
+    pubKey: HexKey,
+    createdAt: Long,
+    tags: List<List<String>>,
+    content: String,
+    sig: HexKey
+) : Event(id, pubKey, createdAt, kind, tags, content, sig) {
+    private var innerEvent: Gossip? = null
+
+    fun cachedGossip(privKey: ByteArray): Gossip? {
+        if (innerEvent != null) return innerEvent
+
+        val myInnerEvent = unseal(privKey = privKey)
+        innerEvent = myInnerEvent
+        return myInnerEvent
+    }
+
+    fun unseal(privKey: ByteArray): Gossip? = try {
+        plainContent(privKey)?.let { gson.fromJson(it, Gossip::class.java) }
+    } catch (e: Exception) {
+        null
+    }
+
+    private fun plainContent(privKey: ByteArray): String? {
+        if (content.isBlank()) return null
+
+        return try {
+            val sharedSecret = CryptoUtils.getSharedSecret(privKey, pubKey.hexToByteArray())
+
+            val toDecrypt = gson.fromJson<EncryptedInfo>(
+                content,
+                EncryptedInfo::class.java
+            )
+
+            return CryptoUtils.decryptXChaCha(toDecrypt, sharedSecret)
+        } catch (e: Exception) {
+            Log.w("GeneralList", "Error decrypting the message ${e.message}")
+            null
+        }
+    }
+
+    companion object {
+        const val kind = 13
+
+        fun create(
+            event: Event,
+            encryptTo: HexKey,
+            privateKey: ByteArray,
+            createdAt: Long = TimeUtils.now()
+        ): SealedGossipEvent {
+            val gossip = Gossip.create(event)
+            return create(gossip, encryptTo, privateKey, createdAt)
+        }
+
+        fun create(
+            gossip: Gossip,
+            encryptTo: HexKey,
+            privateKey: ByteArray,
+            createdAt: Long = TimeUtils.now()
+        ): SealedGossipEvent {
+            val sharedSecret = CryptoUtils.getSharedSecret(privateKey, encryptTo.hexToByteArray())
+
+            val content = gson.toJson(
+                CryptoUtils.encryptXChaCha(
+                    gson.toJson(gossip),
+                    sharedSecret
+                )
+            )
+            val pubKey = CryptoUtils.pubkeyCreate(privateKey).toHexKey()
+            val tags = listOf<List<String>>()
+            val id = generateId(pubKey, createdAt, kind, tags, content)
+            val sig = CryptoUtils.sign(id, privateKey)
+            return SealedGossipEvent(id.toHexKey(), pubKey, createdAt, tags, content, sig.toHexKey())
+        }
+    }
+}
+
+open class Gossip(
+    val id: HexKey,
+    val pubKey: HexKey,
+    val createdAt: Long,
+    val kind: Int,
+    val tags: List<List<String>>,
+    val content: String
+) {
+    companion object {
+        fun create(event: Event): Gossip {
+            return Gossip(event.id, event.pubKey, event.createdAt, event.kind, event.tags, event.content)
+        }
+    }
+}