feat: Consent Proof

library/build.gradle

@@ -86,7 +86,7 @@ dependencies {
     implementation 'org.web3j:crypto:5.0.0'
     implementation "net.java.dev.jna:jna:5.13.0@aar"
     api 'com.google.protobuf:protobuf-kotlin-lite:3.22.3'
-    api 'org.xmtp:proto-kotlin:3.47.0'
+    api 'org.xmtp:proto-kotlin:3.51.0'
 
     testImplementation 'junit:junit:4.13.2'
     androidTestImplementation 'app.cash.turbine:turbine:0.12.1'

library/src/androidTest/java/org/xmtp/android/library/ConversationsTest.kt

@@ -6,6 +6,9 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.runBlocking
 import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.assertTrue
 import org.junit.Test
 import org.junit.runner.RunWith
 import org.xmtp.android.library.codecs.TextCodec
@@ -15,11 +18,15 @@ import org.xmtp.android.library.messages.MessageBuilder
 import org.xmtp.android.library.messages.MessageV1Builder
 import org.xmtp.android.library.messages.PrivateKeyBuilder
 import org.xmtp.android.library.messages.SealedInvitationBuilder
+import org.xmtp.android.library.messages.Signature
 import org.xmtp.android.library.messages.Topic
+import org.xmtp.android.library.messages.consentProofText
 import org.xmtp.android.library.messages.createDeterministic
 import org.xmtp.android.library.messages.getPublicKeyBundle
 import org.xmtp.android.library.messages.toPublicKeyBundle
 import org.xmtp.android.library.messages.walletAddress
+import org.xmtp.proto.message.contents.Invitation
+import org.xmtp.proto.message.contents.Invitation.ConsentProofPayload
 import java.lang.Thread.sleep
 import java.util.Date
 
@@ -172,4 +179,91 @@ class ConversationsTest {
         sleep(2000)
         assertEquals(allMessages.size, 2)
     }
+
+    @Test
+    fun testSendConversationWithConsentSignature() {
+        val bo = PrivateKeyBuilder()
+        val alix = PrivateKeyBuilder()
+        val clientOptions =
+            ClientOptions(api = ClientOptions.Api(env = XMTPEnvironment.LOCAL, isSecure = false))
+        val boClient = Client().create(bo, clientOptions)
+        val alixClient = Client().create(alix, clientOptions)
+        val timestamp = System.currentTimeMillis()
+        val signatureText = Signature.newBuilder().build().consentProofText(boClient.address, timestamp)
+        val digest = signatureText.toByteArray()
+        val signature = runBlocking { alix.sign(Util.keccak256(digest)) }
+        val hex = signature.toByteArray().toHex()
+        val consentProofPayload = ConsentProofPayload.newBuilder().also {
+            it.signature = hex
+            it.timestamp = timestamp
+            it.payloadVersion = Invitation.ConsentProofPayloadVersion.CONSENT_PROOF_PAYLOAD_VERSION_1
+        }.build()
+        val boConversation =
+            runBlocking { boClient.conversations.newConversation(alixClient.address, null, consentProofPayload) }
+        val alixConversations = runBlocking {
+            alixClient.conversations.list()
+        }
+        val alixConversation = alixConversations.find {
+            it.topic == boConversation.topic
+        }
+        assertNotNull(alixConversation)
+        val isAllowed = runBlocking { alixClient.contacts.isAllowed(boClient.address) }
+        assertTrue(isAllowed)
+    }
+
+    @Test
+    fun testNetworkConsentOverConsentProof() {
+        val bo = PrivateKeyBuilder()
+        val alix = PrivateKeyBuilder()
+        val clientOptions =
+            ClientOptions(api = ClientOptions.Api(env = XMTPEnvironment.LOCAL, isSecure = false))
+        val boClient = Client().create(bo, clientOptions)
+        val alixClient = Client().create(alix, clientOptions)
+        val timestamp = System.currentTimeMillis()
+        val signatureText = Signature.newBuilder().build().consentProofText(boClient.address, timestamp)
+        val digest = signatureText.toByteArray()
+
+        val signature = runBlocking { alix.sign(Util.keccak256(digest)) }
+        val hex = signature.toByteArray().toHex()
+        val consentProofPayload = ConsentProofPayload.newBuilder().also {
+            it.signature = hex
+            it.timestamp = timestamp
+            it.payloadVersion = Invitation.ConsentProofPayloadVersion.CONSENT_PROOF_PAYLOAD_VERSION_1
+        }.build()
+        runBlocking { alixClient.contacts.deny(listOf(boClient.address)) }
+        val boConversation = runBlocking { boClient.conversations.newConversation(alixClient.address, null, consentProofPayload) }
+        val alixConversations = runBlocking { alixClient.conversations.list() }
+        val alixConversation = alixConversations.find { it.topic == boConversation.topic }
+        assertNotNull(alixConversation)
+        val isDenied = runBlocking { alixClient.contacts.isDenied(boClient.address) }
+        assertTrue(isDenied)
+    }
+
+    @Test
+    fun testConsentProofInvalidSignature() {
+        val bo = PrivateKeyBuilder()
+        val alix = PrivateKeyBuilder()
+        val clientOptions =
+            ClientOptions(api = ClientOptions.Api(env = XMTPEnvironment.LOCAL, isSecure = false))
+        val boClient = Client().create(bo, clientOptions)
+        val alixClient = Client().create(alix, clientOptions)
+        val timestamp = System.currentTimeMillis()
+        val signatureText = Signature.newBuilder().build().consentProofText(boClient.address, timestamp + 1)
+        val digest = signatureText.toByteArray()
+
+        val signature = runBlocking { alix.sign(Util.keccak256(digest)) }
+        val hex = signature.toByteArray().toHex()
+        val consentProofPayload = ConsentProofPayload.newBuilder().also {
+            it.signature = hex
+            it.timestamp = timestamp
+            it.payloadVersion = Invitation.ConsentProofPayloadVersion.CONSENT_PROOF_PAYLOAD_VERSION_1
+        }.build()
+
+        val boConversation = runBlocking { boClient.conversations.newConversation(alixClient.address, null, consentProofPayload) }
+        val alixConversations = runBlocking { alixClient.conversations.list() }
+        val alixConversation = alixConversations.find { it.topic == boConversation.topic }
+        assertNotNull(alixConversation)
+        val isAllowed = runBlocking { alixClient.contacts.isAllowed(boClient.address) }
+        assertFalse(isAllowed)
+    }
 }

library/src/main/java/org/xmtp/android/library/Conversation.kt

@@ -11,6 +11,7 @@ import org.xmtp.android.library.messages.PagingInfoSortDirection
 import org.xmtp.proto.keystore.api.v1.Keystore.TopicMap.TopicData
 import org.xmtp.proto.message.api.v1.MessageApiOuterClass
 import org.xmtp.proto.message.contents.Invitation
+import org.xmtp.proto.message.contents.Invitation.ConsentProofPayload
 import org.xmtp.proto.message.contents.Invitation.InvitationV1.Aes256gcmHkdfsha256
 import java.util.Date
 
@@ -288,6 +289,15 @@ sealed class Conversation {
         }
     }
 
+    val consentProof: ConsentProofPayload?
+        get() {
+            return when (this) {
+                is V1 -> return null
+                is V2 -> conversationV2.consentProof
+                is Group -> return null
+            }
+        }
+
     // Get the client according to the version
     val client: Client
         get() {

library/src/main/java/org/xmtp/android/library/ConversationV2.kt

@@ -27,6 +27,7 @@ data class ConversationV2(
     val topic: String,
     val keyMaterial: ByteArray,
     val context: Invitation.InvitationV1.Context,
+    var consentProof: Invitation.ConsentProofPayload? = null,
     val peerAddress: String,
     val client: Client,
     val createdAtNs: Long? = null,
@@ -52,6 +53,7 @@ data class ConversationV2(
                 client = client,
                 createdAtNs = header.createdNs,
                 header = header,
+                consentProof = if (invitation.hasConsentProof()) invitation.consentProof else null
             )
         }
     }

library/src/main/java/org/xmtp/android/library/Conversations.kt

@@ -150,6 +150,20 @@ data class Conversations(
         } ?: emptyList()
     }
 
+    private suspend fun handleConsentProof(consentProof: Invitation.ConsentProofPayload, peerAddress: String) {
+        val signature = consentProof.signature
+        val timestamp = consentProof.timestamp
+
+        if (!KeyUtil.validateConsentSignature(signature, client.address, peerAddress, timestamp)) {
+            return
+        }
+        val contacts = client.contacts
+        contacts.refreshConsentList()
+        if (contacts.consentList.state(peerAddress) == ConsentState.UNKNOWN) {
+            contacts.allow(listOf(peerAddress))
+        }
+    }
+
     /**
      * This creates a new [Conversation] using a specified address
      * @param peerAddress The address of the client that you want to start a new conversation
@@ -160,6 +174,7 @@ data class Conversations(
     suspend fun newConversation(
         peerAddress: String,
         context: Invitation.InvitationV1.Context? = null,
+        consentProof: Invitation.ConsentProofPayload? = null,
     ): Conversation {
         if (peerAddress.lowercase() == client.address.lowercase()) {
             throw XMTPException("Recipient is sender")
@@ -216,6 +231,7 @@ data class Conversations(
                         peerAddress = peerAddress,
                         client = client,
                         header = sealedInvitation.v1.header,
+                        consentProof = if (invite.hasConsentProof()) invite.consentProof else null
                     ),
                 )
                 conversationsByTopic[conversation.topic] = conversation
@@ -225,7 +241,7 @@ data class Conversations(
         // We don't have an existing conversation, make a v2 one
         val recipient = contact.toSignedPublicKeyBundle()
         val invitation = Invitation.InvitationV1.newBuilder().build()
-            .createDeterministic(client.keys, recipient, context)
+            .createDeterministic(client.keys, recipient, context, consentProof)
         val sealedInvitation =
             sendInvitation(recipient = recipient, invitation = invitation, created = Date())
         val conversationV2 = ConversationV2.create(
@@ -262,7 +278,12 @@ data class Conversations(
         val invitations = listInvitations(pagination = pagination)
         for (sealedInvitation in invitations) {
             try {
-                newConversations.add(Conversation.V2(conversation(sealedInvitation)))
+                val newConversation = Conversation.V2(conversation(sealedInvitation))
+                newConversations.add(newConversation)
+                val consentProof = newConversation.consentProof
+                if (consentProof != null) {
+                    handleConsentProof(consentProof, newConversation.peerAddress)
+                }
             } catch (e: Exception) {
                 Log.d(TAG, e.message.toString())
             }
@@ -301,6 +322,7 @@ data class Conversations(
                     client = client,
                     createdAtNs = data.createdNs,
                     header = Invitation.SealedInvitationHeaderV1.getDefaultInstance(),
+                    consentProof = if (data.invitation.hasConsentProof()) data.invitation.consentProof else null
                 ),
             )
         }

library/src/main/java/org/xmtp/android/library/KeyUtil.kt

@@ -1,14 +1,34 @@
 package org.xmtp.android.library
 
+import com.google.protobuf.kotlin.toByteString
+import org.web3j.crypto.ECDSASignature
+import org.web3j.crypto.Keys
 import org.web3j.crypto.Sign
 import org.web3j.crypto.Sign.SignatureData
+import org.web3j.utils.Numeric
+import org.xmtp.android.library.messages.Signature
+import org.xmtp.android.library.messages.consentProofText
+import org.xmtp.android.library.messages.rawData
 import java.math.BigInteger
 
 object KeyUtil {
     fun getPublicKey(privateKey: ByteArray): ByteArray {
         return Sign.publicKeyFromPrivate(BigInteger(1, privateKey)).toByteArray()
     }
 
+    private fun recoverPublicKeyKeccak256(signature: ByteArray, digest: ByteArray): BigInteger? {
+        val signatureData = getSignatureData(signature)
+        return Sign.recoverFromSignature(
+            BigInteger(1, signatureData.v).toInt(),
+            ECDSASignature(BigInteger(1, signatureData.r), BigInteger(1, signatureData.s)),
+            digest,
+        )
+    }
+
+    private fun publicKeyToAddress(publicKey: BigInteger): String {
+        return Keys.toChecksumAddress(Keys.getAddress(publicKey))
+    }
+
     fun addUncompressedByte(publicKey: ByteArray): ByteArray {
         return if (publicKey.size >= 65) {
             val newPublicKey = ByteArray(64)
@@ -60,4 +80,13 @@ object KeyUtil {
         }
         return mergedArray
     }
+
+    fun validateConsentSignature(signature: String, clientAddress: String, peerAddress: String, timestamp: Long): Boolean {
+        val messageData = Signature.newBuilder().build().consentProofText(peerAddress, timestamp).toByteArray()
+        val signatureData = Numeric.hexStringToByteArray(signature)
+        val sig = Signature.parseFrom(signatureData)
+        val recoveredPublicKey = recoverPublicKeyKeccak256(sig.rawData.toByteString().toByteArray(), Util.keccak256(messageData))
+            ?: return false
+        return clientAddress == publicKeyToAddress(recoveredPublicKey)
+    }
 }

library/src/main/java/org/xmtp/android/library/messages/InvitationV1.kt

@@ -5,6 +5,7 @@ import com.google.protobuf.kotlin.toByteString
 import org.xmtp.android.library.Crypto
 import org.xmtp.android.library.toHex
 import org.xmtp.proto.message.contents.Invitation
+import org.xmtp.proto.message.contents.Invitation.ConsentProofPayload
 import org.xmtp.proto.message.contents.Invitation.InvitationV1.Context
 import java.security.SecureRandom
 
@@ -16,12 +17,16 @@ class InvitationV1Builder {
             topic: Topic,
             context: Context? = null,
             aes256GcmHkdfSha256: Invitation.InvitationV1.Aes256gcmHkdfsha256,
+            consentProof: ConsentProofPayload? = null
         ): InvitationV1 {
             return InvitationV1.newBuilder().apply {
                 this.topic = topic.description
                 if (context != null) {
                     this.context = context
                 }
+                if (consentProof != null) {
+                    this.consentProof = consentProof
+                }
                 this.aes256GcmHkdfSha256 = aes256GcmHkdfSha256
             }.build()
         }
@@ -60,6 +65,7 @@ fun InvitationV1.createDeterministic(
     sender: PrivateKeyBundleV2,
     recipient: SignedPublicKeyBundle,
     context: Context? = null,
+    consentProof: ConsentProofPayload? = null
 ): InvitationV1 {
     val myAddress = sender.toV1().walletAddress
     val theirAddress = recipient.walletAddress
@@ -95,6 +101,7 @@ fun InvitationV1.createDeterministic(
         topic = topic,
         context = inviteContext,
         aes256GcmHkdfSha256 = aes256GcmHkdfSha256,
+        consentProof = consentProof
     )
 }
 

library/src/main/java/org/xmtp/android/library/messages/Signature.kt

@@ -47,6 +47,9 @@ fun Signature.createIdentityText(key: ByteArray): String =
 fun Signature.enableIdentityText(key: ByteArray): String =
     ("XMTP : Enable Identity\n" + "${key.toHex()}\n" + "\n" + "For more info: https://xmtp.org/signatures/")
 
+fun Signature.consentProofText(peerAddress: String, timestamp: Long): String =
+    ("XMTP : Grant inbox consent to sender\n" + "\n" + "Current Time: ${timestamp}\n" + "From Address: ${peerAddress}\n" + "\n" + "For more info: https://xmtp.org/signatures/")
+
 val Signature.rawData: ByteArray
     get() = if (hasEcdsaCompact()) {
         ecdsaCompact.bytes.toByteArray() + ecdsaCompact.recovery.toByte()