Adding new approach for codecs and crypto

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

@@ -37,7 +37,7 @@ data class NumberCodec(
     override fun decode(content: EncodedContent): Double =
         content.content.toStringUtf8().filter { it.isDigit() || it == '.' }.toDouble()
 
-    override fun shouldPush(): Boolean = false
+    override fun shouldPush(content: Double): Boolean = false
 
     override fun fallback(content: Double): String? {
         return "Error: This app does not support numbers."

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

@@ -229,7 +229,12 @@ class ConversationTest {
             additionalData = headerBytes,
         )
         val tamperedMessage =
-            MessageV2Builder.buildFromCipherText(headerBytes = headerBytes, ciphertext = ciphertext)
+            MessageV2Builder.buildFromCipherText(
+                headerBytes = headerBytes,
+                ciphertext = ciphertext,
+                senderHmac = null,
+                shouldPush = true,
+            )
         val tamperedEnvelope = EnvelopeBuilder.buildFromString(
             topic = aliceConversation.topic,
             timestamp = Date(),
@@ -585,6 +590,7 @@ class ConversationTest {
                             encodedContent,
                             topic = conversation.topic,
                             keyMaterial = conversation.keyMaterial!!,
+                            shouldPush = true,
                         ),
                     ).toByteArray(),
                 ),

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

@@ -91,7 +91,8 @@ class MessageTest {
             client = client,
             encodedContent,
             topic = invitationv1.topic,
-            keyMaterial = invitationv1.aes256GcmHkdfSha256.keyMaterial.toByteArray()
+            keyMaterial = invitationv1.aes256GcmHkdfSha256.keyMaterial.toByteArray(),
+            shouldPush = true,
         )
         val decoded = MessageV2Builder.buildDecode(
             id = "",

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

@@ -162,7 +162,11 @@ sealed class Conversation {
             }
 
             is V2 -> {
-                conversationV2.prepareMessage(encodedContent = encodedContent, options = options)
+                conversationV2.prepareMessage(
+                    encodedContent = encodedContent,
+                    options = options,
+                    false,
+                )
             }
 
             is Group -> throw XMTPException("Groups do not support prepared messages") // We return a encoded content not a preparedmessage which requires a envelope

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

@@ -84,7 +84,7 @@ data class ConversationV2(
         val result = runBlocking {
             client.apiClient.envelopes(
                 topic = topic,
-                pagination = pagination
+                pagination = pagination,
             )
         }
 
@@ -133,7 +133,7 @@ data class ConversationV2(
             topic,
             message.v2,
             keyMaterial,
-            client
+            client,
         )
     }
 
@@ -155,7 +155,7 @@ data class ConversationV2(
             topic = topic,
             message.v2,
             keyMaterial = keyMaterial,
-            client = client
+            client = client,
         )
     }
 
@@ -184,7 +184,12 @@ data class ConversationV2(
     }
 
     fun send(encodedContent: EncodedContent, options: SendOptions?): String {
-        val preparedMessage = prepareMessage(encodedContent = encodedContent, options = options)
+        val codec = Client.codecRegistry.find(options?.contentType)
+        val preparedMessage = prepareMessage(
+            encodedContent = encodedContent,
+            options = options,
+            shouldPush = shouldPush(codec, encodedContent.content),
+        )
         return send(preparedMessage)
     }
 
@@ -202,16 +207,26 @@ data class ConversationV2(
             client = client,
             encodedContent = encodedContent,
             topic = topic,
-            keyMaterial = keyMaterial
+            keyMaterial = keyMaterial,
+            shouldPush = shouldPush(codec, content),
         )
         val envelope = EnvelopeBuilder.buildFromString(
             topic = topic,
             timestamp = Date(),
-            message = MessageBuilder.buildFromMessageV2(v2 = message).toByteArray()
+            message = MessageBuilder.buildFromMessageV2(v2 = message).toByteArray(),
         )
         return envelope.toByteArray()
     }
 
+    fun <Codec : ContentCodec<T>, T> shouldPush(codec: Codec, content: Any?): Boolean {
+        val contentType = content as? T
+        if (contentType != null) {
+            return codec.shouldPush(content = content)
+        } else {
+            throw XMTPException("Codec invalid content")
+        }
+    }
+
     fun <T> prepareMessage(content: T, options: SendOptions?): PreparedMessage {
         val codec = Client.codecRegistry.find(options?.contentType)
 
@@ -235,23 +250,28 @@ data class ConversationV2(
         if (compression != null) {
             encoded = encoded.compress(compression)
         }
-        return prepareMessage(encoded, options = options)
+        return prepareMessage(encoded, options = options, shouldPush = shouldPush(codec, content))
     }
 
-    fun prepareMessage(encodedContent: EncodedContent, options: SendOptions?): PreparedMessage {
+    fun prepareMessage(
+        encodedContent: EncodedContent,
+        options: SendOptions?,
+        shouldPush: Boolean,
+    ): PreparedMessage {
         val message = MessageV2Builder.buildEncode(
             client = client,
             encodedContent = encodedContent,
             topic = topic,
-            keyMaterial = keyMaterial
+            keyMaterial = keyMaterial,
+            shouldPush = shouldPush,
         )
 
         val newTopic = if (options?.ephemeral == true) ephemeralTopic else topic
 
         val envelope = EnvelopeBuilder.buildFromString(
             topic = newTopic,
             timestamp = Date(),
-            message = MessageBuilder.buildFromMessageV2(v2 = message).toByteArray()
+            message = MessageBuilder.buildFromMessageV2(v2 = message).toByteArray(),
         )
         return PreparedMessage(listOf(envelope))
     }

library/src/main/java/org/xmtp/android/library/codecs/AttachmentCodec.kt

@@ -37,5 +37,5 @@ data class AttachmentCodec(override var contentType: ContentTypeId = ContentType
         return "Can’t display \"${content.filename}”. This app doesn’t support attachments."
     }
 
-    override fun shouldPush(): Boolean = true
+    override fun shouldPush(content: Attachment): Boolean = true
 }

library/src/main/java/org/xmtp/android/library/codecs/Composite.kt

@@ -52,7 +52,7 @@ class CompositeCodec : ContentCodec<DecodedComposite> {
         return null
     }
 
-    override fun shouldPush(): Boolean = false
+    override fun shouldPush(content: DecodedComposite): Boolean = false
 
     private fun toComposite(decodedComposite: DecodedComposite): Composite {
         return Composite.newBuilder().also {

library/src/main/java/org/xmtp/android/library/codecs/ContentCodec.kt

@@ -67,7 +67,7 @@ interface ContentCodec<T> {
     fun encode(content: T): EncodedContent
     fun decode(content: EncodedContent): T
     fun fallback(content: T): String?
-    fun shouldPush(): Boolean
+    fun shouldPush(content: T): Boolean
 }
 
 val id: String

library/src/main/java/org/xmtp/android/library/codecs/ReactionCodec.kt

@@ -14,7 +14,7 @@ val ContentTypeReaction = ContentTypeIdBuilder.builderFromAuthorityId(
     "xmtp.org",
     "reaction",
     versionMajor = 1,
-    versionMinor = 0
+    versionMinor = 0,
 )
 
 data class Reaction(
@@ -96,7 +96,11 @@ data class ReactionCodec(override var contentType: ContentTypeId = ContentTypeRe
         }
     }
 
-    override fun shouldPush(): Boolean = true
+    override fun shouldPush(content: Reaction): Boolean = when (content.action) {
+        ReactionAction.Added -> true
+        ReactionAction.Removed -> false
+        ReactionAction.Unknown -> false
+    }
 }
 
 private class ReactionSerializer : JsonSerializer<Reaction> {

library/src/main/java/org/xmtp/android/library/codecs/ReadReceiptCodec.kt

@@ -6,7 +6,7 @@ val ContentTypeReadReceipt = ContentTypeIdBuilder.builderFromAuthorityId(
     "xmtp.org",
     "readReceipt",
     versionMajor = 1,
-    versionMinor = 0
+    versionMinor = 0,
 )
 
 object ReadReceipt
@@ -29,5 +29,5 @@ data class ReadReceiptCodec(override var contentType: ContentTypeId = ContentTyp
         return null
     }
 
-    override fun shouldPush(): Boolean = false
+    override fun shouldPush(content: ReadReceipt): Boolean = false
 }

library/src/main/java/org/xmtp/android/library/codecs/RemoteAttachmentCodec.kt

@@ -80,8 +80,10 @@ data class RemoteAttachment(
         fun <T> encodeEncrypted(content: T, codec: ContentCodec<T>): EncryptedEncodedContent {
             val secret = SecureRandom().generateSeed(32)
             val encodedContent = codec.encode(content).toByteArray()
-            val ciphertext = Crypto.encrypt(secret, encodedContent) ?: throw XMTPException("ciphertext not created")
-            val contentDigest = Hash.sha256(ciphertext.aes256GcmHkdfSha256.payload.toByteArray()).toHex()
+            val ciphertext = Crypto.encrypt(secret, encodedContent)
+                ?: throw XMTPException("ciphertext not created")
+            val contentDigest =
+                Hash.sha256(ciphertext.aes256GcmHkdfSha256.payload.toByteArray()).toHex()
             return EncryptedEncodedContent(
                 contentDigest = contentDigest,
                 secret = secret.toByteString(),
@@ -114,7 +116,7 @@ val ContentTypeRemoteAttachment = ContentTypeIdBuilder.builderFromAuthorityId(
     "xmtp.org",
     "remoteStaticAttachment",
     versionMajor = 1,
-    versionMinor = 0
+    versionMinor = 0,
 )
 
 interface Fetcher {
@@ -127,7 +129,8 @@ class HTTPFetcher : Fetcher {
     }
 }
 
-data class RemoteAttachmentCodec(override var contentType: ContentTypeId = ContentTypeRemoteAttachment) : ContentCodec<RemoteAttachment> {
+data class RemoteAttachmentCodec(override var contentType: ContentTypeId = ContentTypeRemoteAttachment) :
+    ContentCodec<RemoteAttachment> {
     override fun encode(content: RemoteAttachment): EncodedContent {
         return EncodedContent.newBuilder().also {
             it.type = ContentTypeRemoteAttachment
@@ -140,19 +143,21 @@ data class RemoteAttachmentCodec(override var contentType: ContentTypeId = Conte
                     "scheme" to content.scheme,
                     "contentLength" to content.contentLength.toString(),
                     "filename" to content.filename,
-                )
+                ),
             )
             it.content = content.url.toString().toByteStringUtf8()
         }.build()
     }
 
     override fun decode(content: EncodedContent): RemoteAttachment {
-        val contentDigest = content.parametersMap["contentDigest"] ?: throw XMTPException("missing content digest")
+        val contentDigest =
+            content.parametersMap["contentDigest"] ?: throw XMTPException("missing content digest")
         val secret = content.parametersMap["secret"] ?: throw XMTPException("missing secret")
         val salt = content.parametersMap["salt"] ?: throw XMTPException("missing salt")
         val nonce = content.parametersMap["nonce"] ?: throw XMTPException("missing nonce")
         val scheme = content.parametersMap["scheme"] ?: throw XMTPException("missing scheme")
-        val contentLength = content.parametersMap["contentLength"] ?: throw XMTPException("missing contentLength")
+        val contentLength =
+            content.parametersMap["contentLength"] ?: throw XMTPException("missing contentLength")
         val filename = content.parametersMap["filename"] ?: throw XMTPException("missing filename")
         val encodedContent = content.content ?: throw XMTPException("missing content")
 
@@ -172,5 +177,5 @@ data class RemoteAttachmentCodec(override var contentType: ContentTypeId = Conte
         return "Can’t display \"${content.filename}”. This app doesn’t support attachments."
     }
 
-    override fun shouldPush(): Boolean = true
+    override fun shouldPush(content: RemoteAttachment): Boolean = true
 }

library/src/main/java/org/xmtp/android/library/codecs/ReplyCodec.kt

@@ -7,7 +7,7 @@ val ContentTypeReply = ContentTypeIdBuilder.builderFromAuthorityId(
     "xmtp.org",
     "reply",
     versionMajor = 1,
-    versionMinor = 0
+    versionMinor = 0,
 )
 
 data class Reply(
@@ -41,15 +41,15 @@ data class ReplyCodec(override var contentType: ContentTypeId = ContentTypeReply
         return Reply(
             reference = reference,
             content = replyContent,
-            contentType = replyCodec.contentType
+            contentType = replyCodec.contentType,
         )
     }
 
     override fun fallback(content: Reply): String? {
         return "Replied with “${content.content}” to an earlier message"
     }
 
-    override fun shouldPush(): Boolean = true
+    override fun shouldPush(content: Reply): Boolean = true
 
     private fun <Codec : ContentCodec<T>, T> encodeReply(
         codec: Codec,

library/src/main/java/org/xmtp/android/library/codecs/TextCodec.kt

@@ -37,5 +37,5 @@ data class TextCodec(override var contentType: ContentTypeId = ContentTypeText)
         return null
     }
 
-    override fun shouldPush(): Boolean = true
+    override fun shouldPush(content: String): Boolean = true
 }

library/src/main/java/org/xmtp/android/library/messages/MessageV2.kt

@@ -1,6 +1,7 @@
 package org.xmtp.android.library.messages
 
 import com.google.protobuf.kotlin.toByteString
+import com.google.protobuf.kotlin.toByteStringUtf8
 import org.web3j.crypto.ECDSASignature
 import org.web3j.crypto.Hash
 import org.web3j.crypto.Sign
@@ -18,7 +19,12 @@ typealias MessageV2 = org.xmtp.proto.message.contents.MessageOuterClass.MessageV
 
 class MessageV2Builder {
     companion object {
-        fun buildFromCipherText(headerBytes: ByteArray, ciphertext: CipherText?): MessageV2 {
+        fun buildFromCipherText(
+            headerBytes: ByteArray,
+            ciphertext: CipherText?,
+            senderHmac: ByteArray?,
+            shouldPush: Boolean,
+        ): MessageV2 {
             return MessageV2.newBuilder().also {
                 it.headerBytes = headerBytes.toByteString()
                 it.ciphertext = ciphertext
@@ -41,7 +47,7 @@ class MessageV2Builder {
                     topic = decryptedMessage.topic,
                     encodedContent = decryptedMessage.encodedContent,
                     senderAddress = decryptedMessage.senderAddress,
-                    sent = decryptedMessage.sentAt
+                    sent = decryptedMessage.sentAt,
                 )
             } catch (e: Exception) {
                 throw XMTPException("Error decoding message", e)
@@ -69,7 +75,7 @@ class MessageV2Builder {
 
             if (!senderPreKey.signature.verify(
                     senderIdentityKey,
-                    signed.sender.preKey.keyBytes.toByteArray()
+                    signed.sender.preKey.keyBytes.toByteArray(),
                 )
             ) {
                 throw XMTPException("pre-key not signed by identity key")
@@ -109,7 +115,7 @@ class MessageV2Builder {
                 encodedContent = encodedMessage,
                 senderAddress = signed.sender.walletAddress,
                 sentAt = Date(header.createdNs / 1_000_000),
-                topic = topic
+                topic = topic,
             )
         }
 
@@ -118,6 +124,7 @@ class MessageV2Builder {
             encodedContent: EncodedContent,
             topic: String,
             keyMaterial: ByteArray,
+            shouldPush: Boolean,
         ): MessageV2 {
             val payload = encodedContent.toByteArray()
             val date = Date()
@@ -130,7 +137,14 @@ class MessageV2Builder {
             val signedContent = SignedContentBuilder.builderFromPayload(payload, bundle, signature)
             val signedBytes = signedContent.toByteArray()
             val ciphertext = Crypto.encrypt(keyMaterial, signedBytes, additionalData = headerBytes)
-            return buildFromCipherText(headerBytes, ciphertext)
+
+            val thirtyDayPeriodsSinceEpoch =
+                (System.currentTimeMillis() / 60 / 60 / 24 / 30).toInt()
+            val info = "$thirtyDayPeriodsSinceEpoch-${client.address}"
+            val infoEncoded = info.toByteStringUtf8().toByteArray()
+            val senderHmac = Crypto.generateHmacSignature(keyMaterial, infoEncoded, headerBytes)
+
+            return buildFromCipherText(headerBytes, ciphertext, senderHmac, shouldPush)
         }
     }
 }