feat: consent proofs

bench/decode.ts

@@ -65,12 +65,14 @@ const decodeV2 = () => {
         ),
         createdNs: dateToNs(new Date()),
         context: undefined,
+        consentProof: undefined,
       })
       const convo = new ConversationV2(
         alice,
         invite.conversation?.topic ?? '',
         bob.identityKey.publicKey.walletSignatureAddress(),
         new Date(),
+        undefined,
         undefined
       )
       const { payload, shouldPush } = await alice.encodeContent(message)

bench/encode.ts

@@ -49,12 +49,14 @@ const encodeV2 = () => {
         ),
         createdNs: dateToNs(new Date()),
         context: undefined,
+        consentProof: undefined,
       })
       const convo = new ConversationV2(
         alice,
         invite.conversation?.topic ?? '',
         bob.identityKey.publicKey.walletSignatureAddress(),
         new Date(),
+        undefined,
         undefined
       )
       const message = randomBytes(size)

package.json

@@ -98,7 +98,7 @@
   },
   "dependencies": {
     "@noble/secp256k1": "1.7.1",
-    "@xmtp/proto": "3.45.0",
+    "@xmtp/proto": "3.54.0",
     "@xmtp/user-preferences-bindings-wasm": "^0.3.6",
     "async-mutex": "^0.5.0",
     "elliptic": "^6.5.4",

src/Contacts.ts

@@ -1,4 +1,7 @@
-import { privatePreferences } from '@xmtp/proto'
+import { privatePreferences, type invitation } from '@xmtp/proto'
+import { hashMessage, hexToBytes } from 'viem'
+import { ecdsaSignerKey, WalletSigner } from '@/crypto/Signature'
+import { splitSignature } from '@/crypto/utils'
 import type { EnvelopeWithMessage } from '@/utils/async'
 import { fromNanoString } from '@/utils/date'
 import { buildUserPrivatePreferencesTopic } from '@/utils/topic'
@@ -252,10 +255,60 @@ export class Contacts {
     this.jobRunner = new JobRunner('user-preferences', client.keystore)
   }
 
+  private async validateConsentSignature(
+    signature: `0x${string}`,
+    timestampMs: number,
+    peerAddress: string
+  ): Promise<boolean> {
+    const signatureData = splitSignature(signature)
+    const message = WalletSigner.consentProofRequestText(
+      peerAddress,
+      timestampMs
+    )
+    const digest = hexToBytes(hashMessage(message))
+    // Recover public key
+    const publicKey = ecdsaSignerKey(digest, signatureData)
+    return publicKey?.getEthereumAddress() === this.client.address
+  }
+
+  private async handleConsentProof(
+    consentProof: invitation.ConsentProofPayload,
+    peerAddress: string
+  ): Promise<void> {
+    const { signature, timestamp } = consentProof
+    const isValid = await this.validateConsentSignature(
+      signature as `0x${string}`,
+      Number(timestamp),
+      peerAddress
+    )
+    if (!isValid) {
+      return
+    }
+    await this.client.contacts.allow([peerAddress])
+  }
+
   async loadConsentList(startTime?: Date) {
     return this.jobRunner.run(async (lastRun) => {
       // allow for override of startTime
-      return this.consentList.load(startTime ?? lastRun)
+      const entries = await this.consentList.load(startTime ?? lastRun)
+      try {
+        const conversations = await this.client.conversations.list()
+        conversations.forEach((conversation) => {
+          if (
+            conversation.consentProof &&
+            this.consentState(conversation.peerAddress) === 'unknown'
+          ) {
+            this.handleConsentProof(
+              conversation.consentProof,
+              conversation.peerAddress
+            )
+          }
+        })
+      } catch (err) {
+        console.log(err)
+      }
+
+      return entries
     })
   }
 

src/Invitation.ts

@@ -20,11 +20,13 @@ export class InvitationV1 implements invitation.InvitationV1 {
   topic: string
   context: InvitationContext | undefined
   aes256GcmHkdfSha256: invitation.InvitationV1_Aes256gcmHkdfsha256 // eslint-disable-line camelcase
+  consentProof: invitation.ConsentProofPayload | undefined
 
   constructor({
     topic,
     context,
     aes256GcmHkdfSha256,
+    consentProof,
   }: invitation.InvitationV1) {
     if (!topic || !topic.length) {
       throw new Error('Missing topic')
@@ -39,9 +41,13 @@ export class InvitationV1 implements invitation.InvitationV1 {
     this.topic = topic
     this.context = context
     this.aes256GcmHkdfSha256 = aes256GcmHkdfSha256
+    this.consentProof = consentProof
   }
 
-  static createRandom(context?: invitation.InvitationV1_Context): InvitationV1 {
+  static createRandom(
+    context?: invitation.InvitationV1_Context,
+    consentProof?: invitation.ConsentProofPayload
+  ): InvitationV1 {
     const topic = buildDirectMessageTopicV2(
       Buffer.from(crypto.getRandomValues(new Uint8Array(32)))
         .toString('base64')
@@ -56,6 +62,7 @@ export class InvitationV1 implements invitation.InvitationV1 {
       topic,
       aes256GcmHkdfSha256: { keyMaterial },
       context,
+      consentProof,
     })
   }
 

src/Message.ts

@@ -279,6 +279,7 @@ export class DecodedMessage<ContentTypes = any> {
         context: this.conversation.context ?? undefined,
         createdNs: dateToNs(this.conversation.createdAt),
         peerAddress: this.conversation.peerAddress,
+        consentProofPayload: this.conversation.consentProof ?? undefined,
       },
       sentNs: dateToNs(this.sent),
     }).finish()
@@ -395,7 +396,8 @@ function conversationReferenceToConversation<ContentTypes>(
       reference.topic,
       reference.peerAddress,
       nsToDate(reference.createdNs),
-      reference.context
+      reference.context,
+      reference.consentProofPayload
     )
   }
   throw new Error(`Unknown conversation version ${version}`)

src/conversations/Conversation.ts

@@ -1,6 +1,7 @@
 import {
   message,
   content as proto,
+  type invitation,
   type keystore,
   type messageApi,
 } from '@xmtp/proto'
@@ -85,6 +86,11 @@ export interface Conversation<ContentTypes = any> {
    */
   consentState: ConsentState
 
+  /**
+   * Proof of consent for the conversation, used when a user has pre-consented to a conversation
+   */
+  consentProof?: invitation.ConsentProofPayload
+
   /**
    * Retrieve messages in this conversation. Default to returning all messages.
    *
@@ -502,19 +508,22 @@ export class ConversationV2<ContentTypes>
   peerAddress: string
   createdAt: Date
   context?: InvitationContext
+  consentProof?: invitation.ConsentProofPayload
 
   constructor(
     client: Client<ContentTypes>,
     topic: string,
     peerAddress: string,
     createdAt: Date,
-    context: InvitationContext | undefined
+    context: InvitationContext | undefined,
+    consentProof: invitation.ConsentProofPayload | undefined
   ) {
     this.topic = topic
     this.createdAt = createdAt
     this.context = context
     this.client = client
     this.peerAddress = peerAddress
+    this.consentProof = consentProof
   }
 
   get clientAddress() {
@@ -541,6 +550,10 @@ export class ConversationV2<ContentTypes>
     return this.client.contacts.consentState(this.peerAddress)
   }
 
+  get consentProofPayload(): invitation.ConsentProofPayload | undefined {
+    return this.consentProof
+  }
+
   /**
    * Returns a list of all messages to/from the peerAddress
    */

src/conversations/Conversations.ts

@@ -1,4 +1,9 @@
-import type { conversationReference, keystore, messageApi } from '@xmtp/proto'
+import type {
+  conversationReference,
+  invitation,
+  keystore,
+  messageApi,
+} from '@xmtp/proto'
 import Long from 'long'
 import { SortDirection, type OnConnectionLostCallback } from '@/ApiClient'
 import type { ListMessagesOptions } from '@/Client'
@@ -27,7 +32,6 @@ import JobRunner from './JobRunner'
 const messageHasHeaders = (msg: MessageV1): boolean => {
   return Boolean(msg.recipientAddress && msg.senderAddress)
 }
-
 /**
  * Conversations allows you to view ongoing 1:1 messaging sessions with another wallet
  */
@@ -88,6 +92,7 @@ export default class Conversations<ContentTypes = any> {
             createdNs: dateToNs(createdAt),
             topic: buildDirectMessageTopic(peerAddress, this.client.address),
             context: undefined,
+            consentProofPayload: undefined,
           }))
           .filter((c) => isValidTopic(c.topic)),
       })
@@ -148,7 +153,6 @@ export default class Conversations<ContentTypes = any> {
       startTime,
       direction: SortDirection.SORT_DIRECTION_ASCENDING,
     })
-
     return this.decodeInvites(envelopes)
   }
 
@@ -198,7 +202,8 @@ export default class Conversations<ContentTypes = any> {
       convoRef.topic,
       convoRef.peerAddress,
       nsToDate(convoRef.createdNs),
-      convoRef.context
+      convoRef.context,
+      convoRef.consentProofPayload
     )
   }
 
@@ -469,7 +474,8 @@ export default class Conversations<ContentTypes = any> {
    */
   async newConversation(
     peerAddress: string,
-    context?: InvitationContext
+    context?: InvitationContext,
+    consentProof?: invitation.ConsentProofPayload
   ): Promise<Conversation<ContentTypes>> {
     let contact = await this.client.getUserContact(peerAddress)
     if (!contact) {
@@ -484,7 +490,6 @@ export default class Conversations<ContentTypes = any> {
     if (contact instanceof PublicKeyBundle && !context?.conversationId) {
       return new ConversationV1(this.client, peerAddress, new Date())
     }
-
     // If no conversationId, check and see if we have an existing V1 conversation
     if (!context?.conversationId) {
       const v1Convos = await this.listV1Conversations()
@@ -534,20 +539,25 @@ export default class Conversations<ContentTypes = any> {
       if (newItemMatch) {
         return newItemMatch
       }
-
-      return this.createV2Convo(contact as SignedPublicKeyBundle, context)
+      return this.createV2Convo(
+        contact as SignedPublicKeyBundle,
+        context,
+        consentProof
+      )
     })
   }
 
   private async createV2Convo(
     recipient: SignedPublicKeyBundle,
-    context?: InvitationContext
+    context?: InvitationContext,
+    consentProof?: invitation.ConsentProofPayload
   ): Promise<ConversationV2<ContentTypes>> {
     const timestamp = new Date()
     const { payload, conversation } = await this.client.keystore.createInvite({
       recipient,
       context,
       createdNs: dateToNs(timestamp),
+      consentProof,
     })
     if (!payload || !conversation) {
       throw new Error('Required field not returned from Keystore')

src/crypto/Signature.ts

@@ -159,6 +159,20 @@ export class WalletSigner implements KeySigner {
     )
   }
 
+  static consentProofRequestText(
+    peerAddress: string,
+    timestamp: number
+  ): string {
+    return (
+      'XMTP : Grant inbox consent to sender\n' +
+      '\n' +
+      `Current Time: ${timestamp}\n` +
+      `From Address: ${peerAddress}\n` +
+      '\n' +
+      'For more info: https://xmtp.org/signatures/'
+    )
+  }
+
   static signerKey(
     key: SignedPublicKey,
     signature: ECDSACompactWithRecovery

src/keystore/InMemoryKeystore.ts

@@ -421,6 +421,7 @@ export default class InMemoryKeystore implements KeystoreInterface {
         topic: buildDirectMessageTopicV2(topic),
         aes256GcmHkdfSha256: { keyMaterial },
         context: req.context,
+        consentProof: req.consentProof,
       })
 
       const sealed = await SealedInvitation.createV1({
@@ -575,6 +576,7 @@ export default class InMemoryKeystore implements KeystoreInterface {
       createdNs: data.createdNs,
       topic: buildDirectMessageTopic(data.peerAddress, this.walletAddress),
       context: undefined,
+      consentProofPayload: undefined,
     }
   }
 

src/keystore/utils.ts

@@ -118,6 +118,7 @@ export const topicDataToV2ConversationReference = ({
   topic: invitation.topic,
   peerAddress,
   createdNs,
+  consentProofPayload: invitation.consentProof,
 })
 
 export const isCompleteTopicData = (