feat: add near_signMessage method to NEAR (#310)

Co-authored-by: Ben Kremer <contact@bkrem.dev>

.gitignore

@@ -35,3 +35,6 @@ yarn-error.log*
 
 # vercel
 .vercel
+
+# webstorm ide
+.idea

wallets/react-wallet-v2/package.json

@@ -31,6 +31,7 @@
     "@taquito/signer": "^15.1.0",
     "@taquito/taquito": "^15.1.0",
     "@walletconnect/web3wallet": "1.9.1",
+    "borsh": "^1.0.0",
     "bs58": "5.0.0",
     "cosmos-wallet": "1.2.0",
     "ethers": "5.7.2",

wallets/react-wallet-v2/src/data/NEARData.ts

@@ -52,5 +52,6 @@ export const NEAR_SIGNING_METHODS = {
   NEAR_SIGN_AND_SEND_TRANSACTION: 'near_signAndSendTransaction',
   NEAR_SIGN_TRANSACTIONS: 'near_signTransactions',
   NEAR_SIGN_AND_SEND_TRANSACTIONS: 'near_signAndSendTransactions',
-  NEAR_VERIFY_OWNER: 'near_verifyOwner'
+  NEAR_VERIFY_OWNER: 'near_verifyOwner',
+  NEAR_SIGN_MESSAGE: 'near_signMessage'
 }

wallets/react-wallet-v2/src/hooks/useWalletConnectEventsManager.ts

@@ -79,6 +79,7 @@ export default function useWalletConnectEventsManager(initialized: boolean) {
         case NEAR_SIGNING_METHODS.NEAR_SIGN_TRANSACTIONS:
         case NEAR_SIGNING_METHODS.NEAR_SIGN_AND_SEND_TRANSACTIONS:
         case NEAR_SIGNING_METHODS.NEAR_VERIFY_OWNER:
+        case NEAR_SIGNING_METHODS.NEAR_SIGN_MESSAGE:
           return ModalStore.open('SessionSignNearModal', { requestEvent, requestSession })
 
         case MULTIVERSX_SIGNING_METHODS.MULTIVERSX_SIGN_MESSAGE:

wallets/react-wallet-v2/src/lib/NearLib.ts

@@ -9,6 +9,7 @@ import { AccessKeyView } from 'near-api-js/lib/providers/provider'
 
 import { web3wallet } from '@/utils/WalletConnectUtil'
 import { NEAR_TEST_CHAINS, TNearChain } from '@/data/NEARData'
+import { Schema, serialize } from 'borsh'
 
 const MAX_ACCOUNTS = 2
 
@@ -63,6 +64,58 @@ interface SignAndSendTransactionsParams {
   transactions: Array<nearTransactions.Transaction>
 }
 
+export interface SignMessageParamsNEP {
+  message: string
+  recipient: string
+  nonce: Buffer
+  callbackUrl?: string
+  state?: string
+}
+
+interface SignMessageParams {
+  chainId: string
+  messageParams: SignMessageParamsNEP & {
+    accountId?: string
+  }
+}
+
+interface SignedMessage {
+  accountId: string
+  publicKey: string
+  signature: string
+  state?: string
+}
+
+export class MessagePayload {
+  tag: number
+  message: string
+  nonce: Buffer
+  recipient: string
+  callbackUrl?: string
+
+  constructor(data: SignMessageParamsNEP) {
+    // The tag's value is a hardcoded value as per
+    // defined in the NEP [NEP413](https://github.com/near/NEPs/blob/master/neps/nep-0413.md)
+    this.tag = 2147484061
+    this.message = data.message
+    this.nonce = data.nonce
+    this.recipient = data.recipient
+    if (data.callbackUrl) {
+      this.callbackUrl = data.callbackUrl
+    }
+  }
+}
+
+export const payloadSchema: Schema = {
+  struct: {
+    tag: 'u32',
+    message: 'string',
+    nonce: { array: { type: 'u8', len: 32 } },
+    recipient: 'string',
+    callbackUrl: { option: 'string' }
+  }
+}
+
 export class NearWallet {
   private networkId: string
   private keyStore: nearKeyStores.KeyStore
@@ -342,4 +395,35 @@ export class NearWallet {
 
     return results
   }
+
+  async signMessage({ chainId, messageParams }: SignMessageParams): Promise<SignedMessage> {
+    const { message, nonce, recipient, callbackUrl, state, accountId } = messageParams
+    const nonceArray = Buffer.from(nonce)
+
+    if (nonceArray.length !== 32) {
+      throw Error('Expected nonce to be a 32 bytes buffer')
+    }
+
+    const accounts = await this.getAllAccounts()
+    const account = accounts.find(acc => acc.accountId === accountId)
+
+    // If no accountId is provided in params default to the first accountId in accounts.
+    // in a real wallet it would default to the `active/selected` account
+    // this is because we should be able to use `signMessage` without `signIn`.
+    const accId = account ? account.accountId : accounts[0].accountId
+
+    const signer = new InMemorySigner(this.getKeyStore())
+    const networkId = chainId.split(':')[1]
+
+    // Create the message payload and sign it
+    const payload = new MessagePayload({ message, nonce: nonceArray, recipient, callbackUrl })
+    const encodedPayload = serialize(payloadSchema, payload)
+    const signed = await signer.signMessage(encodedPayload, accId, networkId)
+
+    return {
+      accountId: accId,
+      publicKey: signed.publicKey.toString(),
+      signature: Buffer.from(signed.signature).toString('base64')
+    }
+  }
 }

wallets/react-wallet-v2/src/utils/NearRequestHandlerUtil.ts

@@ -162,6 +162,24 @@ export async function approveNearRequest(
         keyType: signed.publicKey.keyType
       })
     }
+    case NEAR_SIGNING_METHODS.NEAR_SIGN_MESSAGE: {
+      console.log('approve', { id, params })
+
+      if (!chainId) {
+        throw new Error('Invalid chain id')
+      }
+
+      const { accountId, publicKey, signature } = await nearWallet.signMessage({
+        chainId,
+        messageParams: params.request.params
+      })
+
+      return formatJsonRpcResult(id, {
+        accountId,
+        publicKey,
+        signature
+      })
+    }
     case NEAR_SIGNING_METHODS.NEAR_SIGN_AND_SEND_TRANSACTIONS: {
       console.log('approve', { id, params })
 

wallets/react-wallet-v2/yarn.lock

@@ -3189,6 +3189,11 @@ borsh@^0.7.0:
     bs58 "^4.0.0"
     text-encoding-utf-8 "^1.0.2"
 
+borsh@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/borsh/-/borsh-1.0.0.tgz#b564c8cc8f7a91e3772b9aef9e07f62b84213c1f"
+  integrity sha512-fSVWzzemnyfF89EPwlUNsrS5swF5CrtiN4e+h0/lLf4dz2he4L3ndM20PS9wj7ICSkXJe/TQUHdaPTq15b1mNQ==
+
 brace-expansion@^1.1.7:
   version "1.1.11"
   resolved "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.11.tgz"