feat: update signing to support non-executing sign thru privy-cross-a…

…pp (#206)

* feat: update signing to support non-executing sign thru privy-cross-app

* update typed data sign flow to pull custom signature from RLP encoded sig

* remove unused imports

* updates for non-executing tx via sign typed data

* update test

* changeset

.changeset/gorgeous-fireants-vanish.md

@@ -0,0 +1,7 @@
+---
+'@abstract-foundation/agw-client': minor
+'@abstract-foundation/agw-react': minor
+'@abstract-foundation/web3-react-agw': minor
+---
+
+Add non executing transaction signing

packages/agw-client/src/actions/sendPrivyTransaction.ts

@@ -11,6 +11,7 @@ import {
 import {
   type ChainEIP712,
   type SendEip712TransactionParameters,
+  type SignEip712TransactionParameters,
   type SignEip712TransactionReturnType,
 } from 'viem/zksync';
 
@@ -71,3 +72,24 @@ export async function sendPrivySignTypedData(
   )) as Hex;
   return result;
 }
+
+export async function signPrivyTransaction<
+  chain extends ChainEIP712 | undefined = ChainEIP712 | undefined,
+  account extends Account | undefined = Account | undefined,
+  chainOverride extends ChainEIP712 | undefined = ChainEIP712 | undefined,
+>(
+  client: Client<Transport, ChainEIP712, Account>,
+  parameters: SignEip712TransactionParameters<chain, account, chainOverride>,
+): Promise<SignEip712TransactionReturnType> {
+  const { chain: _chain, account: _account, ...request } = parameters;
+
+  const result = (await client.request(
+    {
+      method: 'privy_signSmartWalletTx',
+      params: [replaceBigInts(request, toHex)],
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    } as any,
+    { retryCount: 0 },
+  )) as SignEip712TransactionReturnType;
+  return result;
+}

packages/agw-client/src/actions/signTransaction.ts

@@ -27,6 +27,7 @@ import {
 import { AccountNotFoundError } from '../errors/account.js';
 import { VALID_CHAINS } from '../utils.js';
 import { transformHexValues } from '../utils.js';
+import { signPrivyTransaction } from './sendPrivyTransaction.js';
 
 export interface CustomPaymasterParameters {
   nonce: number;
@@ -61,9 +62,14 @@ export async function signTransaction<
   useSignerAddress = false,
   validationHookData: Record<string, Hex> = {},
   customPaymasterHandler: CustomPaymasterHandler | undefined = undefined,
+  isPrivyCrossApp = false,
 ): Promise<SignEip712TransactionReturnType> {
   const chain = client.chain;
 
+  if (isPrivyCrossApp) {
+    return signPrivyTransaction(client, args);
+  }
+
   if (!chain?.serializers?.transaction)
     throw new BaseError('transaction serializer not found on chain.');
 

packages/agw-client/src/actions/signTypedData.ts

@@ -2,21 +2,17 @@ import {
   type Account,
   BaseError,
   type Client,
-  encodeAbiParameters,
+  fromRlp,
   hashTypedData,
   type Hex,
-  parseAbiParameters,
   type Transport,
   type TypedData,
   type TypedDataDefinition,
   type WalletClient,
 } from 'viem';
-import type { SignTypedDataParameters } from 'viem/accounts';
-import { readContract, signTypedData as viemSignTypedData } from 'viem/actions';
+import { type SignTypedDataParameters } from 'viem/accounts';
 import type { ChainEIP712 } from 'viem/chains';
-import { getAction } from 'viem/utils';
 
-import AGWAccountAbi from '../abis/AGWAccount.js';
 import {
   EOA_VALIDATOR_ADDRESS,
   SESSION_KEY_VALIDATOR_ADDRESS,
@@ -32,6 +28,7 @@ import { sendPrivySignTypedData } from './sendPrivyTransaction.js';
 import {
   type CustomPaymasterHandler,
   signEip712TransactionInternal,
+  signTransaction,
 } from './signTransaction.js';
 
 export async function signTypedData(
@@ -40,34 +37,49 @@ export async function signTypedData(
   parameters: Omit<SignTypedDataParameters, 'account' | 'privateKey'>,
   isPrivyCrossApp = false,
 ): Promise<Hex> {
-  if (isPrivyCrossApp) return await sendPrivySignTypedData(client, parameters);
-
   // if the typed data is already a zkSync EIP712 transaction, don't try to transform it
   // to an AGW typed signature, just pass it through to the signer.
   if (isEip712TypedData(parameters)) {
-    const rawSignature = await viemSignTypedData(signerClient, parameters);
-    // Match the expect signature format of the AGW smart account so the result can be
-    // directly used in eth_sendRawTransaction as the customSignature field
-    const hookData: Hex[] = [];
-    const validationHooks = await getAction(
-      client,
-      readContract,
-      'readContract',
-    )({
-      address: client.account.address,
-      abi: AGWAccountAbi,
-      functionName: 'listHooks',
-      args: [true],
-    });
-    for (const _ of validationHooks) {
-      hookData.push('0x');
+    const transformedTypedData = transformEip712TypedData(parameters);
+
+    if (transformedTypedData.chainId !== client.chain.id) {
+      throw new BaseError('Chain ID mismatch in AGW typed signature');
     }
 
-    const signature = encodeAbiParameters(
-      parseAbiParameters(['bytes', 'address', 'bytes[]']),
-      [rawSignature, EOA_VALIDATOR_ADDRESS, hookData],
+    const signedTransaction = await signTransaction(
+      client,
+      signerClient,
+      {
+        ...transformedTypedData,
+        chain: client.chain,
+      },
+      EOA_VALIDATOR_ADDRESS,
+      false,
+      {},
+      undefined,
+      isPrivyCrossApp,
     );
-    return signature;
+
+    if (!signedTransaction.startsWith('0x71')) {
+      throw new BaseError(
+        'Expected RLP encoded EIP-712 transaction as signature',
+      );
+    }
+
+    const rlpSignature: Hex = `0x${signedTransaction.slice(4)}`;
+
+    const signatureParts = fromRlp(rlpSignature, 'hex');
+    if (signatureParts.length < 15) {
+      throw new BaseError(
+        'Expected RLP encoded EIP-712 transaction with at least 15 fields',
+      );
+    }
+    // This is somewhat not type safe as it assumes that the signature from signTransaction is an
+    // RLP encoded 712 transaction and that the customSignature field is the 15th field in the transaction.
+    // That being said, it's a safe assumption for the current use case.
+    return signatureParts[14] as Hex;
+  } else if (isPrivyCrossApp) {
+    return await sendPrivySignTypedData(client, parameters);
   }
 
   return await getAgwTypedSignature({

packages/agw-client/src/utils.ts

@@ -171,30 +171,37 @@ export function transformEip712TypedData(
   return {
     chainId: Number(typedData.domain.chainId),
     account: parseAccount(
-      toHex(typedData.message['from'] as bigint, {
+      toHex(BigInt(typedData.message['from'] as string), {
         size: 20,
       }),
     ),
-    to: toHex(typedData.message['to'] as bigint, {
+    to: toHex(BigInt(typedData.message['to'] as string), {
       size: 20,
     }),
-    gas: typedData.message['gasLimit'] as bigint,
-    gasPerPubdata: typedData.message['gasPerPubdataByteLimit'] as bigint,
-    maxFeePerGas: typedData.message['maxFeePerGas'] as bigint,
-    maxPriorityFeePerGas: typedData.message['maxPriorityFeePerGas'] as bigint,
+    gas: BigInt(typedData.message['gasLimit'] as string),
+    gasPerPubdata: BigInt(
+      typedData.message['gasPerPubdataByteLimit'] as string,
+    ),
+    maxFeePerGas: BigInt(typedData.message['maxFeePerGas'] as string),
+    maxPriorityFeePerGas: BigInt(
+      typedData.message['maxPriorityFeePerGas'] as string,
+    ),
     paymaster:
-      (typedData.message['paymaster'] as bigint) > 0n
-        ? toHex(typedData.message['paymaster'] as bigint, {
+      (typedData.message['paymaster'] as string) != '0'
+        ? toHex(BigInt(typedData.message['paymaster'] as string), {
             size: 20,
           })
         : undefined,
     nonce: typedData.message['nonce'] as number,
-    value: typedData.message['value'] as bigint,
-    data: typedData.message['data'] as Hex,
+    value: BigInt(typedData.message['value'] as string),
+    data:
+      typedData.message['data'] === '0x0'
+        ? '0x'
+        : (typedData.message['data'] as Hex),
     factoryDeps: typedData.message['factoryDeps'] as Hex[],
     paymasterInput:
-      typedData.message['paymasterParams'] !== '0x'
-        ? (typedData.message['paymasterParams'] as Hex)
+      typedData.message['paymasterInput'] !== '0x'
+        ? (typedData.message['paymasterInput'] as Hex)
         : undefined,
   };
 }

packages/agw-client/src/walletActions.ts

@@ -267,6 +267,10 @@ export function globalWalletActions<
         signerClient,
         args as SignEip712TransactionParameters<chain, account>,
         EOA_VALIDATOR_ADDRESS,
+        false,
+        {},
+        undefined,
+        isPrivyCrossApp,
       ),
     signTypedData: (
       args: Omit<SignTypedDataParameters, 'account' | 'privateKey'>,

packages/agw-client/test/src/actions/signTypedData.test.ts

@@ -19,7 +19,7 @@ import {
 } from 'viem';
 import { toAccount } from 'viem/accounts';
 import { getCode } from 'viem/actions';
-import { ChainEIP712 } from 'viem/zksync';
+import { ChainEIP712, getGeneralPaymasterInput } from 'viem/zksync';
 import { describe, expect, it, vi } from 'vitest';
 vi.mock('viem/actions', async (importOriginal) => {
   const actual = await importOriginal();
@@ -132,7 +132,9 @@ describe('signTypedData', async () => {
         value: 0n,
         data: '0x',
         factoryDeps: [],
-        paymasterInput: '0x',
+        paymasterInput: getGeneralPaymasterInput({
+          innerInput: '0x',
+        }),
       },
     });
     expect(signedMessage).toBe(

packages/agw-client/test/src/walletActions.test.ts

@@ -92,6 +92,10 @@ describe('globalWalletActions', () => {
       mockSignerClient,
       mockArgs,
       EOA_VALIDATOR_ADDRESS,
+      false,
+      {},
+      undefined,
+      false,
     );
   });
 

packages/agw-react/package.json

@@ -79,7 +79,7 @@
   "devDependencies": {
     "@abstract-foundation/agw-client": "workspace:*",
     "@privy-io/cross-app-connect": "^0.1.4",
-    "@privy-io/react-auth": "^2.0.5",
+    "@privy-io/react-auth": "^2.0.8",
     "@rainbow-me/rainbowkit": "^2.1.6",
     "@tanstack/query-core": "^5.56.2",
     "@types/react": ">=18.3.1",