implement multidimensional nonces for smart wallets

.changeset/famous-penguins-lay.md

@@ -0,0 +1,5 @@
+---
+"@thirdweb-dev/wallets": patch
+---
+
+Multidimensional nonces for smart wallets

packages/wallets/src/evm/connectors/smart-wallet/lib/erc4337-provider.ts

@@ -149,7 +149,7 @@ export class ERC4337EthersProvider extends providers.BaseProvider {
       hash: userOpHash,
       confirmations: 0,
       from: userOp.sender,
-      nonce: BigNumber.from(userOp.nonce).toNumber(),
+      nonce: 0, // not the real nonce, but good enough for this purpose
       gasLimit: BigNumber.from(userOp.callGasLimit), // ??
       value: BigNumber.from(0),
       data: utils.hexValue(userOp.callData), // should extract the actual called method from this "execFromEntryPoint()" call

packages/wallets/src/evm/connectors/smart-wallet/lib/erc4337-signer.ts

@@ -5,6 +5,7 @@ import { ClientConfig } from "@account-abstraction/sdk";
 import { BaseAccountAPI } from "./base-api";
 import type { ERC4337EthersProvider } from "./erc4337-provider";
 import { HttpRpcClient } from "./http-rpc-client";
+import { randomNonce } from "./utils";
 
 export class ERC4337EthersSigner extends Signer {
   config: ClientConfig;
@@ -40,12 +41,14 @@ export class ERC4337EthersSigner extends Signer {
     const tx = await ethers.utils.resolveProperties(transaction);
     await this.verifyAllNecessaryFields(tx);
 
+    const multidimensionalNonce = randomNonce();
     const userOperation = await this.smartAccountAPI.createSignedUserOp(
       {
         target: tx.to || "",
         data: tx.data?.toString() || "0x",
         value: tx.value,
         gasLimit: tx.gasLimit,
+        nonce: multidimensionalNonce,
       },
       batched,
     );

packages/wallets/src/evm/connectors/smart-wallet/lib/utils.ts

@@ -1,4 +1,4 @@
-import { ethers, utils } from "ethers";
+import { BigNumber, ethers, utils } from "ethers";
 import { UserOperationStruct } from "@account-abstraction/contracts";
 
 export function toJSON(op: Partial<UserOperationStruct>): Promise<any> {
@@ -76,3 +76,31 @@ export async function getUserOpHashV06(
   );
   return utils.keccak256(enc);
 }
+
+const generateRandomUint192 = (): bigint => {
+  const rand1 = BigInt(Math.floor(Math.random() * 0x100000000));
+  const rand2 = BigInt(Math.floor(Math.random() * 0x100000000));
+  const rand3 = BigInt(Math.floor(Math.random() * 0x100000000));
+  const rand4 = BigInt(Math.floor(Math.random() * 0x100000000));
+  const rand5 = BigInt(Math.floor(Math.random() * 0x100000000));
+  const rand6 = BigInt(Math.floor(Math.random() * 0x100000000));
+  return (
+    (rand1 << 160n) |
+    (rand2 << 128n) |
+    (rand3 << 96n) |
+    (rand4 << 64n) |
+    (rand5 << 32n) |
+    rand6
+  );
+};
+
+export const randomNonce = () => {
+  let hexString = generateRandomUint192().toString(16);
+  if (hexString.length % 2 !== 0) {
+    hexString = "0" + hexString;
+  }
+  hexString = "0x" + hexString;
+  return ethers.BigNumber.from(
+    ethers.utils.concat([hexString, "0x0000000000000000"]),
+  );
+};