feat(evm): compute intrinsic gas limit for send on evm

Author: Moustafa-Koterba

.changeset/eleven-countries-pull.md

@@ -0,0 +1,5 @@
+---
+"@ledgerhq/coin-evm": minor
+---
+
+compute intrinsic gas limit for send on evm

libs/coin-modules/coin-evm/src/logic/common.ts

@@ -96,10 +96,12 @@ export function getErc20Data(recipient: string, amount: bigint): Buffer {
   return Buffer.from(data.slice(2), "hex");
 }
 
-function getCallData(intent: TransactionIntent<MemoNotSupported, BufferTxData>): Buffer {
+export function getCallData(intent: TransactionIntent<MemoNotSupported, BufferTxData>): Buffer {
   const data = intent.data?.value;
   if (Buffer.isBuffer(data) && data.length) return data;
-  return isNative(intent.asset) ? Buffer.from([]) : getErc20Data(intent.recipient, intent.amount);
+  return isNative(intent.asset) || !intent.recipient
+    ? Buffer.from([])
+    : getErc20Data(intent.recipient, intent.amount);
 }
 
 export async function prepareUnsignedTxParams(

libs/coin-modules/coin-evm/src/logic/computeGasLimit.test.ts

@@ -0,0 +1,32 @@
+import { DEFAULT_GAS_LIMIT } from "../utils";
+import { computeIntrinsicGasLimit } from "./computeGasLimit";
+
+describe("computeGasLimit", () => {
+  it.each([
+    {
+      callData: "",
+      expectedGasLimit: 21000n,
+    },
+    {
+      callData:
+        "a9059cbb00000000000000000000000066c4371ae8ffed2ec1c2ebbbccfb7e494181e1e30000000000000000000000000000000000000000000000000000000000000000",
+      expectedGasLimit: 21560n,
+    },
+    {
+      callData:
+        "a9059cbb000000000000000000000000d8ff72a08408b97655ee94381b8fa24ba7d6f5ac0000000000000000000000000000000000000000000000000000000000895440",
+      expectedGasLimit: 21596n,
+    },
+    {
+      callData:
+        "a9059cbb00000000000000000000000066c4371ae8ffed2ec1c2ebbbccfb7e494181e1e30000000000000000000000000000000000000000000000000000000000b71b00",
+      expectedGasLimit: 21584n,
+    },
+  ])("should compute intrinsic gas", ({ callData, expectedGasLimit }) => {
+    const intrinsicGasLimit = computeIntrinsicGasLimit(
+      BigInt(DEFAULT_GAS_LIMIT.toFixed(0)),
+      Buffer.from(callData, "hex"),
+    );
+    expect(intrinsicGasLimit).toEqual(expectedGasLimit);
+  });
+});

libs/coin-modules/coin-evm/src/logic/computeGasLimit.ts

@@ -0,0 +1,8 @@
+export function computeIntrinsicGasLimit(defaultGasLimit: bigint, callData: Buffer): bigint {
+  let intrinsicGasLimit = defaultGasLimit;
+  for (let index = 0; index < callData.length; index++) {
+    intrinsicGasLimit += callData[index] === 0 ? 4n : 16n;
+  }
+
+  return intrinsicGasLimit;
+}

libs/coin-modules/coin-evm/src/logic/validateIntent.test.ts

@@ -25,8 +25,14 @@ import { EvmCoinConfig, setCoinConfig } from "../config";
 import ledgerExplorer from "../network/explorer/ledger";
 import ledgerGasTracker from "../network/gasTracker/ledger";
 import ledgerNode from "../network/node/ledger";
+import * as computeGasLimitModule from "./computeGasLimit";
 import { validateIntent } from "./validateIntent";
 
+jest.mock("./computeGasLimit", () => ({
+  ...jest.requireActual("./computeGasLimit"),
+  computeIntrinsicGasLimit: jest.fn(),
+}));
+
 function legacyIntent(
   intent: Omit<Partial<TransactionIntent>, "type">,
 ): TransactionIntent<MemoNotSupported, BufferTxData> {
@@ -106,7 +112,7 @@ describe("validateIntent", () => {
     jest.spyOn(ledgerNode, "getTransactionCount").mockResolvedValue(30);
   });
   afterEach(() => {
-    jest.restoreAllMocks();
+    jest.clearAllMocks();
   });
 
   describe("fee ratio", () => {
@@ -122,7 +128,10 @@ describe("validateIntent", () => {
     ])("%s with too high fees on a %s asset", async (_s, assetType, expectedWarnings) => {
       const res = await validateIntent(
         {} as CryptoCurrency,
-        eip1559Intent({ amount: 1n, asset: { type: assetType } }),
+        eip1559Intent({
+          amount: 1n,
+          asset: { type: assetType },
+        }),
         [{ value: 50n, asset: { type: "native" } }],
         {
           value: 2n,
@@ -479,13 +488,18 @@ describe("validateIntent", () => {
         });
 
         it("detects gas limit being too low in a tx with an error", async () => {
+          const intrinsicGasLimit = 21000n;
+          (computeGasLimitModule.computeIntrinsicGasLimit as jest.Mock).mockReturnValue(
+            intrinsicGasLimit,
+          );
+
           const res = await validateIntent(
             {} as CryptoCurrency,
             createIntent({}),
             [{ value: 50n, asset: { type: "native" } }],
             {
               value: 0n,
-              parameters: { gasLimit: 20000n }, // min should be 21000
+              parameters: { gasLimit: intrinsicGasLimit - 1n }, // min should be 21000
             },
           );
 
@@ -494,16 +508,23 @@ describe("validateIntent", () => {
               gasLimit: new GasLessThanEstimate(),
             }),
           );
+
+          expect(computeGasLimitModule.computeIntrinsicGasLimit).toHaveBeenCalledTimes(1);
         });
 
         it("detects custom gas limit being too low in a tx with an error", async () => {
+          const intrinsicGasLimit = 21000n;
+          (computeGasLimitModule.computeIntrinsicGasLimit as jest.Mock).mockReturnValue(
+            intrinsicGasLimit,
+          );
+
           const res = await validateIntent(
             {} as CryptoCurrency,
             createIntent({}),
             [{ value: 50n, asset: { type: "native" } }],
             {
               value: 0n,
-              parameters: { customGasLimit: 20000n }, // min should be 21000
+              parameters: { customGasLimit: intrinsicGasLimit - 1n },
             },
           );
 
@@ -512,6 +533,8 @@ describe("validateIntent", () => {
               gasLimit: new GasLessThanEstimate(),
             }),
           );
+
+          expect(computeGasLimitModule.computeIntrinsicGasLimit).toHaveBeenCalledTimes(1);
         });
 
         it("detects customGasLimit being lower than gasLimit with a warning", async () => {

libs/coin-modules/coin-evm/src/logic/validateIntent.ts

@@ -30,12 +30,14 @@ import { getGasTracker } from "../network/gasTracker";
 import { isNative, TransactionTypes } from "../types";
 import { DEFAULT_GAS_LIMIT, isEthAddress } from "../utils";
 import {
+  getCallData,
   getTransactionType,
   isApiGasOptions,
   isEip1559FeeEstimation,
   isEip55Address,
   isLegacyFeeEstimation,
 } from "./common";
+import { computeIntrinsicGasLimit } from "./computeGasLimit";
 import estimateFees from "./estimateFees";
 
 function assetsAreEqual(asset1: AssetInfo, asset2: AssetInfo): boolean {
@@ -124,7 +126,7 @@ function validateRecipient(
  */
 async function validateGas(
   currency: CryptoCurrency,
-  intent: TransactionIntent,
+  intent: TransactionIntent<MemoNotSupported, BufferTxData>,
   balances: Balance[],
   estimatedFees: FeeEstimation,
 ): Promise<Pick<TransactionValidation, "errors" | "warnings">> {
@@ -139,17 +141,23 @@ async function validateGas(
     typeof estimatedFees.parameters?.customGasLimit === "bigint" &&
     estimatedFees.parameters.customGasLimit;
 
+  const callData = getCallData(intent);
+  const intrinsicGasLimit = computeIntrinsicGasLimit(
+    BigInt(DEFAULT_GAS_LIMIT.toFixed(0)),
+    callData,
+  );
+
   // Gas Limit
   if (typeof customGasLimit === "bigint") {
     if (customGasLimit === 0n) {
       errors.gasLimit = new FeeNotLoaded();
-    } else if (customGasLimit < BigInt(DEFAULT_GAS_LIMIT.toFixed(0))) {
+    } else if (customGasLimit < intrinsicGasLimit) {
       errors.gasLimit = new GasLessThanEstimate();
     }
   } else {
     if (gasLimit === 0n) {
       errors.gasLimit = new FeeNotLoaded();
-    } else if (gasLimit < BigInt(DEFAULT_GAS_LIMIT.toFixed(0))) {
+    } else if (gasLimit < intrinsicGasLimit) {
       errors.gasLimit = new GasLessThanEstimate();
     }
   }

libs/coin-modules/coin-evm/tsconfig.json

@@ -19,4 +19,4 @@
   "include": [
     "src/**/*"
   ]
-}
+}