Safe Message Decoding

package.json

@@ -41,14 +41,17 @@
   },
   "dependencies": {
     "@safe-global/safe-deployments": "^1.37.0",
+    "@safe-global/safe-gateway-typescript-sdk": "^3.22.2",
     "@safe-global/safe-modules-deployments": "^2.2.0",
     "near-api-js": "^5.0.0",
     "near-ca": "^0.5.2",
+    "semver": "^7.6.3",
     "viem": "^2.16.5"
   },
   "devDependencies": {
     "@types/jest": "^29.5.12",
     "@types/node": "^22.3.0",
+    "@types/semver": "^7.5.8",
     "@types/yargs": "^17.0.32",
     "@typescript-eslint/eslint-plugin": "^8.1.0",
     "@typescript-eslint/parser": "^8.1.0",
@@ -67,4 +70,4 @@
     "glob": "^9.0.0",
     "base-x": "^3.0.0"
   }
-}
+}

src/lib/safe-message.ts

@@ -0,0 +1,148 @@
+/// This file is a viem implementation of the useDecodedSafeMessage hook from:
+/// https://github.com/safe-global/safe-wallet-web
+import { type SafeInfo } from "@safe-global/safe-gateway-typescript-sdk";
+import { gte } from "semver";
+import {
+  Address,
+  fromHex,
+  Hash,
+  hashMessage,
+  hashTypedData,
+  isHex,
+  TypedDataDomain,
+} from "viem";
+
+interface TypedDataTypes {
+  name: string;
+  type: string;
+}
+type TypedMessageTypes = {
+  [key: string]: TypedDataTypes[];
+};
+
+export type EIP712TypedData = {
+  domain: TypedDataDomain;
+  types: TypedMessageTypes;
+  message: Record<string, unknown>;
+  primaryType: string;
+};
+
+export type MinimalSafeInfo = Pick<SafeInfo, "address" | "version" | "chainId">;
+
+/*
+ * From v1.3.0, EIP-1271 support was moved to the CompatibilityFallbackHandler.
+ * Also 1.3.0 introduces the chainId in the domain part of the SafeMessage
+ */
+const EIP1271_FALLBACK_HANDLER_SUPPORTED_SAFE_VERSION = "1.3.0";
+
+const generateSafeMessageMessage = (
+  message: string | EIP712TypedData
+): string => {
+  return typeof message === "string"
+    ? hashMessage(message)
+    : hashTypedData(message);
+};
+
+/**
+ * Generates `SafeMessage` typed data for EIP-712
+ * https://github.com/safe-global/safe-contracts/blob/main/contracts/handler/CompatibilityFallbackHandler.sol#L12
+ * @param safe Safe which will sign the message
+ * @param message Message to sign
+ * @returns `SafeMessage` types for signing
+ */
+const generateSafeMessageTypedData = (
+  { version, chainId, address }: MinimalSafeInfo,
+  message: string | EIP712TypedData
+): EIP712TypedData => {
+  if (!version) {
+    throw Error("Cannot create SafeMessage without version information");
+  }
+  const isHandledByFallbackHandler = gte(
+    version,
+    EIP1271_FALLBACK_HANDLER_SUPPORTED_SAFE_VERSION
+  );
+  const verifyingContract = address.value as Address;
+  return {
+    domain: isHandledByFallbackHandler
+      ? {
+          chainId: Number(BigInt(chainId)),
+          verifyingContract,
+        }
+      : { verifyingContract },
+    types: {
+      SafeMessage: [{ name: "message", type: "bytes" }],
+    },
+    message: {
+      message: generateSafeMessageMessage(message),
+    },
+    primaryType: "SafeMessage",
+  };
+};
+
+const generateSafeMessageHash = (
+  safe: MinimalSafeInfo,
+  message: string | EIP712TypedData
+): Hash => {
+  const typedData = generateSafeMessageTypedData(safe, message);
+  return hashTypedData(typedData);
+};
+
+/**
+ * If message is a hex value and is Utf8 encoded string we decode it, else we return the raw message
+ * @param {string} message raw input message
+ * @returns {string}
+ */
+const getDecodedMessage = (message: string): string => {
+  if (isHex(message)) {
+    try {
+      return fromHex(message, "string");
+    } catch (e) {
+      // the hex string is not UTF8 encoding so return the raw message.
+    }
+  }
+
+  return message;
+};
+
+/**
+ * Returns the decoded message, the hash of the `message` and the hash of the `safeMessage`.
+ * The `safeMessageMessage` is the value inside the SafeMessage and the `safeMessageHash` gets signed if the connected wallet does not support `eth_signTypedData`.
+ *
+ * @param message message as string, UTF-8 encoded hex string or EIP-712 Typed Data
+ * @param safe SafeInfo of the opened Safe
+ * @returns `{
+ *   decodedMessage,
+ *   safeMessageMessage,
+ *   safeMessageHash
+ * }`
+ */
+export function decodedSafeMessage(
+  message: string | EIP712TypedData,
+  safe: MinimalSafeInfo
+): {
+  decodedMessage: string | EIP712TypedData;
+  safeMessageMessage: string;
+  safeMessageHash: Hash;
+} {
+  const decodedMessage =
+    typeof message === "string" ? getDecodedMessage(message) : message;
+
+  return {
+    decodedMessage,
+    safeMessageMessage: generateSafeMessageMessage(decodedMessage),
+    safeMessageHash: generateSafeMessageHash(safe, decodedMessage),
+  };
+}
+
+// const isEIP712TypedData = (obj: any): obj is EIP712TypedData => {
+//   return (
+//     typeof obj === "object" &&
+//     obj != null &&
+//     "domain" in obj &&
+//     "types" in obj &&
+//     "message" in obj
+//   );
+// };
+
+// export const isBlindSigningPayload = (obj: EIP712TypedData | string): boolean =>
+//   !isEIP712TypedData(obj) && isHash(obj);

tests/lib.bundler.spec.ts → tests/lib/bundler.spec.ts

@@ -1,4 +1,4 @@
-import { Erc4337Bundler } from "../src/lib/bundler";
+import { Erc4337Bundler } from "../../src/lib/bundler";
 describe("Safe Pack", () => {
   const entryPoint = "0x0000000071727De22E5E9d8BAf0edAc6f37da032";
 

tests/lib.multisend.spec.ts → tests/lib/multisend.spec.ts

@@ -1,4 +1,4 @@
-import { encodeMulti } from "../src/lib/multisend";
+import { encodeMulti } from "../../src/lib/multisend";
 
 describe("Multisend", () => {
   it("encodeMulti", () => {

tests/lib/safe-message.spec.ts

@@ -0,0 +1,54 @@
+import { zeroAddress } from "viem";
+
+import { decodedSafeMessage } from "../../src/lib/safe-message";
+
+describe("Multisend", () => {
+  const plainMessage = `Welcome to OpenSea!
+
+Click to sign in and accept the OpenSea Terms of Service (https://opensea.io/tos) and Privacy Policy (https://opensea.io/privacy).
+
+This request will not trigger a blockchain transaction or cost any gas fees.
+
+Wallet address:
+0xdcf56f5a8cc380f63b6396dbddd0ae9fa605beee
+
+Nonce:
+2a29a96e-c741-4500-9de3-03a865ff05db`;
+  const safeInfo = {
+    address: {
+      value: "0xDcf56F5a8Cc380f63b6396Dbddd0aE9fa605BeeE",
+    },
+    chainId: "11155111",
+    version: "1.4.1+L2",
+  };
+  it("decodeSafeMessage", () => {
+    expect(decodedSafeMessage(plainMessage, safeInfo)).toStrictEqual({
+      decodedMessage: plainMessage,
+      safeMessageMessage:
+        "0xc90ef7cffa3b5b1422e6c49ca7a5d7c1e9f514db067ec9bad52db13e83cbbb7c",
+      safeMessageHash:
+        "0x19dbea8af895c61831f2830ebba00d6160e4527398ec1d88553a8f0b8318959d",
+    });
+    // Lower Safe Version.
+    expect(
+      decodedSafeMessage(plainMessage, { ...safeInfo, version: "1.2.1" })
+    ).toStrictEqual({
+      decodedMessage: plainMessage,
+      safeMessageMessage:
+        "0xc90ef7cffa3b5b1422e6c49ca7a5d7c1e9f514db067ec9bad52db13e83cbbb7c",
+      safeMessageHash:
+        "0x58daaab88459f40802201741918791f85cb81a435328168ee6a1eaa735442809",
+    });
+  });
+
+  it("decodeSafeMessage", () => {
+    const versionlessSafeInfo = {
+      address: { value: zeroAddress },
+      chainId: "1",
+      version: null,
+    };
+    expect(() => decodedSafeMessage(plainMessage, versionlessSafeInfo)).toThrow(
+      "Cannot create SafeMessage without version information"
+    );
+  });
+});

tests/lib.safe.spec.ts → tests/lib/safe.spec.ts

@@ -1,7 +1,7 @@
 import { zeroAddress } from "viem";
 
-import { ContractSuite as EthPack } from "./ethers-safe";
-import { ContractSuite as ViemPack } from "../src/lib/safe";
+import { ContractSuite as ViemPack } from "../../src/lib/safe";
+import { ContractSuite as EthPack } from "../ethers-safe";
 
 describe("Safe Pack", () => {
   let ethersPack: EthPack;

yarn.lock

@@ -1179,6 +1179,11 @@
   dependencies:
     semver "^7.6.2"
 
+"@safe-global/safe-gateway-typescript-sdk@^3.22.2":
+  version "3.22.2"
+  resolved "https://registry.yarnpkg.com/@safe-global/safe-gateway-typescript-sdk/-/safe-gateway-typescript-sdk-3.22.2.tgz#d4ff9972e58f9344fc95f8d41b2ec6517baa8e79"
+  integrity sha512-Y0yAxRaB98LFp2Dm+ACZqBSdAmI3FlpH/LjxOZ94g/ouuDJecSq0iR26XZ5QDuEL8Rf+L4jBJaoDC08CD0KkJw==
+
 "@safe-global/safe-modules-deployments@^2.2.0":
   version "2.2.1"
   resolved "https://registry.yarnpkg.com/@safe-global/safe-modules-deployments/-/safe-modules-deployments-2.2.1.tgz#a8b88f2afc6ec04fed09968fe1e4990ed975c86e"
@@ -1448,6 +1453,11 @@
   resolved "https://registry.yarnpkg.com/@types/node/-/node-18.15.13.tgz#f64277c341150c979e42b00e4ac289290c9df469"
   integrity sha512-N+0kuo9KgrUQ1Sn/ifDXsvg0TTleP7rIy4zOBGECxAljqvqfqpTfzx0Q1NUedOixRMBfe2Whhb056a42cWs26Q==
 
+"@types/semver@^7.5.8":
+  version "7.5.8"
+  resolved "https://registry.yarnpkg.com/@types/semver/-/semver-7.5.8.tgz#8268a8c57a3e4abd25c165ecd36237db7948a55e"
+  integrity sha512-I8EUhyrgfLrcTkzV3TSsGyl1tSuPrEDzr0yd5m90UgNxQkyDXULk3b6MlQqTCpZpNtWe1K0hzclnZkTcLBe2UQ==
+
 "@types/stack-utils@^2.0.0":
   version "2.0.3"
   resolved "https://registry.yarnpkg.com/@types/stack-utils/-/stack-utils-2.0.3.tgz#6209321eb2c1712a7e7466422b8cb1fc0d9dd5d8"