fix: Add validation for types sign message primary type (#350)

Author: jpuri

src/utils/common.test.ts

@@ -0,0 +1,15 @@
+import { stripArrayTypeIfPresent } from './common';
+
+describe('CommonUtils', () => {
+  describe('stripArrayTypeIfPresent', () => {
+    it('remove array brackets from the type if present', () => {
+      expect(stripArrayTypeIfPresent('string[]')).toBe('string');
+      expect(stripArrayTypeIfPresent('string[5]')).toBe('string');
+    });
+
+    it('return types which are not array without any change', () => {
+      expect(stripArrayTypeIfPresent('string')).toBe('string');
+      expect(stripArrayTypeIfPresent('string []')).toBe('string []');
+    });
+  });
+});

src/utils/common.ts

@@ -0,0 +1,12 @@
+/**
+ * Function to stripe array brackets if string defining the type has it.
+ *
+ * @param typeString - String defining type from which array brackets are required to be removed.
+ * @returns Parameter string with array brackets [] removed.
+ */
+export const stripArrayTypeIfPresent = (typeString: string) => {
+  if (typeString?.match(/\S\[\d*\]$/u) !== null) {
+    return typeString.replace(/\[\d*\]$/gu, '').trim();
+  }
+  return typeString;
+};

src/wallet.test.ts

@@ -626,6 +626,63 @@ describe('wallet', () => {
           '0x68dc980608bceb5f99f691e62c32caccaee05317309015e9454eba1a14c3cd4505d1dd098b8339801239c9bcaac3c4df95569dcf307108b92f68711379be14d81c',
       });
     });
+
+    it('should throw if message does not have types defined', async () => {
+      const { engine } = createTestSetup();
+      const getAccounts = async () => testAddresses.slice();
+      const witnessedMsgParams: TypedMessageParams[] = [];
+      const processTypedMessageV4 = async (msgParams: TypedMessageParams) => {
+        witnessedMsgParams.push(msgParams);
+        // Assume testMsgSig is the expected signature result
+        return testMsgSig;
+      };
+
+      engine.push(
+        createWalletMiddleware({ getAccounts, processTypedMessageV4 }),
+      );
+
+      const messageParams = getMsgParams();
+      const payload = {
+        method: 'eth_signTypedData_v4',
+        params: [
+          testAddresses[0],
+          JSON.stringify({ ...messageParams, types: undefined }),
+        ],
+      };
+
+      const promise = pify(engine.handle).call(engine, payload);
+      await expect(promise).rejects.toThrow('Invalid input.');
+    });
+
+    it('should throw if type of primaryType is not defined', async () => {
+      const { engine } = createTestSetup();
+      const getAccounts = async () => testAddresses.slice();
+      const witnessedMsgParams: TypedMessageParams[] = [];
+      const processTypedMessageV4 = async (msgParams: TypedMessageParams) => {
+        witnessedMsgParams.push(msgParams);
+        // Assume testMsgSig is the expected signature result
+        return testMsgSig;
+      };
+
+      engine.push(
+        createWalletMiddleware({ getAccounts, processTypedMessageV4 }),
+      );
+
+      const messageParams = getMsgParams();
+      const payload = {
+        method: 'eth_signTypedData_v4',
+        params: [
+          testAddresses[0],
+          JSON.stringify({
+            ...messageParams,
+            types: { ...messageParams.types, Permit: undefined },
+          }),
+        ],
+      };
+
+      const promise = pify(engine.handle).call(engine, payload);
+      await expect(promise).rejects.toThrow('Invalid input.');
+    });
   });
 
   describe('sign', () => {

src/wallet.ts

@@ -13,6 +13,7 @@ import {
 } from '@metamask/utils';
 
 import type { Block } from './types';
+import { stripArrayTypeIfPresent } from './utils/common';
 import { normalizeTypedMessage, parseTypedMessage } from './utils/normalize';
 
 /*
@@ -243,6 +244,7 @@ WalletMiddlewareOptions): JsonRpcMiddleware<any, Block> {
 
     const address = await validateAndNormalizeKeyholder(params[0], req);
     const message = normalizeTypedMessage(params[1]);
+    validatePrimaryType(message);
     validateVerifyingContract(message);
     const version = 'V3';
     const msgParams: TypedMessageParams = {
@@ -274,6 +276,7 @@ WalletMiddlewareOptions): JsonRpcMiddleware<any, Block> {
 
     const address = await validateAndNormalizeKeyholder(params[0], req);
     const message = normalizeTypedMessage(params[1]);
+    validatePrimaryType(message);
     validateVerifyingContract(message);
     const version = 'V4';
     const msgParams: TypedMessageParams = {
@@ -457,6 +460,27 @@ WalletMiddlewareOptions): JsonRpcMiddleware<any, Block> {
   }
 }
 
+/**
+ * Validates primary of typedSignMessage, to ensure that it's type definition is present in message.
+ *
+ * @param data - The data passed in typedSign request.
+ */
+function validatePrimaryType(data: string) {
+  const { primaryType, types } = parseTypedMessage(data);
+  if (!types) {
+    throw rpcErrors.invalidInput();
+  }
+
+  // Primary type can be an array.
+  const baseType = stripArrayTypeIfPresent(primaryType);
+
+  // Return if the base type is not defined in the types
+  const baseTypeDefinitions = types[baseType];
+  if (!baseTypeDefinitions) {
+    throw rpcErrors.invalidInput();
+  }
+}
+
 /**
  * Validates verifyingContract of typedSignMessage.
  *