feat: Unblock eth_signTypedData (#2969)

Unblock all variants of `eth_signTypedData` as they are deemed lower
risk following UI changes on the clients.

Also adds logic to use it in the Ethereum provider example Snap.

packages/examples/packages/ethereum-provider/README.md

@@ -33,6 +33,8 @@ JSON-RPC methods:
 - `getVersion`: Get the Ethereum network version from an Ethereum provider.
 - `getAccounts`: Get the Ethereum accounts made available to the snap from an
   Ethereum provider.
+- `personalSign`: Sign a message using an Ethereum account made available to the Snap.
+- `signTypedData`: Sign a struct using an Ethereum account made available to the Snap.
 
 For more information, you can refer to
 [the end-to-end tests](./src/index.test.ts).

packages/examples/packages/ethereum-provider/snap.manifest.json

@@ -7,7 +7,7 @@
     "url": "https://github.com/MetaMask/snaps.git"
   },
   "source": {
-    "shasum": "wGmGlT7y9asBxBtugpaU+ZkK1bzawwMx3upjmMDhygs=",
+    "shasum": "I23+R0H/oTfb5PUA99hAW8ILCCn0kFAk2apS+Q0blPA=",
     "location": {
       "npm": {
         "filePath": "dist/bundle.js",

packages/examples/packages/ethereum-provider/src/index.test.ts

@@ -76,4 +76,48 @@ describe('onRpcRequest', () => {
       ]);
     });
   });
+
+  describe('personalSign', () => {
+    const MOCK_SIGNATURE =
+      '0x16f672a12220dc4d9e27671ef580cfc1397a9a4d5ee19eadea46c0f350b2f72a4922be7c1f16ed9b03ef1d3351eac469e33accf5a36194b1d88923701c2b163f1b';
+
+    it('returns a signature', async () => {
+      const { request, mockJsonRpc } = await installSnap();
+
+      // We can mock the signature request with the response we want.
+      mockJsonRpc({
+        method: 'personal_sign',
+        result: MOCK_SIGNATURE,
+      });
+
+      const response = await request({
+        method: 'personalSign',
+        params: { message: 'foo' },
+      });
+
+      expect(response).toRespondWith(MOCK_SIGNATURE);
+    });
+  });
+
+  describe('signTypedData', () => {
+    const MOCK_SIGNATURE =
+      '0x01b37713300d99fecf0274bcb0dfb586a23d56c4bf2ed700c5ecf4ada7a2a14825e7b1212b1cc49c9440c375337561f2b7a6e639ba25be6a6f5a16f60e6931d31c';
+
+    it('returns a signature', async () => {
+      const { request, mockJsonRpc } = await installSnap();
+
+      // We can mock the signature request with the response we want.
+      mockJsonRpc({
+        method: 'eth_signTypedData_v4',
+        result: MOCK_SIGNATURE,
+      });
+
+      const response = await request({
+        method: 'signTypedData',
+        params: { message: 'foo' },
+      });
+
+      expect(response).toRespondWith(MOCK_SIGNATURE);
+    });
+  });
 });

packages/examples/packages/ethereum-provider/src/index.ts

@@ -5,7 +5,7 @@ import {
 import type { Hex } from '@metamask/utils';
 import { assert, stringToBytes, bytesToHex } from '@metamask/utils';
 
-import type { PersonalSignParams } from './types';
+import type { PersonalSignParams, SignTypedDataParams } from './types';
 
 /**
  * Get the current gas price using the `ethereum` global. This is essentially
@@ -91,13 +91,106 @@ async function personalSign(message: string, from: string) {
   return signature;
 }
 
+/**
+ * Sign a struct using the `eth_signTypedData_v4` JSON-RPC method.
+ *
+ * This uses the Ether Mail struct for example purposes.
+ *
+ * Note that using the `ethereum` global requires the
+ * `endowment:ethereum-provider` permission.
+ *
+ * @param message - The message include in Ether Mail a string.
+ * @param from - The account to sign the message with as a string.
+ * @returns A signature for the struct and account.
+ * @throws If the user rejects the prompt.
+ * @see https://docs.metamask.io/snaps/reference/permissions/#endowmentethereum-provider
+ * @see https://docs.metamask.io/wallet/concepts/signing-methods/#eth_signtypeddata_v4
+ */
+async function signTypedData(message: string, from: string) {
+  const signature = await ethereum.request<Hex>({
+    method: 'eth_signTypedData_v4',
+    params: [
+      from,
+      {
+        types: {
+          EIP712Domain: [
+            {
+              name: 'name',
+              type: 'string',
+            },
+            {
+              name: 'version',
+              type: 'string',
+            },
+            {
+              name: 'chainId',
+              type: 'uint256',
+            },
+            {
+              name: 'verifyingContract',
+              type: 'address',
+            },
+          ],
+          Person: [
+            {
+              name: 'name',
+              type: 'string',
+            },
+            {
+              name: 'wallet',
+              type: 'address',
+            },
+          ],
+          Mail: [
+            {
+              name: 'from',
+              type: 'Person',
+            },
+            {
+              name: 'to',
+              type: 'Person',
+            },
+            {
+              name: 'contents',
+              type: 'string',
+            },
+          ],
+        },
+        primaryType: 'Mail',
+        domain: {
+          name: 'Ether Mail',
+          version: '1',
+          chainId: 1,
+          verifyingContract: '0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC',
+        },
+        message: {
+          from: {
+            name: 'Snap',
+            wallet: from,
+          },
+          to: {
+            name: 'Bob',
+            wallet: '0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB',
+          },
+          contents: message,
+        },
+      },
+    ],
+  });
+  assert(signature, 'Ethereum provider did not return a signature.');
+
+  return signature;
+}
+
 /**
  * Handle incoming JSON-RPC requests from the dapp, sent through the
- * `wallet_invokeSnap` method. This handler handles three methods:
+ * `wallet_invokeSnap` method. This handler handles five methods:
  *
  * - `getGasPrice`: Get the current Ethereum gas price as a hexadecimal string.
  * - `getVersion`: Get the current Ethereum network version as a string.
  * - `getAccounts`: Get the Ethereum accounts that the snap has access to.
+ * - `personalSign`: Sign a message using an Ethereum account.
+ * - `signTypedData` Sign a struct using an Ethereum account.
  *
  * @param params - The request parameters.
  * @param params.request - The JSON-RPC request object.
@@ -122,6 +215,12 @@ export const onRpcRequest: OnRpcRequestHandler = async ({ request }) => {
       return await personalSign(params.message, accounts[0]);
     }
 
+    case 'signTypedData': {
+      const params = request.params as SignTypedDataParams;
+      const accounts = await getAccounts();
+      return await signTypedData(params.message, accounts[0]);
+    }
+
     default:
       // eslint-disable-next-line @typescript-eslint/no-throw-literal
       throw new MethodNotFoundError({ method: request.method });

packages/examples/packages/ethereum-provider/src/types.ts

@@ -1,3 +1,7 @@
 export type PersonalSignParams = {
   message: string;
 };
+
+export type SignTypedDataParams = {
+  message: string;
+};

packages/snaps-execution-environments/src/common/utils.ts

@@ -52,10 +52,6 @@ export const BLOCKED_RPC_METHODS = Object.freeze([
   'wallet_revokePermissions',
   // We disallow all of these confirmations for now, since the screens are not ready for Snaps.
   'eth_sendTransaction',
-  'eth_signTypedData',
-  'eth_signTypedData_v1',
-  'eth_signTypedData_v3',
-  'eth_signTypedData_v4',
   'eth_decrypt',
   'eth_getEncryptionPublicKey',
   'wallet_addEthereumChain',

packages/test-snaps/src/features/snaps/ethereum-provider/EthereumProvider.tsx

@@ -5,7 +5,7 @@ import { Button, ButtonGroup } from 'react-bootstrap';
 import { useInvokeMutation } from '../../../api';
 import { Result, Snap } from '../../../components';
 import { getSnapId } from '../../../utils';
-import { SignMessage } from './components/SignMessage';
+import { SignMessage, SignTypedData } from './components';
 import {
   ETHEREUM_PROVIDER_SNAP_ID,
   ETHEREUM_PROVIDER_SNAP_PORT,
@@ -60,6 +60,7 @@ export const EthereumProvider: FunctionComponent = () => {
         </span>
       </Result>
       <SignMessage />
+      <SignTypedData />
     </Snap>
   );
 };

packages/test-snaps/src/features/snaps/ethereum-provider/components/SignMessage.tsx

@@ -33,6 +33,7 @@ export const SignMessage: FunctionComponent = () => {
 
   return (
     <>
+      <h3 className="h5">Personal Sign</h3>
       <Form onSubmit={handleSubmit} className="mb-3">
         <Form.Label>Message</Form.Label>
         <Form.Control
@@ -48,7 +49,7 @@ export const SignMessage: FunctionComponent = () => {
           Sign Message
         </Button>
       </Form>
-      <Result>
+      <Result className="mb-3">
         <span id="personalSignResult">
           {JSON.stringify(data, null, 2)}
           {JSON.stringify(error, null, 2)}

packages/test-snaps/src/features/snaps/ethereum-provider/components/SignTypedData.tsx

@@ -0,0 +1,60 @@
+import { logError } from '@metamask/snaps-utils';
+import type { ChangeEvent, FormEvent, FunctionComponent } from 'react';
+import { useState } from 'react';
+import { Button, Form } from 'react-bootstrap';
+
+import { useInvokeMutation } from '../../../../api';
+import { Result } from '../../../../components';
+import { getSnapId } from '../../../../utils';
+import {
+  ETHEREUM_PROVIDER_SNAP_ID,
+  ETHEREUM_PROVIDER_SNAP_PORT,
+} from '../constants';
+
+export const SignTypedData: FunctionComponent = () => {
+  const [message, setMessage] = useState('');
+  const [invokeSnap, { isLoading, data, error }] = useInvokeMutation();
+
+  const handleChange = (event: ChangeEvent<HTMLInputElement>) => {
+    setMessage(event.target.value);
+  };
+
+  const handleSubmit = (event: FormEvent<HTMLFormElement>) => {
+    event.preventDefault();
+
+    invokeSnap({
+      snapId: getSnapId(ETHEREUM_PROVIDER_SNAP_ID, ETHEREUM_PROVIDER_SNAP_PORT),
+      method: 'signTypedData',
+      params: {
+        message,
+      },
+    }).catch(logError);
+  };
+
+  return (
+    <>
+      <h3 className="h5">Sign Typed Data</h3>
+      <Form onSubmit={handleSubmit} className="mb-3">
+        <Form.Label>Message</Form.Label>
+        <Form.Control
+          type="text"
+          placeholder="Message"
+          value={message}
+          onChange={handleChange}
+          id="signTypedData"
+          className="mb-3"
+        />
+
+        <Button type="submit" id="signTypedDataButton" disabled={isLoading}>
+          Sign Typed Data
+        </Button>
+      </Form>
+      <Result>
+        <span id="signTypedDataResult">
+          {JSON.stringify(data, null, 2)}
+          {JSON.stringify(error, null, 2)}
+        </span>
+      </Result>
+    </>
+  );
+};

packages/test-snaps/src/features/snaps/ethereum-provider/components/index.ts

@@ -0,0 +1,2 @@
+export * from './SignMessage';
+export * from './SignTypedData';