Add eth_getPlumeSignature RPC handler

src/wallet.test.ts

@@ -414,3 +414,94 @@ describe('wallet', () => {
     });
   });
 });
+
+describe('getPlumeSignature', () => {
+  it('should sign with a valid address', async () => {
+    const { engine } = createTestSetup();
+    const getAccounts = async () => testAddresses.slice();
+    const witnessedMsgParams: MessageParams[] = [];
+    const processPlumeSignature = async (msgParams: MessageParams) => {
+      witnessedMsgParams.push(msgParams);
+      return testMsgSig;
+    };
+
+    engine.push(createWalletMiddleware({ getAccounts, processPlumeSignature }));
+    const message = [
+      {
+        type: 'string',
+        name: 'message',
+        value: 'Hi, Alice!',
+      },
+    ];
+
+    const payload = {
+      method: 'eth_getPlumeSignature',
+      params: [message, testAddresses[0]],
+    };
+    const signMsgResponse = await pify(engine.handle).call(engine, payload);
+    const signMsgResult = signMsgResponse.result;
+
+    expect(signMsgResult).toBeDefined();
+    expect(signMsgResult).toStrictEqual(testMsgSig);
+    expect(witnessedMsgParams).toHaveLength(1);
+    expect(witnessedMsgParams[0]).toStrictEqual({
+      from: testAddresses[0],
+      data: message,
+    });
+  });
+
+  it('should throw with invalid address', async () => {
+    const { engine } = createTestSetup();
+    const getAccounts = async () => testAddresses.slice();
+    const witnessedMsgParams: MessageParams[] = [];
+    const processPlumeSignature = async (msgParams: MessageParams) => {
+      witnessedMsgParams.push(msgParams);
+      return testMsgSig;
+    };
+
+    engine.push(createWalletMiddleware({ getAccounts, processPlumeSignature }));
+    const message = [
+      {
+        type: 'string',
+        name: 'message',
+        value: 'Hi, Alice!',
+      },
+    ];
+
+    const payload = {
+      method: 'eth_getPlumeSignature',
+      params: [message, '0x3d'],
+    };
+    await expect(pify(engine.handle).call(engine, payload)).rejects.toThrow(
+      new Error('Invalid parameters: must provide an Ethereum address.'),
+    );
+  });
+
+  it('should throw with unknown address', async () => {
+    const { engine } = createTestSetup();
+    const getAccounts = async () => testAddresses.slice();
+    const witnessedMsgParams: MessageParams[] = [];
+    const processPlumeSignature = async (msgParams: MessageParams) => {
+      witnessedMsgParams.push(msgParams);
+      return testMsgSig;
+    };
+
+    engine.push(createWalletMiddleware({ getAccounts, processPlumeSignature }));
+    const message = [
+      {
+        type: 'string',
+        name: 'message',
+        value: 'Hi, Alice!',
+      },
+    ];
+
+    const payload = {
+      method: 'eth_getPlumeSignature',
+      params: [message, testUnkownAddress],
+    };
+    const promise = pify(engine.handle).call(engine, payload);
+    await expect(promise).rejects.toThrow(
+      'The requested account and/or method has not been authorized by the user.',
+    );
+  });
+});

src/wallet.ts

@@ -65,6 +65,10 @@
     req: JsonRpcRequest<unknown>,
     version: string,
   ) => Promise<string>;
+  processPlumeSignature?: (
+    msgParams: MessageParams,
+    req: JsonRpcRequest<unknown>,
+  ) => Promise<string>;
 }
 
 export function createWalletMiddleware({
@@ -78,6 +82,7 @@
   processTypedMessage,
   processTypedMessageV3,
   processTypedMessageV4,
+  processPlumeSignature,
 }: WalletMiddlewareOptions): JsonRpcMiddleware<string, Block> {
   if (!getAccounts) {
     throw new Error('opts.getAccounts is required');
@@ -99,6 +104,7 @@
     eth_getEncryptionPublicKey: createAsyncMiddleware(encryptionPublicKey),
     eth_decrypt: createAsyncMiddleware(decryptMessage),
     personal_ecRecover: createAsyncMiddleware(personalRecover),
+    eth_getPlumeSignature: createAsyncMiddleware(plumeSignature),
   });
 
   //
@@ -353,6 +359,30 @@
     res.result = await processDecryptMessage(msgParams, req);
   }
 
+  async function plumeSignature(
+    req: JsonRpcRequest<unknown>,
+    res: PendingJsonRpcResponse<unknown>,
+  ): Promise<void> {
+    if (!processPlumeSignature) {
+      throw ethErrors.rpc.methodNotSupported();
+    }
+
+    const message: string = (req.params as string[])[0];
+    const address: string = await validateAndNormalizeKeyholder(
+      (req.params as string[])[1],
+      req,
+    );
+    const extraParams: Record<string, unknown> =
+      (req.params as Record<string, unknown>[])[2] || {};
+    const msgParams: MessageParams = {
+      ...extraParams,
+      from: address,
+      data: message,
+    };
+
+    res.result = await processPlumeSignature(msgParams, req);
+  }
+
   //
   // utility
   //
@@ -363,7 +393,7 @@
    *
    * @param address - The address to validate and normalize.
    * @param req - The request object.
    * @returns {string} - The normalized address, if valid. Otherwise, throws
    * an error
    */
   async function validateAndNormalizeKeyholder(