feat: add borsh schema to sign transaction (#3)

This commit introduces borsh schema to define the serialization of a transaction. The borsh serialized transaction is the one to be signed, as it is the same to be included on-chain. The schema is always received as parameter so the snap remains stateless & functional.
Sovereign-Labs · Oct 16, 2023 · 723b096 · 723b096
1 parent 18732d5
commit 723b096
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diff --git a/packages/site/package.json b/packages/site/package.json
@@ -26,6 +26,7 @@
   },
   "dependencies": {
     "@metamask/providers": "^9.0.0",
+    "borsh": "^1.0.0",
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
     "react-is": "^18.2.0",

diff --git a/packages/site/src/components/Sovereign.tsx b/packages/site/src/components/Sovereign.tsx
@@ -1,8 +1,15 @@
 import React, { useState } from 'react';
+import { Schema } from 'borsh';
 import { defaultSnapOrigin } from '../config';
 import { ExecuteButton } from './Buttons';
 
-type MethodSelectorState = `signMessage` | `getPublicKey`;
+const callMessageSchema: Schema = {
+  struct: {
+    message: 'string',
+  },
+};
+
+type MethodSelectorState = `signTransaction` | `getPublicKey`;
 type CurveSelectorState = `secp256k1` | `ed25519`;
 
 type SovereignState = {
@@ -16,7 +23,7 @@ type SovereignState = {
 
 export const Sovereign = () => {
   const initialState: SovereignState = {
-    method: `signMessage`,
+    method: `signTransaction`,
     curve: `secp256k1`,
     keyId: 0,
     message: 'Some signature message...',
@@ -36,7 +43,7 @@ export const Sovereign = () => {
             })
           }
         >
-          <option value="signMessage">Sign Message</option>
+          <option value="signTransaction">Sign Transaction</option>
           <option value="getPublicKey">Get Public Key</option>
         </select>
       </div>
@@ -77,7 +84,7 @@ export const Sovereign = () => {
       <div>Signature message:</div>
       <div>
         <textarea
-          disabled={state.method !== `signMessage`}
+          disabled={state.method !== `signTransaction`}
           value={state.message}
           onChange={(ev) =>
             setState({
@@ -99,11 +106,14 @@ export const Sovereign = () => {
             path.push(keyId.toString());
 
             let params;
-            if (method === `signMessage`) {
+            if (method === `signTransaction`) {
               params = {
                 path,
                 curve,
-                message: message || '',
+                schema: callMessageSchema,
+                transaction: {
+                  message: message || '',
+                },
               };
             } else {
               params = {

diff --git a/packages/site/tsconfig.json b/packages/site/tsconfig.json
@@ -5,7 +5,8 @@
     "resolveJsonModule": true,
     "isolatedModules": true,
     "noEmit": true,
-    "jsx": "preserve"
+    "jsx": "preserve",
+    "experimentalDecorators": true
   },
   "include": ["src"]
 }
diff --git a/packages/snap/README.md b/packages/snap/README.md
@@ -33,7 +33,7 @@ if (
 }
 ```
 
-#### `signMessage`
+#### `signTransaction`
 
 Returns the signature of the message as hexadecimal string.
 
@@ -43,22 +43,59 @@ Will emit a confirmation dialog for the user.
 
 - `path`: The BIP-32 derivation path of the wallet (`string['m', "44'", "1551'", ...]`).
 - `curve`: The curve of the public key (`secp256k1` or `ed25519`).
-- `message`: The message to sign (`bigint | number | string | Uint8Array`).
+- `schema`: A [borsh](https://www.npmjs.com/package/borsh) schema for the transaction.
+- `transaction`: A transaction to be serialized using the provided schema. The signature will be performed over the serialized transaction.
 
 ##### Example
 
 ```typescript
+import { Schema } from 'borsh';
+
+const callMessageSchema: Schema = {
+  enum: [
+    {
+      struct: {
+        Invoke: {
+          struct: {
+            method: 'string',
+            payload: { array: { type: 'u8' } },
+          },
+        },
+      },
+    },
+    {
+      struct: {
+        Transfer: {
+          struct: {
+            from: { array: { type: 'u8', len: 32 } },
+            to: { array: { type: 'u8', len: 32 } },
+            amount: 'u64',
+          },
+        },
+      },
+    },
+  ],
+};
+
 const response = request({
-  method: 'signMessage',
+  method: 'signTransaction',
   params: {
-    path: ['m', "44'", "1551'", "1'"],
+    path: ['m', "44'", "1551'"],
     curve: 'ed25519',
-    message: 'some message',
+    schema: callMessageSchema,
+    transaction: {
+      Transfer: {
+        from: Array(32).fill(2),
+        to: Array(32).fill(3),
+        amount: 1582,
+      },
+    },
   },
 });
+
 if (
   !response ===
-  '0x10804459eef93e52f9f01f38775ce4a21eb818d70cb637c602267f48c4e129fb2f68bc24bf74c84a1950227ea76d7c1ce860e4867941ef793c83399621c69c0d'
+  '0xfd2e4b23a3e3f498664af355b341e833324276270a13f9647dd1f043248f92fccaa037d4cfc9d23f13a295f7d505ee13afb2b10cea548890678f9002947cbb0a'
 ) {
   throw new Error('Invalid signature');
 }

diff --git a/packages/snap/package.json b/packages/snap/package.json
@@ -33,6 +33,7 @@
     "@metamask/utils": "^8.1.0",
     "@noble/ed25519": "^1.6.0",
     "@noble/secp256k1": "^1.7.1",
+    "borsh": "^1.0.0",
     "buffer": "^6.0.3"
   },
   "devDependencies": {

diff --git a/packages/snap/snap.manifest.json b/packages/snap/snap.manifest.json
@@ -7,7 +7,7 @@
     "url": "https://github.com/Sovereign-Labs/sov-snap.git"
   },
   "source": {
-    "shasum": "ffF94Uc3L8/OZ4qDYWUAWbUDSs/a4v69Bg24WiT3Mvc=",
+    "shasum": "M4WoRFL+SjnLWRKANC/7e5s/+nwPabd2hvVY77TCck8=",
     "location": {
       "npm": {
         "filePath": "dist/bundle.js",

diff --git a/packages/snap/src/index.test.ts b/packages/snap/src/index.test.ts
@@ -1,6 +1,33 @@
 import { installSnap } from '@metamask/snaps-jest';
 import { expect } from '@jest/globals';
 import { assert } from '@metamask/utils';
+import { Schema } from 'borsh';
+
+const callMessageSchema: Schema = {
+  enum: [
+    {
+      struct: {
+        Invoke: {
+          struct: {
+            method: 'string',
+            payload: { array: { type: 'u8' } },
+          },
+        },
+      },
+    },
+    {
+      struct: {
+        Transfer: {
+          struct: {
+            from: { array: { type: 'u8', len: 32 } },
+            to: { array: { type: 'u8', len: 32 } },
+            amount: 'u64',
+          },
+        },
+      },
+    },
+  ],
+};
 
 describe('onRpcRequest', () => {
   describe('getPublicKey', () => {
@@ -41,16 +68,22 @@ describe('onRpcRequest', () => {
     });
   });
 
-  describe('signMessage', () => {
+  describe('signTransaction', () => {
     it('returns a secp256k1 signature', async () => {
       const { request, close } = await installSnap();
 
       const response = request({
-        method: 'signMessage',
+        method: 'signTransaction',
         params: {
           path: ['m', "44'", "1551'"],
           curve: 'secp256k1',
-          message: 'some message',
+          schema: callMessageSchema,
+          transaction: {
+            Invoke: {
+              method: 'someMethod',
+              payload: Array(176).fill(5),
+            },
+          },
         },
       });
 
@@ -59,7 +92,7 @@ describe('onRpcRequest', () => {
       await ui.ok();
 
       expect(await response).toRespondWith(
-        '0x3044022037e40728bd555a0b18a9a60e56eb1c3ad3f691c13df947a95c177491a23e8a2f02206eb555dd3061ae3fb13292dc90f742111c4329397e2323746bfa2296a478e4f5',
+        '0x3044022037ed1abe499f6699943dc26299e5c24111002ad115e481d126868e68e73eebd40220552312cc86a09ba8160ffc496b24eb04319c6c25ad7f965b59a6938858f00ca5',
       );
 
       await close();
@@ -69,11 +102,18 @@ describe('onRpcRequest', () => {
       const { request, close } = await installSnap();
 
       const response = request({
-        method: 'signMessage',
+        method: 'signTransaction',
         params: {
           path: ['m', "44'", "1551'"],
           curve: 'ed25519',
-          message: 'some message',
+          schema: callMessageSchema,
+          transaction: {
+            Transfer: {
+              from: Array(32).fill(2),
+              to: Array(32).fill(3),
+              amount: 1582,
+            },
+          },
         },
       });
 
@@ -82,7 +122,7 @@ describe('onRpcRequest', () => {
       await ui.ok();
 
       expect(await response).toRespondWith(
-        '0x83207c0ef4117e2cb70fdf6bcce4ed0b54ec2047332205f81f480744375b14ba1239738d0883c21285f96d60259070988b1095e45d7cbb6782393eba2dfdd903',
+        '0xfd2e4b23a3e3f498664af355b341e833324276270a13f9647dd1f043248f92fccaa037d4cfc9d23f13a295f7d505ee13afb2b10cea548890678f9002947cbb0a',
       );
 
       await close();

diff --git a/packages/snap/src/index.ts b/packages/snap/src/index.ts
@@ -2,17 +2,12 @@ import { providerErrors, rpcErrors } from '@metamask/rpc-errors';
 import { DialogType, OnRpcRequestHandler } from '@metamask/snaps-types';
 import { copyable, heading, panel, text } from '@metamask/snaps-ui';
 import { SLIP10Node } from '@metamask/key-tree';
-import {
-  add0x,
-  assert,
-  bytesToHex,
-  remove0x,
-  valueToBytes,
-} from '@metamask/utils';
+import { add0x, assert, bytesToHex, remove0x } from '@metamask/utils';
 import { sign as signEd25519 } from '@noble/ed25519';
 import { sign as signSecp256k1 } from '@noble/secp256k1';
+import { serialize } from 'borsh';
 
-import type { GetBip32PublicKeyParams, SignMessageParams } from './types';
+import type { GetBip32PublicKeyParams, SignTransactionParams } from './types';
 
 /**
  * Handle incoming JSON-RPC requests, sent through `wallet_invokeSnap`.
@@ -32,8 +27,12 @@ export const onRpcRequest: OnRpcRequestHandler = async ({ request }) => {
         params: request.params as unknown as GetBip32PublicKeyParams,
       });
 
-    case 'signMessage': {
-      const { message, curve, ...params } = request.params as SignMessageParams;
+    case 'signTransaction': {
+      const { schema, transaction, curve, ...params } =
+        request.params as SignTransactionParams;
+
+      const serializedTransaction = serialize(schema, transaction);
+
       const json = await snap.request({
         method: 'snap_getBip32Entropy',
         params: {
@@ -53,21 +52,15 @@ export const onRpcRequest: OnRpcRequestHandler = async ({ request }) => {
       assert(node.privateKey);
       assert(curve === 'ed25519' || curve === 'secp256k1');
 
-      // assert the user's approval of the provided message. Note: this message will be a raw bytes
-      // representation. A human-friendly format is currently not supported by the API as the
-      // conversion is expected to be performed before the interaction with the Snap.
-      //
-      // For more information, refer to the tracking issue:
-      // https://github.com/Sovereign-Labs/sovereign-sdk/issues/982
       const approved = await snap.request({
         method: 'snap_dialog',
         params: {
           type: DialogType.Confirmation,
           content: panel([
             heading('Signature request'),
-            text(
-              `Do you want to ${curve} sign "${message}" with the following public key?`,
-            ),
+            text(`Do you want to ${curve} sign`),
+            copyable(JSON.stringify(transaction)),
+            text(`with the following public key?`),
             copyable(add0x(node.publicKey)),
           ]),
         },
@@ -77,16 +70,15 @@ export const onRpcRequest: OnRpcRequestHandler = async ({ request }) => {
         throw providerErrors.userRejectedRequest();
       }
 
-      const messageBytes = valueToBytes(message);
       const privateKey = remove0x(node.privateKey);
 
       let signed;
       switch (curve) {
         case 'ed25519':
-          signed = await signEd25519(messageBytes, privateKey);
+          signed = await signEd25519(serializedTransaction, privateKey);
           break;
         case 'secp256k1':
-          signed = await signSecp256k1(messageBytes, privateKey);
+          signed = await signSecp256k1(serializedTransaction, privateKey);
           break;
         default:
           throw new Error(`Unsupported curve: ${String(curve)}.`);

diff --git a/packages/snap/src/types.ts b/packages/snap/src/types.ts
@@ -1,4 +1,4 @@
-import { Bytes } from '@metamask/utils';
+import { Schema } from 'borsh';
 
 /**
  * The parameters for calling the `getPublicKey` JSON-RPC method.
@@ -29,16 +29,21 @@ export type GetBip32PublicKeyParams = {
 };
 
 /**
- * The parameters for calling the `signMessage` JSON-RPC method.
+ * The parameters for calling the `signTransaction` JSON-RPC method.
  *
  * Note: For simplicity, these are not validated by the snap. In production, you
  * should validate that the request object matches this type before using it.
  */
-export type SignMessageParams = {
+export type SignTransactionParams = {
   /**
-   * The message to sign.
+   * The borsh schema of the transaction.
    */
-  message: Bytes;
+  schema: Schema;
+
+  /**
+   * The transaction to sign.
+   */
+  transaction: any;
 
   /**
    * The BIP-32 path to the account.