feat: Auto grant EVM permissions to preinstalled Snaps

packages/snaps-rpc-methods/jest.config.js

@@ -10,10 +10,10 @@ module.exports = deepmerge(baseConfig, {
   ],
   coverageThreshold: {
     global: {
-      branches: 95.16,
-      functions: 98.71,
-      lines: 98.87,
-      statements: 98.56,
+      branches: 95.32,
+      functions: 98.73,
+      lines: 98.89,
+      statements: 98.59,
     },
   },
 });

packages/snaps-rpc-methods/src/index.ts

@@ -6,5 +6,6 @@ export type { PermittedRpcMethodHooks } from './permitted';
 export { SnapCaveatType } from '@metamask/snaps-utils';
 export { selectHooks } from './utils';
 export * from './endowments';
+export * from './middleware';
 export * from './permissions';
 export * from './restricted';

packages/snaps-rpc-methods/src/middleware/index.ts

@@ -0,0 +1 @@
+export * from './preinstalled-snaps';

packages/snaps-rpc-methods/src/middleware/preinstalled-snaps.test.ts

@@ -0,0 +1,348 @@
+import { JsonRpcEngine } from '@metamask/json-rpc-engine';
+
+import { createPreinstalledSnapsMiddleware } from './preinstalled-snaps';
+import { SnapEndowments } from '../endowments';
+
+describe('createPreinstalledSnapsMiddleware', () => {
+  it('grants permissions for accounts not already permitted', async () => {
+    const hooks = {
+      getAllEvmAccounts: jest
+        .fn()
+        .mockReturnValue(['0x1234567890123456789012345678901234567890']),
+      getPermissions: jest
+        .fn()
+        .mockReturnValue({ [SnapEndowments.EthereumProvider]: {} }),
+      grantPermissions: jest.fn(),
+    };
+
+    const middleware = createPreinstalledSnapsMiddleware(hooks);
+
+    const engine = new JsonRpcEngine();
+
+    engine.push(middleware);
+
+    const request = {
+      jsonrpc: '2.0' as const,
+      id: 1,
+      method: 'eth_signTypedData_v4',
+      params: {},
+    };
+
+    // Since we only have one middleware, this will return an error on a successful test.
+    expect(await engine.handle(request)).toStrictEqual({
+      id: 1,
+      jsonrpc: '2.0',
+      error: {
+        code: -32603,
+        data: {
+          cause: null,
+          request: {
+            id: 1,
+            jsonrpc: '2.0',
+            method: 'eth_signTypedData_v4',
+            params: {},
+          },
+        },
+        message: expect.stringContaining(
+          'JsonRpcEngine: Response has no error or result for request',
+        ),
+        stack: expect.stringContaining(
+          'JsonRpcEngine: Response has no error or result for request',
+        ),
+      },
+    });
+
+    expect(hooks.grantPermissions).toHaveBeenCalledWith({
+      'endowment:caip25': {
+        caveats: [
+          {
+            type: 'authorizedScopes',
+            value: {
+              isMultichainOrigin: false,
+              optionalScopes: {
+                'wallet:eip155': {
+                  accounts: [
+                    'wallet:eip155:0x1234567890123456789012345678901234567890',
+                  ],
+                },
+              },
+              requiredScopes: {},
+              sessionProperties: {},
+            },
+          },
+        ],
+      },
+    });
+  });
+
+  it('merges with existing scopes', async () => {
+    const hooks = {
+      getAllEvmAccounts: jest
+        .fn()
+        .mockReturnValue(['0x1234567890123456789012345678901234567890']),
+      getPermissions: jest.fn().mockReturnValue({
+        [SnapEndowments.EthereumProvider]: {},
+        'endowment:caip25': {
+          caveats: [
+            {
+              type: 'authorizedScopes',
+              value: {
+                requiredScopes: {
+                  'eip155:1': {
+                    accounts: [
+                      'eip155:1:0x1234567890123456789012345678901234567890',
+                    ],
+                  },
+                },
+                optionalScopes: {
+                  'eip155:2': {
+                    accounts: [
+                      'eip155:2:0x1234567890123456789012345678901234567890',
+                    ],
+                  },
+                },
+                sessionProperties: {},
+                isMultichainOrigin: false,
+              },
+            },
+          ],
+        },
+      }),
+      grantPermissions: jest.fn(),
+    };
+
+    const middleware = createPreinstalledSnapsMiddleware(hooks);
+
+    const engine = new JsonRpcEngine();
+
+    engine.push(middleware);
+
+    const request = {
+      jsonrpc: '2.0' as const,
+      id: 1,
+      method: 'eth_signTypedData_v4',
+      params: {},
+    };
+
+    // Since we only have one middleware, this will return an error on a successful test.
+    expect(await engine.handle(request)).toStrictEqual({
+      id: 1,
+      jsonrpc: '2.0',
+      error: {
+        code: -32603,
+        data: {
+          cause: null,
+          request: {
+            id: 1,
+            jsonrpc: '2.0',
+            method: 'eth_signTypedData_v4',
+            params: {},
+          },
+        },
+        message: expect.stringContaining(
+          'JsonRpcEngine: Response has no error or result for request',
+        ),
+        stack: expect.stringContaining(
+          'JsonRpcEngine: Response has no error or result for request',
+        ),
+      },
+    });
+
+    expect(hooks.grantPermissions).toHaveBeenCalledWith({
+      'endowment:caip25': {
+        caveats: [
+          {
+            type: 'authorizedScopes',
+            value: {
+              requiredScopes: {
+                'eip155:1': {
+                  accounts: [
+                    'eip155:1:0x1234567890123456789012345678901234567890',
+                  ],
+                },
+              },
+              optionalScopes: {
+                'wallet:eip155': {
+                  accounts: [
+                    'wallet:eip155:0x1234567890123456789012345678901234567890',
+                  ],
+                },
+                'eip155:2': {
+                  accounts: [
+                    'eip155:2:0x1234567890123456789012345678901234567890',
+                  ],
+                },
+              },
+              isMultichainOrigin: false,
+              sessionProperties: {},
+            },
+          },
+        ],
+      },
+    });
+  });
+
+  it('skips the middleware if the accounts are already permitted', async () => {
+    const hooks = {
+      getAllEvmAccounts: jest
+        .fn()
+        .mockReturnValue(['0x1234567890123456789012345678901234567890']),
+      getPermissions: jest.fn().mockReturnValue({
+        [SnapEndowments.EthereumProvider]: {},
+        'endowment:caip25': {
+          caveats: [
+            {
+              type: 'authorizedScopes',
+              value: {
+                requiredScopes: {},
+                optionalScopes: {
+                  'wallet:eip155': {
+                    accounts: [
+                      'wallet:eip155:0x1234567890123456789012345678901234567890',
+                    ],
+                  },
+                },
+                sessionProperties: {},
+                isMultichainOrigin: false,
+              },
+            },
+          ],
+        },
+      }),
+      grantPermissions: jest.fn(),
+    };
+
+    const middleware = createPreinstalledSnapsMiddleware(hooks);
+
+    const engine = new JsonRpcEngine();
+
+    engine.push(middleware);
+
+    const request = {
+      jsonrpc: '2.0' as const,
+      id: 1,
+      method: 'eth_signTypedData_v4',
+      params: {},
+    };
+
+    // Since we only have one middleware, this will return an error on a successful test.
+    expect(await engine.handle(request)).toStrictEqual({
+      id: 1,
+      jsonrpc: '2.0',
+      error: {
+        code: -32603,
+        data: {
+          cause: null,
+          request: {
+            id: 1,
+            jsonrpc: '2.0',
+            method: 'eth_signTypedData_v4',
+            params: {},
+          },
+        },
+        message: expect.stringContaining(
+          'JsonRpcEngine: Response has no error or result for request',
+        ),
+        stack: expect.stringContaining(
+          'JsonRpcEngine: Response has no error or result for request',
+        ),
+      },
+    });
+
+    expect(hooks.grantPermissions).not.toHaveBeenCalled();
+  });
+
+  it('ignores snap methods', async () => {
+    const hooks = {
+      getAllEvmAccounts: jest.fn(),
+      getPermissions: jest.fn(),
+      grantPermissions: jest.fn(),
+    };
+
+    const middleware = createPreinstalledSnapsMiddleware(hooks);
+
+    const engine = new JsonRpcEngine();
+
+    engine.push(middleware);
+
+    const request = {
+      jsonrpc: '2.0' as const,
+      id: 1,
+      method: 'snap_dialog',
+      params: {},
+    };
+
+    // Since we only have one middleware, this will return an error on a successful test.
+    expect(await engine.handle(request)).toStrictEqual({
+      id: 1,
+      jsonrpc: '2.0',
+      error: {
+        code: -32603,
+        data: {
+          cause: null,
+          request: {
+            id: 1,
+            jsonrpc: '2.0',
+            method: 'snap_dialog',
+            params: {},
+          },
+        },
+        message: expect.stringContaining(
+          'JsonRpcEngine: Response has no error or result for request',
+        ),
+        stack: expect.stringContaining(
+          'JsonRpcEngine: Response has no error or result for request',
+        ),
+      },
+    });
+
+    expect(hooks.grantPermissions).not.toHaveBeenCalled();
+  });
+
+  it('skips the middleware if the Snap doesnt have endowment:ethereum-provider', async () => {
+    const hooks = {
+      getAllEvmAccounts: jest.fn(),
+      getPermissions: jest.fn(),
+      grantPermissions: jest.fn(),
+    };
+
+    const middleware = createPreinstalledSnapsMiddleware(hooks);
+
+    const engine = new JsonRpcEngine();
+
+    engine.push(middleware);
+
+    const request = {
+      jsonrpc: '2.0' as const,
+      id: 1,
+      method: 'eth_signTypedData_v4',
+      params: {},
+    };
+
+    // Since we only have one middleware, this will return an error on a successful test.
+    expect(await engine.handle(request)).toStrictEqual({
+      id: 1,
+      jsonrpc: '2.0',
+      error: {
+        code: -32603,
+        data: {
+          cause: null,
+          request: {
+            id: 1,
+            jsonrpc: '2.0',
+            method: 'eth_signTypedData_v4',
+            params: {},
+          },
+        },
+        message: expect.stringContaining(
+          'JsonRpcEngine: Response has no error or result for request',
+        ),
+        stack: expect.stringContaining(
+          'JsonRpcEngine: Response has no error or result for request',
+        ),
+      },
+    });
+
+    expect(hooks.grantPermissions).not.toHaveBeenCalled();
+  });
+});