Simplify origin handling

Author: FrederikBolding

packages/snaps-controllers/src/multichain/MultichainRoutingController.ts

@@ -274,13 +274,10 @@ export class MultichainRoutingController extends BaseController<
     if (protocolSnap) {
       return this.messagingSystem.call('SnapController:handleRequest', {
         snapId: protocolSnap.snapId,
-        origin: 'metamask',
+        origin,
         request: {
           method: '',
           params: {
-            // We are overriding the origin here, so that the Snap gets the proper origin
-            // while the permissions check is skipped due to the requesting origin being metamask.
-            origin,
             request,
             scope,
           },

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

@@ -79,13 +79,8 @@ export function getHandlerArguments(
     case HandlerType.OnProtocolRequest: {
       assertIsOnProtocolRequestArguments(request.params);
 
-      // For this specific handler we extract the origin from the parameters.
-      const {
-        origin: nestedOrigin,
-        request: nestedRequest,
-        scope,
-      } = request.params;
-      return { origin: nestedOrigin, request: nestedRequest, scope };
+      const { request: nestedRequest, scope } = request.params;
+      return { request: nestedRequest, scope };
     }
 
     case HandlerType.OnRpcRequest:

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

@@ -245,7 +245,6 @@ export function assertIsOnUserInputRequestArguments(
 }
 
 export const OnProtocolRequestArgumentsStruct = object({
-  origin: string(),
   scope: ChainIdStruct,
   request: JsonRpcRequestStruct,
 });