add ability to intercept and transform message requests and responses

CHANGELOG.md

@@ -1,3 +1,7 @@
+### Release v2.1.5-beta.1
+- add mechanism to intercept and transform requests and responses before transmission to mobile
+- add check for from value in sendTx message and add from value if missing
+
 ### Release v2.1.4
 - add missing personal_ecRecover method
 - Fix flipped parameters for persona_sign

example/app/src/App.vue

@@ -579,7 +579,7 @@ export default {
         this.web3.eth.getTransactionCount(this.userAddress).then(nonce => {
           this.web3.eth
             .sendTransaction({
-              from: this.userAddress,
+              // from: this.userAddress,
               to: this.tokenAddress,
               nonce,
               value: 0,

package.json

@@ -1,7 +1,7 @@
 {
   "name": "@myetherwallet/mewconnect-web-client",
   "homepage": "https://github.com/myetherwallet/MEWconnect-web-client",
-  "version": "2.1.4",
+  "version": "2.1.5-beta.1",
   "main": "./dist/index.js",
   "module": "./src/index.js",
   "scripts": {

src/connectClient/WebRtcCommunication.js

@@ -7,6 +7,7 @@ import { isBrowser } from 'browser-or-node';
 
 import uuid from 'uuid/v4';
 import MewConnectCommon from './MewConnectCommon';
+import Interceptor from './interceptor';
 
 const debug = debugLogger('MEWconnect:webRTC-communication');
 const debugPeer = debugLogger('MEWconnectVerbose:peer-instances');
@@ -16,6 +17,7 @@ const logger = createLogger('WebRtcCommunication');
 export default class WebRtcCommunication extends MewConnectCommon {
   constructor(mewCrypto) {
     super();
+    this.Interceptor = new Interceptor();
     this.Peer = SimplePeer;
     this.mewCrypto = mewCrypto;
     this.peersCreated = {};
@@ -60,7 +62,7 @@ export default class WebRtcCommunication extends MewConnectCommon {
     this.usingVersion = version;
   }
 
-  setActiveInitiatorId(id){
+  setActiveInitiatorId(id) {
     this.activeInitiatorId = id;
   }
 
@@ -307,12 +309,18 @@ export default class WebRtcCommunication extends MewConnectCommon {
       }
       if (this.isJSON(decryptedData)) {
         const parsed = JSON.parse(decryptedData);
-        this.emit('data', { type: parsed.type, data: parsed.data, id: parsed.id });
+        this.Interceptor.InspectIncomingMessage(parsed);
+        this.emit('data', {
+          type: parsed.type,
+          data: parsed.data,
+          id: parsed.id
+        });
       } else {
+        this.Interceptor.InspectIncomingMessage(decryptedData);
         this.emit('data', {
           type: decryptedData.type,
           data: decryptedData.data,
-         id: decryptedData.id
+          id: decryptedData.id
         });
       }
     } catch (e) {
@@ -363,6 +371,7 @@ export default class WebRtcCommunication extends MewConnectCommon {
   sendRtcMessage(type, msg, id) {
     debug(msg);
     debug(`[SEND RTC MESSAGE] type:  ${type},  message:  ${msg}, id: ${id}`);
+    // const values = this.Interceptor.InspectOutgoingMessage({type, data: msg})
     this.rtcSend(JSON.stringify({ type, data: msg, id }));
   }
 
@@ -389,8 +398,10 @@ export default class WebRtcCommunication extends MewConnectCommon {
     if (this.isAlive()) {
       let encryptedSend;
       if (typeof arg === 'string') {
+        arg = this.Interceptor.InspectOutgoingMessageString(arg);
         encryptedSend = await this.mewCrypto.encrypt(arg);
       } else {
+        arg = this.Interceptor.InspectOutgoingMessage(arg);
         encryptedSend = await this.mewCrypto.encrypt(JSON.stringify(arg));
       }
       debug('SENDING RTC');

src/connectClient/interceptor.js

@@ -0,0 +1,114 @@
+import debugLogger from 'debug';
+const debug = debugLogger('MEWconnect:webRTC-interceptor');
+
+
+export default class Interceptor {
+  constructor() {
+    this.address = false;
+    this.SIGN_TX = 'signTx';
+    this.ADDRESS = 'address';
+  }
+
+  isJSON(value) {
+    try {
+      JSON.parse(value);
+      return true;
+    } catch (e) {
+      return false;
+    }
+  }
+
+  setWalletAddress(address) {
+    try {
+      if (address.address) {
+        this.address = address.address;
+      } else {
+        this.address = address;
+      }
+    } catch (e) {
+      debug(e);
+    }
+  }
+
+  convertToJson(arg) {
+    let convertBack = false;
+    try {
+      if (typeof arg === 'string') {
+        if (this.isJSON(arg)) {
+          convertBack = true;
+          return [JSON.parse(arg), convertBack]
+        }
+      }
+      return [arg, convertBack]
+    } catch (e) {
+      debug(e);
+      return [arg, convertBack]
+    }
+  }
+
+  InspectOutgoingMessageString(arg) {
+    try {
+      let temp = this.convertToJson(arg);
+      let data2 = temp[0];
+      if (data2.type === this.SIGN_TX) {
+        let temp2 = this.convertToJson(data2.data);
+        let dataUpdated = this.checkForFromValueInSignTx(temp2[0]);
+        if(temp2[1]){
+          data2.data = JSON.stringify(dataUpdated);
+        }
+      }
+      if(temp[1]){
+        return JSON.stringify(data2);
+      }
+      return arg;
+    } catch (e) {
+      debug(e);
+      return arg;
+    }
+  }
+
+  InspectOutgoingMessage({type, data, id}) {
+
+    try {
+      if (type === this.SIGN_TX) {
+        let temp = this.convertToJson(data);
+        let data2 = this.checkForFromValueInSignTx(temp[0]);
+        if(temp[1]){
+          data2 = JSON.stringify(data2);
+        }
+        return {type, data: data2, id};
+      }
+      return {type, data, id};
+    } catch (e) {
+      debug(e);
+      return {type, data, id};
+    }
+  }
+
+  InspectIncomingMessage(data) {
+    try {
+      if (data.type === this.ADDRESS) {
+        this.setWalletAddress(data.data);
+      }
+      return data;
+    } catch (e) {
+      debug(e);
+      return data;
+    }
+  }
+
+  checkForFromValueInSignTx(data) {
+    try {
+      if (!data.from) {
+        if (this.address) {
+          data.from = this.address;
+          return data;
+        }
+      }
+      return data;
+    } catch (e) {
+      debug(e);
+      return data;
+    }
+  }
+}