Merge pull request #506 from PrismarineJS/remove_ursa

remove ursa, uses crypto rsa functionalities instead, and keypair for keys generation

package.json

@@ -42,14 +42,11 @@
     "lodash.get": "^4.1.2",
     "lodash.merge": "^4.3.0",
     "minecraft-data": "^2.17.0",
+    "node-rsa": "^0.4.2",
     "prismarine-nbt": "^1.0.0",
     "protodef": "^1.5.1",
     "readable-stream": "^2.0.5",
-    "ursa-purejs": "^0.0.3",
     "uuid-1345": "^0.99.6",
     "yggdrasil": "^1.0.0"
-  },
-  "optionalDependencies": {
-    "ursa": "^0.9.1"
   }
 }

src/client/encrypt.js

@@ -2,7 +2,6 @@
 
 const crypto = require('crypto');
 const yggserver = require('yggdrasil').server({});
-const ursa=require("../ursa");
 const debug = require('debug')('minecraft-protocol');
 
 module.exports = function(client, options) {
@@ -42,9 +41,9 @@ module.exports = function(client, options) {
       }
 
       function sendEncryptionKeyResponse() {
-        const pubKey = mcPubKeyToURsa(packet.publicKey);
+        const pubKey = mcPubKeyToPem(packet.publicKey);
-        const encryptedSharedSecretBuffer = pubKey.encrypt(sharedSecret, undefined, undefined, ursa.RSA_PKCS1_PADDING);
+        const encryptedSharedSecretBuffer = crypto.publicEncrypt({key:pubKey,padding:crypto.constants.RSA_PKCS1_PADDING},sharedSecret);
-        const encryptedVerifyTokenBuffer = pubKey.encrypt(packet.verifyToken, undefined, undefined, ursa.RSA_PKCS1_PADDING);
+        const encryptedVerifyTokenBuffer = crypto.publicEncrypt({key:pubKey,padding:crypto.constants.RSA_PKCS1_PADDING},packet.verifyToken);
         client.write('encryption_begin', {
           sharedSecret: encryptedSharedSecretBuffer,
           verifyToken: encryptedVerifyTokenBuffer
@@ -55,7 +54,7 @@ module.exports = function(client, options) {
   }
 };
 
-function mcPubKeyToURsa(mcPubKeyBuffer) {
+function mcPubKeyToPem(mcPubKeyBuffer) {
   let pem = "-----BEGIN PUBLIC KEY-----\n";
   let base64PubKey = mcPubKeyBuffer.toString('base64');
   const maxLineLength = 65;
@@ -64,5 +63,5 @@ function mcPubKeyToURsa(mcPubKeyBuffer) {
     base64PubKey = base64PubKey.substring(maxLineLength);
   }
   pem += "-----END PUBLIC KEY-----\n";
-  return ursa.createPublicKey(pem, 'utf8');
+  return pem;
 }

src/createServer.js

@@ -1,6 +1,5 @@
 'use strict';
 
-const ursa=require("./ursa");
 const crypto = require('crypto');
 const yggserver = require('yggdrasil').server({});
 const states = require("./states");
@@ -9,6 +8,7 @@ const Server = require('./server');
 const UUID = require('uuid-1345');
 const endianToggle = require('endian-toggle');
 const pluginChannels = require('./client/pluginChannels');
+const NodeRSA = require('node-rsa');
 
 module.exports=createServer;
 
@@ -36,7 +36,7 @@ function createServer(options) {
   const mcData=require("minecraft-data")(optVersion);
   const version = mcData.version;
 
-  const serverKey = ursa.generatePrivateKey(1024);
+  const serverKey = new NodeRSA({b: 1024});
 
   const server = new Server(version.minecraftVersion,options.customPackets);
   server.motd = options.motd || "A Minecraft server";
@@ -175,9 +175,9 @@ function createServer(options) {
       if(needToVerify) {
         serverId = crypto.randomBytes(4).toString('hex');
         client.verifyToken = crypto.randomBytes(4);
-        const publicKeyStrArr = serverKey.toPublicPem("utf8").split("\n");
+        const publicKeyStrArr = serverKey.exportKey('pkcs8-public-pem').split("\n");
         let publicKeyStr = "";
-        for(let i = 1; i < publicKeyStrArr.length - 2; i++) {
+        for(let i = 1; i < publicKeyStrArr.length - 1; i++) {
           publicKeyStr += publicKeyStrArr[i]
         }
         client.publicKey = new Buffer(publicKeyStr, 'base64');
@@ -210,12 +210,12 @@ function createServer(options) {
     function onEncryptionKeyResponse(packet) {
       let sharedSecret;
       try {
-        const verifyToken = serverKey.decrypt(packet.verifyToken, undefined, undefined, ursa.RSA_PKCS1_PADDING);
+        const verifyToken = crypto.privateDecrypt({key:serverKey.exportKey(),padding:crypto.constants.RSA_PKCS1_PADDING},packet.verifyToken);
         if(!bufferEqual(client.verifyToken, verifyToken)) {
           client.end('DidNotEncryptVerifyTokenProperly');
           return;
         }
-        sharedSecret = serverKey.decrypt(packet.sharedSecret, undefined, undefined, ursa.RSA_PKCS1_PADDING);
+        sharedSecret = crypto.privateDecrypt({key:serverKey.exportKey(),padding:crypto.constants.RSA_PKCS1_PADDING},packet.sharedSecret);
       } catch(e) {
         client.end('DidNotEncryptVerifyTokenProperly');
         return;

src/ursa.js

@@ -1,11 +0,0 @@
-'use strict';
-
-let ursa;
-try {
-  ursa = require("ursa");
-} catch(e) {
-  console.log("You are using a pure-javascript implementation of RSA.");
-  console.log("Your performance might be subpar. Please consider installing URSA");
-  ursa = require("ursa-purejs");
-}
-module.exports=ursa;