spotify: update sendPong, handle MP3_160_ENC

.npmignore

@@ -0,0 +1,4 @@
+login.js
+node_modules
+?.js
+*.mp3

lib/crypto.js

@@ -0,0 +1,123 @@
+
+/**
+ * Module dependencies.
+ */
+
+var crypto = require("crypto");
+var util = require('./util');
+var inherits = require('util').inherits;
+var Transform = require('stream').Transform;
+var debug = require('debug')('spotify-web:crypto');
+
+/**
+ * Generates stream key based off `album_art` result.
+ **/
+
+exports.generateStreamKey = function(songKey) {
+    var param1 = util.hex2bin(songKey);
+
+    var swfKey = util.hex2bin("ed02752011affd6290ea42cf73fe0b99");
+
+    var keys = ["8cb926e087917795914a339035fa3bc6",
+                "a3285211c9d1f2364e4237c7b47cc71d",
+                "72ed1f6317d1923b94ebfd8a3d867c97"];
+
+    var finalKey = param1.slice(-16);
+
+    for(var i=0,j=0;i<keys.length;i+=1,j+=32) {
+        var msg = param1.slice(j, j+16);
+        var correctHmac = param1.slice(j+16, j+32);
+        var checkHmac = crypto.createHmac("sha1", util.hex2bin(keys[i]))
+                              .update(msg)
+                              .digest("binary");
+
+        if (checkHmac.indexOf(correctHmac) == 0) {
+            var finalHmac = crypto.createHmac("sha1", swfKey)
+                                  .update(msg)
+                                  .digest("binary");
+
+            var result = "";
+            for(var k=0;k<finalKey.length;k+=1)
+                result += String.fromCharCode(finalHmac[k].charCodeAt(0) ^ finalKey[k].charCodeAt(0));
+            return util.bin2hex(result);
+        }
+    }
+}
+
+/**
+ * Stream decrypts encrypted MP3_160_ENC files
+ *
+ * @param {String} songKey   song key given in `trackUri` result
+ **/
+
+exports.EncryptedStream = function(songKey, opts) {
+    if (!(this instanceof exports.EncryptedStream)) {
+        return new exports.EncryptedStream(songKey, opts);
+    }
+
+    if (!opts) opts = {};
+    opts.objectMode = true;
+    Transform.call(this, opts);
+
+    // required for RC4
+    this.box = [];
+    this.x = 0;
+    this.y = 0;
+
+    var key = util.hex2bin(exports.generateStreamKey(songKey));
+
+    debug("key(%j)", exports.generateStreamKey(songKey));
+
+    // initialize scheduling
+    for(var i=0;i<256;i+=1)
+        this.box[i] = i;
+
+    this.x = 0;
+    for(var i=0;i<256;i+=1) {
+        this.x = (this.x +
+                  this.box[i] +
+                  key.charCodeAt(i % key.length)) % 256;
+
+        var t = this.box[this.x];
+        this.box[this.x] = this.box[i];
+        this.box[i] = t;
+    }
+
+    // play 4096 pick-up
+    this.x = 0;
+    this.y = 0;
+    for(var i=0;i<4096;i+=1) {
+        this.x = (this.x + 1) % 256;
+        this.y = (this.y + this.box[this.x]) % 256;
+
+        var t = this.box[this.x];
+        this.box[this.x] = this.box[this.y];
+        this.box[this.y] = t;
+    }
+
+    debug([this.x, this.y, this.box]);
+}
+inherits(exports.EncryptedStream, Transform);
+
+exports.EncryptedStream.prototype._transform = function _transform(obj, encoding, callback) {
+    try {
+        debug("_transform(%j)", obj.length);
+
+        var res = new Buffer(obj.length);
+        for(var i=0;i<obj.length;i+=1) {
+            this.x = (this.x + 1) % 256;
+            this.y = (this.y + this.box[this.x]) % 256;
+
+            var t = this.box[this.x];
+            this.box[this.x] = this.box[this.y];
+            this.box[this.y] = t;
+
+            res[i] = obj[i] ^ this.box[(this.box[this.x] + this.box[this.y]) % 256];
+        }
+
+        this.push(res);
+        callback();
+    } catch(e) {
+        callback(e);
+    }
+}

lib/schemas.js

@@ -7,19 +7,13 @@ var fs = require('fs');
 var path = require('path');
 var debug = require('debug')('spotify-web:schemas');
 
-try {
-  var protobuf = require('protobuf');
-  var protobufjs = null;
-} catch(e) {
-  var protobuf = null;
-  var protobufjs = require('protobufjs');
-}
+var protobufjs = require('protobufjs');
 
 /**
  * Protocol Buffer schemas.
  */
 
-var library = (protobuf) ? 'protobuf' : 'protobufjs';
+var library = 'protobufjs';
 
 var protoPath = path.resolve(__dirname, '..', 'proto');
 
@@ -50,25 +44,15 @@ var loadPackage = function(id) {
   }
   if (!Array.isArray(mapping)) mapping = [mapping];
 
-  if (protobuf) {
-    // Protobuf works with compiled .desc files rather than .proto files and doesn't support imports
-    // Therefore, we load in each schema into an array and check each of them when looking for a message object
-    packageCache[id]= mapping.map(function(schema) {
-      return new protobuf.Schema(fs.readFileSync(path.resolve(protoPath, schema + '.desc')));
-    });
-    return packageCache[id];
-
-  } else { // protobufjs
-    // Generate a proto string with import statements
-    var proto = mapping.map(function(schema) {
-      return 'import "' + schema + '.proto";';
-    }).join('\n');
-
-    // Load the generated import file, and return the built package
-    var builder = protobufjs.protoFromString(proto, new protobufjs.Builder(), {root: protoPath, file: id+'_generated_import.proto'});
-    packageCache[id] = builder.build("spotify." + id + ".proto");
-    return packageCache[id];
-  }
+  // Generate a proto string with import statements
+  var proto = mapping.map(function(schema) {
+    return 'import "' + schema + '.proto";';
+  }).join('\n');
+
+  // Load the generated import file, and return the built package
+  var builder = protobufjs.protoFromString(proto, new protobufjs.Builder(), {root: protoPath, file: id+'_generated_import.proto'});
+  packageCache[id] = builder.build("spotify." + id + ".proto");
+  return packageCache[id];
 };
 
 var loadMessage = module.exports.build = function(packageId, messageId) {
@@ -77,44 +61,33 @@ var loadMessage = module.exports.build = function(packageId, messageId) {
   var packageObj = loadPackage(packageId);
   var messageObj = null;
 
-  if (protobuf) {
-    var identifier = "spotify." + packageId + ".proto." + messageId;
-
-    // Loop though each loaded schema looking for the message
-    for (var i = 0; i < packageObj.length; i++) {
-      messageObj = packageObj[i][identifier];
-      if (messageObj) break;
-    }
-
-  } else { // protobufjs
-    // Load the message directly
-    messageObj = packageObj[messageId];
+  // Load the message directly
+  messageObj = packageObj[messageId];
 
-    // Add wrapper functions
-    messageObj.parse = function protobufjs_parse_wrapper() {
-      debug('protobufjs_parse_wrapper(%j)', arguments);
+  // Add wrapper functions
+  messageObj.parse = function protobufjs_parse_wrapper() {
+    debug('protobufjs_parse_wrapper(%j)', arguments);
 
-      // Call the message object decode function with the arguments
-      var message = messageObj.decode.apply(null, arguments);
-      // Convert the object keys to camel case, ByteBuffers to Node Buffers and then return the parsed object
-      return convertByteBuffersToNodeBuffers(reCamelCase(message));
-    }
-    messageObj.serialize = function protobufjs_serialize_wrapper() {
-      debug('protobufjs_serialize_wrapper(%j)', arguments);
+    // Call the message object decode function with the arguments
+    var message = messageObj.decode.apply(null, arguments);
+    // Convert the object keys to camel case, ByteBuffers to Node Buffers and then return the parsed object
+    return convertByteBuffersToNodeBuffers(reCamelCase(message));
+  }
+  messageObj.serialize = function protobufjs_serialize_wrapper() {
+    debug('protobufjs_serialize_wrapper(%j)', arguments);
 
-      // Convert any camel cased properties in the arguments to underscored properties
-      Array.prototype.map.call(arguments, function (argument) {
-        return deCamelCase(argument);
-      });
+    // Convert any camel cased properties in the arguments to underscored properties
+    Array.prototype.map.call(arguments, function (argument) {
+      return deCamelCase(argument);
+    });
 
-      // Call the message object constructor with the modified arguments
-      var message = Object.create(messageObj.prototype);
-      message = messageObj.apply(message, arguments) || message;
+    // Call the message object constructor with the modified arguments
+    var message = Object.create(messageObj.prototype);
+    message = messageObj.apply(message, arguments) || message;
 
-      // Return the node Buffer object containing the serialised data
-      return message.encodeNB();
-    };
-  }
+    // Return the node Buffer object containing the serialised data
+    return message.encodeNB();
+  };
 
   return messageObj;
 };