一般的webgame中都会对资源、消息进行加密，这里只是简单记录一下对文件的加密过程。
上图为实际项目中所使用的加密工具(较为简单的一个air项目)
输入加密key + 需要加密的文件 --> 加密 –> 将加密后的文件保存至另一目录(后缀名视自己的项目的规则进行修改)
实现步骤：
1、读取文件(flash.filesystem.File)，获取文件流(flash.filesystem.FileStream)，获取文件的二进制流(flash.util.ByteArray)
2、对二进制数据进行加密（混淆一下）
3、保存加密后的二进制数据
1: var file:File = new File(path);
2: //file.isDirectory == false && file.exists
3:
4: var fs:FileStream = new FileStream();
5: var bytes:ByteArray = new ByteArray();
6: fs.open(file, FileMode.READ); //只读模式
7: fs.position = 0;
8: fs.readBytes(bytes, 0, fs.bytesAvailable);
9: fs.close();
10:
11:
12: var tempFileName:String = "xxx"; //要保存的文件完整路径
13: var tempFile:File = new File(tempFileName);
14: if (tempFile.exists)
15: {
16: tempFile.deleteFile();
17:
18: tempFile = new File(tempFileName);
19: }
20:
21: var tempFS:FileStream = new FileStream();
22: tempFS.open(tempFile, FileMode.WRITE);
23: tempFS.writeBytes(encrypt(bytes)); //加密数据
24: tempFS.close();
25:
26:
27: //encrypt..
28: var pos:int = 0;
29: var outByteArray:ByteArray = new ByteArray();
30: var key:String = StringUtil.trim(keyTxt.text);
31:
32: for (var i:int = 0, len:int = byte.length; i < len; i++)
33: {
34: //todo...
35:
36: outByteArray.writeByte(byte[i] + //.....);
37: }
38:
39: return outByteArray;
主要的示例代码（加密方法已被隐去>_<）：
1: <?xml version="1.0" encoding="utf-8"?>
2: <mx:Canvas xmlns:mx="http://www.adobe.com/2006/mxml" width="100%" height="100%"
3: horizontalScrollPolicy="off" verticalScrollPolicy="off">
4:
5: <mx:Script>
6: <![CDATA[
7: import mx.controls.Alert;
8: import mx.utils.StringUtil;
9:
10: private var filePath:String;
11: private var directoryPath:String;
12:
13: private function encryptHandler():void
14: {
15: if (!filePath && !directoryPath)
16: {
17: Alert.show("请先选择要加密的文件或目录", "错误");
18: return ;
19: }
20:
21: var key:String = StringUtil.trim(keyTxt.text);
22:
23: if (key == "")
24: {
25: Alert.show("加密KEY不能为空", "错误");
26: return ;
27: }
28:
29: encryptBtn.enabled = false;
30:
31: if (!(!filePath))
32: {
33: encryptFileHandler(filePath);
34:
35: Alert.show("文件“"+filePath+"”加密完成", "温馨提示");
36: }
37: else if (!(!directoryPath))
38: {
39: encryptDirectoryHandler(directoryPath);
40:
41: Alert.show("目录“"+directoryPath+"”文件加密完成", "温馨提示");
42: }
43:
44: outputTxt.validateNow();
45:
46: encryptBtn.enabled = true;
47: }
48:
49: private function getTypeFilter():FileFilter
50: {
51: var str:String = "*.swf;*.jpg;*.png;*.xml;*.zip";
52:
53: var filter:FileFilter = new FileFilter("资源("+str+")", str);
54:
55: return filter;
56: }
57:
58: private function selectFileHandler():void
59: {
60: var file:File = new File();
61: file.addEventListener(Event.SELECT, selectFileCallback);
62: file.browseForOpen("请选择一个文件", [getTypeFilter()]);
63: }
64:
65: private function selectFileCallback(evt:Event):void
66: {
67: clear();
68:
69: var file:File = File(evt.target);
70: file.removeEventListener(Event.SELECT, selectFileCallback);
71:
72: filePath = file.nativePath;
73:
74: inputTxt.htmlText = "选择的文件路径：" + filePath;
75: }
76:
77: private function selectDirectoryHandler():void
78: {
79: var file:File = new File();
80: file.addEventListener(Event.SELECT, selectDirectoryCallback);
81: file.browseForDirectory("请选择一个目录");
82: }
83:
84: private function selectDirectoryCallback(evt:Event):void
85: {
86: clear();
87:
88: directoryPath = File(evt.target).nativePath;
89:
90: inputTxt.htmlText = "选择的目录路径：" + directoryPath;
91:
92: File(evt.target).removeEventListener(Event.SELECT, selectDirectoryCallback);
93: }
94:
95: private function getEncryptSuffix(fileType:String):String
96: {
97: var typeConfig:Object = {
98: 'swf' : 's',
99: 'jpg' : 'j',
100: 'png' : 'p',
101: 'xml' : 'x',
102: 'zip' : 'z'
103: };
104:
105: if (!typeConfig[fileType])
106: {
107: return fileType;
108: }
109:
110: return typeConfig[fileType];
111: }
112:
113: private function clear():void
114: {
115: inputTxt.htmlText = "";
116: outputTxt.htmlText = "";
117:
118: filePath = null;
119: directoryPath = null;
120: }
121:
122: private function encryptFileHandler(path:String):void
123: {
124: var file:File = new File(path);
125:
126: if (file.isDirectory == false && file.exists)
127: {
128: maskPanel.visible = true;
129:
130: var fs:FileStream = new FileStream();
131: var bytes:ByteArray = new ByteArray();
132:
133: fs.open(file, FileMode.READ);
134: fs.position = 0;
135: fs.readBytes(bytes, 0, fs.bytesAvailable);
136: fs.close();
137:
138: loadFileCompleteHandler(file, bytes);
139:
140: maskPanel.visible = false;
141: }
142: else
143: {
144: outputTxt.htmlText += "<br>【error】" + path + "不是一个正确的文件路径！";
145: }
146: }
147:
148: private function encryptDirectoryHandler(path:String):void
149: {
150: var file:File = new File(path);
151:
152: if (file.exists && file.isDirectory)
153: {
154: var fileList:Array = file.getDirectoryListing();
155: var typeArr:Array = ["swf", "zip", "xml", "jpg", "png"];
156:
157: for (var i:int = 0, len:int = fileList.length; i < len; i++)
158: {
159: var tempFile:File = File(fileList[i]);
160: var tempFilePath:String = tempFile.nativePath;
161:
162: if (tempFile.isDirectory == false)
163: {
164: if (typeArr.indexOf(tempFile.extension) > -1)
165: {
166: encryptFileHandler(tempFilePath);
167: }
168: else
169: {
170: outputTxt.htmlText += "<br><font color='#ff0000'>【skip】跳过文件："+tempFilePath+"</font>";
171: }
172: }
173: else if (tempFile.name != ".svn")
174: {
175: encryptDirectoryHandler(tempFilePath);
176: }
177: }
178: }
179: else
180: {
181: outputTxt.htmlText += "<br>【error】" + path + "不是一个正确的目录路径！";
182: }
183: }
184:
185: private function loadFileCompleteHandler(file:File, bytes:ByteArray):void
186: {
187: outputTxt.htmlText += "<br>开始加密文件" + file.nativePath;
188:
189: var tempFileName:String = file.parent.nativePath + "\\" + file.name.replace(new RegExp(file.extension + "$"), "") + getEncryptSuffix(file.extension);
190:
191: tempFileName = tempFileName.replace(/\\abc\\/, '\\encrypt_abc\\abc\\');
192:
193: var tempFile:File = new File(tempFileName);
194:
195: if (tempFile.exists)
196: {
197: tempFile.deleteFile();
198:
199: tempFile = new File(tempFileName);
200: }
201:
202: var tempFS:FileStream = new FileStream();
203: tempFS.open(tempFile, FileMode.WRITE);
204: tempFS.writeBytes(encrypt(bytes));
205: tempFS.close();
206: }
207:
208: private function encrypt(byte:ByteArray):ByteArray
209: {
210: var pos:int = 0;
211: var outByteArray:ByteArray = new ByteArray();
212: var key:String = StringUtil.trim(keyTxt.text);
213: //todo...
214:
215: return outByteArray;
216: }
217:
218: ]]>
219: </mx:Script>
220:
221: <mx:VBox width="100%" height="100%"
222: horizontalScrollPolicy="off" verticalScrollPolicy="off"
223: paddingLeft="10" paddingRight="10" paddingTop="10" paddingBottom="10">
224:
225: <mx:HBox width="100%" height="50" horizontalScrollPolicy="off" verticalScrollPolicy="off"
226: verticalAlign="middle">
227:
228: <mx:Label text="加密KEY" />
229: <mx:TextInput id="keyTxt" width="300" text="abc123" />
230: <mx:Button label="加密" id="encryptBtn" click="encryptHandler()" />
231: <mx:Spacer width="100%" />
232:
233: <mx:Button id="selectFileBtn" click="selectFileHandler()" label="选择文件" />
234: <mx:Button id="selectDirectoryBtn" click="selectDirectoryHandler()" label="选择文件夹" />
235:
236: </mx:HBox>
237:
238: <mx:HBox width="100%" height="100%" horizontalScrollPolicy="off" verticalScrollPolicy="off">
239:
240: <mx:TextArea id="inputTxt" width="100%" height="480" leading="5" letterSpacing="1"
241: borderColor="#eeeeee" borderStyle="solid"
242: paddingTop="5" paddingRight="5" paddingLeft="5" paddingBottom="5" />
243:
244: <mx:TextArea id="outputTxt" width="100%" height="480" leading="5" letterSpacing="1"
245: borderColor="#eeeeee" borderStyle="solid"
246: verticalScrollPolicy="auto"
247: paddingTop="5" paddingRight="5" paddingLeft="5" paddingBottom="5" />
248:
249: </mx:HBox>
250:
251: </mx:VBox>
252:
253: <mx:Canvas width="100%" height="100%" backgroundColor="#000000" backgroundAlpha=".3" visible="false" id="maskPanel">
254: <mx:HBox width="130" height="50" horizontalCenter="0" verticalCenter="0"
255: backgroundColor="#ffffff" verticalAlign="middle" horizontalAlign="center">
256: <mx:Text horizontalCenter="0" verticalCenter="0" text="正在处理..." fontSize="16" fontWeight="bold" color="#3399cc" />
257: </mx:HBox>
258: </mx:Canvas>
259:
260: </mx:Canvas>
