flash处理安全策略

转自：http://www.eb163.com/club/thread-6471-1-1.html

不论是低于还是高于1024端口,基于文件系统时都不会请求策略文件,基于网络时才会请求.
1.首先发出以null结尾的<policy-file-request/>的消息,检查服务器843端口是否有安全策略文件,策略文件格式为:

<cross-domain-policy>
　　<allow-access-from domain="*" to-ports="80-9000" />
</cross-domain-policy>

发回策略文件的时候必要以0结尾,如果843端口在3秒内没有请求到策略文件或者to-ports配置的端口不允许链接,则断掉链接抛securityError,这个是flash主动发起的.
2. 如果您的客户端socket或xmlsocket连接中设置了Security.loadPolicyFile("xmlsocket://服务地址:应用端口"),则连接您的应用目标端口请求安全策略文件,请求和响应的方式如上,不设置是不会请求的.发请求是在调用connect之前.
3. 如果您是http请求方式要设置Security.loadPolicyFile("http://服务地址/crossdomain.xml"),crossdomain.xml文件内容如上,放在网站根目录就行了.例如mop的http://www.mop.com/crossdomain.xml

解决方案1:使用adobe官方提供的文件直接在服务器的843端口上建立服务,这样响应速度最快,但对于应用的部署就麻烦了http://www.adobe.com/devnet/flashplayer/articles/socket_policy_files.html

解决方案2:客户端必须加Security.loadPolicyFile("xmlsocket://服务地址:应用端口")，在服务端的应用端口上的私有协议上处理,一般的协议是长度+类型+数据,这样判断长度是0x3C70类型0x6C69,单独处理这个消息,但对自己的私有协议处理还是有影响。
为什么是这样的长度和类型看图:

解决方案3:单独在服务应用上处理843端口,和其他应用的服务剥离出来:

代码

//安全策略服务

public void startPolicyServer() throws IOException{
IoAcceptor acceptor = new NioSocketAcceptor();
acceptor.setHandler(new PolicyServerHandler());
acceptor.bind( new InetSocketAddress(843));
System.out.println("安全策略服务侦听端口:843");
}
//其他应用服务

..................
..................

//单独的安全策略处理器
public class PolicyServerHandler extends IoHandlerAdapter {

// 22字节+0占1个字节
String security_quest = "<POLICY-FILE-REQUEST />";

// 最后以0结尾
String policyStr = "<CROSS-DOMAIN-POLICY>\r\n<ALLOW-ACCESS-FROM to-ports='\"80-9000\"' domain='\"*\"' />\r\n </CROSS-DOMAIN-POLICY>\r\n\0";

private
final Logger log = Logger.getLogger(PolicyServerHandler.class.getName());

public
void messageReceived(IoSession session, Object message)
throws Exception {
IoBuffer processBuf = (IoBuffer) session.getAttribute("processBuf");
processBuf.put((IoBuffer)message);
processBuf.flip();

if(getRequest(processBuf)){
byte[] reps = policyStr.getBytes("UTF-8");
IoBuffer rb = IoBuffer.allocate(reps.length);
rb.put(reps);//也有putString方法

rb.flip();
session.write(rb);//发回

log.info("send Policy");
}
}

//获得安全请求的字符串
private
Boolean getRequest(IoBuffer buf){

String req = new
String(buf.array());

if (req.indexOf(security_quest) != -1){

return
true;
}

return
false;
}
@Override

public
void messageSent(IoSession session, Object message) throws Exception {
session.close(true);
}

@Override
public
void sessionClosed(IoSession session) throws Exception {

super.sessionClosed(session);
session.removeAttribute("processBuf");
}

@Override

public
void sessionCreated(IoSession session) throws Exception {

super.sessionCreated(session);
IoBuffer processBuf = IoBuffer.allocate(64);
session.setAttribute("processBuf", processBuf);
}
}
}

c#:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net.Sockets;

using System.Net;
using System.Xml;

namespace Server
{
class Program
{
static void Main(string[] args)
{
try
{
int port = 60002;
string host = "192.168.1.103";
IPAddress ip = IPAddress.Parse(host);
IPEndPoint ipe = new IPEndPoint(ip, port);
Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);//创建一个Socket类
s.Bind(ipe);
s.Listen(0);
Console.WriteLine("Wait for connect 60002");

while (true)
{
try
{
Socket temp = s.Accept();//为新建连接创建新的Socket。
Console.WriteLine("Get a new connect   " + DateTime.Now.ToString());
string recvStr = "";
byte[] recvBytes = new byte[1024];
int bytes;
bytes = temp.Receive(recvBytes, recvBytes.Length, 0);//从客户端接受信息
recvStr += Encoding.GetEncoding("UTF-8").GetString(recvBytes, 0, bytes);
Console.WriteLine("Server Get Message:   {0}", recvStr);//把客户端传来的信息显示出来

if (recvStr == "<policy-file-request/>\0")
{
String sendStr = "<cross-domain-policy><allow-access-from domain=\"192.168.1.102\" to-ports=\"60000-60010\"/></cross-domain-policy>\0";

byte[] bs = Encoding.GetEncoding("UTF-8").GetBytes(sendStr);
temp.Send(bs, bs.Length, 0);//返回客户端成功信息
Console.WriteLine("Send:   " + sendStr);
//temp.Close();
//s.Close();
}
else
{
string sendStr = "Ok!Client Send Message Sucessful!";
byte[] bs = Encoding.GetEncoding("UTF-8").GetBytes(sendStr);
temp.Send(bs, bs.Length, 0);//返回客户端成功信息
//temp.Close();
//s.Close();
}
}

catch (Exception ex)
{
Console.WriteLine("SocketException: {0}", ex);
}
}
}
catch (Exception ex2)
{
Console.Write(ex2.Message.ToString());
}
}
}
}

由此可见，服务器端先接收到一个新连接，并得到“<policy-file-request/>”消息，服务器响应后发出
“<cross-domain-policy><allow-access-from domain=\"192.168.1.102\" to-ports=\"60000-60010\"/></cross-domain-policy>\0”
注意一定要以“\0”结尾，
备注:

1 mina2.x对比1.x效率更高,抛弃了原有的btyeBuffer,新写了Iobuffer,原因如下:
It doesn't provide useful getters and putters such as fill, get/putString, and get/putAsciiInt() enough.
It is difficult to write variable-length data due to its fixed capacity
2 demux下DemuxingProtocolCodecFactory和MessageDecoder等功能更完善了,decodable判断是否能解析数据,decode解析实际的数据,在处理私有协议上更简单了
3 Flash10 socket类新增加timeout属性指示建立连接时需等待的毫秒数