Require WebSocket origins to be whitelisted in order to connect.

Fixes #1281.

docs/conf/modules.conf.example

@@ -2167,6 +2167,12 @@
 # WebSocket connections. Compatible with SSL/TLS.
 # Requires SHA-1 hash support available in the sha1 module.
 #<module name="websocket">
+#
+# If you use the websocket module you MUST specify one or more origins
+# which are allowed to connect to the server. You should set this as
+# strict as possible to prevent malicious webpages from connecting to
+# your server.
+# <wsorigin allow="https://webchat.example.com/*">
 
 #-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#
 # XLine database: Stores all *Lines (G/Z/K/R/any added by other modules)

src/modules/m_websocket.cpp

@@ -21,6 +21,8 @@
 #include "iohook.h"
 #include "modules/hash.h"
 
+typedef std::vector<std::string> OriginList;
+
 static const char MagicGUID[] = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
 static const char whitespace[] = " \t\r\n";
 static dynamic_reference_nocheck<HashProvider>* sha1;
@@ -28,6 +30,8 @@ static dynamic_reference_nocheck<HashProvider>* sha1;
 class WebSocketHookProvider : public IOHookProvider
 {
  public:
+	OriginList allowedorigins;
+
 	WebSocketHookProvider(Module* mod)
 		: IOHookProvider(mod, "websocket", IOHookProvider::IOH_UNKNOWN, true)
 	{
@@ -101,6 +105,7 @@ class WebSocketHook : public IOHookMiddle
 
 	State state;
 	time_t lastpingpong;
+	OriginList& allowedorigins;
 
 	static size_t FillHeader(unsigned char* outbuf, size_t sendlength, OpCode opcode)
 	{
@@ -288,6 +293,27 @@ class WebSocketHook : public IOHookMiddle
 		if (reqend == std::string::npos)
 			return 0;
 
+		bool allowedorigin = false;
+		HTTPHeaderFinder originheader;
+		if (originheader.Find(recvq, "Origin:", 7, reqend))
+		{
+			const std::string origin = originheader.ExtractValue(recvq);
+			for (OriginList::const_iterator iter = allowedorigins.begin(); iter != allowedorigins.end(); ++iter)
+			{
+				if (InspIRCd::Match(origin, *iter, ascii_case_insensitive_map))
+				{
+					allowedorigin = true;
+					break;
+				}
+			}
+		}
+
+		if (!allowedorigin)
+		{
+			FailHandshake(sock, "HTTP/1.1 403 Forbidden\r\nConnection: close\r\n\r\n", "WebSocket: Received HTTP request from a non-whitelisted origin");
+			return -1;
+		}
+
 		HTTPHeaderFinder keyheader;
 		if (!keyheader.Find(recvq, "Sec-WebSocket-Key:", 18, reqend))
 		{
@@ -318,10 +344,11 @@ class WebSocketHook : public IOHookMiddle
 	}
 
  public:
-	WebSocketHook(IOHookProvider* Prov, StreamSocket* sock)
+	WebSocketHook(IOHookProvider* Prov, StreamSocket* sock, OriginList& AllowedOrigins)
 		: IOHookMiddle(Prov)
 		, state(STATE_HTTPREQ)
 		, lastpingpong(0)
+		, allowedorigins(AllowedOrigins)
 	{
 		sock->AddIOHook(this);
 	}
@@ -370,7 +397,7 @@ class WebSocketHook : public IOHookMiddle
 
 void WebSocketHookProvider::OnAccept(StreamSocket* sock, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 {
-	new WebSocketHook(this, sock);
+	new WebSocketHook(this, sock, allowedorigins);
 }
 
 class ModuleWebSocket : public Module
@@ -386,6 +413,27 @@ class ModuleWebSocket : public Module
 		sha1 = &hash;
 	}
 
+	void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
+	{
+		ConfigTagList tags = ServerInstance->Config->ConfTags("wsorigin");
+		if (tags.first == tags.second)
+			throw ModuleException("You have loaded the websocket module but not configured any allowed origins!");
+
+		OriginList allowedorigins;
+		for (ConfigIter i = tags.first; i != tags.second; ++i)
+		{
+			ConfigTag* tag = i->second;
+
+			// Ensure that we have the <wsorigin:allow> parameter.
+			const std::string allow = tag->getString("allow");
+			if (allow.empty())
+				throw ModuleException("<wsorigin:allow> is a mandatory field, at " + tag->getTagLocation());
+
+			allowedorigins.push_back(allow);
+		}
+		hookprov->allowedorigins.swap(allowedorigins);
+	}
+
 	void OnCleanup(ExtensionItem::ExtensibleType type, Extensible* item) CXX11_OVERRIDE
 	{
 		if (type != ExtensionItem::EXT_USER)