From 99a487954e32737af1ef12d68375472d5ec3b682 Mon Sep 17 00:00:00 2001
From: Peter Thorson <github@zaphoyd.com>
Date: Sat, 1 Oct 2011 09:05:59 -0500
Subject: [PATCH] frame now generates a random masking key

---
 src/websocket_frame.cpp | 27 +++++++++++++++++++++------
 src/websocket_frame.hpp | 11 ++++++++++-
 2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/src/websocket_frame.cpp b/src/websocket_frame.cpp
index 3709c159c6..db46ff29ea 100644
--- a/src/websocket_frame.cpp
+++ b/src/websocket_frame.cpp
@@ -341,8 +341,10 @@ void frame::process_extended_header() {
 
 void frame::process_payload() {
 	if (get_masked()) {
+		char *masking_key = &m_header[get_header_len()-4];
+		
 		for (uint64_t i = 0; i < m_payload.size(); i++) {
-			m_payload[i] = (m_payload[i] ^ m_masking_key[i%4]);
+			m_payload[i] = (m_payload[i] ^ masking_key[i%4]);
 		}
 	}
 }
@@ -417,7 +419,21 @@ bool frame::validate_basic_header() const {
 }
 
 void frame::generate_masking_key() {
-	throw "masking key generation not implimented";
+	//throw "masking key generation not implimented";
+	
+	int32_t key = m_gen();
+	
+	std::cout << "genkey: " << key << std::endl;
+	
+	//m_masking_key[0] = reinterpret_cast<char*>(&key)[0];
+	//m_masking_key[1] = reinterpret_cast<char*>(&key)[1];
+	//m_masking_key[2] = reinterpret_cast<char*>(&key)[2];
+	//m_masking_key[3] = reinterpret_cast<char*>(&key)[3];
+	
+	*(reinterpret_cast<int32_t *>(&m_header[get_header_len()-4])) = key;
+	
+	//std::cout << "maskkey: " << m_masking_key << std::endl;
+	
 	/* TODO: test and tune
 	
 	boost::random::random_device rng;
@@ -429,8 +445,7 @@ void frame::generate_masking_key() {
 }
 
 void frame::clear_masking_key() {
-	m_masking_key[0] = 0;
-	m_masking_key[1] = 0;
-	m_masking_key[2] = 0;
-	m_masking_key[3] = 0;
+	// this is a no-op as clearing the mask bit also changes the get_header_len
+	// method to not include these byte ranges. Whenever the masking bit is re-
+	// set a new key is generated anyways.
 }
diff --git a/src/websocket_frame.hpp b/src/websocket_frame.hpp
index 7370273a5a..33436306a5 100644
--- a/src/websocket_frame.hpp
+++ b/src/websocket_frame.hpp
@@ -34,6 +34,9 @@
 #include <vector>
 #include <cstring>
 
+#include <boost/random.hpp>
+#include <boost/random/random_device.hpp>
+
 namespace websocketpp {
 
 class frame {
@@ -72,7 +75,8 @@ public:
 	static const uint64_t max_payload_size = 100000000; // 100MB
 	
 	// create an empty frame for writing into
-	frame() {
+	frame() : m_gen(m_rng, 
+	          boost::random::uniform_int_distribution<>(INT32_MIN,INT32_MAX)) {
 		// not sure if these are necessary with c++ but putting in just in case
 		memset(m_header,0,MAX_HEADER_LENGTH);
 	}
@@ -139,6 +143,11 @@ private:
 	
 	char m_masking_key[4];	
 	unsigned int m_extended_header_bytes_needed;
+	
+	boost::random::random_device m_rng;
+	boost::random::variate_generator<boost::random::random_device&, 
+	                                 boost::random::uniform_int_distribution<> > 
+	    m_gen;
 };
 
 }