4 files changed, 120 insertions, 15 deletions

diff --git a/src/Protocol/Protocol17x.cpp b/src/Protocol/Protocol17x.cpp
index 0d349de03..267c18a99 100644
--- a/src/Protocol/Protocol17x.cpp
+++ b/src/Protocol/Protocol17x.cpp
@@ -53,6 +53,12 @@ Implements the 1.7.x protocol classes:
 
 
 
+const int MAX_ENC_LEN = 512;  // Maximum size of the encrypted message; should be 128, but who knows...
+
+
+
+
+
 // fwd: main.cpp:
 extern bool g_ShouldLogCommIn, g_ShouldLogCommOut;
 
@@ -1351,7 +1357,64 @@ void cProtocol172::HandlePacketStatusRequest(cByteBuffer & a_ByteBuffer)
 
 void cProtocol172::HandlePacketLoginEncryptionResponse(cByteBuffer & a_ByteBuffer)
 {
-	// TODO: Add protocol encryption
+	short EncKeyLength, EncNonceLength;
+	a_ByteBuffer.ReadBEShort(EncKeyLength);
+	AString EncKey;
+	if (!a_ByteBuffer.ReadString(EncKey, EncKeyLength))
+	{
+		return;
+	}
+	a_ByteBuffer.ReadBEShort(EncNonceLength);
+	AString EncNonce;
+	if (!a_ByteBuffer.ReadString(EncNonce, EncNonceLength))
+	{
+		return;
+	}
+	if ((EncKeyLength > MAX_ENC_LEN) || (EncNonceLength > MAX_ENC_LEN))
+	{
+		LOGD("Too long encryption");
+		m_Client->Kick("Hacked client");
+		return;
+	}
+
+	// Decrypt EncNonce using privkey
+	cRSAPrivateKey & rsaDecryptor = cRoot::Get()->GetServer()->GetPrivateKey();
+	Int32 DecryptedNonce[MAX_ENC_LEN / sizeof(Int32)];
+	int res = rsaDecryptor.Decrypt((const Byte *)EncNonce.data(), EncNonce.size(), (Byte *)DecryptedNonce, sizeof(DecryptedNonce));
+	if (res != 4)
+	{
+		LOGD("Bad nonce length: got %d, exp %d", res, 4);
+		m_Client->Kick("Hacked client");
+		return;
+	}
+	if (ntohl(DecryptedNonce[0]) != (unsigned)(uintptr_t)this)
+	{
+		LOGD("Bad nonce value");
+		m_Client->Kick("Hacked client");
+		return;
+	}
+	
+	// Decrypt the symmetric encryption key using privkey:
+	Byte DecryptedKey[MAX_ENC_LEN];
+	res = rsaDecryptor.Decrypt((const Byte *)EncKey.data(), EncKey.size(), DecryptedKey, sizeof(DecryptedKey));
+	if (res != 16)
+	{
+		LOGD("Bad key length");
+		m_Client->Kick("Hacked client");
+		return;
+	}
+	
+	StartEncryption(DecryptedKey);
+
+	// Send login success:
+	{
+		cPacketizer Pkt(*this, 0x02);  // Login success packet
+		Pkt.WriteString(Printf("%d", m_Client->GetUniqueID()));  // TODO: proper UUID
+		Pkt.WriteString(m_Client->GetUsername());
+	}
+
+	m_State = 3;  // State = Game
+	m_Client->HandleLogin(4, m_Client->GetUsername());
 }
 
 
@@ -1363,14 +1426,26 @@ void cProtocol172::HandlePacketLoginStart(cByteBuffer & a_ByteBuffer)
 	AString Username;
 	a_ByteBuffer.ReadVarUTF8String(Username);
 	
-	// TODO: Protocol encryption should be set up here if not localhost / auth
-	
 	if (!m_Client->HandleHandshake(Username))
 	{
 		// The client is not welcome here, they have been sent a Kick packet already
 		return;
 	}
 	
+	// If auth is required, then send the encryption request:
+	// if (cRoot::Get()->GetServer()->ShouldAuthenticate())
+	{
+		cPacketizer Pkt(*this, 0x01);
+		Pkt.WriteString(cRoot::Get()->GetServer()->GetServerID());
+		const AString & PubKeyDer = cRoot::Get()->GetServer()->GetPublicKeyDER();
+		Pkt.WriteShort(PubKeyDer.size());
+		Pkt.WriteBuf(PubKeyDer.data(), PubKeyDer.size());
+		Pkt.WriteShort(4);
+		Pkt.WriteInt((int)(intptr_t)this);  // Using 'this' as the cryptographic nonce, so that we don't have to generate one each time :)
+		m_Client->SetUsername(Username);
+		return;
+	}
+	
 	// Send login success:
 	{
 		cPacketizer Pkt(*this, 0x02);  // Login success packet
@@ -1882,6 +1957,27 @@ void cProtocol172::ParseItemMetadata(cItem & a_Item, const AString & a_Metadata)
 
 
 
+void cProtocol172::StartEncryption(const Byte * a_Key)
+{
+	m_Encryptor.Init(a_Key, a_Key);
+	m_Decryptor.Init(a_Key, a_Key);
+	m_IsEncrypted = true;
+	
+	// Prepare the m_AuthServerID:
+	cSHA1Checksum Checksum;
+	const AString & ServerID = cRoot::Get()->GetServer()->GetServerID();
+	Checksum.Update((const Byte *)ServerID.c_str(), ServerID.length());
+	Checksum.Update(a_Key, 16);
+	Checksum.Update((const Byte *)cRoot::Get()->GetServer()->GetPublicKeyDER().data(), cRoot::Get()->GetServer()->GetPublicKeyDER().size());
+	Byte Digest[20];
+	Checksum.Finalize(Digest);
+	cSHA1Checksum::DigestToJava(Digest, m_AuthServerID);
+}
+
+
+
+
+
 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 // cProtocol172::cPacketizer:
 
diff --git a/src/Protocol/Protocol17x.h b/src/Protocol/Protocol17x.h
index 72544b575..6a75e41c8 100644
--- a/src/Protocol/Protocol17x.h
+++ b/src/Protocol/Protocol17x.h
@@ -281,6 +281,8 @@ protected:
 	
 	/// Parses item metadata as read by ReadItem(), into the item enchantments.
 	void ParseItemMetadata(cItem & a_Item, const AString & a_Metadata);
+	
+	void StartEncryption(const Byte * a_Key);
 } ;
 
 
diff --git a/src/Server.cpp b/src/Server.cpp
index 3f9f8a4ac..ba2b46d55 100644
--- a/src/Server.cpp
+++ b/src/Server.cpp
@@ -237,7 +237,8 @@ bool cServer::InitServer(cIniFile & a_SettingsIni)
 	m_bIsConnected = true;
 
 	m_ServerID = "-";
-	if (a_SettingsIni.GetValueSetB("Authentication", "Authenticate", true))
+	m_ShouldAuthenticate = a_SettingsIni.GetValueSetB("Authentication", "Authenticate", true);
+	if (m_ShouldAuthenticate)
 	{
 		MTRand mtrand1;
 		unsigned int r1 = (mtrand1.randInt() % 1147483647) + 1000000000;
diff --git a/src/Server.h b/src/Server.h
index 15eafc00a..b5280c59d 100644
--- a/src/Server.h
+++ b/src/Server.h
@@ -71,13 +71,13 @@ public:												// tolua_export
 
 	bool Command(cClientHandle & a_Client, AString & a_Cmd);
 	
-	/// Executes the console command, sends output through the specified callback
+	/** Executes the console command, sends output through the specified callback */
 	void ExecuteConsoleCommand(const AString & a_Cmd, cCommandOutputCallback & a_Output);
 	
-	/// Lists all available console commands and their helpstrings
+	/** Lists all available console commands and their helpstrings */
 	void PrintHelp(const AStringVector & a_Split, cCommandOutputCallback & a_Output);
 
-	/// Binds the built-in console commands with the plugin manager
+	/** Binds the built-in console commands with the plugin manager */
 	static void BindBuiltInConsoleCommands(void);
 	
 	void Shutdown(void);
@@ -97,13 +97,13 @@ public:												// tolua_export
 	
 	void RemoveClient(const cClientHandle * a_Client);  // Removes the clienthandle from m_SocketThreads
 	
-	/// Don't tick a_Client anymore, it will be ticked from its cPlayer instead
+	/** Don't tick a_Client anymore, it will be ticked from its cPlayer instead */
 	void ClientMovedToWorld(const cClientHandle * a_Client);
 	
-	/// Notifies the server that a player was created; the server uses this to adjust the number of players
+	/** Notifies the server that a player was created; the server uses this to adjust the number of players */
 	void PlayerCreated(const cPlayer * a_Player);
 	
-	/// Notifies the server that a player is being destroyed; the server uses this to adjust the number of players
+	/** Notifies the server that a player is being destroyed; the server uses this to adjust the number of players */
 	void PlayerDestroying(const cPlayer * a_Player);
 
 	/** Returns base64 encoded favicon data (obtained from favicon.png) */
@@ -112,11 +112,13 @@ public:												// tolua_export
 	cRSAPrivateKey & GetPrivateKey(void) { return m_PrivateKey; }
 	const AString & GetPublicKeyDER(void) const { return m_PublicKeyDER; }
 	
+	bool ShouldAuthenticate(void) const { return m_ShouldAuthenticate; }
+	
 private:
 
 	friend class cRoot; // so cRoot can create and destroy cServer
 	
-	/// When NotifyClientWrite() is called, it is queued for this thread to process (to avoid deadlocks between cSocketThreads, cClientHandle and cChunkMap)
+	/** When NotifyClientWrite() is called, it is queued for this thread to process (to avoid deadlocks between cSocketThreads, cClientHandle and cChunkMap) */
 	class cNotifyWriteThread :
 		public cIsThread
 	{
@@ -140,7 +142,7 @@ private:
 		void NotifyClientWrite(const cClientHandle * a_Client);
 	} ;
 	
-	/// The server tick thread takes care of the players who aren't yet spawned in a world
+	/** The server tick thread takes care of the players who aren't yet spawned in a world */
 	class cTickThread :
 		public cIsThread
 	{
@@ -195,18 +197,22 @@ private:
 	cTickThread m_TickThread;
 	cEvent m_RestartEvent;
 	
-	/// The server ID used for client authentication
+	/** The server ID used for client authentication */
 	AString m_ServerID;
 	
+	/** If true, players will be online-authenticated agains Mojang servers.
+	This setting is the same as the "online-mode" setting in Vanilla. */
+	bool m_ShouldAuthenticate;
+	
 
 	cServer(void);
 
-	/// Loads, or generates, if missing, RSA keys for protocol encryption
+	/** Loads, or generates, if missing, RSA keys for protocol encryption */
 	void PrepareKeys(void);
 	
 	bool Tick(float a_Dt);
 	
-	/// Ticks the clients in m_Clients, manages the list in respect to removing clients
+	/** Ticks the clients in m_Clients, manages the list in respect to removing clients */
 	void TickClients(float a_Dt);
 
 	// cListenThread::cCallback overrides: