Merge pull request #772 from majestrate/ssu-revert

don't use heap allocated buffers in ssu and fill uninitialized memory

SSUData.cpp

@@ -154,8 +154,7 @@ namespace transport
 		{	
 			uint32_t msgID = bufbe32toh (buf); // message ID
 			buf += 4;
-			uint8_t frag[4];
+			uint8_t frag[4] = {0};
-			frag[0] = 0;
 			memcpy (frag + 1, buf, 3);
 			buf += 3;
 			uint32_t fragmentInfo = bufbe32toh (frag); // fragment info
@@ -371,7 +370,7 @@ namespace transport
 
 	void SSUData::SendMsgAck (uint32_t msgID)
 	{
-		uint8_t * buf = new uint8_t[48 + 18]; // actual length is 44 = 37 + 7 but pad it to multiple of 16
+		uint8_t buf[48 + 18] = {0}; // actual length is 44 = 37 + 7 but pad it to multiple of 16
 		uint8_t * payload = buf + sizeof (SSUHeader);
 		*payload = DATA_FLAG_EXPLICIT_ACKS_INCLUDED; // flag
 		payload++;
@@ -384,7 +383,6 @@ namespace transport
 		// encrypt message with session key
 		m_Session.FillHeaderAndEncrypt (PAYLOAD_TYPE_DATA, buf, 48);
 		m_Session.Send (buf, 48);
-		delete [] buf;
 	}
 
 	void SSUData::SendFragmentAck (uint32_t msgID, int fragmentNum)
@@ -394,7 +392,7 @@ namespace transport
 			LogPrint (eLogWarning, "SSU: Fragment number ", fragmentNum, " exceeds 64");
 			return;
 		}
-		uint8_t * buf = new uint8_t[64 + 18];
+		uint8_t buf[64 + 18] = {0};
 		uint8_t * payload = buf + sizeof (SSUHeader);
 		*payload = DATA_FLAG_ACK_BITFIELDS_INCLUDED; // flag
 		payload++;	
@@ -414,7 +412,6 @@ namespace transport
 		// encrypt message with session key
 		m_Session.FillHeaderAndEncrypt (PAYLOAD_TYPE_DATA, buf, len);
 		m_Session.Send (buf, len);
-		delete [] buf;
 	}	
 
 	void SSUData::ScheduleResend()

SSUSession.cpp

@@ -350,7 +350,7 @@ namespace transport
 
 	void SSUSession::SendSessionRequest ()
 	{	
-		uint8_t * buf = new uint8_t[320 + 18]; // 304 bytes for ipv4, 320 for ipv6
+		uint8_t buf[320 + 18] = {0}; // 304 bytes for ipv4, 320 for ipv6
 		uint8_t * payload = buf + sizeof (SSUHeader);
 		uint8_t flag = 0;
 		// fill extended options, 3 bytes extended options don't change message size
@@ -381,7 +381,6 @@ namespace transport
 		RAND_bytes (iv, 16); // random iv
 		FillHeaderAndEncrypt (PAYLOAD_TYPE_SESSION_REQUEST, buf, isV4 ? 304 : 320, m_IntroKey, iv, m_IntroKey, flag);
 		m_Server.Send (buf, isV4 ? 304 : 320, m_RemoteEndpoint);
-		delete [] buf;
 	}
 
 	void SSUSession::SendRelayRequest (const i2p::data::RouterInfo::Introducer& introducer, uint32_t nonce)
@@ -393,7 +392,7 @@ namespace transport
 			return;
 		}
 	
-		uint8_t * buf = new uint8_t[96 + 18]; 
+		uint8_t buf[96 + 18] = {0};
 		uint8_t * payload = buf + sizeof (SSUHeader);
 		htobe32buf (payload, introducer.iTag);
 		payload += 4;
@@ -414,7 +413,6 @@ namespace transport
 		else
 			FillHeaderAndEncrypt (PAYLOAD_TYPE_RELAY_REQUEST, buf, 96, introducer.iKey, iv, introducer.iKey);			
 		m_Server.Send (buf, 96, m_RemoteEndpoint);
-		delete [] buf;
 	}
 
 	void SSUSession::SendSessionCreated (const uint8_t * x, bool sendRelayTag)
@@ -429,7 +427,7 @@ namespace transport
 		SignedData s; // x,y, remote IP, remote port, our IP, our port, relayTag, signed on time 
 		s.Insert (x, 256); // x
 
-		uint8_t * buf = new uint8_t[384 + 18];	
+		uint8_t buf[384 + 18] = {0};
 		uint8_t * payload = buf + sizeof (SSUHeader);
 		memcpy (payload, m_DHKeysPair->GetPublicKey (), 256);
 		s.Insert (payload, 256); // y
@@ -475,14 +473,18 @@ namespace transport
 		m_SignedData = std::unique_ptr<SignedData>(new SignedData (s)); 	
 		s.Insert (payload - 4, 4); // BOB's signed on time 
 		s.Sign (i2p::context.GetPrivateKeys (), payload); // DSA signature
-		// TODO: fill padding with random data	
 
 		uint8_t iv[16];
 		RAND_bytes (iv, 16); // random iv
 		// encrypt signature and padding with newly created session key	
 		size_t signatureLen = i2p::context.GetIdentity ()->GetSignatureLen ();
 		size_t paddingSize = signatureLen & 0x0F; // %16
-		if (paddingSize > 0) signatureLen += (16 - paddingSize);
+		if (paddingSize > 0)
+		{
+			// fill random padding
+			RAND_bytes(payload + signatureLen, (16 - paddingSize));
+			signatureLen += (16 - paddingSize);
+		}
 		m_SessionKeyEncryption.SetIV (iv);
 		m_SessionKeyEncryption.Encrypt (payload, signatureLen, payload);
 		payload += signatureLen;
@@ -491,12 +493,11 @@ namespace transport
 		// encrypt message with intro key
 		FillHeaderAndEncrypt (PAYLOAD_TYPE_SESSION_CREATED, buf, msgLen, m_IntroKey, iv, m_IntroKey);	
 		Send (buf, msgLen);
-		delete [] buf;
 	}
 
 	void SSUSession::SendSessionConfirmed (const uint8_t * y, const uint8_t * ourAddress, size_t ourAddressLen)
 	{
-		uint8_t * buf = new uint8_t[512 + 18];
+		uint8_t buf[512 + 18] = {0};
 		uint8_t * payload = buf + sizeof (SSUHeader);
 		*payload = 1; // 1 fragment
 		payload++; // info
@@ -511,9 +512,8 @@ namespace transport
 		auto signatureLen = i2p::context.GetIdentity ()->GetSignatureLen ();
 		size_t paddingSize = ((payload - buf) + signatureLen)%16;
 		if (paddingSize > 0) paddingSize = 16 - paddingSize;
-		// TODO: fill padding	
+		RAND_bytes(payload, paddingSize); // fill padding with random
 		payload += paddingSize; // padding size
-
 		// signature		
 		SignedData s; // x,y, our IP, our port, remote IP, remote port, relayTag, our signed on time 
 		s.Insert (m_DHKeysPair->GetPublicKey (), 256); // x
@@ -535,7 +535,6 @@ namespace transport
 		// encrypt message with session key
 		FillHeaderAndEncrypt (PAYLOAD_TYPE_SESSION_CONFIRMED, buf, msgLen, m_SessionKey, iv, m_MacKey);
 		Send (buf, msgLen);
-		delete [] buf;
 	}
 
 	void SSUSession::ProcessRelayRequest (const uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& from)
@@ -569,7 +568,7 @@ namespace transport
 			LogPrint (eLogWarning, "SSU: Charlie's IP must be v4");
 			return;
 		}
-		uint8_t * buf = new uint8_t[80 + 18]; // 64 Alice's ipv4 and 80 Alice's ipv6
+		uint8_t buf[80 + 18] = {0}; // 64 Alice's ipv4 and 80 Alice's ipv6
 		uint8_t * payload = buf + sizeof (SSUHeader);
 		*payload = 4;
 		payload++; // size
@@ -612,7 +611,6 @@ namespace transport
 			m_Server.Send (buf, isV4 ? 64 : 80, from);
 		}	
 		LogPrint (eLogDebug, "SSU: relay response sent");
-		delete [] buf;
 	}	
 
 	void SSUSession::SendRelayIntro (std::shared_ptr<SSUSession> session, const boost::asio::ip::udp::endpoint& from)
@@ -624,7 +622,7 @@ namespace transport
 			LogPrint (eLogWarning, "SSU: Alice's IP must be v4");
 			return;
 		}	
-		uint8_t * buf = new uint8_t[48 + 18];
+		uint8_t buf[48 + 18] = {0};
 		uint8_t * payload = buf + sizeof (SSUHeader);
 		*payload = 4;
 		payload++; // size
@@ -638,7 +636,6 @@ namespace transport
 		FillHeaderAndEncrypt (PAYLOAD_TYPE_RELAY_INTRO, buf, 48, session->m_SessionKey, iv, session->m_MacKey);
 		m_Server.Send (buf, 48, session->m_RemoteEndpoint);
 		LogPrint (eLogDebug, "SSU: relay intro sent");
-		delete [] buf;
 	}
 	
 	void SSUSession::ProcessRelayResponse (const uint8_t * buf, size_t len)
@@ -1046,7 +1043,7 @@ namespace transport
 	// toAddress is true for Alice<->Chalie communications only
 	// sendAddress is false if message comes from Alice		
 	{
-		uint8_t * buf = new uint8_t[80 + 18];
+		uint8_t buf[80 + 18] = {0};
 		uint8_t iv[16];
 		uint8_t * payload = buf + sizeof (SSUHeader);
 		htobe32buf (payload, nonce);
@@ -1103,7 +1100,6 @@ namespace transport
 			FillHeaderAndEncrypt (PAYLOAD_TYPE_PEER_TEST, buf, 80);
 			Send (buf, 80);
 		}
-		delete [] buf;
 	}	
 
 	void SSUSession::SendPeerTest ()
@@ -1128,7 +1124,7 @@ namespace transport
 	{
 		if (m_State == eSessionStateEstablished)
 		{	
-			uint8_t * buf = new uint8_t[48 + 18];	
+			uint8_t buf[48 + 18] = {0};
 			uint8_t	* payload = buf + sizeof (SSUHeader);
 			*payload = 0; // flags
 			payload++;
@@ -1138,7 +1134,6 @@ namespace transport
 			Send (buf, 48);
 			LogPrint (eLogDebug, "SSU: keep-alive sent");
 			m_LastActivityTimestamp = i2p::util::GetSecondsSinceEpoch ();
-			delete [] buf;
 		}	
 	}
 
@@ -1146,7 +1141,7 @@ namespace transport
 	{
 		if (m_IsSessionKey)
 		{
-			uint8_t * buf = new uint8_t[48 + 18];
+			uint8_t buf[48 + 18] = {0};
 			// encrypt message with session key
 			FillHeaderAndEncrypt (PAYLOAD_TYPE_SESSION_DESTROYED, buf, 48);
 			try
@@ -1158,13 +1153,12 @@ namespace transport
 				LogPrint (eLogWarning, "SSU: exception while sending session destoroyed: ", ex.what ());
 			}
 			LogPrint (eLogDebug, "SSU: session destroyed sent");
-			delete [] buf;
 		}
 	}	
 
 	void SSUSession::Send (uint8_t type, const uint8_t * payload, size_t len)
 	{
-		uint8_t * buf = new uint8_t[SSU_MTU_V4 + 18];
+		uint8_t buf[SSU_MTU_V4 + 18] = {0};
 		size_t msgSize = len + sizeof (SSUHeader); 
 		size_t paddingSize = msgSize & 0x0F; // %16
 		if (paddingSize > 0) msgSize += (16 - paddingSize);
@@ -1177,7 +1171,6 @@ namespace transport
 		// encrypt message with session key
 		FillHeaderAndEncrypt (type, buf, msgSize);
 		Send (buf, msgSize);
-		delete [] buf;
 	}			
 
 	void SSUSession::Send (const uint8_t * buf, size_t size)