correct buffer size for fragments of SessionConfirmed

libi2pd/SSU2.cpp

@@ -374,7 +374,11 @@ namespace transport
 					m_LastSession->ProcessData (buf, len);
 				break;
 				case eSSU2SessionStateSessionCreatedSent:
-					m_LastSession->ProcessSessionConfirmed (buf, len);
+					if (!m_LastSession->ProcessSessionConfirmed (buf, len))
+					{
+						m_LastSession->Terminate ();
+						m_LastSession = nullptr;
+					}	
 				break;
 				case eSSU2SessionStateIntroduced:
 					if (m_LastSession->GetRemoteEndpoint ().address ().is_unspecified ())	

libi2pd/SSU2Session.cpp

@@ -325,7 +325,6 @@ namespace transport
 			LogPrint (eLogDebug, "SSU2: Resending ", (int)m_State);
 			m_Server.Send (m_SentHandshakePacket->header.buf, 16, m_SentHandshakePacket->headerX, 48, 
 				m_SentHandshakePacket->payload, m_SentHandshakePacket->payloadSize, m_RemoteEndpoint);
-			m_SentHandshakePacket->numResends++;
 			m_SentHandshakePacket->nextResendTime = ts + SSU2_HANDSHAKE_RESEND_INTERVAL;
 			return;
 		}	
@@ -678,22 +677,24 @@ namespace transport
 			if (!(header.h.flags[0] & 0xF0))
 			{
 				// first fragment
+				if (!m_SessionConfirmedFragment1)
+				{	
 					m_SessionConfirmedFragment1.reset (new HandshakePacket);
 					m_SessionConfirmedFragment1->header = header;
 					memcpy (m_SessionConfirmedFragment1->payload, buf + 16, len - 16);
 					m_SessionConfirmedFragment1->payloadSize = len - 16;
+				}	
 				return true; // wait for second fragment
 			}
 			else
 			{
 				// second fragment
 				if (!m_SessionConfirmedFragment1) return false; // out of sequence
-				uint8_t fullMsg[2*SSU2_MTU];
 				header = m_SessionConfirmedFragment1->header;
-				memcpy (fullMsg + 16, m_SessionConfirmedFragment1->payload, m_SessionConfirmedFragment1->payloadSize);
-				memcpy (fullMsg + 16 + m_SessionConfirmedFragment1->payloadSize, buf + 16, len - 16);
-				buf = fullMsg;
-				len += m_SessionConfirmedFragment1->payloadSize;
+				memcpy (m_SessionConfirmedFragment1->payload + m_SessionConfirmedFragment1->payloadSize, buf + 16, len - 16);
+				m_SessionConfirmedFragment1->payloadSize += (len - 16);
+				buf = m_SessionConfirmedFragment1->payload - 16;
+				len = m_SessionConfirmedFragment1->payloadSize + 16;
 			}
 		}
 		// KDF for Session Confirmed part 1
@@ -724,6 +725,7 @@ namespace transport
 			return false;
 		}
 		m_NoiseState->MixHash (payload, len - 64); // h = SHA256(h || ciphertext);
+		if (m_SessionConfirmedFragment1) m_SessionConfirmedFragment1.reset (nullptr);
 		// payload
 		// handle RouterInfo block that must be first
 		if (decryptedPayload[0] != eSSU2BlkRouterInfo)

libi2pd/SSU2Session.h

@@ -190,10 +190,13 @@ namespace transport
 			int numResends = 0;
 		};
 
-		struct HandshakePacket: public SentPacket
+		struct HandshakePacket
 		{
 			Header header;
 			uint8_t headerX[48]; // part1 for SessionConfirmed
+			uint8_t payload[SSU2_MAX_PACKET_SIZE*2];
+			size_t payloadSize = 0;
+			uint32_t nextResendTime = 0; // in seconds
 		};
 
 		typedef std::function<void ()> OnEstablished;