Revert "Simple refactor of nested if-statements"

libi2pd_client/I2CP.cpp

@@ -524,31 +524,21 @@ namespace client
 
 	void I2CPSession::CreateSessionMessageHandler (const uint8_t * buf, size_t len)
 	{
-		if (m_Destination || !m_Owner.InsertSession (shared_from_this ()))
-		{
-			LogPrint (eLogError, "I2CP: Session already exists");
-			SendSessionStatusMessage (eI2CPSessionStatusRefused); // refused
-			return;
-		}
-
 		RAND_bytes ((uint8_t *)&m_SessionID, 2);
 		auto identity = std::make_shared<i2p::data::IdentityEx>();
 		size_t offset = identity->FromBuffer (buf, len);
-		
 		if (!offset)
 		{
 			LogPrint (eLogError, "I2CP: Create session malformed identity");
 			SendSessionStatusMessage (eI2CPSessionStatusInvalid); // invalid
 			return;
 		}
-		
 		if (m_Owner.FindSessionByIdentHash (identity->GetIdentHash ()))
 		{
 			LogPrint (eLogError, "I2CP: Create session duplicate address ", identity->GetIdentHash ().ToBase32 ());
 			SendSessionStatusMessage (eI2CPSessionStatusInvalid); // invalid
 			return;
 		}	
-		
 		uint16_t optionsSize = bufbe16toh (buf + offset);
 		offset += 2;
 		if (optionsSize > len - offset)
@@ -557,27 +547,42 @@ namespace client
 			SendSessionStatusMessage (eI2CPSessionStatusInvalid); // invalid
 			return;
 		}
-		
 		std::map<std::string, std::string> params;
 		ExtractMapping (buf + offset, optionsSize, params);
 		offset += optionsSize; // options
 		if (params[I2CP_PARAM_MESSAGE_RELIABILITY] == "none") m_IsSendAccepted = false;
 
 		offset += 8; // date
-		if (!identity->Verify (buf, offset, buf + offset)) // signature
+		if (identity->Verify (buf, offset, buf + offset)) // signature
+		{
+			if (!m_Destination)
+			{
+				m_Destination = m_Owner.IsSingleThread () ?
+					std::make_shared<I2CPDestination>(m_Owner.GetService (), shared_from_this (), identity, true, params):
+					std::make_shared<RunnableI2CPDestination>(shared_from_this (), identity, true, params);
+				if (m_Owner.InsertSession (shared_from_this ()))
+				{		
+					SendSessionStatusMessage (eI2CPSessionStatusCreated); // created
+					LogPrint (eLogDebug, "I2CP: Session ", m_SessionID, " created");
+					m_Destination->Start ();
+				}	
+				else
+				{
+					LogPrint (eLogError, "I2CP: Session already exists");
+					SendSessionStatusMessage (eI2CPSessionStatusRefused);
+				}	
+			}
+			else
+			{
+				LogPrint (eLogError, "I2CP: Session already exists");
+				SendSessionStatusMessage (eI2CPSessionStatusRefused); // refused
+			}
+		}
+		else
 		{
 			LogPrint (eLogError, "I2CP: Create session signature verification failed");
 			SendSessionStatusMessage (eI2CPSessionStatusInvalid); // invalid
-			return;
 		}
-
-		m_Destination = m_Owner.IsSingleThread () ?
-			std::make_shared<I2CPDestination>(m_Owner.GetService (), shared_from_this (), identity, true, params):
-			std::make_shared<RunnableI2CPDestination>(shared_from_this (), identity, true, params);
-
-		SendSessionStatusMessage (eI2CPSessionStatusCreated); // created
-		LogPrint (eLogDebug, "I2CP: Session ", m_SessionID, " created");
-		m_Destination->Start ();
 	}
 
 	void I2CPSession::DestroySessionMessageHandler (const uint8_t * buf, size_t len)