From d5e1d5db9c011faf68b7def8644d55b0c8108bb4 Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Wed, 8 Apr 2015 10:34:16 -0400
Subject: [PATCH] validate leaseset for zero leases

---
 Destination.cpp | 21 ++++++++++++++++++---
 LeaseSet.cpp    | 15 +++++++++++----
 LeaseSet.h      |  2 ++
 NetDb.cpp       | 18 +++++++++++++++---
 4 files changed, 46 insertions(+), 10 deletions(-)

diff --git a/Destination.cpp b/Destination.cpp
index 7cd97d45..4c7d382a 100644
--- a/Destination.cpp
+++ b/Destination.cpp
@@ -223,13 +223,28 @@ namespace client
 			{
 				leaseSet = it->second;
 				leaseSet->Update (buf + offset, len - offset); 
-				LogPrint (eLogDebug, "Remote LeaseSet updated");
+				if (leaseSet->IsValid ())
+					LogPrint (eLogDebug, "Remote LeaseSet updated");
+				else
+				{
+					LogPrint (eLogDebug, "Remote LeaseSet update failed");
+					m_RemoteLeaseSets.erase (it);
+					leaseSet = nullptr;
+				}
 			}
 			else
 			{	
-				LogPrint (eLogDebug, "New remote LeaseSet added");
 				leaseSet = std::make_shared<i2p::data::LeaseSet> (buf + offset, len - offset);
-				m_RemoteLeaseSets[buf + DATABASE_STORE_KEY_OFFSET] = leaseSet;
+				if (leaseSet->IsValid ())
+				{
+					LogPrint (eLogDebug, "New remote LeaseSet added");
+					m_RemoteLeaseSets[buf + DATABASE_STORE_KEY_OFFSET] = leaseSet;
+				}
+				else
+				{
+					LogPrint (eLogError, "New remote LeaseSet verification failed");
+					leaseSet = nullptr;
+				}
 			}	
 		}	
 		else
diff --git a/LeaseSet.cpp b/LeaseSet.cpp
index 3bc5d306..b2e84d23 100644
--- a/LeaseSet.cpp
+++ b/LeaseSet.cpp
@@ -14,7 +14,8 @@ namespace i2p
 namespace data
 {
 	
-	LeaseSet::LeaseSet (const uint8_t * buf, size_t len)
+	LeaseSet::LeaseSet (const uint8_t * buf, size_t len):
+		m_IsValid (true)
 	{
 		m_Buffer = new uint8_t[len];
 		memcpy (m_Buffer, buf, len);
@@ -22,7 +23,8 @@ namespace data
 		ReadFromBuffer ();
 	}
 
-	LeaseSet::LeaseSet (const i2p::tunnel::TunnelPool& pool)
+	LeaseSet::LeaseSet (const i2p::tunnel::TunnelPool& pool):
+		m_IsValid (true)
 	{	
 		// header
 		const i2p::data::LocalDestination * localDestination = pool.GetLocalDestination ();
@@ -30,6 +32,7 @@ namespace data
 		{
 			m_Buffer = nullptr;
 			m_BufferLen = 0;
+			m_IsValid = false;
 			LogPrint (eLogError, "Destination for local LeaseSet doesn't exist");
 			return;
 		}	
@@ -88,6 +91,7 @@ namespace data
 		uint8_t num = m_Buffer[size];
 		size++; // num
 		LogPrint ("LeaseSet num=", (int)num);
+		if (!num)  m_IsValid = false;
 
 		// process leases
 		const uint8_t * leases = m_Buffer + size;
@@ -106,14 +110,17 @@ namespace data
 			if (!netdb.FindRouter (lease.tunnelGateway))
 			{
 				// if not found request it
-				LogPrint ("Lease's tunnel gateway not found. Requested");
+				LogPrint (eLogInfo, "Lease's tunnel gateway not found. Requested");
 				netdb.RequestDestination (lease.tunnelGateway);
 			}	
 		}	
 		
 		// verify
 		if (!m_Identity.Verify (m_Buffer, leases - m_Buffer, leases))
-			LogPrint ("LeaseSet verification failed");
+		{
+			LogPrint (eLogWarning, "LeaseSet verification failed");
+			m_IsValid = false;
+		}
 	}				
 	
 	const std::vector<Lease> LeaseSet::GetNonExpiredLeases (bool withThreshold) const
diff --git a/LeaseSet.h b/LeaseSet.h
index d1164449..fee130ab 100644
--- a/LeaseSet.h
+++ b/LeaseSet.h
@@ -44,6 +44,7 @@ namespace data
 
 			const uint8_t * GetBuffer () const { return m_Buffer; };
 			size_t GetBufferLen () const { return m_BufferLen; };	
+			bool IsValid () const { return m_IsValid; };
 
 			// implements RoutingDestination
 			const IdentHash& GetIdentHash () const { return m_Identity.GetIdentHash (); };
@@ -60,6 +61,7 @@ namespace data
 			
 		private:
 
+			bool m_IsValid;
 			std::vector<Lease> m_Leases;
 			IdentityEx m_Identity;
 			uint8_t m_EncryptionKey[256];
diff --git a/NetDb.cpp b/NetDb.cpp
index 38bc56e9..a647ba5b 100644
--- a/NetDb.cpp
+++ b/NetDb.cpp
@@ -252,12 +252,24 @@ namespace data
 			if (it != m_LeaseSets.end ())
 			{
 				it->second->Update (buf, len); 
-				LogPrint ("LeaseSet updated");
+				if (it->second->IsValid ())
+					LogPrint (eLogInfo, "LeaseSet updated");
+				else
+				{
+					LogPrint (eLogInfo, "LeaseSet update failed");
+					m_LeaseSets.erase (it);
+				}	
 			}
 			else
 			{	
-				LogPrint ("New LeaseSet added");
-				m_LeaseSets[ident] = std::make_shared<LeaseSet> (buf, len);
+				auto leaseSet = std::make_shared<LeaseSet> (buf, len);
+				if (leaseSet->IsValid ())
+				{
+					LogPrint (eLogInfo, "New LeaseSet added");
+					m_LeaseSets[ident] = leaseSet;
+				}
+				else
+					LogPrint (eLogError, "New LeaseSet validation failed");
 			}	
 		}	
 	}