From 86ff0d86dbdc3df86c7a41e7d2ba64adc00a04ab Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Sat, 26 Dec 2020 17:18:29 -0500
Subject: [PATCH] check if new tag was created

---
 libi2pd/ECIESX25519AEADRatchetSession.cpp | 18 ++++++++++++++++--
 libi2pd/Garlic.cpp                        | 13 ++++++++++---
 2 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/libi2pd/ECIESX25519AEADRatchetSession.cpp b/libi2pd/ECIESX25519AEADRatchetSession.cpp
index a2c5b612..01be859b 100644
--- a/libi2pd/ECIESX25519AEADRatchetSession.cpp
+++ b/libi2pd/ECIESX25519AEADRatchetSession.cpp
@@ -45,13 +45,13 @@ namespace garlic
 
 	uint64_t RatchetTagSet::GetNextSessionTag ()
 	{
-		i2p::crypto::HKDF (m_KeyData.GetSessTagCK (), m_SessTagConstant, 32, "SessionTagKeyGen", m_KeyData.buf); // [sessTag_ck, tag] = HKDF(sessTag_chainkey, SESSTAG_CONSTANT, "SessionTagKeyGen", 64)
 		m_NextIndex++;
 		if (m_NextIndex >= 65535)
 		{
 			LogPrint (eLogError, "Garlic: Tagset ", GetTagSetID (), " is empty");
 			return 0;
 		}
+		i2p::crypto::HKDF (m_KeyData.GetSessTagCK (), m_SessTagConstant, 32, "SessionTagKeyGen", m_KeyData.buf); // [sessTag_ck, tag] = HKDF(sessTag_chainkey, SESSTAG_CONSTANT, "SessionTagKeyGen", 64)
 		return m_KeyData.GetTag ();
 	}
 
@@ -687,6 +687,13 @@ namespace garlic
 		auto index = m_SendTagset->GetNextIndex ();
 		CreateNonce (index, nonce); // tag's index
 		uint64_t tag = m_SendTagset->GetNextSessionTag ();
+		if (!tag)
+		{
+			LogPrint (eLogError, "Garlic: can't create new ECIES-X25519-AEAD-Ratchet tag for send tagset");
+			if (GetOwner ())
+				GetOwner ()->RemoveECIESx25519Session (m_RemoteStaticKey);
+			return false;
+		}	
 		memcpy (out, &tag, 8);
 		// ad = The session tag, 8 bytes
 		// ciphertext = ENCRYPT(k, n, payload, ad)
@@ -1050,7 +1057,14 @@ namespace garlic
 		if (GetOwner ())
 		{	
 			for (int i = 0; i < numTags; i++)
-				GetOwner ()->AddECIESx25519SessionNextTag (receiveTagset);
+			{	
+				auto tag = GetOwner ()->AddECIESx25519SessionNextTag (receiveTagset);
+				if (!tag)
+				{
+					LogPrint (eLogError, "Garlic: can't create new ECIES-X25519-AEAD-Ratchet tag for receive tagset");
+					break;
+				}	
+			}	
 		}	
 	}
 
diff --git a/libi2pd/Garlic.cpp b/libi2pd/Garlic.cpp
index 019cc387..aff92837 100644
--- a/libi2pd/Garlic.cpp
+++ b/libi2pd/Garlic.cpp
@@ -546,12 +546,18 @@ namespace garlic
 					if (!session->HandleNextMessage (buf, length, nullptr, 0))
 					{
 						// try to gererate more tags for last tagset 
-						if (m_LastTagset)
+						if (m_LastTagset && m_LastTagset->GetNextIndex () < 2*ECIESX25519_TAGSET_MAX_NUM_TAGS)
 						{
 							auto maxTags = std::max (m_NumRatchetInboundTags, ECIESX25519_MAX_NUM_GENERATED_TAGS);
 							for (int i = 0; i < maxTags; i++)
 							{
-								if (AddECIESx25519SessionNextTag (m_LastTagset) == tag)
+								auto nextTag = AddECIESx25519SessionNextTag (m_LastTagset);
+								if (!nextTag)
+								{
+									LogPrint (eLogError, "Garlic: can't create new ECIES-X25519-AEAD-Ratchet tag for last tagset");
+									break;
+								}	
+								if (nextTag == tag)
 								{
 									LogPrint (eLogDebug, "Garlic: Missing ECIES-X25519-AEAD-Ratchet tag was generated");
 									if (m_LastTagset->HandleNextMessage (buf, length, m_ECIESx25519Tags[tag].index))
@@ -1057,7 +1063,8 @@ namespace garlic
 	{
 		auto index = tagset->GetNextIndex ();
 		uint64_t tag = tagset->GetNextSessionTag ();
-		m_ECIESx25519Tags.emplace (tag, ECIESX25519AEADRatchetIndexTagset{index, tagset});
+		if (tag)
+			m_ECIESx25519Tags.emplace (tag, ECIESX25519AEADRatchetIndexTagset{index, tagset});
 		return tag;
 	}