From 53a6162b0c3c434823ce6b1ce21ef7971b3d2845 Mon Sep 17 00:00:00 2001 From: orignal Date: Sun, 9 Feb 2020 17:19:42 -0500 Subject: [PATCH] generate more receive tags when needed --- libi2pd/ECIESX25519AEADRatchetSession.cpp | 32 ++++++++++++----------- libi2pd/ECIESX25519AEADRatchetSession.h | 5 +++- 2 files changed, 21 insertions(+), 16 deletions(-) diff --git a/libi2pd/ECIESX25519AEADRatchetSession.cpp b/libi2pd/ECIESX25519AEADRatchetSession.cpp index b29c27ed..7f17130c 100644 --- a/libi2pd/ECIESX25519AEADRatchetSession.cpp +++ b/libi2pd/ECIESX25519AEADRatchetSession.cpp @@ -295,13 +295,7 @@ namespace garlic m_ReceiveTagset.NextSessionTagRatchet (); m_SendTagset.DHInitialize (m_CK, keydata + 32); // tagset_ba = DH_INITIALIZE(chainKey, k_ba) m_SendTagset.NextSessionTagRatchet (); - auto numTags = GetOwner ()->GetNumTags (); - for (int i = 0; i < numTags; i++) - { - auto index = m_ReceiveTagset.GetNextIndex (); - uint64_t tag = m_ReceiveTagset.GetNextSessionTag (); - GetOwner ()->AddECIESx25519SessionTag (index, tag, shared_from_this ()); - } + GenerateMoreReceiveTags (GetOwner ()->GetNumTags ()); i2p::crypto::HKDF (keydata + 32, nullptr, 0, "AttachPayloadKDF", keydata, 32); // k = HKDF(k_ba, ZEROLEN, "AttachPayloadKDF", 32) // encrypt payload if (!i2p::crypto::AEADChaCha20Poly1305 (payload, len, m_H, 32, keydata, nonce, out + offset, len + 16, true)) // encrypt @@ -310,7 +304,7 @@ namespace garlic return false; } m_State = eSessionStateEstablished; - + return true; } @@ -353,13 +347,7 @@ namespace garlic m_SendTagset.NextSessionTagRatchet (); m_ReceiveTagset.DHInitialize (m_CK, keydata + 32); // tagset_ba = DH_INITIALIZE(chainKey, k_ba) m_ReceiveTagset.NextSessionTagRatchet (); - auto numTags = GetOwner ()->GetNumTags (); - for (int i = 0; i < numTags; i++) - { - auto index = m_ReceiveTagset.GetNextIndex (); - uint64_t tag = m_ReceiveTagset.GetNextSessionTag (); - GetOwner ()->AddECIESx25519SessionTag (index, tag, shared_from_this ()); - } + GenerateMoreReceiveTags (GetOwner ()->GetNumTags ()); i2p::crypto::HKDF (keydata + 32, nullptr, 0, "AttachPayloadKDF", keydata, 32); // k = HKDF(k_ba, ZEROLEN, "AttachPayloadKDF", 32) // decrypt payload std::vector payload (len - 16); @@ -405,6 +393,9 @@ namespace garlic return false; } HandlePayload (payload.data (), len - 16); + if (m_NumReceiveTags > 0)m_NumReceiveTags--; + if (m_NumReceiveTags <= GetOwner ()->GetNumTags ()*2/3) + GenerateMoreReceiveTags (GetOwner ()->GetNumTags ()); return true; } @@ -513,6 +504,17 @@ namespace garlic memcpy (buf + 9, msg->GetPayload (), msg->GetPayloadLength ()); return cloveSize + 3; } + + void ECIESX25519AEADRatchetSession::GenerateMoreReceiveTags (int numTags) + { + for (int i = 0; i < numTags; i++) + { + auto index = m_ReceiveTagset.GetNextIndex (); + uint64_t tag = m_ReceiveTagset.GetNextSessionTag (); + GetOwner ()->AddECIESx25519SessionTag (index, tag, shared_from_this ()); + } + m_NumReceiveTags += numTags; + } } } diff --git a/libi2pd/ECIESX25519AEADRatchetSession.h b/libi2pd/ECIESX25519AEADRatchetSession.h index 214e47f6..90e21e8a 100644 --- a/libi2pd/ECIESX25519AEADRatchetSession.h +++ b/libi2pd/ECIESX25519AEADRatchetSession.h @@ -80,7 +80,7 @@ namespace garlic { if (!m_Destination) m_Destination.reset (new i2p::data::IdentHash (dest)); } - + private: void ResetKeys (); @@ -101,6 +101,8 @@ namespace garlic std::vector CreatePayload (std::shared_ptr msg); size_t CreateGarlicClove (std::shared_ptr msg, uint8_t * buf, size_t len, bool isDestination = false); + void GenerateMoreReceiveTags (int numTags); + private: uint8_t m_H[32], m_CK[64] /* [chainkey, key] */, m_RemoteStaticKey[32]; @@ -108,6 +110,7 @@ namespace garlic i2p::crypto::X25519Keys m_EphemeralKeys; SessionState m_State = eSessionStateNew; RatchetTagSet m_SendTagset, m_ReceiveTagset; + int m_NumReceiveTags = 0; std::unique_ptr m_Destination;// TODO: might not need it }; }