std::shared_ptr<I2NPMessage> CreateDatabaseStoreMsg (std::shared_ptr<const i2p::data::LeaseSet> leaseSet, uint32_t replyToken)
{
if (!leaseSet) return nullptr;
auto m = NewI2NPShortMessage ();
uint8_t * payload = m->GetPayload ();
memcpy (payload + DATABASE_STORE_KEY_OFFSET, leaseSet->GetIdentHash (), 32);
payload[DATABASE_STORE_TYPE_OFFSET] = 1; // LeaseSet
htobe32buf (payload + DATABASE_STORE_REPLY_TOKEN_OFFSET, replyToken);
size_t size = DATABASE_STORE_HEADER_SIZE;
if (replyToken)
{
auto leases = leaseSet->GetNonExpiredLeases ();
if (leases.size () > 0)
{
htobe32buf (payload + size, leases[0].tunnelID);
size += 4; // reply tunnelID
memcpy (payload + size, leases[0].tunnelGateway, 32);
size += 32; // reply tunnel gateway
}
else
htobe32buf (payload + DATABASE_STORE_REPLY_TOKEN_OFFSET, 0);
}
memcpy (payload + size, leaseSet->GetBuffer (), leaseSet->GetBufferLen ());
size += leaseSet->GetBufferLen ();
m->len += size;
m->FillI2NPMessageHeader (eI2NPDatabaseStore);
return m;
}
size_t GarlicRoutingSession::CreateDeliveryStatusClove (uint8_t * buf, uint32_t msgID)
{
size_t size = 0;
if (m_Owner)
{
auto inboundTunnel = m_Owner->GetTunnelPool ()->GetNextInboundTunnel ();
if (inboundTunnel)
{
buf[size] = eGarlicDeliveryTypeTunnel << 5; // delivery instructions flag tunnel
size++;
// hash and tunnelID sequence is reversed for Garlic
memcpy (buf + size, inboundTunnel->GetNextIdentHash (), 32); // To Hash
size += 32;
htobe32buf (buf + size, inboundTunnel->GetNextTunnelID ()); // tunnelID
size += 4;
// create msg
auto msg = CreateDeliveryStatusMsg (msgID);
if (m_Owner)
{
//encrypt
uint8_t key[32], tag[32];
RAND_bytes (key, 32); // random session key
RAND_bytes (tag, 32); // random session tag
m_Owner->SubmitSessionKey (key, tag);
GarlicRoutingSession garlic (key, tag);
msg = garlic.WrapSingleMessage (msg);
}
memcpy (buf + size, msg->GetBuffer (), msg->GetLength ());
size += msg->GetLength ();
// fill clove
uint64_t ts = i2p::util::GetMillisecondsSinceEpoch () + 8000; // 8 sec
uint32_t cloveID;
RAND_bytes ((uint8_t *)&cloveID, 4);
htobe32buf (buf + size, cloveID); // CloveID
size += 4;
htobe64buf (buf + size, ts); // Expiration of clove
size += 8;
memset (buf + size, 0, 3); // certificate of clove
size += 3;
}
else
LogPrint (eLogError, "Garlic: No inbound tunnels in the pool for DeliveryStatus");
}
else
LogPrint (eLogWarning, "Garlic: Missing local LeaseSet");
return size;
}
size_t GarlicRoutingSession::CreateAESBlock (uint8_t * buf, std::shared_ptr<const I2NPMessage> msg)
{
size_t blockSize = 0;
bool createNewTags = m_Owner && m_NumTags && ((int)m_SessionTags.size () <= m_NumTags*2/3);
UnconfirmedTags * newTags = createNewTags ? GenerateSessionTags () : nullptr;
htobuf16 (buf, newTags ? htobe16 (newTags->numTags) : 0); // tag count
blockSize += 2;
if (newTags) // session tags recreated
{
for (int i = 0; i < newTags->numTags; i++)
{
memcpy (buf + blockSize, newTags->sessionTags[i], 32); // tags
blockSize += 32;
}
}
uint32_t * payloadSize = (uint32_t *)(buf + blockSize);
blockSize += 4;
uint8_t * payloadHash = buf + blockSize;
blockSize += 32;
buf[blockSize] = 0; // flag
blockSize++;
size_t len = CreateGarlicPayload (buf + blockSize, msg, newTags);
htobe32buf (payloadSize, len);
SHA256(buf + blockSize, len, payloadHash);
blockSize += len;
size_t rem = blockSize % 16;
if (rem)
blockSize += (16-rem); //padding
m_Encryption.Encrypt(buf, blockSize, buf);
return blockSize;
}
size_t GarlicRoutingSession::CreateGarlicClove (uint8_t * buf, std::shared_ptr<const I2NPMessage> msg, bool isDestination)
{
uint64_t ts = i2p::util::GetMillisecondsSinceEpoch () + 8000; // 8 sec
size_t size = 0;
if (isDestination)
{
buf[size] = eGarlicDeliveryTypeDestination << 5;// delivery instructions flag destination
size++;
memcpy (buf + size, m_Destination->GetIdentHash (), 32);
size += 32;
}
else
{
buf[size] = 0;// delivery instructions flag local
size++;
}
memcpy (buf + size, msg->GetBuffer (), msg->GetLength ());
size += msg->GetLength ();
uint32_t cloveID;
RAND_bytes ((uint8_t *)&cloveID, 4);
htobe32buf (buf + size, cloveID); // CloveID
size += 4;
htobe64buf (buf + size, ts); // Expiration of clove
size += 8;
memset (buf + size, 0, 3); // certificate of clove
size += 3;
return size;
}
void TunnelGatewayBuffer::CompleteCurrentTunnelDataMessage ()
{
if (!m_CurrentTunnelDataMsg) return;
uint8_t * payload = m_CurrentTunnelDataMsg->GetBuffer ();
size_t size = m_CurrentTunnelDataMsg->len - m_CurrentTunnelDataMsg->offset;
m_CurrentTunnelDataMsg->offset = m_CurrentTunnelDataMsg->len - TUNNEL_DATA_MSG_SIZE - I2NP_HEADER_SIZE;
uint8_t * buf = m_CurrentTunnelDataMsg->GetPayload ();
htobe32buf (buf, m_TunnelID);
RAND_bytes (buf + 4, 16); // original IV
memcpy (payload + size, buf + 4, 16); // copy IV for checksum
uint8_t hash[32];
SHA256(payload, size+16, hash);
memcpy (buf+20, hash, 4); // checksum
payload[-1] = 0; // zero
ptrdiff_t paddingSize = payload - buf - 25; // 25 = 24 + 1
if (paddingSize > 0)
{
// non-zero padding
auto randomOffset = rand () % (TUNNEL_DATA_MAX_PAYLOAD_SIZE - paddingSize + 1);
memcpy (buf + 24, m_NonZeroRandomBuffer + randomOffset, paddingSize);
}
// we can't fill message header yet because encryption is required
m_TunnelDataMsgs.push_back (m_CurrentTunnelDataMsg);
m_CurrentTunnelDataMsg = nullptr;
}
void TunnelGatewayBuffer::CompleteCurrentTunnelDataMessage ()
{
if (!m_CurrentTunnelDataMsg) return;
uint8_t * payload = m_CurrentTunnelDataMsg->GetBuffer ();
size_t size = m_CurrentTunnelDataMsg->len - m_CurrentTunnelDataMsg->offset;
m_CurrentTunnelDataMsg->offset = m_CurrentTunnelDataMsg->len - TUNNEL_DATA_MSG_SIZE - I2NP_HEADER_SIZE;
uint8_t * buf = m_CurrentTunnelDataMsg->GetPayload ();
htobe32buf (buf, m_TunnelID);
CryptoPP::RandomNumberGenerator& rnd = i2p::context.GetRandomNumberGenerator ();
rnd.GenerateBlock (buf + 4, 16); // original IV
memcpy (payload + size, buf + 4, 16); // copy IV for checksum
uint8_t hash[32];
CryptoPP::SHA256().CalculateDigest (hash, payload, size+16);
memcpy (buf+20, hash, 4); // checksum
payload[-1] = 0; // zero
ptrdiff_t paddingSize = payload - buf - 25; // 25 = 24 + 1
if (paddingSize > 0)
{
// non-zero padding
auto randomOffset = rnd.GenerateWord32 (0, TUNNEL_DATA_MAX_PAYLOAD_SIZE - paddingSize);
memcpy (buf + 24, m_NonZeroRandomBuffer + randomOffset, paddingSize);
}
// we can't fill message header yet because encryption is required
m_TunnelDataMsgs.push_back (m_CurrentTunnelDataMsg);
m_CurrentTunnelDataMsg = nullptr;
}
size_t GarlicRoutingSession::CreateGarlicPayload (uint8_t * payload, std::shared_ptr<const I2NPMessage> msg, UnconfirmedTags * newTags)
{
uint64_t ts = i2p::util::GetMillisecondsSinceEpoch () + 8000; // 8 sec
uint32_t msgID;
RAND_bytes ((uint8_t *)&msgID, 4);
size_t size = 0;
uint8_t * numCloves = payload + size;
*numCloves = 0;
size++;
if (m_Owner)
{
// resubmit non-confirmed LeaseSet
if (m_LeaseSetUpdateStatus == eLeaseSetSubmitted &&
i2p::util::GetMillisecondsSinceEpoch () > m_LeaseSetSubmissionTime + LEASET_CONFIRMATION_TIMEOUT)
m_LeaseSetUpdateStatus = eLeaseSetUpdated;
// attach DeviveryStatus if necessary
if (newTags || m_LeaseSetUpdateStatus == eLeaseSetUpdated) // new tags created or leaseset updated
{
// clove is DeliveryStatus
auto cloveSize = CreateDeliveryStatusClove (payload + size, msgID);
if (cloveSize > 0) // successive?
{
size += cloveSize;
(*numCloves)++;
if (newTags) // new tags created
m_UnconfirmedTagsMsgs[msgID] = newTags;
m_Owner->DeliveryStatusSent (shared_from_this (), msgID);
}
else
LogPrint (eLogWarning, "Garlic: DeliveryStatus clove was not created");
}
// attach LeaseSet
if (m_LeaseSetUpdateStatus == eLeaseSetUpdated)
{
m_LeaseSetUpdateStatus = eLeaseSetSubmitted;
m_LeaseSetUpdateMsgID = msgID;
m_LeaseSetSubmissionTime = i2p::util::GetMillisecondsSinceEpoch ();
// clove if our leaseSet must be attached
auto leaseSet = CreateDatabaseStoreMsg (m_Owner->GetLeaseSet ());
size += CreateGarlicClove (payload + size, leaseSet, false);
(*numCloves)++;
}
}
if (msg) // clove message ifself if presented
{
size += CreateGarlicClove (payload + size, msg, m_Destination ? m_Destination->IsDestination () : false);
(*numCloves)++;
}
memset (payload + size, 0, 3); // certificate of message
size += 3;
htobe32buf (payload + size, msgID); // MessageID
size += 4;
htobe64buf (payload + size, ts); // Expiration of message
size += 8;
return size;
}
void TransitTunnelParticipant::HandleTunnelDataMsg(
std::shared_ptr<const i2p::I2NPMessage> tunnelMsg) {
auto newMsg = CreateEmptyTunnelDataMsg();
EncryptTunnelMsg(tunnelMsg, newMsg);
m_NumTransmittedBytes += tunnelMsg->GetLength();
htobe32buf(newMsg->GetPayload(), GetNextTunnelID());
newMsg->FillI2NPMessageHeader(e_I2NPTunnelData);
m_TunnelDataMsgs.push_back(newMsg);
}
std::shared_ptr<I2NPMessage> CreateTunnelDataMsg (uint32_t tunnelID, const uint8_t * payload)
{
auto msg = NewI2NPShortMessage ();
htobe32buf (msg->GetPayload (), tunnelID);
msg->len += 4; // tunnelID
msg->Concat (payload, i2p::tunnel::TUNNEL_DATA_MSG_SIZE - 4);
msg->FillI2NPMessageHeader (eI2NPTunnelData);
return msg;
}
std::shared_ptr<I2NPMessage> CreateDeliveryStatusMsg (uint32_t msgID)
{
auto m = NewI2NPShortMessage ();
uint8_t * buf = m->GetPayload ();
if (msgID)
{
htobe32buf (buf + DELIVERY_STATUS_MSGID_OFFSET, msgID);
htobe64buf (buf + DELIVERY_STATUS_TIMESTAMP_OFFSET, i2p::util::GetMillisecondsSinceEpoch ());
}
else // for SSU establishment
{
RAND_bytes ((uint8_t *)&msgID, 4);
htobe32buf (buf + DELIVERY_STATUS_MSGID_OFFSET, msgID);
htobe64buf (buf + DELIVERY_STATUS_TIMESTAMP_OFFSET, 2); // netID = 2
}
m->len += DELIVERY_STATUS_SIZE;
m->FillI2NPMessageHeader (eI2NPDeliveryStatus);
return m;
}
std::shared_ptr<I2NPMessage> CreateTunnelGatewayMsg (uint32_t tunnelID, const uint8_t * buf, size_t len)
{
auto msg = NewI2NPMessage (len);
uint8_t * payload = msg->GetPayload ();
htobe32buf (payload + TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET, tunnelID);
htobe16buf (payload + TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET, len);
msg->len += TUNNEL_GATEWAY_HEADER_SIZE;
if (msg->Concat (buf, len) < len)
LogPrint (eLogError, "I2NP: tunnel gateway buffer overflow ", msg->maxLen);
msg->FillI2NPMessageHeader (eI2NPTunnelGateway);
return msg;
}
std::shared_ptr<I2NPMessage> CreateTunnelGatewayMsg (uint32_t tunnelID, std::shared_ptr<I2NPMessage> msg)
{
if (msg->offset >= I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE)
{
// message is capable to be used without copying
uint8_t * payload = msg->GetBuffer () - TUNNEL_GATEWAY_HEADER_SIZE;
htobe32buf (payload + TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET, tunnelID);
int len = msg->GetLength ();
htobe16buf (payload + TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET, len);
msg->offset -= (I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE);
msg->len = msg->offset + I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE +len;
msg->FillI2NPMessageHeader (eI2NPTunnelGateway);
return msg;
}
else
return CreateTunnelGatewayMsg (tunnelID, msg->GetBuffer (), msg->GetLength ());
}
std::shared_ptr<I2NPMessage> CreateTunnelGatewayMsg (uint32_t tunnelID, I2NPMessageType msgType,
const uint8_t * buf, size_t len, uint32_t replyMsgID)
{
auto msg = NewI2NPMessage (len);
size_t gatewayMsgOffset = I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE;
msg->offset += gatewayMsgOffset;
msg->len += gatewayMsgOffset;
if (msg->Concat (buf, len) < len)
LogPrint (eLogError, "I2NP: tunnel gateway buffer overflow ", msg->maxLen);
msg->FillI2NPMessageHeader (msgType, replyMsgID); // create content message
len = msg->GetLength ();
msg->offset -= gatewayMsgOffset;
uint8_t * payload = msg->GetPayload ();
htobe32buf (payload + TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET, tunnelID);
htobe16buf (payload + TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET, len);
msg->FillI2NPMessageHeader (eI2NPTunnelGateway); // gateway message
return msg;
}
I2NPMessage * DatagramDestination::CreateDataMessage (const uint8_t * payload, size_t len, uint16_t fromPort, uint16_t toPort)
{
I2NPMessage * msg = NewI2NPMessage ();
CryptoPP::Gzip compressor; // default level
compressor.Put (payload, len);
compressor.MessageEnd();
int size = compressor.MaxRetrievable ();
uint8_t * buf = msg->GetPayload ();
htobe32buf (buf, size); // length
buf += 4;
compressor.Get (buf, size);
htobe16buf (buf + 4, fromPort); // source port
htobe16buf (buf + 6, toPort); // destination port
buf[9] = i2p::client::PROTOCOL_TYPE_DATAGRAM; // datagram protocol
msg->len += size + 4;
FillI2NPMessageHeader (msg, eI2NPData);
return msg;
}
std::shared_ptr<I2NPMessage> CreateRouterInfoDatabaseLookupMsg (const uint8_t * key, const uint8_t * from,
uint32_t replyTunnelID, bool exploratory, std::set<i2p::data::IdentHash> * excludedPeers)
{
auto m = excludedPeers ? NewI2NPMessage () : NewI2NPShortMessage ();
uint8_t * buf = m->GetPayload ();
memcpy (buf, key, 32); // key
buf += 32;
memcpy (buf, from, 32); // from
buf += 32;
uint8_t flag = exploratory ? DATABASE_LOOKUP_TYPE_EXPLORATORY_LOOKUP : DATABASE_LOOKUP_TYPE_ROUTERINFO_LOOKUP;
if (replyTunnelID)
{
*buf = flag | DATABASE_LOOKUP_DELIVERY_FLAG; // set delivery flag
htobe32buf (buf+1, replyTunnelID);
buf += 5;
}
else
{
*buf = flag; // flag
buf++;
}
if (excludedPeers)
{
int cnt = excludedPeers->size ();
htobe16buf (buf, cnt);
buf += 2;
for (auto& it: *excludedPeers)
{
memcpy (buf, it, 32);
buf += 32;
}
}
else
{
// nothing to exclude
htobuf16 (buf, 0);
buf += 2;
}
m->len += (buf - m->GetPayload ());
m->FillI2NPMessageHeader (eI2NPDatabaseLookup);
return m;
}
LeaseSet::LeaseSet (std::shared_ptr<const i2p::tunnel::TunnelPool> pool):
m_IsValid (true)
{
if (!pool) return;
// header
auto localDestination = pool->GetLocalDestination ();
if (!localDestination)
{
m_Buffer = nullptr;
m_BufferLen = 0;
m_IsValid = false;
LogPrint (eLogError, "LeaseSet: Destination for local LeaseSet doesn't exist");
return;
}
m_Buffer = new uint8_t[MAX_LS_BUFFER_SIZE];
m_BufferLen = localDestination->GetIdentity ()->ToBuffer (m_Buffer, MAX_LS_BUFFER_SIZE);
memcpy (m_Buffer + m_BufferLen, localDestination->GetEncryptionPublicKey (), 256);
m_BufferLen += 256;
auto signingKeyLen = localDestination->GetIdentity ()->GetSigningPublicKeyLen ();
memset (m_Buffer + m_BufferLen, 0, signingKeyLen);
m_BufferLen += signingKeyLen;
auto tunnels = pool->GetInboundTunnels (5); // 5 tunnels maximum
m_Buffer[m_BufferLen] = tunnels.size (); // num leases
m_BufferLen++;
// leases
for (auto it: tunnels)
{
memcpy (m_Buffer + m_BufferLen, it->GetNextIdentHash (), 32);
m_BufferLen += 32; // gateway id
htobe32buf (m_Buffer + m_BufferLen, it->GetNextTunnelID ());
m_BufferLen += 4; // tunnel id
uint64_t ts = it->GetCreationTime () + i2p::tunnel::TUNNEL_EXPIRATION_TIMEOUT - i2p::tunnel::TUNNEL_EXPIRATION_THRESHOLD; // 1 minute before expiration
ts *= 1000; // in milliseconds
ts += rand () % 6; // + random milliseconds 0-5
htobe64buf (m_Buffer + m_BufferLen, ts);
m_BufferLen += 8; // end date
}
// signature
localDestination->Sign (m_Buffer, m_BufferLen, m_Buffer + m_BufferLen);
m_BufferLen += localDestination->GetIdentity ()->GetSignatureLen ();
LogPrint (eLogDebug, "LeaseSet: Local LeaseSet of ", tunnels.size (), " leases created");
ReadFromBuffer ();
}
std::shared_ptr<I2NPMessage> CreateLeaseSetDatabaseLookupMsg (const i2p::data::IdentHash& dest,
const std::set<i2p::data::IdentHash>& excludedFloodfills,
const i2p::tunnel::InboundTunnel * replyTunnel, const uint8_t * replyKey, const uint8_t * replyTag)
{
int cnt = excludedFloodfills.size ();
auto m = cnt > 0 ? NewI2NPMessage () : NewI2NPShortMessage ();
uint8_t * buf = m->GetPayload ();
memcpy (buf, dest, 32); // key
buf += 32;
memcpy (buf, replyTunnel->GetNextIdentHash (), 32); // reply tunnel GW
buf += 32;
*buf = DATABASE_LOOKUP_DELIVERY_FLAG | DATABASE_LOOKUP_ENCYPTION_FLAG | DATABASE_LOOKUP_TYPE_LEASESET_LOOKUP; // flags
htobe32buf (buf + 1, replyTunnel->GetNextTunnelID ()); // reply tunnel ID
buf += 5;
// excluded
htobe16buf (buf, cnt);
buf += 2;
if (cnt > 0)
{
for (auto& it: excludedFloodfills)
{
memcpy (buf, it, 32);
buf += 32;
}
}
// encryption
memcpy (buf, replyKey, 32);
buf[32] = 1; // 1 tag
memcpy (buf + 33, replyTag, 32);
buf += 65;
m->len += (buf - m->GetPayload ());
m->FillI2NPMessageHeader (eI2NPDatabaseLookup);
return m;
}
std::shared_ptr<I2NPMessage> CreateDatabaseStoreMsg (std::shared_ptr<const i2p::data::RouterInfo> router, uint32_t replyToken)
{
if (!router) // we send own RouterInfo
router = context.GetSharedRouterInfo ();
auto m = NewI2NPShortMessage ();
uint8_t * payload = m->GetPayload ();
memcpy (payload + DATABASE_STORE_KEY_OFFSET, router->GetIdentHash (), 32);
payload[DATABASE_STORE_TYPE_OFFSET] = 0; // RouterInfo
htobe32buf (payload + DATABASE_STORE_REPLY_TOKEN_OFFSET, replyToken);
uint8_t * buf = payload + DATABASE_STORE_HEADER_SIZE;
if (replyToken)
{
memset (buf, 0, 4); // zero tunnelID means direct reply
buf += 4;
memcpy (buf, router->GetIdentHash (), 32);
buf += 32;
}
uint8_t * sizePtr = buf;
buf += 2;
m->len += (buf - payload); // payload size
i2p::data::GzipDeflator deflator;
size_t size = deflator.Deflate (router->GetBuffer (), router->GetBufferLen (), buf, m->maxLen -m->len);
if (size)
{
htobe16buf (sizePtr, size); // size
m->len += size;
}
else
m = nullptr;
if (m)
m->FillI2NPMessageHeader (eI2NPDatabaseStore);
return m;
}
void TunnelGatewayBuffer::PutI2NPMsg (const TunnelMessageBlock& block)
{
bool messageCreated = false;
if (!m_CurrentTunnelDataMsg)
{
CreateCurrentTunnelDataMessage ();
messageCreated = true;
}
// create delivery instructions
uint8_t di[43]; // max delivery instruction length is 43 for tunnel
size_t diLen = 1;// flag
if (block.deliveryType != eDeliveryTypeLocal) // tunnel or router
{
if (block.deliveryType == eDeliveryTypeTunnel)
{
htobe32buf (di + diLen, block.tunnelID);
diLen += 4; // tunnelID
}
memcpy (di + diLen, block.hash, 32);
diLen += 32; //len
}
di[0] = block.deliveryType << 5; // set delivery type
// create fragments
std::shared_ptr<I2NPMessage> msg = block.data;
auto fullMsgLen = diLen + msg->GetLength () + 2; // delivery instructions + payload + 2 bytes length
if (fullMsgLen <= m_RemainingSize)
{
// message fits. First and last fragment
htobe16buf (di + diLen, msg->GetLength ());
diLen += 2; // size
memcpy (m_CurrentTunnelDataMsg->buf + m_CurrentTunnelDataMsg->len, di, diLen);
memcpy (m_CurrentTunnelDataMsg->buf + m_CurrentTunnelDataMsg->len + diLen, msg->GetBuffer (), msg->GetLength ());
m_CurrentTunnelDataMsg->len += diLen + msg->GetLength ();
m_RemainingSize -= diLen + msg->GetLength ();
if (!m_RemainingSize)
CompleteCurrentTunnelDataMessage ();
}
else
{
if (!messageCreated) // check if we should complete previous message
{
auto numFollowOnFragments = fullMsgLen / TUNNEL_DATA_MAX_PAYLOAD_SIZE;
// length of bytes don't fit full tunnel message
// every follow-on fragment adds 7 bytes
auto nonFit = (fullMsgLen + numFollowOnFragments*7) % TUNNEL_DATA_MAX_PAYLOAD_SIZE;
if (!nonFit || nonFit > m_RemainingSize)
{
CompleteCurrentTunnelDataMessage ();
CreateCurrentTunnelDataMessage ();
}
}
if (diLen + 6 <= m_RemainingSize)
{
// delivery instructions fit
uint32_t msgID;
memcpy (&msgID, msg->GetHeader () + I2NP_HEADER_MSGID_OFFSET, 4); // in network bytes order
size_t size = m_RemainingSize - diLen - 6; // 6 = 4 (msgID) + 2 (size)
// first fragment
di[0] |= 0x08; // fragmented
htobuf32 (di + diLen, msgID);
diLen += 4; // Message ID
htobe16buf (di + diLen, size);
diLen += 2; // size
memcpy (m_CurrentTunnelDataMsg->buf + m_CurrentTunnelDataMsg->len, di, diLen);
memcpy (m_CurrentTunnelDataMsg->buf + m_CurrentTunnelDataMsg->len + diLen, msg->GetBuffer (), size);
m_CurrentTunnelDataMsg->len += diLen + size;
CompleteCurrentTunnelDataMessage ();
// follow on fragments
int fragmentNumber = 1;
while (size < msg->GetLength ())
{
CreateCurrentTunnelDataMessage ();
uint8_t * buf = m_CurrentTunnelDataMsg->GetBuffer ();
buf[0] = 0x80 | (fragmentNumber << 1); // frag
bool isLastFragment = false;
size_t s = msg->GetLength () - size;
if (s > TUNNEL_DATA_MAX_PAYLOAD_SIZE - 7) // 7 follow on instructions
s = TUNNEL_DATA_MAX_PAYLOAD_SIZE - 7;
else // last fragment
{
buf[0] |= 0x01;
isLastFragment = true;
}
htobuf32 (buf + 1, msgID); //Message ID
htobe16buf (buf + 5, s); // size
memcpy (buf + 7, msg->GetBuffer () + size, s);
m_CurrentTunnelDataMsg->len += s+7;
if (isLastFragment)
{
m_RemainingSize -= s+7;
if (!m_RemainingSize)
CompleteCurrentTunnelDataMessage ();
}
else
CompleteCurrentTunnelDataMessage ();
size += s;
fragmentNumber++;
}
}
else
{
// delivery instructions don't fit. Create new message
CompleteCurrentTunnelDataMessage ();
PutI2NPMsg (block);
// don't delete msg because it's taken care inside
}
}
}
size_t GarlicRoutingSession::CreateGarlicPayload (uint8_t * payload, std::shared_ptr<const I2NPMessage> msg, UnconfirmedTags * newTags)
{
uint64_t ts = i2p::util::GetMillisecondsSinceEpoch ();
uint32_t msgID;
RAND_bytes ((uint8_t *)&msgID, 4);
size_t size = 0;
uint8_t * numCloves = payload + size;
*numCloves = 0;
size++;
if (m_Owner)
{
// resubmit non-confirmed LeaseSet
if (m_LeaseSetUpdateStatus == eLeaseSetSubmitted && ts > m_LeaseSetSubmissionTime + LEASET_CONFIRMATION_TIMEOUT)
{
m_LeaseSetUpdateStatus = eLeaseSetUpdated;
SetSharedRoutingPath (nullptr); // invalidate path since leaseset was not confirmed
}
// attach DeviveryStatus if necessary
if (newTags || m_LeaseSetUpdateStatus == eLeaseSetUpdated) // new tags created or leaseset updated
{
// clove is DeliveryStatus
auto cloveSize = CreateDeliveryStatusClove (payload + size, msgID);
if (cloveSize > 0) // successive?
{
size += cloveSize;
(*numCloves)++;
if (newTags) // new tags created
{
newTags->msgID = msgID;
m_UnconfirmedTagsMsgs.insert (std::make_pair(msgID, std::unique_ptr<UnconfirmedTags>(newTags)));
newTags = nullptr; // got acquired
}
m_Owner->DeliveryStatusSent (shared_from_this (), msgID);
}
else
LogPrint (eLogWarning, "Garlic: DeliveryStatus clove was not created");
}
// attach LeaseSet
if (m_LeaseSetUpdateStatus == eLeaseSetUpdated)
{
if (m_LeaseSetUpdateMsgID) m_Owner->RemoveDeliveryStatusSession (m_LeaseSetUpdateMsgID); // remove previous
m_LeaseSetUpdateStatus = eLeaseSetSubmitted;
m_LeaseSetUpdateMsgID = msgID;
m_LeaseSetSubmissionTime = ts;
// clove if our leaseSet must be attached
auto leaseSet = CreateDatabaseStoreMsg (m_Owner->GetLeaseSet ());
size += CreateGarlicClove (payload + size, leaseSet, false);
(*numCloves)++;
}
}
if (msg) // clove message ifself if presented
{
size += CreateGarlicClove (payload + size, msg, m_Destination ? m_Destination->IsDestination () : false);
(*numCloves)++;
}
memset (payload + size, 0, 3); // certificate of message
size += 3;
htobe32buf (payload + size, msgID); // MessageID
size += 4;
htobe64buf (payload + size, ts + 8000); // Expiration of message, 8 sec
size += 8;
if (newTags) delete newTags; // not acquired, delete
return size;
}
std::shared_ptr<I2NPMessage> GarlicRoutingSession::WrapSingleMessage (std::shared_ptr<const I2NPMessage> msg)
{
auto m = NewI2NPMessage ();
m->Align (12); // in order to get buf aligned to 16 (12 + 4)
size_t len = 0;
uint8_t * buf = m->GetPayload () + 4; // 4 bytes for length
// find non-expired tag
bool tagFound = false;
SessionTag tag;
if (m_NumTags > 0)
{
uint32_t ts = i2p::util::GetSecondsSinceEpoch ();
while (!m_SessionTags.empty ())
{
if (ts < m_SessionTags.front ().creationTime + OUTGOING_TAGS_EXPIRATION_TIMEOUT)
{
tag = m_SessionTags.front ();
m_SessionTags.pop_front (); // use same tag only once
tagFound = true;
break;
}
else
m_SessionTags.pop_front (); // remove expired tag
}
}
// create message
if (!tagFound) // new session
{
LogPrint (eLogInfo, "Garlic: No tags available, will use ElGamal");
if (!m_Destination)
{
LogPrint (eLogError, "Garlic: Can't use ElGamal for unknown destination");
return nullptr;
}
// create ElGamal block
ElGamalBlock elGamal;
memcpy (elGamal.sessionKey, m_SessionKey, 32);
RAND_bytes (elGamal.preIV, 32); // Pre-IV
uint8_t iv[32]; // IV is first 16 bytes
SHA256(elGamal.preIV, 32, iv);
BN_CTX * ctx = BN_CTX_new ();
m_Destination->Encrypt ((uint8_t *)&elGamal, buf, ctx);
BN_CTX_free (ctx);
m_Encryption.SetIV (iv);
buf += 514;
len += 514;
}
else // existing session
{
// session tag
memcpy (buf, tag, 32);
uint8_t iv[32]; // IV is first 16 bytes
SHA256(tag, 32, iv);
m_Encryption.SetIV (iv);
buf += 32;
len += 32;
}
// AES block
len += CreateAESBlock (buf, msg);
htobe32buf (m->GetPayload (), len);
m->len += len + 4;
m->FillI2NPMessageHeader (eI2NPGarlic);
return m;
}
