I2NPMessage * CreateDatabaseStoreMsg (const i2p::data::LeaseSet * leaseSet, uint32_t replyToken)
{
if (!leaseSet) return nullptr;
I2NPMessage * m = NewI2NPShortMessage ();
uint8_t * payload = m->GetPayload ();
I2NPDatabaseStoreMsg * msg = (I2NPDatabaseStoreMsg *)payload;
memcpy (msg->key, leaseSet->GetIdentHash (), 32);
msg->type = 1; // LeaseSet
msg->replyToken = htobe32 (replyToken);
size_t size = sizeof (I2NPDatabaseStoreMsg);
if (replyToken)
{
auto leases = leaseSet->GetNonExpiredLeases ();
if (leases.size () > 0)
{
*(uint32_t *)(payload + size) = htobe32 (leases[0].tunnelID);
size += 4; // reply tunnelID
memcpy (payload + size, leases[0].tunnelGateway, 32);
size += 32; // reply tunnel gateway
}
else
msg->replyToken = 0;
}
memcpy (payload + size, leaseSet->GetBuffer (), leaseSet->GetBufferLen ());
size += leaseSet->GetBufferLen ();
m->len += size;
FillI2NPMessageHeader (m, eI2NPDatabaseStore);
return m;
}
std::shared_ptr<I2NPMessage> CreateTunnelDataMsg (const uint8_t * buf)
{
auto msg = NewI2NPShortMessage ();
msg->Concat (buf, i2p::tunnel::TUNNEL_DATA_MSG_SIZE);
msg->FillI2NPMessageHeader (eI2NPTunnelData);
return msg;
}
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;
}
I2NPMessage * CreateDatabaseStoreMsg (const i2p::data::RouterInfo * router)
{
if (!router) // we send own RouterInfo
router = &context.GetRouterInfo ();
I2NPMessage * m = NewI2NPShortMessage ();
I2NPDatabaseStoreMsg * msg = (I2NPDatabaseStoreMsg *)m->GetPayload ();
memcpy (msg->key, router->GetIdentHash (), 32);
msg->type = 0;
msg->replyToken = 0;
CryptoPP::Gzip compressor;
compressor.Put (router->GetBuffer (), router->GetBufferLen ());
compressor.MessageEnd();
auto size = compressor.MaxRetrievable ();
uint8_t * buf = m->GetPayload () + sizeof (I2NPDatabaseStoreMsg);
*(uint16_t *)buf = htobe16 (size); // size
buf += 2;
// TODO: check if size doesn't exceed buffer
compressor.Get (buf, size);
m->len += sizeof (I2NPDatabaseStoreMsg) + 2 + size; // payload size
FillI2NPMessageHeader (m, eI2NPDatabaseStore);
return m;
}
I2NPMessage * CreateTunnelDataMsg (const uint8_t * buf)
{
I2NPMessage * msg = NewI2NPMessage ();
memcpy (msg->GetPayload (), buf, i2p::tunnel::TUNNEL_DATA_MSG_SIZE);
msg->len += i2p::tunnel::TUNNEL_DATA_MSG_SIZE;
FillI2NPMessageHeader (msg, eI2NPTunnelData);
return msg;
}
std::shared_ptr<I2NPMessage> CreateI2NPMessage (I2NPMessageType msgType, const uint8_t * buf, size_t len, uint32_t replyMsgID)
{
auto msg = NewI2NPMessage (len);
if (msg->Concat (buf, len) < len)
LogPrint (eLogError, "I2NP: message length ", len, " exceeds max length ", msg->maxLen);
msg->FillI2NPMessageHeader (msgType, replyMsgID);
return msg;
}
I2NPMessage * CreateI2NPMessage (I2NPMessageType msgType, const uint8_t * buf, int len, uint32_t replyMsgID)
{
I2NPMessage * msg = NewI2NPMessage (len);
memcpy (msg->GetPayload (), buf, len);
msg->len += len;
FillI2NPMessageHeader (msg, msgType, replyMsgID);
return msg;
}
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 * CreateTunnelDataMsg (uint32_t tunnelID, const uint8_t * payload)
{
I2NPMessage * msg = NewI2NPMessage ();
memcpy (msg->GetPayload () + 4, payload, i2p::tunnel::TUNNEL_DATA_MSG_SIZE - 4);
*(uint32_t *)(msg->GetPayload ()) = htobe32 (tunnelID);
msg->len += i2p::tunnel::TUNNEL_DATA_MSG_SIZE;
FillI2NPMessageHeader (msg, eI2NPTunnelData);
return msg;
}
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;
}
I2NPMessage * CreateTunnelGatewayMsg (uint32_t tunnelID, I2NPMessageType msgType,
const uint8_t * buf, size_t len, uint32_t replyMsgID)
{
I2NPMessage * msg = NewI2NPMessage (len);
size_t gatewayMsgOffset = sizeof (I2NPHeader) + sizeof (TunnelGatewayHeader);
msg->offset += gatewayMsgOffset;
msg->len += gatewayMsgOffset;
memcpy (msg->GetPayload (), buf, len);
msg->len += len;
FillI2NPMessageHeader (msg, msgType, replyMsgID); // create content message
len = msg->GetLength ();
msg->offset -= gatewayMsgOffset;
TunnelGatewayHeader * header = (TunnelGatewayHeader *)msg->GetPayload ();
header->tunnelID = htobe32 (tunnelID);
header->length = htobe16 (len);
FillI2NPMessageHeader (msg, eI2NPTunnelGateway); // gateway message
return msg;
}
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);
}
void TransitTunnel::HandleTunnelDataMsg (i2p::I2NPMessage * tunnelMsg)
{
EncryptTunnelMsg (tunnelMsg);
LogPrint ("TransitTunnel: ",m_TunnelID,"->", m_NextTunnelID);
*(uint32_t *)(tunnelMsg->GetPayload ()) = htobe32 (m_NextTunnelID);
FillI2NPMessageHeader (tunnelMsg, eI2NPTunnelData);
i2p::transports.SendMessage (m_NextIdent, tunnelMsg);
m_NumTransmittedBytes += tunnelMsg->GetLength ();
}
void TunnelGateway::SendBuffer ()
{
auto tunnelMsgs = m_Buffer.GetTunnelDataMsgs ();
for (auto tunnelMsg : tunnelMsgs)
{
m_Tunnel->EncryptTunnelMsg (tunnelMsg);
FillI2NPMessageHeader (tunnelMsg, eI2NPTunnelData);
i2p::transports.SendMessage (m_Tunnel->GetNextIdentHash (), tunnelMsg);
m_NumSentBytes += TUNNEL_DATA_MSG_SIZE;
}
}
I2NPMessage * CreateTunnelGatewayMsg (uint32_t tunnelID, const uint8_t * buf, size_t len)
{
I2NPMessage * msg = NewI2NPMessage (len);
TunnelGatewayHeader * header = (TunnelGatewayHeader *)msg->GetPayload ();
header->tunnelID = htobe32 (tunnelID);
header->length = htobe16 (len);
memcpy (msg->GetPayload () + sizeof (TunnelGatewayHeader), buf, len);
msg->len += sizeof (TunnelGatewayHeader) + len;
FillI2NPMessageHeader (msg, eI2NPTunnelGateway);
return msg;
}
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;
}
I2NPMessage * DatagramDestination::CreateDataMessage (const uint8_t * payload, size_t len)
{
I2NPMessage * msg = NewI2NPMessage ();
CryptoPP::Gzip compressor; // default level
compressor.Put (payload, len);
compressor.MessageEnd();
int size = compressor.MaxRetrievable ();
uint8_t * buf = msg->GetPayload ();
*(uint32_t *)buf = htobe32 (size); // length
buf += 4;
compressor.Get (buf, size);
memset (buf + 4, 0, 4); // source and destination are zeroes
buf[9] = i2p::client::PROTOCOL_TYPE_DATAGRAM; // datagram protocol
msg->len += size + 4;
FillI2NPMessageHeader (msg, eI2NPData);
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;
}
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> CreateDatabaseSearchReply (const i2p::data::IdentHash& ident,
std::vector<i2p::data::IdentHash> routers)
{
auto m = NewI2NPShortMessage ();
uint8_t * buf = m->GetPayload ();
size_t len = 0;
memcpy (buf, ident, 32);
len += 32;
buf[len] = routers.size ();
len++;
for (auto it: routers)
{
memcpy (buf + len, it, 32);
len += 32;
}
memcpy (buf + len, i2p::context.GetRouterInfo ().GetIdentHash (), 32);
len += 32;
m->len += len;
m->FillI2NPMessageHeader (eI2NPDatabaseSearchReply);
return m;
}
I2NPMessage * CreateTunnelGatewayMsg (uint32_t tunnelID, I2NPMessage * msg)
{
if (msg->offset >= sizeof (I2NPHeader) + sizeof (TunnelGatewayHeader))
{
// message is capable to be used without copying
TunnelGatewayHeader * header = (TunnelGatewayHeader *)(msg->GetBuffer () - sizeof (TunnelGatewayHeader));
header->tunnelID = htobe32 (tunnelID);
int len = msg->GetLength ();
header->length = htobe16 (len);
msg->offset -= (sizeof (I2NPHeader) + sizeof (TunnelGatewayHeader));
msg->len = msg->offset + sizeof (I2NPHeader) + sizeof (TunnelGatewayHeader) +len;
FillI2NPMessageHeader (msg, eI2NPTunnelGateway);
return msg;
}
else
{
I2NPMessage * msg1 = CreateTunnelGatewayMsg (tunnelID, msg->GetBuffer (), msg->GetLength ());
DeleteI2NPMessage (msg);
return msg1;
}
}
I2NPMessage * CreateDatabaseSearchReply (const i2p::data::IdentHash& ident,
const i2p::data::RouterInfo * floodfill)
{
I2NPMessage * m = NewI2NPShortMessage ();
uint8_t * buf = m->GetPayload ();
size_t len = 0;
memcpy (buf, ident, 32);
len += 32;
buf[len] = floodfill ? 1 : 0; // 1 router for now
len++;
if (floodfill)
{
memcpy (buf + len, floodfill->GetIdentHash (), 32);
len += 32;
}
memcpy (buf + len, i2p::context.GetRouterInfo ().GetIdentHash (), 32);
len += 32;
m->len += len;
FillI2NPMessageHeader (m, eI2NPDatabaseSearchReply);
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;
}
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> 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;
}
I2NPMessage * CreateDatabaseLookupMsg (const uint8_t * key, const uint8_t * from,
uint32_t replyTunnelID, bool exploratory, std::set<i2p::data::IdentHash> * excludedPeers,
bool encryption, i2p::tunnel::TunnelPool * pool)
{
I2NPMessage * m = NewI2NPMessage ();
uint8_t * buf = m->GetPayload ();
memcpy (buf, key, 32); // key
buf += 32;
memcpy (buf, from, 32); // from
buf += 32;
if (replyTunnelID)
{
*buf = encryption ? 0x03: 0x01; // set delivery flag
*(uint32_t *)(buf+1) = htobe32 (replyTunnelID);
buf += 5;
}
else
{
encryption = false; // encryption can we set for tunnels only
*buf = 0; // flag
buf++;
}
if (exploratory)
{
*(uint16_t *)buf = htobe16 (1); // one exlude record
buf += 2;
// reply with non-floodfill routers only
memset (buf, 0, 32);
buf += 32;
}
else
{
if (excludedPeers)
{
int cnt = excludedPeers->size ();
*(uint16_t *)buf = htobe16 (cnt);
buf += 2;
for (auto& it: *excludedPeers)
{
memcpy (buf, it, 32);
buf += 32;
}
}
else
{
// nothing to exclude
*(uint16_t *)buf = htobe16 (0);
buf += 2;
}
}
if (encryption)
{
// session key and tag for reply
auto& rnd = i2p::context.GetRandomNumberGenerator ();
rnd.GenerateBlock (buf, 32); // key
buf[32] = 1; // 1 tag
rnd.GenerateBlock (buf + 33, 32); // tag
if (pool)
pool->GetLocalDestination ().SubmitSessionKey (buf, buf + 33); // introduce new key-tag to garlic engine
else
LogPrint ("Destination for encrypteed reply not specified");
buf += 65;
}
m->len += (buf - m->GetPayload ());
FillI2NPMessageHeader (m, eI2NPDatabaseLookup);
return m;
}