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i2pd/libi2pd_client/I2CP.cpp

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/*
* Copyright (c) 2013-2024, The PurpleI2P Project
*
* This file is part of Purple i2pd project and licensed under BSD3
*
* See full license text in LICENSE file at top of project tree
*/
#include <string.h>
#include <stdlib.h>
#include <openssl/rand.h>
#include "I2PEndian.h"
#include "Log.h"
#include "Timestamp.h"
#include "LeaseSet.h"
#include "ClientContext.h"
#include "Transports.h"
#include "Signature.h"
#include "I2CP.h"
namespace i2p
{
namespace client
{
I2CPDestination::I2CPDestination (boost::asio::io_service& service, std::shared_ptr<I2CPSession> owner,
std::shared_ptr<const i2p::data::IdentityEx> identity, bool isPublic, const std::map<std::string, std::string>& params):
LeaseSetDestination (service, isPublic, &params),
m_Owner (owner), m_Identity (identity), m_EncryptionKeyType (m_Identity->GetCryptoKeyType ()),
m_IsCreatingLeaseSet (false), m_LeaseSetCreationTimer (service)
{
}
void I2CPDestination::Stop ()
{
m_LeaseSetCreationTimer.cancel ();
LeaseSetDestination::Stop ();
m_Owner = nullptr;
}
void I2CPDestination::SetEncryptionPrivateKey (const uint8_t * key)
{
m_Decryptor = i2p::data::PrivateKeys::CreateDecryptor (m_Identity->GetCryptoKeyType (), key);
}
void I2CPDestination::SetECIESx25519EncryptionPrivateKey (const uint8_t * key)
{
if (!m_ECIESx25519Decryptor || memcmp (m_ECIESx25519PrivateKey, key, 32)) // new key?
{
m_ECIESx25519Decryptor = std::make_shared<i2p::crypto::ECIESX25519AEADRatchetDecryptor>(key, true); // calculate public
memcpy (m_ECIESx25519PrivateKey, key, 32);
}
}
bool I2CPDestination::Decrypt (const uint8_t * encrypted, uint8_t * data, i2p::data::CryptoKeyType preferredCrypto) const
{
if (preferredCrypto == i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD && m_ECIESx25519Decryptor)
return m_ECIESx25519Decryptor->Decrypt (encrypted, data);
if (m_Decryptor)
return m_Decryptor->Decrypt (encrypted, data);
else
LogPrint (eLogError, "I2CP: Decryptor is not set");
return false;
}
const uint8_t * I2CPDestination::GetEncryptionPublicKey (i2p::data::CryptoKeyType keyType) const
{
if (keyType == i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD && m_ECIESx25519Decryptor)
return m_ECIESx25519Decryptor->GetPubicKey ();
return nullptr;
}
bool I2CPDestination::SupportsEncryptionType (i2p::data::CryptoKeyType keyType) const
{
return keyType == i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD ? (bool)m_ECIESx25519Decryptor : m_EncryptionKeyType == keyType;
}
void I2CPDestination::HandleDataMessage (const uint8_t * buf, size_t len)
{
uint32_t length = bufbe32toh (buf);
if (length > len - 4) length = len - 4;
if (m_Owner)
m_Owner->SendMessagePayloadMessage (buf + 4, length);
}
void I2CPDestination::CreateNewLeaseSet (const std::vector<std::shared_ptr<i2p::tunnel::InboundTunnel> >& tunnels)
{
GetService ().post (std::bind (&I2CPDestination::PostCreateNewLeaseSet, this, tunnels));
}
void I2CPDestination::PostCreateNewLeaseSet (std::vector<std::shared_ptr<i2p::tunnel::InboundTunnel> > tunnels)
{
if (m_IsCreatingLeaseSet)
{
LogPrint (eLogInfo, "I2CP: LeaseSet is being created");
return;
}
uint8_t priv[256] = {0};
i2p::data::LocalLeaseSet ls (m_Identity, priv, tunnels); // we don't care about encryption key, we need leases only
m_LeaseSetExpirationTime = ls.GetExpirationTime ();
uint8_t * leases = ls.GetLeases ();
leases[-1] = tunnels.size ();
if (m_Owner)
{
uint16_t sessionID = m_Owner->GetSessionID ();
if (sessionID != 0xFFFF)
{
m_IsCreatingLeaseSet = true;
htobe16buf (leases - 3, sessionID);
size_t l = 2/*sessionID*/ + 1/*num leases*/ + i2p::data::LEASE_SIZE*tunnels.size ();
m_Owner->SendI2CPMessage (I2CP_REQUEST_VARIABLE_LEASESET_MESSAGE, leases - 3, l);
m_LeaseSetCreationTimer.expires_from_now (boost::posix_time::seconds (I2CP_LEASESET_CREATION_TIMEOUT));
auto s = GetSharedFromThis ();
m_LeaseSetCreationTimer.async_wait ([s](const boost::system::error_code& ecode)
{
if (ecode != boost::asio::error::operation_aborted)
{
LogPrint (eLogInfo, "I2CP: LeaseSet creation timeout expired. Terminate");
if (s->m_Owner) s->m_Owner->Stop ();
}
});
}
}
}
void I2CPDestination::LeaseSetCreated (const uint8_t * buf, size_t len)
{
m_IsCreatingLeaseSet = false;
m_LeaseSetCreationTimer.cancel ();
auto ls = std::make_shared<i2p::data::LocalLeaseSet> (m_Identity, buf, len);
ls->SetExpirationTime (m_LeaseSetExpirationTime);
SetLeaseSet (ls);
}
void I2CPDestination::LeaseSet2Created (uint8_t storeType, const uint8_t * buf, size_t len)
{
m_IsCreatingLeaseSet = false;
m_LeaseSetCreationTimer.cancel ();
auto ls = (storeType == i2p::data::NETDB_STORE_TYPE_ENCRYPTED_LEASESET2) ?
std::make_shared<i2p::data::LocalEncryptedLeaseSet2> (m_Identity, buf, len):
std::make_shared<i2p::data::LocalLeaseSet2> (storeType, m_Identity, buf, len);
ls->SetExpirationTime (m_LeaseSetExpirationTime);
SetLeaseSet (ls);
}
void I2CPDestination::SendMsgTo (const uint8_t * payload, size_t len, const i2p::data::IdentHash& ident, uint32_t nonce)
{
auto msg = m_I2NPMsgsPool.AcquireSharedMt ();
uint8_t * buf = msg->GetPayload ();
htobe32buf (buf, len);
memcpy (buf + 4, payload, len);
msg->len += len + 4;
msg->FillI2NPMessageHeader (eI2NPData);
auto s = GetSharedFromThis ();
auto remote = FindLeaseSet (ident);
if (remote)
{
GetService ().post (
[s, msg, remote, nonce]()
{
bool sent = s->SendMsg (msg, remote);
if (s->m_Owner)
s->m_Owner->SendMessageStatusMessage (nonce, sent ? eI2CPMessageStatusGuaranteedSuccess : eI2CPMessageStatusGuaranteedFailure);
});
}
else
{
RequestDestination (ident,
[s, msg, nonce](std::shared_ptr<i2p::data::LeaseSet> ls)
{
if (ls)
{
bool sent = s->SendMsg (msg, ls);
if (s->m_Owner)
s->m_Owner->SendMessageStatusMessage (nonce, sent ? eI2CPMessageStatusGuaranteedSuccess : eI2CPMessageStatusGuaranteedFailure);
}
else if (s->m_Owner)
s->m_Owner->SendMessageStatusMessage (nonce, eI2CPMessageStatusNoLeaseSet);
});
}
}
bool I2CPDestination::SendMsg (std::shared_ptr<I2NPMessage> msg, std::shared_ptr<const i2p::data::LeaseSet> remote)
{
auto remoteSession = GetRoutingSession (remote, true);
if (!remoteSession)
{
LogPrint (eLogError, "I2CP: Failed to create remote session");
return false;
}
auto path = remoteSession->GetSharedRoutingPath ();
std::shared_ptr<i2p::tunnel::OutboundTunnel> outboundTunnel;
std::shared_ptr<const i2p::data::Lease> remoteLease;
if (path)
{
if (!remoteSession->CleanupUnconfirmedTags ()) // no stuck tags
{
outboundTunnel = path->outboundTunnel;
remoteLease = path->remoteLease;
}
else
remoteSession->SetSharedRoutingPath (nullptr);
}
else
{
auto leases = remote->GetNonExpiredLeases (false); // without threshold
if (leases.empty ())
leases = remote->GetNonExpiredLeases (true); // with threshold
if (!leases.empty ())
{
remoteLease = leases[rand () % leases.size ()];
auto leaseRouter = i2p::data::netdb.FindRouter (remoteLease->tunnelGateway);
outboundTunnel = GetTunnelPool ()->GetNextOutboundTunnel (nullptr,
leaseRouter ? leaseRouter->GetCompatibleTransports (false) : (i2p::data::RouterInfo::CompatibleTransports)i2p::data::RouterInfo::eAllTransports);
}
if (remoteLease && outboundTunnel)
remoteSession->SetSharedRoutingPath (std::make_shared<i2p::garlic::GarlicRoutingPath> (
i2p::garlic::GarlicRoutingPath{outboundTunnel, remoteLease, 10000, 0, 0})); // 10 secs RTT
else
remoteSession->SetSharedRoutingPath (nullptr);
}
if (remoteLease && outboundTunnel)
{
std::vector<i2p::tunnel::TunnelMessageBlock> msgs;
auto garlic = remoteSession->WrapSingleMessage (msg);
msgs.push_back (i2p::tunnel::TunnelMessageBlock
{
i2p::tunnel::eDeliveryTypeTunnel,
remoteLease->tunnelGateway, remoteLease->tunnelID,
garlic
});
outboundTunnel->SendTunnelDataMsgs (msgs);
return true;
}
else
{
if (outboundTunnel)
LogPrint (eLogWarning, "I2CP: Failed to send message. All leases expired");
else
LogPrint (eLogWarning, "I2CP: Failed to send message. No outbound tunnels");
return false;
}
}
RunnableI2CPDestination::RunnableI2CPDestination (std::shared_ptr<I2CPSession> owner,
std::shared_ptr<const i2p::data::IdentityEx> identity, bool isPublic, const std::map<std::string, std::string>& params):
RunnableService ("I2CP"),
I2CPDestination (GetIOService (), owner, identity, isPublic, params)
{
}
RunnableI2CPDestination::~RunnableI2CPDestination ()
{
if (IsRunning ())
Stop ();
}
void RunnableI2CPDestination::Start ()
{
if (!IsRunning ())
{
I2CPDestination::Start ();
StartIOService ();
}
}
void RunnableI2CPDestination::Stop ()
{
if (IsRunning ())
{
I2CPDestination::Stop ();
StopIOService ();
}
}
I2CPSession::I2CPSession (I2CPServer& owner, std::shared_ptr<boost::asio::ip::tcp::socket> socket):
m_Owner (owner), m_Socket (socket), m_SessionID (0xFFFF),
m_MessageID (0), m_IsSendAccepted (true), m_IsSending (false)
{
}
I2CPSession::~I2CPSession ()
{
Terminate ();
}
void I2CPSession::Start ()
{
if (m_Socket)
{
m_Socket->set_option (boost::asio::socket_base::receive_buffer_size (I2CP_MAX_MESSAGE_LENGTH));
m_Socket->set_option (boost::asio::socket_base::send_buffer_size (I2CP_MAX_MESSAGE_LENGTH));
}
ReadProtocolByte ();
}
void I2CPSession::Stop ()
{
Terminate ();
}
void I2CPSession::ReadProtocolByte ()
{
if (m_Socket)
{
auto s = shared_from_this ();
m_Socket->async_read_some (boost::asio::buffer (m_Header, 1),
[s](const boost::system::error_code& ecode, std::size_t bytes_transferred)
{
if (!ecode && bytes_transferred > 0 && s->m_Header[0] == I2CP_PROTOCOL_BYTE)
s->ReceiveHeader ();
else
s->Terminate ();
});
}
}
void I2CPSession::ReceiveHeader ()
{
if (!m_Socket)
{
LogPrint (eLogError, "I2CP: Can't receive header");
return;
}
boost::asio::async_read (*m_Socket, boost::asio::buffer (m_Header, I2CP_HEADER_SIZE),
boost::asio::transfer_all (),
std::bind (&I2CPSession::HandleReceivedHeader, shared_from_this (), std::placeholders::_1, std::placeholders::_2));
}
void I2CPSession::HandleReceivedHeader (const boost::system::error_code& ecode, std::size_t bytes_transferred)
{
if (ecode)
Terminate ();
else
{
m_PayloadLen = bufbe32toh (m_Header + I2CP_HEADER_LENGTH_OFFSET);
if (m_PayloadLen > 0)
{
if (m_PayloadLen <= I2CP_MAX_MESSAGE_LENGTH)
{
if (!m_Socket) return;
boost::system::error_code ec;
size_t moreBytes = m_Socket->available(ec);
if (!ec)
{
if (moreBytes >= m_PayloadLen)
{
// read and process payload immediately if available
moreBytes = boost::asio::read (*m_Socket, boost::asio::buffer(m_Payload, m_PayloadLen), boost::asio::transfer_all (), ec);
HandleReceivedPayload (ec, moreBytes);
}
else
ReceivePayload ();
}
else
{
LogPrint (eLogWarning, "I2CP: Socket error: ", ec.message ());
Terminate ();
}
}
else
{
LogPrint (eLogError, "I2CP: Unexpected payload length ", m_PayloadLen);
Terminate ();
}
}
else // no following payload
{
HandleMessage ();
ReceiveHeader (); // next message
}
}
}
void I2CPSession::ReceivePayload ()
{
if (!m_Socket)
{
LogPrint (eLogError, "I2CP: Can't receive payload");
return;
}
boost::asio::async_read (*m_Socket, boost::asio::buffer (m_Payload, m_PayloadLen),
boost::asio::transfer_all (),
std::bind (&I2CPSession::HandleReceivedPayload, shared_from_this (), std::placeholders::_1, std::placeholders::_2));
}
void I2CPSession::HandleReceivedPayload (const boost::system::error_code& ecode, std::size_t bytes_transferred)
{
if (ecode)
Terminate ();
else
{
HandleMessage ();
m_PayloadLen = 0;
ReceiveHeader (); // next message
}
}
void I2CPSession::HandleMessage ()
{
auto handler = m_Owner.GetMessagesHandlers ()[m_Header[I2CP_HEADER_TYPE_OFFSET]];
if (handler)
(this->*handler)(m_Payload, m_PayloadLen);
else
LogPrint (eLogError, "I2CP: Unknown I2CP message ", (int)m_Header[I2CP_HEADER_TYPE_OFFSET]);
}
void I2CPSession::Terminate ()
{
if (m_Destination)
{
m_Destination->Stop ();
m_Destination = nullptr;
}
if (m_Socket)
{
m_Socket->close ();
m_Socket = nullptr;
}
if (!m_SendQueue.IsEmpty ())
m_SendQueue.CleanUp ();
if (m_SessionID != 0xFFFF)
{
m_Owner.RemoveSession (GetSessionID ());
LogPrint (eLogDebug, "I2CP: Session ", m_SessionID, " terminated");
m_SessionID = 0xFFFF;
}
}
void I2CPSession::SendI2CPMessage (uint8_t type, const uint8_t * payload, size_t len)
{
auto l = len + I2CP_HEADER_SIZE;
if (l > I2CP_MAX_MESSAGE_LENGTH)
{
LogPrint (eLogError, "I2CP: Message to send is too long ", l);
return;
}
auto sendBuf = m_IsSending ? std::make_shared<i2p::stream::SendBuffer> (l) : nullptr;
uint8_t * buf = sendBuf ? sendBuf->buf : m_SendBuffer;
htobe32buf (buf + I2CP_HEADER_LENGTH_OFFSET, len);
buf[I2CP_HEADER_TYPE_OFFSET] = type;
memcpy (buf + I2CP_HEADER_SIZE, payload, len);
if (sendBuf)
{
if (m_SendQueue.GetSize () < I2CP_MAX_SEND_QUEUE_SIZE)
m_SendQueue.Add (sendBuf);
else
{
LogPrint (eLogWarning, "I2CP: Send queue size exceeds ", I2CP_MAX_SEND_QUEUE_SIZE);
return;
}
}
else
{
auto socket = m_Socket;
if (socket)
{
m_IsSending = true;
boost::asio::async_write (*socket, boost::asio::buffer (m_SendBuffer, l),
boost::asio::transfer_all (), std::bind(&I2CPSession::HandleI2CPMessageSent,
shared_from_this (), std::placeholders::_1, std::placeholders::_2));
}
}
}
void I2CPSession::HandleI2CPMessageSent (const boost::system::error_code& ecode, std::size_t bytes_transferred)
{
if (ecode)
{
if (ecode != boost::asio::error::operation_aborted)
Terminate ();
}
else if (!m_SendQueue.IsEmpty ())
{
auto socket = m_Socket;
if (socket)
{
auto len = m_SendQueue.Get (m_SendBuffer, I2CP_MAX_MESSAGE_LENGTH);
boost::asio::async_write (*socket, boost::asio::buffer (m_SendBuffer, len),
boost::asio::transfer_all (),std::bind(&I2CPSession::HandleI2CPMessageSent,
shared_from_this (), std::placeholders::_1, std::placeholders::_2));
}
else
m_IsSending = false;
}
else
m_IsSending = false;
}
std::string I2CPSession::ExtractString (const uint8_t * buf, size_t len)
{
uint8_t l = buf[0];
if (l > len) l = len;
return std::string ((const char *)(buf + 1), l);
}
size_t I2CPSession::PutString (uint8_t * buf, size_t len, const std::string& str)
{
auto l = str.length ();
if (l + 1 >= len) l = len - 1;
if (l > 255) l = 255; // 1 byte max
buf[0] = l;
memcpy (buf + 1, str.c_str (), l);
return l + 1;
}
void I2CPSession::ExtractMapping (const uint8_t * buf, size_t len, std::map<std::string, std::string>& mapping)
// TODO: move to Base.cpp
{
size_t offset = 0;
while (offset < len)
{
std::string param = ExtractString (buf + offset, len - offset);
offset += param.length () + 1;
if (buf[offset] != '=')
{
LogPrint (eLogWarning, "I2CP: Unexpected character ", buf[offset], " instead '=' after ", param);
break;
}
offset++;
std::string value = ExtractString (buf + offset, len - offset);
offset += value.length () + 1;
if (buf[offset] != ';')
{
LogPrint (eLogWarning, "I2CP: Unexpected character ", buf[offset], " instead ';' after ", value);
break;
}
offset++;
mapping.insert (std::make_pair (param, value));
}
}
void I2CPSession::GetDateMessageHandler (const uint8_t * buf, size_t len)
{
// get version
auto version = ExtractString (buf, len);
auto l = version.length () + 1 + 8;
uint8_t * payload = new uint8_t[l];
// set date
auto ts = i2p::util::GetMillisecondsSinceEpoch ();
htobe64buf (payload, ts);
// echo vesrion back
PutString (payload + 8, l - 8, version);
SendI2CPMessage (I2CP_SET_DATE_MESSAGE, payload, l);
delete[] payload;
}
void I2CPSession::CreateSessionMessageHandler (const uint8_t * buf, size_t len)
{
RAND_bytes ((uint8_t *)&m_SessionID, 2);
auto identity = std::make_shared<i2p::data::IdentityEx>();
size_t offset = identity->FromBuffer (buf, len);
if (!offset)
{
LogPrint (eLogError, "I2CP: Create session malformed identity");
SendSessionStatusMessage (eI2CPSessionStatusInvalid); // invalid
return;
}
if (m_Owner.FindSessionByIdentHash (identity->GetIdentHash ()))
{
LogPrint (eLogError, "I2CP: Create session duplicate address ", identity->GetIdentHash ().ToBase32 ());
SendSessionStatusMessage (eI2CPSessionStatusInvalid); // invalid
return;
}
uint16_t optionsSize = bufbe16toh (buf + offset);
offset += 2;
if (optionsSize > len - offset)
{
LogPrint (eLogError, "I2CP: Options size ", optionsSize, "exceeds message size");
SendSessionStatusMessage (eI2CPSessionStatusInvalid); // invalid
return;
}
std::map<std::string, std::string> params;
ExtractMapping (buf + offset, optionsSize, params);
offset += optionsSize; // options
if (params[I2CP_PARAM_MESSAGE_RELIABILITY] == "none") m_IsSendAccepted = false;
offset += 8; // date
if (identity->Verify (buf, offset, buf + offset)) // signature
{
if (!m_Destination)
{
m_Destination = m_Owner.IsSingleThread () ?
std::make_shared<I2CPDestination>(m_Owner.GetService (), shared_from_this (), identity, true, params):
std::make_shared<RunnableI2CPDestination>(shared_from_this (), identity, true, params);
if (m_Owner.InsertSession (shared_from_this ()))
{
SendSessionStatusMessage (eI2CPSessionStatusCreated); // created
LogPrint (eLogDebug, "I2CP: Session ", m_SessionID, " created");
m_Destination->Start ();
}
else
{
LogPrint (eLogError, "I2CP: Session already exists");
SendSessionStatusMessage (eI2CPSessionStatusRefused);
}
}
else
{
LogPrint (eLogError, "I2CP: Session already exists");
SendSessionStatusMessage (eI2CPSessionStatusRefused); // refused
}
}
else
{
LogPrint (eLogError, "I2CP: Create session signature verification failed");
SendSessionStatusMessage (eI2CPSessionStatusInvalid); // invalid
}
}
void I2CPSession::DestroySessionMessageHandler (const uint8_t * buf, size_t len)
{
SendSessionStatusMessage (eI2CPSessionStatusDestroyed); // destroy
LogPrint (eLogDebug, "I2CP: Session ", m_SessionID, " destroyed");
Terminate ();
}
void I2CPSession::ReconfigureSessionMessageHandler (const uint8_t * buf, size_t len)
{
I2CPSessionStatus status = eI2CPSessionStatusInvalid; // rejected
if(len > sizeof(uint16_t))
{
uint16_t sessionID = bufbe16toh(buf);
if(sessionID == m_SessionID)
{
buf += sizeof(uint16_t);
const uint8_t * body = buf;
i2p::data::IdentityEx ident;
if(ident.FromBuffer(buf, len - sizeof(uint16_t)))
{
if (ident == *m_Destination->GetIdentity())
{
size_t identsz = ident.GetFullLen();
buf += identsz;
uint16_t optssize = bufbe16toh(buf);
if (optssize <= len - sizeof(uint16_t) - sizeof(uint64_t) - identsz - ident.GetSignatureLen() - sizeof(uint16_t))
{
buf += sizeof(uint16_t);
std::map<std::string, std::string> opts;
ExtractMapping(buf, optssize, opts);
buf += optssize;
//uint64_t date = bufbe64toh(buf);
buf += sizeof(uint64_t);
const uint8_t * sig = buf;
if(ident.Verify(body, len - sizeof(uint16_t) - ident.GetSignatureLen(), sig))
{
if(m_Destination->Reconfigure(opts))
{
LogPrint(eLogInfo, "I2CP: Reconfigured destination");
status = eI2CPSessionStatusUpdated; // updated
}
else
LogPrint(eLogWarning, "I2CP: Failed to reconfigure destination");
}
else
LogPrint(eLogError, "I2CP: Invalid reconfigure message signature");
}
else
LogPrint(eLogError, "I2CP: Mapping size mismatch");
}
else
LogPrint(eLogError, "I2CP: Destination mismatch");
}
else
LogPrint(eLogError, "I2CP: Malfromed destination");
}
else
LogPrint(eLogError, "I2CP: Session mismatch");
}
else
LogPrint(eLogError, "I2CP: Short message");
SendSessionStatusMessage (status);
}
void I2CPSession::SendSessionStatusMessage (I2CPSessionStatus status)
{
uint8_t buf[3];
htobe16buf (buf, m_SessionID);
buf[2] = (uint8_t)status;
SendI2CPMessage (I2CP_SESSION_STATUS_MESSAGE, buf, 3);
}
void I2CPSession::SendMessageStatusMessage (uint32_t nonce, I2CPMessageStatus status)
{
if (!nonce) return; // don't send status with zero nonce
uint8_t buf[15];
htobe16buf (buf, m_SessionID);
htobe32buf (buf + 2, m_MessageID++);
buf[6] = (uint8_t)status;
memset (buf + 7, 0, 4); // size
htobe32buf (buf + 11, nonce);
SendI2CPMessage (I2CP_MESSAGE_STATUS_MESSAGE, buf, 15);
}
void I2CPSession::CreateLeaseSetMessageHandler (const uint8_t * buf, size_t len)
{
uint16_t sessionID = bufbe16toh (buf);
if (sessionID == m_SessionID)
{
size_t offset = 2;
if (m_Destination)
{
offset += i2p::crypto::DSA_PRIVATE_KEY_LENGTH; // skip signing private key
// we always assume this field as 20 bytes (DSA) regardless actual size
// instead of
//offset += m_Destination->GetIdentity ()->GetSigningPrivateKeyLen ();
m_Destination->SetEncryptionPrivateKey (buf + offset);
offset += 256;
m_Destination->LeaseSetCreated (buf + offset, len - offset);
}
}
else
LogPrint (eLogError, "I2CP: Unexpected sessionID ", sessionID);
}
void I2CPSession::CreateLeaseSet2MessageHandler (const uint8_t * buf, size_t len)
{
uint16_t sessionID = bufbe16toh (buf);
if (sessionID == m_SessionID)
{
size_t offset = 2;
if (m_Destination)
{
uint8_t storeType = buf[offset]; offset++; // store type
i2p::data::LeaseSet2 ls (storeType, buf + offset, len - offset); // outer layer only for encrypted
if (!ls.IsValid ())
{
LogPrint (eLogError, "I2CP: Invalid LeaseSet2 of type ", storeType);
return;
}
offset += ls.GetBufferLen ();
// private keys
int numPrivateKeys = buf[offset]; offset++;
for (int i = 0; i < numPrivateKeys; i++)
{
if (offset + 4 > len) return;
uint16_t keyType = bufbe16toh (buf + offset); offset += 2; // encryption type
uint16_t keyLen = bufbe16toh (buf + offset); offset += 2; // private key length
if (offset + keyLen > len) return;
if (keyType == i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD)
m_Destination->SetECIESx25519EncryptionPrivateKey (buf + offset);
else
{
m_Destination->SetEncryptionType (keyType);
m_Destination->SetEncryptionPrivateKey (buf + offset);
}
offset += keyLen;
}
m_Destination->LeaseSet2Created (storeType, ls.GetBuffer (), ls.GetBufferLen ());
}
}
else
LogPrint (eLogError, "I2CP: Unexpected sessionID ", sessionID);
}
void I2CPSession::SendMessageMessageHandler (const uint8_t * buf, size_t len)
{
uint16_t sessionID = bufbe16toh (buf);
if (sessionID == m_SessionID)
{
size_t offset = 2;
if (m_Destination)
{
i2p::data::IdentityEx identity;
size_t identsize = identity.FromBuffer (buf + offset, len - offset);
if (identsize)
{
offset += identsize;
uint32_t payloadLen = bufbe32toh (buf + offset);
if (payloadLen + offset <= len)
{
offset += 4;
uint32_t nonce = bufbe32toh (buf + offset + payloadLen);
if (m_IsSendAccepted)
SendMessageStatusMessage (nonce, eI2CPMessageStatusAccepted); // accepted
m_Destination->SendMsgTo (buf + offset, payloadLen, identity.GetIdentHash (), nonce);
}
else
LogPrint(eLogError, "I2CP: Cannot send message, too big");
}
else
LogPrint(eLogError, "I2CP: Invalid identity");
}
}
else
LogPrint (eLogError, "I2CP: Unexpected sessionID ", sessionID);
}
void I2CPSession::SendMessageExpiresMessageHandler (const uint8_t * buf, size_t len)
{
SendMessageMessageHandler (buf, len - 8); // ignore flags(2) and expiration(6)
}
void I2CPSession::HostLookupMessageHandler (const uint8_t * buf, size_t len)
{
uint16_t sessionID = bufbe16toh (buf);
if (sessionID == m_SessionID || sessionID == 0xFFFF) // -1 means without session
{
uint32_t requestID = bufbe32toh (buf + 2);
//uint32_t timeout = bufbe32toh (buf + 6);
i2p::data::IdentHash ident;
switch (buf[10])
{
case 0: // hash
ident = i2p::data::IdentHash (buf + 11);
break;
case 1: // address
{
auto name = ExtractString (buf + 11, len - 11);
auto addr = i2p::client::context.GetAddressBook ().GetAddress (name);
if (!addr || !addr->IsIdentHash ())
{
// TODO: handle blinded addresses
LogPrint (eLogError, "I2CP: Address ", name, " not found");
SendHostReplyMessage (requestID, nullptr);
return;
}
else
ident = addr->identHash;
break;
}
default:
LogPrint (eLogError, "I2CP: Request type ", (int)buf[10], " is not supported");
SendHostReplyMessage (requestID, nullptr);
return;
}
std::shared_ptr<LeaseSetDestination> destination = m_Destination;
if(!destination) destination = i2p::client::context.GetSharedLocalDestination ();
if (destination)
{
auto ls = destination->FindLeaseSet (ident);
if (ls)
SendHostReplyMessage (requestID, ls->GetIdentity ());
else
{
auto s = shared_from_this ();
destination->RequestDestination (ident,
[s, requestID](std::shared_ptr<i2p::data::LeaseSet> leaseSet)
{
s->SendHostReplyMessage (requestID, leaseSet ? leaseSet->GetIdentity () : nullptr);
});
}
}
else
SendHostReplyMessage (requestID, nullptr);
}
else
LogPrint (eLogError, "I2CP: Unexpected sessionID ", sessionID);
}
void I2CPSession::SendHostReplyMessage (uint32_t requestID, std::shared_ptr<const i2p::data::IdentityEx> identity)
{
if (identity)
{
size_t l = identity->GetFullLen () + 7;
uint8_t * buf = new uint8_t[l];
htobe16buf (buf, m_SessionID);
htobe32buf (buf + 2, requestID);
buf[6] = 0; // result code
identity->ToBuffer (buf + 7, l - 7);
SendI2CPMessage (I2CP_HOST_REPLY_MESSAGE, buf, l);
delete[] buf;
}
else
{
uint8_t buf[7];
htobe16buf (buf, m_SessionID);
htobe32buf (buf + 2, requestID);
buf[6] = 1; // result code
SendI2CPMessage (I2CP_HOST_REPLY_MESSAGE, buf, 7);
}
}
void I2CPSession::DestLookupMessageHandler (const uint8_t * buf, size_t len)
{
if (m_Destination)
{
auto ls = m_Destination->FindLeaseSet (buf);
if (ls)
{
auto l = ls->GetIdentity ()->GetFullLen ();
uint8_t * identBuf = new uint8_t[l];
ls->GetIdentity ()->ToBuffer (identBuf, l);
SendI2CPMessage (I2CP_DEST_REPLY_MESSAGE, identBuf, l);
delete[] identBuf;
}
else
{
auto s = shared_from_this ();
i2p::data::IdentHash ident (buf);
m_Destination->RequestDestination (ident,
[s, ident](std::shared_ptr<i2p::data::LeaseSet> leaseSet)
{
if (leaseSet) // found
{
auto l = leaseSet->GetIdentity ()->GetFullLen ();
uint8_t * identBuf = new uint8_t[l];
leaseSet->GetIdentity ()->ToBuffer (identBuf, l);
s->SendI2CPMessage (I2CP_DEST_REPLY_MESSAGE, identBuf, l);
delete[] identBuf;
}
else
s->SendI2CPMessage (I2CP_DEST_REPLY_MESSAGE, ident, 32); // not found
});
}
}
else
SendI2CPMessage (I2CP_DEST_REPLY_MESSAGE, buf, 32);
}
void I2CPSession::GetBandwidthLimitsMessageHandler (const uint8_t * buf, size_t len)
{
uint8_t limits[64];
memset (limits, 0, 64);
htobe32buf (limits, i2p::transport::transports.GetInBandwidth ()); // inbound
htobe32buf (limits + 4, i2p::transport::transports.GetOutBandwidth ()); // outbound
SendI2CPMessage (I2CP_BANDWIDTH_LIMITS_MESSAGE, limits, 64);
}
void I2CPSession::SendMessagePayloadMessage (const uint8_t * payload, size_t len)
{
// we don't use SendI2CPMessage to eliminate additional copy
auto l = len + 10 + I2CP_HEADER_SIZE;
if (l > I2CP_MAX_MESSAGE_LENGTH)
{
LogPrint (eLogError, "I2CP: Message to send is too long ", l);
return;
}
auto sendBuf = m_IsSending ? std::make_shared<i2p::stream::SendBuffer> (l) : nullptr;
uint8_t * buf = sendBuf ? sendBuf->buf : m_SendBuffer;
htobe32buf (buf + I2CP_HEADER_LENGTH_OFFSET, len + 10);
buf[I2CP_HEADER_TYPE_OFFSET] = I2CP_MESSAGE_PAYLOAD_MESSAGE;
htobe16buf (buf + I2CP_HEADER_SIZE, m_SessionID);
htobe32buf (buf + I2CP_HEADER_SIZE + 2, m_MessageID++);
htobe32buf (buf + I2CP_HEADER_SIZE + 6, len);
memcpy (buf + I2CP_HEADER_SIZE + 10, payload, len);
if (sendBuf)
{
if (m_SendQueue.GetSize () < I2CP_MAX_SEND_QUEUE_SIZE)
m_SendQueue.Add (sendBuf);
else
{
LogPrint (eLogWarning, "I2CP: Send queue size exceeds ", I2CP_MAX_SEND_QUEUE_SIZE);
return;
}
}
else
{
auto socket = m_Socket;
if (socket)
{
m_IsSending = true;
boost::asio::async_write (*socket, boost::asio::buffer (m_SendBuffer, l),
boost::asio::transfer_all (), std::bind(&I2CPSession::HandleI2CPMessageSent,
shared_from_this (), std::placeholders::_1, std::placeholders::_2));
}
}
}
I2CPServer::I2CPServer (const std::string& interface, uint16_t port, bool isSingleThread):
RunnableService ("I2CP"), m_IsSingleThread (isSingleThread),
m_Acceptor (GetIOService (),
boost::asio::ip::tcp::endpoint(boost::asio::ip::address::from_string(interface), port))
{
memset (m_MessagesHandlers, 0, sizeof (m_MessagesHandlers));
m_MessagesHandlers[I2CP_GET_DATE_MESSAGE] = &I2CPSession::GetDateMessageHandler;
m_MessagesHandlers[I2CP_CREATE_SESSION_MESSAGE] = &I2CPSession::CreateSessionMessageHandler;
m_MessagesHandlers[I2CP_DESTROY_SESSION_MESSAGE] = &I2CPSession::DestroySessionMessageHandler;
m_MessagesHandlers[I2CP_RECONFIGURE_SESSION_MESSAGE] = &I2CPSession::ReconfigureSessionMessageHandler;
m_MessagesHandlers[I2CP_CREATE_LEASESET_MESSAGE] = &I2CPSession::CreateLeaseSetMessageHandler;
m_MessagesHandlers[I2CP_CREATE_LEASESET2_MESSAGE] = &I2CPSession::CreateLeaseSet2MessageHandler;
m_MessagesHandlers[I2CP_SEND_MESSAGE_MESSAGE] = &I2CPSession::SendMessageMessageHandler;
m_MessagesHandlers[I2CP_SEND_MESSAGE_EXPIRES_MESSAGE] = &I2CPSession::SendMessageExpiresMessageHandler;
m_MessagesHandlers[I2CP_HOST_LOOKUP_MESSAGE] = &I2CPSession::HostLookupMessageHandler;
m_MessagesHandlers[I2CP_DEST_LOOKUP_MESSAGE] = &I2CPSession::DestLookupMessageHandler;
m_MessagesHandlers[I2CP_GET_BANDWIDTH_LIMITS_MESSAGE] = &I2CPSession::GetBandwidthLimitsMessageHandler;
}
I2CPServer::~I2CPServer ()
{
if (IsRunning ())
Stop ();
}
void I2CPServer::Start ()
{
Accept ();
StartIOService ();
}
void I2CPServer::Stop ()
{
m_Acceptor.cancel ();
{
auto sessions = m_Sessions;
for (auto& it: sessions)
it.second->Stop ();
}
m_Sessions.clear ();
StopIOService ();
}
void I2CPServer::Accept ()
{
auto newSocket = std::make_shared<boost::asio::ip::tcp::socket> (GetIOService ());
m_Acceptor.async_accept (*newSocket, std::bind (&I2CPServer::HandleAccept, this,
std::placeholders::_1, newSocket));
}
void I2CPServer::HandleAccept(const boost::system::error_code& ecode,
std::shared_ptr<boost::asio::ip::tcp::socket> socket)
{
if (!ecode && socket)
{
boost::system::error_code ec;
auto ep = socket->remote_endpoint (ec);
if (!ec)
{
LogPrint (eLogDebug, "I2CP: New connection from ", ep);
auto session = std::make_shared<I2CPSession>(*this, socket);
session->Start ();
}
else
LogPrint (eLogError, "I2CP: Incoming connection error ", ec.message ());
}
else
LogPrint (eLogError, "I2CP: Accept error: ", ecode.message ());
if (ecode != boost::asio::error::operation_aborted)
Accept ();
}
bool I2CPServer::InsertSession (std::shared_ptr<I2CPSession> session)
{
if (!session) return false;
if (!m_Sessions.insert({session->GetSessionID (), session}).second)
{
LogPrint (eLogError, "I2CP: Duplicate session id ", session->GetSessionID ());
return false;
}
return true;
}
void I2CPServer::RemoveSession (uint16_t sessionID)
{
m_Sessions.erase (sessionID);
}
std::shared_ptr<I2CPSession> I2CPServer::FindSessionByIdentHash (const i2p::data::IdentHash& ident) const
{
for (const auto& it: m_Sessions)
{
if (it.second)
{
auto dest = it.second->GetDestination ();
if (dest && dest->GetIdentHash () == ident)
return it.second;
}
}
return nullptr;
}
}
}