PurpleI2P
/
i2pd
mirror of https://github.com/PurpleI2P/i2pd.git
1
0
Fork 0
Code Issues Releases Activity
Browse Source

move transit tunnel build requests from I2NPProtocol.cpp to TransitTunnel.cpp

pull/2094/merge
orignal 3 weeks ago
parent
be24a3e336
commit
32921ead80
3 changed files with 279 additions and 270 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 272
      libi2pd/I2NPProtocol.cpp
  2. 272
      libi2pd/TransitTunnel.cpp
  3. 3
      libi2pd/TransitTunnel.h

272
libi2pd/I2NPProtocol.cpp
Unescape View File

@ -10,20 +10,15 @@ @@ -10,20 +10,15 @@
#include <atomic>
#include "Base.h"
#include "Log.h"
#include "Crypto.h"
#include "I2PEndian.h"
#include "Timestamp.h"
#include "RouterContext.h"
#include "NetDb.hpp"
#include "Tunnel.h"
#include "Transports.h"
#include "Garlic.h"
#include "ECIESX25519AEADRatchetSession.h"
#include "TransitTunnel.h"
#include "I2NPProtocol.h"
#include "version.h"
using namespace i2p::transport;
namespace i2p
{
std::shared_ptr<I2NPMessage> NewI2NPMessage ()
@ -376,108 +371,8 @@ namespace i2p @@ -376,108 +371,8 @@ namespace i2p
return !msg->GetPayload ()[DATABASE_STORE_TYPE_OFFSET]; // 0- RouterInfo
}
static bool HandleBuildRequestRecords (int num, uint8_t * records, uint8_t * clearText)
{
for (int i = 0; i < num; i++)
{
uint8_t * record = records + i*TUNNEL_BUILD_RECORD_SIZE;
if (!memcmp (record + BUILD_REQUEST_RECORD_TO_PEER_OFFSET, (const uint8_t *)i2p::context.GetRouterInfo ().GetIdentHash (), 16))
{
LogPrint (eLogDebug, "I2NP: Build request record ", i, " is ours");
if (!i2p::context.DecryptTunnelBuildRecord (record + BUILD_REQUEST_RECORD_ENCRYPTED_OFFSET, clearText))
{
LogPrint (eLogWarning, "I2NP: Failed to decrypt tunnel build record");
return false;
}
if (!memcmp ((const uint8_t *)i2p::context.GetIdentHash (), clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, 32) && // if next ident is now ours
!(clearText[ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_ENDPOINT_FLAG)) // and not endpoint
{
LogPrint (eLogWarning, "I2NP: Next ident is ours in tunnel build record");
return false;
}
uint8_t retCode = 0;
// decide if we should accept tunnel
bool accept = i2p::context.AcceptsTunnels ();
if (accept)
{
auto congestionLevel = i2p::context.GetCongestionLevel (false);
if (congestionLevel >= CONGESTION_LEVEL_MEDIUM)
{
if (congestionLevel < CONGESTION_LEVEL_FULL)
{
// random reject depending on congestion level
int level = i2p::tunnel::tunnels.GetRng ()() % (CONGESTION_LEVEL_FULL - CONGESTION_LEVEL_MEDIUM) + CONGESTION_LEVEL_MEDIUM;
if (congestionLevel > level)
accept = false;
}
else
accept = false;
}
}
// replace record to reply
if (accept)
{
auto transitTunnel = i2p::tunnel::CreateTransitTunnel (
bufbe32toh (clearText + ECIES_BUILD_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET),
clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET,
bufbe32toh (clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET),
clearText + ECIES_BUILD_REQUEST_RECORD_LAYER_KEY_OFFSET,
clearText + ECIES_BUILD_REQUEST_RECORD_IV_KEY_OFFSET,
clearText[ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_GATEWAY_FLAG,
clearText[ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_ENDPOINT_FLAG);
if (!i2p::tunnel::tunnels.AddTransitTunnel (transitTunnel))
retCode = 30;
}
else
retCode = 30; // always reject with bandwidth reason (30)
memset (record + ECIES_BUILD_RESPONSE_RECORD_OPTIONS_OFFSET, 0, 2); // no options
record[ECIES_BUILD_RESPONSE_RECORD_RET_OFFSET] = retCode;
// encrypt reply
i2p::crypto::CBCEncryption encryption;
for (int j = 0; j < num; j++)
{
uint8_t * reply = records + j*TUNNEL_BUILD_RECORD_SIZE;
if (j == i)
{
uint8_t nonce[12];
memset (nonce, 0, 12);
auto& noiseState = i2p::context.GetCurrentNoiseState ();
if (!i2p::crypto::AEADChaCha20Poly1305 (reply, TUNNEL_BUILD_RECORD_SIZE - 16,
noiseState.m_H, 32, noiseState.m_CK, nonce, reply, TUNNEL_BUILD_RECORD_SIZE, true)) // encrypt
{
LogPrint (eLogWarning, "I2NP: Reply AEAD encryption failed");
return false;
}
}
else
{
encryption.SetKey (clearText + ECIES_BUILD_REQUEST_RECORD_REPLY_KEY_OFFSET);
encryption.SetIV (clearText + ECIES_BUILD_REQUEST_RECORD_REPLY_IV_OFFSET);
encryption.Encrypt(reply, TUNNEL_BUILD_RECORD_SIZE, reply);
}
}
return true;
}
}
return false;
}
static void HandleVariableTunnelBuildMsg (uint32_t replyMsgID, uint8_t * buf, size_t len)
{
int num = buf[0];
LogPrint (eLogDebug, "I2NP: VariableTunnelBuild ", num, " records");
if (num > i2p::tunnel::MAX_NUM_RECORDS)
{
LogPrint (eLogError, "I2NP: Too many records in VaribleTunnelBuild message ", num);
return;
}
if (len < num*TUNNEL_BUILD_RECORD_SIZE + 1)
{
LogPrint (eLogError, "I2NP: VaribleTunnelBuild message of ", num, " records is too short ", len);
return;
}
auto tunnel = i2p::tunnel::tunnels.GetPendingInboundTunnel (replyMsgID);
if (tunnel)
{
@ -496,24 +391,7 @@ namespace i2p @@ -496,24 +391,7 @@ namespace i2p
}
}
else
{
uint8_t clearText[ECIES_BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE];
if (HandleBuildRequestRecords (num, buf + 1, clearText))
{
if (clearText[ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_ENDPOINT_FLAG) // we are endpoint of outboud tunnel
{
// so we send it to reply tunnel
transports.SendMessage (clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET,
CreateTunnelGatewayMsg (bufbe32toh (clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET),
eI2NPVariableTunnelBuildReply, buf, len,
bufbe32toh (clearText + ECIES_BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET)));
}
else
transports.SendMessage (clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET,
CreateI2NPMessage (eI2NPVariableTunnelBuild, buf, len,
bufbe32toh (clearText + ECIES_BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET)));
}
}
i2p::tunnel::HandleVariableTransitTunnelBuildMsg (buf, len);
}
static void HandleTunnelBuildMsg (uint8_t * buf, size_t len)
@ -559,18 +437,6 @@ namespace i2p @@ -559,18 +437,6 @@ namespace i2p
static void HandleShortTunnelBuildMsg (uint32_t replyMsgID, uint8_t * buf, size_t len)
{
int num = buf[0];
LogPrint (eLogDebug, "I2NP: ShortTunnelBuild ", num, " records");
if (num > i2p::tunnel::MAX_NUM_RECORDS)
{
LogPrint (eLogError, "I2NP: Too many records in ShortTunnelBuild message ", num);
return;
}
if (len < num*SHORT_TUNNEL_BUILD_RECORD_SIZE + 1)
{
LogPrint (eLogError, "I2NP: ShortTunnelBuild message of ", num, " records is too short ", len);
return;
}
auto tunnel = i2p::tunnel::tunnels.GetPendingInboundTunnel (replyMsgID);
if (tunnel)
{
@ -589,140 +455,8 @@ namespace i2p @@ -589,140 +455,8 @@ namespace i2p
}
return;
}
const uint8_t * record = buf + 1;
for (int i = 0; i < num; i++)
{
if (!memcmp (record, (const uint8_t *)i2p::context.GetRouterInfo ().GetIdentHash (), 16))
{
LogPrint (eLogDebug, "I2NP: Short request record ", i, " is ours");
uint8_t clearText[SHORT_REQUEST_RECORD_CLEAR_TEXT_SIZE];
if (!i2p::context.DecryptTunnelShortRequestRecord (record + SHORT_REQUEST_RECORD_ENCRYPTED_OFFSET, clearText))
{
LogPrint (eLogWarning, "I2NP: Can't decrypt short request record ", i);
return;
}
if (clearText[SHORT_REQUEST_RECORD_LAYER_ENCRYPTION_TYPE]) // not AES
{
LogPrint (eLogWarning, "I2NP: Unknown layer encryption type ", clearText[SHORT_REQUEST_RECORD_LAYER_ENCRYPTION_TYPE], " in short request record");
return;
}
auto& noiseState = i2p::context.GetCurrentNoiseState ();
uint8_t replyKey[32]; // AEAD/Chacha20/Poly1305
i2p::crypto::AESKey layerKey, ivKey; // AES
i2p::crypto::HKDF (noiseState.m_CK, nullptr, 0, "SMTunnelReplyKey", noiseState.m_CK);
memcpy (replyKey, noiseState.m_CK + 32, 32);
i2p::crypto::HKDF (noiseState.m_CK, nullptr, 0, "SMTunnelLayerKey", noiseState.m_CK);
memcpy (layerKey, noiseState.m_CK + 32, 32);
bool isEndpoint = clearText[SHORT_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_ENDPOINT_FLAG;
if (isEndpoint)
{
i2p::crypto::HKDF (noiseState.m_CK, nullptr, 0, "TunnelLayerIVKey", noiseState.m_CK);
memcpy (ivKey, noiseState.m_CK + 32, 32);
}
else
{
if (!memcmp ((const uint8_t *)i2p::context.GetIdentHash (), clearText + SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET, 32)) // if next ident is now ours
{
LogPrint (eLogWarning, "I2NP: Next ident is ours in short request record");
return;
}
memcpy (ivKey, noiseState.m_CK , 32);
}
// check if we accept this tunnel
std::shared_ptr<i2p::tunnel::TransitTunnel> transitTunnel;
uint8_t retCode = 0;
if (!i2p::context.AcceptsTunnels () || i2p::context.GetCongestionLevel (false) >= CONGESTION_LEVEL_FULL)
retCode = 30;
if (!retCode)
{
// create new transit tunnel
transitTunnel = i2p::tunnel::CreateTransitTunnel (
bufbe32toh (clearText + SHORT_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET),
clearText + SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET,
bufbe32toh (clearText + SHORT_REQUEST_RECORD_NEXT_TUNNEL_OFFSET),
layerKey, ivKey,
clearText[SHORT_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_GATEWAY_FLAG,
clearText[SHORT_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_ENDPOINT_FLAG);
if (!i2p::tunnel::tunnels.AddTransitTunnel (transitTunnel))
retCode = 30;
}
// encrypt reply
uint8_t nonce[12];
memset (nonce, 0, 12);
uint8_t * reply = buf + 1;
for (int j = 0; j < num; j++)
{
nonce[4] = j; // nonce is record #
if (j == i)
{
memset (reply + SHORT_RESPONSE_RECORD_OPTIONS_OFFSET, 0, 2); // no options
reply[SHORT_RESPONSE_RECORD_RET_OFFSET] = retCode;
if (!i2p::crypto::AEADChaCha20Poly1305 (reply, SHORT_TUNNEL_BUILD_RECORD_SIZE - 16,
noiseState.m_H, 32, replyKey, nonce, reply, SHORT_TUNNEL_BUILD_RECORD_SIZE, true)) // encrypt
{
LogPrint (eLogWarning, "I2NP: Short reply AEAD encryption failed");
return;
}
}
else
i2p::crypto::ChaCha20 (reply, SHORT_TUNNEL_BUILD_RECORD_SIZE, replyKey, nonce, reply);
reply += SHORT_TUNNEL_BUILD_RECORD_SIZE;
}
// send reply
auto onDrop = [transitTunnel]()
{
if (transitTunnel)
{
auto t = transitTunnel->GetCreationTime ();
if (t > i2p::tunnel::TUNNEL_EXPIRATION_TIMEOUT)
// make transit tunnel expired
transitTunnel->SetCreationTime (t - i2p::tunnel::TUNNEL_EXPIRATION_TIMEOUT);
}
};
if (isEndpoint)
{
auto replyMsg = NewI2NPShortMessage ();
replyMsg->Concat (buf, len);
replyMsg->FillI2NPMessageHeader (eI2NPShortTunnelBuildReply, bufbe32toh (clearText + SHORT_REQUEST_RECORD_SEND_MSG_ID_OFFSET));
if (transitTunnel) replyMsg->onDrop = onDrop;
if (memcmp ((const uint8_t *)i2p::context.GetIdentHash (),
clearText + SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET, 32)) // reply IBGW is not local?
{
i2p::crypto::HKDF (noiseState.m_CK, nullptr, 0, "RGarlicKeyAndTag", noiseState.m_CK);
uint64_t tag;
memcpy (&tag, noiseState.m_CK, 8);
// we send it to reply tunnel
transports.SendMessage (clearText + SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET,
CreateTunnelGatewayMsg (bufbe32toh (clearText + SHORT_REQUEST_RECORD_NEXT_TUNNEL_OFFSET),
i2p::garlic::WrapECIESX25519Message (replyMsg, noiseState.m_CK + 32, tag)));
}
else
{
// IBGW is local
uint32_t tunnelID = bufbe32toh (clearText + SHORT_REQUEST_RECORD_NEXT_TUNNEL_OFFSET);
auto tunnel = i2p::tunnel::tunnels.GetTunnel (tunnelID);
if (tunnel)
{
tunnel->SendTunnelDataMsg (replyMsg);
tunnel->FlushTunnelDataMsgs ();
}
else
LogPrint (eLogWarning, "I2NP: Tunnel ", tunnelID, " not found for short tunnel build reply");
}
}
else
{
auto msg = CreateI2NPMessage (eI2NPShortTunnelBuild, buf, len,
bufbe32toh (clearText + SHORT_REQUEST_RECORD_SEND_MSG_ID_OFFSET));
if (transitTunnel) msg->onDrop = onDrop;
transports.SendMessage (clearText + SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET, msg);
}
return;
}
record += SHORT_TUNNEL_BUILD_RECORD_SIZE;
}
i2p::tunnel::HandleShortTransitTunnelBuildMsg (buf, len);
}
std::shared_ptr<I2NPMessage> CreateTunnelDataMsg (const uint8_t * buf)

272
libi2pd/TransitTunnel.cpp
Unescape View File

@ -8,9 +8,12 @@ @@ -8,9 +8,12 @@
#include <string.h>
#include "I2PEndian.h"
#include "Crypto.h"
#include "Log.h"
#include "RouterContext.h"
#include "I2NPProtocol.h"
#include "Garlic.h"
#include "ECIESX25519AEADRatchetSession.h"
#include "Tunnel.h"
#include "Transports.h"
#include "TransitTunnel.h"
@ -118,5 +121,274 @@ namespace tunnel @@ -118,5 +121,274 @@ namespace tunnel
return std::make_shared<TransitTunnelParticipant> (receiveTunnelID, nextIdent, nextTunnelID, layerKey, ivKey);
}
}
void HandleShortTransitTunnelBuildMsg (uint8_t * buf, size_t len)
{
int num = buf[0];
LogPrint (eLogDebug, "TransitTunnel: ShortTunnelBuild ", num, " records");
if (num > i2p::tunnel::MAX_NUM_RECORDS)
{
LogPrint (eLogError, "TransitTunnel: Too many records in ShortTunnelBuild message ", num);
return;
}
if (len < num*SHORT_TUNNEL_BUILD_RECORD_SIZE + 1)
{
LogPrint (eLogError, "TransitTunnel: ShortTunnelBuild message of ", num, " records is too short ", len);
return;
}
const uint8_t * record = buf + 1;
for (int i = 0; i < num; i++)
{
if (!memcmp (record, (const uint8_t *)i2p::context.GetRouterInfo ().GetIdentHash (), 16))
{
LogPrint (eLogDebug, "TransitTunnel: Short request record ", i, " is ours");
uint8_t clearText[SHORT_REQUEST_RECORD_CLEAR_TEXT_SIZE];
if (!i2p::context.DecryptTunnelShortRequestRecord (record + SHORT_REQUEST_RECORD_ENCRYPTED_OFFSET, clearText))
{
LogPrint (eLogWarning, "TransitTunnel: Can't decrypt short request record ", i);
return;
}
if (clearText[SHORT_REQUEST_RECORD_LAYER_ENCRYPTION_TYPE]) // not AES
{
LogPrint (eLogWarning, "TransitTunnel: Unknown layer encryption type ", clearText[SHORT_REQUEST_RECORD_LAYER_ENCRYPTION_TYPE], " in short request record");
return;
}
auto& noiseState = i2p::context.GetCurrentNoiseState ();
uint8_t replyKey[32]; // AEAD/Chacha20/Poly1305
i2p::crypto::AESKey layerKey, ivKey; // AES
i2p::crypto::HKDF (noiseState.m_CK, nullptr, 0, "SMTunnelReplyKey", noiseState.m_CK);
memcpy (replyKey, noiseState.m_CK + 32, 32);
i2p::crypto::HKDF (noiseState.m_CK, nullptr, 0, "SMTunnelLayerKey", noiseState.m_CK);
memcpy (layerKey, noiseState.m_CK + 32, 32);
bool isEndpoint = clearText[SHORT_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_ENDPOINT_FLAG;
if (isEndpoint)
{
i2p::crypto::HKDF (noiseState.m_CK, nullptr, 0, "TunnelLayerIVKey", noiseState.m_CK);
memcpy (ivKey, noiseState.m_CK + 32, 32);
}
else
{
if (!memcmp ((const uint8_t *)i2p::context.GetIdentHash (), clearText + SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET, 32)) // if next ident is now ours
{
LogPrint (eLogWarning, "TransitTunnel: Next ident is ours in short request record");
return;
}
memcpy (ivKey, noiseState.m_CK , 32);
}
// check if we accept this tunnel
std::shared_ptr<i2p::tunnel::TransitTunnel> transitTunnel;
uint8_t retCode = 0;
if (!i2p::context.AcceptsTunnels () || i2p::context.GetCongestionLevel (false) >= CONGESTION_LEVEL_FULL)
retCode = 30;
if (!retCode)
{
// create new transit tunnel
transitTunnel = i2p::tunnel::CreateTransitTunnel (
bufbe32toh (clearText + SHORT_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET),
clearText + SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET,
bufbe32toh (clearText + SHORT_REQUEST_RECORD_NEXT_TUNNEL_OFFSET),
layerKey, ivKey,
clearText[SHORT_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_GATEWAY_FLAG,
clearText[SHORT_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_ENDPOINT_FLAG);
if (!i2p::tunnel::tunnels.AddTransitTunnel (transitTunnel))
retCode = 30;
}
// encrypt reply
uint8_t nonce[12];
memset (nonce, 0, 12);
uint8_t * reply = buf + 1;
for (int j = 0; j < num; j++)
{
nonce[4] = j; // nonce is record #
if (j == i)
{
memset (reply + SHORT_RESPONSE_RECORD_OPTIONS_OFFSET, 0, 2); // no options
reply[SHORT_RESPONSE_RECORD_RET_OFFSET] = retCode;
if (!i2p::crypto::AEADChaCha20Poly1305 (reply, SHORT_TUNNEL_BUILD_RECORD_SIZE - 16,
noiseState.m_H, 32, replyKey, nonce, reply, SHORT_TUNNEL_BUILD_RECORD_SIZE, true)) // encrypt
{
LogPrint (eLogWarning, "TransitTunnel: Short reply AEAD encryption failed");
return;
}
}
else
i2p::crypto::ChaCha20 (reply, SHORT_TUNNEL_BUILD_RECORD_SIZE, replyKey, nonce, reply);
reply += SHORT_TUNNEL_BUILD_RECORD_SIZE;
}
// send reply
auto onDrop = [transitTunnel]()
{
if (transitTunnel)
{
auto t = transitTunnel->GetCreationTime ();
if (t > i2p::tunnel::TUNNEL_EXPIRATION_TIMEOUT)
// make transit tunnel expired
transitTunnel->SetCreationTime (t - i2p::tunnel::TUNNEL_EXPIRATION_TIMEOUT);
}
};
if (isEndpoint)
{
auto replyMsg = NewI2NPShortMessage ();
replyMsg->Concat (buf, len);
replyMsg->FillI2NPMessageHeader (eI2NPShortTunnelBuildReply, bufbe32toh (clearText + SHORT_REQUEST_RECORD_SEND_MSG_ID_OFFSET));
if (transitTunnel) replyMsg->onDrop = onDrop;
if (memcmp ((const uint8_t *)i2p::context.GetIdentHash (),
clearText + SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET, 32)) // reply IBGW is not local?
{
i2p::crypto::HKDF (noiseState.m_CK, nullptr, 0, "RGarlicKeyAndTag", noiseState.m_CK);
uint64_t tag;
memcpy (&tag, noiseState.m_CK, 8);
// we send it to reply tunnel
i2p::transport::transports.SendMessage (clearText + SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET,
CreateTunnelGatewayMsg (bufbe32toh (clearText + SHORT_REQUEST_RECORD_NEXT_TUNNEL_OFFSET),
i2p::garlic::WrapECIESX25519Message (replyMsg, noiseState.m_CK + 32, tag)));
}
else
{
// IBGW is local
uint32_t tunnelID = bufbe32toh (clearText + SHORT_REQUEST_RECORD_NEXT_TUNNEL_OFFSET);
auto tunnel = i2p::tunnel::tunnels.GetTunnel (tunnelID);
if (tunnel)
{
tunnel->SendTunnelDataMsg (replyMsg);
tunnel->FlushTunnelDataMsgs ();
}
else
LogPrint (eLogWarning, "I2NP: Tunnel ", tunnelID, " not found for short tunnel build reply");
}
}
else
{
auto msg = CreateI2NPMessage (eI2NPShortTunnelBuild, buf, len,
bufbe32toh (clearText + SHORT_REQUEST_RECORD_SEND_MSG_ID_OFFSET));
if (transitTunnel) msg->onDrop = onDrop;
i2p::transport::transports.SendMessage (clearText + SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET, msg);
}
return;
}
record += SHORT_TUNNEL_BUILD_RECORD_SIZE;
}
}
static bool HandleBuildRequestRecords (int num, uint8_t * records, uint8_t * clearText)
{
for (int i = 0; i < num; i++)
{
uint8_t * record = records + i*TUNNEL_BUILD_RECORD_SIZE;
if (!memcmp (record + BUILD_REQUEST_RECORD_TO_PEER_OFFSET, (const uint8_t *)i2p::context.GetRouterInfo ().GetIdentHash (), 16))
{
LogPrint (eLogDebug, "TransitTunnel: Build request record ", i, " is ours");
if (!i2p::context.DecryptTunnelBuildRecord (record + BUILD_REQUEST_RECORD_ENCRYPTED_OFFSET, clearText))
{
LogPrint (eLogWarning, "TransitTunnel: Failed to decrypt tunnel build record");
return false;
}
if (!memcmp ((const uint8_t *)i2p::context.GetIdentHash (), clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, 32) && // if next ident is now ours
!(clearText[ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_ENDPOINT_FLAG)) // and not endpoint
{
LogPrint (eLogWarning, "TransitTunnel: Next ident is ours in tunnel build record");
return false;
}
uint8_t retCode = 0;
// decide if we should accept tunnel
bool accept = i2p::context.AcceptsTunnels ();
if (accept)
{
auto congestionLevel = i2p::context.GetCongestionLevel (false);
if (congestionLevel >= CONGESTION_LEVEL_MEDIUM)
{
if (congestionLevel < CONGESTION_LEVEL_FULL)
{
// random reject depending on congestion level
int level = i2p::tunnel::tunnels.GetRng ()() % (CONGESTION_LEVEL_FULL - CONGESTION_LEVEL_MEDIUM) + CONGESTION_LEVEL_MEDIUM;
if (congestionLevel > level)
accept = false;
}
else
accept = false;
}
}
// replace record to reply
if (accept)
{
auto transitTunnel = i2p::tunnel::CreateTransitTunnel (
bufbe32toh (clearText + ECIES_BUILD_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET),
clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET,
bufbe32toh (clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET),
clearText + ECIES_BUILD_REQUEST_RECORD_LAYER_KEY_OFFSET,
clearText + ECIES_BUILD_REQUEST_RECORD_IV_KEY_OFFSET,
clearText[ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_GATEWAY_FLAG,
clearText[ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_ENDPOINT_FLAG);
if (!i2p::tunnel::tunnels.AddTransitTunnel (transitTunnel))
retCode = 30;
}
else
retCode = 30; // always reject with bandwidth reason (30)
memset (record + ECIES_BUILD_RESPONSE_RECORD_OPTIONS_OFFSET, 0, 2); // no options
record[ECIES_BUILD_RESPONSE_RECORD_RET_OFFSET] = retCode;
// encrypt reply
i2p::crypto::CBCEncryption encryption;
for (int j = 0; j < num; j++)
{
uint8_t * reply = records + j*TUNNEL_BUILD_RECORD_SIZE;
if (j == i)
{
uint8_t nonce[12];
memset (nonce, 0, 12);
auto& noiseState = i2p::context.GetCurrentNoiseState ();
if (!i2p::crypto::AEADChaCha20Poly1305 (reply, TUNNEL_BUILD_RECORD_SIZE - 16,
noiseState.m_H, 32, noiseState.m_CK, nonce, reply, TUNNEL_BUILD_RECORD_SIZE, true)) // encrypt
{
LogPrint (eLogWarning, "TransitTunnel: Reply AEAD encryption failed");
return false;
}
}
else
{
encryption.SetKey (clearText + ECIES_BUILD_REQUEST_RECORD_REPLY_KEY_OFFSET);
encryption.SetIV (clearText + ECIES_BUILD_REQUEST_RECORD_REPLY_IV_OFFSET);
encryption.Encrypt(reply, TUNNEL_BUILD_RECORD_SIZE, reply);
}
}
return true;
}
}
return false;
}
void HandleVariableTransitTunnelBuildMsg (uint8_t * buf, size_t len)
{
int num = buf[0];
LogPrint (eLogDebug, "TransitTunnel: VariableTunnelBuild ", num, " records");
if (num > i2p::tunnel::MAX_NUM_RECORDS)
{
LogPrint (eLogError, "TransitTunnle: Too many records in VaribleTunnelBuild message ", num);
return;
}
if (len < num*TUNNEL_BUILD_RECORD_SIZE + 1)
{
LogPrint (eLogError, "TransitTunnel: VaribleTunnelBuild message of ", num, " records is too short ", len);
return;
}
uint8_t clearText[ECIES_BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE];
if (HandleBuildRequestRecords (num, buf + 1, clearText))
{
if (clearText[ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_ENDPOINT_FLAG) // we are endpoint of outboud tunnel
{
// so we send it to reply tunnel
i2p::transport::transports.SendMessage (clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET,
CreateTunnelGatewayMsg (bufbe32toh (clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET),
eI2NPVariableTunnelBuildReply, buf, len,
bufbe32toh (clearText + ECIES_BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET)));
}
else
i2p::transport::transports.SendMessage (clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET,
CreateI2NPMessage (eI2NPVariableTunnelBuild, buf, len,
bufbe32toh (clearText + ECIES_BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET)));
}
}
}
}

3
libi2pd/TransitTunnel.h
Unescape View File

@ -108,6 +108,9 @@ namespace tunnel @@ -108,6 +108,9 @@ namespace tunnel
const i2p::data::IdentHash& nextIdent, uint32_t nextTunnelID,
const i2p::crypto::AESKey& layerKey, const i2p::crypto::AESKey& ivKey,
bool isGateway, bool isEndpoint);
void HandleShortTransitTunnelBuildMsg (uint8_t * buf, size_t len);
void HandleVariableTransitTunnelBuildMsg (uint8_t * buf, size_t len);
}
}

Write Preview
Loading…
Cancel
Save