i2pd/libi2pd/Garlic.cpp
Anatolii Cherednichenko 55534ea002 Reformat code
2022-08-30 02:11:28 +03:00

1014 lines
46 KiB
C++

/*
* Copyright (c) 2013-2022, 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 <inttypes.h>
#include "I2PEndian.h"
#include <map>
#include <string>
#include "Crypto.h"
#include "RouterContext.h"
#include "I2NPProtocol.h"
#include "Tunnel.h"
#include "TunnelPool.h"
#include "Transports.h"
#include "Timestamp.h"
#include "Log.h"
#include "FS.h"
#include "ECIESX25519AEADRatchetSession.h"
#include "Garlic.h"
namespace i2p {
namespace garlic {
GarlicRoutingSession::GarlicRoutingSession(GarlicDestination *owner, bool attachLeaseSet) :
m_Owner(owner), m_LeaseSetUpdateStatus(attachLeaseSet ? eLeaseSetUpdated : eLeaseSetDoNotSend),
m_LeaseSetUpdateMsgID(0) {
}
GarlicRoutingSession::GarlicRoutingSession() :
m_Owner(nullptr), m_LeaseSetUpdateStatus(eLeaseSetDoNotSend), m_LeaseSetUpdateMsgID(0) {
}
GarlicRoutingSession::~GarlicRoutingSession() {
}
std::shared_ptr<GarlicRoutingPath> GarlicRoutingSession::GetSharedRoutingPath() {
if (!m_SharedRoutingPath) return nullptr;
uint32_t ts = i2p::util::GetSecondsSinceEpoch();
if (m_SharedRoutingPath->numTimesUsed >= ROUTING_PATH_MAX_NUM_TIMES_USED ||
!m_SharedRoutingPath->outboundTunnel->IsEstablished() ||
ts * 1000LL > m_SharedRoutingPath->remoteLease->endDate ||
ts > m_SharedRoutingPath->updateTime + ROUTING_PATH_EXPIRATION_TIMEOUT)
m_SharedRoutingPath = nullptr;
if (m_SharedRoutingPath) m_SharedRoutingPath->numTimesUsed++;
return m_SharedRoutingPath;
}
void GarlicRoutingSession::SetSharedRoutingPath(std::shared_ptr<GarlicRoutingPath> path) {
if (path && path->outboundTunnel && path->remoteLease) {
path->updateTime = i2p::util::GetSecondsSinceEpoch();
path->numTimesUsed = 0;
} else
path = nullptr;
m_SharedRoutingPath = path;
}
bool GarlicRoutingSession::MessageConfirmed(uint32_t msgID) {
if (msgID == GetLeaseSetUpdateMsgID()) {
SetLeaseSetUpdateStatus(eLeaseSetUpToDate);
SetLeaseSetUpdateMsgID(0);
LogPrint(eLogInfo, "Garlic: LeaseSet update confirmed");
return true;
}
return false;
}
void GarlicRoutingSession::CleanupUnconfirmedLeaseSet(uint64_t ts) {
if (m_LeaseSetUpdateMsgID && ts * 1000LL > m_LeaseSetSubmissionTime + LEASET_CONFIRMATION_TIMEOUT) {
if (GetOwner())
GetOwner()->RemoveDeliveryStatusSession(m_LeaseSetUpdateMsgID);
m_LeaseSetUpdateMsgID = 0;
}
}
std::shared_ptr<I2NPMessage> GarlicRoutingSession::CreateEncryptedDeliveryStatusMsg(uint32_t msgID) {
auto msg = CreateDeliveryStatusMsg(msgID);
if (GetOwner()) {
//encrypt
uint8_t key[32], tag[32];
RAND_bytes(key, 32); // random session key
RAND_bytes(tag, 32); // random session tag
GetOwner()->SubmitSessionKey(key, tag);
ElGamalAESSession garlic(key, tag);
msg = garlic.WrapSingleMessage(msg);
}
return msg;
}
ElGamalAESSession::ElGamalAESSession(GarlicDestination *owner,
std::shared_ptr<const i2p::data::RoutingDestination> destination,
int numTags, bool attachLeaseSet) :
GarlicRoutingSession(owner, attachLeaseSet),
m_Destination(destination), m_NumTags(numTags) {
// create new session tags and session key
RAND_bytes(m_SessionKey, 32);
m_Encryption.SetKey(m_SessionKey);
}
ElGamalAESSession::ElGamalAESSession(const uint8_t *sessionKey, const SessionTag &sessionTag) :
m_NumTags(1) {
memcpy(m_SessionKey, sessionKey, 32);
m_Encryption.SetKey(m_SessionKey);
m_SessionTags.push_back(sessionTag);
m_SessionTags.back().creationTime = i2p::util::GetSecondsSinceEpoch();
}
std::shared_ptr<I2NPMessage> ElGamalAESSession::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);
m_Destination->Encrypt((uint8_t * ) & elGamal, buf);
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;
}
size_t ElGamalAESSession::CreateAESBlock(uint8_t *buf, std::shared_ptr<const I2NPMessage> msg) {
size_t blockSize = 0;
bool createNewTags = GetOwner() && 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 ElGamalAESSession::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 (GetOwner()) {
// resubmit non-confirmed LeaseSet
if (GetLeaseSetUpdateStatus() == eLeaseSetSubmitted &&
ts > GetLeaseSetSubmissionTime() + LEASET_CONFIRMATION_TIMEOUT) {
SetLeaseSetUpdateStatus(eLeaseSetUpdated);
SetSharedRoutingPath(nullptr); // invalidate path since leaseset was not confirmed
}
// attach DeviveryStatus if necessary
if (newTags || GetLeaseSetUpdateStatus() == 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
}
GetOwner()->DeliveryStatusSent(shared_from_this(), msgID);
} else
LogPrint(eLogWarning, "Garlic: DeliveryStatus clove was not created");
}
// attach LeaseSet
if (GetLeaseSetUpdateStatus() == eLeaseSetUpdated) {
if (GetLeaseSetUpdateMsgID())
GetOwner()->RemoveDeliveryStatusSession(GetLeaseSetUpdateMsgID()); // remove previous
SetLeaseSetUpdateStatus(eLeaseSetSubmitted);
SetLeaseSetUpdateMsgID(msgID);
SetLeaseSetSubmissionTime(ts);
// clove if our leaseSet must be attached
auto leaseSet = CreateDatabaseStoreMsg(GetOwner()->GetLeaseSet());
size += CreateGarlicClove(payload + size, leaseSet, false);
(*numCloves)++;
}
}
if (msg) // clove message itself 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;
}
size_t
ElGamalAESSession::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;
}
size_t ElGamalAESSession::CreateDeliveryStatusClove(uint8_t *buf, uint32_t msgID) {
size_t size = 0;
if (GetOwner()) {
auto inboundTunnel = GetOwner()->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 = CreateEncryptedDeliveryStatusMsg(msgID);
if (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;
}
ElGamalAESSession::UnconfirmedTags *ElGamalAESSession::GenerateSessionTags() {
auto tags = new UnconfirmedTags(m_NumTags);
tags->tagsCreationTime = i2p::util::GetSecondsSinceEpoch();
for (int i = 0; i < m_NumTags; i++) {
RAND_bytes(tags->sessionTags[i], 32);
tags->sessionTags[i].creationTime = tags->tagsCreationTime;
}
return tags;
}
bool ElGamalAESSession::MessageConfirmed(uint32_t msgID) {
TagsConfirmed(msgID);
if (!GarlicRoutingSession::MessageConfirmed(msgID))
CleanupExpiredTags();
return true;
}
void ElGamalAESSession::TagsConfirmed(uint32_t msgID) {
uint32_t ts = i2p::util::GetSecondsSinceEpoch();
auto it = m_UnconfirmedTagsMsgs.find(msgID);
if (it != m_UnconfirmedTagsMsgs.end()) {
auto &tags = it->second;
if (ts < tags->tagsCreationTime + OUTGOING_TAGS_EXPIRATION_TIMEOUT) {
for (int i = 0; i < tags->numTags; i++)
m_SessionTags.push_back(tags->sessionTags[i]);
}
m_UnconfirmedTagsMsgs.erase(it);
}
}
bool ElGamalAESSession::CleanupExpiredTags() {
auto ts = i2p::util::GetSecondsSinceEpoch();
for (auto it = m_SessionTags.begin(); it != m_SessionTags.end();) {
if (ts >= it->creationTime + OUTGOING_TAGS_EXPIRATION_TIMEOUT)
it = m_SessionTags.erase(it);
else
++it;
}
CleanupUnconfirmedTags();
CleanupUnconfirmedLeaseSet(ts);
return !m_SessionTags.empty() || !m_UnconfirmedTagsMsgs.empty();
}
bool ElGamalAESSession::CleanupUnconfirmedTags() {
bool ret = false;
uint32_t ts = i2p::util::GetSecondsSinceEpoch();
// delete expired unconfirmed tags
for (auto it = m_UnconfirmedTagsMsgs.begin(); it != m_UnconfirmedTagsMsgs.end();) {
if (ts >= it->second->tagsCreationTime + OUTGOING_TAGS_CONFIRMATION_TIMEOUT) {
if (GetOwner())
GetOwner()->RemoveDeliveryStatusSession(it->first);
it = m_UnconfirmedTagsMsgs.erase(it);
ret = true;
} else
++it;
}
return ret;
}
GarlicDestination::GarlicDestination() : m_NumTags(32), // 32 tags by default
m_PayloadBuffer(nullptr),
m_NumRatchetInboundTags(0) // 0 means standard
{
}
GarlicDestination::~GarlicDestination() {
if (m_PayloadBuffer)
delete[] m_PayloadBuffer;
}
void GarlicDestination::CleanUp() {
for (auto it: m_Sessions)
it.second->SetOwner(nullptr);
m_Sessions.clear();
m_DeliveryStatusSessions.clear();
m_Tags.clear();
for (auto it: m_ECIESx25519Sessions) {
it.second->Terminate();
it.second->SetOwner(nullptr);
}
m_ECIESx25519Sessions.clear();
m_ECIESx25519Tags.clear();
}
void GarlicDestination::AddSessionKey(const uint8_t *key, const uint8_t *tag) {
if (key) {
uint32_t ts = i2p::util::GetSecondsSinceEpoch();
m_Tags[SessionTag(tag, ts)] = std::make_shared<AESDecryption>(key);
}
}
void GarlicDestination::AddECIESx25519Key(const uint8_t *key, const uint8_t *tag) {
uint64_t t;
memcpy(&t, tag, 8);
AddECIESx25519Key(key, t);
}
void GarlicDestination::AddECIESx25519Key(const uint8_t *key, uint64_t tag) {
auto tagset = std::make_shared<SymmetricKeyTagSet>(this, key);
m_ECIESx25519Tags.emplace(tag, ECIESX25519AEADRatchetIndexTagset{0, tagset});
}
bool GarlicDestination::SubmitSessionKey(const uint8_t *key, const uint8_t *tag) {
AddSessionKey(key, tag);
return true;
}
void GarlicDestination::SubmitECIESx25519Key(const uint8_t *key, uint64_t tag) {
AddECIESx25519Key(key, tag);
}
void GarlicDestination::HandleGarlicMessage(std::shared_ptr<I2NPMessage> msg) {
uint8_t *buf = msg->GetPayload();
uint32_t length = bufbe32toh(buf);
if (length > msg->GetLength()) {
LogPrint(eLogWarning, "Garlic: Message length ", length, " exceeds I2NP message length ",
msg->GetLength());
return;
}
auto mod = length & 0x0f; // %16
buf += 4; // length
bool found = false;
if (SupportsEncryptionType(i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD))
// try ECIESx25519 tag
found = HandleECIESx25519TagMessage(buf, length);
if (!found) {
auto it = !mod ? m_Tags.find(SessionTag(buf)) : m_Tags.end(); // AES block is multiple of 16
// AES tag might be used even if encryption type is not ElGamal/AES
if (it != m_Tags.end()) // try AES tag
{
// tag found. Use AES
auto decryption = it->second;
m_Tags.erase(it); // tag might be used only once
if (length >= 32) {
uint8_t iv[32]; // IV is first 16 bytes
SHA256(buf, 32, iv);
decryption->SetIV(iv);
decryption->Decrypt(buf + 32, length - 32, buf + 32);
HandleAESBlock(buf + 32, length - 32, decryption, msg->from);
found = true;
} else
LogPrint(eLogWarning, "Garlic: Message length ", length, " is less than 32 bytes");
}
if (!found) // assume new session
{
// AES tag not found. Handle depending on encryption type
// try ElGamal/AES first if leading block is 514
ElGamalBlock elGamal;
if (mod == 2 && length >= 514 && SupportsEncryptionType(i2p::data::CRYPTO_KEY_TYPE_ELGAMAL) &&
Decrypt(buf, (uint8_t * ) & elGamal, i2p::data::CRYPTO_KEY_TYPE_ELGAMAL)) {
auto decryption = std::make_shared<AESDecryption>(elGamal.sessionKey);
uint8_t iv[32]; // IV is first 16 bytes
SHA256(elGamal.preIV, 32, iv);
decryption->SetIV(iv);
decryption->Decrypt(buf + 514, length - 514, buf + 514);
HandleAESBlock(buf + 514, length - 514, decryption, msg->from);
} else if (SupportsEncryptionType(i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD)) {
// otherwise ECIESx25519
auto session = std::make_shared<ECIESX25519AEADRatchetSession>(this, false); // incoming
if (!session->HandleNextMessage(buf, length, nullptr, 0)) {
// try to generate more tags for last tagset
if (m_LastTagset && (m_LastTagset->GetNextIndex() - m_LastTagset->GetTrimBehind() <
3 * ECIESX25519_MAX_NUM_GENERATED_TAGS)) {
uint64_t missingTag;
memcpy(&missingTag, buf, 8);
auto maxTags = std::max(m_NumRatchetInboundTags, ECIESX25519_MAX_NUM_GENERATED_TAGS);
LogPrint(eLogWarning, "Garlic: Trying to generate more ECIES-X25519-AEAD-Ratchet tags");
for (int i = 0; i < maxTags; i++) {
auto nextTag = AddECIESx25519SessionNextTag(m_LastTagset);
if (!nextTag) {
LogPrint(eLogError,
"Garlic: Can't create new ECIES-X25519-AEAD-Ratchet tag for last tagset");
break;
}
if (nextTag == missingTag) {
LogPrint(eLogDebug,
"Garlic: Missing ECIES-X25519-AEAD-Ratchet tag was generated");
if (m_LastTagset->HandleNextMessage(buf, length,
m_ECIESx25519Tags[nextTag].index))
found = true;
break;
}
}
if (!found) m_LastTagset = nullptr;
}
if (!found)
LogPrint(eLogError, "Garlic: Can't handle ECIES-X25519-AEAD-Ratchet message");
}
} else
LogPrint(eLogError, "Garlic: Failed to decrypt message");
}
}
}
bool GarlicDestination::HandleECIESx25519TagMessage(uint8_t *buf, size_t len) {
uint64_t tag;
memcpy(&tag, buf, 8);
auto it = m_ECIESx25519Tags.find(tag);
if (it != m_ECIESx25519Tags.end()) {
if (it->second.tagset->HandleNextMessage(buf, len, it->second.index))
m_LastTagset = it->second.tagset;
else
LogPrint(eLogError, "Garlic: Can't handle ECIES-X25519-AEAD-Ratchet message");
m_ECIESx25519Tags.erase(it);
return true;
}
return false;
}
void GarlicDestination::HandleAESBlock(uint8_t *buf, size_t len, std::shared_ptr<AESDecryption> decryption,
std::shared_ptr<i2p::tunnel::InboundTunnel> from) {
uint16_t tagCount = bufbe16toh(buf);
buf += 2;
len -= 2;
if (tagCount > 0) {
if (tagCount * 32 > len) {
LogPrint(eLogError, "Garlic: Tag count ", tagCount, " exceeds length ", len);
return;
}
uint32_t ts = i2p::util::GetSecondsSinceEpoch();
for (int i = 0; i < tagCount; i++)
m_Tags[SessionTag(buf + i * 32, ts)] = decryption;
}
buf += tagCount * 32;
len -= tagCount * 32;
uint32_t payloadSize = bufbe32toh(buf);
if (payloadSize > len) {
LogPrint(eLogError, "Garlic: Unexpected payload size ", payloadSize);
return;
}
buf += 4;
uint8_t *payloadHash = buf;
buf += 32;// payload hash.
if (*buf) // session key?
buf += 32; // new session key
buf++; // flag
// payload
uint8_t digest[32];
SHA256(buf, payloadSize, digest);
if (memcmp(payloadHash, digest, 32)) // payload hash doesn't match
{
LogPrint(eLogError, "Garlic: Wrong payload hash");
return;
}
HandleGarlicPayload(buf, payloadSize, from);
}
void GarlicDestination::HandleGarlicPayload(uint8_t *buf, size_t len,
std::shared_ptr<i2p::tunnel::InboundTunnel> from) {
if (len < 1) {
LogPrint(eLogError, "Garlic: Payload is too short");
return;
}
int numCloves = buf[0];
LogPrint(eLogDebug, "Garlic: ", numCloves, " cloves");
buf++;
len--;
for (int i = 0; i < numCloves; i++) {
const uint8_t *buf1 = buf;
// delivery instructions
uint8_t flag = buf[0];
buf++; // flag
if (flag & 0x80) // encrypted?
{
// TODO: implement
LogPrint(eLogWarning, "Garlic: Clove encrypted");
buf += 32;
}
ptrdiff_t offset = buf - buf1;
GarlicDeliveryType deliveryType = (GarlicDeliveryType) ((flag >> 5) & 0x03);
switch (deliveryType) {
case eGarlicDeliveryTypeLocal:
LogPrint(eLogDebug, "Garlic: Type local");
if (offset > (int) len) {
LogPrint(eLogError, "Garlic: Message is too short");
break;
}
HandleI2NPMessage(buf, len - offset);
break;
case eGarlicDeliveryTypeDestination:
LogPrint(eLogDebug, "Garlic: Type destination");
buf += 32; // destination. check it later or for multiple destinations
offset = buf - buf1;
if (offset > (int) len) {
LogPrint(eLogError, "Garlic: Message is too short");
break;
}
HandleI2NPMessage(buf, len - offset);
break;
case eGarlicDeliveryTypeTunnel: {
LogPrint(eLogDebug, "Garlic: Type tunnel");
// gwHash and gwTunnel sequence is reverted
uint8_t *gwHash = buf;
buf += 32;
offset = buf - buf1;
if (offset + 4 > (int) len) {
LogPrint(eLogError, "Garlic: Message is too short");
break;
}
uint32_t gwTunnel = bufbe32toh(buf);
buf += 4;
offset += 4;
auto msg = CreateI2NPMessage(buf, GetI2NPMessageLength(buf, len - offset), from);
if (from) // received through an inbound tunnel
{
std::shared_ptr<i2p::tunnel::OutboundTunnel> tunnel;
if (from->GetTunnelPool())
tunnel = from->GetTunnelPool()->GetNextOutboundTunnel();
else
LogPrint(eLogError, "Garlic: Tunnel pool is not set for inbound tunnel");
if (tunnel) // we have sent it through an outbound tunnel
tunnel->SendTunnelDataMsg(gwHash, gwTunnel, msg);
else
LogPrint(eLogWarning, "Garlic: No outbound tunnels available for garlic clove");
} else // received directly
i2p::transport::transports.SendMessage(gwHash, i2p::CreateTunnelGatewayMsg(gwTunnel,
msg)); // send directly
break;
}
case eGarlicDeliveryTypeRouter: {
uint8_t *ident = buf;
buf += 32;
offset = buf - buf1;
if (!from) // received directly
{
if (offset > (int) len) {
LogPrint(eLogError, "Garlic: Message is too short");
break;
}
i2p::transport::transports.SendMessage(ident,
CreateI2NPMessage(buf, GetI2NPMessageLength(buf,
len -
offset)));
} else
LogPrint(eLogWarning, "Garlic: Type router for inbound tunnels not supported");
break;
}
default:
LogPrint(eLogWarning, "Garlic: Unknown delivery type ", (int) deliveryType);
}
if (offset > (int) len) {
LogPrint(eLogError, "Garlic: Message is too short");
break;
}
buf += GetI2NPMessageLength(buf, len - offset); // I2NP
buf += 4; // CloveID
buf += 8; // Date
buf += 3; // Certificate
offset = buf - buf1;
if (offset > (int) len) {
LogPrint(eLogError, "Garlic: Clove is too long");
break;
}
len -= offset;
}
}
std::shared_ptr<I2NPMessage>
GarlicDestination::WrapMessageForRouter(std::shared_ptr<const i2p::data::RouterInfo> router,
std::shared_ptr<I2NPMessage> msg) {
if (router->GetEncryptionType() == i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD)
return WrapECIESX25519MessageForRouter(msg, router->GetIdentity()->GetEncryptionPublicKey());
else {
auto session = GetRoutingSession(router, false);
return session->WrapSingleMessage(msg);
}
}
std::shared_ptr<GarlicRoutingSession> GarlicDestination::GetRoutingSession(
std::shared_ptr<const i2p::data::RoutingDestination> destination, bool attachLeaseSet) {
if (destination->GetEncryptionType() == i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD &&
SupportsEncryptionType(i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD)) {
ECIESX25519AEADRatchetSessionPtr session;
uint8_t staticKey[32];
destination->Encrypt(nullptr, staticKey); // we are supposed to get static key
auto it = m_ECIESx25519Sessions.find(staticKey);
if (it != m_ECIESx25519Sessions.end()) {
session = it->second;
if (session->IsInactive(i2p::util::GetSecondsSinceEpoch())) {
LogPrint(eLogDebug, "Garlic: Session restarted");
session = nullptr;
}
}
if (!session) {
session = std::make_shared<ECIESX25519AEADRatchetSession>(this, true);
session->SetRemoteStaticKey(staticKey);
}
if (destination->IsDestination())
session->SetDestination(destination->GetIdentHash()); // TODO: remove
return session;
} else {
ElGamalAESSessionPtr session;
{
std::unique_lock<std::mutex> l(m_SessionsMutex);
auto it = m_Sessions.find(destination->GetIdentHash());
if (it != m_Sessions.end())
session = it->second;
}
if (!session) {
session = std::make_shared<ElGamalAESSession>(this, destination,
attachLeaseSet ? m_NumTags : 4,
attachLeaseSet); // specified num tags for connections and 4 for LS requests
std::unique_lock<std::mutex> l(m_SessionsMutex);
m_Sessions[destination->GetIdentHash()] = session;
}
return session;
}
return nullptr;
}
void GarlicDestination::CleanupExpiredTags() {
// incoming
uint32_t ts = i2p::util::GetSecondsSinceEpoch();
int numExpiredTags = 0;
for (auto it = m_Tags.begin(); it != m_Tags.end();) {
if (ts > it->first.creationTime + INCOMING_TAGS_EXPIRATION_TIMEOUT) {
numExpiredTags++;
it = m_Tags.erase(it);
} else
++it;
}
if (numExpiredTags > 0)
LogPrint(eLogDebug, "Garlic: ", numExpiredTags, " tags expired for ", GetIdentHash().ToBase64());
// outgoing
{
std::unique_lock<std::mutex> l(m_SessionsMutex);
for (auto it = m_Sessions.begin(); it != m_Sessions.end();) {
it->second->GetSharedRoutingPath(); // delete shared path if necessary
if (!it->second->CleanupExpiredTags()) {
LogPrint(eLogInfo, "Garlic: Routing session to ", it->first.ToBase32(), " deleted");
it->second->SetOwner(nullptr);
it = m_Sessions.erase(it);
} else
++it;
}
}
// delivery status sessions
{
std::unique_lock<std::mutex> l(m_DeliveryStatusSessionsMutex);
for (auto it = m_DeliveryStatusSessions.begin(); it != m_DeliveryStatusSessions.end();) {
if (it->second->GetOwner() != this)
it = m_DeliveryStatusSessions.erase(it);
else
++it;
}
}
// ECIESx25519
for (auto it = m_ECIESx25519Sessions.begin(); it != m_ECIESx25519Sessions.end();) {
if (it->second->CheckExpired(ts)) {
it->second->Terminate();
it = m_ECIESx25519Sessions.erase(it);
} else
++it;
}
numExpiredTags = 0;
for (auto it = m_ECIESx25519Tags.begin(); it != m_ECIESx25519Tags.end();) {
if (it->second.tagset->IsExpired(ts) || it->second.tagset->IsIndexExpired(it->second.index)) {
it->second.tagset->DeleteSymmKey(it->second.index);
it = m_ECIESx25519Tags.erase(it);
numExpiredTags++;
} else {
auto session = it->second.tagset->GetSession();
if (!session || session->IsTerminated()) {
it = m_ECIESx25519Tags.erase(it);
numExpiredTags++;
} else
++it;
}
}
if (numExpiredTags > 0)
LogPrint(eLogDebug, "Garlic: ", numExpiredTags, " ECIESx25519 tags expired for ",
GetIdentHash().ToBase64());
if (m_LastTagset && m_LastTagset->IsExpired(ts))
m_LastTagset = nullptr;
}
void GarlicDestination::RemoveDeliveryStatusSession(uint32_t msgID) {
std::unique_lock<std::mutex> l(m_DeliveryStatusSessionsMutex);
m_DeliveryStatusSessions.erase(msgID);
}
void GarlicDestination::DeliveryStatusSent(GarlicRoutingSessionPtr session, uint32_t msgID) {
std::unique_lock<std::mutex> l(m_DeliveryStatusSessionsMutex);
m_DeliveryStatusSessions[msgID] = session;
}
void GarlicDestination::HandleDeliveryStatusMessage(uint32_t msgID) {
GarlicRoutingSessionPtr session;
{
std::unique_lock<std::mutex> l(m_DeliveryStatusSessionsMutex);
auto it = m_DeliveryStatusSessions.find(msgID);
if (it != m_DeliveryStatusSessions.end()) {
session = it->second;
m_DeliveryStatusSessions.erase(it);
}
}
if (session) {
session->MessageConfirmed(msgID);
LogPrint(eLogDebug, "Garlic: Message ", msgID, " acknowledged");
}
}
void GarlicDestination::SetLeaseSetUpdated() {
{
std::unique_lock<std::mutex> l(m_SessionsMutex);
for (auto &it: m_Sessions)
it.second->SetLeaseSetUpdated();
}
for (auto &it: m_ECIESx25519Sessions)
it.second->SetLeaseSetUpdated();
}
void GarlicDestination::ProcessGarlicMessage(std::shared_ptr<I2NPMessage> msg) {
HandleGarlicMessage(msg);
}
void GarlicDestination::ProcessDeliveryStatusMessage(std::shared_ptr<I2NPMessage> msg) {
uint32_t msgID = bufbe32toh(msg->GetPayload() + DELIVERY_STATUS_MSGID_OFFSET);
HandleDeliveryStatusMessage(msgID);
}
void GarlicDestination::SaveTags() {
if (m_Tags.empty()) return;
std::string ident = GetIdentHash().ToBase32();
std::string path = i2p::fs::DataDirPath("tags", (ident + ".tags"));
std::ofstream f(path, std::ofstream::binary | std::ofstream::out | std::ofstream::trunc);
uint32_t ts = i2p::util::GetSecondsSinceEpoch();
// 4 bytes timestamp, 32 bytes tag, 32 bytes key
for (auto it: m_Tags) {
if (ts < it.first.creationTime + INCOMING_TAGS_EXPIRATION_TIMEOUT) {
f.write((char *) &it.first.creationTime, 4);
f.write((char *) it.first.data(), 32);
f.write((char *) it.second->GetKey().data(), 32);
}
}
}
void GarlicDestination::LoadTags() {
std::string ident = GetIdentHash().ToBase32();
std::string path = i2p::fs::DataDirPath("tags", (ident + ".tags"));
uint32_t ts = i2p::util::GetSecondsSinceEpoch();
if (ts < i2p::fs::GetLastUpdateTime(path) + INCOMING_TAGS_EXPIRATION_TIMEOUT) {
// might contain non-expired tags
std::ifstream f(path, std::ifstream::binary);
if (f) {
std::map<i2p::crypto::AESKey, std::shared_ptr<AESDecryption> > keys;
// 4 bytes timestamp, 32 bytes tag, 32 bytes key
while (!f.eof()) {
uint32_t t;
uint8_t tag[32], key[32];
f.read((char *) &t, 4);
if (f.eof()) break;
if (ts < t + INCOMING_TAGS_EXPIRATION_TIMEOUT) {
f.read((char *) tag, 32);
f.read((char *) key, 32);
} else
f.seekg(64, std::ios::cur); // skip
if (f.eof()) break;
std::shared_ptr<AESDecryption> decryption;
auto it = keys.find(key);
if (it != keys.end())
decryption = it->second;
else
decryption = std::make_shared<AESDecryption>(key);
m_Tags.insert(std::make_pair(SessionTag(tag, ts), decryption));
}
if (!m_Tags.empty())
LogPrint(eLogInfo, "Garlic: ", m_Tags.size(), " tags loaded for ", ident);
}
}
i2p::fs::Remove(path);
}
void CleanUpTagsFiles() {
std::vector<std::string> files;
i2p::fs::ReadDir(i2p::fs::DataDirPath("tags"), files);
uint32_t ts = i2p::util::GetSecondsSinceEpoch();
for (auto it: files)
if (ts >= i2p::fs::GetLastUpdateTime(it) + INCOMING_TAGS_EXPIRATION_TIMEOUT)
i2p::fs::Remove(it);
}
void GarlicDestination::HandleECIESx25519GarlicClove(const uint8_t *buf, size_t len) {
const uint8_t *buf1 = buf;
uint8_t flag = buf[0];
buf++; // flag
GarlicDeliveryType deliveryType = (GarlicDeliveryType) ((flag >> 5) & 0x03);
switch (deliveryType) {
case eGarlicDeliveryTypeDestination:
LogPrint(eLogDebug, "Garlic: Type destination");
buf += 32; // TODO: check destination
#if (__cplusplus >= 201703L) // C++ 17 or higher
[[fallthrough]];
#endif
// no break here
case eGarlicDeliveryTypeLocal: {
LogPrint(eLogDebug, "Garlic: Type local");
I2NPMessageType typeID = (I2NPMessageType) (buf[0]);
buf++; // typeid
int32_t msgID = bufbe32toh(buf);
buf += 4; // msgID
buf += 4; // expiration
ptrdiff_t offset = buf - buf1;
if (offset <= (int) len)
HandleCloveI2NPMessage(typeID, buf, len - offset, msgID);
else
LogPrint(eLogError, "Garlic: Clove is too long");
break;
}
case eGarlicDeliveryTypeTunnel: {
LogPrint(eLogDebug, "Garlic: Type tunnel");
// gwHash and gwTunnel sequence is reverted
const uint8_t *gwHash = buf;
buf += 32;
ptrdiff_t offset = buf - buf1;
if (offset + 13 > (int) len) {
LogPrint(eLogError, "Garlic: Message is too short");
break;
}
uint32_t gwTunnel = bufbe32toh(buf);
buf += 4;
I2NPMessageType typeID = (I2NPMessageType) (buf[0]);
buf++; // typeid
uint32_t msgID = bufbe32toh(buf);
buf += 4; // msgID
buf += 4; // expiration
offset += 13;
if (GetTunnelPool()) {
auto tunnel = GetTunnelPool()->GetNextOutboundTunnel();
if (tunnel)
tunnel->SendTunnelDataMsg(gwHash, gwTunnel,
CreateI2NPMessage(typeID, buf, len - offset, msgID));
else
LogPrint(eLogWarning, "Garlic: No outbound tunnels available for garlic clove");
} else
LogPrint(eLogError, "Garlic: Tunnel pool is not set for inbound tunnel");
break;
}
default:
LogPrint(eLogWarning, "Garlic: Unexpected delivery type ", (int) deliveryType);
}
}
uint64_t GarlicDestination::AddECIESx25519SessionNextTag(ReceiveRatchetTagSetPtr tagset) {
auto index = tagset->GetNextIndex();
uint64_t tag = tagset->GetNextSessionTag();
if (tag)
m_ECIESx25519Tags.emplace(tag, ECIESX25519AEADRatchetIndexTagset{index, tagset});
return tag;
}
void
GarlicDestination::AddECIESx25519Session(const uint8_t *staticKey, ECIESX25519AEADRatchetSessionPtr session) {
i2p::data::Tag<32> staticKeyTag(staticKey);
auto it = m_ECIESx25519Sessions.find(staticKeyTag);
if (it != m_ECIESx25519Sessions.end()) {
if (it->second->CanBeRestarted(i2p::util::GetSecondsSinceEpoch())) {
it->second->Terminate(); // detach
m_ECIESx25519Sessions.erase(it);
} else {
LogPrint(eLogInfo, "Garlic: ECIESx25519 session with static key ", staticKeyTag.ToBase64(),
" already exists");
return;
}
}
m_ECIESx25519Sessions.emplace(staticKeyTag, session);
}
void GarlicDestination::RemoveECIESx25519Session(const uint8_t *staticKey) {
auto it = m_ECIESx25519Sessions.find(staticKey);
if (it != m_ECIESx25519Sessions.end()) {
it->second->Terminate();
m_ECIESx25519Sessions.erase(it);
}
}
uint8_t *GarlicDestination::GetPayloadBuffer() {
if (!m_PayloadBuffer)
m_PayloadBuffer = new uint8_t[I2NP_MAX_MESSAGE_SIZE];
return m_PayloadBuffer;
}
}
}