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introuduce GarlicDestination

pull/102/head
orignal 10 years ago
parent
commit
3787dc80d9
  1. 66
      Garlic.cpp
  2. 19
      Garlic.h

66
Garlic.cpp

@ -14,6 +14,72 @@ namespace i2p
{ {
namespace garlic namespace garlic
{ {
GarlicDestination::~GarlicDestination ()
{
for (auto it: m_Tags)
if (it.second) delete[] it.second;
}
void GarlicDestination::AddSessionKey (const uint8_t * key, const uint8_t * tag)
{
if (key)
{
uint8_t * newKey = new uint8_t[32];
memcpy (newKey, key, 32);
m_Tags[SessionTag(tag)] = newKey;
}
}
void GarlicDestination::HandleGarlicMessage (I2NPMessage * msg)
{
uint8_t * buf = msg->GetPayload ();
uint32_t length = be32toh (*(uint32_t *)buf);
buf += 4; // lentgh
auto it = m_Tags.find (SessionTag(buf));
if (it != m_Tags.end ())
{
// tag found. Use AES
uint8_t iv[32]; // IV is first 16 bytes
CryptoPP::SHA256().CalculateDigest(iv, buf, 32);
if (it->second) // separate key
{
i2p::crypto::CBCDecryption decryption;
decryption.SetKey (it->second);
decryption.SetIV (iv);
decryption.Decrypt (buf + 32, length - 32, buf + 32);
delete[] it->second;
}
else // common key
{
m_Decryption.SetIV (iv);
m_Decryption.Decrypt (buf + 32, length - 32, buf + 32);
}
m_Tags.erase (it); // tag might be used only once
}
else
{
// tag not found. Use ElGamal
if (m_LocalDestination)
{
ElGamalBlock elGamal;
if (i2p::crypto::ElGamalDecrypt (m_LocalDestination->GetEncryptionPrivateKey (), buf, (uint8_t *)&elGamal, true))
{
m_Decryption.SetKey (elGamal.sessionKey);
uint8_t iv[32]; // IV is first 16 bytes
CryptoPP::SHA256().CalculateDigest(iv, elGamal.preIV, 32);
m_Decryption.SetIV (iv);
m_Decryption.Decrypt(buf + 514, length - 514, buf + 514);
}
else
LogPrint ("Failed to decrypt garlic");
}
else
LogPrint ("Can't use ElGamal without local destination");
}
DeleteI2NPMessage (msg);
}
GarlicRoutingSession::GarlicRoutingSession (const i2p::data::RoutingDestination * destination, int numTags): GarlicRoutingSession::GarlicRoutingSession (const i2p::data::RoutingDestination * destination, int numTags):
m_Destination (destination), m_IsAcknowledged (false), m_NumTags (numTags), m_Destination (destination), m_IsAcknowledged (false), m_NumTags (numTags),
m_NextTag (-1), m_SessionTags (0), m_TagsCreationTime (0), m_LocalLeaseSet (nullptr) m_NextTag (-1), m_SessionTags (0), m_TagsCreationTime (0), m_LocalLeaseSet (nullptr)

19
Garlic.h

@ -13,6 +13,7 @@
#include "LeaseSet.h" #include "LeaseSet.h"
#include "Tunnel.h" #include "Tunnel.h"
#include "Queue.h" #include "Queue.h"
#include "Identity.h"
namespace i2p namespace i2p
{ {
@ -39,6 +40,24 @@ namespace garlic
const int TAGS_EXPIRATION_TIMEOUT = 900; // 15 minutes const int TAGS_EXPIRATION_TIMEOUT = 900; // 15 minutes
typedef i2p::data::Tag<32> SessionTag; typedef i2p::data::Tag<32> SessionTag;
class GarlicDestination
{
public:
GarlicDestination (i2p::data::LocalDestination * localDestination = nullptr):
m_LocalDestination (localDestination) {};
~GarlicDestination ();
void AddSessionKey (const uint8_t * key, const uint8_t * tag); // one tag
void HandleGarlicMessage (I2NPMessage * msg);
private:
i2p::crypto::CBCDecryption m_Decryption;
std::map<SessionTag, const uint8_t *> m_Tags; // tag->key, if null use key from decryption
i2p::data::LocalDestination * m_LocalDestination;
};
class GarlicRoutingSession class GarlicRoutingSession
{ {
public: public:

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