Archives
/
i2pd
mirror of https://github.com/PurpleI2P/i2pd
2
0
Fork 0
Code Issues Projects Releases Wiki Activity

process SessionRequest and send SessionCreated for NTCP2

Browse Source
pull/1197/head
orignal 6 years ago
parent 4351a2736c
commit b5682012d3
3 changed files with 123 additions and 15 deletions
Show Stats Download Patch File Download Diff File

2
libi2pd/Crypto.cpp
Unescape Escape View File

@ -8,6 +8,7 @@
#include <openssl/crypto.h>
#include "TunnelBase.h"
#include <openssl/ssl.h>
#include "Crypto.h"
#if LEGACY_OPENSSL
#include "ChaCha20.h"
#include "Poly1305.h"
@ -16,7 +17,6 @@
#endif
#include "I2PEndian.h"
#include "Log.h"
#include "Crypto.h"
namespace i2p
{

123
libi2pd/NTCP2.cpp
Unescape Escape View File

@ -66,7 +66,7 @@ namespace transport
HMAC(EVP_sha256(), tempKey, 32, m_CK, 33, derived, &len);
}
void NTCP2Session::KeyDerivationFunction1 (const uint8_t * rs, const uint8_t * pub, uint8_t * derived)
void NTCP2Session::KeyDerivationFunction1 (const uint8_t * rs, const uint8_t * priv, const uint8_t * pub, uint8_t * derived)
{
static const char protocolName[] = "Noise_XK_25519_ChaChaPoly_SHA256"; // 32 bytes
uint8_t h[64];
@ -81,12 +81,12 @@ namespace transport
// x25519 between rs and priv
uint8_t inputKeyMaterial[32];
BN_CTX * ctx = BN_CTX_new ();
i2p::crypto::GetEd25519 ()->ScalarMul (rs, m_ExpandedPrivateKey, inputKeyMaterial, ctx); // rs*priv
i2p::crypto::GetEd25519 ()->ScalarMul (rs, priv, inputKeyMaterial, ctx); // rs*priv
BN_CTX_free (ctx);
MixKey (inputKeyMaterial, derived);
}
void NTCP2Session::KeyDerivationFunction2 (const uint8_t * pub, const uint8_t * sessionRequest, size_t sessionRequestLen, uint8_t * derived)
void NTCP2Session::KeyDerivationFunction2 (const uint8_t * priv, const uint8_t * pub, const uint8_t * sessionRequest, size_t sessionRequestLen, uint8_t * derived)
{
uint8_t h[64];
memcpy (h, m_H, 32);
@ -106,7 +106,7 @@ namespace transport
// x25519 between remote pub and priv
uint8_t inputKeyMaterial[32];
BN_CTX * ctx = BN_CTX_new ();
i2p::crypto::GetEd25519 ()->ScalarMul (pub, m_ExpandedPrivateKey, inputKeyMaterial, ctx);
i2p::crypto::GetEd25519 ()->ScalarMul (pub, priv, inputKeyMaterial, ctx);
BN_CTX_free (ctx);
MixKey (inputKeyMaterial, derived);
}
@ -122,11 +122,9 @@ namespace transport
void NTCP2Session::CreateEphemeralKey (uint8_t * pub)
{
uint8_t key[32];
RAND_bytes (key, 32);
i2p::crypto::Ed25519::ExpandPrivateKey (key, m_ExpandedPrivateKey);
RAND_bytes (m_EphemeralPrivateKey, 32);
BN_CTX * ctx = BN_CTX_new ();
i2p::crypto::GetEd25519 ()->ScalarMulB (m_ExpandedPrivateKey, pub, ctx);
i2p::crypto::GetEd25519 ()->ScalarMulB (m_EphemeralPrivateKey, pub, ctx);
BN_CTX_free (ctx);
}
@ -148,7 +146,7 @@ namespace transport
encryption.GetIV (m_IV); // save IV for SessionCreated
// encryption key for next block
uint8_t key[32];
KeyDerivationFunction1 (m_RemoteStaticKey, x, key);
KeyDerivationFunction1 (m_RemoteStaticKey, m_EphemeralPrivateKey, x, key);
// fill options
uint8_t options[32]; // actual options size is 16 bytes
memset (options, 0, 16);
@ -184,6 +182,96 @@ namespace transport
}
}
void NTCP2Session::HandleSessionRequestReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred)
{
(void) bytes_transferred;
if (ecode)
{
LogPrint (eLogWarning, "NTCP2: SessionRequest read error: ", ecode.message ());
Terminate ();
}
else
{
// decrypt X
i2p::crypto::CBCDecryption decryption;
decryption.SetKey (i2p::context.GetIdentHash ());
decryption.SetIV (i2p::context.GetNTCP2IV ());
decryption.Decrypt (m_SessionRequestBuffer, 32, m_Y);
decryption.GetIV (m_IV); // save IV for SessionCreated
// decryption key for next block
uint8_t key[32];
KeyDerivationFunction1 (m_Y, i2p::context.GetNTCP2StaticPrivateKey (), m_Y, key);
// verify MAC and decrypt options block (32 bytes), use m_H as AD
uint8_t nonce[12], options[16];
memset (nonce, 0, 12); // set nonce to zero
if (i2p::crypto::AEADChaCha20Poly1305 (m_SessionRequestBuffer + 32, 16, m_H, 32, key, nonce, options, 16, false)) // decrypt
{
uint16_t version = bufbe16toh (options);
if (version == 2)
{
uint16_t paddingLen = bufbe16toh (options + 2);
m_SessionRequestBufferLen = paddingLen + 64;
// TODO: check tsA
if (paddingLen > 0)
boost::asio::async_read (m_Socket, boost::asio::buffer(m_SessionRequestBuffer + 64, paddingLen), boost::asio::transfer_all (),
std::bind(&NTCP2Session::HandleSessionRequestPaddingReceived, shared_from_this (), std::placeholders::_1, std::placeholders::_2));
else
SendSessionCreated ();
}
else
{
LogPrint (eLogWarning, "NTCP2: SessionRequest version mismatch ", version);
Terminate ();
}
}
else
{
LogPrint (eLogWarning, "NTCP2: SessionRequest AEAD verification failed ");
Terminate ();
}
}
}
void NTCP2Session::HandleSessionRequestPaddingReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred)
{
if (ecode)
{
LogPrint (eLogWarning, "NTCP2: SessionRequest padding read error: ", ecode.message ());
Terminate ();
}
else
SendSessionCreated ();
}
void NTCP2Session::SendSessionCreated ()
{
m_SessionCreatedBuffer = new uint8_t[287]; // TODO: determine actual max size
// generate key pair (y)
uint8_t y[32];
CreateEphemeralKey (y);
// encrypt Y
i2p::crypto::CBCEncryption encryption;
encryption.SetKey (i2p::context.GetIdentHash ());
encryption.SetIV (m_IV);
encryption.Encrypt (y, 32, m_SessionCreatedBuffer);
// encryption key for next block (m_K)
KeyDerivationFunction2 (m_EphemeralPrivateKey, m_Y, m_SessionRequestBuffer, m_SessionRequestBufferLen, m_K);
auto paddingLen = rand () % (287 - 56);
uint8_t options[8];
memset (options, 0, 8);
htobe16buf (options, paddingLen); // padLen
htobe32buf (options + 4, i2p::util::GetSecondsSinceEpoch ()); // tsB
// sign and encrypt options, use m_H as AD
uint8_t nonce[12];
memset (nonce, 0, 12); // set nonce to zero
i2p::crypto::AEADChaCha20Poly1305 (options, 8, m_H, 32, m_K, nonce, m_SessionCreatedBuffer + 32, 24, true); // encrypt
// fill padding
RAND_bytes (m_SessionCreatedBuffer + 56, paddingLen);
// send message
boost::asio::async_write (m_Socket, boost::asio::buffer (m_SessionCreatedBuffer, paddingLen + 56), boost::asio::transfer_all (),
std::bind(&NTCP2Session::HandleSessionCreatedSent, shared_from_this (), std::placeholders::_1, std::placeholders::_2));
}
void NTCP2Session::HandleSessionCreatedReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred)
{
if (ecode)
@ -201,7 +289,7 @@ namespace transport
decryption.SetIV (m_IV);
decryption.Decrypt (m_SessionCreatedBuffer, 32, m_Y);
// decryption key for next block (m_K)
KeyDerivationFunction2 (m_Y, m_SessionRequestBuffer, m_SessionRequestBufferLen, m_K);
KeyDerivationFunction2 (m_EphemeralPrivateKey, m_Y, m_SessionRequestBuffer, m_SessionRequestBufferLen, m_K);
// decrypt and verify MAC
uint8_t payload[8];
uint8_t nonce[12];
@ -240,6 +328,7 @@ namespace transport
}
}
void NTCP2Session::SendSessionConfirmed ()
{
// update AD
@ -287,11 +376,25 @@ namespace transport
Terminate (); // TODO
}
void NTCP2Session::HandleSessionCreatedSent (const boost::system::error_code& ecode, std::size_t bytes_transferred)
{
LogPrint (eLogDebug, "NTCP2: SessionCreated sent");
Terminate (); // TODO
}
void NTCP2Session::ClientLogin ()
{
SendSessionRequest ();
}
void NTCP2Session::ServerLogin ()
{
m_SessionRequestBuffer = new uint8_t[287]; // 287 bytes max for now
boost::asio::async_read (m_Socket, boost::asio::buffer(m_SessionRequestBuffer, 64), boost::asio::transfer_all (),
std::bind(&NTCP2Session::HandleSessionRequestReceived, shared_from_this (),
std::placeholders::_1, std::placeholders::_2));
}
NTCP2Server::NTCP2Server ():
m_IsRunning (false), m_Thread (nullptr), m_Work (m_Service)
{

13
libi2pd/NTCP2.h
Unescape Escape View File

@ -25,20 +25,25 @@ namespace transport
boost::asio::ip::tcp::socket& GetSocket () { return m_Socket; };
void ClientLogin (); // Alice
void ServerLogin (); // Bob
void SendI2NPMessages (const std::vector<std::shared_ptr<I2NPMessage> >& msgs) {}; // TODO
private:
void MixKey (const uint8_t * inputKeyMaterial, uint8_t * derived);
void KeyDerivationFunction1 (const uint8_t * rs, const uint8_t * pub, uint8_t * derived); // for SessionRequest
void KeyDerivationFunction2 (const uint8_t * pub, const uint8_t * sessionRequest, size_t sessionRequestLen, uint8_t * derived); // for SessionCreate
void KeyDerivationFunction1 (const uint8_t * rs, const uint8_t * priv, const uint8_t * pub, uint8_t * derived); // for SessionRequest
void KeyDerivationFunction2 (const uint8_t * priv, const uint8_t * pub, const uint8_t * sessionRequest, size_t sessionRequestLen, uint8_t * derived); // for SessionCreate
void KeyDerivationFunction3 (const uint8_t * staticPrivKey, uint8_t * derived); // for SessionConfirmed part 2
void CreateEphemeralKey (uint8_t * pub);
void SendSessionRequest ();
void SendSessionCreated ();
void SendSessionConfirmed ();
void HandleSessionRequestSent (const boost::system::error_code& ecode, std::size_t bytes_transferred);
void HandleSessionRequestReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred);
void HandleSessionRequestPaddingReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred);
void HandleSessionCreatedSent (const boost::system::error_code& ecode, std::size_t bytes_transferred);
void HandleSessionCreatedReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred);
void HandleSessionCreatedPaddingReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred);
void HandleSessionConfirmedSent (const boost::system::error_code& ecode, std::size_t bytes_transferred);
@ -49,8 +54,8 @@ namespace transport
boost::asio::ip::tcp::socket m_Socket;
bool m_IsEstablished, m_IsTerminated;
uint8_t m_ExpandedPrivateKey[64]; // x25519 ephemeral key
uint8_t m_RemoteStaticKey[32], m_IV[16], m_H[32] /*h*/, m_CK[33] /*ck*/, m_K[32] /* derived after SessionCreated */, m_Y[32];
uint8_t m_EphemeralPrivateKey[32]; // x25519
uint8_t m_RemoteStaticKey[32], m_IV[16], m_H[32] /*h*/, m_CK[33] /*ck*/, m_K[32] /* derived after SessionCreated */, m_Y[32] /* or X for Bob */;
uint8_t * m_SessionRequestBuffer, * m_SessionCreatedBuffer, * m_SessionConfirmedBuffer;
size_t m_SessionRequestBufferLen, m_SessionCreatedBufferLen;
};

Write Preview
Loading…
Cancel
Save