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Code Issues Releases Activity

send SessionConfirmed

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orignal 2018-06-14 15:29:36 -04:00
parent 6b37a41e00
commit 2bd7a92d20
2 changed files with 109 additions and 30 deletions
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128
libi2pd/NTCP2.cpp
View File

@ -17,7 +17,7 @@ namespace transport
TransportSession (in_RemoteRouter, 30),
m_Server (server), m_Socket (m_Server.GetService ()),
m_IsEstablished (false), m_IsTerminated (false),
m_SessionRequestBuffer (nullptr), m_SessionCreatedBuffer (nullptr)
m_SessionRequestBuffer (nullptr), m_SessionCreatedBuffer (nullptr), m_SessionConfirmedBuffer (nullptr)
{
auto addr = in_RemoteRouter->GetNTCPAddress ();
if (addr->ntcp2)
@ -33,6 +33,7 @@ namespace transport
{
delete[] m_SessionRequestBuffer;
delete[] m_SessionCreatedBuffer;
delete[] m_SessionConfirmedBuffer;
}
void NTCP2Session::Terminate ()
@ -51,6 +52,19 @@ namespace transport
m_Server.GetService ().post (std::bind (&NTCP2Session::Terminate, shared_from_this ()));
}
void NTCP2Session::MixKey (const uint8_t * inputKeyMaterial, uint8_t * derived)
{
// temp_key = HMAC-SHA256(ck, input_key_material)
uint8_t tempKey[32]; unsigned int len;
HMAC(EVP_sha256(), m_CK, 32, inputKeyMaterial, 32, tempKey, &len);
// ck = HMAC-SHA256(temp_key, byte(0x01))
static uint8_t one[1] = { 1 };
HMAC(EVP_sha256(), tempKey, 32, one, 1, m_CK, &len);
// derived = HMAC-SHA256(temp_key, ck || byte(0x02))
m_CK[32] = 2;
HMAC(EVP_sha256(), tempKey, 32, m_CK, 33, derived, &len);
}
void NTCP2Session::KeyDerivationFunction1 (const uint8_t * rs, const uint8_t * pub, uint8_t * derived)
{
static const char protocolName[] = "Noise_XK_25519_ChaChaPoly_SHA256"; // 32 bytes
@ -68,15 +82,7 @@ namespace transport
BN_CTX * ctx = BN_CTX_new ();
i2p::crypto::GetEd25519 ()->ScalarMul (rs, m_ExpandedPrivateKey, inputKeyMaterial, ctx); // rs*priv
BN_CTX_free (ctx);
// temp_key = HMAC-SHA256(ck, input_key_material)
uint8_t tempKey[32]; unsigned int len;
HMAC(EVP_sha256(), m_CK, 32, inputKeyMaterial, 32, tempKey, &len);
// ck = HMAC-SHA256(temp_key, byte(0x01))
inputKeyMaterial[0] = 1;
HMAC(EVP_sha256(), tempKey, 32, inputKeyMaterial, 1, m_CK, &len);
// derived = HMAC-SHA256(temp_key, ck || byte(0x02))
m_CK[32] = 2;
HMAC(EVP_sha256(), tempKey, 32, m_CK, 33, derived, &len);
MixKey (inputKeyMaterial, derived);
}
void NTCP2Session::KeyDerivationFunction2 (const uint8_t * pub, const uint8_t * sessionRequest, size_t sessionRequestLen, uint8_t * derived)
@ -101,15 +107,16 @@ namespace transport
BN_CTX * ctx = BN_CTX_new ();
i2p::crypto::GetEd25519 ()->ScalarMul (pub, m_ExpandedPrivateKey, inputKeyMaterial, ctx);
BN_CTX_free (ctx);
// temp_key = HMAC-SHA256(ck, input_key_material)
uint8_t tempKey[32]; unsigned int len;
HMAC(EVP_sha256(), m_CK, 32, inputKeyMaterial, 32, tempKey, &len);
// ck = HMAC-SHA256(temp_key, byte(0x01))
inputKeyMaterial[0] = 1;
HMAC(EVP_sha256(), tempKey, 32, inputKeyMaterial, 1, m_CK, &len);
// derived = HMAC-SHA256(temp_key, ck || byte(0x02))
m_CK[32] = 2;
HMAC(EVP_sha256(), tempKey, 32, m_CK, 33, derived, &len);
MixKey (inputKeyMaterial, derived);
}
void NTCP2Session::KeyDerivationFunction3 (const uint8_t * staticPrivKey, uint8_t * derived)
{
uint8_t inputKeyMaterial[32];
BN_CTX * ctx = BN_CTX_new ();
i2p::crypto::GetEd25519 ()->ScalarMul (m_Y, staticPrivKey, inputKeyMaterial, ctx);
BN_CTX_free (ctx);
MixKey (inputKeyMaterial, derived);
}
void NTCP2Session::CreateEphemeralKey (uint8_t * pub)
@ -185,23 +192,30 @@ namespace transport
}
else
{
LogPrint (eLogInfo, "NTCP2: SessionCreated received ", bytes_transferred);
uint8_t y[32];
LogPrint (eLogDebug, "NTCP2: SessionCreated received ", bytes_transferred);
m_SessionCreatedBufferLen = 56;
// decrypt Y
i2p::crypto::CBCDecryption decryption;
decryption.SetKey (GetRemoteIdentity ()->GetIdentHash ());
decryption.SetIV (m_IV);
decryption.Decrypt (m_SessionCreatedBuffer, 32, y);
// decryption key for next block
uint8_t key[32];
KeyDerivationFunction2 (y, m_SessionRequestBuffer, m_SessionRequestBufferLen, key);
decryption.Decrypt (m_SessionCreatedBuffer, 32, m_Y);
// decryption key for next block (m_K)
KeyDerivationFunction2 (m_Y, m_SessionRequestBuffer, m_SessionRequestBufferLen, m_K);
// decrypt and verify MAC
uint8_t payload[8];
uint8_t nonce[12];
memset (nonce, 0, 12); // set nonce to zero
if (i2p::crypto::AEADChaCha20Poly1305 (m_SessionCreatedBuffer + 32, 8, m_H, 32, key, nonce, payload, 8, false)) // decrypt
if (i2p::crypto::AEADChaCha20Poly1305 (m_SessionCreatedBuffer + 32, 8, m_H, 32, m_K, nonce, payload, 8, false)) // decrypt
{
// TODO:
uint16_t paddingLen = bufbe16toh(payload);
LogPrint (eLogDebug, "NTCP2: padding length ", paddingLen);
if (paddingLen > 0)
{
boost::asio::async_read (m_Socket, boost::asio::buffer(m_SessionCreatedBuffer + 56, paddingLen), boost::asio::transfer_all (),
std::bind(&NTCP2Session::HandleSessionCreatedPaddingReceived, shared_from_this (), std::placeholders::_1, std::placeholders::_2));
}
else
SendSessionConfirmed ();
}
else
{
@ -211,6 +225,66 @@ namespace transport
}
}
void NTCP2Session::HandleSessionCreatedPaddingReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred)
{
if (ecode)
{
LogPrint (eLogWarning, "NTCP2: SessionCreated padding read error: ", ecode.message ());
Terminate ();
}
else
{
m_SessionCreatedBufferLen += bytes_transferred;
SendSessionConfirmed ();
}
}
void NTCP2Session::SendSessionConfirmed ()
{
// update AD
uint8_t h[80];
memcpy (h, m_H, 32);
memcpy (h + 32, m_SessionCreatedBuffer + 32, 24); // encrypted payload
SHA256 (h, 56, h);
int paddingLength = m_SessionCreatedBufferLen - 56;
if (paddingLength > 0)
{
std::vector<uint8_t> h1(paddingLength + 32);
memcpy (h1.data (), h, 32);
memcpy (h1.data () + 32, m_SessionCreatedBuffer + 56, paddingLength);
SHA256 (h1.data (), paddingLength + 32, h);
}
// part1 48 bytes
uint8_t s[32]; // public static
CreateEphemeralKey (s); // TODO: take it from RouterContext
m_SessionConfirmedBuffer = new uint8_t[2048]; // TODO: actual size
uint8_t nonce[12];
memset (nonce, 0, 4); htole64buf (nonce + 4, 1); // set nonce to 1
i2p::crypto::AEADChaCha20Poly1305 (s, 32, h, 32, m_K, nonce, m_SessionConfirmedBuffer, 48, true); // encrypt
// part 2
// update AD again
memcpy (h + 32, m_SessionConfirmedBuffer, 48);
SHA256 (h, 80, m_H);
size_t m3p2Len = 550; // TODO: actual size
uint8_t buf[550];
memset (buf, 0, m3p2Len - 16); // TODO: fill
uint8_t key[32];
KeyDerivationFunction3 (m_ExpandedPrivateKey, key); // TODO: take it from RouterContext
memset (nonce, 0, 12); // set nonce to 0 again
i2p::crypto::AEADChaCha20Poly1305 (buf, m3p2Len - 16, m_H, 32, key, nonce, m_SessionConfirmedBuffer + 48, m3p2Len, true); // encrypt
// send message
boost::asio::async_write (m_Socket, boost::asio::buffer (m_SessionConfirmedBuffer, m3p2Len + 48), boost::asio::transfer_all (),
std::bind(&NTCP2Session::HandleSessionConfirmedSent, shared_from_this (), std::placeholders::_1, std::placeholders::_2));
}
void NTCP2Session::HandleSessionConfirmedSent (const boost::system::error_code& ecode, std::size_t bytes_transferred)
{
LogPrint (eLogDebug, "NTCP2: SessionConfirmed sent");
Terminate (); // TODO
}
void NTCP2Session::ClientLogin ()
{
SendSessionRequest ();

11
libi2pd/NTCP2.h
View File

@ -29,14 +29,19 @@ namespace transport
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 KeyDerivationFunction3 (const uint8_t * staticPrivKey, uint8_t * derived); // for SessionConfirmed part 2
void CreateEphemeralKey (uint8_t * pub);
void SendSessionRequest ();
void SendSessionConfirmed ();
void HandleSessionRequestSent (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);
private:
@ -45,9 +50,9 @@ namespace transport
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*/;
uint8_t * m_SessionRequestBuffer, * m_SessionCreatedBuffer;
size_t m_SessionRequestBufferLen;
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_SessionRequestBuffer, * m_SessionCreatedBuffer, * m_SessionConfirmedBuffer;
size_t m_SessionRequestBufferLen, m_SessionCreatedBufferLen;
};
class NTCP2Server