mirror of
https://github.com/PurpleI2P/i2pd.git
synced 2024-10-31 09:20:38 +00:00
472 lines
16 KiB
C++
472 lines
16 KiB
C++
#include <openssl/rand.h>
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#include <openssl/sha.h>
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#include <openssl/hmac.h>
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#include <stdlib.h>
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#include <vector>
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#include "Log.h"
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#include "I2PEndian.h"
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#include "Crypto.h"
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#include "Ed25519.h"
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#include "RouterContext.h"
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#include "NTCP2.h"
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namespace i2p
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{
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namespace transport
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{
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NTCP2Session::NTCP2Session (NTCP2Server& server, std::shared_ptr<const i2p::data::RouterInfo> in_RemoteRouter):
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TransportSession (in_RemoteRouter, 30),
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m_Server (server), m_Socket (m_Server.GetService ()),
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m_IsEstablished (false), m_IsTerminated (false),
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m_SessionRequestBuffer (nullptr), m_SessionCreatedBuffer (nullptr), m_SessionConfirmedBuffer (nullptr)
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{
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auto addr = in_RemoteRouter->GetNTCPAddress ();
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if (addr->ntcp2)
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{
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memcpy (m_RemoteStaticKey, addr->ntcp2->staticKey, 32);
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memcpy (m_IV, addr->ntcp2->iv, 16);
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}
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else
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LogPrint (eLogWarning, "NTCP2: Missing NTCP2 parameters");
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}
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NTCP2Session::~NTCP2Session ()
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{
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delete[] m_SessionRequestBuffer;
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delete[] m_SessionCreatedBuffer;
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delete[] m_SessionConfirmedBuffer;
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}
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void NTCP2Session::Terminate ()
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{
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if (!m_IsTerminated)
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{
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m_IsTerminated = true;
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m_IsEstablished = false;
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m_Socket.close ();
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LogPrint (eLogDebug, "NTCP2: session terminated");
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}
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}
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void NTCP2Session::Done ()
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{
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m_Server.GetService ().post (std::bind (&NTCP2Session::Terminate, shared_from_this ()));
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}
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void NTCP2Session::MixKey (const uint8_t * inputKeyMaterial, uint8_t * derived)
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{
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// temp_key = HMAC-SHA256(ck, input_key_material)
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uint8_t tempKey[32]; unsigned int len;
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HMAC(EVP_sha256(), m_CK, 32, inputKeyMaterial, 32, tempKey, &len);
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// ck = HMAC-SHA256(temp_key, byte(0x01))
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static uint8_t one[1] = { 1 };
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HMAC(EVP_sha256(), tempKey, 32, one, 1, m_CK, &len);
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// derived = HMAC-SHA256(temp_key, ck || byte(0x02))
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m_CK[32] = 2;
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HMAC(EVP_sha256(), tempKey, 32, m_CK, 33, derived, &len);
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}
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void NTCP2Session::KeyDerivationFunction1 (const uint8_t * rs, const uint8_t * priv, const uint8_t * pub, uint8_t * derived)
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{
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static const char protocolName[] = "Noise_XK_25519_ChaChaPoly_SHA256"; // 32 bytes
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uint8_t h[64];
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memcpy (m_CK, protocolName, 32);
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SHA256 ((const uint8_t *)protocolName, 32, h);
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// h = SHA256(h || rs)
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memcpy (h + 32, rs, 32);
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SHA256 (h, 64, h);
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// h = SHA256(h || pub)
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memcpy (h + 32, pub, 32);
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SHA256 (h, 64, m_H);
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// x25519 between rs and priv
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uint8_t inputKeyMaterial[32];
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BN_CTX * ctx = BN_CTX_new ();
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i2p::crypto::GetEd25519 ()->ScalarMul (rs, priv, inputKeyMaterial, ctx); // rs*priv
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BN_CTX_free (ctx);
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MixKey (inputKeyMaterial, derived);
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}
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void NTCP2Session::KeyDerivationFunction2 (const uint8_t * priv, const uint8_t * pub, const uint8_t * sessionRequest, size_t sessionRequestLen, uint8_t * derived)
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{
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uint8_t h[64];
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memcpy (h, m_H, 32);
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memcpy (h + 32, sessionRequest + 32, 32); // encrypted payload
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SHA256 (h, 64, h);
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int paddingLength = sessionRequestLen - 64;
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if (paddingLength > 0)
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{
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std::vector<uint8_t> h1(paddingLength + 32);
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memcpy (h1.data (), h, 32);
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memcpy (h1.data () + 32, sessionRequest + 64, paddingLength);
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SHA256 (h1.data (), paddingLength + 32, h);
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}
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memcpy (h + 32, pub, 32);
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SHA256 (h, 64, m_H);
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// x25519 between remote pub and priv
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uint8_t inputKeyMaterial[32];
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BN_CTX * ctx = BN_CTX_new ();
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i2p::crypto::GetEd25519 ()->ScalarMul (pub, priv, inputKeyMaterial, ctx);
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BN_CTX_free (ctx);
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MixKey (inputKeyMaterial, derived);
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}
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void NTCP2Session::KeyDerivationFunction3 (const uint8_t * staticPrivKey, uint8_t * derived)
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{
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uint8_t inputKeyMaterial[32];
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BN_CTX * ctx = BN_CTX_new ();
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i2p::crypto::GetEd25519 ()->ScalarMul (m_Y, staticPrivKey, inputKeyMaterial, ctx);
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BN_CTX_free (ctx);
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MixKey (inputKeyMaterial, derived);
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}
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void NTCP2Session::CreateEphemeralKey (uint8_t * pub)
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{
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RAND_bytes (m_EphemeralPrivateKey, 32);
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BN_CTX * ctx = BN_CTX_new ();
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i2p::crypto::GetEd25519 ()->ScalarMulB (m_EphemeralPrivateKey, pub, ctx);
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BN_CTX_free (ctx);
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}
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void NTCP2Session::SendSessionRequest ()
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{
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// create buffer and fill padding
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auto paddingLength = rand () % (287 - 64); // message length doesn't exceed 287 bytes
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m_SessionRequestBufferLen = paddingLength + 64;
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m_SessionRequestBuffer = new uint8_t[m_SessionRequestBufferLen];
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RAND_bytes (m_SessionRequestBuffer + 64, paddingLength);
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// generate key pair (X)
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uint8_t x[32];
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CreateEphemeralKey (x);
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// encrypt X
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i2p::crypto::CBCEncryption encryption;
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encryption.SetKey (GetRemoteIdentity ()->GetIdentHash ());
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encryption.SetIV (m_IV);
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encryption.Encrypt (x, 32, m_SessionRequestBuffer);
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encryption.GetIV (m_IV); // save IV for SessionCreated
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// encryption key for next block
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uint8_t key[32];
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KeyDerivationFunction1 (m_RemoteStaticKey, m_EphemeralPrivateKey, x, key);
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// fill options
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uint8_t options[32]; // actual options size is 16 bytes
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memset (options, 0, 16);
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htobe16buf (options, 2); // ver
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htobe16buf (options + 2, paddingLength); // padLen
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htobe16buf (options + 4, i2p::context.GetRouterInfo ().GetBufferLen () + 20); // m3p2Len (RI header + RI + MAC for now) TODO: implement options
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// 2 bytes reserved
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htobe32buf (options + 8, i2p::util::GetSecondsSinceEpoch ()); // tsA
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// 4 bytes reserved
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// sign and encrypt options, use m_H as AD
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uint8_t nonce[12];
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memset (nonce, 0, 12); // set nonce to zero
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i2p::crypto::AEADChaCha20Poly1305 (options, 16, m_H, 32, key, nonce, m_SessionRequestBuffer + 32, 32, true); // encrypt
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// send message
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boost::asio::async_write (m_Socket, boost::asio::buffer (m_SessionRequestBuffer, m_SessionRequestBufferLen), boost::asio::transfer_all (),
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std::bind(&NTCP2Session::HandleSessionRequestSent, shared_from_this (), std::placeholders::_1, std::placeholders::_2));
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}
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void NTCP2Session::HandleSessionRequestSent (const boost::system::error_code& ecode, std::size_t bytes_transferred)
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{
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(void) bytes_transferred;
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if (ecode)
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{
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LogPrint (eLogWarning, "NTCP2: couldn't send SessionRequest message: ", ecode.message ());
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Terminate ();
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}
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else
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{
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m_SessionCreatedBuffer = new uint8_t[287]; // TODO: determine actual max size
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// we receive first 56 bytes (32 Y, and 24 ChaCha/Poly frame) first
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boost::asio::async_read (m_Socket, boost::asio::buffer(m_SessionCreatedBuffer, 56), boost::asio::transfer_all (),
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std::bind(&NTCP2Session::HandleSessionCreatedReceived, shared_from_this (), std::placeholders::_1, std::placeholders::_2));
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}
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}
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void NTCP2Session::HandleSessionRequestReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred)
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{
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(void) bytes_transferred;
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if (ecode)
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{
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LogPrint (eLogWarning, "NTCP2: SessionRequest read error: ", ecode.message ());
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Terminate ();
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}
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else
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{
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// decrypt X
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i2p::crypto::CBCDecryption decryption;
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decryption.SetKey (i2p::context.GetIdentHash ());
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decryption.SetIV (i2p::context.GetNTCP2IV ());
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decryption.Decrypt (m_SessionRequestBuffer, 32, m_Y);
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decryption.GetIV (m_IV); // save IV for SessionCreated
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// decryption key for next block
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uint8_t key[32];
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KeyDerivationFunction1 (m_Y, i2p::context.GetNTCP2StaticPrivateKey (), m_Y, key);
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// verify MAC and decrypt options block (32 bytes), use m_H as AD
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uint8_t nonce[12], options[16];
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memset (nonce, 0, 12); // set nonce to zero
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if (i2p::crypto::AEADChaCha20Poly1305 (m_SessionRequestBuffer + 32, 16, m_H, 32, key, nonce, options, 16, false)) // decrypt
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{
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uint16_t version = bufbe16toh (options);
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if (version == 2)
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{
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uint16_t paddingLen = bufbe16toh (options + 2);
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m_SessionRequestBufferLen = paddingLen + 64;
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// TODO: check tsA
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if (paddingLen > 0)
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boost::asio::async_read (m_Socket, boost::asio::buffer(m_SessionRequestBuffer + 64, paddingLen), boost::asio::transfer_all (),
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std::bind(&NTCP2Session::HandleSessionRequestPaddingReceived, shared_from_this (), std::placeholders::_1, std::placeholders::_2));
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else
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SendSessionCreated ();
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}
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else
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{
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LogPrint (eLogWarning, "NTCP2: SessionRequest version mismatch ", version);
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Terminate ();
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}
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}
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else
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{
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LogPrint (eLogWarning, "NTCP2: SessionRequest AEAD verification failed ");
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Terminate ();
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}
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}
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}
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void NTCP2Session::HandleSessionRequestPaddingReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred)
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{
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if (ecode)
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{
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LogPrint (eLogWarning, "NTCP2: SessionRequest padding read error: ", ecode.message ());
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Terminate ();
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}
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else
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SendSessionCreated ();
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}
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void NTCP2Session::SendSessionCreated ()
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{
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m_SessionCreatedBuffer = new uint8_t[287]; // TODO: determine actual max size
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// generate key pair (y)
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uint8_t y[32];
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CreateEphemeralKey (y);
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// encrypt Y
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i2p::crypto::CBCEncryption encryption;
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encryption.SetKey (i2p::context.GetIdentHash ());
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encryption.SetIV (m_IV);
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encryption.Encrypt (y, 32, m_SessionCreatedBuffer);
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// encryption key for next block (m_K)
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KeyDerivationFunction2 (m_EphemeralPrivateKey, m_Y, m_SessionRequestBuffer, m_SessionRequestBufferLen, m_K);
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auto paddingLen = rand () % (287 - 56);
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uint8_t options[8];
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memset (options, 0, 8);
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htobe16buf (options, paddingLen); // padLen
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htobe32buf (options + 4, i2p::util::GetSecondsSinceEpoch ()); // tsB
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// sign and encrypt options, use m_H as AD
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uint8_t nonce[12];
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memset (nonce, 0, 12); // set nonce to zero
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i2p::crypto::AEADChaCha20Poly1305 (options, 8, m_H, 32, m_K, nonce, m_SessionCreatedBuffer + 32, 24, true); // encrypt
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// fill padding
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RAND_bytes (m_SessionCreatedBuffer + 56, paddingLen);
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// send message
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boost::asio::async_write (m_Socket, boost::asio::buffer (m_SessionCreatedBuffer, paddingLen + 56), boost::asio::transfer_all (),
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std::bind(&NTCP2Session::HandleSessionCreatedSent, shared_from_this (), std::placeholders::_1, std::placeholders::_2));
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}
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void NTCP2Session::HandleSessionCreatedReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred)
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{
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if (ecode)
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{
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LogPrint (eLogWarning, "NTCP2: SessionCreated read error: ", ecode.message ());
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Terminate ();
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}
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else
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{
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LogPrint (eLogDebug, "NTCP2: SessionCreated received ", bytes_transferred);
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m_SessionCreatedBufferLen = 56;
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// decrypt Y
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i2p::crypto::CBCDecryption decryption;
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decryption.SetKey (GetRemoteIdentity ()->GetIdentHash ());
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decryption.SetIV (m_IV);
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decryption.Decrypt (m_SessionCreatedBuffer, 32, m_Y);
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// decryption key for next block (m_K)
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KeyDerivationFunction2 (m_EphemeralPrivateKey, m_Y, m_SessionRequestBuffer, m_SessionRequestBufferLen, m_K);
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// decrypt and verify MAC
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uint8_t payload[8];
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uint8_t nonce[12];
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memset (nonce, 0, 12); // set nonce to zero
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if (i2p::crypto::AEADChaCha20Poly1305 (m_SessionCreatedBuffer + 32, 8, m_H, 32, m_K, nonce, payload, 8, false)) // decrypt
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{
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uint16_t paddingLen = bufbe16toh(payload);
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LogPrint (eLogDebug, "NTCP2: padding length ", paddingLen);
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if (paddingLen > 0)
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{
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boost::asio::async_read (m_Socket, boost::asio::buffer(m_SessionCreatedBuffer + 56, paddingLen), boost::asio::transfer_all (),
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std::bind(&NTCP2Session::HandleSessionCreatedPaddingReceived, shared_from_this (), std::placeholders::_1, std::placeholders::_2));
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}
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else
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SendSessionConfirmed ();
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}
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else
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{
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LogPrint (eLogWarning, "NTCP2: SessionCreated MAC verification failed ");
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Terminate ();
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}
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}
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}
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void NTCP2Session::HandleSessionCreatedPaddingReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred)
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{
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if (ecode)
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{
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LogPrint (eLogWarning, "NTCP2: SessionCreated padding read error: ", ecode.message ());
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Terminate ();
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}
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else
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{
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m_SessionCreatedBufferLen += bytes_transferred;
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SendSessionConfirmed ();
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}
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}
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void NTCP2Session::SendSessionConfirmed ()
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{
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// update AD
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uint8_t h[80];
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memcpy (h, m_H, 32);
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memcpy (h + 32, m_SessionCreatedBuffer + 32, 24); // encrypted payload
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SHA256 (h, 56, h);
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int paddingLength = m_SessionCreatedBufferLen - 56;
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if (paddingLength > 0)
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{
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std::vector<uint8_t> h1(paddingLength + 32);
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memcpy (h1.data (), h, 32);
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memcpy (h1.data () + 32, m_SessionCreatedBuffer + 56, paddingLength);
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SHA256 (h1.data (), paddingLength + 32, h);
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}
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// part1 48 bytes
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m_SessionConfirmedBuffer = new uint8_t[2048]; // TODO: actual size
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uint8_t nonce[12];
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memset (nonce, 0, 4); htole64buf (nonce + 4, 1); // set nonce to 1
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i2p::crypto::AEADChaCha20Poly1305 (i2p::context.GetNTCP2StaticPublicKey (), 32, h, 32, m_K, nonce, m_SessionConfirmedBuffer, 48, true); // encrypt
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// part 2
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// update AD again
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memcpy (h + 32, m_SessionConfirmedBuffer, 48);
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SHA256 (h, 80, m_H);
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size_t m3p2Len = i2p::context.GetRouterInfo ().GetBufferLen () + 20;
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std::vector<uint8_t> buf(m3p2Len - 16);
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buf[0] = 2; // block
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htobe16buf (buf.data () + 1, i2p::context.GetRouterInfo ().GetBufferLen () + 1); // flag + RI
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buf[3] = 0; // flag
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memcpy (buf.data () + 4, i2p::context.GetRouterInfo ().GetBuffer (), i2p::context.GetRouterInfo ().GetBufferLen ());
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uint8_t key[32];
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KeyDerivationFunction3 (i2p::context.GetNTCP2StaticPrivateKey (), key);
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memset (nonce, 0, 12); // set nonce to 0 again
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i2p::crypto::AEADChaCha20Poly1305 (buf.data (), m3p2Len - 16, m_H, 32, key, nonce, m_SessionConfirmedBuffer + 48, m3p2Len, true); // encrypt
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// send message
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boost::asio::async_write (m_Socket, boost::asio::buffer (m_SessionConfirmedBuffer, m3p2Len + 48), boost::asio::transfer_all (),
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std::bind(&NTCP2Session::HandleSessionConfirmedSent, shared_from_this (), std::placeholders::_1, std::placeholders::_2));
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}
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void NTCP2Session::HandleSessionConfirmedSent (const boost::system::error_code& ecode, std::size_t bytes_transferred)
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{
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LogPrint (eLogDebug, "NTCP2: SessionConfirmed sent");
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Terminate (); // TODO
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}
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void NTCP2Session::HandleSessionCreatedSent (const boost::system::error_code& ecode, std::size_t bytes_transferred)
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{
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LogPrint (eLogDebug, "NTCP2: SessionCreated sent");
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Terminate (); // TODO
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}
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void NTCP2Session::ClientLogin ()
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{
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SendSessionRequest ();
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}
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void NTCP2Session::ServerLogin ()
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{
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m_SessionRequestBuffer = new uint8_t[287]; // 287 bytes max for now
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boost::asio::async_read (m_Socket, boost::asio::buffer(m_SessionRequestBuffer, 64), boost::asio::transfer_all (),
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std::bind(&NTCP2Session::HandleSessionRequestReceived, shared_from_this (),
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std::placeholders::_1, std::placeholders::_2));
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}
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NTCP2Server::NTCP2Server ():
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m_IsRunning (false), m_Thread (nullptr), m_Work (m_Service)
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{
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}
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NTCP2Server::~NTCP2Server ()
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{
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Stop ();
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}
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void NTCP2Server::Start ()
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{
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if (!m_IsRunning)
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{
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m_IsRunning = true;
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m_Thread = new std::thread (std::bind (&NTCP2Server::Run, this));
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}
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}
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void NTCP2Server::Stop ()
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{
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if (m_IsRunning)
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{
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m_IsRunning = false;
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m_Service.stop ();
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if (m_Thread)
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{
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m_Thread->join ();
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delete m_Thread;
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m_Thread = nullptr;
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}
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}
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}
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void NTCP2Server::Run ()
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{
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while (m_IsRunning)
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{
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try
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{
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m_Service.run ();
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}
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catch (std::exception& ex)
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{
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LogPrint (eLogError, "NTCP2: runtime exception: ", ex.what ());
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}
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}
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}
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void NTCP2Server::Connect(const boost::asio::ip::address & address, uint16_t port, std::shared_ptr<NTCP2Session> conn)
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{
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LogPrint (eLogDebug, "NTCP2: Connecting to ", address ,":", port);
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m_Service.post([this, address, port, conn]()
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{
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conn->GetSocket ().async_connect (boost::asio::ip::tcp::endpoint (address, port), std::bind (&NTCP2Server::HandleConnect, this, std::placeholders::_1, conn));
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});
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}
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|
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void NTCP2Server::HandleConnect (const boost::system::error_code& ecode, std::shared_ptr<NTCP2Session> conn)
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|
{
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|
if (ecode)
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|
{
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|
LogPrint (eLogInfo, "NTCP2: Connect error ", ecode.message ());
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|
conn->Terminate ();
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}
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|
else
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|
{
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|
LogPrint (eLogDebug, "NTCP2: Connected to ", conn->GetSocket ().remote_endpoint ());
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|
conn->ClientLogin ();
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|
}
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|
}
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|
}
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|
}
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|