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SSU2Session/SSU2OutOfSession split

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orignal 2024-10-13 19:53:40 -04:00
parent 8210911bc5
commit fbd07a5276
5 changed files with 293 additions and 254 deletions
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1
libi2pd/SSU2.h
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@ -17,6 +17,7 @@
#include <random>
#include "util.h"
#include "SSU2Session.h"
#include "SSU2OutOfSession.h"
#include "Socks5.h"
namespace i2p

228
libi2pd/SSU2OutOfSession.cpp Normal file
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@ -0,0 +1,228 @@
/*
* Copyright (c) 2024, 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 "Log.h"
#include "SSU2.h"
#include "SSU2OutOfSession.h"
namespace i2p
{
namespace transport
{
SSU2PeerTestSession::SSU2PeerTestSession (SSU2Server& server, uint64_t sourceConnID, uint64_t destConnID):
SSU2Session (server, nullptr, nullptr, false),
m_MsgNumReceived (0), m_NumResends (0),m_IsConnectedRecently (false), m_IsStatusChanged (false),
m_PeerTestResendTimer (server.GetService ())
{
if (!sourceConnID) sourceConnID = ~destConnID;
if (!destConnID) destConnID = ~sourceConnID;
SetSourceConnID (sourceConnID);
SetDestConnID (destConnID);
SetState (eSSU2SessionStatePeerTest);
SetTerminationTimeout (SSU2_PEER_TEST_EXPIRATION_TIMEOUT);
}
bool SSU2PeerTestSession::ProcessPeerTest (uint8_t * buf, size_t len)
{
// we are Alice or Charlie, msgs 5,6,7
Header header;
memcpy (header.buf, buf, 16);
header.ll[0] ^= CreateHeaderMask (i2p::context.GetSSU2IntroKey (), buf + (len - 24));
header.ll[1] ^= CreateHeaderMask (i2p::context.GetSSU2IntroKey (), buf + (len - 12));
if (header.h.type != eSSU2PeerTest)
{
LogPrint (eLogWarning, "SSU2: Unexpected message type ", (int)header.h.type, " instead ", (int)eSSU2PeerTest);
return false;
}
if (len < 48)
{
LogPrint (eLogWarning, "SSU2: PeerTest message too short ", len);
return false;
}
uint8_t nonce[12] = {0};
uint64_t headerX[2]; // sourceConnID, token
i2p::crypto::ChaCha20 (buf + 16, 16, i2p::context.GetSSU2IntroKey (), nonce, (uint8_t *)headerX);
SetDestConnID (headerX[0]);
// decrypt and handle payload
uint8_t * payload = buf + 32;
CreateNonce (be32toh (header.h.packetNum), nonce);
uint8_t h[32];
memcpy (h, header.buf, 16);
memcpy (h + 16, &headerX, 16);
if (!i2p::crypto::AEADChaCha20Poly1305 (payload, len - 48, h, 32,
i2p::context.GetSSU2IntroKey (), nonce, payload, len - 48, false))
{
LogPrint (eLogWarning, "SSU2: PeerTest AEAD verification failed ");
return false;
}
HandlePayload (payload, len - 48);
SetIsDataReceived (false);
return true;
}
void SSU2PeerTestSession::HandlePeerTest (const uint8_t * buf, size_t len)
{
// msgs 5-7
if (len < 8) return;
uint8_t msg = buf[0];
if (msg <= m_MsgNumReceived)
{
LogPrint (eLogDebug, "SSU2: PeerTest msg num ", msg, " received after ", m_MsgNumReceived, ". Ignored");
return;
}
size_t offset = 3; // points to signed data after msg + code + flag
uint32_t nonce = bufbe32toh (buf + offset + 1); // 1 - ver
switch (msg) // msg
{
case 5: // Alice from Charlie 1
{
if (htobe64 (((uint64_t)nonce << 32) | nonce) == GetSourceConnID ())
{
m_IsConnectedRecently = GetServer ().IsConnectedRecently (GetRemoteEndpoint ());
if (GetAddress ())
{
if (!m_IsConnectedRecently)
SetRouterStatus (eRouterStatusOK);
else if (m_IsStatusChanged && GetRouterStatus () == eRouterStatusFirewalled)
SetRouterStatus (eRouterStatusUnknown);
SendPeerTest (6, buf + offset, len - offset);
}
}
else
LogPrint (eLogWarning, "SSU2: Peer test 5 nonce mismatch ", nonce, " connID=", GetSourceConnID ());
break;
}
case 6: // Charlie from Alice
{
m_PeerTestResendTimer.cancel (); // no more msg 5 resends
if (GetAddress ())
SendPeerTest (7, buf + offset, len - offset);
else
LogPrint (eLogWarning, "SSU2: Unknown address for peer test 6");
GetServer ().AddConnectedRecently (GetRemoteEndpoint (), i2p::util::GetSecondsSinceEpoch ());
GetServer ().RequestRemoveSession (GetConnID ());
break;
}
case 7: // Alice from Charlie 2
{
m_PeerTestResendTimer.cancel (); // no more msg 6 resends
auto addr = GetAddress ();
if (addr && addr->IsV6 ())
i2p::context.SetStatusV6 (eRouterStatusOK); // set status OK for ipv6 even if from SSU2
GetServer ().AddConnectedRecently (GetRemoteEndpoint (), i2p::util::GetSecondsSinceEpoch ());
GetServer ().RequestRemoveSession (GetConnID ());
break;
}
default:
LogPrint (eLogWarning, "SSU2: PeerTest unexpected msg num ", msg);
return;
}
m_MsgNumReceived = msg;
}
void SSU2PeerTestSession::SendPeerTest (uint8_t msg)
{
auto addr = GetAddress ();
if (!addr) return;
Header header;
uint8_t h[32], payload[SSU2_MAX_PACKET_SIZE];
// fill packet
header.h.connID = GetDestConnID (); // dest id
RAND_bytes (header.buf + 8, 4); // random packet num
header.h.type = eSSU2PeerTest;
header.h.flags[0] = 2; // ver
header.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID
header.h.flags[2] = 0; // flag
memcpy (h, header.buf, 16);
htobuf64 (h + 16, GetSourceConnID ()); // source id
// payload
payload[0] = eSSU2BlkDateTime;
htobe16buf (payload + 1, 4);
htobe32buf (payload + 3, (i2p::util::GetMillisecondsSinceEpoch () + 500)/1000);
size_t payloadSize = 7;
if (msg == 6 || msg == 7)
payloadSize += CreateAddressBlock (payload + payloadSize, GetMaxPayloadSize () - payloadSize, GetRemoteEndpoint ());
payloadSize += CreatePeerTestBlock (payload + payloadSize, GetMaxPayloadSize () - payloadSize,
msg, eSSU2PeerTestCodeAccept, nullptr, m_SignedData.data (), m_SignedData.size ());
payloadSize += CreatePaddingBlock (payload + payloadSize, GetMaxPayloadSize () - payloadSize);
// encrypt
uint8_t n[12];
CreateNonce (be32toh (header.h.packetNum), n);
i2p::crypto::AEADChaCha20Poly1305 (payload, payloadSize, h, 32, addr->i, n, payload, payloadSize + 16, true);
payloadSize += 16;
header.ll[0] ^= CreateHeaderMask (addr->i, payload + (payloadSize - 24));
header.ll[1] ^= CreateHeaderMask (addr->i, payload + (payloadSize - 12));
memset (n, 0, 12);
i2p::crypto::ChaCha20 (h + 16, 16, addr->i, n, h + 16);
// send
GetServer ().Send (header.buf, 16, h + 16, 16, payload, payloadSize, GetRemoteEndpoint ());
}
void SSU2PeerTestSession::SendPeerTest (uint8_t msg, const uint8_t * signedData, size_t signedDataLen)
{
#if __cplusplus >= 202002L // C++20
m_SignedData.assign (signedData, signedData + signedDataLen);
#else
m_SignedData.resize (signedDataLen);
memcpy (m_SignedData.data (), signedData, signedDataLen);
#endif
SendPeerTest (msg);
// schedule resend for msgs 5 or 6
if (msg == 5 || msg == 6)
ScheduleResend ();
}
void SSU2PeerTestSession::SendPeerTest (uint8_t msg, const uint8_t * signedData, size_t signedDataLen,
std::shared_ptr<const i2p::data::RouterInfo::Address> addr)
{
if (!addr) return;
SetAddress (addr);
SendPeerTest (msg, signedData, signedDataLen);
}
void SSU2PeerTestSession::Connect ()
{
LogPrint (eLogError, "SSU2: Can't connect peer test session");
}
bool SSU2PeerTestSession::ProcessFirstIncomingMessage (uint64_t connID, uint8_t * buf, size_t len)
{
LogPrint (eLogError, "SSU2: Can't handle incoming message in peer test session");
return false;
}
void SSU2PeerTestSession::ScheduleResend ()
{
if (m_NumResends < SSU2_PEER_TEST_MAX_NUM_RESENDS)
{
m_PeerTestResendTimer.expires_from_now (boost::posix_time::milliseconds(
SSU2_PEER_TEST_RESEND_INTERVAL + GetServer ().GetRng ()() % SSU2_PEER_TEST_RESEND_INTERVAL_VARIANCE));
std::weak_ptr<SSU2PeerTestSession> s(std::static_pointer_cast<SSU2PeerTestSession>(shared_from_this ()));
m_PeerTestResendTimer.async_wait ([s](const boost::system::error_code& ecode)
{
if (ecode != boost::asio::error::operation_aborted)
{
auto s1 = s.lock ();
if (s1)
{
int msg = 0;
if (s1->m_MsgNumReceived < 6)
msg = (s1->m_MsgNumReceived == 5) ? 6 : 5;
if (msg) // 5 or 6
{
s1->SendPeerTest (msg);
s1->ScheduleResend ();
}
}
}
});
m_NumResends++;
}
}
}
}

57
libi2pd/SSU2OutOfSession.h Normal file
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@ -0,0 +1,57 @@
/*
* Copyright (c) 2024, 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
*/
#ifndef SSU2_OUT_OF_SESSION_H__
#define SSU2_OUT_OF_SESSION_H__
#include <vector>
#include "SSU2Session.h"
namespace i2p
{
namespace transport
{
const int SSU2_PEER_TEST_RESEND_INTERVAL = 3000; // in milliseconds
const int SSU2_PEER_TEST_RESEND_INTERVAL_VARIANCE = 2000; // in milliseconds
const int SSU2_PEER_TEST_MAX_NUM_RESENDS = 3;
class SSU2PeerTestSession: public SSU2Session // for PeerTest msgs 5,6,7
{
public:
SSU2PeerTestSession (SSU2Server& server, uint64_t sourceConnID, uint64_t destConnID);
uint8_t GetMsgNumReceived () const { return m_MsgNumReceived; }
bool IsConnectedRecently () const { return m_IsConnectedRecently; }
void SetStatusChanged () { m_IsStatusChanged = true; }
void SendPeerTest (uint8_t msg, const uint8_t * signedData, size_t signedDataLen,
std::shared_ptr<const i2p::data::RouterInfo::Address> addr);
bool ProcessPeerTest (uint8_t * buf, size_t len) override;
void Connect () override; // outgoing
bool ProcessFirstIncomingMessage (uint64_t connID, uint8_t * buf, size_t len) override; // incoming
private:
void SendPeerTest (uint8_t msg, const uint8_t * signedData, size_t signedDataLen); // PeerTest message
void SendPeerTest (uint8_t msg); // send or resend m_SignedData
void HandlePeerTest (const uint8_t * buf, size_t len) override;
void ScheduleResend ();
private:
uint8_t m_MsgNumReceived, m_NumResends;
bool m_IsConnectedRecently, m_IsStatusChanged;
std::vector<uint8_t> m_SignedData; // for resends
boost::asio::deadline_timer m_PeerTestResendTimer;
};
}
}
#endif

218
libi2pd/SSU2Session.cpp
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@ -13,17 +13,12 @@
#include "Gzip.h"
#include "NetDb.hpp"
#include "SSU2.h"
#include "SSU2Session.h"
namespace i2p
{
namespace transport
{
static inline void CreateNonce (uint64_t seqn, uint8_t * nonce)
{
memset (nonce, 0, 4);
htole64buf (nonce + 4, seqn);
}
void SSU2IncompleteMessage::AttachNextFragment (const uint8_t * fragment, size_t fragmentSize)
{
if (msg->len + fragmentSize > msg->maxLen)
@ -3086,216 +3081,5 @@ namespace transport
else if (!sent && !m_SentPackets.empty ()) // if only acks received, nothing sent and we still have something to resend
Resend (i2p::util::GetMillisecondsSinceEpoch ()); // than right time to resend
}
SSU2PeerTestSession::SSU2PeerTestSession (SSU2Server& server, uint64_t sourceConnID, uint64_t destConnID):
SSU2Session (server, nullptr, nullptr, false),
m_MsgNumReceived (0), m_NumResends (0),m_IsConnectedRecently (false), m_IsStatusChanged (false),
m_PeerTestResendTimer (server.GetService ())
{
if (!sourceConnID) sourceConnID = ~destConnID;
if (!destConnID) destConnID = ~sourceConnID;
SetSourceConnID (sourceConnID);
SetDestConnID (destConnID);
SetState (eSSU2SessionStatePeerTest);
SetTerminationTimeout (SSU2_PEER_TEST_EXPIRATION_TIMEOUT);
}
bool SSU2PeerTestSession::ProcessPeerTest (uint8_t * buf, size_t len)
{
// we are Alice or Charlie, msgs 5,6,7
Header header;
memcpy (header.buf, buf, 16);
header.ll[0] ^= CreateHeaderMask (i2p::context.GetSSU2IntroKey (), buf + (len - 24));
header.ll[1] ^= CreateHeaderMask (i2p::context.GetSSU2IntroKey (), buf + (len - 12));
if (header.h.type != eSSU2PeerTest)
{
LogPrint (eLogWarning, "SSU2: Unexpected message type ", (int)header.h.type, " instead ", (int)eSSU2PeerTest);
return false;
}
if (len < 48)
{
LogPrint (eLogWarning, "SSU2: PeerTest message too short ", len);
return false;
}
uint8_t nonce[12] = {0};
uint64_t headerX[2]; // sourceConnID, token
i2p::crypto::ChaCha20 (buf + 16, 16, i2p::context.GetSSU2IntroKey (), nonce, (uint8_t *)headerX);
SetDestConnID (headerX[0]);
// decrypt and handle payload
uint8_t * payload = buf + 32;
CreateNonce (be32toh (header.h.packetNum), nonce);
uint8_t h[32];
memcpy (h, header.buf, 16);
memcpy (h + 16, &headerX, 16);
if (!i2p::crypto::AEADChaCha20Poly1305 (payload, len - 48, h, 32,
i2p::context.GetSSU2IntroKey (), nonce, payload, len - 48, false))
{
LogPrint (eLogWarning, "SSU2: PeerTest AEAD verification failed ");
return false;
}
HandlePayload (payload, len - 48);
SetIsDataReceived (false);
return true;
}
void SSU2PeerTestSession::HandlePeerTest (const uint8_t * buf, size_t len)
{
// msgs 5-7
if (len < 8) return;
uint8_t msg = buf[0];
if (msg <= m_MsgNumReceived)
{
LogPrint (eLogDebug, "SSU2: PeerTest msg num ", msg, " received after ", m_MsgNumReceived, ". Ignored");
return;
}
size_t offset = 3; // points to signed data after msg + code + flag
uint32_t nonce = bufbe32toh (buf + offset + 1); // 1 - ver
switch (msg) // msg
{
case 5: // Alice from Charlie 1
{
if (htobe64 (((uint64_t)nonce << 32) | nonce) == GetSourceConnID ())
{
m_IsConnectedRecently = GetServer ().IsConnectedRecently (GetRemoteEndpoint ());
if (GetAddress ())
{
if (!m_IsConnectedRecently)
SetRouterStatus (eRouterStatusOK);
else if (m_IsStatusChanged && GetRouterStatus () == eRouterStatusFirewalled)
SetRouterStatus (eRouterStatusUnknown);
SendPeerTest (6, buf + offset, len - offset);
}
}
else
LogPrint (eLogWarning, "SSU2: Peer test 5 nonce mismatch ", nonce, " connID=", GetSourceConnID ());
break;
}
case 6: // Charlie from Alice
{
m_PeerTestResendTimer.cancel (); // no more msg 5 resends
if (GetAddress ())
SendPeerTest (7, buf + offset, len - offset);
else
LogPrint (eLogWarning, "SSU2: Unknown address for peer test 6");
GetServer ().AddConnectedRecently (GetRemoteEndpoint (), i2p::util::GetSecondsSinceEpoch ());
GetServer ().RequestRemoveSession (GetConnID ());
break;
}
case 7: // Alice from Charlie 2
{
m_PeerTestResendTimer.cancel (); // no more msg 6 resends
auto addr = GetAddress ();
if (addr && addr->IsV6 ())
i2p::context.SetStatusV6 (eRouterStatusOK); // set status OK for ipv6 even if from SSU2
GetServer ().AddConnectedRecently (GetRemoteEndpoint (), i2p::util::GetSecondsSinceEpoch ());
GetServer ().RequestRemoveSession (GetConnID ());
break;
}
default:
LogPrint (eLogWarning, "SSU2: PeerTest unexpected msg num ", msg);
return;
}
m_MsgNumReceived = msg;
}
void SSU2PeerTestSession::SendPeerTest (uint8_t msg)
{
auto addr = GetAddress ();
if (!addr) return;
Header header;
uint8_t h[32], payload[SSU2_MAX_PACKET_SIZE];
// fill packet
header.h.connID = GetDestConnID (); // dest id
RAND_bytes (header.buf + 8, 4); // random packet num
header.h.type = eSSU2PeerTest;
header.h.flags[0] = 2; // ver
header.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID
header.h.flags[2] = 0; // flag
memcpy (h, header.buf, 16);
htobuf64 (h + 16, GetSourceConnID ()); // source id
// payload
payload[0] = eSSU2BlkDateTime;
htobe16buf (payload + 1, 4);
htobe32buf (payload + 3, (i2p::util::GetMillisecondsSinceEpoch () + 500)/1000);
size_t payloadSize = 7;
if (msg == 6 || msg == 7)
payloadSize += CreateAddressBlock (payload + payloadSize, GetMaxPayloadSize () - payloadSize, GetRemoteEndpoint ());
payloadSize += CreatePeerTestBlock (payload + payloadSize, GetMaxPayloadSize () - payloadSize,
msg, eSSU2PeerTestCodeAccept, nullptr, m_SignedData.data (), m_SignedData.size ());
payloadSize += CreatePaddingBlock (payload + payloadSize, GetMaxPayloadSize () - payloadSize);
// encrypt
uint8_t n[12];
CreateNonce (be32toh (header.h.packetNum), n);
i2p::crypto::AEADChaCha20Poly1305 (payload, payloadSize, h, 32, addr->i, n, payload, payloadSize + 16, true);
payloadSize += 16;
header.ll[0] ^= CreateHeaderMask (addr->i, payload + (payloadSize - 24));
header.ll[1] ^= CreateHeaderMask (addr->i, payload + (payloadSize - 12));
memset (n, 0, 12);
i2p::crypto::ChaCha20 (h + 16, 16, addr->i, n, h + 16);
// send
GetServer ().Send (header.buf, 16, h + 16, 16, payload, payloadSize, GetRemoteEndpoint ());
}
void SSU2PeerTestSession::SendPeerTest (uint8_t msg, const uint8_t * signedData, size_t signedDataLen)
{
#if __cplusplus >= 202002L // C++20
m_SignedData.assign (signedData, signedData + signedDataLen);
#else
m_SignedData.resize (signedDataLen);
memcpy (m_SignedData.data (), signedData, signedDataLen);
#endif
SendPeerTest (msg);
// schedule resend for msgs 5 or 6
if (msg == 5 || msg == 6)
ScheduleResend ();
}
void SSU2PeerTestSession::SendPeerTest (uint8_t msg, const uint8_t * signedData, size_t signedDataLen,
std::shared_ptr<const i2p::data::RouterInfo::Address> addr)
{
if (!addr) return;
SetAddress (addr);
SendPeerTest (msg, signedData, signedDataLen);
}
void SSU2PeerTestSession::Connect ()
{
LogPrint (eLogError, "SSU2: Can't connect peer test session");
}
bool SSU2PeerTestSession::ProcessFirstIncomingMessage (uint64_t connID, uint8_t * buf, size_t len)
{
LogPrint (eLogError, "SSU2: Can't handle incoming message in peer test session");
return false;
}
void SSU2PeerTestSession::ScheduleResend ()
{
if (m_NumResends < SSU2_PEER_TEST_MAX_NUM_RESENDS)
{
m_PeerTestResendTimer.expires_from_now (boost::posix_time::milliseconds(
SSU2_PEER_TEST_RESEND_INTERVAL + GetServer ().GetRng ()() % SSU2_PEER_TEST_RESEND_INTERVAL_VARIANCE));
std::weak_ptr<SSU2PeerTestSession> s(std::static_pointer_cast<SSU2PeerTestSession>(shared_from_this ()));
m_PeerTestResendTimer.async_wait ([s](const boost::system::error_code& ecode)
{
if (ecode != boost::asio::error::operation_aborted)
{
auto s1 = s.lock ();
if (s1)
{
int msg = 0;
if (s1->m_MsgNumReceived < 6)
msg = (s1->m_MsgNumReceived == 5) ? 6 : 5;
if (msg) // 5 or 6
{
s1->SendPeerTest (msg);
s1->ScheduleResend ();
}
}
}
});
m_NumResends++;
}
}
}
}

43
libi2pd/SSU2Session.h
View File

@ -390,43 +390,6 @@ namespace transport
std::unordered_map<uint32_t, uint32_t> m_ReceivedI2NPMsgIDs; // msgID -> timestamp in seconds
uint64_t m_LastResendTime, m_LastResendAttemptTime; // in milliseconds
};
const int SSU2_PEER_TEST_RESEND_INTERVAL = 3000; // in milliseconds
const int SSU2_PEER_TEST_RESEND_INTERVAL_VARIANCE = 2000; // in milliseconds
const int SSU2_PEER_TEST_MAX_NUM_RESENDS = 3;
class SSU2PeerTestSession: public SSU2Session // for PeerTest msgs 5,6,7
{
public:
SSU2PeerTestSession (SSU2Server& server, uint64_t sourceConnID, uint64_t destConnID);
uint8_t GetMsgNumReceived () const { return m_MsgNumReceived; }
bool IsConnectedRecently () const { return m_IsConnectedRecently; }
void SetStatusChanged () { m_IsStatusChanged = true; }
void SendPeerTest (uint8_t msg, const uint8_t * signedData, size_t signedDataLen,
std::shared_ptr<const i2p::data::RouterInfo::Address> addr);
bool ProcessPeerTest (uint8_t * buf, size_t len) override;
void Connect () override; // outgoing
bool ProcessFirstIncomingMessage (uint64_t connID, uint8_t * buf, size_t len) override; // incoming
private:
void SendPeerTest (uint8_t msg, const uint8_t * signedData, size_t signedDataLen); // PeerTest message
void SendPeerTest (uint8_t msg); // send or resend m_SignedData
void HandlePeerTest (const uint8_t * buf, size_t len) override;
void ScheduleResend ();
private:
uint8_t m_MsgNumReceived, m_NumResends;
bool m_IsConnectedRecently, m_IsStatusChanged;
std::vector<uint8_t> m_SignedData; // for resends
boost::asio::deadline_timer m_PeerTestResendTimer;
};
inline uint64_t CreateHeaderMask (const uint8_t * kh, const uint8_t * nonce)
{
@ -434,6 +397,12 @@ namespace transport
i2p::crypto::ChaCha20 ((uint8_t *)&data, 8, kh, nonce, (uint8_t *)&data);
return data;
}
inline void CreateNonce (uint64_t seqn, uint8_t * nonce)
{
memset (nonce, 0, 4);
htole64buf (nonce + 4, seqn);
}
}
}