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srs/trunk/3rdparty/srt-1-fit/srtcore/crypto.cpp
winlin e3bca883e1 SuqashSRS4: Build SRT native
2021-05-16 16:14:00 +08:00

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/*
* SRT - Secure, Reliable, Transport
* Copyright (c) 2018 Haivision Systems Inc.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
*/
/*****************************************************************************
written by
Haivision Systems Inc.
*****************************************************************************/
#include <cstring>
#include <string>
#include <sstream>
#include <iterator>
#include "udt.h"
#include "utilities.h"
#include <haicrypt.h>
#include "crypto.h"
#include "logging.h"
#include "core.h"
using namespace srt_logging;
#define SRT_MAX_KMRETRY 10
//#define SRT_CMD_KMREQ 3 /* HaiCryptTP SRT Keying Material */
//#define SRT_CMD_KMRSP 4 /* HaiCryptTP SRT Keying Material ACK */
#define SRT_CMD_KMREQ_SZ HCRYPT_MSG_KM_MAX_SZ /* */
#if SRT_CMD_KMREQ_SZ > SRT_CMD_MAXSZ
#error SRT_CMD_MAXSZ too small
#endif
/* Key Material Request (Network Order)
See HaiCryptTP SRT (hcrypt_xpt_srt.c)
*/
// 10* HAICRYPT_DEF_KM_PRE_ANNOUNCE
const int SRT_CRYPT_KM_PRE_ANNOUNCE = 0x10000;
#if ENABLE_LOGGING
std::string KmStateStr(SRT_KM_STATE state)
{
switch (state)
{
#define TAKE(val) case SRT_KM_S_##val : return #val
TAKE(UNSECURED);
TAKE(SECURED);
TAKE(SECURING);
TAKE(NOSECRET);
TAKE(BADSECRET);
#undef TAKE
default:
{
char buf[256];
sprintf(buf, "??? (%d)", state);
return buf;
}
}
}
std::string CCryptoControl::FormatKmMessage(std::string hdr, int cmd, size_t srtlen)
{
std::ostringstream os;
os << hdr << ": cmd=" << cmd << "(" << (cmd == SRT_CMD_KMREQ ? "KMREQ":"KMRSP") <<") len="
<< size_t(srtlen*sizeof(int32_t)) << " KmState: SND="
<< KmStateStr(m_SndKmState)
<< " RCV=" << KmStateStr(m_RcvKmState);
return os.str();
}
#endif
void CCryptoControl::updateKmState(int cmd, size_t srtlen SRT_ATR_UNUSED)
{
if (cmd == SRT_CMD_KMREQ)
{
if ( SRT_KM_S_UNSECURED == m_SndKmState)
{
m_SndKmState = SRT_KM_S_SECURING;
}
LOGP(mglog.Note, FormatKmMessage("sendSrtMsg", cmd, srtlen));
}
else
{
LOGP(mglog.Note, FormatKmMessage("sendSrtMsg", cmd, srtlen));
}
}
void CCryptoControl::createFakeSndContext()
{
if (!m_iSndKmKeyLen)
m_iSndKmKeyLen = 16;
if (!createCryptoCtx(Ref(m_hSndCrypto), m_iSndKmKeyLen, HAICRYPT_CRYPTO_DIR_TX))
{
HLOGC(mglog.Debug, log << "Error: Can't create fake crypto context for sending - sending will return ERROR!");
m_hSndCrypto = 0;
}
}
int CCryptoControl::processSrtMsg_KMREQ(
const uint32_t* srtdata SRT_ATR_UNUSED,
size_t bytelen SRT_ATR_UNUSED,
uint32_t* srtdata_out, ref_t<size_t> r_srtlen, int hsv SRT_ATR_UNUSED)
{
size_t& srtlen = *r_srtlen;
//Receiver
/* All 32-bit msg fields swapped on reception
* But HaiCrypt expect network order message
* Re-swap to cancel it.
*/
#ifdef SRT_ENABLE_ENCRYPTION
srtlen = bytelen/sizeof(srtdata[SRT_KMR_KMSTATE]);
HtoNLA(srtdata_out, srtdata, srtlen);
unsigned char* kmdata = reinterpret_cast<unsigned char*>(srtdata_out);
std::vector<unsigned char> kmcopy(kmdata, kmdata + bytelen);
// The side that has received KMREQ is always an HSD_RESPONDER, regardless of
// what has called this function. The HSv5 handshake only enforces bidirectional
// connection.
bool bidirectional = hsv > CUDT::HS_VERSION_UDT4;
// Local macro to return rejection appropriately.
// CHANGED. The first version made HSv5 reject the connection.
// This isn't well handled by applications, so the connection is
// still established, but unable to handle any transport.
//#define KMREQ_RESULT_REJECTION() if (bidirectional) { return SRT_CMD_NONE; } else { srtlen = 1; goto HSv4_ErrorReport; }
#define KMREQ_RESULT_REJECTION() { srtlen = 1; goto HSv4_ErrorReport; }
int rc = HAICRYPT_OK; // needed before 'goto' run from KMREQ_RESULT_REJECTION macro
bool SRT_ATR_UNUSED wasb4 = false;
size_t sek_len = 0;
// What we have to do:
// If encryption is on (we know that by having m_KmSecret nonempty), create
// the crypto context (if bidirectional, create for both sending and receiving).
// Both crypto contexts should be set with the same length of the key.
// The problem with interpretinting this should be reported as SRT_CMD_NONE,
// should be appropriately handled by the caller, as it expects that this
// function normally return SRT_CMD_KMRSP.
if ( bytelen <= HCRYPT_MSG_KM_OFS_SALT ) //Sanity on message
{
LOGC(mglog.Error, log << "processSrtMsg_KMREQ: size of the KM (" << bytelen << ") is too small, must be >" << HCRYPT_MSG_KM_OFS_SALT);
m_RcvKmState = SRT_KM_S_BADSECRET;
KMREQ_RESULT_REJECTION();
}
HLOGC(mglog.Debug, log << "KMREQ: getting SEK and creating receiver crypto");
sek_len = hcryptMsg_KM_GetSekLen(kmdata);
if ( sek_len == 0 )
{
LOGC(mglog.Error, log << "processSrtMsg_KMREQ: Received SEK is empty - REJECTING!");
m_RcvKmState = SRT_KM_S_BADSECRET;
KMREQ_RESULT_REJECTION();
}
// Write the key length
m_iRcvKmKeyLen = sek_len;
// Overwrite the key length anyway - it doesn't make sense to somehow
// keep the original setting because it will only make KMX impossible.
#if ENABLE_HEAVY_LOGGING
if (m_iSndKmKeyLen != m_iRcvKmKeyLen)
{
LOGC(mglog.Debug, log << "processSrtMsg_KMREQ: Agent's PBKEYLEN=" << m_iSndKmKeyLen
<< " overwritten by Peer's PBKEYLEN=" << m_iRcvKmKeyLen);
}
#endif
m_iSndKmKeyLen = m_iRcvKmKeyLen;
// This is checked only now so that the SRTO_PBKEYLEN return always the correct value,
// even if encryption is not possible because Agent didn't set a password, or supplied
// a wrong password.
if (m_KmSecret.len == 0) //We have a shared secret <==> encryption is on
{
LOGC(mglog.Error, log << "processSrtMsg_KMREQ: Agent does not declare encryption - won't decrypt incoming packets!");
m_RcvKmState = SRT_KM_S_NOSECRET;
KMREQ_RESULT_REJECTION();
}
wasb4 = m_hRcvCrypto;
if (!createCryptoCtx(Ref(m_hRcvCrypto), m_iRcvKmKeyLen, HAICRYPT_CRYPTO_DIR_RX))
{
LOGC(mglog.Error, log << "processSrtMsg_KMREQ: Can't create RCV CRYPTO CTX - must reject...");
m_RcvKmState = SRT_KM_S_NOSECRET;
KMREQ_RESULT_REJECTION();
}
if (!wasb4)
{
HLOGC(mglog.Debug, log << "processSrtMsg_KMREQ: created RX ENC with KeyLen=" << m_iRcvKmKeyLen);
}
// We have both sides set with password, so both are pending for security
m_RcvKmState = SRT_KM_S_SECURING;
// m_SndKmState is set to SECURING or UNSECURED in init(),
// or it might have been set to SECURED, NOSECRET or BADSECRET in the previous
// handshake iteration (handshakes may be sent multiple times for the same connection).
rc = HaiCrypt_Rx_Process(m_hRcvCrypto, kmdata, bytelen, NULL, NULL, 0);
switch(rc >= 0 ? HAICRYPT_OK : rc)
{
case HAICRYPT_OK:
m_RcvKmState = SRT_KM_S_SECURED;
HLOGC(mglog.Debug, log << "KMREQ/rcv: (snd) Rx process successful - SECURED.");
//Send back the whole message to confirm
break;
case HAICRYPT_ERROR_WRONG_SECRET: //Unmatched shared secret to decrypt wrapped key
m_RcvKmState = m_SndKmState = SRT_KM_S_BADSECRET;
//Send status KMRSP message to tel error
srtlen = 1;
LOGC(mglog.Error, log << "KMREQ/rcv: (snd) Rx process failure - BADSECRET");
break;
case HAICRYPT_ERROR: //Other errors
default:
m_RcvKmState = m_SndKmState = SRT_KM_S_NOSECRET;
srtlen = 1;
LOGC(mglog.Error, log << "KMREQ/rcv: (snd) Rx process failure (IPE) - NOSECRET");
break;
}
LOGP(mglog.Note, FormatKmMessage("processSrtMsg_KMREQ", SRT_CMD_KMREQ, bytelen));
// Since now, when CCryptoControl::decrypt() encounters an error, it will print it, ONCE,
// until the next KMREQ is received as a key regeneration.
m_bErrorReported = false;
if (srtlen == 1)
goto HSv4_ErrorReport;
// Configure the sender context also, if it succeeded to configure the
// receiver context and we are using bidirectional mode.
if ( bidirectional )
{
// Note: 'bidirectional' means that we want a bidirectional key update,
// which happens only and exclusively with HSv5 handshake - not when the
// usual key update through UMSG_EXT+SRT_CMD_KMREQ was done (which is used
// in HSv4 versions also to initialize the first key, unlike HSv5).
if (m_RcvKmState == SRT_KM_S_SECURED)
{
if (m_SndKmState == SRT_KM_S_SECURING && !m_hSndCrypto)
{
m_iSndKmKeyLen = m_iRcvKmKeyLen;
if (HaiCrypt_Clone(m_hRcvCrypto, HAICRYPT_CRYPTO_DIR_TX, &m_hSndCrypto) != HAICRYPT_OK)
{
LOGC(mglog.Error, log << "processSrtMsg_KMREQ: Can't create SND CRYPTO CTX - WILL NOT SEND-ENCRYPT correctly!");
if (hasPassphrase())
m_SndKmState = SRT_KM_S_BADSECRET;
else
m_SndKmState = SRT_KM_S_NOSECRET;
}
else
{
m_SndKmState = SRT_KM_S_SECURED;
}
LOGC(mglog.Note, log << FormatKmMessage("processSrtMsg_KMREQ", SRT_CMD_KMREQ, bytelen)
<< " SndKeyLen=" << m_iSndKmKeyLen
<< " TX CRYPTO CTX CLONED FROM RX"
);
// Write the KM message into the field from which it will be next sent.
memcpy(m_SndKmMsg[0].Msg, kmdata, bytelen);
m_SndKmMsg[0].MsgLen = bytelen;
m_SndKmMsg[0].iPeerRetry = 0; // Don't start sending them upon connection :)
}
else
{
HLOGC(mglog.Debug, log << "processSrtMsg_KMREQ: NOT cloning RX to TX crypto: already in "
<< KmStateStr(m_SndKmState) << " state");
}
}
else
{
HLOGP(mglog.Debug, "processSrtMsg_KMREQ: NOT SECURED - not replaying failed security association to TX CRYPTO CTX");
}
}
else
{
HLOGC(mglog.Debug, log << "processSrtMsg_KMREQ: NOT REPLAYING the key update to TX CRYPTO CTX.");
}
return SRT_CMD_KMRSP;
HSv4_ErrorReport:
if (bidirectional && hasPassphrase())
{
// If the Forward KMX process has failed, the reverse-KMX process was not done at all.
// This will lead to incorrect object configuration and will fail to properly declare
// the transmission state.
// Create the "fake crypto" with the passphrsae you currently have.
createFakeSndContext();
}
#undef KMREQ_RESULT_REJECTION
#else
// It's ok that this is reported as error because this happens in a scenario,
// when non-encryption-enabled SRT application is contacted by encryption-enabled SRT
// application which tries to make a security association.
LOGC(mglog.Error, log << "processSrtMsg_KMREQ: Encryption not enabled at compile time - must reject...");
m_RcvKmState = SRT_KM_S_NOSECRET;
#endif
srtlen = 1;
srtdata_out[SRT_KMR_KMSTATE] = m_RcvKmState;
return SRT_CMD_KMRSP;
}
int CCryptoControl::processSrtMsg_KMRSP(const uint32_t* srtdata, size_t len, int /* XXX unused? hsv*/)
{
/* All 32-bit msg fields (if present) swapped on reception
* But HaiCrypt expect network order message
* Re-swap to cancel it.
*/
uint32_t srtd[SRTDATA_MAXSIZE];
size_t srtlen = len/sizeof(uint32_t);
HtoNLA(srtd, srtdata, srtlen);
int retstatus = -1;
// Unused?
//bool bidirectional = hsv > CUDT::HS_VERSION_UDT4;
// Since now, when CCryptoControl::decrypt() encounters an error, it will print it, ONCE,
// until the next KMREQ is received as a key regeneration.
m_bErrorReported = false;
if (srtlen == 1) // Error report. Set accordingly.
{
SRT_KM_STATE peerstate = SRT_KM_STATE(srtd[SRT_KMR_KMSTATE]); /* Bad or no passphrase */
m_SndKmMsg[0].iPeerRetry = 0;
m_SndKmMsg[1].iPeerRetry = 0;
switch (peerstate)
{
case SRT_KM_S_BADSECRET:
m_SndKmState = m_RcvKmState = SRT_KM_S_BADSECRET;
retstatus = -1;
break;
// Default embraces two cases:
// NOSECRET: this KMRSP was sent by secured Peer, but Agent supplied no password.
// UNSECURED: this KMRSP was sent by unsecure Peer because Agent sent KMREQ.
case SRT_KM_S_NOSECRET:
// This means that the peer did not set the password, while Agent did.
m_RcvKmState = SRT_KM_S_UNSECURED;
m_SndKmState = SRT_KM_S_NOSECRET;
retstatus = -1;
break;
case SRT_KM_S_UNSECURED:
// This means that KMRSP was sent without KMREQ, to inform the Agent,
// that the Peer, unlike Agent, does use password. Agent can send then,
// but can't decrypt what Peer would send.
m_RcvKmState = SRT_KM_S_NOSECRET;
m_SndKmState = SRT_KM_S_UNSECURED;
retstatus = 0;
break;
default:
LOGC(mglog.Fatal, log << "processSrtMsg_KMRSP: IPE: unknown peer error state: "
<< KmStateStr(peerstate) << " (" << int(peerstate) << ")");
m_RcvKmState = SRT_KM_S_NOSECRET;
m_SndKmState = SRT_KM_S_NOSECRET;
retstatus = -1; //This is IPE
break;
}
LOGC(mglog.Error, log << "processSrtMsg_KMRSP: received failure report. STATE: " << KmStateStr(m_RcvKmState));
}
else
{
HLOGC(mglog.Debug, log << "processSrtMsg_KMRSP: received key response len=" << len);
// XXX INSECURE << ": [" << FormatBinaryString((uint8_t*)srtd, len) << "]";
bool key1 = getKmMsg_acceptResponse(0, srtd, len);
bool key2 = true;
if ( !key1 )
key2 = getKmMsg_acceptResponse(1, srtd, len); // <--- NOTE SEQUENCING!
if (key1 || key2)
{
m_SndKmState = m_RcvKmState = SRT_KM_S_SECURED;
HLOGC(mglog.Debug, log << "processSrtMsg_KMRSP: KM response matches " << (key1 ? "EVEN" : "ODD") << " key");
retstatus = 1;
}
else
{
retstatus = -1;
LOGC(mglog.Error, log << "processSrtMsg_KMRSP: IPE??? KM response key matches no key");
/* XXX INSECURE
LOGC(mglog.Error, log << "processSrtMsg_KMRSP: KM response: [" << FormatBinaryString((uint8_t*)srtd, len)
<< "] matches no key 0=[" << FormatBinaryString((uint8_t*)m_SndKmMsg[0].Msg, m_SndKmMsg[0].MsgLen)
<< "] 1=[" << FormatBinaryString((uint8_t*)m_SndKmMsg[1].Msg, m_SndKmMsg[1].MsgLen) << "]");
*/
m_SndKmState = m_RcvKmState = SRT_KM_S_BADSECRET;
}
HLOGC(mglog.Debug, log << "processSrtMsg_KMRSP: key[0]: len=" << m_SndKmMsg[0].MsgLen << " retry=" << m_SndKmMsg[0].iPeerRetry
<< "; key[1]: len=" << m_SndKmMsg[1].MsgLen << " retry=" << m_SndKmMsg[1].iPeerRetry);
}
LOGP(mglog.Note, FormatKmMessage("processSrtMsg_KMRSP", SRT_CMD_KMRSP, len));
return retstatus;
}
void CCryptoControl::sendKeysToPeer(Whether2RegenKm regen SRT_ATR_UNUSED)
{
if ( !m_hSndCrypto || m_SndKmState == SRT_KM_S_UNSECURED)
{
HLOGC(mglog.Debug, log << "sendKeysToPeer: NOT sending/regenerating keys: "
<< (m_hSndCrypto ? "CONNECTION UNSECURED" : "NO TX CRYPTO CTX created"));
return;
}
#ifdef SRT_ENABLE_ENCRYPTION
uint64_t now = 0;
/*
* Crypto Key Distribution to peer:
* If...
* - we want encryption; and
* - we have not tried more than CSRTCC_MAXRETRY times (peer may not be SRT); and
* - and did not get answer back from peer; and
* - last sent Keying Material req should have been replied (RTT*1.5 elapsed);
* then (re-)send handshake request.
*/
if ( ((m_SndKmMsg[0].iPeerRetry > 0) || (m_SndKmMsg[1].iPeerRetry > 0))
&& ((m_SndKmLastTime + ((m_parent->RTT() * 3)/2)) <= (now = CTimer::getTime())))
{
for (int ki = 0; ki < 2; ki++)
{
if (m_SndKmMsg[ki].iPeerRetry > 0 && m_SndKmMsg[ki].MsgLen > 0)
{
m_SndKmMsg[ki].iPeerRetry--;
HLOGC(mglog.Debug, log << "sendKeysToPeer: SENDING ki=" << ki << " len=" << m_SndKmMsg[ki].MsgLen
<< " retry(updated)=" << m_SndKmMsg[ki].iPeerRetry);
m_SndKmLastTime = now;
m_parent->sendSrtMsg(SRT_CMD_KMREQ, (uint32_t *)m_SndKmMsg[ki].Msg, m_SndKmMsg[ki].MsgLen/sizeof(uint32_t));
}
}
}
if (now == 0)
{
HLOGC(mglog.Debug, log << "sendKeysToPeer: NO KEYS RESENT, will " <<
(regen ? "" : "NOT ") << "regenerate.");
}
if (regen)
regenCryptoKm(
true, // send UMSG_EXT + SRT_CMD_KMREQ to the peer, if regenerated the key
false // Do not apply the regenerated key to the to the receiver context
); // regenerate and send
#endif
}
#ifdef SRT_ENABLE_ENCRYPTION
void CCryptoControl::regenCryptoKm(bool sendit, bool bidirectional)
{
if (!m_hSndCrypto)
return;
void *out_p[2];
size_t out_len_p[2];
int nbo = HaiCrypt_Tx_ManageKeys(m_hSndCrypto, out_p, out_len_p, 2);
int sent = 0;
HLOGC(mglog.Debug, log << "regenCryptoKm: regenerating crypto keys nbo=" << nbo <<
" THEN=" << (sendit ? "SEND" : "KEEP") << " DIR=" << (bidirectional ? "BOTH" : "SENDER"));
for (int i = 0; i < nbo && i < 2; i++)
{
/*
* New connection keying material
* or regenerated after crypto_cfg.km_refresh_rate_pkt packets .
* Send to peer
*/
// XXX Need to make it clearer and less hardcoded values
int kix = hcryptMsg_KM_GetKeyIndex((unsigned char *)(out_p[i]));
int ki = kix & 0x1;
if ((out_len_p[i] != m_SndKmMsg[ki].MsgLen)
|| (0 != memcmp(out_p[i], m_SndKmMsg[ki].Msg, m_SndKmMsg[ki].MsgLen)))
{
uint8_t* oldkey SRT_ATR_UNUSED = m_SndKmMsg[ki].Msg;
HLOGC(mglog.Debug, log << "new key[" << ki << "] index=" << kix
<< " OLD=[" << m_SndKmMsg[ki].MsgLen << "]"
<< FormatBinaryString(m_SndKmMsg[ki].Msg, m_SndKmMsg[ki].MsgLen)
<< " NEW=[" << out_len_p[i] << "]"
<< FormatBinaryString((const uint8_t*)out_p[i], out_len_p[i]));
/* New Keying material, send to peer */
memcpy(m_SndKmMsg[ki].Msg, out_p[i], out_len_p[i]);
m_SndKmMsg[ki].MsgLen = out_len_p[i];
m_SndKmMsg[ki].iPeerRetry = SRT_MAX_KMRETRY;
if (bidirectional && !sendit)
{
// "Send" this key also to myself, just to be applied to the receiver crypto,
// exactly the same way how this key is interpreted on the peer side into its receiver crypto
int rc = HaiCrypt_Rx_Process(m_hRcvCrypto, m_SndKmMsg[ki].Msg, m_SndKmMsg[ki].MsgLen, NULL, NULL, 0);
if ( rc < 0 )
{
LOGC(mglog.Fatal, log << "regenCryptoKm: IPE: applying key generated in snd crypto into rcv crypto: failed code=" << rc);
// The party won't be able to decrypt incoming data!
// Not sure if anything has to be reported.
}
}
if (sendit)
{
HLOGC(mglog.Debug, log << "regenCryptoKm: SENDING ki=" << ki << " len=" << m_SndKmMsg[ki].MsgLen
<< " retry(updated)=" << m_SndKmMsg[ki].iPeerRetry);
m_parent->sendSrtMsg(SRT_CMD_KMREQ, (uint32_t *)m_SndKmMsg[ki].Msg, m_SndKmMsg[ki].MsgLen/sizeof(uint32_t));
sent++;
}
}
else if (out_len_p[i] == 0)
{
HLOGC(mglog.Debug, log << "no key[" << ki << "] index=" << kix << ": not generated");
}
else
{
HLOGC(mglog.Debug, log << "no key[" << ki << "] index=" << kix << ": key unchanged");
}
}
HLOGC(mglog.Debug, log << "regenCryptoKm: key[0]: len=" << m_SndKmMsg[0].MsgLen << " retry=" << m_SndKmMsg[0].iPeerRetry
<< "; key[1]: len=" << m_SndKmMsg[1].MsgLen << " retry=" << m_SndKmMsg[1].iPeerRetry);
if (sent)
m_SndKmLastTime = CTimer::getTime();
}
#endif
CCryptoControl::CCryptoControl(CUDT* parent, SRTSOCKET id):
m_parent(parent), // should be initialized in createCC()
m_SocketID(id),
m_iSndKmKeyLen(0),
m_iRcvKmKeyLen(0),
m_SndKmState(SRT_KM_S_UNSECURED),
m_RcvKmState(SRT_KM_S_UNSECURED),
m_KmRefreshRatePkt(0),
m_KmPreAnnouncePkt(0),
m_bErrorReported(false)
{
m_KmSecret.len = 0;
//send
m_SndKmLastTime = 0;
m_SndKmMsg[0].MsgLen = 0;
m_SndKmMsg[0].iPeerRetry = 0;
m_SndKmMsg[1].MsgLen = 0;
m_SndKmMsg[1].iPeerRetry = 0;
m_hSndCrypto = NULL;
//recv
m_hRcvCrypto = NULL;
}
bool CCryptoControl::init(HandshakeSide side, bool bidirectional SRT_ATR_UNUSED)
{
// NOTE: initiator creates m_hSndCrypto. When bidirectional,
// it creates also m_hRcvCrypto with the same key length.
// Acceptor creates nothing - it will create appropriate
// contexts when receiving KMREQ from the initiator.
HLOGC(mglog.Debug, log << "CCryptoControl::init: HS SIDE:"
<< (side == HSD_INITIATOR ? "INITIATOR" : "RESPONDER")
<< " DIRECTION:" << (bidirectional ? "BOTH" : (side == HSD_INITIATOR) ? "SENDER" : "RECEIVER"));
// Set UNSECURED state as default
m_RcvKmState = SRT_KM_S_UNSECURED;
// Set security-pending state, if a password was set.
m_SndKmState = hasPassphrase() ? SRT_KM_S_SECURING : SRT_KM_S_UNSECURED;
m_KmPreAnnouncePkt = m_parent->m_uKmPreAnnouncePkt;
m_KmRefreshRatePkt = m_parent->m_uKmRefreshRatePkt;
if ( side == HSD_INITIATOR )
{
if (hasPassphrase())
{
#ifdef SRT_ENABLE_ENCRYPTION
if (m_iSndKmKeyLen == 0)
{
HLOGC(mglog.Debug, log << "CCryptoControl::init: PBKEYLEN still 0, setting default 16");
m_iSndKmKeyLen = 16;
}
bool ok = createCryptoCtx(Ref(m_hSndCrypto), m_iSndKmKeyLen, HAICRYPT_CRYPTO_DIR_TX);
HLOGC(mglog.Debug, log << "CCryptoControl::init: creating SND crypto context: " << ok);
if (ok && bidirectional)
{
m_iRcvKmKeyLen = m_iSndKmKeyLen;
int st = HaiCrypt_Clone(m_hSndCrypto, HAICRYPT_CRYPTO_DIR_RX, &m_hRcvCrypto);
HLOGC(mglog.Debug, log << "CCryptoControl::init: creating CLONED RCV crypto context: status=" << st);
ok = st == 0;
}
// Note: this is sanity check, it should never happen.
if (!ok)
{
m_SndKmState = SRT_KM_S_NOSECRET; // wanted to secure, but error occurred.
if (bidirectional)
m_RcvKmState = SRT_KM_S_NOSECRET;
return false;
}
regenCryptoKm(
false, // Do not send the key (will be attached it to the HSv5 handshake)
bidirectional // replicate the key to the receiver context, if bidirectional
);
#else
LOGC(mglog.Error, log << "CCryptoControl::init: encryption not supported");
return true;
#endif
}
else
{
HLOGC(mglog.Debug, log << "CCryptoControl::init: CAN'T CREATE crypto: key length for SND = " << m_iSndKmKeyLen);
}
}
else
{
HLOGC(mglog.Debug, log << "CCryptoControl::init: NOT creating crypto contexts - will be created upon reception of KMREQ");
}
return true;
}
void CCryptoControl::close()
{
/* Wipeout secrets */
memset(&m_KmSecret, 0, sizeof(m_KmSecret));
}
std::string CCryptoControl::CONID() const
{
if ( m_SocketID == 0 )
return "";
std::ostringstream os;
os << "%" << m_SocketID << ":";
return os.str();
}
#if ENABLE_HEAVY_LOGGING
static std::string CryptoFlags(int flg)
{
using namespace std;
vector<string> f;
if (flg & HAICRYPT_CFG_F_CRYPTO)
f.push_back("crypto");
if (flg & HAICRYPT_CFG_F_TX)
f.push_back("TX");
if (flg & HAICRYPT_CFG_F_FEC)
f.push_back("fec");
ostringstream os;
copy(f.begin(), f.end(), ostream_iterator<string>(os, "|"));
return os.str();
}
#endif
#ifdef SRT_ENABLE_ENCRYPTION
bool CCryptoControl::createCryptoCtx(ref_t<HaiCrypt_Handle> hCrypto, size_t keylen, HaiCrypt_CryptoDir cdir)
{
if (*hCrypto)
{
// XXX You can check here if the existing handle represents
// a correctly defined crypto. But this doesn't seem to be
// necessary - the whole CCryptoControl facility seems to be valid only
// within the frames of one connection.
return true;
}
if ((m_KmSecret.len <= 0) || (keylen <= 0))
{
LOGC(mglog.Error, log << CONID() << "cryptoCtx: missing secret (" << m_KmSecret.len << ") or key length (" << keylen << ")");
return false;
}
HaiCrypt_Cfg crypto_cfg;
memset(&crypto_cfg, 0, sizeof(crypto_cfg));
#if 0//test key refresh (fast rate)
m_KmRefreshRatePkt = 2000;
m_KmPreAnnouncePkt = 500;
#endif
crypto_cfg.flags = HAICRYPT_CFG_F_CRYPTO | (cdir == HAICRYPT_CRYPTO_DIR_TX ? HAICRYPT_CFG_F_TX : 0);
crypto_cfg.xport = HAICRYPT_XPT_SRT;
crypto_cfg.cryspr = HaiCryptCryspr_Get_Instance();
crypto_cfg.key_len = (size_t)keylen;
crypto_cfg.data_max_len = HAICRYPT_DEF_DATA_MAX_LENGTH; //MTU
crypto_cfg.km_tx_period_ms = 0;//No HaiCrypt KM inject period, handled in SRT;
crypto_cfg.km_refresh_rate_pkt = m_KmRefreshRatePkt == 0 ? HAICRYPT_DEF_KM_REFRESH_RATE : m_KmRefreshRatePkt;
crypto_cfg.km_pre_announce_pkt = m_KmPreAnnouncePkt == 0 ? SRT_CRYPT_KM_PRE_ANNOUNCE : m_KmPreAnnouncePkt;
crypto_cfg.secret = m_KmSecret;
//memcpy(&crypto_cfg.secret, &m_KmSecret, sizeof(crypto_cfg.secret));
HLOGC(mglog.Debug, log << "CRYPTO CFG: flags=" << CryptoFlags(crypto_cfg.flags) << " xport=" << crypto_cfg.xport << " cryspr=" << crypto_cfg.cryspr
<< " keylen=" << crypto_cfg.key_len << " passphrase_length=" << crypto_cfg.secret.len);
if (HaiCrypt_Create(&crypto_cfg, &hCrypto.get()) != HAICRYPT_OK)
{
LOGC(mglog.Error, log << CONID() << "cryptoCtx: could not create " << (cdir == HAICRYPT_CRYPTO_DIR_TX ? "tx" : "rx") << " crypto ctx");
return false;
}
HLOGC(mglog.Debug, log << CONID() << "cryptoCtx: CREATED crypto for dir=" << (cdir == HAICRYPT_CRYPTO_DIR_TX ? "tx" : "rx") << " keylen=" << keylen);
return true;
}
#else
bool CCryptoControl::createCryptoCtx(ref_t<HaiCrypt_Handle>, size_t, HaiCrypt_CryptoDir)
{
return false;
}
#endif
EncryptionStatus CCryptoControl::encrypt(ref_t<CPacket> r_packet SRT_ATR_UNUSED)
{
#ifdef SRT_ENABLE_ENCRYPTION
// Encryption not enabled - do nothing.
if ( getSndCryptoFlags() == EK_NOENC )
return ENCS_CLEAR;
CPacket& packet = *r_packet;
int rc = HaiCrypt_Tx_Data(m_hSndCrypto, (uint8_t*)packet.getHeader(), (uint8_t*)packet.m_pcData, packet.getLength());
if (rc < 0)
{
return ENCS_FAILED;
}
else if ( rc > 0 )
{
// XXX what happens if the encryption is said to be "succeeded",
// but the length is 0? Shouldn't this be treated as unwanted?
packet.setLength(rc);
}
return ENCS_CLEAR;
#else
return ENCS_NOTSUP;
#endif
}
EncryptionStatus CCryptoControl::decrypt(ref_t<CPacket> r_packet SRT_ATR_UNUSED)
{
#ifdef SRT_ENABLE_ENCRYPTION
CPacket& packet = *r_packet;
if (packet.getMsgCryptoFlags() == EK_NOENC)
{
HLOGC(mglog.Debug, log << "CPacket::decrypt: packet not encrypted");
return ENCS_CLEAR; // not encrypted, no need do decrypt, no flags to be modified
}
if (m_RcvKmState == SRT_KM_S_UNSECURED)
{
if (m_KmSecret.len != 0)
{
// We were unaware that the peer has set password,
// but now here we are.
m_RcvKmState = SRT_KM_S_SECURING;
LOGC(mglog.Note, log << "SECURITY UPDATE: Peer has surprised Agent with encryption, but KMX is pending - current packet size="
<< packet.getLength() << " dropped");
return ENCS_FAILED;
}
else
{
// Peer has set a password, but Agent did not,
// which means that it will be unable to decrypt
// sent payloads anyway.
m_RcvKmState = SRT_KM_S_NOSECRET;
LOGP(mglog.Error, "SECURITY FAILURE: Agent has no PW, but Peer sender has declared one, can't decrypt");
// This only informs about the state change; it will be also caught by the condition below
}
}
if (m_RcvKmState != SRT_KM_S_SECURED)
{
// If not "secured", it means that it won't be able to decrypt packets,
// so there's no point to even try to send them to HaiCrypt_Rx_Data.
// Actually the current conditions concerning m_hRcvCrypto are such that this object
// is cretaed in case of SRT_KM_S_BADSECRET, so it will simply fail to decrypt,
// but with SRT_KM_S_NOSECRET m_hRcvCrypto is not even created (is NULL), which
// will then cause an error to be reported, misleadingly. Simply don't try to
// decrypt anything as long as you are not sure that the connection is secured.
// This problem will occur every time a packet comes in, it's worth reporting,
// but not with every single packet arriving. Print it once and turn off the flag;
// it will be restored at the next attempt of KMX.
if (!m_bErrorReported)
{
m_bErrorReported = true;
LOGC(mglog.Error, log << "SECURITY STATUS: " << KmStateStr(m_RcvKmState) << " - can't decrypt packet.");
}
HLOGC(mglog.Debug, log << "Packet still not decrypted, status=" << KmStateStr(m_RcvKmState)
<< " - dropping size=" << packet.getLength());
return ENCS_FAILED;
}
int rc = HaiCrypt_Rx_Data(m_hRcvCrypto, (uint8_t *)packet.getHeader(), (uint8_t *)packet.m_pcData, packet.getLength());
if ( rc <= 0 )
{
LOGC(mglog.Error, log << "decrypt ERROR (IPE): HaiCrypt_Rx_Data failure=" << rc << " - returning failed decryption");
// -1: decryption failure
// 0: key not received yet
return ENCS_FAILED;
}
// Otherwise: rc == decrypted text length.
packet.setLength(rc); /* In case clr txt size is different from cipher txt */
// Decryption succeeded. Update flags.
packet.setMsgCryptoFlags(EK_NOENC);
HLOGC(mglog.Debug, log << "decrypt: successfully decrypted, resulting length=" << rc);
return ENCS_CLEAR;
#else
return ENCS_NOTSUP;
#endif
}
CCryptoControl::~CCryptoControl()
{
#ifdef SRT_ENABLE_ENCRYPTION
if (m_hSndCrypto)
{
HaiCrypt_Close(m_hSndCrypto);
}
if (m_hRcvCrypto)
{
HaiCrypt_Close(m_hRcvCrypto);
}
#endif
}
std::string SrtFlagString(int32_t flags)
{
#define LEN(arr) (sizeof (arr)/(sizeof ((arr)[0])))
std::string output;
static std::string namera[] = { "TSBPD-snd", "TSBPD-rcv", "haicrypt", "TLPktDrop", "NAKReport", "ReXmitFlag", "StreamAPI" };
size_t i = 0;
for ( ; i < LEN(namera); ++i )
{
if ( (flags & 1) == 1 )
{
output += "+" + namera[i] + " ";
}
else
{
output += "-" + namera[i] + " ";
}
flags >>= 1;
//if ( flags == 0 )
// break;
}
#undef LEN
if ( flags != 0 )
{
output += "+unknown";
}
return output;
}
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