stun.cxx

这是国外的resip协议栈

               return false;
            }
            break;

            //overlay on parse, ownership is buffer parsed from
         case TurnData:
            msg.hasTurnData = true;
            msg.turnData = new resip::Data(resip::Data::Share, body, attrLen);
            break;

            //case TurnNonce:
            //break;
            //case TurnRealm:
            //break;
					
         default:
            if (verbose) clog << "Unknown attribute: " << atrType << endl;
            if ( atrType <= 0x7FFF ) 
            {
               return false;
            }
      }
		
      body += attrLen;
      size -= attrLen;
   }
    
   return true;
}

static char* 
encode16(char* buf, UInt16 data)
{
   UInt16 ndata = htons(data);
   memcpy(buf, reinterpret_cast<void*>(&ndata), sizeof(UInt16));
   return buf + sizeof(UInt16);
}

static char* 
encode32(char* buf, UInt32 data)
{
   UInt32 ndata = htonl(data);
   memcpy(buf, reinterpret_cast<void*>(&ndata), sizeof(UInt32));
   return buf + sizeof(UInt32);
}


static char* 
encode(char* buf, const char* data, unsigned int length)
{
   memcpy(buf, data, length);
   return buf + length;
}

static char* 
encodeTurnData(char *ptr, const resip::Data* td)
{
   ptr = encode16(ptr, TurnData);
   ptr = encode16(ptr, td->size());
   memcpy(ptr, td->data(), td->size());
   ptr += td->size();
   
   return ptr;
}

static char*
encodeAtrUInt32(char* ptr, UInt16 type, UInt32 value)
{
   ptr = encode16(ptr, type);
   ptr = encode16(ptr, 4);
   ptr = encode32(ptr, value);
   return ptr;
}

static char* 
encodeAtrAddress4(char* ptr, UInt16 type, const StunAtrAddress4& atr)
{
   ptr = encode16(ptr, type);
   ptr = encode16(ptr, 8);
   *ptr++ = atr.pad;
   *ptr++ = IPv4Family;
   ptr = encode16(ptr, atr.ipv4.port);
   ptr = encode32(ptr, atr.ipv4.addr);
	
   return ptr;
}

static char* 
encodeAtrChangeRequest(char* ptr, const StunAtrChangeRequest& atr)
{
   ptr = encode16(ptr, ChangeRequest);
   ptr = encode16(ptr, 4);
   ptr = encode32(ptr, atr.value);
   return ptr;
}

static char* 
encodeMagicCookie(char* ptr, const UInt32& cookie)
{
   ptr = encode16(ptr, TurnMagicCookie);
   ptr = encode16(ptr, 4);
   ptr = encode32(ptr, cookie);
   return ptr;
}


static char* 
encodeAtrError(char* ptr, const StunAtrError& atr)
{
   ptr = encode16(ptr, ErrorCode);
   ptr = encode16(ptr, 4 + atr.sizeReason);
   ptr = encode16(ptr, atr.pad);
   *ptr++ = atr.errorClass;
   *ptr++ = atr.number;
   ptr = encode(ptr, atr.reason, atr.sizeReason);
   return ptr;
}


static char* 
encodeAtrUnknown(char* ptr, const StunAtrUnknown& atr)
{
   ptr = encode16(ptr, UnknownAttribute);
   ptr = encode16(ptr, 2+2*atr.numAttributes);
   for (int i=0; i<atr.numAttributes; i++)
   {
      ptr = encode16(ptr, atr.attrType[i]);
   }
   return ptr;
}


static char* 
encodeXorOnly(char* ptr)
{
   ptr = encode16(ptr, XorOnly );
   return ptr;
}


static char* 
encodeAtrString(char* ptr, UInt16 type, const StunAtrString& atr)
{
   assert(atr.sizeValue % 4 == 0);
	
   ptr = encode16(ptr, type);
   ptr = encode16(ptr, atr.sizeValue);
   ptr = encode(ptr, atr.value, atr.sizeValue);
   return ptr;
}


static char* 
encodeAtrIntegrity(char* ptr, const StunAtrIntegrity& atr)
{
   ptr = encode16(ptr, MessageIntegrity);
   ptr = encode16(ptr, 20);
   ptr = encode(ptr, atr.hash, sizeof(atr.hash));
   return ptr;
}


unsigned int
stunEncodeMessage( const StunMessage& msg, 
                   char* buf, 
                   unsigned int bufLen, 
                   const StunAtrString& password, 
                   bool verbose)
{
   assert(bufLen >= sizeof(StunMsgHdr));
   char* ptr = buf;
	
   if (verbose) clog << "Encoding stun message: " << endl;

   ptr = encode16(ptr, msg.msgHdr.msgType);
   char* lengthp = ptr;
   ptr = encode16(ptr, 0);
   ptr = encode(ptr, reinterpret_cast<const char*>(msg.msgHdr.id.octet), sizeof(msg.msgHdr.id));

   if (msg.hasTurnMagicCookie)
   {
      if (verbose) clog << "Encoding TurnMagicCookie: " << msg.turnMagicCookie << endl;
      ptr = encodeMagicCookie(ptr, msg.turnMagicCookie);
   }
   if (msg.hasTurnDestinationAddress)
   {
      if (verbose) clog << "Encoding TurnDestinationAddress: " << msg.turnDestinationAddress.ipv4 << endl;
      ptr = encodeAtrAddress4 (ptr, TurnDestinationAddress, msg.turnDestinationAddress);
   }
   if (msg.hasMappedAddress)
   {
      if (verbose) clog << "Encoding MappedAddress: " << msg.mappedAddress.ipv4 << endl;
      ptr = encodeAtrAddress4 (ptr, MappedAddress, msg.mappedAddress);
   }
   if (msg.hasResponseAddress)
   {
      if (verbose) clog << "Encoding ResponseAddress: " << msg.responseAddress.ipv4 << endl;
      ptr = encodeAtrAddress4(ptr, ResponseAddress, msg.responseAddress);
   }
   if (msg.hasTurnAlternateServer )
   {
      if (verbose) clog << "Encoding AlternateServer: " << msg.turnAlternateServer.ipv4 << endl;
      ptr = encodeAtrAddress4 (ptr, TurnAlternateServer, msg.turnAlternateServer);
   }
   if (msg.hasChangeRequest)
   {
      if (verbose) clog << "Encoding ChangeRequest: " << msg.changeRequest.value << endl;
      ptr = encodeAtrChangeRequest(ptr, msg.changeRequest);
   }
   if (msg.hasSourceAddress)
   {
      if (verbose) clog << "Encoding SourceAddress: " << msg.sourceAddress.ipv4 << endl;
      ptr = encodeAtrAddress4(ptr, SourceAddress, msg.sourceAddress);
   }
   if (msg.hasChangedAddress)
   {
      if (verbose) clog << "Encoding ChangedAddress: " << msg.changedAddress.ipv4 << endl;
      ptr = encodeAtrAddress4(ptr, ChangedAddress, msg.changedAddress);
   }
   if (msg.hasUsername)
   {
      if (verbose) clog << "Encoding Username: " << msg.username.value << endl;
      ptr = encodeAtrString(ptr, Username, msg.username);
   }
   if (msg.hasPassword)
   {
      if (verbose) clog << "Encoding Password: " << msg.password.value << endl;
      ptr = encodeAtrString(ptr, Password, msg.password);
   }
   if (msg.hasErrorCode)
   {
      if (verbose) clog << "Encoding ErrorCode: class=" 
			<< int(msg.errorCode.errorClass)  
			<< " number=" << int(msg.errorCode.number) 
			<< " reason=" 
			<< msg.errorCode.reason 
			<< endl;
		
      ptr = encodeAtrError(ptr, msg.errorCode);
   }
   if (msg.hasUnknownAttributes)
   {
      if (verbose) clog << "Encoding UnknownAttribute: ???" << endl;
      ptr = encodeAtrUnknown(ptr, msg.unknownAttributes);
   }
   if (msg.hasReflectedFrom)
   {
      if (verbose) clog << "Encoding ReflectedFrom: " << msg.reflectedFrom.ipv4 << endl;
      ptr = encodeAtrAddress4(ptr, ReflectedFrom, msg.reflectedFrom);
   }
   if (msg.hasXorMappedAddress)
   {
      if (verbose) clog << "Encoding XorMappedAddress: " << msg.xorMappedAddress.ipv4 << endl;
      ptr = encodeAtrAddress4 (ptr, XorMappedAddress, msg.xorMappedAddress);
   }
   if (msg.xorOnly)
   {
      if (verbose) clog << "Encoding xorOnly: " << endl;
      ptr = encodeXorOnly( ptr );
   }
   if (msg.hasServerName)
   {
      if (verbose) clog << "Encoding ServerName: " << msg.serverName.value << endl;
      ptr = encodeAtrString(ptr, ServerName, msg.serverName);
   }
   if (msg.hasSecondaryAddress)
   {
      if (verbose) clog << "Encoding SecondaryAddress: " << msg.secondaryAddress.ipv4 << endl;
      ptr = encodeAtrAddress4 (ptr, SecondaryAddress, msg.secondaryAddress);
   }
   if (msg.hasTurnLifetime)
   {
      if (verbose) clog << "Encoding Turn Lifetime: " << msg.turnLifetime << endl;
      ptr = encodeAtrUInt32(ptr, TurnLifetime, msg.turnLifetime);
   }
   if (msg.hasTurnBandwidth)
   {
      if (verbose) clog << "Encoding Turn Bandwidth: " << msg.turnBandwidth << endl;
      ptr = encodeAtrUInt32(ptr, TurnBandwidth, msg.turnBandwidth);
   }   
   if (msg.hasTurnData)
   {
      if (verbose) clog << "Encoding TurnData (not shown)" << endl;
      ptr = encodeTurnData (ptr, msg.turnData);
   }
   if (password.sizeValue > 0)
   {
      if (verbose) clog << "HMAC with password: " << password.value << endl;

      // allocate space for message integrity attribute (hash + attribute type + size)
      char* ptrMessageIntegrity = ptr;
	  ptr += 20 + sizeof(MessageIntegrity) + sizeof(UInt16);
      encode16(lengthp, UInt16(ptr - buf - sizeof(StunMsgHdr)));
   
      StunAtrIntegrity integrity;
      // pad with zeros prior to calculating message integrity attribute	   
      int padding = 0;
      int len = ptrMessageIntegrity - buf;
      if (len % 64)
      {
         padding = 64 - (len % 64);
         memset(ptrMessageIntegrity, 0, padding);
      }
	   computeHmac(integrity.hash, buf, len + padding, password.value, password.sizeValue);
	   encodeAtrIntegrity(ptrMessageIntegrity, integrity);
   }

   if (verbose) clog << endl;
   encode16(lengthp, UInt16(ptr - buf - sizeof(StunMsgHdr)));
   return int(ptr - buf);
}

int 
stunRand()
{
   // return 32 bits of random stuff
   assert( sizeof(int) == 4 );
   static bool init=false;
   if ( !init )
   { 
      init = true;
		
      UInt64 tick;
		
#if defined(WIN32) 
#if !defined(UNDER_CE) && !defined(__GNUC__)
      volatile unsigned int lowtick=0,hightick=0;
      __asm
         {
            rdtsc 
               mov lowtick, eax
               mov hightick, edx
               }
      tick = hightick;
      tick <<= 32;
      tick |= lowtick;
#else
	  tick = GetTickCount();
#endif
#elif defined(__GNUC__) && ( defined(__i686__) || defined(__i386__) || defined(__x86_64__) )
      asm("rdtsc" : "=A" (tick));
#elif defined (__SUNPRO_CC) || defined( __sparc__ )	
      tick = gethrtime();
#elif defined(__APPLE__) || defined(__MACH__)
      int fd=open("/dev/random",O_RDONLY);
      read(fd,&tick,sizeof(tick));
      closeSocket(fd);
#elif defined(__linux__)
      int fd=open("/dev/urandom",O_RDONLY);
      read(fd,&tick,sizeof(tick));
      closeSocket(fd);
#else
#     error Need some way to seed the random number generator 
#endif 
      int seed = int(tick);
#ifdef WIN32
      srand(seed);
#else
      srandom(seed);
#endif
   }
	
#ifdef WIN32
   assert( RAND_MAX == 0x7fff );
   int r1 = rand();
   int r2 = rand();
	
   int ret = (r1<<16) + r2;
	
   return ret;
#else
   return random(); 
#endif
}


/// return a random number to use as a port 
int
stunRandomPort()
{
   int min=0x4000;
   int max=0x7FFF;
	
   int ret = stunRand();
   ret = ret|min;
   ret = ret&max;
	
   return ret;
}


#ifndef USE_SSL
void
computeHmac(char* hmac, const char* input, int length, const char* key, int sizeKey)
{
   strncpy(hmac,"hmac-not-implemented",20);
}
#else
#include <openssl/hmac.h>

void
computeHmac(char* hmac, const char* input, int length, const char* key, int sizeKey)
{
   unsigned int resultSize=0;
   HMAC(EVP_sha1(), 
        key, sizeKey, 
        reinterpret_cast<const unsigned char*>(input), length, 
        reinterpret_cast<unsigned char*>(hmac), &resultSize);
   assert(resultSize == 20);
}
#endif


static void
toHex(const char* buffer, int bufferSize, char* output) 
{
   static char hexmap[] = "0123456789abcdef";
	
   const char* p = buffer;
   char* r = output;
   for (int i=0; i < bufferSize; i++)
   {
      unsigned char temp = *p++;
		
      int hi = (temp & 0xf0)>>4;
      int low = (temp & 0xf);
		
      *r++ = hexmap[hi];
      *r++ = hexmap[low];
   }
   *r = 0;
}

void
stunCreateUserName(const StunAddress4& source, StunAtrString* username)
{
   UInt64 time = stunGetSystemTimeSecs();
   time -= (time % 20*60);
   //UInt64 hitime = time >> 32;
   UInt64 lotime = time & 0xFFFFFFFF;
	
   char buffer[1024];
   sprintf(buffer,
           "%08x:%08x:%08x:", 
           UInt32(source.addr),
           UInt32(stunRand()),
           UInt32(lotime));
   assert( strlen(buffer) < 1024 );
	
   assert(strlen(buffer) + 41 < STUN_MAX_STRING);
	
   char hmac[20];
   char key[] = "Jason";
   computeHmac(hmac, buffer, strlen(buffer), key, strlen(key) );
   char hmacHex[41];
   toHex(hmac, 20, hmacHex );
   hmacHex[40] =0;
	
   strcat(buffer,hmacHex);
	
   int l = strlen(buffer);
   assert( l+1 < STUN_MAX_STRING );
   assert( l%4 == 0 );
   
   username->sizeValue = l;
   memcpy(username->value,buffer,l);
   username->value[l]=0;
	
   //if (verbose) clog << "computed username=" << username.value << endl;
}

void
stunCreatePassword(const StunAtrString& username, StunAtrString* password)
{
   char hmac[20];
   char key[] = "Fluffy";
   //char buffer[STUN_MAX_STRING];
   computeHmac(hmac, username.value, strlen(username.value), key, strlen(key));
   toHex(hmac, 20, password->value);