rtp/srtpstack/src/srtppacketrtp.cpp
changeset 0 307788aac0a8
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rtp/srtpstack/src/srtppacketrtp.cpp	Tue Feb 02 01:03:15 2010 +0200
@@ -0,0 +1,326 @@
+/*
+* Copyright (c) 2004 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:    General packet handling routines.
+*
+*/
+
+
+
+
+// INCLUDES
+#include "srtppacketrtp.h"
+#include "srtputils.h"
+#include "srtpcryptohandler.h"
+#include "srtpcryptocontext.h"
+#include "srtpmasterkey.h"
+#include "srtpmastersalt.h"
+
+// -----------------------------------------------------------------------------
+// CSRTPPacketRTP::CSRTPPacketRTP
+// -----------------------------------------------------------------------------
+//
+CSRTPPacketRTP::CSRTPPacketRTP(const TDesC8& aPacket,
+                   CSRTPCryptoHandler& aHandler)
+    : CSRTPPacket(aPacket, aHandler),
+        iSequenceNumber(0),
+        iPacketIndex(0)
+            {
+            
+            }
+
+// -----------------------------------------------------------------------------
+// CSRTPPacketRTP::~CSRTPPacketRTP
+// -----------------------------------------------------------------------------
+//
+CSRTPPacketRTP::~CSRTPPacketRTP()
+            {
+            
+            }
+
+// ---------------------------------------------------------------------------
+// Two-phased constructor. 
+// 
+// ---------------------------------------------------------------------------
+//
+CSRTPPacketRTP* CSRTPPacketRTP::NewL(const TDesC8& aPacket,
+                      CSRTPCryptoHandler& aHandler)
+    {
+    CSRTPPacketRTP* self = new( ELeave )CSRTPPacketRTP( aPacket, aHandler);
+    CleanupStack::PushL( self );    
+    self->ConstructL();
+    CleanupStack::Pop( self );        
+    return self;
+    }
+
+// -----------------------------------------------------------------------------
+// void CSRTPPacketRTP::ConstructL
+// -----------------------------------------------------------------------------
+//
+void CSRTPPacketRTP::ConstructL()
+    {            
+    CSRTPPacket::ConstructL(); 
+    UpdateHeaderLengthL();
+    
+    SRTP_DEBUG_TINT_VALUE( "RTP header length", iHeaderLength );
+        
+    UpdateSequenceNumber();        
+    UpdatePayloadLength();
+    
+    SRTP_DEBUG_TINT_VALUE( "RTP payload length", iPayloadLength );
+     
+    UpdatePayload();           
+    
+    }
+// ---------------------------------------------------------------------------
+// CSRTPPacketRTP::UpdateHeaderLengthL()
+// ---------------------------------------------------------------------------
+//
+void CSRTPPacketRTP::UpdateHeaderLengthL()
+    {    
+    //TUint payloadOffset = KMinSizeRtpHeader;
+    TInt size = iPacket.Length();
+    if (size < KMinSizeRtpHeader)
+    	{
+    	User::Leave(KErrCorrupt);
+    	}
+	const TUint8 *pointer = iDataP;	
+
+    //CC
+    TUint8 numCSRC = static_cast<TUint8>( iDataP[0] & 0x0F );
+    
+    //header extension
+    TUint8 headerExt = static_cast<TUint8>( ( iDataP[0] & 0x10 ) >> 4 );    
+    
+    //go to the end of SSRC
+    pointer +=KMinSizeRtpHeader;
+    
+    if (numCSRC)
+        {
+        pointer += numCSRC * 4;  
+        }
+    
+    if (headerExt)
+        {        
+        // Make sure there is a header extension to read
+        if ( ( size - ( pointer - iDataP ) ) < 4 )
+            {
+            User::Leave(KErrCorrupt);
+            }
+
+        // bypass header extension type
+        pointer += 2;
+
+        // header extension length in number of 32-bit words
+        TUint16 extLength = TSRTPUtils::Read16( pointer );
+        pointer += 2;
+
+		// jump the extension length
+        pointer += extLength * 4;
+
+        // Make sure the extension length is valid
+        if ( (size - ( pointer - iDataP ) ) < (extLength * 4) )
+            {
+            User::Leave(KErrCorrupt);            
+            }         
+        }
+    
+    iHeaderLength = pointer - iDataP;
+    if ( iHeaderLength > size )
+    	{
+    	User::Leave( KErrCorrupt );
+    	}
+    }
+
+// ---------------------------------------------------------------------------
+// CSRTPPacketRTP::UpdatePayloadLength()
+// ---------------------------------------------------------------------------
+//
+void CSRTPPacketRTP::UpdatePayloadLength()
+    {    
+     // In RTP case the payload length is easy to calculate
+     //This is only for sending the packe while payload is 512bits 
+    TInt packetlen= iPacket.Length() - iHeaderLength;
+   	iPayloadLength = packetlen;
+   	if ( iPacket.Length() <= iHeaderLength )
+     	{
+     	iPayloadLength = 0;
+     	}
+    }
+
+// ---------------------------------------------------------------------------
+// CSRTPPacketRTP::UpdateSeqNumber()
+// ---------------------------------------------------------------------------
+//
+void CSRTPPacketRTP::UpdateSequenceNumber( )
+    {
+//    search the Seq number and update iCurrentSeq here
+	const TUint8 *pointer = iDataP;	
+	pointer+=2;
+    
+    iSequenceNumber = static_cast<TUint16>( TSRTPUtils::Read16( pointer ) );
+    }
+
+
+// ---------------------------------------------------------------------------
+// CSRTPPacketRTP::CountEncryptedPacketSizeL()
+// ---------------------------------------------------------------------------
+//
+TUint CSRTPPacketRTP::CountEncryptedPacketSizeL()
+    {
+    TUint srtpPacketSize = iHeaderLength + iPayloadLength;
+    	srtpPacketSize += iHandler.Context().MasterKey().MKI().Length();  
+	//in Normal case
+    if ( iHandler.Context().CryptoParams().iSrtpAuthAlg != EAuthNull )
+        {
+        srtpPacketSize += iHandler.Context().CryptoParams().iSrtpAuthTagLen/8;
+        }
+    if (!TagWithROCLengthL() &&(
+    	iHandler.Context().CryptoParams().iSrtpAuthAlg != EAuthNull &&
+    	iHandler.Context().CryptoParams().iSrtpAuthAlg != EAuthHMAC_SHA1))
+    	{
+    	srtpPacketSize -= KSRTPROCLength4;
+    	}
+    if (!TagWithROCLengthL() &&
+    	iHandler.Context().CryptoParams().iSrtpAuthAlg == EAuthRCCm1)
+    	{
+    	srtpPacketSize -= (KSRTPAuthTagLength80/8);
+    	}	
+    return srtpPacketSize;
+    }
+        
+        
+// ---------------------------------------------------------------------------
+// CSRTPPacketRTP::CreateEncryptedPacketL()
+// ---------------------------------------------------------------------------
+//
+HBufC8* CSRTPPacketRTP::CreateEncryptedPacketL(TUint8* aEncryptedPayloadPtr)
+    {
+    // create encrypted SRTP packet
+    // first count needed packet size
+    TUint srtpPacketSize = CountEncryptedPacketSizeL();
+    
+    return CopyHeaderAndPayloadL(srtpPacketSize, aEncryptedPayloadPtr);    
+    }
+
+    
+// ---------------------------------------------------------------------------
+// CSRTPPacketRTP::CountSenderPacketIndex()
+// ---------------------------------------------------------------------------
+//
+void CSRTPPacketRTP::CountSenderPacketIndex()
+    {   
+    TUint32 roc= iHandler.ROC();//note it uses local ROC
+    
+    iPacketIndex = ((65536/*K2EXP16*/* roc) + iSequenceNumber);
+    
+    }
+
+    
+// ---------------------------------------------------------------------------
+// CSRTPPacketRTP::SequenceNumber()
+// ---------------------------------------------------------------------------
+//
+TUint16 CSRTPPacketRTP::SequenceNumber()
+    {
+    return iSequenceNumber;
+    }
+
+// ---------------------------------------------------------------------------
+// CSRTPPacketRTP::PacketIndex()
+// ---------------------------------------------------------------------------
+//
+TUint64 CSRTPPacketRTP::PacketIndex()
+    {
+    return iPacketIndex;
+    }
+
+// ---------------------------------------------------------------------------
+// CSRTPPacketRTP::SetPacketIndex()
+// ---------------------------------------------------------------------------
+//
+void CSRTPPacketRTP::SetPacketIndex(TUint64 aPacketIndex)
+    {
+    iPacketIndex = aPacketIndex;
+    }
+
+// ---------------------------------------------------------------------------
+// CSRTPPacketRTP::GetSenderROC
+// ---------------------------------------------------------------------------
+//
+TUint32 CSRTPPacketRTP::GetSenderROC()    
+	{
+	//Note that SenderROC is now only attached with RTP/SRTP packet
+	/*RCCm1 and RCCm2
+	Only when SEQ % R (ROC transmission rate) =0
+	Then there is attached sender ROC in the packet 4 octets before MAC
+	so after payload there is 14 (4+ 10) octets if HMAC-SHA1-80 is used
+	*/
+	/*RCCm3
+	Only when SEQ % R (ROC transmission rate )=0
+	Then there is attached sender ROC in the packet 4 octets after packet payload
+	but no MAC
+	*/
+	const TUint8 *pointer = iDataP;	
+	pointer+= iHeaderLength;
+	pointer+= iPayloadLength;
+	pointer+= iHandler.Context().MasterKey().MKI().Length();  
+    iSenderROC = static_cast<TUint16>( TSRTPUtils::Read32( pointer ) );
+	
+	//return
+	return iSenderROC;
+	}
+
+// ---------------------------------------------------------------------------
+// CSRTPPacketRTP::TagWithROCLengthL()
+// ---------------------------------------------------------------------------
+//
+TBool CSRTPPacketRTP::TagWithROCLengthL()
+	{
+	//mode 1 and 2 add ROC when SEQ%TransRate =0
+	//mode 1 will not have any tag if SEQ%TransRate !=0
+	TReal remainder;
+	TUint16 rate = iHandler.Context().CryptoParams().iROCTransRate;
+	User::LeaveIfError( Math::Mod(remainder ,iSequenceNumber,rate));
+	if (remainder==0 && 
+		((iHandler.Context().CryptoParams().iSrtpAuthAlg == EAuthRCCm1 )||
+		(iHandler.Context().CryptoParams().iSrtpAuthAlg  == EAuthRCCm2) ||
+		(iHandler.Context().CryptoParams().iSrtpAuthAlg  == EAuthRCCm3)))
+		{
+		return ETrue;
+		}
+	return EFalse;
+	}
+
+
+    
+// VIRTUAL functions    
+HBufC8* CSRTPPacketRTP::CreateDecryptedPacketL(TUint8* /*aDecryptedPayloadPtr*/)
+    {    
+    ////should call inherited class
+    User::Leave(KErrTotalLossOfPrecision);
+    return  NULL;    
+    }
+
+TPtrC8 CSRTPPacketRTP::AuthenticationTag()
+    {   
+    //should call inherited class
+    return  NULL;     
+    }
+
+TPtrC8 CSRTPPacketRTP::MasterKeyIdentifier()
+    {
+    ////should call inherited class
+    return  NULL;        
+    }
+