rtp/srtpstack/inc/srtputils.h
changeset 0 307788aac0a8
child 33 b8a7e07b2677
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rtp/srtpstack/inc/srtputils.h	Tue Feb 02 01:03:15 2010 +0200
@@ -0,0 +1,262 @@
+/*
+* 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:    Contains SRTP utility functions (mostly mathematical
+*                 and calculation oriented).
+*
+*/
+
+
+
+
+#ifndef __SRTPUTILS_H__
+#define __SRTPUTILS_H__
+
+// INCLUDES
+#include <e32def.h>
+#include <e32err.h>
+#include <e32math.h>
+
+#include <e32std.h>
+#include <f32file.h>
+
+#ifdef SRTP_UNIT_TEST_COVERAGE
+
+#undef _DEBUG
+#undef SRTP_LOG
+#endif
+
+
+#if ( defined( _DEBUG ) && ( defined ( SRTP_LOG )  ) )
+#define _SRTP_FILE                     
+
+#endif   
+
+         
+
+
+#if ( defined( _DEBUG ) && !( defined ( _SRTP_FILE )  ) )
+
+#define SRTP_DEBUG_DETAIL( a ) { TSRTPUtils::Print( _L( a ) ); }
+#define SRTP_DEBUG_PACKET( a ) 
+#define SRTP_DEBUG_TINT_VALUE( a, b ) { TSRTPUtils::Print( _L( a ), static_cast<TInt>( b ) ); }
+#define SRTP_DEBUG_TUINT_VALUE( a, b ) { TSRTPUtils::Print( _L( a ), static_cast<TInt>( b ) );}
+#define SRTP_DEBUG_TUINT32_VALUE( a, b ) { TSRTPUtils::Print( _L( a ), static_cast<TInt>( b ) );}
+
+#endif
+
+#ifdef _SRTP_FILE 
+
+#define SRTP_DEBUG_DETAIL( a ) { TSRTPUtils::Print( KLogFile,  _L( a ) ); }
+#define SRTP_DEBUG_PACKET( a ) { TSRTPUtils::SrtpPrintToFile( a ); }
+#define SRTP_DEBUG_TINT_VALUE( a, b ) { TSRTPUtils::Print( KLogFile, _L( a ), b ); }
+#define SRTP_DEBUG_TUINT_VALUE( a, b ) { TSRTPUtils::Print( KLogFile, _L( a ), static_cast<TInt>( b ) ); }
+#define SRTP_DEBUG_TUINT32_VALUE( a, b ) { TSRTPUtils::Print( KLogFile, _L( a ), static_cast<TInt>( b ) ); }
+
+#endif
+
+#if ( !defined( _DEBUG )  )
+
+#define SRTP_DEBUG_DETAIL( a )
+#define SRTP_DEBUG_PACKET( a ) 
+#define SRTP_DEBUG_TINT_VALUE( a, b ) 
+#define SRTP_DEBUG_TUINT_VALUE( a, b ) 
+#define SRTP_DEBUG_TUINT32_VALUE( a, b ) 
+
+#endif
+
+
+// DATA TYPES
+_LIT( KDefaultPath, "c:\\system\\data\\" );
+_LIT( KLogFile, "LogFileSRTP.dat" );
+_LIT( KSRTPString, "SRTP : ");
+
+
+// 
+const TUint16 K2EXP16           = 65536;
+const TUint32 K2EXP32           = 4294967296;
+const TUint64 KSRTPIndexLength  = 0x1000000000000;
+const TUint64 KSRTCPIndexLength  = 0x100000000;
+
+class TSRTPUtils
+    {
+    public: 
+        /**
+        * Count IV to be used as Integer Value in
+        * AES-CM RTP/RTCP encryption/decryption.
+        * @param aRes resulting 128 bit IV
+        * @param aSalt 112 bit session salt (not padded)
+        * @param aSSRC 32 bit SSRC value from packet (not padded)
+        * @param aIndex 48 bit packet index (RTP, not padded) or
+        *               31 bit SRTCP index (RTCP, not padded)
+        * @return KErrNone/KErrArgument        
+        */
+        static TInt CountIV(TDes8& aRes, 
+                        const TDesC8& aSalt,
+                        TUint aSSRC,
+                        TUint64 aIndex);
+                        
+                        
+        /**
+        * Add 16 bit padding for 112 bit session salt        
+        * @param aRes resulting 128 bit padded session salt
+        * @param aSalt 112 bit session salt 
+        * @return void        
+        */
+        static void GetIVFirstTerm(TDes8& aRes, const TDesC8& aSalt);
+        /**
+        * Add 64 bit padding for 32 bit SSRC value
+        * @param aRes resulting 96 bit padded SSRC value
+        * @param aSSRC 32 bit SSRC value from packet
+        * @return void        
+        */
+        static void GetIVSecondTerm(TDes8& aRes, TUint aSSRC);
+        /**
+        * Add 16 bit padding for RTP/RTCP packet index
+        * @param aRes resulting 64/47 bit index
+        * @param aIndex 48 bit packet index (RTP, not padded) or
+        *               31 bit SRTCP index (RTCP, not padded)
+        * @return void        
+        */
+        static void GetIVThirdTerm(TDes8& aRes, TUint64 aIndex);
+    
+        /*
+        * r is calculated in following way:
+        * 'index DIV key_derivation_rate'
+        * This function is common to RTP and RTCP.
+        * @param aIndex packet index
+        * @param derivation rate 
+        * @return 'index DIV key_derivation_rate'
+        */
+        static TUint64 Cnt_r(const TUint64 aIndex, const TUint32 aDerivRate);
+
+        /*
+        * key_id is calculated in following way:
+        * 'label || r'
+        * This function is common to RTP and RTCP.
+        * @param aLabel 8 bit RTP/RTCP value
+        * @param a_R, 'index DIV key_derivation_rate'
+        * @param aIndexLength, packet index length (RTP or RTCP)
+        * @return key_id ('label || r')
+        */
+        static TUint64 Cnt_key_id(const TUint8 aLabel,
+                              const TUint64 a_R,
+                              const TUint64 aIndexLength);
+
+        /*
+        * TUint16 SRTPUtils::Read16()
+        * Read a 16-bit value given as 2 consecutive bytes in MSB order
+        * Memory (at least 2 bytes) must have been allocated to pointer
+        * before the function is called.
+        */
+        static TUint16 Read16( const TUint8* const aPointer );
+         
+        /*
+        * Write a 16-bit value as 2 consecutive bytes in MSB order
+        * Memory (at least 2 bytes) must have been allocated to pointer
+        * before the function is called.
+        */
+        static void Write16( TUint8* const aPointer, TUint16 aValue );
+        
+        /*
+        * TUint32 SRTPUtils::Read32()
+        * Read a 32-bit value given as 2 consecutive bytes in MSB order
+        * Memory (at least 2 bytes) must have been allocated to pointer
+        * before the function is called.
+        */
+        static TUint32 Read32( const TUint8* const aPointer );
+         
+        /*
+        * Write a 32-bit value as 2 consecutive bytes in MSB order
+        * Memory (at least 2 bytes) must have been allocated to pointer
+        * before the function is called.
+        */
+        static void Write32( TUint8* const aPointer, TUint32 aValue );
+                
+        /*
+        * Calculates 'x', which is needed in key derivation.
+        * Is calculated in following way:
+        * 'key_id XOR master_salt'
+        * This function is common to RTP and RTCP.
+        * @param a_key_id, 
+        * @param aRes, result
+        * @param aSalt master salt
+        * @return 'x', ('key_id XOR master_salt')
+        */
+        static void Cnt_x(const TUint64 a_key_id, TDes8& aRes, const TDesC8& aSalt);
+
+
+        /*
+        * Integer division of "a div b",
+        * with exception that 'a div 0' == 0 for all a
+        * This function is common to RTP and RTCP.
+        * @param aA, value A
+        * @param aB, value B
+        * @return SRTP style "a div b"
+        */
+        static TUint64 SrtpDIV(const TUint64 aA ,const TUint64 aB);
+
+        /*
+        * Converts 8 bit descriptor ASCII values to hex values
+        * @param aSrc, source descriptor
+        * @param aDest, source descriptor
+        * @return void
+        */
+        static void DeHex(const TDesC8 &aSrc, TDes8 &aDest);
+
+        /*
+        * Converts an 8 bit ASCII value to hex value
+        * @param c, character
+        * @return hex value 
+        */
+        static TUint8 HexVal(TUint8 c);
+
+        /*
+        * Converts a string into hex
+        * @param aString, string to convert
+        * @return none.
+        */
+        static void HexString(HBufC8& aString);
+
+#ifdef _DEBUG        
+		static TUint GtGetTime();
+        
+        static void Print( const TDesC& aP );
+		static void Print( const TDesC& aP , TInt aValue );
+		
+
+#endif
+
+#ifdef _SRTP_FILE
+		static void Print( const TDesC& name, const TDesC& aP );
+        static void Print( const TDesC& name, const TDesC& aP, TInt aValue );
+
+		static void OctetToHexString(TPtrC8 aString, int length, const TDesC& aName);
+		static void SrtpPrint( TPtrC8 aString );
+		static void SrtpPrintToFile( TPtrC8 aString );
+#endif
+        
+    };
+    
+#ifdef _SRTP_FILE    
+
+class TFileUtil
+    {
+    public:
+        static TInt LogMessage( const TFileName&, const TDesC& );
+        static TInt InitLogFile( const TFileName& name );
+    };
+
+#endif
+
+#endif // __SRTPUTILS_H__