1 // Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies).

     2 // All rights reserved.

     3 // This component and the accompanying materials are made available

     4 // under the terms of "Eclipse Public License v1.0"

     5 // which accompanies this distribution, and is available

     6 // at the URL "http://www.eclipse.org/legal/epl-v10.html".

     7 //

     8 // Initial Contributors:

     9 // Nokia Corporation - initial contribution.

    10 //

    11 // Contributors:

    12 //

    13 // Description:

    14 // INCLUDE FILES

    15 // 

    16 //

    17 

    18 #include <e32std.h>

    19 #include <bafl/qpcodec.h>

    20 

    21 /**

    22 Decode the string

    23 @param aSrcString source string

    24 @param rDestString Destination string

    25 @return  KErrNone  if decode is complete

    26 @return  KErrCorrupt if string is not QuotedPrintable compliant

    27 */

    28 EXPORT_C TInt QuotedPrintableCodec::Decode( const TDesC8& aSrcString, TDes8& rDestString )

    29 	{

    30 	

    31 #ifdef _DEBUG

    32 	TInt KPanicInvalidSMTPLine = 6;

    33 	_LIT(KDllName,"MultipartParser");

    34 #endif

    35 	

    36 	const TUint8 KImcvSP			= ' ';

    37 	const TUint8 KImcvCR			= '\r';

    38 	const TUint8 KImcvLF			= '\n';	

    39 	const TUint8 KImcvTab			= '\t';

    40 	const TUint8 KImcvEquals		= '=';

    41 	TUint8 qpCharacter = KImcvEquals;

    42 	

    43 	TInt error = KErrNone;

    44 	

    45 	__ASSERT_DEBUG(aSrcString.Length(), User::Panic( KDllName ,KPanicInvalidSMTPLine));

    46 

    47 	rDestString = KNullDesC8;

    48 

    49 	TPtrC8 source( aSrcString.Ptr(), aSrcString.Length() );

    50 	const TUint8* pSource = source.Ptr();

    51 	const TUint8* pEnd = pSource+aSrcString.Length();

    52 	

    53 	// find out if this is a blank line, if so then we'll add a paragraph delimiter instead

    54 	// assume it's blank and then look for non-blank characters

    55 	// avoid the CRLF at the end of the line (we know it's there thanks to the assertion above)

    56 

    57 	TBool blankLine = ETrue; 

    58 	while (pSource < pEnd-2) 

    59 		{

    60 		if (*pSource!=KImcvSP && *pSource!=KImcvTab)

    61 			{

    62 			blankLine = EFalse;

    63 			break;

    64 			}

    65 		pSource++;

    66 		}

    67 

    68 	if ( blankLine )

    69 		{

    70 		rDestString.Copy( aSrcString );

    71 		return KErrNone;

    72 		}

    73 

    74 	TInt outputLength=0;

    75 	TUint8 loBits;

    76 	TUint8 hiBits;

    77 	TUint8 asciiValue;

    78 	pSource = source.Ptr();	// reset to start of source data

    79 	const TUint8 zero = '0';

    80 	const TUint8 alphaAdjust = 55;  // 'A' is ascii 65 so we need to subtract 55 from 

    81 									// alphabetical hex digits to get their numeric value

    82 	while( pSource < pEnd )

    83 		{

    84 		if (*pSource != qpCharacter )

    85 			{

    86 			//  Quoted character or Attachment bound, just bung it on & move to the next one

    87 			// *ptr++ = *pSource;

    88 			outputLength++;

    89 			rDestString.Append( *pSource );

    90 			}

    91 		else	// check for encoded character

    92 			{

    93 			// start looking at the next two characters, if they are there.

    94 

    95 			if ( pSource+2 < pEnd )

    96 				{

    97 				pSource++;

    98 

    99 				// check for '=' at EOL => this is a soft break, so remove it

   100 				if (*pSource != KImcvCR) 

   101 					{

   102 					if(*pSource != KImcvLF) 

   103 						{

   104 					 	 // now decode hex value into ASCII code : hi-order bits come first

   105 						 hiBits = (TUint8)(0x0F & (IsDigit( *pSource ) ? (TUint8)(*pSource-zero) : (TUint8)(*pSource-alphaAdjust)));

   106 						 pSource++;

   107 						 loBits = (TUint8)(0x0F & (IsDigit( *pSource ) ? (TUint8)(*pSource-zero) : (TUint8)(*pSource-alphaAdjust)));

   108 						 asciiValue = (TUint8)( (hiBits<<4) + loBits);

   109 						 // bung the character thus formed onto the decoded string

   110 						 rDestString.Append( asciiValue );

   111 						 // *ptr++ = asciiValue;

   112 						 outputLength++;

   113 						}

   114 					}

   115 				else

   116 					{

   117 					pSource++;

   118 					if(*pSource != KImcvLF)

   119 						{

   120 						error=KErrCorrupt;

   121 						pSource-=2;

   122 						rDestString.Append( *pSource );

   123 						pSource++;

   124 						rDestString.Append( *pSource );

   125 						pSource++;

   126 						outputLength+=2;

   127 						}

   128 					}

   129 				}

   130 			else

   131 				{

   132 				// copy the rest of the data & use up the input string in the process.

   133 

   134 				while (pSource < pEnd)

   135 					{

   136 					error=KErrCorrupt; // not QP compliant

   137 					//*ptr++ = *pSource++;

   138 					outputLength++;

   139 					rDestString.Append( *pSource );

   140 					pSource++;

   141 					}

   142 				}

   143 			} // check for '=' char

   144 		

   145 		pSource++;  // next source charactery

   146 	} // while

   147 

   148 	rDestString.SetLength(outputLength);

   149 

   150 	return error;

   151 	}

   152 

   153 /**

   154 Check for digit

   155 @param aChar charcter to be check

   156 @return  ETrue if passed charcter is digit

   157 @return  EFalse if passed charcter is not digit

   158 */	

   159 TBool QuotedPrintableCodec::IsDigit( TChar aChar )

   160 {

   161 	return ( (aChar >= '0') && (aChar <= '9') );

   162 }