crypto/weakcrypto/source/hash/hmac.cpp
changeset 72 de46a57f75fb
equal deleted inserted replaced
65:970c0057d9bc 72:de46a57f75fb
       
     1 /*
       
     2 * Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).
       
     3 * All rights reserved.
       
     4 * This component and the accompanying materials are made available
       
     5 * under the terms of the License "Eclipse Public License v1.0"
       
     6 * which accompanies this distribution, and is available
       
     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".
       
     8 *
       
     9 * Initial Contributors:
       
    10 * Nokia Corporation - initial contribution.
       
    11 *
       
    12 * Contributors:
       
    13 *
       
    14 * Description: 
       
    15 *
       
    16 */
       
    17 
       
    18 
       
    19 /**
       
    20  @file
       
    21 */
       
    22 
       
    23 
       
    24 #include <e32std.h>
       
    25 #include <hash.h>
       
    26 
       
    27 #define EXPANDLOOP
       
    28 
       
    29 //
       
    30 // HMAC implementation
       
    31 //
       
    32 
       
    33 CHMAC::CHMAC()
       
    34 :CMessageDigest(){}
       
    35 
       
    36 CHMAC::CHMAC(CMessageDigest* aDigest)
       
    37 	:CMessageDigest(),
       
    38 	iDigest(aDigest),
       
    39 	iInnerPad(KMaxBlockSize),
       
    40 	iOuterPad(KMaxBlockSize)
       
    41 {}
       
    42 
       
    43 CHMAC::CHMAC(const CHMAC& aMD)
       
    44 	:CMessageDigest(aMD), 
       
    45 	iDigest(NULL),
       
    46 	iInnerPad(aMD.iInnerPad), 
       
    47 	iOuterPad(aMD.iOuterPad),
       
    48 	iBlockSize(aMD.iBlockSize)
       
    49 	{}
       
    50 
       
    51 EXPORT_C CHMAC::~CHMAC(void)
       
    52 	{
       
    53 	delete iDigest;
       
    54 	}
       
    55 
       
    56 EXPORT_C CHMAC* CHMAC::NewL(const TDesC8& aKey,CMessageDigest* aDigest)
       
    57 	{
       
    58 	CHMAC* self=new(ELeave) CHMAC(aDigest);
       
    59 	CleanupStack::PushL(self);
       
    60 	self->InitialiseL(aKey);
       
    61 	CleanupStack::Pop(self);
       
    62 	return self;
       
    63 	}
       
    64 void CHMAC::InitialiseL(const TDesC8& aKey)
       
    65 	{
       
    66 	InitBlockSizeL();
       
    67 	// initialisation
       
    68 	if (iDigest)
       
    69 		{
       
    70 		iDigest->Reset();
       
    71 		if( (TUint32)aKey.Size() > iBlockSize)
       
    72 			{
       
    73 			iInnerPad = iDigest->Final(aKey);
       
    74 			}
       
    75 		else 
       
    76 			{
       
    77 			iInnerPad = aKey;
       
    78 			}
       
    79 			
       
    80 		TUint i;
       
    81 		for (i=iInnerPad.Size();i<iBlockSize;i++)
       
    82 			iInnerPad.Append(0);
       
    83 
       
    84 		iOuterPad=iInnerPad;
       
    85 
       
    86 		const TUint8 Magic1=0x36, Magic2=0x5c;
       
    87 		for (i=0;i<iBlockSize;i++)
       
    88 		{
       
    89 			iInnerPad[i]^=Magic1;
       
    90 			iOuterPad[i]^=Magic2;
       
    91 		}
       
    92 		//start inner hash
       
    93 		iDigest->Hash(iInnerPad);
       
    94 		}
       
    95 	}
       
    96 
       
    97 void CHMAC::InitBlockSizeL()
       
    98  	{
       
    99 	
       
   100  	 iBlockSize = iDigest->BlockSize();
       
   101 	 if(iBlockSize > KMaxBlockSize)
       
   102 		 {
       
   103 		 User::Leave(KErrNotSupported);
       
   104 		 }
       
   105  	 
       
   106  	 iInnerPad.SetLength(iBlockSize);
       
   107  	 iOuterPad.SetLength(iBlockSize);
       
   108  	 iInnerPadCopy.SetLength(iBlockSize);
       
   109  	 iOuterPadCopy.SetLength(iBlockSize);
       
   110    	}
       
   111 
       
   112 EXPORT_C CMessageDigest* CHMAC::CopyL(void)
       
   113 	{
       
   114 	CHMAC* that=new(ELeave) CHMAC(*this);
       
   115 	CleanupStack::PushL(that);
       
   116 	that->iDigest=iDigest ? iDigest->CopyL() : NULL;
       
   117 	CleanupStack::Pop();
       
   118 	return that;
       
   119 	}
       
   120 EXPORT_C CMessageDigest*  CHMAC::ReplicateL(void)
       
   121 	{
       
   122 	CHMAC* that=new(ELeave) CHMAC(*this);
       
   123 	CleanupStack::PushL(that);
       
   124 	that->iDigest=iDigest ? iDigest->ReplicateL() : NULL;
       
   125 	that->Reset();
       
   126 	CleanupStack::Pop();
       
   127 	return that;
       
   128 	}
       
   129 EXPORT_C TInt CHMAC::BlockSize(void)
       
   130 	{
       
   131 	return iBlockSize;
       
   132 	}
       
   133 
       
   134 EXPORT_C TInt CHMAC::HashSize(void)
       
   135 	{
       
   136 	return iDigest ? iDigest->HashSize() : 0;
       
   137 	}
       
   138 EXPORT_C void CHMAC::Reset(void)
       
   139 	{
       
   140 	if (iDigest)
       
   141 		{
       
   142 		iDigest->Reset();
       
   143 		iDigest->Update(iInnerPad);
       
   144 		}
       
   145 	}
       
   146 
       
   147 //	JCS, There may be a more efficient method but I can't find it
       
   148 //	because using the DoFinal/DoUpdate functions directly calls
       
   149 //	Store/Restore at inappropriate times and scribbles over stored
       
   150 //	data
       
   151 //	This is the only way I've found to both generate a hash value
       
   152 //	and get this in the correctly updated state
       
   153 EXPORT_C TPtrC8 CHMAC::Hash(const TDesC8& aMessage)
       
   154 {
       
   155 	TPtrC8 ptr(KNullDesC8());
       
   156 	TPtrC8 finalPtr(KNullDesC8());
       
   157 	StoreState();
       
   158 	if (iDigest)
       
   159 	{
       
   160 		ptr.Set(iDigest->Final(aMessage));
       
   161 		iDigest->Update(iOuterPad);
       
   162 		finalPtr.Set(iDigest->Final(ptr));
       
   163 	}
       
   164 
       
   165 	RestoreState();
       
   166 	iDigest->Update(aMessage);
       
   167 
       
   168 	return (finalPtr);
       
   169 }
       
   170 
       
   171 EXPORT_C void CHMAC::Update(const TDesC8& aMessage)
       
   172 	{
       
   173 	if(iDigest)
       
   174 		{
       
   175 		iDigest->Update(aMessage);
       
   176 		}
       
   177 	}
       
   178 
       
   179 EXPORT_C TPtrC8 CHMAC::Final(const TDesC8& aMessage)
       
   180 	{
       
   181 	TPtrC8 ptr(KNullDesC8());
       
   182 	if(iDigest)
       
   183 		{
       
   184 		ptr.Set(iDigest->Final(aMessage));
       
   185 		iDigest->Update(iOuterPad);
       
   186 		iDigest->Final(ptr);
       
   187 		Reset();
       
   188 		}
       
   189 	return (ptr);
       
   190 	}
       
   191 
       
   192 EXPORT_C TPtrC8 CHMAC::Final()
       
   193 	{
       
   194 	TPtrC8 ptr(KNullDesC8());
       
   195 	if(iDigest)
       
   196 		{
       
   197 		ptr.Set(iDigest->Final());
       
   198 		iDigest->Update(iOuterPad);
       
   199 		iDigest->Final(ptr);
       
   200 		Reset();
       
   201 		}
       
   202 	return (ptr);
       
   203 	}
       
   204 
       
   205 void CHMAC::RestoreState()
       
   206 {
       
   207 	iOuterPad.Copy(iOuterPadCopy);
       
   208 	iInnerPad.Copy(iInnerPadCopy);
       
   209 	if (iDigest)
       
   210 		iDigest->RestoreState();
       
   211 }
       
   212 
       
   213 void CHMAC::StoreState()
       
   214 {
       
   215 	iOuterPadCopy.Copy(iOuterPad);
       
   216 	iInnerPadCopy.Copy(iInnerPad);
       
   217 	if (iDigest)
       
   218 		iDigest->StoreState();
       
   219 }
       
   220 
       
   221