1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/os/security/crypto/weakcrypto/source/pkcs5kdf/pkcs5kdf.cpp	Fri Jun 15 03:10:57 2012 +0200
     1.3 @@ -0,0 +1,115 @@
     1.4 +/*
     1.5 +* Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).
     1.6 +* All rights reserved.
     1.7 +* This component and the accompanying materials are made available
     1.8 +* under the terms of the License "Eclipse Public License v1.0"
     1.9 +* which accompanies this distribution, and is available
    1.10 +* at the URL "http://www.eclipse.org/legal/epl-v10.html".
    1.11 +*
    1.12 +* Initial Contributors:
    1.13 +* Nokia Corporation - initial contribution.
    1.14 +*
    1.15 +* Contributors:
    1.16 +*
    1.17 +* Description: 
    1.18 +*
    1.19 +*/
    1.20 +
    1.21 +
    1.22 +/**
    1.23 + @file
    1.24 +*/
    1.25 +
    1.26 +#include "pkcs5kdf.h"
    1.27 +
    1.28 +/* Before complaining about the variable names in this file, 
    1.29 + * read the pkcs5 spec and all will become clear.
    1.30 + */
    1.31 +
    1.32 +EXPORT_C void TPKCS5KDF::DeriveKeyL(TDes8& aKey, const TDesC8& aPasswd, const TDesC8& aSalt, 
    1.33 +	const TUint aIterations)
    1.34 +{
    1.35 +	CSHA1* sha1 = CSHA1::NewL();
    1.36 +	CleanupStack::PushL(sha1);
    1.37 +	CHMAC* hmac = CHMAC::NewL(aPasswd, sha1);
    1.38 +	CleanupStack::Pop(sha1); //hmac now owns it
    1.39 +	CleanupStack::PushL(hmac);
    1.40 +
    1.41 +	TUint hashBytes = hmac->HashSize();
    1.42 +	TUint c = aIterations;
    1.43 +	TUint l = aKey.Length() / hashBytes; 
    1.44 +	if(aKey.Length() % hashBytes != 0) //round up if mod !=0
    1.45 +		{
    1.46 +		l+=1;
    1.47 +		}
    1.48 +	TUint r = aKey.Length() - (l-1) * hashBytes; //r == length of last block
    1.49 +	
    1.50 +	HBufC8* TiTemp = HBufC8::NewLC(hashBytes);
    1.51 +	TUint32* Ti = (TUint32*)(TiTemp->Ptr());
    1.52 +	aKey.SetLength(0); //we've already saved the length we want
    1.53 +
    1.54 +	HBufC8* STemp = HBufC8::NewLC(aSalt.Length() + sizeof(TUint32));
    1.55 +	TUint32* S = (TUint32*)(STemp->Ptr());
    1.56 +
    1.57 +	HBufC8* UiTemp = HBufC8::NewLC(hashBytes);
    1.58 +	TUint32* Ui = (TUint32*)(UiTemp->Ptr());
    1.59 +
    1.60 +	const TUint32* salt = (TUint32*)(aSalt.Ptr());
    1.61 +	TUint saltBytes = aSalt.Length();
    1.62 +
    1.63 +	for(TUint i = 1; i<=l; i++)
    1.64 +		{
    1.65 +		F(*hmac, Ti, S, Ui, hashBytes, salt, saltBytes, c, i);
    1.66 +		if(i == l)
    1.67 +			aKey.Append((TUint8*)Ti, r);
    1.68 +		else 
    1.69 +			aKey.Append((TUint8*)Ti, hashBytes);
    1.70 +		}
    1.71 +
    1.72 +	CleanupStack::PopAndDestroy(UiTemp);
    1.73 +	CleanupStack::PopAndDestroy(STemp);
    1.74 +	CleanupStack::PopAndDestroy(TiTemp);
    1.75 +	CleanupStack::PopAndDestroy(hmac);
    1.76 +	}
    1.77 +
    1.78 +void TPKCS5KDF::F(CMessageDigest& aDigest, TUint32* aAccumulator, 
    1.79 +	TUint32* S, TUint32* Ui, TUint aHashBytes, const TUint32* aSalt, 
    1.80 +	TUint aSaltBytes, TUint c, TUint i)
    1.81 +	{
    1.82 +	TUint8 itmp[4];
    1.83 +	itmp[0] = (TUint8)((i >> 24) & 0xff);
    1.84 +	itmp[1] = (TUint8)((i >> 16) & 0xff);
    1.85 +	itmp[2] = (TUint8)((i >> 8) & 0xff);
    1.86 +	itmp[3] = (TUint8)(i & 0xff);
    1.87 +	TUint8* endOfS = Mem::Copy(S, aSalt, aSaltBytes);
    1.88 +	Mem::Copy((TUint32*)endOfS, (TUint32*)&itmp, 4);
    1.89 +
    1.90 +	TPtr8 sptr((TUint8*)S, aSaltBytes+4);
    1.91 +	sptr.SetLength(aSaltBytes+4);
    1.92 +	Mem::Copy(aAccumulator, (TUint32*)((aDigest.Final(sptr)).Ptr()),aHashBytes);
    1.93 +	Mem::Copy(Ui, aAccumulator, aHashBytes);
    1.94 +
    1.95 +	for(TUint j=1; j<c; j++)
    1.96 +		{
    1.97 +		TPtr8 uiptr((TUint8*)Ui, aHashBytes);
    1.98 +		uiptr.SetLength(aHashBytes);
    1.99 +		Mem::Copy(Ui, (TUint32*)((aDigest.Final(uiptr)).Ptr()), aHashBytes);
   1.100 +		XORString(Ui, aAccumulator, aHashBytes);
   1.101 +		}
   1.102 +	}
   1.103 +
   1.104 +inline void TPKCS5KDF::XORString(const TUint32* aOp1, TUint32* aOp2,
   1.105 +	TUint aLength)
   1.106 +	{
   1.107 +	const TUint32* i = aOp1;
   1.108 +
   1.109 +	//this will overflow the whole final word if aLength % 4 != 0 
   1.110 +	//but I can't see this mattering cuz all memory allocation is on a word by word basis
   1.111 +	//i don't want to do this byte by byte as it'll be way slower
   1.112 +	//also, every sane digest is going to be a multiple of 4 -- so this isn't a problem
   1.113 +	for( ; aOp1 != (TUint32*)((TUint8*)i + aLength); )
   1.114 +		{
   1.115 +			*aOp2++ ^= *aOp1++;	
   1.116 +		}
   1.117 +	}
   1.118 +