1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/os/security/cryptoplugins/cryptospiplugins/source/softwarecrypto/dsasignerimpl.cpp	Fri Jun 15 03:10:57 2012 +0200
     1.3 @@ -0,0 +1,137 @@
     1.4 +/*
     1.5 +* Copyright (c) 2006-2009 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 +#include "dsasignerimpl.h"
    1.23 +#include "pluginconfig.h"
    1.24 +
    1.25 +using namespace SoftwareCrypto;
    1.26 +
    1.27 +// Implementation of CDSASignerImpl 
    1.28 +CDSASignerImpl* CDSASignerImpl::NewL(const CKey& aKey)
    1.29 +	{
    1.30 +	CDSASignerImpl* self = CDSASignerImpl::NewLC(aKey);
    1.31 +	CleanupStack::Pop(self);
    1.32 +	return self;
    1.33 +	}
    1.34 +	
    1.35 +CDSASignerImpl* CDSASignerImpl::NewLC(const CKey& aKey)
    1.36 +	{
    1.37 +	CDSASignerImpl* self = new(ELeave) CDSASignerImpl();
    1.38 +	CleanupStack::PushL(self);
    1.39 +	self->ConstructL(aKey);
    1.40 +	return self;
    1.41 +	}
    1.42 +
    1.43 +CDSASignerImpl::CDSASignerImpl() 
    1.44 +	{
    1.45 +	}
    1.46 +	
    1.47 +CDSASignerImpl::~CDSASignerImpl()
    1.48 +	{
    1.49 +	}
    1.50 +	
    1.51 +void CDSASignerImpl::ConstructL(const CKey& aKey)
    1.52 +	{
    1.53 +	CSignerImpl::ConstructL(aKey);
    1.54 +	}
    1.55 +
    1.56 +CExtendedCharacteristics* CDSASignerImpl::CreateExtendedCharacteristicsL()
    1.57 +	{
    1.58 +	// All Symbian software plug-ins have unlimited concurrency, cannot be reserved
    1.59 +	// for exclusive use and are not CERTIFIED to be standards compliant.
    1.60 +	return CExtendedCharacteristics::NewL(KMaxTInt, EFalse);
    1.61 +	}
    1.62 +
    1.63 +const CExtendedCharacteristics* CDSASignerImpl::GetExtendedCharacteristicsL()
    1.64 +	{
    1.65 +	return CDSASignerImpl::CreateExtendedCharacteristicsL();
    1.66 +	}
    1.67 +
    1.68 +TUid CDSASignerImpl::ImplementationUid() const
    1.69 +	{
    1.70 +	return KCryptoPluginDsaSignerUid;
    1.71 +	}
    1.72 +	
    1.73 +void CDSASignerImpl::SetKeyL(const CKey& aPrivateKey) 
    1.74 +	{
    1.75 +	DoSetKeyL(aPrivateKey);
    1.76 +	Reset();
    1.77 +	}
    1.78 +
    1.79 +TInt CDSASignerImpl::GetMaximumInputLengthL() const 
    1.80 +	{
    1.81 +	return KSha1HashLength;
    1.82 +	}
    1.83 +
    1.84 +void CDSASignerImpl::SignL(const TDesC8& aInput, CCryptoParams& aSignature) 
    1.85 +	{
    1.86 +	
    1.87 +	//see HAC 11.56 or DSS section 5
    1.88 +	//I'll follow HAC as I like its description better
    1.89 +	//We don't check that r and s are non both non-null like the DSS
    1.90 +	//states you _optionally_ can.  The chances of this are _incredibly_ small.
    1.91 +	//You've got a much better chance of a bit failure ocurring in the hardware
    1.92 +	//than this.
    1.93 +
    1.94 +	const TInteger& tQ=iKey->GetBigIntL(KDsaKeyParameterQUid);
    1.95 +		
    1.96 +	// a) Select a random secret integer (k | 0 < k < q)
    1.97 +	RInteger qminus1 = RInteger::NewL(tQ);
    1.98 +	CleanupStack::PushL(qminus1);
    1.99 +	--qminus1;
   1.100 +	RInteger k = RInteger::NewRandomL(TInteger::One(), qminus1);
   1.101 +	CleanupStack::PopAndDestroy(&qminus1);
   1.102 +	CleanupStack::PushL(k);
   1.103 +	
   1.104 +	
   1.105 +	// b) compute r = (g^k mod p) mod q
   1.106 +	
   1.107 +	const TInteger& tG=iKey->GetBigIntL(KDsaKeyParameterGUid);
   1.108 +	const TInteger& tP=iKey->GetBigIntL(KDsaKeyParameterPUid);
   1.109 +	RInteger r = TInteger::ModularExponentiateL(tG, k, tP);
   1.110 +	CleanupStack::PushL(r);
   1.111 +	r %=tQ;
   1.112 +	
   1.113 +	
   1.114 +	// c) compute k^(-1) mod q
   1.115 +
   1.116 +	RInteger kinv = k.InverseModL(tQ);
   1.117 +	CleanupStack::PushL(kinv);
   1.118 +
   1.119 +
   1.120 +	// d) compute s = k^(-1) * {h(m) + xr} mod q
   1.121 +	// Note that in order to be interoperable, compliant with the DSS, and
   1.122 +	// secure, aInput must be the result of a SHA-1 hash
   1.123 +
   1.124 +	RInteger hm = RInteger::NewL(aInput);
   1.125 +	CleanupStack::PushL(hm);
   1.126 +	
   1.127 +	const TInteger& tX=iKey->GetBigIntL(KDsaKeyParameterXUid);	
   1.128 +	RInteger s = tX.TimesL(r);
   1.129 +	CleanupStack::PushL(s);
   1.130 +	s += hm;
   1.131 +	s *= kinv;
   1.132 +	s %= tQ;
   1.133 +
   1.134 +
   1.135 +	// e) signature for m is the pair (r,s)
   1.136 +	aSignature.AddL(r, KDsaSignatureParameterRUid);
   1.137 +	aSignature.AddL(s, KDsaSignatureParameterSUid);
   1.138 +	
   1.139 +	CleanupStack::PopAndDestroy(5, &k);
   1.140 +	}