1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/os/security/crypto/weakcrypto/source/asymmetric/dsaverifier.cpp	Fri Jun 15 03:10:57 2012 +0200
     1.3 @@ -0,0 +1,109 @@
     1.4 +/*
     1.5 +* Copyright (c) 2003-2009 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 <asymmetric.h>
    1.23 +#include <asymmetrickeys.h>
    1.24 +#include <bigint.h>
    1.25 +
    1.26 +EXPORT_C CDSAVerifier* CDSAVerifier::NewL(const CDSAPublicKey& aKey)
    1.27 +	{
    1.28 +	CDSAVerifier* self = new(ELeave)CDSAVerifier(aKey);
    1.29 +	return self;
    1.30 +	}
    1.31 +
    1.32 +EXPORT_C CDSAVerifier* CDSAVerifier::NewLC(const CDSAPublicKey& aKey)
    1.33 +	{
    1.34 +	CDSAVerifier* self = NewL(aKey);
    1.35 +	CleanupStack::PushL(self);
    1.36 +	return self;
    1.37 +	}
    1.38 +
    1.39 +TInt CDSAVerifier::MaxInputLength(void) const
    1.40 +	{
    1.41 +	// return CSHA1::DIGESTBYTES
    1.42 +	return 160;
    1.43 +	}
    1.44 +
    1.45 +TBool CDSAVerifier::VerifyL(const TDesC8& aInput, 
    1.46 +	const CDSASignature& aSignature) const
    1.47 +	{
    1.48 +	//see HAC 11.56 or DSS section 6
    1.49 +	//I'll follow HAC as I like the description better
    1.50 +
    1.51 +	// a) Obtain A's authenticate public key
    1.52 +
    1.53 +	// b) Verify that 0 < r < q and 0 < s < q; if not reject signature
    1.54 +	if (aSignature.R() <= 0 || aSignature.R() >= iPublicKey.Q())
    1.55 +		{
    1.56 +		return EFalse;
    1.57 +		}
    1.58 +	if (aSignature.S() <= 0 || aSignature.S() >= iPublicKey.Q())
    1.59 +		{
    1.60 +		return EFalse;
    1.61 +		}
    1.62 +
    1.63 +	TBool result = EFalse;
    1.64 +
    1.65 +	// c) Compute w = s^(-1) mod q and h(m)
    1.66 +	RInteger w = aSignature.S().InverseModL(iPublicKey.Q());
    1.67 +	CleanupStack::PushL(w);
    1.68 +	// Note that in order to be interoperable, compliant with the DSS, and
    1.69 +	// secure, aInput must be the result of a SHA-1 hash
    1.70 +	RInteger hm = RInteger::NewL(aInput);
    1.71 +	CleanupStack::PushL(hm);
    1.72 +
    1.73 +	// d) Compute u1 = w * hm mod q and u2 = r * w mod q
    1.74 +	RInteger u1 = TInteger::ModularMultiplyL(w, hm, iPublicKey.Q());
    1.75 +	CleanupStack::PushL(u1);
    1.76 +
    1.77 +	RInteger u2 = TInteger::ModularMultiplyL(aSignature.R(), w, iPublicKey.Q());
    1.78 +	CleanupStack::PushL(u2);
    1.79 +
    1.80 +	// e) Compute v = ((g^u1 * y^u2) mod p) mod q
    1.81 +	RInteger temp = TInteger::ModularExponentiateL(iPublicKey.G(), u1,
    1.82 +		iPublicKey.P());
    1.83 +	CleanupStack::PushL(temp);
    1.84 +	RInteger temp1 = TInteger::ModularExponentiateL(iPublicKey.Y(), u2,
    1.85 +		iPublicKey.P());
    1.86 +	CleanupStack::PushL(temp1);
    1.87 +	RInteger v = TInteger::ModularMultiplyL(temp, temp1, iPublicKey.P());
    1.88 +	CleanupStack::PushL(v);
    1.89 +	v %= iPublicKey.Q();
    1.90 +
    1.91 +	// f) Accept the signature iff v == r
    1.92 +	if(v == aSignature.R())
    1.93 +		{
    1.94 +		result = ETrue;
    1.95 +		}
    1.96 +
    1.97 +	CleanupStack::PopAndDestroy(&v);
    1.98 +	CleanupStack::PopAndDestroy(&temp1);
    1.99 +	CleanupStack::PopAndDestroy(&temp);
   1.100 +	CleanupStack::PopAndDestroy(&u2);
   1.101 +	CleanupStack::PopAndDestroy(&u1);
   1.102 +	CleanupStack::PopAndDestroy(&hm);
   1.103 +	CleanupStack::PopAndDestroy(&w); 
   1.104 +
   1.105 +	return result;	
   1.106 +	}
   1.107 +
   1.108 +CDSAVerifier::CDSAVerifier(const CDSAPublicKey& aKey)  
   1.109 +	: iPublicKey(aKey)
   1.110 +	{
   1.111 +	}
   1.112 +