1 /*

     2 * Copyright (c) 2007-2009 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 #include "dhkeypairshim.h"

    20 #include <bigint.h>

    21 #include "cryptokeypairgeneratorapi.h"

    22 #include "keypair.h"

    23 #include <cryptospi/cryptoparams.h>

    24 #include <cryptospi/cryptospidef.h>

    25 

    26 

    27 using namespace CryptoSpi;

    28 

    29 

    30 /* CDHKeyPair */

    31 CDHKeyPairShim* CDHKeyPairShim::NewLC(RInteger& aN, RInteger& aG)

    32 	{

    33 	CDHKeyPairShim* self = new(ELeave) CDHKeyPairShim();

    34 	CleanupStack::PushL(self);

    35 	self->ConstructL(aN, aG);

    36 	return self;

    37 	}

    38 

    39 CDHKeyPairShim* CDHKeyPairShim::NewLC(RInteger& aN, RInteger& aG, RInteger& ax)

    40 	{

    41 	CDHKeyPairShim* self = new(ELeave) CDHKeyPairShim();

    42 	CleanupStack::PushL(self);

    43 	self->ConstructL(aN, aG, ax);

    44 	return self;

    45 	}

    46 

    47 CDHKeyPairShim::~CDHKeyPairShim(void)

    48 	{

    49 	}

    50 

    51 CDHKeyPairShim::CDHKeyPairShim(void)

    52 	{

    53 	}	

    54 

    55 void CDHKeyPairShim::ConstructL(RInteger& aN, RInteger& aG)

    56 	{

    57 	RInteger x = RInteger::NewL();

    58 	CleanupClosePushL(x);

    59 	KeyConstructorL(aN, aG, x, EFalse);

    60 	CleanupStack::PopAndDestroy(1, &x);

    61 	}

    62 

    63 void CDHKeyPairShim::ConstructL(RInteger& aN, RInteger& aG, RInteger& ax)

    64 	{

    65 	KeyConstructorL(aN, aG, ax, ETrue);

    66 	}

    67 

    68 void CDHKeyPairShim::KeyConstructorL(RInteger& aN, RInteger& aG, RInteger& ax, TBool xIncluded)

    69 	{

    70 	RInteger& nminus2 = aN;

    71 	

    72 	/*

    73 	 * do some sanity checks

    74 	 */

    75 	--nminus2;

    76 	--nminus2;

    77 	if( aG < TInteger::Two() || aG > nminus2 )

    78 		{

    79 		User::Leave(KErrArgument);

    80 		}

    81 

    82 	if (xIncluded)

    83 		{

    84 		if( ax < TInteger::One() || ax > nminus2 )

    85 			{

    86 			User::Leave(KErrArgument);

    87 			}

    88 		}

    89 

    90 	/*

    91 	 *find out how big the key should be - the key must be in the range x | 1 <= x <= n-2

    92 	 * nminus2 is the largest the key can be so get the number of bits required to represent that number

    93 	 */

    94 	const TInt keySize = nminus2.BitCount();

    95 

    96 	// increment aN back to its original value

    97 	++nminus2;

    98 	++nminus2;

    99 

   100 	// obtain an RSA key pair generator interface

   101 	

   102 	CKeyPairGenerator* keyPairGeneratorImpl=NULL;

   103 	CKeyPairGeneratorFactory::CreateKeyPairGeneratorL(

   104 											keyPairGeneratorImpl,

   105 											KDHKeyPairGeneratorUid,

   106 											NULL);

   107 	CleanupStack::PushL(keyPairGeneratorImpl);

   108 	

   109 	/* 

   110 	 * put the DH parameters into an array

   111 	 */

   112 	CCryptoParams* keyParameters = CCryptoParams::NewLC();

   113 	keyParameters->AddL(aN, KDhKeyParameterNUid);

   114 	keyParameters->AddL(aG, KDhKeyParameterGUid);

   115 	if (xIncluded)

   116 		{

   117 		// the private key x has been supplied so add it to the params array so the key generator algo can use it

   118 		keyParameters->AddL(ax, KDhKeyParameterxUid);

   119 		ax.Close();

   120 		}

   121 

   122 	/* 

   123 	 * call the api to create a DH key pair

   124 	 */

   125 	CKeyPair* keyPair = 0;

   126 	keyPairGeneratorImpl->GenerateKeyPairL(keySize, *keyParameters, keyPair);

   127 	CleanupStack::PushL(keyPair);

   128 

   129 	/* 

   130 	 * for compatibility convert the CKeyPair to CDHPrivateKey and CDHPublicKey

   131 	 */

   132 

   133 	// create new RInteger copies of aN, aG and x so the private key can own them

   134 	RInteger NCopy = RInteger::NewL(aN);

   135 	CleanupClosePushL(NCopy);

   136 	RInteger GCopy = RInteger::NewL(aG);

   137 	CleanupClosePushL(GCopy);

   138 	RInteger x = RInteger::NewL(keyPair->PrivateKey().GetBigIntL(KDhKeyParameterxUid));

   139 	CleanupClosePushL(x);

   140 	iPrivate = CDHPrivateKey::NewL(NCopy, GCopy, x);

   141 	CleanupStack::Pop(3, &NCopy);

   142 	

   143 	// the public key becomes the owner of aN, aG and X

   144 	RInteger X = RInteger::NewL(keyPair->PublicKey().GetBigIntL(KDhKeyParameterXUid));

   145 	CleanupClosePushL(X);

   146 	iPublic = CDHPublicKey::NewL(aN, aG, X);

   147 	CleanupStack::Pop(&X);	

   148 

   149 	/* 

   150 	 * cleanup stack - it should contain keyPairGeneratorImpl, keyParameters, keyPair, X, NCopy, GCopy and x

   151 	 */	

   152 	CleanupStack::PopAndDestroy(3, keyPairGeneratorImpl);

   153 	}