crypto/weakcryptospi/source/asymmetric/dhkeypairshim.cpp
changeset 19 cd501b96611d
child 43 2f10d260163b
equal deleted inserted replaced
15:da2ae96f639b 19:cd501b96611d
       
     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 	}