/*

* Copyright (c) 2002-2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

*

*/

#include <e32std.h>

#include <random.h>

#include <pbedata.h>

#include "pkcs5kdf.h"

#include "pbencryptor.h"

#include "pbe.h"

#include <securityerr.h>

#include "pbesymmetricfactory.h"

EXPORT_C CPBEncryptSet* CPBEncryptSet::NewL(const TPBPassword& aPassword)

	{

	CPBEncryptSet* self = NewLC(aPassword);

	CleanupStack::Pop();

	return self;

	}

EXPORT_C CPBEncryptSet* CPBEncryptSet::NewLC(const TPBPassword& aPassword)

	{

	CPBEncryptSet* self = new(ELeave) CPBEncryptSet;

	CleanupStack::PushL(self);

	self->ConstructL(aPassword.Password());

	return self;

	}

EXPORT_C CPBEncryptSet* CPBEncryptSet::NewL(const TPBPassword& aPassword, 

	const TPBECipher aCipher)

	{

	CPBEncryptSet* self = NewLC(aPassword, aCipher);

	CleanupStack::Pop();

	return self;

	}

EXPORT_C CPBEncryptSet* CPBEncryptSet::NewLC(const TPBPassword& aPassword, 

	const TPBECipher aCipher)

	{

	CPBEncryptSet* self = new(ELeave) CPBEncryptSet;

	CleanupStack::PushL(self);

	self->ConstructL(aPassword.Password(), aCipher);

	return self;

	}

EXPORT_C CPBEncryptSet* CPBEncryptSet::NewL(const TPBPassword& aPassword,

	const CPBEncryptParms& aParms)

	{

	CPBEncryptSet* self = NewLC(aPassword, aParms);

	CleanupStack::Pop();

	return self;

	}

EXPORT_C CPBEncryptSet* CPBEncryptSet::NewLC(const TPBPassword& aPassword, 

	const CPBEncryptParms& aParms)

	{

	CPBEncryptSet* self = new(ELeave) CPBEncryptSet;

	CleanupStack::PushL(self);

	self->ConstructL(aPassword.Password(), aParms);

	return self;

	}

EXPORT_C CPBEncryptSet* CPBEncryptSet::NewL(const CPBEncryptionData& aData, 

	const TDesC8& aEncryptedKey, const TPBPassword& aPassword)

	{

	CPBEncryptSet* self = NewLC(aData, aEncryptedKey, aPassword);

	CleanupStack::Pop();

	return self;

	}

EXPORT_C CPBEncryptSet* CPBEncryptSet::NewLC(const CPBEncryptionData& aData,

	const TDesC8& aEncryptedKey, const TPBPassword& aPassword)

	{

	CPBEncryptSet* self = new(ELeave) CPBEncryptSet;

	CleanupStack::PushL(self);

	self->ConstructL(aData, aEncryptedKey, aPassword);

	return self;

	}

void CPBEncryptSet::ConstructL(const TDesC8& aPassword)

	{

	CPBEncryptElement::ConstructL(aPassword);

	ConstructMasterKeyL();

	}

void CPBEncryptSet::ConstructL(const TDesC8& aPassword,

	const TPBECipher aCipher)

	{

	CPBEncryptElement::ConstructL(aPassword, aCipher);

	ConstructMasterKeyL();

	}

void CPBEncryptSet::ConstructL(const TDesC8& aPassword, 

	const CPBEncryptParms& aParms)

	{

	CPBEncryptElement::ConstructL(aPassword, aParms);

	ConstructMasterKeyL();

	}

void CPBEncryptSet::ConstructMasterKeyL(void)

	{

	TBuf8<KAESKeyBytes256> masterKey(KAESKeyBytes256);

	TRandom::RandomL(masterKey);

	iEncryptedMasterKey = HBufC8::NewL(KAESKeyBytes256);

	EncryptMasterKeyL(masterKey);

	}

void CPBEncryptSet::ConstructL(const CPBEncryptionData& aData,

	const TDesC8& aEncryptedMasterKey, const TPBPassword& aPassword)

	{

	CPBEncryptElement::ConstructL(aData, aPassword);

	iEncryptedMasterKey = aEncryptedMasterKey.AllocL();

	}

EXPORT_C void CPBEncryptSet::ChangePasswordL(const TPBPassword& aNewPassword)

	{

	//1) Decrypt master key with old encrypt key 

	TBuf8<KPBEMaxCipherKeyBytes> masterKey;

	DecryptMasterKeyL(masterKey);

	//2) create new encrypt parms

	TBuf8<KPBEMaxSaltBytes> authSalt(KPBEMaxSaltBytes);

	TRandom::RandomL(authSalt);

	//3) create a totally new CPBEncryptionData representing the new password

	CPBEncryptionData* newData = CPBEncryptionData::NewL(

		aNewPassword.Password(), authSalt, iData->EncryptParms());

	delete iData;

	iData = newData;

	// regenerate the password using a maximum length salt.

	CPBEncryptParms& epNonConst =

		const_cast<CPBEncryptParms&>(iData->EncryptParms());

	epNonConst.ResizeSaltL(KPBEMaxSaltBytes);

	TPtr8 iEncryptKeyBuf(iEncryptKey->Des());

	iEncryptKeyBuf.SetLength(PBE::GetKeyBytes(iData->EncryptParms().Cipher()));

	iData->EncryptParms().DeriveKeyL(aNewPassword.Password(), iEncryptKeyBuf);

	//4) Encrypt master key with new encrypt key

	EncryptMasterKeyL(masterKey);

	}

EXPORT_C const TDesC8& CPBEncryptSet::EncryptedMasterKey(void) const

	{

	return *iEncryptedMasterKey;

	}

CPBEncryptor* CPBEncryptSet::NewEncryptLC(void) const

	{

	CPBEncryptor* encryptor = NewEncryptL();

	CleanupStack::PushL(encryptor);

	return encryptor;

	}

CPBEncryptor* CPBEncryptSet::NewEncryptL(void) const

	{

	TBuf8<KPBEMaxCipherKeyBytes> masterKey;

	DecryptMasterKeyL(masterKey);

	CPBEncryptor* encryptor = 0;

	//make sure the masterkey we pass is exactly the right length for the cipher

	encryptor = CPBEncryptorSet::NewL(iData->EncryptParms().Cipher(),

		masterKey.Left(PBE::GetKeyBytes(iData->EncryptParms().Cipher())));		

	return encryptor;

	}

CPBDecryptor* CPBEncryptSet::NewDecryptLC(void) const

	{

	CPBDecryptor* decryptor = NewDecryptL();

	CleanupStack::PushL(decryptor);

	return decryptor;

	}

CPBDecryptor* CPBEncryptSet::NewDecryptL(void) const

	{

	TBuf8<KPBEMaxCipherKeyBytes> masterKey;

	DecryptMasterKeyL(masterKey);

	CPBDecryptor* decryptor = 0;

	//make sure the masterkey we pass is exactly the right length for the cipher

	decryptor = CPBDecryptorSet::NewL(iData->EncryptParms().Cipher(),

		masterKey.Left(PBE::GetKeyBytes(iData->EncryptParms().Cipher())));		

	return decryptor;

	}

void CPBEncryptSet::DecryptMasterKeyL(TDes8& aMasterKey) const

	{

	CPBDecryptorElement* decryptor = CPBDecryptorElement::NewLC(

		iData->EncryptParms().Cipher(), *iEncryptKey, iData->EncryptParms().IV());

	aMasterKey.SetLength(0);

	decryptor->Process(*iEncryptedMasterKey, aMasterKey);

	CleanupStack::PopAndDestroy(decryptor);

	}

void CPBEncryptSet::EncryptMasterKeyL(const TDesC8& aMasterKey)

	{

	CPBEncryptorElement* encryptor = CPBEncryptorElement::NewLC(

		iData->EncryptParms().Cipher(), *iEncryptKey, iData->EncryptParms().IV());

	TPtr8 encryptedMasterKeyBuf(iEncryptedMasterKey->Des());

	encryptedMasterKeyBuf.SetLength(0);

	encryptor->Process(aMasterKey, encryptedMasterKeyBuf);

	CleanupStack::PopAndDestroy(encryptor);

	}

CPBEncryptSet::CPBEncryptSet()

	{

	}

CPBEncryptSet::~CPBEncryptSet()

	{

	delete iEncryptedMasterKey;

	}

// Warning: This function is only valid BEFORE you call NewEncryptL

// After creating the cipher, ask it about itself, not me!

// This is _very_ dodgy as I assume all sorts of things about the encryptor.

// 1) That it uses SSLv3 or similar style padding

// 2) That it stores the IV for that stream at the front.

// This is here for specific application that requires this and aren't able to

// actually construct the cipher and ask it.  In almost all other cases you

// should construct the cipher and ask it.

TInt CPBEncryptSet::MaxCiphertextLength(TInt aPlaintextLength) const

    {

	TUint blocksize = PBE::GetBlockBytes(iData->EncryptParms().Cipher());

	TUint padding = blocksize - aPlaintextLength % blocksize;

	//totallength = blocksize of iv hidden at beginning + inputLength + padding

	return blocksize + aPlaintextLength + padding;

    }

// Warning: This function is only valid BEFORE you call NewDecryptL

// After creating the cipher, ask it about itself, not me!

TInt CPBEncryptSet::MaxPlaintextLength(TInt aCiphertextLength) const

    {

	/*It's impossible to determine anything about how much padding will be

	 * removed.  So we'll return a max length that is longer than will ever

	 * happen by at most a blocksize - 1.

	 */

	//In all cases SSLv3 padding has at least one byte of padding.

	TUint blocksize = PBE::GetBlockBytes(iData->EncryptParms().Cipher());

	//totallength = inputlength - iv hidden at beginning - 1 byte of padding

    return aCiphertextLength - blocksize - 1;

    }