/*

* Copyright (c) 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: 

* This class implements the reference Crypto Token Hardware Abstraction 

* Interface (HAI). It is just intended to show how operations using 

* device keys can be performed using crypto token framework. In the 

* real world scenario, this HAI should be replaced by device drivers 

* by the licensees. In such a case, all the operations performed by 

* the replacing class would be performed in Kernel Space.

*

*/

#include "tcryptotokenhai.h"

#include "tkeydetails.h"

#include "cryptosignatureapi.h"

#include "keys.h"

#include <cryptospi/cryptoparams.h>

#include <cryptospi/cryptospidef.h>

EXPORT_C CCryptoTokenHai* CCryptoTokenHai::NewLC(MCTToken* aToken)

	{

	CCryptoTokenHai* instance = new(ELeave) CCryptoTokenHai(*aToken);

	CleanupStack::PushL(instance);

	instance->ConstructL();

	return instance;

	}

EXPORT_C CCryptoTokenHai* CCryptoTokenHai::NewL(MCTToken* aToken)

	{

	CCryptoTokenHai* instance = CCryptoTokenHai::NewLC(aToken);

	CleanupStack::Pop(instance);

	return instance;

	}

void CCryptoTokenHai::ConstructL()

	{

	User::LeaveIfError(iFs.Connect());

	OpenStoreL();

	}

CCryptoTokenHai::CCryptoTokenHai(MCTToken& aToken)

	:iToken(aToken)

	{}

EXPORT_C CCryptoTokenHai::~CCryptoTokenHai()

	{

	if(iFileStore)

        {

        CompactStore();

        delete iFileStore;

        }

	iFs.Close();

	iKeys.ResetAndDestroy();

    iKeys.Close();

	}

/**

 * Performs the decryption operation.

 * 

 * This API gets called when the decryption is supposed to be done in  

 * the hardware.

 * 

 * @param aHandle The key handle

 * @param aCiphertext The cipher text. This is not being used presently 

 * due to decryption logic used in this function.

 * @param aPlainText Output param. The decrypted plain text. Ownership 

 * of the pointer lies with the caller.

 * 

 * @leave This function can leave with following error codes:-

 * - KErrNotFound - If the key corresponding to given handle is not 

 * found.

 * - Any other error code returned by AllocL().

 *

 * @note This function does not actually implement ECC decryption. It 

 * just intends to show that the key is with this class and it can 

 * do actual ECC decryption here. This function just returns the 

 * private key as decrypted text. The caller can verify the decryption 

 * by ensuring that test case has same public and private keys and then 

 * comparing the decrypted text with public key. 

 */

EXPORT_C void CCryptoTokenHai::DecryptL(	TInt aHandle,	

											const TDesC8& /* aCiphertext */,

											HBufC8*& aPlainText )

	{

    TInt keyIndex = KeyPresent(aHandle);

    if(keyIndex == KErrNotFound)

        {

        User::Leave(KErrNotFound);

        }

    ExportPrivateKeyL(aHandle, aPlainText);

	}

/**

 * Performs the signing operation.

 * 

 * This API gets called when the signing is supposed to be done inside 

 * the hardware.

 * 

 * @param aHandle The key handle

 * @param aPlaintext The text which has to be signed. This is not being 

 * used due to signing logic used in this function.

 * @param aSignature Output param. The signature in HBufC8 format.  

 * Ownership of the pointer lies with the caller. This should be 

 * converted to CCryptoParams by the crypto token reference plugin. 

 * 

 * @leave This function can leave with following error codes:-

 * - KErrNotFound - If the key corresponding to given handle is not 

 * found.

 * - Any other error code returned by AllocL().

 * 

 * @note This function does not actually implement ECC signing. It 

 * just intends to show that the key is with this class and it can 

 * do actual ECC signing here. Currently this function just returns 

 * the private key as output signature. The caller can verify the 

 * signature by ensuring that test case has same public and private 

 * keys and then comparing the signature with public key.

 */

EXPORT_C void CCryptoTokenHai::SignL( 	TInt aHandle,

										const TDesC8& /* aPlaintext */,

										HBufC8*& aSignature )

	{

	TInt keyIndex = KeyPresent(aHandle);

	if(keyIndex == KErrNotFound)

	    {

	    User::Leave(KErrNotFound);

	    }

	ExportPrivateKeyL(aHandle, aSignature);

	}

/**

 * Returns the index of the key whose handle is given.

 * 

 * @param aHandle Handle of the key. This is used to search the key.

 * 

 * @return index of the key if search is successful, KErrNotFound 

 * otherwise.

 */

EXPORT_C TInt CCryptoTokenHai::KeyPresent( TInt aHandle )

	{

	int keysCount = iKeys.Count();

	for(TInt i=0; i < keysCount; ++i)

		{

		if(iKeys[i]->Handle() == aHandle)

			{

			return i;

			}

		}

	return KErrNotFound;

	}

/**

 * Extracts the private key.

 * 

 * @param aHandle Handle of the private key to be extracted.

 * @param aKey Output Parameter. Stores the private key on success. 

 * Ownership of pointer is with the caller.

 * 

 * @leave Following leave codes possible:-

 * - Any leave code returned by AllocL().

 * - KErrNotFound - If key corresponding to the given handle is not 

 * found.

 * 

 * @note In the actual implementation, licensees should ensure that 

 * this function can be called only in Kernel space. In the reference 

 * implementation, this function gets called only by CCryptoSpiHai, 

 * which is assumed to operate in kernel space. This would ensure that 

 * the private key always stays inside the hardware.

 */

EXPORT_C void CCryptoTokenHai::ExportPrivateKeyL( TInt aHandle, HBufC8*& aKey )

	{

	int keysCount = iKeys.Count();

	for(int i = 0; i < keysCount; ++i)

		{

		if(iKeys[i]->Handle() == aHandle)

			{

			aKey = iKeys[i]->PrivateKey()->AllocL();

			return;

			}

		}

	User::Leave(KErrNotFound);

	}

/**

 * Extracts the public key.

 * 

 * @param aHandle Handle of the public key to be extracted.

 * @param aKey Output Parameter. Stores the public key on success.

 * Ownership of pointer is with the caller.

 * 

 * @leave Following leave codes possible:-

 * - Any leave code returned by AllocL().

 * - KErrNotFound - If key corresponding to the given handle is not 

 * found.

 */

EXPORT_C void CCryptoTokenHai::ExportPublicKeyL( TInt aHandle, HBufC8*& aKey )

    {

    int keysCount = iKeys.Count();

    for(int i = 0; i < keysCount; ++i)

        {

        if(iKeys[i]->Handle() == aHandle)

            {

            aKey = iKeys[i]->PublicKey()->AllocL();

            return;

            }

        }

    User::Leave(KErrNotFound);

    }

/**

 * Stores the key with given details.

 * 

 * @param aLabel Label of the key.

 * @param aPrivateKey Private component of the key.

 * @param aPublicKey Public component of the key.

 * 

 * @leave Following leave codes possible:-

 * - KErrAlreadyExists If there is already a key with the inputted

 * label.

 * - Any other leave code returned by NewL() or AppendL().

 *  

 * @note In the present reference implementation this function is not 

 * being used, since device keys are pre-provisioned by the licensees. 

 * Hence licensees may decide not to implement this function in their 

 * real implementation. 

 */

EXPORT_C void CCryptoTokenHai::ImportKeyL(const TDesC& aLabel, 

        const TDesC8& aPrivateKey, const TDesC8& aPublicKey)

	{

	int keysCount = iKeys.Count();

	for(int i = 0; i < keysCount; ++i)

		{

		if(iKeys[i]->Label() == aLabel)

			{

			User::Leave(KErrAlreadyExists);

			}

		}

	CKeyDetails* keyDetails = CKeyDetails::NewL(keysCount+1,aLabel,aPrivateKey,aPublicKey);

	iKeys.AppendL(keyDetails);

	}

/**

 * Populates the string containing full RAM path of file containing 

 * keys.

 */

void CCryptoTokenHai::MakePrivateFilenameL(RFs& aFs, const TDesC& aLeafName, TDes& aNameOut)

    {

    aNameOut.SetLength(0);  

    aNameOut.Append(RFs::GetSystemDriveChar());

    aNameOut.Append(':');

    // Get private path

    TBuf<20> privatePath;

    User::LeaveIfError(aFs.PrivatePath(privatePath));

    aNameOut.Append(privatePath);

    aNameOut.Append(aLeafName);

    }

/**

 * Creates the corresponding directory, if it does not exist.

 */

void CCryptoTokenHai::EnsurePathL(RFs& aFs, const TDesC& aFile)

    {

    TInt err = aFs.MkDirAll(aFile);

    if (err != KErrNone && err != KErrAlreadyExists)

        {

        User::Leave(err);

        }

    }

/**

 * Populates the string containing full ROM path of the keys file.

 */

void CCryptoTokenHai::MakePrivateROMFilenameL(RFs& aFs, const TDesC& aLeafName, TDes& aNameOut)

    {

    _LIT(KFileStoreROMDrive, "Z:");

    aNameOut.Copy(KFileStoreROMDrive);

    // Get private path

    TBuf<20> privatePath;

    User::LeaveIfError(aFs.PrivatePath(privatePath)); 

    aNameOut.Append(privatePath);

    aNameOut.Append(aLeafName);

    }

/**

 * Copies the contents of source file to destination file.

 * 

 * This is typically used to copy the keys file from ROM to RAM.

 */

void CCryptoTokenHai::CopyL(RFs& aFs, const TDesC& aSouce, const TDesC& aDest)

    {

    RFileReadStream in;

    User::LeaveIfError(in.Open(aFs, aSouce, EFileRead | EFileShareReadersOnly));

    CleanupClosePushL(in);

    RFileWriteStream out;

    User::LeaveIfError(out.Replace(aFs, aDest, EFileWrite | EFileShareExclusive));

    CleanupClosePushL(out);

    in.ReadL(out);  

    CleanupStack::PopAndDestroy(2, &in);

    }

/**

 * Keys corresponding to this store are present in hwkeys.dat. 

 * In the production code written by licensees, this would be the path 

 * where device keys are stored.

 */

_LIT(KKeyStoreFilename,"hwkeys.dat");

/**

 * Opens a store containing hardware keys.

 * 

 * This function uses the following logic to open the store:-

 * -# Try to open the store from the private directory.

 * -# If this fails copy the file from ROM to RAM.

 * -# If both fail, create your own keys store from scratch.

 */

void CCryptoTokenHai::OpenStoreL()

	{

	TFileName fullPath;

	MakePrivateFilenameL(iFs, KKeyStoreFilename, fullPath);

	EnsurePathL(iFs, fullPath);

	TRAPD(result, OpenStoreInFileL(fullPath));

	if (result == KErrInUse  ) 

		{		

		// Cannot access the file now. Abort rather than wiping the keystore.

		User::Leave(result); 

		}

	if (result != KErrNone )

		{		

		/*

		 * Not yet opened a valid store, either no file to be found, or 

		 * no valid store in it. Copy the original one stored in the 

		 * ROM.

		 */

		TRAPD(result2, CopyStoreFromROML(fullPath, result));

		if (KErrNone != result2)

			{

			/*

			 * We tried to copy the keystore from ROM. For some reason this

			 * failed and we still cannot open the file. Create a new one from

			 * scratch.

			 */ 

			CreateStoreInFileL(fullPath);

			}

		}

	}

/**

 * Copies the key store file from ROM to RAM.

 */

void CCryptoTokenHai::CopyStoreFromROML(const TDesC& fullPath, TInt result)

    {

    if (result != KErrNotFound)

        {

        // Wipe the keystore if we can't open it (it's corrupt anyway)

        User::LeaveIfError(iFs.Delete(fullPath));

        }

    TFileName romPath;

    MakePrivateROMFilenameL(iFs, KKeyStoreFilename, romPath);

    // Copy data from rom and open it   

    CopyL(iFs, romPath, fullPath);

    OpenStoreInFileL(fullPath);

    }

/**

 * Opens a store from the given file.

 */

void CCryptoTokenHai::OpenStoreInFileL(const TDesC& aFile)

	{

	RFile file;

	User::LeaveIfError(file.Open(iFs, aFile, EFileRead | EFileWrite | EFileShareAny));

	CleanupClosePushL(file);

    delete iFileStore;

    iFileStore = NULL;

	iFileStore = CPermanentFileStore::FromL(file);

    // iFileStore takes ownership of file now

	CleanupStack::Pop(&file);

    // Get the salt, root and manager TStreamIds

    iRootStreamId = iFileStore->Root();

    if (iRootStreamId == KNullStreamId)

        {

        User::Leave(KErrCorrupt);

        }

    RStoreReadStream rootStream;

    rootStream.OpenLC(*iFileStore, iRootStreamId);

    ReadKeysFromStoreL();

    CleanupStack::PopAndDestroy(&rootStream);

    }

/**

 * Creates a keys store in RAM from scratch.

 * 

 * @note This function should never get called as hwkeys.dat should be 

 * always present in ROM. If this function somehow gets called, it 

 * will create a hwkeys.dat file from scratch. However, this file would 

 * not contain any keys and tests would not pass.

 */

void CCryptoTokenHai::CreateStoreInFileL(const TDesC& aFile)

	{

	TInt r = iFs.MkDirAll(aFile);

	if ( (r!=KErrNone) && (r!=KErrAlreadyExists) )

		User::Leave(r);

    delete iFileStore;

    iFileStore = NULL;

	iFileStore = CPermanentFileStore::ReplaceL(iFs, aFile, EFileRead | EFileWrite | EFileShareExclusive);

	iFileStore->SetTypeL(KPermanentFileStoreLayoutUid);

	TCleanupItem cleanupStore(RevertStore, iFileStore);

	CleanupStack::PushL(cleanupStore);

	// Create root stream - just contains id of info stream

	RStoreWriteStream rootStream;

	iRootStreamId = rootStream.CreateLC(*iFileStore);

	iFileStore->SetRootL(iRootStreamId);

	WriteKeysToStoreL(rootStream);

	iFileStore->CommitL();

	CleanupStack::PopAndDestroy(&rootStream);

	CleanupStack::Pop(); // cleanupStore

	}

/**

 * Copies the keys stored in the instance to inputted write stream.

 * 

 * This invokes the CKeyDetails::ExternalizeL() function.

 */

void CCryptoTokenHai::WriteKeysToStoreL(RStoreWriteStream& aRootStream)

	{

	TInt keyCount = iKeys.Count();

	aRootStream.WriteInt32L(keyCount);

	for (TInt index = 0; index < keyCount; index++)

		{

		aRootStream << *iKeys[index];

		}

	aRootStream.CommitL();

	}

/**

 * Copies the keys present in the read store to instance of class.

 * 

 * This eventually invokes the CKeyDetails::InternalizeL() function.

 */

void CCryptoTokenHai::ReadKeysFromStoreL()

	{

	RStoreReadStream rootStream;

	rootStream.OpenLC(*iFileStore, iRootStreamId);

	TInt keyCount = rootStream.ReadInt32L();

	for (TInt index = 0; index < keyCount; index++)

		{

		CKeyDetails* keyDetails = CKeyDetails::NewL(rootStream);

		iKeys.Append(keyDetails);

		}

	CleanupStack::PopAndDestroy(&rootStream);

	}

/**

 * This is a cleanup item that reverts the store.

 */

void CCryptoTokenHai::RevertStore(TAny* aStore)

	{

	CPermanentFileStore* store = reinterpret_cast<CPermanentFileStore*>(aStore);

	TRAP_IGNORE(store->RevertL());

	}

/**

 * Compacts the store.

 */

void CCryptoTokenHai::CompactStore()

    {

    ASSERT(iFileStore);

    TRAP_IGNORE(iFileStore->ReclaimL(); iFileStore->CompactL());

    }

/**

 * Populates the list of keys based on the input filter.

 * 

 * @param aFilter Set of conditions to be used to decide which keys 

 * should be listed

 * @param aKeys Output param. Contains the array of keys which fulfil 

 * criteria mentioned in filter. Caller should take responsibility of 

 * this array.

 * 

 * @leave Any of the system wide error codes.

 * 

 * @note Though Crypto Token HAI internally operates in CKeyDetails, 

 * this function returns CCTKeyInfo array.

 */

EXPORT_C void CCryptoTokenHai::ListL(const TCTKeyAttributeFilter&  aFilter , 

                RPointerArray<CCTKeyInfo>& aKeys) const

    {

    TInt count = iKeys.Count();

    for(TInt index = 0 ;index < count; ++ index)

    	{

    	const CKeyDetails* keyDetails = iKeys[index];

    	if(KeyMatchesFilterL(*keyDetails,aFilter))

    		{

			MCTAuthenticationObject* authObject = NULL;

			HBufC8* attribute = keyDetails->PKCS8AttributeSet().AllocLC();

			HBufC* label = keyDetails->Label().AllocLC();

			CCTKeyInfo* keyInfo = CCTKeyInfo::NewL(

					keyDetails->ID(),keyDetails->Usage(),keyDetails->Size(),

					authObject,label,iToken,keyDetails->Handle(),keyDetails->UsePolicy(),

					keyDetails->ManagementPolicy(),keyDetails->Algorithm(),keyDetails->AccessType(),

					keyDetails->Native(),keyDetails->StartDate(),keyDetails->EndDate(),attribute);

			CleanupStack::Pop(2, attribute); // label

			CleanupReleasePushL(*keyInfo);

			User::LeaveIfError(aKeys.Append(keyInfo));

			CleanupStack::Pop(keyInfo); 

			}

    	}

    }

/**

 * Takes in a filter and key details and decides if key fulfils the 

 * filter criteria.

 * 

 * @param aInfo The Key Details

 * @param aFilter Filter specifying the conditions to be satisfied for 

 * listing the keys.

 * 

 * @retval ETrue if key satisfies the conditions specified in filter

 * @retval EFalse otherwise.

 * 

 * @leave KErrArgument If there is an issue in policy filter.

 */

TBool CCryptoTokenHai::KeyMatchesFilterL(const CKeyDetails& aInfo,

										   const TCTKeyAttributeFilter& aFilter) const

	{

	if (aFilter.iKeyId.Length() && aFilter.iKeyId != aInfo.ID())

		{

		return EFalse;

		}

	if (aFilter.iUsage != EPKCS15UsageAll)

		{

		if ((aInfo.Usage() & aFilter.iUsage) == 0)

			return EFalse;

		}

	if (aFilter.iKeyAlgorithm != CCTKeyInfo::EInvalidAlgorithm && 

		aFilter.iKeyAlgorithm != aInfo.Algorithm())

		{

		return EFalse;

		}

	switch (aFilter.iPolicyFilter)

		{

		case TCTKeyAttributeFilter::EAllKeys:

			// All keys pass

			break;

		case TCTKeyAttributeFilter::EUsableKeys:

			if (!aInfo.UsePolicy().CheckPolicy(RThread()))

				{

				return EFalse;

				}

			break;

		case TCTKeyAttributeFilter::EManageableKeys:

			// As this key store implementation is a hardware simulation,

			// the support for managing through software interface has been diabled.

			return EFalse;

		case TCTKeyAttributeFilter::EUsableOrManageableKeys:

			if (!aInfo.UsePolicy().CheckPolicy(RThread()) &&

				!aInfo.ManagementPolicy().CheckPolicy(RThread()))

				{

				return EFalse;

				}

			break;

		default:

			User::Leave(KErrArgument);

		}

	return ETrue;

	}