sl@0: /*
sl@0: * Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: * All rights reserved.
sl@0: * This component and the accompanying materials are made available
sl@0: * under the terms of the License "Eclipse Public License v1.0"
sl@0: * which accompanies this distribution, and is available
sl@0: * at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: *
sl@0: * Initial Contributors:
sl@0: * Nokia Corporation - initial contribution.
sl@0: *
sl@0: * Contributors:
sl@0: *
sl@0: * Description: 
sl@0: *
sl@0: */
sl@0: 
sl@0: 
sl@0: #include "pkcs7encrypteddataobject.h"
sl@0: 
sl@0: /** The last character in the PKCS7 EncryptedData OID */
sl@0: const TInt KPkcs7EncryptedData = 6;
sl@0: 
sl@0: EXPORT_C CPKCS7EncryptedDataObject* CPKCS7EncryptedDataObject::NewL(const CPKCS7ContentInfo& aContentInfo)
sl@0: 	{
sl@0: 	CPKCS7EncryptedDataObject* self = new (ELeave) CPKCS7EncryptedDataObject();
sl@0: 	CleanupStack::PushL(self);
sl@0: 	self->ConstructL(aContentInfo);
sl@0: 	CleanupStack::Pop(self);
sl@0: 	return self;	
sl@0: 	}
sl@0: 
sl@0: CPKCS7EncryptedDataObject::CPKCS7EncryptedDataObject(void)
sl@0: 	{
sl@0: 	}
sl@0: 
sl@0: CPKCS7EncryptedDataObject::~CPKCS7EncryptedDataObject()
sl@0: 	{
sl@0: 	delete iEncryptParams;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInt CPKCS7EncryptedDataObject::Version() const
sl@0: 	{
sl@0: 	return iVersion;
sl@0: 	}
sl@0: 	
sl@0: EXPORT_C CPKCS7EncryptedDataObject::TContentType CPKCS7EncryptedDataObject::ContentType() const
sl@0: 	{
sl@0: 	return iContentType;
sl@0: 	}
sl@0: 	
sl@0: EXPORT_C const TDesC8& CPKCS7EncryptedDataObject::EncryptedContentInfoData() const
sl@0: 	{
sl@0: 	return iEncryptedContent;
sl@0: 	}	
sl@0: 
sl@0: EXPORT_C const CPBEncryptParms& CPKCS7EncryptedDataObject::EncryptParams() const
sl@0: 	{
sl@0: 	return *iEncryptParams;
sl@0: 	}
sl@0: 
sl@0: CPBEncryptParms* CPKCS7EncryptedDataObject::DecodeContentEncryptionAlgorithmL(const TDesC8& aBinaryData) const
sl@0: 	{
sl@0: 	TASN1DecGeneric seqGen(aBinaryData);
sl@0: 	seqGen.InitL();
sl@0: 	if (seqGen.Tag() != EASN1Sequence || seqGen.Class() != EUniversal)
sl@0: 		{
sl@0: 		User::Leave(KErrArgument);
sl@0: 		}
sl@0: 	
sl@0:     TPtrC8 theContent(seqGen.Encoding());
sl@0:     CPBEncryptParms* encryptParams =  TASN1DecPKCS5::DecodeDERL(theContent);
sl@0:     return encryptParams;
sl@0: 	}	
sl@0: 
sl@0: EXPORT_C HBufC8* CPKCS7EncryptedDataObject::DecryptDataL(const TDesC& aPassword) const
sl@0: 	{
sl@0: 	CPBEncryptElement* encryptElement;
sl@0:     HBufC8* pkcs12Pwd = PKCS12KDF::GeneratePasswordLC(aPassword);
sl@0:     if(iEncryptParams->Kdf() == CPBEncryptParms::EKdfPkcs12)
sl@0: 		{
sl@0: 	 	TPtrC8 iv = iEncryptParams->IV();
sl@0: 	    HBufC8* ivValue = HBufC8::NewMaxLC(iv.Length());
sl@0: 	    TPtr8 encryptKeyBuf = ivValue->Des();
sl@0: 
sl@0: 	 	switch(iEncryptParams->Cipher())	
sl@0: 			{
sl@0: 	 		case ECipherARC4_128:
sl@0: 	 		case ECipherARC4_40:
sl@0: 	 			{
sl@0: 	 	    	//derive only key it is unnecessary to derive an IV for RC4
sl@0: 	 	    	break;
sl@0: 	 			}
sl@0: 			case ECipher3DES_CBC:
sl@0: 			case ECipher2Key3DES_CBC:
sl@0: 			case ECipherRC2_CBC_128_16:	 
sl@0: 			case ECipherRC2_CBC_40_5:	
sl@0: 				{
sl@0: 				PKCS12KDF::DeriveKeyL(encryptKeyBuf, PKCS12KDF::EIDByteIV, *pkcs12Pwd, iEncryptParams->Salt(), iEncryptParams->Iterations());
sl@0: 				iEncryptParams->SetIV(encryptKeyBuf);
sl@0: 		    	break;
sl@0: 				}
sl@0: 			default:
sl@0: 				{
sl@0: 		    	User::Leave(KErrNotSupported);
sl@0: 		    	break;
sl@0: 				}
sl@0: 	 		}
sl@0: 	 	CleanupStack::PopAndDestroy(ivValue);
sl@0: 		// Create the decryptor	
sl@0: 		encryptElement = CPBEncryptElement::NewLC(*pkcs12Pwd, *iEncryptParams);
sl@0: 		}
sl@0: 	else
sl@0: 		{
sl@0: 		TPBPassword password(aPassword);
sl@0: 		// Create the decryptor	
sl@0: 		encryptElement = CPBEncryptElement::NewLC(password.Password(), *iEncryptParams);	
sl@0: 		}
sl@0: 	 
sl@0: 	CPBDecryptor* decryptor = encryptElement->NewDecryptLC();
sl@0:    	
sl@0: 	TPtrC8 encryptedKey(iEncryptedContent);
sl@0: 	TUint encryptLength = encryptedKey.Length();
sl@0: 	TUint maxDecryptLength = decryptor->MaxOutputLength(encryptLength);
sl@0: 	
sl@0: 	if ( maxDecryptLength <= 0 )
sl@0: 		{
sl@0: 		User::Leave(KErrGeneral);		
sl@0: 		}
sl@0: 	
sl@0: 	HBufC8* decryptedContent = HBufC8::NewLC(maxDecryptLength);
sl@0: 	TPtr8 dcDes(decryptedContent->Des());
sl@0: 	decryptor->Process(encryptedKey, dcDes);
sl@0: 	CleanupStack::Pop(decryptedContent);
sl@0: 	CleanupStack::PopAndDestroy(3, pkcs12Pwd); // pkcs12Pwd, encryptElement, decryptor
sl@0:    	return decryptedContent;
sl@0:    	}
sl@0: 
sl@0:  void CPKCS7EncryptedDataObject::ConstructL(const CPKCS7ContentInfo& aContentInfo)
sl@0: 	{
sl@0: 	if(aContentInfo.ContentType() != KPkcs7EncryptedData)
sl@0: 		{
sl@0: 		User::Leave(KErrArgument);
sl@0: 		}
sl@0:     
sl@0: 	// EncryptedData SEQUENCE
sl@0: 	TASN1DecGeneric decGen(aContentInfo.ContentData());
sl@0: 	decGen.InitL();
sl@0: 	if(decGen.Tag() != EASN1Sequence || decGen.Class() != EUniversal)
sl@0: 		{
sl@0: 	    User::Leave(KErrArgument);
sl@0: 		}
sl@0:     TASN1DecSequence seq1;
sl@0:     CArrayPtrFlat<TASN1DecGeneric>* EncryptedDataContents = seq1.DecodeDERLC(decGen);       					
sl@0: 			    
sl@0: 	// Both version and encryptedContentInfo should be present
sl@0: 	if (EncryptedDataContents->Count() != 2)
sl@0: 		{
sl@0: 		User::Leave(KErrArgument);
sl@0: 		}
sl@0: 		            
sl@0: 	// VERSION
sl@0: 	// version is the syntax version number. It shall be 0 for this version of the standard
sl@0: 	const TASN1DecGeneric* EncryptedDataContentsAt0 = EncryptedDataContents->At(0);
sl@0: 	if(EncryptedDataContentsAt0->Tag() != EASN1Integer || EncryptedDataContentsAt0->Class() != EUniversal)
sl@0: 		{
sl@0: 		User::Leave(KErrArgument);
sl@0: 		}
sl@0: 	 
sl@0: 	TASN1DecInteger intDecoder;
sl@0: 	iVersion = intDecoder.DecodeDERShortL(*EncryptedDataContentsAt0);
sl@0: 	if (iVersion != 0)
sl@0: 		{
sl@0: 	    User::Leave(KErrArgument);		
sl@0: 	    }
sl@0: 		                
sl@0:     // ENCRYPTED CONTENT INFO a SEQUENCE
sl@0:     const TASN1DecGeneric* EncryptedDataContentsAt1 = EncryptedDataContents->At(1);
sl@0: 	if (EncryptedDataContentsAt1->Tag() != EASN1Sequence || EncryptedDataContentsAt1->Class() != EUniversal)
sl@0: 		{
sl@0: 	    User::Leave(KErrArgument);
sl@0: 	    }		               
sl@0: 	TASN1DecSequence seq2;
sl@0:     CArrayPtrFlat<TASN1DecGeneric>* EncryptedContentInfo = seq2.DecodeDERLC(*EncryptedDataContentsAt1);       
sl@0: 		        
sl@0:     // CONTENT TYPE IDENTIFIED BY AN OBJECT IDENTIFIER
sl@0: 	// Gets the oid
sl@0: 	TASN1DecObjectIdentifier ContentTypeoidDec;
sl@0: 	HBufC* contentType = ContentTypeoidDec.DecodeDERL(*EncryptedContentInfo->At(0));
sl@0: 	if(contentType->Compare(KPkcs7DataOID()) == 0)
sl@0: 		{
sl@0: 		iContentType = EPkcs7Data;
sl@0: 		}
sl@0: 	else
sl@0: 		{
sl@0: 		User::Leave(KErrNotSupported);
sl@0: 		}
sl@0: 	delete contentType;	        
sl@0: 	// CONTENT ENCRYPTION ALGORITHM
sl@0: 	// Get the Cipher used and the encoded params in it
sl@0:     iEncryptParams = DecodeContentEncryptionAlgorithmL(EncryptedContentInfo->At(1)->Encoding());
sl@0:                 
sl@0:     // ENCRYPTED CONTENT
sl@0: 	// This is an OPTIONAL field
sl@0: 	TInt encryptedContentInfoCount = EncryptedContentInfo->Count();
sl@0: 	if(encryptedContentInfoCount == 3)
sl@0: 		{
sl@0: 		TASN1DecGeneric decOctetString(*EncryptedContentInfo->At(2));
sl@0: 		decOctetString.InitL();
sl@0: 	    iEncryptedContent.Set(decOctetString.GetContentDER());
sl@0: 	   	}
sl@0: 	else if(encryptedContentInfoCount > 3 || encryptedContentInfoCount < 2)
sl@0: 	    {
sl@0: 	    User::Leave(KErrArgument);
sl@0: 	    }
sl@0: 	else if(encryptedContentInfoCount == 2)
sl@0: 		{
sl@0: 		iEncryptedContent.Set(KNullDesC8());
sl@0: 		}
sl@0: 
sl@0: 	CleanupStack::PopAndDestroy(2, EncryptedDataContents); //EncryptedDataContents, EncryptedContentInfo    	
sl@0: 	}
sl@0: