crypto/weakcryptospi/source/pbe/pbe.cpp
changeset 19 cd501b96611d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/crypto/weakcryptospi/source/pbe/pbe.cpp	Fri Nov 06 13:21:00 2009 +0200
@@ -0,0 +1,266 @@
+/*
+* 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 <cryptostrength.h>
+#include <securityerr.h>
+#include <pbedata.h>
+#include "pkcs5kdf.h"
+#include "pbe.h"
+#include <pbencryptor.h>
+#include "pbesymmetricfactory.h"
+
+EXPORT_C CPBEncryptElement* CPBEncryptElement::NewL(const TPBPassword& aPassword)
+	{
+	CPBEncryptElement* self = NewLC(aPassword);
+	CleanupStack::Pop();
+	return self;
+	}
+
+EXPORT_C CPBEncryptElement* CPBEncryptElement::NewLC(const TPBPassword& aPassword)
+	{
+	CPBEncryptElement* self = new(ELeave) CPBEncryptElement;
+	CleanupStack::PushL(self);
+	self->ConstructL(aPassword.Password());
+	return self;
+	}
+
+EXPORT_C CPBEncryptElement* CPBEncryptElement::NewL(const TPBPassword& aPassword, 
+	const TPBECipher aCipher)
+	{
+	CPBEncryptElement* self = NewLC(aPassword, aCipher);
+	CleanupStack::Pop();
+	return self;
+	}
+
+EXPORT_C CPBEncryptElement* CPBEncryptElement::NewLC(const TPBPassword& aPassword, 
+	const TPBECipher aCipher)
+	{
+	CPBEncryptElement* self = new(ELeave) CPBEncryptElement;
+	CleanupStack::PushL(self);
+	self->ConstructL(aPassword.Password(), aCipher);
+	return self;
+	}
+
+EXPORT_C CPBEncryptElement* CPBEncryptElement::NewL(const TPBPassword& aPassword, 
+	const CPBEncryptParms& aParms)
+	{
+	CPBEncryptElement* self = NewLC(aPassword, aParms);
+	CleanupStack::Pop();
+	return self;
+	}
+
+EXPORT_C CPBEncryptElement* CPBEncryptElement::NewLC(const TPBPassword& aPassword, 
+	const CPBEncryptParms& aParms)
+	{
+	CPBEncryptElement* self = new(ELeave) CPBEncryptElement;
+	CleanupStack::PushL(self);
+	self->ConstructL(aPassword.Password(), aParms);
+	return self;
+	}
+
+EXPORT_C CPBEncryptElement* CPBEncryptElement::NewL(
+	const CPBEncryptionData& aData, const TPBPassword& aPassword)
+	{
+	CPBEncryptElement* self = CPBEncryptElement::NewLC(aData, aPassword);
+	CleanupStack::Pop();
+	return self;
+	}
+
+EXPORT_C CPBEncryptElement* CPBEncryptElement::NewLC(
+	const CPBEncryptionData& aData, const TPBPassword& aPassword)
+	{
+	CPBEncryptElement* self = new(ELeave) CPBEncryptElement;
+	CleanupStack::PushL(self);
+	self->ConstructL(aData, aPassword);
+	return self;
+	}
+
+CPBEncryptElement::CPBEncryptElement(void) 
+	{
+	}
+
+CPBEncryptElement::~CPBEncryptElement(void)
+	{
+	delete iData;
+	delete iEncryptKey;
+	}
+
+void CPBEncryptElement::ConstructL(const TDesC8& aPassword)
+	{
+	// Construct based on cryptography strength
+	if (TCrypto::Strength() == TCrypto::EStrong)
+		{
+		ConstructL(aPassword, KPBEDefaultStrongCipher);
+		}
+	else
+		{
+		ConstructL(aPassword, KPBEDefaultWeakCipher);
+		}
+	}
+
+void CPBEncryptElement::ConstructL(const TDesC8& aPassword, TPBECipher aCipher)
+	{
+	TBuf8<KPBEMaxCipherIVBytes> iv(KPBEMaxCipherIVBytes);
+	iv.SetLength(PBE::GetBlockBytes(aCipher));
+	TRandom::RandomL(iv);
+
+	TBuf8<KPBEDefaultSaltBytes> encryptSalt(KPBEDefaultSaltBytes);
+	TRandom::RandomL(encryptSalt);
+
+	TBuf8<KPBEDefaultSaltBytes> authSalt(KPBEDefaultSaltBytes);
+	TRandom::RandomL(authSalt);
+
+	iData = CPBEncryptionData::NewL(aPassword, aCipher, authSalt, encryptSalt,
+		iv, KDefaultIterations);
+
+	MakeEncryptKeyL(PBE::GetKeyBytes(aCipher), aPassword);
+	}
+
+void CPBEncryptElement::ConstructL(const CPBEncryptionData& aData, 
+	const TPBPassword& aPassword)
+	{
+	iData = CPBEncryptionData::NewL(aData);
+	if(!AuthenticateL(aPassword))
+		{
+		User::Leave(KErrBadPassphrase);
+		}
+	}
+
+void CPBEncryptElement::ConstructL(const TDesC8& aPassword,
+	const CPBEncryptParms& aParms)
+	{
+	TUint keySize = PBE::GetKeyBytes(aParms.Cipher());
+
+	TBuf8<KPBEDefaultSaltBytes> authSalt(KPBEDefaultSaltBytes);
+	TRandom::RandomL(authSalt);
+
+	//Recreate parms with given data and create a totally new auth
+	iData = CPBEncryptionData::NewL(aPassword, authSalt, aParms);
+	MakeEncryptKeyL(keySize, aPassword);
+	}
+
+const CPBEncryptionData& CPBEncryptElement::EncryptionData(void) const
+	{
+	return *iData;
+	}
+
+CPBEncryptor* CPBEncryptElement::NewEncryptL() const 
+	{
+	CPBEncryptor* encryptor = NewEncryptLC();
+	CleanupStack::Pop();
+	return encryptor;
+	}
+
+CPBEncryptor* CPBEncryptElement::NewEncryptLC() const
+	{
+	CPBEncryptor* encryptor = CPBEncryptorElement::NewLC( 
+		iData->EncryptParms().Cipher(), *iEncryptKey, 
+		iData->EncryptParms().IV());
+	return encryptor;
+	}
+
+TBool CPBEncryptElement::AuthenticateL(const TPBPassword& aPassword)
+	{
+	TBool retval = EFalse;
+
+	//create a new auth to test against the existing one
+	//therefore we use the same key size, and salt as the current one
+	CPBAuthData* auth = CPBAuthData::NewLC(aPassword.Password(),
+		iData->AuthData().Salt(), iData->AuthData().Key().Size(),
+		iData->AuthData().Iterations());
+	if(*auth==iData->AuthData())
+		{
+		//We've got a valid password, regenerate the key so they can decrypt
+		//stuff.  We don't the change the length of iEncryptKey as we assume the
+		//previous key size is appropriate for the new one
+		MakeEncryptKeyL(PBE::GetKeyBytes(iData->EncryptParms().Cipher()),
+			aPassword.Password());
+		retval = ETrue;
+		}
+	CleanupStack::PopAndDestroy(auth);
+	return retval;
+	}
+
+CPBDecryptor* CPBEncryptElement::NewDecryptL() const
+	{
+	CPBDecryptor* decryptor = NewDecryptLC();
+	CleanupStack::Pop();
+	return decryptor;
+	}
+
+CPBDecryptor* CPBEncryptElement::NewDecryptLC() const
+	{
+	CPBDecryptor* decryptor = CPBDecryptorElement::NewLC(
+		iData->EncryptParms().Cipher(), *iEncryptKey,
+		iData->EncryptParms().IV());
+	return decryptor;
+	}
+
+// 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 CPBEncryptElement::MaxCiphertextLength(TInt aPlaintextLength) const
+	{
+	TUint blocksize = PBE::GetBlockBytes(iData->EncryptParms().Cipher());
+	TUint padding = blocksize - aPlaintextLength % blocksize;
+	//len = inputLength + padding
+	return aPlaintextLength + padding;
+	}
+
+// Warning: This function is only valid BEFORE you call NewDecryptL
+// After creating the cipher, ask it about itself, not me!
+TInt CPBEncryptElement::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.
+	 */
+	//totallength = inputlength - 1 byte of padding min
+	return aCiphertextLength - 1;
+	}
+
+void CPBEncryptElement::MakeEncryptKeyL(TUint aKeySize, const TDesC8& aPassword)
+	{
+	iEncryptKey = HBufC8::NewMaxL(aKeySize);
+	TPtr8 encryptKeyBuf = iEncryptKey->Des();
+	iData->EncryptParms().DeriveKeyL(aPassword, encryptKeyBuf);
+	}
+
+EXPORT_C TPBPassword::TPBPassword(const TDesC8& aPassword)
+	{
+	iPassword.Set(aPassword);
+	}
+
+EXPORT_C TPBPassword::TPBPassword(const TDesC16& aPassword)
+	{
+	iPassword.Set(reinterpret_cast<const TUint8*>(aPassword.Ptr()), aPassword.Size());
+	}
+
+EXPORT_C const TDesC8& TPBPassword::Password(void) const
+	{
+	return iPassword;
+	}
+
+