/*
 Derived from source code of TrueCrypt 7.1a, which is
 Copyright (c) 2008-2012 TrueCrypt Developers Association and which is governed
 by the TrueCrypt License 3.0.

 Modifications and additions to the original source code (contained in this file) 
 and all other portions of this file are Copyright (c) 2013-2015 IDRIX
 and are governed by the Apache License 2.0 the full text of which is
 contained in the file License.txt included in VeraCrypt binary and source
 code distribution packages.
*/

#include "EncryptionAlgorithm.h"
#include "EncryptionModeXTS.h"

namespace VeraCrypt
{
	EncryptionAlgorithm::EncryptionAlgorithm () : Deprecated (false)
	{
	}

	EncryptionAlgorithm::~EncryptionAlgorithm ()
	{
	}

	void EncryptionAlgorithm::Decrypt (byte *data, uint64 length) const
	{
		if_debug (ValidateState ());
		Mode->Decrypt (data, length);
	}

	void EncryptionAlgorithm::Decrypt (const BufferPtr &data) const
	{
		Decrypt (data, data.Size());
	}

	void EncryptionAlgorithm::DecryptSectors (byte *data, uint64 sectorIndex, uint64 sectorCount, size_t sectorSize) const
	{
		if_debug (ValidateState());
		Mode->DecryptSectors (data, sectorIndex, sectorCount, sectorSize);
	}

	void EncryptionAlgorithm::Encrypt (byte *data, uint64 length) const
	{
		if_debug (ValidateState());
		Mode->Encrypt (data, length);
	}

	void EncryptionAlgorithm::Encrypt (const BufferPtr &data) const
	{
		Encrypt (data, data.Size());
	}

	void EncryptionAlgorithm::EncryptSectors (byte *data, uint64 sectorIndex, uint64 sectorCount, size_t sectorSize) const
	{
		if_debug (ValidateState ());
		Mode->EncryptSectors (data, sectorIndex, sectorCount, sectorSize);
	}

	EncryptionAlgorithmList EncryptionAlgorithm::GetAvailableAlgorithms ()
	{
		EncryptionAlgorithmList l;
		
		l.push_back (shared_ptr <EncryptionAlgorithm> (new AES ()));
		l.push_back (shared_ptr <EncryptionAlgorithm> (new Serpent ()));
		l.push_back (shared_ptr <EncryptionAlgorithm> (new Twofish ()));
		l.push_back (shared_ptr <EncryptionAlgorithm> (new AESTwofish ()));
		l.push_back (shared_ptr <EncryptionAlgorithm> (new AESTwofishSerpent ()));
		l.push_back (shared_ptr <EncryptionAlgorithm> (new SerpentAES ()));
		l.push_back (shared_ptr <EncryptionAlgorithm> (new SerpentTwofishAES ()));
		l.push_back (shared_ptr <EncryptionAlgorithm> (new TwofishSerpent ()));

		return l;
	}

	size_t EncryptionAlgorithm::GetLargestKeySize (const EncryptionAlgorithmList &algorithms)
	{
		size_t largestKeySize = 0;

		foreach_ref (const EncryptionAlgorithm &ea, algorithms)
		{
			if (ea.GetKeySize() > largestKeySize)
				largestKeySize = ea.GetKeySize();
		}

		return largestKeySize;
	}

	size_t EncryptionAlgorithm::GetKeySize () const
	{
		if (Ciphers.size() < 1)
			throw NotInitialized (SRC_POS);

		size_t keySize = 0;

		foreach_ref (const Cipher &c, Ciphers)
			keySize += c.GetKeySize();

		return keySize;
	}
	
	size_t EncryptionAlgorithm::GetMaxBlockSize () const
	{
		size_t blockSize = 0;

		foreach_ref (const Cipher &c, Ciphers)
			if (c.GetBlockSize() > blockSize)
				blockSize = c.GetBlockSize();

		return blockSize;
	}

	size_t EncryptionAlgorithm::GetMinBlockSize () const
	{
		size_t blockSize = 0;

		foreach_ref (const Cipher &c, Ciphers)
			if (blockSize == 0 || c.GetBlockSize() < blockSize)
				blockSize = c.GetBlockSize();

		return blockSize;
	}

	shared_ptr <EncryptionMode> EncryptionAlgorithm::GetMode () const
	{
		if (Mode.get() == nullptr)
			throw NotInitialized (SRC_POS);

		return Mode;
	}

	wstring EncryptionAlgorithm::GetName (bool forGuiDisplay) const
	{
		if (Ciphers.size() < 1)
			throw NotInitialized (SRC_POS);

		wstring name;

		int depth = 0;
		foreach_reverse_ref (const Cipher &c, Ciphers)
		{
			if (name.empty())
				name = c.GetName();
			else
			{
				depth++;
				if (forGuiDisplay)
					name += wstring (L"(");
				else
					name += wstring (L"-");
				name += c.GetName();				
			}
		}
		
		if (forGuiDisplay && depth)
		{
			for (int i = 0; i < depth; i++)
				name += wstring(L")");
		}

		return name;
	}

	bool EncryptionAlgorithm::IsModeSupported (const EncryptionMode &mode) const
	{
		bool supported = false;

		foreach_ref (const EncryptionMode &em, SupportedModes)
		{
			if (typeid (mode) == typeid (em))
			{
				supported = true;
				break;
			}
		}

		return supported;
	}

	
	bool EncryptionAlgorithm::IsModeSupported (const shared_ptr <EncryptionMode> mode) const
	{
		return IsModeSupported (*mode);
	}

	void EncryptionAlgorithm::SetMode (shared_ptr <EncryptionMode> mode)
	{
		if (!IsModeSupported (*mode))
			throw ParameterIncorrect (SRC_POS);

		mode->SetCiphers (Ciphers);
		Mode = mode;
	}
	
	void EncryptionAlgorithm::SetKey (const ConstBufferPtr &key)
	{
		if (Ciphers.size() < 1)
			throw NotInitialized (SRC_POS);

		if (GetKeySize() != key.Size())
			throw ParameterIncorrect (SRC_POS);

		size_t keyOffset = 0;
		foreach_ref (Cipher &c, Ciphers)
		{
			c.SetKey (key.GetRange (keyOffset, c.GetKeySize()));
			keyOffset += c.GetKeySize();
		}
	}

	void EncryptionAlgorithm::ValidateState () const
	{
		if (Ciphers.size() < 1 || Mode.get() == nullptr)
			throw NotInitialized (SRC_POS);
	}

	// AES
	AES::AES ()
	{
		Ciphers.push_back (shared_ptr <Cipher> (new CipherAES()));

		SupportedModes.push_back (shared_ptr <EncryptionMode> (new EncryptionModeXTS ()));
	}

	// AES-Twofish
	AESTwofish::AESTwofish ()
	{
		Ciphers.push_back (shared_ptr <Cipher> (new CipherTwofish ()));
		Ciphers.push_back (shared_ptr <Cipher> (new CipherAES ()));

		SupportedModes.push_back (shared_ptr <EncryptionMode> (new EncryptionModeXTS ()));
	}

	// AES-Twofish-Serpent
	AESTwofishSerpent::AESTwofishSerpent ()
	{
		Ciphers.push_back (shared_ptr <Cipher> (new CipherSerpent ()));
		Ciphers.push_back (shared_ptr <Cipher> (new CipherTwofish ()));
		Ciphers.push_back (shared_ptr <Cipher> (new CipherAES ()));

		SupportedModes.push_back (shared_ptr <EncryptionMode> (new EncryptionModeXTS ()));
	}

	// Serpent
	Serpent::Serpent ()
	{
		Ciphers.push_back (shared_ptr <Cipher> (new CipherSerpent()));

		SupportedModes.push_back (shared_ptr <EncryptionMode> (new EncryptionModeXTS ()));
	}

	// Serpent-AES
	SerpentAES::SerpentAES ()
	{
		Ciphers.push_back (shared_ptr <Cipher> (new CipherAES ()));
		Ciphers.push_back (shared_ptr <Cipher> (new CipherSerpent ()));

		SupportedModes.push_back (shared_ptr <EncryptionMode> (new EncryptionModeXTS ()));
	}

	// Twofish
	Twofish::Twofish ()
	{
		Ciphers.push_back (shared_ptr <Cipher> (new CipherTwofish()));

		SupportedModes.push_back (shared_ptr <EncryptionMode> (new EncryptionModeXTS ()));
	}

	// Twofish-Serpent
	TwofishSerpent::TwofishSerpent ()
	{
		Ciphers.push_back (shared_ptr <Cipher> (new CipherSerpent ()));
		Ciphers.push_back (shared_ptr <Cipher> (new CipherTwofish ()));

		SupportedModes.push_back (shared_ptr <EncryptionMode> (new EncryptionModeXTS ()));
	}

	// Serpent-Twofish-AES
	SerpentTwofishAES::SerpentTwofishAES ()
	{
		Ciphers.push_back (shared_ptr <Cipher> (new CipherAES ()));
		Ciphers.push_back (shared_ptr <Cipher> (new CipherTwofish ()));
		Ciphers.push_back (shared_ptr <Cipher> (new CipherSerpent ()));

		SupportedModes.push_back (shared_ptr <EncryptionMode> (new EncryptionModeXTS ()));
	}
}