/*
 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) 2013-2016 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 "Platform/Platform.h"
#include "Cipher.h"
#include "Crypto/Aes.h"
#include "Crypto/Serpent.h"
#include "Crypto/Twofish.h"
#include "Crypto/Camellia.h"

#ifdef TC_AES_HW_CPU
#	include "Crypto/Aes_hw_cpu.h"
#endif

namespace VeraCrypt
{
	Cipher::Cipher () : Initialized (false)
	{
	}

	Cipher::~Cipher ()
	{
	}

	void Cipher::DecryptBlock (byte *data) const
	{
		if (!Initialized)
			throw NotInitialized (SRC_POS);

		Decrypt (data);
	}

	void Cipher::DecryptBlocks (byte *data, size_t blockCount) const
	{
		if (!Initialized)
			throw NotInitialized (SRC_POS);

		while (blockCount-- > 0)
		{
			Decrypt (data);
			data += GetBlockSize();
		}
	}

	void Cipher::EncryptBlock (byte *data) const
	{
		if (!Initialized)
			throw NotInitialized (SRC_POS);

		Encrypt (data);
	}

	void Cipher::EncryptBlocks (byte *data, size_t blockCount) const
	{
		if (!Initialized)
			throw NotInitialized (SRC_POS);

		while (blockCount-- > 0)
		{
			Encrypt (data);
			data += GetBlockSize();
		}
	}

	CipherList Cipher::GetAvailableCiphers ()
	{
		CipherList l;

		l.push_back (shared_ptr <Cipher> (new CipherAES ()));
		l.push_back (shared_ptr <Cipher> (new CipherSerpent ()));
		l.push_back (shared_ptr <Cipher> (new CipherTwofish ()));
		l.push_back (shared_ptr <Cipher> (new CipherCamellia ()));

		return l;
	}

	void Cipher::SetKey (const ConstBufferPtr &key)
	{
		if (key.Size() != GetKeySize ())
			throw ParameterIncorrect (SRC_POS);

		if (!Initialized)
			ScheduledKey.Allocate (GetScheduledKeySize ());

		SetCipherKey (key);
		Key.CopyFrom (key);
		Initialized = true;
	}

#define TC_EXCEPTION(TYPE) TC_SERIALIZER_FACTORY_ADD(TYPE)
#undef TC_EXCEPTION_NODECL
#define TC_EXCEPTION_NODECL(TYPE) TC_SERIALIZER_FACTORY_ADD(TYPE)

	TC_SERIALIZER_FACTORY_ADD_EXCEPTION_SET (CipherException);


	// AES
	void CipherAES::Decrypt (byte *data) const
	{
#ifdef TC_AES_HW_CPU
		if (IsHwSupportAvailable())
			aes_hw_cpu_decrypt (ScheduledKey.Ptr() + sizeof (aes_encrypt_ctx), data);
		else
#endif
			aes_decrypt (data, data, (aes_decrypt_ctx *) (ScheduledKey.Ptr() + sizeof (aes_encrypt_ctx)));
	}

	void CipherAES::DecryptBlocks (byte *data, size_t blockCount) const
	{
		if (!Initialized)
			throw NotInitialized (SRC_POS);

#ifdef TC_AES_HW_CPU
		if ((blockCount & (32 - 1)) == 0
			&& IsHwSupportAvailable())
		{
			while (blockCount > 0)
			{
				aes_hw_cpu_decrypt_32_blocks (ScheduledKey.Ptr() + sizeof (aes_encrypt_ctx), data);

				data += 32 * GetBlockSize();
				blockCount -= 32;
			}
		}
		else
#endif
			Cipher::DecryptBlocks (data, blockCount);
	}

	void CipherAES::Encrypt (byte *data) const
	{
#ifdef TC_AES_HW_CPU
		if (IsHwSupportAvailable())
			aes_hw_cpu_encrypt (ScheduledKey.Ptr(), data);
		else
#endif
			aes_encrypt (data, data, (aes_encrypt_ctx *) ScheduledKey.Ptr());
	}

	void CipherAES::EncryptBlocks (byte *data, size_t blockCount) const
	{
		if (!Initialized)
			throw NotInitialized (SRC_POS);

#ifdef TC_AES_HW_CPU
		if ((blockCount & (32 - 1)) == 0
			&& IsHwSupportAvailable())
		{
			while (blockCount > 0)
			{
				aes_hw_cpu_encrypt_32_blocks (ScheduledKey.Ptr(), data);

				data += 32 * GetBlockSize();
				blockCount -= 32;
			}
		}
		else
#endif
			Cipher::EncryptBlocks (data, blockCount);
	}

	size_t CipherAES::GetScheduledKeySize () const
	{
		return sizeof(aes_encrypt_ctx) + sizeof(aes_decrypt_ctx);
	}

	bool CipherAES::IsHwSupportAvailable () const
	{
#ifdef TC_AES_HW_CPU
		static bool state = false;
		static bool stateValid = false;

		if (!stateValid)
		{
			state = is_aes_hw_cpu_supported() ? true : false;
			stateValid = true;
		}
		return state && HwSupportEnabled;
#else
		return false;
#endif
	}

	void CipherAES::SetCipherKey (const byte *key)
	{
		if (aes_encrypt_key256 (key, (aes_encrypt_ctx *) ScheduledKey.Ptr()) != EXIT_SUCCESS)
			throw CipherInitError (SRC_POS);

		if (aes_decrypt_key256 (key, (aes_decrypt_ctx *) (ScheduledKey.Ptr() + sizeof (aes_encrypt_ctx))) != EXIT_SUCCESS)
			throw CipherInitError (SRC_POS);
	}

	// Serpent
	void CipherSerpent::Decrypt (byte *data) const
	{
		serpent_decrypt (data, data, ScheduledKey);
	}

	void CipherSerpent::Encrypt (byte *data) const
	{
		serpent_encrypt (data, data, ScheduledKey);
	}

	size_t CipherSerpent::GetScheduledKeySize () const
	{
		return 140*4;
	}

	void CipherSerpent::SetCipherKey (const byte *key)
	{
		serpent_set_key (key, ScheduledKey);
	}


	// Twofish
	void CipherTwofish::Decrypt (byte *data) const
	{
		twofish_decrypt ((TwofishInstance *) ScheduledKey.Ptr(), (unsigned int *)data, (unsigned int *)data);
	}

	void CipherTwofish::Encrypt (byte *data) const
	{
		twofish_encrypt ((TwofishInstance *) ScheduledKey.Ptr(), (unsigned int *)data, (unsigned int *)data);
	}

	size_t CipherTwofish::GetScheduledKeySize () const
	{
		return TWOFISH_KS;
	}

	void CipherTwofish::SetCipherKey (const byte *key)
	{
		twofish_set_key ((TwofishInstance *) ScheduledKey.Ptr(), (unsigned int *) key);
	}
	
	// Camellia
	void CipherCamellia::Decrypt (byte *data) const
	{
		camellia_decrypt (data, data, ScheduledKey.Ptr());
	}

	void CipherCamellia::Encrypt (byte *data) const
	{
		camellia_encrypt (data, data, ScheduledKey.Ptr());
	}

	size_t CipherCamellia::GetScheduledKeySize () const
	{
		return CAMELLIA_KS;
	}

	void CipherCamellia::SetCipherKey (const byte *key)
	{
		camellia_set_key (key, ScheduledKey.Ptr());
	}


	bool Cipher::HwSupportEnabled = true;
}