ext-cryptopp/arc4.h
2015-11-05 01:59:46 -05:00

81 lines
2.6 KiB
C++

// arc4.h - written and placed in the public domain by Wei Dai
//! \file
//! \brief Implementation of ARC4
#ifndef CRYPTOPP_ARC4_H
#define CRYPTOPP_ARC4_H
#include "cryptlib.h"
#include "strciphr.h"
#include "secblock.h"
#include "smartptr.h"
NAMESPACE_BEGIN(CryptoPP)
namespace Weak1 {
//! \class ARC4_Base
//! \brief Allegedly RC4
class CRYPTOPP_NO_VTABLE ARC4_Base : public VariableKeyLength<16, 1, 256>, public RandomNumberGenerator, public SymmetricCipher, public SymmetricCipherDocumentation
{
public:
~ARC4_Base();
static const char *StaticAlgorithmName() {return "ARC4";}
void GenerateBlock(byte *output, size_t size);
void DiscardBytes(size_t n);
void ProcessData(byte *outString, const byte *inString, size_t length);
bool IsRandomAccess() const {return false;}
bool IsSelfInverting() const {return true;}
bool IsForwardTransformation() const {return true;}
typedef SymmetricCipherFinal<ARC4_Base> Encryption;
typedef SymmetricCipherFinal<ARC4_Base> Decryption;
protected:
void UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs &params);
virtual unsigned int GetDefaultDiscardBytes() const {return 0;}
FixedSizeSecBlock<byte, 256> m_state;
byte m_x, m_y;
};
//! <a href="http://www.weidai.com/scan-mirror/cs.html#RC4">Alleged RC4</a>
DOCUMENTED_TYPEDEF(SymmetricCipherFinal<ARC4_Base>, ARC4)
//! _
class CRYPTOPP_NO_VTABLE MARC4_Base : public ARC4_Base
{
public:
static const char *StaticAlgorithmName() {return "MARC4";}
typedef SymmetricCipherFinal<MARC4_Base> Encryption;
typedef SymmetricCipherFinal<MARC4_Base> Decryption;
protected:
unsigned int GetDefaultDiscardBytes() const {return 256;}
};
//! Modified ARC4: it discards the first 256 bytes of keystream which may be weaker than the rest
DOCUMENTED_TYPEDEF(SymmetricCipherFinal<MARC4_Base>, MARC4)
}
#if CRYPTOPP_ENABLE_NAMESPACE_WEAK >= 1
namespace Weak {using namespace Weak1;} // import Weak1 into CryptoPP::Weak
#else
using namespace Weak1; // import Weak1 into CryptoPP with warning
#ifdef __GNUC__
#warning "You may be using a weak algorithm that has been retained for backwards compatibility. Please '#define CRYPTOPP_ENABLE_NAMESPACE_WEAK 1' before including this .h file and prepend the class name with 'Weak::' to remove this warning."
#else
#pragma message("You may be using a weak algorithm that has been retained for backwards compatibility. Please '#define CRYPTOPP_ENABLE_NAMESPACE_WEAK 1' before including this .h file and prepend the class name with 'Weak::' to remove this warning.")
#endif
#endif
NAMESPACE_END
#endif