lubyrack.h

来自「各种加密算法的集合」· C头文件 代码 · 共 125 行

#ifndef CRYPTOPP_LUBYRACK_H 
#define CRYPTOPP_LUBYRACK_H 
 
#include "cryptlib.h" 
#include "misc.h" 
 
NAMESPACE_BEGIN(CryptoPP) 
 
template <class T> class LRBase : public BlockTransformation 
{ 
public: 
	enum {KEYLENGTH=16};    // default key length 
 
protected: 
	LRBase(const byte *userKey, unsigned int keyLen); 
	unsigned int BlockSize() const {return 2*S;} 
 
	const unsigned int S;    // block size / 2 
	const unsigned int L;    // key length / 2 
	SecByteBlock key; 
 
	mutable T hm; 
	mutable SecByteBlock buffer; 
}; 
 
template <class T> class LREncryption : public LRBase<T> 
{ 
public: 
	// keyLen must be even 
	LREncryption(const byte *userKey, int keyLen=KEYLENGTH) 
		: LRBase<T>(userKey, keyLen) {} 
 
	void ProcessBlock(byte * inoutBlock) const 
		{LREncryption<T>::ProcessBlock(inoutBlock, inoutBlock);} 
 
	void ProcessBlock(const byte *inBlock, byte * outBlock) const; 
}; 
 
template <class T> class LRDecryption : public LRBase<T> 
{ 
public: 
	// keyLen must be even 
	LRDecryption(const byte *userKey, int keyLen=KEYLENGTH) 
		: LRBase<T>(userKey, keyLen) {} 
 
	void ProcessBlock(byte * inoutBlock) const 
		{LRDecryption<T>::ProcessBlock(inoutBlock, inoutBlock);} 
 
	void ProcessBlock(const byte *inBlock, byte * outBlock) const; 
}; 
 
template <class T> LRBase<T>::LRBase(const byte *userKey, unsigned int keyLen) 
: S(T::DIGESTSIZE), L(keyLen/2), key(2*L), buffer(2*S) 
{ 
	memcpy(key, userKey, 2*L); 
} 
 
#define KL key 
#define KR key+L 
#define BL buffer 
#define BR buffer+S 
#define IL inBlock 
#define IR inBlock+S 
#define OL outBlock 
#define OR outBlock+S 
 
template <class T> void LREncryption<T>::ProcessBlock(const byte *inBlock, byte * outBlock) const 
{ 
	hm.Update(KL, L); 
	hm.Update(IL, S); 
	hm.Final(BR); 
	xorbuf(BR, IR, S); 
 
	hm.Update(KR, L); 
	hm.Update(BR, S); 
	hm.Final(BL); 
	xorbuf(BL, IL, S); 
 
	hm.Update(KL, L); 
	hm.Update(BL, S); 
	hm.Final(OR); 
	xorbuf(OR, BR, S); 
 
	hm.Update(KR, L); 
	hm.Update(OR, S); 
	hm.Final(OL); 
	xorbuf(OL, BL, S); 
} 
 
template <class T> void LRDecryption<T>::ProcessBlock(const byte *inBlock, byte * outBlock) const 
{ 
	hm.Update(KR, L); 
	hm.Update(IR, S); 
	hm.Final(BL); 
	xorbuf(BL, IL, S); 
 
	hm.Update(KL, L); 
	hm.Update(BL, S); 
	hm.Final(BR); 
	xorbuf(BR, IR, S); 
 
	hm.Update(KR, L); 
	hm.Update(BR, S); 
	hm.Final(OL); 
	xorbuf(OL, BL, S); 
 
	hm.Update(KL, L); 
	hm.Update(OL, S); 
	hm.Final(OR); 
	xorbuf(OR, BR, S); 
} 
 
#undef KL 
#undef KR 
#undef BL 
#undef BR 
#undef IL 
#undef IR 
#undef OL 
#undef OR 
 
NAMESPACE_END 
 
#endif