bigint.h

RSA VC++实现

#ifndef CLASS_BIGINT
#define CLASS_BIGINT
#define TOTALBITS 64//大数采用的进制
#define TOTALBOXS 66//大数存储数组的位数
#define FULL 0xFFFFFFFFFFFFFFFF//大数每位的最大值,在大数的移位和减法中有很好的应用
#define ZERO 0x0
#define LenMAXHEX 16//16进制长度
#define LenMAXWRD 8//字节长度
typedef unsigned __int64 unsigned_int64;
typedef unsigned char byte;

//大数类
class BigInt
{
public:
	BigInt();
	virtual~BigInt();
	unsigned __int64 iVal[TOTALBOXS];//存储大数的数组，采用"unsigned_int64'进制'"
	unsigned short iIdx;//数组的位置
public:
	void setZero();//置0
	void setUpperBlock(const short &which);//找出比当前大数大的第一个2的幂
	void loadHEX(const byte* itext,int size_num=0);//将itext以16进制形式装入大数
	void loadSTR(const byte* itext,int size_num=0);//将itext以byte形式装入大数
	byte* outputHEX();//将大数以16进制形式装入byte
	byte* outputSTR();//将大数以String形式装入byte
	//一系列的运算符重载,即大数运算库
	BigInt& operator<<=(const short &iBit);
	BigInt& operator>>=(const short &iBit);
	BigInt& operator=(BigInt &p1);
	BigInt& operator=(const unsigned_int64 &p1);
	friend BigInt operator+(BigInt &p1,BigInt &p2);
	friend BigInt operator+(BigInt &p1,const unsigned_int64 &p2);
	friend BigInt operator-(BigInt &p1,BigInt &p2);
	friend BigInt operator*(BigInt &p1,BigInt &p2);
	friend BigInt operator*(BigInt &p1,const unsigned_int64 &p2);
	friend BigInt operator/(BigInt &p1,BigInt &p2);
	friend BigInt operator%(BigInt &p1,BigInt &p2);
	friend inline bool operator>(BigInt &p1,BigInt &p2);
	friend inline bool operator==(BigInt &p1,BigInt &p2);
	friend inline bool operator!=(BigInt &p1,BigInt &p2);
	BigInt& operator ++();
	BigInt& operator --();
	unsigned char Get4BitBlock(const short &which);//得到大数第which位(第which个4位块)
	unsigned char Get4BitBlockZero();//得到存储大数数组最高位的0的个数(每位占4位2进制)
};

//BigInt operator-(BigInt &p1,BigInt &p2);
unsigned char hdigit(unsigned char c);//将字符转换成16进制字符
bool BIisZero(BigInt &x );//判断大数是否为0
int BIcompare(BigInt &p1,BigInt &p2);//大数间的比较
int BIcompare(BigInt &p1,const unsigned_int64 &p2);
void BIswap(BigInt &p1,BigInt &p2);//大数交换
BigInt BIdivision(BigInt &p1,BigInt &p2,BigInt &pr);//除法，返回商，pr余数
BigInt BImodmul(BigInt &p1,BigInt &p2,BigInt &pp);//大数模乘
BigInt BIinverse(BigInt &p1,BigInt &p2);//求逆
//用于大数的乘法，即每位相乘
void BImul(const unsigned_int64 &p1,const unsigned_int64 &p2,unsigned_int64 &high,																unsigned_int64 &low);
//在除法和模运算中的应用,主要是使2个大数相近
void MakeThemClose(BigInt &p1,BigInt &p2);
short FindZeroBit(const unsigned_int64 &p1);//返回存储大数数组最高位的0的个数
void MakeModBaseTable(BigInt &p1);//建立预运算表,在两个大数模乘中的应用
BigInt MontMult(BigInt &p1,BigInt &p2,BigInt &pp);//蒙哥马利乘法
BigInt MontExpo(BigInt &p1,BigInt &p2,BigInt &pp);//蒙哥马利模幂

#endif