RSA算法C语言实现

一、源文件三个rsa.h , rsa.c , main.c

//rsa.h#include <stdio.h>#define MAX_NUM 63001#define MAX_PRIME 251//! 返回代码#define OK 100#define ERROR_NOEACHPRIME 101#define ERROR_NOPUBLICKEY 102#define ERROR_GENERROR 103unsigned int MakePrivatedKeyd( unsigned int uiP, unsigned int uiQ );unsigned int GetPrivateKeyd( unsigned int iWhich );unsigned int MakePairkey( unsigned int uiP, unsigned int uiQ, unsigned int uiD );unsigned int GetPairKey( unsigned int &d, unsigned int &e );void rsa_encrypt( int n, int e, char *mw, int iLength, int *&cw );void rsa_decrypt( int n, int d, int *&cw, int cLength, char *mw );void outputkey();//rsa.c#include "rsa.h"//!　保存私钥d集合struct pKeyset{unsigned int set[ MAX_NUM ];unsigned int size;}pset;//! 保存公、私钥对struct pPairkey{unsigned int d;unsigned int e;unsigned int n;}pairkey;// 名称：isPrime// 功能：判断两个数是否互质//  参数：m: 数a; n: 数b// 返回：m、n互质返回true; 否则返回falsebool isPrime( unsigned int m, unsigned int n ){unsigned int i=0;bool Flag = true;if( m<2 || n<2 )return false;unsigned int tem = ( m > n ) ? n : m;for( i=2; i<=tem && Flag; i++ ){bool mFlag = true;bool nFlag = true;if( m % i == 0 )mFlag = false;if( n % i == 0 )nFlag = false;if( !mFlag && !nFlag )Flag = false;}if( Flag )return true;elsereturn false;}// 名称：MakePrivatedKeyd// 功能：由素数Q、Q生成私钥d//  参数：uiP: 素数P; uiQ: 素数Q// 返回：私钥dunsigned int MakePrivatedKeyd( unsigned int uiP, unsigned int uiQ ){unsigned int i=0;//! 得到所有与z互质的数( 私钥d的集合 )unsigned int z = ( uiP -1 ) * ( uiQ -1 );pset.size = 0;for( i=0; i<z; i++ ){if( isPrime( i, z ) ){pset.set[ pset.size++ ] = i;}}return pset.size;}// 名称：MakePairKey// 功能：生成RSA公、私钥对//  参数：uiP: 素数P; uiQ: 素数Q; uiD: 私钥d// 返回：错误代码unsigned int MakePairkey( unsigned int uiP, unsigned int uiQ, unsigned int uiD ){bool bFlag = true;unsigned int i = 0, e;unsigned int z = ( uiP-1 ) * ( uiQ-1 );unsigned int d = pset.set[uiD];//d=uiD;if( !isPrime( z, d ) )return ERROR_NOEACHPRIME;for( i=2; i<z; i++ ){if( (i*d)%z == 1 ){e = i;bFlag = false;}}if( bFlag )return ERROR_NOPUBLICKEY;if( (d*e)%z != 1 )ERROR_GENERROR;pairkey.d = d;pairkey.e = e;pairkey.n = uiP * uiQ;return OK;}// 名称：GetPairKey// 功能：对外提供接口，获得公、私钥对//  参数：uiP: 素数P; uiQ: 素数Q; uiD: 私钥d// 返回：unsigned int GetPairKey( unsigned int &d, unsigned int &e ){d = pairkey.d;e = pairkey.e;return pairkey.n;}// 名称：GetPrivateKeyd// 功能：对外提供接口，由用户选择ID得以私钥d//  参数：iWhich: 用户选择私钥d的ID// 返回：私钥d值unsigned int GetPrivateKeyd( unsigned int iWhich ){if( pset.size >= iWhich )return pset.set[ iWhich ];elsereturn 0;}// 名称：rsa_encrypt// 功能：RSA加密运算//  参数：n: 公钥n; e: 公钥e; mw: 加密明文; iLength: 明文长度; cw: 密文输出// 返回：无void rsa_encrypt( int n, int e, char *mw, int mLength, int *&cw ){int i=0, j=0;__int64 temInt = 0;for( i=0; i<mLength; i++ ){temInt = mw[i];if( e!=0 ){for( j=1; j<e; j++ ){temInt = ( temInt * mw[i] ) % n;}}else{temInt = 1;}cw[i] = (int)temInt;}}// 名称：rsa_decrypt// 功能：RSA解密运算//  参数：n: 私钥n; d: 私钥d; cw: 密文; cLength: 密文长度; mw: 明文输出// 返回：无void rsa_decrypt( int n, int d, int *&cw, int cLength, char *mw ){int i=0, j=-1;__int64 temInt = 0;for( i=0; i<cLength/4; ++i ){mw[i] = 0;temInt = cw[i];if( d != 0 ){for( j=1; j<d; j++ ){temInt = (__int64)( temInt * cw[i] ) % n;}}else{temInt = 1;}mw[i] = (char)temInt;}}void outputkey(){printf("PublicKey(e,n): (%d,%d)\n",pairkey.e,pairkey.n);printf("PrivateKey(d,n): (%d,%d)\n",pairkey.d,pairkey.n);}//main.c// 工程：RSA// 功能：RSA加、解密文件//  作者：jlcss|ExpNIS#include <stdio.h>#include <afxwin.h>#include <math.h>#include "rsa.h"#define DECRYPT_FILE "RSA加密密文.txt"#define ENCRYPT_FILE "RSA解密明文.txt"//! 约束文件最大2M#define MAX_FILE 1024*1024*2// 名称：usage// 功能：帮助信息//  参数：应用程序名称// 返回：提示信息void Usage( const char *appname ){printf( "\n\tusage:rsa -k 素数P 素数Q\n" );printf( "\tusage: rsa -e 明文文件 公钥e 公钥n\n" );printf( "\tusage: rsa -d 密文文件 私钥d 私钥n\n" );}// 名称：IsNumber// 功能：判断数字字符数组//  参数：strNumber:字符数组// 返回：数字字组数组返回true，否则返回false;bool IsNumber( const char *strNumber ){unsigned int i;if( !strNumber )return false;for ( i = 0 ; i < strlen(strNumber) ; i++ ){if ( strNumber[i] < '0' || strNumber[i] > '9' )return false;}return true;}// 名称：IsPrimeNumber// 功能：判断素数//  参数：num: 输入整数// 返回：素数返回true，否则返回false;bool IsPrimeNumber( unsigned int num ){unsigned int i;if( num <= 1 )return false;unsigned int sqr = (unsigned int)sqrt((double)num);for( i = 2; i <= sqr; i++ ){if( num % i == 0 )return false;}return true;}// 名称：FileIn// 功能：读取磁盘文件到内存//  参数：strFile:文件名称；inBuff:指向文件内容缓冲区// 返回：实际读取内容大小(字节)int FileIn( const char *strFile, unsigned char *&inBuff ){int iFileLen=0, iBuffLen=0;//! 打开密文文件CFile file( strFile, CFile::modeRead );iFileLen = ( int )file.GetLength();if( iFileLen>MAX_FILE ){printf( "文件长度不能大于 %dM,!\n", MAX_FILE/(1024*1024) );goto out;}iBuffLen = iFileLen;inBuff = new unsigned char[iBuffLen];if( !inBuff )goto out;ZeroMemory( inBuff, iBuffLen );file.Read( inBuff, iFileLen );file.Close();out:return iBuffLen;}// 名称：FileOut// 功能：加/解密结果输出到当前目录磁盘文件中//  参数：strOut指向输出字符缓冲区，输出大小len，strFile为输出文件// 返回：无void FileOut( const void *strOut, int len, const char *strFile ){//! 输出到文件CFile outfile( strFile , CFile::modeCreate | CFile::modeWrite );outfile.Write( strOut , len );outfile.Close();}// 名称：CheckParse// 功能：校验应用程序入口参数//  参数：argc等于main主函数argc参数，argv指向main主函数argv参数// 返回：若参数合法返回true，否则返回false//  备注：简单的入口参数校验bool CheckParse( int argc, char** argv ){bool bRes = false;if( argc != 4 && argc != 5 )goto out;if( argc == 4 && argv[1][1] == 'k' ){//! 生成公、私钥对if( !IsNumber( argv[2] ) || !IsNumber( argv[3] ) ||atoi( argv[2] ) > MAX_PRIME ||atoi( argv[3] ) > MAX_PRIME )goto out;}else if( (argc == 5) && (argv[1][1] == 'e' || argv[1][1] == 'd') ){//! 加密、解密操作if( !IsNumber( argv[3] ) ||!IsNumber( argv[4] ) ||atoi( argv[3] ) > MAX_NUM ||atoi( argv[4] ) > MAX_NUM )goto out;}elseUsage(*argv);bRes = true;out:return bRes;}// 名称：kOption1// 功能：程序k选项操作：由素数P、Q生成私钥d集合//  参数：uiP: 程序入口参数P; uiQ: 程序入口参数Q// 返回：执行正确返回生成私钥数目，否则返回0unsigned int kOption1( unsigned int uiP, unsigned int uiQ ){unsigned int uiRes = 0;if( !IsPrimeNumber( uiP ) ){printf( "P输入错误，P必须为(0, %d]素数", MAX_PRIME );return uiRes;}if( !IsPrimeNumber( uiQ ) ){printf( "Q输入错误，Q必须为(0, %d]素数", MAX_PRIME );return uiRes;}if( uiP == uiQ ){printf( "素数P与素数Q相同，很容易根据公钥n开平方得出素数P和Q，这种加密不安全，请更换素数!\n" );return uiRes;}printf( "正在生成私钥d集合......\n" );uiRes = MakePrivatedKeyd( uiP, uiQ );return uiRes;}//! 程序主函数int main( int argc, char **argv ){unsigned int p , q , d , n , e;//two prime p & q, public key(n, e) , private key(n , d)CheckParse(argc,  argv );d=4828; //uidif(argc == 4){p = atoi( argv[2] );q = atoi( argv[3] );MakePrivatedKeyd(p, q);MakePairkey(p, q, d );outputkey();}else if(argc == 5){char FileName[20];strcpy(FileName, argv[2]);int len;if(argv[1][1] == 'e' ){unsigned char *inBuffer=(unsigned char *)malloc(MAX_FILE); //输入缓冲区int *cw=(int *)malloc(MAX_FILE);len = FileIn(FileName , inBuffer);e = atoi(argv[3]);n = atoi(argv[4]);rsa_encrypt( n, e, (char *)inBuffer, len, cw );FileOut( cw, 4*len, DECRYPT_FILE );}else if(argv[1][1] == 'd'){char *Buffer=(char *)malloc(MAX_FILE); //输入缓冲区int *cw=(int *)malloc(MAX_FILE);len = FileIn(FileName, (unsigned char *&)cw);d = atoi(argv[3]);n = atoi(argv[4]);rsa_decrypt( n, d, cw, len, Buffer );FileOut( Buffer, len/4, ENCRYPT_FILE );}}return 0;}

二 运行