RSA加密的简单实现【C++ Code】

原理不再细述, 下面是简单的实现,没有使用比较大的质数, 主要是用C++不想写大数…
支持对中文的加密

#include <bits/stdc++.h>using namespace std;typedef long long LL;const int MAX_N = 1000;wifstream wfin;wofstream wfout;//locale loc("zh_CN.UTF-8"); //Linux 下需要//拓展欧几里得  已知a,b 求满足ax + by = gcd(a, b) 的一组解int exgcd(int a, int b, int &x, int &y){    if (b == 0){        x = 1;        y = 0;        return a;    }    int ans = exgcd(b, a % b, x, y);    int tmp = x;    x = y;    y = tmp - a / b * y;    return ans;}// 暴力找出200 ~ MAX_N 的所有质数void get_Prime_Number(int *Prime, int &cnt){    cnt = 0;    for (int i = 201;i < MAX_N; i+=2){        bool flag = false;        for (int j = 2;(j * j) <= i; j++){            if (i % j == 0){                flag = true;                break;            }        }        if (!flag) Prime[cnt++] = i;    }}//RSA初始化void RSA_Initialize(int &n, int &e, int &d){    int Prime[MAX_N], cnt = 0;    get_Prime_Number(Prime, cnt);    srand((unsigned)time(NULL));    int r1 = rand() % cnt;    int r2 = rand() % cnt;    int p1 = Prime[r1], p2 = Prime[r2]; // 随机取两个质数.    n = p1 * p2; // 计算n    int  m = (p1 - 1) * (p2 - 1);    int y;    // 选择一个与n互质的元素,记为e,求得模反元素d    for (int i = 3; i < m; i += 1331){        int gcd = exgcd(i, m, d, y);        if (gcd == 1 && d > 0){            e = i;            break;        }    }}// 快速幂求 a^b % cint Quick_Pow(int a, int b, int c){    int tot = 1;    while (b){        if (b & 1) tot = (1LL * tot * a) % c; //可能会溢出        a = (1LL * a * a) % c;        b >>= 1;    }    return tot;}//RSA 加密void RSA_Encrypt(int e, int n, wstring wstr){    int len = wstr.size();    for (int i = 0; i < len; i++){        wfout << Quick_Pow(wstr[i], e, n) << " "; //输出密文    }    wfout << endl;}//RSA 解密void RSA_Decrypt(int d, int n, wstring wstr){    wstringstream wss(wstr);    int x;    while (wss >> x){        wfout << (wchar_t)Quick_Pow(x, d, n); //输出解密后的原文对应字符    }    wfout << endl;}int main(){    wstring wstr;    wfin.open("Plain_text.txt");    wfout.open("Cipher_text.txt");    //wfin.imbue(loc); //Linux 下需要    int n, e, d;    RSA_Initialize(n, e, d);    printf("Public  Key (e, n) : (%d, %d).\n",e, n);    printf("Private Key (d, n) : (%d, %d).\n\n",d, n);    int Case = 0;    while (getline(wfin, wstr)){        printf("Line %d data is being encrypted.\n",++Case);        RSA_Encrypt(e, n, wstr);    }    wfin.close();    wfout.close();    wfin.open("Cipher_text.txt");    wfout.open("Decrypt_text.txt");    //wfout.imbue(loc); //Linux 下需要    Case = 0;    while (getline(wfin, wstr)){        printf("Line %d data is being decrypted.\n",++Case);        RSA_Decrypt(d, n, wstr);    }    wfin.close();    wfout.close();}