【C/C++】:C++语言做加解密

客官°小女子只卖身不卖艺 2022-06-16 12:18 191阅读 0赞

# 思路 #

这个梗来自于自己想装逼发朋友圈，自己先写了一个加解密的思路，  
思路如下：  
1，输入字符串  
2，将字符串按每位分解成int型再转为char型，这样能够获得字符串的字符串值，其中对中文也能解析，然后将输出结果保存发朋友圈。

这种效果是解析出来的字符不够好看，所以问了实验室的张哥，张哥告诉了我一种办法，通过base64加密的办法能够变得更好看，所以后来用了下base64,觉得自己之前做的那个加密太垃圾了，所以后面干脆就不做了，就直接用base64了。

之前加密解析的方法都在思路里面了，就不贴代码了

# base64加解密代码 #

## 加密 ##

加密文件放在了d盘目录下

#include <iostream>
    #include <string>
    #include <time.h>
    #include <fstream>
    using namespace std;
    
    static const std::string base64_chars =   
                 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"  
                 "abcdefghijklmnopqrstuvwxyz"  
                 "0123456789+/";  
    
    
    static inline bool is_base64(unsigned char c) {  
      return (isalnum(c) || (c == '+') || (c == '/'));  
    }  
    
    std::string base64_encode(unsigned char const* bytes_to_encode, unsigned int in_len) {  
      std::string ret;  
      int i = 0;  
      int j = 0;  
      unsigned char char_array_3[3];  
      unsigned char char_array_4[4];  
    
      while (in_len--) {  
        char_array_3[i++] = *(bytes_to_encode++);  
        if (i == 3) {  
          char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;  
          char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);  
          char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);  
          char_array_4[3] = char_array_3[2] & 0x3f;  
    
          for(i = 0; (i <4) ; i++)  
            ret += base64_chars[char_array_4[i]];  
          i = 0;  
        }  
      }  
    
      if (i)  
      {  
        for(j = i; j < 3; j++)  
          char_array_3[j] = '\0';  
    
        char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;  
        char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);  
        char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);  
        char_array_4[3] = char_array_3[2] & 0x3f;  
    
        for (j = 0; (j < i + 1); j++)  
          ret += base64_chars[char_array_4[j]];  
    
        while((i++ < 3))  
          ret += '=';  
    
      }  
    
      return ret;  
    
    }  
    
    std::string base64_decode(std::string const& encoded_string) {  
      int in_len = encoded_string.size();  
      int i = 0;  
      int j = 0;  
      int in_ = 0;  
      unsigned char char_array_4[4], char_array_3[3];  
      std::string ret;  
    
      while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {  
        char_array_4[i++] = encoded_string[in_]; in_++;  
        if (i ==4) {  
          for (i = 0; i <4; i++)  
            char_array_4[i] = base64_chars.find(char_array_4[i]);  
    
          char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);  
          char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);  
          char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];  
    
          for (i = 0; (i < 3); i++)  
            ret += char_array_3[i];  
          i = 0;  
        }  
      }  
    
      if (i) {  
        for (j = i; j <4; j++)  
          char_array_4[j] = 0;  
    
        for (j = 0; j <4; j++)  
          char_array_4[j] = base64_chars.find(char_array_4[j]);  
    
        char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);  
        char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);  
        char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];  
    
        for (j = 0; (j < i - 1); j++) ret += char_array_3[j];  
      }  
    
      return ret;  
    }  
    
    int main(){
        //获取时间的代码
        time_t rawtime;
        time(&rawtime);
        ofstream out("d:\\out.txt");  
        string s;
        cin>>s;
        string  encoded = base64_encode(reinterpret_cast<const unsigned char*>(s.c_str()), s.length());
        out<<encoded<<endl;
        out<<endl<<ctime(&rawtime);
        out.close();
    
    }

## 解密 ##

#include <iostream>
    #include <string>
    #include <time.h>
    #include <fstream>
    using namespace std;
    
    static const std::string base64_chars =   
                 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"  
                 "abcdefghijklmnopqrstuvwxyz"  
                 "0123456789+/";  
    
    
    static inline bool is_base64(unsigned char c) {  
      return (isalnum(c) || (c == '+') || (c == '/'));  
    }  
    
    std::string base64_encode(unsigned char const* bytes_to_encode, unsigned int in_len) {  
      std::string ret;  
      int i = 0;  
      int j = 0;  
      unsigned char char_array_3[3];  
      unsigned char char_array_4[4];  
    
      while (in_len--) {  
        char_array_3[i++] = *(bytes_to_encode++);  
        if (i == 3) {  
          char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;  
          char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);  
          char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);  
          char_array_4[3] = char_array_3[2] & 0x3f;  
    
          for(i = 0; (i <4) ; i++)  
            ret += base64_chars[char_array_4[i]];  
          i = 0;  
        }  
      }  
    
      if (i)  
      {  
        for(j = i; j < 3; j++)  
          char_array_3[j] = '\0';  
    
        char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;  
        char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);  
        char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);  
        char_array_4[3] = char_array_3[2] & 0x3f;  
    
        for (j = 0; (j < i + 1); j++)  
          ret += base64_chars[char_array_4[j]];  
    
        while((i++ < 3))  
          ret += '=';  
    
      }  
    
      return ret;  
    
    }  
    
    std::string base64_decode(std::string const& encoded_string) {  
      int in_len = encoded_string.size();  
      int i = 0;  
      int j = 0;  
      int in_ = 0;  
      unsigned char char_array_4[4], char_array_3[3];  
      std::string ret;  
    
      while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {  
        char_array_4[i++] = encoded_string[in_]; in_++;  
        if (i ==4) {  
          for (i = 0; i <4; i++)  
            char_array_4[i] = base64_chars.find(char_array_4[i]);  
    
          char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);  
          char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);  
          char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];  
    
          for (i = 0; (i < 3); i++)  
            ret += char_array_3[i];  
          i = 0;  
        }  
      }  
    
      if (i) {  
        for (j = i; j <4; j++)  
          char_array_4[j] = 0;  
    
        for (j = 0; j <4; j++)  
          char_array_4[j] = base64_chars.find(char_array_4[j]);  
    
        char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);  
        char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);  
        char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];  
    
        for (j = 0; (j < i - 1); j++) ret += char_array_3[j];  
      }  
    
      return ret;  
    }  
    int main(){
        //第二段代码
        string  s,encoded,decoded;
        cin>>s;
        encoded = base64_encode(reinterpret_cast<const unsigned char*>(s.c_str()), s.length());
        decoded = base64_decode(s);
        cout<<"解密"<<decoded;
        return 0;
    }