ubuntu下c++中base64编解码测试和图片编解码测试

转载

wx636261b2d66e0 2018-07-24 11:31:23 博主文章分类：c++ 开发手册

文章标签 ubuntu c++ base64 opencv Data 文章分类 HarmonyOS 后端开发

全栈工程师开发手册（作者：栾鹏）
架构系列文章

字符数组的base64编解码

base64.h

#include <string>
 
std::string base64_encode(unsigned char const* , unsigned int len);
std::string base64_decode(std::string const& s);

base64.cpp

#include "base64.h"
#include <iostream>
 
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;
}

测试文件 base64_test.cpp

#include "base64.h"  
#include <iostream>  
  
int main() {  
  const std::string s = "hello world\n11111111111 & 333333333\n444 dasssss" ;  
  
  std::string encoded = base64_encode(reinterpret_cast<const unsigned char*>(s.c_str()), s.length());  
  std::string decoded = base64_decode(encoded);  
  
  std::cout << "encoded: " << encoded << std::endl;  
  std::cout << "decoded: " << decoded << std::endl;  
  
  return 0;  
}

运行测试:

当前目录下执行

g++ -c base64.cpp       编译成.o格式
g++ -c base64_test.cpp    编译成.o格式
ar -rc base64.a base64.o        打包成静态库文件
g++ -o test base64_test.o base64.a    链接成可执行文件
./test      运行可执行文件

图片的base64位编解码

base64.h

#include <string>
using namespace std;
 
class ZBase64
{
public:
    /*编码
    DataByte
        [in]输入的数据长度,以字节为单位
    */
    string Encode(const unsigned char* Data,int DataByte);
    /*解码
    DataByte
        [in]输入的数据长度,以字节为单位
    OutByte
        [out]输出的数据长度,以字节为单位,请不要通过返回值计算
        输出数据的长度
    */
    string Decode(const char* Data,int DataByte,int& OutByte);
};

base64.cpp

#include "base64.h"
 
string ZBase64::Encode(const unsigned char* Data,int DataByte)
{
    //编码表
    const char EncodeTable[]="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
    //返回值
    string strEncode;
    unsigned char Tmp[4]={0};
    int LineLength=0;
    for(int i=0;i<(int)(DataByte / 3);i++)
    {
        Tmp[1] = *Data++;
        Tmp[2] = *Data++;
        Tmp[3] = *Data++;
        strEncode+= EncodeTable[Tmp[1] >> 2];
        strEncode+= EncodeTable[((Tmp[1] << 4) | (Tmp[2] >> 4)) & 0x3F];
        strEncode+= EncodeTable[((Tmp[2] << 2) | (Tmp[3] >> 6)) & 0x3F];
        strEncode+= EncodeTable[Tmp[3] & 0x3F];
        if(LineLength+=4,LineLength==76) {strEncode+="\r\n";LineLength=0;}
    }
    //对剩余数据进行编码
    int Mod=DataByte % 3;
    if(Mod==1)
    {
        Tmp[1] = *Data++;
        strEncode+= EncodeTable[(Tmp[1] & 0xFC) >> 2];
        strEncode+= EncodeTable[((Tmp[1] & 0x03) << 4)];
        strEncode+= "==";
    }
    else if(Mod==2)
    {
        Tmp[1] = *Data++;
        Tmp[2] = *Data++;
        strEncode+= EncodeTable[(Tmp[1] & 0xFC) >> 2];
        strEncode+= EncodeTable[((Tmp[1] & 0x03) << 4) | ((Tmp[2] & 0xF0) >> 4)];
        strEncode+= EncodeTable[((Tmp[2] & 0x0F) << 2)];
        strEncode+= "=";
    }
    
    return strEncode;
}
 
string ZBase64::Decode(const char* Data,int DataByte,int& OutByte)
{
    //解码表
    const char DecodeTable[] =
    {
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        62, // '+'
        0, 0, 0,
        63, // '/'
        52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // '0'-'9'
        0, 0, 0, 0, 0, 0, 0,
        0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
        13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // 'A'-'Z'
        0, 0, 0, 0, 0, 0,
        26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
        39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // 'a'-'z'
    };
    //返回值
    string strDecode;
    int nValue;
    int i= 0;
    while (i < DataByte)
    {
        if (*Data != '\r' && *Data!='\n')
        {
            nValue = DecodeTable[*Data++] << 18;
            nValue += DecodeTable[*Data++] << 12;
            strDecode+=(nValue & 0x00FF0000) >> 16;
            OutByte++;
            if (*Data != '=')
            {
                nValue += DecodeTable[*Data++] << 6;
                strDecode+=(nValue & 0x0000FF00) >> 8;
                OutByte++;
                if (*Data != '=')
                {
                    nValue += DecodeTable[*Data++];
                    strDecode+=nValue & 0x000000FF;
                    OutByte++;
                }
            }
            i += 4;
        }
        else// 回车换行,跳过
        {
            Data++;
            i++;
        }
     }
    return strDecode;
}

测试 base64_test.cpp

用到了opencv来读取图片

#include<opencv2/opencv.hpp>
#include<iostream>
#include"ZBase64.h"
#include<vector>
 
 
using namespace std;
using namespace cv;
 
void main()
{
  Mat img = imread("1.bmp");
 
  vector<uchar> vecImg;                               //Mat 图片数据转换为vector<uchar>
  vector<int> vecCompression_params;
  vecCompression_params.push_back(CV_IMWRITE_JPEG_QUALITY);
  vecCompression_params.push_back(90);
  imencode(".jpg", img, vecImg, vecCompression_params);
 
  ZBase64 base64;
  string imgbase64 = base64.Encode(vecImg.data(), vecImg.size());     //实现图片的base64编码
 
  cout << imgbase64 << endl;
}

运行测试:

当前目录下执行

g++ -c base64.cpp       编译成.o格式
g++ -c base64_test.cpp    编译成.o格式
ar -rc base64.a base64.o        打包成静态库文件
g++ -o test base64_test.o base64.a    链接成可执行文件
./test      运行可执行文件