base64.cpp.svn-base

来自「这是一个很好的参考代码」· SVN-BASE 代码 · 共 206 行

#include <vector>
#include <string>
#include "base64.h"

char getbase64character(const char& in)
{
  switch(in) {
  case B64_A:
    return 'A';
  case B64_B:
    return 'B';
  case B64_C:
    return 'C';
  case B64_D:
    return 'D';
  case B64_E:
    return 'E';
  case B64_F:
    return 'F';
  case B64_G:
    return 'G';
  case B64_H:
    return 'H';
  case B64_I:
    return 'I';
  case B64_J:
    return 'J';
  case B64_K:
    return 'K';
  case B64_L:
    return 'L';
  case B64_M:
    return 'M';
  case B64_N:
    return 'N';
  case B64_O:
    return 'O';
  case B64_P:
    return 'P';
  case B64_Q:
    return 'Q';
  case B64_R:
    return 'R';
  case B64_S:
    return 'S';
  case B64_T:
    return 'T';
  case B64_U:
    return 'U';
  case B64_V:
    return 'V';
  case B64_W:
    return 'W';
  case B64_X:
    return 'X';
  case B64_Y:
    return 'Y';
  case B64_Z:
    return 'Z';
  case B64_a:
    return 'a';
  case B64_b:
    return 'b';
  case B64_c:
    return 'c';
  case B64_d:
    return 'd';
  case B64_e:
    return 'e';
  case B64_f:
    return 'f';
  case B64_g:
    return 'g';
  case B64_h:
    return 'h';
  case B64_i:
    return 'i';
  case B64_j:
    return 'j';
  case B64_k:
    return 'k';
  case B64_l:
    return 'l';
  case B64_m:
    return 'm';
  case B64_n:
    return 'n';
  case B64_o:
    return 'o';
  case B64_p:
    return 'p';
  case B64_q:
    return 'q';
  case B64_r:
    return 'r';
  case B64_s:
    return 's';
  case B64_t:
    return 't';
  case B64_u:
    return 'u';
  case B64_v:
    return 'v';
  case B64_w:
    return 'w';
  case B64_x:
    return 'x';
  case B64_y:
    return 'y';
  case B64_z:
    return 'z';
  case B64_0:
    return '0';
  case B64_1:
    return '1';
  case B64_2:
    return '2';
  case B64_3:
    return '3';
  case B64_4:
    return '4';
  case B64_5:
    return '5';
  case B64_6:
    return '6';
  case B64_7:
    return '7';
  case B64_8:
    return '8';
  case B64_9:
    return '9';
  case plus:
    return '+';
  case slash:
    return '/';
  case padding:
    return '=';
  }
  return '\0'; // ?????? yikes
}

std::vector<char> base64encode(const std::vector<char>& input, 
			       const bool returns) {
  std::vector<char> output;
  
  // add a newline (SMTP demands less than 1000 characters in a message line).
  long count = 0;
  for(std::vector<char>::size_type p = 0; p < input.size(); p+=3) {
    output.push_back(getbase64character((input[p] & 0xFC) >> 2));
    ++count;
    
    if(p+1 < input.size()) {
      output.push_back(getbase64character(((input[p] & 0x03) <<4) | 
					  ((input[p+1] & 0xF0) >> 4)));
      ++count;
    }
    if(p+2 < input.size()) {
      output.push_back(getbase64character(((input[p+1] & 0x0F) <<2) | 
					  ((input[p+2] & 0xC0) >>6)));
      output.push_back(getbase64character((input[p+2] & 0x3F)));
      ++count;
    }
    
    if(p+1 == input.size()) {
      output.push_back(getbase64character(((input[p] & 0x03) <<4)));
    } else if(p+2 == input.size()) {
      output.push_back(getbase64character(((input[p+1] & 0x0F) <<2)));
    }
    
    if(returns) {
      // 79 characters on a line.
      if(count > 75) {
	output.push_back('\r');
	output.push_back('\n');
	count = 0;
      }
    }
  }
  int pad(input.size() % 3);
  if(pad) {
    if(pad == 1) {
      pad = 2;
    } else {
      pad = 1;
    }
  }
  for(int i = 0; i < pad; ++i) {
    output.push_back('=');
  }
  return output;
}

std::string base64encode(const std::string& input, const bool returns) {
  std::vector<char> in, out;
  for(std::string::const_iterator it = input.begin(); it != input.end(); ++it){
    in.push_back(*it);
  }
  out = base64encode(in, returns);
  std::string ret;
  for(std::vector<char>::const_iterator it1 = out.begin(); it1 != out.end(); 
      ++it1) {
    ret += *it1;
  }
  return ret;
}