base64.cpp

Smtp mail sender with attachments.

#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;
																													    }