C 中如何将2进制字符串进行Base64编码
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进行Base64转化

[解决办法]

C/C++ code

#include <stdio.h> #define CHAR_BIT 8#define BITMASK(b) (1 << ((b) % CHAR_BIT))#define BITSLOT(b) ((b) / CHAR_BIT)#define BITSET(a, b) ((a)[BITSLOT(b)] |= BITMASK(b))#define BITTEST(a, b) ((a)[BITSLOT(b)] & BITMASK(b)) // Returns the length of the base64 stringint base64_encode(unsigned char str[], unsigned char base64[], int len){   int idx=0,idx2=0,base64_chars=0;   unsigned char charset[]={"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"},t=0;      // Initialize the base64 array   memset(base64,0,(len+1) * 1.334);   // Continue converting while the bit limit for the str array has not been reached   while (idx < len * CHAR_BIT) {      // Pick off bits in chunks of 6      for (idx2=0; idx2 < 6; idx++,idx2++) {         if (BITTEST(str,idx))            BITSET(&t,idx2);      }      // Map the binary value to its ASCII representation      t = charset[t];      // Save the new converted char to the base64 array, increment the base64 len counter,      // and re-initialize the temp var      base64[base64_chars] = t;      base64_chars++;      t = 0;   }      // Return the number of Base64 characters that were used   return(base64_chars);} // Returns the length of the plain text stringint base64_decode(unsigned char base64_t[], unsigned char str[], int len){   int idx=0,idx2=0,idx3,str_chars=0;   unsigned char charset[]={"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"},t=0,base64[1000];      // Initialize the str array   memset(str,0,(len+1) * .75);   // Un-map the ASCII characters to their binary representations   for (idx=0; idx < len; idx++) {      for (idx3=0; 1; idx3++) {         if (charset[idx3] == base64_t[idx]) {            base64[idx] = idx3;            break;         }         }   }      // Combine the significant 6-bit blocks from each byes of the base64 array   for (idx=0,idx2=0; idx < len * CHAR_BIT; idx++,idx2++) {      // Skip two "lame" bits ever six      if (!(idx2 % 6) && idx2)         idx += 2;      // Log how many full 8-bit chars have been filled      if (!(idx2 % 8) && idx2)         str_chars++;      if (BITTEST(base64,idx))         BITSET(str,idx2);   }    // Return the length of the text array   return(str_chars);}  int main(){   unsigned char str[100]={"sadfymkf7 6756"},base[100],t;      t = base64_encode(str,base,strlen(str));   printf("\n");   t = base64_decode(base,str,t);      getchar();}