Base64Code.cpp

#include "Base64Code.h"

//////////////////////////////////////////////////////////////////////////

///Base64 加解密

const char *codes = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";  

const unsigned char map[256] = {  
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 253, 255,  
255, 253, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,  
255, 255, 255, 255, 255, 255, 255, 255, 253, 255, 255, 255,  
255, 255, 255, 255, 255, 255, 255,  62, 255, 255, 255,  63,  
52,  53,  54,  55,  56,  57,  58,  59,  60,  61, 255, 255,  
255, 254, 255, 255, 255,   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, 255, 255, 255, 255, 255,  
255,  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, 255, 255, 255, 255, 255, 255, 255, 255, 255,  
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,  
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,  
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,  
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,  
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,  
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,  
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,  
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,  
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,  
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,  
255, 255, 255, 255 };  

int base64_encode(const unsigned char *in,  unsigned long len, unsigned char *out)  

{  
unsigned long i, len2, leven;  
unsigned char *p;  
/* valid output size ? */  
len2 = 4 * ((len + 2) / 3);  
p = out;  
leven = 3*(len / 3);  
for (i = 0; i < leven; i += 3) {  
*p++ = codes[in[0] >> 2];  
*p++ = codes[((in[0] & 3) << 4) + (in[1] >> 4)];  
*p++ = codes[((in[1] & 0xf) << 2) + (in[2] >> 6)];  
*p++ = codes[in[2] & 0x3f];  
in += 3;  
}  
/* Pad it if necessary...  */  
if (i < len) {  
unsigned a = in[0];  
unsigned b = (i+1 < len) ? in[1] : 0;  
unsigned c = 0;  

*p++ = codes[a >> 2];  
*p++ = codes[((a & 3) << 4) + (b >> 4)];  
*p++ = (i+1 < len) ? codes[((b & 0xf) << 2) + (c >> 6)] : '=';  
*p++ = '=';  
}  

/* append a NULL byte */  
*p = '\0';  

return p - out;  

}  

int base64_decode(const unsigned char *in, unsigned char *out)  

{  
unsigned long t, x, y, z;  
unsigned char c;  
int g = 3;  

for (x = y = z = t = 0; in[x]!=0;) {  
c = map[in[x++]];  
if (c == 255) return -1;  
if (c == 253) continue;  
if (c == 254) { c = 0; g--; }  
t = (t<<6)|c;  
if (++y == 4) {  
//          if (z + g > *outlen) { return CRYPT_BUFFER_OVERFLOW; }  
out[z++] = (unsigned char)((t>>16)&255);  
if (g > 1) out[z++] = (unsigned char)((t>>8)&255);  
if (g > 2) out[z++] = (unsigned char)(t&255);  
y = t = 0;  
}  
}  
//  if (y != 0) {  
//      return -1;  
//  }  
return z;  

}