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Base64.c
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Base64.c
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#include "Base64.h"
#define WHITESPACE 64
#define EQUALS 65
#define INVALID 66
static const unsigned char d[] =
{
66,66,66,66,66,66,66,66,66,64,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,
66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,62,66,66,66,63,52,53,
54,55,56,57,58,59,60,61,66,66,66,65,66,66,66, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,66,66,66,66,66,66,26,27,28,
29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,66,66,
66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,
66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,
66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,
66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,
66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,
66,66,66,66,66,66
};
int base64decode (const unsigned char* in, int inLen, unsigned char *out, int *outLen)
{
const unsigned char* end = in + inLen;
int buf = 1, len = 0;
while (*in < 'A')
in++;
while (in < end)
{
unsigned char c = d[*in++];
switch (c)
{
case WHITESPACE:
continue; /* skip whitespace */
case INVALID:
return 1; /* invalid input, return error */
case EQUALS: /* pad character, end of data */
in = end;
continue;
default:
buf = buf << 6 | c;
/* If the buffer is full, split it into bytes */
if (buf & 0x1000000)
{
if ((len += 3) > *outLen) return 1; /* buffer overflow */
*out++ = (unsigned char)(buf >> 16);
*out++ = (unsigned char)(buf >> 8);
*out++ = (unsigned char)(buf);
buf = 1;
}
}
}
if (buf & 0x40000)
{
if ((len += 2) > *outLen) return 1; /* buffer overflow */
*out++ = (unsigned char)(buf >> 10);
*out++ = (unsigned char)(buf >> 2);
}
else if (buf & 0x1000)
{
if (++len > *outLen) return 1; /* buffer overflow */
*out++ = (unsigned char)(buf >> 4);
}
*outLen = len; /* modify to reflect the actual output size */
return 0;
}