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/* See LICENSE file for copyright and license details. */
#include "common.h"
#define FF 0xFF
static const unsigned char lut[256] = {
FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF,
FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF,
FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, 62, FF, FF, FF, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, FF, FF, FF, FF, FF, FF,
FF, 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, FF, FF, FF, FF, FF,
FF, 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, FF, FF, FF, FF, FF,
FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF,
FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF,
FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF,
FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF,
FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF,
FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF,
FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF,
FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF, FF
};
size_t
libar2_decode_base64(const char *str_, void *data_, size_t *lenp)
{
const unsigned char *str = (const unsigned char *)str_;
unsigned char *data = data_;
unsigned char a, b, c, d;
size_t ret = 0;
*lenp = 0;
for(;; str += 4) {
if (lut[str[0]] == FF || lut[str[1]] == FF)
break;
a = lut[str[0]];
b = lut[str[1]];
ret += 2;
if (data)
*data++ = (unsigned char)((a << 2) | (b >> 4));
++*lenp;
if (lut[str[2]] == FF) {
ret += (str[2] == '=');
ret += (str[2] == '=' && str[3] == '=');
break;
}
c = lut[str[2]];
ret += 1;
if (data)
*data++ = (unsigned char)((b << 4) | (c >> 2));
++*lenp;
if (lut[str[3]] == FF) {
ret += (str[3] == '=');
break;
}
d = lut[str[3]];
ret += 1;
if (data)
*data++ = (unsigned char)((c << 6) | (d >> 0));
++*lenp;
}
return ret;
}
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