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#include "base64.h"
int base64_decode_part(const char encoded[4], unsigned char bin[3])
{
int e0;
int e1;
int e2;
int e3;
if (encoded[0] == BASE64_PAD) return 0;
if ((e0 = base64_asc2bin[(unsigned char)encoded[0]]) == -1 ||
(e1 = base64_asc2bin[(unsigned char)encoded[1]]) == -1) return -1;
bin[0] = (e0 << 2) | (e1 >> 4);
if (encoded[2] == BASE64_PAD) return 1;
if ((e2 = base64_asc2bin[(unsigned char)encoded[2]]) == -1) return -1;
bin[1] = (e1 << 4) | (e2 >> 2);
if (encoded[3] == BASE64_PAD) return 2;
if ((e3 = base64_asc2bin[(unsigned char)encoded[3]]) == -1) return -1;
bin[2] = (e2 << 6) | e3;
return 3;
}
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