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/*
base64.c
Copyright (C) 1999 Lars Brinkhoff. See COPYING for terms and conditions.
*/
#include <string.h>
#include <stdlib.h>
#include "config.h"
#include "base64.h"
#include "common.h"
static int encode[] =
{
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z', '0', '1', '2', '3',
'4', '5', '6', '7', '8', '9', '+', '/'
};
/*
Base64-encode LENGTH bytes of DATA in *CODE, which will be a newly
malloced area. *CODE will be a null-terminated string.
Return -1 on failure, or number of bytes of base64 code on success.
*/
ssize_t
encode_base64 (const void *data, size_t length, char **code)
{
const unsigned char *s, *end;
unsigned char *buf;
unsigned int x;
ssize_t n;
int i, j;
if (length == 0)
return 0;
end = (char *)data + length - 3;
buf = malloc (4 * ((length + 2) / 3) + 1);
if (buf == NULL)
return -1;
n = 0;
for (s = data; s < end;)
{
x = *s++ << 24;
x |= *s++ << 16;
x |= *s++ << 8;
*buf++ = encode[x >> 26];
x <<= 6;
*buf++ = encode[x >> 26];
x <<= 6;
*buf++ = encode[x >> 26];
x <<= 6;
*buf++ = encode[x >> 26];
n += 4;
}
end += 3;
x = 0;
for (i = 0; s < end; i++)
x |= *s++ << (24 - 8 * i);
for (j = 0; j < 4; j++)
{
if (8 * i >= 6 * j)
{
*buf++ = encode [x >> 26];
x <<= 6;
n++;
}
else
{
*buf++ = '=';
n++;
}
}
*buf = 0;
*code = buf - n;
return n;
}
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