freeswitch/libs/iksemel/src/base64.c

104 lines
2.0 KiB
C

/* iksemel (XML parser for Jabber)
** Copyright (C) 2000-2003 Gurer Ozen <madcat@e-kolay.net>
** This code is free software; you can redistribute it and/or
** modify it under the terms of GNU Lesser General Public License.
*/
#include "common.h"
#include "iksemel.h"
static const char base64_charset[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
char *iks_base64_decode(const char *buf)
{
char *res, *save;
char val;
const char *foo;
const char *end;
int index;
size_t len;
if (!buf)
return NULL;
len = iks_strlen(buf) * 6 / 8 + 1;
save = res = iks_malloc(len);
if (!save)
return NULL;
memset(res, 0, len);
index = 0;
end = buf + iks_strlen(buf);
while (*buf && buf < end) {
if (!(foo = strchr(base64_charset, *buf)))
foo = base64_charset;
val = (int)(foo - base64_charset);
buf++;
switch (index) {
case 0:
*res |= val << 2;
break;
case 1:
*res++ |= val >> 4;
*res |= val << 4;
break;
case 2:
*res++ |= val >> 2;
*res |= val << 6;
break;
case 3:
*res++ |= val;
break;
}
index++;
index %= 4;
}
*res = 0;
return save;
}
char *iks_base64_encode(const char *buf, int len)
{
char *res, *save;
int k, t;
len = (len > 0) ? (len) : (iks_strlen(buf));
save = res = iks_malloc((len*8) / 6 + 4);
if (!save) return NULL;
for (k = 0; k < len/3; ++k) {
*res++ = base64_charset[*buf >> 2];
t = ((*buf & 0x03) << 4);
buf++;
*res++ = base64_charset[t | (*buf >> 4)];
t = ((*buf & 0x0F) << 2);
buf++;
*res++ = base64_charset[t | (*buf >> 6)];
*res++ = base64_charset[*buf++ & 0x3F];
}
switch (len % 3) {
case 2:
*res++ = base64_charset[*buf >> 2];
t = ((*buf & 0x03) << 4);
buf++;
*res++ = base64_charset[t | (*buf >> 4)];
*res++ = base64_charset[((*buf++ & 0x0F) << 2)];
*res++ = '=';
break;
case 1:
*res++ = base64_charset[*buf >> 2];
*res++ = base64_charset[(*buf++ & 0x03) << 4];
*res++ = '=';
*res++ = '=';
break;
}
*res = 0;
return save;
}