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kamailio/lib/cds/base64.c

104 lines
3.1 KiB

/*
* base64 encoding / decoding
*
* $Id$
*
* Copyright (C) 2001-2003 FhG Fokus
*
* This file is part of ser, a free SIP server.
*
* ser is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version
*
* For a license to use the ser software under conditions
* other than those described here, or to purchase support for this
* software, please contact iptel.org by e-mail at the following addresses:
* info@iptel.org
*
* ser is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
void base64decode(char* src_buf, int src_len, char* tgt_buf, int* tgt_len) {
int pos, i, n;
unsigned char c[4];
for (pos=0, i=0, *tgt_len=0; pos < src_len; pos++) {
if (src_buf[pos] >= 'A' && src_buf[pos] <= 'Z')
c[i] = src_buf[pos] - 65; /* <65..90> --> <0..25> */
else if (src_buf[pos] >= 'a' && src_buf[pos] <= 'z')
c[i] = src_buf[pos] - 71; /* <97..122> --> <26..51> */
else if (src_buf[pos] >= '0' && src_buf[pos] <= '9')
c[i] = src_buf[pos] + 4; /* <48..56> --> <52..61> */
else if (src_buf[pos] == '+')
c[i] = 62;
else if (src_buf[pos] == '/')
c[i] = 63;
else /* '=' */
c[i] = 64;
i++;
if (pos == src_len-1) {
while (i < 4) {
c[i] = 64;
i++;
}
}
if (i==4) {
if (c[0] == 64)
n = 0;
else if (c[2] == 64)
n = 1;
else if (c[3] == 64)
n = 2;
else
n = 3;
switch (n) {
case 3:
tgt_buf[*tgt_len+2] = (char) (((c[2] & 0x03) << 6) | c[3]);
/* no break */
case 2:
tgt_buf[*tgt_len+1] = (char) (((c[1] & 0x0F) << 4) | (c[2] >> 2));
/* no break */
case 1:
tgt_buf[*tgt_len+0] = (char) ((c[0] << 2) | (c[1] >> 4));
break;
}
i=0;
*tgt_len+= n;
}
}
}
void base64encode(char* src_buf, int src_len, char* tgt_buf, int* tgt_len, int quoted) {
static char code64[64+1] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
int pos;
for (pos=0, *tgt_len=0; pos < src_len; pos+=3,*tgt_len+=4) {
tgt_buf[*tgt_len+0] = code64[(unsigned char)src_buf[pos+0] >> 2];
tgt_buf[*tgt_len+1] = code64[(((unsigned char)src_buf[pos+0] & 0x03) << 4) | ((pos+1 < src_len)?((unsigned char)src_buf[pos+1] >> 4):0)];
if (pos+1 < src_len)
tgt_buf[*tgt_len+2] = code64[(((unsigned char)src_buf[pos+1] & 0x0F) << 2) | ((pos+2 < src_len)?((unsigned char)src_buf[pos+2] >> 6):0)];
else {
if(!quoted)
(*tgt_len)--;
else
/* this data is going to be quoted */
tgt_buf[*tgt_len+2] = '=';
}
if (pos+2 < src_len)
tgt_buf[*tgt_len+3] = code64[(unsigned char)src_buf[pos+2] & 0x3F];
else {
if(!quoted)
(*tgt_len)--;
else
tgt_buf[*tgt_len+3] = '=';
}
}
}