freebsd-dev/crypto/kerberosIV/appl/ftp/common/base64.c

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/*
* Copyright (c) 1995, 1996, 1997 Kungliga Tekniska H<EFBFBD>gskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the Kungliga Tekniska
* H<EFBFBD>gskolan and its contributors.
*
* 4. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
RCSID("$Id: base64.c,v 1.6 1997/05/30 17:24:06 assar Exp $");
#endif
#include <stdlib.h>
#include <string.h>
#include "base64.h"
static char base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static int pos(char c)
{
char *p;
for(p = base64; *p; p++)
if(*p == c)
return p - base64;
return -1;
}
int base64_encode(const void *data, int size, char **str)
{
char *s, *p;
int i;
int c;
unsigned char *q;
p = s = (char*)malloc(size*4/3+4);
q = (unsigned char*)data;
i=0;
for(i = 0; i < size;){
c=q[i++];
c*=256;
if(i < size)
c+=q[i];
i++;
c*=256;
if(i < size)
c+=q[i];
i++;
p[0]=base64[(c&0x00fc0000) >> 18];
p[1]=base64[(c&0x0003f000) >> 12];
p[2]=base64[(c&0x00000fc0) >> 6];
p[3]=base64[(c&0x0000003f) >> 0];
if(i > size)
p[3]='=';
if(i > size+1)
p[2]='=';
p+=4;
}
*p=0;
*str = s;
return strlen(s);
}
int base64_decode(const char *str, void *data)
{
const char *p;
unsigned char *q;
int c;
int x;
int done = 0;
q=(unsigned char*)data;
for(p=str; *p && !done; p+=4){
x = pos(p[0]);
if(x >= 0)
c = x;
else{
done = 3;
break;
}
c*=64;
x = pos(p[1]);
if(x >= 0)
c += x;
else
return -1;
c*=64;
if(p[2] == '=')
done++;
else{
x = pos(p[2]);
if(x >= 0)
c += x;
else
return -1;
}
c*=64;
if(p[3] == '=')
done++;
else{
if(done)
return -1;
x = pos(p[3]);
if(x >= 0)
c += x;
else
return -1;
}
if(done < 3)
*q++=(c&0x00ff0000)>>16;
if(done < 2)
*q++=(c&0x0000ff00)>>8;
if(done < 1)
*q++=(c&0x000000ff)>>0;
}
return q - (unsigned char*)data;
}