freebsd-dev/crypto/kerberosIV/appl/bsd/encrypt.c
1999-09-19 14:19:32 +00:00

306 lines
8.7 KiB
C

/* Copyright (C) 1995 Eric Young (eay@mincom.oz.au)
* All rights reserved.
*
* This file is part of an SSL implementation written
* by Eric Young (eay@mincom.oz.au).
* The implementation was written so as to conform with Netscapes SSL
* specification. This library and applications are
* FREE FOR COMMERCIAL AND NON-COMMERCIAL USE
* as long as the following conditions are aheared to.
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed. If this code is used in a product,
* Eric Young should be given attribution as the author of the parts used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* 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 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 Eric Young (eay@mincom.oz.au)
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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 AUTHOR 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.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
#include "bsd_locl.h"
RCSID("$Id: encrypt.c,v 1.4 1999/06/17 18:47:26 assar Exp $");
/* replacements for htonl and ntohl since I have no idea what to do
* when faced with machines with 8 byte longs. */
#define HDRSIZE 4
#define n2l(c,l) (l =((u_int32_t)(*((c)++)))<<24, \
l|=((u_int32_t)(*((c)++)))<<16, \
l|=((u_int32_t)(*((c)++)))<< 8, \
l|=((u_int32_t)(*((c)++))))
#define l2n(l,c) (*((c)++)=(unsigned char)(((l)>>24)&0xff), \
*((c)++)=(unsigned char)(((l)>>16)&0xff), \
*((c)++)=(unsigned char)(((l)>> 8)&0xff), \
*((c)++)=(unsigned char)(((l) )&0xff))
/* This has some uglies in it but it works - even over sockets. */
extern int errno;
int des_rw_mode=DES_PCBC_MODE;
int LEFT_JUSTIFIED = 0;
int
des_enc_read(int fd, char *buf, int len, struct des_ks_struct *sched, des_cblock *iv)
{
/* data to be unencrypted */
int net_num=0;
unsigned char net[DES_RW_BSIZE];
/* extra unencrypted data
* for when a block of 100 comes in but is des_read one byte at
* a time. */
static char unnet[DES_RW_BSIZE];
static int unnet_start=0;
static int unnet_left=0;
int i;
long num=0,rnum;
unsigned char *p;
/* left over data from last decrypt */
if (unnet_left != 0)
{
if (unnet_left < len)
{
/* we still still need more data but will return
* with the number of bytes we have - should always
* check the return value */
memcpy(buf,&(unnet[unnet_start]),unnet_left);
/* eay 26/08/92 I had the next 2 lines
* reversed :-( */
i=unnet_left;
unnet_start=unnet_left=0;
}
else
{
memcpy(buf,&(unnet[unnet_start]),len);
unnet_start+=len;
unnet_left-=len;
i=len;
}
return(i);
}
/* We need to get more data. */
if (len > DES_RW_MAXWRITE) len=DES_RW_MAXWRITE;
/* first - get the length */
net_num=0;
while (net_num < HDRSIZE)
{
i=read(fd,&(net[net_num]),(unsigned int)HDRSIZE-net_num);
if ((i == -1) && (errno == EINTR)) continue;
if (i <= 0) return(0);
net_num+=i;
}
/* we now have at net_num bytes in net */
p=net;
num=0;
n2l(p,num);
/* num should be rounded up to the next group of eight
* we make sure that we have read a multiple of 8 bytes from the net.
*/
if ((num > DES_RW_MAXWRITE) || (num < 0)) /* error */
return(-1);
rnum=(num < 8)?8:((num+7)/8*8);
net_num=0;
while (net_num < rnum)
{
i=read(fd,&(net[net_num]),(unsigned int)rnum-net_num);
if ((i == -1) && (errno == EINTR)) continue;
if (i <= 0) return(0);
net_num+=i;
}
/* Check if there will be data left over. */
if (len < num)
{
if (des_rw_mode & DES_PCBC_MODE)
des_pcbc_encrypt((des_cblock *)net,(des_cblock *)unnet,
num,sched,iv,DES_DECRYPT);
else
des_cbc_encrypt((des_cblock *)net,(des_cblock *)unnet,
num,sched,iv,DES_DECRYPT);
memcpy(buf,unnet,len);
unnet_start=len;
unnet_left=num-len;
/* The following line is done because we return num
* as the number of bytes read. */
num=len;
}
else
{
/* >output is a multiple of 8 byes, if len < rnum
* >we must be careful. The user must be aware that this
* >routine will write more bytes than he asked for.
* >The length of the buffer must be correct.
* FIXED - Should be ok now 18-9-90 - eay */
if (len < rnum)
{
char tmpbuf[DES_RW_BSIZE];
if (des_rw_mode & DES_PCBC_MODE)
des_pcbc_encrypt((des_cblock *)net,
(des_cblock *)tmpbuf,
num,sched,iv,DES_DECRYPT);
else
des_cbc_encrypt((des_cblock *)net,
(des_cblock *)tmpbuf,
num,sched,iv,DES_DECRYPT);
/* eay 26/08/92 fix a bug that returned more
* bytes than you asked for (returned len bytes :-( */
if (LEFT_JUSTIFIED || (len >= 8))
memcpy(buf,tmpbuf,num);
else
memcpy(buf,tmpbuf+(8-num),num); /* Right justified */
}
else if (num >= 8)
{
if (des_rw_mode & DES_PCBC_MODE)
des_pcbc_encrypt((des_cblock *)net,
(des_cblock *)buf,num,sched,iv,
DES_DECRYPT);
else
des_cbc_encrypt((des_cblock *)net,
(des_cblock *)buf,num,sched,iv,
DES_DECRYPT);
}
else
{
if (des_rw_mode & DES_PCBC_MODE)
des_pcbc_encrypt((des_cblock *)net,
(des_cblock *)buf,8,sched,iv,
DES_DECRYPT);
else
des_cbc_encrypt((des_cblock *)net,
(des_cblock *)buf,8,sched,iv,
DES_DECRYPT);
if (!LEFT_JUSTIFIED)
memcpy(buf, buf+(8-num), num); /* Right justified */
}
}
return(num);
}
int
des_enc_write(int fd, char *buf, int len, struct des_ks_struct *sched, des_cblock *iv)
{
long rnum;
int i,j,k,outnum;
char outbuf[DES_RW_BSIZE+HDRSIZE];
char shortbuf[8];
char *p;
static int start=1;
/* If we are sending less than 8 bytes, the same char will look
* the same if we don't pad it out with random bytes */
if (start)
{
start=0;
srand(time(NULL));
}
/* lets recurse if we want to send the data in small chunks */
if (len > DES_RW_MAXWRITE)
{
j=0;
for (i=0; i<len; i+=k)
{
k=des_enc_write(fd,&(buf[i]),
((len-i) > DES_RW_MAXWRITE)?DES_RW_MAXWRITE:(len-i),sched,iv);
if (k < 0)
return(k);
else
j+=k;
}
return(j);
}
/* write length first */
p=outbuf;
l2n(len,p);
/* pad short strings */
if (len < 8)
{
if (LEFT_JUSTIFIED)
{
p=shortbuf;
memcpy(shortbuf,buf,(unsigned int)len);
for (i=len; i<8; i++)
shortbuf[i]=rand();
rnum=8;
}
else
{
p=shortbuf;
for (i=0; i<8-len; i++)
shortbuf[i]=rand();
memcpy(shortbuf + 8 - len, buf, len);
rnum=8;
}
}
else
{
p=buf;
rnum=((len+7)/8*8); /* round up to nearest eight */
}
if (des_rw_mode & DES_PCBC_MODE)
des_pcbc_encrypt((des_cblock *)p,(des_cblock *)&(outbuf[HDRSIZE]),
(long)((len<8)?8:len),sched,iv,DES_ENCRYPT);
else
des_cbc_encrypt((des_cblock *)p,(des_cblock *)&(outbuf[HDRSIZE]),
(long)((len<8)?8:len),sched,iv,DES_ENCRYPT);
/* output */
outnum=rnum+HDRSIZE;
for (j=0; j<outnum; j+=i)
{
/* eay 26/08/92 I was not doing writing from where we
* got upto. */
i=write(fd,&(outbuf[j]),(unsigned int)(outnum-j));
if (i == -1)
{
if (errno == EINTR)
i=0;
else /* This is really a bad error - very bad
* It will stuff-up both ends. */
return(-1);
}
}
return(len);
}