freebsd-nq/eBones/des/enc_writ.c
1995-09-15 06:18:56 +00:00

100 lines
1.8 KiB
C

/* enc_writ.c */
/* Copyright (C) 1993 Eric Young - see README for more details */
/*-
* $Id: enc_writ.c,v 1.2 1995/05/30 06:40:12 rgrimes Exp $
*/
#include <sys/types.h>
#include <sys/uio.h>
#include <unistd.h>
#include <stdlib.h>
#include <time.h>
#include <errno.h>
#include "des_locl.h"
int des_enc_write(fd,buf,len,sched,iv)
int fd;
char *buf;
int len;
des_key_schedule sched;
des_cblock *iv;
{
long rnum;
int i,j,k,outnum;
char outbuf[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;
srandom(time(NULL));
}
/* lets recurse if we want to send the data in small chunks */
if (len > MAXWRITE)
{
j=0;
for (i=0; i<len; i+=k)
{
k=des_enc_write(fd,&(buf[i]),
((len-i) > MAXWRITE)?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)
{
p=shortbuf;
bcopy(buf,shortbuf,len);
for (i=len; i<8; i++)
shortbuf[i]=random();
rnum=8;
}
else
{
p=buf;
rnum=((len+7)/8*8); /* round up to nearest eight */
}
if (des_rw_mode & DES_PCBC_MODE)
pcbc_encrypt((des_cblock *)p,(des_cblock *)&(outbuf[HDRSIZE]),
(long)((len<8)?8:len),sched,iv,DES_ENCRYPT);
else
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]),(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);
}