freebsd-dev/crypto/libdes/enc_writ.c

173 lines
5.5 KiB
C

/* crypto/des/enc_writ.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library 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 cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* 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.]
*
* $FreeBSD$
*/
#include <sys/types.h>
#include <sys/uio.h>
#include <errno.h>
#include <stdio.h>
#include <time.h>
#include <unistd.h>
#include "des_locl.h"
/*
* WARNINGS:
*
* - The data format used by des_enc_write() and des_enc_read()
* has a cryptographic weakness: When asked to write more
* than MAXWRITE bytes, des_enc_write will split the data
* into several chunks that are all encrypted
* using the same IV. So don't use these functions unless you
* are sure you know what you do (in which case you might
* not want to use them anyway).
*
* - This code cannot handle non-blocking sockets.
*/
int des_enc_write(int fd, const void *_buf, int len,
des_key_schedule sched, des_cblock *iv)
{
#ifdef _LIBC
extern unsigned long time();
extern int write();
#endif
const unsigned char *buf=_buf;
long rnum;
int i,j,k,outnum;
static unsigned char *outbuf=NULL;
unsigned char shortbuf[8];
unsigned char *p;
const unsigned char *cp;
static int start=1;
if (outbuf == NULL)
{
outbuf=malloc(BSIZE+HDRSIZE);
if (outbuf == NULL) return(-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;
}
/* 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)
{
cp=shortbuf;
memcpy(shortbuf,buf,len);
des_rand_data(shortbuf+len, 8-len);
rnum=8;
}
else
{
cp=(unsigned char*)buf;
rnum=((len+7)/8*8); /* round up to nearest eight */
}
if (des_rw_mode & DES_PCBC_MODE)
des_pcbc_encrypt(cp,&(outbuf[HDRSIZE]),(len<8)?8:len,sched,iv,
DES_ENCRYPT);
else
des_cbc_encrypt(cp,&(outbuf[HDRSIZE]),(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]),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);
}