232 lines
7.1 KiB
C
232 lines
7.1 KiB
C
/* crypto/des/enc_read.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 <stdio.h>
|
|
#include <errno.h>
|
|
#include <unistd.h>
|
|
|
|
#include "des_locl.h"
|
|
|
|
/* This has some uglies in it but it works - even over sockets. */
|
|
int des_rw_mode=DES_PCBC_MODE;
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* - This function uses an internal state and thus cannot be
|
|
* used on multiple files.
|
|
*/
|
|
|
|
|
|
int des_enc_read(int fd, void *buf, int len, des_key_schedule sched,
|
|
des_cblock *iv)
|
|
{
|
|
/* data to be unencrypted */
|
|
int net_num=0;
|
|
static unsigned char *net=NULL;
|
|
/* extra unencrypted data
|
|
* for when a block of 100 comes in but is des_read one byte at
|
|
* a time. */
|
|
static unsigned char *unnet=NULL;
|
|
static int unnet_start=0;
|
|
static int unnet_left=0;
|
|
static unsigned char *tmpbuf=NULL;
|
|
int i;
|
|
long num=0,rnum;
|
|
unsigned char *p;
|
|
|
|
if (tmpbuf == NULL)
|
|
{
|
|
tmpbuf=malloc(BSIZE);
|
|
if (tmpbuf == NULL) return(-1);
|
|
}
|
|
if (net == NULL)
|
|
{
|
|
net=malloc(BSIZE);
|
|
if (net == NULL) return(-1);
|
|
}
|
|
if (unnet == NULL)
|
|
{
|
|
unnet=malloc(BSIZE);
|
|
if (unnet == NULL) return(-1);
|
|
}
|
|
/* 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 > MAXWRITE) len=MAXWRITE;
|
|
|
|
/* first - get the length */
|
|
while (net_num < HDRSIZE)
|
|
{
|
|
i=read(fd,&(net[net_num]),HDRSIZE-net_num);
|
|
#ifdef EINTR
|
|
if ((i == -1) && (errno == EINTR)) continue;
|
|
#endif
|
|
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 > 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]),rnum-net_num);
|
|
#ifdef EINTR
|
|
if ((i == -1) && (errno == EINTR)) continue;
|
|
#endif
|
|
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(net,unnet,num,sched,iv,DES_DECRYPT);
|
|
else
|
|
des_cbc_encrypt(net,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)
|
|
{
|
|
|
|
if (des_rw_mode & DES_PCBC_MODE)
|
|
des_pcbc_encrypt(net,tmpbuf,num,sched,iv,
|
|
DES_DECRYPT);
|
|
else
|
|
des_cbc_encrypt(net,tmpbuf,num,sched,iv,
|
|
DES_DECRYPT);
|
|
|
|
/* eay 26/08/92 fix a bug that returned more
|
|
* bytes than you asked for (returned len bytes :-( */
|
|
memcpy(buf,tmpbuf,num);
|
|
}
|
|
else
|
|
{
|
|
if (des_rw_mode & DES_PCBC_MODE)
|
|
des_pcbc_encrypt(net,buf,num,sched,iv,
|
|
DES_DECRYPT);
|
|
else
|
|
des_cbc_encrypt(net,buf,num,sched,iv,
|
|
DES_DECRYPT);
|
|
}
|
|
}
|
|
return num;
|
|
}
|
|
|