1 /* crypto/des/enc_read.c */
\r/* Copyright (C) 1995-1997 Eric Young (eay@mincom.oz.au)
\r * All rights reserved.
\r *
\r * This package is an SSL implementation written
\r * by Eric Young (eay@mincom.oz.au).
\r * The implementation was written so as to conform with Netscapes SSL.
\r *
\r * This library is free for commercial and non-commercial use as long as
\r * the following conditions are aheared to. The following conditions
\r * apply to all code found in this distribution, be it the RC4, RSA,
\r * lhash, DES, etc., code; not just the SSL code. The SSL documentation
\r * included with this distribution is covered by the same copyright terms
\r * except that the holder is Tim Hudson (tjh@mincom.oz.au).
\r *
\r * Copyright remains Eric Young's, and as such any Copyright notices in
\r * the code are not to be removed.
\r * If this package is used in a product, Eric Young should be given attribution
\r * as the author of the parts of the library used.
\r * This can be in the form of a textual message at program startup or
\r * in documentation (online or textual) provided with the package.
\r *
\r * Redistribution and use in source and binary forms, with or without
\r * modification, are permitted provided that the following conditions
\r * are met:
\r * 1. Redistributions of source code must retain the copyright
\r * notice, this list of conditions and the following disclaimer.
\r * 2. Redistributions in binary form must reproduce the above copyright
\r * notice, this list of conditions and the following disclaimer in the
\r * documentation and/or other materials provided with the distribution.
\r * 3. All advertising materials mentioning features or use of this software
\r * must display the following acknowledgement:
\r * "This product includes cryptographic software written by
\r * Eric Young (eay@mincom.oz.au)"
\r * The word 'cryptographic' can be left out if the rouines from the library
\r * being used are not cryptographic related :-).
\r * 4. If you include any Windows specific code (or a derivative thereof) from
\r * the apps directory (application code) you must include an acknowledgement:
\r * "This product includes software written by Tim Hudson (tjh@mincom.oz.au)"
\r *
\r * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
\r * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
\r * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
\r * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
\r * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
\r * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
\r * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
\r * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
\r * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
\r * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
\r * SUCH DAMAGE.
\r *
\r * The licence and distribution terms for any publically available version or
\r * derivative of this code cannot be changed. i.e. this code cannot simply be
\r * copied and put under another distribution licence
\r * [including the GNU Public Licence.]
\r */
\r\r#include <stdio.h>
\r#include <errno.h>
\r#include "des_locl.h"
\r\r/* This has some uglies in it but it works - even over sockets. */
\r/*extern int errno;*/
\rint des_rw_mode=DES_PCBC_MODE;
\r\rint des_enc_read(fd, buf, len, sched, iv)
\rint fd;
\rchar *buf;
\rint len;
\rdes_key_schedule sched;
\rdes_cblock (*iv);
\r {
\r /* data to be unencrypted */
\r int net_num=0;
\r static unsigned char *net=NULL;
\r /* extra unencrypted data
\r * for when a block of 100 comes in but is des_read one byte at
\r * a time. */
\r static char *unnet=NULL;
\r static int unnet_start=0;
\r static int unnet_left=0;
\r static char *tmpbuf=NULL;
\r int i;
\r long num=0,rnum;
\r unsigned char *p;
\r\r if (tmpbuf == NULL)
\r {
\r tmpbuf=(char *)malloc(BSIZE);
\r if (tmpbuf == NULL) return(-1);
\r }
\r if (net == NULL)
\r {
\r net=(unsigned char *)malloc(BSIZE);
\r if (net == NULL) return(-1);
\r }
\r if (unnet == NULL)
\r {
\r unnet=(char *)malloc(BSIZE);
\r if (unnet == NULL) return(-1);
\r }
\r /* left over data from last decrypt */
\r if (unnet_left != 0)
\r {
\r if (unnet_left < len)
\r {
\r /* we still still need more data but will return
\r * with the number of bytes we have - should always
\r * check the return value */
\r memcpy(buf,&(unnet[unnet_start]),
\r (unsigned int)unnet_left);
\r /* eay 26/08/92 I had the next 2 lines
\r * reversed :-( */
\r i=unnet_left;
\r unnet_start=unnet_left=0;
\r }
\r else
\r {
\r memcpy(buf,&(unnet[unnet_start]),(unsigned int)len);
\r unnet_start+=len;
\r unnet_left-=len;
\r i=len;
\r }
\r return(i);
\r }
\r\r /* We need to get more data. */
\r if (len > MAXWRITE) len=MAXWRITE;
\r\r /* first - get the length */
\r while (net_num < HDRSIZE)
\r {
\r i=read(fd,&(net[net_num]),(unsigned int)HDRSIZE-net_num);
\r if ((i == -1) && (errno == EINTR)) continue;
\r if (i <= 0) return(0);
\r net_num+=i;
\r }
\r\r /* we now have at net_num bytes in net */
\r p=net;
\r /* num=0; */
\r n2l(p,num);
\r /* num should be rounded up to the next group of eight
\r * we make sure that we have read a multiple of 8 bytes from the net.
\r */
\r if ((num > MAXWRITE) || (num < 0)) /* error */
\r return(-1);
\r rnum=(num < 8)?8:((num+7)/8*8);
\r\r net_num=0;
\r while (net_num < rnum)
\r {
\r i=read(fd,&(net[net_num]),(unsigned int)rnum-net_num);
\r if ((i == -1) && (errno == EINTR)) continue;
\r if (i <= 0) return(0);
\r net_num+=i;
\r }
\r\r /* Check if there will be data left over. */
\r if (len < num)
\r {
\r if (des_rw_mode & DES_PCBC_MODE)
\r des_pcbc_encrypt((des_cblock *)net,(des_cblock *)unnet,
\r num,sched,iv,DES_DECRYPT);
\r else
\r des_cbc_encrypt((des_cblock *)net,(des_cblock *)unnet,
\r num,sched,iv,DES_DECRYPT);
\r memcpy(buf,unnet,(unsigned int)len);
\r unnet_start=len;
\r unnet_left=(int)num-len;
\r\r /* The following line is done because we return num
\r * as the number of bytes read. */
\r num=len;
\r }
\r else
\r {
\r /* >output is a multiple of 8 byes, if len < rnum
\r * >we must be careful. The user must be aware that this
\r * >routine will write more bytes than he asked for.
\r * >The length of the buffer must be correct.
\r * FIXED - Should be ok now 18-9-90 - eay */
\r if (len < rnum)
\r {
\r\r if (des_rw_mode & DES_PCBC_MODE)
\r des_pcbc_encrypt((des_cblock *)net,
\r (des_cblock *)tmpbuf,
\r num,sched,iv,DES_DECRYPT);
\r else
\r des_cbc_encrypt((des_cblock *)net,
\r (des_cblock *)tmpbuf,
\r num,sched,iv,DES_DECRYPT);
\r\r /* eay 26/08/92 fix a bug that returned more
\r * bytes than you asked for (returned len bytes :-( */
\r memcpy(buf,tmpbuf,(unsigned int)num);
\r }
\r else
\r {
\r if (des_rw_mode & DES_PCBC_MODE)
\r des_pcbc_encrypt((des_cblock *)net,
\r (des_cblock *)buf,num,sched,iv,
\r DES_DECRYPT);
\r else
\r des_cbc_encrypt((des_cblock *)net,
\r (des_cblock *)buf,num,sched,iv,
\r DES_DECRYPT);
\r }
\r }
\r return((int)num);
\r }
\r\r
projects / cyrus-sasl.git / blob