sl@0: /* crypto/des/enc_read.c */
sl@0: /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
sl@0:  * All rights reserved.
sl@0:  *
sl@0:  * This package is an SSL implementation written
sl@0:  * by Eric Young (eay@cryptsoft.com).
sl@0:  * The implementation was written so as to conform with Netscapes SSL.
sl@0:  * 
sl@0:  * This library is free for commercial and non-commercial use as long as
sl@0:  * the following conditions are aheared to.  The following conditions
sl@0:  * apply to all code found in this distribution, be it the RC4, RSA,
sl@0:  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
sl@0:  * included with this distribution is covered by the same copyright terms
sl@0:  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
sl@0:  * 
sl@0:  * Copyright remains Eric Young's, and as such any Copyright notices in
sl@0:  * the code are not to be removed.
sl@0:  * If this package is used in a product, Eric Young should be given attribution
sl@0:  * as the author of the parts of the library used.
sl@0:  * This can be in the form of a textual message at program startup or
sl@0:  * in documentation (online or textual) provided with the package.
sl@0:  * 
sl@0:  * Redistribution and use in source and binary forms, with or without
sl@0:  * modification, are permitted provided that the following conditions
sl@0:  * are met:
sl@0:  * 1. Redistributions of source code must retain the copyright
sl@0:  *    notice, this list of conditions and the following disclaimer.
sl@0:  * 2. Redistributions in binary form must reproduce the above copyright
sl@0:  *    notice, this list of conditions and the following disclaimer in the
sl@0:  *    documentation and/or other materials provided with the distribution.
sl@0:  * 3. All advertising materials mentioning features or use of this software
sl@0:  *    must display the following acknowledgement:
sl@0:  *    "This product includes cryptographic software written by
sl@0:  *     Eric Young (eay@cryptsoft.com)"
sl@0:  *    The word 'cryptographic' can be left out if the rouines from the library
sl@0:  *    being used are not cryptographic related :-).
sl@0:  * 4. If you include any Windows specific code (or a derivative thereof) from 
sl@0:  *    the apps directory (application code) you must include an acknowledgement:
sl@0:  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
sl@0:  * 
sl@0:  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
sl@0:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
sl@0:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
sl@0:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
sl@0:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
sl@0:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
sl@0:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
sl@0:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
sl@0:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
sl@0:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
sl@0:  * SUCH DAMAGE.
sl@0:  * 
sl@0:  * The licence and distribution terms for any publically available version or
sl@0:  * derivative of this code cannot be changed.  i.e. this code cannot simply be
sl@0:  * copied and put under another distribution licence
sl@0:  * [including the GNU Public Licence.]
sl@0:  */
sl@0: /*
sl@0:  © Portions copyright (c) 2006 Nokia Corporation.  All rights reserved.
sl@0:  */
sl@0: 
sl@0: #include <stdio.h>
sl@0: #include <errno.h>
sl@0: #include "cryptlib.h"
sl@0: #include "des_locl.h"
sl@0: #if (defined(SYMBIAN) && (defined(__WINSCW__) || defined(__WINS__)))
sl@0: #include "libcrypto_wsd_macros.h"
sl@0: #include "libcrypto_wsd.h"
sl@0: #endif
sl@0: /* This has some uglies in it but it works - even over sockets. */
sl@0: /*extern int errno;*/
sl@0: #ifndef EMULATOR
sl@0: OPENSSL_IMPLEMENT_GLOBAL(int,DES_rw_mode)=DES_PCBC_MODE;
sl@0: #else
sl@0: #define DES_rw_mode libcrypto_ImpurePtr()->_shadow_DES_rw_mode
sl@0: #endif
sl@0: 
sl@0: /*
sl@0:  * WARNINGS:
sl@0:  *
sl@0:  *  -  The data format used by DES_enc_write() and DES_enc_read()
sl@0:  *     has a cryptographic weakness: When asked to write more
sl@0:  *     than MAXWRITE bytes, DES_enc_write will split the data
sl@0:  *     into several chunks that are all encrypted
sl@0:  *     using the same IV.  So don't use these functions unless you
sl@0:  *     are sure you know what you do (in which case you might
sl@0:  *     not want to use them anyway).
sl@0:  *
sl@0:  *  -  This code cannot handle non-blocking sockets.
sl@0:  *
sl@0:  *  -  This function uses an internal state and thus cannot be
sl@0:  *     used on multiple files.
sl@0:  */
sl@0: 
sl@0: #ifdef EMULATOR
sl@0:   GET_STATIC_VAR_FROM_TLS(net,enc_read,unsigned char *)
sl@0:   #define net (*GET_WSD_VAR_NAME(net,enc_read, s)())
sl@0:   
sl@0:   GET_STATIC_VAR_FROM_TLS(unnet,enc_read,unsigned char *)
sl@0:   #define unnet (*GET_WSD_VAR_NAME(unnet,enc_read, s)())
sl@0:   
sl@0:   GET_STATIC_VAR_FROM_TLS(unnet_start,enc_read,int)
sl@0:   #define unnet_start (*GET_WSD_VAR_NAME(unnet_start,enc_read, s)())
sl@0:   
sl@0:   GET_STATIC_VAR_FROM_TLS(unnet_left,enc_read,int)
sl@0:   #define unnet_left (*GET_WSD_VAR_NAME(unnet_left,enc_read, s)())
sl@0: 
sl@0:   GET_STATIC_VAR_FROM_TLS(tmpbuf,enc_read,unsigned char *)
sl@0:   #define tmpbuf (*GET_WSD_VAR_NAME(tmpbuf,enc_read, s)())
sl@0:   
sl@0: 
sl@0: #endif
sl@0: 
sl@0: 
sl@0: EXPORT_C int DES_enc_read(int fd, void *buf, int len, DES_key_schedule *sched,
sl@0: 		 DES_cblock *iv)
sl@0: 	{
sl@0: 	/* data to be unencrypted */
sl@0: 	int net_num=0;
sl@0: #ifndef EMULATOR	
sl@0: 	static unsigned char *net=NULL;
sl@0: 
sl@0: 	/* extra unencrypted data 
sl@0: 	 * for when a block of 100 comes in but is des_read one byte at
sl@0: 	 * a time. */
sl@0: 	static unsigned char *unnet=NULL;
sl@0: 	static int unnet_start=0;
sl@0: 	static int unnet_left=0;
sl@0: 	static unsigned char *tmpbuf=NULL;
sl@0: #endif		
sl@0: 	int i;
sl@0: 	long num=0,rnum;
sl@0: 	unsigned char *p;
sl@0: 
sl@0: 	if (tmpbuf == NULL)
sl@0: 		{
sl@0: 		tmpbuf=OPENSSL_malloc(BSIZE);
sl@0: 		if (tmpbuf == NULL) return(-1);
sl@0: 		}
sl@0: 	if (net == NULL)
sl@0: 		{
sl@0: 		net=OPENSSL_malloc(BSIZE);
sl@0: 		if (net == NULL) return(-1);
sl@0: 		}
sl@0: 	if (unnet == NULL)
sl@0: 		{
sl@0: 		unnet=OPENSSL_malloc(BSIZE);
sl@0: 		if (unnet == NULL) return(-1);
sl@0: 		}
sl@0: 	/* left over data from last decrypt */
sl@0: 	if (unnet_left != 0)
sl@0: 		{
sl@0: 		if (unnet_left < len)
sl@0: 			{
sl@0: 			/* we still still need more data but will return
sl@0: 			 * with the number of bytes we have - should always
sl@0: 			 * check the return value */
sl@0: 			memcpy(buf,&(unnet[unnet_start]),
sl@0: 			       unnet_left);
sl@0: 			/* eay 26/08/92 I had the next 2 lines
sl@0: 			 * reversed :-( */
sl@0: 			i=unnet_left;
sl@0: 			unnet_start=unnet_left=0;
sl@0: 			}
sl@0: 		else
sl@0: 			{
sl@0: 			memcpy(buf,&(unnet[unnet_start]),len);
sl@0: 			unnet_start+=len;
sl@0: 			unnet_left-=len;
sl@0: 			i=len;
sl@0: 			}
sl@0: 		return(i);
sl@0: 		}
sl@0: 
sl@0: 	/* We need to get more data. */
sl@0: 	if (len > MAXWRITE) len=MAXWRITE;
sl@0: 
sl@0: 	/* first - get the length */
sl@0: 	while (net_num < HDRSIZE) 
sl@0: 		{
sl@0: 		i=read(fd,(void *)&(net[net_num]),HDRSIZE-net_num);
sl@0: #ifdef EINTR
sl@0: 		if ((i == -1) && (errno == EINTR)) continue;
sl@0: #endif
sl@0: 		if (i <= 0) return(0);
sl@0: 		net_num+=i;
sl@0: 		}
sl@0: 
sl@0: 	/* we now have at net_num bytes in net */
sl@0: 	p=net;
sl@0: 	/* num=0;  */
sl@0: 	n2l(p,num);
sl@0: 	/* num should be rounded up to the next group of eight
sl@0: 	 * we make sure that we have read a multiple of 8 bytes from the net.
sl@0: 	 */
sl@0: 	if ((num > MAXWRITE) || (num < 0)) /* error */
sl@0: 		return(-1);
sl@0: 	rnum=(num < 8)?8:((num+7)/8*8);
sl@0: 
sl@0: 	net_num=0;
sl@0: 	while (net_num < rnum)
sl@0: 		{
sl@0: 		i=read(fd,(void *)&(net[net_num]),rnum-net_num);
sl@0: #ifdef EINTR
sl@0: 		if ((i == -1) && (errno == EINTR)) continue;
sl@0: #endif
sl@0: 		if (i <= 0) return(0);
sl@0: 		net_num+=i;
sl@0: 		}
sl@0: 
sl@0: 	/* Check if there will be data left over. */
sl@0: 	if (len < num)
sl@0: 		{
sl@0: 		if (DES_rw_mode & DES_PCBC_MODE)
sl@0: 			DES_pcbc_encrypt(net,unnet,num,sched,iv,DES_DECRYPT);
sl@0: 		else
sl@0: 			DES_cbc_encrypt(net,unnet,num,sched,iv,DES_DECRYPT);
sl@0: 		memcpy(buf,unnet,len);
sl@0: 		unnet_start=len;
sl@0: 		unnet_left=num-len;
sl@0: 
sl@0: 		/* The following line is done because we return num
sl@0: 		 * as the number of bytes read. */
sl@0: 		num=len;
sl@0: 		}
sl@0: 	else
sl@0: 		{
sl@0: 		/* >output is a multiple of 8 byes, if len < rnum
sl@0: 		 * >we must be careful.  The user must be aware that this
sl@0: 		 * >routine will write more bytes than he asked for.
sl@0: 		 * >The length of the buffer must be correct.
sl@0: 		 * FIXED - Should be ok now 18-9-90 - eay */
sl@0: 		if (len < rnum)
sl@0: 			{
sl@0: 
sl@0: 			if (DES_rw_mode & DES_PCBC_MODE)
sl@0: 				DES_pcbc_encrypt(net,tmpbuf,num,sched,iv,
sl@0: 						 DES_DECRYPT);
sl@0: 			else
sl@0: 				DES_cbc_encrypt(net,tmpbuf,num,sched,iv,
sl@0: 						DES_DECRYPT);
sl@0: 
sl@0: 			/* eay 26/08/92 fix a bug that returned more
sl@0: 			 * bytes than you asked for (returned len bytes :-( */
sl@0: 			memcpy(buf,tmpbuf,num);
sl@0: 			}
sl@0: 		else
sl@0: 			{
sl@0: 			if (DES_rw_mode & DES_PCBC_MODE)
sl@0: 				DES_pcbc_encrypt(net,buf,num,sched,iv,
sl@0: 						 DES_DECRYPT);
sl@0: 			else
sl@0: 				DES_cbc_encrypt(net,buf,num,sched,iv,
sl@0: 						DES_DECRYPT);
sl@0: 			}
sl@0: 		}
sl@0: 	return num;
sl@0: 	}
sl@0: