[thirdparty/openssl.git] / crypto / des / enc_read.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.]
 */

#include <stdio.h>
#include <errno.h>
#include "cryptlib.h"
#include "des_locl.h"

/* This has some uglies in it but it works - even over sockets. */
/*extern int errno;*/
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, char *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]),
				(unsigned int)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]),(unsigned int)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,(unsigned int)len);
		unnet_start=len;
		unnet_left=(int)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,(unsigned int)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((int)num);
	}
Commit	Line	Data
d02b48c6	1	/* crypto/des/enc_read.c */
58964a49	2	/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
d02b48c6 RE	3	* All rights reserved.
	4	*
	5	* This package is an SSL implementation written
	6	* by Eric Young (eay@cryptsoft.com).
	7	* The implementation was written so as to conform with Netscapes SSL.
	8	*
	9	* This library is free for commercial and non-commercial use as long as
	10	* the following conditions are aheared to. The following conditions
	11	* apply to all code found in this distribution, be it the RC4, RSA,
	12	* lhash, DES, etc., code; not just the SSL code. The SSL documentation
	13	* included with this distribution is covered by the same copyright terms
	14	* except that the holder is Tim Hudson (tjh@cryptsoft.com).
	15	*
	16	* Copyright remains Eric Young's, and as such any Copyright notices in
	17	* the code are not to be removed.
	18	* If this package is used in a product, Eric Young should be given attribution
	19	* as the author of the parts of the library used.
	20	* This can be in the form of a textual message at program startup or
	21	* in documentation (online or textual) provided with the package.
	22	*
	23	* Redistribution and use in source and binary forms, with or without
	24	* modification, are permitted provided that the following conditions
	25	* are met:
	26	* 1. Redistributions of source code must retain the copyright
	27	* notice, this list of conditions and the following disclaimer.
	28	* 2. Redistributions in binary form must reproduce the above copyright
	29	* notice, this list of conditions and the following disclaimer in the
	30	* documentation and/or other materials provided with the distribution.
	31	* 3. All advertising materials mentioning features or use of this software
	32	* must display the following acknowledgement:
	33	* "This product includes cryptographic software written by
	34	* Eric Young (eay@cryptsoft.com)"
	35	* The word 'cryptographic' can be left out if the rouines from the library
	36	* being used are not cryptographic related :-).
	37	* 4. If you include any Windows specific code (or a derivative thereof) from
	38	* the apps directory (application code) you must include an acknowledgement:
	39	* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
	40	*
	41	* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
	42	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	43	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	44	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
	45	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	46	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	47	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	48	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	49	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	50	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	51	* SUCH DAMAGE.
	52	*
	53	* The licence and distribution terms for any publically available version or
	54	* derivative of this code cannot be changed. i.e. this code cannot simply be
	55	* copied and put under another distribution licence
	56	* [including the GNU Public Licence.]
	57	*/
	58
	59	#include <stdio.h>
	60	#include <errno.h>
199d59e5	61	#include "cryptlib.h"
d02b48c6 RE	62	#include "des_locl.h"
	63
	64	/* This has some uglies in it but it works - even over sockets. */
	65	/extern int errno;/
	66	int des_rw_mode=DES_PCBC_MODE;
	67
7c0f3d09 BM	68
	69	/*
	70	* WARNINGS:
	71	*
	72	* - The data format used by des_enc_write() and des_enc_read()
	73	* has a cryptographic weakness: When asked to write more
	74	* than MAXWRITE bytes, des_enc_write will split the data
	75	* into several chunks that are all encrypted
	76	* using the same IV. So don't use these functions unless you
	77	* are sure you know what you do (in which case you might
	78	* not want to use them anyway).
	79	*
	80	* - This code cannot handle non-blocking sockets.
	81	*
	82	* - This function uses an internal state and thus cannot be
	83	* used on multiple files.
	84	*/
	85
	86
6b691a5c UM	87	int des_enc_read(int fd, char *buf, int len, des_key_schedule sched,
6b691a5c UM	88	des_cblock iv)
d02b48c6 RE	89	{
	90	/* data to be unencrypted */
	91	int net_num=0;
	92	static unsigned char *net=NULL;
	93	/* extra unencrypted data
	94	* for when a block of 100 comes in but is des_read one byte at
	95	* a time. */
95dc05bc	96	static unsigned char *unnet=NULL;
d02b48c6 RE	97	static int unnet_start=0;
d02b48c6 RE	98	static int unnet_left=0;
95dc05bc	99	static unsigned char *tmpbuf=NULL;
d02b48c6 RE	100	int i;
	101	long num=0,rnum;
	102	unsigned char *p;
	103
	104	if (tmpbuf == NULL)
	105	{
cb145b99	106	tmpbuf=Malloc(BSIZE);
d02b48c6 RE	107	if (tmpbuf == NULL) return(-1);
	108	}
	109	if (net == NULL)
	110	{
cb145b99	111	net=Malloc(BSIZE);
d02b48c6 RE	112	if (net == NULL) return(-1);
	113	}
	114	if (unnet == NULL)
	115	{
cb145b99	116	unnet=Malloc(BSIZE);
d02b48c6 RE	117	if (unnet == NULL) return(-1);
	118	}
	119	/* left over data from last decrypt */
	120	if (unnet_left != 0)
	121	{
	122	if (unnet_left < len)
	123	{
	124	/* we still still need more data but will return
	125	* with the number of bytes we have - should always
	126	* check the return value */
	127	memcpy(buf,&(unnet[unnet_start]),
	128	(unsigned int)unnet_left);
	129	/* eay 26/08/92 I had the next 2 lines
	130	* reversed :-( */
	131	i=unnet_left;
	132	unnet_start=unnet_left=0;
	133	}
	134	else
	135	{
	136	memcpy(buf,&(unnet[unnet_start]),(unsigned int)len);
	137	unnet_start+=len;
	138	unnet_left-=len;
	139	i=len;
	140	}
	141	return(i);
	142	}
	143
	144	/* We need to get more data. */
	145	if (len > MAXWRITE) len=MAXWRITE;
	146
	147	/* first - get the length */
	148	while (net_num < HDRSIZE)
	149	{
cb145b99	150	i=read(fd,&(net[net_num]),HDRSIZE-net_num);
58964a49	151	#ifdef EINTR
d02b48c6	152	if ((i == -1) && (errno == EINTR)) continue;
58964a49	153	#endif
d02b48c6 RE	154	if (i <= 0) return(0);
	155	net_num+=i;
	156	}
	157
	158	/* we now have at net_num bytes in net */
	159	p=net;
	160	/* num=0; */
	161	n2l(p,num);
	162	/* num should be rounded up to the next group of eight
	163	* we make sure that we have read a multiple of 8 bytes from the net.
	164	*/
	165	if ((num > MAXWRITE) \|\| (num < 0)) /* error */
	166	return(-1);
	167	rnum=(num < 8)?8:((num+7)/8*8);
	168
	169	net_num=0;
	170	while (net_num < rnum)
	171	{
cb145b99	172	i=read(fd,&(net[net_num]),rnum-net_num);
58964a49	173	#ifdef EINTR
d02b48c6	174	if ((i == -1) && (errno == EINTR)) continue;
58964a49	175	#endif
d02b48c6 RE	176	if (i <= 0) return(0);
	177	net_num+=i;
	178	}
	179
	180	/* Check if there will be data left over. */
	181	if (len < num)
	182	{
	183	if (des_rw_mode & DES_PCBC_MODE)
4e31df2c	184	des_pcbc_encrypt(net,unnet,num,sched,iv,DES_DECRYPT);
d02b48c6	185	else
4e31df2c	186	des_cbc_encrypt(net,unnet,num,sched,iv,DES_DECRYPT);
d02b48c6 RE	187	memcpy(buf,unnet,(unsigned int)len);
	188	unnet_start=len;
	189	unnet_left=(int)num-len;
	190
	191	/* The following line is done because we return num
	192	* as the number of bytes read. */
	193	num=len;
	194	}
	195	else
	196	{
	197	/* >output is a multiple of 8 byes, if len < rnum
	198	* >we must be careful. The user must be aware that this
	199	* >routine will write more bytes than he asked for.
	200	* >The length of the buffer must be correct.
	201	* FIXED - Should be ok now 18-9-90 - eay */
	202	if (len < rnum)
	203	{
	204
	205	if (des_rw_mode & DES_PCBC_MODE)
4e31df2c BL	206	des_pcbc_encrypt(net,tmpbuf,num,sched,iv,
4e31df2c BL	207	DES_DECRYPT);
d02b48c6	208	else
4e31df2c BL	209	des_cbc_encrypt(net,tmpbuf,num,sched,iv,
4e31df2c BL	210	DES_DECRYPT);
d02b48c6 RE	211
	212	/* eay 26/08/92 fix a bug that returned more
	213	* bytes than you asked for (returned len bytes :-( */
	214	memcpy(buf,tmpbuf,(unsigned int)num);
	215	}
	216	else
	217	{
	218	if (des_rw_mode & DES_PCBC_MODE)
cb145b99 BL	219	des_pcbc_encrypt(net,buf,num,sched,iv,
cb145b99 BL	220	DES_DECRYPT);
d02b48c6	221	else
cb145b99 BL	222	des_cbc_encrypt(net,buf,num,sched,iv,
cb145b99 BL	223	DES_DECRYPT);
d02b48c6 RE	224	}
	225	}
	226	return((int)num);
	227	}
	228